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Biomedical subjects

A Cohen

Publications and source records attributed to A Cohen.

At least 325 records · Page 18Linked to original sources
PubMed1996

Dorsal penile nerve block in children undergoing circumcision in a day-care surgery.

PURPOSE: Circumcision is performed under general anaesthesia (GA) with dorsal penile nerve block (DPNB) as an analgesic technique for postoperative pain. The purpose of this study was to compare DPNB as the sole anaesthetic procedure vs GA and DPNB for circumcision in children as an outpatient procedure. METHODS: In a six-month prospective study, 250 boys aged 6 to 17 yr (mean age 11.5 +/- 3.5 yr) were randomized into two groups. Group A (n = 122) received DPNB only prior to circumcision, and Group B (n = 128) received GA + DPNB. The groups were compared for complications of the block, effectiveness of anaesthesia, operating room time, postoperative time and ease of recovery. RESULTS: There were no major operative complications in the two groups. Minor block complications, including oedema and haematoma, occurred in 16 (13.1%) boys in Group A and 27 (21.10%) boys in Group B (NS). At surgery, 3 (2.6%) from Group A received additional GA and 1 (0.8%) received additional local anaesthesia. They represent a DPNB failure rate of 3.3%. Mean operating room time was 11 +/- 2.5 min in Group A and 19 +/- 3.5 min in Group B, and post-anaesthesia care unit (PACU) time was 51 +/- 10 min in Group A and 101 +/- 14.5 min in Group B (P < 0.001). Nausea and vomiting in the PACU were noted in one patient in Group A and in 15 in Group B (P < 0.05). Only patients in Group B required additional analgesia and tranquilizers in the PACU (0 versus 20; P < 0.05). CONCLUSIONS: These data confirm that DPNB has advantages over GA + DPNB for paediatric circumcision in day-care surgery.

Adolescent↗
PubMed1996

Prenatal diagnosis and the pediatric surgeon: the impact of prenatal consultation on perinatal management.

PURPOSE: Pediatric surgeons are increasingly called on by obstetrical colleagues to counsel parents about the implications of a prenatal ultrasound finding. Our understanding of the natural history of many prenatally diagnosed surgical conditions has grown significantly in recent years. Whether prenatal surgical consultation can influence perinatal course had not been investigated. METHODS: During an 21-month period, 12,865 prenatal ultrasound studies were performed on a total of 4,551 patients, and 221 prenatal surgical consultations were obtained through a newly established fetal treatment program at a tertiary care prenatal diagnostic center. To evaluate the impact of prenatal pediatric surgical consultation on perinatal course, the authors reviewed changes in management including termination of pregnancy, in utero intervention, and altered site, mode, or timing of delivery. RESULTS: Two hundred twenty-one fetuses were referred for consultation; their 234 congenital anomalies included genitourinary (36%), thoracic (16%), intraabdominal (14.5%), abdominal wall (10.6%), neurological (9%), skeletal (6%), and head and neck (2.5%) defects; 2.5% had tumors and 2.5% were twin pregnancies. Pregnancy was terminated in 9.5% of cases, because of patient request, chromosomal abnormality, or dismal prognosis. In 3.6%, the decision to terminate was changed as a result of consultation. Site of delivery was changed as a result of consultation in 37% to facilitate postnatal evaluation and initiate immediate treatment. Mode of delivery was changed in 6.8% to prevent dystocia, hemorrhage into a tumor, as in sacrococcygeal teratoma, or to provide an emergency airway, as in cervical teratoma. The timing of delivery was changed in 4.5% to avoid further damage to fetal organs in cases of obstructive uropathy, gastroschisis, sacrococcygeal teratoma with high-output failure, and hydrocephalus. Five percent (11) underwent treatment in utero for fetal hydrothorax, obstructive uropathy, twin-twin transfusion syndrome, or lymphangioma. The overall perinatal mortality rate was 2.5%. CONCLUSION: Prenatal pediatric surgical consultation may have a significant impact on the perinatal management of the fetus with a surgically correctable congenital anomaly. Providing obstetric colleagues and families with valuable insight into the surgical management of anomalies allows fetal intervention when appropriate, and delivery in an appropriate setting, by the safest mode of delivery, and at the gestational age appropriate to minimize effects of the anomaly.

