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Biomedical subjects

V Ganesh

Publications and source records attributed to V Ganesh.

At least 37 records · Page 2Linked to original sources
PubMed1996

Bromocriptine related atypical vascular accidents postpartum identified through medicolegal reviews.

Recent literary case reports indicate that bromocriptine mesylate, when used for the suppression of lactation in the puerperium, can cause serious and even lethal side effects. The untoward sequelae are attributed to generalized or focal vasospasm affecting the cardiac and/or cerebral bold vessels. Apart from pre-existing hypertension and use in association with other ergot derivatives, the factors predisposing to such complications have not been elucidated, The authors present three atypical bromocriptine related postpartum accidents which may expand the understanding both of the predisposing factors and the potential consequences of bromocriptine related severe side effects. One of the cases raises the suspicion that the manifestations of hyperthyroidism may be aggravated by this method of pharmacologic ablactation. Another observation appears to imply that the drug may trigger the onset of chronic hypertension in women so predisposed. The development of cerebral infarcts, identified by MRI, in a clinically asymptomatic woman, exemplifies the threat of recurrent seizure activity in cases of bromocriptine related stroke.

Adult↗
PubMed1996

Intracerebral hemorrhage in normotensive mothers using bromocriptine postpartum.

Three cases of cerebral hemorrhage that occurred in the puerperium in normotensive women who used bromocriptine for milk suppression postpartum are described. Unlike in some other instances reported in the past, the extent of the bleeding was limited in these patients and the long range outcome was relatively benign. All episodes were associated with the development of hypertension. These incidents occurred between the 10th and 17th days postpartum; somewhat later than the usually observed peak time period (6th to 8th day) for the development of severe bromocriptine related side effects.

Adult↗
PubMed1995

Fetal renal artery and umbilical artery Doppler flow and fetal urine output.

The object of this study was to determine if a correlation exists between the resistance index (RI) of the umbilical artery, the RI of the fetal renal artery, and hourly urine output by fetuses of normal pregnancies. Doppler flow study of the fetal renal artery and the umbilical artery was performed in 110 fetuses between 19 and 40 weeks' gestation. Color and pulse wave Doppler was used to obtain the flow velocity waveforms. The RI of the flow velocity waveforms was calculated. Fetal bladder volume was calculated by transverse, anteroposterior, and longitudinal diameters obtained from coronal and transverse sonographic images of the fetal urinary bladder. The difference in bladder volume at 30-minute intervals was used to determine hourly urine output. Gestational age has a positive linear association with fetal urine output (P < 0.01). The RI of the fetal renal artery has a negative linear association with gestational age (P < 0.05). The RI of the umbilical artery decreased with an increase in gestation age (P < 0.01). There was a significant correlation between the RI of the umbilical artery (P < 0.01) and the fetal renal artery (P < 0.05) and hourly urine output by the fetus. The RI of the fetal renal artery decreased with gestational age. Hourly urine output of the fetus increased with gestational age. The RI of the umbilical artery and the fetal renal artery had a significant correlation with fetal urine output.

Blood Flow Velocity↗
PubMed1994

Crystallographic structures of thrombin complexed with thrombin receptor peptides: existence of expected and novel binding modes.

Many of the vital actions of thrombin on platelets and other cells appear to be mediated by the recently cloned seven-transmembrane-domain thrombin receptor. Thrombin activates this receptor by a novel proteolytic mechanism. The amino-terminal exodomain of the receptor contains the sequence LDPRSFLLRNPNDKYEPF. Structure-activity studies with mutant receptors and receptor peptides suggest that this sequence binds to thrombin at two sites: LDPR with the active center of thrombin and KYEPF with the fibrinogen recognition exosite of thrombin. Thrombin then cleaves the Arg41-Ser42 bond to unmask a new amino terminus, which functions as a tethered peptide ligand binding to as yet undefined sites within the body of the receptor to effect receptor activation. We have determined eight crystal structures of thrombin complexed with receptor-based peptides. Each of the two components of the bidentate docking model was captured in individual cocrystals. In one crystal type, the LDPR sequence docked in the active center of thrombin in a manner analogous to d-PheProArg chloromethyl ketone. In other crystals, the KYEPF sequence bound in the fibrinogen anion binding exosite of thrombin in a manner analogous to the DFEEI sequence of the carboxylate-terminal peptide of hirudin. Strikingly, however, generation of a single crystal that includes both components of the anticipated bidentate binding mode was not achieved, apparently because the peptides have a dominant solution S-like conformation that does not bind in a productive way at the active center. This peptide structure apparently favored a novel alternative mode of receptor peptide-thrombin interaction in which the receptor peptides formed an intermolecular bridge between neighboring thrombin molecules, resulting in an infinite peptide thrombin chain in crystals. In this structure, the KYEPF sequence docked in the expected manner at the exosite of one thrombin molecule, but the LDPR sequence docked in an unusual nonproductive mode with the active center of a neighboring molecule. Mutations that removed important determinants of the S-like receptor peptide structure underlying the bridging mode in the receptor itself did not significantly alter thrombin signaling. Additionally, a comparison of receptor density to the responsiveness of a cell did not support a role for receptor oligomerization in signaling. The physiological role for this unexpected intermolecular binding mode, if any, remains to be identified.(ABSTRACT TRUNCATED AT 400 WORDS)

