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Biomedical subjects

E Nash

Publications and source records attributed to E Nash.

At least 37 records · Page 2Linked to original sources
PubMed1992

Analysis of four diverse population groups indicates that a subset of cystic fibrosis mutations occur in common among Caucasians.

To determine the nature and frequency of non-delta F508 cystic fibrosis (CF) mutations among diverse populations, we have sequenced exons 9-12 and 19-23 of the CF transmembrane conductance regulator (CFTR) gene from 128 CF chromosomes (39 U.S. Caucasian, 27 African-American, 42 Northern Irish, and 20 Israeli chromosomes). These regions were chosen because they encode the two putative ATP-binding folds of CFTR, domains which appear to have functional significance. In addition, CFTR exons 1 and 2 were analyzed in the American patients. Mutations were found on 49 of the 128 CF chromosomes. Nineteen different mutations were observed; six were novel, while the remaining 13 had been reported previously by our group or by other investigators. Six of nine different mutations found in African-American patients were unique to that population. However, the vast majority of the mutations found in U.S. Caucasians (eight of nine), Northern Irish (four of five), and Israelis (three of three) also occurred in other Caucasian groups. The preponderance of previously reported mutations in these three groups suggested that a subset of the non-delta F508 mutations occur in common among Caucasians. A survey of mutation frequencies in other Caucasian groups confirmed this observation. Unfortunately, this subset accounts for less than half of non-delta F508 CF mutations in most groups. These data suggest that screening for delta F508 and this select group of mutations will efficiently and economically maximize the number of CF mutations identified in Caucasian groups. However, it will be difficult to detect more than 90% of mutant CFTR alleles except in ethnically and geographically discrete populations where CF is the result of founder effect.

Amino Acid Sequence↗
PubMed1992

Cervical soft tissue metastasis of typical carcinoid tumor preceding diagnosis of ileal primary by 4 years.

A solitary cervical metastasis of a typical carcinoid tumor was found in the subcutaneous tissue of an asymptomatic 38-yr-old woman. Investigations failed to disclose the primary site until the 5th yr, when she presented with carcinoid syndrome. Multifocal ileal carcinoid tumors were resected and debulking of abdominal metastases performed. Interferon and somatostatin analogue treatment resulted in remission. Solitary cervical metastasis is an exceedingly rare initial manifestation of a mid-gut carcinoid tumor, and poses a therapeutic dilemma. There are no directions in the literature as to whether a "wait-and-see" approach or exploration surgery is the preferred management when one is confronted by a cervical metastasis of typical carcinoid tumor of unknown primary site.

Adult↗
PubMed1990

[Peripelvic tumors: approach and management].

The peripelvic area consists of the bony pelvis, hip joints and adjacent mesenchymal soft tissues. Malignant lesions in this area present unique diagnostic and therapeutic problems, in particular when tumor removal is involved. Between 1986 and 1988 we treated 7 females and a male, aged 8-75 years, for malignant tumors of this area. Diagnoses (histologic) included 4 cases of malignant fibrous histiocytoma, a malignant schwannoma, a Ewing sarcoma, a chondrosarcoma, and an osteosarcoma. Operations included marginal resection (4 cases), radical resection and reconstruction (2), radical resection (1), and modified hemipelvectomy (2). Adjuvant therapy consisted of radiotherapy in 1 case, chemotherapy in 2, and a combination of both in another 2. A patient who underwent radical resection and reconstruction of his left hemipelvis and hip joint died of local infection that progressed to generalized sepsis 2 months after operation. 2 patients died of recurrent disease, 3 and 30 months, respectively, after primary therapy. 1 died of myocardial infarction 20 months after the first and 3 months after the last of a series of marginal resections. 3 patients are alive and well 3-24 months following their first operation, and the fourth is doing well 24 months following first operation and 23 months after resection of lung metastases. Soft tissue sarcomas and osteosarcomas are the most frequent malignant tumors encountered in the pelvis and peripelvic areas. Their varying grades of malignancy and metastatic potential influence the approach on the one hand, while invalidity and compromised quality of life associated with tumor resection, influence it on the other.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1989

Radiation carcinogenesis in the male breast.

A 53-year-old man developed cystic papillary carcinoma of the breast 30 years after radiotherapy to his chest. This rare type of carcinoma has not been previously reported following irradiation. In contrast to the comprehensive literature on irradiation as an etiological factor in carcinogenesis of the female breast, only 10 cases have been reported in males. The subject is reviewed together with the experience gained on human females and with animals. The carcinogenic characteristics of irradiation are analyzed.

Animals↗
PubMed1986

Postoperative acute cholecystitis complicating unrelated operations.

