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Biomedical subjects

J H Green

Publications and source records attributed to J H Green.

At least 19 recordsLinked to original sources
PubMed1992

Comparisons between basal metabolic rate and diet-induced thermogenesis in different types of chronic obstructive pulmonary disease.

1. Some patients with the emphysematous type of tobacco-related chronic obstructive pulmonary disease are hypermetabolic. Since the likely mechanism is the increased work of breathing, other groups of patients with chronic obstructive pulmonary disease should be similar. We have now measured basal metabolic rate and diet-induced thermogenesis in six patients with chronic obstructive pulmonary disease with an arterial partial pressure of CO2 of less than 5 kPa (emphysematous), nine patients with chronic obstructive pulmonary disease with an arterial partial pressure of CO2 of greater than 6 kPa (bronchitic), eight patients with chronic obstructive pulmonary disease due to chronic asthma and seven control subjects. Diet-induced thermogenesis was measured for 4h after a meal of 87% carbohydrate, 11% protein and 2% fat as energy, with a total energy content of 40% of basal metabolic rate. 2. There was no difference between measured and predicted basal metabolic rate in the control (5541 +/- 272 versus 5881 +/- 245 kJ/24h) or emphysematous (5552 +/- 370 versus 6239 +/- 197 kJ/24h) groups, but measured basal metabolic rate was significantly higher than predicted in the bronchitic (6126 +/- 387 versus 5405 +/- 250 kJ/24h) and asthmatic (6293 +/- 197 versus 5701 + 245, mean +/- SEM, P less than 0.01) groups. All the control subjects had measured basal metabolic rates within 10% of predicted, whereas two out of six emphysematous patients, four out of nine bronchitic patients and five out of eight asthmatic patients were hypermetabolic. The contributions of fat, carbohydrate and protein oxidation rates to the overall basal metabolic rate were similar between groups. 3. Diet-induced thermogenesis was similar between groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Anthropometry↗
PubMed1992

Catabolic effect of dexamethasone in the preterm baby.

Most babies treated with dexamethasone for bronchopulmonary dysplasia exhibit an appreciable rise in the blood urea concentration, from a mean of 2.3 mmol/l before steroid to a mean of 7.1 mmol/l after. In order to discover whether this was primarily the result of increased protein catabolism, nitrogen balance studies before and after the start of dexamethasone were performed and a mean deficit in nitrogen retention of 158 mg/kg/24 hours was found. Similarly the urinary 3-methylhistidine (3MH):creatinine ratio before and after the commencement of dexamethasone treatment in a group of preterm babies was measured. It was found that there was a substantial increase in 3MH excretion after dexamethasone: from a mean 3MH:creatinine ratio of 46 in the week before steroids to a mean ratio of 77 in the week after. As 3MH emanates almost exclusively from the breakdown of actin in skeletal muscle cell, this finding implies the loss of muscle tissue. It was also found that the babies were in less positive nitrogen balance after dexamethasone, to a degree which is significant relative to their protein reserves. The long term consequences of a period of increased catabolism are not yet known but the authors suggest caution in the use of dexamethasone, at least in babies with milder degrees of bronchopulmonary dysplasia in whom the ratio of benefit to risk may be less favourable.

Bronchopulmonary Dysplasia↗
PubMed1991

Glycolysis at the climacteric of bananas.

