In vivo and in vitro studies on the differential role of luteinizing hormone and follicle-stimulating hormone in regulating follicular function in the bonnet monkey (Macaca radiata) using specific gonadotropin antibodies

Although a distinct need for FSH in the regulation of follicular maturation in the primate is well recognized, it is not clear how FSH controls the functionality of different cellular compartments of the follicle. It is also not evident whether there is a requirement for LH in follicular maturation in the primate. In the first part of the present study, female bonnet monkeys were administered a well-characterized ovine (o) LH antiserum to neutralize endogenous monkey LH for different periods during the follicular phase, and the effect on the overall follicular maturation process was assessed by analyzing serum estrogen (E) and progesterone (P) profiles. Neither continuous LH deprivation from Day 8 of the cycle nor deprivation of LH on any one day between Days 6 and 10 had a significant effect on serum E and P profiles and the follicular maturation process. The period for which the antiserum was effective was dependent upon the dose injected; 1 ml of the antiserum given on Day 8 blocked ovulation but not follicular maturation. To assess the effect of deprivation of LH/FSH at the cellular level, animals were deprived in vivo of LH (on Days 8 and 9 of the cycle) or of FSH (on Day 6 of the cycle) by injection of highly characterized hCG and ovine (o) FSH antisera, respectively; the in vitro responsiveness of granulosa and thecal cells isolated on Day 10 from these animals was then determined.(ABSTRACT TRUNCATED AT 250 WORDS)

A large conductance Ca2+-activated K+ channel in alpha T3-1 pituitary gonadotrophs

The Ca2+-activated K+ channel in endocrine cells is responsible for membrane hyperpolarization and rhythmic firing of action potentials. The probability of opening of this channel is sensitive to intracellular-free Ca2+ concentration. In this study we have identified one such large conductance Ca2+-activated K+ channel in alpha T3-1 pituitary gonadotroph cell. This channel is ohmic with a unit conductance of 170 pS in symmetrical KCl (135 mM) and its current reverses near zero millivolts. When more than one channel is present in the patch membrane they open and close independent of each other, exhibiting no cooperativity between them as expected of a binomial distribution. The regulatory mechanism of this channel in modulating hormone secretion from alpha T3-1 gonadotroph cells is indicated.

Evidence for follicle-stimulating hormone mediation in the hemiorchidectomy-induced compensatory increase in the function of the remaining testis of the adult male bonnet monkey (Macaca radiata)

Hemiorchidectomy (HO) in the adult male bonnet monkey results in a selective increase in circulating concentrations of FSH and testosterone, and this is accompanied by compensatory increase in sperm production by the remaining testis. We investigated the possible role of increased FSH concentration that occurs after HO in the compensatory increase in the activity of the remaining testis. Of eight adult male bonnet monkeys that underwent HO, four received i.v. injections every other day for 30 days of a well-characterized ovine FSH antiserum (a/s) that cross-reacts with monkey FSH. The remaining four males received normal monkey serum (NMS) as control treatment in a protocol similar to that employed for ais-treated males. Blood samples were collected between 2100 and 2200 h before and 1/2, 1, 3, 5, 7, 14, 22, and 29 days after HO. Testicular weight, number of 3 beta-hydroxy steroid dehydrogenase-positive (3 beta-HSD+) cells, and DNA flow cytometric analysis of germ cell populations were obtained for testes collected before and at the termination of NMS or ais treatment. In NMS-treated males, circulating serum FSH concentrations progressively increased to reach a maximal level by Day 7 after HO (1.95 +/- 0.3 vs. 5.6 +/- 0.7 ng/ml on Days -1 and 7, respectively). Within 30 min of ais injection, FSH antibodies were detected in circulation, and the antibody level was maintained at a constant level between Day 7 and end of treatment (exhibiting 50-60% binding to I-125-hFSH). Although circulating mean nocturnal serum testosterone concentration showed an initial decrease, it rose gradually to pre-HO concentrations by Day 7 in NMS-treated males. In contrast, nocturnal mat serum testosterone concentrations in a/s-treated males remained lower than in NMS-treated controls (p < 0.05) up to Day 22 and thereafter only marginally increased. Testicular weights increased (p < 0.05) over the pre-HO weight in NMS- but not in ais-treated males. After HO, the number of 3 beta-HSD+ cells (Leydig cells) was markedly increased but was significantly (p < 0.05) higher in NMS-treated males compared to a/s-treated males. A significant (p < 0.05) reduction in the primary spermatocyte population of germ cells was observed in ais-treated compared to NMS-treated males. These results suggest that the increased FSH occurring after HO could be intimately involved in increasing the compensatory functional activity of the remaining testis in the male bonnet monkey.

