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Biomedical subjects

S Baker

Publications and source records attributed to S Baker.

At least 37 records · Page 2Linked to original sources
PubMed1997

Inflammatory markers in chronic hepatitis C.

To test the hypothesis that inflammation in hepatitis C follows mechanisms common to immune-activated pathways, the distributions of T and B cells, adhesion molecules and transforming growth factor-beta (TGF-beta) were assessed in liver biopsies with chronic inflammation due to hepatitis C (HCV, n = 8) and other causes (non-HCV, n = 10). Frozen sections were immunostained using primary antibodies to CD2, CD20, CD4, CD8, intercellular adhesion molecule (ICAM-1), vascular cell adhesion molecule (VCAM)-1, HLA-DR, lymphocyte function-associated antigen (LFA)-1, and TGF-beta. Inflammatory cells positive for each immunophenotypic marker were counted, and positive staining for adhesion molecules, HLA-DR and TGF beta was graded in triads and lobules and compared in HCV and non-HCV biopsies. In all biopsies, T cells were more frequent than B cells, both in triads and lobules. CD20+, CD4+, CD8+ and LFA-1+ cells were increased in HCV compared to non-HCV biopsies. Portal lymphoid aggregates were present in 6 of 8 HCV biopsies and 3 of 10 non-HCV biopsies. Aggregates consisted of CD20+, CD4+, CD8+ and LFA-1+ cells, and ICAM-1 and VCAM-1 were increased. Sinusoidal lining cells in HCV biopsies and non-HCV biopsies with inflammation expressed HLA-DR, ICAM-1, and CD4. TGF-beta was increased in foci of necrosis. Inflammation in chronic HCV involves common immune-mediated cellular effector pathways and the inflammation in the portal triads represents aggregation of both T and B cells, mediated in part by upregulation of adhesion molecules on portal stromal cells; this is possibly in response to antigens draining from necroinflammatory foci in the lobules. TGF-beta is increased in active necroinflammatory foci, but not in portal lymphoid aggregates.

Adult↗
PubMed1997

Frequency and distribution of DNA fragmentation as a marker of cell death in chronic liver diseases.

To study the early stages of cell death in various types of chronic liver injury, liver biopsies from a total of 26 patients, including 7 with chronic hepatitis C(CHC), 4 with chronic hepatitis B(CHB), 7 with alcoholic liver disease (ALD), 4 with autoimmune or drug hepatitis (AI/DH), and 4 with primary biliary cirrhosis(PBC), were examined by an in situ nucleotidyl transferase assay (ISNTA), which detects DNA fragmentation. Positive nuclei in hepatocytes and sinusoidal lining cells were counted in all parenchymal areas, excluding triads and areas of fibrosis, using a computer with Sigmascan software. The number of positive hepatocytes/mm2 was similar in the biopsies of patients with CHC, CHB, ALD and AI/DH, but significantly lower in PBC. The number of positive sinusoidal lining cells/mm2 was significantly greater in biopsies with CHC compared to CHB, ALD, AI/DH and PBC. Double staining revealed that the ISNTA-positive sinusoidal lining cells were also CD68 positive, indicating that they were Kupffer cells. The frequency of ISNTA positivity did not correlate with serum AST or ALT levels, steatosis, cell swelling or cirrhosis. ISNTA-positive hepatocytes were more frequent than acidophilic bodies in every disease category. We conclude that apoptosis may be a common pathway of cell death in different liver diseases, that the high frequency of DNA fragmentation in Kupffer cells in CHC suggests that during chronic hepatitis C infection activated Kupffer cells may be subject to regulatory control by apoptosis and that ISNTA is more sensitive than acidophilic bodies in assessing the degree of cell injury in the liver.

Adult↗
PubMed1997

A comparison of duplex scanning and continuous wave Doppler in the assessment of primary and uncomplicated varicose veins.

