Fibronectin binding to thrombin-stimulated platelets: evidence for fibrin(ogen) independent and dependent pathways

Plasma fibronectin binds in a specific and saturable manner to thrombin- stimulated platelets. gamma-Thrombin stimulated 80% as much fibronectin binding to platelets as alpha-thrombin with conversion of less than or equal to 1% of platelet fibrinogen to fibrin. Afibrinogenemic and normal platelets bound similar quantities of fibronectin in the presence of calcium or magnesium-ethylene glycol tetra-acetic acid (EGTA). These observations indicate that fibronectin can interact with platelets without involvement of fibrin or fibrinogen. Nevertheless, two different effects of fibrin(ogen) on fibronectin binding were observed. First, exogenous fibrinogen inhibited fibronectin binding to thrombin-stimulated platelets. This inhibition was unidirectional, as fibronectin did not inhibit fibrinogen binding to ADP or thrombin- stimulated cells. Second, formaldehyde-fixed cells with surface- associated fibrin bound significant quantities of fibronectin. This interaction required calcium and did not occur on fixed cells with or without surface-bound fibrinogen. A portion of the ligand bound to fixed cells with surface-associated fibrin was modified to form a derivative with a molecular weight identical to that of the fibronectin subunit cross-linked to the alpha-chain of fibrin. This high mol wt derivative was also observed to a variable extent with living cells in the presence of magnesium or calcium but not in the presence of magnesium-EGTA. Thus, fibronectin binds to platelets by at least two mechanisms: (1) a fibrin(ogen)-independent pathway that requires divalent ions and is inhibited by exogenous fibrinogen; and (2) a fibrin-dependent pathway with an absolute calcium requirement. With nonaggregated, thrombin-stimulated platelets, the former pathway appears to predominate.     

Efficacy of Crocus sativus L. on reduction of cadmium‐induced toxicity on spermatogenesis in adult rats

Cadmium is a toxic heavy metal element, which probably cause infertility by impairment in spermatogenesis. The present work aimed (i) to study the toxic effect of cadmium on spermatogenesis in rat, as well as (ii) the protective effect of Crocus sativus L. on cadmium‐intoxicated rats. Cadmium chloride was administered intraperitoneally during 16 days at intervals of 48 h between subsequent treatments. Crocus sativus L. was pre‐treated in both of control and cadmium‐injected rats. Animals were sacrificed on day 17 after the first treatment. The left cauda epididymis was removed and immediately immersed into Hank's balanced salt solution for the evaluation of sperm count and viability, and left testis was fixed in 10% formalin for histological evaluation. Following contamination with cadmium, a decrease was observed in the number and viability of cauda epididymis sperm, which were increased by Crocus sativus L. pre‐treatment (P < 0.05). In addition, cadmium decreased both cell proliferation and Johnsen Scores in the seminiferous tubules, which were reversed by Crocus sativus pre‐treatment (P < 0.05). Furthermore, cadmium‐induced decrease in the amount of free serum testosterone as well as an increase in lipid peroxidation activity in the testicular tissue was reversed by Crocus sativus L. (P < 0.05). These findings may support the concept that Crocus sativus L. can improve the cadmium toxicity on spermatogenesis.     

The influence of displacement on shoulder function in patients with minimally displaced fractures of the greater tuberosity

INTRODUCTION: There is little outcome data on functional results after non-operative treatment of greater tuberosity fractures, and no clear evidence in minimally displaced (1-5 mm) fractures of the greater tuberosity showing that the results of non-operative treatments are good enough. This study assesses the relationship between degree of displacement in non-operatively treated patients and shoulder function. MATERIALS AND METHODS: We evaluated the radiographs and function in 135 patients after non-operative treatment of minimally displaced (1-5 mm) fractures of the greater tuberosity at a mean time of 3.7 years (2-20 years) after injury. Shoulder function was assessed using the Vienna Shoulder Score (VSS), the Constant Score (CS) and the UCLA-Score. RESULTS: 97% of the evaluated patients had good or excellent results. Patients with a displacement of more than 3 mm had slightly worse results compared to those with less displacement, but this was not statistically significant. Female patients had significantly better results than male patients, and patients in the eighth and ninth decade had significantly worse results compared to younger patients. CONCLUSION: We recommend non-operative treatment in all patients with minimally displaced fractures of the greater tuberosity, as most obtain very good results. The best results followed treatment with Gilchrist bandages or Mitella slings for 3 weeks, followed by intensive rehabilitation.     

