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Biomedical subjects

J G Bell

Publications and source records attributed to J G Bell.

At least 55 records · Page 3Linked to original sources
PubMed1988

Antibiotic resistance of Escherichia coli strains isolated from chickens with colisepticaemia in Morocco.

Sixty-two strains of Escherichia coli were isolated in 58 farms from broiler chickens showing respiratory signs and lesions characteristic of avian colibacillosis. Serological examination of these strains showed that the types 078, 01 and 02 (for the somatic antigen) and K1 (for the capsular antigen) were the most frequently found. Newcastle disease virus was also isolated in two cases. All the strains of E. coli isolated were sensitive to colistin, flumequine and gentamicin. A few strains were resistant to neomycin, nalidixic acid and trimethoprim. The frequency of strains resistant to nitrofurans, sulfonamides, chloramphenicol, spectinomycin and ampicillin was intermediate. Most strains were resistant to tetracycline. Multiple resistance was common.

Animals↗
PubMed1988

Radioimmunoguided surgery using monoclonal antibody.

The potential proficiency of radioimmunoguided surgery in the intraoperative detection of tumors was assessed using labeled monoclonal antibody B72.3 in 66 patients with tissue-proved tumor. Monoclonal antibody B72.3 was injected 5 to 42 days preoperatively, and the hand-held gamma-detecting probe was used intraoperatively to detect the presence of tumor. Intraoperative probe counts of less than 20 every 2 seconds, or tumor-to-adjacent normal tissue ratios less than 2:1 were considered negative (system failure). Positive probe counts were detected in 5 of 6 patients with primary colon cancer (83 percent), in 31 of 39 patients with recurrent colon cancer (79 percent), in 4 of 5 patients with gastric cancer (80 percent), in 3 of 8 patients with breast cancer (37.5 percent), and in 4 of 8 patients with ovarian cancer (50 percent) undergoing second-look procedures. Additional patients in each group were scored as borderline positive. Overall, radioimmunoguided surgery using B72.3 identified tumors in 47 patients (71.2 percent), bordered on positive in 6 patients (9.1 percent), and failed to identify tumor in 13 patients (19.7 percent). Improved selection of patients for antigen-positive tumors, the use of higher affinity second-generation antibodies, alternate routes of antibody administration, alternate radionuclides, and more sophisticatedly bioengineered antibodies and antibody combinations should all lead to improvements in radioimmunoguided surgery.

Antibodies, Monoclonal↗
PubMed1988

Effect of phytate removal on zinc absorption from soy formula.

Low zinc bioavailability from soy formula may be the result of the formula's phytate content. We assessed the effect of phytate removal from soy formula on Zn absorption using infant rhesus monkeys and suckling rat pups as animal models. Zn absorption in monkeys, as determined by whole-body counting, was 65% from human milk, 54% from monkey milk, 60% from whey-predominant formula, 46% from casein-predominant formula, and only 27% from conventional soy formula (0.621 mmol phytate/L). In contrast, Zn absorption from dephytinized soy formula (0.067 mmol phytate/L) was 45%. In suckling rats, Zn absorption from conventional soy formula was only 16% vs 47% from dephytinized soy formula. Phytate concentration in a variety of experimental soy formulas was inversely correlated to Zn absorption. These results suggest that the low bioavailability of Zn from soy formula is a function of its phytate concentration and can be overcome by the removal of phytate.

Animals↗
PubMed1988

Wrist pain.

Acute and chronic wrist pain are problems frequently seen by primary care physicians. The impact of wrist pain on function is substantial and requires prompt attention and treatment by physicians. In this article we summarize the causes of wrist problems, provide an approach to wrist pain, and discuss some of the common disorders seen by primary physicians.

Diagnosis, Differential↗
PubMed1987

Effect of infant cereals on zinc and copper absorption during weaning.

Zinc and copper absorption from five infant cereal products mixed with water, human milk, or cow's milk was measured using an in vivo absorption model (rat pup) involving gastric intubation of extrinsically radiolabeled diets. Whole-body copper 64 uptake, nine hours after intubation, ranged from 14% to 31% of the dose given for the different cereal combinations. The resultant bioavailability of copper from human milk-cereal combinations (23% to 26%) was significantly lower than that from human milk alone (38%). Whole-body zinc 65 uptake, nine hours after intubation, ranged from 13% to 54% of the dose given for the different cereal combinations. These values were significantly lower than the whole-body zinc 65 uptake from milk alone (61%). Zinc availability was lower (13% to 25%) from dry cereal combinations that contained phytic acid (oatmeal and high-protein varieties) compared with the ready-to-serve cereal-fruit combinations (24% to 54%). The highest zinc uptake (37% to 54%) was from rice-fruit combinations that do not contain phytic acid. We estimated the amounts of zinc and copper that would be absorbed from these cereal products and speculated on the potential impact of these foods on the weaning infant's zinc and copper nutriture. Depending on the feeding practices employed during the weaning period, it is apparent that infant cereals may compromise utilization of zinc and copper from milk diets during weaning.

