A model of socioeconomic analysis: its construction and results

Genetic structure of 20 of the 37 linguistic groups in the Eastern Highlands of New Guinea including the kuru region is analyzed using information on blood groups and serum protein polymorphisms. The average individual is heterozygous at 28.6% of loci and the average number of alleles per locus is 1.234. Coefficients of kinship for linguistic groups range from 0.005 for the sweet potato cultivating North Fore to 0.075 for the isolated Pawaians whose dietary staple is sago and who depend more on hunting and gathering. As one selects linguistic groups with smaller and smaller population size and increasing isolation, one finds that kinship coefficients rise as much as tenfold, but there is no concomitant loss of heterozygosity or trend toward fixation of alleles. Genetic relationships established by genetic distance trees and by principal components analysis are comparable and are consistent with other anthropological observations.     

Semen backflow after insemination and its effect on fertilisation results in sows

Formalin fixation, the chemical process in which formaldehyde binds to cells and tissues, is widely used to preserve human brain specimens from autolytic decomposition. Ultrastructure of cellular and mitochondrial membranes is markedly altered by vesiculation, but this does not interfere with diagnostic evaluation of neurohistology by light microscopy. Serious difficulties are encountered, however, when immunocytochemical staining is attempted. Antigens that are immunoreactive in unfixed frozen sections and protein extracts appear to be concealed or destroyed in formalin-fixed tissues. In dilute aqueous solution, formaldehyde is in equilibrium with methylene glycol and its polymeric hydrates, the balance by far in favor of methylene glyco. Carbonylic formaldehyde is a reactive electrophilic species well known for crosslinking functional groups in tissue proteins, nucleic acids, and polysaccharides. Some of its methylene crosslinks are readily hydrolyzed. Others are stable and irreversible. During immunostaining reactions, intra- and inter-molecular links between macromolecules limit antibody permeation of tissue sections, alter protein secondary structure, and reduce accessibility of antigenic determinants . Accordingly, immunoreactivity is diminished for many antigens. Tissues are rapidly penetrated by methylene glycol, but formaldehyde binding to cellular constituents is relatively slow, increasing progressively until equilibrium is reached. In addition, prolonged storage in formalin may result in acidification of human brain specimens. Low pH favors dissociation of methylene glycol into formaldehyde, further reducing both classical staining and antigen detectability. Various procedures have been devised to counter the antigen masking effects of formaldehyde. Examples include pretreatment of tissue sections with proteases, formic acid, or ultrasound. Recently, heating of mounted sections in ionic salt solution by microwave energy was found to restore many antigens. Theory and practice of microwave antigen retrieval are covered extensively in the handbook Microwave Cookbook for Microscopists. A concise overview of microwave methods in the neurosciences has been published, and clinical applications have been reviewed. In this context, it should be noted that fresh tissues may be stabilized for immunocytochemistry by reversible, non-chemical binding processes such as cryosectioning after microwave treatment and freeze-drying. Thus, it may be possible to enhance immunostaining for some antigens by microwave irradiation of unfixed as well as fixed specimens. Parameters to be optimized for microwave retrieval of specific antigens include temperature, irradiation time, tissue buffer composition, salt concentration, and pH. Temperature, irradiation time, and pH are key variables. With this in mind, an optimal method was developed for retrieval of a wide variety of antigens in human brain tissues. Typical microwave protocols employ elevated temperatures that may reach 100 degrees C, where denaturation causes irreversible uncoiling and disruption of protein secondary and tertiary structures. Under these conditions, stable covalent bonds securing methylene crosslinks between polypeptides remain intact, but more reactive links formed by Schiff bases may be hydrolyzed. Resultant conformational changes presumably expose buried loops of continuous amino acids and protruding regions, increasing accessibility of their epitopes. Protein denaturation seems to be a reasonable explanation for the effects of microwaves on antigen retrieval. This idea is supported by the observation that denaturing solutions such as 6 M urea increase immunoreactivity of some antigens. Still, the molecular basis of these effects remains unresolved, in part due to the complex chemistry of formaldehyde reactions with tissue constituents. Indeed, some methylene bridges between similar groups such as NH2 and NH may be hydrolyzed by washing fixed tissues in distilled wa     

Fractures of the thoracolumbar spine. Late results of dorsal instrumentation and its consequences

