Search PubMed⌕ Search

Biomedical subjects

S Fowler

Publications and source records attributed to S Fowler.

At least 19 recordsLinked to original sources
PubMed2006

Gender-related differences in recovery of locomotor function after spinal cord injury in mice.

STUDY DESIGN: In order to study the role of gender in recovery, we induced a thoracic compression spinal cord injury (SCI) separately in 2-month-old male and female C57Bl/6 mice. OBJECTIVES: We intended to assess effects of gender on recovery of hindlimb motor function and to correlate these with histomorphologic profiles of injured spinal cord tissue. METHODS: Locomotor function was evaluated by three means: a modified locomotor scoring system for rodents, beam walking and computerized activity meter. Histology was analyzed by comparison of hematoxylin and eosin-stained perfused specimens. RESULTS: Locomotor scores were 2.2+/-0.9 on day 1 in male mice, while, in contrast, they were significantly higher, 7.3+/-1.7, in females (P<0.02). On day 14 Basso, Beattie and Bresnahan scores were 9.5+/-2.2 in male mice and 16.0+/-2.2 in females (P<0.03). Terminal histology showed that the spinal cord architecture was relatively better preserved in female mice and that the extent of necrosis and infiltration of inflammatory cells was less compared to males. SETTING: Neurobiology Research Laboratory of University of Kansas Medical School in US Department of Veterans Affairs Medical Center, Kansas City, Missouri. CONCLUSION: We found that the severity of the initial injury as well as the ultimate recovery of motor function after SCI is significantly influenced by gender, being remarkably better in females. The mechanism(s) of neuroprotection in females, although not yet elucidated, may be associated with the effects of estrogen on pathophysiological processes (blood flow, leukocyte migration inhibition, antioxidant properties, and inhibition of apoptosis). SPONSORSHIP: Medical Research, US Department of Veterans Affairs, the Christopher Reeve Paralysis Foundation and NIH.

Animals↗
PubMed2006

Evaluation of tight junction protein 1 encoding zona occludens 1 as a candidate gene for albuminuria in a Mexican American population.

Albuminuria, a hallmark of diabetic nephropathy, has been shown to be significantly heritable in multiple studies. Therefore, the identification of genes that affect susceptibility to albuminuria may lead to novel avenues of intervention. Current evidence suggests that the podocyte and slit diaphragm play a key role in controlling the selective sieve of the glomerular filtration barrier, and podocyte-specific genes have been identified that are necessary for maintaining its integrity. We therefore investigated the role of gene variants of tight junction protein (TJP1) which encodes another slit diaphragm-associated protein zona occludens 1 as risk factors for albuminuria in the San Antonio Family Diabetes/Gallbladder Study (SAFDGS), which consists of extended Mexican-American families with a high prevalence of type 2 diabetes. Albuminuria, defined as an albumin (mg/dl) to creatinine (mg/dl) ratio (ACR) of 0.03, which is approximately equivalent to a urinary albumin excretion (UAE) >30 mg/day, was present in a total of 14.9% of participants, and 31% had type 2 diabetes. The TJP1 exons, flanking intronic sequence, and putative proximal promoter regions were investigated in this population. Twentynine polymorphisms, including 7 nonsynonymous SNPs, were identified and genotyped in all subjects of this study for association analysis. Three sets of correlated SNPs, which include 3 exonic SNPs, were nominally associated with ACR (p value range 0.007-0.049); however, the association with the discrete trait albuminuria was not significant (p value range 0.094-0.338). We conclude that these variants in TJP1 do not appear to be major determinants for albuminuria in the SAFDGS; however, they may play a minor role in its severity in this Mexican-American population. Further examination of the TJP1 gene region in this and other cohorts will be useful to determine whether ZO-1 plays a significant role in glomerular permselectivity.

Adolescent↗
PubMed2005

Yellow filters can improve magnocellular function: motion sensitivity, convergence, accommodation, and reading.

The magnocellular system plays an important role in visual motion processing, controlling vergence eye movements, and in reading. Yellow filters may boost magnocellular activity by eliminating inhibitory blue input to this pathway. It was found that wearing yellow filters increased motion sensitivity, convergence, and accommodation in many children with reading difficulties, both immediately and after three months using the filters. Motion sensitivity was not increased using control neutral density filters. Moreover, reading-impaired children showed significant gains in reading ability after three months wearing the filters compared with those who had used a placebo. It was concluded that yellow filters can improve magnocellular function permanently. Hence, they should be considered as an alternative to corrective lenses, prisms, or exercises for treating poor convergence and accommodation, and also as an aid for children with reading problems.