Frequency of germline genomic homozygosity associated with cancer cases

Guillaume Assié, MD, PhD; Thomas LaFramboise, PhD; Petra Platzer, PhD; Charis Eng, MD, PhD

JAMA. 2008;299(12):1437-1445.

Context  Cancer is a multigenic disease resulting from both germline susceptibility and somatic events. While studying loss of heterozygosity (LOH) in cancer tissues, we anecdotally observed a low frequency of heterozygosity in cancer patients compared with controls, raising the question whether homozygosity could play a role in cancer predisposition.

Objectives  To determine the frequency of germline homozygosity in a large series of patients with 3 different types of solid tumors compared with population-based controls.

Design, Setting, and Patients  Germline and corresponding tumor DNA isolated from 385 patients with carcinomas (147 breast, 116 prostate, and 122 head and neck carcinomas) were subjected to whole genome (345-microsatellite marker) LOH analysis.

Main Outcome Measures  Frequency of homozygosity at microsatellite markers in cancer cases vs controls and frequency of somatic LOH in cancers at loci with the highest homozygosity.

Results  We identified 16 loci in common among the 3 cancer types, with significantly increased germline homozygosity frequencies in the cancer patients compared with controls (P < .001). In the cases who happened to be germline heterozygous at these 16 loci, we found a mean (SD) LOH frequency of 58% (4.2%) compared with 50% (7.5%) at 197 markers without increased germline homozygosity (P < .001). Across the genome, this relationship holds as well (r = 0.46; 95% confidence interval, 0.37-0.53; P < .001). We validated the association of specific loci with high germline homozygosity frequencies in an independent, single-nucleotide polymorphism–based, public data set of 205 lung carcinomas from white individuals (P < .05 to P < .001) as well as the correlation between genome-wide germline homozygosity and LOH frequencies (r = 0.21; 95% confidence interval, 0.18-0.24; P < .001).

Conclusions  In our study of 4 different types of solid tumors (our data for 3 types validated in a fourth type), increased germline homozygosity occurred at specific loci. When the germline was heterozygous at these loci, high frequencies of LOH/allelic imbalance occurred at these loci in the corresponding carcinomas.

     

β-阻滞剂塞利洛尔的合成

报道了β－阻滞剂塞利洛尔的简便制备方法，即以对乙氧基苯胺为原料，经酰胺化，傅克反应，以环氧氯丙烷取代，最后用叔丁胺直接与环氧基反应开环等４步反应制得。比文献五步反应缩短了一步，产物经元素分析、红外光谱、核磁共振谱、质谱等分析确定结构。     

X-linked chronic granulomatous disease: correction of NADPH oxidase defect by retrovirus-mediated expression of gp91-phox

Chronic granulomatous disease (CGD) is an inherited immunodeficiency resulting from the inability of an individual's phagocytes to produce superoxide anions because of defective NADPH oxidase. The disease may be treated by bone marrow transplantation and as such is a candidate for somatic gene therapy. Two thirds of patients have defects in an X- linked gene (X-CGD) encoding gp91-phox, the large subunit of the membrane cytochrome b-245 component of NADPH oxidase. Epstein-Barr virus-transformed B-cell lines from patients with CGD provide a model system for the disease. We have used retrovirus-mediated expression of gp91-phox to reconstitute functionally NADPH oxidase activity in B-cell lines from three unrelated patients with X-CGD. The protein is glycosylated and membrane associated, and the reconstituted oxidase is appropriately activated via protein kinase C. The kinetics of superoxide production by such reconstituted cells is similar to that of normal B-cell lines. These data show the potential of gene therapy for this disease.     