This work was carried out to investigate the relative roles of phosphofructokinase and pyrophosphate-fructose-6-phosphate 1-phosphotransferase during the increased glycolysis at the climacteric in ripening bananas (Musa cavendishii Lamb ex Paxton). Fruit were ripened in the dark in a continuous stream of air in the absence of ethylene. CO2 production, the contents of glucose 6-phosphate, fructose 6-phosphate, fructose 1,6-bisphosphate, phosphoenolpyruvate and PPi; and the maximum catalytic activities of pyrophosphate-fructose-6-phosphate 1-phosphotransferase, 6-phosphofructokinase, pyruvate kinase and phosphoenolpyruvate carboxylase were measured over a 12-day period that included the climacteric. Cytosolic fructose-1,6- bisphosphatase could not be detected in extracts of climacteric fruit. The peak of CO2 production was preceded by a threefold rise in phosphofructokinase, and accompanied by falls in fructose 6-phosphate and glucose 6-phosphate, and a rise in fructose 1,6-bisphosphate. No change in pyrophosphate-fructose-6-phosphate 1-phosphotransferase or pyrophosphate was found. It is argued that phosphofructokinase is primarily responsible for the increased entry of fructose 6-phosphate into glycolysis at the climacteric.

Carbon Dioxide↗
PubMed1991

Enzyme-linked immunosorbent assay for products of the 60-megadalton plasmid of Escherichia coli serotype O157:H7.

Eighty strains of pathogenic Escherichia coli, representing each of the major diarrheal disease-causing groups, were examined by direct enzyme-linked immunosorbent assay (ELISA) for the presence of proteins associated with a 60-MDa plasmid from E. coli serotype O157:H7. Antiserum specific for plasmid-encoded proteins was prepared by immunizing a rabbit with a wild-type E. coli O157:H7 strain (strain 7785) and absorbing the serum with a plasmid-cured derivative (strain 2-45). Use of this antiserum in Western immunoblot analysis detected two proteins of 82 and 92 kDa in strain 7785 but not in strain 2-45. All 16 wild-type E. coli O157:H7 strains and all 10 Shiga-like toxin (SLT)-producing E. coli strains of serotypes other than O157 were ELISA positive. Thirteen of 14 enterotoxigenic and all of 24 enteroinvasive E. coli strains were ELISA negative, as were all of 16 E. coli strains isolated from healthy persons. Of 16 traditional enteropathogenic E. coli (EPEC) serotypes, 10 were ELISA positive, including 10 of 12 strains carrying the EPEC adherence factor gene. Absorption of the serum with an EPEC adherence factor-positive EPEC eliminated EPEC reactivity. This study demonstrates that two plasmid-mediated proteins are common to E. coli O157:H7 strains and to SLT-producing strains of other serotypes. Detection of these proteins by ELISA provides a sensitive and specific screening test for identifying SLT-producing E. coli of both O157 and non-O157 serotypes. Identification of the cross-reactive proteins found in EPEC could provide the basis for a single assay to detect both EPEC and SLT-producing E. coli.

Bacterial Adhesion↗
PubMed1991

Isolation of Escherichia coli serotype O157:H7 and other Shiga-like-toxin-producing E. coli from dairy cattle.

We examined 1,266 fecal specimens from healthy cattle during the investigations of two sporadic cases of hemolytic uremic syndrome associated with raw milk consumption and an outbreak of gastroenteritis and hemolytic uremic syndrome caused by Escherichia coli serotype O157:H7. We collected specimens from heifers, calves, and adult cows on 22 farms, in a stockyard, and in a packing house. We also collected 3 raw hamburger specimens from a restaurant and 23 raw milk samples from two farms. All specimens were examined for E. coli O157:H7 by using sorbitol-MacConkey agar, H immobilization, O157 agglutination, and tissue culture cytotoxicity. E. coli O157:H7 was isolated from 16 heifers or calves and 1 adult cow on 22 farms, 1 stockyard calf, 2 beef specimens, and 1 raw milk sample. Selected fecal specimens were also examined for the presence of other Shiga-like-toxin-producing E. coli (SLTEC) by testing polymyxin B extracts of colony sweeps and then testing individual colonies for toxin production. SLTEC other than O157 was isolated from 8 of 10 farms investigated and from the stockyard; 8% of adult cows and 19% of heifers and calves were positive for SLTEC. Several animals were positive for SLTEC by colony sweep only. This investigation demonstrates that dairy cattle are a reservoir of E. coli O157:H7 and other SLTEC.