Amino Acid Sequence↗
PubMed1994

Crystal structure of peanut lectin, a protein with an unusual quaternary structure.

The x-ray crystal structure of the tetrameric T-antigen-binding lectin from peanut, M(r) 110,000, has been determined by using the multiple isomorphous replacement method and refined to an R value of 0.218 for 22,155 reflections within the 10- to 2.95-A resolution range. Each subunit has essentially the same characteristic tertiary fold that is found in other legume lectins. The structure, however, exhibits an unusual quaternary arrangement of subunits. Unlike other well-characterized tetrameric proteins with identical subunits, peanut lectin has neither 222 (D2) nor fourfold (C4) symmetry. A noncrystallographic twofold axis relates two halves of the molecule. The two monomers in each half are related by a local twofold axis. The mutual disposition of the axes is such that they do not lead to a closed point group. Furthermore, the structure of peanut lectin demonstrates that differences in subunit arrangement in legume lectins could be due to factors intrinsic to the protein molecule and, contrary to earlier suggestions, are not necessarily caused by interactions involving covalently linked sugar. The structure provides a useful framework for exploring the structural basis and the functional implications of the variability in the subunit arrangement in legume lectins despite all of them having nearly the same subunit structure, and also for investigating the general problem of "open" quaternary assembly in oligomeric proteins.

Arachis↗
PubMed1994

Effect of maternal cocaine abuse on renal arterial flow and urine output of the fetus.

OBJECTIVE: Our purpose was to study the short-term effect of maternal cocaine abuse on blood flow of the fetal kidney and the fetal hourly urine output. STUDY DESIGN: Thirty-three pregnant patients of various gestational ages with a history of cocaine abuse were studied. Patients were included if the urine specimen was positive for cocaine on the day of study. Patients were excluded if the urine specimen was positive for any other vasoactive substances or medications. Color and pulsed wave Doppler studies were used to obtain the flow velocity waveform of the fetal renal artery. The resistance index was calculated from systolic and diastolic values of flow velocity waveforms, Longitudinal, transverse, and anteroposterior diameters of the fetal urinary bladder were measured from transverse and coronal images at their maximum diameters, and the bladder volume was calculated. The hourly urine output of the fetus was measured from the difference in the bladder volume at half-hour intervals. As controls, 110 normal pregnancies between 19 and 40 weeks were similarly studied for normal values. The resistance index of the fetal renal artery and the hourly fetal urine output of the two groups were compared. RESULTS: The resistance index of the fetal renal artery of normal pregnancies had a negative association with gestational age (p < 0.05). Cocaine-exposed fetuses had a significantly higher resistance index of the renal artery (p < 0.01) than did normal fetuses of corresponding gestational ages. A decrease in the hourly urine output of cocaine-exposed fetuses was observed, compared with normal controls of corresponding gestational ages (p < 0.001). CONCLUSION: The resistance index values of fetal renal artery and fetal urine output were affected by maternal cocaine abuse.

Cesarean Section↗
PubMed1994

Rates of cesarean section and perinatal outcome. Perinatal mortality.

