Sequence and comparative analysis of the mouse 1-megabase region orthologous to the human 11p15 imprinted domain

A major barrier to conceptual advances in understanding the mechanisms and regulation of imprinting of a genomic region is our relatively poor understanding of the overall organization of genes and of the potentially important cis-acting regulatory sequences that lie in the nonexonic segments that make up 97% of the genome. Interspecies sequence comparison offers an effective approach to identify sequence from conserved functional elements. In this article we describe the successful use of this approach in comparing a approximately 1-Mb imprinted genomic domain on mouse chromosome 7 to its orthologous region on human 11p15.5. Within the region, we identified 112 exons of known genes as well as a novel gene identified uniquely in the mouse region, termed Msuit, that was found to be imprinted. In addition to these coding elements, we identified 33 CpG islands and 49 orthologous nonexonic, nonisland sequences that met our criteria as being conserved, and making up 4.1% of the total sequence. These conserved noncoding sequence elements were generally clustered near imprinted genes and the majority were between Igf2 and H19 or within Kvlqt1. Finally, the location of CpG islands provided evidence that suggested a two-island rule for imprinted genes. This study provides the first global view of the architecture of an entire imprinted domain and provides candidate sequence elements for subsequent functional analyses.     

Frequency of stages of the seminiferous cycle in the thick-tailed bush baby (<Emphasis Type="Italic">Otolemur garnetti</Emphasis>), a prosimian primate: possible phylogenetic implications?

Spermatogenesis in the thick-tailed bush baby, Otolemur garnetti, was studied using light microscopy. The stages and stage frequencies of the cycle of the seminiferous epithelium were determined using semithin sections stained with methylene blue-azure II. These sections were obtained from the testes of six healthy adult males (n=6). They revealed 11 stages of the seminiferous epithelial cycle in this species. The mean relative frequencies of the stages I–XI were 10.9, 6.0, 5.9, 7.3, 13.2, 10.7, 11.7, 9.2, 7.6, 8.9 and 8.6, respectively. Comparisons were made between the frequency data in the thick-tailed bush baby and equivalent data in the rat, hamster, macaque, baboon, chimpanzee and man. There was a significant correlation (P<0.05) between the Otolemur data and equivalent stage frequency data of two rodent species (rat and hamster) and monkey (Macaca arctoides). However, there was no significant correlation between the present data and those of the baboon, chimpanzee and man. Possible phylogenetic implications of these findings are discussed.     

Species composition of the Anopheles gambiae complex (diptera: Culicidae) at two sites in western Kenya

At two sites in the Kisumu area of western Kenya, the species composition of the Anopheles gambiae complex was determined by analysis of ovarian polytene chromosomes. Of 1,915 females, 26.1% were An. arabiensis Patton and 73.9% were An. gambiae Giles; one arabiensis x gambiae hybrid was identified. No major differences in the proportions of An. arabiensis and An. gambiae were observed between sites or between years. The ratio of An. arabiensis/An. gambiae was 6.7:1 (n = 231) in cow-baited traps, 0.2:1 (n = 1,525) in indoor resting samples, and 0.5:1 (n = 145) in all-night human bait catches. The proportion of An. arabiensis decreased progressively from 50.0% to 8.3% (n = 1,129) during 11 wk from September to November 1987; this change was correlated negatively with night temperature and positively with temperature range. In cow-baited traps, 97.4% (n = 194) of An. arabiensis were cow-fed and 95.8% (n = 1,054) of An. gambiae from indoor resting collections were human-fed. In indoor collections, 37.2% (n = 215) of An. arabiensis were cow-fed and 23.1% (n = 26) of An. gambiae from cow traps were human-fed. This demonstrates post-blood-feeding endophily by An. arabiensis and suggests post-blood-feeding exophily by An. gambiae. Malaria infection rates were higher for An. gambiae than for An. arabiensis by a ratio of 3:1 in 1986 (by Plasmodium falciparum ELISA) and 2.3:1 in 1987 (by dissection). Despite the higher proportion of infective An. gambiae, both species in this area serve as efficient vectors through their remarkably stable contact with the human population as demonstrated by their blood feeding and resting behavior.     

