Behaviour of the transgenic (mREN2)27 rat

The first model of genetically engineered hypertension, the transgenic rat TGR (mREN2)27, provides a unique opportunity to study the behavioural effects of an altered brain renin-angiotensin system. The TGR (mREN2)27 rats, characterised by fulminant hypertension, show differences in both the peripheral and central angiotensin systems. The behaviour of male transgenic TGR (mREN2)27 and male Sprague-Dawley rats were determined by 4 behavioural tests. While on the elevated X-maze the TGR (mREN2)27 rat showed a greater 'anxiogenic' profile (fewer open arm entries) than the control Sprague-Dawley rats, this 'anxiogenic' profile increased further during a second exposure to the elevated X-maze 24 h later. In comparison the behaviour of the male Sprague-Dawley rats was not different between the two exposures to the elevated X-maze. Locomotor activity did not differ between either the TGR (mREN2)27 or Sprague-Dawley rats when placed in a 1 m2 open-field for 10 min. A short period of fluid-deprivation (3 h) reversed the 'anxiogenic' profile of the TGR (mREN2)27 on the elevated X-maze. Administration of captopril (20 mg . kg-1 body weight) in the drinking water of the TGR (mREN2)27 rats and Sprague-Dawley rats reversed the anxiogenic profile of the TGR (mREN2)27 rat on the elevated X-maze but did not alter the behaviour of the Sprague-Dawley rats.

Acoustically activated c-fos expression in auditory nuclei of the anaesthetised guinea pig

The spatial expression of the immediate-early gene c-fos in central auditory nuclei of the anaesthetised guinea pig was investigated following exposure of the animal to acoustic stimulation. Accurate control of both the spectra and the level of the stimulus was designed so that the presumed excitation of central auditory nuclei was similar across animals. For unstimulated anaesthetised control animals levels of labelling were significantly higher when compared with unanaesthetised controls. This appeared to a result of the combination of the experimental manipulations and also the use of the anaesthetic. A surprising finding was that unstimulated control animals placed in an anechoic chamber demonstrated the highest levels of fos-like immunoreactivity (Fos-LIR). When anaesthetised animals were exposed to acoustic stimuli the total number of cells showing Fos-LIR was elevated when compared to anaesthetised, but unstimulated animals. There was no evidence at any level of the auditory pathway that these animals demonstrated spatially restricted Fos-LIR which may have suggested place-frequency mapping. In contrast, spatially restricted labelling was found in awake animals exposed to an identical stimulus.

D, L-(tetrazol-5-yl)glycine stimulation of NMDA receptors in neonatal dissociated neurons: inhibition by ethanol

Ethanol inhibition of NMDA receptor stimulation by the high-affinity selective agonist D, L-(tetrazol-5-yl)glycine (T5G) was studied using acutely dissociated neonatal whole-brain neurons loaded with the fluorescent indicator fura-2. T5G induced a concentration-dependent increase in intracellular calcium with a maximal increase above basal of 70nM at 16 microM T5G (EC50 of 0.66 +/- 0.18 microM). T5G agonist specificity was verified using the NMDA antagonists MK-801 (40 nM), APV (100 microM), and Mg2+ (1 mM). The T5G stimulation of calcium entry was both blocked and reversed by these antagonists. Ethanol significantly inhibited the T5G-mediated increase in intracellular calcium only at concentrations > or = 100 mM. In addition, the effect of increasing concentrations of ethanol in the presence of the glycine-site antagonist 5, 7-dichlorokynurenic acid (DCKA, 0.37 microM) on T5G-stimulated calcium entry was examined. A significant inhibition of the T5G-stimulated response in the presence of DCKA was observed at ethanol concentrations as low as 20 mM. These results support previous findings that T5G is a potent agonist of the NMDA receptor and indicate that stimulation of calcium entry by this agonist is less sensitive to ethanol inhibition than stimulation by NMDA.

Common sense, insight, and neuropsychological test performance in schizophrenia patients

We report an exploratory study examining the interrelationships among common sense, insight into psychosis, and performance on a battery of neuropsychological tests in 32 patients with schizophrenia evaluated at the time of discharge from involuntary hospitalization at a State psychiatric hospital. Common sense, as measured by the Social Knowledge Questionnaire, was associated with better performance across tests measuring parietal lobe functioning and vocabulary. In addition, patients with more common sense were more likely to say that they were ill and needed treatment. A global measure of insight, the Insight and Treatment Attitudes Questionnaire (ITAQ), was related to performance on a test of left parietal lobe function. However, the responses to the ITAQ item that may best reflect current awareness of mental illness in patients at the time of discharge ("After you are discharged, is it possible you may have mental problems again?") were related to performance on tests of the functioning of the prefrontal lobes and the right and left parietal lobes. These results add to the growing evidence that some of the deficits in awareness of illness among patients with schizophrenia are related to the neuropsychological dysfunction commonly seen in patients with this disorder.