Accommodation, Ocular↗
PubMed2001

An outbreak of hepatitis A associated with green onions.

Forty-three cases of serologically confirmed hepatitis A occurred among individuals who ate at restaurant A in Ohio in 1998. Serum samples from all restaurant A employees who worked during the exposure period were negative for IgM antibodies to hepatitis A virus (HAV). A matched case-control study determined that foods containing green onions, which were eaten by 38 (95%) of 40 case patients compared with 30 (50%) of 60 control subjects, were associated with illness (matched odds ratio, 12.7; 95% confidence interval, 2.6-60.8). Genetic sequences of viral isolates from 14 case patients were identical to each other and to those of viral isolates from 3 patients with cases of hepatitis A acquired in Mexico. Although the implicated green onions, which could have come from one of 2 Mexican farms or from a Californian farm, were widely distributed, no additional green onion-associated cases were detected. More sensitive methods are needed to detect foodborne hepatitis A. A better understanding of how HAV might contaminate raw produce would aid in developing prevention strategies.

California↗
PubMed2001

Management of paediatric otitis media with effusion in the UK: a survey conducted with the guidance of the Clinical Effectiveness Unit at the Royal College of Surgeons of England.

A survey was undertaken of the practice of all Otorhinolaryngologists in England and Wales looking both at practice in general and at management of individual patients, including a patient satisfaction questionnaire, under the auspices of the Clinical Effectiveness Unit at the Royal College of Surgeons. Postal questionnaires enquired about practice in general and management in particular of 20 sequential patients per consultant. Parent questionnaires were sent six weeks and one year post-operatively. Ninety consultants took part and 1503 individual patient proformas were returned. Results showed that these consultants are managing children with otitis media with effusion (OME) in a manner very close to the recommendations of the Effective Healthcare Bulletin (1992) and consistent with the recent Clinical Effectiveness Statement of the BAOHNS, and that the intervention is popular with parents.

Child↗
PubMed2000

Comparative audit of tonsillectomy.

The Comparative Audit Service of the Royal College of Surgeons of England undertook an audit of tonsillectomy throughout England and Wales in 1997. There were three parts to the audit: a management questionnaire related to tonsillectomy and its indications; an inpatient questionnaire for patients undergoing tonsillectomy; and a postoperative patient questionnaire. One hundred and fourteen ENT consultants returned the management questionnaire, 2450 questionnaires on inpatient details were returned by 132 consultants, and 1408 patients returned postoperative questionnaires. Two-thirds of the patients underwent tonsillectomy for recurrent acute tonsillitis, and most stayed 1 night in hospital; only 3% were day cases. Postoperative haemorrhage necessitated return to theatre for 0.75% of patients. Almost 7% of patients had to be readmitted after discharge. Overall, 92% of patients felt that their throat was better than before the operation, but slightly less than this number (88%) were pleased that they had the operation. The results are further discussed in the paper. The ability to cross-reference each part of the audit for individual patients proved extremely useful.

Adolescent↗
PubMed2000

A review of intensive care nurse staffing practices overseas: what lessons for Australia?

In view of market-driven health-care policies and the move to greater efficiencies within the health-care system, the cost of nursing care is being increasingly scrutinised. Different overseas practices are commonly cited as justification for changing practices within Australia. This study is based on a review of the literature on intensive care nurse staffing requirements in Australasia; specifically, New South Wales, the United States (US) and, to a lesser extent, Europe. It was found that looking to the US for cost-cutting strategies in intensive care units (ICUs) is based on a false premise: that we are comparing like with like. ICUs in the US have a different historical trajectory and culture, service wider constituencies, have technicians and unregistered personnel providing nursing care and do not provide demonstrably better outcomes or significant cost savings. Research indicates that continuous nursing care by trained professionals provides the best outcomes. If costs must be cut, technology, pharmaceuticals and laboratory tests should be targeted. Further, a greater commitment to the development of a 'progressive patient care' model in hospital planning is required, in order to establish or consolidate an intermediate level of nursing care between the ward and the ICU. Programs aiming to improve and continuously monitor patient care, such as adverse event monitoring, the prevention of unplanned extubation and facilitation of early extubation, should be instituted, as these have been shown to not only reduce ICU costs but also improve patient outcomes. (c) 2000 Harcourt Publishers Ltd.

