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Biomedical subjects

S M Turner

Publications and source records attributed to S M Turner.

At least 19 recordsLinked to original sources
PubMed2006

Dissociation between adipose tissue fluxes and lipogenic gene expression in ob/ob mice.

Recent evidence has been presented that expression of lipogenic genes is downregulated in adipose tissue of ob/ob mice as well as in human obesity, suggesting a functionally lipoatrophic state. Using (2)H(2)O labeling, we measured three adipose tissue biosynthetic processes concurrently: triglyceride (TG) synthesis, palmitate de novo lipogenesis (DNL), and cell proliferation (adipogenesis). To determine the effect of the ob/ob mutation (leptin deficiency) on these parameters, adipose dynamics were compared in ob/ob, leptin-treated ob/ob, food-restricted ob/ob, and lean control mice. Adipose tissue fluxes for TG synthesis, de novo lipogenesis (DNL), and adipogenesis were dramatically increased in ob/ob mice compared with lean controls. Low-dose leptin treatment (2 microg/day) via miniosmotic pump suppressed all fluxes to control levels or below. Food restriction in ob/ob mice only modestly reduced DNL, with no change in TG synthesis or adipogenesis. Measurement of mRNA levels in age-matched ob/ob mice showed generally normal expression levels for most of the selected lipid anabolic genes, and leptin treatment had, with few exceptions, only modest effects on their expression. We conclude that leptin deficiency per se results in marked elevations in flux through diverse lipid anabolic pathways in adipose tissue (DNL, TG synthesis, and cell proliferation), independent of food intake, but that gene expression fails to reflect these changes in flux.

Adipogenesis↗
PubMed2005

Fractures of the distal third of the clavicle treated by hook plating.

We retrospectively assessed the union and shoulder function following hook plate fixation in 18 patients with Neer type 2 fractures of the lateral end of the clavicle. The average age was 40 (range 22-62) years, and the mean follow-up was 25 (range 6-48) months. Fifteen patients had acute fractures and the rest were non-unions. Complications included two non-unions, one following a deep infection. There were no iatrogenic fractures. Acromial osteolysis was seen in five patients who had their plates in situ. The average pain score at rest was 1 (range 0-4), and the average pain score on abduction was 2.2 (range 0-5). The average Constant score was 88.5 (range 63-100). Patients were asked to rate their shoulder function; three rated it as normal, 11 as nearly normal and one as not normal. Hook plate fixation appears to be a valuable method of stabilising Neer type 2 fractures of the clavicle, resulting in high union rates and good shoulder function. These plates need to be removed after union to prevent acromial osteolysis.

Bone Plates↗
PubMed2005

Validation of the Social Phobia and Anxiety Inventory for Children (SPAI-C) in a sample of Brazilian children.

The purpose of the present study was to examine the factor structure and psychometric properties of the Social Phobia and Anxiety Inventory for Children (SPAI-C), an instrument developed in the United States and applied to a sample of Brazilian schoolchildren. The process included the translation of the original material from English into Portuguese by two bilingual psychiatrists and a back translation by a bilingual physician. Both the front and back translations were revised by a bilingual child psychiatrist. The study was performed using a cross-sectional design and the Portuguese version of the SPAI-C was applied to a sample of 1954 children enrolled in 3rd to 8th grade attending 2 private and 11 public schools. Eighty-one subjects were excluded due to an incomplete questionnaire and 2 children refused to participate. The final sample consisted of 1871 children, 938 girls (50.1%) and 933 boys (49.8%), ranging in age from 9 to 14 years. The majority of the students were Caucasian (89.0%) and the remainder were African-Brazilian (11.0%). The Pearson product-moment correlation showed that the two-week test-retest reliability coefficient was r = 0.780 and Cronbach's alpha was 0.946. The factor structure was almost similar to that reported in previous studies. The results regarding the internal consistency, the test-retest reliability and the factor structure were similar to the findings obtained in studies performed on English speaking children. The present study showed that the Portuguese language version of SPAI-C is a reliable and valid measure of social anxiety for Brazilian children.