Abortion, Therapeutic↗
PubMed1996

Association of epidural analgesia with cesarean delivery in nulliparas.

OBJECTIVE: To evaluate whether epidural analgesia during the first stage of labor is associated with an increased risk of cesarean delivery. METHODS: The association of epidural analgesia and cesarean delivery was examined in a retrospective study of 1733 low-risk, term nulliparas with singleton infants in vertex presentations, in which labor began spontaneously. To evaluate the effect of epidural analgesia on cesarean deliveries, independent of other factors influencing the use of epidural analgesia, we used propensity scores to create five subgroups (quintiles) of women who, based on characteristics discernible at admission, appeared equally likely to receive epidural analgesia. Multivariate logistic regression analysis was used to control for confounding. RESULTS: Overall, the cesarean rate among women receiving epidural analgesia was 17% (168 of 991), compared with 4% (30 of 742) among those who did not receive epidural analgesia. An increased cesarean rate among women receiving epidural analgesia was present in all propensity quintiles. In an adjusted logistic regression analysis, women receiving epidural analgesia were 3.7 times more likely to undergo a cesarean (95% confidence interval 2.4, 5.7). The greatest increase in cesarean risk was noted when epidural analgesia was administered earlier in labor, but there was a more than twofold increase regardless of the dilation and station at administration of epidural analgesia. CONCLUSIONS: Epidural analgesia may increase substantially the risk of cesarean delivery. Although the causal nature of this association remains open to debate, prenatal care providers should routinely discuss the risks and benefits of epidural analgesia with women during their pregnancies so that they can make informed decisions about the use of pain relief during labor.

Adult↗
PubMed1996

Prior exposure to superantigen can inhibit or exacerbate autoimmune encephalomyelitis: T-cell repertoire engaged by the autoantigen determines clinical outcome.

Experimental allergic encephalomyelitis (EAE) is inducible in experimental animals immunized with myelin basic protein (MBP), proteolipid protein (PLP) or their peptides. We compared T-cell responses to encephalitogenic epitopes of PLP(43-64) and MBP(Ac1-11) in a single mouse strain, (PL/J x SJL)F1. MBP(1-11)-specific T-cell hybridomas expressed predominantly TCR V beta 8 or V beta 4, while PLP(43-64)-specific hybridomas expressed a diverse TCR repertoire. To analyze the biologic significance of the TCR repertoire (limited vs. diverse) to disease susceptibility, we pretreated mice with a superantigen (SEB), and then induced disease with these autoantigens. Mice injected with SEB and immunized with MBP(Ac1-11) showed significant inhibition of EAE, whereas SEB-pretreated mice immunized with PLP(43-64) had an increased severity of EAE and developed a chronic disease. These data demonstrate that prior exposure to microbial superantigens can significantly alter the autoimmune disease course depending upon the TCR repertoire used by the autoantigen.

Animals↗
PubMed1996

The significance of microbial cultures of the hematopoietic support for patients receiving high-dose chemotherapy.

The use of hematopoietic support for patients receiving high-dose chemotherapy has increased over the past 10 years. Various quality controls are performed on the hematopoietic cells, including microbiologic cultures. There is considerable expense associated with the serial cultures performed at different times during the collection, processing, and use of the cells. We reviewed all the microbiologic cultures performed on bone marrow harvests and leukaphereses over a 17 month period. Of the 227 bone marrow harvests, 16 cultures were positive, but only 3 (1.3%) were repeat positives with the same organism after processing or at the time of reinfusion. Of the 560 leukaphereses, 4 (0.7%) were cultured positive at the time of collection and reinfusion. Two patients were bacteremic with gram-negative bacilli at the time of leukaphereses despite being asymptomatic, and these were the only two products that had to be collected again. No patient suffered an adverse clinical result after receiving culture-positive cells. Bone marrow and peripheral blood progenitor cells can be safely collected, and a culture after processing is adequate to ensure the safety of the product.

