Distribution of colonic polyps: increased incidence of proximal lesions in older patients

Several recent studies have shown a proximal shift in the distribution of colonic carcinoma compared to older studies. Because of the association between polyps and cancer, the authors evaluated the distribution of colonic polyps in 3,664 consecutive patients who had a colon examination over a period of 14 months. A total of 967 colorectal polyps were found in 633 patients. In all, 502 polyps (52%) were proximal to the rectosigmoid. Older patients had significantly more right-sided polyps and fewer rectosigmoid lesions. Large polyps occurred more frequently in the right colon, and this was also statistically significant. Gender has no effect on polyp distribution. The authors conclude that the importance of screening for polyps, particularly on the right side of the colon, increases with age.     

The malaria vectors of the Lower Shire valley,Malawi

The aim of this study was to characterise breeding sites and climatic factors that influence the abundance of malaria vectors in the Lower Shire valley, Malawi. We regularly sampled adult and larval mosquitoes over the transition periods between the wet and dry seasons during 2000 and 2001. Three potential malaria vectors, An. arabiensis, An. gambine sensu stricto and An. funestus, and a fourth non-vector species An. quadriannulatus, were identified. (This is the first record of An. quadriannulatus in Malawi). These four species bred predominately in larger water bodies, particularly rice paddies, and to a lesser extent in boreholes and puddles. Smaller temporary pools and puddles evaporated too quickly to permit the completion of larval development. Abundance of An. gambiae s.l. was closely associated with minimum temperatures. We discuss the relevance of the findings to malaria vector control in Malawi.     

New South Wales population-based birthweight percentile charts

Objective : To derive newborn percentile charts using NSW population and hospital-based data.
Methodology : Birthweight data for liveborn singleton infants were obtained from the New South Wales Midwives Data Collection (MDC) from 1990 to 1994 inclusive ( n = 422139). Data were also collected from King George V Hospital (KGV) for liveborn singleton infants less than 35 weeks of gestation for 1982-89 inclusive, and for all gestations for 1990-95 inclusive ( n = 30 610). Birthweight percentiles were derived using the MDC data separately for mates and females. Head circumference ( n = 29 090) and birth length percentiles ( n = 26 973) were derived from the KGV data.
Results : The charts derived from MDC data had generally higher percentiles than previously published charts. These represent the largest Australian population-based study published to date.
Conclusions : Periodic review of newborn growth charts is recommended because of changing ethnic and socio-economic factors.     

The presurgical management with erythrocytapheresis of a patient with a high-oxygen-affinity, unstable Hb variant (Hb Bryn Mawr)

BACKGROUND: Hemoglobin (Hb) Bryn Mawr is an unstable Hb variant resulting in congenital hemolytic anemia. This variant Hb also has an increased affinity for oxygen. The perioperative transfusion management of this disorder is described, and the first genomic analysis of this Hb variant is given. CASE REPORT: An 11-year-old boy, heterozygous for Hb Bryn Mawr, was referred for cholecystectomy. Sequence analysis of genomic DNA confirmed that the patients was heterozygous for a T–>C transition in the codon for amino acid 85, causing a substitution of serine for phenylalanine in the beta-globin chain. On the basis of whole-blood O2 dissociation studies, projected tissue O2 delivery would have been suboptimal during general anesthesia; therefore, a partial red cell exchange transfusion was performed to lower variant Hb and prevent tissue hypoxia during surgery. The red cell mass to be exchanged (50%) was determined from the calculated increase in O2 delivery capacity required to maintain an O2 extraction of 4 to 5 mL of O2 per dL of whole blood. The p50 of whole blood from the patients immediately after the exchange transfusion was 16.0 torr. At the time of surgery, the p50 was normal (25.9 torr). The patient's whole blood 2,3 DPG levels were 4.70 mmol per mL of red cells (before transfusion) (normal range=4.8 +/? 0.3 mmol/mL red cells), 4.07 mmol per mL of red cells (immediately after transfusion), and 4.55 mmol per mL of red cells (48 hours after transfusion). CONCLUSION: This patient with Hb Bryn Mawr was prepared for surgery with a partial exchange transfusion to prevent tissue hypoxia during anesthesia. Decreased 2,3 DPG levels immediately after transfusion resulted in increased O2 affinity of whole blood; however, 48 hours after exchange transfusion, a normal p50 (due to both removal of variant Hb and regeneration of 2,3, DPG) was observed. Partial exchange transfusion is useful in the preoperative management of patients with Hb variants characterized by increased O2 affinity.     

Evidence that SE is distal to LU on chromosome 19q

Analysis of a family informative for chromosome 19 loci establishes that the Lutheran blood group locus (LU) lies between the third component of human complement (C3) and the secretor loci (SE). Previously published lod scores for C3:LU are increased from 2.94 to 3.80. The linkage relationships (zeta and theta) between C3, LU, and SE are examined, and the proposed order and approximate genetic distances are determined to be: pter--C3-10.6cM-cen-7.4cM-LU-9cM-SE--qter.