The effects of erythromycin on the electrocardiogram

BACKGROUND

Various cardiac electrophysiologic effects have been attributed to erythromycin. During the course of treating a pneumonia patient with IV erythromycin, the conversion of atrial fibrillation to a sinus rhythm, and its subsequent reversal, appeared to be causally related to the introduction and cessation of this antibiotic.

OBJECTIVE

This observation suggested the need for studying the changes in the ECG following the use of IV erythromycin in a typical clinical setting.

DESIGN

A prospective comparative drug study.

SETTING

A university-affiliated teaching hospital.

PATIENTS

Nineteen patients being treated for uncomplicated community-acquired pneumonia.

INTERVENTION

IV erythromycin, 500 mg, and/or IV cefuroxime, 750 mg, infused in 250 mL of saline over 20 min. In the 11 patients who were receiving both of the antibiotics, cefuroxime was administered immediately before erythromycin was infused.

MEASUREMENTS

The 12-lead ECG measurements were obtained before infusion, at 5-min intervals during each infusion, and at 5 and 10 min after the infusions had been completed. All of the ECG complexes and intervals were measured using a software program (Interpretive Cardiograph; Hewlett Packard; Palo Alto, CA).

RESULTS

The administration of IV erythromycin increased heart rate and prolonged the corrected QT (QTc) interval. These changes were significant at 15 min of the infusion, and were no longer evident 5 min after the infusion had been stopped. The administration of IV cefuroxime did not produce any ECG changes.

CONCLUSIONS

A single, standard dose of IV erythromycin prolongs the QTc interval; therefore, the drug should always be administered as a slow infusion. ECG monitoring should accompany erythromycin therapy in critically ill patients, in patients with electrolyte disorders, or in patients taking other drugs with similar cardiac effects.

Ehrlich's ascites fluid adsorbed over protein A containing Staphylococcus aureus Cowan I produces inhibition of tumor growth

Our earlier studies have shown that removal of various blocking factors from the sera of tumor-bearing animals and humans by adsorption over heat-attenuated and formalin-fixed-Staphylococcus aureus Cowan I (SAC) containing Protein A (PA) causes antitumor immune response. It was also shown that this procedure caused regression of a wide variety of established animal and human tumors. In the present investigation, the therapeutic potential of inoculation of ascites fluid adsorbed in vitro over non-viable SAC containing PA has been demonstrated in Ehrlich' s ascites tumor (EAT) in mouse. The antitumor effect was evident by a significant decrease in body weight (p<0.001) as well as significant reduction in viability of ascites tumor cells (p<0.001) in peritoneal cavity. However, some of the responding animals died earlier than controls, this may be due to the toxicity associated with therapy. The toxic effects were evident in decreased contents of glutathione, and increased activity of glutathione-S-transferase, decreased activity of microsomal enzymes and also in an early death of some of tumor regressed animals. The probable causes of toxicity of the therapy and prospects of reversing these toxic effects are discussed.

Polylysine-Gd-DTPAn and polylysine-Gd-DOTAn coupled to anti-CEA F(ab')2 fragments as potential immunocontrast agents. Relaxometry, biodistribution, and magnetic resonance imaging in nude mice grafted with human colorectal carcinoma

RATIONALE AND OBJECTIVES

Immunocontrast agents used for magnetic resonance imaging require antibodies that preserve the immunoreactivity while containing a high number of chelated paramagnetic ions.

METHODS

Anti-CEA F(ab')2 fragments were coupled to polylysine-Gd-DOTA and polylysine-Gd-DTPA. A paramagnetic load as high as n = 24 to 28 metal ions per antibody was reached.

RESULTS

The immunoreactivity of the gadolinium (Gd)-labeled anti-CEA F(ab')2 immunoconjugates was 80% to 85%. Compared with that of commercial chelates, the relaxivity (R1) increase is as follows: Gd-DTPA < Gd-DOTA < Gd-H2O < PL-Gd-DTPA24-28 < PL-Gd-DTPA24-28 F(ab')2 < PL-Gd-DOTA24-28 < PL-Gd-DOTA24-28 F(ab')2. 1H nuclear magnetic relaxation dispersion data of immunoconjugates showed that the high relaxivity enhancement was the result of a reduction of the molecular tumbling rate. Twenty-four hours after intravenous injection of 50 micrograms (1 mumol Gd/kg) of Gd-labeled immunoconjugates to nude mice grafted with human colorectal carcinoma LS 174T, the tumor uptake was 10% to 15%, resulting in an increase of R1 of up to 15% to 20% versus noninjected mice. No difference was found between PL-Gd-DTPA24-28 F(ab')2 and PL-Gd-DOTA24-28 F(ab')2 immunoconjugates for tumor, liver, and kidney uptake. A high signal intensity of tumor was observed in 50% of the tested mice.

Acinetobacter sepsis in newborns

OBJECTIVE

To evaluate the clinico-epidemiological profile of Acinetobacter sepsis in neonates.

DESIGN

Retrospective study.

SETTING

Level II Neonatal Care Unit.

SUBJECTS

79 neonates with blood culture positive for Acinetobacter.

METHODS

Relevant information was collected on a predesigned proforma from the case records and analyzed for clinical and epidemiological characteristics.

