Dietary polyunsaturated to saturated fatty acid ratio alters hepatic LDL transport in cynomolgus macaques fed low cholesterol diets.

To determine effect of interaction between dietary cholesterol and triglyceride, i.e., polyunsaturated to saturated (P:S) fatty acid ratio, on LDL metabolism, male cynomolgus macaques were fed purified diets for 83 wk with cholesterol levels of 0.01, 0.06 and 0.50 mg/kJ and P:S ratios of 0.5 and 0.9, oleic acid constant. There were six groups of five animals each (cholesterol, mg/kJ--P:S ratio): Group 1, 0.01--0.5; Group 2, 0.01--0.9; Group 3, 0.06--0.5; Group 4, 0.06--0.9; Group 5, 0.50-0.5; Group 6, 0.50-0.9. LDL (1.019 less than d less than 1.063 kg/L) and glucosylated LDL were iodinated for turnover studies. Hepatic LDL transport was determined using 125I-tyramine-cellobiose-LDL as tracer. Plasma cholesterol increased in proportion to dietary cholesterol, and concentrations (mmol/L) at 77-78 wk were (mean +/- SEM): Group 1, 434 +/- 0.31; Group 2, 3.03 +/- 0.14; Group 3, 8.28 +/- 1.48; Group 4, 7.34 +/- 1.31; Group 5, 15.54 +/- 1.44; Group 6, 15.54 +/- 1.41. LDL cholesterol was 45% higher in Group 1 (2.43 mmol/L) than in Group 2 (1.68 mmol/L). In vivo studies showed that LDL clearance was suppressed by excess dietary cholesterol; receptor-independent LDL clearance was relatively constant. Hepatic LDL protein transport was greater in Group 2 (P:S 0.9) compared with Group 1 (P:S 0.5). The LDL protein synthetic rate was lower in Groups 2, 4 and 6 (P:S 0.9) relative to Groups 1, 3 and 5 (P:S 0.5). We conclude that in this model hepatic LDL receptor activity is altered by degree of saturation in dietary triglycerides when dietary cholesterol is minimal, and that saturated dietary triglycerides enhance LDL protein secretion when dietary cholesterol is ample.     

Eighteen-month Coronal Caries Incidence in North Carolina Older Adults

In this longitudinal study of a random sample of North Carolinians over the age of 65 and living in their homes, 325 blacks and 280 whites were examined and interviewed 18 months after baseline examinations. Coronal caries incidence was greater among whites than blacks. The increment due to teeth becoming root fragments were similar for both races; however, there were more newly crowned teeth among whites. Newly crowned surfaces were not used as part of the caries increment in logistic regression models to investigate potential risk predictors. For blacks, caries development over the 18-month period was associated with a higher lactobacillus score and more coronal caries at baseline, more previously filled coronal surfaces, and lack of active membership in clubs or other groups. For whites, having no self-reported tooth sensitivity, having a lower socioeconomic index score, taking antihistamine medications at baseline, and having the perception of more problems after the age of 40 than before were all associated with the development of coronal caries.     

Directly measured tissue oxygen tension and arterial oxygen tension assess tissue perfusion

Mean subcutaneous tissue PO2 (PsqO2) measurements were obtained in dogs with an unheated electrode placed in an implanted Silastic tonometer, while PaO2 was increased in increments from 40 to 600 torr during normal, increased, and reduced blood volume. These changes reflect that the mean PsqO2 is approximately 10 torr below the PO2 of venous blood draining that tissue. Since PaO2 was already known, the oxygen content of arterial and venous blood entering and leaving this tissue could be determined by reference to blood-oxygen dissociation curves. Therefore, relative changes in blood flow could be calculated using the Fick principle. After a 20% blood loss, the PsqO2 measured during breathing of room air fell to 20% of baseline, corresponding to an 80% fall in sc blood flow; it remained low until the shed blood was returned despite compensatory changes in cardiac output. Rapid infusion of electrolyte solutions in normovolemic animals produced a temporary increase in local blood flow. Subcutaneous oximetry seems capable of quantifying peripheral perfusion and may be clinically useful.     

Where patients with cancer die in South Australia

In a sample of 1582 deaths among South Australian patients with cancer (795 deaths in 1981 and 787 deaths in 1985), 67% of deaths occurred in a hospital, 9% of deaths in a hospice, 10% of deaths in a nursing home, and 14% of deaths in a private residence. More patients died in a hospice or nursing home in 1985 than in 1981, and fewer died in a hospital. With increasing age, fewer patients died in a hospital and more in a nursing home. Compared with men, women were less likely to die at a private residence and more likely to die in a nursing home. A greater proportion of men with a living wife died at a private residence than was so among single or widowed men. However, conjugal status was not associated with the place of death of women. Patients who lived in the more affluent metropolitan suburbs tended more to die at a private residence than did those from poorer suburbs or country areas. Patients with haematological malignancies died in major metropolitan public hospitals more frequently than did patients with other tumours. Possible explanations are given for these findings.     

Polycythaemia and neuroblastoma

The treatment of primary proliferative polycythaemia (polycythaemia rubra vera) may include radioactive phosphorus (P32) in conjunction with venesection. Acute leukaemia or carcinoma can be associated with the use of P32. We present a case of primary proliferative polycythaemia treated by repeat venesection together with P32 whose follow-up was complicated by the development of malignant neuroblastoma.     

Risk of Respiratory Complications and Wound Infection in Patients Undergoing Ambulatory Surgery: Smokers versus Nonsmokers

Background: Smoking is considered to be a risk factor for patients undergoing surgery and anesthesia, but it is unclear whether this is applicable to patients undergoing ambulatory surgery. The aim of this study was to determine the risk of respiratory complications and wound infection among smokers.

Methods: The authors studied a random selection of 489 adult patients undergoing ambulatory surgery. Smoking status was determined by self-report and confirmed with end-expired carbon monoxide analysis. The risk of respiratory complications (i.e., desaturation, cough, laryngospasm, bronchospasm, breath-holding, or apnea) and wound infection (i.e., wound redness or discharge +/- positive microbial culture, requiring antibiotic therapy) in smokers versus nonsmokers was ascertained. Odds ratios were estimated from multivariable logistic regression and adjusted for age, gender, body mass index, partner's smoking status, domiciliary smoking exposure, and extent and duration of surgery.

Results: Most smokers continued to smoke up until the day of surgery. Smokers had a higher rate of respiratory complications (32.8%vs. 25.9%; adjusted odds ratio, 1.71; 95% confidence interval, 1.03-2.84;P = 0.038) and wound infection (3.6%vs. 0.6%; odds ratio, 16.3; 95% confidence interval, 1.58-175;P = 0.019). Odds ratios comparing current plus ex-smokers with nonsmokers were of similar magnitude for most of these complications.