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Biomedical subjects

J Baker

Publications and source records attributed to J Baker.

At least 145 records · Page 8Linked to original sources

Serum 25-hydroxyvitamin D3 levels decreased in impaired glucose tolerance and diabetes mellitus.

A cross-sectional survey was carried out in a New Zealand Polynesian and Caucasian workforce of 5677 staff aged 40-64 years to determine whether serum concentrations of 25-hydroxyvitamin D3 are altered in people with newly diagnosed diabetes mellitus and impaired glucose tolerance (IGT). Serum 25-hydroxyvitamin D3 concentration was significantly lower in newly detected cases with diabetes and IGT (n = 238) compared with controls individually matched by sex, age (+/- 2 years), ethnicity, and date of interview (mean (S.D.): 69 (31) vs. 76 (34) nmol/l; P = 0.0016). Among controls, serum concentrations were significantly lower in Maori (mean (S.E.) = 65 (5) nmol/l; P = 0.0013) and Pacific Islanders (59 (4) nmol/l; P = 0.0001) compared with Europeans (82 (3) nmol/l), after adjusting for age, sex, and time of year. We conclude that diabetes and IGT are associated with low serum concentrations of 25-hydroxyvitamin D3 and that low concentrations of this hormone in New Zealand Polynesians may partly explain their increased prevalence of diabetes/IGT compared with Europeans.

Adult↗

Serum 25-hydroxycholecalciferol concentration in newly detected hypertension.

Although blood concentrations of the active metabolite 1,25-dihydroxyvitamin D are raised in hypertension, concentrations of 25-hydroxyvitamin D, the main vitamin D metabolite, do not appear to have been reported in newly detected hypertension. Serum levels of 25-hydroxycholecalciferol were measured in 186 newly detected hypertensive patients (blood pressure > 160/95 mm Hg and never on antihypertensive medication) and normotensive controls individually matched by sex, age (+/- 2 years), ethnicity, and date of interview. Serum 25-hydroxycholecalciferol levels were similar in cases (mean (SD) = 64 (21) nmol/L) and controls (67 (28) nmol/L, P = .20). We conclude that serum 25-hydroxycholecalciferol, a marker of body vitamin D, is normal in hypertension.

Age Factors↗

Failure of intrathymic inoculation of donor-specific splenocytes to prolong cardiac or renal allograft survival in dogs.

The intrathymic inoculation (ITI) of donor splenocytes into potential organ transplant recipients has been demonstrated to result in donor-specific unresponsiveness and greatly prolonged survival of subsequent organ allografts in rodents without the need for long-term pharmacological immunosuppressive therapy. We have studied the effect of the ITI of saline (controls) (groups 1 (n = 6) and 3 (n = 6)) or donor splenocytes (groups 2 (n = 10) and 4 (n = 8)) in dogs that received either pharmacological immunosuppression (with cyclosporine and prednisone, +/- azathioprine/cyclophosphamide) (groups 1 and 2) or rabbit anti-dog antithymocyte globulin (groups 3 and 4) at the time of ITI. Kidney or heart allografting (from the donor of the splenocytes) was carried out 16-74 days after ITI; all but four transplants were performed within 16-22 days after ITI. Mean kidney allograft survival was 6, 10, 9, and 9 days, respectively, in groups 1-4. Mean cardiac allograft survival was 7, 14, 8, and 7 days, respectively. There was no statistical difference in allograft survival between those dogs that received ITI of saline and those that received donor splenocytes. These results would suggest that the protocols developed to date using ITI in rodent species may not be successful in dogs.

Animals↗

Determinants of postoperative hypothermia after normothermic cardiopulmonary bypass.

Inadvertent postoperative hypothermia in the cardiac surgical patient can have various adverse physiologic effects. Previous studies have investigated the relationship of patient, surgical, and anesthetic factors with postoperative hypothermia in patients undergoing noncardiac surgery. This study was designed to assess the relationship between postoperative hypothermia after normothermic cardiopulmonary bypass (CPB) for cardiac surgery and a variety of perioperative and patient factors. Fifty-six patients undergoing daytime elective or urgent cardiac surgery with warm (37 degrees C) CPB were studied. The following patient variables were included: age, weight, height, sex, history of previous cardiac surgery, and prebypass temperature. The following treatment factors were recorded: type of surgery, type and dose of anesthetic, use of airway humidifier, use of an intravenous (i.v.) fluid warmer, total volume of i.v. fluid administered during surgery, net fluid volume administered via CPB, total time spent on CPB, use of nitroglycerin, use of alpha-agonists during surgery, and elapsed time from end of CPB to end of surgery. Core temperature readings, as measured by a pulmonary artery catheter thermistor, were noted as follows: (1) on insertion of the pulmonary artery catheter; (2) after the patient was weaned from CPB; (3) within 30 minutes of intensive care unit (ICU) arrival; (4) 3 to 5 hours after ICU arrival; (5) 7 to 9 hours after ICU arrival; and (6) 11 to 13 hours after ICU arrival. Multiple linear regression and logistic regression for categorical variables with backward elimination were employed to determine the impact of all variables on lowest postoperative temperature. The lowest mean temperature occurred during CPB.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗

Health status and occupation: use of a health status index to measure the health of occupations.

