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Biomedical subjects

B Anderson

Publications and source records attributed to B Anderson.

At least 109 records · Page 6Linked to original sources
PubMed1997

Dietary L-arginine supplementation normalizes platelet aggregation in hypercholesterolemic humans.

OBJECTIVES: The present study was designed to test the hypothesis that long-term dietary supplementation with the nitric oxide precursor L-arginine would enhance vascular or platelet-derived nitric oxide activity, or both, and thereby inhibit platelet reactivity in hypercholesterolemic humans. BACKGROUND: We have shown that reduced vascular activity of nitric oxide in hypercholesterolemic rabbits can be restored by L-arginine supplementation. The improvement in nitric oxide activity is associated with an inhibition of platelet aggregation ex vivo. This effect is most likely due to increased elaboration of endothelium- or platelet-derived nitric oxide, or both, because the inhibition of platelet reactivity was associated with elevation of intraplatelet cyclic guanosine monophosphate and was reversed by the nitric oxide synthase antagonist N-methyl-arginine. METHODS: In a double-blinded, randomized, placebo-controlled trial, hypercholesterolemic patients were assigned to L-arginine hydrochloride, 8.4 g/day orally, or placebo for 2 weeks. Platelet-rich plasma was obtained for aggregometry induced by collagen (1 to 10 micrograms/ml) at four points: baseline, after 2 weeks of treatment, after a 2-week washout and after a long-term washout of 16 weeks on average. Aggregation was quantified by light transmittance and expressed as a percent transmittance observed with platelet-poor plasma. RESULTS: Compared with normocholesterolemic control subjects, platelets from hypercholesterolemic subjects stimulated with 5 micrograms/ml of collagen showed increased aggregability (68.6% in hypercholesterolemic patients vs. 54.5% in normocholesterolemic control subjects, p < or = 0.02). After 2 weeks of treatment with L-arginine (but not placebo), platelet reactivity was modestly reduced; this effect persisted for 2 weeks after discontinuation of arginine (52.6% in arginine-treated patients vs. 65.1% in normocholesterolemic control subjects, p = 0.07). After 18 weeks (i.e., 16 weeks after discontinuing arginine treatment), the platelets of hypercholesterolemic patients once again became hyperaggregable, and the extent of platelet aggregation was significantly increased compared with the 4-week point (73.6% after vs. 52.6% during arginine treatment, p < 0.01). No significant change in platelet reactivity was seen in placebo-treated hypercholesterolemic patients throughout the study. L-Arginine treatment was well tolerated without side effects. CONCLUSIONS: This double-blinded, placebo-controlled study demonstrates that dietary supplementation with L-arginine can modestly attenuate the increased platelet reactivity seen in hypercholesterolemic patients. The data are consistent with our previous studies in hypercholesterolemic animals, demonstrating that L-arginine restores endogenous nitric oxide activity and inhibits platelet aggregation. Enhancement of endogenous nitric oxide activity is a potential novel therapeutic strategy worthy of further study.

Arginine↗
PubMed1997

The polymerase chain reaction in the diagnosis of early mycosis fungoides.

The earliest or patch stage of mycosis fungoides may present diagnostic difficulty both clinically and pathologically. The present study of the polymerase chain reaction (PCR) as a diagnostic tool in early mycosis fungoides was therefore undertaken, using a rapid PCR method for the detection of gamma- and beta-chain T-cell receptor (TCR) gene rearrangements in routine formalin-fixed, paraffin-embedded histological sections. Forty-two biopsies were studied from 26 patients with mycosis fungoides. Twenty-three skin biopsies with a clinicopathological diagnosis of early, or patch stage, mycosis fungoides were investigated. Of these, 18 (78 per cent) showed TCR-gamma or both beta- and gamma-chain TCR gene rearrangements. TCR gene rearrangements were shown in seven of the 14 plaque stage lesions (50 per cent) and also in the single case of tumour stage disease. Where gene rearrangements were identified, these were identical in all biopsies from an individual patient, irrespective of the site of the lesion, the disease stage, or the time lapse between the biopsies. The PCR is therefore a highly sensitive technique, which can be performed on routine pathological material, in cases where the diagnosis of early mycosis fungoides cannot be made with certainty on conventional histopathological and immunohistochemical grounds.

Adult↗
PubMed1997

Posterior exenteration through groin incision in a patient with stage III vulvar carcinoma.