Blood↗
PubMed1996

Safety of dobutamine stress echocardiography. A 24 h Holter monitoring study.

BACKGROUND: Dobutamine-atropine stress echocardiography is an efficient method in the evaluation of patients with coronary artery disease. However, because high-dose dobutamine is potentially arrhythmogenic, the safety of this stress modality has been questioned. METHODS: We performed a 24 h Holter monitoring, before and immediately after this test, in 73 consecutive patients (60 men and 13 women), mean age 60 +/- 12 years. Twenty-eight patients had had a recent myocardial infarction, 25 had stable chronic angina, 10 chronic ischaemic cardiomyopathy and 10 idiopathic dilated cardiomyopathy. Dobutamine was progressively increased (5-40 micrograms.kg-1.min-1) and atropine was injected in 30 patients. Arrhythmias and ST-segment deviation before and after the stress test were evaluated. RESULTS: The mean peak dobutamine dose was 32 +/- 11 micrograms.kg-1.min-1. The heart rate at rest and at peak dose was, respectively, 69 +/- 16 and 110 +/- 28 beats.min-1. Side effects during the injection of dobutamine were mainly ventricular (n = 14) or atrial (n = 4) premature contractions. Three patients had non-sustained ventricular tachycardia and five had hypotension during the test. No sustained episode of supraventricular or ventricular tachycardia was observed during the study. Non-sustained supraventricular and ventricular tachycardias were detected in 8 and 21 patients before and in 11 and 16 patients after dobutamine stress echocardiography (P = ns). Asymptomatic ST-segment deviation was observed in two patients before and four after dobutamine stress echocardiography. An increase in total ischaemic time (20 vs 102 mn) was observed after the test, but only five patients had ST modifications. A separate analysis of patients with and without beta-blocker did not alter these results. In addition, when the occurrence of significant arrhythmias was stratified according to a left ventricular ejection fraction threshold of 45%, we observed no difference in frequency and severity of cardiac arrhythmias. CONCLUSION: This study demonstrates that dobutamine stress echocardiography does not significantly increase arrhythmia during the following 24 h. Further studies are required to evaluate the influence of the test on ST-segment modification during the same period.

Aged↗
PubMed1996

A comparison of risk factors for preterm labor and term small-for-gestational-age birth.

This study estimates the effects of 23 factors on the prevalence of premature labor and fetal growth retardation across the entire birthweight spectrum. We studied risk factors for premature labor within the domain of babies of appropriate size for their gestational age (N = 9,490). We also studied risk factors for fetal growth retardation among babies born at term (N = 10,889). Preterm labor was associated independently with young maternal age, low pre-pregnant weight, low weekly weight gain, nulliparity, previous preterm birth, histories of two or more induced abortions, spontaneous abortions, or stillbirths, uterine exposure to diethylstilbestrol (DES), incompetent cervix, uterine anomaly, and pyelonephritis. Odds ratios ranged from 1.7 to 5.9. Fetal growth retardation, as estimated by small-for-gestational-age birth, was associated independently with black race, young maternal age, short maternal height, low prepregnancy weight, low weekly weight gain, and smoking, as well as nulliparity, previous preterm birth, three or more abortions, uterine anomaly, and uterine exposure to DES. Odds ratios ranged from 1.6 to 2.8. Our study shows the importance for etiologic understanding of separating diverse routes to low birthweight and considering the occurrence of adverse pregnancy outcomes along the entire birthweight spectrum. The findings reinforce the need for comprehensive control of confounding in studies of pregnancy outcome.

