A newly characterized HLA-DP beta-chain allele. Evidence for DP beta heterogeneity within the DPw4 specificity

cDNA clones corresponding to the DPw4 alpha- and DPw4 beta-chains were isolated from a cDNA library prepared from a DPw4 homozygous cell line, their nucleotide sequences were determined, and the corresponding amino acid sequences were deduced. This DPw4 alpha-chain is identical to the conserved DP alpha-chains from DPw4 and DPw2 haplotypes, although the DPw4 beta-chain (referred to as DPw4b beta) differs from all reported DP beta-chain sequences. The DPw4b beta-chain differs from the reported DPw4 beta sequence (referred to as DPw4a beta) at three amino acid positions in the first domain (36, 55, and 56). The DPw4b beta-chain sequence differs from the DPw2 beta-chain sequence only at position 69 in the first domain, suggesting that the lysine at position 69 in DPw4b beta and the glutamic acid at position 69 in DPw2 beta contribute to the epitopes that define "DPw4-ness" and "DPw2-ness," respectively. In addition, the patterns of sequence identities and differences among the DPw4b beta-, DPw4a beta-, DPw2 beta-, and DPw3 beta-chains suggest that the DPw4b beta sequence arose via a gene conversion event or a point mutation. The I-LR1 mAb, which was previously found to bind only to DPw2, DPw3, and DR5 molecules, binds to an L cell transfectant expressing the DPw4 alpha:DPw4b beta molecule. The DPw4b beta sequence provides the first evidence for structural heterogeneity within the DPw4 specificity.

Comparative effects of the calcium antagonist isradipine and some other dihydropyridine derivatives on regional blood flow in anesthetized open-chest dogs

The effects of isradipine (PN 200-110), isopropyl 4-(2,1,3-benzoxadiazol-4-yl)-1,4-dihydro-5-methoxycarbonyl-2,6-dim ethyl-3- pyridinecarboxylate, on some cardiovascular parameters and regional blood flow were compared with those of other dihydropyridine derivatives in anesthetized open-chest dogs. Intravenous (i.v.) administrations of isradipine 3 and 10 micrograms/kg, nifedipine 10 micrograms/kg, nicardipine 10 micrograms/kg and nisoldipine 10 micrograms/kg, decreased aortic blood pressure and increased aortic (AoF), vertebral (VBF) and coronary blood flow (CBF), but did not affect heart rate and left ventricular end-diastolic pressure. Renal blood flow was reduced by isradipine 10 micrograms/kg and nifedipine 10 micrograms/kg, but was not influenced by isradipine 3 micrograms/kg, nicardipine 10 micrograms/kg and nisoldipine 10 micrograms/kg. Left ventricular dP/dt was increased by isradipine 3 micrograms/kg, nicardipine 10 micrograms/kg and nisoldipine 10 micrograms/kg, but remained essentially unchanged following isradipine 10 micrograms/kg and nifedipine 10 micrograms/kg. The increase in AoF, VBF and CBF lasted 5-9 min following nifedipine 10 micrograms/kg or nicardipine 10 micrograms/kg, 17-30 min following nifedipine 10 micrograms/kg or nicardipine 10 micrograms/kg, 17-30 min following nisoldipine 10 micrograms/kg, and 16-44 min following isradipine 3 micrograms/kg i.v., but persisted for at least 60 min following isradipine 10 micrograms/kg. Under the experimental conditions and at the doses used in this study, all 4 drugs reduced total peripheral resistance as well as resistance in the vertebral, coronary and renal vascular beds. The results suggest that isradipine exerts cardiovascular effects similar to other calcium antagonists of the dihydropyridine group, but possesses a longer duration of action and shows a greater specificity in reducing coronary vascular resistance than nifedipine, nicardipine and nisoldipine.

Isolated colonic tuberculosis

Two cases of isolated colonic tuberculosis are reported, and recent literature on this field is reviewed. Isolated colonic tuberculosis is defined as a tuberculosis which exists in the colon except for ileocaecum, without focus in any other organ. The morphological changes are tuberculous granulation primarily located to the submucosa layer of the colon with smooth surfaces of both mucous and serous membrane. Its clinical features are atypical, just like those on X-ray examination, and even on frozen biopsy, it may sometimes be misdiagnosed. The treatment of choice is resecting the diseased segment of colon combined with anti-tuberculosis therapy.

Correlation between auditory reaction time and intelligence

Discriminative reaction times to auditory stimuli were measured for 150 students of the local Chinese population. Pearson's correlation with scores on the Standard Progressive Matrices and RTs was negative, becoming -0.30 when slower trials were eliminated. The possible basis for improvement was discussed in relation to cognitive processes and the general theory of assessing intelligence.

Closed reduction of lumbosacral fracture dislocations

A unique method for closed reduction of lumbosacral fracture dislocations that uses a circle-electric bed is described. Fine radiological description of the injury with computed tomography scanning allows the application of appropriate forces to facilitate the reduction, while having the patient awake during the procedure greatly reduces the chance of introducing further neurological deficit.

Colonic variceal bleeding in a child

A 5-year-old girl with biliary atresia is described who developed lower gastrointestinal bleeding from colonic varices. Vasopressin infusions temporarily controlled the bleeding. Following a right hemicolectomy the bleeding has not recurred.

Detection of interaural time differences for clicks and tone pips: effects of interaural signal disparity

The ability to detect small interaural time differences (delta t) was determined in 4 subjects using clicks or long tone pips of various interaural signal disparities which are expressed as the extent of interaural spectral overlaps. The interaural signal disparity was varied by changing (a) the interaural pulse duration difference (delta d) for clicks, or (b) the interaural carrier frequency difference (delta f) for tone pips. In either case, the sensitivity to delta t was maximal under diotic presentations and declined with delta d or delta f. The overall sensitivity to delta t was remarkably higher for clicks than for long tone pips. The results indicate that both (a) the extent of binaural spectral overlaps and (b) the structure of acoustic stimuli are important in detecting small interaural time differences of binaural sounds.

Mechanicla properties and mineral content of avascular and revascularizing cortical bone

The mechanical properties of avascular and revascularizing bone and their mineral content were studied in thirty adult dogs. The strength and mineral content of avascular bone decreased in the early phase of avascular necrosis, and with revascularization the bone-mineral content increased but the mechanical strength decreased further. In the normal bone the mechanical strength increased with an increase in mineral content.