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Biomedical subjects

R Maymon

Publications and source records attributed to R Maymon.

At least 91 records · Page 5Linked to original sources

Prevention of post-surgical adhesion formation using aspirin in a rodent model: a preliminary report.

Pelvic adhesions are one of the major factors which significantly and adversely affect surgery outcome due to intra- and postoperative morbidity and reduce future female fertility. Using a rodent model, we evaluated the efficacy of aspirin, a non-steroidal anti-inflammatory drug, in the prevention of adhesion formation. A total of 72 female Wistar rats received a standardized primary traumatic lesion to the right uterine horn. They were randomly divided into eight groups: group I (control) had no treatment and group II received a single pre-operative 0.70 mg aspirin. All the succeeding groups (III-VIII) received aspirin in doses of 0.35, 0.70, or 1.40 mg every 6 h for either 48 or 96 h in addition to the pre-operative aspirin (0.70 mg). All animals were killed 4 weeks later and adhesions were assessed using a modified adhesion scoring scale. The lowest adhesion score was found in the group treated with 0.35 mg of aspirin for 96 h, and the highest was found among the groups treated with either 0.70 or 1.40 mg for 48-96 h respectively (P < 0.05). These results are in line with the hypothesis that administration of a low dose of aspirin selectively inhibits the production of thromboxane A2, whereas basal prostacyclin biosynthesis is preserved. This phenomenon might contribute to reducing postoperative adhesion formation in a rat model. Thus, future studies into the prevention of adhesion formation may require the additional use of a non-steroidal anti-inflammatory drug, for which aspirin deserves further attention, before extrapolation into human therapy.

Animals↗

Placental isoferritin patterns during normal first trimester and tubal gestations.

Placental isoferritin (PLF) has been shown to be involved in the down-regulation of the maternal immune system during pregnancy. In a prospective study, serum PLF concentrations were measured in 33 pregnant women with singleton, normal, ongoing first trimester gestations and compared with those of 22 women with tubal gestations. Diagnoses were based on endocrinological, sonographic, intra-operative and histopathological criteria. Venous blood was obtained from both groups for PLF determination before evacuation of the pregnancy products. beta-Human chorionic gonadotrophin (HCG), 17 beta-oestradiol and progesterone were determined at surgery for the tubal pregnancy patients. The mean +/- SD PLF concentrations were 18 +/- 14, 25.4 +/- 42.3 IU/ml among normal and tubal gestations respectively. Significant differences between normal and tubal pregnancies were found (P < 0.05). Based on PLF measurements, sensitivity (67%) and specificity (33%) values were found to be similar for the normal and ectopic pregnancies. No correlation was found between the other measured pregnancy hormones and PLF for the tubal pregnancy group. Low PLF concentrations among pathological gestations may reflect abnormal trophoblastic activity. The simultaneous assessment of PLF and beta-HCG concentrations which probably originate from different trophoblastic cells, is recommended for better diagnosis and monitoring of first trimester placental activity.

Adult↗

Changes in uterine artery Doppler flow velocity waveforms during the third stage of labor.

Transabdominal Doppler velocity waveform measurements of the uterine arteries during the third stage of labor were performed upon 25 patients with uncomplicated vaginal deliveries and 5 with prolonged third stage in order to further assess third-stage mechanisms. Based on Doppler flow measurements, three phases of the third stage of labor were observed: (1) a latent phase with a systolic/diastolic ratio (S/D) and a pulsatility index (PI) of 2.14 +/- 0.49 and 0.89 +/- 0.17, respectively; (2) a contraction and detachment phase with an S/D and PI of 2.53 +/- 0.53 and 1.28 +/- 0.37, respectively, and (3) an expulsion phase with an S/D and PI of 2.20 +/- 0.34 and 0.91 +/- 0.20, respectively (p < 0.05). During the third stage of labor, it was shown that uterine contractions squeezed the uterine vessels as they traversed the myometrium, leading to an increase in the extrinsic resistance, which was reflected by high resistance flow. Following placental separation and changes in the placental-site wall, there was slight uterine relaxation resulting in decreased uterine vessel resistance. This observation encourages the authors to continue investigating the contribution of ultrasound and Doppler flow for studies of the postpartum period.

