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Biomedical subjects

M M Singh

Publications and source records attributed to M M Singh.

At least 91 records · Page 5Linked to original sources
PubMed1992

Duration of antiestrogenecity of compound CDRI-85/287: a new orally active nonsteroidal antiimplantation agent.

Duration of antiestrogenic and antiimplantation action of CDRI-85/287, (2-(4-(2-N-piperidino)ethoxy phenyl)-3-phenyl(2H)benzo(2)pyran), was studied in rat. Pretreatment of ovariectomized immature rats with this compound caused translocation of cytoplasmic estrogen receptor (ER) to the nucleus and a marked depletion of cytoplasmic ER pool resulting in a nonresponsive state of the uterus to subsequent estrogen administration until day 4. While in rats pretreated with estradiol, increased cytoplasmic ER level made the uterus responsive to a second injection of estrogen. In the delayed implantation model, 85/287 pretreated rats were given estrone on days 4, 5 or 6 post-antiestrogen treatment. No implantations were observed after estrone administration on day 4, but were present when estrone was given on days 5 or 6. Summation of these results suggests the duration of action of 85/287 to be 3-4 days in rat.

Administration, Oral↗
PubMed1992

CDRI-85/287: studies on competition to estrogen binding sites in the immature rat uterus.

Ability of compound CDRI-85/287, a new nonsteroidal antiestrogen with negligible inherent estrogenicity, to inhibit uptake of 3H-estradiol (3H-E2) by the immature rat uterus in vivo was investigated. Different doses of 85/287 were administered either intraperitoneally 30 min before 3H-E2 or orally 1 and 6 hr before 3H-E2. A dose dependent inhibition in 3H-E2 uptake was observed after administration of the compound by either route and was 69% at 50 micrograms/rat ip dose and 80% at 2.5 mg/kg po dose. In in vitro competitive binding assay, however, the compound showed poor affinity (RBA 0.42% of estradiol-17 beta) for cytosolic estrogen receptors. Considering the potent anti-estrogenic as well as anti-implantation efficacy of the compound, its action in vivo appears to be mediated via its active metabolite(s).

Animals↗
PubMed1991

Synthesis and pregnancy-inhibiting activity of 7-substituted androst-5-ene derivatives.

Synthesis of 7-aryl/allyl-substituted androstene derivatives 3a through 3g has been carried out by Grignard reaction on 3 beta,17 beta-diacetoxyandrost-5-en-7-one (2) with aryl/allyl magnesium bromide. Isomeric mixture of products 3b and 3c/3e and 3f/3h was separated by column chromatography. Stereochemical assignment at C-7 has been made on the basis of 13C nuclear magnetic resonance studies and chemical considerations. Compounds 6a and 6b were synthesized by alkylation of compound 5 with beta-(N,N-diethylamino)ethyl chloride hydrochloride and 1-(2-chloroethyl)pyrrolidine hydrochloride, respectively. Compound 3g (isomeric mixture) prevented pregnancy in 60% of rats at 10 mg/kg daily dose administered orally on days 1 to 7 of pregnancy; however, its only isolable 7 beta-hydroxy isomer, 3h, was inactive at this dose.

Androstenes↗
PubMed1991

Determination of mevalonolactone in capsules by capillary gas-liquid chromatography.

A wide bore capillary gas chromatographic method was developed to determine mevalonolactone in capsule formulations. The method uses beta,beta-dimethyl-gamma-hydroxymethyl-gamma- butyrolactone as an internal standard and has been validated for its accuracy, precision and linearity. The method has been applied for stability testing of the capsule formulation. High-performance liquid chromatographic and gas chromatographic studies demonstrated cyclization of mevalonic acid (open-chain form) to mevalonolactone (cyclic form) under the described gas chromatography conditions. Mass spectrometric analysis indicated that mevalonolactone prepared in water or an organic solvent emerged from the gas chromatographic column as the intact cyclic lactone.

Capsules↗
PubMed1991

Effect of prolonged centchroman treatment on pituitary gonadotrophic activity in rhesus monkeys.

Daily oral administration of antiestrogen centchroman at 6.25, 12.5 and 25 mg/kg doses to adult female rhesus monkeys continuously for one year caused no significant effect on their total pituitary gonadotrophin content as evidenced by an almost similar extent of uterine weight gain, premature opening of vagina and cornification of vaginal epithelium in immature female mice treated with pituitary homogenates from control and centchroman treated monkeys.

