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Biomedical subjects

J G Tchabo

Publications and source records attributed to J G Tchabo.

At least 19 recordsLinked to original sources
PubMed1999

Analysis and characterization of hematopoietic progenitor cells from fetal bone marrow, adult bone marrow, peripheral blood, and cord blood.

Hematopoietic stem cell transplantation has been increasingly used to replace a defective hematopoietic system and to treat various genetic defects as well as malignant diseases. However, the limitations of conventional bone marrow transplantation have stimulated an intense interest in exploring the use of alternative sources of hematopoietic stem cells, including peripheral blood mononuclear cells (PBMC) and cord blood (CB). A major investigative effort of our laboratory has been focused on evaluating fetal bone marrow (FBM) for transplantation. The current study compares and characterizes the functional and phenotypic characteristics of FBM, CB, adult bone marrow (ABM), and PBMC by clonogenicity assays, immunogenicity, and the quantification of progenitor cells. There was a striking difference in the proportion of CD34+ cells in FBM, ABM, PBMC, and CB (24.6%, 2.1%, 0.5%, and 2.0%, respectively). The clonogenic potential, as measured by colony forming unit in culture (CFU-C) assay, was significantly higher in FBM when compared with ABM, PBMC, and CB (202.5, 73.5, 40.8, and 65.5 colonies/10(5) cells, respectively). There was a significant decrease in proliferative responsiveness in mixed lymphocyte reaction (MLR) assay of FBM and CB compared with ABM and PBMC. These observations indicate that each source of hematopoietic stem cells has different intrinsic properties closely correlated with ontogenetic age that is a vital determinant for phenotypic characteristics, lineage commitments, immunogenicity, and proliferative potentials.

Adult↗
PubMed1994

Prenatal diagnosis of trisomy 12 mosaicism: physical and developmental follow-up.

Follow-up evaluations were performed on a child at the ages of 2 years 8 months and also at 5 years who had been found on prenatal amniocentesis to be mosaic for trisomy 12. Eight of 36 colonies (22 per cent) were trisomy 12 at amniocentesis, with the remaining colonies showing a normal female karyotype. Cord blood, amnion, chorion, placental, and skin fibroblast chromosome studies failed to show any further evidence of a trisomy 12 cell line. At her evaluations, the child had normal physical and neurological findings. Psychomotor development was appropriate for age on screening.

Adult↗
PubMed1994

Zona-opening of hamster oocytes: a comparative study using macro- and micro-manipulation methods.

The present study compared a new macro-manipulation technique for zona-opening of hamster oocytes with existing micro-manipulation techniques. In experiment I the zona pellucida of hamster oocytes was partially opened with a 32 gauge steel needle (macro-manipulation) and these oocytes were then co-incubated with human spermatozoa at 36.5 degrees C in 5% CO2 in air for 3.5 h. Zona-free and zona-intact oocytes similarly inseminated served as controls. Of 113 oocytes, 30 (26%) lysed following zona-opening with the macro technique. The sperm penetration rates of zona-opened and zona-free oocytes were 37% (31/83) and 60% (49/81) respectively (P < 0.01), with 12 and 28% oocytes respectively showing polyspermia (P < 0.05). No sperm penetration occurred in zona-intact oocytes. In experiment II the zona pellucida of hamster oocytes was partially opened by macro- or micro-manipulation techniques before the oocytes were coincubated with human spermatozoa as in experiment I. Nine of 156 (6%) macro-manipulated and 11 of 133 (8%) micro-manipulated oocytes lysed following zona-opening. Of 147 remaining macro-manipulated and 122 remaining micro-manipulated oocytes, 80 (55%) and 79 (64%) respectively were penetrated (P > 0.05), with 30 and 37% respectively showing polyspermia (P > 0.05). These results demonstrate that macro-manipulation results in similar penetration and polyspermia rates as compared to conventional micro-manipulation.

Animals↗
PubMed1994

Timing of the postpartum Papanicolaou smear.

OBJECTIVE: To study the relation between the timing of the postpartum examination and the postpartum Papanicolaou smear. METHODS: One hundred eighty-four women in labor at Arlington Community Hospital were randomized to receive their postpartum Papanicolaou smear at 4, 6, or 8 weeks after delivery. Samples from the exocervix and endocervix were obtained and submitted to the pathology department, which was unaware of the study. RESULTS: Twenty-three women were lost to follow-up. Among 161 women who had a postpartum examination, 48 (30%) had it at 4 weeks, 61 (38%) at 6 weeks, and 52 (32%) at 8 weeks. The groups were similar with respect to age, ethnicity, gravidity, parity, marital status, number of sexual partners, age at first intercourse, history of cervical infections, previous history of abnormal Papanicolaou smears, and cervical surgery. Among the 139 women who had a normal prenatal smear, 26 (59%) had an abnormal smear at 4 weeks (24 [92%] had inflammation, one [4%] had inflammation with nuclear atypia, and one [4%] had cervical intraepithelial neoplasia [CIN] III), 17 (32%) were abnormal at 6 weeks (15 [88%] had inflammation, one [6%] had inflammation with nuclear atypia, and one [6%] had CIN III), and 12 (28%) were abnormal at 8 weeks (11 [92%] had inflammation and one [8%] had inflammation with nuclear atypia). There were no differences in the distribution of abnormal Papanicolaou smears at the repeat smear done 3 months after the postpartum examination. CONCLUSION: The incidence of abnormal Papanicolaou smears increased as the postpartum interval decreased from 8 to 4 weeks.

