Analysis of ultrastructural changes in the myocardium of rats during withdrawal syndrome after gradual decreasing of metipranolol doses.

Hypersensitization of the myocardium occurring in rats after remission of metipranolol's beta-blocking effect in experiments manifested itself by marked proliferation of the mitochondrial apparatus of myocytes accompanied by an increase in SDH activity as well as its ultrastructural pattern return to control values after a shorter period of A characteristic feature of the withdrawal syndrome occurring in the myocardium of rats exposed to stress following discontinuation of premedication with metipranolol, is partial damage to the mitochondrial apparatus of myocytes associated with a decrease in SDH activity and presence of hyperactive nuclei. Based on the results obtained, the author concludes that, while the withdrawal syndrome sets in during gradual decrease in long-term metipranolol doses in the rat myocardium on stress, it lasts shorter than after sudden interruption of treatment, and myocardial metabolism as well as its ultrastructural pattern return to control values after a shorter period of time.


[Pancreatojejunostomy or pancreatogastrostomy after cephalic pancreatoduodenectomy].

The propensity for leakage at the site of pancreatojejunostomy continues to be a major reason for morbidity and death after pancreaticoduodenectomy. Pancreatogastrostomy has been introduced as a possible alternative to pancreatojejunostomy and although this procedure was developed experimentally more than 50 years ago its use has not gained widespread clinical use. The purpose of this study was to evaluate the role of pancreatogastrostomy. Pancreatogastrostomy was performed in 15 patients with pancreatic resection for carcinoma and compared with 57 pancreatojejunostomy. Our experience confirms that pancreatogastrostomy is a safe and easy method and suggest that it may be used more frequently.


Efficacy of levocabastine in conjunctival provocation studies.

Levocabastine is a new topical histamine H1 antagonist. The antihistaminic and antiallergic effects of levocabastine eye drops have been evaluated in eight conjuctival provocation studies (n = 238). Two studies used a histamine challenge; five studies used allergen challenge; one study used both and in one study allergic provocation was with compound 48/80. In all but one study, only one single dose of levocabastine (one or two drops) was given. Six studies were against placebo only; one was against cromoglycate and one study used both placebo and cromoglycate as reference drugs. Single instillation of levocabastine eye drops protected against histamine and allergen-induced ocular symptoms within a period of 10 minutes. Levocabastine eye drops significantly alleviated conjunctival itching, redness, chemosis, eyelid swelling and tearing induced by histamine or allergen challenge (p < or = 0.05). Four hours after administration levocabastine was still active. With levocabastine, but not with cromoglycate, a significant increase was observed in the allergen threshold. Even when compared to cromoglycate given as a pre-treatment four times daily for two weeks before the allergen challenge, a single dose of levocabastine was significantly more effective in inhibiting hyperaemia, eyelid swelling, chemosis and tearing (all p < 0.05). In conclusion, conjunctival provocation studies have established that levocabastine has a rapid and long-lasting effect in protecting against histamine or allergen-induced conjunctival symptoms.


New trends in the treatment of allergic conjunctivitis.

Histamine is the key mediator producing itching, redness and chemosis in allergic conjunctivitis. Histamine levels in tears are increased ten-fold in patients with this allergic condition. Levocabastine is a newly synthesized histamine H1 antagonist which has been formulated as both eye drops and nasal spray. In well established assays of antihistamine activity, levocabastine was found to be the most potent antihistamine compound available, being 15,000 times more potent than chlorpheniramine. Ocular provocation studies in man have shown that levocabastine protects against the symptoms of allergen-induced conjunctivitis. Ophthalmological examinations, including slit lamp and ophthalmoscopy showed no adverse effects. Data from therapeutic studies are available for more than 1700 patients with allergic conjunctivitis treated for 2-16 weeks. One drop of levocabastine (0.5 mg/ml) per eye given two to four times daily provided significantly better symptom control than placebo, with good to excellent results in 71% of patients on levocabastine compared to 55% on placebo (p < 0.001). Levocabastine has a fast onset of action. In one study 94% of patients experienced symptom relief within 15 minutes after the first instillation. The effects observed with levocabastine were at least as good as those with ocular cromoglycate or oral terfenadine. The incidence of adverse experiences was not different from placebo. Levocabastine promises to be a valuable treatment for patients with allergic conjunctivitis.


Peripheral nerve segments promote consistent long-term survival of adrenal medulla transplants in the brain.

Patients with Parkinson's disease have received intracerebral transplants of autologous adrenal medulla in the attempt to counteract their severe motor dysfunctions. Unfortunately, in the majority of cases, clinical improvement has not persisted and there has been extremely poor survival of the grafts. Based on the recent observations of long-term viability of adrenal medulla grafts in the interior of transected peripheral nerves, adrenal medulla/peripheral nerve complexes were constructed in the brain to promote extended viability of chromaffin cells. A three-step, time-dependent transplantation procedure is described that results in a 100% survival rate of the adrenal medulla graft. The grafts consist of a stable population of approximately 2.0 x 10(3) chromaffin cells that survive for at least 6 months (longest time point studied): Immunoreactivity to catecholamine-related enzymes (tyrosine hydroxylase, dopamine beta-hydroxylase) and the low-affinity NGF receptor (192-IgG) are expressed by the chromaffin cells. The ultrastructural characteristics of the cells are normal and comparable to their in vivo counterparts. Construction of these peripheral nerve/adrenal medulla complexes evidently improves local conditions in and around the grafts, enabling the chromaffin cells to remain viable. This new methodology achieves the goal of reliable and extended survival of the adrenal medulla graft after intracerebral transplantation. The enhanced longevity now provides an opportunity to reevaluate the efficacy of the adrenal medulla transplant to ameliorate the functional disorders associated with striatal dopamine depletion, especially over long time periods.


Autocrine and paracrine effects of peptides on human pituitary cells.

In contrast to normal human pituitaries, GH-secreting adenomas cannot process in vivo ProSRIH whereas they do it in vitro. The existence of an endogenous factor able to inhibit ProSRIH processing in vivo was postulated and such a role was analyzed for GHRH. Results showed that when GH adenomas are incubated in vitro with GHRH 10(-8) M, their ProSRIH contents are decreased, percent inhibition being negatively correlated to the amount of endogenously released GHRH. When incubation is performed in the presence of GHRH antibody in order to block the effect of endogenous GHRH, Pro-SRIH content is increased. The same effects are observed on SRIH release: inhibition by GHRH, stimulation by GHRH antibody. Normal rabbit serum had no effect. It may therefore be concluded that the absence of ProSRIH maturation observed in adenomas in vivo may be the consequence of the GHRH release that is known to be higher from GH adenomas than from normal pituitaries.


[Sulfasalazine in the treatment of rheumatoid arthritis. A multicenter open study of 150 patients during 6 months].

One hundred and fifty patients with rheumatoid arthritis were given sulfasalazine in a daily dosage of 2 g during an open-label, multicenter, six-month trial. Improvements were apparent as early as four weeks after initiation of the drug. Improvements in clinical parameters and erythrocyte sedimentation rate were statistically significant. In the patients who remained on the study protocol, clinical and biological improvements continued over time and were more marked after six months. Overall clinical safety was satisfactory: 30 patients were withdrawn from the trial for adverse events, all of which resolved after discontinuation of the study drug. Most of these adverse events (93%) developed within two months of initiation of the drug, demonstrating the need for hematologic and hepatic tests at regular intervals during the first three months of sulfasalazine therapy. Thirty-four patients had not previously received maintenance therapy; in this subgroup, only one patient was withdrawn for ineffectiveness. In view of its favorable risk/benefit ratio and fast action, sulfasalazine may be a useful first-line drug in patients with rheumatoid arthritis.


[Gold salt deposits in the conjunctiva in rheumatoid arthritis after gold therapy. A systematic study of 15 biopsies].

Ocular abnormalities have long been recognized as a potential adverse effect of gold therapy in patients with rheumatoid arthritis. Clinical symptoms and ocular tissue lesions possibly related to use of gold therapy were routinely evaluated in eleven patients. There were few clinical manifestations: only one patient had typical accumulation of gold in the anterior crystalloid. In contrast, routine ultrastructural and microprobe studies of conjunctival biopsy specimens disclosed accumulation of gold salts in every case. Gold was visible as aurosomes in the conjunctival macrophages. Aurosomes were seen in patients treated for as little as one month, occurred even with low doses (0.3 g), and were still visible after several years. Duration of accumulation can be roughly estimated on the basis of the morphologic appearance of aurosomes which are lamellar after a few weeks of gold therapy and rod-shaped beyond one month.


The glycoprotein B gene and its syn3 locus of herpes simplex virus type 1 are involved in the synthesis of virus-associated growth factor (HSGF-1).

A putative growth factor (HSGF-1) associated with herpes simplex virus type 1 (HSV-1), which is similar to PRGF associated with pseudorabies virus, and/or HSGF-2 associated with HSV-2, was described. Experiments with four syncytial (syn) and four nonsyncytial (syn+) HSV-1 strains showed that the ability of this virus to produce HSGF-1 in infected cells is associated with the syn+ phenotype. Double infection of cells with syn+ and syn strain resulted either in enhancement or complete inhibition of HSGF-1 production, depending on the chosen pair of syn+ and syn strains. The studies with the recombinants between the syn+ strain KOS and syn strain ANGpath in the gene for glycoprotein B (gB) and syn3 locus revealed that the gB gene and its syn3 locus play a role in the HSGF-1 synthesis.


Induction of MHC class I antigen expression following infection of a human esthesioneuroblastoma cell line with cytomegalovirus and human immunodeficiency virus.

Productive infections with cytomegalovirus (CMV) and human immunodeficiency virus (HIV) were established in the Tp41ON cell line derived from a human esthesioneuroblastoma. HIV antigen expression was highest in cultures coinfected with CMV and HIV. Viral infection caused increased MHC class I antigen expression while class II and CD4 antigens remained undetectable using immunofluorescence methods. Uninfected cultures showed 10% and coinfected cultures 80% class I antigen positive cells. In coinfected cultures, CMV and HIV antigens were detected in 4% and 8% of the cells, respectively. The detection of CMV antigens in some multinucleated cells suggests coinfection with both viruses in these cells, as multinucleated cells were not found in cultures infected with CMV only. The study shows that a cell line showing neuronal differentiation in vitro can be infected with CMV and HIV and that this infection increases MHC class I antigen expression.


Wild measles virus strain: isolation and identification.