Adult↗

Improved techniques for first-trimester fetal reduction using simultaneous abdominal and transvaginal ultrasonographic guidance. Preliminary report.

Simultaneous transabdominal injection of potassium chloride (KCl) assisted by transvaginal ultrasonographic guidance was evaluated in 5 patients who conceived due to various assisted reproductive techniques and ovarian stimulation. All 5 underwent first-trimester fetal reduction for multiplicity of high-order pregnancies. Four sets of triplets were reduced to twin, and 1 twin pregnancy was reduced to a singleton. Less than 2 ml of 2 mEq/ml KCl per fetus was needed for each case. No fetal or maternal complications nor technical failure attributable to the procedure were recorded. All pregnancies were delivered > or = 35 weeks of gestation. Transabdominal fetal reduction using simultaneous transvaginal ultrasonographic guidance for selective feticide combines the benefits of both the transabdominal and transvaginal approaches, mainly in selected cases in which some experts prefer the abdominal route, but find it technically difficult to practice. Further experience is needed to confirm our encouraging preliminary results before drawing any definitive conclusions.

Abdomen↗

Clinical and subclinical condyloma. Rates among male sexual partners of women with genital human papillomavirus infection.

Sixty-three regular male sexual partners of women with proven genital human papillomavirus (HPV) infection or its associated lesions were examined by colposcopy and biopsy (when necessary) to determine the prevalence of penile condyloma among them. Fifteen (24%) were found to have histologic evidence of condyloma. The severity of the women's lesions did not necessarily reflect that of lesions found in their sexual partners. The majority (54%) of the HPV-associated lesions were located on the penile body, followed by the penile root (25%). We found no cases of premalignant or malignant penile lesions. After controlling for the confounding factors of socioeconomic status and lesion location and comparing the data to those compiled from the English-language literature, we arrived at various theories about the very low rate of infection in our population. One possibility is the protective effect of circumcision, partly because the preputium is a major site of bacterial and viral colonization. The possibility of different strains of HPV in the Jewish Israeli population and certain socioeconomic factors that may limit the spread of sexually transmitted diseases may be the basis for future study.

Adult↗

[International postgraduate training program in medicine: survey of 13 training courses, 1988-1994].

In 1988 an International Postgraduate Training Program in Medicine was established as a joint venture of the Tel Aviv University School of Continuing Medical Education and the Ministry for Foreign Affairs, Division of International Cooperation. During 1988-1994, 359 physicians participated. A survey of 271 graduates was carried out within 1-5 years following the completion of training, and 57% responded to our questionnaire. The program fulfilled the academic expectations of 78% of the trainees, and the practical clinical expectations of 80%. 95% graded the program as good-to-excellent from the sociocultural aspect. 75% and 67.5% of the trainees graded the program as good-to-excellent with regard to improvement in their theoretical and practical skills, respectively. Regretfully, only 45% have continued their ties with the host departments and only 11% have carried out joint research projects. These results imply that further attention should be paid to the trainees' real-time input, in order to increase satisfaction. Personal tutors should be nominated in each department, and should be adequately compensated. More emphasis should be given to initiation of bilateral research projects and maintenance of professional ties between the trainees and their host departments.

Attitude of Health Personnel↗

Enhancing effect of ATP on intracellular adriamycin penetration in human ovarian cancer cell lines.

