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Biomedical subjects

M Nelson

Publications and source records attributed to M Nelson.

At least 181 records · Page 10Linked to original sources
PubMed1998

Anal endosonography in patients with anorectal symptoms after haemorrhoidectomy.

BACKGROUND: Anorectal symptoms after haemorrhoidectomy are common and treatment is often empirical. Because of this, an audit was carried out of the value of anal endosonography in patients with anorectal symptoms after haemorrhoidectomy. METHODS: Between May 1993 and February 1997, 16 patients (ten men and six women of median age 56 (range 35-77) years) were investigated by anal endosonography for anorectal symptoms after haemorrhoidectomy which involved anorectal incontinence (n = 10), anal pain (n = 4) and obstructive defaecation (n = 2). The findings were compared with those in a matched group of asymptomatic patients after haemorroidectomy. RESULTS: Anal endosonography demonstrated an abnormality in 12 symptomatic patients. Of the ten patients with anorectal incontinence, endosonography showed an internal anal sphincter defect (n = 5), a combined sphincter defect (n = 2) and an isolated external anal sphincter defect (n = 1). Normal appearances were seen in all asymptomatic patients. The endosonographic abnormalities of the four patients with anal pain included internal anal sphincter defect (n = 1), extrinsic mass (n = 1), and intersphincteric abscess (n = 1). One of the two patients with obstructive defaecation had an isolated external anal sphincter defect on endosonography. CONCLUSION: These results show a high yield of endosonographic abnormalities in patients who experience symptoms after haemorrhoidectomy. In particular, occult sphincter injury as a cause of incontinence in these patients can frequently be demonstrated.

Adult↗
PubMed1998

Total iron-binding capacity-estimated transferrin correlates with the nutritional subjective global assessment in hemodialysis patients.

We examined the value of transferrin concentrations in estimating nutritional status as determined by the subjective global assessment (SGA) score. Fifty-nine hemodialysis patients (37 men and 22 women, aged 59+/-16 years, dialyzed for 3.6+/-3.9 years) were selected by predetermined criteria. All received erythropoietin (EPO) and oral iron therapy. SGA evaluation was conducted twice by both a dietitian and a physician. Serum iron, total iron-binding capacity (TIBC; which is linearly correlated with transferrin), transferrin saturation ratio, ferritin, albumin, total protein, and cholesterol were measured. Twenty-seven (46%) patients were well nourished (group A), 20 (34%) were moderately nourished (group B), and 12 (20%) were poorly nourished (group C) according to the SGA. TIBC values were 276+/-47 mg/dL, 217+/-54 mg/dL, and 176+/-41 mg/dL, respectively (P < 0.00001), and thus directly correlated with the state of nutrition. The relationship between TIBC and nutritional status was independent of age and number of years on hemodialysis. Serum ferritin values were 104+/-93 ng/mL, 161+/-154 ng/mL, and 363+/-305 ng/mL, respectively (P < 0.0003), and thus inversely correlated with the state of nutrition. Transferrin saturation ratios were slightly higher in the severely malnourished patients. The number of years on dialysis were a determinant of nutritional status. These values were 2.4+/-2.4 years for group A, 3.9+/-4.0 years for group B, and 5.7+/-3.9 years for group C (P < 0.05). The average age of the poorly nourished patients was 10 years older than the well-nourished patients. Serum iron values were lower but transferrin saturation ratios were higher in the severely malnourished patients. The required EPO doses were higher in the poorly nourished patients. We suggest that transferrin values are superior to other laboratory tests in assessing nutrition and will supplement SGA criteria. Serum ferritin may be useful as a predictor of illness. Older patients who have been on dialysis longer warrant special concern. Malnutrition may be an indicator of EPO resistance in dialysis patients. Finally, since a decreased TIBC level in poorly nourished patients may erroneously increase the transferrin saturation ratio, our findings may have implications in making the diagnosis and treatment of anemia and iron deficiency in malnourished dialysis patients.

Adult↗
PubMed1998

A study of rural Latino women seeking cancer-detection examinations.

The Latino women's breast and cervical cancer screening project, A Day for Latino Women, was a well-organized, collaborative effort between the Catholic community outreach program serving the rural Latino community, the local university, the university nursing program, and a rural-nurse-managed clinic. Eighty-one women were screened at the rural-nurse-managed clinic (TCHC) at no cost. Barriers to access such as the need for transportation, cost, and the need for child care were essentially eliminated to encourage use of the TCHC as a usual site of medical care for this ethnic population. Use of female FNP students attempted to eliminate traditional cultural embarrassment regarding examination by men. Peer relationships and social support for bilingual members of Centro Cuerpo de Cristo Catholic Ministry assisted in promotion and delivery of services to these women.

Adolescent↗
PubMed1998

Efficacy of doxycycline and ciprofloxacin against experimental Yersinia pestis infection.

