Sending signals from the synapse to the nucleus: possible roles for CaMK, Ras/ERK, and SAPK pathways in the regulation of synaptic plasticity and neuronal growth

The ability to learn and form memories depends on specific patterns of synaptic activity and is in part transcription dependent. However, the signal transduction pathways that connect signals generated at synapses with transcriptional responses in the nucleus are not well understood. In the present report, we discuss three signal transduction pathways: the Ca(2+)/calmodulin-dependent kinase (CaMK) pathway, the Ras/ERK pathway, and the SAPK pathways that might function to couple synaptic activity to long-term adaptive responses, in part through the regulation of new gene expression. Evidence suggests that these pathways become activated in response to stimuli that regulate synaptic function such as the influx of extracellular Ca(2+) and certain neurotrophin growth factors such as brain-derived neurotrophic factor. Once activated, the CaMK, Ras/ERK, and SAPK pathways lead to the phosphorylation and activation of transcription factors in the nucleus such as the cyclic AMP response element binding protein (CREB). Genes regulated by CREB or other transcription factor targets of the CaMK, Ras/ERK, and SAPK pathways could mediate important adaptive responses to changes in synaptic activity such as changes in synaptic strength and the regulation of neuronal survival and death.

Studies on anti-folate antimalarials in east Africa

Chlorproguanil-dapsone (CD) appears to be a promising anti-folate combination (Amukoye et al., 1997) to substitute for pyrimethamine-sulfadoxine (PS), which has a long half-life and against which there is resistance in several Plasmodium falciparum populations including the highly endemic lowland area near Muheza, Tanzania (Trigg et al., 1997).

Secondary acute myeloid leukemia 4 years after the diagnosis of hairy cell leukemia: case report and review of the literature

A 49-year-old man diagnosed with hairy cell leukemia (HCL) achieved a complete remission lasting 4 years after treatment with cladrabine and subsequently developed acute myeloid leukemia. Although a wide variety of second malignancies have been noted in HCL with an incidence of 8.7%, acute myeloid leukemia (AML) has been reported only once previously in a splenectomized patient who had been treated with alpha interferon.

Leishmania major proteophosphoglycan is expressed by amastigotes and has an immunomodulatory effect on macrophage function

Proteophosphoglycan (PPG) is a newly described mucin-like glycoprotein found on the surface of Leishmania major promastigotes and secreted in the culture supernatant. We show here that antigenically similar PPGs are present in several Leishmania species. PPG could also be detected on the surface of amastigotes and in small, parasite-free vesicles in infected macrophages. Because of the similarity of its carbohydrate chains to lipophosphoglycan, a parasite receptor for host macrophages, PPG was tested for binding to macrophages. PPG bound to macrophages and was internalized in a time-dependent manner. PPG inhibited the production of tumor necrosis factor-alpha and synergized with interferon-gamma to stimulate the production of nitric oxide by macrophages. PPG may contribute to the binding of Leishmania to host cells and may play a role in modulating the biology of the infected macrophage at the early stage of infection.

Plasmodium falciparum: selection of serine 108 of dihydrofolate reductase during treatment of uncomplicated malaria with co-trimoxazole in Ugandan children

In vivo testing for resistance of Plasmodium falciparum to co-trimoxazole (trimethoprim/sulfamethoxazole) was performed in Uganda in 41 children with uncomplicated malaria, and blood samples were screened before and after treatment for polymorphisms in the antifolate target genes for dihydrofolate reductase (DHFR) and dihydropteroate synthetase (DHPS). Selection towards a specific genotype at some codons of the DHFR and DHPS genes was observed in samples collected after exposure to co-trimoxazole drug pressure. The alleles 51-isoleucine, 59-arginine, and 108-serine of DHFR were significantly associated with clinical resistance, as was allele 581-alanine of DHPS. Resistance against antifolate combinations probably requires resistance-related polymorphisms in both the DHFR and the DHPS genes. In addition, it appears that the trimethoprim-resistant DHFR genotype differs from that for pyrimethamine at residue 108.

Antileukemic action of buthionine sulfoximine: evidence for an intrinsic death mechanism based on oxidative stress

The glutathione-depleting agent buthionine sulfoximine (BSO) was found to be toxic to some AML blast populations. This toxicity was manifested as the appearance of high levels of reactive oxygen generation in GSH-depleted cells, and later by the loss of mitochondrial membrane potential and an increase in intracellular calcium. Striking heterogeneity in BSO sensitivity was observed in a series of four human AML cell lines, and in fresh leukemic blasts obtained from eight AML patients. In some cases, toxicity was seen at BSO concentrations as low as 1 microM; approximately 100-fold less than the plasma levels achieved in patients treated with BSO as a drug resistance reversing agent. Based on these results we propose that some AML blast populations are unusually dependent on GSH-based antioxidant mechanisms, due to high intrinsic rates of reactive oxygen generation. The mitochondrial respiratory chain is the most likely source of this reactive oxygen. Because toxicity is seen at clinically achievable concentrations of BSO, this agent might have antileukemic activity in patients.