During performance of bilateral groin incisions, an abdominal incision and a colostomy has the potential risks of devascularization of the lower abdominal wall and infection. A patient with locally advanced vulvar carcinoma requiring a posterior exenteration is presented. The posterior exenteration was performed by developing an abdominal skin flap from the groin incisions. This approach offers adequate exposure and a unique solution to the potential problems associated with combining an abdominal skin incision with bilateral groin incisions and end-descending sigmoid colostomy. In addition, this approach may be cosmetically more acceptable.

Carcinoma, Squamous Cell↗
PubMed1997

The clinical course of cervical carcinoma in situ diagnosed during pregnancy.

OBJECTIVE: The objective was to determine the frequency with which regression or progression of disease without treatment occurred in women diagnosed with squamous cell cervical carcinoma in situ (CIS) during pregnancy. METHODS: . A retrospective chart review of all women evaluated at the University of Iowa Colposcopy Clinic diagnosed with CIS during pregnancy from 1987 through 1992 was used. Thirty-four women were evaluated during pregnancy, of which 26 also had postpartum evaluation. All pathology reports of initial cytology and biopsies, as well as colposcopic impressions, were reviewed and compared to the same evaluations postpartum. RESULTS: Of the 26 women evaluated both antepartum and postpartum, only 1 was treated (cone biopsy) during pregnancy. She had disease suspicious for microinvasion. She was disease free postpartum. Of the remaining 25, 20 (80%) had persistent disease, 2 (8%) had either missed disease or progressive disease postpartum, and 3 (12%) resolved without treatment at postpartum evaluation. No statistical significance was found between route of delivery and persistence (P = 0.34). No statistical significance was found between smoking and persistence of disease (P = 1.0). In 46% of women the initial cytology was CIN I or II, and the initial colposcopic impression was found to underestimate the severity of the disease in 35% of cases. Two women were found to have invasive disease postpartum. CONCLUSIONS: There is a high persistence rate of CIS complicating pregnancy. Given the relatively high rate of underestimation of disease severity by both cytology and colposcopic impression, the use of routine biopsy at the time of colposcopy is recommended. Invasive disease may be encountered on postpartum evaluation.

Adult↗
PubMed1997

Hepatic necrosis masquerading as trauma.

We report the case of a child who had deterioration of hepatic function 3 days after suffering a depressed compound skull fracture with underlying brain contusion. An abdominal enhanced CT scan revealed a wedge-shaped region of devitalised liver with associated free intraperitoneal fluid, consistent with a traumatic lesion but due to necrosis secondary to acetaminophen toxicity. Acetaminophen toxicity may occur with therapeutic doses in the presence of an ischaemic hepatitis. Any delay in the performance of CT from the time of trauma should prompt the consideration of alternative diagnoses.

Acetaminophen↗
PubMed1997

Enantioselective reduction of 3,4-methylene-dioxyphenylacetone using Candida famata and Zygosaccharomyces rouxii.

In an effort to prepare 3,4-methylene-dioxyphenyl-(S)-isopropanol from 3,4-methylene-dioxyphenylacetone, an initial screen of microbes indicated that Candida famata could catalyze this reaction efficiently at low substrate concentration. A dilute, large-scale process was developed to provide experimental material for the chemical synthesis to be explored. However, the productivity number of this process [0.134 g product (g wet weight cells)-1 day-1 was too low to be practical. C. famata was also extremely sensitive to concentrations of both the ketone and the alcohol greater than 2 g/l. A more extensive screen of yeast and fungi revealed that Zygosaccharomyces rouxii was more tolerant to higher substrate concentrations and had a higher productivity number [0.8 g (g wet weight cells)-1 day-1]. These characteristics suggested that Z. rouxii could be used in a large-scale process at high substrate concentrations.

Acetone↗
PubMed1997

Parental involvement in diabetes management tasks: relationships to blood glucose monitoring adherence and metabolic control in young adolescents with insulin-dependent diabetes mellitus.