Four isolates of measles virus (Gag, Il, Buk and Shed) were obtained from suspensions of mononuclear cells from patients at the active stage of the disease. Vero cells were used for the virus isolation. All the isolates caused in the infected cell culture the appearance of symplasts of differently sized, star- or spindle-shaped multinuclear cells. The specificity of cytopathic effect was proved by the adsorption of monkey erythrocytes on the surface of cells infected by virus. The isolates were identified in virus neutralization (VN) and haemagglutination inhibition (HI) tests with different immune preparations: measles-globulin (standard), hyperimmune sera to rubella and mumps viruses, Sch. Zonne and Sch. Flexneria, as well as with conjugates of sera from measles patients and those vaccinated with live measles vaccine (LMV) L-16.


Expression of Helenium virus S coat protein in Escherichia coli, in vitro in rabbit reticulocyte lysate and transgenic tobacco.

The coat protein open reading frame (ORF) sequence of Helenium virus S (HelVS) was cloned and expressed in E. coli, rabbit reticulocyte and transgenic tobacco. In E. coli the size of the protein was identical to that obtained for the coat protein from purified virus particles and less than that predicted for the fusion protein. This may be due to ribosome binding at a potential ribosome binding site present on the viral sequence, approximately 45 nucleotides upstream from the initiating methionine of the coat protein ORF. This region of HelVS, equivalent to the 1.5 kb subgenomic RNA, also produced high levels of protein when transcribed and translated in vitro. When introduced into Nicotiana tabacum by leaf disk transformation via Agrobacterium tumefaciens, high levels of stable coat protein were detected which were identical in molecular weight to that of HelVS coat protein and constituted approximately 0.1-0.5% of the total extracted protein.


ELISA and indirect immunofluorescence in the diagnosis of LCM virus infections.

Thirty-seven matched samples of patient sera with the clinical diagnosis of a lymphocytic choriomeningitis (LCM) infection, as well as 56 matched samples of patient sera with the clinical diagnosis of a CNS infection of vague etiology were examined. Two serological techniques, indirect immunofluorescence (IF) and ELISA were used. They revealed 16.2% of positive sera confirming the clinical diagnosis of the disease; in the cases of clinical diagnosis of CNS infection of vague etiology 8.9% of positive sera were found, which points to an LCM virus-caused infection.


SSPE in Slovakia: immunocytochemical study.

In a retrospective study of two patients from Slovakia with clinical, virological and histopathological diagnosis of subacute sclerosing panencephalitis (SSPE), measles virus antigen was detected by immunocytochemical labelling studies. The formalin fixed, paraffin-embedded thin brain sections labelled with anti-measles antibodies and avidin-biotin complex peroxidase were counterstained with haematoxylin. Only a single area of brain was examined in each patient: cerebellum and parietal lobe. Viral antigen positive reaction was identified within Purkinje cells and extending along dendritic processes in cerebellum, and also in oligodendrocytes of subparietal white matter.


Immunoelectron microscopy of rabbit haemorrhagic disease virus using monoclonal antibodies.

Five monoclonal antibodies (MoAbs) to rabbit haemorrhagic disease virus (RHDV), prepared and tested in ELISA, immunoperoxidase (IP) and immunofluorescence (IF) test previously, reacted specifically in immunoelectron microscopy (IEM), too. No differences in binding of individual MoAbs with full or empty RHDV particles were found by IEM.


[Heart valvular and coronary manifestations of Takayasu disease. Apropos of a surgically-treated case].

Cardiac involvement in Takayasu's disease is well documented. This is often the result of severe hypertension. However, severe clinical manifestations of aortic regurgitation and coronary insufficiency are much less common. The authors report a case in which post-infarction angina and severe left ventricular failure led to a double valve replacement and an aorto-right coronary bypass graft procedure. The diagnosis of Takayasu's disease was suspected before surgery and was confirmed by histological examination.


[The study of rapid calculation on clearance creatinine rate in normal and epidemic hemorrhagic fever].

Height, weigh, urine volume/24 hours, serum creatinine (Scr) and urine creatinine were measured in 207 normal people and 232 patients with EHF. The clearance Creatinine rate (Ccr) was calculated by 24 hour urine volume method (therapy measure method) and Cockcroft's method (formulation method). The clearance creatinine rates between the two methods compared were significantly positive correlation, but the average values of Ccr in different stages in EHF were significantly different (P < 0.01). The result indicated that Cockcroft's Formulation was not fit for HFRS. According to the difference of Ccr in each stages of EHF, the adjustment values (ad) were presented and used to correct Cockcroft's formulation, thus, the adjusted Cockcroft's formulation could be obtained: Ccr = (140-ad-Age) x W/72 x Scr. In this paper, the Ccr of the adjusted method was compared with that of therapy measure method, the average values calculated by two methods were not different (P > 0.05). The result of 14 EHF Clinic practice demonstrated that between adjustment and practice measured methods were not significantly different. It shows that adjustment method is practical and available and can be used easily by clinic doctors in basic hospital.


[Familial pheocromocytoma. Report of 4 families].

Twelve patients with pheochromocytomas were found in members of 4 families in the recent 25 years. Nine of them were treated and confirmed surgically. Follow-up showed that 50% of the members were found to suffer from pheochromocytomas. Six of the 9 patients had bilateral and multiple tumors. The tumors developed in the adrenal glands and benign in nature. Three of the 12 patients were associated with thyroid tumors. Peripheral leukocyte chromosomes were studied in two families. Chromosomal analysis showed no evidence of marker on the 15th chromosomal pair. These findings were not consistent with the previous results. Tumor tissue contents of catecholamine were determined in 4 familial tumors and 14 sporadic pheochromocytomas. Familial pheochromocytomas tissue contained significantly higher norepinephrine and epinephrine than the sporadic tumors.


Effects of sexual condition and age on carcass characteristics and grading of Sussex cattle in Zimbabwe.

The effects of sexual condition and age at slaughter on carcass characteristics were investigated in Sussex cattle. At three months of age 93 male calves were allocated to three sexual treatments: entire, cryptorchid and castrate. The cattle were weaned at eight months, grazed on range and then placed into feedlots for 90 days prior to slaughter at 15, 18 or 21 months of age. Entire and cryptorchid cattle gained more (P < 0.01) weight and had heavier and learner carcasses than the castrates. Although cattle slaughtered at 15 months of age had better fleshing grades than those slaughtered at 18 or 21 months of age, no animal was down-graded for exhibiting marked secondary sexual characteristics.


[Drug treatments of atrial fibrillation].

Atrial fibrillation is a daily cardiological problem which poses three types of questions, which, though old, are only partially mastered: anticoagulation, reduction and prevention of recurrence. It is a potent source of embolism. The risk is the greatest in patients with rheumatic valvular disease when the fibrillation is recent and when underlying cardiac disease is uncompensated. Long term anticoagulation is mandatory when the cause is rheumatic heart disease. In other pathologies, though anticoagulation has not been shown to reduce mortality, it significantly reduces the number of cerebrovascular accidents, including in the elderly and with low-dose vitamin K antagonist drugs. The efficacy of anticoagulation in preventing arterial embolism has not been established. Reduction of atrial fibrillation is not essential if the arrhythmia is well tolerated, chronic, especially in elderly patients and when several recurrences have occurred despite preventive therapy. In other cases, medical reduction is to be preferred to cardioversion if the fibrillation is recent and well tolerated. Of the oral and injectable preparations, amiodarone seems to be the drug with best benefit/risk ratio. Prevention of recurrence of fibrillation is unnecessary for many after a first episode, especially when idiopathic. In other cases, there are many available drugs but results are uncertain except in those observed in atrial fibrillation related to the autonomic nervous system. Strictly controlled and statistically exploitable studies show comparable efficacy of quinine and other Class I drugs. Beta-blockers are not very useful and the excellent long term results with amiodarone require confirmation.(ABSTRACT TRUNCATED AT 250 WORDS)


Age-related changes in immune reactivity: the influence of intrinsic defects and of a changed composition of the CD4+ T cell compartment.

Aging is accompanied by a decline in immune reactivity which to a major extent can be attributed to changes at the level of regulatory CD4+ T cells. In addition to evidence pointing to intrinsic defects, resulting in improper responsiveness of lymphocytes, it is likely that many age-related phenomena can be explained by a changed composition of the T cell compartment. Most likely as a consequence of thymic involution, the fraction of naive T cells in the periphery decreases, resulting in poor responses to neoantigens in particular. Moreover, due to antigenic exposure the fraction of memory cells increases. It is likely that, regardless of their phenotype, cells from aged individuals are subject to intrinsic defects or to immunosuppression, resulting in a lower responsiveness. As far as CD4+ T cells are concerned, recent studies have demonstrated that naive and memory cells behave differently with regard to activation requirements and lymphokine production. Age-related changes in T cell reactivity will be discussed in the context of these observations.


Hidden amyloidoses.

The pathogenesis as well as the genetic disposition to develop clinical symptoms in transmissible spongiform encephalopathies (e.g. Creutzfeldt-Jakob disease, scrapie, bovine spongiform encephalopathy) relate these diseases to classical noninfectious amyloidoses (familial amyloidotic polyneuropathy as an example) and to Alzheimer's disease. This is not obvious to the nonexpert at first glance. This communication tries to elucidate this association, to reveal which immunochemical techniques have contributed their share.


[The late results of using evicrol and stomadent for eliminating dental tissue defects in children].

Clinical analysis of the efficacies of evikrol and stomadent used to replace dental hard tissue defects in children has shown similar results, but stomadent is preferable because the filling made of it virtually does not change its color. The authors claim that the development of such complications as caries recurrence, change of the color of the filling in sites of their union with dental tissues, abnormal edge union is related to the technique of enamel acid tanning of immature children's teeth, that should be modified.


Takayasu's arteritis with aortoaortic bypass graft and renal autotransplantation: report of one case.

Takayasu's arteritis is a rare inflammatory disease of the aorta and its major branches which occurs predominantly in young women. The clinical course has been described as two stages: 1) initial phase, with inflammatory process and systemic manifestations; and later 2) pulseless phase, with multiple arterial occlusions. A 20-year-old female came to visit this hospital for the first time at 10 years of age with occlusion of the left subclavian artery and of the thoracoabdominal aorta. Aortoaortic bypass surgery was performed using a 14 mm woven graft from the ascending aorta to the descending aorta on the infrarenal portion. The postoperative course was uneventful. Exertional dyspnea and hypertension progressively developed. However, in the past year, angiograms have shown a marked stenosis on the proximal portion of the left renal artery. Autotransplantation for the left-sided kidney was performed. The patient did well, and remained free of symptoms until this time of writing, 12 months after the operation.