Intraspecific variation in the rDNA its loci of 37-collar-spined echinostomes from North America: implications for sequence-based diagnoses and phylogenetics

The recent finding of the 37-collar-spined Echinostoma revolutum in North America prompted rDNA nucleotide sequence comparisons between this worm and the sympatric Echinostoma trivolvis. Three isolates of E. revolutum from distinct sites and 2 isolates of E. trivolvis collected from a single site were used in this analysis. Sequence data were compared to those from previously sequenced members of the 37-collar-spine group. The 3 North American isolates of E. revolutum were found to be identical, but they differed from Eurasian isolates of E. revolutum at 9 of the 1,006 sites sequenced. Further, 1 of the E. trivolvis isolates studied herein was identical to the published sequence for this species, but 6 nucleotide changes were observed in the second E. trivolvis isolate. Restriction fragment length polymorphisms at this locus support the nucleotide differences found between the E. trivolvis isolates. The degree of intraspecific variation detected raises questions regarding the utility of the internal-transcribed spacer regions of the ribosomal DNA repeat for taxonomic diagnosis and in phylogenetic studies for poorly differentiated groups, such as the 37-collar-spined congeners.

Polymorphisms in the dihydrofolate reductase (DHFR) and dihydropteroate synthetase (DHPS) genes of Plasmodium falciparum and in vivo resistance to sulphadoxine/pyrimethamine in isolates from Tanzania

The efficacy of sulphadoxine/pyrimethamine (S/P) in treatment of uncomplicated falciparum malaria in Africa is increasingly compromised by development of resistance. The occurrence of mutations associated with the active site sequence in the Plasmodium falciparum genes coding for dihydrofolate reductase (DHFR) and dihydropteroate synthetase (DHPS) is associated with in vitro resistance to pyrimethamine and sulphadoxine. This study investigates the occurrence of these mutations in infected blood samples taken from Tanzanian children before treatment with S/P and their relationship to parasite breakthrough by day 7. The results show that alleles of DHPS (436-alanine, 437-alanine and 540-lysine) were significantly reduced in prevalence on day 7 after S/P treatment. In this area, a DHPS with 436-serine, 437-glycine and 540-glutamate appears to play a major role in resistance to S/P in vivo. Evidence for the influence of mutations in the DHFR gene in this investigation is not clear, probably because of the high prevalence of 'resistance-related' mutations at day 0 in the local parasite population. For apparently the same reason, it was not possible to show a statistical association between S/P resistance and the presence of particular polymorphisms in the DHFR and DHPS genes before treatment.

In vivo selection for a specific genotype of dihydropteroate synthetase of Plasmodium falciparum by pyrimethamine-sulfadoxine but not chlorproguanil-dapsone treatment

Plasmodium falciparum present in blood samples collected before and 3 weeks after treatment with either pyrimethamine-sulfadoxine or chlorproguanil-dapsone was analyzed for variants of the genes coding for the target enzymes of antifolate drugs, dihydrofolate reductase (DHFR) and dihydropteroate synthetase (DHPS). Fragments of the genes were amplified by polymerase chain reactions, and variants were identified by specific restriction endonuclease digestion. Treatment with either drug combination selected for the variants Ile51, Arg59, and Asn108 of DHFR, which have been associated with in vitro resistance to pyrimethamine and cycloguanil. The genotype Ser436, Gly437, and Glu540 of DHPS was selected by pyrimethamine-sulfadoxine but not chlorproguanil-dapsone treatment, showing that a combination of these three variants is important for in vivo resistance to sulfadoxine in the area studied.

Plasmodium falciparum: detection of polymorphisms in the dihydrofolate reductase and dihydropteroate synthetase genes by PCR and restriction digestion

With the spread of resistance to chloroquine, the combination of sulphadoxine and pyrimethamine is growing in importance for the treatment of infection with the malaria parasite Plasmodium falciparum. Mutations in the dhfr gene of P. falciparum have been associated with resistance to pyrimethamine. Recently, several polymorphisms have been identified in the P. falciparum dhps gene which may correlate with sulphadoxine-resistance. Simple and rapid tests have been developed to detect these polymorphisms, using PCR followed by restriction digestion. These tests can accurately identify all the polymorphisms described to date at codons 16, 51, 59, 108, and 164 in the dhfr gene and those at codons 436, 437, 540, 581, and 613 in the dhps gene. A nested system has been developed which allows the accurate detection of these polymorphisms in samples of fingerprick blood collected on glass fiber membranes and filter papers, some with very low parasitaemias.

