Clinical profile of myasthenia gravis

Seventy three patients with myasthenia gravis were studied over 9 years period (1987-1995) in departments of neuromedicine, respiratory care unit, cardiothoracic unit of Institute of Postgraduate Medical Education and Research and Bangur Institute of Neurology, Calcutta, with reference to their clinical presentations, laboratory findings and various modes of treatment. Commonest age of presentation was 5th decade in men and 3rd decade in women. Fifty five percent of patients belong to type 2A myasthenia gravis (Osserman classification). Presentation was insidious (67.2%) and course was slowly progressive (65.7%) in majority of cases. Fatigability and ptosis were commonest clinical presentation and diurnal variation was noticed in 60% of cases. Edrophonium test was positive in 90.4% of cases and repetitive nerve stimulation showed 93.5% positivity in 30 cases. 27 patients (36.9%) underwent thymectomy and out of these, 89% of patients showed hyperplastic change and thymoma in 11% of cases. Mortality rate including both operated and nonoperated patients was recorded to be 9.6%. We observed earlier onset of myasthenia in male, higher incidence of oculo-bulbar involvement and lower incidence of respiratory problem and thymoma.

Intramolecular Excited State Proton Transfer of 2-(2'-Hydroxyphenyl)benzimidazole in Nonionic Micelles: Tweens

Spectral characteristics and prototropic reactions of 2-(2'-hydroxyphenyl)benzimidazole (HPBI) in Tween-20, Tween-40, Tween-60, Tween-80, and dioxane-water mixtures of different compositions have been studied. Comparison of the fluorescence band maxima of the tautomer band in nonionic micelles with the correlation diagram, drawn between the fluorescence band maxima and the dielectric constants of the dioxane-water mixtures, have shown that the effective dielectric constant (epsiloneff) at the binding site of HPBI is 18 +/- 2 for all the Tweens. Fluorescence lifetimes (tauf) and fluorescence quantum yields (phifl) have shown that the hydrophobicity of these micelles is maximum for Tween-80 and at a minimum for Tween-20. Similar results have also been observed from the pKa values for the deprotonation of HPBI, whereas the protonation reaction of HPBI occurs at the site in nonionic micelles which is more hydrophilic than that where the deprotonation reaction takes place. The protonation reaction in 2-(2'-methoxyphenyl)benzimidazole (MPBI) has shown that the value of epsiloneff in Tweens where this reaction occurs is less hydrophobic than the site where the same reaction occurs in HPBI. Copyright 1998 Academic Press.

Histidine decarboxylase gene in the mouse uterus is regulated by progesterone and correlates with uterine differentiation for blastocyst implantation

Cell-cell interactions between the blastocyst trophectoderm and uterine luminal epithelium are essential to the process of implantation. The factors that participate in these interactions or their mechanism of actions are poorly understood. Histamine has long been suspected as one of the factors that is involved in implantation. Histamine is formed from L-histidine by histidine decarboxylase (HDC). We examined the expression and regulation of HDC gene in the mouse uterus during early pregnancy and under steroid hormonal stimulation. Northern blot hybridization detected a 2.6-kb transcript of HDC messenger RNA (mRNA) in uterine poly(A)+ RNA samples. Maximum uterine accumulation of HDC mRNA occurred on days 3 and 4 of pregnancy, followed by marked declines on later days (days 5-8). In ovariectomized mice, uterine mRNA levels were up-regulated by an injection of progesterone (P4) by 6 h, and the levels were maintained through 24 h. In contrast, an injection of estradiol-17beta neither stimulated nor antagonized P4-induced HDC mRNA accumulation. P4-induced up-regulation was considerably abrogated by pretreatment with RU-486, a P4 receptor antagonist, suggesting involvement of P4 receptor. In situ hybridization detected HDC mRNA specifically in uterine epithelial cells but not in other cell types. Again, high epithelial accumulation occurred on day 4 of pregnancy. With the progression of implantation (days 5-8), HDC mRNA levels declined in the luminal epithelium surrounding the implanting blastocysts, as compared with that away from the blastocysts. Immunoreactive histamine and HDC were colocalized with HDC mRNA. Western blotting detected a 54-kDa protein in epithelial cell extracts, which also exhibited HDC activity. Expression of HDC in epithelial cells, preceding implantation on day 4, at lower levels after initiation of implantation on day 5, and its regulation by P4 suggest that this gene plays an important role in implantation.