[Prevention of pancreatic fistula in pancreaticoduodenectomy: cannulation of the pancreatic duct].

Fifty-two patients with malignant tumours underwent pancreaticoduodenectomy in the past 13 years. A plastic catheter, 3 mm in diameter and 40 cm in length, was used for pancreatic duct drainage and stent, with one end of it inserted into the pancreatic duct and the other end in the jejunal lumen. The cannulation was found to be very effective in stenting the stump pancreatic duct and draining the pancreatic juice away from the anastomotic stoma, hence preventing postoperative leakage. Temporary postoperative fistula occurred in only one patient, and operative death was noted.


Effects of urogastrone-epidermal growth factor and age at administration on five enzymes in the small intestine of suckling rats.

Suckling rats were given urogastrone-epidermal growth factor (EGF: 1,000 micrograms/kg body weight) or vehicle by gavage at one of three stages of development: 8 to 10, 11 to 13 or 14 to 16 days of age. Intubation was carried out at 8-hourly intervals over these periods. Fourteen to 16 h after the last intubation the rats were killed; that is, at 11, 14 and 17 days respectively. Samples of proximal and distal small intestine (SI) were taken for enzyme analysis. Five enzymes were assayed; sucrase, lactase, gamma-glutamyl transferase, alkaline phosphatase and neutral amino-peptidase, and their activities expressed per g protein. Treatment with EGF had no effect on body weight or on the length of the small intestine at any age. The nature of the effects on enzyme activities depended on the specific enzyme concerned, the site within the small intestine and the timing of the treatment. Lactase was increased by EGF at both sites only on day 14, whereas gamma-glutamyl transferase was increased in proximal samples at 11 and 14 days, and in distal samples at 17 days. Nor was the outcome always to increase activity. On day 11 alkaline phosphatase was increased in proximal SI, but decreased in distal SI; and so too was aminopeptidase N decreased in distal SI at 11 days. Sucrase showed no response at all. The pattern is complex. Certainly it does not indicate accelerated functional maturation.


[Culicidae (Diptera: Culicidae) of the Perus river basin, Acre, Amazonia (Brazil)].

Mosquito (Diptera: Culicidae) collections were made on the Pedro Peixoto Colonization Project in the State of Acre, Brazil. Four thousand, five hundred and eighty-eight (4,588) specimens were collected and fifty-three (53) species or group recognised. The occurrence of Anopheles (Nyssorhynchus) oswaldoi is given special emphasis.


Evidence for an altered kinetics of DNA excision-repair in cells infected by herpes simplex virus type 1.

In cells infected with herpesviruses a series of host cell nuclear changes can be observed in a temporal sequence. Such changes include chromosome aberrations. The precise mechanism by which virus infection produces chromosome damage is not known, but we have previously reported that herpes simplex virus type 1 (HSV-1) induces a significant number of single-stranded breaks in the host cell DNA at early hours of infection and in a time-dependent fashion. Here, it is reported that HSV-1-infected cells subjected to irradiation with ultraviolet light, show an altered kinetics in the normal process of DNA excision-repair at early hours of infection.


HPLC-monitoring of AZT in HIV-infected patient's plasma: a critical study.

3'-azido-2', 3'-deoxythymidine (AZT) concentrations in spiked human plasma were determined by means of reversed-phase high performance liquid chromatography (RP-HPLC). Samples were first cleaned-up for analysis using solid-phase extraction (SPE) columns filled with Silipore C18. In the concentration range comprising usual peak plasma concentrations during AZT therapy (0.1-20 mumol/l, i.e. 0.026-5.34 micrograms/ml) mean efficiency of the extraction procedure reached as high as 75.3% of original AZT concentrations in standard unextracted aqueous solutions. Replicate analyses in this range gave satisfactory intra-assay precision and reproducibility with coefficient of variation less than 11.3%. Calibration curves both in water and plasma showed good linearity (r > 0.999). The detection limit in plasma was 2 mumol/l, i.e. 5.3 ng per a 20 microliter of sample injected to the HPLC column. Plasma levels of AZT after a single dose administration, determined by HPLC and RIA showed rather poor correlation (r = 0.8900). In RIA about 1.7-4.5 times higher concentration values were obtained in a relatively short time, and, consequently, this method may better fulfil the needs of routine drug monitoring.


Factors influencing immune electron microscopy of flexuous potato viruses.

Effects of pH of extraction buffers, pH and titer of trapping antisera and their combinations, virus acquisition time and virus host on the trapping efficiency of flexuous potato viruses X, S and Y (PVX, PVS and PVY) in immune electron microscopy were evaluated. Addition of ethylene-diamine-tetraacetic acid to the extraction buffer improved trapping of PVY, adversely affected PVS but not PVX. Combinations of antisera had differential adverse effect on trapping which was maximum with the mixture of three antisera. Mixture of antisera to PVX and PVY had the least adverse effect on trapping of PVX and PVY as compared to the mixture with PVS antiserum. Trapping of PVX and PVY was good and almost at par at all the dilutions of the antisera while that of PVS was good up to 1000-fold only. Prolonged virus acquisition time significantly increased the number of virions trapped. Trapping was affected both by the pH of the antiserum and the extraction buffer, while in the case of PVY it was also affected by the host species.


Effect of enterovirus infection on susceptibility of HeLa cells to Shigella flexneri invasivity.

Invasiveness of Shigella flexneri M90T in HeLa cells was significantly increased when cells were preinfected with poliovirus 1, coxsackievirus B3 and echovirus 6. This effect was dependent on the dose of virus used, evident at early stages of viral infection and lasted hours before the appearance of a cytopathic effect. An increase of bacterial invasion ability was also noticed when HeLa cells were incubated with UV-inactivated enteroviruses. This enhancing effect obtained with both viable and UV-inactivated enteroviruses was not observed when in coinfection experiments HN555, a mutant of S. flexneri M90T which lacked invasive properties, was used. The data presented here suggest that the early steps of enterovirus infection induce some alterations of HeLa cells which are responsible for the enhancing of the invasiveness of S. flexneri M90T, but not sufficient to promote internalization of a non-invasive strain.


Significance of long lasting persistence of influenza virus antigens at the portal of infection and in the spleen of mice.

Distribution of virus, its antigens and development of cellular factors of immunity were followed in the course of different forms of acute influenza virus infection in mice. Long term persistence of influenza virus antigens in the portal of entry and spleen were typical for of acute influenza. Lethal effect of influenza infection was caused by massive lesions induced by the virus and due to cell mediated immune response. The fate of infected individual seems to be decided during the first days of post-inoculation and depends on the ability of the virus to modify the cell membranes of the infected individual.


Study of cross-reaction between Coxiella burnetii and Legionella pneumophila using indirect immunofluorescence assay and immunoblotting.

Patients with Q fever and legionellosis may present identical clinical symptom. Differentiation of these diseases is made by serology, mainly the indirect immunofluorescence assay (IFA). Using IFA the authors tested 154 Q fever positive sera from 55 patients with acute Q fever and 28 patients with chronic Q fever for Legionella pneumophila antibodies and 57 sera from 57 patients with legionellosis for Coxiella burnetii antibodies. Of the 211 sera tested, four sera from different patients had antibodies to both C. burnetii and L. pneumophila. Using cross-adsorption studies and protein immunoblotting, no cross-reaction between C. burnetii and L. pneumophila antibodies could be identified. The moderate antibody titers against L. pneumophila in two Q fever patients and vice versa for one legionellosis patient are consistent with the incidence of seroprevalence in healthy blood donors and were not due to cross-reactivity. One patient was identified with concurrent Q fever and legionellosis.


Peroral immunization of adult white mice with the Skalica strain from the tick-borne encephalitis virus complex.

Adult white mice immunized perorally with the infectious Skalica strain from the tick-borne encephalitis (TBE) virus complex did not show any clinical symptoms of illness. 56% of experimental animals immunized with two doses of the Skalica virus (the titer of virus was 6 x 10(10) LD50) were protected against the challenge with the Hypr strain of TBE virus. All mice immunized with the Skalica virus and having haemagglutination-inhibiting antibodies higher than 1:80 survived the challenge with the given dose of virulent TBE virus. No differences in the immunogenicity and protectivity were observed in experimental animals infected with infectious Skalica virus by oesophageal probe, or by drinking virus-containing medium. A higher protective activity against the virulent Hypr virus was observed in adult white mice immunized subcutaneously with the Skalica virus.


A study on the immune response of sheep to foot and mouth disease virus vaccine type 'O' prepared with different inactivants and adjuvants.

Foot and mouth disease virus (FMDV) type 'O' was inactivated either with formaldehyde or binaryethyleneimine (BEI). Vaccines were prepared with inactivated virus incorporating aluminum hydroxide gel or mineral oil as an adjuvant. The antibody response in sheep was monitored by serum neutralization and ELISA test for a period of six months. Significant difference in antibody response was not observed between vaccines inactivated with formaldehyde or BEI. On the other hand significant difference in the antibody response was noticed between alhydrogel and oil vaccines. The high titer of antibodies stimulated by oil adjuvant vaccines persisted longer than those of alhydrogel vaccines within the period of study.


The effect of an Egyptian isolate of Streptomyces afghanensis on some plant viruses.

An Egyptian isolate of Streptomyces afghanensis was examined for the production of antiviral metabolites. Concentrated broth exudates of this microorganism were tested against tobacco mosaic virus (TMV), tomato mosaic virus (ToMV) and potato virus X (PVX) infecting Nicotiana tabacum L. cv. White Burley. Both concentrated metabolites and their acetone extract inhibited local lesion development of the tested viruses. In all cases, maximum antiviral effect was observed 2 hr after infection. The ultrafiltrate of broth culture reduced the number of local PVX lesions produced on the challenged half leaves in the case of later applications.


A method for the preparation of purified antigens of coxsackievirus B3 from a large volume of cell culture supernatant.

A simple procedure was used for the concentration and partial purification of coxsackievirus B3 (Nancy strain). For a large-scale production of virus. Vero cells grown in roller bottles were used. Virus concentrate from a large volume of cell culture supernatant was prepared by precipitation with 6% (w/w) polyethylene glycol. This crude antigen was further purified by banding in cesium chloride gradient using ultracentrifugation. The infectivity and haemagglutination activity of virus were checked up during the whole procedure and the final recovery of infections virus was about 60%.


The use of consensus sequence for amplification and oriented cloning of human alpha interferon genes.

