PubMed Health⌕ Search

Biomedical subjects

J L Hodgson

Publications and source records attributed to J L Hodgson.

At least 37 records · Page 2Linked to original sources
PubMed1996

Equine neonatal septicaemia: 24 cases.

Equine neonatal septicaemia was confirmed in 24 foals hospitalised at the Rural Veterinary Centre between 1989 and 1992 with suspected septicaemia. Septicaemia was confirmed by culture of bacteria from blood of live foals and tissues obtained at necropsy of foals that died or were euthanased. Pathogenic bacteria isolated were predominantly Enterobacteriaceae (including Escherichia coli and Salmonella serovars) and Actinobacillus equuli. Clinical manifestations of septicaemia included signs of depression, dehydration, abnormalities in body temperature and manifestations of localised infection including diarrhoea, pneumonia, and septic arthritis. Most common haematological abnormalities were neutropenia and increase of circulating band neutrophils. Survival rate of foals with confirmed septicaemia was 70.8%. Survival was found to be less likely in the presence of pneumonia, severe signs of depression, marked haematological changes or septic arthritis at the time of admission. Seven foals were confirmed to have septic arthritis without concurrent septicaemia. Of these, 4 had multiple joint involvement. Bacteria isolated from infected joints were predominantly Salmonella serovars. Four foals with septic arthritis failed to survive, due to multiple joint infection, which was unresponsive to treatment. The clinical and haematological abnormalities present in foals with confirmed septicaemia and septic arthritis were consistent with those observed in other studies. The bacterial isolates from foals with confirmed septicaemia were similar to those isolated in other studies. In contrast, the bacteria isolated from foals with septic arthritis without concurrent septicaemia were different from other studies.

Animals↗
PubMed1995

Acute febrile diarrhoea in horses: 86 cases (1986-1991).

Eighty-six horses presented for examination at the Rural Veterinary Centre between January 1986 to December 1991 with acute diarrhoea. The average age of affected horses was 3.2 +/- 0.2 years (mean +/- SE), with 69% three years or younger. Sixty-one horses were male (36 stallions, 25 geldings) and 83 horses were Thoroughbreds (47) or Standardbreds (36). Sixty-six horses were undergoing routine training at the time of onset of diarrhoea. Eight horses were afflicted with a non-specific illness within one to five days before the onset of diarrhoea, whereas eight horses developed diarrhoea during or within 48 h of discontinuation of antimicrobial therapy. Three horses developed the diarrhoea within 24 h of road transportation. Clinically, the disorder was characterised by a fever, sudden onset of profuse diarrhoea, clinical evidence of dehydration (estimated to be 5 to 12% of body weight at the time of admission) and shock. Degenerative leucopaenia, hyponatraemia, hypochloraemia, hyperkalaemia, hyperglycaemia and azotaemia were characteristic laboratory findings. Laminitis was a sequel in about 30% of cases. The cause of diarrhoea remained undetermined in most cases. Salmonellas were isolated from faecal or tissue samples in only two cases. Similarly, there was no evidence of seroconversion to Erhlichia risticii in 17 cases. Sixty-two of the horses survived the acute phase of the disease in response to supportive care. In horses that did not survive, necropsies were performed and revealed sanguineous or turbid peritoneal fluid. The colonic and caecal walls were oedematous and thickened with serosal congestion and discolouration of these organs evident grossly.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1994

A haemolytic cell-free preparation of Moraxella bovis confers protection against infectious bovine keratoconjunctivitis.

Protection conferred by a cell-free preparation from a haemolytic Moraxella bovis isolate, UQV 148NF, was compared to an equivalent fraction from a non-haemolytic M. bovis isolate, Gordon 26L3, and to a recombinant DNA-derived pili vaccine. Three groups of ten calves were vaccinated twice with one of the three preparations and, together with ten non-vaccinated calves, challenged with virulent M. bovis isolate Dal 2d. Compared to the control group, significant protection was observed in the group receiving the pili vaccine and the group receiving the preparation from haemolytic isolate, UQV 148NF.

Animals↗
PubMed1994

Peritonitis associated with Actinobacillus equuli in horses: 15 cases (1982-1992).

