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Biomedical subjects

A Fleischer

Publications and source records attributed to A Fleischer.

At least 19 recordsLinked to original sources
PubMed1995

Genetic threshold hypothesis of neocortical spike-and-wave discharges in the rat: an animal model of petit mal epilepsy.

Neocortical high-voltage spike-and-wave discharges (HVS) in the rat are an animal model of petit mal epilepsy. Genetic analysis of total duration of HVS (s/12 hr) in reciprocal F1 and F2 hybrids of F344 and BN rats indicated that the phenotypic variability of HVS cannot be explained by a simple, monogenic Mendelian model. Biometrical analysis suggested the presence of additive, dominance, and sex-linked-epistatic effects, buffering maternal influence, and heterosis. High correlation was observed between average duration (s/episode) and frequency of occurrence of spike-and-wave episodes (n/12 hr) in parental and segregating generations, indicating that common genes affect both duration and frequency of the spike-and-wave pattern. We propose that both genetic and developmental-environmental factors control an underlying quantitative variable, which, above a certain threshold level, precipitates HVS discharges. These findings, together with the recent availability of rat DNA markers for total genome mapping, pave the way to the identification of genes that control the susceptibility of the brain to spike-and-wave discharges.

Action Potentials↗
PubMed1995

Prenatal diagnosis of congenital lipoid adrenal hyperplasia.

Congenital lipoid adrenal hyperplasia (lipoid CAH) is a rare genetic disorder of adrenal and gonadal steroidogenesis of unknown cause in which cholesterol cannot be converted to pregnenolone. As a result, affected individuals can make no steroid hormones, so that all affected newborns are phenotypic females, irrespective of karyotype. We studied two pregnancies in a family with two previously affected children by examining fetal karyotype, genital ultrasonography, and amniotic fluid steroid concentrations and by performing ACTH tests on family members. Prenatal diagnosis correctly identified both an unaffected XX fetus and an affected XY fetus. In the affected pregnancy, amniotic fluid concentrations of progesterone and pregnenolone were 30% and 50% of normal, respectively, but concentrations of 17 alpha-hydroxypregnenolone, 17 alpha-hydroxyprogesterone, cortisol, dehydroepiandrosterone, androstenedione, and estriol were either extremely low or undetectable, suggesting that these detected steroids were donated by maternal steroidogenesis. Fetal cord blood obtained at the termination of pregnancy showed very low concentrations of estrogens donated by the mother's circulation. Absent fetal steroidogenesis was confirmed by gas chromatography and mass spectrometry of both fetal and maternal serum. The responses of 10 different steroids to adrenal stimulation with ACTH in the obligately heterozygous parents were normal. Thus, unlike the case with other forms of CAH, heterozygosity cannot be determined by hormonal responses to provocative testing with ACTH. Immunocytochemistry and Western blotting showed that the affected placental tissue contained P450scc protein, confirming that P450scc is intact in these patients.

Adrenal Hyperplasia, Congenital↗
PubMed1994

Erythrocyte-depleted allogeneic human umbilical cord blood transplantation.

Cord blood is a recently recognized source of hematopoietic stem cells. It can be employed successfully to reconstitute hematopoiesis following allogeneic transplantation. One current drawback of cord blood as a treatment has been a risk of transfusion reactions attributable to ABO blood group mismatch. Removal of red cells from the cord blood has led to reduction of the stem cells by 30-50%. In this paper we report red cell depletion by a method that employs 3% gelatin to effectively sediment the erythrocytes and selectively deplete red cells but permits 94% recovery of nucleated cells and enrichment of colony-forming cells by granulocyte-macrophage colony-forming units, erythrocyte burst-forming units, and granulocyte-macrophage-megakaryocyte colony-forming units in the cord blood preparation. This technique has been employed in our study to remove red cells from the cord blood of a male infant delivered by cesarean section, which has permitted treatment of a female sibling suffering from leukemia. The recipient was 8 years old and weighted 36.7/kg. Complete HLA identity between the two siblings was established. A cord blood cell transplant of cryopreserved and later thawed cells (4 x 10(7) nucleated cells per kilogram) was administered to the patient after intensive myeloablative chemotherapy. The patient exhibited a prompt hematologic recovery (absolute neutrophil count > 500 by day 31, 100% male cells in bone marrow and peripheral blood by day 25) and has experienced a 13-month disease-free survival to date.(ABSTRACT TRUNCATED AT 250 WORDS)

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1992

A persistent clinical problem: profile of the term infant with significant respiratory complications.

