Canine lung transplantation after more than twenty-four hours of normothermic preservation

BACKGROUND: Consistent clinical results have not been achieved when lung preservation times exceed 6 hours. The aim of this study was to use an alternative normothermic autoperfusion technique for lung preservation and transplantation. METHODS: In six paired dogs, donor lungs were removed, along with the heart, liver, pancreas, duodenum, and both kidneys, and were preserved for 24 to 33 hours in a normothermic autoperfused multiple organ block. Orthotopic left lung transplantation was performed at the end of the preservation period. RESULTS: Lung function was good during the preservation period. With a gas mixture of 50% O2 + 3% CO2 + 47% N2 delivered to the multiorgan block, arterial oxygen tension ranged from 331 +/- 19 to 383 +/- 8 mm Hg; carbon dioxide tension ranged from 18 +/- 5 to 32 +/- 5 mm Hg; and pH ranged from 7.36 +/- 0.02 to 7.45 +/- 0.08. After transplantation, the dogs were kept anesthetized and ventilated for 24 hours with the same gas mixture. The opposite pulmonary artery was occluded 0 to 6 hours after transplantation. Arterial blood pressures were stable after surgery. Arterial oxygen tension was maintained between 205 +/- 39 and 320 +/- 57 mm Hg, and arterial carbon dioxide tension was maintained between 23 +/- 2 and 34 +/- 2 mm Hg. Lung tissue wet/dry weight ratio was 4.94 +/- 0.17 after preservation; this ratio did not differ from that found in normal controls (4.91 +/- 0.10). CONCLUSIONS: This study shows that the lungs were well preserved for more than 24 hours of preservation when the normothermic multiorgan block preparation was used. The transplanted left lung was able to support the anesthetized dog after the opposite pulmonary artery was occluded.     

Long-term consequences of subtle stimuli during the first twenty-four hours of seizure-induced brain injury

Chronically epileptic (induced by a single systemic injection of lithium and pilocarpine about 30 days before the experiment began) male rats were trained within a radial maze while they were administered either GABA-pentin (Neurontin), or prednisolone or given no treatment. There was no significant improvement in learning or memory between the groups. Numbers of trials per day were positively correlated with the time required to display the overt stereotyped forelimb clonus after the single pilocarpine injection. The numbers of correct trials completed during the first few days of acquisition were significantly greater for the rats that had receive weak (1 microT) complex, pulsed magnetic fields over the right hemisphere during the first 24 hr. after seizure induction than for those who received the same field over the left hemisphere or that had been exposed to reference conditions. Implications of the enhanced sensitivity of limbic neurons to subtle electromagnetic interaction during electrical lability are discussed.     

Effects of testosterone on glomerular growth after uninephrectomy

BACKGROUND: Renal functional prognosis is consistently more adverse in male individuals with renal disease. Male animals develop more marked proteinuria and glomerulosclerosis in several models of renal damage. Renal and glomerular growth are important permissive factors for progression of renal failure. PURPOSE OF THE STUDY: To investigate the influence of testosterone on renal and glomerular growth. DESIGN: Renal compensatory growth after uninephrectomy (UNX) was chosen as a model of renal growth. The effect of testosterone was assessed in control male, in orchidectomized (OX) male, and in ovariectomized (OV) female SD rats. Observation time was 10 months. MEASUREMENTS: Albuminuria by nephelometry; glomerular diameter, glomerular tuft area, renal zonal analysis by quantitative stereology. Testosterone and dihydroxytestosterone by gas chromatography and RIA. RESULTS: In sham-operated male rats, testosterone administration did not change the (left) kidney:body-weight ratio after uninephrectomy. In contrast, in OX male rats, testosterone administration caused a significant increase in kidney:body-weight ratio and in albuminuria. In these animals, glomerular diameter and outer stripe width were significantly lower in OX rats than in sham-operated controls. Glomerular volume and outer stripe width in OX animals were significantly higher after uninephrectomy (UNX) and were further increased in OX-UNX animals by administration of testosterone. Similar effects on glomerular diameter, cortical width (single) kidney:body-weight ratio were seen when OV female rats were treated with testosterone. CONCLUSION: After gonadal ablation, administration of testosterone amplifies compensatory glomerular and tubular growth in uninephrectomized male and female rats, i.e. testosterone is a permissive factor. Stimulation of glomerular growth may favour development of glomerulosclerosis.     