Peritonitis attributable to Actinobacillus equuli was diagnosed in 15 horses examined at the veterinary center between 1982 and 1992. In 13 horses, historical findings included acute onset of mild to severe signs of abdominal pain, lethargy, and inappetence. Two other horses had a history of weight loss for 3 to 6 weeks prior to examination. Diagnosis was based on the physical signs and laboratory findings, including results of peritoneal fluid analysis (gross characteristics, total protein, total and differential nucleated cell counts, and morphologic findings) and culture of A equuli. Actinobacillus equuli was consistently susceptible in vitro to penicillin, trimethoprim/sulfadiazine, and aminoglycosides. All horses in the study had marked clinical improvement within 24 to 48 hours of commencing antibiotic and supportive treatment. Antibiotic treatment was continued for variable periods, depending on the horse, but ranged from 5 to 21 days. In 11 horses for which follow-up information was available, long-term response to treatment was excellent, with horses returning to original activity.

Actinobacillus↗
PubMed1994

Imposed breathing pattern alters respiratory work during exercise.

Previous studies have shown the existence of an ideal respiratory rate (fR) for a given ventilation at which the respiratory work rate (J.s-1) is minimum. The purpose of the present study was to measure the effect of fR, tidal volume and breathing pattern on the respiratory work per breath and respiratory work rate during exercise on a cycle ergometer. Three work rates on the cycle ergometer were used and at each work rate the ventilation was kept constant. Two different breathing patterns were applied at each ventilation. Nine male trained cyclists [mean (SD) maximum oxygen consumption, 57 (5.47) ml.kg-1.min-1] participated in this study. The results indicated that there was a significant difference in the respiratory work per breath, with different breathing patterns at a given ventilation and for all levels of ventilation. There was no significant difference in the respiratory work rate with different breathing patterns at a given ventilation and for all levels of ventilation. In addition, the respiratory work per breath and respiratory work rate were increased with increasing ventilation. Thus, the data indicated that the manipulation of tidal volume, respiratory rate and breathing pattern had no significant effect on the energy cost of breathing for a given ventilation. The absence of this significant effect on respiratory work rate was observed across a range of ventilation from 24 to 72 l.min-1. These findings suggest that the breathing pattern is predominantly an expression of the function of the higher respiratory brain center instead of energy economy, at least within this range of ventilation.

Adult↗
PubMed1992

Babesia bigemina: quantitation of infection in nymphal and adult Boophilus microplus using a DNA probe.

Candidates for a subunit vaccine against bovine babesiosis include surface proteins of infective forms found in the salivary glands of tick vectors. However, low numbers of infective forms are present within ticks and hinder analysis of this stage. To solve this problem, conditions which yield high numbers of infective forms were investigated with the use of a Babesia bigemina-specific DNA probe. DNA from progeny of female Boophilus microplus infected with B. bigemina was hybridized to probe DNA to detect and quantitate infection. There was no difference in the prevalence of infection in progeny of three strains of Bo. microplus. However, within a strain, prevalence could be increased to 30% by combining selection of progeny from heavily (3+) infected female ticks and selection of eggs laid 120 hr postengorgement. Quantitation of infective forms within pooled salivary gland preparations of 10 infected nymphal and adult Bo. microplus demonstrated that Day 9 and 10 nymphal ticks contained the highest numbers of parasites and represented approximately 10(6) infective forms. This number of infective forms is suitable for isolation and further characterization.

Animals↗
PubMed1991

Fat-free mass in relation to stature: ratios of fat-free mass to height in children, adults, and elderly subjects.

A cross-sectional relationship of fat-free mass to height expressed as a ratio (FFM:ht) is presented for 1103 people aged 6-86 y. Data are presented for 13 specific age groups by gender. By providing information for normal, healthy individuals, these data may be of comparative value for nutritionists and clinicians concerned with body composition of patients with wasting diseases. The data were collected over 20 y in our laboratory by using the same densitometric procedure. A significant increase in FFM:ht occurs during the preadolescent and adolescent years. The adolescent spurt continues for a longer period for boys than for girls, resulting in a significant gender difference beginning at approximately age 16 y and continuing throughout adulthood. A decline in FFM:ht, not statistically significant, appears to occur in men greater than 60 y of age, and a significant decline occurs among women greater than 50 y of age (alpha less than 0.01). Thus, both gender- and age-related trends that have implications for the interpretation of comparative body-composition status are suggested.

Adolescent↗
PubMed1991

Immunoglobulin binding by Tritrichomonas foetus.

