Metabolic responses of the neonatal rabbit brain to hydrocephalus and shunting

The metabolic changes that occur in the neonatal brain as a result of hydrocephalus, and the response to ventriculoperitoneal shunting, vary with the maturational stage of the brain. In this study, local glucose utilization (LCMRglu) and oxidative metabolic capacity were estimated using 2-deoxyglucose autoradiography and cytochrome oxidase histochemistry, respectively. Hydrocephalus was induced in rabbit pups via intracisternal kaolin injections at 4-6 days of age. Shunting occurred at 19-26 days of age and the animals were sacrificed at ages ranging from 33 to 331 days. In normal animals there was a high glucose demand early in life which showed a decrease at about 60 days of age. In rabbits sacrificed prior to 60 days of age the controls showed the highest LCMRglu with significant decreases in both the hydrocephalic and shunted animals. After 60 days of age the shunted animals had higher LCMRglu than both the hydrocephalic and control subjects. Oxidative metabolic capacity peaked before 50 days of age in normal animals. At the youngest age, both the hydrocephalic and shunted animals showed higher cytochrome oxidase density rates than the control rabbits. In the older group, the hydrocephalic animals remained high while the shunted animals approximated the control densities. Neither the changes seen in the LCMRglu nor the oxidative metabolic capacity were correlated with changes in cell packing density or increased intracranial pressure. These data suggest that when the brain is compromised by hydrocephalus, there is an initial compensatory increase in oxidative metabolic capacity. The development of the glycolytic pathway appears to be retarded by hydrocephalus, but with shunting and the passage of time, the LCMRglu rebounds to levels above that of controls.     

Verbal learning and memory in children with myelomeningocele

Examined verbal learning and memory in children with myelomeningocele using the California Verbal Learning Test (CVLT). Participants included 41 children with myelomeningocele, 8 to 15 years of age, 33 of whom had a history of shunted hydrocephalus, and 41 matched, unaffected controls. Children with myelomeningocele and shunted hydrocephalus performed worse than controls on the CVLT. They recalled as many words as controls on the first learning trial, but acquired words more slowly across trials, so that their overall recall was lower. Their learning was characterized by a pronounced recency effect. Their delayed recall of the original list was worse than controls, but not their recognition. Performance of children with myelomeningocele but without shunts was generally not significantly different from that of the other two groups, although they did demonstrate better long-delay free recall than children with shunts. Myelomeningocele is associated with significant retrieval problems when accompanied by shunted hydrocephalus.     

Clinical, gross morphological and neurochemical follow-up in normal, hydrocephalic and hydrocephalic-shunted rats

The optimal time for treating congenital hydrocephalus is still unknown. The following study tries to answer this question by shunting hydrocephalic rats around the 10th day of life when the brain development corresponds to that of humans at birth. The animals were allocated to 4 groups: normal, hydrocephalic, normal sham-operated and hydrocephalic-shunted rats (groups 1-4). Body weight and neurological development was tested every 2nd-3rd day. X-rays of the skull were performed in groups 2, 3 and 4 at 10 days and in all at 20 days. In groups 2 and 4 0.1 ml lohexolum was instilled into the lateral ventricle at 10 days and in all at 20 days. X-rays were used to calculate the volume of the neurocranium and to identify ventriculomegaly and its grade (1-3). The x-rays and shunting were performed under general anesthesia, the latter using Kausch's technique. At 20 days of age the animals were sacrificed, the homogenized brain tissue was used to measure Protein, DNA, GAD and CNP by photometry, fluorometry and enzymatically. Time-course of neurological development in group 1: The locomotor patterns were attained gradually up to the ability to hold on to a bar. In group 2 there were larger variations and holding on to a bar was possible only in 6/13. In addition, a distinct tremor was observed in 34%. In group 4 holding on to a bar was possible in all, tremor was observed in 20% of examinations and diminishing following surgery. The volume of the neurocranium in groups 2 and 4 was significantly larger than in groups 3 at 10 days; and in group 2 significantly larger than in groups 1, 3 and 4 at 20 days. In group 4 the ventriculomegaly was distinctly reduced in 7 and remained the same in 1. Protein was significantly lower in group 4. DNA was the same in all groups. GAD was the lowest and the CNP significantly low in group 2. The study shows that an effective shunt may reverse the progressive clinical, radiological and neurochemical changes of hydrocephalus, and that surgery must not be performed necessarily earlier (e.g. prenatally in humans).     