Anatomy and distribution of foliar idioblasts in Scrophularia and Verbascum (Scrophulariaceae)

Internal secretory structures have rarely been reported from Scrophulariaceae, and foliar idioblasts only once before, in 1887. Presented here are the first unambiguous descriptions of subepidermal foliar idioblasts in the family, from Scrophularia and Verbascum, genera regarded as closely allied on other grounds. Leaf samples from 183 mostly herbarium specimens (128 species, with 55 replicates) were cleared and stained, which revealed idioblasts in 62 (69.7%) of 89 Scrophularia species and 13 (33.3%) of 39 Verbascum species. We then chose 14 representative species to examine by resin sectioning and scanning electron microscopy. Idioblasts occurred both adaxially and abaxially. Most were conspicuous, in some species penetrating to vasculature level. Idioblasts had a thin primary wall and were empty at maturity. Verbascum and Scrophularia species with and without idioblasts were scattered among the subgeneric taxa without taxonomic clustering; likewise, both types occurred in approximately proportionate numbers throughout the geographic range, except that 14 of 15 North American Scrophularia species had idioblasts. Petals of two species had abundant idioblasts. The 1887 report illustrated a huge idioblast in S. deserti and we also found the largest in either genus in this species. We also noted trichome and stomata types and report that paraveinal mesophyll and foliar endodermis with casparian strip were both absent.

High prevalence of mutations in the dihydrofolate reductase gene of Plasmodium falciparum in isolates from Tanzania without evidence of an association to clinical sulfadoxine/pyrimethamine resistance

Recently the efficacy of sulfadoxine/pyrimethamine (S/P) in treatment of uncomplicated falciparum malaria in Tanzania has been seriously compromised by the development of resistance. The occurrence of active site mutations in the Plasmodium falciparum gene sequence coding for dihydrofolate reductase (DHFR) is known to confer resistance to pyrimethamine. This study investigates the occurrence of these mutations in infected blood samples taken from Tanzanian children before treatment with S/P and their relationship to parasite breakthrough by day 7. The results confirm the occurrence of one or more DHFR mutations in all the samples, but no relationship was found with the presence of parasites in the blood at day 7. The results suggest that alterations in the coding region for dihydropteroate synthetase (DHPS), the enzyme target for sulfadoxine, should be studied in order to predict resistance to the S/P combination. It has been proposed earlier that sulfadoxine could itself act on DHFR, because of a false dihydrofolate produced by drug metabolism through DHPS and dihydrofolate synthase. The results of this treatment study suggest that such a possibility is unlikely.

Separation anxiety in adulthood: a phenomenological investigation

Separation anxiety disorder is well recognized as a juvenile psychiatric disorder, but it appears to be rarely diagnosed in adulthood. Drawing on our clinical impressions and a review of the relevant literature, we sought to investigate whether separation anxiety symptoms could be identified in adulthood. Forty-four subjects recruited by a media campaign were administered a semistructured interview and a self-report checklist for adult separation anxiety (ASA) symptoms, as well as the Separation Anxiety Symptom Inventory (SASI), a retrospective measure of early separation anxiety symptoms. Diagnoses of major depressive disorder (MDD), panic disorder (PD), agoraphobia (Ag), and dependent personality disorder were made using the SCID-P and SCID-II. Thirty-six subjects met criteria for a putative diagnosis of ASA based on a global clinical rating and/or endorsement of DSM-IV-derived criteria. Although most subjects dated the separation anxiety symptoms to their juvenile years, it was notable that one third reported the first onset of separation anxiety symptoms in adulthood. Although comorbid lifetime anxiety or depressive disorders were common, the majority of subjects reported that the separation anxiety symptoms predated other axis I disorders. Only six subjects (17%) were diagnosed with dependent personality disorder. Although limited by the method of sampling, this preliminary study suggests the need to examine more systematically whether a form of separation anxiety disorder may occur in adulthood.

Gender and perceived pay entitlement: testing for effects of experience with income

This article reports on 2 studies where variations on a research design from the literature on gender and perceived pay entitlement were used to test for effects of past pay experience and salience of the pay experience for the participants. In Study 1, level of previous income was not a predictor of self-payment behavior for women or men, and men allocated more pay to themselves than did women. In Study 2, women and men did not differ on perceived entitlement when the income and work experience were made salient, but they did in the nonsalient condition, as in Study 1. Also, past income and self-pay were positively correlated for women in the salient condition. Further, when the data from Study 1 and Study 2 from the same condition (past income nonsalient) were combined, those with the higher previous income level paid themselves more than others, among both men and women.