RESULTS

The incidence of Acinetobacter septicemia was 11.1/1000 live births. Fifty-five babies were hospital born, 24 were outborn. Out of these, 64.6% babies were born at term and 40.5% had a birth weight of 2500 g or more. A cluster of 53 cases was seen between May and September 1995. In cases with early onset sepsis (onset < 7 days of postnatal age), difficulty in breathing (n = 54), chest retraction (n = 35) and refusal to feed (n = 46) were seen more commonly as compared to late onset sepsis (p < 0.05). Complications observed included meningitis, bleeding manifestations and necrotising enterocolitis in three, six and five babies, respectively. The organism was sensitive to ciprofloxacin (96.2%), amikacin (92.4%) and gentamicin (87.3%). A response rate of 52.4% was observed with Ciprofloxacin in babies not responding to cefotaxime and amikacin combination. The overall mortality was 13.9%.

CONCLUSION

Nosocomial Acinetobacter sepsis may affect fullterm, appropriate for gestational age babies. Clinical presentation is indistinguishable from Gram negative septicemia. Life threatening complications can also occur. Ciprofloxacin may prove to be useful drug in resistant cases.

The congested-like tracheae gene of Drosophila melanogaster encodes a member of the mitochondrial carrier family required for gas-filling of the tracheal system and expansion of the wings after eclosion

A recessive semi-lethal mutation resulting from the insertion of a P-lacW transposon at the cytological position 23A on the polytene chromosomes of Drosophila melanogaster was found to affect the unfolding and expansion of the wings resulting in a loss of venation and a marked decrease in their size. Lethality was polyphasic with numerous animals dying during early larval development and displaying apparently collapsed tracheal trees. The gene was therefore designated as congested-like tracheae, or colt. The colt mutation resulted from the insertion of a P-lacW transposon within the coding region of a 1.4-kb transcript. Wild-type function was restored by inducing a precise excision of the P-lacW transposon, while a deletion of the colt locus, produced by imprecise excision of the P element, showed a phenotype similar to that of the original P insert. The colt gene consists of a single exon and encodes a protein of 306 amino acids made of three tandem repeats, each characterized by two predicted transmembrane segments and a loop domain. The COLT protein shares extensive homology with proteins in the mitochondrial carrier family and particularly with the DIF-1 protein of Caenorhabditis elegans, which has been shown to be maternally required for embryonic tissue differentiation. Our analysis revealed that zygotic colt function is dispensable for normal embryonic morphogenesis but is required for gas-filling of the tracheal system at hatching time of the embryo and for normal epithelial morphogenesis of the wings.

Coronary artery bypass surgery without cardiopulmonary bypass: short- and mid-term results

From March 1994 to April 1997, 433 patients had undergone coronary artery bypass grafting without cardiopulmonary bypass in our institute. Sixty-eight patients had various organ dysfunctions and/or aortic atheroma or calcification and were regarded as high risk for cardiopulmonary bypass. In 277 patients surgery was performed through midline sternotomy, while in 156 minithoracotomy approach was used. In 361 patients single coronary artery bypass grafting was done, and in 72 two-coronary arteries were bypassed. In 63 patients who had graftable vessels in anterior wall and diffusely diseased ungraftable vessels in posterolateral and/or inferior wall, transmyocardial laser revascularisation was also done along with coronary artery bypass grafting to achieve complete myocardial revascularisation. Nine patients in this series were also subjected to simultaneous carotid endarterectomy along with myocardial revascularisation. In two patients complementary percutaneous transluminal coronary angioplasty of left circumflex coronary artery was done five days after minithoracotomy and left internal mammary artery to left anterior descending coronary artery bypass grafting. Forty-two cases were extubated in operating room. Average blood loss was 260 ml. Six patients were reexplored for postoperative bleeding. Seven patients had perioperative myocardial infarction. One developed neurological complication. Hospital mortality was 2.3 percent (10/433 cases) and four deaths were due to malignant ventricular arrhythmias. Nine patients developed chest wound complications. Average hospital stay after operation was six days, 423 patients were discharged from hospital and all of them were asymptomatic. During three years follow-up (range 3 to 38 months) there were three known cardiac deaths. Ninety percent (391) patients reported to the follow-up clinic and 91 percent of them were angina-free. In patients who were subjected to transmyocardial laser revascularisation along with coronary artery bypass grafting, myocardial perfusion scan showed a step-wise improvement in reversible ischemia. The perfusion index increased from 52 percent at three months to 90 percent at 12 months. We conclude that coronary artery bypass grafting without cardiopulmonary bypass can be done with relatively low mortality, more so in a group of patients in whom cardiopulmonary bypass poses a high risk. Transmyocardial laser revascularisation is a suitable means to provide complete myocardial revascularisation along with coronary artery bypass surgery in patients who have graftable vessels in anterior wall and ungraftable vessels in posterolateral and inferior walls.

Transmyocardial laser revascularisation combined with coronary artery bypass grafting without cardiopulmonary bypass

OBJECTIVE

To achieve complete myocardial revascularisation in patients with diffuse coronary artery disease, patients with inordinately high risk of cardiopulmonary bypass (CPB) like severe systemic disease or diffuse atherosclerosis of the aorta.

