Induction of anaesthesia with propofol according to the adjusted ideal body mass in obese and non-obese patients: an observational study

Background: Obesity changes body composition including fat free mass (FFM), regarded as the "pharmacologically active mass". Scaling drug doses to obese patients by total body mass (TBM) results in overdose. We aimed to determine the success rate of inducing anaesthesia in normal, overweight and obese patients with propofol, using an adjusted body mass scalar (ABM), which embodies the increased FFM of obese patients. Methods: Ninety-six patients were divided into three groups according to body mass index (BMI): normal, overweight and obese. Propofol 2 mg/kg ABM was administered according to the equation: ABM = IBM + 0.4(TBM ­ IBM), where IBM = ideal body mass. Induction success was assessed clinically and by electroencephalographic spectral entropy. Results: The groups were similar regarding gender, age, height and IBM. One patient was morbidly obese (BMI = 44). State entropy (SE) decreased to < 60 in 33/33, 28/29 and 33/34 patients in the normal-weight, overweight and obese groups respectively, an overall success rate of 97.5% (95% confidence interval 92.7% to 99.4%). Median lowest achieved SE values and median times that SE remained < 60 did not differ between groups, however the individual values ranged widely in allthree groups. Induction failed in the two patients whose SE did not decrease to < 60 (one overweight and one obese). Conclusions: The ABM-based propofol induction dose has a high success rate in normal, overweight and obese patients. Further studies are required to determine the feasibility among morbidly obese patients

Knowledge of and Misconceptions about the Spread and Prevention of HIV Infection among Older Urban Women Attending the Tshwane District Hospital; South Africa

Background:Statistics around the world show a rapid increase in HIV infection in the older population. Many older women remain sexually active and are therefore exposed to heterosexual transmission of HIV infection. Older women are most likely considered respected opinion leaders within the families and communities and are likely to influence others' attitudes and behaviours. An increase in knowledge through information plays a fundamental role and is a prerequisite for behavioural change that may prevent new HIV infections. The purpose of the current study was to assess the knowledge and misconceptions regarding the spread and prevention of HIV in older women attending the Tshwane District Hospital (TDH) in South Africa. Methods: A prospective cross-sectional study of 100 women; aged 50 to 80 years; attending the TDH out-patient section during November and December 2006 was done. The levels of knowledge were determined by using a directed questionnaire. Results: Eight per cent of the participants answered all the questions correctly; showing knowledge gaps in the remaining 92(95confidence interval: 86.7-97.3). Many participants were unaware of the protective effects of condom use; especially female condoms; and of HIV spread by anal transmission; the sharing of needles and blood transfusion. Three or more misconceptions were present in 48of the participants; such as HIV spread by casual contact; the sharing of personal items; air-borne infection; mosquito bites; HIV testing and AIDS prevention or cure by traditional medicines or alternatives. Sixty-two per cent of the older women were found to have adequate knowledge (95confidence interval: 52-71.5); knowing the basic concepts regarding HIV transmission.Conclusion: There is a significant need for HIV-related preventive health education in older women; not only to decrease potential high-risk behaviours; but also to reduce unnecessary feelings of anxiety and misconceptions. Family physicians; due to their unique role; might be able to use the present study in their practices in order to optimise the planning and structuring of awareness interventions and prevention programmes

Hereditary Non-Polyposis Colorectal Cancer is Predicted to Contribute towards Colorectal Cancer in Young South African Blacks

A disproportionately large number of young (50 years); those from young black patients presented more often with a low methylation phenotype (CIMP-L) and high levels of microsatellite instability (MSI-H). Furthermore; as determined by real-time PCR using probe technology; the tissues from35of young blacks showed mutations within exon 1 of the KRAS gene. The BRAF-V600E mutation was only evident in the case of a single young black patient. Based on these results it seems likely that a proportion of CRC cases in young black patients from South Africa develop through the accumulation of mutations resulting in a mismatch repair deficiency linked to MSI-H and; possibly; germline mutations in the mismatch repair genes. The features in these patients are consistent with a diagnosis of the Hereditary Non-Polyposis Colorectal Cancer (HNPCC) syndrome. This finding has important implications for patient management and suggests that family members may be at high risk for CRC

Biological Variation of Ischaemia-Modified Albumin in Healthy Subjects : Cardiovascular Topic