OBJECTIVES: To compare the findings of continuous wave Doppler (CWD) with duplex ultrasound in the assessment of primary and uncomplicated varicose veins, and to determine how their relative roles might be best applied. MATERIALS AND METHODS: One hundred consecutive limbs were studied in 73 patients with primary (no previous surgery) and uncomplicated (no significant skin change) varicose veins. CWD was employed by a single observer; followed by duplex scanning performed "blind" and independently. RESULTS: There were 87 limbs with long saphenous incompetence on duplex; all but four of which were correctly identified by CWD, by which technique there were no false positives. (Sensitivity 95%, specificity 100%.) There were 21 limbs with short saphenous incompetence on duplex, all but two of which were recognised on CWD. However, CWD incorrectly diagnosed reflux at the saphenopopliteal junction in five limbs (false positives) with what was, in fact, segmental reflux in the long saphenous trunk on duplex (sensitivity 90%, specificity 93%.) This would have led to inappropriate exploration of the saphenopopliteal junction had surgery proceeded without checking with duplex. CONCLUSIONS: CWD is adequate for long saphenous incompetence. All "reflux" demonstrated on CWD in the popliteal fossa (about 25% of cases) should be checked by duplex. If this policy had been followed, all the patients in this study would have undergone the correct procedure. The only "errors" would have been missing coexistent short saphenous incompetence in two limbs undergoing appropriate long saphenous exploration.

Female↗
PubMed1997

Recurrent synovial chondromatosis treated with meniscectomy and synovectomy.

Synovial chondromatosis is a rare benign intraarticular metaplasia of synovium. This process may result in the production of detached particles of highly cellular cartilage in the involved joint spaces. It is most often reported in the larger joints of the body including the knee, hip, elbow, and ankle. Since Axhausen in 1993 reported the first case affecting the temporomandibular joint, several articles have been listed in the literature regarding the presentation, diagnosis, and management of this form of an arthropathy. This is a case of a recurrent synovial chondromatosis that was approached with a meniscectomy and a complete synovectomy.

Arthroscopy↗
PubMed1997

Formation and development of the Aromatherapy Organisations Council.

Aromatherapy is increasingly used alongside orthodox medicine in hospitals and via GP referral. However, doctors and other health professionals are concerned about training standards, codes of conduct, and standards of practice. These concerns were the focus of a Working Party established in 1990 to promote a single body for the practice of aromatherapy. Today the range of training courses available may seem confusing and this is compounded by aromatherapy massage courses run by many further education colleges under the health and beauty umbrella, which claim to offer recognized qualifications in aromatherapy. So what is a 'qualified aromatherapist'? What are the recognized training standards for the profession? Which professional associations are recognized? Is there a self-regulating and governing body for aromatherapy and what is its remit? What is happening on the European front? This paper describes the role and remit of the Aromatherapy Organisations Council (AOC) who are committed towards identifying unified training standards and maintaining a register of training establishments.

Aromatherapy↗
PubMed1997

Clostridium difficile-associated diarrhea: epidemiology, risk factors, and infection control.

OBJECTIVES: To evaluate the effectiveness of specific infection control measures on the incidence of Clostridium difficile-associated diarrhea (CDAD) and to identify risk factors for its development. SETTING: 370-bed, tertiary-care teaching hospital with approximately 12,000 to 15,000 admissions per year. METHODS: Several infection control measures were implemented in 1991 and 1992, and the attack rates of CDAD were calculated quarterly. Antibiotic use for 1988 through 1993 was analyzed. A case-control study was conducted from January 1992 to December 1992 to identify risk factors for acquisition of CDAD. RESULTS: From 1989 to 1992, the attack rate of CDAD increased from 0.49% to 2.25%. An increase in antibiotic use preceded the rise in the incidence of CDAD in 1991. Despite implementation of various infection control measures, the attack rate decreased to 1.32% in 1993, but did not return to baseline. Ninety-two cases and 78 controls (patients with diarrhea but with negative toxin assay) were studied. By univariate analysis, history of prior respiratory tract infections (odds ratio [OR], 3.6; 95% confidence interval [CI95], 1.2-10.4), the number of antibiotics, and the duration of exposure to second-generation cephalosporins (OR, 3.55; CI95, 1.47-9.41) and to ciprofloxacin (OR, 7.27; CI95, 1.13-166.0) were related significantly to the development of CDAD. By stepwise logistic regression analysis, only exposure to antibiotics and prior respiratory tract infections (P = .0001 and .0203, respectively) were found to be significant. CONCLUSION: Antibiotic pressure might have contributed to failure of infection control measures to reduce the incidence of CDAD to baseline.

Analysis of Variance↗
PubMed1997

History of violent behaviour and schizophrenia in different cultures. Analyses based on the WHO study on Determinants of Outcome of Severe Mental Disorders.