Journal Article↗
PubMed2000

Control of experimental inflammatory bowel disease by regulatory T cells.

A helper T cell type 1-mediated colitis driven by enteric bacteria develops in severe combined immunodeficient mice after transfer of CD45RB(high)CD4(+) T cells. Development of disease can be prevented by cotransfer of the reciprocal CD45RB(low) subset. Analysis of the mechanism of immune suppression transferred by CD45RB(low)CD4(+) cells revealed essential roles for both IL-10 and TGF-beta. These data indicate that a functionally specialized population of regulatory T (Treg) cells exists in normal mice and that these can prevent the development of pathogenic responses toward commensal bacteria. The role of Treg cells in the control of the immune response is discussed.

Adoptive Transfer↗
PubMed2000

Molecular, biochemical and functional analysis of a novel and developmentally important fibrillar collagen (Hcol-I) in hydra.

The body wall of hydra (a member of the phylum Cnidaria) is structurally reduced to an epithelial bilayer with an intervening extracellular matrix (ECM). Previous studies have established that cell-ECM interactions are important for morphogenesis and cell differentiation in this simple metazoan. The ECM of hydra is particularly interesting because it represents a primordial form of matrix. Despite progress in our understanding of hydra ECM, we still know little about the nature of hydra collagens. In the current study we provide a molecular, biochemical and functional analysis of a hydra fibrillar collagen that has similarity to vertebrate type I and type II collagens. This fibrillar collagen has been named hydra collagen-I (Hcol-I) because of its structure and because it is the first ECM collagen to be identified in hydra. It represents a novel member of the collagen family. Similar to vertebrate type I and II collagens, Hcol-I contains an N-terminal propeptide-like domain, a triple helical domain containing typical Gly-X-Y repeats and a C-terminal propeptide domain. The overall identity to vertebrate fibrillar collagens is about 30%, while the identity of the C-terminal propeptide domain is 50%. Because the N-terminal propeptide domain is retained after post-translational processing, Hcol-I does not form thick fibers as seen in vertebrates. This was confirmed using transmission electron microscopy to study rotary shadow images of purified Hcol-I. In addition, absence of crucial lysine residues and an overall reduction in proline content, results in reduced crosslinking of fibrils and increased flexibility of the molecule, respectively. These structural changes in Hcol-I help to explain the flexible properties of hydra ECM. Immunocytochemical studies indicate that Hcol-I forms the 10 nm fibrils that comprise the majority of molecules in the central fibrous zone of hydra ECM. The central fibrous zone resides between the two subepithelial zones where hydra laminin is localized. While previous studies have shown that basal lamina components like laminin are expressed by the endoderm, in situ hybridisation studies show that Hcol-I mRNA expression is restricted to the ectoderm. Hcol-I expression is upregulated during head regeneration, and antisense studies using thio-oligonucleotides demonstrated that blocking the translation of Hcol-I leads to a reversible inhibition of head morphogenesis during this regenerative process. Taken in total, the data presented in this study indicate that Hcol-I is required for morphogensis in hydra and represents a novel fibrillar collagen whose structural characteristics help to explain the unique biophysical properties of hydra ECM. Interestingly, the structure of Hcol-I mimics what is seen in Ehlers-Danlos syndrome type VII in humans; an inherited pathological condition that leads to joint and skin abnormalities. Hcol-I therefore illustrates an adaptive trait in which the normal physiological situation in hydra translates into a pathological condition in humans.

Amino Acid Sequence↗
PubMed2000

Hypoglycemic counterregulatory responses differ between men and women with type 1 diabetes.