Animals↗
PubMed1990

Psychopathology of delayed resumption of sexual activity after myocardial infarction.

A total of 300 male cases of myocardial infarction were analyzed to evaluate the effect of myocardial infarction on sexual activity with particular stress on resumption of sexual activity and to determine the factors in cases of delayed resumption. Sexual activity decreased with age and correlated negatively to total sexual activity. 26 per cent cases developed one or other symptoms which occurred during all the phases of sexual activity but were more marked during resolution phase. Sexual activity returned to normal within six months only in 11.33 per cent cases and in the remaining cases resumption was delayed. In 27.8 per cent cases phobia of marked exertion involved in sex act, created by physicians in 12.7 per cent was the factor responsible for the delayed resumption. Quality of sexual activity decreased in 39 per cent cases and it was due to change in position from Male on top to male on bottom position in 31 per cent cases. Counselling for sexual rehabilitation has been discussed.

Adult↗
PubMed1990

Serum cholesterol binding reserve and its ratio to serum cholesterol in first degree relatives of patients with ischaemic heart disease.

Serum total cholesterol and serum cholesterol binding reserve (SCBR) were estimated in 50 healthy subjects and 25 cases with ischaemic heart disease (IHD) and their seventy asymptomatic first degree relatives. In normal subjects mean values of SCBR tended to expand with increasing levels of serum cholesterol, while this relationship was reversed in cases with IHD. The relatives showed a direct correlation between serum cholesterol and SCBR upto serum cholesterol level of 220 mg/dl, but the correlation was lost beyond this level. The critical levels for predicting risk of IHD were 30 mg/dl for SCBR and 8 for cholesterol: SCBR ratio. The latter was found to be a more sensitive index for predicting the risk of IHD as compared to SCBR alone.

Adult↗
PubMed1990

Right precordial mapping. Diagnostic sensitivity and specificity of leads V3R to V6R in different intercostal spaces in cases with right ventricular infarction.

Twelve lead conventional electrocardiography and right precordial mapping including precordial leads V2R to V6R in the 2nd to 5th intercostal spaces were obtained in 150 cases with acute myocardial infarction. There were 27 (18%) cases with right ventricular infarction: 24 associated with inferior wall infarction and 3 with anterior wall infarction. In the right precordial mapping, leads V3R to V6R in all intercostal spaces had equal sensitivity of 100%; 3rd intercostal space recording, however, had the maximum specificity of 92.6%.

Electrocardiography↗
PubMed1989

The positive-negative distinction in drug-free schizophrenic patients. Stability, response to neuroleptics, and prognostic significance.

Fundamental questions about the validity and significance of positive and negative syndromes in schizophrenia were addressed by a prospective, double-blind longitudinal study that involved a drug-free placebo baseline, three to four months of neuroleptic treatment, and a three-year poststudy follow-up. From pooled data on 62 schizophrenics, the following findings were observed: (1) a high stability of both syndromes during drug-free conditions; (2) significant correlations of syndrome ratings between the placebo baseline and final neuroleptic week; (3) significant neuroleptic-related improvement in both positive and negative syndromes, with a marginally greater reduction of positive features; (4) independence of the two syndromes during the drug-free baseline but not under neuroleptic conditions; (5) greater symptomatic improvement but more residual disorder portended by both positive and negative syndromes in the drug-free baseline; and (6) poorer functional reconstitution and earlier relapse predicted by a positive syndrome alone. These data supported the validity of the positive-negative distinction in schizophrenia but challenged basic assumptions about its import.

Adolescent↗
PubMed1988

Luteolytic action of two antiprogestational agents (RU-38486 and ZK-98734) in the rat.

RU-38486 or ZK-98734 treatment (3 mg/day, s.c.) to intact or hysterectomized adult female rats on Days 5-7 post coitum induced changes characteristic of luteolysis. Ultrastructurally, the luteal cells exhibited an extensive vacuolization of the cytoplasm and perinuclear areas, degeneration of mitochondrial cristae, massive accumulation of lipid droplets, increase in number of lysosome like granules and heterochromatinization of the nucleus. In general, RU-38486 induced more marked degeneration of the luteal cells than did ZK-98734. There was also a significant decrease in peripheral plasma progesterone concentrations in treated rats. We suggest that these antiprogestagens act via inhibition of luteal function in addition to their antagonism at the uterine progesterone receptor level.