Ovarian cancer has the highest mortality rate of all gynecological malignancies probably due to the evolution of clones resistant to cytotoxic drugs. Exploring possibilities to overcome such resistance constitutes a challenge in this study. We present the effect of adenosine triphosphate (ATP), serving as a chemosensitizer, in combination with adriamycin on three human ovarian cancer cell lines of epithelial origin, OC-109, OC-238 and OC-7-NU, obtained from malignant ascites of different patients, and were proven to be tumorigenic in nude mice. The three lines differ in their sensitivity to the ATP-induced increase in adriamycin accumulation. FACS analysis showed a pronounced increase in intracellular adriamycin accumulation after treatment with various concentrations of ATP. In the OC-238 line, a 50.1% increase was observed at a low ATP concentration (200 microM), whereas higher concentrations (400 microM and 500 microM) were needed to obtain an increase in ADR accumulation of 30% with the other two lines. Our study demonstrates that ATP improves the penetration of adriamycin at the neoplastic cellular level. Furthermore, our results may indicate that intratumoral ATP may serve as an alternative chemosensitizer which lacks the deleterious side effects of other chemosensitizing options.

Adenosine Triphosphate↗

Augmentative effects of intracellular chemotherapy penetration combined with hyperthermia in human ovarian cancer cells lines.

A significant proportion of ovarian cancer patients do not achieve a complete response to chemotherapy, due mainly to the evolution of clones resistant to cytotoxic drugs. Exploring possibilities to overcome this resistance constitutes a challenge in the study of ovarian cancer experimental therapy. In the present study, we tested the effect of hyperthermia (40 and 43 degrees C) in combination with adriamycin on three human epithelial ovarian cell lines: OC-109, OC-238, and OC-7-NU. The first was derived from the mucinous and the other two from serous cystadenocarcinomas, and all proved to be tumorigenic in nude mice. FACS analysis showed a pronounced increase in intracellular adriamycin accumulation in the presence of hyperthermia. A significant effect (P < 0.0005) observed at 40 degrees C was even more pronounced at 43 degrees C with the three cell lines. High percentages of cells (up to 70%) shifted into higher fluorescence intensities. The lines differed in their sensitivity to the hyperthermia-induced increase in adriamycin accumulation. Under mild conditions, the OC-109 line was more sensitive than the OC-238 and the OC-7-NU lines. Quantitative determination of intraneoplastic adriamycin by spectrofluorometry also showed a hyperthermia-related increase in intracellular adriamycin (P < 0.005). Our results may indicate that supranormal temperature might serve as an alternative chemosensitizer which lacks the deleterious side effects of other chemosensitizing options.

Combined Modality Therapy↗

Ovarian cyst formation in two pre-menopausal patients treated with tamoxifen for breast cancer.

Pre-menopausal tamoxifen treatment causes hyperoestrogen production and ovarian cyst formation. Two pre-menopausal breast cancer patients who were treated with tamoxifen developed both permanent supraphysiological oestrogen concentration and ovarian cysts. Serum oestrogen decreased to post-menopausal concentrations and ovarian cysts completely resolved during and following simultaneous treatment with tamoxifen and gonadotrophin-releasing hormone agonist (GnRHa). In pre-menopausal breast cancer patients, GnRHa may prevent possible side-effects of tamoxifen, such as ovarian cysts and supraphysiological oestrogen production.

Adult↗

The role of color Doppler flow in the management of nonmetastatic gestational trophoblastic disease.

Three patients with findings suggestive of invasive gestational trophoblastic neoplasm and lung metastasis were assessed by color Doppler transvaginal ultrasound, before and during chemotherapy. The sonographic findings were correlated with beta-hCG levels measured at various stages of treatment. Results were compared with blood flow indices found during normal first trimester pregnancies, and those following elective termination of pregnancy. The mean resistance indices were significantly lower in the patients treated with chemotherapy (0.410 +/- 0.04) than in the early pregnancy control group (5-8 weeks gestation; n = 20, resistance index = 0.494 +/- 0.06). The difference between the groups was statistically significant (chi 2; p < 0.05). No pathological flow patterns could be discerned in 10 patients, who after termination of pregnancy had beta-hCG levels below 5 IU/ml. The response of gestational trophoblastic neoplasms to chemotherapy could be reliably assessed by observing the changes in flow resistance, which paralleled the gradual decrements in serial measurements of beta-hCG levels. Thus, the statistically significant results of our study are very encouraging and may indicate that color Doppler flow is a noninvasive, reproducible, useful and highly reliable new diagnostic approach for the diagnosis and management of patients suffering from uterine malignant gestational trophoblastic disease.