OBJECTIVES: The goal of this study was to identify parental behaviors that relate to adherence and metabolic control in a population of young adolescents with insulin-dependent diabetes mellitus (IDDM), and to understand the interrelationships among the variables of parental involvement, adherence to blood glucose monitoring, and glycemic control. STUDY DESIGN: A cross-sectional design was used to investigate parental involvement in diabetes regimen tasks in 89 youth, aged 10 to 15 years, with IDDM. Levels of parental involvement in blood glucose monitoring (BGM) and insulin administration were evaluated through interviews. Assessment of adherence was made by physicians or nurses, independent of patient or parent reports of adherence. Glycemic control was assessed with glycosylated hemoglobin (HbA1c) (reference range, 4% to 6%). RESULTS: There were significant differences in the mean HbA1c values between the older (13 to 15 years of age) (HbA1c = 8.9% +/- 1.03%) and younger (10 to 12 years) patients (HbA1c = 8.4% +/- 1.06%) (p < 0.02). Parental involvement in BGM was significantly related to adherence to BGM (number of blood sugar concentrations checked daily) in both groups of adolescent patients. The younger patients monitored their blood glucose levels more frequently than did the older patients, 39% of the younger patients checked sugar concentrations four or more times daily compared with only 10% of the older group (p < 0.007). In a multivariate model controlling for age, gender, Tanner staging, and duration of diabetes, the frequency of BGM was a significant predictor of glycemic control (R2 = 0.19, p < 0.02). Increased frequency of BGM was associated with lower HbA1c levels. When the frequency of BGM was zero or once a day, the mean HbA1c level was 9.9% +/- 0.44 (SE); when the frequency of BGM was two or three times a day, the mean HbA1c level was 8.7% +/- 0.17; and when the frequency of BGM was four or more times daily, the mean HbA1c level was 8.3% +/- 0.22. CONCLUSIONS: Parental involvement in BGM supports more frequent BGM in 10- to 15-year-old patients with IDDM. This increased adherence to BGM is associated with better metabolic control (i.e., lower HbA1c levels). These findings suggest that encouraging parental involvement in BGM with 10- to 15-year-old patients with IDDM may help to prevent the well-documented deterioration in glycemic control and adherence to treatment that often occurs in later adolescence.

Adolescent↗
PubMed1997

Analysis of 36-kilodalton protein (PapA) associated with the bacteriophage particle of Bartonella henselae.

A library of Bartonella henselae DNA was screened with antibody raised to the bacteriophage particle associated with this organism. A clone was isolated that expresses a 36-kD protein (termed PapA for particle-associated protein) when examined by immunoblot analysis using antibody raised to the particle. Southern blot hybridization indicates that the gene is present on the bacterial chromosome and packaged into the 14-kb particle-associated DNA. A papA-specific probe hybridized to multiple bands of B. henselae genomic DNA digested with several different restriction endonucleases. Thus, the gene is present in multiple copies on the genome or in different arrangements within a given population of B. henselae cells. The gene coding for PapA has been sequenced and codes for a 326-amino-acid protein with a deduced molecular weight of 36,161 daltons. The deduced protein shows 33.3% identity over a 108-amino-acid sequence with the P-min gene product of Escherichia coli. P-min is partially located within the invertible P region of the excisable element e14, found on the E. coli chromosome. Taken together, these results suggest that papA is present on a mobile genetic element of the B. henselae genome and is also packaged into the bacteriophage particle.

Amino Acid Sequence↗
PubMed1997

Patients' perceptions of outcomes of a Canadian hospitalization.

Notes that with health care reform moving at tremendous speed throughout Canada, a great deal of interest in outcomes research has been generated. States that the research team consisted of 17 professional practice leaders from eight disciplines. Proposes, through the research, to identify from the perspective of former patients what results they hoped to achieve prior to discharge from hospital and what facilitated and hindered them in achieving these results. Reports that a representative sample was selected for the study. Forty-one former patients each participated in up to two focus groups, with a total of 16 focus groups conducted. Hierarchical analysis revealed themes that fell within the framework of structure, process and outcomes. The findings will assist in ensuring that more appropriate and effective care is offered to patients by a variety of disciplines.

Adult↗
PubMed1997

The 75-kilodalton antigen of Bartonella bacilliformis is a structural homolog of the cell division protein FtsZ.

A genomic library of Bartonella bacilliformis was constructed and screened with human anti-Bartonella serum from a patient with the chronic, verruga peruana phase of bartonellosis. An immunoreactive clone isolated from this library was found to code for a 591-amino-acid protein with a high degree of sequence similarity to the FtsZ family of proteins. The degree of amino acid identity between the B. bacilliformis protein (FtsZ[Bb]) and the other FtsZ proteins is especially pronounced over the N-terminal 321 amino acids (N-terminal domain) of the sequence, with values ranging from 45% identity for the homolog from Micrococcus luteus (FtsZ[Ml]) to 91% identity for the homolog from Rhizobium melliloti, (FtsZ[Rm1]). All of the functional domains required for FtsZ activity are conserved in FtsZ(Bb) and are located within the N-terminal domain of the protein. FtsZ(Bb) is approximately twice as large as most of the other FtsZ proteins previously reported, a property it shares with FtsZ(Rm1). Like the Rhizobium homolog, FtsZ(Bb) has a C-terminal region of approximately 256 amino acids that is absent in the other FtsZ proteins. Evidence is presented that implicates this region in the protein's antigenicity and suggests that, unlike most other FtsZ homologs, FtsZ(Bb) is at least partly exposed at the cell surface. PCR analysis revealed that an ftsZ gene similar in size to the B. bacilliformis gene is present in Bartonella henselae, a bacterium that is closely related to B. bacilliformis.

