Thermal inactivation of Alkhumra hemorrhagic fever virus

The physico-chemical and biological characteristics of Alkhumra hemorrhagic fever virus (AHFV) are not yet known. The present study describes the thermal stability of this virus at different temperatures for different periods. The kinetics of thermal inactivation were studied, linear regressions were plotted, the Arrhenius equation was applied, and the activation energy was calculated accordingly. Titers of the residual virus were determined in median tissue culture infective dose (TCID₅₀), and the rate of destruction of infectivity at various temperatures was determined. Infectivity of AHFV was completely lost upon heating for 3 minutes at 60 °C and for 30 min at 56 °C. However, the virus could maintain 33.2 % of its titer after heating for 60 min at 45 °C and 32 % of its titer after heating for 60 min at 50 °C. In conclusion, AHFV is thermo-labile, and its inactivation follows first-order kinetics.     

Epidemiology and clinical features of methicillin-resistant Staphylococcus aureus in the University Hospital, Jeddah, Saudi Arabia.

OBJECTIVE: To describe the prevalence, demography and clinical characteristics of patients who were colonized or infected with methicillin-resistant Staphylococcus aureus (MRSA) in 1998 at King Abdulaziz University Hospital, Jeddah, Saudi Arabia. PATIENTS AND METHODS: Results of MRSA-positive cultures of clinical specimens obtained as part of investigations for suspected infections were retrieved from the King Abdulaziz University Hospital Infection Control Department's records. Charts of patients were reviewed. RESULTS: Of 292 S aureus isolates identified, 111 (38%) were MRSA, or 6.0 MRSA isolates/1000 admissions, which represented a marked increase over MRSA prevalence in 1988 (less than 2%). Nosocomial acquisition occurred in 74.8% of isolates. All age groups were affected, but 45.9% of patients were in the 'extremes of age' group (younger than one or older than 60 years of age). The prevalence was highest in the medical ward (27%), followed by the paediatrics combined medical and surgical ward (20.7%), the outpatient department (18%), the adult surgical ward (17.1%) and the intensive care units (17.1%). Two-thirds (66.7%) of cases represented infection and the remainder represented colonization. Surgical wounds (31.1%), the chest (27%) and endovascular catheters (20.3%) were the most common sites of infection. Bacteremia occurred in 27% of patients. Local signs (68.9%) and fever (60.8%) were the most common clinical manifestations. Respiratory distress and septic shock occurred in 28.4% and 6.8% of cases, respectively. Of 74 patients with MRSA infection and 37 patients with MRSA colonization, 91.9% and 56.8% received antibiotics in the preceding six weeks, respectively (P<0.0001). The total mortality of patients with MRSA infection was 60.8%; 37.8% of deaths were the result of MRSA infection and 23% were the result of other diseases. CONCLUSIONS: The prevalence of MRSA is high and rapidly increasing at King Abdulaziz University Hospital, as it is worldwide. Control measures to prevent the spread of MRSA in hospitals should continue with reinforcement of hygienic precautions and development of policies to restrict the use of antibiotics.     

Identification of a gene disrupted by a microdeletion in a patient with X-linked retinitis pigmentosa (XLRP)

The gene for the most frequent from of X-linked retinitis pigmentosa (XLRP), RP3, has been assigned by genetic and physical mapping to a segment of less than 1000 kbp, which is flanked by the marker DXS1110 and the ornithine transcarbamylase (OTC) gene. In search of microdeletions, we have screened the DNA of 30 unrelated patients with XLRP by employing a representative set of YAC-derived DNA fragments that were generated by restriction enzyme digestion and PCR amplification. In one of these patients, a 6.4 kbp microdeletion was detected which was not present in the DNA of 444 male controls. A cosmid contig spanning the deletion was constructed and used to isolate cDNAs from retina-specific libraries. Exons corresponding to these expressed sequences as well as other putative exons were identified by sequencing more than 30 kbp of the critical region. So far, no point mutations in these putative exon sequences have been identified.      