Hypoxaemia and supplemental oxygen therapy in the first 24 hours after myocardial infarction: the role of pulse oximetry

SIV infection of rhesus macaques is an excellent model for HIV infection of humans. Unfortunately, it is has been difficult to identify macaques expressing particular MHC class I alleles. Here we describe the use of PCR-SSP for Mamu-A*01 typing of rhesus macaques. The Mamu-A*01 allele was amplified from genomic DNA using Mamu-A*01-specific primers and positive PCR products were directly sequenced. Our technique identified 15 Mamu-A*01-positive animals of 68 tested. We validated our molecular analysis by showing that lymphocytes from 8 Mamu-A*01-positive animals expressed Mamu-A*01 as determined by immunoprecipitation and 1-D IEF. The technical simplicity and accuracy of this typing method should facilitate selection of Mamu-A*01-positive rhesus macaques for AIDS virus pathogenesis and vaccine studies.     

Renal trauma and hypertension: the role of renin

Three patients developed hypertension following renal trauma. Trauma produced perinephric hematoma in two and renal artery thrombosis in one. Renal vein plasma renin activity (PRA) from the traumatized kidney was three to eight times greater than renal vein PRA from the untraumatized (contralateral) kidney. Peripheral PRA was elevated in all. A surgical operation lowered peripheral PRA to normal in all, but corrected hypertension in only two of three. Preoperative medical treatment with renin-suppressing pharmacologic agents correctly predicted this response to surgery. Postoperative renal vein PRA in the remaining hypertensive patient demonstrated that surgery successfully alleviated the abnormality in renin secretion. These studies suggest that excessive renin secretion initiate but other unidentified factors may contribute to the hypertension observed after renal trauma.     

Regulation of experimental autoimmune encephalomyelitis with insulin-like growth factor (IGF-1) and IGF-1/IGF-binding protein-3 complex (IGF-1/IGFBP3)

Insulin-like growth factor (IGF)-1 is a cytokine that promotes oligodendrocyte development and myelin production. This study investigated whether treatment of chronic, relapsing murine experimental autoimmune encephalomyelitis (EAE) with IGF-1 or IGF-1 associated with its binding protein, IGFBP3, altered the course of disease. Administration of IGF-1/IGFBP3 (1-100 mg/kg per day) delayed the onset of disease in a dose-dependent manner and histologic examination showed a delay in inflammatory cells entering the central nervous system. However, once signs of EAE developed, disease was enhanced in the mice that had been given the highest dose of IGF-1/IGFBP3. Treatment with IGF-1/IGFBP3 after the onset of signs resulted in a severe relapse. Administration of free IGF-1 (10 mg/kg per day) provided mild protection when given before disease onset, but did not significantly alter the course of disease if given after disease onset. Possible mechanisms that could explain the altered disease in IGF-1/IGFBP3-treated mice included (a) IGF-1/IGFBP3 administration delayed the onset of EAE by downregulating ICAM-1 gene expression in the central nervous system, and (b) IGF-1/IGFBP3 treatment of EAE resulted in more severe disease due to enhanced expansion of encephalitogenic T cells. Although IGF-1 may enhance remyelination, these results indicate that administration of IGF-1 associated with IGFBP3 may also accentuate autoimmune demyelinating disease.     

