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Biomedical subjects

T A Klein

Publications and source records attributed to T A Klein.

At least 55 records · Page 3Linked to original sources
PubMed1988

Modulation of hepatic cholesterol metabolism by ethinyl estradiol and norgestrel.

Previous investigators reported that certain combination oral contraceptives are associated with significant alterations in serum lipid concentrations, namely a decrease in high density lipoprotein and increase in low density lipoprotein fractions. The mechanism(s) responsible for these changes remain unclear. In the present study we sought to determine the effect of the oral contraceptive components, ethinyl estradiol (EE) and norgestrel (N) on hepatic cholesterol metabolism, specifically on 3-hydroxy-3-methylglutaryl coenzyme A (HMG) reductase. Forty-eight cycling female Sprague-Dawley rats were divided into six groups and treated daily with either 0.1 mg or 1.0 mg EE daily, 1.0 mg or 10.0 mg N daily, or 0.1/1.0 mg or 1.0/10.0 mg EE/N in combination daily. Twelve age- and weight-matched animals served as controls. No significant changes in hepatic HMG reductase activity were observed between those groups treated with either EE or N alone and the control group. However, hepatic HMG reductase activity was increased significantly in both EE/N combination-treated groups when compared to controls, the EE-treated groups and the N-treated groups. These results are suggestive that the changes in serum lipids noted clinically in association with oral contraceptive use may be related to the induction specifically of hepatic HMG reductase activity and subsequent changes in cellular cholesterol synthesis or metabolism.

Animals↗
PubMed1988

Natural killer cell activity and serum autoantibodies in women with postpartum thyroiditis.

Postpartum thyroiditis (PPT) is a form of painless lymphocytic thyroiditis which is thought to be caused by an exacerbation of underlying subclinical autoimmune thyroid disease during a postpartum period of immune rebound. The purposes of this study were to analyze natural killer cell (NK) functional activity and antibody-dependent cell-mediated cytotoxicity (ADCC) of peripheral blood mononuclear cells in patients with PPT compared to those in normal nonpostpartum and postpartum women. NK activity and ADCC were determined by specific lysis of 51Cr-labeled K562 human erythroleukemia tumor cells at varying effector (mononuclear cell) to target cell ratios. Nineteen PPT patients between 4-9 months [mean, 6.5 +/- 0.4 (+/- SE)] postpartum were compared to 20 nonpostpartum women, 31 healthy women between 4-9 months (6.7 +/- 0.3) postpartum, and 14 women 2 days after delivery. There were significant differences in the NK functional activities of the 4 groups (F = 7.95; P = 0.0002). The mean NK activities, as measured by percent specific lysis at an effector to target cell ratio of 10:1, were 31.1 +/- 3.3%, 20.9 +/- 2.3%, 22.5 +/- 2.8%, and 11.5 +/- 2.0% in the nonpostpartum, PPT, postpartum, and 2-day postpartum groups, respectively. Specific lysis by ADCC was not significantly different from lysis by NK activity in any group. The PPT, postpartum, and 2-day postpartum groups had significantly lower NK activity compared to that in nonpostpartum women (P less than 0.05). Both the PPT and postpartum women had higher NK activities than the 2-day postpartum women (P less than 0.05). However, there were no significant differences in the NK activities of the PPT patients compared to those of the healthy postpartum women. Patients with PPT were also found to have associated autoimmune dysfunction. The PPT group had significantly higher serum antinuclear antibody titers; 8 of 24 patients (33%) had titers of 1:160 or greater compared to only 2 of 29 healthy postpartum women (7.4%; P less than 0.05). Seven of the PPT patients had serum immune complexes, and 3 had TSH receptor antibodies. We conclude that functional NK activity and ADCC in peripheral lymphocytes of PPT patients are not different from those in healthy postpartum women; however, the postpartum women had significantly decreased activity compared to that in nonpostpartum women. These data emphasize the importance of studying healthy postpartum women in investigations of PPT, since the immunological changes in pregnancy and the postpartum period remain largely undefined.

Adult↗
PubMed1987

Histology of proximal tubal occlusion.