A clone from human cDNA library was amplified in polymerase chain reaction (PCR) by the synthetic oligonucleotides. The final construct after linker ligation and digestion with restriction endonucleases was suitable for oriented cloning into E. coli expression vector. The interferon (IFN) expression could be detected by SDS-PAGE electrophoresis. Western blotting and biological antiviral assay. This set of oligonucleotides can be used also for amplification of genomic DNA or cDNA libraries.


Protective effects of berberine and phentolamine on myocardial reoxygenation damage.

The protective effects of berberine and phentolamine against anoxia and reoxygenation damage in isolated rat hearts have been investigated. Incorporation of berberine (24.5 mumol/L) in both anoxic and aerobic perfusion media resulted in a significant reduction of CPK release during the reoxygenation period, and the ultrastructural damage was reduced as compared with the control group; the myocytes in the berberine-treated group displayed mild intracellular edema, well-registered myofibrils without contracted bands, and swollen mitochondria with partially broken cristae but without dense bodies. Berberine did not inhibit calcium and sodium accumulation or magnesium and potassium loss. Treatment with phentolamine (6.6 mumol/L), an alpha-adrenoceptor antagonist, had similar effects, though the CPK release profile was shifted to the right and downwards. These results suggest that although berberine and phentolamine have some beneficial effects on myocardial reoxygenation injury, they may not abolish the injury. Therefore alpha-adrenoceptor stimulation may not be the major mechanism behind the injury.


Microtubules and regulation of granulosa cell steroidogenesis by porcine granulosa cell conditioned medium.

Possible involvement of microtubules in the regulation of granulosa cell steroidogenesis by large follicle granulosa cell conditioned media (LGCCM) was assessed by monitoring the effect of agents that alter the cytoplasmic microtubule-tubulin equilibrium. The changes in microtubule organization and cell shape were examined by immunohistochemical procedure and morphometric analysis. Progesterone production stimulated by LGCCM was reduced by colchicine (agent that polymerizes microtubules) in a dose-dependent manner. In contrast, LGCCM stimulated progesterone secretion was significantly decreased by microtubule stabilizing agent (taxol: 1-10 microM). Cultured granulosa cells with a flattened appearance and projections after 24 h of incubation assumed a spherical configuration and were devoid of cytoplasmic processes when cultured with these agents. LGCCM stimulated GCs showed a reduction in the perimeter as compared with controls, although some cytoplasmic processes were observed. These findings suggest the involvement of microtubules in the regulation of cultured granulosa cell progesterone production by LGCCM, possibly through an effect on subcellular organelle distribution by altering the morphology of granulosa cells.


Pheochromocytoma in the pregnant patient: a case study.

This is a case study of a patient 32 weeks pregnant who presented with multiple endocrine neoplasia type IIa, with severe pheochromocytoma complicated by adult respiratory distress syndrome. The patient's blood pressure was labile, with systolic variations from 50 to 230 mm Hg and tachycardia ranging from 150 to 180 beats per minute. The patient was treated with a variety of alpha- and beta-blockers whose efficacy is compared. Hemodynamic measures are compared with the clinical presentation. The importance of fluid replacement is discussed.


Peptide YY inhibits gastric acid secretion stimulated by the autonomic nervous system.

Peptide YY (PYY), a new peptide found primarily in mucosal endocrine cells of the terminal ileum and colon, inhibits pentagastrin-stimulated gastric acid secretion in several species, including man. Several studies indicate that PYY can affect autonomic neurotransmission, and we have recently shown that PYY can inhibit neurally stimulated release of insulin. The purpose of the present study was to examine the effect of PYY on gastric acid secretion stimulated by the autonomic nervous system. On separate days, 6 dogs that were prepared with chronic gastric cannulas were given 2-deoxy-D-glucose (2-DG; 90 mg/kg, i.v.) for 6 min, either alone, or in combination with PYY (100, 200, or 400 pmol.kg-1.h-1, i.v.) for 60 min. The effect of PYY, at 400 pmol.kg-1.h-1, on gastric acid secretion stimulated by either 2-DG or PG (1 micrograms.kg-1.h-1, i.v.) was studied after treatment with propranolol (0.5 mg/kg, i.v. bolus) or phentolamine 1 mg/kg, i.v. bolus). PYY reduced the 2-DG-stimulated secretion of gastric acid in a dose-dependent manner. PYY, given at 100 pmol.kg-1.h-1, reduced gastric acid output by 29 +/- 17%; PYY, at 200, by 41 +/- 7% (p < 0.05), and PYY, at 400, by 52 +/- 8% (p < 0.05). The inhibitory action of PYY on 2-DG-stimulated secretion of gastric acid persisted after treatment with phentolamine (69 +/- 14%; p < 0.05), but it was blocked by treatment with propranolol.(ABSTRACT TRUNCATED AT 250 WORDS)


Tyrosine-hydroxylase-immunoreactive neurons in retinal transplants in the rat.

Embryonic rat retinae were transplanted to the brains of newborn rats, and the distribution of catecholaminergic neurons in the retinal tissue was studied 1-2 months after transplantation, using the tyrosine hydroxylase (TH) immunohistochemical method. The results showed that distinct TH-positive cells were identified in all retinal transplants examined. The somata of the majority of these TH-immunoreactive cells were located along the inner margin of the inner nuclear layer in the retinal transplants; the processes of these cells were distributed mainly in the outer portion of the inner plexiform layer. This pattern is comparable to that observed in retinae of normal and host rats, suggesting that the organization of the catecholaminergic neurons in the transplant is largely similar to that in the normal retina. However, a reduction of the immunoreactivity in the plexiform layers and subpopulations of TH-positive cells with somatic diameter smaller than 8 microns or larger than 18 microns was observed in most of the retinal transplants studied. This implies that the organization of the catecholaminergic system in the transplant may not be as intact as in the normal retina.


Somatostatin inhibits VIP- and forskolin-stimulated cyclic AMP accumulation in enterocytes from rat jejunum.

This study demonstrates the dual regulation by somatostatin of vasoactive intestinal peptide (VIP)-stimulated and forskolin-stimulated cyclic AMP accumulation by isolated rat intestinal epithelial cells. Somatostatin non-competitively inhibited (IC50 = 1 microM) the stimulatory effect of VIP on cyclic AMP accumulation, suggesting that the two neuropeptides act through separate receptors. The cyclic AMP accumulation produced by forskolin (a diterpene that stimulates directly the catalytic subunit of adenylate cyclase) was also inhibited by somatostatin in a dose-dependent manner. However, somatostatin did not modify the stimulatory effect of VIP on adenylate cyclase activity in a membrane preparation from the same cells, making it difficult to explain the mechanism of somatostatin action at this level. The data presented here suggest that somatostatin may play a physiological role in the regulation of nutrient absorption and the release of gut hormones or exocrine secretions by intestinal epithelial cells through the modulation of cyclic AMP production.


Keratinocyte transglutaminase: differentiation marker and member of an extended family.

Transglutaminases stabilize a variety of biological structures by cross-linking constituent proteins. This action appears physiologically important in stabilizing (1) keratinocyte cornified envelopes, (2) fibrin clots, (3) the copulation plug in rodents, and (4) the fertilized egg surface in aquatic species. Several transglutaminases that participate in such processes have been well characterized and found, though highly divergent, to differ in sequence primarily at the amino terminus. Comparison of their gene structures suggests a likely mechanism by which new members may arise that assume a diversity of functions. The functions of some members of this family are presently unknown, including the tissue transglutaminase found in many mammalian cell types, and those found in plants. Most of the transglutaminases identified are soluble enzymes, but several that are membrane-bound have gained recognition recently. The best characterized of the latter is keratinocyte transglutaminase, which is anchored in the membrane by acylated fatty acid. Important for proper epidermal cell maturation, expression of this enzyme is greatly altered by physiological effectors and toxic agents. In addition, it is induced by cultivation of cells from non-squamous epithelia. Thus, it is a promising marker for helping to elucidate the molecular basis by which keratinocyte differentiation is elicited or altered.


Functional modifications of the coupling of solubilized dopamine D2 receptors to guanine-nucleotide-binding proteins.

The molecular basis for the regulation of high-affinity agonist, [3H]N-n-propylnorapomorphine ([3H]NPA), binding to cholate-solubilized dopamine D2 receptors was characterized using cations, guanine nucleotides and sulfhydryl-modifying agents. [3H]NPA binding displayed an absolute requirement for divalent cations in the solubilized preparation. Removal of Na+ from the solubilized preparation caused an apparent reconstitution of soluble receptors resulting in a reduced sensitivity of the agonist binding to divalent cations. The pharmacological profile of [3H]NPA binding was found to be similar in membrane and solubilized preparations. N-ethylmaleimide (NEM) and thermal exposure mimicked the effects of guanine nucleotides in reducing the proportion of high-affinity agonist sites in the solubilized state. [3H]NPA binding was much more susceptible to NEM-induced alkylation or heat inactivation compared to the antagonist [3H]spiroperidol binding. Pertussis-toxin-catalyzed ADP-ribosylation of G-proteins in the solubilized preparation resulted in the labelling of only one protein with the apparent molecular weight of 39-41 kDa. Both NEM and heat treatments caused the loss of ADP-ribosylation in the solubilized preparations. A consistent pattern of correlation between receptor binding data and ADP-ribosylation response suggests functional coupling of dopamine D2 receptors to the components of the effector system in solution.


Genome type analysis of adenovirus type 4.

Twenty AV4 isolates were analysed with 18 restriction endonucleases. They could be classified into two genome types (genomic clusters) AV4p and AV4a. Combined with data from Li and Wadell [Arch Virol 1988;101:65-77], DNA variants p1-p8 and al-a3 were defined. The genetic relatedness within the genome types was in the range of 88-99% comigrating fragments, whereas < 62% of the fragments were comigrating between the genome types.


Multidrug resistance in leukaemia.