The efficacies of ciprofloxacin and doxycycline prophylaxis and therapy were assessed against experimental pneumonic plague infections induced by two strains of Yersinia pestis in a mouse model. When exposed to an aerosol of Y. pestis strain GB, containing 8.39 x 10(5) +/- 4.17 x 10(4) cfu, the retained dose was 7.3 x 10(3) +/- 2.3 x 10(3) cfu. When exposed to an aerosol of Y. pestis strain CO-92, containing 1.86 x 10(5) +/- 7.4 x 10(3) cfu, the retained dose was 3.4 x 10(4) +/- 2.6 x 10(3) cfu. Both strains resulted in a respiratory and systemic infection closely resembling human pneumonic plague. Ciprofloxacin prophylaxis and therapy was successful against both strains for up to 24 h after challenge, but not after 48 h. Both doxycycline prophylaxis and therapy regimens were ineffective against both strains, although strain CO-92 was more susceptible in vitro to doxycycline than strain GB and supra-MIC levels were achieved in the serum and lungs of the animal.

Animals↗
PubMed1998

Significance of abnormalities of chromosomes 5 and 8 in chondroblastoma.

Tumor specific chromosomal abnormalities have been identified in several histologic subtypes of benign and malignant bone tumors. These anomalies have proven to be useful diagnostically. Characterization of recurrent chromosomal abnormalities also has provided direction for molecular investigations of pathogenetically important genes. Cytogenetic reports of chondroblastoma, a rare benign bone tumor, are few. Cytogenetic analysis of a benign and a malignant chondroblastoma in this study revealed the following abnormal chromosomal complements: 47,XY,+5,t(5;5)(p10;q10) and 45, XY,del(2)(p23),del(3)(q23q27),dup(8)(q12q21.), del(11) (q14q23), -13, add (17) (q25) x 2, respectively. Although a specific chromosomal abnormality has not yet emerged for chondroblastoma, abnormalities of chromosomes 5 and 8 have been reported previously in this neoplasm, suggesting preferential involvement of these two chromosomes.

Adult↗
PubMed1998

Characterization of a variant SYT-SSX1 synovial sarcoma fusion transcript.

Synovial sarcoma is characterized cytogenetically by an X;18 translocation [t (X;18) (p11;q11)] that results in the fusion of the SYT gene from chromosome 18 to either of two highly homologous genes at Xp11, SSX1 or SSX2. Heterogeneity within the synovial sarcoma fusion junctions is rare. Examination of a primary monophasic synovial sarcoma for an SYT-SSX fusion transcript by reverse-transcription polymerase chain reaction revealed a smaller-than-expected product. Direct sequencing of the product disclosed a novel SYT-SSX1 fusion transcript that contained an additional 51 bp of normal SSX1 sequence but lost 135 bp of the SYT sequence. Detection of synovial sarcoma hybrid transcripts is useful for diagnosis and should include the recognition of distinct variants.

Amino Acid Sequence↗
PubMed1998

Ex vivo expansion of human hematopoietic stem cells: implications for the modern blood bank.

Pluripotent hematopoietic stem cells (PHSC) are rare cells within the marrow that are capable of self-renewal and differentiation into multiple hematopoietic lineages. Following myeloablative chemotherapy and radiation therapy and marrow transplantation, hematological reconstitution occurs after a period of 2-3 weeks. Recently, a number of laboratories have shown that both early and delayed phases of engraftment are mediated by PHSC within a graft and that engraftment can be accelerated by transplanting greater numbers of PHSC. Increasing efforts have been directed, therefore, towards developing methods to expand PHSC ex vivo. In this report, we describe an endothelial cell-based culture system to which exogenous cytokines are added which appears to permit the ex vivo expansion of PHSC. Refinement of these technologies will potentially have a major impact on the ability of blood banks to improve the quality of hematopoietic stem cell grafts.

Adult↗
PubMed1998

Energy and nutrient intakes of the United States National Women's Artistic Gymnastics Team.

The nutrient intakes and dietary practices of elite, U.S. national team, artistic female gymnasts (n = 33) were evaluated using 3-day food records. The gymnasts' reported energy intake was 43.4 kcal/kg (total 1,678 kcal/day), which was 20% below the estimated energy requirement. The contributions of protein, fat, and carbohydrate to total energy intake were 17%, 18%, and 66%, respectively. All reported vitamin intakes, except vitamin E, were above the RDA. The reported mineral intakes, especially calcium, zinc, and magnesium, were less than 100% of the RDA. The overall nutrient densities of the subjects' diets were higher than expected. Eighty-two percent of the gymnasts reported taking nonprescription vitamin and mineral supplements, and 10% reported taking prescription vitamin and mineral supplements. Forty-eight percent of the gymnasts reported being on a self-prescribed diet. Compared to NHANES III, the reported nutrient intake of these gymnasts was different from that of the average U.S. adolescent female. In summary, certain key nutrients such as calcium, iron, and zinc should be given more attention to prevent nutrient deficiencies and subsequent health consequences.