Adolescent↗
PubMed2005

Sources of plasma glucose and liver glycogen in fasted ob/ob mice.

Alterations in intrahepatic carbohydrate fluxes in ob/ob mice and the effects of acute leptin administration were studied in vivo by use of a dual-isotope tracer infusion. Metabolic sources of plasma glucose (gluconeogenesis (GNG) and glycogenolysis) and hepatic glycogen (GNG, direct synthesis and pre-existing) were determined in 20-h-fasted mice infused with [2-13C1]glycerol and [U13C6]glucose for 3 h. Total glucose output (TGO) and the rate of appearance (Ra) of plasma glycerol were measured by isotope dilution. GNG, the direct pathway of hepatic glycogen synthesis and hepatic triose-phosphate flux were determined by mass isotopomer distribution analysis (MIDA). Serum glucose, insulin, leptin and liver glycogen concentrations were also measured. After a 24-h fast, ob/ob mice had 2-fold higher TGO, 2.5-fold elevated liver glycogen content and markedly higher glycogenolytic flux to glucose, absolute GNG and direct glycogen synthesis rates (10-fold increased) compared to the control group. Ob/ob mice also had elevated triose-phosphate flux compared to controls (40 vs. 22 mg/kg lean body mass/min). A model of intrahepatic flux distributions in control and ob/ob mice is presented. In summary, elevated fasting plasma glucose concentrations are due to increased TGO in ob/ob mice, which is maintained by both increased GNG and increased glycogenolysis. Furthermore, the ob/ob mice have major alterations in fasting hepatic carbohydrate fluxes into triose-phosphate pools and glycogen. We support the model that actions of leptin on hepatic glucose metabolism require insulin or other factors.

Animals↗
PubMed2003

Measurement of TG synthesis and turnover in vivo by 2H2O incorporation into the glycerol moiety and application of MIDA.

A method is presented for measurement of triglyceride (TG) synthesis that can be applied to slow-turnover lipids. The glycerol moiety of TG is labeled from 2H2O, and mass isotopomer distribution analysis (MIDA) is applied. Mice and rats were given 4-8% 2H2O in drinking water; TG-glycerol was isolated from adipose and liver during < or =12-wk of 2H2O labeling. Mass isotopomer abundances in the glycerol moiety of TG were measured by GC-MS. The combinatorial pattern of isotopomers revealed the number of H atoms in glycerol incorporating label from 2H2O (n) to be 3.8-4.0 of a possible 5 for adipose tissue and 4.6-4.8 for liver TG. Hepatic TG-glycerol in fact reached 97% predicted maximal value of label incorporation (4.4-4.6 x body 2H2O enrichment), indicating near-complete replacement of the liver TG pool. Label incorporation into adipose tissue revealed turnover of mesenteric TG to be faster (k = 0.21 day-1) than other depots (k = 0.04-0.06 day-1) in mice. TG isolated from subcutaneous depots of growing adult rats plateaued at 85-90% of calculated maximal values at 12 wk (k = 0.05 day-1), excluding significant dilution by unlabeled alpha-glycerol phosphate. Turnover of plasma TG, modeled from 2H incorporation over 60 min, was 0.06 min-1 (half-life 11.5 min). In summary, use of 2H2O labeling with MIDA of TG-glycerol allows measurement of new alpha-glycerol phosphate-derived TG synthesis and turnover. The hypothesis that mesenteric TG is more lipolytically active than other depots, previously difficult to prove by isotope dilution techniques, was confirmed by this label incorporation approach.

Adipose Tissue↗
PubMed2003

Posterior sternoclavicular joint dislocation: the value of intra-operative ultrasound.

