Sequencing of the alpha-synuclein gene in a large series of cases of familial Parkinson's disease fails to reveal any further mutations. The European Consortium on Genetic Susceptibility in Parkinson's Disease (GSPD)

A mutation in exon 4 of the human alpha-synuclein gene was reported recently in four families with autosomal dominant Parkinson's disease (PD). In order to examine whether mutations in this exon or elsewhere in the gene are common in familial PD, all seven exons of the alpha- synuclein gene were amplified by PCR from index cases of 30 European and American Caucasian kindreds affected with autosomal dominant PD. Each product was sequenced directly and examined for mutations in the open reading frame. No mutations were found in any of the samples examined. We conclude that the A53T change described in the alpha- synuclein gene is a rare cause of PD or may even be a rare variant. Mutations in the regulatory or intronic regions of the gene were not excluded by this study.      

Preliminary observations on polar body extrusion and pronuclear formation in human oocytes using time-lapse video cinematography

In this study, we have used time-lapse video cinematography to study fertilization in 50 human oocytes that had undergone intracytoplasmic sperm injection (ICSI). Time-lapse recording commenced shortly after ICSI and proceeded for 17-20 h. Oocytes were cultured in an environmental chamber which was maintained under standard culture conditions. Overall, 38 oocytes (76%) were fertilized normally, and the fertilization rate and embryo quality were not significantly different from 487 sibling oocytes cultured in a conventional incubator. Normal fertilization followed a defined course of events, although the timing of these events varied markedly between oocytes. In 35 of the 38 fertilized oocytes (92%), there were circular waves of granulation within the ooplasm which had a periodicity of 20-53 min. The sperm head decondensed during this granulation phase. The second polar body was then extruded, and this was followed by the central formation of the male pronucleus. The female pronucleus formed in the cytoplasm adjacent to the second polar body at the same time as, or slightly after, the male pronucleus, and was subsequently drawn towards the male pronucleus until the two abutted. Both pronuclei then increased in size, the nucleoli moved around within the pronuclei and some nucleoli coalesced. During pronuclear growth, the organelles contracted from the cortex towards the centre of the oocyte, leaving a clear cortical zone. The oocyte decreased in diameter from 112 to 106 microm (P < 0.0001) during the course of the observation period. The female pronucleus was significantly smaller in diameter than the male pronucleus (24.1 and 22.4 microm respectively, P = 0.008) and contained fewer nucleoli (4.2 and 7.0 respectively, P < 0.0001). After time-lapse recording, oocytes were cultured for 48 h prior to embryo transfer or cryopreservation. Embryo quality was related to fertilization events and periodicity of the cytoplasmic wave, and it was found that good quality embryos arose from oocytes that had more uniform timing from injection to pronuclear abuttal and tended to have a longer cytoplasmic wave. In conclusion, we have shown that time-lapse video cinematography is an excellent tool for studying fertilization and early embryo development, and have demonstrated that human fertilization comprises numerous complex dynamic events.      

Translocation (4;11) in acute myelogenous leukemia

A child with acute myelogenous leukemia is presented. Cytogenetic analysis of her leukemic cells revealed a (4;11)(q12;q23) translocation. The slight difference in the breakpoint on chromosome #4 from previously reported cases of t(4;11) may account for the degree of myeloid differentiation expressed. Acute leukemia associated with t(4;11) is a unique subgroup that originates in an early myeloid stem cell and carries a poor prognosis.     

A family of closely related bovine viral diarrhea virus recombinants identified in an animal suffering from mucosal disease: new insights into the development of a lethal disease in cattle

Induction of lethal mucosal disease (MD) in cattle is linked to the generation of cytopathogenic (cp) bovine viral diarrhea virus (BVDV) in animals persistently infected with a noncytopathogenic BVDV. In most cases the cp variants are generated by recombination with cellular or viral sequences. BVDV was obtained from the serum of an MD animal and propagated in tissue culture without plaque purification. Analysis of cDNA clones established from RNA of these cells showed that apparently a variety of different viral RNAs were present. Seven of the cDNA clones contained a cellular sequence coding for light chain 3 (LC3) of microtubule-associated proteins 1A and 1B. This insertion had already been found in the cp virus JaCP obtained from the same animal and isolated by plaque purification. Analysis of further plaque-purified cp viruses showed that the diseased animal contained a family of closely related cp BVDV recombinants. A set of viruses with different duplications of viral sequences in their genomes and a variety of defective viral RNAs with deletions were found that all contained the LC3* insertion. For all the recombinants the 3' recombination sites and, in all but one case, also the 5' recombination sites between cellular and viral sequence were identical. Variation between the individual deduced genome structures resulted from different duplications or deletions of viral sequences located upstream of the cellular insertion. These results suggest that within the animal a primary recombinant with a genome containing the LC3* insertion was generated. In a trimming process a set of secondary virus recombinants was generated from this hypothetical primary recombined RNA. These secondary recombinants display genome structures that represent variations of the basic scheme already present in the primary recombinant. Apparently this trimming process that finally led to an outbreak of MD lasted a long time since recombined RNA with the basic genome structure of the cp viruses could be demonstrated in samples already taken a long time before outbreak of the disease.     

