Genetic differentiation between and within strains of the saw-toothed grain beetle, Oryzaephilus surinamensis (Coleoptera: Silvanidae) at RAPD loci

Nine strains of Oryzaephilus surinamensis have been kept in laboratory culture for periods ranging from 5 to 30 years (30–180 generations). Two RAPD primers provided sufficient information to separate the strains reliably and unambiguously. The strains are maintained at a population size of 200 breeding adults. The marked divergence between strains is consistent with the small population size, which for the older strains, according to population genetics theory, implies that roughly half the original genetic variation should now be lost from within strains. However, there is no indication that the older strains have less inter-strain variation. The results demonstrate RAPD loci can reliably detect population subdivision, which in field populations of pest species is of fundamental importance in understanding the population genetics of insecticide resistance.     

Treatment of refractoriness to platelet transfusion by protein A column therapy

Ten thrombocytopenic patients (platelets < 10–24 × 10(9)/L) who were refractory to platelet transfusion were investigated for their responsiveness to staphylococcal protein A column therapy. Nine patients had previously been treated with steroids, intravenous immune globulin, and/or other forms of immunosuppressive therapy without improvement in their transfusion response. All patients were receiving multiple platelet transfusions without achieving 1-hour corrected count increments (CCIs) > or = 7500. Eight patients had antibodies that reacted with platelets and were directed against HLA class I antigens, ABO antigens, and/or platelet-specific alloantigens. Plasma (500-2000 mL) from each patient was passed over a protein A silica gel column and then returned to the patient. Patients received from 1 to 14 treatments. A positive response to protein A therapy was defined as at least a doubling of the pretreatment platelet count and/or two successive 10- to 120-minute posttransfusion CCIs > or = 7500. Following plasma treatments, 6 of 10 patients responded with daily platelet counts that averaged 48 +/− 11 × 10(9) per L as compared with counts of 16 +/− 7 × 10(9) per L (p < 0.0005) before treatment. Posttransfusion CCI values determined in four of these patients averaged 2480 +/− 810 and 10,010 +/− 3540 (p < 0.005) before and after treatment, respectively. In contrast, among the four unresponsive patients, platelet counts averaged 10 +/− 9 and 13 +/− 10 × 10(9) per L (p = NS), respectively, while posttransfusion CCIs were 700 +/− 1410 and 1520 +/− 2460 (p = NS), respectively.(ABSTRACT TRUNCATED AT 250 WORDS)     

A comparative analysis of radiological and surgical placement of central venous catheters

Purpose To compare the differences in practice and outcome of all radiologically and surgically placed central venous catheters retrospectively over a 2-year period simultaneously, at a single institution. Methods A total of 253 Hickman catheters were inserted in 209 patients; 120 were placed radiologically in 102 patients and 133 were placed surgically in 107 patients. The indication was chemotherapy in 76% of radiological and in 47% of surgical cases; the remainder were for total parenteral nutrition and venous access. Results There were 6 (4.5%) primary surgical failures and a further 17 (13%) surgical cases requiring multiple placement attempts. Pneumothorax occurred once (0.8%) surgically and four times (3.3%) radiologically. There were no radiological primary misplacements but there were five (3.7%) surgical ones. Catheter or central vein thrombosis occurred in four (3.3%) radiological and five (3.7%) surgical cases. The rate of infection per 1000 catheter-days was 1.9 in radiologically placed catheters and 4.0 in surgically placed ones (p<0.001). Average catheter life-span was similar for the two placement methods (100±23 days). Conclusion Radiological placement is consistently more reliable than surgical placement. There are fewer placement complications and fewer catheter infections overall.     

Ancient,highly polymorphic human major histocompatibility complex DQA1 intron sequences

A 438 basepair intron 1 sequence adjacent to exon 2 in the human major histocompatibility complex DQA1 gene defined 16 allelic variants in 69 individuals from wide ethnic backgrounds. In contrast, the most variable coding region spanned by the 247 basepair exon 2 defined 11 allelic variants. Our phylogenetic human intron 1 tree derived by the Bootstrap algorithm reflects the same relative allelic relationships as the reported DQA1 exon 2 tree [Gyllensten and Erlich, Hum Immunol 36:1–10, 1989]. Thus 3′ DQA1 intron 1 and exon 2 have cosegregated since divergence of the human races. Comparison of human alleles to a Rhesus monkey DQA1 first intron sequence found only 10 nucleotide substitutions unique to Rhesus, with the other 428 positions (98%) found in at least one human allele. This high degree of homology reflects the evolutionary stability of intron sequences since these two species diverged over 20 million years ago. Because more intron 1 alleles exist than exon 2 alleles, these polymorphic introns can be used to improve tissue typing for transplantation, paternity testing, and forensics and to derive more complete phylogenetic trees. These results suggest that introns represent a previously underutilized polymorphic resource. © 1994 Wiley-Liss, Inc.     

Cognitive rehabilitation in the elderly: overview and future directions.

This study provides an overview of the papers emanating from the experimental trial that evaluated a new cognitive rehabilitation program in older adults who were experiencing normal cognitive decline. The main features of the design are summarized, along with evidence that the training produced long-lasting improvement in memory performance, goal management, and psychosocial status. The benefits were attributed to several factors, including the program's emphasis on techniques that promoted efficient strategic processing. Limitations of the program and directions for future research are discussed.     

Minimising neonatal brain injury: how research in the past five years has changed my clinical practice.

With improving neonatal survival for extremely premature babies, the challenge for neonatology is to improve outcome of surviving babies. This review concentrates on best evidence emerging in recent years on prevention of brain damage by early administration of drugs as well as avoidance of induced brain damage by hyperventilation and dexamethasone therapy given postnatally for chronic lung disease.