A group of 72 term infants with significant respiratory complications were compared with 11,428 term infants delivered during the same time period and without respiratory morbidity. Compared with controls, the study group had a higher incidence of postdatism (36 versus 7%), intrauterine growth retardation (33 versus 8%), meconium-stained amniotic fluid (AF) (90 versus 9%), fetal heart rate (FHR) abnormalities upon admission to labor and delivery (58 versus 7%), and low 5-minute Apgar scores (46 versus 1.4%). Even in the presence of normal intrapartum FHR and 5-minute Apgar scores, infants with meconium-stained AF had an incidence of respiratory complications 100 times higher than those with clear AF. Of infants with a low 5-minute Apgar score at birth, only 20% went on to develop respiratory complications. The remaining 80% had a significantly lower incidence of postdatism, intrauterine growth retardation, and meconium-stained AF.

Apgar Score↗
PubMed1991

Prenatal diagnosis of fetal cephalocele: a sonographic spectrum.

We present the findings in a series of 15 fetuses diagnosed as having a cephalocele. Eleven cephaloceles were located in the occipital region and two each at the vertex and the frontonasal region. Eleven fetuses were diagnosed before 24 week's gestation. Nine families opted for an interruption. Of the two fetuses that went to term, one had a benign meningocele and is growing normally at 18 months, the other died in the neonatal period of associated cardiac anomalies. Of the four fetuses diagnosed after 24 weeks, one is normal (after surgery) at 9 months, two are severely handicapped, and one died in the immediate postpartum period.

Diagnosis, Differential↗
PubMed1991

Association between umbilical artery cord pH, five-minute Apgar scores and neonatal outcome.

A prospective study was conducted of 270 intrapartum patients admitted in labor to investigate the independent and combined relationships between umbilical arterial cord pH and Apgar scores and neonatal outcome. The results revealed that when assessed independently, a low 5-min Apgar score (less than 7) was associated with both NICU admission and neonatal sepsis. When categorized by both cord pH and 5-min Apgar, the majority of patients (75.9%) had both parameters normal, 20.7% had an abnormal pH (less than 7.20) and normal Apgar (greater than or equal to 7) and few patients had either both normal or an abnormal Apgar given a normal pH. Given a normal 5-min Apgar score, additional information about the cord pH did not enhance the predictability for either NICU admission or neonatal sepsis. Neonates with both an abnormal pH and 5-min Apgar had the highest incidence of NICU admission. For all neonates, the presence of meconium greatly increased the likelihood of being admitted to the NICU.

Acidosis↗
PubMed1990

Design of a 13C (1H) RF probe for monitoring the in vivo metabolism of [1-13C]glucose in primate brain.

The design of an RF probe suitable for obtaining proton-decoupled 13C spectra from a subhuman primate brain is described. Two orthogonal saddle coils, one tuned to the resonant frequency of 13C and the other to the resonant frequency of 1H, were used to monitor the in vivo metabolism of [1-13C]glucose in rhesus monkey brain at 2.1 T. Difference spectra showed the appearance of 13C-enriched glutamate and glutamine 30 to 40 min after a bolus injection of [1-13C]glucose.

Animals↗
PubMed1990

Effects of epidural block with lignocaine and lignocaine-adrenaline on umbilical artery velocity wave ratios.

Umbilical artery blood velocity A/B ratios were recorded in term fetuses once before and twice after the maternal epidural injection of either 8 ml of lignocaine plain (15 women) or lignocaine with adrenaline 1:200,000 (40 micrograms) (16 women). The administration of lignocaine plain led to decreases in the ratio of varying degrees in all fetuses regardless of the height of the initial A/B ratio. The injection of lignocaine with adrenaline produced identical results in fetuses with initially normal A/B ratios. In contrast, all six fetuses with initially high A/B ratios (above 2.90) who received the adrenaline-containing anaesthetic reacted with a rise in the ratio, and two of these developed transient heart rate decelerations. Thus, if the initial resistance in umbilical blood flow is high, even the small epidural dose of 40 micrograms of adrenaline produces a further increase which may be associated with clinical implications.

Adult↗
PubMed1989

Acute hemodilution in an anemic Jehovah's Witness during extensive abdominal wall resection and reconstruction.

A 47-year-old anemic Jehovah's Witness with Gardner's syndrome presented with a large abdominal wall desmoid tumor requiring extensive resection with a musculocutaneous flap reconstruction. At surgery a technique of acute limited normovolemic hemodilution (ALNH) was used to minimize blood loss and avoid blood transfusions. Complications that follow transfusions of homologous blood are reviewed, and a recommendation is made to use ALNH because of its advantages in those patients in whom significant blood loss is expected.

