RESUMEN

Visuospatial memory (VSM) is the ability to represent and manipulate visual and spatial information. This cognitive function depends on the functioning of the hippocampal formation (HF), located in the medial portion of the temporal cortex. The present study aimed to investigate whether there is an association between the volume of the HF and performance in VSM tests. High-resolution structural images (T1) and neuropsychological tests evaluating VSM were performed on 31 healthy individuals. A VSM index was created by grouping 5 variables from 5 tasks (4 from the CANTAB battery and 1 from the Rey-Osterrieth Complex Figure test). Multiple linear regression models using the volumes of HF subregions as independent variables and the VSM index as the dependent variable were conducted to test the hypothesis that memory performance could be predicted by HF volumes. We also conducted analyses to explore the role of covariates that may mediate this relationship, specifically age and intelligence quotient (IQ). We found significant associations between the hippocampal subregions of the left hemisphere and the VSM index (F(7,22)=2.758, P=0.032, R2a=0.298). When IQ was accounted for as a covariate, we also found significant results for the right hemisphere (F(8,21)=2.804, P=0.028, R2a=0.517). We concluded that the bilateral hippocampal formations contributed to performance on VSM tasks. Also, VSM processing is essential for a diverse set of daily activities and may be influenced by demographic variables in healthy subjects.

Asunto(s)

RESUMEN

Visuospatial memory (VSM) is the ability to represent and manipulate visual and spatial information. This cognitive function depends on the functioning of the hippocampal formation (HF), located in the medial portion of the temporal cortex. The present study aimed to investigate whether there is an association between the volume of the HF and performance in VSM tests. High-resolution structural images (T1) and neuropsychological tests evaluating VSM were performed on 31 healthy individuals. A VSM index was created by grouping 5 variables from 5 tasks (4 from the CANTAB battery and 1 from the Rey-Osterrieth Complex Figure test). Multiple linear regression models using the volumes of HF subregions as independent variables and the VSM index as the dependent variable were conducted to test the hypothesis that memory performance could be predicted by HF volumes. We also conducted analyses to explore the role of covariates that may mediate this relationship, specifically age and intelligence quotient (IQ). We found significant associations between the hippocampal subregions of the left hemisphere and the VSM index (F(7,22)=2.758, P=0.032, R2a=0.298). When IQ was accounted for as a covariate, we also found significant results for the right hemisphere (F(8,21)=2.804, P=0.028, R2a=0.517). We concluded that the bilateral hippocampal formations contributed to performance on VSM tasks. Also, VSM processing is essential for a diverse set of daily activities and may be influenced by demographic variables in healthy subjects.

Asunto(s)

RESUMEN

OBJECTIVE: To produce standard curves of birth weight according to gestational age validated by ultrasonography in the British population, with particular reference to the effects of ethnic origin. DESIGN: Retrospective analysis of computerised obstetric database. SETTING: Three large maternity units associated with Nottingham University with over 16,000 deliveries a year. PATIENTS: 41,718 women with ultrasound dated singleton pregnancies and delivery between 168 and 300 days' gestation. MAIN OUTCOME MEASURES: Length of gestation, ethnic origin, parity, maternal height and weight at booking, smoking during pregnancy; the effect of these variables on birth weight. RESULTS: Birth weights from ultrasound dated pregnancies have a higher population mean and show less flattening of the birthweight curve at term than those of pregnancies dated from menstrual history. Significant differences were observed in mean birth weights of babies of mothers of European origin (3357 g), of Afro-Caribbean origin (3173 g), and from the Indian subcontinent (3096 g). There were also significant interethnic differences in length of gestation, parity, maternal height, booking weight, and smoking habit which affected birth weight. The ethnic differences in birth weight were even greater when the effect of smoking was excluded. CONCLUSIONS: Birthweight standards require precise dating of pregnancy and should describe the population from which they were derived. In a heterogeneous maternity population the accurate assessment of an individual baby's weight needs to take the factors which affect birthweight standards into consideration.