Direct evidence that asparagine at position 108 of the Plasmodium falciparum dihydrofolate reductase is involved in resistance to antifolate drugs in Tanzania

A nested polymerase chain reaction was used to amplify a fragment of the gene for dihydrofolate reductase of Plasmodium falciparum containing codon 108, where a point mutation, causing a serine to asparagine change, occurs in pyrimethamine resistant parasites. The presence of the mutation was detected by restriction enzyme digestion. Parasites in blood samples collected from asymptomatic children before, and 3 weeks after, treatment with pyrimethamine-sulfadoxine or chlorproguanil-dapsone were analysed. Parasites in the samples taken at 3 weeks carried only the asparagine mutant.

Alpha-interferon and pregnancy in a patient with CML

A 34-year-old woman on interferon for CML for 7 years, experienced problems with conception. Full work-up revealed a short luteal phase and therapy with clomiphene was initiated. Pregnancy occurred and a normal infant was delivered by C-section. The detailed infertility evaluation is described and the impact of interferon therapy on pregnancy is reviewed. Successful pregnancy appears possible in woman taking interferon on a chronic basis.

Ethical considerations in the management of asylum seekers on hunger strike

Hunger strikes have confronted physicians with complex ethical dilemmas throughout history. Asylum seekers under threat of forced repatriation have emerged as a new category of hunger strikers, posing novel challenges for management. The management of 3 Cambodian asylum seekers on hunger strike admitted to a hospital in Sydney, New South Wales, Australia, posted important ethical dilemmas for the physicians and mental health experts involved in their care. Several factors confounded the task of assessment and decision making, including language and cultural barriers, the patients' past exposure to persecution by authorities, and the complexities of the legal procedures being pursued. Different rules appeared to govern the actions of the hunger strikers, the medical team, and the immigration authorities, creating a ¿malignant triangle¿ of mounting confrontation. Recent recommendations for the management of asylum-seeking hunger strikers include the appointment of an external physician of confidence and the writing of a confidential advance directive specifying the hunger striker's wishes about resuscitation in the event of collapse. In addition, we consider the value of constituting an ad hoc ethics committee to advise the responsible physician on points of conflict in managing the hunger strike. The advantages and limitations of these proposals in relation to the particular cultural, historical, and contextual issues relevant to asylum seekers are examined herein.

Subchronic centrifugal mechanical assist in an unheparinized calf model

The purpose of this study was to determine whether the major centrifugal pumps currently in use in the United States (Medtronic, BioMedicus BioPump and Carmeda-coated BioPump, Sarns 3M centrifugal pump, and St. Jude Medical Lifestream) could function as left mechanical assist devices in the subchronic (72 h) unheparinized calf model. Calves were instrumented for left atrial to aorta ex vivo assist, and the pump flow was set at 3.5 +/- 0.4 L/min. Two calves (Sarns 3M and St. Jude) survived 72 h of pumping without clinical complications. The other 2 calves died at 62 and 66 h (Medtronic BioPump and Carmeda-coated BioPump, respectively); both had pelvic limb paralysis. The seal of the Sarns 3M pump head ruptured after approximately 36 h of pumping and required replacement. On postmortem examination, pump-associated thromboembolic lesions were detected in 3 of the 4 calves in one or more of the following organs: kidneys, pancreas, abomasum, duodenum, ileum, spleen, and lumbar spinal cord. The calf with the Sarns 3M pump had no discernable lesions. Because of the clinical abnormalities and postmortem lesions in the unheparinized calf model, it was suggested that anticoagulation is necessary for conducting centrifugal mechanical assist studies in calves using presently available technology.

Subchronic use of the St. Jude centrifugal pump as a mechanical assist device in calves

The purpose of this experiment was to study the effects of the St. Jude Lifestream centrifugal pump on hemodynamic and hematologic parameters and the incidence of postmortem findings in a subchronic ex vivo left ventricular assist animal model. Five calves were implanted with the pump as a left ventricular assist device (left atrial to thoracic aorta bypass) and studied for 96 h of continuous pumping under identical conditions. Heparin (100 IU/kg) was administered only in the initial saline pump prime. Throughout the protocol, mean arterial and central venous pressures averaged 102.1 +/- 4.6 and 3.4 +/- 2.2 mm Hg, respectively. Pump flow was 47.8 +/- 8.4 ml/kg/min at a mean pump speed of 1,676.3 +/- 106.1 rpm. No clinical abnormalities or mechanical malfunctions attributable to the pump were detected during the 96 h of continuous pumping for each calf. Mean plasma-free hemoglobin after 96 h was 3.9 +/- 3.7 mumol/L (p = 0.337 compared to baseline). At post mortem, renal infarctions were detected in 1 calf. No other pump-associated lesions were detected in any of the other calves. We have concluded that the St. Jude Lifestream centrifugal pump functions reliably during 96 h of continuous left heart bypass in a calf model.