Anti-Pneumocystis carinii pneumonia activity of dicationic 2,4-diarylpyrimidines

A synthesis of 2,4-bis-(4-amidinophenyl)pyrimidine 6, 2,4-bis-[(4-imidazolin-2-yl)phenyl)]pyrimidine 7, 2,4-bis [(4-tetrahydropyrimidinyl-2-yl)phenyl]pyrimidine 8, 2,4-bis[(4-N-n-propylamidino)phenyl]pyrimidine 9, 2,4-bis[(4-N-isopropylamidino)-phenyl]pyrimidine 10 and 2,4-bis[(4-N-isobutylamidino)phenyl]pyrimidine 11 starting from 4-bromobenzamidine and 4-bromoaceto-phenone is reported. A synthesis of 2-(4-amidinopnenyl)-4-(2-methoxy-4-amidinophenyl)pyrimidine 20, 2-[4-(imidazolin2-yl)-phenyl]-4-[2-me thoxy-4-(imidazolin-2-yl)phenyl]pyrimidine 21, and 2-[4-(N-iso-propylamidino)phenyl]-4-[2-methoxy-4-(N-isopro-pylamidino)phenyl]pyrimidine 22 beginning with 4-bromobenzamidine and 2-methoxy-4-bromoacetophenone is described. Compounds 6-11 and 20-22 all bind strongly to DNA. Compounds 6, 9-11, and 20 given at 5 mg/kg are more active and less toxic than pentamidine at its effective dose when evaluated against Pneumocystis carinii pneumonia (PCP) in the immunosuppressed rat model. Several compounds in this series are being evaluated further as potential new anti-PCP agents.

Laboratory assessment of antibacterial activity of zwitterionic 7-methoxyimino cephalosporins

Zwitterionic 7-methoxyimino cephalosporins (cefpirome, cefepime, cefclidin, DQ2556, FK037 and SCE2787) possess a variable substitution at C3 which contains a quarternary nitrogen. These cephalosporins display low affinities for Class I beta-lactamase and rapid penetration through the outer membrane of Gram-negative bacilli, so that an increased number of periplasmic beta-lactam molecules interact with PBP's per unit of time. As a consequence, the new zitterionic compounds remain active against some, but not all, ceftazidime-resistant Enterobacteriaceae producing high levels of Class I beta-lactamase or Bush type 2b beta-lactamases. Antipseudomonas activities are generally similar to that of ceftazidime except that cefclidin is more active. The new zwitterionic compounds, especially cefpirome and FK037, express greater antistaphylococcal potency than does ceftazidime. A variety of animal models including meningitis and endocarditis have confirmed the potential of these compounds in-vivo. On the basis of structural and antibacterial characteristics, the expression 'forth generation' is acceptable to describe the zwitterionic 7-methoxyimino cephalosporins.

The effect of training on equine metacarpal bone breaking strength

Right third metacarpal bones (n = 24) from Thoroughbreds, 24 to 48 months old and in race training, were tested to failure in 3 point bending. The neutral load axis was estimated and the distance from the axis to the outer dorsal cortical surface measured. Mid-diaphyseal dorsopalmar and lateromedial outer cortical and medullary diameters were measured. Breaking strength, cortical area and area moment of inertia were also calculated. Significant correlations were demonstrated between months in training and dorsopalmar bone diameter, cortical area and area moment of inertia. Significant linear models were illustrated between the same 3 variables and number of months in training. It was concluded that increased duration of training significantly enlarges dorsopalmar bone diameter, cortical area and area moment of inertia. Training did not affect metacarpal bone breaking strength as determined by 3 point bending.

A prospective, randomized comparison of open vs arthroscopically assisted ACL reconstruction

A prospective, randomized study comparing arthroscopic and open anterior cruciate ligament (ACL) reconstructions was undertaken. Neither the patients nor the physical therapists were made aware of which technique was used. The central one third of the patellar tendon with proximal and distal bone plugs was utilized as the graft material to reconstruct the ACL in all cases. Rehabilitation was identical for each group. The following variables were compared: postoperative pain score, operating time, estimated blood loss (EBL), quantity of analgesics used, complications, range of motion at 1, 3, and 6 months, a 6-month evaluation consisting of Lachman's, anterior drawer, and pivot shift tests, amount of thigh atrophy, and Cybex II tests. Statistical significance was achieved (P < .05) in only three parameters. The 1-month postoperative range of motion, the 6-month postoperative thigh atrophy, and the Cybex II test (knee extension at 60 degrees/sec) were statistically different favoring the arthroscopic method.

