Kidney transplants in mice. An analysis of the immune status of mice bearing long-term, H-2 incompatible transplants

Kidney transplants between strains of mice which are incompatible at either the K or the D end of the H-2 complex usually function for prolonged periods supporting the lives of nephrectomized recipients. This occurs with no recipient treatment. With multiple H-2 and non-H-2 determined incompatibilities, transplants may be rejected but more slowly than skin grafts. In the strain combination studied most extensively in these experiments (B10.D2 to B6AF(1)) in which the incompatibility was confined to the K end of the H-2 region, about 70 percent of recipients survived for many weeks with normal blood urea nitrogen levels. Skin grafts between untreated members of these strains were rejected promptly (mean survival time of 13.5 +/- 1.1 days) as were kidney transplants to recipients of prior skin grafts. Donor strain skin grafts to recipients of kidney transplants after kidney transplantation enjoyed greatly prolonged survival whereas skin grafts from a third party (A.SW) were rejected normally. If kidney tissue was transferred in the form of free grafts without primary vascular union, it was rejected promptly leaving its recipient highly immunized. Cellular and humoral immunity to donor antigens declined over the first few weeks after transplantation, and the spleens of long-term recipients contained no “killer cells.” Recipient lymphoid cells could mount active graft versus host reactions to donor strain antigens on transfer to neonatal mice. Nevertheless, they were distinctly less able to respond specifically by the production of killer cells to donor strain antigens after sensitization in vitro. No evidence that this defect was associated with the presence of suppressor cells was forthcoming from several types of in vivo and in vitro tests.     

COVID-19 disease in hospitalized young adults in India and China: Evaluation of risk factors predicting progression across two major ethnic groups

Data pertaining to risk factor analysis in coronavirus disease 2019 (COVID-19) is confounded by the lack of data from an ethnically diverse population. In addition, there is a lack of data for young adults. This study was conducted to assess risk factors predicting COVID-19 severity and mortality in hospitalized young adults. A retrospective observational study was conducted at two centers from China and India on COVID-19 patients aged 20–50 years. Regression analysis to predict adverse outcomes was performed using parameters including age, sex, country of origin, hospitalization duration, comorbidities, lymphocyte count, and National Early Warning Score 2 (NEWS2) score at admission. A total of 420 patients (172 East Asians and 248 South Asians) were included. The predictive model for intensive care unit (ICU) admission with variables NEWS2 Category II and higher, diabetes mellitus, liver dysfunction, and low lymphocyte counts had an area under the curve (AUC) value of 0.930 with a sensitivity of 0.931 and a specificity of 0.784. The predictive model for mortality with NEWS2 Category III, cancer, and decreasing lymphocyte count had an AUC value of 0.883 with a sensitivity of 0.903 and a specificity of 0.701. A combined predictive model with bronchial asthma and low lymphocyte count, in contrast, had an AUC value of 0.768 with a sensitivity of 0.828 and a specificity of 0.719 for NEWS2 score (5 or above) at presentation. NEWS2 supplemented with comorbidity profile and lymphocyte count could help identify hospitalized young adults at risk of adverse COVID-19 outcomes.     

Polycystic Kidney Disease Re-evaluated: A Population-based Study

A genetic register of all known cases of autosomal dominantpolycystic kidney disease occurring in South and Mid-Wales hasbeen established. In a population of 2.1 million, 209 familieswith affected members were identified, 303 of whom are currentlyalive, 70 on renal replacement therapy. An additional 551 caseswould be predicted amongst family members at 50 per cent and25 per cent risk, giving an apparent prevalence of 1:2459 inthe general population. Five possible new mutations were seenwhere adults with phenotypic autosomal dominant polycystic kidneydisease had both parents alive, age > 55 years with no cystsvisible on ultrasound. The take-on rate for renal replacementtherapy increased during 1970–79 but has apparently reacheda plateau of 4.8 cases per million population per year overthe last 8 years, despite a rapidly increasing acceptance ofuraemic patients as a whole (72/10⁶/year in 1988–89).Considerably more patients with autosomal dominant polycystickidney disease aged over 50 years were started on treatmentin 1980–89 than in 1970–79, but the survival overallimproved with time. All cases of autosomal dominant polycystickidney disease reaching end-stage renal disease are now beingtreated, but the apparent clinical prevalence of this conditionin our region is less than half the supposed gene frequency,suggesting that undiagnosed cases have a benign prognosis.     

