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Biomedical subjects

D Kleinman

Publications and source records attributed to D Kleinman.

At least 19 recordsLinked to original sources
PubMed1990

The use of heuristic strategies in the interpretation of pronouns.

The aim of the two experiments reported here was to distinguish between two heuristic strategies that have been proposed to account for the assignment of pronouns: the subject assignment strategy and the parallel function strategy. According to the subject assignment strategy, a pronoun is assigned to a preceding subject noun phrase, whereas according to the parallel function strategy, a pronoun is assigned to a previous noun phrase in the same grammatical position as the pronoun. These two strategies were tested by examining the interpretation of single object pronouns, first in a reading task and second in an assignment task. In both experiments, there was a strong preference for assigning an object pronoun to the preceding subject noun phrase, thus supporting the subject assignment strategy. However, this was only the case for pronouns that were linguistically ambiguous. When assignment was constrained by gender, there was no effect of either strategy. It is suggested that heuristic strategies are only used in the absence of other strong cues to assignment.

Attention↗
PubMed1990

Role of midcycle FSH surge in follicular development.

The present study was undertaken to examine the importance of the proestrous surge of FSH for follicular development during the following cycles in the rat. The midcycle FSH surges were blocked in several consecutive cycles (1-5) by injecting proestrous rats with pentobarbital. The rats were sacrificed on the day of proestrus following the appropriate number of blocked FSH surges and their ovaries were removed for either direct measurements or for histological workout. The number and diameter of follicles were determined in the excised ovaries. Two or three cycles of barbiturate treatment reduced the number and diameter of the follicles. No large follicles (greater than 0.4 mm) were observed in the ovaries of rats in which four or five gonadotropin surges were blocked. A repeat experiment with concomitant supplementary hCG administration yielded the same results. Addition of exogenous FSH canceled the effect of pentobarbital. The cohort observed on ovaries after four cycles of treatment with pentobarbital and FSH resembled that observed in control rats. Histological measurements supported the results obtained with fresh ovaries. It is therefore suggested that in the third cycle preceding the ovulatory one, the midcycle FSH surge determines which follicles will be able to adequately develop in the following three cycles. In the cycle preceding the ovulatory one, the midcycle FSH peak 'rescues' a group of follicles and prepares them for a proper response to the FSH elevation taking place at the beginning of the subsequent ovulatory cycle. This process allows the selection of the dominant follicles which will respond by ovulation to the ensuing LH peak.

Animals↗
PubMed1989

Inhibition of Chlamydia trachomatis growth in endometrial cells by copper: possible relevance for the use of the copper IUD.

There is agreement that the relative risk of developing pelvic inflammatory disease (PID) increases among women who use the intrauterine contraceptive device (IUD). The role of Chlamydia in causing PID among IUD users is not clear. The present study demonstrates that Chlamydia trachomatis growth can be inhibited in cultured human endometrial cells by copper ions at concentrations known to be released by the copper IUDs. More than 98% inhibition was produced with 10(-5) and 10(-6) M of copper. Both C. trachomatis serovar E and a lymphogranuloma venereum Chlamydia serovar L2 (LGV) were inhibited by the copper ions. Although the mechanism of the inhibition is not known, the continuous presence of the copper ions during and after adherence appeared to be necessary for maximal effect. If such inhibition occurs in vivo, it is possible that copper ions released from the copper-containing IUD may partially protect against chlamydial infection.

Cells, Cultured↗
PubMed1989

Thromboembolization complicating left ventricular pseudoaneurysm: serial two-dimensional and color-flow Doppler echocardiographic observations.

A left ventricular pseudoaneurysm was diagnosed by two-dimensional echocardiography and color-flow Doppler imaging, and confirmed by computerized tomography and angiocardiography, in a man with known coronary disease who had had recent recurrent systemic emboli. A thrombus within the pseudoaneurysm was visualized, and its disappearance on serial echocardiograms coincided with the occurrence of embolization to the aortic bifurcation.

Aged↗
PubMed1988

Results of in vitro fertilization in women with antisperm antibodies in serum, cervical mucus, and follicular fluid.

This study was undertaken to investigate the presence of antisperm antibodies (ASA) in serum, cervical mucus, and follicular fluid (FF) of women undergoing in vitro fertilization and embryo transfer (IVF-ET). IgG and IgA ASA directed mostly against sperm head were found at similar concentrations in serum, cervical mucus, and FF of 2 of 34 patients. Ninety-one percent fertilization and 100% cleavage rates, respectively, were observed in one of the two patients. No fertilization occurred in the second patient. In both women, in vitro sperm penetration tests revealed hostile mucus and repeated postcoital tests were poor. It is concluded that the sperm-cervical mucus penetration test and mucus ASA measurements are useful in establishing the diagnosis of immunological infertility.

Adult↗
PubMed1987

Acid phosphatase levels in follicular fluids following induction of ovulation in in vitro fertilization patients.