Optical penalization can improve vision after occlusion treatment

BACKGROUND: Optical penalization (OP) has previously been shown to successfully maintain vision in amblyopic eyes of older children when patching compliance is poor and when vision decreases once patching is discontinued. This study shows that the final vision in optically penalized eyes is often better than the vision obtained after patching alone. SUBJECTS AND METHODS: During the 5-year period from January 1992 to February 1997, 28 children aged between 3.7 and 8.2 years (average age, 6.5+/-1.1 years) were optically penalized for an average of 1.5+/-0.75 years. The maximum length of penalization was 3.3 years, whereas the minimum time was 6 months. There were 21 children with strabismic amblyopia and 7 children with anisometropic amblyopia. All 28 children had worn a patch to achieve their best visual levels and then had shown a loss of best vision when occlusion was stopped. Patching was usually resumed and continued until the previous best vision was obtained; at this point OP was started to "maintain" vision. Eighteen of the 28 children have discontinued penalization and have been followed up an average of 1(1/2) years. RESULTS: Twenty-six (93%) of the 28 patients showed an increase in best vision from that found at the conclusion of patching, and 2 patients maintained their vision at the initial level. The average visual acuity at the start of penalization was 20/50 (0.42+/-0.11 logarithm of the minimum angle of resolution [log MAR]). Final average visual acuity was 20/27 (0.15+/-0.12 log MAR). The average increase in vision was nearly 3 lines or 0.27+/-0.12 log MAR. CONCLUSION: OP alone (without the use of pharmacologic agents such as atropine) not only maintains vision after patching therapy, but also appears to improve the final visual outcome.     

Analysis of location and integrity of the human PITSLRE (p58(cdc2L1)) genes in neuroblastoma cell genomes

The family of PITSLRE kinase genes, located in chromosome 1p36, has recently been associated with neuroblastoma tumorigenesis. In order to evaluate the role of these genes as putative tumor suppressor genes, we have analyzed the integrity of the coding region in primary tumors and its location relative to a neuroblastoma consensus deletion. A subset of aggressive neuroblastoma tumors with allelic loss of different parts of chromosome 1p were investigated. Single-strand conformation polymorphism (SSCP), heteroduplex (HD) and sequencing analysis of tumor DNA did not reveal any significant changes in the coding region. In particular, a primary tumor with an interstitial allelic deletion in 1p36 did not reveal concomitant loss of heterozygosity of the PITSLRE gene region when analyzed with a C/T DNA sequence polymorphism in exon 5 of PITSLRE1. FISH analysis on neuroblastoma cell lines with small interstitial deletions and with a balanced translocation in 1p36 revealed that the PITSLRE gene cluster was localized distal to the neuroblastoma consensus deletion. against an involvement of the PITSLRE genes in neuroblastoma tumorigenesis.     

青霉素高产菌株的推理选育

目的：筛选一株优良的抗生素产生菌。方法：通过人为诱变来动摇产生菌原有的严密控制机制。结果：得到一种抗生素生物合成能力异常的突变株。结论：此方法可过量合成人们所期望的抗生素。     

盐酸特拉唑嗪胶囊的稳定性研究

目的：考察盐酸特拉唑嗪胶囊的稳定性。方法：通过影响因素(强光照射、高温、高温)，加速和留样考察实验，以含量为测定指标，考察胶囊的含量变化。结果：在温度40℃、60℃、光照3500LX及RH75％等因素影响下，胶囊的含量无明显变化。结论：在25℃时，通过经典恒温加速试验推测盐酸特拉唑嗪胶囊的失效期为2年。     

Drop‐offs in the isoniazid preventive therapy cascade among children living with HIV in western Kenya, 2015–2019