微创经皮钢板置入内固定治疗胫腓骨骨折的技术操作特点

目的:总结微创经皮钢板置入内固定治疗胫腓骨骨折的技术操作特点,并观察材料及宿主反应。方法:2004-06/2006-10在济宁医学院附属金乡医院对18例胫腓骨骨折患者在微创手术下进行了手术置入内固定材料。男13例,女5例,年龄17～73岁。术后按Johner-Wruhs方法评价测试各大关节功能,分为优、良、中、差。全部病例进行临床随访。术前、术后1周、6周、3个月、半年及1年分别摄X线片与健侧对比测量患肢外观、成角、旋转和短缩情况,并观察材料及宿主反应。结果:①本组病例切口均顺利愈合,术后3～14d出院。②全部获得随访,平均随访时间14个月;骨愈合时间3～10个月。③按Johner-Wruhs方法评价功能,优13例,良4例,中1例,差0例,以优良为满意标准,本组病例总体满意率94.4%。④术后1例出现跛行步态,中度疼痛,骨成角畸形15°,可能因为患者对不锈钢材料有排斥反应造成固定不牢所致。结论:微创经皮钢板置入内固定材料治疗胫腓骨骨折具有手术创伤小、骨折愈合快、功能恢复好的特点;内固定材料未出现特殊材料反应与宿主反应。     

Acquisition, expression, and reinstatement of ethanol-induced conditioned place preference in mice: effects of exposure to stress and modulation by mecamylamine

Nicotinic acetylcholine receptors mediate some of the rewarding and motivational effects of ethanol, including relapses. Relapses are common in drug addicts during abstinence when exposure to any stressor ensues. However, the role of nicotinic acetylcholine receptors in the ethanol- and stress-induced reinstatement of ethanol-induced conditioned place preference has not yet been explored. Therefore, the present study investigated the influence of mecamylamine, a nicotinic acetylcholine receptors antagonist on acquisition, expression, and reinstatement of ethanol-induced conditioned place preference in adult male Swiss mice. The results revealed that mecamylamine (0.1-10 μg/mouse, intracerebroventricularly) dose dependently prevented the development, expression, and reinstatement of ethanol-induced conditioned place preference. Further, acute treatment with mecamylamine blocked the restraint stress and forced swim stress-induced reinstatement of ethanol-induced conditioned place preference. All of these treatments had no influence on the locomotor activity. Therefore, it is concluded that mecamylamine blocks the acquisition, expression and reinstatement of conditioned reinforcing effects of ethanol without per se reinforcing or aversive influence. This ability of mecamylamine might be a potential advantage in the treatment of alcoholism.     

Retrospective Study on Efficacy of Intermaxillary Fixation Screws

Background

We evaluated the efficacy of intermaxillary fixation (IMF) screws in the treatment of mandibular fractures.

Methods

Two hundred patients with mandibular fractures, treated by IMF using these screws, were evaluated by pre and postoperative panoramic radiographs. Clinical testing was carried out for vitality and abnormal mobility of teeth adjacent to the site of screw insertions. Other factors such as possible iatrogenic dental injuries, loss, breakage or screw cover by oral mucosa and postoperative occlusion were also studied.

Result

The most important complication noticed was iatrogenic damage to dental roots.

