Algebraic Isotopy in Genetics

It is shown that many of the algebras arising in nonselectivegenetics are isotopes of the algebras for particularly simplesystems of inheritance. Moreover, interesting aspects of thestructure are preserved under the relevant isotopies.     

EXTRAPULMONARY TUBERCULOSIS A CONTINUING PROBLEM IN AUSTRALIA

Abstract Extrapulmonary tuberculosis (TB) remains a major health problem in Australia, with 24.3% of all new tuberculosis notifications in 1984 of extrapulmonary origin. We have reviewed our recent experience to assess the epidemiology and clinical features that may allow the earlier recognition and treatment of patients at risk for this disease. From 1980–1985, 51 cases of extrapulmonary TB were identified at Westmead Hospital. Thirty-eight patients were born outside Australia, mainly in South-East Asia and Europe. The commonest sites of disease were the lymph nodes, genitourinary tract, pleura and bone. Tuberculous lymphadenitis occurred predominantly in South-East Asians, whilst genitourinary tract disease was confined to Caucasians. A history of previous exposure to tuberculosis was obtained in 45% of patients. Fever, sweats and weight loss were noted in less than half of the cases. Changes consistent with old pulmonary disease were found on routine chest X-ray in 34% of cases. Laboratory confirmation of TB was made in 88% of cases, with typical histopathology in 90% and isolation of Mycobacterium tuberculosis in 69% of specimens submitted for analysis. Drug resistance was confined to isolates from South-East Asian patients. (Aust NZ J Med 1987; 17: 507–511).     

The Diagnosis of Absence of the Corpus Callosum by Ultrasound

A case of absence of the corpus callosum is described in which the correct diagnosis was made by ultrasonography. The diagnosis led to appropriate investigations and the subsequent discovery of associated hypothalamic hypopituitarism.     

Femoral Vasodilation to Cromakalim is Blocked by U37883A,a Non-sulphonylurea that Selectively Inhibits KATP Channels

The purpose of the present study was to determine the effects of U37883A, a non-sulphonylurea inhibitor of K_ATP channels, in the femoral vascular bed of the anaesthetized dog. Administration of U37883A, 4-morpholinecarboxamidine-N-1-adamentyl-N-cyclohexyl hydrochloride (2·5 mg kg^?1, i.v.), significantly inhibited the femoral vasodilator response to intra-femoral arterial injection of cromakalim, an activator of K_ATP channels. In contrast, U37883A had no effect on the femoral vasodilator responses to nitroglycerin, isoprenaline, 5-HT, or 5-carboxamidotryptamine, suggesting this agent is a novel and selective inhibitor of hindlimb vasodilation induced by K_ATP-channel activation. Since U37883A did not significantly alter baseline femoral blood flow and femoral vascular resistance, the present data suggest that K_ATP channels do not contribute, in large measure, to regulating the canine femoral vascular bed under resting conditions in-vivo.     

一个中国先天性有汗性外胚层发育不良家系的GJB6基因筛查

目的: 先天性有汗性外胚层发育不良是一种常染色体显性遗传病,GJB6基因突变与之相关。调查一个来自中国的先天性有汗性外胚层发育不良家系与GJB6基因的关系。方法: 收集一个共有17个家系成员(患者8人,5男3女)的先天性有汗性外胚层发育不良家系,采集家系成员的外周血,抽提DNA。然后针对GJB6基因的每个外显子设计引物,应用聚合酶链式反应(PCR)方法扩增GJB6基因的整个编码区,测序、筛查突变。结果: 通过对家系患者的GJB6基因筛查,发现了一个杂合错义突变c.31G>A(p.G11R)。结论: GJB6基因错义突变c.31G>A(p.G11R)导致该家系先天性有汗性外胚层发育不良。     

The Use of Transcranial Doppler in the Hemodynamic Assessment of Implanted Pacemakers

Twenty patients with DDD pacemakers had their intracranial cerebral circulation assessed in different pacing modes, using transcranial Doppler. The studies were performed at the vertebral artery in a sitting position. Although DDD pacing was pre/ered to VVI pacing in 18 of the 20 patients, the figures did not reach statistical significance. There was no stotistical difference in maximal blood flow velocity between DDD pacing at 60 and 80 beats/min. Varying the AV interval from 150–250 msec also demonstrated no clear difference in maximal peak Doppler velocity, in the group as a whole, though there was a greater individual preference for 150 msec. Transcranial Doppler assessment of the hemodynamics of the cerebral circulation is of limited value as an indicator of mode or rate preference in the pacemaker population.     

Mechanisms of Late Stent Malapposition After Primary Stenting in ST-Elevation Myocardial Infarction: A Subanalysis of the Selection Trial

Background: One of the major predictors of late stent malapposition (LSM) is primary stenting in acute myocardial infarction. However, mechanisms of LSM are still under debate.
Methods: Patients with ST-elevation myocardial infarction (STEMI) and enrolled in the SELECTION trial (38 patients in the paclitaxel-eluting stent, PES, and 35 in the bare metal stent, BMS, cohort) were retrospectively analyzed to evaluate LSM, by means of intravascular ultrasound (IVUS) data recorded at the index and 7-month follow-up procedures.
Results: Stent malapposition was documented in 21 lesions in 21 patients (28.8%): in 8 of these 21 patients (38.1%) it was LSM. Although statistical significance was not reached, LSM was more frequent after PES than BMS implantation (15.8% vs. 5.7%). LSM was mainly located within the body of the stent (62.5% of the cases). At the LSM segment, a significant increase of vessel area (19.2 ± 3.3 mm² vs. 21.9 ± 5.3 mm², P = 0.04) and a reduction of plaque area (12.6 ± 4.6 mm² vs. 9.1 ± 3.9 mm², P = 0.04) were observed at IVUS between the index and follow-up procedure.
Conclusions: After primary stenting for STEMI, LSM seems to be more frequent after PES rather than BMS implantation. In the STEMI setting, possible mechanisms leading to LSM include positive remodeling and plaque mass decrease.     

Trypanosoma cruzi infection in mice enhances the membrane expression of low-affinity Fc receptors for IgG and the release of their soluble forms

The membrane expression of low-affinity Fc receptors for IgG (FcγRII/III) on cells and the number of FcγRII/III(+) cells were studied by flow cytometry, using the 2-4G2 MoAb, in mice infected by Trypanosoma cruzi. Cells from spleen, mesenteric lymph nodes and peritoneum were collected on days 10, 20, 30 and 40 post infection (p.i.). The in vivo serum level of soluble FcγRII/III, as well as its in vitro release by cells from infected mice were studied. Parasitaemia and IgG1, IgG2a and IgG2b T. cruzi-specific antibody titres were also recorded. Both the expression of FcγR on cell membrane and the absolute number of FcγR(+) cells increased in spleen and in mesenteric lymph nodes, but not in peritoneum. The modifications in spleen occurred in the early and late parasitaemic phase of infection, i.e., before and after detection of T. cruzi-specific antibodies (from day 10 to 40 p.i.). In mesenteric lymph nodes, the variations were observed only in the early acute infection, when antibodies were not yet detectable at significant levels (on days 10 and 20 p.i.). Higher levels of soluble FcγR were detected in sera and in culture supernatants of spleen and lymph node cells from day 20 to 40 p.i. These results show that T. cruzi infection in mice upregulates the expression and the release of FcγRII/III, in the acute phase of infection, before as well as after the rise of antibody response.