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Biomedical subjects

T A Klein

Publications and source records attributed to T A Klein.

At least 19 recordsLinked to original sources
PubMed1992

Natural killer cell activity from pregnant subjects is modulated by RU 486.

Natural killer cells form an integral component of the body's innate immune system. Natural killer cell activity is reduced during pregnancy, especially in the latter half. To investigate the role progesterone may play in immunomodulating natural killer cell activity during pregnancy, we evaluated the effect of RU 486 on natural killer cells isolated from pregnant subjects. Natural killer cell activity was measured with an 18-hour, Chromium 51 release, microcytotoxicity assay with K-562 cells as target cells. We demonstrated that RU 486, in a concentration range from 5 to 40 mumol/L, augmented natural killer activity threefold to fivefold over baseline. This augmentation of activity was suppressed to baseline by the addition of excess progesterone. The addition of hydrocortisone resulted in an insignificant reduction in this augmented activity. This study suggests that progesterone may play a role as an immunomodulating factor in maternal acceptance of the fetal allograft.

Adolescent↗
PubMed1992

Vector incrimination and effects of antimalarial drugs on malaria transmission and control in the Amazon basin of Brazil.

World ecosystems differ significantly and a multidisciplinary malaria control approach must be adjusted to meet these requirements. These include a comprehensive understanding of the malaria vectors, their behavior, seasonal distribution and abundance, susceptibility to insecticides (physiological and behavioral), methods to reduce the numbers of human gametocyte carriers through effective health care systems and antimalarial drug treatment, urban malaria transmission versus rural or forest malaria transmission, and the impact of vaccine development. Many malaria vectors are members of species complexes and individual relationships to malaria transmission, seasonal distribution, biting behavior, etc. is poorly understood. Additionally, malaria patients are not examined for circulating gametocytes and both falciparum and vivax malaria patients may be highly infective to mosquitoes after treatment with currently used antimalarial drugs. Studies on the physiological and behavioral effects of DDT and other insecticides are inconclusive and need to be evaluated.

Animals↗
PubMed1991

Comparative susceptibility of anopheline mosquitoes to Plasmodium falciparum in Rondonia, Brazil.

Five anopheline species, Anopheles deaneorum, An. albitarsis, An. triannulatus, An. oswaldoi, and An. mediopunctatus were compared to An. darlingi for susceptibility to infection by P. falciparum in Costa Marques, Rondonia, Brazil. Laboratory reared F1 An. darlingi and anopheline test species were allowed to feed at the same time on falciparum malaria patients who had gametocytes in their blood, and who had not yet been treated with quinine. Mosquitoes were dissected and examined for oocysts on day 9, and for sporozoites on days 16-20 after feeding. Anopheles mediopunctatus had higher mean numbers of oocysts and oocyst positive rates than An. darlingi. The oocyst positive rate and the mean number of oocysts in An. deaneorum and An. darlingi were similar. Anopheles triannulatus and An. oswaldoi had fewer oocysts than An. darlingi. The salivary gland sporozoite infection rate was similar for An. mediopunctatus and An. deaneorum and much lower for An. triannulatus and An. oswaldoi when compared to An. darlingi. Anopheles albitarsis developed oocysts, but sporozoites did not invade the salivary glands. In relative levels of susceptibility to P. falciparum, An. darlingi was equal to An. mediopunctatus which was greater than An. deaneorum, which was greater than An. triannulatus, which was greater than An. oswaldoi.

Animals↗
PubMed1991

Infection of Anopheles darlingi fed on patients with Plasmodium falciparum before and after treatment with quinine or quinine plus tetracycline.

Anopheles darlingi fed on eight falciparum malaria patients with gametocytes before and after treatment with quinine sulfate or quinine sulfate plus tetracycline became infected. Quinine and quinine plus tetracycline had no apparent sporontocidal or gametocytocidal effect on late stage immature and mature gametocytes. Plasmodium falciparum gametocytes are persistent and infected mosquitoes for up to 21 days after patients were treated with quinine plus tetracycline. Sporogonic development was similar for groups of mosquitoes fed before and after patients were treated with these schizontocides. The percentages of infected mosquitoes that developed salivary gland infections were also similar for groups of mosquitoes fed before and after treatment. Twenty-four hours after treatment with 45 mg of primaquine phosphate, falciparum malaria patients were not infective to An. darlingi.

Animals↗
PubMed1991

Comparative susceptibility of anopheline mosquitoes in Rondonia, Brazil to infection by Plasmodium vivax.

Seven anopheline species from Costa Marques, Rondonia, Brazil were compared with Anopheles darlingi for susceptibility to infection by Plasmodium vivax. Laboratory-reared F1 progeny of field-collected An. darlingi and the test anopheline species were fed at the same time on the same patients, all of whom had gametocytes in peripheral blood before treatment. Mosquitoes were dissected on day 8 after infection for oocysts and on days 14-16 after infection for sporozoites. The mean numbers of P. vivax oocysts and the percent of salivary gland infections for An. darlingi and An. deaneorum were similar and far exceeded those found in the other anopheline species tested. Anopheles albitarsis and An. mediopunctatus were less susceptible to infection by oocyst measurements than An. darlingi. However, for oocyst-infected An. albitarsis and An. mediopunctatus, the percent of mosquitoes with salivary gland infections and the numbers of sporozoites in the salivary glands were similar to An. darlingi. Anopheles triannulatus and An. oswaldoi were both susceptible to P. vivax infection, but the sporozoite infection rates and the numbers of sporozoites observed in the salivary glands were very low. Anopheles braziliensis and An. benarrochi both developed oocysts, but were never observed to have sporozoites in the salivary glands. These studies implicate some anopheline species as potential malaria vectors, but also show that species previously incriminated by ELISA techniques are not vectors of malaria parasites in Costa Marques, Rondonia, Brazil.

