A principal components analysis self-organizing map.

We propose a new self-organizing neural model that performs principal components analysis. It is also related to the adaptive subspace self-organizing map (ASSOM) network, but its training equations are simpler. Experimental results are reported, which show that the new model has better performance than the ASSOM network.     

Causes of B chromosome variant substitution in the grasshopper Eyprepocnemis plorans

We have analysed B chromosome frequency for three consecutive years, B transmission rate at population and individual levels, clutch size, egg fertility and embryo–adult viability in a natural population of the grasshopper Eyprepocnemis plorans containing two different B chromosome variants, i.e. B₂ and B₂₄, the second being derived from the first and having replaced it in nearby populations. From 2002 to 2003 the relative frequency of both variants changed, although the differences did not reach significance. A mother–offspring analysis showed no significant effect of any of the two B variants on clutch size, egg fertility or embryo–adult viability, but B₂₄ was more efficiently transmitted than B₂ through males from the 2002 season, which explains the observed frequency change. Controlled crosses, at individual level, showed significant drive through some females for B₂₄ but not for B₂, suggesting that this difference in transmission rate might also be important for the substitution process. The analysis of relative fitness for B₂ and B₂₄ carriers for all fitness components, as a whole, showed a significantly better performance of B₂₄-carrying individuals, suggesting that the cumulative effect of these slight differences might contribute to the replacement of B₂ by B₂₄. Electronic Supplementary Material Supplementary material is available for this article at .     

Conventional and experimental drug therapy in myelofibrosis with myeloid metaplasia

Myelofibrosis with myeloid metaplasia (MMM) is currently classified as a classic (ie, BCR-ABL-negative) myeloproliferative disorder characterized by anemia, multiorgan extramedullary hematopoiesis, constitutional symptoms, and premature death from either leukemic transformation or other disease complications. Stem cell transplantation can be curative, but many patients either are not appropriate candidates or do not choose to accept the significant risks associated with transplantation. Current pharmacologic therapy has been beneficial mainly in terms of palliating disease-associated cytopenias, constitutional symptoms, splenomegaly, and other organ damage from excess myeloproliferation. Novel treatment strategies are under investigation, including targeted inhibition of JAK2^V617F, the activating tyrosine kinase point mutation present in about half of patients with MMM. In this article, we review both the old and new pharmacologic options for MMM.     

Panhypopituitarism as first manifestation of a lung cancer

Pituitary metastases of solid tumours are infrequent, specially as a first manifestation. When they happen, they are usually due to breast or lung cancer and are asymptomatic or produce diabetes insipidus. It is very strange that they produce hormonal deficiency. We present a case report of a bronchogenic adenocarcinoma in a 65-year-old man which began with panhypopituitarism, diabetes insipidus and visual alterations. Magnetic resonance imaging revealed a large sellar mass, with clivus infiltration and invading the right cavernous sinus. The biopsy result was adenocarcinoma metastases from lung cancer.     

Corneal fistulas and their management

We reviewed three representative cases of chronic corneal fistula formation and provide a systematic approach to the assessment and therapeutic alternatives for this problem. In two of our patients, the fistula was managed surgically. The third patient developed endophthalmitis, which resulted in loss of light perception. Chronic corneal fistulization is a rare clinical entity resulting from malapposition of corneal tissue after traumatic, surgical, or infectious perforation. Fistulas may result in prolonged or recurrent hypotony, peripheral anterior synechia formation, or endophthalmitis. Accurate assessment of the risks associated with corneal fistula formation takes into account the type of fistula, its location in the cornea, and the condition of the ocular adnexae. We reviewed the risk factors that will determine the urgency and type of therapy used.     

Prospective study of antigenemia,plasma viremia and lymphocytic viremia in HIV-infected hemophiliacs

A total of 186 blood samples from 24 HIV-1 seropositive hemophiliac patients, monitored every four months for 29 months, were investigated for the presence of viral antigen in plasma. In addition, peripheral blood mononuclear cells (PBMC) were cultured for HIV-1, using normal PBMC as a target for replication. Antigenemia was detected in 51 % of the patients and from PBMC in 87.5 % of the patients. The incidence of HIV isolation in asymptomatic patients (42.8 %) was similar to that found in symptomatic patients (51.4 %). Patients with opportunistic infections had a higher incidence of lymphocytic viremia (p<0.05). Plasma viremia was closely associated (p<0.05) with low CD4+ counts and infection progression. The persistence of antigenemia was also a marker of a poor clinical course. In treated patients, plasma viremia was the marker that better correlated with the clinical course, and it did not appear during the first nine months of therapy. Zidovudine doses of >500 mg/day significantly lowered the appearance of antigenemia and lymphocytic viremia (p<0.05).     

白内障超声乳化吸出及囊袋内人工晶体植入术

为观察和评价超声乳化白内障吸出术的临床效果、特点、并发病及防治措施，对４１　眼白内障施行超声乳化吸出术及小切口（６ｍｍ）囊袋内人工晶体植入术，并以同期的白内障患者４１眼行现代囊外摘除及后房型人工晶体植入做对照。结果：术后６个月，视力≥１．０者占４３．９％＞０．８者占７０．７≥０．５者占９２．７％，均明显高于对照组（Ｐ＜０．００１），术后平均散光为１．０４±０．８１，１，低于对照组（Ｐ＜０．０１）。白内障超声乳化吸出并囊袋内人工晶体植入术的复明效果优于囊外摘除并后房型人工晶体植入术。     

成人高原心脏病临床分型的探讨

本文总结了６８０例成人高原心脏病临床资料，依照其临床表现、Ｘ线、心电图等项检查，提出了临床上较为实用的诊断和分型意见。