Multidrug resistance hampers successful chemotherapy in many haematological neoplasms and is mediated by several cellular proteins. In some cases, the genes encoding these proteins have been shown to confer resistance on transfer to drug-sensitive cell lines. This is true for the efflux pump product of the MDR1 gene, P-170. Upregulation of enzymes such as GST has been observed, although the contribution of this enzyme in drug resistance expressed by malignant haematopoietic cells is still uncertain. Cells also appear to be able to downregulate enzymes which are drug targets. Examples include the decrease in Topo II which accompanies the resistance shown by cells to VP-16 and VM-26. Although many reports include both presentation and relapsed patients, there are few data on samples drawn from the same patients before and after chemotherapy. While P-170 and GST appear to be raised more often in cells from resistant and relapsed disease, it is quite clear that such mechanisms can be active in de novo malignancy and do not necessarily emerge as a consequence of prior chemotherapy. Methods of detecting drug resistance are reviewed here; these include in vitro cellular assays for drug toxicity, and molecular, immunological and functional detection of P-170 or Topo II. The clinical evaluation of such assays is only just beginning and some of the data are contradictory. To some extent, this may reflect the complex way in which the various resistance mechanisms may interact. Nevertheless, there are some encouraging early signs that the application of these assays to clinical material will yield valuable data on the relative contributions of these mechanisms and on ways in which they may be overcome. At present, much attention has focused on the potential of agents which prevent the P-170 efflux pump from exporting cytotoxics from the cell. This is likely to be only the first of new therapies arising from an improved understanding of multidrug resistance. More immediately, assays for multidrug resistance and its parameters may find their place as routine diagnostic and prognostic tools in the laboratory.


Factors governing the potentiation of NMDA receptor-mediated responses in hippocampus.

A modified medium containing an AMPA receptor antagonist and low concentrations of magnesium was used to investigate the factors governing the potentiation of synaptic responses mediated by NMDA receptors. When long-term potentiation (LTP) was induced in standard medium and NMDA responses were analyzed by changing to the modified medium, no statistically significant differences were observed between potentiated and control pathways. Returning the slices to the standard medium showed that LTP was still present, indicating that the potentiation effect was not reversed by the modified medium. High-frequency stimulation applied in the modified medium produced an enhancement of synaptic responses, but this was not occluded by prior potentiation in standard medium. The degree of potentiation induced in the modified medium and expressed by NMDA responses was larger in the presence than in the absence of inhibition and, unlike LTP, was proportionately larger when recorded in the stratum pyramidale than in the stratum radiatum. These results indicate that the potentiation of NMDA receptor-mediated responses triggered by high-frequency stimulation applied in modified medium differs in several respects from the LTP induced in standard conditions. They confirm that LTP is expressed to a markedly different degree by NMDA and non-NMDA receptors and suggest that events that do not necessarily accompany LTP affect the potentiation of NMDA receptor-dependent synaptic responses.


Effects of chronic alcohol consumption and withdrawal on the somatostatin-immunoreactive neurons of the rat hippocampal dentate hilus.

Previous studies have demonstrated that the dentate granule and the CA3 pyramidal cells of the rat hippocampal formation are neuronal populations vulnerable to the toxic effects of ethanol. It also has been shown that the resulting alterations do not end after withdrawal from ethanol. As the neurons in the dentate hilus are heavily interconnected with the dentate granule cells, the authors decided to examine the fate of the hilar neurons after chronic alcohol consumption and withdrawal, inasmuch as the hilar somatostatin-immunoreactive (SS-I) neurons were found to be sensitive to cerebral ischemia and to seizures. The following groups of adult rats were studied: (1) alcohol-fed for 6 and 12 months; (2) alcohol-fed for 6 months and then switched to water for a further 6 months; (3) pair-fed controls; and (4) controls fed ad libitum. The authors determined the numerical density of hilar neurons and the number of its SS-I subpopulation. These were found to be significantly reduced in both the alcohol-fed and withdrawal groups when compared with the respective age-matched controls. The consequent loss of the integrative action of the hilar neurons, including the SS-Is, could explain some of the alcohol-related functional deficits as well as their persistence after withdrawal.


Characterization in vivo of the NMDA receptor-mediated component of dentate granule cell population synaptic responses to perforant path input.

The NMDA receptor-mediated component of the hippocampal granule cell population excitatory postsynaptic potential response to low frequency (< 0.2 Hz) stimulation of the medial perforant path was characterized in vivo. Extracellular recordings were obtained from the dentate molecular layer in anesthetized rabbits, and glutamatergic and GABAergic antagonists were applied locally by pressure ejection. To measure the NMDA-mediated component, the NMDA receptor antagonist D-5-aminophosphonovalerate (APV) was applied during the constant ejection of physiological saline, 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX), and/or bicuculline methiodide. In general agreement with the results of attempts by other investigators to identify NMDA responses in vivo, APV did not significantly reduce the response to a single stimulus impulse in the presence of saline. However, an NMDA-mediated response was revealed when alpha-amino-3-hydroxy-5-methyl-4-isoxazoleproprianate receptor-mediated current flow was eliminated by applying the non-NMDA receptor antagonist CNQX. The NMDA component was negative-going as predicted, but its duration was considerably less than indicated in other studies of the dentate in vitro. The relative magnitudes of the NMDA and non-NMDA components of the EPSP were found to vary as a function of stimulus intensity or frequency. The NMDA receptor-mediated component represented 12% of the control response and increased to over 25% in response to higher stimulus intensities. A brief, high-frequency burst of impulses evoked a larger NMDA component in the presence of CNQX and was able to evoke an NMDA component in the presence of saline. Surprisingly, short trains of stimulation at lower frequencies typically produced suppression of the NMDA component. In a final series of experiments, it was found that many characteristics of the NMDA component were substantially altered by GABAergic inhibition. In the presence of the GABAA antagonist bicuculline, the magnitude of NMDA receptor-mediated responses was increased and their duration was greatly extended. Additionally, in the presence of bicuculline, the NMDA component facilitated markedly in response to frequencies of stimulus input > 20 Hz. These results indicate in vivo that the initiation and duration of NMDA current flow depend strongly upon the intensity and frequency of perforant path stimulation. In addition, the NMDA response to a single impulse appears to be reduced and truncated by input from GABAA receptor-mediated feedback and/or feedforward inhibition, and this inhibition affects temporal summation of NMDA receptor-mediated responses over a wide range of input frequencies. It is suggested that such inhibition results from the activation of GABAA receptors located on granule cell dendritic shafts.(ABSTRACT TRUNCATED AT 400 WORDS)


Species identification of spiny lobster phyllosome larvae via ribosomal DNA analysis.

Within the tropical northwestern Atlantic, Panulirus argus, P. guttatus, and P. laevicauda (Palinuridae family), are sympatric. Numerous studies have examined the distribution and abundance of planktonic phyllosome larvae with respect to recruitment of spiny lobsters to the benthic population, but the data are of limited use because larvae of these species cannot yet be distinguished from one another by morphological characteristics. A simple molecular method that unambiguously differentiates adults or larvae of P. argus, P. guttatus, and P. laevicauda is described: a 5' region of 28s ribosomal DNA is amplified in vitro and then cut with a diagnostic restriction enzyme to identify each species. Data are also presented from the application of this method to representative plankton tows.


Diagnostic value of ophthalmologic findings in myotonic dystrophy: comparison with risks calculated by haplotype analysis of closely linked restriction fragment length polymorphisms.

To determine diagnostic value of lens opacities in myotonic dystrophy (DM), we examined 98 at-risk members of 9 DM kindreds. Haplotype analysis of restriction fragment length polymorphisms (RFLPs) using ApoC2, CKMM, and pEFD4.2 supported the diagnosis of DM in 33 and excluded the diagnosis in 51 members. The sensitivities of bilateral iridescent lens opacities, posterior cortical lens opacities, orbicularis oculi weakness, low intraocular pressure, ptosis, and ocular myotonia were 46.7, 50.0, 60.6, 59.3, 51.5, and 3.0%, while their specificities were 100.0, 100.0, 98.0, 94.1, 96.1, and 100.0%, respectively. A peripheral pigmentary degeneration and central macular lesions of retina were not found on indirect fundoscopy. In 86.2% of DM patients, bilateral iridescent lens opacities, posterior cortical lens opacities, or both were present. Unilateral iridescent lens opacities occurred in only 3 of our DM patients, and 2 of non-DM relatives showed a few unilateral iridescent particles. Posterior cortical lens opacities in DM patients always affected both eyes in this series. We conclude that 1) bilateral iridescent lens opacities and posterior cortical lens opacities are highly specific for DM and useful for establishing clinical diagnosis of DM, 2) unilateral iridescent lens opacities are infrequent in DM and are seen in some non-DM members, and 3) ocular myotonia and clinical retinopathies are rare in DM.


Renal cell tumors induced in CBA male mice by 1,2-dimethylhydrazine.

Epithelial kidney tumors induced in CBA male mice by 1,2-dimethylhydrazine (DMH) were studied histochemically and immunohistochemically. A total of 48 tumors studied histologically were diagnosed as clear-cell, acidophilic, or mixed adenomas located in the renal cortex. Gamma-glutamyl transpeptidase (GGT) was strongly positive in normal proximal convoluted tubules, slightly positive in the cells of Bowman's capsule, and negative in 47 of 48 tumors examined. Antibodies against the new antigen obtained from the mouse liver oval cells, antigen A6, were also used. This antigen is negative in normal kidney proximal tubules but always positive in distal tubules and collecting ducts. It was also positive in all 47 GGT-negative tumors studied here. One tumor was GGT-positive and antigen A6-negative. Based on our data, it was concluded that the majority of renal cell adenomas induced by DMH in mice probably originate from the distal tubules or collecting ducts and not from the proximal tubules.


Seasonal distribution and diel biting patterns of culicine mosquitoes in Costa Marques, Rondônia, Brazil.

A study of peridomestic man-biting culicines in the Amazon Basin was conducted from January through December, 1987. Fifteen species of mosquitoes from six genera were collected by volunteers in all-night human-bait indoor and outdoor collections at five houses in and near the town of Costa Marques, Rondônia, Brazil. Culex quinquefasciatus and members of the Mansonia titillans/indubitans Group comprised 61 and 33%, respectively, of all culicines collected from human-bait outside houses and 62 and 35%, respectively, of those collected from volunteers inside houses in the town. In rural areas, Cx. quinquefasciatus was less abundant and only comprised 2 and 5% of the culicines, respectively, collected inside and outside houses. Mansonia titillans/indubitans Group comprised 75% and 86% of the culicines collected inside and outside houses, respectively, from rural residences. Culex quinquefasciatus and members of the Mn. titillans/indubitans Group were more endophilic than other culicines collected. Nocturnal and seasonal biting rhythms for the more common culicines are described.


Correlation of cardiovascular and respiratory responses to glutamate excitation of pressor areas of the medulla in cats.