The aim of this study was to determine whether sex-related differences occur in counterregulatory responses to hypoglycemia in adult type 1 diabetic patients. Experiments were carried out on 16 (8 men/8 women) type 1 diabetic patients and compared with 16 (8 men/8 women) age- and weight-matched normal individuals. Men and women with type 1 diabetes were matched for age (26+/-2 vs. 25+/-1 years), duration of diabetes (9+/-1 vs. 8+/-1 years), glycemic control (HbA1c 7.7+/-0.3 vs. 7.8+/-0.2%), and weight (BMI 22.8+/-1 vs. 22.1+/-1 kg/m2), respectively. After normalizing plasma glucose overnight, patients underwent a 2-h hyperinsulinemic-hypoglycemic clamp study. Plasma glucose (3.0+/-0.1 mmol/l) and insulin (510+/-48 pmol/l) levels were equated in all groups. Plasma epinephrine, norepinephrine, growth hormone (GH), muscle sympathetic nerve activity (MSNA), and endogenous glucose production (EGP) responses were significantly lower (P<0.01) in type 1 diabetic women compared with men. Autonomic symptom scores, lipid oxidation, nonesterified fatty acids (NEFAs), and glycerol responses were equivalent between men and women with type 1 diabetes despite significantly reduced sympathoadrenal and MSNA responses in women. Autonomic nervous system (ANS) and EGP responses were equivalent in type 1 diabetic and normal individuals. However, lipid oxidation (assessed by indirect calorimetry), glycerol, and NEFA responses were increased (P<0.01) in type 1 diabetic patients compared with normal control subjects. We conclude that counterregulatory responses to fixed hypoglycemia differ markedly in men and women with type 1 diabetes: 1) sympathetic nervous system, GH, and EGP responses are significantly reduced in type 1 diabetic women, 2) autonomic symptom awareness and lipolytic responses appear to be relatively increased in type 1 diabetic women compared with men, and 3) during conditions of similar hyperinsulinemic hypoglycemia and ANS drive, lipid oxidation and lipolytic responses can be increased in type 1 diabetic patients compared with normal individuals.

Adult↗
PubMed2000

Monitoring of diphtheria, pertussis and tetanus toxoids by circular dichroism, fluorescence spectroscopy and size-exclusion chromatography.

A combination of spectroscopic and chromatographic methods has been used to monitor the quality and integrity of diphtheria, pertussis and tetanus toxoids (DTxd, PTxd and TTxd) which have been prepared from the toxins by formaldehyde treatment. Different processes for detoxifying all three toxins have yielded toxoids varying in their molecular size, including oligomers (associated monomers) and aggregates (high molecular weight complexes of non-specifically associated monomers). Changes in the intrinsic fluorescence spectra of the polypeptides have been observed in some sized fractions of DTxd and PTxd. Some physico-chemical changes have been observed to correlate with a loss of antigenicity. Spectroscopic and chromatographic methods are useful not only in monitoring the stability and consistency of vaccine starting materials, but can also be used to dissect heterogeneous toxoid preparations.

Chemical Phenomena↗
PubMed1999

GIGANTEA: a circadian clock-controlled gene that regulates photoperiodic flowering in Arabidopsis and encodes a protein with several possible membrane-spanning domains.

Flowering of Arabidopsis is promoted by long days and delayed by short days. Mutations in the GIGANTEA (GI) gene delay flowering under long days but have little or no effect under short days. We have now isolated the GI gene and show that it encodes a novel, putative membrane protein. By comparing the sequence of the Arabidopsis gene with that of a likely rice orthologue and by sequencing mutant alleles, we identify regions of the GI protein that are likely to be important for its function. We show that GI expression is regulated by the circadian clock with a peak in transcript levels 8-10 h after dawn. The timing, height and duration of this peak are influenced by daylength. We analysed the interactions between GI and the LHY, CCA1 and ELF3 genes, previously shown to affect daylength responses; we show that the rhythmic pattern of GI expression is altered in the elf3, CCA1-OX and lhy genotypes, and that CCA1 and LHY expression are reduced by gi mutations. Our results are consistent with the idea that GI plays an important role in regulating the expression of flowering time genes during the promotion of flowering by photoperiod.

Alleles↗
PubMed1999

Hope and anxiety of individual family members of critically ill adults.

This correlational study describes levels of hope and states of anxiety of individual family members of critically ill patients and investigates the relationship between hope and state of anxiety. Forty-four family members of critically ill patients participated in the study and revealed a high level of hope and a high level of anxiety within 72 hours of the patient's hospitalization, regardless of personal or situational characteristics. Hope and anxiety were not significantly related in this sample; themes of hope focused on past and present experiences, whereas anxiety centered on death of the loved one. Participants looked to the past, recalling happy times, and to the future, in relation to goals and potential. Family members acknowledged feeling secure, self-confident, and steady, and were able to make decisions because they were not confused about the situation. Nurses are challenged to inspire the family's hope and decrease their anxiety.

Adaptation, Psychological↗