Amino Acid Sequence↗
PubMed1997

Adhesiveness of mononuclear cells in hypercholesterolemic humans is normalized by dietary L-arginine.

Hypercholesterolemia reduces vascular nitric oxide (NO) activity. This dysfunction may promote endothelial monocyte interaction, as NO is a potent inhibitor of cell adhesion. We have previously shown that in hypercholesterolemic (HC) rabbits, chronic oral supplementation of L-arginine (Arg) restores NO activity and inhibits monocyte-endothelial cell interaction, in association with a reduction in atherogenesis. We hypothesized that enhancement of endothelial NO activity in HC humans would reduce monocyte adhesiveness. We used a functional binding assay to assess the adhesiveness of human mononuclear cells (MNCs) ex vivo to determine the effects of hypercholesterolemia and L-arginine administration. MNCs from HC subjects adhered in greater numbers (50% more cells per high-power field; P < .0001) than cells derived from normocholesterolemic (NC) subjects. To determine whether enhancement of endogenous NO activity could inhibit mononuclear cell adhesiveness, in a double-blinded placebo-controlled study, oral arginine HCl (8.4 g/d) was administered to HC subjects. Over a course of 2 weeks, this treatment abolished the increased adhesiveness of HC MNCs (160 +/- 11% versus 104 +/- 5%; before and after 2 weeks of Arg treatment; results expressed as a percentage of the binding values obtained using cells derived from paired NC individuals). By contrast, MNC adhesion remained significantly elevated in placebo-treated HC subjects. To examine whether endothelium-derived NO could act as a paracrine modulator of monocyte behavior, monocytes were exposed to NO donors or cocultered in the presence of endothelial cells exposed to antagonists of NO synthase in the presence or absence of L-arginine. NO donors inhibited monocyte adhesiveness. Furthermore, the adhesiveness of monocytes cocultured with endothelial cells was increased by antagonists of NO synthase; this effect was reversed by L-arginine. This study shows that the adhesiveness of human MNCs is increased by hypercholesterolemia. The increase in adhesiveness was reversed in vivo by administration of the NO precursor L-arginine. NO donors or endothelium-derived NO inhibits the adhesiveness of monocytes in vitro, supporting the hypothesis that the effects of L-arginine are mediated by NO.

Adult↗
PubMed1997

Randomized trial of cisplatin versus cisplatin plus mitolactol versus cisplatin plus ifosfamide in advanced squamous carcinoma of the cervix: a Gynecologic Oncology Group study.

PURPOSE: Cisplatin, mitolactol (dibromodulcitol), and ifosfamide have been the most active single agents in squamous carcinoma of the cervix identified so far by the Gynecologic Oncology Group (GOG). Combinations of cisplatin plus ifosfamide and cisplatin plus mitolactol are prospectively compared with cisplatin alone. PATIENTS AND METHODS: Patients were randomized to receive cisplatin 50 mg/m2 or the same dose of cisplatin plus mitolactol (C + M) 180 mg/m2 orally on days 2 to 6, or cisplatin plus ifosfamide (CIFX) 5 g/m2 given as a 24-hour infusion plus mesna 6 g/m2 during and for 12 hours after the ifosfamide infusion, every 3 weeks for up to six courses. Of 454 patients entered, 438 were eligible and analyzed for response and survival. RESULTS: CIFX had a higher response rate (31.1% v 17.8%, p = .004) and longer progression-free survival (PFS) time (P = .003) compared with cisplatin alone. The median times to progression or death were 4.6 and 3.2 months, respectively. C + M showed no significant improvement in these parameters compared with cisplatin alone. Survival was associated with initial performance score (PS; 0 was more favorable; P < .001) and with age (younger was unfavorable, P = .025). There was no significant difference in overall survival between cisplatin and either of the combinations. Leukopenia, renal toxicity, peripheral neurotoxicity, and CNS toxicity were more frequent with CIFX (P < .05). CONCLUSION: CIFX improved the response rate and PFS duration in advanced cervix cancer compared with cisplatin alone, but at the cost of greater toxicity and with no improvement in survival.

Adult↗
PubMed1997

Pieces of the true crossover effect in neglect.