Animals↗

Distribution of carbohydrates in the zona pellucida of human oocytes.

The purpose of the present study was to investigate the distribution pattern of carbohydrates in the zona pellucida of human oocytes using lectins and ruthenium red as histochemical probes. For lectin analyses, oocytes that failed to undergo fertilization following in vitro insemination were collected, washed, fixed with glutaraldehyde and embedded in araldite. For ruthenium red labelling, the oocytes were fixed with glutaraldehyde containing ruthenium red, post-fixed with OsO4 and embedded in araldite. Araldite sections (1 micron) were de-resined with sodium methoxide, rehydrated, labelled with ten different biotinylated lectins as probes and avidin-biotin-peroxidase complex as visualant, and examined under a light microscope. The zonae pellucidae of all oocytes studied exhibited a common lectin-binding pattern, expressed in intense binding of lectins from Concanavalia ensiformis (ConA), Lens culinaris (LCA), Ricinus communis (RCA-I), wheat germ agglutinin (WGA), and of succinylated WGA (S-WGA). Peanut lectin (PNA) bound to the zona pellucida only after neuraminidase treatment, whereas the lectins from Griffonia simplisifolia (GS-I), Dolichos biflorus (DBA), Ulex europhaeus (UEA-I) and soybean (SBA) did not bind at all. There was almost no binding of ruthenium red to the matrix of the zona pellucida. The results indicate that the human zona pellucida is characterized by normally exposed mannosyl, N-acetylglucosaminyl and beta-galactosyl residues. In addition, it contains masked beta Gal-(1-3)GalNAc sugar sequences that can be exposed only after removing terminal sialic acid residues.(ABSTRACT TRUNCATED AT 250 WORDS)

Carbohydrates↗

Penile condylomata: a gynecological epidemic disease: a review of the current approach and management aspects.

Viral venereal infection caused by human Papillomavirus has reached epidemic state. The proper management of this infection in men is of great benefit, because it may possibly decrease the reservoir of disease in both sexes from which genital condylomata and associated lesions may arise. We report a selection of current knowledge about the epidemiology, etiology, diagnosis, and treatment of male condyloma, occurring predominantly among male consorts of women with genital human Papillomavirus infection. In a review of 1455 affected women, compiled from the literature, 1019 (70 per cent) of their sexual partners were diagnosed as having been infected with the same viral disease. The current diagnostic and treatment modalities and their outcomes are discussed with appropriate recommendations for their use.

Algorithms↗

Enhancement of cytotoxic agent accumulation by Doppler flow sonication of human ovarian cancer cells.

The intracellular accumulation of adriamycin (ADR) by Doppler flow sonication was investigated in a human ovarian carcinoma line. Cytofluorometry was performed on cells treated by ADR (0.5, 1 and 2 micrograms/mL) alone, or in conjunction with Doppler flow sonication for 5, 10, and 15 minutes. Increased intracellular accumulation of ADR was observed in cells treated at each of these test intervals. Statistically significant increases in high permeability, due to Doppler sonication, were around 1.5 fold at each of the test intervals, with a maximum observed at 10 minutes of treatment. Examination of ADR dose effect showed that the most vigorous to Doppler sonication occurred at 1 micrograms/mL ADR. Although statistically non-significant, a trend towards the most prominent egect of 91.6% cell validity was noticed after 15 minutes of treatment. Our findings demonstrate that an improvement of ADR penetration into malignant cells can be obtained in this bioultrasound model. Wowever, caution is advised when extrapolating in vitro experimental results to in vivo phenomena.