Magnetic resonance imaging and behavioral analysis of immature rats with kaolin-induced hydrocephalus: pre- and postshunting observations

The motor and cognitive dysfunction associated with hydrocephalus remains a clinical problem in children. We hypothesized that young rats with hydrocephalus should exhibit similar dysfunction and that the dysfunction should be reversible by shunting. Hydrocephalus was induced in 3-week-old rats by injection of kaolin into the cisterna magna. Rats were assessed by T2-weighted images obtained with a 7-T magnetic resonance device and by repeated behavioral testing including ability to traverse a narrow beam and ability to find a hidden platform in a water pool. Some of the rats underwent a shunting procedure 1 or 4 weeks after kaolin injection. Magnetic resonance images were used to measure ventricle size. They clearly demonstrated increased signal in periventricular white matter, which corresponded to increased brain water content. A flow-void phenomenon was observed in the cerebral aqueduct. Ability to traverse the beam did not correlate with the degree of ventriculomegaly. Ability to swim to the hidden platform demonstrated a progressive impairment of learning function which may have been accentuated by motor disability. When rats were shunted after 1 week, the behavioral dysfunction was prevented. Late shunting after 4 weeks was associated with gradual recovery of the behavioral disability which was not complete after 4 weeks. We conclude that early shunting is superior to late shunting with regard to behavioral dysfunction. High-resolution MR imaging shows features in hydrocephalic rats similar to those found in hydrocephalic humans.     

Amyloid precursor protein fragment and acetylcholinesterase increase with cell confluence and differentiation in a neuronal cell line

BACKGROUND: Physiopathology of hepatic encephalopathy remains unclear. Recent studies have suggested that ammonia would not act by itself but through an increase in glutamine in the brain. We have previously demonstrated that transplantation of syngeneic hepatocytes into the spleen was able to correct both behavioral deficits and plasma amino acid changes observed in portacaval shunted rats. The aim of the present work was to show a correlation between the correction of chronic hepatic encephalopathy by means of intrasplenic hepatocyte transplantation and two parameters, brain glutamine concentration and ultrastructural aspects of astrocytes. METHODS: Inbred male Wistar Furth rats were divided into three groups: sham-operated rats (n = 10), rats subjected to portacaval shunt (n = 10), and rats subjected to portacaval shunt and intrasplenic hepatocellular transplantation of 10(7) hepatocytes isolated from livers of syngeneic rats (n = 10). Chronic hepatic encephalopathy was quantified 30 and 60 days after operation by means of nose-poke exploration and spontaneous activity. Pathologic examination and measurement of glutamine concentrations in the corpus striatus and in the cerebral cortex were performed 60 days after operation. RESULTS: Portacaval shunt rats showed reduced spontaneous activity and nose-poke exploration scores. After portacaval shunt a significant glutamine increase occurred in the corpus striatus and in the cerebral cortex when compared with sham rats (p < 0.05). Ultrastructural examination showed modification of astrocytes named Alzheimer type II after portacaval shunt. Correction of behavioral abnormalities by means of intrasplenic hepatocyte transplantation was associated with partial correction of striatal glutamine increase and with decrease in astrocyte alterations. Cortex glutamine concentration in portacaval shunt-intrasplenic hepatocyte transplantation group and in portacaval shunt rats did not differ significantly. CONCLUSIONS: These data show that intrasplenic hepatocyte transplantation not only prevents neurologic disorders of hepatic encephalopathy but can also decrease glutamine and ultrastructural alterations in the corpus striatus in an experimental model of chronic liver failure. These data are in favor of the involvement of glutamine in chronic hepatic encephalopathy. These results suggest that intrasplenic hepatocyte transplantation might be of therapeutic interest in chronic liver failure.     