Influence of carbohydrate-electrolyte drinks on marathon running performance

The aim of this study was to compare the effects of drinking two carbohydrate (CHO) electrolyte solutions and water on marathon running performance. Seven endurance-trained runners completed three 42.2-km treadmill time-trials which were randomly assigned and 4 weeks apart. On each occasion the subjects ingested 3 ml.Kg-1 body weight of either water (W), a 6.9% CHO solution (O) or a 5.5% CHO solution (L) immediately prior to the start of the run and 2 ml.kg-1 body weight every 5 km thereafter. The total volume of fluid ingested [mean (SEM)] was 1112 (42), 1116 (44) and 1100 (44) ml, respectively. Running times for W, O and L trials were 193.9 (5.0), 192.4 (3.3) and 190.0 (3.9) min, respectively. Performance time for the L trial was faster (P < 0.05) compared with that of the W trial. Running speed was maintained in the L trial, whereas it decreased after 10 km (P < 0.05) in the W and after 25 km (P < 0.05) in the O trial. Blood glucose and lactate, and hormonal responses to fluid ingestion were similar in all three trials. Higher plasma free fatty acid and glycerol concentrations were observed at the end of the W trial compared with those obtained after the O and L trials, respectively (P < 0.05). Plasma ammonia concentration was higher (P < 0.01) at the end of the L trial compared with the W trial. Plasma creatine kinase concentration was higher (P < 0.05) 24 h after the completion of the L trial than after the W trial.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison between carbohydrate feedings before and during exercise on running performance during a 30-km treadmill time trial

The purpose of this study was to compare the effects of a carbohydrate-electrolyte solution, ingested during exercise, with the effects of a preexercise carbohydrate meal on endurance running performance. Ten endurance-trained males completed two 30-km treadmill runs. In one trial subjects consumed a placebo solution 4 hr before exercise and a carbohydrate-electrolyte solution immediately before exercise and every 5 km (C). In the other trial, subjects consumed a 4-hr preexercise high-carbohydrate meal and water immediately before exercise and every 5 km (M). Performance times were identical for M and C, and there was no difference in the self-selected speeds. Oxygen uptake, heart rates, perceived rate of exertion, and respiratory exchange ratios were also similar. However, blood glucose concentration was higher in C during the first 20 km of the 30-km run. In M, blood glucose concentration was maintained above 4.5 mmol.L-1 throughout exercise. Thus, the two conditions produced the same 30-km treadmill running performance time.

The Internet: will this highway serve the digital library?

The future of the biomedical enterprise and the biomedical libraries that serve it is tied closely to digital information. The changing nature of this type of information will create new pressures on libraries, particularly in health care organizations. Libraries must learn to deal with these pressures. Currently, libraries depend on the Internet primarily for connections to resources and other libraries; thus enhancements to the Internet will impact the libraries of the present and future significantly. This paper provides an overview of the technical capabilities that will be available in the near to midterm, what libraries will be able to do with those capabilities, and how libraries can position themselves to take advantage of the impending changes.

Invasive zygomycosis due to Conidiobolus incongruus

During the past decade, an increasing spectrum of pathogenic Zygomycetes fungi have caused infections in humans. The preponderance of these deeply invasive infections have been caused by members of the order Mucorales. However, deeply invasive zygomycoses due to genera of the order Entomophthorales (Conidiobolus species and Basidiobolus species) have seldom been reported. We describe a granulocytopenic patient with pulmonary and pericardial zygomycosis due to Conidiobolus incongruus, describe this organism's susceptibility to antifungal agents, characterize its diagnostic microbiological characteristics, and review previously reported cases of deeply invasive zygomycosis due to Conidiobolus species. In immunocompromised patients, C. incongruus is an uncommon but highly invasive fungal pathogen that may be resistant to amphotericin B and can be distinguished from other Zygomycetes fungi by characteristic mycological features.