Acute treatment with corticosteroids decreases IGF-1 and IGF-2 expression in the rat diaphragm and gastrocnemius

Massive doses of methylprednisolone (M) or triamcinolone (T) induced diaphragmatic type IIx/b atrophy, resulting in a leftward shift of the force-frequency curve in rats (). To examine the role of insulin-like growth factors (IGFs) in these changes, IGF mRNA content was measured in costal diaphragm, gastrocnemius, and liver removed from 32 rats treated daily during 5 d either with saline (control, C and pair-fed, PF), M, or T (80 mg/kg). Blood samples were taken to measure IGF-1 serum levels. RNA levels were measured by Northern and dot-blots after hybridization with rat IGF-1 or IGF-2 cDNA probes labeled with alpha-32P. Compared with C (845 +/- 128 ng/ml), IGF-1 serum levels were significantly decreased in M (699 +/- 90 ng/ml, p < 0.001 versus C) and PF animals (505 +/- 33 ng/ml, p < 0.001 versus others) and even more so, in T-treated animals (273 +/- 134 ng/ml, p < 0.001 versus others). Along the same lines, IGF-1 expression in the liver was depressed after corticosteroid treatment and in PF, whereas IGF-2 mRNA content remained unchanged. Compared with C, the relative expression of IGF-1 mRNA in the diaphragm was depressed by 44% and 69% in the M and T groups, respectively (p < 0.0001 versus C), while it was unchanged in PF animals. In the gastrocnemius, IGF-1 expression was reduced after M and T (-51% and -59%, respectively, p < 0.0001 versus C) as well as in PF animals (-40%, p < 0.001 versus C). For IGF-2, a similar pattern of expression was found in the diaphragm and the gastrocnemius. Indeed, IGF-2 mRNA tended to decrease in corticosteroid-treated rats (NS) whereas it was unchanged in PF rats. We conclude that decreased IGF expression after corticosteroid treatment was similar in diaphragm and gastrocnemius and may be responsible for the diaphragmatic changes observed after steroid treatment.     

Management of severe burns during the 1st 72 hours

Early and efficient management of severely burned patients facilitates outcome improvement. Pre-hospital care includes fluid loading with 2 mL.kg-1/% burn over the first six hours, sedation and analgesia, prevention of hypothermia and ventilatory support for either critically burned patients or facial, cervical or pulmonary burn injury. The transient stay in a general hospital before transfer to a burn centre allows extension of initial care, the critical investigation for associated injuries (intoxication, multiple trauma) and to perform initial local treatment with sterile coverage or vaseline gauze after a revised assessment of the burned skin area, and possibly escharotomies. The main aim of care in the burn centre is to control hypovolaemia and to obtain maximal tissue perfusion and oxygen delivery to burned tissues, as well as to healthy organs. To manage the burn shock (initially hypovolemic and later on hyperdynamic) catecholamines are often indicated when appropriate fluid loading remains insufficient. Mechanical ventilation is indicated in case of either a deep extensive burn over 60% of total body surface area, or facial and cervical burns or severe pulmonary burn injury from smoke inhalation, carbon monoxide intoxication, tracheobronchial thermal injury and blast injury. Because of the severity of burn-related pain, and the stimulus linked to intensive care, continuous sedation is usually required. Early surgical treatment such as escharotomies, excision and grafting, which cause significant pain as well as blood loss, and hydrotherapy, often require general anaesthesia. Burn injury can modify the volume of distribution and the pharmacokinetics of anaesthetic agents. Finally, chemical or electrical burn, radiation, associated CO intoxication or multiple trauma, as well as burn injury in infants, raise specific problems. With improvement in early intensive care, the survival rate of the most severely burned patients is obviously improving. New techniques in skin substitution will probably further improve the final outcome.     