Randomized trial of cerebrospinal fluid shunt valve design in pediatric hydrocephalus

OBJECTIVE: Forty percent of standard cerebrospinal fluid shunts implanted for the treatment of pediatric hydrocephalus fail within the first year. Two new shunt valves designed to limit excess flow, particularly in upright positions, were studied to compare treatment failure rates with those for standard differential-pressure valves. METHODS: Three hundred-forty-four hydrocephalic children (age, birth to 18 yr) undergoing their first cerebrospinal fluid shunt insertion were randomized at 12 North American or European pediatric neurosurgical centers. Patients received one of three valves, i.e., a standard differential-pressure valve; a Delta valve (Medtronic PS Medical, Goleta, CA), which contains a siphon-control component designed to reduce siphoning in upright positions; or an Orbis-Sigma valve (Cordis, Miami, FL), with a variable-resistance, flow-limiting component. Patients were monitored for a minimum of 1 year. Endpoints were defined as shunt failure resulting from shunt obstruction, overdrainage, loculations of the cerebral ventricles, or infection. Outcome events were assessed by blinded independent case review. RESULTS: One hundred-fifty patients reached an endpoint; shunt obstruction occurred in 108 (31.4%), overdrainage in 12 (3.5%), loculated ventricles in 2 (0.6%), and infection in 28 (8.1%). Sixty-one percent were shunt failure-free at 1 year and 47% at 2 years, with a median shunt failure-free duration of 656 days. There was no difference in shunt failure-free duration among the three valves (P = 0.24). CONCLUSION: Cerebrospinal fluid shunt failure, predominantly from shunt obstruction and infection, remains a persistent problem in pediatric hydrocephalus. Two new valve designs did not significantly affect shunt failure rates.     

Regulation of bovine interleukin-1 receptors

We examined the changes in ornithine decarboxylase (ODC) immunoreactivity in the hydrocephalic cerebral cortex of HTX rats after decompression by shunt operation. The ODC immunoreactivity reached a very low level after the completion of cortical layer formation, and only faint staining was found on postnatal day (Pd) 11. The ODC immunoreactivity re-appeared after the shunt operation when the operation was done in the early days of life: the ODC immunoreactivity was first found on day 2 after shunting and persisted until day 8 after shunting. However, this was not apparent when the operation was not performed until Pd 14. The re-expression of ODC in hydrocephalic brain after shunting appears to cause resumption of the developmental process by relieving neurons from increased hydrostatic pressure. The dependence of ODC re-expression on the timing of the operation indicates that there may be a period of neocortical decompression that is critical for effective compensatory development, so that when delayed, decompression fails to re-activate the ODC-dependent development.     

Relapsed chronic myeloid leukemia in accelerated phase 10 years after allogeneic bone marrow transplantation: full chimera reconversion with donor peripheral blood stem cells infusion

The authors calculated the shunt revision rate for 77 consecutive patients with tumoural obstructive hydrocephalus. At a mean follow up of 23.7 months, the annual revision rate was 0.06 which is significantly lower than the annual revision rate of 0.39 for other hydrocephalic patients treated during the same period. Shunted patients who had total excision of their lesions had a significantly lower revision rate than patients who had a partial excision or a biopsy. It is therefore, suggested that cases with tumoural obstructive hydrocephalus may represent a subset of hydrocephalic patients who are associated with a relatively low risk of shunt complications. The observation has to be addressed when the role of endoscopic third ventriculostomy in these patients is being considered.     

Spatial learning and memory deficits induced by dopamine administration with decreased glutathione

Administration of buthionine sulfoximine (BSO) selectively inhibits glutathione (GSH) biosynthesis and induces a GSH deficiency. Decreased GSH levels in the brain may result in less oxidative stress (OS) protection, because GSH contributes substantially to intracellular antioxidant defense. Under these conditions, administration of the pro-oxidant, dopamine (DA), which rapidly oxidizes to form reactive oxygen species, may increase OS. To test the cognitive behavioral consequences of decreased GSH, BSO (3.2 mg in 30 microliters, intracerebroventricularly) was administered to male Fischer 344 rats every other day for 4 days. In addition, DA (15 microliters of 500 microM) was administered every day [either 1 h after BSO (BSO + DA group) or 1 h before BSO (DA + BSO group), when given on the same day as BSO] and spatial learning and memory assessed (Morris water maze, six trials/day). BSO + DA rats, but not DA + BSO rats, demonstrated cognitive impairment compared to a vehicle group, as evidenced by increased latencies to find the hidden platform, particularly on the first trial each day. Also, the BSO + DA group utilized non-spatial strategies during the probe trials (swim with no platform): i.e., less time spent in the platform quadrant, fewer crossings and longer latencies to the previous platform location, and more time spent in the platform quadrant, fewer crossings and longer latencies to the previous platform location, and more time spent around the edge of the pool rather than in the platform zone. Therefore, the cognitive behavioral consequences of decreasing GSH brain levels with BSO in conjunction with DA administration depends on the order of administration. These findings are similar to those seen previously on rod and plank walking performance, as well as to those seen in aged rats, suggesting that the oxidation of DA coupled with a reduced capacity to respond to oxidative stress may be responsible for the induction of age-related cognitive deficits.     

