Lack of clonal BCRA2 gene deletion on chromosome 13 in chronic lymphocytic leukaemia

Chromosome 13q deletion is among the most common cytogenetic abnormalities in chronic lymphocytic leukaemia (CLL). We investigated the 13q14.3 deletion in 44 CLL patients by Southern blotting following purification of clonal B CLL cells to >90%. Two sets of probes were used to investigate the site of clonal deletion, the D13S25 and D13S319 markers (at 13q14.3) and probes for exons 11 and 26-27 of the BRCA2 gene (at 13q12). Homozygous and heterozygous deletion at the 13q14.3 region was found in five and 17 patients, respectively. Despite the recent report of the BRCA2 gene involvement in >80% of CLL patients, we failed to detect a single case of homozygous or heterozygous deletion involving the 13q12 region. Our data support previous findings that the 13q14.3, and not the 13q12 region, is the major site of candidate tumour suppressor gene(s) in CLL.     

A trematode metacercaria causing gill cartilage proliferation in steelhead trout from Oregon

The aim of the present study was to determine the association between the presence of Ureaplasma urealyticum in endotracheal aspirates and bronchopulmonary dysplasia (BPD). In addition, a review of similar studies from the English literature is presented. During the period February 1990 until March 1991, 108 mechanically-ventilated infants were included in a prospective study. Endotracheal aspirates were cultured for U. urealyticum. Birth weight, gestational age and development of BPD was recorded. Cultures were positive in 23 infants, resulting in a 21% colonization. The infants with positive cultures had a significantly lower gestational age (mean 28.9 vs 31.5 weeks; range 25-40 vs 25-42 weeks; p=0.0014). A positive U. urealyticum culture was not associated with a low birth weight (mean 1,390 vs 1,690 g; range 675-4,090 vs 700-3,600 g; p=0.0712). A positive U. urealyticum culture was significantly associated with BPD (p=0.0373). However, after correction for gestational age by logistic regression analysis, BPD failed to correlate with the presence of positive U. urealyticum cultures. A MEDLINE search of the English language literature was performed to identify all studies having the association of U. urealyticum colonization and BPD. Fourteen controlled studies were found. Five studies found no significant association between U. urealyticum colonization and BPD. In two studies, after correction for gestational age, the association between U. urealyticum colonization and BPD did not remain significant. In five studies with a significant association between U. urealyticum colonization and BPD, no correction for gestational age had taken place. In conclusion, U. urealyticum colonization is not associated with the development of bronchopulmonary dysplasia. U. urealyticum is often associated with gestational age and/or low birth weight; to investigate the association between U. urealyticum and bronchopulmonary dysplasia correction for both parameters should be made.     

On the molecular etiology of decreased arachidonic (20:4n-6), docosapentaenoic (22:5n-6) and docosahexaenoic (22:6n-3) acids in Zellweger syndrome and other peroxisomal disorders

Alterations in the metabolism of arachidonic (20:4n-6), docosapentaenoic (22:5n-6), and docosahexaenoic (22:6n-3) acids and other polyunsaturated fatty acids in Zellweger syndrome and other peroxisomal disorders are reviewed. Previous proposals that peroxisomes are necessary for the synthesis of 22:6n-3 and 22:5n-6 are critically examined. The data suggest that 22:6n-3 is biosynthesized in mitochondria via a channelled carnitine-dependent pathway involving an n-3-specific delta-4 desaturase, while 20:4n-6, 20:5n-3 and 22:5n-6 are synthesized by both mitochondrial and microsomal systems; these pathways are postulated to be interregulated as compensatory-redundant systems. Present evidence suggests that 22:6n-3-containing phospholipids may be required for the biochemical events involved in successful neuronal migration and developmental morphogenesis, and as structural cofactors for the functional assembly and integration of a variety of membrane enzymes, receptors, and other proteins in peroxisomes and other subcellular organelles. A defect in the mitochondrial desaturation pathway is proposed to be a primary etiologic factor in the clinicopathology of Zellweger syndrome and other related disorders. Several implications of this proposal are examined relating to effects of pharmacological agents which appear to inhibit steps in this pathway, such as some hypolipidemics (fibrates), neuroleptics (phenothiazines and phenytoin) and prenatal alcohol exposure.     

American Indian adolescent inhalant use

Inhalant use and use patterns, decision-making pertaining to inhalant use, cognitive capacity, cognitive egocentrism, and adherence to traditional ways were studied in a sample of male and female American Indian adolescents residing in a boarding home. Significant differences were not found for gender. Inhalant use group differences were found for only one variable, participation in tribal activities. For males, cognitive ability, cognitive egocentrism and participation in tribal activities were significant predictors of inhalant use/non-use. For females, tribal activities was the only significant predictor.     

A redescription of Cylicocyclus triramosus (Nematoda: Strongyloidea): a parasite of the zebra, Equus burchelli antiquorum

Cylicocyclus triramosus, a rare species of Cyathostominae from the southern African Burchell's zebra (Equus burchelli antiquorum) is redescribed, and a neotype is proposed. The external leaf-crown of the species consists of 30 elements and the internal leaf-crown numerous small and clear elements. The buccal capsule is cylindrical, oval in cross section, and approximately 3 times as wide as deep. The thin walls of the buccal capsule taper anteriorly from a large ringlike, hoop-shaped thickening around the posterior margin. The dorsal gutter is nipple-shaped. The mouth collar is notched dorsally and ventrally. The dorsal ray of the copulatory bursa is slightly elongate and distinctly set off from the lateral lobes. The branches of the dorsal ray have auxiliary branches. Appendages of the genital cone consist of 2 separated, large, semilunar plates with finger-shaped processes on the margins. The vulva-to-anus distance is greater than the tail length. The species is most similar to Cylicocyclus radiatus. Cylicocyclus triramosus differs from all similar species in the presence of dorsal and ventral notches in its mouth collar. In addition, C. triramosus also has a distinctive form of male genital cone appendage. Cylicocyclus radiatus differs further from C. triramosus in lacking a dorsal gutter and having a more elongate dorsal ray and a female tail nearly equal in length to the vulva-to-anus distance.     

Tetraplegia after a tracheal resection procedure

We describe a 27-year-old patient who was admitted to our hospital for a tracheal stenosis caused by an adenocystic carcinoma. A tracheal resection procedure was performed and the head was fixed to the anterior chest wall by two sutures. Postoperatively he became tetraplegic, from which he completely recovered after the sutures were removed. We think that the decreased blood flow in the arterial spinal artery with flexion of the neck in combination with hypotension was the direct cause of this major complication.