A test of the chromosomal theory of ecotypic speciation in Anopheles gambiae

The role of chromosomal inversions in speciation has long been of interest to evolutionists. Recent quantitative modeling has stimulated reconsideration of previous conceptual models for chromosomal speciation. Anopheles gambiae, the most important vector of human malaria, carries abundant chromosomal inversion polymorphism nonrandomly associated with ecotypes that mate assortatively. Here, we consider the potential role of paracentric inversions in promoting speciation in A. gambiae via "ecotypification," a term that refers to differentiation arising from local adaptation. In particular, we focus on the Bamako form, an ecotype characterized by low inversion polymorphism and fixation of an inversion, 2Rj, that is very rare or absent in all other forms of A. gambiae. The Bamako form has a restricted distribution by the upper Niger River and its tributaries that is associated with a distinctive type of larval habitat, laterite rock pools, hypothesized to be its optimal breeding site. We first present computer simulations to investigate whether the population dynamics of A. gambiae are consistent with chromosomal speciation by ecotypification. The models are parameterized using field observations on the various forms of A. gambiae that exist in Mali, West Africa. We then report on the distribution of larvae of this species collected from rock pools and more characteristic breeding sites nearby. Both the simulations and field observations support the thesis that speciation by ecotypification is occurring, or has occurred, prompting consideration of Bamako as an independent species.     

Numerical chromosomal abnormality in gastric MALT lymphoma and diffuse large B-cell lymphoma

Background: We investigated numerical chromosomal abnormalities, using the fluorescence in situ hybridization (FISH) method, in gastric mucosa-associated lymphoid tissue (MALT) lymphoma and diffuse large B-cell lymphoma (DLBL). We also compared the histopathological findings, including the presence or absence of Helicobacter pylori infection, with the analytical results. Methods: Sixteen patients who underwent operation for malignant gastric lymphoma in our department were divided into three groups: patients with low-grade gastric MALT lymphoma (l-MALT; n = 5), those with high-grade gastric MALT lymphoma (h-MALT; n = 8), and those with DLBL (n = 3). Numerical abnormalities of chromosomes 8, 9, 12, and 17 were investigated by the FISH method, and the presence or absence of H. pylori infection was microscopically examined. Results: Numerical abnormality was observed in chromosome 12 in 11 patients (68.8%), in chromosome 8 in 10 (62.5%), and in chromosome 17 in 5 (31.3%), showing a high frequency. H. pylori infection was detected in 80% and 50% of patients with l-MALT and h-MALT, respectively, but no H. pylori infection was observed in patients with DLBL. Conclusions: A new biological characteristic of gastric MALT lymphoma was obtained, i.e., a high frequency of numerical abnormalities of chromosomes 12, 8, and 17. There was no correlation between the numerical chromosomal abnormalities and the clinicopathological findings. Received: September 5, 2001 / Accepted: February 22, 2002 Acknowledgments. We sincerely appreciate the instruction and cooperation provided by Mr. A. Furuhata, Mr. S. Nakamura, and the staff, Department of Collaborative Pathology, Juntendo University, Tokyo, Japan. Reprint requests to: I. Watanobe     

Dichorionic twin pregnancy with sirenomelia and chromosomal anomaly in 1 fetus: A case report

Rationale:Sirenomelia is a rare congenital malformation that threatens fetal survivals. The cases in which twin with sirenomelia and chromosomal abnormality have been seldomly reported. We reported a dichorionic twin case in which one twin had sirenomelia, the other twin had a normal phenotype, and they had different chromosomal abnormalities.Patient concerns:The abnormal twin was found at 22 weeks by ultrasound. The sirenomelia fetus was complicated with a thoracic stenosis, enlarged rectum without anal opening, the absence of bilateral kidneys, a single umbilical artery, a single lower limb, the abnormal curvature of spine, double outlet of right ventricle, which were the indicatives of the chromosome detection.Diagnosis:The copy number variation of the sirenomelia fetus was detected as a deletion of 4.8Mb in 11p11.12-11q11. The co-twin was found with del(Y)(q11.223q11.23), which was as the same as his father''s. The mother had normal chromosome. The parents had normal phenotypes. It was firstly reported a microdeletion with sirenomelia fetus.Interventions:There was no specific treatments for the twins.Outcomes:Intrauterine death of the sirenomelia fetus was found at 27 weeks and postnatal death after inevitable abortion happened to the co-twin.Lessons:Prenatal ultrasound was responsible for recognizing sirenomelia, and the detailed ultrasound scanning and chromosome detection should be done for the co-twin. The etiology of sirenomelia remains unclear, and genetic detection is also necessary for its pathogenesis research.     