Is early separation anxiety a risk factor for adult panic disorder?: a critical review

Heightened levels of early separation anxiety (SA) have long been linked to the risk of adult panic disorder (PD), suggesting that the two types of anxiety arise from a common diathesis--a proposition that has considerably influenced the classification of the anxiety disorders. However, the SA-PD link remains contentious, with some recent studies failing to confirm that putative association. All published research studies investigating the relationship of early SA to PD and/or other anxiety disorders were reviewed. Taken as a whole, the evidence provides support for the SA-PD hypothesis, although the specificity of that relationship needs further clarification. Problems of sample selection, retrospective measurement of early SA and comorbid diagnoses limit the certainty with which inferences can be drawn from existing data. Nevertheless, a recent community-based study provides additional support for the SA-PD hypothesis. Possible developmental pathways linking SA to PD are considered. One possibility that has not received adequate research attention is that early SA disorder (SAD) may persist into adulthood, rendering the sufferer vulnerable to panic and other anxiety symptoms when confronted with salient life stressors. We conclude that it is premature to reject the SA hypothesis of PD. Only well-designed longitudinal studies can map the complex developmental pathways linking early and later manifestations of morbid anxiety.

Production of pulmonary vasodilation by tolazoline, independent of nitric oxide production in neonatal lambs

OBJECTIVE

To determine whether tolazoline reduces pulmonary vascular resistance (PVR) by means of endogenous nitric oxide production.

DESIGN

Thirty newborn lambs (2 to 7 days of age) were anesthetized with pentobarbital, and their lungs were ventilated through an endotracheal tube. Intravascular catheters were placed in the left ventricle, descending aorta, right atrium, and pulmonary artery for continuous monitoring of intravascular pressures. Cardiac output was measured with radiolabeled microspheres. Arterial carbon dioxide pressure and pH were maintained in a normal range throughout the experiments. Animals were randomly assigned to the following groups: group 1, lungs ventilated with a hypoxic gas mixture and administered tolazoline; group 2, given N omega-nitro-L-arginine (L-NA) (5 mg/min intravenously for 60 minutes) and tolazoline; group 3, given L-NA with hypoxia and tolazoline. Acetylcholine (0.5 microgram/kg) was injected into the right atrium to assess pulmonary nitric oxide synthase activity before and after the L-NA infusion. Data were analyzed by analysis of variance.

RESULTS

L-NA inhibited the acetylcholine-induced reduction in mean pulmonary artery pressure (MPAP) by more than 75%. Hypoxia and L-NA increased both MPAP and PVR. Tolazoline produced immediate reductions in both MPAP and PVR in all three groups (group 1, 27% +/- 3% and 50% +/- 5%; group 2, 34% +/- 5% and 50% +/- 6%; and group 3, 31% +/- 4% and 46% +/- 5%, respectively).

CONCLUSIONS

These results suggest that tolazoline produces vasodilation independent of nitric oxide production. Understanding the mechanism by which tolazoline produces pulmonary vasodilation may provide insight into the clinical use of this drug and information regarding other potential endogenous mediators of pulmonary vasomotor tone in the neonate.

The clinical significance of serial creatine phosphokinase estimations in acute ward admissions

The aim of the study was to assess the effects of a number of physical factors on serial total creatine phosphokinase (CK) levels within the first few days of admission to an acute psychiatric ward. Patients (n = 17) who received parenteral injections within 48 hours of admission were compared with those (n = 30) who did not, looking at factors such as method of admission, alcohol use, presence of restraint and serial CK estimations. Those receiving injections had significantly raised CK levels over the first few days post-admission; these levels tended to normalise over 72 hours of admission. A small number of the patients who were given intramuscular injections demonstrated CK levels of over 1000 U/L. It is suggested that where CK levels are elevated, NMS should be excluded on clinical grounds. CK levels should return to normal over the next 72 hours (in the absence of NMS) if there are no further intramuscular injections.

Application of robotic technology to automated sequence fingerprint analysis by oligonucleotide hybridisation

We describe our production line for the rapid analysis of large cDNA libraries applying robotic techniques to automatically pick, amplify, array, hybridise and analyse the clones. We also outline the current state of the hybridisation techniques and describe anticipated future developments of the system. Our approach faces the large-scale analysis of cDNA clones with partial sequence analysis by oligonucleotide fingerprinting in the following way: after picking of individual colonies and arraying them automatically in quadruple density (384-well) microtitre plates, the cDNA clones are amplified by an automated waterbath polymerase chain reaction (PCR), which allows us to run about 46,000 reactions in parallel. The PCR products are automatically transferred to nylon membranes in a high density pattern using a robotic device. We routinely produce twelve 22 cm x 22 cm membranes in 90 min. Each membrane contains 20,736 clones, although much higher densities might be feasible using both miniaturized glass matrices and fluorescence based hybridisation techniques. Theoretical analysis and preliminary computer simulations indicate that about 100-200 sequence specific hybridisations of octanucleotides to about 100,000 PCR products of 1000-1500 base-pairs length will generate sufficient information for classifying the clones into groups of identical or related genes and to identify a large number of previously uncharacterized cDNA clones.