Short-term macrophage interleukin-1 response to injected silicone in a rat model

The short-term effects of silicone particles on the ability of splenic and peritoneal macrophages to produce Interleukin-1 (IL-1) were assessed. Lewis rats were divided into three groups. Group 1 animals (n=12) were injected subcutaneously with 2.5 ml of sterile saline; Group 2 animals (n=12) received 2.5 ml of Freund's Complete Adjuvant (FCA); Group 3 animals (n=12) received subcutaneous injections (2.5 ml) of a sonicated slurry comprised of equal parts of FCA and silicone. At days 1, 4, and 7 single-cell suspensions of splenic (10(8) cells/ml) and peritoneal (10(6) cells/ml) macrophages of four animals from each group were prepared. The supernatants from macrophages cultured in the presence or absence of lipopolysaccharide (LPS) were added to IL-1 dependent mouse thymocytes for 72 hrs, and subsequently pulsed with 3H-thymidine. Radioactivity incorporation was determined after 18 hrs. Peritoneal macrophage culture supernatants had significantly higher activity than splenic macrophages and all macrophages stimulated with LPS had significantly higher activity. At days 1 and 7, there were no significant differences in 3H-thymidine uptake. At day 4 there was an elevation of 3H-thymidine uptake from supernatant of peritoneal macrophages treated with FCA/silicone suggesting subcutaneous silicone injection has short-term effects.

A Hindi version of the Diagnostic Interview for Genetic Studies

The validity of a Hindi version of the Diagnostic Interview for Genetic Studies (DIGS) was investigated. The original English version was initially translated into Hindi. The Hindi version was then back-translated and compared with the original. Next, a group of psychiatric inpatients and outpatients were interviewed using the Hindi version. The resultant diagnoses were compared with those obtained for the same patients using a Hindi version of the Present State Examination (PSE), and the clinical diagnoses given by the treating psychiatrists. The DIGS diagnoses were significantly correlated with both the PSE diagnoses (Cohen's kappa = 0.80) and the clinical diagnoses (kappa = 0.56). Interrater reliability between three interviewers for diagnoses obtained using the Hindi version of the DIGS varied (kappa = 0.45-1.00). Possible causes for this variability are discussed. The Hindi version of the DIGS fulfills the need for a current comprehensive interview schedule not only for psychiatric genetic research in India, but also for nongenetic research.

Effect of immunostimulation on cytotoxic activity of intestinal intraepithelial lymphocytes of chickens in infectious bursal disease and Eimeria tenella infections

In chickens, intestinal intraepithelial lymphocytes (iIELs) exhibit spontaneous natural killer (NK) cell like activity, by which they are active in the first line of defence on gut epithelial linings. In the present study, the cytotoxic activity of iIELs was found to be drastically suppressed in chickens experimentally infected with infectious bursal disease (IBD) virus at the age of 5 weeks and also in chickens experimentally infected with Eimeria tenella oocysts at the age of 8 weeks (p < 0.01). As nonspecific immunostimulation is gaining importance, immunostimulants such as immunostimulating Mycobacterium phlei (ISMP) and bone marrow culture supernatant (BMCS) were tested for their influence on the functional activity of iIELs of chickens in IBD and E. tenella infections. In chickens primed with ISMP a week prior to respective experimental infections, it was found that the cytotoxic activity of iIELs was restored (p < 0.01) in both IBD and E. tenella infections. At the same time, in chickens primed with BMCS a week prior to respective experimental infections, the cytotoxic activity of iIELs was restored to a certain extent (p < 0.01) in E. tenella but not at all in IBD infection. These results showed that application of immunostimulation helped potentiate and restore the functional activity of iIELs of chickens in IBD and E. tenella infections.

