Abacavir once or twice daily combined with once-daily lamivudine and efavirenz for the treatment of antiretroviral-naive HIV-infected adults: results of the Ziagen Once Daily in Antiretroviral Combination Study

The long intracellular half-life of abacavir (ABC) supports its once-daily use, and this would be expected to simplify treatment if ABC could be given as part of a complete once-daily regimen. A randomized double-blind clinical trial compared the efficacy and safety of 600 mg of ABC administered once daily (n = 384) versus 300 mg of ABC administered twice daily (n = 386) in combination with 300 mg of lamivudine (3TC) and 600 mg of efavirenz (EFV) administered once daily in antiretroviral-naive patients over 48 weeks. The baseline median plasma HIV-1 RNA level was 4.89 log10 copies/mL (44% with viral load >100,000 copies/mL), and the median CD4 cell count was 262 cells/mm. ABC administered once daily was non-inferior to the twice-daily regimen, with 66% and 68% of patients in these respective treatment arms achieving a confirmed plasma HIV-1 RNA level <50 copies/mL (95% confidence interval: -8.4%, 4.9%). The ABC once-daily and twice-daily regimens were similar with respect to infrequency of virologic failure (10% vs. 8%), emergence of resistance mutations, CD4 cell increases from baseline (median, 188 vs. 200 cells/mm), safety profile, and incidence of ABC-related hypersensitivity reactions (9% vs. 7%). ABC administered once daily in combination with 3TC and EFV administered once daily was non-inferior to the ABC twice-daily dosing schedule when combined with 3TC and EFV over 48 weeks.     

The ATAC ('Arimidex', Tamoxifen, Alone or in Combination) adjuvant breast cancer trial: baseline endometrial sub-protocol data on the effectiveness of transvaginal ultrasonography and diagnostic hysteroscopy

BACKGROUND: The 'Arimidex', Tamoxifen, Alone or in Combination (ATAC) trial is a randomized, double-blind trial comparing anastrozole ('Arimidex'), alone or in combination with tamoxifen, relative to tamoxifen alone as 5 year adjuvant treatment for post-menopausal women with early breast cancer. Since tamoxifen is associated with endometrial pathology, the ATAC endometrial sub-protocol was initiated to establish the background prevalence of intrauterine pathology, and to assess prospectively the incidence and nature of intrauterine changes following endocrine therapy. Another aim was to provide data from which advice could be generated on the best endometrium screening method for patients receiving tamoxifen. METHODS: Patients underwent endometrial assessments at entry to the sub-protocol. The baseline investigations comprised transvaginal ultrasound scanning (TVUS), a hysteroscopy and an endometrial biopsy. RESULTS: A total of 285 gynaecologically asymptomatic women from 31 centres in 10 countries entered the endometrial sub-protocol. The mean uterine volume was 47.7 cm3. The median endometrial thickness overall was 3 mm. Twenty-four histologically confirmed, pathological changes were observed. Twenty-three pathologies were confirmed by TVUS, and 21 were identified by hysteroscopy and confirmed by histopathology. Women with or without intrauterine pathology had median endometrial thickness of 5 and 3 mm respectively. CONCLUSIONS: The presence of pathology was associated with increased endometrial thickness. The relative sensitivity and specificity of hysteroscopy and endometrial thickness for the diagnosis of endometrial pathology was comparable to other studies. If screening of the endometrium prior to treatment is appropriate, this study supports the use of an endometrial thickness of 3 mm, as assessed by TVUS, as a threshold for needing further investigation. This study demonstrates that if the endometrial thickness is >3 mm, hysteroscopy and biopsy is the optimal method of detecting intrauterine pathology in women with breast cancer who are about to commence endocrine treatment.     