A better method for diagnosis of bovine trichomoniasis is needed because culture is slow and somewhat lacking in sensitivity. Immunodiagnosis of Tritrichomonas foetus infection usually involves detection of antigen-antibody reactions with an anti-immunoglobulin conjugate. However, nonspecific immunoglobulin (Ig), bound to the surface of T. foetus, would also be detected by an anti-Ig conjugate and thus would interfere with the specificity of the immunoassay. The goals of this study were to define the binding of bovine immunoglobulins to T. foetus. To determine whether nonimmune binding of Ig to T. foetus occurs, we immunized rabbits with organisms that had been grown in medium containing normal bovine serum and vigorously washed three times with phosphate-buffered saline. The rabbit antiserum had similar titers to T. foetus and to normal bovine serum by enzyme-linked immunosorbent assay (ELISA). Furthermore, two bovine serum proteins were immunoprecipitated by the rabbit antiserum in an immunoelectrophoretogram. One of the serum proteins had a distribution characteristic of IgG2. The rabbit antiserum was then shown to react with purified bovine IgG and IgM by ELISA. Reactivity to IgG was greater. To identify the IgG subisotypes bound and to confirm nonimmune binding of Ig, we grew T. foetus in agammaglobulinemic fetal calf serum and reacted it with IgG1, IgG2, and IgM specific for dinitrophenol (DNP) in ELISA. The binding of IgG2 was greatest, that of IgG1 was next, and that of IgM was least. Little competitive inhibition by DNP was detected, indicating that binding of DNP-specific antibodies was predominantly nonimmune rather than antigen-specific Ig binding. We also demonstrated that T. foetus grew well in medium containing agammaglobulinemic fetal calf serum or serum made agammaglobulinemic by ammonium sulfate precipitation of Igs. This may overcome the problem of low specificity in diagnostic assays as a result of antigen with Ig bound by nonimmune mechanisms.

Animals↗
PubMed1991

Ventilatory response of moderately obese women to submaximal exercise.

To investigate the effect of moderate obesity on ventilatory responses to graded exercise, we compared the ventilatory responses of ten moderately obese (35 +/- 5 percent body fat) and nine leaner women (22 +/- 2 percent body fat) during walking on a treadmill with incremental increases in percent grade. Speed remained constant at 3.0 mph. In the obese women, VO2 in l/min and ml/FFW/min, fb (b/min), VE (l/min), and HR were significantly greater (P less than 0.05) at all four absolute workloads. At 10.0 and 12.5 percent grade, VO2 (ml/kg/min) was smaller and VE/VO2 was greater in the obese women. The difference in VE/VO2 suggests a lower ventilatory threshold for the obese women. Percent VO2 max and R (VCO2/VO2) were significantly different at 12.5 percent grade only. When VO2 was divided by HR (oxygen pulse), the two groups were not significantly different at any of the four workloads tested. The groups were compared further at workloads representing approximately 55, 65, 75, and 85 percent of VO2 max. HR was not significantly different at any of the four relative exercise intensities. VE was significantly greater in the obese at 85 percent of maximum only (P less than 0.05) and fb was significantly greater at 55, 75, and 85 percent of maximum. Whereas cardiorespiratory responses of moderately obese women are increased at absolute workloads when compared to that of leaner women, HR is similar at comparable intensities of exercise. VE is also similar at comparable intensities of exercise below ventilatory threshold but fb is greater. The effect of the higher fb on exercise tolerance is unknown.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

Characterization of Tritrichomonas foetus antigens by use of monoclonal antibodies.

The specificity for and function of monoclonal antibodies against Tritrichomonas foetus were characterized. Four monoclonal antibodies generated by immunization of mice with live T. foetus were selected on the basis of enzyme-linked immunosorbent assay reactions. The approximate molecular masses of the predominant proteins were determined by Western blotting (immunoblotting). Monoclonal antibody TF3.8 recognized a predominant band at approximately 155 kilodaltons, whereas TF3.2 reacted with several bands. Monoclonal antibodies TF1.17 and TF1.15 recognized broad bands between 45 and 75 kilodaltons. The first two antibodies (TF3.8 and TF3.2) did not react with the surface of T. foetus, as determined by live-cell immunofluorescence, agglutination, and immobilization, whereas two other monoclonal antibodies (TF1.17 and TF1.15) did react with surface epitopes, as determined by these criteria. The latter two monoclonal antibodies also mediated complement-dependent killing of T. foetus and prevented of adherence of organisms to bovine vaginal epithelial cells. One antibody, TF1.15, also killed in the absence of complement. Since these functions are in vitro correlates of protection, the antigens recognized by these monoclonal antibodies may induce protective immunity.