From 1979 to 1985, 18 patients who were found to have proximal tubal obstruction by hysterosalpingography and laparoscopic chromopertubation underwent resection of the obstructed tubal segment and reimplantation or microanastomosis. Resected tubal segments were studied histologically, and in 11 of the 18 cases no tubal occlusion could be demonstrated. A variety of histologic abnormalities were noted, however, including six cases in which the tubal lumen contained an amorphous material of unknown etiology, often appearing to form a cast of the tube. Such "plugs," which the authors believe to be previously unreported, have no clearly established clinical significance at present. However, if they cause tubal occlusion, this would explain several previously published findings, and would also have implications for therapy.

Adult↗
PubMed1987

The role of laparoscopy in the evaluation of candidates for sterilization reversal.

An algorithm that avoids preliminary laparoscopy for sterilization reversal (SR) candidates with previous Pomeroy, loop, Hulka clip, Irving, and single-burn cautery tubal ligation techniques was used. Anastomosis was attempted only when it could be anticipated that the final length of at least one tube would be 3 cm or more. Of 259 SR candidates evaluated according to the algorithm, 235 had SR procedures. Seven of 185 patients (3.8%) who did not undergo laparoscopy were found to have inoperable tubes at laparotomy. Four of these patients had histories of a prior unilateral salpingectomy. The authors conclude that, given their criteria for proceeding with tubal anastomosis, laparoscopy can be avoided in properly selected SR candidates. The results also indicate that patients with a history of unilateral salpingectomy should undergo preliminary laparoscopy.

Fallopian Tubes↗
PubMed1987

Experimental transmission of Plasmodium mexicanum by bites of infected Lutzomyia vexator (Diptera: Psychodidae).

Lutzomyia vexator is an efficient experimental vector of Plasmodium mexicanum, infecting 69.2% (9/13) of the Sceloporus undulatus lizards with as few as one bite. Sporozoites were present in the salivary glands by day 6.5 postfeed and infective by day 8 postfeed at 27 degrees C. The prepatent period was relatively long, ranging from 23 to 40 days for bite-induced infections and appears to be related to the number of sporozoites injected. The acute phase of the infection is initially exponential and rapid. All lizards (6) that were not sacrificed, died of fulminating infections from 13 to 56 days after parasites were seen in the blood films. Gametocytes from 2 experimentally infected lizards were infective to L. vexator during the course of the acute infection. The majority of P. mexicanum parasites were in erythrocytes of Sc. undulatus. Exoerythrocytic forms were observed in circulating lymphocytes and thrombocytes, lymphocytes of spleen and bone marrow, and endothelial cells of brain capillaries.

Animals↗
PubMed1987

Vector incrimination and experimental transmission of Plasmodium floridense by bites of infected Culex (Melanoconion) erraticus.

A survey of mosquitoes which are attracted to and readily feed upon lizards in a northcentral Florida area where there is a relatively high prevalence of Plasmodium floridense in Anolis carolinensis was conducted. Culex erraticus and Cx. territans, collected in lizard-baited traps, readily fed on lizards in the traps and in the laboratory, and the former mosquito species is an experimental vector of Plasmodium floridense. Sporozoites were observed in the salivary glands from 11 to 14 days at 21-25 degrees C following an infective blood meal. The prepatent period of P. floridense in A. carolinensis at 18-24 degrees C was relatively long, 24-25 days (n = 2). At 32 degrees C, the prepatent period was decreased to 13-17 days (n = 4). The transmission rate of P. floridense by bite of Cx. erraticus and intraperitoneal inoculation of sporozoites from the salivary glands of Cx. erraticus, was relatively low (16.2%). Peak parasitemias ranged from 912 to 4,280 parasites per 10,000 red blood cells. Sporogonic development of P. floridense in Cx. territans which fed on infected lizards was not observed.

Animals↗
PubMed1986

Correlation of survival rates of Anopheles dirus A (Diptera: Culicidae) with different infection densities of Plasmodium cynomolgi.