METHODS

We have adopted the technique of combining coronary artery bypass grafting (CABG) with transmyocardial laser revascularisation (TMLR) using 1000 W CO2 laser machine. TMLR is done to areas supplied by ungraftable arteries, while CABG without cardiopulmonary bypass is done to the left anterior descending artery (LAD) and/or right coronary artery (RCA). TMLR + CABG on beating heart without CPB has been performed on 56 patients. Age ranged from 37 to 81 years with a mean of 56.17. Four patients were in renal failure, two were redo CABG. Preoperatively 39.28% patients had angina class III and 10.71% had angina class IV. Four patients were on preoperative IABP support.

RESULTS

The mean number of grafts was 1.09. Internal thoracic artery (ITA) was used in 96.4% of the patients. Five patients showed elevation of CPK-MB, while three patients had an increase in Troponin T. Mortality was 1.8% (one patient died of intractable ventricular arrhythmia). The mean follow-up is 9.2 months. Myocardial perfusion scanning showed a stepwise improvement in reversible ischemia increasing from 52% at baseline to 91% at 12 months; 90.9% of the patients were angina free at 12 months. Metabolic stress test demonstrated an average increase in exercise tolerance from 5.2 min at baseline to 9.4 min at 12 months. Metabolic equivalents (METs) increased from 4.5 at baseline to 9.4 at 12 months. The average 44% Karnofsky score preoperative also increased to 86% at 12 months.

CONCLUSIONS

Our results indicate that the technique is surgically feasible and safe, with excellent short term results.

The international index of erectile function (IIEF): a multidimensional scale for assessment of erectile dysfunction

OBJECTIVES

To develop a brief, reliable, self-administered measure of erectile function that is cross-culturally valid and psychometrically sound, with the sensitivity and specificity for detecting treatment-related changes in patients with erectile dysfunction.

METHODS

Relevant domains of sexual function across various cultures were identified via a literature search of existing questionnaires and interviews of male patients with erectile dysfunction and of their partners. An initial questionnaire was administered to patients with erectile dysfunction, with results reviewed by an international panel of experts. Following linguistic validation in 10 languages, the final 15-item questionnaire, the international index of Erectile Function (IIEF), was examined for sensitivity, specificity, reliability (internal consistency and test-retest repeatability), and construct (concurrent, convergent, and discriminant) validity.

RESULTS

A principal components analysis identified five factors (that is, erectile function, orgasmic function, sexual desire, intercourse satisfaction, and overall satisfaction) with eigenvalues greater than 1.0. A high degree of internal consistency was observed for each of the five domains and for the total scale (Cronbach's alpha values of 0.73 and higher and 0.91 and higher, respectively) in the populations studied. Test-retest repeatability correlation coefficients for the five domain scores were highly significant. The IIEF demonstrated adequate construct validity, and all five domains showed a high degree of sensitivity and specificity to the effects of treatment. Significant (P values = 0.0001) changes between baseline and post-treatment scores were observed across all five domains in the treatment responder cohort, but not in the treatment nonresponder cohort.

CONCLUSIONS

The IIEF addresses the relevant domains of male sexual function (that is, erectile function, orgasmic function, sexual desire, intercourse satisfaction, and overall satisfaction), is psychometrically sound, and has been linguistically validated in 10 languages. This questionnaire is readily self-administered in research or clinical settings. The IIEF demonstrates the sensitivity and specificity for detecting treatment-related changes in patients with erectile dysfunction.

Inhaled asbestos fibers induce p53 expression in the rat lung

Humans and rodents exposed to an aerosol of asbestos fibers develop lung injury that can lead to a fibroproliferative response culminating in excessive scarring and impaired lung function. To define the early events that precede asbestos-induced fibrotic lung disease, rats were exposed to an aerosol of chrysotile asbestos fibers for 5 h. At various times after exposure, the lungs of the asbestos-exposed animals were evaluated immunohistochemically for expression of the p53 tumor suppressor protein, a growth regulatory protein. p53 became detectable by immunostaining at the predicted sites of fiber deposition (the bronchiolar-alveolar duct bifurcations) by 24 h after exposure. The number of cells positive for p53 immunostaining increased to a maximal level at 8 days after exposure, decreased by 14 days and returned to a low basal level at the 30-day time point. Control groups of rats that were unexposed or exposed to an aerosol of iron beads were negative for p53 immunostaining throughout the 30-day assessment period. Simultaneous detection of the proliferating cell nuclear antigen (PCNA) at the sites of fiber deposition in the asbestos-exposed animals agrees with our previous finding that p53 binds and regulates the PCNA promoter.

Significantly reduced incidence of stroke during coronary artery bypass grafting using transesophageal echocardiography

OBJECTIVE

Protruding atheromas of thoracic aorta have been identified as a source of systemic emboli and a major cause of stroke following cardiac surgery. This prospective study used transesophageal echocardiography (TEE) to identify atherosclerosis of thoracic aorta intraoperatively. The influence of risk factors was studied. Finally the impact of modifying surgical technique on the outcome was evaluated.

METHODS

Seven-hundred and ninety-two patients undergoing coronary artery bypass grafting (CABG) were evaluated with TEE. Depending on the location and extent of thoracic aortic disease various surgical modifications were carried out, e.g. hypothermic circulatory arrest with aortic arch atherectomy, CABG on beating heart and others. The stroke rate in this group of patients was determined and analysed.

RESULTS

Of the 114 patients with grade II and III atheromas of aortic arch and ascending aorta in whom surgical modifications were done, none had stroke. The overall stroke rate in the study group was 0.76%, six patients had stroke. Stepwise logistic regression identified age, diabetes, serum triglycerides and VLDL as important risk factors. Associated carotid artery disease and calcium on chest X-ray (CXR) were identified as important predictors of disease.