Human immunodeficiency virus type 1 integrase: effect on viral replication of mutations at highly conserved residues

Sequence comparisons of the integrase (IN) proteins from different retroviruses have identified several highly conserved residues. We have introduced mutations at 16 of these sites into the integrase gene of human immunodeficiency virus type 1 and analyzed the phenotypes of the resulting viruses. The viruses were all normal for p24 content and reverse transcriptase activity. In addition, all of the mutants could infect T-cell lines and undergo reverse transcription, as assessed by PCR analysis. Most of the mutant viruses also had normal Western blot (immunoblot) profiles, although three of the mutations resulted in reduced signals for IN relative to the wild type on the immunoblots and mutation of residue W235 completely abolished recognition of the protein by pooled sera from human immunodeficiency virus type 1-positive patients. Mutations that have previously been shown to abolish activity in in vitro studies produced noninfectious viruses. The substitution of W235 was notable in producing a noninfectious virus, despite previous reports of this residue being nonessential for IN activity in vitro (A.D. Leavitt, L. Shiue, and H.E. Varmus, J. Biol. Chem. 268:2113-2119, 1993). In addition, we have identified four highly conserved residues that can be mutated without any affect on viral replication in T-cell lines.

Retroviral mediated transfer of the human multidrug resistance gene (MDR-1) into hematopoietic stem cells during autologous transplantation after intensive chemotherapy for metastatic breast cancer

Patients with metastatic breast cancer will receive 4-5 cycles of induction chemotherapy on one of the ongoing Medicine Branch protocols. Patients achieving at least a partial response, and who do not have evidence of bone marrow involvement and who do not have metastatic bone disease, will undergo PBSC and bone marrow harvest when hematologic recovery has occurred. Patients who have not achieved a PR, but who are responding to therapy, may be treated with additional cycles of therapy in an attempt to achieve a PR. Such patients will be eligible for transplant if a PR is obtained. 70% of the bone marrow and PBSC will be cryopreserved. The CD34+ subpopulation from the remaining 30% of the bone marrow and PBSC harvest will be obtained using an anti-CD34+ antibody and immunoabsorption column. The bone marrow and peripheral blood CD34 cells will be transduced with a retroviral vector expressing the human MDR-1 cDNA. Patients with positive bone scans or histologic evidence of bone marrow involvement will be excluded from the gene transfer component of the protocol. The MDR-1 transduced CD34 cells will be reinfused along with the non-transduced bone marrow and PBSC into patients following high dose ICE chemotherapy. Serial peripheral blood and bone marrow samples will be obtained to study hematopoietic reconstitution with MDR-1 transduced cells. Patients with residual or progressive disease after ABMT will be treated with taxol or vinblastine. In these relapsed patients, peripheral blood and bone marrow samples will be obtained to study whether chemotherapy amplifies the proportion of hematopoietic cells containing the MDR-1 provirus. We will monitor the nadir blood counts of each patient receiving salvage chemotherapy for evidence of myeloprotection and correlate this data with changes in the mean proviral copy number. Sites of relapsed tumor will be biopsied to test for the presence of the MDR-1 provirus.

Molecular and phenotypic mapping of the short arm of chromosome 5: sublocalization of the critical region for the cri-du-chat syndrome

Forty-nine individuals have been identified with deletions or translocations involving the short arm of chromosome 5. While most display the classical phenotype of the cri-du-chat syndrome, several of the patients do not have the syndrome or have only a subset of the clinical features. Somatic cell hybrids containing the deleted chromosome 5 were derived from each patient. Each somatic cell hybrid was analyzed at the DNA level using 136 chromosome 5p-specific DNA fragments. It was possible to unambiguously order most of the chromosomal breakpoints present in the somatic cell hybrids based on the hybridization patterns of Southern blots. Further comparisons between the deletions present in the patients and their clinical features identified several chromosomal regions that were involved in specific clinical features. A critical chromosomal region involved the high-pitched cry mapped to 5p15.3, while the chromosomal region involved in the remaining features of the cri-du-chat syndrome mapped to a small region within 5p15.2. Deletions that did not include these two chromosomal regions presented varying clinical phenotypes from severe mental retardation and microcephaly to a clinically normal phenotype. These results demonstrate the need for careful characterization of a 5p deletion in prenatal cases before clinical predictions are made.

Guidelines for long-term management of patients with Kawasaki disease. Report from the Committee on Rheumatic Fever, Endocarditis, and Kawasaki Disease, Council on Cardiovascular Disease in the Young, American Heart Association

Long-term management of patients with Kawasaki disease should be tailored to the degree of coronary arterial involvement. This committee has made recommendations for each risk level about antiplatelet and anticoagulant therapy, physical activity, follow-up assessment by a pediatric cardiologist or primary care physician, and the appropriate diagnostic procedures that may be performed to evaluate cardiac disease. The risk level for a given patient with coronary arterial involvement may change over time because of changes in coronary artery morphology. The recommendations for management presented here are intended as practical interim guidelines until additional prospective or retrospective data are compiled to define more clearly the natural history of Kawasaki disease.