Animals↗
PubMed1991

Are patients with primary biliary cirrhosis hypermetabolic? A comparison between patients before and after liver transplantation and controls.

Wasting is common in end-stage primary biliary cirrhosis and causes concern in patients facing liver transplantation. We have quantified resting metabolic rate and diet-induced thermogenesis in seven patients with primary biliary cirrhosis, in seven patients after liver transplantation who had previously been diagnosed as having primary biliary cirrhosis and in seven controls. Resting metabolic rate was elevated in the primary biliary cirrhosis group (4.44 +/- 0.81 kJ/hr/kg body wt; mean +/- S.D.) compared with the post-liver-transplantation group (3.39 +/- 0.40 kJ/hr/kg body wt) (p less than 0.005) and compared with control subjects (3.65 +/- 0.23 kJ/hr/kg body wt) (p less than 0.01). A highly significant relationship was found between the severity of liver disease in the primary biliary cirrhosis group, as assessed by Child-Pugh score, and the resting metabolic rate group (r = 0.93; p less than 0.005). After a liquid meal (41 kJ/kg body wt), the metabolic rate increased, with similar peak changes from baseline occurring in all three groups. However, the rise persisted significantly longer in the primary biliary cirrhosis patients, and thus the integrated mean postprandial energy expenditure over the 4-hr postprandial observation period was greater in the primary biliary cirrhosis group than in the other two groups (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Glucose↗
PubMed1991

The thermic effect of food in underweight patients with emphysematous chronic obstructive pulmonary disease.

Malnutrition and weight loss commonly occur in patients with the emphysematous type of chronic obstructive pulmonary disease (COPD), despite normal energy intakes. The present study was designed to assess energy expenditure, basal metabolic rate (BMR) and diet-induced thermogenesis (DIT) in ten patients with COPD, together with the oxidation rates of carbohydrate, protein and fat. The BMR was elevated when tested against the Harris-Benedict equation (p less than 0.001) or when compared with six age- and sex-matched controls (11.11 +/- 2.52 vs 8.12 +/- 1.31 kJ.h-1.kg muscle-1, p less than 0.05). The main difference in fuel oxidation rate was an elevated fasting fat oxidation rate in the patients compared with controls (8.31 +/- 3.09 vs 4.76 +/- 2.53 kJ.h-1.kg muscle-1, p less than 0.05). The overall thermic response to food (41.2 kJ.kg-1 liquid meal) as a percentage of energy intake was greater in the patients (49.5 +/- 6.3 vs 39.8 +/- 2.9%, p less than 0.01). The patients also displayed a greater post-prandial rate of protein oxidation as a percentage of protein intake than controls (56.9 +/- 18.5 vs 34.1 +/- 6.5%, p less than 0.05). These data suggest an increased energy cost of feeding and fasting in patients with the emphysematous type of COPD.

Aged↗
PubMed1990

The influence of bicycle exercise, with or without hand immersion in cold water, on forearm sweating in young and middle-aged women.

Forearm sweat production rate (SPR) and external auditory meatal temperature (TEAM) were examined in five young and five middle-aged women in response to intermittent exercise, on three separate occasions. The first experiment was a control study, while in the second study the left hand was immersed in cold water at the onset of sweating during each exercise bout, and in the third study this immersion was accompanied by venous occlusion of the upper left arm. TEAM increased by 0.5 degrees C during exercise with no significant differences between the groups on any occasion. The young women displayed a greater peak SPR during exercise in the control than the middle-aged women (52.5 +/- 23.9 vs. 16.7 +/- 6.5 mg cm2 h-1, P less than 0.001). With hand immersion, peak SPR was depressed to 14.0 +/- 4.6 mg cm2 h-1 (P less than 0.001) in the young women and to 13.1 +/- 4.5 mg cm2 h-1 in the middle-aged (P less than 0.05). With hand immersion and venous occlusion the peak SPR in young women increased (43.0 +/- 9.2 mg cm2 h-1). In the older women SPR was 14.9 +/- 6.1 mg cm2 h-1, which was not different from either control or cold-immersed values. Thus, forearm SPR during low-intensity intermittent exercise is greater in young compared with middle-aged women, despite similar changes in TEAM. The response to hand immersion in cold water was more marked in the young subjects.