Renal injury mediated calcium oxalate nephrolithiasis: role of lipid peroxidation

1. Intrathecal (i.t.) administration of nociceptin and high doses of morphine induced allodynia in response to innocuous tactile stimuli, and i.t. nociceptin evoked hyperalgesia in response to noxious thermal stimuli in conscious mice. Here we have characterized the nociceptin-induced allodynia and compared it with the morphine-induced allodynia and the nociceptin-evoked hyperalgesia. 2. Nociceptin-induced allodynia was evoked by the first stimulus 5 min after i.t. injection, reached a maximum at 10 min, and continued for a 50 min experimental period. Dose-dependency of the allodynia showed a bell-shaped pattern from 50 pg to 5 ng kg-1, and the maximum effect was observed at 2.5 ng kg-1. 3. Morphine-induced allodynia reached the maximum effect at 15 min and declined progressively until cessation by 40-50 min. The dose-response curve showed a bell-shaped pattern, similar to that induced by nociceptin, with a maximum effect at 0.5 mg kg-1, five orders of magnitude higher than that of nociceptin. 4. The allodynia evoked by nociceptin and morphine were dose-dependently blocked by glycine, D(-)-2-amino-5-phosphonovaleric acid (D-AP5, an N-methyl-D-aspartate (NMDA) receptor antagonist), gamma-D-glutamylaminomethyl sulphonic acid (GAMS, a non-NMDA receptor antagonist) and methylene blue (a soluble guanylate cyclase inhibitor), but were not affected by muscimol (a gamma-aminobutyric acidA (GABAA) receptor agonist) and baclofen (a GABAB receptor agonist). 5. Morphine did not inhibit forskolin-stimulated cyclicAMP formation in cultured cells expressing the nociceptin receptor. 6. Nociceptin-induced hyperalgesia was evoked 10-15 min after i.t. injection. Nociceptin produced a monophasic hyperalgesic action over a wide range of doses from 5 fg to 50 ng kg-1. The nociceptin-induced hyperalgesia was blocked by glycine only among the agents examined. 7. None of the pain responses evoked by nociceptin and morphine were blocked by naloxone. 8. These results demonstrate that, whereas the mechanisms of the nociceptin-induced allodynia and hyperalgesia are evidently distinct, they involve a common neurochemical event beginning with the disinhibition of the inhibitory glycinergic response. Morphine may induce allodynia through a pathway common to nociceptin, but the nociceptin receptor does not mediate the action of high doses of morphine.     

Renal insufficiency after heart transplantation: a case-control study

BACKGROUND: In Rotterdam 304 heart transplants have been performed since 1984. End-stage renal failure, necessitating renal replacement therapy, has developed in 24 patients (8%) after an interval of 25-121 months (median 79 months). After starting renal replacement therapy one-year survival was only 60%. Overall survival after heart transplantation, however, was favourable: 5 and 10 year survival rates of 79% and 50% respectively. METHODS: A case-control study was performed to identify possible risk factors in cases who went on to develop end-stage renal failure compared to controls. RESULTS: We found that renal failure was not limited to elderly patients with ischaemic heart disease, but also occurred in young patients having dilated cardiomyopathy. A significant rise in the serum creatinine was found in cases compared to controls as early as 3 months after transplantation. Cyclosporin dose and trough levels were not different between cases and controls. Neither were there differences in the use of calcium-antagonists or other antihypertensive drugs, allopurinol or diuretics. Rejection incidence was also similar between the two groups. CONCLUSIONS: Renal failure after heart transplantation is a long term complication of cyclosporin use that is not limited to elderly patients with ischaemic heart disease. Cyclosporin dose and trough levels in the cases were not different from patients maintaining stable good renal function, indicating that cyclosporin nephrotoxicity is the result of an individually determined susceptibility to cyclosporin. Suggestions for future strategies to prevent renal failure are given.     

The ionic mechanisms of early after depolarization in mouse ventricular myocytes: the role of IK1