Boston↗
PubMed1996

A phase I safety and pharmacokinetic study of a recombinant amino terminal fragment of bactericidal/permeability-increasing protein in healthy male volunteers.

A phase I pharmacokinetic and safety clinical trial of rBPI23, a recombinant amino terminal fragment of bactericidal/permeability-increasing protein, was conducted in healthy male volunteers. rBPI23 was administered as a 5 or 30 min infusion at doses of .1 to 1 mg/kg. The pharmacokinetics of rBPI23 in human subjects were described by a bi-exponential disposition function with evidence of concentration-dependent kinetics. The alpha half-life increased significantly with increasing dose, from 4-5 min at .1 mg/kg to 7-8 min at 1 mg/kg. The beta half-life varied between 18 and 29 min regardless of dose and the clearance varied from 5 to 10 mL/min/kg. Very little, if any, of the administered rBPI23 was excreted intact in the urine. Electrocardiograms, ionized calcium concentration, prothrombin and partial prothrombin times, hematologic parameters, and blood chemistries remained normal. Furthermore, no antibody response to rBPI23 was observed in any of the subjects.

Adolescent↗
PubMed1996

Sleep architecture as related to temperature changes in neonates at term.

Sleep architecture was assessed under different environmental temperatures in 10 full-term and 10 preterm infants who reached term. Five 30-min periods of baseline, normothermia heating, peak temperature, cooling and normothermia were analysed. A significant decrease in the proportion of active sleep (AS) and an increase in quiet sleep (QS) was noted among the full-term infants during the heating and peak temperature conditions, whereas, among the preterm infants, a similarly significant difference was noted during the heating and cooling stages of the study, but not during the stage of peak temperature. This differential response to environmental hyperthermia is possibly related to maturational factors. This phenomenon may be related to the increased vulnerability of low birth weight infants to apnoea and sudden infant death syndrome.

Body Temperature↗
PubMed1996

Decreased hospital utilization by older adults attributable to a home hospitalization program.

OBJECTIVE: To evaluate the cost effectiveness of a short-term home health care program for older people, Home Hospitalization (HH), compared with the alternative of regular ambulatory care with general or geriatric hospitalization as necessary. SETTING: Our HH was initiated in November 1991 to serve Jerusalem residents. Program staff included physicians, nurses, and paramedical professionals. Other medical/hospital services were provided nonselectively by the general medical personnel of the various hospitals in Jerusalem. STUDY DESIGN: Patients over the age of 65 were either referred to the HH program (study group, n = 36,500) or to routine medical care (control group; n = 9000) depending on their Sick Fund assignment. Hospital utilization rates per enrollee were studied prospectively and compared both between the two groups and with hospitalization rates in the year before the initiation of the program. RESULTS: During the first 26 months of operations, the HH program cared for 741 older persons for a total of 37,290 days' care at an average daily costs of $30.06 (1992) and $23.64 (1993). Annual general hospitalization rates per person declined in the study group from 2.80 days in the 1991 baseline period to 2.65 days in 1992 and to 2.54 days in 1993. Hospitalization rates in the control group increased from 2.62 in 1991 to 2.70 days/member and 2.71 days/member in 1992 and 1993, respectively. Annual geriatric hospitalization rates declined considerably in the study group from the 1991 baseline of 1.49 to 1.34 (1992) to 1.33 (1993). The control group experienced a small decrease from 1.64 (1991) to 1.58 (1992) and then a rise to 1.68 days per member in 1993. For the 26-month duration of the program, estimated savings of 20,773 general hospital days ($5.54 million) and 8486 geriatric hospital days ($0.98 million) exceeded its costs ($0.97 million), providing a cost/benefit ratio of 5.7/1. In addition, patient satisfaction was high. CONCLUSION: The HH program provided a cost effective substitute for care in a geriatric or general hospital for Jerusalem's elderly.