Towards a consensus for classification of mandibular condyle fractures

The merits of surgical treatment of fractures of the mandibular condyle versus non-surgical management remains highly controversial, despite a large volume of literature dedicated to this topic. One reason the controversy remains, is because most of the outcomes in the literature are not directly comparable. The disparate range of condylar fracture classifications used is one of the reasons that studies are not comparable. We sought to review classification systems for condylar fractures used in the recent scientific literature.Review of the literature from 2016 to 2019, looking for papers relating to fractures of the mandibular condyle. Papers identified were assessed for type of study, focus of study, classification system used.88 studies were identified, including prospective and retrospective cohort studies, randomised and non-randomised prospective studies, randomised controlled trials and case series. More studies focussed on epidemiological factors than surgical access, fixation or outcomes. 31 used no classification system, whilst 17 used unique classification systems and 40 used previously referenced classification systems.Classification systems are used to help separate clinical problems into distinguishable groups, where there is a difference in management or outcome depending on the distinguishing features.There is currently a wide diversity of classification systems used for condyle fractures, and as a result, comparisons of surgical access, fixation and outcomes are difficult to make. Having a single classification system across the published literature would allow easier comparison and the classification proposed by the AO group is recommended for future use.     

Failure of recombinant human interleukin-3 therapy to induce erythropoiesis in patients with refractory Diamond-Blackfan anemia [see comments]

In two previous studies, we observed that recombinant human interleukin- 3 (IL-3) induced an increase in marrow burst-forming unit-erythroid- derived colonies in vitro in some patients with Diamond-Blackfan anemia (DBA). To determine whether a similar erythropoietic response could be induced in vivo, we treated 13 patients with DBA (aged 4 to 19 years) with two preparations of IL-3. All patients had absent absolute reticulocyte counts and markedly reduced to absent recognizable bone marrow erythroid elements; patients with circulating reticulocytes in the previous 12 months were excluded from study. All patients except 1 had failed steroid therapy and had been transfusion-dependent since infancy; 1 patient was maintained on high-dose prednisone at the time of enrollment. On the first arm of the study, IL-3 (Immunex Corp, Seattle, WA) was administered subcutaneously using a dose escalation regimen of 125 to 500 micrograms/m2/day in divided dosage at 12-hour intervals, coadministered with 1.5 mg/kg/d of oral ferrous sulphate. Of the 13 patients that entered the trial, 4 stopped prematurely because of adverse side effects. In the other 9 evaluable cases, reticulocytes increased transiently in 1 patient from 0 to 65 x 10(9)/L after 35 days of IL-3 therapy at 250 micrograms/m2, but transfusion dependency persisted. One transient peak in absolute reticulocyte count was noted in 6 other patients, but no erythroid response was observed after completion of a full course of IL-3. Oral prednisone at 0.5 mg/kg/d was then coadministered with IL-3 at 500 micrograms/m2 to 5 of the patients without effect, and treatment was stopped. In 2 patients, a second preparation of IL-3 (Sandoz Canada Inc, Dorval, Quebec, Canada) was initiated in a dose escalation regimen of 2.5 to 10 micrograms/kg and was coadministered with ferrous sulphate. No erythroid response was observed in either patient, and in one of the two, alternate-day subcutaneous recombinant erythropoietin at 300 U/kg was administered for 3 weeks in combination with daily IL-3 at 10 micrograms/kg, but no increased erythropoiesis was seen. Significant increases in white blood cell and eosinophil counts during administration of both preparations of IL-3 were observed in all patients. These data show that the response of DBA patients to IL-3 in vivo is heterogeneous and cannot be predicted from in vitro studies. The absence of a corrective effect of IL-3 in these patients with DBA indicates that a deficiency of the cytokine is not central in the pathogenesis of the disorder.