Adult↗
PubMed1992

Selected intrapartum external cephalic version of the second twin.

After delivery of twin A, external cephalic version was attempted on 30 malpositioned second twins (12 transverse and 18 breech). Version was successful and resulted in subsequent vertex vaginal delivery for 11 of the 12 transverse presentations and 16 of 18 breech presentations. Successful version was not associated with parity or with birth weight. Among the 30 attempted versions, only one infant had a 1-minute Apgar score below 7. There were not enough cases to determine an association of delivery interval between twins and poor neonatal outcome. External cephalic version in selected twin gestations is useful for management of the second twin with abnormal presentation. Technique refinement and greater experience may improve the overall success rate with external version of the second twin. Although external cephalic version cannot yet be recommended as the method of choice, the procedure seems safe, and routine cesarean delivery may not always be indicated.

Female↗
PubMed1992

Incidence of bacteremia at dilation and curettage.

The American Heart Association does not recommend prophylactic antibiotics for patients undergoing dilation and curettage (D & C) except in the case of septic abortion or the presence of prosthetic valves. This recommendation is based on a retrospective analysis of case reports of infectious complications of D & C. To date we are unaware of prospective studies that answer this question. At a community hospital we studied 20 patients undergoing D & C for noninfectious indications. Aerobic and anaerobic blood cultures were performed before and during the D & C. All baseline cultures were negative. In one patient we were able to isolate Lactobacillus after the D & C, thus finding a 5% incidence of bacteremia. That places D & C in the same risk category as other diagnostic procedures considered low risk in the pathogenesis of subacute bacterial endocarditis. Our study thus validated the recommendations made by the American Heart Association.

Adult↗
PubMed1990

Oral contraceptive use, human papillomavirus infection, and risk of early cytological abnormalities of the cervix.

Oral contraceptive (OC) use was examined as a risk factor for cytological abnormalities of the cervix among 1964 women receiving Papanicolaou smears at three hospitals in the Washington, D.C., area. A single pathologist classified cytological results from all women as normal (n = 1423), atypia (n = 314), low grade squamous intraepithelial lesion (SIL; n = 208), or high grade SIL (n = 19). Women in each of the three abnormal groups were compared to women with normal cytological diagnoses. A subset of 579 patients, including most of the women with low or high grade SIL and a matched group of controls, was tested for human papillomavirus (HPV) by type-specific Southern blot hybridization to examine the effects of OC use while taking into account the effects of HPV infection. OC use was found to be unrelated to risk of atypia or low grade SIL but was associated with an elevated risk of high grade SIL that increased with longer duration of use (relative risk = 4.6, 95% confidence interval = 1.1-18.1 for greater than or equal to 5 years of use). HPV infection was associated, as expected, with risk of low and high grade SIL but not with atypia. Taking the HPV results into consideration did not alter the OC findings. There was no evidence that OC use synergistically increased the risk of cervical neoplasia among HPV-infected women, although small numbers prevented a reliable evaluation for high grade SIL. OC use did appear to increase the detection of HPV types 16/18, but the etiological importance of this finding is unclear.

Adult↗
PubMed1989

Gravidic macromastia: case report.

Gravidic macromastia is a rare condition. Breast enlargement in pregnancy is influenced by several hormones, including ovarian steroids and somatotropic or lactogenic polypeptide hormone. Evaluation showed minimal reactive stromal and periductal fibrosis. The treatment is surgical.

Adult↗
PubMed1989

Nutrition intervention program in a prenatal clinic.

Pregnant women who are underweight for height and gestational age are at risk of delivering infants weighing less than infants born to women of standard weight. This study demonstrated that a nutrition intervention program geared toward these high-risk women improved infant outcome. A group of 57 underweight and failure-to-gain pregnant women (treated) who received extensive nutrition counseling and follow-up from a nutritionist throughout their pregnancy was compared with a similar group of 52 underweight pregnant women (control) who received no counseling. Women in the treated group gained significantly more weight during their pregnancy than did controls. The treated women also delivered infants who averaged 300 g heavier than those born to the control group, a statistically significant difference. Other factors reported to compromise infant outcome such as ethnic background, income status, age, and smoking did not significantly affect infant birth weight.

Birth Weight↗
PubMed1984

Use of contact hysteroscopy in evaluating postpartum bleeding and incomplete abortion.

