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Biomedical subjects

A Schoenfeld

Publications and source records attributed to A Schoenfeld.

At least 37 records · Page 2Linked to original sources
PubMed1996

Microalbuminuria in early pregnancy in normal and high-risk patients.

The albumin excretion rate (AER) is elevated in normal pregnant women in the third trimester of pregnancy, compared to the second and first trimesters, and to the non-pregnant state. The effect of early pregnancy on AER values was tested in normal and high-risk pregnant patients using radioimmunoassay. All pregnant patients demonstrated significantly higher AER values as compared to non-pregnant women, and the results were in correlation with higher urinary creatinine clearance values. The appearance of microalbuminuria in the first trimester can indicate underlying renal damage in patients at high risk of hypertensive complications.

Adult↗
PubMed1995

Crush injury in pregnancy: an unusual experience in obstetrics.

BACKGROUND: Crush injury is the result of prolonged pressure to the limbs when individuals are trapped under the debris of earthquakes, bombings, and other disasters. Muscle integrity is compromised, and the local and systemic manifestations, including rhabdomyolysis, hyperkalemia, renal failure, and disseminated intravascular coagulation may be fatal. CASE: A 32-year-old woman, gravida 2, para 1, was trapped under fallen masonry at 6 weeks' gestation for approximately 6 hours. On initial examination, she showed early signs of hypovolemic shock and crush injury, including hyperkalemia. Prompt management with fluid therapy and careful monitoring led to a rapid recovery. Antenatal follow-up was routine and concluded in spontaneous delivery of a healthy infant. CONCLUSION: The unique physiology of the pregnant woman may affect the outcome of crush injury, and it presents a particular challenge to the trauma team. The obstetrician should be aware of its dangers and should be an active participant in the prompt management of pregnant victims of crush injury to ensure a satisfactory outcome for both mother and fetus.

Adult↗
PubMed1995

Yolk sac concentration of prostaglandin E2 in diabetic pregnancy: further clues to the etiology of diabetic embryopathy.

Fetal malformation associated with maternal diabetes occurs before the seventh week of pregnancy. Current hypotheses suggest that the diabetic milieu causes a reduction in phosphatidylinositol turnover, leading to a disruption in the arachidonic acid cascade and resulting in a deficiency of prostaglandins, particularly prostaglandin E2. This in turn results in a wide variety of congenital anomalies. This hypothesis has not been tested experimentally in humans. The yolk sac is thought to be the most important source of nutrition in early pregnancy. We sought to compare yolk sac prostaglandin levels in normal and diabetic women. Under ultrasonographic guidance, yolk sacs were aspirated form 8 normal and 12 diabetic women ranging from 8 to 10 weeks gestational age prior to elective abortion. Prostaglandin E2 levels were determined using RIA. The mean prostaglandin E2 level in normal controls was 3605 pg/mL, and was undetected in all of the yolk sacs aspirated from diabetic women (P < 0.001). Yolk sac diameter in diabetic pregnancies was 1.2 mm larger than that of normal pregnancies. The functional and morphological changes demonstrated in this study may increase our understanding of the pathophysiology of diabetic embryopathy.

Blood Glucose↗
PubMed1995

Basal promoter of the rat connexin 32 gene: identification and characterization of an essential element and its DNA-binding protein.

The connexin 32 (Cx32) gene, a member of a multigene family, is expressed preferentially in the liver. The basal promoter complex of the rat Cx32 gene was previously localized to a 146-bp region (map positions [mp] -179 to -34) immediately upstream of the first exon. To investigate the biochemical factors contributing to the basal promoter activity, nuclear protein-DNA complexes within this region (mp -177 to -106) were investigated by using a DNA mobility shift assay. Three DNA-protein binding activities, termed Cx32-B1, Cx32-B2, and Cx32-B3, were identified with nuclear protein extracts from hepatoma cell lines, HuH7 and FAO-1. However, only Cx32-B2 binding activity was detected in nuclear protein extract from normal rat liver tissue. This activity was significantly more abundant in rat liver tissue than in hepatoma cell lines and tissues from various other organs. By using methylation interference footprinting, the Cx32-B2 complex was localized to the region between mp -152 and -127 and a DNA probe containing this region bound to a 60-kDa protein in rat liver nuclear extracts. Mutation of two nucleotides in the Cx32-B2 binding site abrogated the formation of the Cx32-B2 protein-DNA complex and significantly reduced the transcriptional activity of the Cx32 promoter. These results indicate that the Cx32-B2 complex is an essential component of the rat Cx32 basal promoter and is likely a major factor in the preferential expression of this gene in the liver.

