PubMed Health⌕ Search

Biomedical subjects

J B Hunter

Publications and source records attributed to J B Hunter.

At least 19 recordsLinked to original sources
PubMed2005

Human papillomavirus prevalence at the USA-Mexico border among women 40 years of age and older.

The incidence of cervical cancer increases with age among USA Hispanics and women living in Latin America starting in the fourth decade of life. We conducted a study of women > or = 40 living at the USA-Mexico border to determine the prevalence and risk factors for human papillomavirus (HPV) infection detected by polymerase chain reaction. In all, 9.2% of participants tested HPV positive. Compared with women aged 50-59, odds ratios of 8.82 and 6.67 were observed for women > or = 60 and 40-49, respectively. Among women aged 40-49, both oncogenic and non-oncogenic HPV infections were detected; however, women > or = 60 were positive for predominantly oncogenic genotypes. HPV risk significantly increased with > or = 2 lifetime sexual partners in adjusted models. These data suggest that the prevalence of HPV infection may have a second peak among post-menopausal Hispanic women.

Adult↗
PubMed2003

Bier's block using prilocaine: safe, cheap and well tolerated.

OBJECTIVES: To examine the safety of prilocaine Bier's block performed for Colles fracture manipulation, and assess patient satisfaction. METHOD: Fifteen-year retrospective review of all patients undergoing Colles fracture manipulation with a prilocaine Bier's block looking for the incidence of significant neurological or cardiovascular events. A confidential questionnaire was administered to 50 consecutive patients to assess patient satisfaction with the method of anaesthesia. RESULTS: 1504 males with mean age 48 years and 5906 females with mean age 66 years received a prilocaine Bier's block for distal radial fracture manipulation. There were no documented incidences of anaphylaxis, arrhythmia, convulsions or collapse. Of 50 consecutive patients, all but two were satisfied with this form of anaesthesia. The pressure cuff inflation was considered the worst part of the procedure. CONCLUSION: Bier's block performed with prilocaine is at least as safe as other commonly used methods of anaesthesia for distal radial fracture reduction with high patient satisfaction. The procedure can be safely carried out by a single medical practitioner with appropriate patient monitoring and assistance from trained nursing staff.

Aged↗
PubMed2002

The effect of microgravity and space flight on the chemical senses.

The effect of space flight and microgravity on the chemical senses is reviewed. Skylab-4 and Soyuz 30-31 studies revealed changes in taste thresholds while no effect was found in a Canadian investigation (41-G) and conflicting results were obtained on another Soyuz mission. Two simulated microgravity studies found no effect on taste or smell sensitivity; while 5 other studies found an effect. Microgravity induces physiological changes including an upward shift of body fluids toward the head, which may lead to an attenuation of the olfactory component in the flavor of foods. Chemosensory changes may also relate to space sickness, Shuttle atmosphere, stress, radiation, and psychological factors.

Adult↗
PubMed2002

Arthroscopic washout of the shoulder for septic arthritis in infants. A new technique.

The operative treatment of septic arthritis of the shoulder in infants has been facilitated by the use of a 30 degrees wrist arthroscope. We have treated three children under the age of three years using this technique. After initial aspiration of the joint, an arthroscope was inserted using the posterior approach. Washout was performed under direct vision and complete clearance of pus allowed assessment of the inflammation and the damage to articular cartilage. The procedure was minimally invasive and gave excellent cosmesis without compromising care. Full recovery was achieved with a single intervention.

Arthritis, Infectious↗
PubMed2001

Distal radial fractures in young goalkeepers: a case for an appropriately sized soccer ball.

OBJECTIVES: To assess the rate of wrist fractures in young goalkeepers sustained by the specific mechanism of "saving the ball" and the potential influence of ball size and environmental conditions. METHODS: A prospective, clinic based study in one institution over a 17 month period. Patients were identified by specific questioning. Information on play circumstances and subsequent clinical progress was documented. RESULTS: Twenty nine fractures of the distal radius were identified in young goalkeepers (age range 6-15 years) as a direct result of saving the ball. Most were managed simply in a plaster cast. Three patients required minor surgical interventions, and all fractures went on to unite without significant complications. Where ball size was known, 12 of the 15 fractures in children aged 11 years or less occurred as the result of impact with an adult sized ball compared with three when a junior ball was involved. This is statistically significant (p = 0.039). In the 10 children aged 12-15 years, only one fracture involved a junior ball; this is also statistically significant (p = 0.027). Six of the injuries (21%) occurred when the ball was kicked by an adult. Injuries occurred in both organised and informal games throughout the year. CONCLUSIONS: This specific mechanism of injury has not been widely acknowledged nor has the potential influence of ball size as a causative factor been examined. Recommendations for an appropriately sized soccer ball for young players exist but are not in universal use. Increased awareness of this particular injury mechanism is required.