Abdominal Neoplasms↗
PubMed1989

Reconstruction of the mediastinal trachea with a tubed pectoralis major myocutaneous flap.

A young patient with a massive postirradiation recurrence of thyroid cancer invading the larynx and mediastinal trachea had been treated by resecting the larynx and trachea to within three rings of the carina. A mediastinal tracheostomy was avoided by using a tubed pectoralis major myocutaneous flap to replace the ablated trachea. The flap, transferred into the mediastinum subclavicularly, was connected to the tracheal stump and exteriorized as a cervical tracheostomy. This resulted in direct closure of the donor site and primary healing. Four years after the operation, the patient remains free of disease and is tolerating the neotrachea without difficulty or complications. The technique described is offered as an alternative to conventional mediastinal tracheostomy methods, which have acknowledged shortcomings.

Adult↗
PubMed1989

The subcutaneous rheumatoid nodule.

The subcutaneous rheumatoid nodule is a common and diagnostically significant finding in rheumatoid arthritis. The presence of these extra-articular lesions correlates with the extent of joint involvement and they are an index of disease severity. The nodules themselves may give rise to clinical problems and the indications for surgical treatment include erosion and infection, peripheral neuropathy or pain from pressure, and limitation of motion because of the location of the lesion. Less frequently, rheumatoid nodules present in patients with rheumatoid nodulosis, a variant of rheumatoid disease where the nodules themselves are the primary manifestation of the disease and surgical treatment is highly useful. While subcutaneous nodules are very characteristic of rheumatoid arthritis and its variants, they are not quite pathognomonic. Rarely, they are found in the absence of rheumatoid disease, especially in lupus erythematosus and in healthy children.

Female↗
PubMed1989

Management of postirradiation recurrent enterocutaneous fistula by muscle flaps.

Occasionally surgeons have to operate on patients who have had previous abdominal or pelvic operations and irradiations for malignancies. Bowel resection with primary anastomosis under these circumstances is fraught with major complications such as anastomotic breakdown with intra-abdominal sepsis or recurrent enterocutaneous fistula, which are refractory to conventional management. New techniques for using vascularized muscle flaps from a distant nonirradiated field to achieve safe repair of the bowel defects in three such instances are presented.

Adenocarcinoma↗
PubMed1988

Pregnancy termination after detection of fetal chromosomal or metabolic abnormalities.

In 3400 midtrimester amniocenteses, 68 fetuses had abnormal findings. Three women elected to continue their pregnancies and the remainder chose terminations. Of these, 29 were cared for in our hospitals. Pregnancy termination was carried out in gestations averaging 21.6 +/- 2.3 weeks and fetal weights averaging 531 +/- 351 g. Three prostaglandins techniques were used, two of which proved to be effective. Dosages employed were comparable to those used in early second trimester pregnancy terminations. Side effects were similar; one retained placenta occurred. We have used a multidisciplinary counseling approach for these couples and have restricted ourselves to the medical aspects of their problems. Techniques are described for the psychologic support of the couple during this stressful period.

Abortion, Induced↗
PubMed1987

The significance of absent end-diastolic velocity in umbilical artery velocity waveforms.

Doppler umbilical artery velocimetry has been used to study high-risk pregnancies. The most extreme waveform abnormality is the absence of end-diastolic velocity. To examine the significance of this finding, events outcome was evaluated in 161 women studied between 31 and 36 weeks. Ten had absence of end-diastolic velocity. When compared with fetuses with normal and less severely abnormal waveforms, there was a higher incidence of intrauterine growth retardation, pregnancy-induced hypertension, cesarean section for fetal distress, neonatal intensive care unit admission, and low Apgar scores. Average birth weight and gestational age at delivery were lower. Five other fetuses with absence of end-diastolic velocity were identified that were delivered between 27 and 30 weeks, making a total of 15 patients with absence of end-diastolic velocity. Of 12 patients monitored, 11 had an abnormal fetal heart rate pattern. Four fetuses had lethal anomalies. There were eight perinatal deaths. Acute or chronic hypoxia was evident in all fetuses with absence of end-diastolic velocity. Absent end-diastolic velocity represents a unique and severe fetal condition that cannot be identified by present surveillance methods and requires a Doppler study for diagnosis.

Blood Flow Velocity↗