Epilepsy in shunt-treated hydrocephalus

Although epilepsy is commonly associated with shunt-treated hydrocephalus, its relation to the shunting procedure and the criteria identifying postoperative epilepsy remain controversial. Of 283 patients shunted at Würzburg University Hospital over a 24-year period (1970 to 1994), 182 were followed up for a minimum of 1 year after shunt insertion and entered the study. The data were analyzed retrospectively in 1995 and 1996. Epilepsy was analyzed in relation to the etiology of hydrocephalus, functional status, time and site of shunt insertion, onset of seizures and seizure type, EEG changes, sex, shunt systems, and shunt revisions. Of the 182 patients studied, 37 (20%) developed epilepsy. The incidence of epilepsy varied according to the etiology of hydrocephalus: posthemorrhagic (5%), postinfectious (4%), connatal/miscellaneous/unknown (3%), myelomeningocele (2%), tumor/arachnoidal cyst/aqueduct stenosis (0%). Early shunting and poor functional status was associated with a higher risk for epilepsy. Epilepsy was not influenced by sex, shunt systems, or number of shunt revisions. Twenty-two (12%) of 182 patients developed epilepsy (generalized N=13, focal N=9) after intracranial shunting. Focal EEG abnormalities (N=16) were located mainly at the anatomical site of the shunt (N=14), but only three patients (2%) presented with focal seizures contralateral and focal EEG abnormalities ipsilateral to the site of the shunt. The presence of epilepsy was determined by the etiology of hydrocephalus rather than by surgical intervention. The incidence of postoperative epilepsy (12%) was low. Onset of epilepsy, clinical presentation of seizures, and EEG changes did not appear to be valid criteria for identifying shunt-related epilepsy. Thus, epilepsy as a complication of intracranial shunting might be overestimated in the literature.     

Treatment of unresectable hepatocellular carcinoma with lipiodol chemoembolization: a multicenter randomized trial. Groupe CHC

We investigated the effect of successive administrations of SA4503 (1-(3,4-dimethoxyphenethyl)-4-(3-phenylpropyl)piperazine dihydrochloride), a novel cognitive enhancer with high affinity and selectivity for the sigma1 receptor subtype, on the cortical cholinergic dysfunction-induced impairment of the spatial learning performance in the Morris water maze (MWM) task in rats. The impairment of the spatial learning performance was produced by the ibotenic acid-induced lesion of the basal forebrain (BF) area in rats. Escape latencies to find the platform during the training trials of the MWM task were significantly prolonged in the BF-lesioned rats compared with the sham-operated rats. Daily treatment with SA4503 (0.1-0.5 mg/kg, P.O./day) for 13 days ameliorated this learning deficit. In the probe trial, BF-lesioned rats reduced the number of times each rat crossed the former platform location during the training trials (goal area) in comparison with sham-operated rats. Successive administrations of SA4503 (0.25 mg/kg, P.O./day) also significantly increased the BF lesion-induced reduction of the number of times each rat crossed the goal area. These results suggest that the successive administrations of SA4503 attenuate the impairment of the spatial learning performance in rats with cortical cholinergic dysfunction, and that SA4503 is useful as a therapeutic drug for Alzheimer's disease.     