Cell Membrane Permeability↗

Histochemical characterization of anionic constituents in oocyte-cumulus complex of rats.

Fertilization is a process that involves the recognition and adhesion of negatively charged spermatozoa to the oocyte investments. It is not known, however, if charge properties of the interacting gametes play a role in fertilization. The present study evaluates the content and distribution of anionic constituents in the oocyte-cumulus complex of rats. Polycationic colloidal gold (PCG), ruthenium red (RR) and wheat germ agglutinin (WGA) were used as cytochemical markers of anionic sites at the light (LM) and electron microscopical (EM) levels. Isolated oocyte-cumulus complexes were fixed with glutaraldehyde (GA) and OsO4 containing RR, or with GA without RR, and embedded in araldite or LR-gold. For LM, deresined, semi-thin, araldite-embedded sections were labelled with PCG intensified by silver, or with biotinylated lectins visualized by avidin-peroxidase. For EM, thin LR-gold sections were labelled with PCG, whereas RR labelling was examined in araldite sections. The zona pellucida (ZP) failed to bind any of the polycationic markers used, but intensely bound neutralized WGA. In contrast, cumulus cell membranes bound PCG but not RR, whereas the oolemma bound RR but not PCG. The results indicate that the ZP is practically devoid of negatively charged constituents, and tends to repel positively charged ligands possibly due to the presence of cationic determinants. The binding of PCG to cumulus cells probably reflects a high content of membrane-bound heparan sulphate, whereas the binding of RR to the oolema indicates the presence of membrane sialoglycoconjugates.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Conservative treatment of ectopic pregnancy and its effect on corpus luteum activity.

Corpus luteum activity was monitored in 15 women undergoing nonsurgical management of ectopic pregnancy with local methotrexate injection followed by alternating oral methotrexate and citrovorum factor (group A, n = 8) or local methotrexate injection alone (group B, n = 7). All patients initially demonstrated a viable corpus luteum (plasma progesterone ranged from 1.4 to 19 ng/ml). The treatment was successful in 14, with the exception of one whose tube ruptured 11 days after local administration of methotrexate, despite a continuous decrease in beta human chorionic gonadotropin, 17 beta-estradiol and plasma progesterone levels. There seems to be no correlation between the success of the treatment and the behavior of beta human chorionic gonadotropin, 17 beta-estradiol and plasma progesterone. Three patients from group A and two from group B displayed an initial rise in beta human chorionic gonadotropin following the initiation of the therapy, but the corpus luteum response differed. In group B patients, 17 beta-estradiol and plasma progesterone levels increased in parallel with beta human chorionic gonadotropin. Group A patients displayed a continuous decrease in 17 beta-estradiol and plasma progesterone levels despite the elevation of beta human chorionic gonadotropin, suggesting a possible effect of the systemic methotrexate on corpus luteum activity.

Adolescent↗

Percutaneous catheter drainage of tubo-ovarian abscesses.

We present the successful treatment of tubo-ovarian abscesses in three young patients by continuous percutaneous drainage, inserted under the guidance of real-time ultrasonography using only local anesthesia. Each patient had been diagnosed laparoscopically as suffering from acute pelvic inflammatory disease, but had formed abscesses despite extensive broad-spectrum antibiotic therapy. One case involved a complication of the ovum pick-up procedure; the woman had tubo-ovarian abscesses with infected hematomas. Because the abscesses were localized anteriorly in the lower abdomen and did not reach the pouch of Douglas, they could not be drained through a posterior colpotomy. Ultrasound guidance allowed us to drain all the areas of the multioculated abscesses. We suggest that percutaneous abscess drainage be the initial treatment of choice for tubo-ovarian abscesses before laparotomy is considered.

Abscess↗