A morphological and functional assessment of Mycobacterium leprae-induced nerve damage in a guinea-pig model of leprous neuritis

Nerve damage, resembling that caused by Mycobacterium leprae in man, was created by the injection of cobalt-irradiated M. leprae organisms into the tibial nerve of guinea-pigs. Assessment of nerve damage was made by clinical, electrophysiological and morphometric means at intervals up to 13 weeks after injection. Quantitative immunohistochemical analysis of neuropeptide-containing fibres in the skin of the foot was also carried out. Significant nerve damage occurred 3 weeks after injection of M. leprae organisms. Motor and sensory functional loss peaked at 5 weeks after injection, and there was a significant decrease of peptide-immunoreactive nerves in all skin compartments. The nerve damage was self-limiting and functional recovery had occurred by 13 weeks. The model shows many of the features found in the nerve damage of treated leprosy patients.

Denatured muscle grafts for nerve repair in an experimental model of nerve damage in leprosy. 1. A functional and morphometric study

The effectiveness of denatured autologous muscle grafts for nerve repair in an experimental model of leprosy was assessed. Nerve damage resembling that caused by Mycobacterium leprae in humans was induced by the injection of cobalt-irradiated M. leprae into the tibial nerve of guinea pigs. At the time of maximum functional loss, caused by the formation of a granuloma within the nerve, the area of damage was excised and a denatured autologous muscle graft was used to repair the nerve. Assessment of nerve regeneration through the graft was made using clinical, electrophysiological and microscopic morphometric analysis at intervals up to 20 weeks. The results were compared with regeneration after grafting of a normal nerve. Clinically, some motor and sensory recovery occurred in all of the graft recipients in the normal nerve by 8 weeks, and by 11 weeks in the recipients of grafts in the granulomatous nerve. Full sensory recovery occurred in all but one animal by 20 weeks. Motor function recovered to near normal levels at 14 weeks after repair of the normal nerve but, at 20 weeks, there was variation in motor recovery after repair of the granulomatous nerve. Electrophysiology showed increased conduction velocity of the nerve fibers at each time-point. The conduction velocity at 8 weeks after grafting of the normal nerve was similar to that at 12 weeks after grafting of the granulomatous nerve. Morphometry showed an increasing number of myelinated fibers repopulating the distal nerve up to 20 weeks. Myelin fiber numbers, at this time, were one third of normal after repair of the granulomatous nerve and two thirds after repair of the normal nerve.(ABSTRACT TRUNCATED AT 250 WORDS)

Denatured muscle grafts for nerve repair in an experimental model of nerve damage in leprosy. 2. Recovery of peripheral peptide-containing nerves assessed by quantitative immunohistochemical study

A marked depletion of neuropeptide-immunoreactive nerves, a consequence of the nerve damage which is commonly found in leprosy, has been reported in peripheral tissues of leprosy patients and of a leprosy animal model. The aim of this study was to investigate peripheral reinnervation following a denatured autologous muscle graft in an animal model of leprosy nerve damage. Possible reinnervation of the foot-pad skin was studied by immunohistochemistry using antisera to the neuronal marker protein gene product 9.5 (PGP), the neuropeptides calcitonin gene-related peptide (CGRP), substance P (SP), vasoactive intestinal peptide (VIP), and the C-flanking peptide of neuropeptide Y (CPON). The extent of the reinnervation process was assessed by image analysis quantification at different time points. At 8 weeks after muscle grafting, there were small numbers of immunoreactive nerves (p < 0.05). At 12, 16, and 20 weeks postoperatively there was a gradual increase in all immunostaining. At 20 weeks, no significant difference was found for PGP-, CGRP-, and SP-immunoreactive nerves in the epidermal and subepidermal layers compared to control (contralateral) tissue. In experimental tissue the recovery of immunoreactive nerves around sweat glands took longer (up to 12 weeks) than in other skin compartments, but after that time the recovery was rapid and at 20 weeks no difference was measured for VIP-immunoreactive nerves in comparison with controls. Around blood vessels, the recovery of CGRP- and CPON-immunoreactive fibers was slow, and at 20 weeks a difference with control samples (p < 0.01) was noted. In the same area, there was no significant difference for PGP immunoreactivity between controls and tissues at 20 weeks. In contrast, the immunoreactive nerve bundles in the dermis showed a faster recovery than nerves in other skin areas, with amounts similar to controls at 20 weeks. The significant recovery of immunoreactive nerves, in particular of those containing sensory neuropeptide, is consistent with the described functional recovery.