L-ornithine vs. L-ornithine-L-aspartate as a treatment for hyperammonemia-induced encephalopathy in rats

BACKGROUND/AIMS: The effect of L-ornithine (ORN) and L-ornithine-L-aspartate (OA) therapy on "extracerebral" nitrogen metabolism, brain metabolism and neurotransmission has been investigated in portacaval shunted rats with hyperammonemia-induced encephalopathy. METHODS: One day before ammonium-acetate infusion, a portacaval shunt was performed in three experimental groups: 1-control rats, 2-ORN-treated rats and 3-OA-treated rats. Ammonium-acetate was given as an intravenous bolus injection (0.4 mmol.kg bw-1) followed by a constant infusion (1.9 mmol.kg bw-1.h-1) so that steady-state blood ammonia concentrations (500-800 microM) were obtained in the course of 5 h. After 1 h, ammonium-acetate infusion, either L-ornithine or L-ornithine-L-aspartate, was infused for the next 4 h (3.0 mmol.kg bw-1.h-1) in the treated groups. The following parameters were measured: clinical grade of encephalopathy, EEG activity (n = 10 - 20/group), amino acids in plasma (n = 10 - 20/group) and brain dialysate (n = 5 - 9/group), and brain metabolites obtained by in vivo cerebral 1H-MRS (n = 4 - 6/group). RESULTS: ORN and OA treatment resulted in significantly lower blood (34% and 39%) and brain (42% and 22%) ammonia concentrations, significantly higher urea production (39% and 86%) and significantly smaller increases in brain glutamine and lactate concentrations than in controls. These changes were associated with a significantly smaller increase in clinical grade of encephalopathy in ORN- and OA-treated rats, and a significant improvement in EEG activity in ORN-treated rats. OA-treated rats showed a significant increase in aspartate and glutamate concentrations in brain dialysate. CONCLUSIONS: The beneficial effects of both treatments on the manifestations of hyperammonemia-induced encephalopathy can be explained by a reduction in blood and brain ammonia concentrations. It is suggested that when OA is administered, the effect of ornithine is partly counteracted by aspartate, inducing high brain extracellular concentrations of the two excitatory amino acids glutamate and aspartate, and perhaps causing overstimulation of NMDA receptors.     

Epilepsy in children with shunted hydrocephalus

OBJECT: The incidence of epilepsy among children with hydrocephalus and its relation to shunts and their complications, raised intracranial pressure (ICP), and developmental outcome are explored in a retrospective study. METHODS: The authors studied a series of 802 children with hydrocephalus due to varying causes, who were treated by ventriculoperitoneal shunt placement between 1980 and 1990, with a mean follow-up period of 8 years. Patients who had tumoral hydrocephalus and those whose files lacked significant data were excluded. Data extracted from medical records, including history of the hydrocephalus and history of seizures, if any, were analyzed. Thirty-two percent of the children had epilepsy, the onset of which frequently occurred at approximately the same time that the diagnosis of hydrocephalus was made. The majority of the affected children had severe uncontrolled epilepsy. The incidence of epilepsy was significantly affected by the original cause of the hydrocephalus. The presence of radiological abnormalities was also found to be a significant predictor of epilepsy. Similarly, shunt complications predisposed to epilepsy. Episodes of raised ICP related to hydrocephalus or in association with shunt malfunction may also predispose to epileptic seizures. Furthermore, the presence of a shunt by itself seems able to promote an epileptogenic focus. Finally, epilepsy appears to be an important predictor of poor intellectual outcome in hydrocephalic children with shunts. CONCLUSIONS: A prospective study is needed to identify clearly and confirm avoidable factors predisposing to seizures in these children so that we can strive to reduce the incidence of these seizures and, subsequently, improve these children's quality of life.     