Zur histogenese und cytogenese des tapetum lucidum cellulosum der katze

Zusammenfassung Die postnatale Entwicklung des Tapetum lucidum cellulosum der Katze wird mit licht- und elektronenmikroskopischen Methoden untersucht. Bereits am ersten postnatalen Tag sind im Bereich des prospektiven Tapetum zwei Zellarten voneinander zu unterscheiden: 1. mesenchymale Bindegewebszellen und 2. prospektive Tapetumzellen, die durch elektronendichte Tapetumstäbchen gekennzeichnet sind. Die Mesenchymzellen unterteilen als parallel zur Retinaoberfläche ausgebreitete Zellplatten in der Choriodea am hinteren Augenpol den weiten extracellulären Raum in 20–25 etwa 5 m hohe Schichten. Die Tapetumzellen liegen zwischen den Mesenchymzellplatten und wachsen im Verlaufe der ersten vier postnatalen Wochen innerhalb der Schichten in die Breite, bis sie den extracellulären Raum vollständig ausfüllen und als polygonale Zellen direkt aneinander grenzen. Im weiteren Verlauf der Entwicklung werden die Mesenchymzellplatten rückgebildet, so daß bei der adulten Katze die Tapetumzellschichten direkt übereinander liegen und nur von Netzen elastischer und kollagener Fasern getrennt sind.Die von einer Elementarmembran umgebenen Tapetumstäbchen enthalten einen elektronendichten, in den ersten postnatalen Wochen mit einer Periode von 100 Å quergestreiften Kern. Zunächst nehmen sie an Zahl und Länge zu und füllen am Ende der vierten postnatalen Woche, zu Bündeln von parallel verlaufenden Stäbchen geordnet, das Cytoplasma der Tapetumzellen. Dann nehmen die Tapetumstäbchen an Dicke zu, und ihre Querstreifung wird von einem elektronendichten Material überlagert. Die Entwicklung der Tapetumstäbchen hat eine starke Ähnlichkeit mit der in der Literatur beschriebenen Entwicklung von Melanosomen in Melanocyten. Das Tapetum lucidum cellulosum wird als ein dichter Verband hochdifferenzierter extrakutaner Melanocyten angesehen.

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Summary The postnatal development of the tapetum lucidum cellulosum of the cat was studied by light and electron microscopy. Already by the first postnatal day two cell types can be distinguished in the prospective tapeta area: 1. mesenchymal cells and 2. prospective tapetal cells, characterized by electron dense, membrane bound, rod-like inclusions. The flattened mesenchymal elements form 20–25 separate layers of cells, which are arranged parallel to the surface of the retina, subdividing the extracellular space of the chorioidea at the posterior pole of the eye into 5 m high compartments. These compartments contain the tapetal cells which enlarge (in their longitudinal axis) during the first four weeks post partum until they occupy the extracellular space almost completely. At this stage, the tapetal cells are polygonal in shape and closely attached to each other. During the subsequent period of development there is a gradual involution of the mesenchymal cell plates. Thus, in adult cats the individual layers of tapetal cells are only separated from each other by networks of collagen and elastic fibers.The tapetal rods are bound by unit membranes and contain an electron dense core which, during the early postnatal weeks, exhibits a periodic cross-striation (100 Å). The tapetal rods increase in number and length during the first four weeks post partum; by the end of the fourth week, they occupy the whole cytoplasm of the tapetal cells. Parallelly arranged rods are grouped into individual bundles coursing inside the cytoplasm in different directions. Thereafter, the tapetal rods increase in thickness and their cross-striation becomes obscured by an electron dense material. This development of the tapetal rods closely resembles that of melanosomes.Thus the tapetum lucidum cellulosum can be regarded as a compact tissue made up of modified extracutaneous melanocytes.

Auszugsweise vorgetragen auf der 69. Versammlung der Anatomischen Gesellschaft in Kiel, Juni 1974.     

急性鸭乙型肝炎病毒感染病毒清除机理研究

目的 :进一步阐明嗜肝病毒自然感染过程中病毒清除机理。方法 :7只 2～ 3月龄成年重庆麻鸭静脉接种 10～ 2 0mlDHBV阳性血清 (5× 10 8～ 1× 10 9genome) ,接种后每周采血检测外周血中DHBVDNA、DHBsAg和特异抗体的产生 ;感染后第10、35天分离外周血单个核细胞用于抗原特异细胞增殖实验 ;第 5、30、6 0天取肝组织标本进行DHBVDNASouthern杂交、DHB sAg免疫组化及肝组织病理检测。结果 :DHBV感染成年鸭在 1～ 2w潜伏期后出现急性、一过性感染 ,感染高峰期肝内存在多拷贝的DHBV所有复制中间体形式 ,包括cccDNA。进一步分析显示病毒血症的消失是在快速抗原特异细胞增殖反应和高滴度特异抗体产生之后 ;与此同时 ,整个急性感染期间 ,肝细胞并无明显的损害。结论 :非细胞直接损伤机制在嗜肝病毒清除过程中发挥了重要作用。     

Identification of a type 1 diabetes-associated CD4 promoter haplotype with high constitutive activity