A comparison of relevant statistics from National Maternity Hospital, Dublin, Ireland and University Hospital, Newark, New Jersey, USA, for the years 1983-1989, revealed that after removal of major confounding factors, such as a fourfold difference in < 2500 gram births and an about tenfold discrepancy in the frequency of lethal congenital defects, the perinatal survival rates in all weight categories were significantly higher in the American center. The findings suggest that optimum perinatal results could not be achieved in an American high risk center with the approximately 6% abdominal delivery rate favored in Dublin. The same data also suggest, however, that the 17.5% rate of abdominal deliveries in Newark was unnecessarily high. The favorable impact of the relatively liberal use of cesarean section might have been derived in this study from a marked reduction of in utero losses, in the absence of an identifiable effect upon the rate of neonatal mortality.

Birth Weight↗
PubMed1993

Crystallization and preliminary X-ray studies of the basic lectin from winged bean (Psophocarpus tetragonolobus).

The basic lectin from winged bean (Psophocarpus tetragonolobus) could be crystallized using polyethyleneglycol (PEG) 4000 (I), PEG 8000 (II) and 2-methylpentane-2,4-diol (MPD) (III) as precipitants. Crystal forms I and II grew in the presence of methyl-alpha-D-galactopyranoside or N-acetylgalactosamine while III grew in the absence of sugar. The three forms have the same space group (P2(1)2(1)2) and similar unit cell dimensions with two dimeric molecules in the asymmetric unit. The unit cell dimensions are a = 156.8 A, b = 89.0 A, c = 73.3 A for I, a = 155.5 A, b = 92.3 A, c = 72.5 A for II and a = 148.3 A, b = 90.7 A, c = 73.8 A for III. The crystals, particularly those grown using PEG 8000, are suitable for high resolution X-ray analysis, which is in progress.

Crystallization↗
PubMed1993

Rates of cesarean section and perinatal outcome: stillbirths.

Based on their yearly clinical statistics for 1983-1989, the cesarean section and stillbirth rates at National Maternity Hospital (Dublin), where the patients are generally white, and University Hospital (Newark), where the patients are predominantly black, were compared. After adjusting for confounding factors, such as unregistered mothers admitted subsequent to fetal demise, differing rates of < 2500 g births and lethal congenital defects, the overall rates of intrauterine fetal demise were identical. When analyzed according to birth weights, in all weight groups, the stillbirth rates were significantly lower in Newark than in Dublin. However, for every 1000 births, more < or = 2500 g fetuses died in utero in Newark than in Dublin. This trend was reversed in the > 2500 g group, where the respective rate at National Maternity Hospital exceeded that of University Hospital more than twice. The latter result largely derived from an almost 7-fold higher rate of intrapartum deaths in the > 2500 g weight group at National Maternity Hospital as compared to University Hospital. When projected against prevailing American statistics, which reflect a stillbirth rate about twice as high among blacks than among whites, the results suggest that the management patterns favored in Newark, including a relatively liberal cesarean section rate (17.5% versus 5.8%), affected the rate of in utero losses favorably.

Black or African American↗
PubMed1992

Rates of caesarean section and neonatal mortality.

A comparison of the yearly statistics of National Maternity Hospital (Dublin) and University Hospital (Newark) was undertaken for the years 1983-1989. The findings appear to indicate that after the elimination of major confounding factors, the substantially higher rates of Caesarean section in Newark (17.5% versus 5.8%) did not bring about a measurable reduction in the rate of neonatal losses. The impact of paediatric care upon the respective neonatal outcomes could not be assessed on the ground of the reviewed data.

Cesarean Section↗
PubMed1992

Prenatal ultrasonographic fetal iliac bone measurement. Correlation with gestational age.

The variety of circumstances under which ultrasound examinations are performed makes fetal iliac bone measurement an important indicator of gestational age. We studied 322 well-dated pregnancies from 13 to 40 weeks' gestation with sonogram measurements of the fetal iliac bone in order to examine the relationship between gestational age and bone length. The results indicate a linear relationship, as described by the equation iliac length = -0.376 + (0.0887) (gestational age). The fit of the data to a straight line was quite close (R2 = .877, P = .0001). The data were used to obtain a nomogram for growth of the fetal iliac bone.

Age Determination by Skeleton↗
PubMed1991

Factors affecting perinatal mortality in an urban center.