Considerable evidence indicates that changes in acid phosphatase (AP) activity at the ovarian level play a role in the process of ovulation. In this study the concentrations of AP were determined in follicular fluids collected from follicles of 52 women at the time of laparoscopy performed in connection with an in vitro fertilization program. In each of the 52 women at least one ovum was harvested. Of the 52 ova, 28 cleaved in vitro, while in 24 ova cleavage was not seen. Levels of AP in follicular fluids of women whose ova did not cleave were significantly lower than those found in follicular fluids of women with at least one ovum undergoing cleavage: 0.45 +/- 0.14 (SE) and 4.78 +/- 0.37 Bess Lowry Units (BLU), respectively. Comparison of AP levels in follicular fluids of women who conceived (5) and women whose ova cleaved, but in whom pregnancy was not achieved (23), did not reveal significant differences: 5.87 +/- 1.29 and 4.55 +/- 0.35 BLU, respectively. Moreover, the enzyme level was typical for a woman and not for a follicle. Fluids of two different follicles of the same woman, when one ovum cleaved and one did not, showed similar AP levels. AP levels were high in all samples follicles of women in whom at least one ovum cleaved. These findings indicate that the presence of certain levels of acid phosphatase represents an important, albeit not the sole, condition for ovum maturation. Moreover, the follicular fluid levels of AP could serve as an indicator of proper timing of the follicular puncture in relation to the human chorionic gonadotropin injection (or the luteinizing hormone peak).

Acid Phosphatase↗
PubMed1987

The effects of contraceptive hormones on the replication of Chlamydia trachomatis in human endometrial cells.

Several recent reports have documented a lower incidence of pelvic inflammatory disease (PID) among oral contraceptive users. The interpretation of this observation is difficult because the action of the contraceptive hormones may be directly by action on a specific host cell-parasite relationship, or indirectly via their action on other systems. In the present study we investigated the susceptibility of cultured human epithelial cells of the endometrium to infection by chlamydia and the influence of contraceptive steroids (ethinyl estradiol, mestranol and medroxyprogesterone acetate) upon replication of chlamydia in these cells. Forty-eight hours post-infection, elementary and reticulate bodies were observed in vacuoles of the infected endometrial cells by electron microscopy. Treatment of chlamydial-infected cells with contraceptive steroids in three different concentrations (10(-5)M, 10(-6)M and 10(-7)M) resulted in no effect on chlamydial replication, as examined by one-step growth curve. These results indicate that contraceptive hormones do not prevent chlamydial infection by direct effect on the replication of the agent.

Chlamydia Infections↗
PubMed1986

Reactivation of cytomegalovirus in endometrial cells by estradiol.

The present study uses an in vitro model to test the influence of hormones on the replication and reactivation of cytomegalovirus (CMV) in endometrial tissue culture. Infection of epithelial cells of the endometrium with CMV in the presence of a high concentration of estradiol resulted in only a slightly higher yield of infectious virus. Progesterone did not cause any effect on viral replication. Arrest of CMV replication was achieved by reduction of the pH of the incubation medium. No infectious virus was detectable after incubation of infected cultures at pH 5.8. In the above-described conditions following the arrest of CMV replication by low pH, estradiol treatment was capable of reactivating the virus. The possibility that the increase in CMV infection observed in pregnancy is caused by reactivation of latent virus provoked by hormonal factors will be discussed.

Cytomegalovirus↗
PubMed1985

Serum IgG and IgA antibodies specific for Chlamydia trachomatis in salpingitis patients as determined by the immunoperoxidase assay.

The feasibility of applying elevated Chlamydia trachomatis specific IgG antibody and serum IgA antibodies as a non-invasive screening test for C. trachomatis associated salpingitis was analysed in 54 salpingitis patients and 294 apparently healthy women by the single antigen (L2) immunoperoxidase assay (IPA). The prevalence rate of C. trachomatis IgG antibody (titre greater than or equal to 64) was significantly higher in the salpingitis patients in comparison to control (67% versus 23%). The prevalence rate of elevated C. trachomatis IgG titres (greater than or equal to 128, greater than or equal to 256 and greater than or equal to 512) was significantly higher in the salpingitis patients as compared to the controls. For example, at an IgG titre of greater than or equal to 128 the prevalence rate was 57% in the salpingitis patients and 8% in the healthy controls (p less than 0.0001). The prevalence of C. trachomatis IgA antibodies (titre greater than or equal to 16) was significantly higher in salpingitis patients in comparison to controls (37% versus 4%). The prevalence of elevated IgA titres (greater than or equal to 32 and greater than or equal to 64) was found to be significantly higher in salpingitis patients as compared to controls. All the IgG seropositive salpingitis patients were also found to have C. trachomatis IgG antibodies. It appears that testing for IgG antibodies at a serum dilution of 1:128, and for IgA antibodies at a dilution of 1:16 by the IPA test comprises the best combination for the differentiation between the salpingitis patients and apparently healthy controls, and it is suggested that this be used as a marker of active C. trachomatis infection.

Adolescent↗
PubMed1984

The effect of eccentricity and colour on negativity in pattern onset visual evoked potentials.