Animals↗
PubMed1991

Infection of Anopheles darlingi fed on patients infected with Plasmodium vivax before and during treatment with chloroquine in Costa Marques, Rondonia, Brazil.

Patients with asexual and sexual parasites of Plasmodium vivax were treated orally with 600 mg of chloroquine diphosphate at hour zero, followed by 300 mg at 8, 24 and 48 hr. Anopheles darlingi were fed before the first dose (-0.5 hr) and at 0.5, 1, 2, 4, 6, 8, 9, 10, 11, 12, 20, 24, 36, 48, 60, and 72 hr later. Mosquitoes were examined for oocysts on day 8 and sporozoites on day 15 after infection. The frequency of infected mosquitoes and the mean number of oocysts were lower in mosquitoes that fed on patients 2-4 hr after the initial dose of chloroquine than in mosquitoes fed before treatment and at 0.5 and 1 hr. This sporontocidal effect was temporary, since the frequency of infected mosquitoes and the mean number of oocysts increased in mosquitoes fed 4-8 hr after the first dose. Nearly all mosquitoes fed on patients after the third dose of chloroquine, at 24 hr, were negative for P. vivax oocysts. Oocysts in mosquitoes fed on patients before, during, and after chloroquine treatment appeared normal and produced sporozoites. We conclude that chloroquine affects either the gametocytes, fertilization, zygotes, and/or ookinetes of P. vivax, but not subsequent stages of development.

Animals↗
PubMed1991

Comparative susceptibility of Southeast Asian Anopheles mosquitoes to the simian malaria parasite Plasmodium cynomolgi.

Seven Anopheles species/isolates were compared with Anopheles dirus (control) for susceptibility to Plasmodium cynomolgi B strain. The mean numbers of oocysts in paired replicates of An. dirus and An. takasagoensis were not significantly different. The remaining test species had significantly fewer mean numbers of oocysts than Anopheles dirus (P less than 0.01). Anopheles dirus had the highest percentage of mosquitoes infected with P. cynomolgi sporozoites (82%). Of the test groups, Anopheles dirus B and An. takasagoensis had the highest percentage of mosquitoes with sporozoites, 77 and 78%, respectively. Fewer than 50% of Anopheles maculatus E and An. maculatus B (NN isolate) had sporozoites in the salivary glands. Anopheles maculatus B (HK isolate) and Anopheles philippinensis were the least susceptible, with fewer than 30% having sporozoites in the salivary glands.

Animals↗
PubMed1990

Seasonal distribution and biting patterns of Anopheles mosquitoes in Costa Marques, Rondonia, Brazil.

Thirteen species of anopheline mosquitoes were collected in all-night human-bait indoor and outdoor collections at 5 houses from July 1986 through December 1987 in and near the town of Costa Marques, Rondonia, Brazil. Anopheles darlingi and An. deaneorum accounted for more than 92 and 6%, respectively, of all anophelines collected from human-bait outside houses and 90 and 9%, respectively, inside houses in the town. The diversity of anophelines was greater in human-bait collections in rural areas. However, An. darlingi still accounted for more than 90% of all the anophelines collected from human-bait inside and outside rural houses. Data on nocturnal and seasonal biting rhythms for the more common anophelines are given.

Animals↗
PubMed1990

Tubal and peritoneal factors in the infertile woman: use of patient history in selection of diagnostic and therapeutic surgical procedures.

For facilities with both ambulatory and inpatient surgical capabilities, we have attempted to develop an efficient strategy for the evaluation of infertile women. The strategy was intended to (1) avoid inpatient laparoscopy, (2) minimize the number of patients having laparoscopy who subsequently required laparotomy, and (3) minimize hysterosalpingography (HSG). Patients were selected for ambulatory laparoscopy or inpatient laparotomy by means of an algorithm based on their history and the selective use of HSG. Laparoscopy was avoided in 18.1% of patients and HSG in 41.6% of patients. We conclude that, when both inpatient and outpatient surgical facilities are available, the evaluation of female infertility may not always require HSG or laparoscopy.

Algorithms↗
PubMed1990

Colonization and maintenance of Anopheles deaneorum in Brazil.

Anopheles deaneorum, an important malaria vector and a member of the Anopheles albitarsis complex, was colonized by an artificial mating technique. Morphological and behavioral differences between An. deaneorum and An. albitarsis from Costa Marques, Rondonia, Brazil, are discussed. The essential methods and colonization techniques are described. Immature development and mortality rates were reduced when dried grass was added to larval rearing pans. Males frequently mate more than once using the force mating technique. However, insemination and larval eclosion rates decline as males are successively mated with unmated females.

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↗
PubMedDate not supplied

Biting behavior of Anopheles mosquitoes in Costa Marques, Rondonia, Brazil.

Mosquito collections were made in and near Costa Marques, Rondonia, Brazil, to determine anopheline anthropophilic/zoophilic behavior. Collections from a non-illuminated, bovine-baited trap and indoor and outdoor human-bait collections were compared. Anopheles darlingi and Anopheles deaneorum were more anthropophilic than the other anophelines collected. The remainder of the Anopheles species were collected much more frequently in bovine-baited traps than in human-bait collections. Anopheles darlingi and An. deaneorum were more frequently collected inside houses than the other anopheline species. But, when collections were made in a house with numerous openings in the walls, there were few differences in the percentages of each species biting man indoors versus outdoors. Anopheles darlingi was the predominant mosquito collected, both inside and outside houses, and had the strongest anthropophilic feeding behavior of the anophelines present.

Animals↗