Responsiveness of human male volunteers to immunization with ovine follicle stimulating hormone vaccine: Results of a pilot study

A study of 140 days duration was performed to examine if human male volunteers (n = 5) respond to ovine follicle stimulating hormone (oFSH) immunization (administered adsorbed on Alugel on days 1, 20, 40 and 70) by producing antibodies capable of both binding and neutralizing bioactivity of human FSH. The kinetics of antibody production for both the immunogen (oFSH) and the cross-reactive antigen (hFSH) were essentially similar, The volunteers responded only to the first two immunizations, The boosters given on days 40 and 70 were ineffective, probably because of the presence of substantial amounts of circulating antibody to oFSH. Of the antibodies generated to oFSH, 25-45% bound hFSH with a mean binding affinity of 0.65 x 10(9) +/- 0.53 M(-1). The binding capacities at the time of high (30-80 days of immunization) and low (>110 days) titres were 346 +/- 185 and 10.5 +/- 5.8 ng hFSH/ml respectively, During the period of high titre, free serum FSH (value in normal males 1-5 ng/ml) was not monitorable, A 50 mu l aliquot of the antiserum obtained from different volunteers between days 30 and 80 and on day 140 blocked binding of I-125-labelled hFSH to its receptor by 82 +/- 9.7 and 53 +/- 12.2% respectively, The antibody produced was specific for FSH, and no significant change in the values of related glycoprotein hormones (luteinizing hormone/testosterone and thyroid stimulating hormone/thyroxine) were recorded, Seminal plasma transferrin, a marker of Sertoli cell as well as of seminiferous tubular function, showed marked reduction (30-90%) following immunization with oFSH. Considering that endogenous FSH remained neutralized for approximately one sperm cycle only (65 days), the reduction in sperm counts (30-74%) exhibited by some volunteers is encouraging, Immunization with oFSH did not result in any significant changes in haematology, serum biochemistry or hormonal profiles, There was no production of antibodies capable of interacting with non-specific tissues, It is concluded that it should be possible to obtain a sustained long-term blockade of endogenous FSH action in men by using oFSH as an immunogen, This is a prerequisite for obtaining significant reduction in the quality and quantity of spermatozoa produced, thus leading to infertility.

Molecular mimicry by antiidiotypic monoclonal antibody to gonadotropin releasing hormone

Antipeptide and antiidiotypic antibodies to several receptors are known to mimic their respective ligands in transducing signals on binding their receptors. In our attempts to study gonadotropin releasing hormone receptor, antipeptide and antiidiotypic monoclonal antibodies specific to the receptor were established earlier. The antipeptide mAb F1G4 was to a synthetic peptide corresponding to the extracellular domain of human GnRH receptor and the antiidiotypic mAb 4D10C1 was to the idiotype of a GnRH specific mAb. Here we report the physiological effects of the two mAbs on binding the receptor, as investigated using in vitro cultures of(a) human term placental villi and (b) rat pituitaries. The mAb 4D10C1 exerted a dose-dependent release of human chorionic gonadonopin in cultures of human term placental villi as well as luteinising and follicle stimulating hormones in cultures of rat pituitaries.

Regulation of an 8-kDa peptide involved in testosterone production by luteinizing hormone in rat Leydig cells

Results of Western blot analysis carried out with an interstitial cell extract from male guinea pig and ovarian extract from immature female rats administered equine chorionic gonadotropin (eCG) provide supportive evidence to our earlier suggestion that an 8-kDa peptide is involved in acquisition of steroidogenic capacity by the rat Leydig cells. It was found that though the signal was observed in other tissues such as liver, kidney and lung which do not produce gonadal hormones, the peptide was modulated only by lutenizing hormone (LH) in the rat Leydig cells.