PIP: A new set of standard curves of birth weight for singleton pregnancies with gestational age dated by ultrasonography was generated for the British population. The source of data was a computerized obstetric database of 41,718 pregnancies delivered between 168 and 300 days' gestation, taken from 3 large maternity units in East Midlands, the Nottingham University and City Hospitals, and Derby City Hospital. There were significant differences between the birthweights of 37,336 babies of mothers of English-European origin (3357 gm), 1008 babies of Afro-Caribbean origin (3173 gm), and 1547 babies of Indian subcontinent origin (3096 gm). There were also significant differences between ethnic groups for gestational length, parity, maternal height, weight, and smoking. These differences were greater than smoking was controlled. The effect of smoking was dose-related: at 40 weeks' gestation mean birthweights were 3580 gm for nonsmokers, 3416 gm for 1-9 cigarettes daily, 3374 gm for 10-19 cigarettes daily, and 3377 gm, for over 20 cigarettes daily. About 30% of the European and Afro-Caribbean women smoker, but almost none of the east Indians did. As had been seen elsewhere, ultrasound dating showed a lower gestational age than did menstrual dating (276 vs. 279 days), a discrepancy that is most likely to be clinically relevant in postdate gestations. While ultrasound dating is much more accurate, ethnic origin must be taken into account when assessing individuals.

Asunto(s)

Asunto(s)

RESUMEN

The circulating lymphocytes in peripheral blood comprise a group of cells with different origins, life span, fine structure, and proliferative capacity. Under normal circumstances, these lymphocytes do not divide and peripheral blood from healthy individuals contains only about 0.1 percent of lymphocytes in DNA synthesis. This proportion is much increased in infectious mononucleosis, several viral, bacterial and rickettsial diseases and is even greater in acute and chronic myeloid leukaemia and other reticuloses. This study was undertaken to assess the DNA-synthesising ability of lymphocytes in peripheral blood of patients with infectious diseases and to ascertain if the proliferative response was related to the nature of the infecting agent. The agents studied included leptospira, proteus, pneumococcus, staphylococcus, streptococcus, tetanus, klebsiella and some viruses. DNA synthesis was assessed by the ability of the cells to incorporate tritiated thymidine (H3T) or I125 deoxyuridine (I125DU) into DNA, following a one-hour pulse in vitro I125 DU uptake was measured by scintillation counting which provided an index of the per cent isotope incorporation in a given population of cells. By H3T autoradiography, specific cell types undergoing DNA synthesis were identified and quantitated by the Labelling Index (number of cells labelled/total cells counted). A total of 84 patients and 16 normal control subjects were studied. The results by both method indicated a definite increase in percentage of DNA-Synthesising cells in all infected patients, the greatest response being in leptospira, proteus and pneumococcus infections. Response was low in klebsiella infections and in sickle cell anaemia patients with infected leg ulcers. The labelling indices showed a mean of 3.01 + 019 percent and 0.04ñ0.09 percent in leptospirosis and sickle cell anaemia respectively, as compared with a 0.3 percentñ0.00 percent in normals. These studies demonstrated that lymphoid elements stimulated in vivo initiate a phase of proliferation in what is apparently an immunologic reaction mounted against the foreign infectious agents. This proliferative response may provide a means of increasing the numbers of antigenically-activated cells or may function in a reparative way. The measurement of DNA-synthesising cells represents a sensitive tool in the investigation of inflammatory and immunoproliferative disorders (AU)

Asunto(s)

Asunto(s)

Asunto(s)

Asunto(s)

RESUMEN

The purpose of this paper is to assess: (1) the adequacy of the food supply of the nation obtained according to FAO methodology from the 1972 Food Balance Sheet; (2) the food consumption patterns of families in four expenditure groups studied in a Household Budget Survey of 1971-72 (Department of Statistics, Jamaica)

Asunto(s)