The sternoclavicular joint dislocates posteriorly if the costoclavicular ligaments, posterior capsule, and anterior capsule have all been disrupted. Diagnosis of a posteriorly dislocated sternoclavicular joint is difficult on clinical examination and with plain X-rays. The treatment objective is to obtain a closed reduction, and failing this an open reduction is indicated. In the intra-operative setting the evaluation of the reduction when performed through closed means can be somewhat difficult, and intra-operative plain films do not give clear answers. Ultrasound as an imaging modality for these injuries was shown to demonstrate the state of the joint in terms of reduction, more clearly than X-rays (P<0.001). It was accurately interpreted by the vast majority of orthopaedic surgeons in an investigation, and is of great value in the intra-operative setting to confirm whether a closed reduction has been successful or not. A case is reported illustrating its use.

Adult↗
PubMed2002

Apoptosis and proliferation of acinar and islet cells in chronic pancreatitis: evidence for differential cell loss mediating preservation of islet function.

BACKGROUND: Chronic pancreatitis is characterised clinically by early exocrine insufficiency, with diabetes mellitus occurring as a late phenomenon. This is mirrored pathologically by extensive acinar cell destruction and islet preservation. The mechanisms underlying this differential rate of cellular destruction are unknown. AIMS: To test the hypothesis that acinar loss and islet preservation in chronic pancreatitis occurs due to differential epithelial kinetics and investigate the role of inflammatory cells and cell cycle associated molecules. METHODS: Archival tissue from six chronic pancreatitis cases was compared with six normal controls using TUNEL and immunohistochemistry for CD3, CD20, CD68, MIB-1, Bcl-2, Bax, Fas, Fas ligand, retinoblastoma protein (Rb), and tissue inhibitor of metalloproteinases 1 (TIMP-1) and 2 (TIMP-2). RESULTS: The acinar cell apoptotic index (AI) and proliferation index were higher in chronic pancreatitis than controls. T lymphocytes diffusely infiltrated fibrous bands and acini but rarely islets. Acinar Bcl-2 expression exceeded islet expression in chronic pancreatitis and controls while Bax was strongly expressed by a subset of islet cells and weakly by centroacinar cells. Islet Fas and Fas ligand expression exceeded acinar expression in chronic pancreatitis and controls. Acinar Rb expression was higher in chronic pancreatitis than in controls. Islets in chronic pancreatitis and controls showed intense TIMP-1 and TIMP-2 expression. CONCLUSION: Apoptosis plays a significant role in acinar loss in chronic pancreatitis. Acinar Bcl-2 and islet Bax expression indicates complex AI control. Increased acinar Rb expression in chronic pancreatitis may differentially promote acinar loss. Fas ligand expression may be restricted to islet cell membranes through TIMP-1 expression and inhibit islet damage by promoting apoptosis of cytotoxic T lymphocytes.

Apoptosis↗
PubMed2001

Gender differences in psychological distress among patients with irritable bowel syndrome.

OBJECTIVE: We examined possible gender differences in psychological distress in a sample of treatment-seeking Irritable Bowel Syndrome (IBS) patients. METHODS: A total of 341 IBS patients (238 females, 83 males) were studied. Structured psychiatric interviews were available on 250 participants. RESULTS: We found significantly higher scores for females than males on the Beck Depression Inventory (BDI), Trait Anxiety of the State-Trait Anxiety Inventory (STAI), and Scales 2 and 3 of the MMPI. However, there were no differences in the percentages of the two samples meeting criteria for one or more Axis I psychiatric disorders, with 65.6% of the total sample meeting these criteria. CONCLUSION: Gender differences in psychological distress appear to be a function of method of measurement.

Adult↗
PubMed2001

Recognition of facial affect by children and adolescents diagnosed with social phobia.