The entity of postoperative acute cholecystitis has striking features that demand special attention. The process may follow intra- and extra-abdominal procedures, and the diagnosis may be especially difficult after recent abdominal operations. The course of the disease is frequently obscure and fulminant, progressing rapidly to gangrene and perforation of the gallbladder, with a high mortality rate. Six such patients, aged 69 to 83 years, were managed in our department, with one death. The cause of this complication is probably multifactorial and includes: stasis of bile of high viscosity induced by dehydration, hypovolemia, fever, and shock; obstruction at the sphincter of Oddi following starvation, anesthesia, narcotics or other possible factors such as pigment load following blood transfusion; and impaired circulation to the gallbladder secondary to sympathetic stimulation or blood-borne toxic factors induced by septicemia. The key to successful treatment is awareness, early diagnosis, intensive preoperative treatment with fluids and antibiotics, and percutaneous drainage or immediate cholecystectomy.

Acute Disease↗
PubMed1984

Comparative value of maximal treadmill testing, exercise thallium myocardial perfusion scintigraphy and exercise radionuclide ventriculography for distinguishing high- and low-risk patients soon after acute myocardial infarction.

The prognostic value of symptom-limited treadmill exercise electrocardiography, exercise thallium myocardial perfusion scintigraphy and rest and exercise radionuclide ventriculography was compared in 117 men, aged 54 +/- 9 years, tested 3 weeks after a clinically uncomplicated acute myocardial infarction (MI). During a mean follow-up period of 11.6 months, 8 men experienced "hard" medical events (cardiac death, nonfatal ventricular fibrillation or recurrent MI) and 14 were hospitalized for unstable angina pectoris, congestive heart failure or coronary bypass surgery (total of 22 combined events). By multivariate analysis (Cox proportional hazards model), peak treadmill work load and the change in left ventricular ejection fraction (EF) during exercise were significant (p less than 0.01) predictors of hard medical events; these 2 risk factors and recurrent ischemic chest pain in the coronary care unit were also significantly predictive (p less than 0.001) for combined events. A peak treadmill work load of 4 METs or less or a decrease in EF of 5% or more below the value at rest during submaximal effort distinguished 22 high-risk patients (20% of the study population) from 89 low-risk patients. The rate of hard medical events within 12 months was 23% (5 of 22 patients), vs 2% (2 of 89 patients) in the high- and low-risk patient subsets, respectively (p less than 0.001). Thus, in patients who underwent evaluation 3 weeks after a clinically uncomplicated MI, exercise radionuclide ventriculography contributed independent prognostic information to that provided by symptom-limited treadmill testing and was superior to exercise thallium scintigraphy for this purpose.

Aged↗
PubMed1984

Remodeling of sperm chromatin following fertilization: nucleosome repeat length and histone variant transitions in the absence of DNA synthesis.

Within the first cell cycle following fertilization the average nucleosomal repeat length of sea urchin male pronuclear chromatin declines by 30-40 base pairs to a value typical of that found in the embryo. This decline occurs after a lag of about 30 min postfertilization, and is accompanied by replication of the male chromatin and accumulation of cleavage-stage (CS) core histone variants. When replication is inhibited by greater than 95% with aphidicolin, the decline in repeat length still occurs, although it is slightly retarded. The decline in repeat length also occurs when protein synthesis is blocked by greater than 98% and DNA synthesis by 60-70% with emetine. The adjustment of nucleosome repeat length therefore can occur in vivo without extensive movement of replication forks across the length of the chromatin, or normal progression of the cell cycle, and appears to require no proteins synthesized postfertilization. Blocking of DNA synthesis or protein synthesis also does not prevent the normal histone variant transitions involved in male pronuclear chromatin remodeling. Although their accumulation is slowed, CS core variants eventually become the predominant male pronuclear histones in their classes when replication is inhibited. Since a shortening of the average nucleosomal repeat length of approximately 10-20% is not sufficient to account for this large acquisition of CS variants, some of the sperm (Sp) core histones are probably displaced from the replication-blocked pronucleus. Therefore, accumulation of CS H2A and CS H2B are temporally correlated with the repeat length transition, whereas replication, normal progression of the cell cycle, and the early histone transitions involving SpH1 and SpH2B are not.

Animals↗
PubMed1984

Neuropraxis secondary to hemorrhage in a traumatic dislocation of the shoulder.

A case of traumatic shoulder dislocation associated with a tear of the subscapular artery is presented. The main clinical feature was a dramatic neurologic loss of the brachial plexus, reversed by exploration, evacuation of hematoma, and ligation of the bleeding vessel. Early surgical decompression to achieve neurologic recovery is emphasized.

Aged↗
PubMed1983

Stepwise risk stratification soon after acute myocardial infarction.