A total of 4466 employed persons completed the short Auckland University Health Status Index (AUHSI) questionnaire and a health score was assigned to each individual on the basis of their responses. This health score was found to have statistically significant associations with a number of health-related measures, including socio-economic status (P < 0.001), and with occupational group: administrative, clerical/sales/service, skilled trades and unskilled labour (P < 0.001). Within the occupational groups, 3361 employees could be assigned to 42 specific occupations having 19 or more members each. After controlling for age and gender, significant differences in mean health score for specific occupation were found in the clerical/sales/service (P < 0.05), skilled trades (P = 0.002) and unskilled manual (P < 0.05) groups. It is postulated that these differences may be due to the nature of the specific occupation. Some possible reasons are listed. It is concluded that a global measure of health status such as this may be useful in the planning and evaluation of occupational health services.

Female↗

Serum 25-hydroxyvitamin D3 is related to physical activity and ethnicity but not obesity in a multicultural workforce.

BACKGROUND: Recent research suggests that body vitamin D levels are decreased in coronary heart disease and diabetes, but it is unclear which cardiovascular risk factors are related to vitamin D status. AIMS: To examine the relation between vitamin D status and major cardiovascular risk factors. METHODS: Serum 25-hydroxyvitamin D3, a marker of recent sun exposure and vitamin D status, was measured in 390 New Zealand residents (95 Pacific Islanders, 74 Maori and 221 others mostly of European descent), who were part of a larger cross-sectional survey of a workforce (n = 5677) aged 40-64 years. RESULTS: Serum 25-hydroxyvitamin D3 levels were significantly lower in Pacific Islanders (mean (SE) = 56 (3) nmol/L; p = 0.0001) and Maoris (68 (3) nmol/L; p = 0.036) compared with Europeans (75 (2) nmol/L) after adjusting for age, sex and time of year. Also adjusting for ethnic group, 25-hydroxyvitamin D3 was higher in people doing vigorous (aerobic) leisure physical activities (71 (2) nmol/L; p = 0.0066) and moderate (non-aerobic) activities (68 (3) nmol/L; p = 0.12) compared with those who were inactive (63 (2) nmol/L). However, 25-hydroxyvitamin D3 was unrelated to body mass index, serum lipids, blood pressure or cigarette smoking. CONCLUSIONS: People with increased skin pigmentation, such as Polynesians, and people who are inactive, have decreased body levels of vitamin D; this might partly explain their increased risk of cardiovascular disease.

Adult↗

Fibroid arising in a müllerian duct remnant and presenting as a pelvic mass in a patient with vaginal agenesis: an unusual finding.

We report a case of vaginal agenesis associated with a large fibroid arising from a Müllerian duct remnant. Vaginal agenesis is rare and infrequently encountered by gynaecologists. Its association with a pelvic mass is even more uncommon, and a medline search by the authors has failed to uncover another reported case. We provide the clinical details of this case and discuss the differential diagnoses.

Adult↗

Postnatal change in inhibitory regulation of intestinal motor activity in human and canine neonates.

Motor activity was recorded in 19 preterm infants three times during the first postnatal month. There was a paucity of small intestinal motor quiescence during fasting in the first postnatal week; however, its duration significantly increased with postnatal age (p < 0.03). Although fasting motor patterns changed with postnatal age, motor responses to feeding were present within the first few days of life. Motor activity was also recorded weekly in 11 newborn dogs for 6 wk. Intestinal motor quiescence was also absent during fasting for the first postnatal week but it significantly increased with postnatal age (p < 0.002). As in the human preterm infant, a motor response to feeding was present within the first few days of life. Plasma concentrations of gastrin and peptide YY during fasting were low in the preterm human and canine neonate during the first postnatal week but plasma concentrations of both peptides increased with postnatal age. Although plasma concentrations of gastrin were low during fasting for the first postnatal week, plasma concentrations of gastrin increased significantly postprandially compared with fasting (p < 0.05). We conclude that motor quiescence during fasting becomes a more prominent feature of newborn intestinal motor function postnatally. In addition the release of two peptides that regulate motor patterns also change postnatally. Thus, postnatal changes in motor patterns and peptide release change in a parallel fashion in human preterm neonates and canine neonates.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Enzyme replacement therapy for Gaucher disease: skeletal responses to macrophage-targeted glucocerebrosidase.