Adult↗
PubMed1990

Invalidity of hand heating as a method to arterialize venous blood.

We have assessed in normal subjects the validity of using hand heating to obtain "arterialized" venous blood by biochemical comparison of results for "arterialized" venous and true arterial (radial artery) blood samples. The heating regimen involved placing one hand in an air-heated box at 45-50 degrees C for 45 min. This method produced blood that was "arterialized" for lactate, PCO2, HbO2, and Hb but not for ammonia or PO2; it had no effect on determinations of pyruvate or glucose in plasma. Despite using a lower air temperature than previous workers, we observed thermal injury in one volunteer. Further, there was considerable between-subject variation in the effect of hand heating on blood gases. This suggests that blood gases should be measured in the "arterialized" samples at regular intervals from the start of hand heating in each patient to determine whether maximal "arterialization" has been achieved, to avoid making misleading biochemical measurements. Given the wide range in degree of observed "arterialization," we question the validity of this method.

Adult↗
PubMed1990

Heart rate and oxygen consumption during walking on land and in deep water.

Oxygen consumption and heart rate were measured during treadmill walking and during walking in deep water in a group of women and in a group of men. In both groups predicted maximum oxygen uptakes were similar on land as in the water. However, there were obvious individual differences in the responses to land versus water exercise. These differences suggest that if deep water walking is used for training, the intensity of work should be assessed from preliminary fitness tests in water and not on land.

Adult↗
PubMed1989

Back pain in childhood.

Sixty-one children with back pain presented to the authors' department between 1978 and 1984, accounting for less than 2% of referrals in this age group. Approximately 50% had serious spinal disease, yet clinical findings could be unreliable in distinguishing such patients. In the absence of compelling physical signs, children with normal radiographs, white cell count, and sedimentation rate can be treated symptomatically and observed for some months before more invasive investigations are considered.

Adolescent↗
PubMed1989

Development and evaluation of enzyme-linked immunosorbent assays for detection of shiga-like toxin I and shiga-like toxin II.

Shiga-like toxin (SLT)-producing Escherichia coli has been associated with a spectrum of human illnesses, including hemorrhagic colitis and hemolytic uremic syndrome. It produces at least two antigenically distinct toxins designated SLT-I and SLT-II, which have been implicated in disease. Currently available toxin assays, however, are not suitable for most clinical or public health laboratories. In this study, we have developed two sandwich enzyme-linked immunosorbent assays (ELISAs) based on toxin-specific murine monoclonal capture antibodies and rabbit polyclonal second antibodies which are specific for SLT-I and SLT-II. The SLT-I ELISA detected 200 pg of purified SLT-I, and the SLT-II ELISA detected 75 pg of purified SLT-II. The types of SLT produced by 166 human and 54 animal isolates of E. coli that produced moderate to high levels of toxin were determined by the ELISA, and results were confirmed by cytotoxin neutralization assays. With the exception of results from three strains, the tests agreed on the types of toxin present. DNA probe assays of 86 of 87 isolates also agreed with the ELISA and neutralization results. Although the SLT-II ELISA was specific for the SLT-II variant produced by porcine edema strains, most of the isolates examined produced levels of toxin (less than 50 50% cytotoxic doses [CD50] per ml) below the detection limit of the test. The ELISAs were not sufficiently sensitive to consistently detect low levels of toxin (less than 50 CD50 per ml) found in fecal extracts. On the basis of these findings, both ELISAs appeared to detect significant levels of SLT-I ( > 100 CD50 per ml) and SLT-II ( > 50 CD50 per ml) in E. coli culture extracts and should be useful diagnostic tools in many microbiology laboratories.