Contact hysteroscopy is a new endoscopic technique that allows direct visual examination of the uterine cavity. Such direct visualization has several potential advantages, including localization of pathology, determination of the adequacy of dilatation and curettage and of biopsy, and precise diagnosis of uterine anomalies. Contact hysteroscopy was used to examine 95 patients with postabortal or postpartum bleeding. The technique was judged successful from the standpoint of technical simplicity, diagnostic accuracy and absence of complications.

Abortion, Incomplete↗
PubMedDate not supplied

Determinants of genital human papillomavirus infection in low-income women in Washington, D.C.

OBJECTIVES: To confirm the risk factors for genital human papillomavirus (HPV) infection. GOAL OF THIS STUDY: To investigate risk factors for HPV detection independent of the correlated risk factors for cervical neoplasia, in a high-risk population. STUDY DESIGN: We investigated 404 cytologically normal women attending medical assistance clinics in the Washington, D.C. area. Risk factor information was obtained and a cervicovaginal lavage was collected and used for HPV detection and typing by a PCR-based technique. RESULTS: The point prevalence of HPV was 33.7%. This contrasts with the 17.7% and 44.3% observed in the companion reports published in this issue of the journal. HPV prevalence decreased with age and increased with greater numbers of sexual partners. Moreover, more recent sexual behavior was a better predictor of current HPV detection than lifetime number of sexual partners. Numbers of pregnancies and current pregnancy were positively associated with HPV prevalence and there was an indication that current oral contraceptive users had a higher prevalence of HPV compared to never users. Smoking was not associated with increased HPV prevalence. CONCLUSION: Findings support the sexual route of transmission of HPV and confirm the association of HPV detection with age, suggesting the host's ability to clear infection or the virus' ability to become latent.

Adolescent↗
PubMedDate not supplied

The effect of hysteroscopy on the incidence of meconium aspiration in high risk obstetric patient.

Four hundred amnioscopies were performed from April to December 1984 using a 6 mm contact hysteroscope to detect the presence of intrauterine meconium on 360 high risk obstetric patients. During that eight month period, out of 400 clinic patients delivered, 25 cases of intrauterine meconium were identified. Two infants had meconium aspiration. In comparable periods of 1982 and 1983, 320-356 clinic patients were delivered. Ten-twelve infants had meconium aspiration in their respective groups. The technique of contact hysteroscopy was demonstrated to be easy to perform with few, if any, complications.

Amniotic Fluid↗
PubMedDate not supplied

The use of the contact hysteroscope in the diagnosis of cord prolapse.

The presence of the umbilical cord in the birth canal either by prolapse or as a funis presentation is a potential obstetrical catastrophe. The contact hysteroscope is a tool which permits rapid and decisive assessment of the position of the cord or of the presenting part.

Endoscopes↗
PubMedDate not supplied

Fractured clavicle in newborns.

A five year retrospective study was undertaken to determine the incidence and associated factors of fractured clavicle in newborns. The time period 1.1.1980 to 12.31.1984 was studied with the finding of 60 cases of fractured clavicle (1% of total vaginal births no. 5,847). An extensive neonatal and maternal chart review found birth weight, gestational age, and prolonged 2nd stage in primiparous patients as predisposing factors. The level of obstetrical experience and difficulty of delivery were also statistically significant. There was no increase in operative deliveries. Most of the cases of fractured clavicles were not appreciated at time of delivery by the delivering physician. One case ended in neurological injury with an Erb's palsy with partial resolution at two week follow-up. Fractured clavicle occurs in a certain high risk population, most cases of which ended up with no long term problems.

Birth Injuries↗
PubMedDate not supplied

Ovarian tumors in pregnancy. A community hospital's five year experience.

Ovarian tumor in pregnancy is a distressing problem for the obstetrician. A physician must differentiate between a manifestation of a normal physiological condition and a serious pathological condition. Fortunately an ovarian tumor in pregnancy is rare. Once the condition is suspected, a physician should use all available tools to confirm the diagnosis. A patient should be treated accordingly, keeping in mind the age of the patient, the gestational age, and the biology of different types of the tumor.

Adult↗
PubMedDate not supplied

Prophylactic antibiotics in patients undergoing total vaginal or abdominal hysterectomy.

A prospective study to evaluate the effect of antibiotic prophylaxis in 57 patients undergoing total abdominal or vaginal hysterectomy was conducted at Arlington Hospital. Patients were assigned randomly to one of two regimens. Group I received a single 1 gram preoperative dose of Cefotaxime (Claforan). Group II received a 2 gram dose of Cefoxitin (Mefoxin) preoperatively and also four 2 gram doses postoperatively. There was no significant group difference in the incidence of postoperative infection or in the mean duration in hospital stay. One dose of Cefotaxime was as effective as five doses of Cefoxitin in preventing infection.

Adolescent↗