High level production of soluble single chain antibodies in small-scale Escherichia coli cultures

We have investigated the effect of growth and induction conditions on the production of soluble single-chain Fv antibody fragments in Escherichia coli under the control of wt lac promoter. The scFv was directed into the periplasmic space by a pelB leader sequence. Addition of sucrose to the medium gave a 15–25-fold increase in the yield of soluble scFv-phOx (3.0 mg/l) for bacterial shake-tube cultures and an increase of 80–150-fold (16.5 mg/l) for shake-flask cultures. Using flask culture in the presence of 0.4 M sucrose, a significant amount of scFv was released into the medium. We found that the scFv could be made to accumulate in the periplasm or be secreted into the medium by simply changing the incubation conditions and the concentration of the inducer. The ratio between soluble antibody fragments and insoluble scFv aggregates proved to be dependent on the strength of the promoter. Lowering the incubation temperature below 20°C had no effect on the yield of soluble antibody fragments in the periplasm, but they were no longer secreted into the medium. An example of high level production in shake-flask cultures and one-step purification by immobilized metal affinity chromatography (IMAC) is described for a soluble scFv specific for the T cell surface antigen CD3. The biological activity of the purified anti-CD3 scFv was demonstrated by flow cytometry. This method should be especially useful for the functional screening of a large number of clones in small-scale cultures.     

No correlation between number of MRI-evident lesions in cerebrum and the soleus stretch reflex in multiple sclerosis patients

The aim of the study was to investigate if the stretch reflex of the soleus muscle was useful in quantifying upper motor neuron lesions. The soleus stretch reflex was recorded in 10 healthy subjects and 20 patients with active relapsing-remitting multiple sclerosis and correlated to the number of MRI lesions in cerebrum and clinical scores (expanded disability status scale and regional functional scoring system). The short latency stretch reflex was elicited by rotating the left ankle joint 4 degrees with a rise time in the interval of 40-640 ms. The amplitude of the stretch was larger in multiple sclerosis patients being 88.5 microV in patients and 12.8 microV in controls, P = 0.007. The sensitivity of the stretch reflex expressed as the slope of the best linear fit was increased in MS patients to 2.6 microVs/degree compared with 0.6 microVs/degree (0.1-2.2) in controls, P = 0.009. There was no correlation between amplitude of the stretch reflex and number of MRI lesions (r = -0.03). In conclusion, the soleus stretch reflex might be useful to quantify spasticity but is not useful in detecting dysfunction of upper motor neurons in MS.     

The Reactivity of Psychosis Rating Form (RPRF): background,development and psychometrics

The ICD-10 and DSM-IV classifications have both given low priority to “reactivity” to acute stress as a classificatory principle for functional psychoses. In Scandinavia, reactivity is still considered an important factor in the development of such psychoses. Reactivity is a complex concept, and its various components are historically examined. The Reactivity of Psychosis Rating Form (RPRF) was developed in order to operationalize reactivity. Seven of the 10 elements of RPRF can be rated reliably. Factor analysis of the RPRF yields three factors: stressor, onset and change, that also show high interrater reliability. Our results indicate that RPRF has both construct and discriminant validity. Further studies with the RPRF may elucidate the true status of reactivity in functional psychoses.     

Infrared spectroscopy: A new diagnostic tool in Alzheimer disease

Biological markers play an evolving role in the diagnosis of Alzheimer disease (AD). We compare conventional measurements of cerebrospinal fluid (CSF) tau and β-amyloid_1–42 proteins to a novel approach – Fourier transformed infrared (FT-IR) spectroscopy – a simple technique derived from chemical and physical sciences that characterizes intramolecular bonds. For automatic diagnostic analysis, we developed an artificial neural network (ANN). We examined 71 patients with a clinical diagnosis of AD and 66 controls. β-Amyloid_1–42 was decreased (sensitivity 80% and specificity 78%); tau was elevated (sensitivity 76% and specificity 88%) in CSF of AD patients. The combined tau/β-amyloid_1–42 quotient was able to distinguish healthy from diseased subjects with 99% sensitivity and 86% specificity. The ANN could separate FT-IR spectroscopy data with 88.5% sensitivity and 80% specificity. FT-IR spectroscopy proved to be cost-effective and simple to perform. Diagnostic sensitivity and specificity is in the range of CSF tau and β-amyloid_1–42 protein analysis. Larger sample numbers for ANN training and validation could increase diagnostic accuracy and thus prove to be a useful screening tool.     