Aim : Ischaemia-modified albumin (IMA); as measured by the albumin-cobalt binding (ACB) testr; has been cleared by the US Food and Drug administration as a biomarker to exclude the presence of myocardial ischaemia in patients. Although there are a number of published studies detailing the clinical utility of IMA; data on the biological variation of IMA are still lacking. In this study we determined the analytical and biological variance components of ischaemia-modified albumin; and compared the distribution of IMA values in our patient population to those provided by the kit manufacturer. Methods : IMA was determined once a week for five consecutive weeks on a cohort of healthy subjects using a colorimetric method; the ACB testr on a Roche modular analyser. Results : The analytical coefficient of variation (CVA) was 5; and the within-subject (CVI) and between-subject (CVG) biological variations were 3 and 7; respectively. Analysis of the repeated measures with gender and race (black and Caucasian) as between-subject factors; and weeks (1-5) as the within-subject factor showed that gender had no significant effect on circulating IMA concentrations (p = 0.3146); whereas race did have a significant effect (p = 0.0062). A significant (p = 0.0185) interaction was observed between gender and race. Conclusion : The ACB testr could bring a new dimension to the care and management of patients with acute coronary syndrome. Further studies for normal population distributions by gender and ethnicity; and an optimum cut-off value appear to be required

Transfer of DDT used in malaria control to infants via breast milk

The transfer of p,p'-DDT (1,1,1-tricholoro-2,2-bis(4-chlorophenyl)ethane) and its metabolites to infants via breast-feeding was studied in an area of KwaZulu, South Africa, where DDT is used to interrupt malaria transmission. Samples of whole blood were collected from 23 infants, together with samples of breast milk from their respective mothers. The mean sigma DDT (total DDT) in the whole blood was 127.03 micrograms.l-1 and that in the breast milk, 15.06 mg.kg-1 (milk fat). The % DDT (% DDT of sigma DDT) was significantly higher in the infant blood than in the breast milk (P less than 0.05). A multiplicative regression analysis indicated that sigma DDT increased significantly (P less than 0.01) in infant whole blood with infant age. Multiple regression showed that 70.0% of the variation in sigma DDT was due to the variation in parity of the mother, age of the infant, and the sigma DDT in breast milk. These variables accounted also for 76.3% of the variation in p,p'-DDE but only for 38.2% of that in p,p'-DDT. Organochlorines were therefore largely transferred to the infant from the mother, with DDT in the environment playing a secondary role

Lack of efficacy of the standard potency Edmonston-Zagreb live, attenuated measles vaccine in African infants

The efficacy of standard potency Edmonston-Zagreb (E-Z) measles vaccine was tested in a randomized trial of Black infants in a rural area of South Africa where a measles epidemic was occurring. The following immunization schedules were used: 48 infants aged 4-8.5 months who received 3.9 log 50 infectious units of E-Z vaccine (group A); 48 infants aged 4-8.5 months who received 3.28 log 50 infectious units of Schwarz vaccine (group B); and 28 infants aged greater than 9 months who received 3.28 log 50 infectious units of Schwarz vaccine and served as controls (group C). For infants aged less than 23 weeks who were given either the E-Z or Schwarz vaccine, the number of seropositives was low (28%), irrespective of the pre-vaccination level of measles antibody. There was a higher number of seropositives (68%) among those in the age range greater than 23 weeks to less than 36 weeks who received the E-Z vaccine rather than the Schwarz vaccine (36%). When administered to children aged greater than 36 weeks, the Schwarz vaccine produced a satisfactory, though suboptimal response rate (61%). There was no correlation between seropositivity and pre-vaccination measles antibody status. Use of the standard dose of E-Z vaccine may have been one of the factors for this poor response, and this supports the WHO recommendation that titres higher than the standard potency vaccine are needed if 6-month-old infants are to be successfully immunized against measles

Levels of DDT and metabolites in breast milk from Kwa-Zulu mothers after DDT application for malaria control

Concentrations of DDT, DDE and DDD were determined in the breast milk of Kwa-Zulu mothers residing in two different areas--with and without annual intra-domiciliary applications of DDT for the interruption of malaria transmission (exposed and control groups, respectively). While no significant change in levels with time was found in the control group, both DDT and DDE in breast milk of the exposed group increased after DDT application and this continued for three more months, after which it did not decrease appreciably. Percentage DDT increased from 42.57% (sigma DDT = 12.21 mg/kg milk fat) before spraying to 50.87% (sigma DDT = 13.79 mg/kg milk fat) following DDT application. At 6 and 9 months after the application it was 45.85% (sigma DDT = 19.49 mg/kg milk fat) and 43.27% (sigma DDT = 18.34 mg/kg milk fat), respectively. These results suggest a risk to the health of the infants in the exposed group