Low-pressure hydrocephalic state and viscoelastic alterations in the brain

Most shunt-dependent hydrocephalic patients present with predictable symptoms of headache and mental status changes when their cerebrospinal fluid shunts malfunction. Their intracranial pressure (ICP) is usually high, and they usually respond to routine shunt revision. This report describes 12 shunted patients who were admitted with the full-blown hydrocephalic syndrome but with low to low-normal ICP. All 12 patients had been maintained previously on medium-pressure shunts. Their symptoms included headache, lethargy, obtundation, and cranial neuropathies. At peak symptoms, their ventricular sizes were large (ventricular/biparietal ratio of 0.35 to 0.45) in six and massive (ventricular/biparietal ratio > 0.45) in six and their ICPs ranged from 2.2 to 6.6 mm Hg, with a mean of 4.4 +/- 1.3 mm Hg (+/- standard deviation), i.e., below or well within the pressure range of their shunts. The pressure volume index of three patients at peak symptoms ranged from 39.2 to 48.5 ml, with a mean of 43.9 +/- 4.6 ml, which represents a 190% increase from the predicted normal value. Seven patients failed to improve with multiple shunt revisions, including the use of low-pressure valves. In 11 patients, symptoms and ventriculomegaly were not reversed except with prolonged external ventricular drainage at subzero pressures (mean external ventricular drainage nadir pressure of -5.7 +/- 3.6 mm Hg, for a mean period of 22.2 days). During external ventricular drainage treatment, symptoms correlated only with ventricular size and not with ICP. All 11 were subsequently treated successfully with a new medium- or low-pressure shunt. One patient was treated successfully with prolonged shunt pumping. We postulate that: 1) the development of this low-pressure hydrocephalic state is related to alteration of the viscoelastic modulus of the brain, secondary to expulsion of extracellular water from the brain parenchyma, and to structural changes in brain tissues due to prolonged overstretching; 2) certain patients are susceptible to developing low-pressure hydrocephalic state because of an innate low brain elasticity due to bioatrophic changes; 3) low-pressure hydrocephalic state symptoms are due not to pressure changes but to brain tissue distortion and cortical ischemia secondary to severe ventricular distortion and elevated radial compressive stresses within the brain; and 4) treatment must be directed toward allowing the entry of water into the brain parenchyma and the restoration of baseline brain viscoelasticity.     

Rotation of water in the Morris water maze interferes with path integration mechanisms of place navigation

The idea that place navigation in the Morris water maze is implemented by path integration between locations determined by landmark sighting was investigated in a 200-cm-diameter pool in which circular (7.2 degrees/s) motion of water could be induced by tangentially arranged water jets. The rats were trained at 8 trials per day to navigate to an erectable platform which was raised after the rat had spent a criterion time in the target annulus (30 cm in diameter) in the midpoint of the NW quadrant. Asymptotic escape latency of 7 s was reached after 9 days in moving water (n = 8) and after 6 days in stationary water (n = 8). The group overtrained for 13 days in stable water performed well even after it was transferred to moving water. Changing the sense of rotation of water from counterclockwise to clockwise did not affect the asymptotic performance. The above findings show that overtrained rats rely on landmark sighting rather than on path integration. The influence of water movement reappeared when place navigation to a new target (SW) was examined in alternating 2-s periods of light (L) and darkness (D). On the first day, the latencies were 15.2 +/- 1.2 and 22.8 +/- 1.9 s in stable and moving water, respectively, but dropped to 10 s on the following day. The tracks generated in the L period were more tortuous than those generated in the D period and this difference was more pronounced in moving than in stable water. It is concluded that path integration mechanisms supporting navigation during intervals of darkness are impaired in moving water but that this impairment disappears in overtrained animals.     

The ethical problem of the health-environment relationship]

The effects of sustained stress on response rate and temporal patterning (quarter-life) of rats performing either a previously learned fixed-interval schedule (FI 60) or learning an FI 60 simultaneously with stress onset were determined. Rats lived 24 h/day in operant cages, where they earned all of their food via lever-pressing. During the stress portion of each experiment, one group of rats was able to avoid or escape signalled intermittent footshock (Avoidance/ Escape Group), a second group (Yoked) did not have control over shock termination, a third group never received shock (Control). Shock trials were presented around the clock at approximately 5-min intervals and the stress portion of each study lasted 1-2 weeks. We have previously reported that rats tolerate this paradigm well and avoid/escape 99% of the shock trials. In rats previously trained on the FI task, both rate of responding and quarter-life values were significantly decreased on the first day of stress for both the Avoidance/Escape and Yoked Groups. Food intakes and quarter-life values were not significantly different from the controls by stress Days 3 and 2, respectively. In the acquisition study, controls learned the F1 task by Day 4 as judged by quarter-life of responding. FI task acquisition was significantly impaired in stressed rats compared to controls, not reaching asymptotic performance until Day 9 of stress. There were no major differences between the 2 stress groups in either study. These data demonstrate that stress may impair both the rate and patterning of behavior, and suggest that this rodent paradigm may usefully model some aspects of the effects of stress in humans.     

Effects of differential rearing on cortical evoked potentials of the albino rat.