OBJECTIVES: Reversal of the hematologic and visceral abnormalities characteristic of Gaucher disease, the most common lipid storage disorder, with biweekly infusions of macrophage-targeted glucocerebrosidase (glucosylceramidase) is well documented. The extent to which the skeleton responds to enzyme replacement therapy has not been systematically investigated. METHODS: To assess the skeletal response to enzyme replacement therapy, we treated 12 patients with type 1 Gaucher disease, who had intact spleens, with macrophage-targeted glucocerebrosidase. The initial dose of enzyme was 60 U/kg body weight every 2 weeks for 24 months, followed by reduction in dosage to 30 and then 15 U/kg body weight every 2 weeks, each for 9 months. RESULTS: The lipid composition of bone marrow, determined by direct chemical analysis, began to improve after 6 months of treatment at a time when noninvasive imaging studies showed no significant changes. By 42 months, improvement in marrow composition was demonstrable on all noninvasive, quantitative imaging modalities (magnetic resonance score, quantitative xenon scintigraphy, and quantitative chemical shift imaging) used in this study. Quantitative chemical shift imaging, the most sensitive technique, demonstrated a dramatic normalization of the marrow fat content in all patients. Net increases in either cortical or trabecular bone mass, as assessed by combined cortical thickness measurements and dual-energy quantitative computed tomography, respectively, occurred in 10 patients. CONCLUSIONS: Prolonged treatment over 3 1/2 years with macrophage-targeted glucocerebrosidase produces objective reversal of disease in both the axial and appendicular skeleton in patients with Gaucher disease. Marked improvement occurs in marrow composition and bone mass in both children and adults.

Adolescent↗

Does thalidomide affect IL-2 response and production?

The exact mechanism of immunosuppression by thalidomide is poorly understood. A common denominator in the pathogenesis of graft-vs.-host disease, graft rejection, reactional lepromatous leprosy, and autoimmune disorders modulated by thalidomide is the activation of T lymphocytes culminating in the synthesis of interleukin-2 (IL-2), the expression of high-affinity IL-2 receptors, and the induction of proliferation. We investigated the effect of thalidomide on the production of IL-2 by the human leukemia cell line Jurkat through induction of IL-2 gene enhancer activity and through the presence of IL-2 in supernatants. beta-galactosidase activity, encoded by a reporter lac z construct and controlled by a transcription factor in thalidomide-treated PMA- and ionomycin-stimulated Jurkat cells, was similar (97 +/- 1.33%; p > 0.1) to non-thalidomide-treated controls at all drug concentrations tested. IL-2 enhancer-driven beta-galactose activity of thalidomide-treated and stimulated cells was also similar to that of untreated controls (p > 0.2). The IL-2 production of activated nontransfected Jurkat cells was gauged by using the IL-2-dependent cell line HT-2 as a readout and by ELISA. Jurkat cells were subcloned by limiting dilution. Bulk cultures and three subclones (J.5.2.5., J.5.2.9., and J.5.3.8.) were assayed at 6, 12, and 24 hours after PHA/PMA-induced stimulation. No inhibitory effect on the IL-2 production by thalidomide could be detected at any of the drug concentrations tested (5-30 micrograms/mL), whereas 10 to 100 ng/mL of cyclosporine inhibited the IL-2 production by 95 to 100%. In addition, we observed neither inhibition of IL-2-dependent proliferation of HT-2 nor inhibition of PHA-induced proliferation of peripheral mononuclear cells by thalidomide at all drug concentrations used (5-30 micrograms/mL). These results do not support the possibility of a modulatory effect on the immune response by thalidomide via IL-2 production and IL-2 response.

Cells, Cultured↗

A nursing career leadership program.

A three-level leadership track to parallel the clinical career ladder focuses on communication and interpersonal skills, professional, clinical and leadership experience, continuing education and leadership training. The program's success has led to career ladders in respiratory, physical and occupational therapy.

Career Mobility↗

Bacillary angiomatosis: a treatable cause of acute psychiatric symptoms in human immunodeficiency virus infection.

BACKGROUND: Bacillary angiomatosis is a systemic infection that has been most commonly reported in the setting of immunosuppression, especially human immunodeficiency virus (HIV) disease. METHOD: We report two patients who had bacillary angiomatosis who presented with psychiatric symptoms. RESULTS: The first patient presented with marked exacerbation of previous depressive disease. The second patient presented with new psychotic symptoms. In both cases psychiatric symptoms did not resolve until antibiotic treatment was given. CONCLUSION: Our report expands the clinical spectrum of bacillary angiomatosis and identifies a new cause of treatable psychiatric disease in HIV-infected persons.