BACKGROUND: Information on patterns and correlates of the violent behaviour of individuals with schizophrenia is largely limited to populations in developed countries. Data from a World Health Organization epidemiological study of schizophrenia and related disorders, the Determinants of Outcome of Severe Mental Disorders (DOSMD), presented an opportunity to study patterns of violence across multinational settings. METHOD: Centres in 10 countries participated in the DOSMD study. An incidence sample of 1017 patients with schizophrenia who had their first-in-lifetime contact with a helping agency as a result of their psychotic symptoms was obtained. Data were available on their history of violent behaviour, substance use, and demographics. RESULTS: The occurrence rate of assault in the entire cohort was 20.6 per hundred, but the rate was three times higher in the developing countries (31.5 per hundred) than in developed countries (10.5 per hundred). History of assault was associated with positive symptoms, such as excitement and auditory hallucinations, and with serious alcohol problems. CONCLUSIONS: The cultural context and the specific characteristics of the disease in individuals with schizophrenia may interactively affect rates of violent behaviour.

Adolescent↗
PubMed1997

The relationships of self-care agency and self-care actions to caregiver strain as perceived by female family caregivers of elderly parents.

The relationships of self-care agency and self-care actions to perceived caregiver strain among female family caregivers of elderly parents were examined in this descriptive correlational study. The length of time in the caregiver role, the quantity of multiple roles, and types of caregiving tasks performed by the caregiver were examined with the self-care variables to note their association with caregiver strain. This study was based on Orem's (1991) conceptual model. A convenience sample of 131 primary caregivers completed. The Burden Interview, Denyes Self Care Agency Instrument and Denyes Self Care Practice Instrument by mail survey. Significant findings show an inverse relationship between self-care agency and caregiver strain; self-care actions mediated relationships between household tasks, emotional support, and caregiver strain; the moderating effects of multiple roles on self-care actions increased caregiver strain, and the moderator effects of personal care tasks on self-care actions decreased caregiver strain. These findings suggest the need for nurses to educate caregivers to use effective self-care actions and to assess for factors that may influence caregivers and affect caregiving outcomes.

Adult↗
PubMed1997

The epidemiology of fecal carriage of vancomycin-resistant enterococci.

An outbreak of vancomycin-resistant enterococci (VRE) began at the University of Massachusetts Medical Center in May 1993. As of September 1995, we had a total of 253 patients infected or colonized with VRE, with consequent increasing demand for private rooms. We analyzed results of surveillance cultures for VRE of 49 patients known to be colonized or infected with VRE. Of these, 34 (70%) were classified as persistent carriers, defined as patients with at least three consecutively positive cultures from any site taken over at least a 2-week period. The length of carriage varied from 19 to 303 days (median, 41 days); 11 patients were converters, defined as patients with three consecutive negative cultures from all previously colonized sites taken over a 3-week period. These patients were free of VRE for 39 to 421 days (median, 142 days). Four were recolonizers after they were documented to be clear of VRE for 33 to 106 days. VRE carriage tends to be prolonged, and hospitalization of patients with VRE will require continued isolation and contact precautions for control of transmission.

Carrier State↗
PubMed1996

Human non-pancreatic (group II) secreted phospholipase A2 expressed from a synthetic gene in Escherichia coli: characterisation of N-terminal mutants.

A gene coding for human non-pancreatic (group II) secreted phospholipase A2 (hnpsPLA2) has been constructed by the single-step ligation of twelve synthetic oligonucleotides. The gene has been cloned into a modification of the bacterial expression vector pET 11 which allows protein over-expression as inclusion bodies and enables about 3 mg/litre of pure refolded fully active enzyme to be obtained. The protein was expressed as a 1-Ala mutant (N1A) to allow removal of the initiator methionine by the Escherichia coli amino-peptidase. This mutant had very similar properties to the wild-type enzyme. A double mutant, N1A, V3W was also constructed and expressed in high yield. This tryptophan-containing mutant showed similar properties to the wild-type and N1A mutant but had about 40% of the activity under the assay conditions used. This tryptophan was used as a reporter group for interfacial binding and its properties were compared to those of the corresponding tryptophan in PLA2 from procine pancreas. Expression of the wild-type gene sequence for hnpsPLA2 in E. coli gave the expected mutant protein still with the initiator methionine and with much reduced activity. Interfacial binding of all hnpsPLA2 mutants to anionic phospholipids was very similar when assessed by fluorescence methods. Comparisons of these mutants with the pancreatic enzyme revealed significant differences in terms of the effect of calcium on interfacial binding. The ability to express reasonably large amounts of the N1A mutant in E. coli will provide a basis for future site directed mutagenesis studies of this important human enzyme.