Between January 1989 and July 1992, 76 patients with thoracolumbar fractures were operatively treated at the Department of Trauma Surgery, Hannover Medical School. After a mean of more than 3 years, 56 of 62 patients (90%) still alive who had their implants removed were examined. According to the ASIF classification 33 patients sustained type A fractures, 13 type B and 10 type C. Three patients with incomplete paraplegia returned to normal; in one case of complete paraplegia no change occurred. In 40 cases the dorsal instrumentation was combined with transpedicular cancellous bone grafting. The mean operative time totaled 3 h. In this series, two complications (3.6%) were observed: one iatrogenic vertebral arch fracture without consequences and one deep infection. Compared to the preoperative status, our follow-up examinations demonstrated permanent physical and social sequelae; the percentage of individuals able to do physical labor was reduced by half (22 to 11 patients) whereas the share of unemployed or retired patients doubled (4 to 8 patients). At the time of follow-up examination only 21 of 42 patients continued in sports. The assessment of complaints and functional outcome with the "Hannover Spinal Trauma Score" reflected a significant difference (P < 0.001) between the status before injury (96.6/100 points) and at the time of follow-up (71.4/100 points). The radiographic assessment in the lateral plane (Cobb technique) demonstrated a significant (P < 0.001) mean restoration from an initial angle of -15.6 degrees (kyphosis) to +0.4 degree (lordosis). Serial postoperative radiographic follow-up showed progressive loss of correction; at follow-up examination we found a mean of 10.1 degrees (P < 0.001). Compared to the preoperative deformity a mean improvement of 6.1 degrees to an average of -9.7 degrees at follow-up examination was noted. The addition of transpedicular cancellous bone grafting did not decrease the loss of correction. CT scans after implant removal were performed in 9 cases: only 3 of 9 patients showed evidence of intervertebral fusion. No correlation could be found between ASIF classification and radiographic outcome. However, the preoperative wedge angle of the vertebral body correlated significantly with the postoperative loss of reduction. Due to disappointing results after dorsal stabilization with transpedicular cancellous bone grafting we recommend a combined procedure with dorsal stabilization and ventral fusion in cases of complete or incomplete burst injury of the vertebral body.     

A coaxial HOM coupler for a superconducting RF cavity and its low-power measurement results

A resonant buildup of beam-induced fields in a superconducting radio frequency （RF） cavity may make a beam unstable or a superconducting RF cavity quench. Higher-order mode （HOM） couplers are used for damping higher-order modes to avoid such a resonant bu     

Late results of local transrectal hyperthermia in patients with benign prostatic hyperplasia and its complications

LTH on Yakhta-4M unit was used in benign prostatic hyperplasia (BPH). The prostate was heated transrectally by directional radiation. The course of treatment comprised 5 sessions for 60 min twice a week. The efficacy of the treatment was assessed 3 years later in 78 patients which were divided into 4 groups: 31 patients with BPH, 30 patients with BPH in combination with chronic prostatitis, 9 patients with acute urine retention and 8 patients with cystostomy fistula. 5 patients underwent surgery. LTH is safe in relation to side effects, may be used both at early stage of the disease and in risk of operative intervention.     

A new method of endoscopic mucosal resection of neoplastic lesions in the stomach: its technical features and results

BACKGROUND/AIMS: In gastric cancer, endoscopic treatment can be expected to provide an absolute cure only if the lesion is mucosal and not accompanied by metastatic lymph nodes. To further evaluate such possibly curable lesions, we retrospectively reviewed 208 cases of early gastric cancer surgically resected over the past 20 years. METHODOLOGY: Our new method of endoscopic mucosal resection using a cap-fitted panendoscope, which is called EMRC, has been employed in the treatment of 73 gastric neoplastic lesions. RESULTS: It was found that curable lesions would, as the primary condition, be histologically well-differentiated carcinomas and measure 2 cm or less of the elevated type and less than 1 cm of the depressed type. The lesions were consequently identified as 49 early cancers (46 mucosal, 3 submucosal), 23 adenomas and 1 carcinoid. Although resection was completed in a single session of EMRC treatment in all cases, approximately 40% of them required fractionated resection, leaving an ulcer measuring 3 cm or more in approximately 30%. Bleeding or muscle resection occurred in 7 patients, in whom conservative treatment was effective. No recurrence has been found in any of the 73 lesions, demonstrating a favorable outcome. CONCLUSIONS: This method is advantageous in that it is simple and relatively easily applied at almost any location within the stomach. In addition, the size of the specimen obtained by en bloc resection is approximately 2 cm. The method is thus fairly likely to come into widespread use.     