Animals↗
PubMed1987

Contraceptive and hormonal properties of a new 1,4-dihydro-2-oxoquinoline derivative (compound 84-182) in rodents and rhesus monkeys.

Compound 84-182 prevented pregnancy when administered subcutaneously at 10 mg/kg dose on days 3-8 post-coitum in hamsters and on days 6-10 post-coitum in guinea pigs. At lower doses, while in hamsters there was a marked reduction in implantation number, majority of implantations in guinea pigs showed signs of resorption. The compound was ineffective when administered at 10 mg/kg dose on days 1-3 or 6-7 post-coitum in hamsters and on days 1-5 or 4-8 post-coitum in rats. In rhesus monkeys, treatment with the compound at 5 and 10 mg/kg doses on days 16-21 of the menstrual cycle induced frank vaginal bleeding between days 21 and 24. Treatment on days 21-30 or after confirmation of pregnancy on days 32-36 was ineffective. In conventional bioassays, the compound was devoid of any estrogenic, antiestrogenic, progestational, antiprogestational, androgenic or antiandrogenic properties at the contraceptive dose. In competitive protein binding assay, the compound showed relative binding affinity (RBA) of less than 0.1% and 0.28% of progesterone, respectively, for rabbit and hamster uterine cytosol progesterone receptors. Its RBA for rat uterine cytosol estrogen receptors was less than 0.1% of estradiol-17 beta.

Animals↗
PubMed1987

Enhanced antifertility activity of non-steroidal molecules with 3-n-butylamino-2-hydroxypropyloxy side chain.

A comparative study of relative binding affinity (RBA) for estradiol-17 beta-receptors, estrogenicity and antifertility activity of compounds 2,2-dimethyl-3-phenyl-4-p-(3-n-butylamino-2-hydroxypropyloxy-pheny l)- 7-methoxycoumarin 4, 2,2-dimethyl-3-phenyl-4-p-(3-n-butylamino-2-hydroxy-propyloxyphenyl++ +)-7-methoxy chromene 5 and trans-2,2-dimethyl-3-phenyl-4-p-(3-n-butylamino-2-hydroxypropyloxyphe nyl)- 7-methoxychroman 6 with the corresponding 4-p-(beta-pyrrolidinoethoxyphenyl) compounds 1-3, is reported. It has been found that the introduction of the novel 3-n-butylamino-2-hydroxypropyloxy moiety in place of the classical tert-beta-aminoethoxy group leads to enhancement of antifertility activity.

Animals↗
PubMed1987

Anticholinergic-neuroleptic antagonism in terms of positive and negative symptoms of schizophrenia: implications for psychobiological subtyping.

In three studies of comparable design, 47 schizophrenics received anticholinergic anti-Parkinsonism (AP) medications for two to four weeks along the course of neuroleptic treatment. Clinical ratings during the AP phase were contrasted against the preceding and following two-week periods on neuroleptic alone, and these changes were analysed for a total of 27 psychopathology dimensions and for clusters of seven positive and seven negative symptoms. Schizophrenics overall exhibited significant exacerbation of total psychopathology, and positive but not negative symptoms. Only those with a predominantly positive syndrome when drug-free were susceptible to AP therapeutic reversal. However, other subgroup analyses revealed worsening of total psychopathology and positive symptoms among catatonic, schizophreniform, chronic, and good outcome cases, but negative symptoms alone were significantly increased among paranoids. The results were not supportive of a positive-negative dichotomy of schizophrenia, but instead suggested a tripartite model: a distinct paranoid group and a division of the non-paranoids into a positive and a negative type.

Adolescent↗
PubMed1987

Ethological study of facial behavior in nonparanoid and paranoid schizophrenic patients.

This investigation addressed the question of affective disturbance in schizophrenia by applying quantitative measurement techniques to patients' facial behavior. The subjects were medication-free male inpatients: nine nonparanoid and six paranoid schizophrenic patients and 12 drug- or alcohol-abuse rehabilitation control patients. Two judges scored the subjects' behavior, which was recorded on videotape, according to a system that included 16 different types of facial movements. Eye blinks, eye contact, and words spoken were also scored. Compared to the control patients, the nonparanoid schizophrenic patients spoke significantly fewer words and had significantly less eye contact, while the paranoid schizophrenic patients had significantly fewer eyebrow and lower facial movements.

Adult↗