Fertility suppression in male albino rats by administration of methanolic extract of Opuntia dillenii.

To control growing world population, there is a need for male contraceptive methods that are comparable to female contraceptives, but due to lack of knowledge or investigation, no sufficient safe and effective contraceptives were developed till now. In the present investigation, the effect of 100% methanol extract of Opuntia dillenii phylloclade on reproduction in male rats was studied. A first group (I) received vehicle alone to serve as control. The second group (II) was further divided into treated and recovery groups, and the plant extract at 50 mg kg body weight(-1) was administered orally for 30 days. Biochemical, haematological and histopathological analyses were carried out to reveal the effects on reproductive organs in the male rats. The weights of reproductive organs were recorded. It was found that the number of fertile males, number of inseminated females, number of litters delivered and testosterone levels were reduced significantly. Epididymal sperm count and motility were also significantly decreased. Biochemical parameters support the antifertility activity of O. dillenii i.e. decreases in protein, glycogen content and elevation in cholesterol level. Testes and sperm morphology were altered significantly. Haematological parameters have not shown any significant changes. It is concluded that 100% methanol extract of O. dillenii possesses antifertility effects on male reproduction without change in general physiology.

High-Field Dynamic Nuclear Polarization for Solid and Solution Biological NMR.

Dynamic nuclear polarization (DNP) results in a substantial nuclear polarization enhancement through a transfer of the magnetization from electrons to nuclei. Recent years have seen considerable progress in the development of DNP experiments directed towards enhancing sensitivity in biological nuclear magnetic resonance (NMR). This review covers the applications, hardware, polarizing agents, and theoretical descriptions that were developed at the Francis Bitter Magnet Laboratory at Massachusetts Institute of Technology for high-field DNP experiments. In frozen dielectrics, the enhanced nuclear polarization developed in the vicinity of the polarizing agent can be efficiently dispersed to the bulk of the sample via (1)H spin diffusion. This strategy has been proven effective in polarizing biologically interesting systems, such as nanocrystalline peptides and membrane proteins, without leading to paramagnetic broadening of the NMR signals. Gyrotrons have been used as a source of high-power (5-10 W) microwaves up to 460 GHz as required for the DNP experiments. Other hardware has also been developed allowing in situ microwave irradiation integrated with cryogenic magic-angle-spinning solid-state NMR. Advances in the quantum mechanical treatment are successful in describing the mechanism by which new biradical polarizing agents yield larger enhancements at higher magnetic fields. Finally, pulsed methods and solution experiments should play a prominent role in the future of DNP.

Correlation of Foot Bimalleolar Angle and Ultrasonography in Assessing the Severity of Club Foot in Neonates Treated by the Ponseti Method.

Introduction: Correlation of Pirani score and foot bimalleolar (FBM) angle has been used in few studies but correlation of FBM angle with ultrasonography has never been evaluated so they are being correlated in assessing the severity of clubfoot in neonates treated by Ponseti method. Material and Methods: Thirty-two feet with congenital talipes equinovarus (CTEV) deformity in neonates were prospectively treated by the Ponseti method. FBM angle and ultrasound parameters were measured three times i.e. at the time of initial presentation, at four weeks of treatment and at completion of treatment. The feet were divided according to the Pirani score in groups: one (0-2.0), two (2.5-4) and three (4.5-6). Correlation between FBM angle and ultrasound parameters were evaluated using Pearson correlation/regression. Results: Correlation between FBM angle and ultrasound parameters were statistically significant (p-value < 0.05). Conclusion: Ultrasound has the potential to accurately depict the pathoanatomy in clubfoot. FBM angle and ultrasound are objective methods to assess the severity of clubfoot. FBM angle and ultrasonography correlated in severity of deformity and correction achieved along the course of treatment.

QRS detection using adaptive filters: A comparative study.

