Changing survival, memory cell compartment, and T-helper balance of lymphocytes between severe and mild asthma

Background

In rural Gambia, birth season predicts infection-related adult mortality, providing evidence that seasonal factors in early life may programme immune development. This study tested whether lymphocyte subpopulations assessed by automated full blood count and flow cytometry in cord blood and at 8, 16 and 52 weeks in rural Gambian infants (N = 138) are affected by birth season (DRY = Jan-Jun, harvest season, few infections; WET = Jul-Dec, hungry season, many infections), birth size or micronutrient status.

Results

Geometric mean cord and postnatal counts were higher in births occurring in the WET season with both season of birth and season of sampling effects. Absolute CD3+, CD8+, and CD56+ counts, were higher in WET season births, but absolute CD4+ counts were unaffected and percentage CD4+ counts were therefore lower. CD19+ counts showed no association with birth season but were associated with concurrent plasma zinc status. There were no other associations between subpopulation counts and micronutrient or anthropometric status.

Conclusion

These results demonstrate a seasonal influence on cell counts with a disproportionate effect on CD8+ and CD56+ relative to CD4+ cells. This seasonal difference was seen in cord blood (indicating an effect in utero) and subsequent samples, and is not explained by nutritional status. These findings are consistent with the hypothesis than an early environmental exposure can programme human immune development.     

Assessment of acuity in human infants using face and grating stimuli

In a variety of ocular disorders, square-wave gratings yield more optimistic estimates of visual acuity than more complex stimuli such as letters. However, for clinical vision testing of preverbal patients, square-wave gratings are usually employed in conjunction with preferential looking procedures. We developed a complex stimulus--a schematic face--for use in preferential looking procedures. Using the method of constant stimuli, the acuities of 1-, 3-, and 5-month-old infants with normal eyes were estimated using schematic faces and square-wave gratings. Within each age group, thresholds for face and grating stimuli were not significantly different, but psychometric functions obtained with faces were significantly steeper than those obtained with square-wave gratings. This suggests that complex stimuli such as the schematic face could yield more precise acuity estimates than gratings in some pediatric eye patients.     

Modified mesh panel for radiation therapy treatment table

The design and construction of a mesh panel for radiation therapy treatment tables is described. With the new design, sagging is virtually eliminated. The panels have been successfully used for a variety of patient sizes and weights.     

Integration of physical, genetic and cytogenetic maps of human chromosome 7: isolation and analysis of yeast artificial chromosome clones for 117 mapped genetic markers

An Important goal of the human genome project is to assemblefully integrated physical, genetic and cytogenetic maps foreach human chromosome. Towards that end, we have isolated yeastartificial chromosome (YAC) clones containing 117 of the 119genetic markers that constitute a recently constructed, detailedgenetic map of human chromosome 7. Analysis of these clonesreveals numerous examples where adjacent genetic markers havebeen physically connected, either In Individual YACs or in multi-YACcontigs. At present, the 117 genetic markers are contained Infewer than 80 YAC contigs, with most of these contigs uniquelyordered relative to one another based on the genetic map positionsof the corresponding markers. These YAC and YAC contigs areestimated to contain {small tilde}60–85% of the DNA fromhuman chromosome 7. YACs representing 36 genetic markers weremapped by fluorescence In situ hybridization (FISH) to metaphasechromosomes, allowing assignment of these genetic markers tocytogenetic bands along chromosome 7 and placement of the centromerewithin the genetic map. Together, these studies provide geneticallyand cytogenetically anchored YAC clones covering the majorityof chromosome 7 that will be useful both for the positionalcloning of genes and as a framework for assembling a completeYAC-based physical map of the chromosome.     

Is familial hemiplegic migraine a hereditary form of basilar migraine?

We studied aura symptoms in 83 patients from 6 unrelated families suffering from familial hemiplegic migraine. Fifty-five of the patients reported symptoms that allowed us to categorize them as basilar migraine (BM) patients, in accordance with the International Headache Society (IHS) criteria. In a control group of 33 patients suffering from migraine with aura and 33 patients suffering from migraine without aura, 9 patients complained of vertigo, and only one patient of diplopia during one of her attacks. None of these control patients fulfilled the IHS criteria for BM We suggest that familial hemiplegic migraine and BM may share certain pathophysiologic mechanisms, which may consist of a (genetically determined) disturbance of basilar artery blood flow.     

Restoration of neutrophil and platelet function in feline Chediak-Higashi syndrome by bone marrow transplantation

Allogeneic bone marrow transplantation (BMT) was successfully performed in four Chediak-Higashi (CHS) syndrome affected cats. Preparatory regimens included selective intestinal flora decontamination, fractionated total body irradiation for myeloablation, and prophylactic treatment for graft-versus-host disease with cyclosporin A. Neutrophil chemotaxis under-agarose and whole-blood platelet aggregation/secretion were characterized prior to BMT and after engraftment of donor-origin marrow cells. Liver and kidney biopsies were obtained and evaluated by light and electron microscopy before, and at 6 months post-BMT to determine what effect BMT might have on abnormal lysosome fusion in hepatocytes and renal tubule cells. The platelet storage pool defect was resolved by day 40 post-BMT. In vitro neutrophil migration in all cats appeared to improve with time after BMT and complete restoration was evident by day 175 post-BMT. No apparent differences were evident in either the liver or the kidney at 6 months post-BMT. One cat developed seizures and one developed posterior paresis 5 months post-BMT; neurologic impairment ultimately resulted in death of two cats at 6 and 8 months post-BMT, respectively. Neurologic lesions in both cats were characterized by non-suppurative encephalitis. Allogeneic BMT successfully corrected the neutrophil migration defect and platelet storage pool deficiency but had no effect on lysosome distribution in liver and kidney cells of CHS cats.     

Superinfection by strains of tobacco streak virus

Synthesis of vaccinia virus DNA was studied by following the incorporation of [³H]thymidine in the cytoplasm of infected cells. During short pulses (1–5 min) the radioactive precursor was incorporated into single-stranded DNA fragments that sedimented as 10–12 S in neutral sucrose gradients. After the chase, these fragments were converted into a 34 S intermediate before becoming mature size molecules (68 S). Following longer periods of chase, the labeled DNA sedimented as cross-linked molecules in alkaline sucrose gradients (91–106 S) suggesting that the formation of cross-links is a postreplicative process. The presence of RNA covalently linked to DNA in the 12 S fragments was suggested by a shift in the equilibrium density sedimentation and by sensitivity to spleen phosphodiesterase after alkaline hydrolysis. Determination of the molecular weight of vaccinia DNA synthesized in cultures containing bromodeoxyuridine (BrUdR) demonstrated that replication proceeds in two directions.