Adolescent↗
PubMed2000

The posterolateral approach to the distal humerus for open reduction and internal fixation of fractures of the lateral condyle in children.

Our study describes a posterolateral approach to the distal humerus for open reduction and internal fixation of displaced fractures of the lateral condyle. A total of 20 patients had open reduction and internal fixation over a four-year period using this approach, and at a mean follow-up of 12 months had full union, range of movement and no complications, either clinical or radiological. This approach is well suited to the exact visualisation and accurate reduction of this difficult fracture with minimal dissection of tissues.

Adolescent↗
PubMed2000

Ozonation and alkaline-peroxide pretreatment of wheat straw for Cryptococcus curvatus fermentation.

Crop residues in an Advanced Life Support System (ALS) contain many valuable components that could be recovered and used. Wheat is 60% inedible, with approximately 90% of the total sugars in the residue cellulose and hemicellulose. To release these sugars requires pretreatment followed by enzymatic hydrolysis. Cryptococcus curvatus, an oleaginous yeast, uses the sugars in cellulose and hemicellulose for growth and production of storage triglycerides. In this investigation, alkaline-peroxide and ozonation pretreatment methods were compared for their efficiency to release glucose and xylose to be used in the cultivation of C. curvatus. Leaching the biomass with water at 65 degrees C for 4 h prior to pretreatment facilitated saccharification. Alkaline-peroxide and ozone pretreatment were almost 100% and 80% saccharification efficient, respectively. The sugars derived from the hydrolysis of alkaline-peroxide-treated wheat straw supported the growth of C. curvatus and the production of edible single-cell oil.

Biomass↗
PubMed1999

A structural explanation for the binding of multiple ligands by the alpha-adaptin appendage domain.

The alpha subunit of the endocytotic AP2 adaptor complex contains a 30 kDa "appendage" domain, which is joined to the rest of the protein via a flexible linker. The 1.9 A resolution crystal structure of this domain reveals a single binding site for its ligands, which include amphiphysin, Eps15, and epsin. This domain when overexpressed in COS7 fibroblasts is shown to inhibit transferrin uptake, whereas mutants in which interactions with its binding partners are abolished do not. DPF/W motifs present in appendage domain-binding partners are shown to play a crucial role in their interactions with the domain. A single site for binding multiple ligands would allow for temporal and spatial regulation in the recruitment of components of the endocytic machinery.

Adaptor Protein Complex 2↗
PubMed1999

Engineering concepts for food processing in bioregenerative life support systems.

Long-duration manned missions, such as Mars exploration, will require development of new and cost-effective food production and delivery systems. Requirements for both carry-on preserved food and food processed from on-board crops exceed the capabilities of existing food processing and preservation technologies. For the transit phase, new food products, preservation methods, and processing technologies for ground-based food processing are required. The bioregenerative surface phase requires methods for processing of in situ-grown crops, treatment of food wastes, preparation of daily meals, and design of nutritious and appealing plant-based menus, all within severe cost and labor constraints. In design of the food supply for a long-term mission, the designers must select and apply both the packaged food and in situ processing technologies most appropriate for the specific mission requirements. This study aims to evaluate the strengths and weaknesses of different food system strategies in the context of different types of mission, and to point out the most important areas for future technology development.

Diet↗
PubMed1997

NAD-independent lactate and butyryl-CoA dehydrogenases of Clostridium acetobutylicum P262.

Clostridium acetobutylicum P262 cells that were growing on lactate and acetate had an NAD-independent lactate dehydrogenase(iLDH) activity of 200 nmol mg protein-1 min-1. Ammonium sulfate precipitation and DEAE cellulose caused a 35-fold purification. Gel filtration indicated that the iLDH had a molecular weight of approximately 55 kDa, but two bands were always observed. Phenyl sepharose could not separate the two proteins, and hydroxyapatite caused a complete loss of activity. The semi-purified iLDH had a Vmax of 13,000 nmol mg protein-1 min-1 and a Km value of 3.5 mM for D-lactate. The Vmax and Km values for L-lactate were 300 nmol mg protein-1 min-1 and 0.7 mM. The iLDH had a pH optimum of 7.5, was not activated by fructose-1,6-bisphosphate (FDP), and could be coupled to either 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) or dichlorophenol-indophenol (DCPIP), but not methyl viologen (MV) or benzyl viologen (BV). The iLDH did not have strong absorbance between 500 and 300 nm, and trichloroacetic acid or acid ammonium sulfate extracts had virtually no fluorescence at 450 nm. The crude extracts also had MTT-linked butyryl-CoA dehydrogenase activity (60 nmol mg protein-1 min-1). The NAD-independent butyryl-CoA dehydrogenase eluted from DEAE-cellulose as two fractions. The yellow fraction was extremely unstable, but the green fraction could be stored for short periods of time at 5 degrees C. The green-colored butyryl-CoA dehydrogenase had strong absorption at 450 nm, and gel filtration indicated that it had a molecular weight of 90 kDa. The NAD-independent butyryl-CoA dehydrogenase could be coupled to MTT, DCPIP, or MV, but not BV. Because the NAD-independent lactate and butyryl-CoA dehydrogenase could both be linked to low potential carriers, these two enzymes may function as oxidation-reduction system in vivo.