Conclusion

Use of intraoral cortical bone screws for IMF is a valid alternative to arch bars in the treatment of mandibular fractures. Iatrogenic injury to dental roots is the commonest problem which can be minimized by an experienced surgeon.Key Words: Intermaxillary fixation, Bone screws, Mandibular fractures, Iatrogenic injury     

Radiation Induced Oral Mucositis

Patients receiving radiotherapy or chemotherapy will receive some degree of oral mucositis The incidence of oral mucositis was especially high in patients: (i) With primary tumors in the oral cavity, oropharynx, or nasopharynx; (ii) who also received concomitant chemotherapy; (iii) who received a total dose over 5,000 cGy; and (iv) who were treated with altered fractionation radiation schedules. Radiation-induced oral mucositis affects the quality of life of the patients and the family concerned. The present day management of oral mucositis is mostly palliative and or supportive care. The newer guidelines are suggesting Palifermin, which is the first active mucositis drug as well as Amifostine, for radiation protection and cryotherapy. The current management should focus more on palliative measures, such as pain management, nutritional support, and maintenance, of good oral hygiene     

Berberine protects C57BL/6J mice against ethanol withdrawal‐induced hyperexcitability

Berberine ([C20H18NO4]⁺), one of the major constituents of the Chinese herb Rhizoma coptidis, is an isoquinoline alkaloid. Plethora of recent reports has indicated its ability to modulate several neurotransmitter systems, especially those implicated in ethanol dependence. Thus, the influence of berberine treatment on the development and expression of ethanol dependence was tested by using the ethanol withdrawal‐induced hyperexcitability paradigm. Mice were provided with a nutritionally balanced control liquid diet as the sole nutrient source on day 0; from day 1–4 (ethanol, 3% v/v), from day 5–7 (ethanol, 6% v/v) and from day 8–10 (ethanol, 10% v/v) was incorporated into the liquid diet. On day 11, the ethanol liquid diet was replaced with nutritionally balanced control liquid diet, and ethanol withdrawal‐induced hyperexcitability signs were recorded. The results revealed that acute administration of berberine (10 and 20 mg/kg, i.p.) dose‐dependently attenuated ethanol withdrawal‐induced hyperexcitability signs, and these results were comparable to diazepam (1.25 and 2.5 mg/kg, i.p.). Further, chronic administration of berberine (10 and 20 mg/kg, i.p.) to the ethanol diet fed mice markedly attenuated the ethanol withdrawal‐induced hyperexcitability signs. In conclusion, the results and evidence suggest that berberine exhibited an inhibitory influence against ethanol withdrawal‐induced hyperexcitability signs, which could be mediated through its neuromodulatory action. Copyright © 2010 John Wiley & Sons, Ltd.     

HDAC6 Deacetylates Ku70 and Regulates Ku70-Bax Binding in Neuroblastoma

Ku70 was first characterized as a nuclear factor that binds DNA double-strand breaks in nonhomolog end-joining DNA repair. However, recent studies have shown that Ku70 is also found in the cytoplasm and binds Bax, preventing Bax-induced cell death. We have shown that, in neuroblastoma cells, the binding between Ku70 and Bax depends on the acetylation status of Ku70, such that, when Ku70 is acetylated, Bax is released from Ku70, triggering cell death. Thus, to survive, in neuroblastoma cells, cytoplasmic Ku70 acetylation status is carefully regulated such that Ku70 is maintained in a deacetylated state, keeping Bax complexed with Ku70. We have shown that overexpression of CREB-binding protein (CBP), a known acetyltransferase that acetylates Ku70, releases Bax from Ku70, triggering apoptosis. Although we have shown that blocking deacetylase activity using non-type-specific inhibitors also triggers Ku70 acetylation and Bax-dependent cell death, the targets of these deacetylase inhibitors in neuroblastoma cells remain unknown. Here, we demonstrate that, in neuroblastoma cells, histone deacetylase 6 (HDAC6) binds Ku70 and Bax in the cytoplasm and that knocking down HDAC6 or using an HDAC6-specific inhibitor triggers Bax-dependent cell death. Our results show that HDAC6 regulates the interaction between Ku70 and Bax in neuroblastoma cells and may be a therapeutic target in this pediatric solid tumor.