Absorption↗
PubMed1987

Studies on the putative role of gamma-glutamyl transpeptidase in intestinal transport of amino acids in Atlantic salmon.

The gamma-glutamyl cycle is considered to function in the membrane transport of amino acids, particularly glutamine and cysteine. When groups of Atlantic salmon were fed either a control diet containing 45% crude protein or an amino acid diet (of similar overall amino acid composition but containing elevated levels of glutamine and cysteine) for 16 weeks, weight gains were significantly greater in the former group than in those given the amino acid diet. There were no significant differences between treatments in gamma-glutamyl transpeptidase (GT) activity in the proximal intestine; in distal intestine there was significantly more activity in control fish. Mean levels of GSH were higher in tissues (pyloric caeca, distal intestine and kidney) of amino acid diet fish than in those of control fish. Glutamine was less effective as a gamma-glutamyl acceptor than several other amino acids when tested with salmon caecal GT. There were no morphological adaptations to the two feeds. Nutrient uptake studies showed an increased uptake of glutamine, but decreased uptakes of proline and methionine in proximal intestine of salmon fed amino acid diet. Much the greater part of the glutamine uptake, even at high concentrations was shown to be by Na+ dependent processes. There is no evidence that GT itself is Na+ dependent. The results do not support the view that the gamma-glutamyl cycle and GT in particular are involved in the transport of amino acids in the intestine and are discussed in this context.

Amino Acids↗
PubMed1987

Vaccination against Moroccan strains of Newcastle disease virus.

Different vaccination programmes commonly used in Moroccan poultry farms were tested for their capacity to protect chickens against two representative Moroccan strains of velogenic viscerotropic Newcastle disease virus under controlled conditions. All vaccination programmes protected the chickens against mortality and the inactivated vaccine gave the highest antibody titres and the best protection against respiratory symptoms.

Animals↗
PubMed1986

Some effects of selenium deficiency on glutathione peroxidase (EC 1.11.1.9) activity and tissue pathology in rainbow trout (Salmo gairdneri).

1. Two duplicate groups of rainbow trout (Salmo gairdneri; mean weight 27 g) were given diets of differing selenium content (deficient 0.025 mg Se/kg; supplemented 1.022 mg Se/kg) for 30 weeks. 2. There were no significant differences between treatments in weight gain but packed cell volume, liver vitamin E and liver and plasma Se concentrations were all significantly lower in the Se-deficient trout. 3. Ataxia occurred in about 10% of the Se-deficient trout and histopathologies were evident in nerve cord (damage to axon sheath) and liver (loss of integrity in endoplasmic reticulum and mitochondria with appearance of increased vesiculation). 4. Glutathione peroxidase (EC 1.11.1.9) activity was significantly reduced in liver and plasma of Se-deficient fish but there was no indication, from differential assay, of any non-Se-dependent glutathione peroxidase activity. Glutathione transferase (EC 2.5.1.18) activity was significantly increased in Se-deficient trout.

Animals↗
PubMed1986

Effect of selenium deficiency on hydroperoxide-stimulated release of glutathione from isolated perfused liver of rainbow trout (Salmo gairdneri).

1. Duplicate groups of rainbow trout (Salmo gairdneri) were each given partially purified diets which were either adequate or depleted in selenium for 40 weeks. 2. Although there was no significant difference in weight gain, liver Se concentration was significantly lower in fish given the deficient diet. 3. Glutathione (GSH) peroxidase (EC 1.11.1.9) activity was significantly reduced in liver of Se-deficient fish but a differential assay did not indicate the presence of a non-Se-dependent GSH peroxidase activity, although liver GSH S-transferase (EC 2.5.1.18) was significantly increased. 4. Perfusion of livers from trout given Se-adequate diets with t-butyl hydroperoxide (BuOOH) or hydrogen peroxide caused an increase in the rate of release of glutathione disulphide (GSSG) into the perfusate. 5. Perfusion of livers from Se-deficient trout with BuOOH or H2O2 did not result in any change in rate of release of GSSG into the perfusate. 6. These findings confirm the absence of any compensatory non-Se-dependent peroxidase activity in Se-depleted trout.

Animals↗
PubMed1986

The effect of age on manganese uptake and retention from milk and infant formulas in rats.