Butyryl-CoA Dehydrogenase↗
PubMed1997

Early femoral loosening in one design of cemented hip replacement.

We have studied aseptic loosening of the femoral component in 76 patients with primary total hip replacement using the Capital prosthesis. The mean follow-up was 26 months (10 to 37). Twelve femoral components (16%) were definitely and eight (10%) were possibly loose. They were characterised by a thin cement mantle (p < 0.001) and excessive residual cancellous bone in the proximomedial region (p < 0.01). We recommend that the cement mantle around the prosthesis should be 2 to 3 mm and that further long-term studies are needed to evaluate the wear properties of titanium-nitride-coated titanium femoral heads.

Cementation↗
PubMed1996

The acetate kinase of Clostridum acetobutylicum strain P262.

Clostridum acetobutylicum strain P262 fermented glucose, pyruvate, or lactate, and the butyrate production was substrate-dependent. Differences in butyrate yield could not be explained by changes in butyrate kinase activities, but the butyrate production was inversely related to acetate kinase activity. The acetate kinase had a pH optimum of 8.0, a Km for acetate of 160 mM, and a kcat of 16, 800 min-1. The enyzme had a native molecular mass of 78 kDa; the size of 42 kDa on SDS-PAGE indicated that the acetate kinase of strain P262 was a homodimer.

Acetate Kinase↗
PubMed1994

The prevalence of degenerative arthritis of the base of the thumb in post-menopausal women.

The prevalence of basal thumb osteoarthritis was assessed in 143 post-menopausal women. The radiological prevalences of isolated carpometacarpal and scapho-trapezial osteoarthritis were 25% and 2% respectively. The prevalence of combined carpometacarpal and scapho-trapezial osteoarthritis was 8%. 28% of women with isolated carpometacarpal osteoarthritis and 55% with combined carpometacarpal and scapho-trapezial osteoarthritis complained of basal thumb pain.

Aged↗
PubMed1994

Increased incidence of HLA-B40 group antigens in children with hemolytic-uremic syndrome.

Hemolytic uremic syndrome (HUS) develops in 25-30% of children infected with Escherichia coli strains that produce Shiga-like toxins, also known as verocytotoxins. Mild HUS also occurs in 1 in 4 of the other family members, suggesting a familial predisposition to HUS. To understand the possible genetic predisposition, the frequency of HLA antigens was evaluated in 30 children (12 boys, 18 girls; mean age 3.8 years) with HUS following a prodrome of bloody diarrhea. When compared to a blood donor population from the same geographic area and ethnic background, no significant differences were noted in the frequency of HLA-A, HLA-C, HLA-DR, and HLA-DQ antigens. However, the frequency of HLA-B40 and its splits (B60, 61, 41, 47) was significantly higher in the study population (corrected p < 0.005). The relative risk of developing HUS was 6.04 when HLA-B40 and HLA-B40 split products were present, and the risk increased to 8.5 when the analysis was extended to include the cross-reactive antigens B44 and B13. These HLA-B antigens share common amino acid sequences at positions 41-45 and 67-74 on the alpha-1 domain of the HLA class I molecule. Our data suggest that the inheritance of HLA-B40, its splits, and cross-reactive antigens increases the risk of developing HUS.

Adolescent↗
PubMed1994

Excision of the trapezium for osteoarthritis at the base of the thumb.

We have assessed the results of 34 simple excisions of the trapezium, with no additional soft-tissue procedures, in 30 patients. At a median follow-up of five years (2 to 22), 16 thumbs (47%) were completely painfree and a further 10 (29%) were slightly painful after use. Nineteen thumbs (56%) had no functional disability, but thumb-pinch strength was reduced by about 20%. No patient had painful degeneration at the scaphotrapezial pseudarthrosis.

Adult↗
PubMed1993

Heparin induced thrombosis: an important complication of heparin prophylaxis for thromboembolic disease in surgery.

Heparin induced thrombocytopenia with thrombosis, or the "white clot syndrome," is a rare but recognised complication of heparin therapy. The syndrome is idiosyncratic, immune mediated, and not dose dependent and therefore is equally likely to occur with prophylactic and therapeutic heparin dosage regimens. Despite published reports on the subject we were alarmed that many surgeons who regularly use heparin to prevent or treat thrombosis were unaware that heparin can induce thrombotic complications in susceptible patients. We present three typical case histories, a brief discussion of the condition, and some guidelines on its prevention and treatment.

Aged↗