Animals↗
PubMed1989

Adherence of Tritrichomonas foetus to bovine vaginal epithelial cells.

Adherence of Tritrichomonas foetus to bovine vaginal epithelial cells (VECs) in vitro was investigated with fresh washed bovine VECs and log-phase cultures of T. foetus. Observation under phase-contrast microscopy showed that T. foetus usually adhered first by the posterior flagellum and later by the body. Significantly more keratinized squamous epithelial cells were detected with attached parasites than nonkeratinized round epithelial cells. The optimal pH range for attachment was 6.0 to 7.5, with peak attachment at pH 6.5 for squamous VECs. Surface-reactive bovine antiserum to T. foetus prevented adherence to bovine squamous VECs. Inhibition of adherence occurred at nonagglutinating, nonimmobilizing serum dilutions. Antiserum fractions enriched for immunoglobulin G1 inhibited adherence, but fractions enriched for immunoglobulin G2 did not. The inhibitory antiserum was specific for several medium- to high-molecular-weight membrane antigens as detected in Western blots (immunoblots). The ability of surface-reactive antibodies to prevent adherence and to agglutinate and immobilize T. foetus indicates that they may be protective.

Animals↗
PubMed1989

Exercise end-expiratory lung volumes in lean and moderately obese women.

End-expiratory lung volumes (EELV) and expiratory flow rates were determined in 10 moderately obese (mean, 35 percent fat) and 10 relatively lean women (22 percent fat) at rest and during exercise on a treadmill at 55 and 85 percent of VO2max. Expiratory reserve volume (ERV) as a percentage of forced vital capacity (FVC) was used as an index of EELV. Differences in body weight, body fatness, and VO2max were significant (P less than 0.05). The resting EELV in the obese women was less than (P less than 0.01) that in the leaner women (32 vs 37 percent). During exercise at the two intensities, the EELV remained near the resting value in the obese women (approximately 30 percent). In contrast, the leaner women experienced an initial decrease in EELV during exercise at 55 percent of VO2max (i.e., from 37 to 32 percent) (P less than 0.01); thereafter, the EELV changed no further during exercise at 85 percent of VO2max. There were no significant differences in relative expiratory flow rates at rest or during exercise between the obese and lean women. In conclusion, moderately obese women fail to decrease their EELV during exercise in contrast to leaner women who do. A non-linear respiratory system pressure-volume curve, plus increased resistance as maximal flow is approached may combine to determine a lower limit of EELV during exercise.

Body Composition↗
PubMed1988

Lactate and gas exchange responses to incremental and steady state running.

This study compared the oxygen uptake (VO2) and running velocity at which the lactate threshold (LT), the ventilatory threshold (VT), and the maximal lactate steady state (MSSLA), and the maximal VO2 steady state (MSSVO2) occurred in 11 trained male runners (mean age = 22.4 years, range 18-28 years). Each underwent an incremental treadmill test to exhaustion. The LT was defined by a systematic, continuous increase in arterialised venous blood lactate; the VT was determined by an abrupt rise in VE.VO2(-1) without an increase in VE.VCO2(-1). Each subject also completed a series of steady state treadmill runs of 20 minutes duration. The MSSLA was determined as the highest velocity and VO2 at which lactate concentration increased by less than 0.2 mmol.l-1 from minute 10 to minute 20. The MSSVO2 was determined as the highest velocity or VO2 at which a steady state in VO2 was not delayed for more than 3 minutes (with a steady state defined as VO2 within 0.2 l.min-1 of the average VO2 over the last 10 minutes of each test). Each subject also completed a 5 km time trial run to assess performance. No significant differences were found among the four variables expressed either as VO2 or velocity. Significant correlations were found between MSSLA and MSSVO2 (r = 0.74) expressed as VO2, and between MSSLA and MSSVO2 (r = 0.90), MSSVO2 and VT (r = 0.70) and MSSLA and VT (r = 0.67) expressed as velocity. A stepwise regression analysis found MSSLA (expressed as velocity) to be the best predictor of 5 km performance (r = 0.87). It was concluded that (a) MSSLA and MSSVO2 are closely related, and (b) MSSLA is a good predictor of performance and may be an important, objective measure of cardiorespiratory endurance capacity.