A Negative Symptom Rating Scale

Renewed interest in the role of negative symptoms in "defect state" schizophrenia calls for the design of a standardized, easy to use, reliable, and valid instrument to assess these aspects of psychopathology. In order to measure negative symptoms, we developed the Negative Symptom Rating Scale (NSRS). We report on the design, interrater reliability, and construct-validation of NSRS against the most frequently used negative symptom scales or subscales. In summary, the NSRS is a short, sensitive, highly specific, reliable, and apparently valid instrument for measuring negative symptoms in schizophrenia.     

食管癌与心理社会因素的关系探讨

目的 :本文采用 1:1配对的病例对照研究方法 ,探讨食管癌与病前心理社会因素的关系。方法 :采用 C型行为问卷和生活事件量表 ,调查病例和对照共 10 0对。结果 :食管癌病人 C型行为的 OR值为 3.0 9,明显高于对照组 ,P<0 .0 0 1;生活事件量表中病例与对照配对得分差的均数为 118.4 2± 52 .36 (LEU) ,食管癌病人得分明显高于对照组 ,P<0 .0 0 1。结论 :食管癌与不良的心理社会因素有关。     

上海市中心城轨道交通网络规划合理规模研究

介绍了估算城市轨道交通网络规划规模的3种方法--几何分析法、运输强度分析法及类比分析法,并结合上海市的实际情况对上海市中心城轨道交通网络规划规模进行了估算。通过对比和分析各种估算结果,提出了上海市中心城轨道交通网络规划的合理规模。     

Measuring quality of life from the point of view of HIV-positive subjects: the HIV-QL31

Assessment of the quality of life (QoL) of human immunodeficiency virus (HIV)-infected subjects is often based on questionnaires in which the items or questions are not seen to be relevant by patients, nor by the users of the data obtained. It therefore seemed appropriate to return to the issue. The methodological and bibliographical research as well as the consultations we conducted convinced us that the elaboration of a new questionnaire was both necessary and possible. In order to do so, we adopted methodological principles based on the Sickness Impact Profile development methodology. First a bibliographical research was conducted in order to study instruments already used for HIV infection. Then, experts concerned with HIV infection and members of patients' associations were interviewed to assess how opportune the development of a new instrument could be. Following this, a methodology was established for the design and construction of the new instrument. One hundred and eighteen candidate questions were generated from an analysis of the content of 20 patients' interviews, which were subsequently submitted to 102 patients, to obtain finally a set of 31 questions from the interpretation of the results obtained from classic psychometric analysis and also from non-classic methods (item response theory and Rasch model). The concept being measured is the impact of illness being experienced by HIV-infected subjects from their own perspective. The range of health states covered by this questionnaire relates to fairly mild conditions. Rasch analysis of this set of 31 questions (HIV-QL31) shows that it corresponds to one unidimensional construct. A single score can be calculated by simple summation of dichotomous response options. This score is highly reliable (Cronbach's coefficient = 0.93) and is also discriminant regarding the severity of clinical status.     

Stress, attachment and skin diseases: a case-control study

Objectives In this case-control study we tested the hypothesis of an association between some psychosomatic skin diseases, attachment style and stress. Patients and methods A total of 177 cases and 194 controls seen between November 1992 and November 1993 at the Istituto Dermopatico dell'lmmacolata (IDD) in Rome, were enrolled into the study. Cases were outpatients with first diagnosis of hyperidrosis, chronic urticaria, generalized pruritus or alopecia areata. Controls were outpatients seen in the same period of time with first diagnosis of pigmenled nevi, keratosis or mycosis. The presence and weight of life stress events were assessed by u standard precoded questionnaire based on the Schedule of Recent Experiences (SRE) and on the Life Experiences Survey (LES). The attachment style was assessed by a modified version of the Shaver and Hazan questionnaire about feelings in a love relationship. We calculated 3 scores for each individual and classified study subjects in 2 groups: 1) "free" (= secure attachment); 2) "not free" (not secure attachment: anxious-ambivalent or avoidant). Questionnaires were self-administered in the presence of a trained psychologist. Adjusted odds ratios (OR) were calculated using a multiple logistic function. Results No association was found between the different stress scores and the skin diseases considered. The crude odds ratio for life stress events in the previous year was 1.4 (95% CI 0.8–2.7). After multiple adjustment for age, sex, marital status and education, the estimated OR was 1.6 (95% CI 0.8–3.0). One significant association emerged between the adult attachment style defined as “not free” and psychosomatic skin diseases: the adjusted OR was 4.0 (95% CI 1.4–12).