Preparation and in vitro dissolution profile of dual polymer (Eudragit RS100 and RL100) microparticles of diltiazem hydrochloride

A microparticulate dosage form for a highly soluble drug, diltiazem hydrochloride, was formulated with Eudragit RS100 and RL100 using a novel dual polymer technique. A mixture of diltiazem with Eudragit RS100 (low water permeability) in acetone was coacervated into soft polymer microdrops, following which a mixture of diltiazem and RL100 (high water permeability) was added to produce microparticles consisting of both polymers with diltiazem dispersed in the matrix. A second formulation was developed using the same method except using Eudragit RS100 for both steps. For a comparative study, diltiazem, Eudragit RS100 and RL100 were combined together in a single matrix and formulated into microparticles. In vitro drug release profiles using USP paddle dissolution apparatus 2 revealed that dual polymer matrix microparticles containing Eudragit RS100 in the inner and Eudragit RL100 in the outer core exhibit a suitable release profile with an initial release of the drug followed by a plateau level for the test period of 5 h. Differential scanning calorimetric analysis showed no interaction of the drug with the polymers.

Composition of lipids from the glands of the external ear canal of the adult chicken

Six classes of neutral lipids, i.e. triacylglycerol (TG), free fatty acids (FFA), monoester waxes (MW), free- and esterified sterols (FST and SE), and squalene (SQ) were identified by thin layer chromatography of the lipid materials extracted separately from the secretion as well as from the isolated whole glands present in the skin of the floor of the external ear canal of the domestic fowl. Secretory lipids contained considerable proportions of MW fractions (17.03%), TG (22.23%), and SQ (14.66%), while TG was the major component (41.10%) in the lipids from the isolated glands. Polar lipids, which comprised about 16-20% of total glandular lipids, were shown to be composed primarily of sphingomyelin.

Regain of fertility and normality of progeny born during below protective threshold antibody titers in women immunized with the HSD-hCG vaccine

PROBLEM

Phase II clinical trials with the heterospecies dimer of beta hCG and alpha-subunit of ovine luteinizing hormone (HSD)-human chorionic gonadotrophin (hCG) vaccine showed that pregnancy was prevented at and above 50 ng/ml titers, whereas conceptions occurred below 35 ng/ml of hCG bioneutralization capacity. The effect of below-protective threshold anti-hCG antibodies on the progression of pregnancy and the normality of progeny was studied.

METHOD OF STUDY

Four women enrolled by informed consent in the Phase II trials. The women studied were immunized with the HCG vaccine and did not receive booster injections in consideration of their desire to have another child. They were examined clinically at least once every month until delivery. The babies were followed up from 2 to 3.5 years, and their anthropometric indices were compared with elder siblings.

RESULTS

The pregnancies progressed to 35 to 38 weeks with the usual obstetric problems, and the children developed normally.

CONCLUSIONS

The anti-fertility effect of the HSD-hCG vaccine is reversible and low titers of antibodies below the protective threshold have no apparent side effects on the progression of pregnancy and on the early development of the progeny.

Differential spatiotemporal regulation of lactoferrin and progesterone receptor genes in the mouse uterus by primary estrogen, catechol estrogen, and xenoestrogen