CONCLUSIONS

Intraoperative TEE is an invaluable modality for evaluating the thoracic aorta. There is significant reduction in stroke rate following identification of atheromas and modification of surgical technique.

Transmyocardial laser revascularisation as an adjunct to CABG

Transmyocardial laser revascularisation (TMLR), a new technique in which the ischaemic myocardium is perfused via laser-created transmural channels, was performed in 116 patients at the Escorts Heart Institute. TMLR was combined with CABG in 104 of these patients. The main indication for the combined procedure was the presence of one or more bypassable vessels along with diffuse disease in the other vessels. The age of the patients ranged from 37 to 73 years. Preoperatively, 53.84 percent of patients had Canadian Cardiovascular Society (CCS) class III angina while 24 percent had class IV angina. The mean LVEF was 46 percent; however, 19 percent of the patients had LVEF < 35 percent. Thirteen patients were operated upon a beating heart without cardiopulmonary bypass. The early mortality was 2.88 percent, 7.69 percent of patients showed elevation in CPK-MB, while 5.76 percent had a rise in Troponin 'T' and 2 percent of patients showed ECG changes. The mean follow-up was 7.6 months. Myocardial perfusion scan showed a step-wise improvement in reversible ischaemia, the perfusion index increasing from 52 percent at 3 months to 91 percent at 12 months. At 12 months, 91.6 percent of patients were angina-free. The Karnofsky score of 46 percent at baseline also increased to 86 percent at 12 months.

Pharmacokinetics and biodistribution of samarium-153-labelled OC125 antibody coupled to CITCDTPA in a xenograft model of ovarian cancer

The use of samarium-153 in the context of radioimmunotherapy of cancers has been limited by the instability of antibody labelling, which produces high uptake concentrations in liver and bone. This study compares the pharmacokinetics and biodistribution of 153Sm-labelled OC125 monoclonal antibody, in whole or F(ab')2 fragment form and with diethylene triamine penta-acetic acid (DTPA) or 6-p-isothiocyanatobenzyl diethylene triamine penta-acetic acid (CITCDTPA) coupling, in nude mice grafted subcutaneously with an ovarian adenocarcinoma line (SHIN-3) expressing CA125 antigen. The specific activity of the immunoconjugates was 18.5-55.5 MBq/mg, and their immunoreactivity exceeded 65%. With 153Sm-DTPA-OC125F(ab')2, the stability study in serum indicated that 50% of the metal remained bound to the antibody. The pharmacokinetic study showed a retention half-life of 25.1 h and blood clearance of 0.72 ml/h. The biodistribution study indicated tumour uptake of 4.53%+/-0.49% of injected activity per gram (%ID/g) at 24 h and tumour-to-liver and tumour-to-bone ratios of 0.23+/-0.02 and 1.54+/-0.49 respectively at 24 h. With 153Sm-CITCDTPA-OC125F(ab')2, serum stability was greater (87% of the metal remaining bound to the antibody), retention half-life was 22.25 h and blood clearance was 2.23 ml/h. Tumour was better targeted (8.30%+/-3.56%ID/g at 24 h), and tumour-to-liver and tumour-to-bone ratios were 1.17+/-0.36 and 7.08+/-3.09 respectively at 24 h. However, renal retention remained elevated (29.76%+/-9. 41%ID/g at 24 h). With intact IgG, renal uptake decreased (1.41%+/-0. 49%ID/g at 24 h), but tumour uptake was lower than with fragments (1. 46%+/-0.58%ID/g at 24 h). Liver uptake was higher (tumour-to-liver ratio 0.10+/-0.05), and blood clearance was slower. The stability and distribution of 153Sm-CITCDTPA were more favourable than those of 153Sm-DTPA for application in radioimmunotherapy. Quantitative analysis performed using digitized images obtained by conventional autoradiography and the imaging plate system indicated that the latter system is suitable for biodistribution studies of immunoconjugates.

Inclusion of supine period in short-duration pH monitoring is essential in diagnosis of gastroesophageal reflux disease

Prolonged esophageal pH monitoring is the most accurate method for detecting abnormal gastroesophageal reflux (GER) in patients with gastroesophageal reflux disease (GERD). However, some investigators have found that short-duration postprandial pH monitoring in the upright position is also useful, while others have failed to find such results. Therefore, we have compared a 6-hr period of pH monitoring (3-hr postprandial period after daytime meal and 3-hr supine period) with a total 24-hr period in detecting abnormal gastroesophageal reflux. Sixty-five patients (44 men, mean age 41.3 years) with GERD and 16 healthy volunteers (11 men, mean age 34.3 years) underwent 24-hr pH monitoring according to a standard protocol. Various reflux parameters during 24-hr pH monitoring were compared with reflux parameters during the 6-hr period. Abnormal GER was detected in 56 patients presenting with typical symptoms of GERD (sensitivity 86.2%). These patients could be further divided into upright (N = 18), supine (N = 15), and combined (N = 23) refluxers, depending on the posture in which abnormal reflux occurred. Esophageal pH monitoring during the 3-hr postprandial upright period showed abnormal reflux in only 35 patients (sensitivity 53.8%; P < 0.00005, compared with the 24-hr pH monitoring period). Abnormal GER was identified in 13 of 18 upright, 19 of 23 combined, and only one of 15 supine refluxers, as well as in two of nine patients with normal 24-hr pH-metry. However, inclusion of the 3-hr supine monitoring period in the 3-hr postprandial upright period improved detection of abnormal GER to 78.5% (51 patients; P = NS compared with 24-hr pH monitoring period). This was related mainly to improved detection of abnormal GER in supine refluxers (11 of 15; 73.3%). Esophageal acid exposure time correlated significantly with severity of esophagitis only during the total and supine periods of both the 24- and 6-hr periods and not during the upright period. Esophageal acid clearance correlated significantly with increasing grades of esophagitis for the supine and total periods only. We conclude that 3-hr postprandial pH monitoring, as has been conventionally practiced, is not appropriate in the detection of abnormal GER; inclusion of a supine period in the short-duration pH monitoring schedule increases the detection of pathological reflux. We therefore recommend that a supine period should be included in short-duration pH monitoring schedules. We also found that supine reflex was the most important factor in the development of esophagitis.

