How do normal subjects learn a simple adaptative task: How and why do paranoid schizophrenic patients fail?

Summary The authors studied the behavior of normal subjects and paranoid schizophrenic patients in a simple problem-solving situation. The schizophrenics were divided into two sample groups, one of individuals under treatment and the other of individuals not under treatment.The learning process involved in this problem-solving situation is very similar to an instrumental conditioning, and can be understood by means of the following assumptions: (1) the subjects use decision functions in reacting to the stimuli, although they may be not fully aware of this; (2) learning is the result of successive transformations of these decisions in the course of time; (3) the changes have specific probabilities and are related to (a) those responses which are made to the latest stimuli, and (b) a differential probability for decision functions which were effective, or only interrupted painful reinforcement, or were completely ineffective.In schizophrenics further factors of importance were (1) an inertia factor and (2) the rigidly continued use of unsuccessful or only partially successful decision criteria.The authors used a systems theory based on Galois field theory and a calculus of operators specifying three groups of subjects. A computer program based on these hypotheses was tested in a simulation experiment.The statistical evaluation of the results showed a congruence between the theoretical approach and the experimental data.This work was carried out with financial support from the Institute de Alta Cultura, Lisbon, between 1970 and 1974     

Comparative assessment of bone mineral density of the forearm using single photon and dual X-ray absorptiometry

Summary Forearm bone mineral density (BMD) was measured at proximal and distal sites by ¹²⁵I single photon absorptiometry (SPA) and by dual energy X-ray absorptiometry (DXA) in 67 consecutive subjects, aged 18–75 years. Correlations and regression equations between these two techniques were determined. All forearm measurements were significantly correlated with each other (r=0.599–0.926; P0.0001). Although SPA and DXA correct for fat in different ways, we found similar correlation and regression equations in women with body mass index measurements above and below the mean. In addition, forearm measurements by both techniques were moderately correlated with vertebral spine and hip BMD. We conclude that overall, SPA forearm measurements in a population can be calibrated to DXA measurements if necessary, and that DXA forearm measurements are as predictive of the remainder of the skeleton as SPA measurements.     

Acquired hyperoxaluria and haematuria in children

Two children with extensive ileal resection are reported. They developed gross haematuria of non-glomerular origin, without stones or nephrocalcinosis. Previous reports indicate that acquired hyperoxaluria is common in children with a variety of intestinal disorders. Our patients had hyperoxaluria. We think that hyperoxaluria may be the cause of haematuria through a pathogenetic mechanism similar to the one ascribed to haematuria secondary to hypercalciuria and hyperuricosuria.     

Effects of Sex,Handedness, Stimulus and Visual Field on “Mental Rotation”

Shepard's mental rotation paradigm (e.g. Shepard and Metzler, 1971) was modified to allow tachistoscopic presentation of stimuli at varying angles of orientation (0° to 180°) in the right and left visual fields. Thirty male and thirty female subjects divided into three handedness groups (right-handers, non-familial and familial left-handers) judged whether a stimulus was a standard form or its mirror image. In general response times for correct judgements (RT_c) increased monotonically as a function of angle of orientation though the curves tended to be negatively accelerated rather than linear. Right-handers showed a slower rate of increase in RT_c as a function of angle than either left-handed group. Mean RT_c and the rate of increase in RT_c were equivalent for the two sexes and for the two visual fields. Both mean RT_cs and on the rate of increase in RT_c varied as a function of the stimulus.Error rates also increased monotonically as a function of angle of orientation. No sex or handedness differences in error rates were found. However, errors increased significantly less rapidly when stimuli were presented in the left visual field. It is argued that right hemisphere specialization for spatial processing minimizes the rate of increase in errors.The present failure to find sex differences may be of interest and it is argued that rapid presentation of stimuli results in subjects setting maximum and minimun response times. Within this relatively restricted “bandwith” of response times males and females may perform spatial tasks equally efficiently. Some confirmation for this hypothesis vs. an alternative based upon differences in hemispheric organization was found in a second experiment.     

Effect of carbon disulphide intoxication on fecal excretion of end products of cholesterol metabolism

Summary The aim of this study was to compare the time course of ¹⁴C-steroid excretion following administration of ¹⁴C-cholesterol in normal and CS₂intoxicated rats. The excretion of steroid with the feces was evaluated in the normal and CS₂ intoxicated rats at the end of 7 month exposure to CS₂. The results of the experiment indicated that in rats exposed to CS₂ excretion of ¹⁴C-steroid is lower. It was due to a reduced excretion of ¹⁴C-bile acid fraction while at the same time the share of sterol + rose. On the basis of our former results which excluded the influence of CS₂ on absorption of cholesterol and indicated its effect on cholesterol synthesis it was revealed in this experiment that intoxication with CS₂ also inhibits cholesterol degradation. Disturbances of both processes can be essential for accumulation of cholesterol in blood of animals intoxicated with CS₂.This investigation has been carried out under the Polish-American agreement No. 05-008-2 with the Occupational Health Program, U.S. Public Health Service     

Specific language impairment in families: evidence for co-occurrence with reading impairments.