Cardiorespiratory responses, including changes of systemic arterial pressure (SAP), renal or splanchnic sympathetic nerve activity (SNA) and phrenic nerve activity (PNA), were elicited by microinjection of monosodium glutamate solution (0.5 M, 100 nl) into the dorsal (DM) and rostral ventrolateral medulla (RVLM) in 15 vagotomized cats anesthetized by urethane-chloralose and paralyzed by gallamine triethiodide. Artificial ventilation was adjusted to keep the end-tidal CO2 concentration at 4.0-0.5%. Sixty two pressor and 17 non-pressor sites were stimulated. Most of the stimulations inhibited the PNA. The responses of SNA was variable, showing increases, decreases or no change. Inhibition of SNA during SAP increase was not secondary to baroreceptor activation as the inhibition persisted in carotid sinus/aortic denervated animals. Although various combinations of changes of SNA and PNA were observed, their temporal courses were similar in many instances. Attenuation of SNA and PNA was synchronized, suggesting that these changes are coupled in the stimulating sites. The findings suggest that some neurons in DM and RVLM act as a functional unit to modulate cardiorespiratory functions whereas others simply coexist in the same area independent from each other.


Comparative studies of the neurotoxicity of MPTP in rats of different ages.

The present study investigated the neurotoxic effects of repeated MPTP injections on monoamine neurotransmitters and locomotor activity in rats of different ages. We also examined the mortality of MPTP-treated rats at different ages. Male Sprague-Dawley rats were used in all experiments. In the first experiment, we examined the mortality of rats (11-12 month old) subject to different doses of MPTP. In the second experiment, rats of 2-3 months old were randomly divided into five groups. Group 1 served as the control; Groups 2,3,4 and 5 received daily MPTP injections (30 mg/kg, ip) for a continuation of 7 days. Biochemical and behavioral assays were conducted at 1,7,14 and 28 days after withdrawal of MPTP, respectively. In the third and fourth experiments, the same experimental design was adopted except that rats of 5-6 months old and rats of 11-12 months old were used, respectively. Besides, the doses of MPTP used were 22.5 mg/kg and 12.5 mg/kg, respectively. Immunohistochemical experiments were always conducted 7 days after withdrawal of MPTP. Results indicated that, in young rats, repeated MPTP injections did not significantly decrease DA, and 5HT levels as well as TH and DBH immunoreactivities although it impaired locomotor activity. The same treatment significantly depleted DA, NE and 5HT levels in the middle-aged rats. It also decreased the density of TH and DBH immunoreactivities and altered the morphology of DA and NE neurons. Meanwhile, it impaired locomotor activity. In old rats, MPTP injections produced effects similar to those observed in the middle-age rats except that the hippocampal serotonergic system was also affected. However, all these effects recovered 28 days after withdrawal of MPTP injection. Finally, the dose of MPTP required to exert similar extent of neurotoxicity decreased as the age of rats increased, and the dose required to result in mortality markedly decreased in old rats. These results together suggest that MPTP does exert a toxicity on DA, NE and 5HT neurons and impair motor activity in rats. These effects are age-dependent while the irreversibility of MPTP's toxicity in rats requires further investigation.


Age-related effects of MPTP on norepinephrine concentrations of various areas of rat brains.

The effects of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) on the norepinephrine (NE) levels of 11 areas of rat brains were investigated. Male Long-Evans rats, aged 4 weeks (young group) and 21 months (old group), were injected intraperitoneally (i.p.) with MPTP (3 mg/kg) daily for 8 days. Control rats received an i.p. injection of saline. Rats were sacrificed 24 h after the last injection. NE in various brain areas were assayed by high pressure liquid chromatography with electrochemical detection. Multidose treatment of MPTP caused no alteration of levels of NE in any brain area of young rats. In contrast, a marked increase in concentration of NE was found in locus coeruleus, dorsal raphe nuclei and amygdala of old rats. These results indicate that MPTP selectively causes lesions in the noradrenergic system of rats and that the neurotoxic effects of MPTP in rats may depend on age.


Amyloidoses of the nervous system in the transmissible dementias.

The transmissible spongiform encephalopathies, both in humans and in animals, are neurodegenerative diseases which do not evoke an immune response in the host. The search for the etiological agent has led to the prion hypothesis, which proposes that a host-encoded protein may be the causal agent itself or a part of it. In humans, a low percentage of these transmissible encephalopathies are familial. Investigations centered on the understanding of the pathogenesis of the transmissible spongiform encephalopathies have implications, not only in basic sciences, but in clinical medicine as well.


Molecular and biological diversity of HIV-1 in Brazil.

To determine the genomic polymorphism and biological properties present in HIV-1 Brazilian isolates, we analyzed five viral isolates obtained from patients residing in Rio de Janeiro (P1 and P5), São Paulo (P3) and Bahia (P2 and P4) states. For each viral isolate in vitro characteristics such as replication rate, syncytium-inducing capacity and cell death were observed in lymphoblastoid (H9, CEM and peripheral blood mononuclear cells) as well as monocytoid (U937) cells. In addition, the evaluation of the restriction fragment length polymorphism of these isolates was also performed using a panel of endonucleases such as Hind III, Bgl II, Sac I, Pst I, Kpn I and Eco RI. One of the isolates (P1), showed the highest phenotypic and genotypic divergence, when compared to others. The results found suggest a HIV heterogeneity in Brazil similar to that already described in other regions of the world.


[Torsades de pointes during sultopride poisoning].

A case of sultopride poisoning (ingested dose 16 g) in a 35-year-old, 65 Kg man is described. On admission myoclonus, mydriasis, vomiting and cardio-respiratory arrest were observed. Torsades de pointes were treated with potassium chloride infusion and pace maker stimulation. Plasma sultopride concentration was 25 mg/l and urinary concentration 12 g/l. A prolongation of Q-T interval may announce severe arrhythmias in sultopride poisoning.


[Rheumatoid arthritis in Morocco. Apropos of 404 observations].

A retrospective study of 404 cases of rheumatoid arthritis seen in a department of internal medicine in Casablanca highlights a number of specific features of the disease in Morocco. Onset occurred early and mean age of patients was 34.4 years. Analysis of joint manifestations showed that the disease tended to be mild in the hips and perhaps in the cervical spine. Thirty-five percent of patients were Steinbrocker's class II and 25.5% had carpal bone fusion. Only 20 patients had severely erosive disease, which manifested as giant geodes in 8 cases and as main en lorgnette deformity in one case. Subcutaneous nodules (7.9%) and systemic visceral disorders were fairly infrequent. Only three cases of malignant rheumatoid arthritis were found. Gougerot-Sjögren syndrome was present in 13.6% of patients. Among comorbid conditions, thyroid gland diseases and tuberculosis were fairly common. Serologic tests were positive in 61.14% of cases, often in low titres. Gold salt therapy was well tolerated. No patients in this group had surgical treatment. These data suggest that in Morocco rheumatoid arthritis may be less aggressive than in Europe.


Homing of liver-derived hemopoietic stem cells to fetal bone marrow.

Tissue distribution of HSC in fetal sheep was studied by in utero transplantation during the period when a switch in the site of hemopoiesis occurs from liver/spleen to the bone marrow. At day 50 of gestation, transplanted cells exclusively homed to the liver/spleen. By day 60, some HSC also homed to the marrow and, between days 60-80, their proportion in the marrow increased. By day 100 almost all engrafted donor HSC homed to the marrow. Nonetheless, expression of these stem cells did not occur in the blood until birth (day 145) when marrow assumed the function of hemopoiesis from liver/spleen. During this latter part of gestation, although homing sites in the marrow are available to transplanted HSC, the marrow does not contribute to the function of hemopoiesis. The significance of these observations in the context of in utero gene therapy via stem cell transplantation is discussed.


Transgene transmission and expression in rainbow trout and tilapia.

We describe the production of transgenic rainbow trout (Oncorhynchus mykiss) and tilapia (Oreochromis niloticus) by microneedle injection of fertilized eggs with cloned copies of novel gene constructs. Two aspects of the work with transgenic trout are presented; namely, patterns of inheritance of transgenes by the F1 generation following in vitro fertilization of gametes from transgenic and nontransgenic fish, and the degree of DNA methylation of transgenes in different fish and in different tissues of the same fish. Work with transgenic tilapia has been only of short duration, and evidence is presented simply to indicate their transgenic status. Transient expression studies using the bacterial gene chloramphenicol acetyltransferase when driven by fish-derived promoters are also discussed.


Spasmodic torticollis: medical and botulinum A toxin treatment.

The exact pathophysiologic mechanisms of spasmodic torticollis and other idiopathic torsion dystonias remain largely unknown. Thus, a variety of drugs have been used alone or in combination on an empirical basis to treat these disorders, but to date none have efficacy that is proven and consistent. The drugs in use include anticholinergics, benzodiazepines, dopaminergics and dopamine antagonists with variable degrees of clinical improvement. Botulinum toxin A injection treatment for spasmodic torticollis is safe and efficacious with minimal adverse effect. However, it is expensive and beneficial effects are short-lasting. Only when a spasmodic torticollis patient's symptoms are refractory to combined treatment, using various drugs and Botulinum toxin injections, should the patient be considered a candidate for neurosurgical procedures.


Twenty-four-hour intragastric pH-metry: H2-receptor antagonist restoration of nightly gastric spontaneous alkalinization in duodenal ulcer healing.

Continuous 24-hour intragastric pH monitoring allows the evaluation of spontaneous late night gastric alkalinization phenomenon (SNA). This nocturnal increase of intragastric pH is strongly evident in healthy volunteers but is insignificant in patients with active duodenal ulcer. Gastric acidity was monitored by 24-hour continuous pH-metry in nine patients with active duodenal ulcer disease before and after two weeks of therapy with ranitidine. A twice daily dose of the drug (150 mg at 08.00 h and 150 mg at 20.00 h) was orally administered to each subject. Before treatment the ulcer patients did not show the SNA phenomenon, but the therapy led it to reappear. Ranitidine significantly reduced the time during which the gastric acidity was lower than 4 pH units; moreover the drug was effective on the ulcer healing during a period as brief as two weeks of therapy. At least a complete healing of the duodenal ulcer could be seen in patients whose overall gastric acidity time was reduced almost to the 40% of the pre-treatment value, meal times excluded from the pH-metric calculation.


Inhibitory role of somatostatin on calcitonin secretion.