Clinical and endoscopic features of hereditary hemorrhagic telangiectasia (Osler-Weber-Rendu disease) in India

Hereditary hemorrhagic telangiectasis (HHT) is an autosomal dominant disease characterized by recurrent epistaxis and telangiectasia of the skin and mucous membranes. Most reports of HHT are from Europe and N. America. In this report of 7 patients from India we postulate that increased skin pigmentation in Asians and Negroids masks the cutaneous manifestations of the disease but without any discernible effect on mucosal lesions. The median hemoglobin value in these patients was 4 g/dl. Endoscopic lesions in the stomach or duodenum were detected in six patients. Most patients in our report (5/7) presented with a chronic iron deficiency anaemia. The treatment of HHT is mainly supportive although our preliminary data shows that low dose ethinyl estradiol therapy decreases transfusion requirement in these patients.

Neoplastic transformation and aberrant cell-cell interactions in genetic mosaics of lethal(2)giant larvae (lgl), a tumor suppressor gene of Drosophila

Homozygosity for lethal(2)giant larvae (lgl), a mutation in a tumor suppressor gene of Drosophila, induces neoplasia of the imaginal discs. To explore the developmental capacities of lgl mutant cells, we have investigated their growth and differentiation in genetic mosaics. Adult wings mosaic for lgl displayed abnormal growth and differentiation of the lgl mutant and neighboring wild-type cells, suggesting aberrant cell-cell interactions during development. lgl mutant clones also straddled the anteroposterior boundary of the wing imaginal disc, apparently due to failure of the cells of the anterior and the posterior compartment to segregate at the boundary. To further test if anteroposterior compartmentalization takes place in the neoplastic imaginal discs of lgl mutant larvae, we studied the expression of an engrailed (en)-specific lacZ reporter gene during progressive stages of their tumorous growth. Our results show that en is activated in the posterior compartments of the neoplastic imaginal discs. However, during later stages of tumorous overgrowth, the en-expressing and nonexpressing cells appear to show extensive intermixing. These observations suggest that neoplastic transformation of imaginal discs involves loss of their normal cell-cell interactions and signaling.

Uterine rupture in association with alkaloidal ("crack") cocaine abuse

The use of alkaloidal ("crack") cocaine in pregnancy can result in systemic and focal vasoconstriction and abnormal uterine contractions forceful enough to cause the complete rupture of a gravid uterus along a previous vertical cesarean section scar. A 43-year-old woman was admitted to the emergency department with acute abdominal pain at 34 weeks' gestation. She had had a low vertical cesarean section 3 years previously for breech presentation with acute fetal distress at 28 weeks' gestation. The patient had a history of heavy "crack" abuse and admitted to inhaling "crack" throughout the day until 4 hours before admission. Within 15 minutes after presentation a laparotomy was performed, revealing an infant floating in the abdominal cavity. A live baby was promptly delivered, and the ruptured uterus was repaired. The patient was discharged 4 days post partum. "Crack" cocaine, through its known effects on the vasculature and contractility of the myometrium, likely facilitated the uterine rupture in this patient. The edges of the rupture wound were surprisingly clean, with little bleeding, perhaps owing to the drug's vasoconstrictive effects. It was therefore feasible to repair the uterus as an alternative approach to hysterectomy.

Epithelial hyperplasia of imaginal discs induced by mutations in Drosophila tumor suppressor genes: growth and pattern formation in genetic mosaics

Lethal mutations in the giant discs (lgd) and fat (ft) tumor suppressor genes of Drosophila cause epithelial hyperplasia in all imaginal discs. By contrast, mutations in the vestigial (vg) gene adversely affect cell viability in the wing imaginal discs and consequently cause loss of pattern in the adult wings. However, combining homozygous lgd or ft mutations with homozygous vg1 increases the size of the wing imaginal discs and partially restores the bristle pattern in the wings of pharate adults. Comparable pattern restoration in vg1 wings is also induced by a newly isolated weak hypomorphic lgd3 allele. Further, mosaic analysis revealed that whereas lgd clones generated by the Minute technique display abnormal differentiation, those induced in a homozygous vg1 background exhibit autonomous restoration of wing pattern. These results suggest that pattern restoration in vg1 wings can serve as an assay for hyperplasia induced by mutations in Drosophila tumor suppressor genes.