The occurrence of early after depolarization (EAD) in single mouse ventricular myocytes was observed and its ionic mechanisms were studied using the patch clamp technique. Under treatment with perfusion of Tyrode's solution containing 3 mM KCl and 3 mM CsCl, 3/6 cases exhibited EAD, while with 3 mM KCl or 3 mM CsCl alone, EAD was not induced. The background steady-state current-voltage (I-V) curves of the myocytes showed no negative slope, i.e., the slope in the range of 50 mV positive to the reversal potential was virtually flat and stayed at a low current level. Under perfusion of 3 mM KCl and 3 mM CsCl, the outward current in the above region decreased nearly to 0: in the myocytes which exhibited EAD, a net inward current (crossover) was displayed in the same region, which was abolished by 10 microM TTX and 10 microM nifedipine. The results of whole-cell inward rectifier current I-V curves were similar to the above background steady-state I-V curves. In mouse ventricular myocytes, transient outward current was very strong with a peak current density of 63 +/- 19 pA/pF, whereas low K+ and Cs+ had no significant effect. 11/30 cases showed obvious delayed rectifier current, but the tail current recorded by envelope method was relatively weak (1.19 +/- 0.35 pA/pF) and insensitive to CsCl or changing of the KCl concentration. The results suggest that under treatment with low K+ and Cs+, the inhibition of inward rectifier current is the basis of the formation of second plateau, while Na and Ca currents contribute to the generation of triggered bursts.     

Synergistic action of R-Ras and IGF-1 on Bcl-xL expression and caspase-3 inhibition in BaF3 cells: R-Ras and IGF-1 control distinct anti-apoptotic kinase pathways

R-Ras and insulin-like growth factor-1 (IGF-1) synergistically inhibit apoptosis of BaF3 cells upon interleukin-3 deprivation. To characterize the mechanism of this synergistic inhibition, we examined the effect of R-Ras and IGF-1 on several apoptosis-related proteins. Extracellular signal-regulated kinase (ERK) was activated by IGF-1, but not by R-Ras. In contrast, Akt was activated strongly by R-Ras, but weakly by IGF-1. It was also found that R-Ras and IGF-1 cooperatively induced Bcl-xL expression and inhibited caspase-3 activation.     

Insulin-like growth factor-1 (IGF-1) receptor-insulin receptor substrate complexes in the uterus. Altered signaling response to estradiol in the IGF-1(m/m) mouse

Some of the actions of estradiol occur through stimulation of growth factor pathways in target organs. Tyrosine-phosphorylated (Tyr(P)) insulin-like growth factor-1 receptor (IGF-1R) and the insulin receptor substrate (IRS)-1 are found in the uterus of mice treated with estradiol. Immunoprecipitates of uterine Tyr(P) IRS-1 contained both p85, the regulatory subunit of phosphatidylinositol (PI) 3-kinase, and PI 3-kinase catalytic activity. Estradiol also stimulated binding of IRS-1 and PI 3-kinase to the IGF-1R. Depletion of IRS-1 from uterine extracts reduced PI 3-kinase associated with the receptor, which suggests that binding of the enzyme to IGF-1R occurs primarily in a complex that also contains IRS-1. Following treatment with estradiol, formation of Tyr(P) IGF-1R, Tyr(P) IRS-1, and the p85.IRS-1 complex was very weak in the uterus of IGF-1(m/m) mice, which are severely deficient in IGF-1. This indicated that most, if not all, of the estradiol-stimulated Tyr phosphorylation of uterine IRS-1 originates from ligand activation of IGF-1R kinase. IRS-2 was also Tyr-phosphorylated in the normal uterus and bound more IGF-1R and p85 in response to estradiol; however, a marked decrease in levels of uterine IRS-2 occurred 12-24 h after treatment with estradiol. Since IRS-2 was present in IGF-1R precipitates and a recombinant form of IGF-1 (long R3 IGF-1) stimulated formation of Tyr(P) IRS-2, hormonal activation of this docking protein probably occurs through the IGF-1R. In summary, our findings show that estrogen activation of uterine IGF-1R kinase results in enhanced binding of p85 (PI 3-kinase) to IRS-1 and IRS-2. The formation of one or both of these complexes may be important for the potent mitogenic action of this steroid. That estradiol stimulated a decrease of IRS-2, but not of IRS-1, suggests that these docking proteins have different roles in hormone-induced signaling in the uterus.     