Animals↗
PubMed1995

Laser versus loop electrosurgical excision in vulvar condyloma for eradication of subclinical reservoir demonstrated by assay for 2'5' oligosynthetase human papillomavirus.

We studied, in an open clinical trial, 28 women with giant solitary human papillomavirus (HPV) lesions of the vulva that were treated by both laser and the loop electrosurgical excision procedure (LEEP), and analyzed the biopsy specimens of normal skin adjacent to the lesions for papillomavirus sequences by Southern blot hybridization and 2'-5' oligo-A synthetase (interferon) activity. The patients were reexamined after 3 weeks when a second treatment to the still infected areas was reapplied. They were reexamined for recurrence after 3 months: 4 patients harbored HPV-DNA genomes on the laser-treated side, adjacent to the original lesion, compared to 1 patient who developed recurrence on the LEEP side in a more distant, previously untreated, area. The optimal extent of laser or LEEP treatment necessary to reduce recurrence of vulvar condyloma remains to be established. Good in situ hybridization tests combined with the polymerase chain reaction and measurements of oligosynthetase activity to determine the types of cells involved at different sites of infection and to assess harboring of latent HPV genomes in histologically normal tissue are necessary in order to plan proper HPV treatment modality strategies.

2',5'-Oligoadenylate Synthetase↗
PubMed1995

External cephalic version at term using broad criteria: effect on mode of delivery.

We sought to determine whether external cephalic version (ECV) with tocolytic agents in term patients with breech presentation could safely reduce the incidence of breech-related cesarean sections and vaginal breech deliveries. Four hundred and thirty-two patients with breech presentation at term who fulfilled broad criteria for attempted ECV and a control group of 330 patients with breech presentation at term in whom ECV was not attempted, were retrospectively reviewed. ECV was attempted following an infusion of ritodrine hydrochloride, using either the back flip of Saling and Muller-Holve or the classic forward roll. Following successful ECV, an infusion of oxytocin was administered to fix the head in the pelvis. Of the 432 patients, 311 (72%) underwent successful ECV; 86% delivered vaginally. Cesarean sections were performed in 76% of the patients with unsuccessful ECV and in 64% in whom the version was not attempted (control group). We conclude that ECV at term, using tocolytic agents, when applied to a broad spectrum of patients, is a safe and useful procedure for reducing the incidence of breech presentation, and as a direct consequence, for reducing the incidence of cesarean sections.

Breech Presentation↗
PubMed1994

Three-dimensional modelling of tumor-induced ovarian angiogenesis.

It is now well established that unrestricted growth of tumors is dependent upon angiogenesis. However, previous studies on tumor growth have not yet revealed how the transition to an angiogenetic state in ovarian malignancy is reflected in the vascular architecture of the ovary. We report here our preliminary observations based upon three-dimensional imaging of normal and tumor-induced ovarian angiogenesis created with a computer-assisted three-dimensional interactive application. The findings suggest that tumor-induced angiogenesis creates a bizarre vascular architecture, with a possible link to chaotic behavior.

Cystadenocarcinoma, Serous↗
PubMed1994

Detection of breast cancer micrometastases in axillary lymph nodes by using polymerase chain reaction.

Breast cancer micrometastases in axillary lymph nodes have been detected by serial sectioning and immunohistochemistry, and shown to have prognostic significance. We have used polymerase chain reaction (PCR) to see whether we could further improve the detection rate of micrometastases. Fifty-seven axillary lymph nodes from patients with breast cancer were examined histologically to assess the proportion of tumor involvement. Immunohistochemical staining with the use of an anti-keratin 19 antibody confirmed the histological findings. Reverse transcription PCR was then performed on extracted RNA by using K19 primers, and all 18 histologically involved nodes yielded the expected 460-base pair product. Of 39 histologically negative nodes, 4 (10%) gave K19 bands detectable with ethidium staining and a further 10 (28%) gave K19 bands after Southern hybridization. To further increase the detection sensitivity a two stage amplification was performed by using nested primers, and K19 product was found in lymph nodes from patients without cancer, as well as in all the nodes from cancer patients. This was shown to be genuine low level expression from endogenous mRNA template, and not derived from amplification of a K19 pseudogene. Reducing the number of PCR cycles in the two amplification steps did not allow sufficient discrimination between normal nodes and those involved nodes in which K19 expression was only detectable after Southern hybridization. The optimal "cut-off" point to distinguish involved nodes from normal nodes remained at the level of 40 cycles of PCR and Southern hybridization. PCR, using K19 as a tumor marker, has been demonstrated in this study to improve the detection of micrometastases in axillary lymph nodes in patients with breast cancer: sensitivity is limited by the specificity of the tumor marker.