Manganese nutrition of the neonate is poorly understood, due in part to a paucity of information on the amount and availability of manganese in infant foods. We have developed a suckling pup model to assess the uptake of manganese from fluid diets by using extrinsic labeling. Human milk, cow milk and infant formulas were fed by intubation to fasted rat pups and adults. Rats were killed after varying time periods, and tissues were removed and counted. A period of 6 h was found to be adequate to allow for stomach emptying while limiting tissue redistribution; 24 h was found to reflect pup manganese retention. From human milk, manganese retention was highest (greater than or equal to 80%) in pups less than or equal to 15 days of age; in older pups average retention decreased to 40%. Using d 14 pups to assess relative Mn uptake from diets, wholebody Mn uptake was highest from cow milk (approximately 89%); uptake from human and cow milk formula was similar (approximately 80%) whereas it was lower from soy formula (approximately 60%). These findings suggest that bioavailability of Mn from infant diets is very high during the suckling period. Since most formulas contain considerably more manganese than is found in human milk, Mn deficiency may be less of a concern than possible toxicity from formulas.

Absorption↗
PubMed1986

Intracellular mechanism of action of isoflurane and halothane on striated muscle of the rabbit.

Studies were conducted on the effects of isoflurane and halothane on intracellular mechanisms of striated muscle contraction: Ca2+ activation of the contractile proteins and Ca2+ uptake and release from the sarcoplasmic reticulum. Functionally skinned muscle fibers (sarcolemma disrupted by homogenization) from isolated papillary muscle (PM), soleus (SL) (slow-twitch skeletal muscle), and adductor magnus (AM) (fast-twitch skeletal muscle) of rabbits were mounted on a photodiode tension transducer. They were immersed in control solution (saturated with N2), then in test solution (saturated with anesthetic-N2 mixture), and in control solution again. The following two studies were carried out: 1) in the study of Ca2+ -activated tension development of the contractile proteins, free Ca2+ concentration in the bathing solution was controlled by the use of a high EGTA (7 mM), and 2) in the study of Ca2+ uptake and release from the sarcoplasmic reticulum (SR), Ca2+ was loaded into the SR and released with caffeine and the resulting tension transients were measured. Isoflurane (1-4%) decreased (6-9%) the maximal Ca2+ -activated tension development in PM and SL but more in PM than in SL. In AM, however, isoflurane and halothane (1-3%) produced no change. Isoflurane decreased submaximal Ca2+ -activated tension development in PM, but effected no change in it in SL. Isoflurane and halothane increased the tension development in AM to the extent of producing a shift to the left in the pCa-tension curves of less than or equal to 0.1 pCa unit.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1985

Some effects of vitamin E and selenium deprivation on tissue enzyme levels and indices of tissue peroxidation in rainbow trout (Salmo gairdneri).

Duplicate groups of rainbow trout (Salmo gairdneri) (mean weight 11 g) were given for 40 weeks one of four partially purified diets that were either adequate or low in selenium or vitamin E or both. Weight gains of trout given the dually deficient diet were significantly lower than those of trout given a complete diet or a diet deficient in Se. No mortalities occurred and the only pathology seen was exudative diathesis in the dually deficient trout. There was significant interaction between the two nutrients both with respect to packed cell volume and to malondialdehyde formation in the in vitro NADPH-dependent microsomal lipid peroxidation system. Tissue levels of vitamin E and Se decreased to very low levels in trout given diets lacking these nutrients. For plasma there was a significant effect of dietary vitamin E on Se concentration. Glutathione (GSH) peroxidase (EC 1.11.1.9) activity in liver and plasma was significantly lower in trout receiving low dietary Se but was independent of vitamin E intake. The ratios of hepatic GSH peroxidase activity measured with cumene hydroperoxide and hydrogen peroxide were the same for all treatments. This confirms the absence of a Se-independent GSH peroxidase activity in trout liver. Se deficiency did not lead to any compensatory increase in hepatic GSH transferase (EC 2.5.1.18) activity; values were essentially the same in all treatments. Plasma pyruvate kinase (EC 2.7.1.40) activity increased significantly in the trout deficient in both nutrients. This was thought to be due to leakage of the enzyme from the muscle and may be indicative of incipient (subclinical) muscle damage.

Animals↗
PubMed1985

Copper absorption from human milk, cow's milk, and infant formulas using a suckling rat model.

Since copper deficiency is known to occur during infancy, it becomes important to assess copper uptake from various infant diets. We have investigated the uptake of copper from human milk, cow's milk, cow's milk formulas, cereal/milk formula and soy formula, compensating for the decay of 64Cu and using the suckling rat as a model. Radiocopper was added to the diet in trace amounts. Ultracentrifugation, ultrafiltration, and gel filtration were used to show that the added 64Cu bound to milk fractions and individual binding compounds in a manner analogous to the distribution of native copper, thus validating the use of extrinsically labeled diets. Labeled diets were intubated into 14-day-old suckling rats. Animals were killed after 6 h and tissues removed and counted. Liver copper uptake was 25% from human milk, 23% from cow's milk formula, 18% from cow's milk, 17% from premature (cow's milk based) infant formula, 17% from cereal/milk formula and 10% from soy formula. These results show that the rat pup model may provide a rapid, inexpensive, and sensitive method to assay bioavailability of copper from infant foods.