3 groups of Sprague-Dawley albino rats were reared in different environments from weaning to the age of 95 days. One group was in a visually enriched environment (n = 8), a 2nd group was in an auditorily enriched environment (n = 8) and a 3rd group, controls, received no enrichment (n = 16). Photic and auditory evoked potentials were recorded in unanesthetized Ss from chronically implanted epidural electrodes over the visual and auditory cortex. Ss whose enrichment included visual stimulation yielded significantly shorter latencies in their photic evoked responses recorded over the visual cortex than latencies recorded from controls or from Ss whose enrichment excluded visual stimulation. (17 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The Yale Geriatric Care Program is not effective in a pilot study in The Netherlands

Brain temperature was measured at various depths beneath the pial surface in patients with hydrocephalus of varying aetiology. Temperature increased gradually with depth in all patients, with the highest temperature found in the ventricle. The difference between intraventricular and rectal temperatures (delta v-r) was greater in patients who underwent continuous ventricular drainage than in patients who underwent ventriculoperitoneal shunt (continuous ventricular drainage; 1.2 (SD 0.40) degrees C, mean (SD), n=5 v ventriculoperitoneal shunt; 0.4 (SD 0.45) degrees C, n=16; p< 0.05). The difference between intracerebral and rectal temperatures (delta b2-r) was also greater in patients with continuous ventricular drainage than in patients with ventriculoperitoneal shunt (continuous ventricular drainage; 0.1 (SD 0.86) degrees C, n=5 v ventriculoperitoneal shunt; -0.7 (0.86) degrees C, n=16; p< 0.05). Among patients with normal pressure hydrocephalus, these differences were greater in the patients with better outcomes after shunt surgery than in the less improved group (delta v-r; 0.7 (SD 0.27) degrees C, n=7 v 0.1 (SD 0.40) degrees C, n=5, p< 0.01, delta b2-r; -0.2 (SD 0.61) degrees C, n=7 v -1.4 (0.90) degrees C, n=5, p< 0.01).     

Induction of donor-specific tolerance to cardiac xenografts in utero

BACKGROUND: Problems associated with heart transplantation, such as shortage of suitable organs and the side effects of immunosuppressive therapy, are especially serious for patients in the pediatric age group. Induction of donor-specific immunologic tolerance without immunosuppressive drugs would be ideal for clinical organ transplantation. In this study, we used a vascularized cardiac xenograft model to achieve donor-specific unresponsiveness without immunosuppression by manipulating the intrauterine immune response. METHODS: Lewis rats and Golden Syrian hamsters were used as the recipients and donors, respectively. Donor bone marrow cells (15 x 10(6) in 0.05 mL) were injected into each fetus of pregnant Lewis rats on days 9 (n = 2) and 16 (n = 2) of gestation. Donor hearts were heterotopically transplanted into each surviving (n = 8, n = 5) fetus of the Lewis rats at 8 weeks of age. Donor hearts were also transplanted into untreated rats as controls (n = 8). RESULTS: The mean cardiac xenograft survival time was 2.5 +/- 0.5, 7.4 +/- 4.1, and 2.8 +/- 0.8 days in the control group, gestational day 9 group, and gestational day 16 group, respectively. Chromosomal analysis of the day 9 group showed Golden Syrian hamster chromosomes as well as Lewis rat chromosomes. CONCLUSIONS: Cardiac xenograft survival was significantly prolonged by intrauterine exposure to xenograft bone marrow cells on day 9 but not on day 16 of gestation. Cardiac xenograft survival and chromosomal analysis of the recipient bone marrow suggested that chimerism was achieved between Golden Syrian hamsters and Lewis rats. Cardiac xenotransplantation may be possible by induction of donor-specific tolerance in utero.     

The Sophy valve and the el-Shafei shunt system for adult hydrocephalus

A selected series of 22 adult patients with hydrocephalus were treated by a shunt system incorporating a variable pressure Sophy valve or by ventriculojugular shunting against the direction of blood flow using the El-Shafei system. One patient had insertion of two Sophy valves and an El-Shafei shunt. Patient selection was reserved to those with hydrocephalus thought to be at high risk when shunted with systems containing a conventional unipressure valve. None of the eight patients who had ventriculojugular shunting by the El-Shafei method demonstrated any notable clinical or radiological improvement subsequent to shunt insertion. Of the 16 Sophy devices inserted only seven produced a satisfactory result. The current evaluation of shunt malfunction could be improved by support for a national register.