低中度近视EPI- LASIK术后视觉质量探讨

目的：：综合评价低中度近视机械法激光上皮下角膜磨镶术( EPI-LASIK)后视觉质量。方法：将行EPI-LASIK 术的60例120眼按等效屈光度( SE)分为两组：低度近视组(60眼),中度近视组(60眼)。测量术前和术后1 wk;1,6 mo的客观视力、像差、对比敏感度和眩光敏感度并进行比较。结果：术后两组裸眼视力( UCVA )均优于术前最佳矫正视力(UCVA)(P<0.05);两组术后6mo 总高阶像差值RMS比较有统计学差异( P<0.05)。两组术前及术后6mo高阶像差值比较均有统计学差异(P<0.05);术后1wk;1mo两组在五个频率上均有统计学差异(P<0.05);术后6 mo低度近视组恢复至术前水平,中度近视组在高频区(18.0c/d)和术前有统计学差异(P<0.05);术后1wk两组在3.0,6.0,12.0,18.0c/d频率上差异均有统计学差异(均P<0.05),术后1mo两组在12.0,18.0c/d频率上有统计学差异(均P<0.05),术后6mo两组均恢复至术前水平,比较均无明显差异。结论：低中度近视 EPI-LASEK 术后早期的视觉质量较差,中晚期有较好的视觉质量。     

Protecting effect of caffeine against vinblastine (an anticancer drug) induced genotoxicity in mice

Vinblastine a DNA non-intercalating agent has wide application against several human neoplasms, and found to cause cytogenotoxicity. In this study, clastogenotoxicity of vinblastine (1.5?mg/kg b w) and its prevention by caffeine at different doses (25, 50 and 100?mg/kg b w) administered intraperitoneally was assessed in in vivo mice. It was found that micronucleus level had decreased significantly (up to 28.8%) in 100?mg caffeine treated group at 30?h post treatment. However, it did not exhibit protective effect against chromosomal aberration in spaermatogonial cells at 24?h post treatment. The frequencies of aberrant primary spermatocytes had decreased significantly in 25 and 100?mg caffeine at 4th week of post treatment. Similarly, in 100?mg of caffeine administered, abnormal sperm level had reduced (4.01%) significantly at 8th week post treatment. Thus, caffeine decreased the vinblastine induced chromosomal aberrations and mitotic index in bone marrow cells. In conclusion, this study shows that caffeine exerts protective effect against vinblastin induced cytogenotoxicity. Further studies on molecular mechanism are interesting in order to develop it as an effective drug in cancer chemotherapy.     

Wentilactone A的遗传毒性评价

目的 检测Wentilactone A的遗传毒性。方法 应用经典遗传毒性检测组合(Ames试验、体外培养CHO细胞染色体畸变试验和小鼠骨髓微核试验)检测Wentilactone A的遗传毒性。结果 Ames试验结果提示,Wentilactone A在每皿5 000、500、50、5、0.5 μg 5个剂量下,在加和不加代谢活化系统（S9）时,对鼠伤寒沙门菌均无致突变性。CHO细胞染色体畸变试验结果提示,在终浓度23.74、47.48、94.96 μg/ml 3个剂量组,在加和不加S9中,于作用4 h和24 h的条件下培养的CHO细胞,均未诱发染色体畸变。小鼠骨髓微核试验在100、200、400 mg/kg 3个剂量下作用24 h以及400 mg/kg剂量下作用48 h对骨髓细胞的微核诱发率,与溶剂对照组比较均无显著差异（P>0.05）。结论 Wentilactone A对鼠伤寒沙门菌无致突变性,对CHO细胞的染色体无致畸变作用,对ICR小鼠无诱发骨髓细胞微核的效应。上述结果提示Wentilactone A不具有遗传毒性和潜在致癌性。     

Multicolour fluorescence in situ hybridization analysis of t(14;18)-positive follicular lymphoma and correlation with gene expression data and clinical outcome

In order fully to identify secondary chromosomal alterations, such as duplications, additions and marker chromosomes that remained unresolved by G banding, 60 cases of t(14;18)-positive follicular lymphoma (FL) were analysed by multicolour karyotyping techniques [multicolour fluorescence in situ hybridization (MFISH)/multicolour banding for chromosome 1 (MBAND1)]. A total of 165 additional structural chromosomal aberrations were delineated. An increased frequency of chromosomal gains involving X, 1q, 2, 3q27-q29, 5, 6p11-p21, 7, 8, 11, 12, 14q32, 17q, 18 and 21 and deletions of 1p36, 3q28-q29, 6q, 10q22-q24 and 17p11-p13 was revealed by the MFISH/MBAND1 analysis. Balanced translocations other than t(14;18) were uncommon, whereas unbalanced translocations were numerous. Deletion of 1p36 and duplication of 1p33-p35, 1p12-p21 and 1q21-q41 were regularly involved in chromosome 1 alterations, seen in 53% of the cases. A strong correlation was demonstrated between gains of individual chromosomal bands and increased gene expression, including 1q22/MNDA, 6p21/CDKN1A, 12q13-q14/SAS, 17q23/ZNF161, 18q21/BCL2 and Xq13/IL2RG. Unfavourable overall survival was associated with del(1)(p36) and dup(18q). These data support the notion that translocation events are primarily responsible for FL disease initiation, whereas the unbalanced chromosomal gains and losses that mirror the gene expression patterns characterize clonal evolution and disease progression, and thus provide further insights into the biology of FL.