Animals↗
PubMed1984

Rainbow trout liver microsomal lipid peroxidation. The effect of purified glutathione peroxidase, glutathione S-transferase and other factors.

Glutathione peroxidase (glutathione: hydrogen-peroxide oxidoreductase, EC 1.11.1.9) was purified approximately 600-fold from rainbow trout liver soluble fraction and its activity in the NADPH microsomal lipid peroxidation system tested. The enzyme has an approximate molecular weight of 100 000, contains four subunits and four atoms of selenium per mol protein. No selenium-independent glutathione peroxidase activity could be attributed to glutathione S-transferase (EC 2.5.1.18) in trout liver. Glutathione peroxidase together with glutathione (GSH) did not provide any additional protection in the in vitro liver microsomal lipid peroxidation system over and above that provided by GSH alone. Microsomal lipid peroxidation was, however, reduced by a partially purified glutathione S-transferase together with GSH. The protection provided by dialysed liver cytosol in this system was not GSH-dependent, showing that other factors in addition to glutathione S-transferase are involved. Of other possible factors, vitamin E reduced lipid peroxidation in this system. Concentrations of vitamin E in microsomes before and after peroxidation in vitro indicated that protective cytosolic factor(s) act prior to the termination of the free radical chain reactions effected by vitamin E. A GSH-dependent protective factor was present in microsomal protein, malondialdehyde formation in the in vitro microsomal system being markedly reduced in the presence of 5 mM GSH but not significantly lowered by 1 mM GSH.

Animals↗
PubMed1984

The effect of vitamin E and oxidized fish oil on the nutrition of rainbow trout (Salmo gairdneri) grown at natural, varying water temperatures.

Groups of rainbow trout (Salmo gairdneri) of approximate mean initial weight 8 g were grown in outdoor tanks over a 14-week period at water temperatures between 12 degrees (start) and 6 degrees (end). Four diets were used. Two contained non-oxidized fish oil (120 g/kg) with or without supplementary DL-alpha tocopheryl acetate and two contained moderately oxidized fish oil again with or without DL-alpha-tocopheryl acetate. The measured selenium content of the diets was 0.10 mg/kg. No significant differences occurred as a consequence of the use of moderately oxidized oil compared with the corresponding treatments using non-oxidized oil. Significant differences did occur between dietary treatments that contained supplementary DL-alpha-tocopheryl acetate and those that did not. These differences applied to weight gain, haematocrit, erythrocyte fragility, mortalities, liver and muscle tocopherol concentrations and lipid peroxidation of liver mitochondria in vitro. Liver glutathione peroxidase (EC 1.11.1.9) activity was unaffected by the dietary treatments used and the proportions of fatty acids in polar lipids of liver and muscle were little changed by the diets used. Severe muscle damage occurred in trout given diets lacking supplementary DL-alpha-tocopheryl acetate. Previous experiments carried out on rainbow trout at a constant water temperature of 15 degrees ( Hung et al. 1981; Cowey et al. 1981, 1983), using diets lacking supplementary vitamin E, did not lead to differences in weight gain, pathological changes or mortalities. Vitamin E requirement may increase as water temperature decreases; minimum dietary requirements for vitamin E measured at a constant water temperature of 15 degrees may not be valid under practical conditions where water temperatures vary over the year.

Animal Nutritional Physiological Phenomena↗
PubMed1982

Cuspal failures of MOD restored teeth.

It is observed clinically that some years after MOD restoration of molar and premolar teeth, cuspal failures commonly occur. The period between restoration and failure is usually from eight to fifteen years. Evidence has been found, both from observations of fractured cusps and from a mathematical model of an idealized molar tooth, that allows a clear description of the mechanism of these slow failures. Suggested changes in clinical practice are recommended if such failures are to be prevented in the future.

Dental Cavity Preparation↗
PubMed1980

Gracilis muscle repair of perineal hernia following pelvic exenteration.

This report describes the use of a rotated gracilis muscle to repair a perineal hernia that occurred 18 months following pelvic exenteration for recurrence of cervical carcinoma. The anatomy of the gracilis muscle and the operative technique of the hernia repair are described. The gracilis muscle procedure offers a satisfactory correction for this complication of pelvic exenteration. The ability to mobilize the gracilis muscle for reconstructive procedures in the pelvis is a valuable procedure for the gynecologist.

Female↗