IntroductionIsoniazid preventive therapy (IPT) can reduce the risk of tuberculosis (TB) in children living with HIV (CLHIV), but data on the outcomes of the IPT cascade in CLHIV are limited.MethodsWe evaluated the IPT cascade among CLHIV aged <15 years and newly enrolled in HIV care in eight HIV clinics in western Kenya. Medical record data were abstracted from September 2015 through July 2019. We assessed the proportion of CLHIV completing TB symptom screening, IPT eligibility assessment, IPT initiation and completion. TB incidence rate was calculated stratified by IPT initiation and completion status. Risk factors for IPT non‐initiation and non‐completion were assessed using Poisson regression with generalized linear models.ResultsOverall, 856 CLHIV were newly enrolled in HIV care, of whom 98% ([95% CI 97–99]; n = 841) underwent screening for TB symptoms and IPT eligibility. Of these, 13 (2%; 95% CI 1–3) were ineligible due to active TB and 828 (98%; 95% CI 97–99) were eligible. Five hundred and fifty‐nine (68%; 95% CI 64–71) of eligible CLHIV initiated IPT; median time to IPT initiation was 3.6 months (interquartile range [IQR] 0.5–10.2). Overall, 434 (78%; 95% CI 74–81) IPT initiators completed. Attending high‐volume HIV clinics (aRR = 2.82; 95% CI 1.20–6.62) was independently associated with IPT non‐initiation. IPT non‐initiation had a trend of being higher among those enrolled in the period 2017–2019 versus 2015–2016 (aRR = 1.91; 0.98–3.73) and those who were HIV virally non‐suppressed (aRR = 1.90; 95% CI 0.98–3.71). Being enrolled in 2017–2019 versus 2015–2016 (aRR = 1.40; 1.01–1.96) was independently associated with IPT non‐completion. By 24 months after IPT screening, TB incidence was four‐fold higher among eligible CLHIV who never initiated (8.1 per 1000 person years [PY]) compared to CLHIV who completed IPT (2.1 per 1000 PY; rate ratio [RR] = 3.85; 95% CI 1.08–17.15), with a similar trend among CLHIV who initiated but did not complete IPT (8.2/1000 PY; RR = 4.39; 95% CI 0.82–23.56).ConclusionsDespite high screening for eligibility, timely IPT initiation and completion were suboptimal among eligible CLHIV in this programmatic cohort. Targeted programmatic interventions are needed to address these drop‐offs from the IPT cascade by ensuring timely IPT initiation after ruling out active TB and enhancing completion of the 6‐month course to reduce TB in CLHIV.     

Functional significance of the signal transduction pathways Akt and Erk in ovarian follicles: in vitro and in vivo studies in cattle and sheep

Background

The intracellular signalling mechanisms that regulate ovarian follicle development are unclear; however, we have recently shown differences in the Akt and Erk signalling pathways in dominant compared to subordinate follicles. The aim of this study was to investigate the effects of inhibiting Akt and Erk phosphorylation on IGF- and gonadotropin- stimulated granulosa and theca cell function in vitro, and on follicle development in vivo.

Methods

Bovine granulosa and theca cells were cultured for six days and stimulated with FSH and/or IGF, or LH in combination with PD98059 (Erk inhibitor) and/or LY294002 (Akt inhibitor) and their effect on cell number and hormone secretion (estradiol, activin-A, inhibin-A, follistatin, progesterone and androstenedione) determined. In addition, ovarian follicles were treated in vivo with PD98059 and/or LY294002 in ewes on Day 3 of the cycle and follicles were recovered 48 hours later.

Results

We have shown that gonadotropin- and IGF-stimulated hormone production by granulosa and theca cells is reduced by treatment with PD98059 and LY294002 in vitro. Furthermore, treatment with PD98059 and LY294002 reduced follicle growth and oestradiol production in vivo.

Conclusion

These results demonstrate an important functional role for the Akt and Erk signalling pathways in follicle function, growth and development.