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Biomedical subjects

S Mittal

Publications and source records attributed to S Mittal.

At least 127 records · Page 7Linked to original sources
PubMed1987

Clinical evaluation of steroid receptors in ovarian neoplasms.

Estrogen and progesterone receptors were estimated in a total of 25 ovarian neoplasms. None of the benign tumors showed steroid receptors. In malignant tumors serous tumors were more often receptor positive than the mucinous. Receptor levels were correlated with the staging of the disease, menstrual status and the resectability of the tumor. The response to chemotherapeutic drugs was better in patients with low estrogen and progesterone receptors as compared to those with high levels. The latter group showed a definite response to progesterone treatment in vitro. These are the group of patients who may benefit by combination of hormones and chemotherapeutic drugs.

Cystadenoma↗
PubMed1987

Ultrasound detection of antenatal meconium.

A new method for antenatal diagnosis of the presence of meconium in the amniotic cavity is reported. Ultrasonographic placental grading is a routine procedure in the monitoring of high-risk pregnancy. During serial scans of 58 patients, it was noted that in 11 cases placental grading was impossible after a certain period. At delivery, thick meconium was noted in all these cases.

Adult↗
PubMed1986

Oestrogenic and antioestrogenic actions in a series of triphenylbut-1-enes: modulation of prolactin synthesis in vitro.

The oestrogenic and antioestrogenic activities of a series of substituted derivatives of 1,1,2 triphenylbut-1-ene have been determined using primary cultures of rat pituitary gland cells to monitor prolactin synthesis in vitro. The relative binding affinity of the agonists for the oestrogen receptor was consistent with their oestrogenic potency. Bis para substitution at C1 of 1,1,2 triphenylbut-1-ene with either phenolic or acetoxy groups produced partial agonists. The antioestrogenic properties were reversible by the incubation of cells with increasing concentrations of oestradiol. The results lend support to a hypothetical single binding site model of oestrogen action, based upon an adaptation of Belleau's macromolecular perturbation theory.

Alkenes↗
PubMed1986

Management of translocated and incarcerated intrauterine contraceptive devices.

Thirty-seven consecutive patients who reported with absent or snapped strings and failed attempts at removal of intrauterine contraceptive devices (IUCD) by hooks or curette were posted for hysteroscopy/laparotomy following a plain X-ray of the pelvis to exclude unrecognized spontaneous expulsion. Direct visualization of the endometrial cavity was invaluable in locating and removing IUCDs, particularly the embedded and fragmented ones. Translocated medicated devices were associated with dense adhesions, suggesting the need for their prompt removal. There appears to be an increased risk of translocation in lactating women.

Adult↗
PubMed1986

Rearrangements and insertions in the Moloney murine leukemia virus long terminal repeat alter biological properties in vivo and in vitro.

The effects of rearrangement and insertion of sequences in the Moloney murine leukemia virus (M-MuLV) long terminal repeat (LTR) were investigated. The alterations were made by recombinant DNA manipulations on a plasmid subclone containing an M-MuLV LTR. Promoter activity of altered LTRs was measured by fusion to the bacterial chloramphenicol acetyltransferase gene, followed by transient expression assay in NIH 3T3 cells. M-MuLV proviral organizations containing the altered LTRs were also generated, and infectious virus was recovered by transfection. Infectivity of the resulting virus was quantified by XC plaque assay, and pathogenicity was determined by inoculating neonatal NIH Swiss mice. Inversion of sequences in the U3 region containing the tandemly repeated enhancer sequences (-150 to -353 base pairs [bp]) reduced promoter activity approximately fivefold in the transient-expression assays. Infectious virus containing the inverted sequences (Mo- M-MuLV) showed a 20-fold reduction in relative infectivity compared with wild-type M-MuLV, but the virus still induced thymus-derived lymphoblastic lymphoma or leukemia in mice, with essentially the same kinetics as for wild-type M-MuLV. We previously derived an M-MuLV which carried inserted enhancer sequences from the F101 strain of polyomavirus (Mo + PyF101 M-MuLV) and showed that this virus is nonleukemogenic. In Mo + PyF101 M-MuLV, the PyF101 sequences were inserted between the M-MuLV promoter and the M-MuLV enhancers (at -150 bp). A new LTR was generated in which the PyF101 sequences were inserted to the 5' side of the M-MuLV enhancers (at -353 bp, PyF101 + Mo M-MuLV). The PyF101 + Mo LTR exhibited promoter activity similar (40 to 50%) to that of wild-type M-MuLV, and infectious PyF101 + Mo M-MuLV had high infectivity on NIH 3T3 cells (50% of wild type). In contrast to the nonleukemogenic Mo + PyF101 M-MuLV, PyF101 + Mo M-MuLV induced leukemia with kinetics similar to that of wild-type M-MuLV. Thus, the position of the PyF101 sequences relative to the M-MuLV LTR affected the biological behavior of the molecular construct. Furthermore, PyF101 + Mo M-MuLV induced a different spectrum of neoplastic disease. In comparison with wild-type M-MuLV, which induces a characteristic thymus-derived lymphoblastic lymphoma with extremely high frequency, PyF101 + Mo M-MuLV was capable of inducing both acute myeloid leukemia or thymus-derived lymphoblastic lymphoma, or both. Tumor DNA from both the PyF101 + Mo- and Mo- M-MuLV-inoculated animals contained recombinant proviruses with LTRs that differed from the initially inoculated virus.