Calcitonin (CT) secretion is not exclusively controlled by calcemia, but the secretory tonus is maintained by the beta-stimulatory adrenergic system Somatostatin (SMS) plays a neuromodulatory role with the reduction of CT secretion by its interference at the central and peripheral level of the beta adrenergic receptors. The experiments were carried out on groups of rats in which the effect of SMS on CT content of the thyroid gland was followed up. Thus, SMS administered i.c.v. significantly reduced the basal CT secretion without blocking the stimulatory effect of calcium. The results were comparable with those obtained after the blockade of the sympatho-adrenergic system by chemical sympathectomy with 6HODA or propranolol. Central blockade of alpha receptors with phentolamine determined a significant rise of CT. This effect was annihilated by SMS. The i.v. administration of SMS did not induce a change in CT content of the thyroid, but blocked the stimulatory action of hypercalcemia. The results are identical with those obtained by blocking the beta-receptors with propranolol. SMS also blocked the stimulatory effects of isoproterenol on CT secretion. The data obtained revealed the fact that SMS lowers CT secretion by the central and peripheral interference of the sympatho-adrenergic path, maintaining the secretory tonus of the thyroid C cells.


[Magnesium oxide and tocolysis. Our clinical experience and comparison with beta-mimetic (isoxusprine) therapy].

The authors propose the use of oral Magnesium Oxide in the quantity of 200 mg every 3-4 hours for the tocolytic treatment of the pre-term pain, once intravenous tocolysis has decreased or stopped uterine activity (since it has considerably more rapid effect). This treatment constitutes a valid alternative to the use of Beta Mimetic agents in all cases where their use is contraindicated. In the present study, we followed one heterogeneous group of 130 patients, suffering from premature labor hospitalized in our department. After decreasing the uterine contractions by intravenous isossuprine, sixty patients were subsequently treated with magnesium Oxide, fifty with oral isossisuprine, twenty with a simple antispasmodic and the remaining constituted the control group. The percentage of pre-term births has been almost the same in the first two groups (around 17%). The percentage of the patients who exhibited side effects of Beta Mimetic was 30-40%, against 2% of the patients treated with Magnesium Oxide. The intensity of the symptoms was however so slight in the patients treated with Magnesium Oxide, that it failed to disturb the compliance of the patients which allowed to continue the therapy for the necessary period.


Molecular biology for platelet alloantigen typing.

Hitherto, full investigation of patients with alloimmunization to platelet-specific antigens has been difficult due to the limited availability of both typing reagents and panels of typed platelets. Following recent advances in the understanding of the molecular and genetic basis of platelet alloantigens, it is now possible to genotype individuals for the alleles coding for the epitopes of four platelet antigen systems (HPA-1-4). This is based on the finding that the two alleles differ by only a single base pair substitution, resulting in one amino acid difference in the relevant platelet glycoprotein. The technique involves amplification of the relevant segments of genomic DNA from any nucleated cell by the polymerase chain reaction, followed by restriction fragment length polymorphism analysis. The technique allows investigation of thrombocytopenic individuals and fetuses/neonates, and can be readily applied to large-scale typing of platelet donors.


[Effects of four adrenergic drugs on electroacupuncture analgesia].

The role of central nor-epinephrine (NE) in electroacupuncture (EA) analgesia is a controversial question., it is probably due to the complication of adrenergic receptors. The present results show: (1) Clonidine 30 micrograms/2ml/kg ip had no significant effect on the pain threshold, but decreased the analgesic effect of EA. Clonidine 1.5 and 3 micrograms were injected into the lateral cerebral ventricles. After 45 minutes, the analgesic effect of EA was lowered as compared with the saline controls respectively. (2) Yohimbine had no significant effect on the basal pain threshold, but (icv Yoh 50 micrograms) elevated the analgesic effect of EA. (3) 2-adrenoceptor agonist methoxamine decreased the analgesic effect of EA. (4) Another 2-adrenoceptor antagonist prazosin (icv 16 micrograms) enhanced the analgesic effect of EA. These results suggest that an activation of alpha 1- or alpha 2-adrenoceptors would decrease the analgesic effect of EA.


[A critical study of conditions for prescription and evaluation criteria of neuroleptic treatment in resistant schizophrenia].

From the study of Kane et al. (1988), devoted to clozapine, a critical analysis of criteria of assessments about studies in treatment of resistant schizophrenic patients was drawn up. Therefore, among the inclusion criteria, the authors strengthen the necessity of a very long past neuroleptic treatment (beyond six months) before diagnosing a resistance, the "drug-free improvers" characterized by improvement when patients had been treated by a placebo, the necessity of a very long placebo wash-out (beyond six weeks), and the improvement by a second treatment after a first ineffective treatment. Moreover, the doses of neuroleptics opposed to clozapine are often too high leading to adverse effects and so decreasing the positive benefits. For instance, the dose of chlorpromazine is often increased to 1,800 mg/day whereas the doses required should be only 600 mg/day in equivalence to 500 mg/day of clozapine. Lastly, the scales more specific of the symptomatology of schizophrenia such as SANS-SAPS or PANSS should be used in the clinical trials whereas until now, all the studies were made by standard and global evaluations with BPRS, CPRS and AMDP.


[The atypical neuroleptic concept].

Atypical neuroleptics can be defined as dopamine (DA) receptor blockers which differ from typical neuroleptics in that they have a markedly lower or absent propensity for the induction of parkinsonian side effects of tardive dyskinesias. Some of them, but not all, are also more effective in treating schizophrenic patients, i.e. those with negative symptoms or who resist to classical treatments. There may be four classes of potential atypical neuroleptics: 1) Antipsychotics such as sulpiride and remoxipride that block a subgroup of D2 receptors; 2) D1 antagonists that may prove to be a valuable new type of antipsychotic drug; 3) Partial D2 agonists and 4) Antipsychotics such as clozapine and risperidone which block DA as well as other receptors and which appear to have the most pronounced antipsychotic effect. The differences between typical and atypical neuroleptics may first relate to regional specificity in site of actions. Animal studies suggest that atypical neuroleptics may act preferentially on mesolimbic and mesocortical as opposed to striatal DA systems. Most studies which have attempted to define the biological mechanisms which subserve the differences between atypical and typical neuroleptic drugs have focused on receptor binding profile of these drugs. Relatively higher affinity for the serotonin (5HT2) receptor than for the D2 receptor may be important to the action of clozapine-like compounds. However, many other systems might be involved and it seems likely that the atypical neuroleptic profile could be achieved in more than one way.(ABSTRACT TRUNCATED AT 250 WORDS)


[Use of pharmacological data in the choice of antipsychotic drugs].

The choice of antipsychotic drug should be based on experimental data from biochemistry and animal pharmacology, according to the targeted clinical effects. However, owing to the lack of good animal models of mental disease only the clinical approach can validate the antipsychotic efficacy of a drug. Within the theoretical frame of dopaminergic activity in schizophrenia a specificity of the various neuroleptics according to the four dopaminergic structure is evidenced through cellular electrophysiological studies. Classical provisional pharmacology of antipsychotics uses in animals on the one hand naturalistic observation tests, and on the other hand interactions vis-à-vis behaviours induced by stimulating dopaminergic agents, as amphetamine and apomorphine. Differential analysis of antipsychotic effects on each of those behaviours allows to discriminate between the various neuroleptics and to refine their pharmacological profile, specially to predict a disinhibitory action with some of them. Progress in the identification, localisation, number modification of target receptors of different neurotransmitters as well as the biochemical response to their stimulation by agonist or antagonist allows to delineate more precisely the neurobiochemical action of antipsychotic drugs. On top of antidopaminergic D2 effect, anti D1 effect begin to be investigated. More over the role of antiserotonergic 5-HT2 and central anticholinergic actions seems to be important in the "atypical" aspect of some neuroleptic drugs. More recently, contributions from molecular biology made it possible to clone and to synthetize five subtypes of dopaminergic receptors.(ABSTRACT TRUNCATED AT 250 WORDS)


Effects of the medium chain octanoic fatty acid on the contractile activity of vascular smooth muscle tissues.

Multiple elevation of the octanoic fatty acid level in human sera is often observed in some hepatic diseases which are accompanied by cardiovascular disorders, hypotension, and increased cardiac stroke volume. Different experiments reveal the hypotensive effect of octanoate. The present study investigates the octanoate action on the bioelectric and contractile activity of vascular smooth muscle tissues. Octanoate is shown to cause hyperpolarization of smooth muscle cells, reduction of spike potential frequency, and relaxation of vascular muscles. These effects are inhibited by indomethacin, which proves their prostaglandin nature. Octanoate action on stomach smooth muscle strips is inhibited by SC 19220, a specific competitive inhibitor of the contractile action of prostaglandins E2 and F2 alpha on the same tissues in vitro. Using thin-layer chromatography two PG fractions were isolated from arterial blood of octanoate treated rats and from a control group of rats. These fractions have identical chromatographic characteristics with those of PGE2 and PGF2 alpha. The level of the PG fraction with Rf value similar to that of PGE2 is significantly increased in octanoate treated animals while the other fraction tends to decrease.


Mechanisms of neurotransmission of valproate sodium in suppressing barbiturate and phenytoin withdrawal syndrome.

The present study was undertaken to investigate some important processes of neurotransmission which occur in rat brains under the influence of valproate sodium. Valproate sodium is used for the suppression of the withdrawal effects resulting from sudden discontinuation of phenobarbital and phenytoin treatment. Corpus striatum, hippocampus and cortex were isolated operatively. The amounts of neuromediators (dopamine, noradrenaline, serotonin and gamma-aminobutyric acid) were determined using fluorometry. The results show that the anti-withdrawal effect of valproate sodium established in previous research probably is due to active metabolites which increase the amount of gamma-aminobutyric acid in all brain structures. In suppressing barbiturate and phenytoin withdrawal syndrome using valproate sodium, the previously established anti-withdrawal effect probably is due to high tissue levels of dopamine in hippocampus and to noradrenaline in the cortex, hippocampus and corpus striatum. This anti-withdrawal effect continues for three days after the discontinuation of valproate sodium. This probably is due to the accumulation of the inhibitory neuromediator GABA in the cortex, hippocampus and corpus striatum and to the elevated level of dopamine in hippocampus. The results raise new possibilities for developing medicinal substances, which possess anti-withdrawal action, from the metabolites of the valproate sodium.


[Effect of denopamine on residual left ventricular dysfunction after complete revascularization].

Denopamine (15 mg/day) was administered to 20 patients with residual left ventricular dysfunction after successful percutaneous transluminal coronary angioplasty (75% or more diameter stenosis). Echocardiography was performed before and 6 months after denopamine administration to analyze the left ventricular function. There were significant decreases in both end-diastolic and end-systolic dimensions from 58 +/- 8.3 to 54 +/- 8.4 mm (p = 0.001), and from 44 +/- 10.1 to 40 +/- 10.3 mm (p = 0.005)), respectively, while % fractional shortening remained nearly constant (from 25 +/- 8.3 to 27 +/- 9.6%). Thus, denopamine improved the left ventricular function by decreasing left ventricular size while maintaining wall contractility.


