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Biomedical subjects

S Kogan

Publications and source records attributed to S Kogan.

At least 19 recordsLinked to original sources
PubMed2001

Vaginal reconstruction with a rectus abdominis musculoperitoneal flap.

In more than 300 clinical cases, the authors have observed and documented the presence of a branch of the deep inferior epigastric artery that penetrates the posterior rectus sheath near the umbilicus. Their cadaveric anatomic and animal injection studies confirm the vascularity of the peritoneum via the deep inferior epigastric artery. They report 2 patients treated with a new technique of vaginal reconstruction using a thin, pliable flap with a peritoneal-lined rectus abdominis muscle based on the deep inferior epigastric vessels.

Adolescent↗
PubMed2001

Patient and clinician vocabulary: how different are they?

Consumers and patients are confronted with a plethora of health care information, especially through the proliferation of web content resources. Democratization of the web is an important milestone for patients and consumers since it helps to empower them, make them better advocates on their own behalf and foster better, more-informed decisions about their health. Yet lack of familiarity with medical vocabulary is a major problem for patients in accessing the available information. As a first step to providing better vocabulary support for patients, this study collected and analyzed patient and clinician terms to confirm and quantitatively assess their differences. We also analyzed the information retrieval (IR) performance resulting from these terms. The results showed that patient terminology does differ from clinician terminology in many respects including misspelling rate, mapping rate and semantic type distribution, and patient terms lead to poorer results in information retrieval.

Humans↗
PubMed2001

Problems and challenges in patient information retrieval: a descriptive study.

Many patients now turn to the Web for health care information. However, a lack of domain knowledge and unfamiliarity with medical vocabulary and concepts restrict their ability to successfully obtain information they seek. The purpose of this descriptive study was to identify and classify the problems a patient encounters while performing information retrieval tasks on the Web, and the challenges it poses to informatics research. In this study, we observed patients performing various retrieval tasks, and measured the effectiveness of, satisfaction with, and usefulness of the results. Our study showed that patient information retrieval often failed to produce successful results due to a variety of problems. We propose a classification of patient IR problems based on our observations.

Adult↗
PubMed1998

Compliance of frail elderly with health services prescribed at discharge from an acute-care geriatric ward.

OBJECTIVES: A model of compliance by frail elderly with prescribed healthcare services was developed and tested. The discrepancy between primary care, geriatric and community health center (CLSC) services prescribed at discharge after comprehensive geriatric evaluation and treatment was measured, as were those services actually used during a 6-week interval (compliance). In this model, compliance was directly related to elders' intention to adhere to prescribed services, but this relationship was modified by organizational factors, reinforcing factors, and changes in health status during the observation period. Intention to adhere resulted from individual and reinforcing factors existing before discharge. METHODS: This model was tested on 211 patients discharged to community settings from an acute-care hospital geriatrics ward. Information was obtained through interviews with the patients or care givers and from hospital, outpatient, and local community health center charts. RESULTS: On average, patients used 56.9% of services prescribed; 13% of patients did not use any of the services prescribed for them, whereas 22% used all the services prescribed. Intention to adhere was influenced by patients' perception of the benefits of prescribed services and by their perception of the ease of access to transportation. Intention itself was not found to be an important determinant of overall compliance. Among organizational factors, having the ward staff make a follow-up appointment with the patients' family doctor and with the geriatric clinic before discharge and communication with the local community health center increased overall compliance. Moreover, patients who perceived they had access to transportation and to an accompanying person were more likely to comply. CONCLUSIONS: The results suggest that when discharging patients to the community, steps taken for them by the discharging healthcare providers will improve compliance.

Aged↗
PubMed1997

A PMLRARalpha transgene initiates murine acute promyelocytic leukemia.

The malignant cells of acute promyelocytic leukemia (APL) contain a reciprocal chromosomal translocation that fuses the promyelocytic leukemia gene (PML) with the retinoic acid receptor alpha gene (RAR alpha). To test the hypothesis that the chimera PMLRAR alpha plays a role in leukemogenesis, we expressed a PMLRAR alpha cDNA in myeloid cells of transgenic mice. PMLRAR alpha transgenic mice exhibited impaired neutrophil maturation early in life, which progressed at a low frequency over the course of several months to overt APL. Both the preleukemic state and the leukemia could be transplanted to nontransgenic mice, and the transplanted preleukemia could progress to APL. The APL recapitulated features of the human disease, including a response to retinoic acid. Retinoic acid caused the leukemic cells to differentiate in vitro and in vivo, eliciting remissions of both the preleukemic state and APL in mice. Our results demonstrate that PMLRAR alpha impairs neutrophil differentiation and initiates the development of APL. The transgenic mice described here provide an apparently accurate model for human APL that includes clear evidence of tumor progression. The model should be useful for exploring the molecular pathogenesis of APL and the mechanisms of the therapeutic response to retinoic acid, as well as for preclinical studies of therapeutic regimens.

Animals↗
PubMed1997

Cryptorchidism. Current concepts.