Many xenobiotics are considered reproductive toxins because of their ability to interact with the nuclear estrogen receptors (ERalpha and ERbeta). However, there is evidence that these xenobiotics can regulate gene expression in the reproductive targets by mechanisms that do not involve these ERs. To examine this further, we compared the effects of estrogenic (o,p'-DDT [1-(o-chlorophenyl)-1-(p-chlorophenyl)2,2,2-trichloroethane] and Kepone, chlordecone) and nonestrogenic (p,p'-DDD [1,1-dichloro-2,2-bis(p-chlorophenyl)ethane], a metabolite of p,p'-DDT) xenobiotics with those of 17beta-estradiol (E2) and 4-hydroxyestradiol-17beta (4-OH-E2), a catechol metabolite of E2, on uterine expression of lactoferrin (LF) and progesterone receptor (PR). These genes are estrogen responsive in the mouse uterus. Normally, LF is expressed in the uterine epithelium, whereas PR is expressed in both the epithelium and stroma in response to estrogenic stimulation. Ovariectomized mice were injected with xenobiotics (7.5 mg/kg), E2 (10 microg/kg), 4-OH-E2 (10 microg/kg), or the vehicle (oil, 0.1 ml/mouse), and uterine tissues were processed for Northern blot and in situ hybridization. The pure antiestrogen ICI-182780 (ICI; 1 or 20 mg/kg) was used to interfere with estrogenic responses that were associated with the ERs. The results of Northern and in situ hybridization demonstrated increased uterine levels of PR and LF messenger RNAs (mRNAs) by all of these xenobiotics, but quantitatively the responses were much lower than those induced by E2 or 4-OH-E2. The results further showed that the E2-inducible epithelial LF mRNA accumulation was markedly abrogated by pretreatment with ICI (20 mg/kg). In contrast, this treatment retained the epithelial expression of PR mRNA, but down-regulated the stromal expression. In contrast, ICI had negligible effects on LF and PR mRNA responses to 4-OH-E2, indicating that this catechol estrogen exerted its effects primarily via a mechanism(s) other than the ERs. The heightened accumulation of LF mRNA in the epithelium in response to Kepone and o,p'-DDT was also severely compromised by pretreatment with ICI, but this antiestrogen had little effect on responses to p,p'-DDD. Similar to E2, Kepone increased the expression of PR mRNA in both uterine epithelium and stroma. However, pretreatment with ICI decreased stromal cell expression, whereas epithelial cell expression remained unaltered or increased. These responses were not noted in mice treated with o,p'-DDT or p,p'-DDD. Collectively, the results demonstrate that catechol estrogens or xenobiotics can alter uterine expression of estrogen-responsive genes by mechanisms that are not totally mediated by the classical nuclear ERs, and these alterations are cell type specific. We conclude that an interaction of a compound with the nuclear ERalpha and/or ERbeta is not an absolute requirement for producing specific estrogen-like effects in the reproductive target tissues.

Left ventricular long axis disturbances as predictors for thallium perfusion defects in patients with known peripheral vascular disease

OBJECTIVE

To compare resting long axis echocardiography with adenosine thallium-201 emission tomography in detecting myocardial ischaemic abnormalities in patients before peripheral vascular surgery.

DESIGN

A prospective and blinded preoperative examination of resting left ventricular minor and long axes and myocardial perfusion during adenosine vasodilatation using thallium-201 emission tomography.

SETTING

A tertiary referral centre for cardiac and vascular disease equipped with invasive, non-invasive, and surgical facilities.

SUBJECTS

65 patients (40 men) with significant peripheral vascular disease, mean (SD) age 63 (10) years, and 21 control subjects of similar age.

METHODS

Segments were classified as normal, with fixed or reversible defects according to thallium-201 myocardial perfusion tomography. Systolic long axis abnormalities were either reduced excursion and/or abnormal shortening after A2, and diastolic abnormalities either delayed onset of lengthening > 80 ms and/or reduced peak lengthening rate < 4.5 cm/s. Segmental perfusion defects were compared with the equivalent long axes; anteroseptal for septal, inferoseptal for posterior, and lateral for left side giving a total of 195 segments.

RESULTS

Systolic long axis abnormalities predicted fixed thallium defects (sensitivity 86%, specificity 87%, positive predictive value 0.78, negative predictive value 0.93, p < 0.001), and diastolic abnormalities correlated with reversible perfusion defects (sensitivity 90%, specificity 85%, positive predictive value 0.72, negative predictive value 0.95, p < 0.001). Echocardiography characteristics of the true and false positive segments were not different in the site or the extent of abnormalities.

