Synergistic interaction of 3 M KCl-extracted donor antigens (e-HAg) with cyclosporine or cyclosporine/sirolimus for prolongation of rat heart allograft survival

This article examines the attaching and detaching experience of a mother encountering the perinatal death of a twin. Her experience is related to the relevant theoretical and research literature pertaining to prebirth and postbirth maternal-infant attachment and detachment (grieving). Literature for both single infants and twins is considered. The experience of this mother suggests that elements of postbirth attachment may have been accelerated into the prebirth period. In addition, her postbirth attaching and detaching experience suggests that an attachment and detachment to the twins as a unit preceded detachment from the twin who died. The health care provider's role in promoting maternal well-being, and indirectly the well-being of the surviving infant, is described.     

Bacterial and Ureaplasma colonization of the airway: radiologic findings in infants with bronchopulmonary dysplasia

OBJECTIVE: We designed this retrospective study to compare radiologic findings in premature infants with bronchopulmonary dysplasia (BPD) in whom gram-positive cocci (GPC), gram-negative bacilli (GNB), or Ureaplasma urealyticum were colonized. Another objective was to correlate the radiologic findings of these patients with the clinical severity of BPD. STUDY DESIGN: We correlated serial tracheal aspirates with radiographic findings from 183 infants whose birth weight was < or = 1250 gm. BPD severity was assessed by oxygen dependency at 36 weeks of postconceptional age (36 w PCA) and at the time of discharge. Two radiologists independently scored films taken at birth and 1, 7, 14, 21, 28, and 35 days of life. RESULTS: Of the study population, 55% were male and 35% were black; 80% received surfactant and 69% received dexamethasone; 91% survived. GPC isolates from throat cultures were mainly Staphylococcus [corrected] epidermidis and Streptococcus haemolyticus. A superimposed GNB colonization was present in 37% of these infants. Most common isolates were Klebsiella pneumoniae, Enterobacter cloacae, and Escherichia coli. Sepsis caused by GPC developed in 16% of all patients; 7% had sepsis caused by GNB. Infants infected with GNB remained receiving oxygen at 36 w PCA and at the time of discharge twice as often as those noninfected. RADIOLOGIC FINDINGS: Hyperinflation, interstitial changes, and generalized or localized emphysema were prominent features throughout. Mean radiologic scores increased over time in a pattern similar among GPC, GNB, and U. urealyticum infected and noninfected infants. High radiologic scores were not predictive at any time of infants who needed supplemental oxygen at 28 days and at 36 w PCA. Infants infected with U. urealyticum were neither clinically nor radiologically different than noncolonized neonates. CONCLUSION: GPC, GNB, and U. urealyticum airway colonization is not associated with particular radiographic changes at any time. GNB-infected infants had the most severe BPD course, and yet they were radiologically indistinguishable from the other patients. U. urealyticum colonization does not result in more clinically severe BPD or demonstrate a unique radiologic course.     

Eyedness

Study of the activities of hyaluronidase, lactate dehydrogenase isoenzyme-X and the dehydrogenases of sorbitol, alpha-glycerophosphate, glucose-6-phosphate, malate, glyceraldehyde-3-phosphate and isocitrate in the testes of mice of different ages showed that the changes were correlated with the stages of spermatogenic cell differentiation. The first 4 enzymes had activities which were low in newborn mice and high in adults; this pattern was reversed for the other enzymes.     

Studies of the spatial distribution of firearms discharge residues

Fingerprint lifting tape has been applied to the lifting of firearms discharge residue from various surfaces. Lifting efficiencies from coarse fabric ranged from 30 to 70%. Use of the technique has been demonstrated in identifying a bullet hole and in measuring residue patterns on floor and firing hand surfaces. In hand lifts it has been shown that autoradiography alone does not uniquely distinguish the hand of someone who has fired a revolver from the hand of someone who has not. Neutron activation analysis of lifts from selected hand areas may, however, provide such a distinction.     

Patterns of connections between zona incerta and brainstem in rats

To understand better the organisation of zona incerta of the thalamus, this study has examined the patterns of connections that this nucleus has with various nuclei of the brainstem. Injections of biotinylated dextran or cholera toxin subunit B were made into the dorsal raphe, midbrain reticular nucleus, pedunculopontine tegmental nucleus, periaqueductal grey matter, pontine reticular nucleus, substantia nigra, superior colliculus, and ventral tegmental area of Sprague-Dawley rats, and their brains were processed by using standard tracer-detection methods. In general, our results show that zona incerta forms the major zone in the thalamus where these ascending brainstem axons terminate and from which descending axons that travel back to these same brainstem centres originate. These incertal inputs and outputs are limited largely to a distinct sector of zona incerta, the dorsal sector. An exception to this pattern is evident in the incertal projection to the deep layers of the superior colliculus; this projection, unlike all of the others, arises from cells in the ventral sector of zona incerta. Our results also show little evidence for a well-defined topography of projection between the brainstem and the zona incerta. For instance, small injections into each brainstem nucleus result in labelled terminals and in cells spread throughout much of the dorsal sector of zona incerta, with no local zone of concentration within the sector. Again, an exception to this pattern is seen in the incertal projection to the superior colliculus. This projection, unlike the others, shows a clear topographical organisation: A medial-lateral shift in the injection site in the colliculus results in a lateral-medial shift in the position of labelled cells in zona incerta. Curiously, even though the incertal projection to the colliculus appears to be mapped, the collicular projection back to zona incerta is not mapped. In conclusion, then, a number of brainstem nuclei (except for the deep collicular layers) have strong and overlapping connections within the same sector of zona incerta. This convergence of many functionally diverse brainstem afferents within zona incerta places this nucleus in a strategic position to sample the general activity of the brainstem and, perhaps, acts as a relay of this information to higher centres, such as the dorsal thalamic relay nuclei and the cerebral hemispheres.     