Animals↗
PubMed1986

Generation of infectious Moloney murine leukemia viruses with deletions in the U3 portion of the long terminal repeat.

Deletional analysis within the long terminal repeat (LTR) of Moloney murine leukemia virus (M-MuLV) was performed. By molecular cloning, deletions were made in the vicinity of the XbaI site at -150 base pairs (bp) in the U3 region, between the tandemly repeated enhancers and the TATA box. The effects of the deletions on LTR function were measured in two ways. First, deleted LTRs were fused to the bacterial chloramphenicol acetyltransferase gene and used in transient expression assays. Second, infectious M-MuLVs were generated by transfection of M-MuLV proviruses containing the deleted LTRs, and the relative infectivity of the mutant viruses was assessed by XC-syncytial assay. Most of the deleted LTRs examined showed relatively high promoter activity in the transient chloramphenicol acetyltransferase assays, with values ranging from 20 to 50% of the wild-type M-MuLV LTR. Thus, the sequences between the enhancers and the TATA box were not absolutely required for transient expression. However, infectivity of viruses carrying the same deleted LTRs showed more pronounced effects. Deletion of sequences from -195 to -174 bp reduced infectivity 20- to 100-fold. Deletion of sequences within the region from -174 to -122 bp did not affect infectivity, indicating that this region is dispensable. On the other hand, deletion of sequences from -150 to -40 bp reduced infectivity from 5 to 6 logs, although the magnitude of the reduction partly may have reflected threshold envelope protein requirements for positive XC assays. The reduced infectivity did not appear to result from a failure of proviral DNA synthesis or integration by the mutant. Thus, the infectivity measurements identified three functional domains in the region between the enhancers and the TATA box.

Animals↗
PubMed1985

Uterine perforation following medical termination of pregnancy by vacuum aspiration.

Out of 9344 first trimester elective abortions performed by vacuum aspiration, 37 uterine perforation cases occurred. The suction cannula was responsible for more than 50% of perforations. All cases were multiparous. In 56.8%, the duration of gestation was 6 weeks or less. One third of the cases had a history of child birth within the previous 6 months. Fundal and anterior wall perforations were most common. Cases with a retroverted uterus had a higher incidence of perforation (59.4%) than those with an anteverted uterus (32.4%). Exact pelvic assessment and proper technique and case management are important for preventing perforation.

Abortion, Induced↗
PubMed1985

Structure-activity relationship of estrogens: receptor affinity and estrogen antagonist activity of certain (E)- and (Z)-1,2,3-triaryl-2-propen-1-ones.

(E)- and (Z)-1,2,3-triphenyl-2-propen-1-ones and some of their phenolic and alkoxy analogues, substituted at the para position in one or more of the aromatic rings, were synthesized and assigned geometry on the basis of their spectroscopic data. The structure-activity relationship of the triarylpropenones was studied from the point of view of their estrogen receptor affinity and estrogen agonist and antagonist activities. (E)- as well as (Z)-propenones were found to compete with estradiol for binding with the mouse uterine cytosol receptors, with phenolic analogues usually more potent than the unsubstituted as well as alkoxypropenones. The (E)-propenones, which have now emerged as a new group of estrogen receptor ligands, were found to differ from Z isomers quite markedly in their binding specificities. The uterotrophic and antiuterotrophic assays in immature mice revealed that while some of the compounds were marginally estrogenic, nearly all the isomeric propenones were antiestrogenic to a varying degree.

Animals↗
PubMed1985

Culdocentesis in tubal pregnancy.

Culdocentesis was carried out in 92 suspected cases of ectopic pregnancy and was positive in 90%. Laparotomy confirmed the accuracy of culdocentesis in 97.5% of the cases of acute tubal rupture, 87.5% of tubal abortions and 80% of 'intact' tubal pregnancies.

Female↗
PubMed1985

Structure-activity relationships of estrogens.

The last 50 years has seen an exponential rise in the published reports about estrogen action. The model to describe the early events in the mechanism of action of estrogens via the estrogen receptor is updated in this paper to incorporate some of the recent data on the subcellular localization of the receptor. New evidence suggests that the receptor is a nuclear protein, so it appears that estrogens must first diffuse into the nuclear compartment to initiate estrogen action via the receptor complex. This review traces the development of potent estrogenic compounds by the study of their structure-activity relationships. Studies of structure-activity relationships in vivo using Allen Doisy or 3-day uterine weight tests can provide much valuable information, but the assays suffer from the complex problems of pharmacokinetics and metabolic transformation. Studies in vitro using primary cultures of rat pituitary or uterine cells to assay the ability of a compound to induce prolactin synthesis or progesterone receptor synthesis, respectively, can provide essential information about the structural requirements for a compound to produce estrogenic effects. Nevertheless, it should be pointed out that studies in vivo are required to determine whether a compound is metabolically activated to an estrogen. Estrogen receptor binding models are presented to describe the changes in a molecule that will predict high affinity for the ligand and agonist, partial agonist and antagonist properties of the ligand-receptor complex. Most estrogenic pesticides and phytoestrogens comform to the predictions of the estrogen receptor binding model.

Animals↗
PubMed1980

Conceptual representation of patient data bases.

Design of a computer-based assistant for patient data bases is discussed. A conceptual model for such an assistant, which can represent signs, symptoms, lab data, and radiological and morphological findings is described. The query language, interpretive reports, summary findings, and related issues in providing intelligent consultation are discussed. The role of such assistants in the context of a decision-making environment--human or automated--is emphasized.

Cholestasis↗