Mapping quantitative trait loci controlling milk production in dairy cattle by exploiting progeny testing

We have exploited "progeny testing" to map quantitative trait loci (QTL) underlying the genetic variation of milk production in a selected dairy cattle population. A total of 1,518 sires, with progeny tests based on the milking performances of > 150,000 daughters jointly, was genotyped for 159 autosomal microsatellites bracketing 1645 centimorgan or approximately two thirds of the bovine genome. Using a maximum likelihood multilocus linkage analysis accounting for variance heterogeneity of the phenotypes, we identified five chromosomes giving very strong evidence (LOD score > or = 3) for the presence of a QTL controlling milk production: chromosomes 1, 6, 9, 10 and 20. These findings demonstrate that loci with considerable effects on milk production are still segregating in highly selected populations and pave the way toward marker-assisted selection in dairy cattle breeding.

Effect of sulphite on the oxidative metabolism of human neutrophils: studies with lucigenin- and luminol-dependent chemiluminescence

To assess the effect of sulphite on the oxidative metabolism of human neutrophils, chemiluminescence (CL) measurements were performed using lucigenin and luminol as chemiluminigenic probes. Lucigenin-dependent CL was used for measuring superoxide anion (O2-) production, and luminol-dependent CL was used for determination of myeloperoxidase (MPO)-connected processes. With sulphite concentrations of 0.01 to 1 mmol/L, resting neutrophils showed an up to sixfold increase of lucigenin-dependent CL, but only a 1.9-fold increase of luminol-dependent CL. Subsequent stimulation of sulphite-treated neutrophils with phorbol myristate acetate (PMA) (soluble stimulant) or zymosan (particulate stimulant) resulted in an additional significant increase of lucigenin-dependent CL compared to stimulated control cells, whereas luminol-dependent CL increased slightly by 0.01 mmol/L sulphite and decreased then continuously. Sulphite concentrations above 1 mmol/L decreased both lucigenin- and luminol-dependent CL of resting and PMA- or zymosan-stimulated neutrophils. Lucigenin-dependent CL of sulphite-treated and subsequently stimulated neutrophils was strongly inhibited by extracellularly added superoxide dismutase, whereas luminol-dependent CL was markedly reduced by the MPO inhibitor azide. The intracellular activity of MPO in neutrophils stimulated with PMA in the presence of sulphite (2 mmol/L) was reduced by 55%. Sulphite (0.1 mmol/L) also inhibited strongly the activity of MPO in a cell-free system. These results indicate that micromolar concentrations of sulphite exert a stimulating effect on the O2- production of neutrophils extracellularly, but have an inhibitory effect on MPO-catalysed reactions intracellularly.

Correlation of 24-hr esophageal pH patterns with clinical features and endoscopy in gastroesophageal reflux disease

We performed 24-hr ambulatory esophageal pH monitoring in north Indian patients with gastroesophageal reflux disease (GERD) and correlated it with symptom severity and endoscopic abnormalities. Thirty-six consecutive patients with symptomatic GERD and 16 healthy volunteers underwent objective grading of clinical symptoms and endoscopic findings. Total, supine, and upright reflux periods as well as frequency and duration of reflux episodes were determined from the 24-h pH-metry record using standard software. This was abnormal in 32 patients, who could be categorized into upright refluxers (31.2%), supine refluxers (34.4%), and combined refluxers (34.4%). Supine reflux and upright reflux were distinct entities that did not correlate with each other (r = 0.22, P = NS). In upright refluxers, symptoms (P < 0.02) and endoscopic abnormalities (P < 0.005) were milder than in combined refluxers. Total duration of acid exposure correlated significantly with severity of symptoms (P < 0.001) and endoscopic esophagitis (P < 0.005). Patients with GERD had three distinct patterns of abnormal gastroesophageal reflux, with upright refluxers having milder disease and supine and combined refluxers having more severe disease. This may reflect differences in underlying mechanisms of reflux.

Human T-helper cell responses to a synthetic peptide derived from the hepatitis B surface antigen

Hepatitis B virus surface antigen peptide OS (aa124-147) self oligomerizes to form conformational B-cell immunogen with several properties of a candidate peptide vaccine. It gives a T-cell blastogenic response in vaccinated as well as naturally infected individuals. To study the nature and localization of the T-helper cell epitopes, the T-lymphocyte proliferative responses in humans exposed to hepatitis B surface antigen (HBsAg) were examined with a synthetic peptide representing residues 124-147 of this antigen [peptide OS (aa24-147)]. Positive responses were obtained in most cases regardless of whether HBsAg exposure was due to vaccination or a hepatitis B viral infection. Epitope localization studies with truncated peptides indicated the presence of more than two HBsAg-relevant T-helper cell epitopes. This was also corroborated by our fine mapping studies which revealed that the amino acid residues crucial for eventual T-helper cell activation were diverse amongst the various individuals. Together these studies suggest that immunization with peptide OS (aa124-147) may result in an HBsAg cross-reactive T-helper cell response in a broad spectrum of the human population.

Microsatellite mapping of a gene affecting horn development in Bos taurus

The presence or absence of horns in Bos taurus is thought to be under the genetic control of the autosomal polled locus, characterized by two alleles: P dominant over p, and causing the polled or hornless phenotype. We have demonstrated genetic linkage between the polled locus and two microsatellite markers, GMPOLL-1 and GMPOLL-2, and have assigned the corresponding linkage group to bovine chromosome 1. This confirms the existence of the postulated polled locus and the hypothesized inheritance pattern. It will allow marker assisted selection for the polledness trait in breeding programs and is a first step towards positional cloning and molecular study of a gene that has been subjected to both natural and artificial selection.

