Dietary intake and the insulin-like growth factor system: effects of migration in two related populations in India and Britain with markedly different dietary intake

BACKGROUND: The insulin-like growth factor (IGF) system is implicated in the pathogenesis of diabetes and cardiovascular disease. OBJECTIVE: We report the effects of total energy intake on the IGF system in two populations with markedly different dietary macronutrient intake and cardiovascular event rate. DESIGN, SUBJECTS AND SETTING: Dietary macronutrient intake was measured in a specific Gujarati migrant community in Sandwell, UK (n=205) compared with people still resident in the same villages of origin in India (n=246). Fasting IGF-I, IGF-binding protein (IGFBP)-1 and IGFBP-3, insulin and glucose (0 and 2-hour) were measured. RESULTS: Total energy and total fat intake were higher in UK migrants, as were IGFBP-3 and IGF-I (mean (95% confidence interval): 145.9 (138.1-153.6) vs. 100.9 (94.6-107.3) ng ml(-1); F=76.6, P<0.001). IGFBP-1 was lower in UK migrants (29.5 (25.9-33.0) vs. 56.5 (50.6-62.5) microg l(-1); F=48.4, P<0.001). At both sites, IGF-I correlated positively with total energy (Spearman's rho=0.45, P<0.001) and total fat (rho=0.44, P<0.001) as did IGFBP-3 with total energy (rho=0.21, P<0.05) and fat (rho=0.26, P<0.001). Conversely, in Indian Gujaratis, IGFBP-1 fell with increasing total energy (rho=-0.27, P<0.001) and fat intake (rho=-0.26, P<0.01) but not in UK Gujaratis. Multiple linear regression modelling showed that increasing quartiles of fat intake were associated with higher IGF-I (beta=0.42, P=0.007) independent of age, body mass index, plasma insulin, fatty acids and 2-hour glucose. CONCLUSION: In these genetically similar groups, migration to the UK and adoption of a different diet is associated with marked changes in the IGF system, suggesting that environmental factors profoundly modulate serum concentrations and actions of IGFs.     

Examination of the role of L‐α‐polyglutamic acid in the maintenance of the fertility of avian spermatozoa in vivo

The possible role of L‐α‐polyglutamic acid in the maintenance of fertility of spermatozoa in the avian oviduct was examined. Birds were immunised against poly‐a‐glutamic acid and when mature the oviducts of such birds did not contain polyglutamate. Even so, the fertility of these birds was identical with that of the control non‐immunised group. It is concluded that poly‐L‐α‐glutamic acid is not essential to the maintenance of fertility in the domestic fowl.     

Renal concentrating ability in dehydrated hyponatremic dogs

Eleven hyponatremic dogs were unable to concentrate their urine during periods of severe dehydration and azotemia. When normonatremia was reestablished in eight of the dogs, their renal concentrating ability returned. Six dogs, including the 3 dogs in which normonatremia was not reestablished, died or were euthanatized; renal lesions were not found during postmortem examination. Two dogs had hypoadrenocorticism, which has been documented as a cause of hyponatremia and impaired renal concentrating ability. Two dogs had gastrointestinal disease, which has been documented as a cause of hyponatremia, but not of impairment of renal concentrating ability. All dogs without hypoadrenocorticism had clinical and clinicopathologic indications of blood loss, which has not been documented as a cause of hyponatremia or impairment of renal concentrating ability. Hyponatremia (less than 120 mEq/L) was induced by chronic blood removal in a dog maintained on a low-sodium diet. During the period of hyponatremia, the dog became azotemic, hypotensive, and severely dehydrated; renal concentrating ability was impaired. We conclude that hyponatremia may be caused by hemorrhage, but irrespective of the cause, hyponatremia impairs renal concentrating ability.     

Effect of the intramammary device on milk infection status, yield, and somatic cell count and on the morphological features of the lactiferous sinus of the bovine udder

Twenty primiparous heifers were fitted intramammarily with polyethylene coils in both quarters of one random right or left udder half at 5 days after parturition. Foremilk samples were collected and udder-half milk yields were measured at the afternoon milking on days - 1, 3, 7, and 14 and on every 14th day for 8 months after the device was inserted. Three weeks after the heifers were fitted with the intramammary device, 6 were euthanatized for gross observation of devices and tissues and cytologic evaluation of the gland cistern epithelium. There were significantly fewer bacterial isolations (P less than 0.01) and less clinical mastitis (P less than 0.05) in treated quarters than in the control quarters. Coagulase-negative staphylococci were isolated at frequencies of 0 and 15.2% for treated and control quarters. The reduction in isolation frequency for treated, compared with control, quarters was less marked with other organisms. Intramammary devices in no way interfered with the milking process. Milk yields per milking were 4.2 kg for treated udder halves compared with 4.4 kg for control halves; however, this 0.2 kg difference was not significant. Mean milk somatic cell counts, as determined by electronic counter, were 34 X 10(3) and 81 X 10(3) cells/ml for control and treated quarters (P less than 0.05). Mean bovine serum albumin values were 0.160 and 0.175 mg/ml for control and treated udder halves (P less than 0.05), indicating an increased capillary permeability due to the device. Quantitative morphologic analysis of gland cisterns showed a significant (P less than 0.05) change toward a single layer of epithelial cells in treated quarters compared with a double layer in control quarters.(ABSTRACT TRUNCATED AT 250 WORDS)     

Morphometric study of experimentally induced Staphylococcus bovis mastitis in the cow

Comparisons were made of bovine mammary tissue at 12 and 24 hours after 5,000 colony-forming units of Staphylococcus aureus 305 was injected into the mammary parenchyma with control tissue from the contralateral udder half. A mild form of staphylococcal mastitis was induced routinely. Generally, S aureus was found in udder tissue removed centrally from the site of injection. Varied degrees of tissue damage were found in infected quarters from alveolar epithelium without damage (similar to control) to extremely swollen epithelium which were typical of cells undergoing disruption. Infected tissues frequently displayed areas of swollen stroma and areas of diminished alveolar lumens. Cellular debris was often found in lumens, and neutrophils frequently filled the alveolar lumen in areas of greatest damage. Thus, a parenchymal injection of bacteria induced early forms of staphylococcal mastitis at the alveolar level.