A subject with left hemispatial neglect exhibited the crossover effect on bisecting lines of varying lengths. On long lines he misbisected to the right and on shorter lines he misbisected to the left. Rather than being an idiosyncrasy of this one task, the crossover effect also occurred on variations of Milner's Landmark task and Bisiach's Endpoint task. Performances across different bisection task variations were highly correlated. The crossover effect is not specific to the traditional line bisection task but is a pervasive aspect of this subject's performance. As the crossover effect is not explained by current theories of neglect, determining the bases for the crossover effect constitutes a challenge in understanding neglect.

Attention↗
PubMed1997

Multilaboratory comparison of in vitro tests for chromosome aberrations in CHO and CHL cells tested under the same protocols.

Different test results have been reported for the same chemicals in two in vitro chromosome aberration test systems, CHL cells tested by a Japanese protocol and CHO cells tested by the US National Toxicology Program [Sofuni et al., Mutat Res 241:173-213,1990]. Here, laboratories in Japan, the US and the UK tested 9 such chemicals in CHL and CHO cells using the same protocols and found all 9 positive in both cell types; differences in earlier conclusions with these chemicals were due mainly to test protocol, not to different sensitivities of the cells. The most important protocol difference is sampling time. Chemicals that were negative in the NTP series using a sampling time of 10 to 13 hours often produced positive results when retested here with a 20- to 24-hour sampling time. While positive results were obtained in both cell types, CHL cells sometimes had higher aberration levels and survived at higher doses than CHO cells would tolerate. This may reflect some intrinsic difference in sensitivity but may also be affected by factors such as cell cycle length and culture media (e.g., oxygen scavenging capacity). The collaboration reported here also contributed to a better understanding of scoring aberrations, especially "gaps"; there was good agreement on what types of aberrations should be included in the totals when scoring criteria were clearly defined, for example, many changes classified as "gaps" by the Japanese system were classified as "breaks" in the scoring systems used in the United States and the United Kingdom, and were appropriately included in total aberration counts.

Animals↗
PubMed1997

Is life stress more likely to provoke depressive episodes in women than in men?

One of the most consistent findings in psychiatric research is that rates of major depression are at least twofold higher among women than among men. Although there is considerable agreement in the literature that life events play a role in producing, triggering, or maintaining episodes of depression, less is known about the relationship among gender, life events, and depression. In the present study, we compared the rates, focus ("interpersonal" vs. "non-interpersonal"), and timing of stressful life experiences reported in rigorous interviews of male and female patients with unipolar recurrent depression and nondepressed contrast subjects. Consistent with hypotheses, female patients were more likely to experience stressful life experiences than their male counterparts; rates of stressful life experiences did not differ between female and male controls. Unexpectedly, rates of interpersonal stress did not differ among males and females regardless of patient or control status. We also found no significant differences in the timing of pre-onset events: stressful events were generally concentrated in the period immediately preceding onset for both men and women. Thus, although these data suggest that life stress may play a larger role in the provocation of recurrent episodes of depression for women than for men, there do not seem to be sex differences in the extent to which interpersonal vs. noninterpersonal events and difficulties are associated with depression onset or in the temporal distribution of events. Implications of these results are discussed in the context of research on other putative factors contributing to gender differences in rates of depression.

Adult↗
PubMed1996

Acute renal failure in the paediatric intensive care unit.

AIMS: To review a group of children with acute renal failure (ARF) requiring renal replacement therapy in a paediatric intensive care unit (PICU). METHODS: Case records of children admitted to paediatric intensive care unit between January 1992 and July 1995 were reviewed for demography, diagnosis, modality of treatment, duration, complications of therapy and renal outcome. Long term follow up was sought from patients' referring paediatricians. RESULTS: Twenty children with a mean age of 2 years and 3 months required acute renal replacement therapy. The most common cause was diarrhoea associated haemolytic uraemic syndrome with a mean duration of dialysis of 11.5 (SD 3.1) days (range 5-15. Four children had septicaemic illnesses; three with multiorgan system failure, one of whom died. Peritoneal dialysis was the only modality in 16 patients and four children were treated with continuous venovenous haemofiltration. Eight of the 20 patients were discharged from the paediatric intensive care unit with normal renal function as judged by serum creatinine. Long-term follow up showed normalisation of serum creatinine in a further eight of ten patients. CONCLUSIONS: The most common cause of acute renal failure was diarrhoea associated haemolytic uraemic syndrome with an excellent outcome (100% patient survival). Children who had acute renal failure due to other illnesses had a higher mortality (27%).

Acute Disease↗