CONCLUSION

Systolic long axis abnormalities predict fixed and diastolic reversible thallium perfusion defects in patients with peripheral vascular disease. Ventricular long axis may thus have a value as a screening test before peripheral vascular surgery as well as providing a means of monitoring myocardial perfusion. The high negative predictive values indicate that a negative long axis study makes significant perfusion abnormalities very unlikely in patients with high pretest probability of coronary artery disease.

Expression of neu differentiation factor during the periimplantation period in the mouse uterus

Complex cellular interactions occur between the blastocyst and the uterus during implantation. The expression of various polypeptide growth factors and their receptors in the uterus and/or blastocyst during the periimplantation period suggest that growth factors participate in the implantation process. Neu differentiation factor (NDF) is a member of the epidermal growth factor (EGF) family of growth factors and is represented by multiple conserved isoforms. The expression of several EGF-like ligands in the periimplantation uterus has been characterized, including EGF, heparin binding-EGF, transforming growth factor alpha, amphiregulin, betacellulin, and epiregulin. We analyzed the expression pattern of NDF in the periimplantation mouse uterus because of its mitogenic and differentiation-promoting effects. By using Northern analysis and isoform-specific polymerase chain reaction, we found that multiple isoforms are expressed in the periimplantation uterus. NDF displays a highly restricted temporal and spatial expression, with autoradiographic signals localized to the uterine stroma immediately surrounding the implanting blastocyst. NDF expression was absent in mice with delayed implantation but briefly reappeared with the same restricted distribution after termination of the delay by an injection of estrogen. Taken together, these results suggest that an activated blastocyst is required for the expression of NDF and that multiple isoforms may be involved in the complex network of cell-signaling events between the implanting blastocyst and the receptive uterus.

Cytohormonal evaluation of vaginal smears by phase contrast microscopy with special reference to progesterone deficiency pattern during early pregnancy as predictor of abortion

Cytohormonal profile of unstained vaginal smears were studied under phase contrast microscope to define various cell morphologies in detail and build up of smear pattern serially in various stages of menstrual cycle and first trimester of pregnancy. The findings were correlated clinically and found comparable to Papanicolaou stained smears. The maturation index was calculated more objectively by phase contract microscopy because of the refractile appearance of the pyknotic nuclei of superficial cells. The prognostication of abortion was done by combining abnormal maturation index and the presence of syncytiotrophoblasts in vaginal smears. Under phase contrast microscope, the sensitivity of abnormal smear was 87.5%, the specificity was 95%, the positive predictive value was 96.55% and the overall accuracy was 90% as compared to positive Papanicolaou smear whose sensitivity though 93%, had low specificity of 50% only. Phase contrast study appears to offer certain distinct advantage over the conventional light microscopy for quick, comprehensive and quantitative assessment of the study material. It allows the physician to detect changes in the material obtained from the patients without detour of laboratory fixation and staining. It is technically easy as errors in interpretation due to unsatisfactory fixation, staining and artefacts are obviated. Thus phase contrast microscopy offers an alternative and easy method of cytohormonal evaluation of wet and unstained smears.

Partial characterization of guinea pig cholinephosphotransferase cDNA

An alternative molecular biology strategy is needed to characterize cholinephosphotransferase (CPT) gene because of the complexity of the problem associated with the solubilization of the membrane-bound enzyme without denaturation. We have synthesized five heterologous oligonucleotide probes based on the published yeast CPT gene sequence. Each probe (24 to 30 mers) was used as either forward or reverse flanking primers in combination with lambda gt11 primers to amplify a segment of DNA from a guinea pig liver 5'cDNA library by polymerase chain reaction (PCR). We detected several clones of varied size (0.1 kb to 2.2 kb) by subjecting the PCR products to 1.2% agarose gel electrophoresis. Southern blot of a 0.7 kb PCR product did hybridize with a 32P-labeled internal probe. Slot blot hybridization of guinea pig liver total RNA with the 32P-labeled 0.7 kb PCR product yielded positive transcripts with intensities proportional to the concentration of RNA. Furthermore, a 0.1 kb clone was sequenced and the observed sequence shared 96% homology with the yeast CPT gene sequence.