Electrocardiogram (ECG) is one of the most important physiological signals of human body, which contains important clinical information about the heart. Monitoring of ECG signal is done through QRS detection. In this paper, an improved QRS detection algorithm, based on adaptive filtering principle, has been designed. Enumeration of the effectiveness of various LMS variants used in adaptive filtering based QRS detection algorithm has been done through fidelity parameters like sensitivity and positive predictivity. Whole family of LMS algorithm has been implemented for comparison. Sign-sign LMS, sign error LMS, basic LMS and normalized LMS are re-implemented, while variable leaky LMS, variable step-size LMS, leaky LMS, recursive least squares (RLS), and fractional LMS are novel combination presented in this paper. After analysis of the obtained results, performance of leaky-LMS algorithm is found to be the best with sensitivity, positive predictivity, and processing time of 99.68%, 99.84%, and 0.45s respectively. Reported results are tested and evaluated over MIT/BIH arrhythmia database. Presented study also concludes that the performance of most of the variants gets affected due to low SNR but the Leaky LMS performs better even under heavy noise conditions.

Nutrition and somatomedin. XI. Studies of somatomedin inhibitors in rats with streptozotocin-induced diabetes.

Diabetics may have normal somatomedins by radioimmunoassay yet decreased somatomedin activity by bioassay. The discrepancy appears due to circulating inhibitory factors; inhibitors in whole diabetic serum antagonize the action of both somatomedins and insulin via noncompetitive interactions. Since little is known about the nature of the inhibitory activity, serum from streptozotocin-diabetic rats was fractionated, and inhibitory activity measured as the ability of fractions to blunt stimulation of SO4 uptake by hypophysectomized rat costal cartilage exposed in vitro to somatomedins in normal rat serum. After establishing that inhibitory activity was stable to pH and lyophilization, diabetic rat serum was gel filtered at pH 7 (somatomedins bound to carrier proteins) and 2.4 (somatomedins dissociated, mol wt approximately 8000). Using Sephadex and Sephacryl columns at neutral pH, inhibitors were detected at mol wt approximately 250,000, approximately 24,000, and approximately 940. Predominant activity was at approximately 24,000 and approximately 940. In contrast, Sephadex columns at acid pH revealed inhibitors only at mol wt approximately 21,000. Diabetic rat serum was also subjected to ion-exchange chromatography on CM-Sepharose. A single band of activity at pH 5-7 was found on elution with increasing pH, suggesting an isoelectric point(s) lower than that of the somatomedins. However, three areas of activity were seen on elution with increasing ionic strength at pH 5-at 0.02 M and 0.14-1.4 M and at 2.0 M pH 5.0-5.5. These studies indicate that reduced anabolism in diabetes may be due in part to three species of circulating somatomedin inhibitors, largely of mol wt approximately 21-24,000 and approximately 940, and also of mol wt approximately 250,000.(ABSTRACT TRUNCATED AT 250 WORDS)

Alpha-adrenergic blockade improves glucose-potentiated insulin secretion in non-insulin-dependent diabetes mellitus.

The impairment of glucose-potentiated insulin secretion present in non-insulin-dependent diabetes mellitus (NIDDM) can be approximated in normal subjects by an epinephrine infusion. Therefore, we sought to determine the role of the endogenous sympathetic nervous system in glucose-potentiated insulin secretion in both NIDDM (n = 6) and normal (n = 6) subjects. Glucose-potentiated insulin secretion was calculated as the slope of the curve relating increasing ambient glucose levels to the acute insulin response to an intravenous pulse of 5 g of L-arginine. Glucose-potentiated insulin secretion was determined on separate days during alpha-, beta-, and combined alpha- plus beta-adrenergic blockade and compared with a saline control. In normal subjects, there was no effect of alpha-, beta-, or alpha- plus beta-blockade on the slope of glucose potentiation. In NIDDM, the initially decreased slope of glucose potentiation (0.25 +/- 0.06 microU X ml-1 X mg-1 X dl, mean +/- SE; P less than .01) was not affected by beta-blockade but increased during alpha-blockade (0.91 +/- 0.22 microU X ml-1 X mg-1 X dl; P less than .05). However, this improvement was abolished by combined alpha- plus beta-blockade (0.32 +/- 0.07 microU X ml-1 X mg-1 X dl). Plasma norepinephrine was increased above basal levels in both normal (+260 +/- 89 pg/ml) and NIDDM (+438 +/- 162 pg/ml) subjects during alpha-blockade (P less than .05 for both). This increase in plasma norepinephrine strongly suggests that there is an increase in synaptic cleft norepinephrine concentration.(ABSTRACT TRUNCATED AT 250 WORDS)