Risk-sensitive optimal control for Markov decision processes with monotone cost

The existence of an optimal feedback law is established for the risk-sensitive optimal control problem with denumerable state space. The main assumptions imposed are irreducibility and a near monotonicity condition on the one-step cost function. A solution can be found constructively using either value iteration or policy iteration under suitable conditions on initial feedback law.

Ellipsometry as a Sensitive Technique to Probe film -Substrate Interfaces: Al2O3 on Si(100)

An attempt has been made to study the film-substrate interface by using a sensitive, non- conventional tool. Because of the prospective use of gate oxide in MOSFET devices, we have chosen to study alumina films grown on silicon. Film-substrate interface of alumina grown by MOCVD on Si(100) was studied systematically using spectroscopic ellipsometry in the range 1.5-5.0 eV, supported by cross-sectional SEM, and SIMS. The (ε1,ε2) versus energy data obtained for films grown at 600°C, 700°C, and 750°C were modeled to fit a substrate/interface/film “sandwich”. The experimental results reveal (as may be expected) that the nature of the substrate -film interface depends strongly on the growth temperature. The simulated (ε1,ε2) patterns are in excellent agreement with observed ellipsometric data. The MOCVD precursors results the presence of carbon in the films. Theoretical simulation was able to account for the ellipsometry data by invoking the presence of “free” carbon in the alumina films.

Scalable Context-Sensitive Points-To Analysis Using Multi-Dimensional Bloom Filters

Context-sensitive points-to analysis is critical for several program optimizations. However, as the number of contexts grows exponentially, storage requirements for the analysis increase tremendously for large programs, making the analysis non-scalable. We propose a scalable flow-insensitive context-sensitive inclusion-based points-to analysis that uses a specially designed multi-dimensional bloom filter to store the points-to information. Two key observations motivate our proposal: (i) points-to information (between pointer-object and between pointer-pointer) is sparse, and (ii) moving from an exact to an approximate representation of points-to information only leads to reduced precision without affecting correctness of the (may-points-to) analysis. By using an approximate representation a multi-dimensional bloom filter can significantly reduce the memory requirements with a probabilistic bound on loss in precision. Experimental evaluation on SPEC 2000 benchmarks and two large open source programs reveals that with an average storage requirement of 4MB, our approach achieves almost the same precision (98.6%) as the exact implementation. By increasing the average memory to 27MB, it achieves precision upto 99.7% for these benchmarks. Using Mod/Ref analysis as the client, we find that the client analysis is not affected that often even when there is some loss of precision in the points-to representation. We find that the NoModRef percentage is within 2% of the exact analysis while requiring 4MB (maximum 15MB) memory and less than 4 minutes on average for the points-to analysis. Another major advantage of our technique is that it allows to trade off precision for memory usage of the analysis.

A near-singular, flexure jointed, moment sensitive Stewart platform based fore-torque sensor

A force-torque sensor capable of accurate measurement of the three components of externally applied forces and moments is required for force control in robotic applications involving assembly operations. The goal in this paper is to design a Stewart platform based force torque sensor at a near-singular configuration sensitive to externally applied moments. In such a configuration, we show an enhanced mechanical amplification of leg forces and thereby higher sensitivity for the applied external moments. In other directions, the sensitivity will be that of a normal load sensor determined by the sensitivity of the sensing element and the associated electronic amplification, and all the six components of the force and torque can be sensed. In a sensor application, the friction, backlash and other non-linearities at the passive spherical joints of the Stewart platform will affect the measurements in unpredictable ways. In this sensor, we use flexural hinges at the leg interfaces of the base and platform of the sensor. The design dimensions of the flexure joints in the sensor have been arrived at using FEA. The sensor has been fabricated, assembled and instrumented. It has been calibrated for low level loads and is found to show linearity and marked sensitivity to moments about the three orthogonal X, Y and Z axes. This sensor is compatible for usage as a wrist sensor for a robot under development at ISRO Satellite Centre.