Characterisation and epitope analysis of monoclonal antibodies to virions of clover yellow vein and Johnsongrass mosaic potyviruses

Mouse monoclonal antibodies (MAbs) against the Australian B strain of clover yellow vein (ClYVV-B) and the JG strain of Johnsongrass mosaic (JGMV) potyviruses were produced, characterised and the epitopes with which they reacted were deduced. Using intact particles of ClYVV a total of ten MAbs were obtained which reacted strongly with ClYVV-B in an enzyme-linked immunosorbent assay and Western blots. Four of these MAbs (1, 2, 4, and 13) were found to be ClYVV-specific, as they reacted with all five ClYVV strains from Australia and the U.S.A. but not with 11 strains of bean yellow mosaic (BYMV), pea mosaic (PMV), and white lupin mosaic (WLMV) viruses which, together with ClYVV, form the BYMV subgroup of potyvirses. These MAbs failed to react with eight other potyvirus species, including six which infect legumes like the viruses in the BYMV subgroup. The ClYVV MAb 10 was found to be BYMV subgroup-specific. It reacted strongly with 15 of the 16 strains of viruses in the subgroup and gave no reaction with eight other potyviruses. The other five ClYVV MAbs reacted with varying degrees of specificity with the BYMV subgroup viruses and also with other potyviruses. Eight of the ClYVV MAbs (1, 2, 4, 5, 13, 17, 21, and 22) reacted with the intact coat proteins only and not with the truncated (minus amino terminus) coat protein of ClYVV suggesting that the epitopes for these MAbs are located in the surface-exposed, amino-terminal region of the ClYVV coat protein. Comparison of published coat protein sequences of BYMV and ClYVV isolates indicated that the epitopes for the four ClYVV-specific MAbs may be in the amino-terminal region spanning amino acid residues 18 to 30, whereas those for the other four MAbs may be located in the first 17 amino-terminal amino acid residue region. The epitopes that reacted with BYMV subgroup-specific MAb 10 and MAb 30 which reacted with 20 of the 24 potyvirus isolates, are probably located in the core region of ClYVV coat protein as these MAbs reacted with the intact as well as truncated coat protein of ClYVV. Analysis, in Western blot immunoassay, of 17 MAbs raised against virions of JGMV revealed that only two MAbs (1-25 and 4-30) were JGMV-specific, whereas others displayed varying degrees of specificity to different potyviruses.(ABSTRACT TRUNCATED AT 400 WORDS)

Microsatellite mapping of the gene causing weaver disease in cattle will allow the study of an associated quantitative trait locus

A genetic disease in cattle, progressive degenerative myeloencephalopathy (weaver disease), is associated with increased milk production. This association could result from population stratification, from a pleiotropic effect of a single gene, or from linkage disequilibrium between the gene causing weaver disease and a quantitative trait locus (QTL) for milk production. To test these hypotheses, we performed an extensive linkage study in a bovine pedigree segregating for the weaver condition and identified a microsatellite locus (TGLA116) closely linked to the weaver gene (zmax, 8.15; theta, 0.03). TGLA116 and, by extension, the weaver locus were assigned to bovine synteny group 13. This microsatellite can be used to identify weaver carriers, to select against this genetic defect, and to study the effect of the corresponding chromosomal region on milk production in Brown Swiss and other breeds of cattle.

Mechanism of enhanced phagocytic response in protein a treated rat macrophages

Protein A of S. aureus Cowan I has been shown to stimulate macrophage mediated phagocytosis. The present study was undertaken to understand the mechanism involved in the enhancement of phagocytosis of peritoneal macrophages by protein A. The lucigenin and luminol-dependent chemiluminescence (CL) of rat peritoneal macrophages, after incubation with various concentrations of protein A, flow-cytometric studies using DCFH-DA as a fluorescent compound and phagocytosis of sheep red blood cells (SRBCs) by rat peritoneal macrophages were studied. A significant increase in lucigenin dependent CL due to formation of superoxide anions (O2-.) and in luminol dependent CL due to formation of hydrogen peroxide (H2O2) was observed in protein A treated macrophages. A significant increase in intracellular hydrogen peroxide (H2O2) was also observed along with an increase in phagocytosis of SRBCs by protein A treated macrophages. The present findings indicate that protein A helps to increase phagocytosis and triggers respiratory burst of macrophages. Thus, both increased phagocytic response and respiratory burst of macrophages in protein A treated animals may be contributing to the antitumor property of protein A reported earlier.

Immune response to hepatitis B virus surface antigen peptides during HBV infection

Antibody responses of patients with acute (n = 73), fulminant (n = 30) and chronic (n = 51) hepatitis B virus (HBV) infection as well as recovered individuals (n = 7) were studied against three synthetic peptides, Pre-S1 amino acids (aa. 12-32), Pre-S2 amino acids (aa. 120-145), and S amino acids (aa. 124-147) of the envelope region (HBsAg). T cell blastogenic response was investigated in a proportion of the patients (27 acute, nine fulminant, 13 chronic hepatitis and seven recovered individuals) along with seven HBV vaccinated and three normal individuals. The presence of T cell response against S peptide was observed in all the cases (9/9, 100%) during early acute hepatitis. This was suppressed during late stages (8/18, 44%) followed by partial reversal during recovery (5/7, 71%). T cell response and antibodies to Pre-S1 and Pre-S2 peptides were present only in one-third of the patients throughout these periods. The T cell blastogenic response as well as antibody reactivity against these peptides were absent and minimal in chronic hepatitis. Immune response against envelope protein appears to play a major role in acute hepatic injury due to HBV infection and help in virus clearance.