Adult↗
PubMed1994

[Large loop transformation zone excision in premalignant cervical lesions].

Colposcopic expertise is necessary in cases of cervical intraepithelial neoplasia (CIN) to avoid conservative treatment of microinvasive and invasive lesions. Large loop excision of the transformation zone (LLETZ) enables the pathologist to examine the entire tumor, and especially its margins. We describe this method and its indications, and review the results of our first 100 cases (mean age 28 years, range 19-46). Indications for LLETZ were biopsy findings of CIN III or of a large CIN II, a lesion entering the endocervical canal, and recurrent CIN after CO2-laser treatment. The procedure was performed under local anesthesia in 93 patients; complications were minimal (8 cases of bleeding requiring local tamponade). In 14% marginal involvement was found, but in only 4 was re-treatment necessary during follow-up of 12-33 months. Only 3 developed recurrent CIN, which was again treated by LLETZ. The cure rate of the initial treatment was 97%. This ablative, nondestructive method is easy to perform, requires only local anesthesia, has few, mild complications and gives an accurate histopathological result, including information on margins. The procedure is becoming the method of choice for treating high-grade and recurrent CIN.

Adult↗
PubMed1994

Expanded polytetrafluoroethylene patch versus braided polyester tape for the repair of incompetent cervix.

BACKGROUND: This study was done to evaluate pregnant patients with cervical incompetence using an expanded polytetrafluoroethylene (ePTFE) patch versus the commonly used braided polyester tape, comparing the rate of local tissue reaction or onset of contractions, or both. STUDY DESIGN: This study was a prospective clinical trial on 20 patients divided into two groups. Patients having tissue reactions or contractions were identified and each material was analyzed using a new approach by means of scanning electron microscopy (SEM) and roentgenogram diffraction studies. RESULTS: In the group of pregnant patients sutured with polyester tape there were four failures because of infection and contractions. There were no direct or indirect complications encountered in the ePTFE group. Bacteriologic evaluations of the failures revealed Escherichia coli, Gardnerella vaginalis, Bacteroides species, and Trichomonas vaginalis in various combinations, in addition to crystal structure degradation and layers of phagocytes. CONCLUSIONS: Our results provide a rationale for understanding the differences in morphologic integrity and the superiority of the ePTFE patch over the polyester tape using a new analytic approach of SEM and roentgenographic diffraction studies. Because of the small number of patients and because the procedure was performed in a select patient population, we recommend that further trials be undertaken with a larger number of patients in more advanced gestational age and in patients presenting with emergent cervical incompetence.

Abortion, Spontaneous↗
PubMed1993

Dizygotic triplet pregnancy following in-vitro fertilization.

We present a case of dizygotic triplet pregnancy (mono-amniotic twins and a singleton) that, as far as we know, is the first reported one induced by artificial reproductive technology. It ended in the delivery of three healthy normal babies: two monozygotic twin boys and a girl. It appears that zygote splitting is significantly more common in patients treated with ovulation-inducing agents than in the general population. Also, in-vitro conditions of embryonic growth might influence the chances of multifetal gestation and the incidence of identical twinning. This may be due to changes in the physical properties of the zona pellucida and subsequent partial hatching of the pre-embryo. Evaluation of similar cases in the future may shed more light on the mechanism underlying their occurrence following in-vitro fertilization.

Adult↗
PubMed1992

Prevalence of minor congenital anomalies in newborns of diabetic mothers.

Minor congenital anomalies (MCA) were assessed in the offspring of 802 gestational diabetic mothers, 117 pre-gestational diabetic mothers, and 380 offspring born to normal mothers. The prevalence of infants with MCA ranged between 19.4% and 20.5% in the three groups without any significant difference between them. There was no correlation between the prevalence and type of MCA and the severity of the diabetic state. Neither was there any correlation between the prevalence or type of MCA and the appearance or type of major congenital anomalies.

Abnormalities, Multiple↗