Measurement of serum p53 protein in patients with small cell lung cancer and results of its clinicopathological evaluation

Serum p53 protein levels were measured in 36 patients with small cell lung cancer (SCLC) and 35 patients with benign lung diseases in order to evaluate the relationship of these levels to clinicopathological features of SCLC. Serum levels of p53 protein were measured by an enzyme-linked immunosorbent assay, p53 protein level was 23.92 +/- 6.78 pg/ml in patients with SCLC, and similar to that (17.47 +/- 2.86 pg/ml) in patients with benign lung diseases. By the clinical stage of SCLC, the mean level of p53 protein was 16.68 +/- 4.62 pg/ml in 21 patients with limited disease, and lower than that in 15 patients with extensive disease (34.05 +/- 14.84 pg/ml) (P = 0.23). The levels of p53 protein were not correlated with age, smoking index, or presence of cancer history for patients with SCLC. However, immunohistochemical examination disclosed a mild correlation between the expression of p53 protein by SCLC tumor and p53 protein serum level (r = 0.45, P = 0.02). Two patients with SCLC had an elevated serum level of p53 protein (> 2 S.D. above the mean for benign lung diseases). However, measurement of p53 protein serum level was not found to be clinically useful for detection of SCLC.     

能力验证检测数据的两种稳健统计分析方法比较及结果合理性判断

四分位法和迭代法均是计算检测能力验证数据目标标准偏差的稳健统计分析方法, 其计算结果将直接用于判断实验室上报数据是否合格。利用195套(100多个检测项目)检测能力验证数据, 比较了两种稳健统计分析方法计算结果。模拟和实际数据计算结果均表明, 当数据分布趋势是正态分布时, 两种方法结果基本吻合, 但对于数据分布明显偏离正态分布检测项目, 四分位法计算得到的标准偏差过严, 导致实验室上报数据满意率明显下降, 出现统计学“弃真”错误。以删掉离群值后的经典统计法结果作为依据, 对两种方法合理性进行了判断。对于固体样品, 四分法与迭代法结果(标准偏差)比较接近, 两者相对偏差平均值为5.7%;液体样品为13.8%, 两者差别较大。迭代法既减小了离群值对统计分析结果的影响, 又避免了判断离群值时采用不同规则可能带来的人为因素影响。建议尽快将迭代法纳入国内检测能力验证数据评价标准体系。     

Surgical limb lengthening--experiences and results

This paper describes the experiences and results in 172 operative lengthening procedures on 134 patients, performed in the Orthopaedic Department of Charité Hospital in Berlin. The bone length increase was on an average 8.5 cm (min.: 1 cm, max.: 20 cm), this gives altogether a bone increase of over 14 meters. Patients are differentiated in groups of age, indication, localization, mode of procedure (callus-distraction, epiphysealdistraction) and in regard to the used external fixation devices. Authors present their own model of wire fixed external fixateur (so called "Berlin type-external fixateur"), a modification of the original Ilizarov-device. Importance of procedure-planning and time-balance as well as the high rates of complications (146 complications = 84.8%) are discussed.     

High incidence of chromosome 8 monosomy and chromosome 7 trisomy in prostatic primary tumor and its related lymphatic metastasis. Preliminary results

SETTING: Chest Clinic, University Teaching Hospital, Zambia. OBJECTIVE: To study the pre-diagnosis economic impact, burden, and barriers to care-seeking for tuberculosis patients in urban Zambia. DESIGN: In-depth interviews conducted over a 9-week period with adult in-patients and out-patients registering with new pulmonary tuberculosis; data analysis using Epi Info. RESULTS: Interviews were completed by 202 patients: 64% normally worked, but 31% stopped due to their tuberculosis, with an average of 48 days off. The mean duration of illness prior to their tuberculosis registration was 63 days, with 64% of patients delaying in presenting to the Chest Clinic. Of these, 38% blamed money shortages for their delay. In seeking diagnosis, patients incurred a mean total cost equivalent to 127% of their mean monthly income (pounds sterling UK 40 [$US 59]); direct expenditures represented 60% of this cost. In addition, patients lost, on average, 18 work days prior to diagnosis. Care-givers incurred costs equivalent to 31% of the mean monthly income (pounds sterling UK 10 [$US 15]). CONCLUSION: The economic burden of tuberculosis on patients creates barriers to prompt diagnosis which may lead to continuing transmission of the infection. Important economic barriers include transportation expenditure, cost of 'special food', and lost income. These barriers may be reduced through interventions that reduce the number of health encounters, travel distances and duration of illness before diagnosis.     

MRI-controlled facet block--technique and initial results

In a clinical study, 5 patients with chronic low back pain were treated by MR-guided facet injection of the motion segments L4/L5 and L5/S1. For the infiltration, special nonmagnetic needles were used. The investigations were carried out in an MR unit having a field strength of 1.0 tesla. In all patients, MR visualisation of the facet joints and measurement of the distance to the reference point was readily accomplished. Placement of the special MR needle, however, proved difficult in situations in which the needle had to be advanced through dense fibrous tissue. Nevertheless, the needle was successfully placed at the first attempt in two patients; in all other patients a second attempt was necessary. The entire procedure took about 30 to 40 minutes per patient. The needles were identified without any artefacts. All the patients were pain-free for at least 3 weeks after injection.