The endocrine outcome after surgical removal of craniopharyngiomas

The postoperative course of children undergoing surgery for craniopharyngioma was reviewed. Typically they were below height at presentation. All had an attempt at radical surgical resection of the tumor. Most developed diabetes insipidus in the postoperative period, which was permanent in all but 1 child. 94% required thyroid replacement therapy, and sex steroids were administered in 100% when they reached the age of puberty. 91% required maintenance corticosteroids. 54% required growth hormone replacement, but some children showed continued growth despite apparent growth hormone deficiency. Postoperative obesity develops in one half of patients, and may be improved with administration of growth hormone; a controlled trial is underway.

Endotracheal administration of tolazoline in hypoxia-induced pulmonary hypertension

STUDY OBJECTIVE

To compare the pulmonary and systemic vascular responses to intravenously (IV) and endotracheally (ET) administered tolazoline (Tz) in newborn lambs with hypoxia-induced pulmonary hypertension.

DESIGN

Randomized, controlled study design.

METHODS

Twenty lambs, 2 to 7 days of age, were anesthetized, intubated, and surgically catheterized for continuous physiologic monitoring and cardiac output measurements using radiolabeled microspheres. After a postoperative stabilization period, the lambs were ventilated with a hypoxic gas mixture which was titrated to increase mean pulmonary artery pressure (MPAP) 30% to 50% above baseline. Each animal was randomly assigned to receive either IV-Tz (2 mg/kg), ET-Tz (4 mg/kg), or ET-saline (Sal, control group).

RESULTS

ET-Tz significantly (P < .05) reduced MPAP, PVRI (pulmonary vascular resistance index), MPAP/mean artery pressure (MAP) and PVRI/systemic vascular resistance index (SVRI), but not SVRI. IV-Tz lowered (P < .05) MPAP, PVRI, and PVRI/SVRI but also produced significant reductions in MAP and SVRI while only transiently decreasing MPAP/MAP: MPAP/MAP and PVRI/SVRI ratios were consistently lower in the ET-Tz animals than either the IV-Tz or ET-Sal animals.

CONCLUSIONS

Our results suggest that ET-Tz produced a more selective pulmonary vascular response than IV-Tz and may warrant further investigation for potential clinical applications.

Immunostaining of cardiac biopsy specimens in the diagnosis of acute vascular (humoral) rejection: a control study

The diagnosis of acute vascular (humoral) rejection in heart transplant biopsies is classically based on immunofluorescent studies of frozen tissue that show vascular staining for immunoglobulin and complement. We have noted that some pathologists have used immunostaining of formalin-fixed, paraffin-embedded tissue in testing for vascular rejection. To determine the specificity of immunostaining of heart biopsy specimens in the diagnosis of vascular rejection, we studied tissue from 68 consecutive endomyocardial biopsies from 16 patients without clinical or histologic evidence of vascular rejection. In each case, routinely processed formalin-fixed, paraffin-embedded tissue was stained for immunoglobulin G and immunoglobulin M with an avidin-biotin immunoperoxidase technique. Frozen tissue from each case was also stained for immunoglobulin G, immunoglobulin M, C3, and Clq by immunofluorescence. Immunoperoxidase stains on formalin-fixed tissue showed vascular staining for immunoglobulin in 67 of 68 (99%) of the cases. Staining was ablated if the antibodies were absorbed with their appropriate immunoglobulin. Immunofluorescent studies on frozen tissue showed no vascular staining for immunoglobulin or complement. We conclude that immunoperoxidase studies of routinely processed, formalin-fixed, paraffin-embedded tissues are nonspecific in the diagnosis of heart acute vascular rejection. The positive staining in fixed tissues may be due to labeling of passive immunoglobulins that are "fixed" in the vessels during routine processing but are washed away in techniques using frozen tissue.

ESR studies on reactivity of protein-derived tyrosyl radicals formed by prostaglandin H synthase and ribonucleotide reductase