Two family aggregation studies report the occurrence and co-occurrence of oral language impairments (LIs) and reading impairments (RIs). Study 1 examined the occurrence (rate) of LI and RI in children with specific language impairment (SLI probands), a matched control group, and all nuclear family members. Study 2 included a larger sample of SLI probands, as well as their nuclear and extended family members. Probands and their family members who met specific criteria were classified as language and/or reading impaired based on current testing. In Study 1, the rates of LI and RI for nuclear family members (excluding probands) were significantly higher than those for control family members. In the SLI families, affected family members were more likely to have both LI and RI than either impairment alone. In Study 2, 68% of the SLI probands also met the diagnostic classification for RI. The language and RI rates for the other family members, excluding probands, were 25% and 23% respectively, with a high degree of co-occurrence of LI and RI (46%) in affected individuals. Significant sex ratio differences were found across generations in the families of SLI probands. There were more male than female offspring in these families, and more males than females were found to have both LIs and RIs. Results demonstrate that when LIs occur within families of SLI probands, these impairments generally co-occur with RIs. Our data are also consistent with prior findings that males show impairments more often than females.     

Factores pronósticos del cáncer de mama. Modelo predictivo

Introduction. Breast cancer remains the most frecuent tumor among women in developed countries. The prognosis is linked to a great variety clinic and pathological factors. The objectives from this study are to identify markers related to survival of patients with primary diagnosis of breast cancer. Material and methods. We have reviewed the medical dossier from 2.227 consecutive women diagnosed for infiltrating breast cancer between January 1966 and december 2000 in a single institution. For statistic analysis we used 10.0 SPSS software. Results. In the univariate analysis, factors with the strongest predictive value for overall survival were: PEV, estrogene and progesterone receptors, TNM stage, lymphatic vessel involvement, histologic grade, Scarff differentiation and mitosis rate, elastosis, presence of histiocitosis, and the percentage of involved stage I and III lymph nodes (Berg clasification). In the multivariate analysis, 5 factors; progesterone receptors, Scarff mitotic rate, lymphatic vessel involvement, percentage of involved stage I lymph nodes, and presence of metastasis; were independent prognostic markers of survival. Conclusions. Many independent factors interact in the survival of patients with primary breast cancer. Determination of hormonal receptors, mainly progesterone’s, appear as the most powerful indicators. The analysis has generated a prognostic simplified classification, based in the 5 independent variables, that provides specific rates for survival at 2, 5 and 10 years.     

Nuclear Pedigree Criteria for the Identification of Individuals Suspected to Be at Risk of an Inherited Predisposition to Gastric Cancer

Gastric cancer is the second most frequently diagnosed malignancy worldwide and therefore represents a significant healthcare burden. Environmental and genetic factors are involved in the development of gastric cancer. To date only one clear genetic predisposition has been identified involving mutations in the E-cadherin gene. The disease phenotype in patients harbouring E-cadherin mutations appears to be specifically related to diffuse gastric cancer. Little is known genetically about the other forms of gastric cancer. Since there is a growing awareness about the necessity of early intervention criteria have been developed that aid the identification of hereditary forms of gastric cancer. The aim of the current study was to identify minimal inclusion criteria so that nuclear pedigree families can be provided with risk assessment and/or genetic testing.The results reveal that inclusion features described herein such as (a) gastric cancer diagnosed before 46 years of age; (b) two gastric cancers among first degree relatives diagnosed over the age of 50 are useful in identifying suspected hereditary gastric cancer patients.     

Use of the humanized anti-epidermal growth factor receptor monoclonal antibody h-R3 in combination with radiotherapy in the treatment of locally advanced head and neck cancer patients.

PURPOSE: To evaluate safety and preliminary efficacy of the humanized anti-epidermal growth factor receptor monoclonal antibody h-R3 in combination with radiotherapy (RT) in unresectable head and neck cancer patients. Secondary end points were the measurement of h-R3 serum levels and the assessment of the potential mechanisms of antitumor effect on patient biopsies. Anti-idiotypic response to h-R3 was assessed. To predict pharmacologic effect, a mathematical model for antibodies recognizing antigens expressed in tumors and normal tissues was built. PATIENTS AND METHODS: Twenty-four patients with advanced carcinomas of the head and neck received six once-weekly infusions of h-R3 at four dose levels in combination with RT. Pretreatment tumor biopsies were obtained to evaluate epidermal growth factor receptor expression as an enrollment criterion. Second biopsies were taken to evaluate the proliferative activity and angiogenesis in comparison with the pretreatment samples. Patient serum samples were collected to measure h-R3 levels and anti-idiotypic response. RESULTS: The combination of h-R3 and RT was well tolerated. Antibody-related adverse events consisted in infusion reactions. No skin or allergic toxicity appeared. Overall survival significantly increased after the use of the higher antibody doses. Immunohistochemistry studies of tumor specimens before and after treatment revealed that antitumor response correlated with antiproliferative and antiangiogenic effect. One patient developed antibodies to h-R3. The mathematical model predicted that the maximum difference between the area under the curve in tumors and normal tissues is reached when the antibody has intermediate affinity. CONCLUSION: h-R3 is a well-tolerated drug that may enhance radiocurability of unresectable head and neck neoplasms.