Cryptorchidism is the most common genitourinary disorder of childhood. Even though its incidence has changed only slightly over the years, the number of operations for cryptorchid testes has tripled. Better understanding of the natural history of cryptorchidism, as well as changes that occur in testicular histology both in the cryptorchid and the contralateral descended testis very early in life, are the cause. This experience has led us to advocate early orchiopexy as the optimum means of treatment.

Child↗
PubMed1996

Do consensus conferences influence their participants?

OBJECTIVE: To determine whether participation in a consensus conference on the assessment of dementia would influence conference participants with respect to their recommendations to primary care physicians for the assessment of dementia. DESIGN: Questionnaire before and after the conference. SETTING: Canadian Consensus Conference on the Assessment of Dementia, held in Montreal, Oct. 5 and 6, 1989. PARTICIPANTS: All 38 experts representing relevant health disciplines who participated in the consensus conference; 36 completed both questionnaires. OUTCOME MEASURES: Participants' opinion before and after the conference as to how frequently each of 28 manoeuvres (12 blood tests, 4 neurologic imaging procedures, 4 types of consultation and 8 "other" tests) should be ordered by primary care physicians as part of an assessment of a patient with dementia suspected in clinical grounds. RESULTS: For 18 (64%) of the 28 manoeuvres (10 of the 12 blood tests, 3 of the 4 neurologic imaging procedures and 5 of the 8 "other" tests), there was a shift in opinion after the conference toward recommending that primary care physicians order them less often; for 10 of these 18 (5 blood tests and 5 "other" tests) the shift was statistically significant. For the remaining 10 manoeuvres (36%) the shift in opinion was toward a recommendation that primary care physicians order them more often; the shift was not statistically significant for any of these 10 manoeuvres. CONCLUSION: Expert members of a consensus conference are influenced by the process of having participated in such a conference and are capable and willing to chance their initial recommendations when confronted with relevant data.

Clinical Laboratory Techniques↗
PubMed1995

The impact of external cephalic version on the rate of vaginal and cesarean breech deliveries: a 3-year cumulative experience.

The authors have reviewed the impact of their practice of external cephalic version (ECV) at term, with respect to success rate, factors associated with successful version and the effect of this protocol on the overall breech and cesarean breech rate. Two hundred and forty-nine parturients identified as having a breech presenting fetus after the 36th gestational week over a 3-year period, after excluding contraindicated cases, were offered a trial of ECV, with the use of ritodrine tocolysis. ECV was effected by one operator, using the minimally effective force necessary. Successful ECV was achieved in 196 attempts (78.7%). No deleterious effects in fetuses or mothers were noted. Of successfully turned fetuses, 78% eventually had a vaginal vertex delivery. Parity, birthweight and amount of amniotic fluid were found to have a significant effect on the success rate of ECV, whereas gestational age at version or placental location were not found to have a significant effect on success rate. Introduction of the ECV protocol effected a significant decrease in breech presentation at term, from 3.9 to 2.4% (P < 0.01), which can be translated into a decrease of 5.5% in the overall cesarean section rate. The authors conclude that ECV is a safe and effective procedure, in properly selected cases. Institution of a screening protocol to identify breech presentation after 36 weeks, and utilizing ECV where possible, may lead to a significant reduction in the breech delivery rate, and may prevent serious infant morbidity.

Amniotic Fluid↗
PubMed1994

External cephalic version after previous cesarean section--a clinical dilemma.

OBJECTIVES: To describe our limited experience with external cephalic version from breech to vertex presentation at term, with the use of ritodrine tocolysis, in women who had undergone a previous cesarean delivery. METHODS: Eleven parturients after previous cesarean delivery underwent external version after 36 gestational weeks, utilizing tocolysis with ritodrine, after excluding cases of low-lying placenta, severe oligohydramnion or ruptured membranes. Patients were then followed until delivery and scar examination was carried out after vaginal delivery, or at re-cesarean section, according to mode of delivery. RESULTS: All 11 attempted versions were successful. Six patients subsequently delivered vaginally and five by re-cesarean section. None of the uterine scars showed any signs of dehiscence. Three of the five infants delivered by re-cesarean section weighed over 4000 g, whereas all of the vaginally-delivered infants weighed under 3500 g. CONCLUSIONS: External cephalic version to vertex presentation after previous cesarean section was successful in all 11 carefully selected patients. No untoward effects were noted, and no signs of scar dehiscence were found. The safety and efficacy of this procedure after previous cesarean delivery should be examined further.

Adult↗
PubMed1993

Apolipoprotein E polymorphism and Alzheimer's disease.