The ventral pallidum mediates disruption of prepulse inhibition of the acoustic startle response induced by dopamine agonists, but not by NMDA antagonists

Prepulse inhibition (PPI) of the acoustic startle response is observed when the startling noise pulse is preceded by a weak, non-startling stimulus. PPI has been considered as a measure for sensorimotor gating mechanisms. Disruption of PPI can be found in schizophrenic patients as well as after blockade of NMDA receptors or stimulation of dopamine receptors in rats. The neuronal circuitry which regulates PPI consists of cortico-limbic brain structures where the nucleus accumbens (NAC) plays a key role. The NAC exerts its modulating effects on PPI by way of a projection from the ventral pallidum (VP) to the pedunculopontine tegmental nucleus (PPTg). We recently postulated that the reduction of PPI by intra-NAC infusion of glycine-site NMDA antagonists is not mediated by the VP. We tested here this hypothesis in rats with excitotoxic lesions of the VP which were systemically treated with apomorphine or MK-801 or received intraNAC infusions of dopamine or the glycine-site NMDA antagonist 7-chlorokynurenic acid. Lesioned rats showed a marked deficit in PPI after MK-801 and 7-chlorokynurenate treatment but not after apomorphine or dopamine injection, in contrast to sham-lesioned controls showing deficits in PPI under all conditions. These data provide behavioral evidence for the existence of a pathway which does not include the VP for the mediation of sensorimotor gating deficits. We propose that a direct connection between the NAC and PPTg may be responsible for the effects of NMDA/glycine receptor blockade, whereas the VP is an indispensable relay for the disruptive effects on PPI exerted by the NAC dopamine system.     

Noninvasive measurement of distal radius instability

Except for subjective clinical criteria, there is no formal definition of distal radius fracture instability in the literature. The purposes of this ex vivo biomechanical study were (1) to provide an objective mechanical definition of fracture instability and (2) to demonstrate a noninvasive method that allows for direct measurement of instability. The following 3 questions are addressed: (1) Can the stability of distal radius fractures be measured using computed tomography (CT)? (2) Are the stability measurements reproducible? (3) How does external fixation change stability? A CT technique is described that was used to measure displacement of fracture fragments and measure the compliance of ex vivo distal radius fractures before and after external fixation. Validation studies of the CT technique revealed a mean coefficient of variation of 0.38. There was a linear relationship between measured and known displacements for all 3 orthogonal planes (coefficient of determination 0.99; p < .01). There was significant fracture displacement with loads as small as 20 N. The slope of the load-displacement curve (structural compliance) provided a quantitative measure of fracture instability. Fracture compliance decreased up to 69% after application of an external fixator.     

Bacillary angiomatosis and bacillary peliosis in patients infected with human immunodeficiency virus: clinical characteristics in a case-control study

Clinical characteristics associated with bacillary angiomatosis and bacillary peliosis (BAP) in patients with human immunodeficiency virus (HIV) infection were evaluated in a case-control study; 42 case-patients and 84 controls were matched by clinical care institution. Case-patients presented with fever (temperature, > 37.8 degrees C; 93%), a median CD4 lymphocyte count of 21/mm3, cutaneous or subcutaneous vascular lesions (55%), lymphadenopathy (21%), and/or abdominal symptoms (24%). Many case-patients experienced long delays between medical evaluation and diagnosis of BAP (median, 4 weeks; range, 1 day to 24 months). Case-patients were more likely than controls to have fever, lymphadenopathy, hepatomegaly, splenomegaly, a low CD4 lymphocyte count, anemia, or an elevated serum level of alkaline phosphatase (AP) (P < .001). In multivariate analysis, a CD4 lymphocyte count of < 200/mm3 (matched odds ratio [OR], 9.9; P < .09), anemia reflected by a hematocrit value of < 0.36 (OR, 19.7; P < .04), and an elevated AP level of > or = 2.6 mukat/L (OR, 23.9; P < .05) remained associated with disease after therapy with zidovudine was controlled for. BAP should be considered an AIDS-defining opportunistic infection and should be included in the differential diagnosis for febrile, HIV-infected patients with cutaneous or osteolytic lesions, lymphadenopathy, abdominal symptoms, anemia, or an elevated serum level of AP.     

Adrenoceptor-mediated elevation of ambient GABA levels activates presynaptic GABA(B) receptors in rat sensorimotor cortex

At inhibitory synapses in the mature neocortex and hippocampus in vitro, spontaneous action-potential-dependent and -independent release of gamma-aminobutyric acid (GABA) activates postsynaptic GABA(A) receptors but not pre- or postsynaptic GABA(B) receptors. Elevation of synaptic GABA levels with pharmacological agents or electrical stimulation can cause activation of GABA(B) receptors, but the physiological conditions under which such activation occurs need further elucidation. In rodent sensorimotor cortex, epinephrine produced a depression in the amplitude of evoked monosynaptic inhibitory postsynaptic currents (IPSCs) and a concomitant, adrenoceptor-mediated increase in the frequency of spontaneous IPSCs. Blockade of GABA(B) receptors prevented the depression of evoked IPSC amplitude by epinephrine but did not affect the increase in spontaneous IPSC frequency. These data show that adrenoceptor-mediated increases in spontaneous IPSCs can cause activation of presynaptic GABA(B) receptors and indirectly modulate impulse-related GABA release, presumably through elevation of synaptic GABA levels.