A stepwise rise stratification procedure sequentially combining historical and clinical characteristics and treadmill exercise test results was applied to 702 consecutive men aged less than or equal to 70 years who were alive 21 days after acute myocardial infarction (MI). Historical characteristics alone (prior MI and prior angina or recurrence of pain in the coronary care unit) identified 10% of patients with the highest rate of reinfarction and death within 6 months (18%). Clinical contraindications to exercise testing identified another 40% of patients with an intermediate rate of cardiac events (6.4%). In the 50% of patients who underwent treadmill testing 3 weeks after MI, the rate of cardiac events within 6 months was 4.4%: 3.9% in patients with a negative test and 9.7% in patients with a positive test (ischemic ST-segment depression greater than or equal to 0.2 mV and a peak heart rate less than or equal to 135 beats/min). Patients with negative treadmill tests, who comprised 46% of patients less than or equal to 70 years and 53% of patients less than or equal to 60 years, had a cardiac death rate of less than 2% in the 6 months after MI. The stepwise classification procedure correctly classified 72% of patients with hard medical events within 6 months. Thus, most patients who experience subsequent cardiac events are correctly classified on the basis of historical and clinical risk characteristics. In patients without these risk characteristics, early treadmill testing is useful for further discriminating high-risk from very low risk patients.

Aged↗
PubMedDate not supplied

Cholesterol screening in the emergency department.

OBJECTIVE: To determine the feasibility of providing cholesterol screening in the emergency department (ED) and to determine compliance with follow-up recommendations. DESIGN: A prospective observational study. SETTING: The Ambulatory Care and Treatment Section of the George Washington University Medical Center ED. PATIENTS/PARTICIPANTS: All patients seen in the Ambulatory Care and Treatment Section of the ED who were 18 years of age or older and who were residents of the metropolitan Washington, D.C., area were eligible to participate. During the six-month study period, 660 patients were asked to participate and 539 (82%) agreed. INTERVENTIONS: Fingerstick cholesterol measurements were performed on all participants. Participants who had elevated cholesterol levels, as determined by the National Cholesterol Education Program guidelines, were scheduled for a six-week follow-up visit in the Lipid Research Clinic, where repeat fingerstick cholesterol measurements were performed. Those participants with elevated cholesterol levels were instructed to follow up with their primary care physicians. Compliance with follow-up was assessed by a telephone contact four months after the initial ED visit. MEASUREMENTS AND MAIN RESULTS: Of the 539 participants, 100 (19%) were found to have elevated cholesterol levels. Fifty-three (53%) returned for the six-week follow-up visit. Of the 53 who returned, 7 (13%) had normal and 46 (87%) had elevated cholesterol levels. Of the 46 participants with elevated cholesterol levels, 15 (33%) reported four months after their ED visit that they had received further follow-up care. CONCLUSIONS: Cholesterol screening in the ED is feasible, but compliance with follow-up is less than desirable.

Adult↗
PubMedDate not supplied

The history of OSHA's asbestos rule makings and some distinctive approaches that they introduced for regulating occupational exposure to toxic substances.

The Occupational Safety and Health Administration (OSHA) has regulated occupational exposure to asbestos since 1971. Since issuing its first asbestos standard, OSHA has modified it several times in response to new information about the health risk of exposure and concern expressed by workers and public health groups. As each modification has reduced worker exposure and disease risk, each also has introduced new concepts including emphasis on ancillary provisions in standards regulating occupational exposure to toxic substances to enhance worker health; medical removal protection; two attempts at emergency temporary standards; use of historical and objective exposure data to assess worker exposure; the need to eliminate significant risk of disease posed by asbestos; and the presumption of hazard in absence of exposure information. These and other advances have affected all subsequent OSHA standards aimed at reducing occupational exposure to toxic substances.

Air Pollutants, Occupational↗
PubMedDate not supplied

Rational and cost-effective management of the patient with a solid breast lump.

The rational management of the palpable breast lump requires a tissue diagnosis. The more conventional approach is biopsy under general anesthesia, examination of frozen sections and "follow-on" mastectomy when indicated. In the present study, we aimed at arriving at an unequivocal tissue diagnosis by studying permanent sections at a separate ambulatory procedure either with formal biopsy under local anesthetic or, in suspicious lumps, with the Trucut biopsy needle (Travenol Laboratories, Inc. USA). Only 7 (14%) of the 56 women with 64 breast lumps were hospitalized for biopsy under general anesthesia. In 13 out of 22 breast cancers, the definitive diagnosis was made by examining Trucut needle biopsy specimens. This alternative approach provides a significant reduction of costs, more efficient utilization of operating time and a fully evaluated, psychologically prepared patient, when mastectomy is indicated.

Adolescent↗