Amino Acid Sequence↗
PubMed1996

Monoclonal antibody 197 (anti-Fc gamma RI) infusion in a patient with immune thrombocytopenia purpura (ITP) results in down-modulation of Fc gamma RI on circulating monocytes.

A 44-year old woman with refractory immune thrombocytopenia purpura was treated with the murine monoclonal antibody 197 in a phase 1 trial. It vitro studies have demonstrated that the monoclonal antibody 197 (subclass IgG2a) binds to two distinct epitopes of Fc gamma RI, with the constant domain binding to the Fc-binding portion of the Fc gamma RI and the variable domain binding to a different epitope, resulting in crosslinking and modulation of this receptor. The monoclonal antibody 197 was administered on days 1, 3 and 5 at doses of 0.25 mg/kg, 0.35 mg/kg and 0.45 mg/kg, respectively. The fusions were well tolerated with transient facial flushing, and wheal-and-flare rash during the first infusion, which resolved with a slower infusion rate and the administration of diphenhydramine and acetaminophen. Although a marked clinical improvement did occur with resolution of oral ecchymoses and epistaxis after the first mAb infusion, the initial platelet count of 6 x 10(9)/I did not change appreciable over the 5 d course of monoclonal antibody treatment. Binding of fluorescein-labelled monoclonal antibody 197 to peripheral monocytes showed a rapid and persistently decreased mean fluorescein intensity, indicated binding of administered 197 to the monocytes in vivo. Indirect staining for FcgammaRI using fluorescein-labelled goat anti-mouse immunoglobulin was also decreased, suggesting modulation of the receptor. The patient experienced monocytopenia which persisted throughout the 5 d of monoclonal antibody 197 therapy, but reversed following institution of intravenous IgG. These data indicate that intravenous monoclonal antibody 197 induces specific down-modulation of Fc gamma RI expression on monocytes.

Adult↗
PubMed1996

Muscle tenderness and peak torque changes after downhill running following a prior bout of isokinetic eccentric exercise.

Unaccustomed exercise (usually of an eccentric nature) is often followed by delayed onset muscle soreness (DOMS). Previous studies have found that prior eccentric activity produces a training effect which reduces DOMS and morphological changes. The aim of this study was to examine the effects of a prior bout of maximal isokinetic eccentric exercise on DOMS, strength loss and plasma creatine kinase (CK) changes following a downhill run. Ten male subjects with a mean (+/- S.D.) age of 22.5 +/- 2.8 years, body mass of 62.67 +/- 0.05 kg and height of 176 +/- 3 cm were allocated to either a treatment group or a control group. The treatment group performed 100 maximal eccentric activations of the knee extensors in the dominant leg at 0.52 rad s-1. Two weeks later, the downhill run was performed on a motor-driven treadmill. This consisted of five bouts of 8 min at a gradient of -10% at a speed corresponding to 80% of the predicted maximal heart rate. The untrained group performed the downhill run as above but without the prior isokinetic session. Tenderness measurements, plasma CK activity and concentric and eccentric isokinetic peak torque measurements of the knee extensors at 0.52 and 2.83 rad s-1 were recorded prior to, immediately following and 2, 4 and 7 days after each protocol. The isokinetic protocol caused an increase (P < 0.01) in CK and tenderness and a decrease (P < 0.05) in concentric and eccentric torque at both speeds in the treatment group. Following the downhill run, a reduction in peak torque (P < 0.01) was observed in the eccentric and concentric modes at both isokinetic speeds in the control group. For the treatment group, the decrease in peak torque occurred only at the faster eccentric speed. With the exception of the faster eccentric speed, the decrement in peak torque was greater in the control group in all post-exercise isokinetic strength tests. There was less tenderness (P < 0.01) in the trained knee extensor muscle group. Peak torque also returned to pre-downhill values earlier for the trained group. Although plasma CK activity increased in both groups after downhill running, it was much lower (P < 0.01) in the trained group. The results suggest that a prior bout of isokinetic eccentric training reduces muscle damage, reduces the amount of strength loss and decreases the sensation of DOMS after downhill running.

Adult↗
PubMed1996

Mutation of lysine residues in the nucleotide binding segments of the poliovirus RNA-dependent RNA polymerase.