Post streptococcal glomerulonephritis co-existing with acute rheumatic fever--a case report

A case of post streptococcal acute glomerulonephritis co-existing with acute rheumatic fever is reported. The relevant literature is briefly reviewed.

Characterization of a set of variable number of tandem repeat markers conserved in bovidae

Screening purpose-built libraries with minisatellite probes, we have isolated 36 bovine variable number of tandem repeat markers (VNTRs) characterized by a mean heterozygosity of 59.3 within the American Holstein breed. Matching probabilities and exclusion powers were estimated by Monte-Carlo simulation, showing that the top 5 to 10 markers could be used as a very efficient DNA-based system for individual identification and paternity diagnosis. The isolated VNTR systems should contribute significantly to the establishment of a bovine primary DNA marker map. Linkage analysis, use of somatic cell hybrids, and in situ hybridization demonstrate that these bovine VNTRs are scattered throughout the bovine genome, without evidence for proterminal confinement as in the human, and that at least some of them are organized as clusters. Moreover, Southern blot analysis and in situ hybridization demonstrate conservation of sequence and map location of minisatellites within Bovidae.

Idiopathic oedema--a missed entity

Twenty nine patients were diagnosed to have idiopathic oedema; 27 (93.1%) of these were females. Associated psychological symptoms were observed in 86.2% of patients. The most common associated symptoms were related to autonomic dysfunction. Obesity and diuretic abuse were found in 48.3% and 41.4% of patients respectively. The association of bizarre symptoms with idiopathic oedema is a common feature.

Reactivity of Cryptococcus neoformans & Candida species with concanavalin A & blood grouping sera

Forty strains of Cryptococcus neoformans, 30 of Candida albicans, 24 of C. parapsilosis and 10 strains each of C. tropicalis and C. (Torulopsis) glabrata were examined. A 0.2 per cent solution of concanavalin A (Con A) in phosphate buffered saline and commercial anti-A and anti-B blood grouping sera were used in the whole cell slide agglutination test. All the isolates of Candida species strongly reacted with Con A and over 90 per cent were agglutinated by anti-A and -B blood grouping sera. In contrast, except for one strain, Cryptococcus neoformans did not agglutinate with Con A or blood grouping sera. These findings suggest, on one hand, a fundamental difference in the sugar mosaic of the cell surface components of Cryptococcus neoformans and Candida species, and on the other, presence of similar antigenic determinant(s)/receptors on the cell surface of Candida species and human erythrocytes.

Protein A protects mice from depletion of biotransformation enzymes and mortality induced by Salmonella typhimurium endotoxin

Changes in hepatic microsomal mixed-function oxidase enzyme levels (aniline hydroxylase, aminopyrine demethylase, glutathione S-transferase), glutathione content, total sulphydryl content, and plasma enzyme levels of aspartate transaminase, alanine transaminase and alkaline phosphatase were studied in male Swiss albino mice exposed to Salmonella typhimurium endotoxin (50-150 micrograms per mouse, LC50 141.82 micrograms). Animals exposed to the same dose of endotoxin but pretreated with protein A of Staphylococcus aureus (5 micrograms/per mouse) protected the animals from both mortality and depletion of biotransformation enzymes.

Antithrombotic effect of thiopurinol

Antithrombotic activity of ten pyrazolo pyrimidine derivatives was tested in mouse pulmonary thromboembolism model. Out of these compounds, Thiopurinol (C5H4N4S) showed dose-dependent protection in mice from death/paralysis induced by collagen + adrenaline. It also caused dose-dependent inhibition of thrombus formation in the cat. Thiopurinol inhibited aggregation of platelets induced by ADP and arachidonic acid but did not inhibit superoxide generation. It had no antiinflammatory activity nor any effect on cardiovascular system. The results indicate that the antithrombotic activity of the compound is mediated via inhibition of platelet aggregation.

Denial and medical outcome in unstable angina

Denial may be adaptive during hospitalization for acute coronary disease. We studied the impact of denial in 48 patients referred to a tertiary care center for treatment of unstable angina. Using the Hackett-Cassem Denial Scale, we divided the group into 25 high deniers and 23 low deniers. The two groups were comparable in baseline demographic and social data, coronary risk factors, cardiac history, medical treatment, vital signs, and cardiac catheterization results (number of diseased vessels and ejection fraction). Compared to low deniers, high deniers had half as many episodes of angina during hospitalization (1.3 vs. 2.5; p less than 0.03, t = 2.2, df = 46) and were more likely to reach medical stabilization, i.e., pain free for 36 hr (92% vs. 65%, p less than 0.03, Fisher exact probability test). Intravenous nitroglycerin drips were also required less often in high deniers (32% vs. 78%, p = 0.002, Fisher exact). Two myocardial infarctions and one death occurred, all in low deniers. We conclude that denial independently predicts better medical outcome during acute hospitalization for unstable angina.