Estrogenic responses in estrogen receptor-alpha deficient mice reveal a distinct estrogen signaling pathway

Estrogens are thought to regulate female reproductive functions by altering gene transcription in target organs primarily via the nuclear estrogen receptor-alpha (ER-alpha). By using ER-alpha "knock-out" (ERKO) mice, we demonstrate herein that a catecholestrogen, 4-hydroxyestradiol-17beta (4-OH-E2), and an environmental estrogen, chlordecone (kepone), up-regulate the uterine expression of an estrogen-responsive gene, lactoferrin (LF), independent of ER-alpha. A primary estrogen, estradiol-17beta (E2), did not induce this LF response. An estrogen receptor antagonist, ICI-182,780, or E2 failed to inhibit uterine LF gene expression induced by 4-OH-E2 or kepone in ERKO mice, which suggests that this estrogen signaling pathway is independent of both ER-alpha and the recently cloned ER-beta. 4-OH-E2, but not E2, also stimulated increases in uterine water imbibition and macromolecule uptake in ovariectomized ERKO mice. The results strongly imply the presence of a distinct estrogen-signaling pathway in the mouse uterus that mediates the effects of both physiological and environmental estrogens. This estrogen response pathway will have profound implications for our understanding of the physiology and pathophysiology of female sex steroid hormone actions in target organs.

Characterization of primed lymphocytes on the basic of sensitivity of chromatin to DNase I

Certain qualitative criteria for primed lymphocytes in the expression of cytotoxic function have been studied. Unlike normal lymphocytes, primed lymphocytes expressed cytotoxicity even when DNA synthesis and new gene expression were inhibited by hydroxyurea (HU) and bromodeoxyuridine (BU) respectively. Such differential cytotoxic expression in presence of HU and BU by primed lymphocytes might have their basis in conformational change within the chromatin. Chromatin from primed lymphocytes was more susceptible to DNase I digestion than virgin lymphocytes indicating exposition of more DNase I sensitive sites in primed state. The result suggest the presence of more ready to act sites for the polymerases in the genomic material of primed lymphocytes even at quiescent state.

Multiple female reproductive failures in cyclooxygenase 2-deficient mice

Cyclooxygenase (COX) is the rate-limiting enzyme in the synthesis of prostaglandins (PGs) and exists in two isoforms, COX-1 and COX-2. In spite of long-standing speculation, definitive roles of PGs in various events of early pregnancy remain elusive. We demonstrate herein that the targeted disruption of COX-2, but not COX-1, in mice produces multiple failures in female reproductive processes that include ovulation, fertilization, implantation, and decidualization. Using multiple approaches, we conclude that these defects are the direct result of target organ-specific COX-2 deficiency but are not the result of deficiency of pituitary gonadotropins or ovarian steroid hormones, or reduced responsiveness of the target organs to their respective hormones.

Expression of betacellulin and epiregulin genes in the mouse uterus temporally by the blastocyst solely at the site of its apposition is coincident with the "window" of implantation

In the mouse, the process of implantation is initiated by the attachment reaction between the blastocyst trophectoderm and uterine luminal epithelium that occurs at 2200-2300 h on day 4 (day 1 = vaginal plug) of pregnancy. Several members of the EGF family are considered important in embryo-uterine interactions during implantation. This investigation demonstrates that the expression of two additions to the family, betacellulin and epiregulin, are exquisitely restricted to the mouse uterine luminal epithelium and underlying stroma adjacent to the implanting blastocyst. These genes are not expressed during progesterone-maintained delayed implantation, but are rapidly switched on in the uterus surrounding the implanting blastocyst following termination of the delay by estrogen. These results provide evidence that expression of betacellulin and epiregulin in the uterus requires the presence of an active blastocyst and suggest an involvement of these growth factors in the process of implantation.