The effects of stimulus size, eccentricity and colour on the amplitudes of N100 and N130 were investigated in pattern onset VEPs. For black-and-white pattern stimulation, the first set of stimuli was derived from a full dartboard pattern. Central stimulation of various extents was produced by patterns with reduced number of outer rings and for eccentric stimuli a number of central rings were removed from the full pattern. It was found that amplitude of N100 was maximal in VEPs to central stimuli and that it was greatly reduced when eccentric stimulation was applied. The amplitude of N130 showed no significant change in relation to the type of stimulus. When checkerboard stimuli of identical configuration were used for black-and-white pattern stimulation instead of dartboards, systematic changes in peak latencies of N100 were observed in relation to check size. In VEPs to centrally presented small checks the emergence of an early negative peak preceding N100 was recorded at 75 msec. In VEPs to coarse checkerboards presented centrally N100 was often observed with a delayed peak latency of 110 msec. Changes in N130 were not regular when checkerboards with different check sizes were presented centrally. For eccentric checkerboard stimulation, both negative peaks N100 and N130 were revealed. Their peak latencies were similar to those observed in the case of dartboard paracentral stimulation. In VEPs to patterns projected through red or blue filters, regular changes were observed in both negative peaks. Introduction of the red filter led to enhancement of the N100 amplitude in VEPs to dartboard and to checkerboards with fine checks, but it caused no effect on N100 in the VEPs to coarse checkerboards. Introduction of the blue filter led to a decrease in the N100 amplitude in VEPs to dartboard and fine checkerboards and to a slight increase of N100 in VEPs to coarse checkerboards. Changes in N130 were observed only when the blue filter was introduced and they corresponded to those which take place when the level of illumination changes from photopic to mesopic.

Color Perception↗
PubMed1984

Antigenicity of sperm cells after freezing and thawing.

Freezing and thawing is thought to result in removal of spermatozoal membrane antigens. We investigated the presence of sperm antigens before and after freezing and thawing by means of the immunoperoxidase assay (IPAMA), sperm immobilization test (SIT), and separation of proteins by gel electrophoresis. The results of the IPAMA and SIT assays showed no difference in the membrane antigens before and after freezing and thawing. Analysis of surface proteins by gel electrophoresis demonstrated that freezing and thawing did not remove any particular group of proteins from the surface membrane of spermatozoa. According to the evidence of the three tests performed, there is no meaningful removal of antigens from the sperm cell surface membrane by the process of freezing, preservation, and thawing when carried out by the specific methods used. This work does not support the suggestion that in cases of immunologic incompatibility between spermatozoa and cervical mucus it would be possible to overcome the couple's infertility by employing the process of freezing, preservation, and thawing.

Antigens, Surface↗
PubMed1984

Renal clearance of urea, inulin, and p-aminohippurate in heat-acclimated rats.

Clearance values of urea, inulin, and p-aminohippurate (PAH) were measured in heat-acclimated (HA) rats exposed for 3 wk to 35 degrees C, in control rats (C) exposed to 23 degrees C, and in HA rats deacclimated (DA) for 3 wk. In HA rats, urea clearance was lower by 73%, inulin clearance by 61%, and PAH clearance by 56%, compared with C rats. The clearance values of these substances returned to the control values in DA rats. The data suggest that the low clearance values reflect both reduced renal blood flow and possible changes in the capacity of the glomeruli for filtration and the tubules for either reabsorption or secretion.

Acclimatization↗
PubMed1984

Infection of endometrial cells with human cytomegalovirus.

In order to understand the mechanism of congenital human cytomegalovirus (CMV) infection we studied the effect of CMV on epithelial cell culture of the endometrium. Endometrial cells proved to be sensitive to CMV as indicated by morphologic alterations, success to support growth of infectious virus and positive immunoperoxidase staining. The infected cells were enlarged, multinuclear and revealed intranuclear inclusions. Electron microscopy detected the presence of the viral particles in the CMV-infected endometrial cells. The possibility that CMV infection of the endometrial cells may play a role in transmitting the virus to the embryo will be discussed.

Cells, Cultured↗
PubMed1984

The undesirable effects of various changes of monoplane occlusion on complete denture retention.

The most commonly seen undesirable alterations to the occlusal plane, when using monoplane occlusion with nonanatomic teeth, have been outlined verbally and graphically. The introduction of dislodging forces to denture retention brought about by these variations in the monoplane have been examined, as well as methods for their correction. The order of presentation of undesirable alterations to the occlusal plane is a guide for a step-by-step correction of these changes. It provides the practitioner with a sequential checklist for correcting undesirable occlusal changes in monoplane denture occlusion with nonanatomic teeth.

Dental Occlusion, Balanced↗
PubMed1983

Human endometrium in cell culture: a new method for culturing human endometrium as separate epithelial and stromal components.

The present study describes a simple method for culturing human endometrium as separate epithelial and stromal components. Fifty-two samples of normal human endometrium have been initiated in tissue culture: endometrium from both the proliferative and luteal phases of the menstrual cycle showed satisfactory growth in vitro with a success rate of about 94%. Epithelial cultures remained viable for 60 days, while from stromal cells it was possible to establish cell lines. Both cell types possessed estrogen receptors. Epithelial cells showed no clear estrogen or progesterone response. Our observations suggest that this simple method for culturing human endometrium may serve as a tool in further investigations.

Connective Tissue↗