p53 and related proteins in epithelial ovarian cancer.

We conducted a retrospective immunohistochemical evaluation of the prognostic significance of the expression of p53 and the related proteins Bax, Bcl-2, growth arrest and DNA damage (Gadd45), murine double minute 2 (Mdm2) and p21(WAF1/CIP1) in chemonaive tumours taken from 66 patients with ovarian cancer. Ki-67 expression (a marker of cell proliferation) was also evaluated immunohistochemically, while apoptosis within malignant cells was determined with the terminal deoxynucleotidyltransferase-mediated dUTP nick-end labelling (TUNEL) assay. The expression of each of the following proteins was significantly associated in the tumours (P < 0.05 unless otherwise stated): Bax with Bcl-2 (P < 0.01); Bax with Mdm2; p21(WAF1/CIP1) with Gadd45 (P < 0.01); p21(WAF1/CIP1) with p53; p53 with Mdm2. Univariate analysis showed that expression of p53, Bax, bulk residual disease and International Federation of Gynecology and Obstetricians (FIGO) stage were all strongly correlated with response to chemotherapy (P < 0.01). Similarly, the FIGO stage and Ki-67 expression (P < 0.01), as well as pathological subtype and bulk residual disease (P < 0.05), were prognostic factors for disease progression. The FIGO stage and Ki-67 expression were significant prognostic factors for overall survival (P < 0.01), with Gadd45 expression and pathological subtype also significant (P < 0.05) in a univariate analysis. Multivariate analysis for response to chemotherapy showed that expression of p53, Bax and FIGO stage were all independent prognostic factors (P < 0.01). The FIGO stage was the most important independent prognostic factor for progression and survival on multivariate analysis (P < 0.01). However, Ki-67 expression was also an independent prognostic factor for disease progression (P < 0.05) and approached significance for survival (P = 0.055). Taken together, these data suggest that determination of Ki-67 expression could supplement established prognostic factors.

Dynamic nuclear polarization at 9T using a novel 250GHz gyrotron microwave source.

In this communication, we report enhancements of nuclear spin polarization by dynamic nuclear polarization (DNP) in static and spinning solids at a magnetic field strength of 9T (250 GHz for g=2 electrons, 380 MHz for 1H). In these experiments, 1H enhancements of up to 170+/-50 have been observed in 1-13C-glycine dispersed in a 60:40 glycerol/water matrix at temperatures of 20K; in addition, we have observed significant enhancements in 15N spectra of unoriented pf1-bacteriophage. Finally, enhancements of approximately 17 have been obtained in two-dimensional 13C-13C chemical shift correlation spectra of the amino acid U-13C, 15N-proline during magic angle spinning (MAS), demonstrating the stability of the DNP experiment for sustained acquisition and for quantitative experiments incorporating dipolar recoupling. In all cases, we have exploited the thermal mixing DNP mechanism with the nitroxide radical 4-amino-TEMPO as the paramagnetic dopant. These are the highest frequency DNP experiments performed to date and indicate that significant signal enhancements can be realized using the thermal mixing mechanism even at elevated magnetic fields. In large measure, this is due to the high microwave power output of the 250 GHz gyrotron oscillator used in these experiments.