Disturbed testicular descent in the rat after prenatal exposure to the antiandrogen flutamide.

Exposure of rats in utero to the anti-androgen flutamide resulted in feminization of the external genitalia that was noticeable at birth. This exposure also resulted in a high degree of cryptorchidism during adulthood. In most affected animals, testes were lying in 'ovary position' close to the caudal pole of the ipsilateral kidney. Cryptorchidism occurred despite normal prenatal development of the gubernacular cones and the transformation of these structures, postnatally, into muscular cremaster sacs. Inter- and intralitter variation in the response to prenatal exposure to flutamide was observed as well as intra-individual variation. Cryptorchidism frequently occurred unilaterally with right side cryptorchidism predominating. Cryptorchidism occurred in association with marked suppression of the growth of the ipsilateral epididymis and deferent duct. The possibility is considered that the poor development or absence of these structures contributes to cryptorchidism. Intra-individual variation supports the concept of the local nature of the influence of testis hormones in stabilization and further differentiation of the ipsilateral Wolffian duct derivatives. Cryptorchidism was enhanced when rats were treated postnatally with testosterone or oestradiol. The effect of testosterone was unexpected in view of the generally held hypothesis that androgens enhance testis descent. The effect of oestradiol was as expected: other animal models have been described in which induction of cryptorchidism by oestradiol occurs. Additional treatment with oestradiol caused further suppression of growth of the epididymis and deferent duct. The response to prenatal exposure to flutamide was not altered by further injections of flutamide postnatally. Such injections were without effect in males not exposed to flutamide prenatally except for minor, but statistically significant, testicular enlargement during adulthood. A model is thus presented that describes cryptorchidism as an endogenous developmental disorder.


Bovine spongiform encephalopathy (BSE): a stimulus to wider research.

The severity of the epidemic of bovine spongiform encephalopathy which is currently afflicting cattle in the British Isles has stimulated a considerable research effort, much of which is directed toward understanding the aetiology and pathogenesis of the bovine disease. However, a significant thrust has also been orchestrated to address more fundamental issues such as the nature of the uncharacterized causal agents of the wider range of unusual animal and human diseases which share similar characteristics. The background to some of these research programmes is discussed, together with current aims and progress.


A comparative study of gastrointestinal nematode egg output in N'Dama, Zebu and N'Dama x Zebu crossbred cattle.

Strongyle faecal egg output was estimated in N'Dama, Zebu and N'Dama x Zebu crossbred (F1) cattle. N'Dama cattle showed a significantly lower prevalence of strongyle infection, as measured by faecal egg output, than F1 (P < 0.01) and Zebu (P < 0.001) cattle. In strongyle-infected animals, mean egg output was also significantly lower in N'Damas (P < 0.03) than in Zebus. A previous trypanosomiasis infection did not affect the results. The presence of a natural resistance trait to strongyle infection in N'Dama cattle is postulated.


[Restriction fragment length polymorphism of the 5'-region of the bovine ribosomal spacer repeat].

The restriction map of bovine 28S rRNA gene and adjacent 5'-spacer region was determined. The high level of intragenomic and population length polymorphism of EcoRI-BamHI restriction fragment was demonstrated to originated from the 3'-end of 28S rDNA and 5'-spacer of rDNA repeat. This polymorphism is more pronounced than the ones revealed in human and murine rDNA repeats and could be compared with genomic fingerprints obtained by M13 or minisatellite DNA hybridization probes. From family blot-panel analysis we concluded that in progeny only parental sets of length variants were inherited and that the copy number of definite variants does not change in the progeny as well. From these results it was proposed that the definite sets of linked in genome length variants are inherited independently from each other.


Regional differences in the contractile activity of neuropeptide Y, endothelin, oxytocin and vasopressin: comparison with non-peptidergic constrictors. An in vitro study in the basilar and mesenteric arteries of the rat.

The vasoconstrictor effect of the peptides neuropeptide Y (NPY), endothelin (ENDO), vasopressin (VPR) and oxytocin (OXY) (10(-11)-10(-7) M) was compared in the isolated basilar (BAS) and mesenteric (MES) arteries of rat. The contractile activity of these peptides was compared to that of three nonpeptidergic constrictors: noradrenaline (NA), serotonin (5-hydroxytryptamine, 5-HT) and prostaglandin F2 alpha (PGF2 alpha) (10(-8)-10(-4) M). As regards EC50 values, PGF2 alpha was equally potent in both vessels studied, 5-HT was more potent in BAS and NA was without contractile effect in BAS. Pronounced regional differences were found for the peptides studied. BAS was more sensitive in EC50 values to the peptides in the order ENDO > or = VRP > OXY > NPY. In MES, OXY and NPY caused no and VPR caused weak contraction, whereas the effect of ENDO was pronounced, with a similar EC50 value as in BAS. In conclusion, marked regional differences were found in response to contractile agents in the vascular beds studied. Peptidergic constrictor mechanisms might be of large importance in the regulation of cerebral blood flow during physiological or pathophysiological conditions.


Factors controlling pancreatic islet neogenesis.

We have established a model in which cellophane wrapping induces reiteration of the normal ontogeny of beta-cell differentiation from ductal tissue. The secretion of insulin is physiologic and coordinated to the needs of the animal. Streptozotocin-induced diabetes in hamsters can be "cured" at least half the time. There appears to be activation of growth factor(s) within the pancreas, acting in an autocrine, paracrine, or juxtacrine manner to induce ductal cell proliferation and differentiation into functioning beta cells. Given the results of our studies to date, it does not seem premature to envisage new approaches to the treatment of diabetes mellitus. Identification of the factor(s) regulating islet-cell proliferation and differentiation in our model may permit islets to be grown in culture. This concept could be extended to induce endocrine cell differentiation in vitro as well. Furthermore, islet-cell growth factors could be used to provide "trophic support" to islet transplants as a means of maintaining graft viability. There may also be greater scope for gene therapy when the growth factor(s) have been isolated, purified, sequenced, and cloned.


The presence of somatostatin receptors in malignant neuroendocrine tumor tissue predicts responsiveness to octreotide.

In 77 percent of patients suffering from a malignant carcinoid syndrome, administration of the somatostatin analog, octreotide (SMS 201-995, Sandostatin) induced clinical improvement coupled with a decrease in 24-hour urinary 5-hydroxyindole acetic acid (5-HIAA). This finding prompted an evaluation to determine the correlation between the presence of somatostatin receptors in tumor tissue and the response to octreotide in patients with advanced, metastatic, neuroendocrine tumors. In tissues of 31 tumors (20 carcinoid, eight islet-cell carcinoma, three medullary thyroid carcinomas), the presence of somatostatin receptors was analyzed by binding of the somatostatin analog 125I-Tyr3-SMS 201-995 and autoradiography. Receptors were detected in 16 of 20 samples of carcinoid tissues; all but one patient with receptor-positive tumors improved clinically after treatment with octreotide, and the urine 5-HIAA level was reduced a median of 63 percent (range, 39-94 percent) compared to values before treatment. Of the receptor-negative carcinoid patients, only one showed clinical improvement, which was minimal, and there was a negligible reduction in 5-HIAA after octreotide therapy. All eight patients with metastatic islet-cell carcinomas were positive for somatostatin receptors. Symptomatic improvement and a > 50 percent decrease in the level of at least one of the pathologically elevated marker hormones was seen in all eight. None of the three patients with medullary carcinoma of the thyroid had a decrease in calcitonin, and all three were initially somatostatin receptor-negative. We conclude that the presence of somatostatin receptors in malignant neuroendocrine tumor tissue appears to correlate with the response to octreotide therapy. Analysis of somatostatin receptors in malignant neuroendocrine carcinoma tissue should be included in future prospective clinical trials of this synthetic peptide.


Natural killer cell stimulatory factor (NKSF) or interleukin-12 is a key regulator of immune response and inflammation.

Natural Killer cell Stimulatory Factor (NKSF) or interleukin-12 (IL-12) is a heterodimeric cytokine of 70 kDa formed by a heavy chain of 40 kDa (p40) and a light chain of 35 kDa (p35). Although it was originally identified and purified from the supernatant of Epstein-Barr virus-transformed B cell lines, it has been shown that among peripheral blood cells NKSF/IL-12 is predominantly produced by monocytes, with lower production by B cells and other accessory cells. The most powerful inducers of NKSF/IL-12 production are bacteria, bacterial products and parasites. In addition to the biologically active p70 heterodimer, the cells producing NKSF/IL-12 also secrete a large excess of monomeric p40, a molecule with no demonstrable biological activity. NKSF/IL-12 is active on T lymphocytes and NK cells on which it induces production of lymphokines, enhancement of cytotoxic activity and mitogenic effects. NKSF/IL-12 induces T and NK cells to produce IFN-gamma and synergizes with other IFN-gamma inducers in this effect. In vitro, and probably in vivo, NKSF/IL-12 is required for optimal IFN-gamma production. When human lymphocytes are stimulated with antigens in vitro, addition of exogenous NKSF/IL-12 to the culture induces differentiation of T helper type 1 (Th1) cells, whereas neutralization of endogenous NKSF/IL-12 with antibodies favors differentiation of Th2 cells. IFN-gamma, a product of Th1 cells, enhances NKSF/IL-12 production by mononuclear cells, whereas IL-10 and IL-4, products of Th2 cells, efficiently inhibit it. Therefore, NKSF/IL-12 appears to be an important inducer of Th1 responses produced by accessory cells during early antigenic stimulation and its production is regulated by a positive feedback mechanism mediated by Th1 cells through IFN-gamma and a negative one by Th2 cells through IL-10 and IL-4. The balance of IL-12 production versus IL-10 and IL-4 production early during an immune response might therefore be instrumental in determining Th1-type versus Th2-type immune responses. Because of this potential role of IL-12 during immune responses, our results demonstrating the impaired ability of HIV seropositive patients to produce NKSF/IL-12 in response to bacterial stimulation suggest that this defect in NKSF/IL-12 production might be a factor contributing to their immune depression.


Differentiation of pathogenic Entamoeba histolytica from other intestinal protozoa by riboprinting.

Differentiation of the pathogen Entamoeba histolytica from the variety of other amebas that can infect the human intestinal tract is vital for accurate diagnosis and treatment. Morphology and serology alone are not adequate for positive identification to be achieved. We have developed methods using the polymerase chain reaction to amplify amebal ribosomal RNA genes that allow either specific detection of E. histolytica or species identification.