Output-Sensitive Construction of Reeb Graphs

The Reeb graph of a scalar function represents the evolution of the topology of its level sets. This paper describes a near-optimal output-sensitive algorithm for computing the Reeb graph of scalar functions defined over manifolds or non-manifolds in any dimension. Key to the simplicity and efficiency of the algorithm is an alternate definition of the Reeb graph that considers equivalence classes of level sets instead of individual level sets. The algorithm works in two steps. The first step locates all critical points of the function in the domain. Critical points correspond to nodes in the Reeb graph. Arcs connecting the nodes are computed in the second step by a simple search procedure that works on a small subset of the domain that corresponds to a pair of critical points. The paper also describes a scheme for controlled simplification of the Reeb graph and two different graph layout schemes that help in the effective presentation of Reeb graphs for visual analysis of scalar fields. Finally, the Reeb graph is employed in four different applications-surface segmentation, spatially-aware transfer function design, visualization of interval volumes, and interactive exploration of time-varying data.

Measurement of probability-distribution functions sensitive technique for the study of conduction phenomena in liquid dielectrics

The paper outlines a technique for sensitive measurement of conduction phenomena in liquid dielectrics. The special features of this technique are the simplicity of the electrical system, the inexpensive instrumentation and the high accuracy. Detection, separation and analysis of a random function of current that is superimposed on the prebreakdown direct current forms the basis of this investigation. In this case, prebreakdown direct current is the output data of a test cell with large electrodes immersed in a liquid medium subjected to high direct voltages. Measurement of the probability-distribution function of a random fluctuating component of current provides a method that gives insight into the mechanism of conduction in a liquid medium subjected to high voltages and the processes that are responsible for the existence of the fluctuating component of the current.

l-pGlu-(2-propyl)-l-His-l-ProNH2 attenuates 4-aminopyridine-induced epileptiform activity and sodium current: a possible action of new thyrotropin-releasing hormone analog for its anticonvulsant potential

L-PGlu-(2-proPyl)-L-His-L-ProNH(2) (NP-647) is a CNS active thyrotropin-releasing hormone (TRH) analog with potential application in various CNS disorders including seizures. In the present study, mechanism of action for protective effect of NP-647 was explored by studying role of NP-647 on epileptiform activity and sodium channels by using patch-clamp methods. Epileptiform activity was induced in subicular pyramidal neurons of hippocampal slice of rat by perfusing 4-aminopyridine (4-AP) containing Mg(+2)-free normal artificial cerebrospinal fluid (nACSF). Increase in mean firing frequency was observed after perfusion of 4-AP and zero Mg(+2) (2.10+/-0.47 Hz) as compared with nACSF (0.12+/-0.08 Hz). A significant decrease in mean firing frequency (0.61+/-0.22 Hz), mean frequency of epileptiform events (0.03+/-0.02 Hz vs. 0.22+/-0.05 Hz of 4-AP+0 Mg), and average number of action potentials in paroxysmal depolarization shift-burst (2.54+/-1.21 Hz vs. 8.16+/-0.88 Hz of 4-AP +0 Mg) was observed. A significant reduction in peak dV/dt (246+/-19 mV ms(-1) vs. 297 18 mV ms-1 of 4-AP+0 Mg) and increase (1.332+/-0.018 ms vs. 1.292+/-0.019 ms of 4-AP+0 Mg) in time required to reach maximum depolarization were observed indicating role of sodium channels. Concentration-dependent depression of sodium current was observed after exposure to dorsal root ganglion neurons to NP-647. NP-647 at different concentrations (1, 3, and 10 mu M) depressed sodium current (15+/-0.5%, 50+/-2.6%, and 75+/-0.7%, respectively). However, NP-647 did not show change in the peak sodium current in CNa18 cells. Results of present study demonstrated potential of NP-647 in the inhibition of epileptiform activity by inhibiting sodium channels indirectly. (C) 2011 IBRO. Published by Elsevier Ltd. All rights reserved.