Contribution of atrial contraction to left ventricular filling in patients with sick sinus syndrome on AAI pacing.

Doppler echocardiographic evaluation of the contribution of atrial contraction to left ventricular filling, its determinants and relationship with early diastolic filling was studied in 20 patients with sick sinus syndrome without structural heart disease on AAI pacing over a wide range of physiological atrioventricular delays (PR intervals). The results were compared with 20 normal controls matched for age, sex and heart rate. Left ventricular filling pattern, and the contribution of left atrial contraction to diastolic filling, were similar in the two groups. AAI pacing restores the physiological dynamics of left ventricular filling in patients with sick sinus syndrome without organic heart disease.

Comparison of atrial and VVI pacing modes in symptomatic sinus node dysfunction without associated tachyarrhythmias.

The natural course of patients with symptomatic sinus node dysfunction who did not have associated tachyarrhythmias before pacemaker implantation was compared after VVI and atrial pacemaker implantation. Between April 1981 and June 1989, forty-seven such patients (mean age 52 + 13 years) received VVI pacemakers and forty patients (mean age 54 + 13 years) received AAI or DDD pacemakers. Baseline clinical characteristics and severity of sinus node dysfunction were comparable in the two groups. Over a follow up of 10 to 96 months (mean 49.2 + 26 months), 11 (23.4%) VVI patients were in functional class II or more compared to 2 (5%) atrially paced patients (p less than 0.01). Other complication rates were also higher in the VVI group as compared to AAI group viz. atrial fibrillation (21.2% vs 2.5% p less than 0.01) and stroke (10.6% vs 2.5%) though the number of deaths (14.9% vs 10%) was not significantly different in the two groups. Two patients in atrial paced group and one patient in VVI group developed first degree heart block. There was no incidence of second or third degree heart block. Transient loss of atrial sensing occurred in 3 patients and atrial lead displacement in 2 cases, but overall incidence of lead related problems was low and comparable in both groups. Thus atrial pacing is superior to ventricular pacing in sinus node dysfunction and risk of developing high grade atrioventricular block on follow up is low.

Long term performance of dual chamber pacemakers.

Records of 98 patients who had dual chamber pacemakers implanted at our institution and had a follow up for at least 6 months (range 6-90 months, mean 47.8 months) were analysed for long term performance of the pacemakers. There were 78 males and 20 females in the age range of 14 to 81 (mean 51.1 +/- 13.6) years. The mode of pacing was VDD in 12, DVI in 9 and DDD in 77 patients. Atrial malsensing was seen in 15 (16.7%) cases and generally occurred within the first week of implantation. Atrial lead dislodgement occurred in 4 cases (4.1%). Most of the problems related to atrial lead could be managed conservatively and re-operation was performed in only 4 cases. Other problems encountered on follow up included cross talk in one, endless loop tachycardia in 4, and pulse generator pocket erosion or infection in 4 (4.1%) patients. There were two instances of ventricular undersensing and one instance of insulation failure in the ventricular lead. A total of 16 patients underwent elective replacement of pulse generator 53-84 months (mean 66.3) following the initial implants. It is concluded that the incidence of pacemaker malfunction and other problems with dual chamber pacemaker implantation are not high; and most cases can be managed by conservative measures such as reprogramming.

Background noise in healthy volunteers--a consideration in adverse drug reaction studies.

In adverse drug reaction studies proper control over 'Back ground noise' is to be maintained to avoid erroneous conclusions to be drawn for adverse drug effects. Healthy volunteers, not taking any medication, were surveyed by a questionnaire to obtain data on the occurrence of any symptoms, often ascribed to side effects of drugs. Only 62 subjects out of a total of 236 (26.27%) stated experiencing none of these symptoms during the previous 3 days. The remaining subjects reported some symptoms, with an median number of symptoms experienced per person being 2; the most common being fatigue; headache, inability to concentrate and excessive sleepiness.