Positional cloning of the gene for X-linked retinitis pigmentosa 3: homology with the guanine-nucleotide-exchange factor RCC1

The gene for retinitis pigmentosa 3 (RP3), the most frequent form of X- linked RP (XLRP), has been mapped previously to a chromosome interval of less than 1000 kbp between the DXS1110 marker and the OTC locus at Xp21.1-p11.4. Employing a novel technique, YAC Representation Hybridization (YRH)', we have recently identified a small XLRP associated microdeletion in this interval, as well as several putative exons including the 3' end of a gene that was truncated by the deletion. cDNA library screening and sequencing of a cosmid centromeric to the deletion has now enabled us to identify numerous additional exons and to detect several point mutations in patients with XLRP. The predicted gene product shows homology to RCC1, the guanine-nucleotide- exchange factor (GEF) of the Ras-like GTPase Ran. Our findings suggest that we have cloned the long-sought RP3 gene, and that it may encode the GEF of a retina-specific GTP-binding protein.      

Preparation and characterization of specific and high-affinity monoclonal antibodies against morphine

A C6-hemisuccinate derivative of morphine was prepared and conjugated to bovine serum albumin. High titer antibody producing spleen cells were removed and fused with myeloma cells of Sp2/0 origin. A C3-hemisuccinate derivative of morphine was prepared and conjugated to enzyme penicillinase used as a tracer molecule. A novel enzyme-linked immunoadsorbent assay was developed using this conjugate to screen and characterize the monoclonal antibody produced in these experiments. After two successive limiting dilutions, antibodies produced by 5 clones with good affinities ranging from 10(8) to 10(12) M(-1) and less cross-reaction (least for codeine and other structurally related molecules) were selected. These clones were found to be of IgG class with kappa light chain. Subclass determination showed that two of the clones produced IgG2b and three of them produced IgG1 type of antibody. Affinity purifications were performed for the selected clone (MOR-I). Purified antibody was coated onto the wells of microtiter plate. The standard curve was constructed with a sensitivity of 100 pg/mL covering up to 10 ng/mL in buffer and urine. The slope of the standard curve for selected clone in buffer and urine was calculated to be -0.7 and -0.64, respectively.     

Conservative management of early endometrial adenocarcinoma with repeat curettage and hormone therapy under assistance of hysteroscopy and laparoscopy

We report a rare case of early-stage endometrial adenocarcinoma in a 22 year old nullipara with polycystic ovaries undergoing conservative treatment. Pretreatment evaluation including tumour grade, depth of myometrial invasion, tumour size, hormone receptor status and flow cytometric analysis indicated a favourable prognosis. The patient underwent repeat endometrial curettage and a 6 month period of therapy with megestrol acetate and tamoxifen. A combination contraceptive pill was then prescribed to ensure withdrawal of the menstrual cycle thereafter. Now, 1 year after the last curettage, there is no evidence of disease. During the treatment period, hysteroscopy allowed for a more precise approach in panoramically examining the tumour nest in the endometrial cavity, and the subsequent endometrial response to hormone therapy. Laparoscopy using bulldog clamps applied to the isthmic portion of the Fallopian tubes prevented i.p. spread of endometrial tissue from retrograde regurgitation during hysteroscopy. Laparoscopic ovarian electrocautery resulted in the reduction of abnormal hypervascularization on the surface of polycystic ovaries postoperatively but caused a peri-ovarian adhesion complication. It is interesting that this case posed a unique opportunity to demonstrate the tumour regression under the assistance of laparoscopy and hysteroscopy.      

不同补锌方法对儿童免疫功能的影响

研究不同补锌方法（补锌，补充微量营养素，补充锌加微量营养素）改善缺锌儿童免疫功能的作用，结果显示：实验１０ｗｋ后，三个实验组缺锌儿童血清锌浓度明显升高，同时淋巴细胞刺激指数明显高于对照组，流式细胞仪检测细胞周期显示对照组Ｇ０／Ｇ１期细胞增多，而实验组Ｓ＋Ｇ０／Ｇ１期细胞增多，细胞处于增殖活化状态。三组中又以锌＋微量营养素作用效果最好。表明：锌和微量营养素单独使用均增强缺锌儿童的免疫功能，但锌和微量     

治疗性单克隆抗体药动学相互作用的风险评估策略

生物制剂可用于治疗各种疾病,包括肿瘤、风湿、胃肠道疾病、皮肤科疾病、呼吸道疾病、激素缺乏症和感染。尽管近来批准了很多生物制品,但有关其药物间相互作用临床研究还不多。单克隆抗体是最主要的一类治疗性生物制品,本文介绍评价其药物间相互作用的风险评估策略,指出了评估中的关键因素,并建议将相互作用风险评估作为治疗性生物制品综合药物开发的一部分。