This study compared the ability of children with social phobia and children with no psychiatric disorder to accurately judge facial affect. Fifteen children and adolescents with social phobia and 14 control children were asked to identify emotions depicted in slides from the Pictures of Facial Affect. In addition, they rated their level of anxiety on a pictorial Likert scale prior to and upon completion of the facial recognition task. The results indicated that children with social phobia had significantly poorer facial affect recognition skills than normal controls and reported greater anxiety upon completion of the recognition task. Multivariate analysis revealed significant differences between groups in the number of errors based on the type of facial affect. Posthoc analysis indicated that deficits were most pronounced for facial representations of happiness, sadness, and disgust. The results are discussed in relation to an integrated model of social skills training that includes facial affect recognition training as a integral component in treatment programs for children and adolescents with social phobia. Directions for future research with larger samples of more ethnically diverse children and adolescents are presented.

Adolescent↗
PubMed2000

Irritable bowel syndrome.

Within the literature, it appears evident that neither a univariate etiologic model nor a single-agent treatment approach is sufficient to address the many diagnostic, assessment, and therapeutic challenges posed by irritable bowel syndrome (IBS). Various scientific advances have been made over the past 5 years, particularly in the areas of nonpharmacologic management of IBS. However, further collaboration between scientists and clinicians from multiple disciplines is strongly encouraged.

Colonic Diseases, Functional↗
PubMed2000

Behavioral treatment of childhood social phobia.

Sixty-seven children (ages 8 and 12) with social phobia were randomized to either a behavioral treatment program designed to enhance social skills and decrease social anxiety (Social Effectiveness Therapy for Children, SET-C) or an active, but nonspecific intervention (Testbusters). Children treated with SET-C were significantly more improved across multiple dimensions, including enhanced social skill, reduced social fear and anxiety, decreased associated psychopathology, and increased social interaction. Furthermore, 67% of the SET-C group participants did not meet diagnostic criteria for social phobia at posttreatment compared with 5% of those in the Testbusters group. Treatment gains were maintained at 6-month follow-up. The results are discussed in terms of treatment of preadolescent children with social phobia and the durability of treatment effects.

Behavior Therapy↗
PubMed1999

Metabolic adaptations to dietary fat malabsorption in chylomicron-deficient mice.

A mouse model of chylomicron deficiency was recently developed; these mice express a human apolipoprotein (apo) B transgene in the liver but do not synthesize any apoB in the intestine. Despite severe intestinal fat malabsorption, the mice maintain normal concentrations of plasma lipids and liver-derived apoB 100-containing lipoproteins. We investigated the metabolic mechanisms by which plasma lipid levels are kept normal. De novo lipogenesis (DNL) and cholesterogenesis were measured by mass isotopomer distribution analysis (MIDA). Plasma non-esterified fatty acid (NEFA) fluxes and hepatic re-esterification of labelled plasma NEFA were also measured. Hepatic and plasma triacylglycerol (TG) concentrations and plasma NEFA fluxes were not different between chylomicron-deficient mice and controls. The contribution from DNL to the hepatic TG pool was only modestly higher in chylomicron-deficient mice [12+/-2.1% (n=7) compared with 3.7+/-1.0% (n=9); means+/-S.E.M.], whereas cholesterogenesis was markedly elevated. The fractional contribution from plasma NEFA to hepatic TG was greatly elevated in the chylomicron-deficient animals (62% compared with 23%). Accordingly, 73% of hepatic TG was neither from DNL nor from plasma NEFA in controls, presumably reflecting prior contribution from chylomicron remnants, compared with only 26% in the chylomicron-deficient group. The long-term contribution from DNL to adipose fat stores reached approximately the same steady-state values (approximately 30%) in the two groups. Body fat accumulation was much lower in chylomicron-deficient animals; thus, whole-body absolute DNL was significantly lower. We conclude that plasma and hepatic TG pools and hepatic secretion of apoB-containing particles are maintained at normal levels in chylomicron-deficient mice, not by de novo fatty acid synthesis, but by more avid re-esterification of plasma NEFA, replacing the normally predominant contribution from chylomicrons, and that some dietary fat can be absorbed by apoB-independent mechanisms.