CD4 is a candidate gene in autoimmune diseases, including Type 1 diabetes mellitus (T1DM), because the CD4 receptor is crucial for appropriate antigen responses of CD4(+) T cells. We previously found linkage between a CD4-1188(TTTTC)(5-14) promoter polymorphism and T1DM. In the present study, we screened the human CD4 promoter for mutations and identified three frequent single nucleotide polymorphisms (SNPs): CD4-181C/G, CD4-521C/G and CD4-1050T/C. The SNPs are in strong linkage disequilibrium (LD) and association with the CD4-1188(TTTTC)(5-14) alleles, and we observed nine CD4 promoter haplotypes, of which four are frequent. We genotyped the SNPs in 253 Danish T1DM families (1129 individuals) and found evidence for linkage and association of a CD4 (A4(-1188)T(-1050)G(-521)C(-181)) haplotype to T1DM. In reporter studies, we show that (1) the T1DM-associated CD4 haplotype encodes high constitutive promoter activity and (2) the CD4-181G variant encodes higher stimulated promoter activity than the CD4-181C variant. This difference is in part neutralized in the frequently occurring CD4 promoter haplotypes by the more upstream genetic variants. Thus, we report functional impact of a novel CD4-181C/G SNP on stimulated CD4 promoter activity and the identification of a novel CD4 haplotype with high constitutive promoter activity that is linked and associated with T1DM.     

HIV-1 p24 antigen is a significant inverse correlate of CD4 T-cell change in patients with suppressed viremia under long-term antiretroviral therapy

An HIV-1 p24 antigen test involving signal amplification-boosted ELISA of heat-denatured plasma was evaluated prospectively in 55 patients whose viral RNA in plasma had previously been suppressed for at least 6 months under antiretroviral combination therapy. During a median follow-up of 504 days, CD4 counts increased by a median of 62 cells per year. By univariate and multivariate linear regression analysis, the level of p24 antigen as expressed by the absorbance/cutoff ratio was a significant inverse correlate of both the CD4 count in a sample (p =.013) and its annual change in a patient (p <.0001). The p24 antigen retained significance even among 48 individuals whose HIV-1 RNA, apart from occasional blips, remained below 400 copies/mL. Batch-wise retesting of 70 samples from 5 such patients with a further improved procedure showed measurable p24 antigen in all but 1 sample and an inverse correlation with both the CD4 count (p =.0331) and percentage (p <.0001), thus confirming the prospectively generated data. Comparison of p24 antigen and HIV-1 RNA concentrations indicate that the p24 antigen detected in these samples is not associated with viral RNA-containing particles and may originate from other compartments of virus expression.     

Inferring alternative splicing patterns in mouse from a full-length cDNA library and microarray data

Although many studies on alternative splicing of specific genes have been reported in the literature, the general mechanism that regulates alternative splicing has not been clearly understood. In this study, we systematically aligned each pair of the 21,076 cDNA sequences of Mus musculus, searched for putative alternative splicing patterns, and constructed a list of potential alternative splicing sites. Two cDNAs are suspected to be alternatively spliced and originating from a common gene if they share most of their region with a high degree of sequence homology, but parts of the sequences are very distinctive or deleted in either cDNA. The list contains the following information: (1) tissue, (2) developmental stage, (3) sequences around splice sites, (4) the length of each gapped region, and (5) other comments. The list is available at http://www.bioinfo.sfc.keio.ac.jp/intron. Our results have predicted a number of unreported alternatively spliced genes, some of which are expressed only in a specific tissue or at a specific developmental stage.     

Exploring cancer register data to find risk factors for recurrence of breast cancer – application of Canonical Correlation Analysis

Background  

A common approach in exploring register data is to find relationships between outcomes and predictors by using multiple regression analysis (MRA). If there is more than one outcome variable, the analysis must then be repeated, and the results combined in some arbitrary fashion. In contrast, Canonical Correlation Analysis (CCA) has the ability to analyze multiple outcomes at the same time.     

Drug resistance mutations and newly recognized treatment-related substitutions in the HIV-1 protease gene: prevalence and associations with drug exposure and real or virtual phenotypic resistance to protease inhibitors in two clinical cohorts of antiretroviral experienced patients

This study aimed at identifying HIV-1 protease amino acid changes associated with protease inhibitor (PI) exposure and susceptibility. New amino acid substitutions were correlated with the number of experienced PIs, reaching statistical significance only for those at positions 3, 44, and 74. The correspondence multivariate model demonstrated that > or =3 experienced PIs and substitutions or mutations at positions 3, 46, 54, 73, 74, and 84 were correlated with PI cross-resistance, including resistance for lopinavir and amprenavir in this cohort of patients who were naive for these drugs.