Aged↗
PubMed1996

Altered mRNA binding activity and decreased translational initiation in a nuclear mutant lacking translation of the chloroplast psbA mRNA.

Translational regulation has been identified as one of the key steps in chloroplast-encoded gene expression. Genetic and biochemical analysis with Chlamydomonas reinhardtii has implicated nucleus-encoded factors that interact specifically with the 5' untranslated region of chloroplast mRNAs to mediate light-activated translation. F35 is a nuclear mutation in C. reinhardtii that specifically affects translation of the psbA mRNA (encoding D1, a core polypeptide of photosystem II), causing a photosynthetic deficiency in the mutant strain. The F35 mutant has reduced ribosome association of the psbA mRNA as a result of decreased translation initiation. This reduction in ribosome association correlates with a decrease in the stability of the mRNA. Binding activity of the psbA specific protein complex to the 5' untranslated region of the mRNA is diminished in F35 cells, and two members of this binding complex (RB47 and RB55) are reduced compared with the wild type. These data suggest that alteration of members of the psbA mRNA binding complex in F35 cells results in a reduction in psbA mRNA-protein complex formation, thereby causing a decrease in translation initiation of this mRNA.

Acetates↗
PubMed1996

Final height of patients who underwent bone marrow transplantation during childhood.

OBJECTIVE: To determine the impact on final adult height of bone marrow transplantation. METHODS: The final height of 28 long term survivors (18 males; 10 females), allografted before or at the onset of puberty, at a median age of 10.8 years (range 6.3 to 14.6) and who did not receive growth hormone (GH) treatment or other growth promoting agents, was evaluated. Median follow up period after bone marrow transplantation was 7.9 years (range 3.2 to 11.4), and age at the most recent evaluation 18.1 years (range 15.6 to 24.5). Height values were expressed in standard deviation score (SDS) from the mean of the normal population. Height at bone marrow transplantation was compared with final height as well as with parental genetic height. Patients were divided into three groups: severe aplastic anaemia (SAA): three patients given no radiotherapy; leukaemia-total body irradiation (TBI): 14 patients with acute or chronic leukaemia conditioned with chemotherapy and TBI; leukaemia-TBI with previous cranial radiation therapy (CRT): 11 patients. None of the patients had solid tumour. RESULTS: There was a decrease in final height SDS compared to pre-transplantation height SDS (paired t test, p < 0.0001). All patients except one reached an adult height above -2.0 SDS. A significant decrease in height SDS was found in the TBI and the CRT groups (paired t test, p = 0.02 and p = 0.0002, respectively). Whereas height SDS value at the time of transplant was higher than the genetic height SDS, final height SDS values were lower. CONCLUSIONS: Despite the decrease in height SDS found after bone marrow transplantation, 27 of the 28 patients spontaneously achieved what is considered to be a normal height SDS (above -2.0 SDS). This should be taken into account when considering GH treatment in children who underwent bone marrow transplantation for malignant haematological diseases.

Adolescent↗
PubMed1996

Machado-Joseph disease in east Arnhem Land, Australia: chromosome 14q32.1 expanded repeat confirmed in four families.

Four kindreds of east Arnhem Land Australian aboriginal people from Groote Eylandt and adjacent communities display symptoms of a similar spinocerebellar degeneration (multiple-system degenerative disease). The familial pattern indicates an autosomal dominant inheritance, though with varying penetrance in different families. This condition is clinically and pathologically consistent with Machado-Joseph disease (MJD), and there is the possibility of Portuguese ancestry. These families exhibit anticipation, particularly in the case of paternal inheritance, with those with earlier age of onset presenting a clinical pattern consistent with MJD type I. There was no expansion of the CAG repeat region of the SCA1 gene in these families. The demonstration of expansion of the CAG repeat on chromosome 14q32.1 in all four families confirms the diagnosis of MJD.

Australia↗