The structuring of an allergy index based on IgE-mediated skin sensitivity to common environmental allergens

We computed skin-test sensitivity levels in 485 adults puncture-tested with eight standardized, high-quality inhalant allergens tested at single concentrations. In order to quantitate the "average" IgE-mediated skin sensitivity of each subject, we used both nonparametric and parametric statistical methods to generate two "allergy indices" (Allergy Index I and Allergy Index II) based on sensitivity end-point data from the subpopulations of individuals positive to six of the eight allergens. For the 192 skin test-positive subjects, Allergy Index I and Allergy Index II were significantly correlated with each other (rs = 0.98, p less than 0.001) and with the number of positive skin-test reactions (rs congruent to 0.9, p less than 0.001) as well as with log[total serum IgE] (r congruent to 0.4, p less than 0.01). In 102 ragweed-positive subjects, log[specific IgE to ragweed] was significantly correlated with ragweed-specific "ragweed indices I and II" (r congruent to 0.6, p less than 0.01). Furthermore, the average daily symptom scores reported by 14 ragweed-positive subjects during the ragweed pollination season were significantly correlated with ragweed indices I and II (p less than 0.05). We propose the use of Allergy Index II in epidemiologic and genetic studies of allergic phenotypes as well as in clinical decisions for diagnosis and immunotherapeutic intervention.     

In situ characterization of T lymphocyte subpopulations in leprosy in the mangabey monkey.

Leprosy in the mangabey monkey is an experimental model which is similar both clinically and histologically to human lepromatous leprosy. The immunopathology of these diseases was compared using monoclonal antibodies against T lymphocyte subpopulations in frozen tissue sections with an immunoperoxidase technique. In both mangabey and human lepromatous granulomas OKT4 (or Leu 3a) and Leu 2a cells were scattered among macrophages with greater numbers of Leu 2a as compared with OKT4 (or Leu 3a) cells. The results suggest that from an immunopathological standpoint experimental leprosy in mangabeys will provide a suitable model for the investigation of the pathogenesis of human lepromatous leprosy and for the evaluation of new antileprosy vaccines.     

Effects of a single-dose pretreatment with captopril on the immediate response to nasal challenge with allergen

We performed a double-blind, placebo-controlled, crossover study using 12 subjects to determine the effects of a single 50-mg dose of captopril on the response to nasal challenge with increasing doses of allergen. Levels of kinins, histamine and N-alpha-p-tosyl-L-arginine methyl ester (TAME)-esterase activity were measured in nasal lavages, and symptom scores and the number of sneezes were recorded. Captopril had no significant effects on histamine, TAME-esterase, sneezing or symptom scores. Peak postchallenge kinin levels, however, were significantly elevated (p less than 0.05) compared to placebo, while an increase in the magnitude of the dose-response curve was of marginal significance (p = 0.058). Thus, captopril causes increases in the kinin levels in nasal secretions during the allergic response. If increased kinin levels persist or worsen with chronic therapy, it is possible that they could exacerbate allergic symptoms during repeated seasonal exposure.     

Genetic ascertainment with heterogeneous risk

Analysis of the bias of ascertainment is reformulated to deal with more general patterns commonly encountered in practice. The goal is to provide a unifying theory that will both replace the traditional, rather piecemeal, treatment of the problem and free it from certain restrictive assumptions. A compact algebraic method is furnished for analyzing the properties of the distributions by means of the probability generating function (PGF). The scope of the generalization is illustrated by applying it to the various classical patterns of bias of ascertainment. It is extended to other patterns in which the conditions of ascertainment, though more plausible, are also logically more complicated. It also accommodates cases hitherto inadequately dealt with, such as where the segregation ratios are heterogeneous (for example because of age-dependence); and cases where the ascertainment function is of arbitrary form and denies us such valuable, but demanding, assumptions as independence. Not only is the result unifying, but it leads to usable results in specific application such as diseases that depend on age or birth order. While the commonest applications are in human genetics, there are many other issues (such as the use of batteries of tests) in which it is equally important.     

Inflammatory mediators in late antigen-induced rhinitis

To investigate the mechanisms responsible for the late-phase response in patients with allergies, we measured four biochemical mediators (histamine, tosyl-L-arginine methyl ester [TAME]-esterase, kinin, and prostaglandin D2) in nasal secretions after nasal challenge with pollen antigen in 12 patients with allergy. Nine patients had an immediate response and a recurrence of symptoms 3 to 11 hours after challenge. The clinical symptoms during recurrence were accompanied by a second increase in levels of histamine, TAME--esterase, and kinin over base-line values, although kinin levels were lower than during the immediate response. In contrast, although the levels of prostaglandin D2 were significantly increased during the immediate response, they did not increase above base line during the late response. Rechallenge with allergen 11 hours after the initial provocation, however, was associated with reappearance of all four biochemical mediators, including prostaglandin D2. We conclude that the late response to nasal challenge with allergen is accompanied by a second increase in the concentrations of histamine and TAME--esterase but differs from the immediate response in the lack of prostaglandin D2 production and in the amount of kinin generated. Since histamine is released only by mast cells and basophils and prostaglandin D2 is not produced by basophils, we suggest that these cells are partly responsible for the late-phase response.