Adipose Tissue↗
PubMed1999

Psychopathology of childhood social phobia.

OBJECTIVE: To describe the clinical syndrome of social phobia in preadolescent children. METHOD: Fifty children with DSM-IV social phobia were assessed with semistructured diagnostic interviews, self-report instruments, parental and teacher ratings, a behavioral assessment, and daily diary recordings. In addition, the behaviors of these children were compared with those of a sample of normal peers. RESULTS: Children with social phobia had a high level of general emotional over-responsiveness, social fear and inhibition, dysphoria, loneliness, and general fearfulness. Sixty percent suffered from a second, concurrent disorder. Socially distressing events occurred quite frequently and were accompanied by maladaptive coping behaviors. In addition, children with social phobia had significantly poorer social skills. There were few differences based on gender or race. CONCLUSIONS: Children with social phobia suffer pervasive and serious functional impairment. In addition, the clinical presentation suggests specific avenues for psychosocial interventions.

Adolescent↗
PubMed1999

Teaching study skills and test-taking strategies to elementary school students. The Testbusters Program.

A pilot program to reduce test anxiety and related social-evaluative concerns is presented. Testbusters is a program designed specifically for elementary and middle school children in grades 4 through 7 that teaches effective study habits, study skills, and test-taking strategies and includes a behavioral contract to ensure consistent study behavior. The assessment strategy includes self-report instruments, a behavioral assessment, and children's grade point averages. After a 6-month waiting period, eight children with moderate to severe test anxiety participated in the 11-week program. The results indicated that Testbusters decreased general levels of test anxiety and self-ratings of distress when taking a test. Overall grade point average improved significantly and grades in the majority of the subjects showed positive improvement. There was no change in overall self-esteem or judgments of cognitive competence. The results are discussed in terms of the use of a skills strategy to decrease anxiety and improve academic achievement.

Anxiety↗
PubMed1997

Direction of temperature control in the thermal biofeedback treatment of vascular headache.

In order to test for the specific therapeutic effects of thermal biofeedback (TBF) for hand warming on vascular headache (HA), 70 patients with chronic vascular HA were randomly assigned to TBF for hand warming, TBF for hand cooling, TBF for stabilization of hand temperature, or biofeedback to suppress alpha in the EEG. Patients in each condition initially had high levels of expectation of therapeutic benefit and found the treatment rationales highly credible. Participants in each condition received 12 treatment sessions on a twice-per-week basis. Based on daily HA diary data gathered for 4 weeks prior to treatment and 4 weeks after treatment, HA Index was significantly (p = .003) reduced as was HA medication consumption. There were no differential reductions in HA Index or Medication Index among the four conditions. Global self-reports of improvement gathered at the end of the post-treatment monitoring period also did not differ among the four conditions. We were unable to demonstrate a specific effect of TBF for hand warming on vascular HA activity.

Adolescent↗
PubMed1997

At risk for anxiety: I. Psychopathology in the offspring of anxious parents.

OBJECTIVE AND METHOD: Children of parents with anxiety disorders, depressive disorders, mixed anxiety/depressive disorders, and no psychiatric disorder were assessed with semistructured interviews to determine rates of overall psychopathology and to determine specifically the presence of anxiety disorders. RESULTS: Children of the three "high-risk" groups were significantly more likely to have a diagnosable disorder (including anxiety disorders) than offspring of normal parents, but there were no differences among the children from the three parental diagnostic groups. However, when examined specifically for anxiety disorders, offspring of anxious parents were significantly more likely to have only anxiety disorders. Offspring of depressed or mixed anxious/depressed parents had a broader range of disorders and more comorbid disorders. Family socioeconomic status was related to the probability that a child would have a disorder. CONCLUSIONS: Anxiety disorders are common among offspring of anxious and depressed parents. However, when a parent has depression, children exhibit a broader range of psychopathology than when a parent has an anxiety disorder alone.

Anxiety Disorders↗