AIDS Dementia Complex↗

Sequence and characterization of the Escherichia coli genome between the ndk and gcpE genes.

The region of the chromosome immediately upstream of the Escherichia coli gene gcpE has been cloned and sequenced. This region contains two functional open reading frames, orf 384 and orf 337, encoding proteins of 43,082 and 36,189 Da, respectively. Sequencing analysis (this paper) and the isolation of a DNA fragment containing a functional promoter (Talukder, A.A., Yanai, S., and Yamada, M. (1994) Biosci. Biotech. Biochem. 58, 117-120) indicate that orf 337 is in an operon with gcpE. The gene orf 384 is immediately downstream of the gene ndk, which encodes nucleoside diphosphate kinase.

Bacterial Proteins↗

Selective decontamination of the digestive tract reduces gram-negative pulmonary colonization but not systemic endotoxemia in patients undergoing elective liver transplantation.

OBJECTIVE: To examine the effect of selective antibiotic decontamination of the digestive tract in patients undergoing elective orthotopic liver transplantation. DESIGN: Prospective, randomized, concurrent allocation to either selective decontamination or standard antibiotic prophylaxis. SETTING: Operating theater and intensive care unit at a tertiary referral, university teaching hospital. PATIENTS: Fifty-nine adult patients were recruited into the study and underwent liver transplantation. INTERVENTIONS: Thirty-two patients were randomized to standard treatment (control group) and 27 patients were randomized to receive selective decontamination. After early deaths and exclusions, 31 controls and 21 decontamination patients were available for analysis. MEASUREMENTS AND MAIN RESULTS: Portal and systemic endotoxemia, colonization and infection rates, severity of illness (organ system failures, Acute Physiology and Chronic Health Evaluation II score, Therapeutic Intervention Scoring System score), antibiotic costs, and hospital survival rates were measured. Selective decontamination significantly reduced pulmonary infections and enteric, aerobic, and Gram-negative bacillary colonization without facilitating the emergence of resistant organisms, but selective decontamination had no effect on endotoxemia or the development of organ system failures. The financial costs of the selective decontamination regimen outweighed the advantages gained from an associated reduction in antibiotic usage. CONCLUSION: The failure of selective decontamination to enhance survival rates in many studies of the regimen in critically ill patients may, in part, be related to the inability of selective decontamination to abolish endotoxemia.

Adult↗

Urinary catecholamines in attention-deficit hyperactivity disorder with and without comorbid anxiety.

OBJECTIVE: To determine whether there are differences in noradrenergic or adrenergic functioning in children with attention-deficit hyperactivity disorder (ADHD) with and without anxiety. METHOD: ADHD children with and without a comorbid overanxious (ANX) disorder were compared to each other and to normal controls in terms of 2-hour urinary excretion of norepinephrine (NE), epinephrine (EPI), and their metabolites. All subjects performed a fixed series of mentally stressful tasks during the collection period. RESULTS: Children with ADHD, regardless of comorbid anxiety, excreted more normetanephrine (NMN), the chief extracellular metabolite of NE, than controls, as well as more vanillylmandelic acid. Children with ADHD alone had lower NE/NMN and EPI/metanephrine ratios compared to controls. Children with ADHD/ANX excreted more EPI than ADHD children without anxiety. CONCLUSIONS: Children with ADHD may have a higher tonic activity of the noradrenergic system than controls, while children with comorbid ADHD/ANX may be differentiated from those with ADHD alone by higher adrenergic activity.

Anxiety Disorders↗

Maternal-fetal HLA sharing and risk of newborn encephalopathy and seizures: a pilot study.

A pilot case-control study was done to collect data on whether susceptibility to newborn encephalopathy and neonatal seizures is influenced by the degree of maternal-fetal sharing of HLA antigens. Cases included 13 infants with moderate or severe newborn encephalopathy and seven infants with neonatal seizures but no other signs of encephalopathy. Controls were neurologically normal infants matched to cases by date of birth, sex, race, and payment status. Infants and their mothers were typed for HLA-A, -B, -DR, and -DQ antigens. The observed frequency of sharing of maternal antigens was greater than expected (ie, 0.5) for cases compared to controls at the HLA-B, -DR, and -DQ loci but not for HLA-A. The risk of neurologic problems in the neonatal period was increased 6.3 times when there was more than one match at the HLA-DR or -DQ locus. Placental abnormalities were noted at delivery only among cases, and the mean placental weight in cases was 598 g versus 695 g in controls. Further studies with sample sizes sufficiently large to statistically test this hypothesis are needed.

Alleles↗