The survival rates are described for 36 paired replicates of Anopheles dirus A mosquitos that had been allowed to engorge themselves on rhesus monkeys that were either infected or non-infected with Plasmodium cynomolgi. The survival rates of infected mosquitos with a mean number of oocysts less than 10 did not differ significantly from those that were non-infected; however, there was a significant difference in the survival rates of non-infected groups and those with a mean number of oocysts in the range 10-40, 41-70, or >/=71.Daily survival rates for non-infected and infected mosquitos did not differ significantly during the first 8 days of extrinsic incubation. In contrast, for the period 9-30 days the survival rates of mosquitos with mean number of oocysts >/=41 were significantly different from those of non-infected mosquitos. The cumulative daily survival rates of mosquitos with mean number of oocysts up to 40, 41-70, or >/=71 decreased with the oocyst count. Mosquitos with a mean number of oocysts >/=71 frequently exhibited excessive numbers of bacteria and deterioration of both their guts and salivary glands.

Animals↗
PubMed1978

Transitory hCG-like activity in the urine of some IUD users.

Using an antiserum (H-93) specific to the COOH-terminal peptide of hCG beta and gel chromatography, we found the transitory (1-2 days) presence of a gonadotropin having immunological, biological, and physical similarity to hCG, but not typical hLH, in the late luteal phase (days 24-29) urine of some (5 of 26) IUD users. We did not detect hCG in sera from any of the women. Although the source of the hCG-like gonadotropin is unknown, the data suggest that late luteal phase implantation may have occurred transiently.

Adult↗
PubMed1977

Absence of circulating chorionic gonadotropin in wearers of intrauterine contraceptive devices.

Daily measurements of human chorionic gonadotropin (HCG) beta subunit, luteinizing hormone (LH), and progesterone were carried out in 24 subjects wearing intrauterine contraceptive devices. Detectable HCG was not found in any subject, but in four subjects delayed LH pulses resulted in apparent low levels of HCG because of cross-reactivity in the HCG beta subunit radioimmunoassay.

Adult↗
PubMed1977

Gonadotropin, prolactin, and steroid hormone levels after discontinuation of oral contraceptives.

Serum levels of LSH, LH, estradiol, progesterone, and prolactin were measured daily for 2 months in six women after discontinuation of combination oral contraceptives. The initial LH peak occurred from 21 to 28 days after ingestion of the last tablet. Apart from variable prolongation of the follicular phase in the first postcontraceptive cycle, the patterns and levels of all hormones were indistinguishable from those found in normal ovulatory subjects. These results indicate that after a variable brief interval following discontinuation of oral contraceptive steroids, their suppressive effect on the hypothalamic-pituitary-ovarian axis disappears. This initial recovery results in completely normal endocrine function.

Adult↗
PubMed1977

Diagnosis of pregnancy with a radioreceptor assay for hCG.

A new serum assay for human chorionic gonadotropin, the radioreceptor assay (RRA), was compared with three commercial urinary agglutination inhibition pregnancy tests (AITs) in a group of women with suspected early pregnancies and ectopic gestations. The accepted definitions by which a laboratory test is characterized, including clinical sensitivity and specificity as well as predictive value of positive and negative tests and efficiency, were calculated for each test in three different time periods of gestation: less than 7 days, between 7 and 14 days, or more than 14 days after the expected menses had been missed. The results of the study showed that the RRA had greater clinical sensitivity and efficiency than the AITs in cases of both early gestation and ectopic pregnancy. The RRA has the disadvantages of requiring the capability to handle radioactive materials and gamma counter. This test is chiefly useful for those patients desiring early termination of pregnancy and those infertility patients anxious for early confirmation of pregnancy.

Chorionic Gonadotropin↗
PubMed1976

Pelvic tuberculosis.

Pelvic tuberculosis (TBC) was diagnosed in 20 patients studied during the years 1971 to 1975. Fourteen patients were born outside the United States. The most frequent presenting complaints were infertility (14 patients), pelvic pain (6), and amenorrhea (4). Only 5 patients gave a history of previous treatment for TBC. Results of pelvic examination were normal in 11 patients; results of chest X-rays were normal in 15. Sixteen patients had endometrial biopsies, 10 of which showed granulomatous endometritis. Fifteen patients had hysterosalpingograms, all of which yielded abnormal results, and 14 were indicative of TBC. Cultures were positive for Mycobacterium tuberculosis in 6 of 16 patients. Genital TBC should be considered as a possible cause of infertility, especially in foreign-born patients. Although a conclusive diagnosis can be made only from a positive culture or histologic specimen, hysterosalpingography is a very useful aid in establishing the diagnosis.

Adolescent↗