In the Division of Obstetrics of the Statewide Perinatal Center, Newark, NJ, the rate of perinatal mortality fell from 51 in 1000, to 15 in 1000, between 1971 and 1986, and increased thereafter to 28 in 1000 by 1988. This development is analyzed against the background of changes in the environment and inside the Center. It is noted that during 2 study years (1983 and 1986) in our extremely high-risk patient population, the perinatal mortality rate was kept at, or under, the national average. It appears, therefore, that with well-coordinated management and optimum use of resources, marked nationwide differences in mortality rates between white and non-white populations can be greatly reduced or eliminated. An inverse relationship between the rates of caesarean section and perinatal mortality was documented, as the former increased from 4.5% to 17%. Paradoxically, a further increase of caesarean section rates was accompanied by a parallel increase of intrauterine fetal and neonatal losses.

Academic Medical Centers↗
PubMed1989

Comparison of parenteral ciprofloxacin with clindamycin-gentamicin in the treatment of pelvic infection.

A prospective, randomized study of intravenous followed by oral ciprofloxacin compared with the combination of intravenous clindamycin and gentamicin was conducted in 122 women hospitalized with pelvic infections. Clinical diagnoses included endometritis (97 patients) and uncomplicated pelvic inflammatory disease (25 patients). Treatment successes for endometritis included 42 of 50 (84 percent) patients treated with ciprofloxacin compared with 35 of 47 (75 percent) treated with the clindamycin-gentamicin combination. Treatment successes for acute salpingitis included 10 of 10 (100 percent) treated with ciprofloxacin and 13 of 15 (87 percent) treated with clindamycin-gentamicin. Ciprofloxacin successfully eradicated Chlamydia trachomatis in 11 of 12 patients as did clindamycin-gentamicin in six of seven patients. In this study of pelvic infection, ciprofloxacin demonstrated efficacy comparable with the combination of clindamycin and gentamicin, and is effective against C. trachomatis.

Acute Disease↗
PubMed1989

Ergotism: a possible etiology for puerperal psychosis.

Some reports in the medical literature have mentioned the occurrence of psychotic reactions in response to the use of certain ergot alkaloids in therapeutic doses. Prompted by these observations, we undertook a search for cases of "pure" puerperal psychosis (ie, typical manifestations 3-14 days postpartum) in order to evaluate the clinical background of this phenomenon. Special attention was paid to the medications that the patients had received peripartum. In the last 10 years, out of eight perinatal centers, we found only three cases that fulfilled the criteria of the quoted entity. In all instances, the manifestations of puerperal psychosis had been preceded by the administration of ergot derivatives. Based on the presented data, we hypothesize that typical postpartum psychosis may represent an idiosyncratic reaction to potent vasoactive drugs including ergot derivatives. The similarities between the clinical manifestations of ergotism and puerperal psychosis, and some of the epidemiologic features of the latter condition, appear to implicate ergot alkaloids as potential causative agents. Although the validity of the suggested interpretation requires further evaluation, we believe that the currently available data warrant caution with regard to the administration of ergot derivatives postpartum. These drugs should not be used in the absence of clear indication or in unnecessarily high doses. We suggest that ergotism be included in the differential diagnosis in cases of pure puerperal psychosis.

Adolescent↗
PubMed1988

Comparison of ticarcillin plus clavulanic acid with clindamycin and gentamicin in the treatment of postcesarean endomyometritis.

The efficacy of a single antibiotic--Timentin (ticarcillin with clavulanic acid)--was compared with a standard two antibiotic regimen (clindamycin and gentamicin) for the treatment of endomyometritis after cesarean delivery. The regimens were 3 grams of ticarcillin plus 100 milligrams of clavulanic acid given intravenously every four hours, or 600 milligrams of clindamycin given intravenously every six hours plus 3 to 5 milligrams per kilogram per day of gentamicin given intramuscularly. The diagnosis of endomyometritis was based upon an oral temperature of 100.4 degrees F. or higher on any two occasions, excluding the first 24 hours post partum, uterine tenderness and the absence of another focus of infection. Ninety-one patients were treated. Treatment failure rates were three of 49 in the clindamycin and gentamicin group and four of 42 of the ticarcillin plus clavulanic acid group. Treatment failures did not appear to be different from successes demographically or in risk factors for endomyometritis. The results of this study suggest that ticarcillin with clavulanic acid is as effective in the treatment of postcesarean endomyometritis as the standard regimen of clindamycin and gentamicin.

Adult↗