Apolipoprotein E (apoE) is associated with Alzheimer's neurofibrillary tangles and beta-amyloid protein in senile plaques. It also appears to play an important part in the redistribution of lipids that follows deafferentation and neurodegeneration in the brain. The gene for apoE is on chromosome 19, within the genomic region previously associated with late-onset familial Alzheimer's disease (AD). We have studied apoE phenotype expression and the corresponding allele frequencies (epsilon 2, epsilon 3, epsilon 4) in 91 patients with sporadic AD and 74 controls. There was a significant association between epsilon 4 and sporadic AD (epsilon 4 frequency 0.380 in AD and 0.122 in controls, p < 0.01). Analysis of epsilon 4 in whom AD develops this tended to happen earlier in life than in those with epsilon 3 or epsilon 2. The epsilon 4/AD association was more pronounced in women. Octogenarians with AD had an epsilon 4 allele frequency that was 3 times higher than one reported, in a different study, in healthy octogenarians. ApoE may be an important susceptibility factor in the aetiopathology of sporadic AD.

Age Factors↗
PubMed1993

Genitourinary malformations associated with agenesis of the corpus callosum.

Agenesis of the corpus callosum is an infrequent congenital anomaly that occurs in partial or complete forms, and is frequently associated with other craniofacial and skeletal abnormalities. An increased association with genitourinary abnormalities has not been previously defined. We reviewed the records of 22 boys and 11 girls with agenesis of the corpus callosum. Of the patients 18 had complete radiological or necroscopic evaluation and 15 had physical examinations as the sole means of evaluation. Renal anomalies were the most frequent genitourinary abnormalities identified in these children, although ureteral, genital and bladder abnormalities were also encountered. There was an exceptionally high incidence of undescended testes (23%), approximately 20-fold greater than the frequency in the normal population, possibly resulting from hypothalamic insufficiency associated with midline cranial defects. We suggest, therefore, that all patients with agenesis of the corpus callosum should be thoroughly evaluated with bladder and renal ultrasound studies to rule out any genitourinary abnormalities. Male patients with agenesis of the corpus callosum and undescended testes should undergo hypothalamic/pituitary axis testing.

Abnormalities, Multiple↗
PubMed1992

Unsuspected involvement of the female genitalia in pemphigus vulgaris.

A 56-year-old woman had erosions due to pemphigus vulgaris in the inner thighs and perineum. The cutaneous lesions cleared following intramuscular gold therapy. However, because of complaints of dyspareunia, a colposcopic examination was performed and involvement of the cervix was demonstrated. The need for a vaginal examination in the monitoring of pemphigus vulgaris is emphasized.

Colposcopy↗
PubMed1992

Amino acid substitutions in conserved domains of factor VIII and related proteins: study of patients with mild and moderately severe hemophilia A.

Mutations leading to hemophilia A by substitution of amino acids in coagulation factor VIII may provide important clues to the structure and function of this large and enigmatic protein. To efficiently find missense mutations, hemophiliacs with mild and moderately severe forms of the disease were surveyed. DNA samples from affected individuals were assayed for mutations by denaturing gradient gel electrophoresis following DNA amplification of target regions, which included all coding regions except for that of the dispensable B domain. Missense mutations were observed in 20 of the 34 patients examined, with identical mutations found in five pairs of patients. All mutations were found in the repetitive A and C domains. By aligning these domains in factor VIII with homologous domains in factor V, ceruloplasmin, and the mouse milk fat globule membrane protein, it was determined that most mutations change amino acids in areas of strong sequence conservation. Three additional mutations were detected, including a point mutation in an intron, a stop codon mutation, and a silent base change. Ten of the 18 different mutations discovered in this patient population are reported here for the first time.

Amino Acid Sequence↗
PubMed1991

Environment, genetics and idiopathic Parkinson's disease.

Since Idiopathic Parkinson's disease (IPD) was first described more than 170 years ago, there have been major advances in the understanding of the etiology of the disease as well as in its treatment. This article will review current knowledge concerning the role of the environment, genetic hypotheses and the aging factor in the etiology of IPD and proposes a complex interaction involving all these factors. Hypotheses regarding mitochondrial inhibition and free radical generation in IPD are discussed in relation to the mechanism of action of neurotoxins known to produce parkinsonian syndromes.

Aging↗
PubMed1990

Mutations and a polymorphism in the factor VIII gene discovered by denaturing gradient gel electrophoresis.

Hemophilia A results from mutations in the gene coding for coagulation factor VIII. We used denaturing gradient gel electrophoresis to screen for mutations in the region of the factor VIII gene coding for the first acidic domain. Amplification primers were designed employing the MELTMAP computer program to optimize the ability to detect mutations. Screening of amplified DNA from 228 unselected hemophilia A patients revealed two mutations and one polymorphism. Rescreening the same population by making heteroduplexes between amplified patient and control samples prior to electrophoresis revealed one additional mutation. The mutations include two missense and one 4-base-pair deletion, and each mutation was found in patients with severe hemophilia. The polymorphism, located adjacent to the adenine branch site in intron 7, is useful for genetic prediction in some cases where the Bcl I and Xba I polymorphisms are uninformative. These results suggest that DNA amplification and denaturing gradient gel electrophoresis should be an excellent strategy for identifying mutations and polymorphisms in defined regions of the factor VIII gene and other large genes.

Base Sequence↗