Adolescent↗
PubMed1987

Cross-reactive antibody in immunity to colisepticemia in calves.

Cattle were immunized with a uridine diphosphate galactose epimerase deficient mutant of Escherichia coli to prepare antiserum cross-reactive with different serotypes of E. coli. Hypogammaglobulinemic calves were given bovine anti-J5 serum before oral challenge with virulent E. coli derived from a septicemic calf. Passively immunized calves had delayed and decreased bacteremia compared with calves given saline before challenge. Calves given antiserum also lived longer than control calves. A second experiment using ampicillin and antibody to treat colisepticemia also showed increased survival in anti-serum-treated calves. Decreased bacteremia was probably not due to the killing of the challenge strain by antibody and complement, as the strain was serum-resistant. However, anti-J5 serum did increase phagocytosis of the challenge strain of E. coli (JL9) by bovine neutrophils. Thus, partial protection by antiserum was probably due to increased clearance of bacteria as well as neutralization of endotoxin.

Ampicillin↗
PubMed1987

Effect of resistive training on plasma lipid and lipoprotein levels in male adolescents.

We studied fourteen 14 to 17-year old male adolescents before and after a 9-week resistive exercise program and compared the changes in lipid and lipoprotein profiles with those in 14 non-exercising control subjects. Studies included determination of weight, body mass index (weight for height2), percent body fat, blood pressure and resting heart rate, maximum heart rate and maximum oxygen consumption, and plasma lipids and lipoproteins. No significant differences were present between the two groups before training except that percent body fat was lower in the control subjects. After training, low-density lipoprotein cholesterol in the exercising subjects decreased from 120 +/- 15 to 95 +/- 13 mg/dL (P less than 0.001), high-density lipoprotein cholesterol increased from 35 +/- 12 to 45 +/- 8 mg/dL (P less than 0.01), and high-density lipoprotein cholesterol/total cholesterol ratio increased from 0.2 +/- 0.06 to 0.27 +/- 0.05 (P less than 0.001). Control subjects showed a significant increase in weight (P less than 0.01) and body mass index (P less than 0.01) and a decrease in maximum heart rate (P less than 0.01) at the end of the 9 weeks. Adjustment for body mass index resulted in no alteration in the favorable response of the lipoprotein profile. No change occurred in body composition or maximum oxygen consumption with training. These findings indicate that resistive training is associated with a favorable alteration in the lipoprotein profile in adolescent males.

Adolescent↗
PubMed1987

Age and aerobic power: the rate of change in men and women.

The historic studies by Robinson and Astrand as well as more recent studies present a fairly uniform rate of decline in VO2max with age at 0.40-0.50 ml X kg-1 X min-1 X year-1 in men. In women the rate of decline appears to be less--approximately 0.20-0.35 ml X kg-1 X min-1 X year-1, at least in cross-sectional studies. Further, there is no clear distinction in the rate of change in VO2max when comparing active and inactive populations. Longitudinal studies varying from 2.5 to 21 to 56 years present a confounding picture. The rate of decline in VO2max varies from 0.04 to 1.43 ml X kg-1 X min-1 X year-1. There is some indication that active individuals decline at a slower rate than inactive persons but the results are not uniform. A possible explanation is that changes in VO2max over the entire age range may be curvilinear, with active individuals declining slowly as long as they maintain a regular exercise program, and sedentary individuals declining at a rapid rate during their 20's and 30's followed by a slower rate of decline of their VO2max as they age further.

Adult↗
PubMed1985

Variables predictive of performance in elite middle-distance runners.

The purpose of this study was to investigate possible factors which may account for differences in performance times within a closely-matched group (in terms of performance) of elite distance runners. The runners were training for competition in the 1984 Olympic Games in either the 5000 m or the 3000 m steeplechase events. Each runner's best performance time (BPT) was obtained and a stepwise regression analysis was performed with the following independent variables: age, weight, % body fat, VO2 max, aerobic threshold (AerT), and anaerobic threshold (AnT). For the 5000 m-runners, a multiple correlation of age and AnT accounted for 77% of the variance (p less than 0.02); for the 3000 m steeplechase runners, body weight alone and body weight and AnT accounted for 94% (p less than .01) and 98% (p less than .05) of the variance, respectively. The results suggest that, among elite middle-distance runners, these parameters deserve attention as potential predictors of performance.

Adipose Tissue↗