Using ESR spectroscopy, the ability of enzyme inhibitors to quench protein-derived tyrosyl radicals was studied in two different enzymes, prostaglandin H synthase and ribonucleotide reductase. The prostaglandin H synthase inhibitors indomethacin, eugenol, and MK-410 effectively prevent the formation of tyrosyl radicals during the oxidation of arachidonic acid by prostaglandin H synthase from ram seminal vesicles. A direct reaction with preformed tyrosyl radicals was observed only with eugenol. The other prostaglandin H synthase inhibitors were ineffective. The ribonucleotide reductase inhibitors hydroxyurea and 4-hydroxyanisole, which effectively inactivate the tyrosyl radical in the active site of ribonucleotide reductase present in tumor cells, exhibit a different reactivity with tyrosyl radicals formed by prostaglandin H synthase. Hydroxyurea quenches preformed tyrosyl radicals in prostaglandin H synthase weakly, whereas 4-hydroxyanisole does not quench tyrosyl radicals in prostaglandin H synthase at all. Eugenol, which quenches preformed prostaglandin H synthase-derived tyrosyl radicals, also quenches the tyrosyl radical in ribonucleotide reductase. The results suggest that the reactivity of protein-linked tyrosyl radicals in ribonucleotide reductase and those formed during prostaglandin H synthase catalysis are very different and have unrelated roles in enzyme catalysis.

Chondrodysplasia punctata: a boy with X-linked recessive chondrodysplasia punctata due to an inherited X-Y translocation with a current classification of these disorders

Chondrodysplasia punctata (CDP) is a heterogeneous group of rare bone dysplasias characterized by punctate calcification of cartilage. The punctate calcifications are non-specific and have been seen in a wide variety of disorders including the Zellweger syndrome, warfarin, dilantin, alcohol and rubella embryopathies, vitamin-K-epoxide-reductase deficiency, chromosome trisomies 18 and 21, the Smith-Lemli-Opitz syndrome, prenatal infectious chondritis, hypothyroidism, and other rare disorders. We report on a boy with short stature, developmental delay, nasal hypoplasia, telebrachydactyly, hypoplastic genitalia, CDP, ichthyosis, hypoplastic genitalia, and a 46-X,+der(X),t(X;Y)(p22.31;q11.21), Y karyotype. Genomic DNA probe analysis was interpreted as showing that the translocation breakpoint was within the X-linked Kallmann syndrome gene. We review a current classification of these disorders that includes 3 well-defined single gene disorders. These include an autosomal recessive rhizomelic type with early lethality, an X-linked dominant type with presumed male lethality, and an X-linked recessive type that has only been described as part of a contiguous gene deletion syndrome.

Centrifugal pump support for repair of thoracic aortic injury

Spinal cord ischemia and the potential for paraplegia are always of concern during operations for repair of traumatic thoracic pseudoaneurysm. Patients who experience hypotension, loss of intercostal blood supply, or normothermic aortic cross clamp times greater than 30 minutes are more likely to become paraplegic. The preservation of renal perfusion is also a concern.

Denatured autologous muscle graft in leprosy

Autologous muscle grafts were used to repair 12 mixed peripheral nerves (9 posterior tibial, 3 median) in 10 patients with leprosy who had total anaesthesia and analgesia of the area supplied by the nerve. Postoperatively, 7 patients reported improved sensation in the foot or hand, with a return of vibration sense and joint position sense in 11 and of perception of a 10 g pin in 5; the ability to sweat in the affected area was also restored in 7.

Diagnosis of physical illness in psychiatric patients using axis III and a standardized medical history

Psychiatrists' axis III diagnoses of physical illnesses in 357 psychiatric patients were compared with diagnoses by a physician's assistant using a standardized medical history form. The physician's assistant detected nearly three times as many physical illnesses as the psychiatrists. The psychiatrists were significantly more likely to miss diagnoses among older patients and women. Patients who met criteria for depressive disorders appeared to be at greatest risk for undetected illnesses, followed by patients with bipolar disorders and schizophrenia. Patients with a secondary diagnosis of substance abuse had significantly more undetected illness than those who did not abuse substances. The authors suggest that current axis III guidelines are inadequate and that a systematic review of physical health problems should be part of the psychiatric diagnostic assessment.

Direct CO2 laser "revascularization" of the myocardium

Evidence of regional myocardial perfusion and contractile function after direct CO2 laser myocardial revascularization (DLR) is lacking. We examined myocardial segment shortening, adenine nucleotide concentrations, and regional blood flow after DLR of the left anterior descending coronary artery (LAD) distribution before and after its proximal ligation in seven anesthetized conditioned dogs. Sonomicrometry assessed myocardial fiber shortening and radioactive microspheres were used to estimate baseline regional blood flows. Cardiopulmonary bypass was followed by cardioplegia arrest. Laser channels (1 mm diameter) were made every 3 to 5 mm in the LAD region with an 80 watt Laser-sonics CO2 unit. Bypass was terminated, the LAD occluded, and parameters reassessed. Core samples of myocardium from the lased LAD and control circumflex area were taken to assess adenine nucleotides. After occlusion, LAD distribution blood flow and myocardial shortening were reduced to pre-lasting ischemic controls. Adenine nucleotides were reduced in the LAD region relative to the control CMX area. DLR cannot be relied upon to acutely revascularize the ischemic myocardium.