Activation of vagal afferents after intravenous injection of interleukin-1beta: role of endogenous prostaglandins

Intravenous administration of interleukin-1 (IL-1) activates central autonomic neuronal circuitries originating in the nucleus of the solitary tract (NTS). The mechanism(s) by which blood-borne IL-1 regulates brain functions, whether by operating across the blood-brain barrier and/or by activating peripheral sensory afferents, remains to be characterized. It has been proposed that vagal afferents originating in the periphery may monitor circulating IL-1 levels, because neurons within the NTS are primary recipients of sensory information from the vagus nerve and also exhibit exquisite sensitivity to blood-borne IL-1. In this study, we present evidence that viscerosensory afferents of the vagus nerve respond to intravenously administered IL-1beta. Specific labeling for mRNAs encoding the type 1 IL-1 receptor and the EP3 subtype of the prostaglandin E2 receptor was detected in situ over neuronal cell bodies in the rat nodose ganglion. Moreover, intravenously applied IL-1 increased the number of sensory neurons in the nodose ganglion that express the cellular activation marker c-Fos, which was matched by an increase in discharge activity of vagal afferents arising from gastric compartments. This response to IL-1 administration was attenuated in animals pretreated with the cyclooxygenase inhibitor indomethacin, suggesting partial mediation by prostaglandins. In conclusion, these results demonstrate that somata and/or fibers of sensory neurons of the vagus nerve express receptors to IL-1 and prostaglandin E2 and that circulating IL-1 stimulates vagal sensory activity via both prostaglandin-dependent and -independent mechanisms.     

Heart rate variability during the first 24 hours of successfully reperfused acute myocardial infarction: paradoxic decrease after reperfusion

Heart rate variability (HRV) was evaluated during the first 24 hours of hospitalization in 36 patients with acute myocardial infarction. Reperfusion was achieved by 60 minutes in 21 patients (group M1) and by 130 minutes in the remaining 15 (group M2). Mean 24-hour HRV measures were not significantly different between groups M1 and M2. Hourly spectral analysis revealed a decrease in total power (0.01 to 1.0 Hz) from 0 to 8 hours to 9 to 16 and 17 to 24 hours in groups M1 (7.04 +/- 0.27 to 6.94 +/- 0.28 and 6.52 +/- 0.18; p = 0.0006) and in group M2 (6.88 +/- 0.30 to 6.57 +/- 0.23 and 6.40 +/- 0.15; p = 0.002). Total power decreased immediately after reperfusion: in group M1 it decreased during the second hour (7.32 +/- 0.96 to 6.42 +/- 1.2; p = 0.001) and in group M2 during the third (7.47 +/- 1.2 to 6.73 +/- 1.4; p = 0.049) and fourth hours (7.47 +/- 1.2 to 6.48 +/- 1.4; p = 0.029). Mean change in total power in the second hour was -11.6% in group M1 and +3.9% in group M2 (p = 0.0001) and in the third hour, +14.5% in group M1 and -8.6% in group M2 (p = 0.006). During the remaining 21 hours, there was no significant difference in hourly change in total power between groups. Similar changes were noted in high-frequency power, but the ratio of low-frequency to high-frequency power was unchanged. In acute myocardial infarction, HRV is higher during the early phase and decreases as hours progress. Reperfusion causes an immediate, transient, and seemingly paradoxic decrease in HRV, probably because of an abrupt decrease in parasympathetic tone.     

The expression of IGF-1 and its receptor in cultured tendon cell

In order to study the expression change of insulin-like growth factor-1 (IGF-1) and its receptor genes in different generations of tendon cell in culture, Dig-labeled synthesized oligonucleotide probes were used to detect the mRNA expression in primary, 6th and 13th generation of tendon cell. The results showed that IGF-1 receptor mRNA was expressed in all of the 3 above generation tendon cells. IGF-1 mRNA was expressed only in primary and 6th generation cells. Tendon cell of 13th generation did not express IGF-1 mRNA. It might suggest that the absence of IGF-1 mRNA expression be one of the causes which led to the decrease of reproductive ability of 13th generation tendon cell.