Adolescent↗
PubMed1998

Cefepime versus ceftriaxone for empiric treatment of hospitalized patients with community-acquired pneumonia. The Cefepime Study Group.

Effective empiric treatment of pneumonia requires antibiotic coverage against gram-negative and gram-positive pathogens, including drug-resistant isolates. We compared the safety and efficacy of intravenous (i.v.) cefepime (2 g administered every 12 h) to those of i.v. ceftriaxone (1 g administered every 12 h) for the empiric treatment of hospitalized patients with community-acquired pneumonia. Of the 115 patients randomized to the study, 86 (cefepime recipients, n = 40; ceftriaxone recipients, n = 46) were evaluated for clinical efficacy (clinically evaluated patients). Favorable clinical outcomes (cure or improvement) were comparable among clinically evaluated patients in the cefepime and ceftriaxone treatment arms (95.0 versus 97.8%, respectively; 95% confidence interval for treatment difference [data for ceftriaxone group minus data for cefepime group], -5.1 to +10.8%). The most common bacteria isolated from patients in both treatment groups were Streptococcus pneumoniae, Haemophilus influenzae, and Staphylococcus aureus. In clinically evaluated patients with a microbiologic response, all (100%) of the 32 pathogens from cefepime-treated patients and 97.4% (38 of 39) of the pathogens from ceftriaxone-treated patients were eradicated (documented or presumed eradication). The one persistent infection in the ceftriaxone group was caused by Pseudomonas fluorescens. Both treatments were well tolerated. Our data thus suggest that cefepime and ceftriaxone have comparable safety and efficacy for the treatment of pneumonia in hospitalized patients.

Cefepime↗
PubMed1998

Bilateral sequential inferior petrosal sinus sampling with corticotrophin-releasing hormone stimulation in the diagnosis of Cushing's disease.

OBJECTIVE: The demonstration of a central to peripheral ACTH gradient in a hypercortisolaemic patient is diagnostic of Cushing's disease. We tried to determine whether single blood samples for ACTH obtained sequentially from each of the inferior petrosal sinuses following human corticotrophin-releasing hormone (hCRH) stimulation can reliably establish such a gradient. DESIGN: Prospective study. PATIENTS: Seventeen patients with clinical and biochemical features of Cushing's syndrome. METHODS: After the administration of hCRH, the patients underwent bilateral sequential inferior petrosal sinus sampling, with a single blood sample obtained from each of the inferior petrosal sinuses sequentially, along with a peripheral venous sample. The petrosal sinus catheter was withdrawn immediately after obtaining a blood sample. Patients did not require indwelling catheters in the petrosal sinuses, nor heparinisation. RESULTS: Bilateral sequential inferior petrosal sinus sampling correctly identified a pituitary source of ACTH, as shown by a central to peripheral ACTH ratio >2, in all patients in whom the procedure was successfully carried out. All patients underwent transsphenoidal pituitary surgery resulting in remission. CONCLUSIONS: The simplified method of inferior petrosal sinus sampling, using a single sequential sample from each of the inferior petrosal sinuses, following initial hCRH stimulation, is as accurate as the more complex test using multiple bilateral simultaneous inferior petrosal sinus samples. It avoids the use of indwelling cerebral venous catheters and is therefore unlikely to cause brain stem damage.

Adult↗
PubMed1998

An ecological life support system for fish for 100-day experiments.

An aquatic habitat of 1.7 L was designed to support three adult fish (medaka, Oryzias latipes) for 100 days with minimal exchange of water. The Aquatic Habitat consisted of a specimen chamber (800 ml), biofilter chamber and associated tubing (250 ml), and a microbial control chamber (650 ml), filled with water. Fish were fed daily. The water was oxygenated via a hollow fiber oxygenator. The liquid flow rate was 30 ml/min and the air flow as 100 ml/min. Six units were established. Fish mortalities, when they occurred, were often associated with failures of the water flow system and lack of oxygen being supplied from the oxygenator. The bacterial community, from three "Bio-Chem Stars" inoculated from a medaka aquarium, transformed ammonia and prevented toxic conditions from occurring. The bacteria were grazed by protozoa, rotifers, nematodes, oligochaetes, and ostracods in all habitats. In three of six habitats, Daphnia and amphipods had been purposely introduced; their survival was variable. Biofilm and settled particulates accumulated during the experiment and eventually exceeded the weight of the fish. Of six units, two supported the initial fish through the whole experiment, another experienced fish mortalities, but replacement fish survived, and three units did not support fish survival for the 100 days. Our results demonstrated the feasibility of the system, but many improvements are needed such as improved water flow and oxygen monitoring to assure prompt corrective action.

Ammonia↗