The poliovirus 3D RNA-dependent RNA polymerase contains two peptide segments previously shown to cross-link to nucleotide substrates via lysine residues. To determine which lysine residue(s) might be implicated in catalytic function, we engineered mutations to generate proteins with leucine residues substituted individually for each of the lysine residues in the NTP binding regions. These proteins were expressed in Escherichia coli and were examined for their abilities to bind nucleotides and to catalyze RNA chain elongation in vitro. Replacement of each lysine residue in the NTP binding segment located in the central portion of the 3D molecule (Lys-276, -278, or -283) with leucine produced no impairment of GTP binding or polymerase activity. Substitution of leucine for Lys-61 in the N-terminal portion of the protein, however, abolished the binding of protein to GTP-agarose and all detectable polymerase activity. A nearby lysine replacement with leucine at position 66 had no effect on enzyme activity. The three mutations in the central region of 3D were introduced into full-length viral cDNAs, and the infectivities of RNA transcripts were examined in transfected HeLa cells. Growth of virus containing 3D with a mutation at residue 278 (3Dmu278) or 3Dmu283 was indistinguishable from that of the wild type; however, 3Dmu276 generated extremely slow-growing, small-plaque virus. Polyprotein processing by 3CDmu276 was unaffected. Large-plaque variants, in which the Leu-276 codon had mutated again to an arginine codon, emerged at high frequency. The results suggest that a lysine residue at position 61 of 3Dpol is essential for polymerase catalytic function and that a basic (lysine or arginine) residue at position 276 is required for some other function of 3D important for virus growth but not for RNA chain elongation or polyprotein processing.

Chromatography, Agarose↗
PubMed1996

A method of detecting the muscle pain threshold using an objective software-mediated technique.

This paper describes the reliability of a new procedure of applying force to a muscle site using a computer-mediated myometric procedure to measure a discomfort-pain threshold. 24 female subjects were divided into four groups. Each group was tested on three occasions (trial) at four muscle sites (site) repeated daily over four days (day). Each group received one of four different rates of force application (ramp). Analysis of variance (ramp by day by site by trial) showed a significant main effect for trials and discomfort-pain threshold at different muscle sites, but no significant main effect for days or ramps. Intraclass correlations for each muscle site were in the range of R = 0.73 to 0.98. This procedure appears to be a valid, reliable and nonintrusive means of assessing the muscle discomfort-pain threshold.

Adult↗
PubMed1996

Social support and patterns of adjustment to breast cancer.

The effect of marital support and support from other adults on the emotional and physical adjustment of 128 women with breast cancer was examined. Role function and satisfaction with health care also were evaluated as predictors of adjustment. Intact data series were obtained at 7-10 days, at 1, 2, 3, and 6 months, and 1 year postsurgery. Emotional adjustment could be predicted by satisfaction with a spouse's response to interactional and emotional needs and by support from other adults. The relationships were significant at concurrent times, across contiguous times, and predicting from the 7-10 day postsurgical period to both the 6-month and 1-year end points. Physical adjustment was not predicted by support but satisfaction with health care was predictive of perceived overall health status. Functional status in vocational, domestic, and social roles was significantly related to emotional and physical adjustment at all phases with few exceptions.

Adaptation, Psychological↗
PubMed1996

Sonographic appearance of the endometrium and ovaries during cycles stimulated with human menopausal gonadotropin.

OBJECTIVE: To determine the measurable factors that correlated with a higher conception ratio in one of our subpopulations of infertility patients. STUDY DESIGN: We analyzed 58 menstrual cycles in 24 consecutive infertility patients treated only with human menopausal gonadotropin (hMG) and intrauterine insemination between January 1992 and February 1993 to compare those cycles leading to conception with those that did not with regard to certain factors: endometrial thickness, endometrial layering, number of follicles > or = 15 mm in diameter, peak estradiol level and number of cycles prior to conception. RESULTS: All conceptions occurred in cycles that showed endometrial layering. No patient conceived if the endometrial thickness was < 8 mm. The incidence of conception increased with the number of follicles (one to three) measuring > 15 mm in average diameter. No patient conceived if the serum estradiol was < 192 pg/mL. No conceptions occurred after three successive cycles of treatment. CONCLUSION: Endometrial layering, endometrial thickness of at least 8 mm, a higher number of follicles (up to three) with an average of 15 mm and a serum estradiol level of at least 192 pg/mL correlated with a higher rate of conception.

Adult↗