Animals↗
PubMed1989

Long-term home care research.

The population of seniors is growing and health service reimbursement is shrinking. Long-term home health care services were developed with an assumption that the services would decrease costs. This assumption has not been validated. What has been recognized is that long-term home health care targets a new and growing population of frail seniors who need services but are probably not at risk for institutionalization. The impact of long-term home care services on the health status and quality of life of seniors and caregivers has been limited by outcome measurement problems. There are indications that the services improved life satisfaction and reduced services needs, but further evaluations need to replicate the outcomes. In effect, long-term outcomes have not been sufficiently explored. Further research also needs to assist us in identifying outcomes for certain services with precise target populations. Public policy questions are ahead. Should a program that can increase costs, has demonstrated some but not dramatic impacts on quality of life and health status, and has the possibility of expansion, be funded? The question is obviously debatable. From a nursing perspective of health promotion and prevention, the answer is "yes." Funding should be continued in conjunction with increased research on the program impacts. In Kane's (1988) analysis of the Channeling experiments, she summarized the situation effectively: Knowing these facts, we are now in a position to reformulate public policies to design a system of long-term care that satisfies the preferences of consumers and protects them from catastrophic long-term expenses, while promoting the triple virtues of acceptable, quality, equitable access, and defensible costs. . . Nothing in the Channeling results should prevent us from going ahead and trying to develop both community based and institutionally based long-term services in which this country can take pride.

Aged↗
PubMed1988

Affinity purification and characterization of Shiga-like toxin II and production of toxin-specific monoclonal antibodies.

Shiga-like toxin (SLT-II) was purified to apparent homogeneity from Escherichia coli K-12 strain NM522 containing the cloned toxin genes on recombinant plasmid pEB1. Purification was accomplished by a series of column chromatography techniques: anion-exchange, chromatofocusing, cation-exchange, and monoclonal antibody affinity chromatography. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of the pure toxin showed that SLT-II consisted of A and B subunits with apparent molecular weights of 32,000 and 10,200 +/- 800, respectively. A band of molecular weight 25,000 was also observed after sodium dodecyl sulfate-polyacrylamide gel electrophoresis and identified as the A1 subunit by Western immunoblot analysis with toxin-specific monoclonal antibodies (MAbs). The pI of the purified toxin was 5.2. Approximately 1 pg of pure SLT-II, but was not neutralized by polyclonal antibodies or MAbs to SLT-I. Five hybridomas against SLT-II were produced (BC5 BB12, DC1 EH5, EA5 BA3, ED5 DF3, and GB6 BA4). Culture supernatant fluids containing MAbs from these hybridomas did not neutralize the cytotoxicity of SLT-I or Shiga toxin. Western blot analysis showed that two MAbs (MAb DC1 EH5 and MAb GB6 BA4) recognized the A and A1 subunits of SLT-II and three MAbs (MAb BC5 BB12, MAb EA5 BA3, and MAb ED5 DF3) recognized the B subunit of SLT-II. MAb BC5 BB12 was used to prepare an affinity column for toxin purification.

Animals↗
PubMed1988

Frequent rehospitalization and noncompliance with treatment.

The relationship between frequent rehospitalization and compliance with treatment (medication and aftercare) was examined in a retrospective chart review of patients treated at an urban community mental health center over an 18-month period. Twenty-five patients who had been hospitalized three or more times during the study period were compared with a matched group of 25 patients who had been hospitalized less than three times and with the total group of 698 patients active at the center throughout that period. The study found a highly significant correlation between noncompliance with medication and frequent rehospitalization. Compared with the general psychiatric patient population, frequently hospitalized patients tended to be younger and to have a chronic psychiatric illness, particularly one with an affective component, that featured at least intermittent psychosis. The author recommends study of outpatient commitment to treatment as a means of reducing noncompliance.

Adult↗