Properties of memory-guided saccades toward targets flashed during smooth pursuit in human subjects

PURPOSE: This study in human subjects investigated whether or not the saccade system can monitor smooth changes of the eye position in total darkness. METHODS: The authors studied the properties of memory-guided saccades toward targets flashed during pursuit eye movements (target velocities of 15 degrees/s, 30 degrees/s, and 45 degrees/s) in four normal human subjects. Subjects were instructed to execute memory-guided saccades toward the position of the flashed target in total darkness when the pursuit target was extinguished. RESULTS: The vector of the saccade was more highly correlated with the vector of "spatial error" (the vector from the position of the eye at the time of the saccade to the position of the flashed target in space) than with the vector of "retinal error" (the vector from the position of the eye at the time of the presentation of the flashed target to the position of the flashed target). The amplitude and direction errors of memory-guided saccades were correlated with the amplitude of the retinal error but not with amplitude of eye deviation after the presentation of the flashed target. Pursuit velocity did not affect the error of the saccade. CONCLUSIONS: These findings suggest that the saccade system can monitor smooth changes of the eye position in total darkness, regardless of the velocity of pursuit, and that the accuracy of memory-guided saccades is dependent only on the amplitude of the retinal error.     

Spatial working memory deficits in the relatives of schizophrenic patients

BACKGROUND: Studies in nonhuman primates provide evidence that intact spatial working memory depends on the integrity of specific areas in the prefrontal cortex. Patients with schizophrenia have been shown to be impaired on spatial working memory tasks. Relatives of schizophrenic patients show a range of cognitive deficits in the absence of clinical symptoms (eg, thought disorder, eye tracking dysfunctions). We predicted that a significant proportion of relatives of schizophrenic patients would show deficits in working memory as measured by a delayed response task. METHODS: In experiment 1, we tested 18 schizophrenic patients, 15 first-degree relatives of schizophrenic patients, and 18 normal control subjects on an oculomotor delayed response task. In experiment 2, we assessed the performance of another group of 12 first-degree relatives of schizophrenic patients and 16 different normal control subjects on a visual-manual delayed response task. RESULTS: Relatives of schizophrenic patients showed significant deficits in working memory on both the oculomotor and visual-manual delayed response tasks. CONCLUSIONS: Some relatives of schizophrenic patients are impaired on tasks that tap spatial working memory and that implicate the prefrontal system. The delayed response paradigm may be useful in elucidating the multidimensionality of the schizophrenic phenotype.     

Spatial organization and plasticity of the primary and secondary olfactory projections in goldfish

Crystals of the lipophilic tracer DiI were applied to discrete regions of the olfactory epithelium of goldfish to trace the primary sensory projection to the olfactory bulb. Receptors from the anterior half of the sensory sheet project primarily to glomeruli in the medial half of the bulb and receptors in the posterior half terminate mainly within the lateral half of the bulb. This pattern disappeared following ablation of selected, discrete epithelial regions. In order to investigate reorganization of secondary olfactory projections, unoperated control and unilaterally bulbectomized animals received injections of [3H]proline into the right olfactory bulb. Densities of silver grains per unit area were determined within six different forebrain nuclei in both the right and left hemispheres of each animal. Of the six areas examined, three demonstrated a significantly greater density of afferent innervation from the ipsilateral versus contralateral bulb; a difference which disappeared in two of these three regions after bulbectomy. Thus, for at least two forebrain nuclei, bulb removal caused a change in the afferent input from the spared olfactory bulb to those regions. We conclude that both primary and secondary olfactory projections in goldfish are capable of some degree of reorganization following insult.     

Accuracy of visually and memory-guided antisaccades in man

Primary saccades to remembered targets are generally not precise, but rather undershoot target position. The major source of this saccadic undershoot may be (a) a memory-related process or (b) a poor spatial resolution in those processes which transfer the retinotopic target information into an intermediate memory-linked representation of space. The aim of this study was to investigate whether distortions of eye positions in the antisaccade task, which are characterized by inherent co-ordinate transformation processes, may completely account for the spatial inaccuracies of memory-guided antisaccades. The results show that the spatial inaccuracy of primary and secondary eye movements in the visually guided antisaccade task was comparable to that in the memory-guided antisaccade task. In both conditions, the direction error component was less dysmetric than the amplitude error component. Secondary eye movements were significantly corrective. This increase of eye position accuracy was achieved by reducing the amplitude error only. It is concluded from this study that at least some of the distortion of memory-guided saccades is due to inaccuracies in the sensorimotor co-ordinate transformations.     

Custom made total knee-replacement in patients with primary and secondary bone tumors

The authors present an account of a group of 51 patients to whom an individual endoprosthesis of the knee joint was implanted on account of a tumour. A primary bone tumour was involved in 42 cases and a metastatic process in 9 cases. Twenty-four endoprostheses were cemented, 26 were implanted without cement. The mean follow-up period was 43 months. Functional results excellent and good in 61%, poor results only in 5%.     

A prospective study of primary and secondary risk factor management in stroke patients

Stroke is a common event which often results in death or major loss of independence with immense human and financial costs, so identification of patients at risk, and prevention of stroke at the individual and population levels, is a high clinical and health priority. From August 1993 to July 1994, 468 stroke patients admitted to our hospital were assessed for the presence of stroke risk factors. All patients were followed up in hospital, and on discharge or death all hospital records were reviewed. We show that many risk factors remain uncorrected in stroke patients and that preventive measures are less than ideal at the community and hospital levels alike.     

Relations between cardiac and vascular structure in patients with primary and secondary hypertension

BACKGROUND: Data on cardiac and vascular structure in secondary hypertension are generally scarce, and no data on the interrelations between cardiac mass and structural characteristics of the vessel wall, both in large and in small resistance arteries, are presently available. OBJECTIVES: The aim of this study was to investigate the relation between structural changes in subcutaneous small arteries, left ventricular mass and wall thickness of the common carotid artery in patients with primary and secondary hypertension. METHODS: Seventy-four subjects were included in the study: 11 patients with pheochromocytoma, 14 with primary aldosteronism (PA), 19 with renovascular hypertension (RVH), 18 with essential hypertension (EH) and 12 normotensive (NT) control subjects. All subjects were submitted to a biopsy of subcutaneous fat. Morphologic characteristics of subcutaneous small resistance arteries (relaxed diameter <300 microm) were directly evaluated using a micromyographic technique. All subjects were submitted to calculation of left ventricular mass index (LVMI) and common carotid artery intima-media thickness (CCIMT), using ultrasound technique. RESULTS: The correlation coefficients between the media to lumen ratio in subcutaneous small arteries (M/L) and LVMI or between M/L and CCIMT were closer in RVH than in pheochromocytoma, EH or NT; in PA the correlation coefficients were slightly less close than those in RVH. An excess prevalence of carotid plaques in RVH was observed. CONCLUSIONS: A close relation between small resistance artery morphology and cardiac or carotid artery structure may be observed in those hypertensive patients in whom the renin-angiotensin-aldosterone system is activated. In constrast, in NT, EH and pheochromocytoma no significant correlation between M/L and LVMI or CCIMT was observed.     

Cardiovascular prevention, primary or secondary, in high risk patients

Two groups of patients admitted to hospital consecutively for coronary artery disease in 36 university hospital departments were interrogated about the advice received and followed concerning cardiovascular prevention both before the clinical onset of the disease (Group I), those with disease of less than one month duration (primary prevention), or after this period (Group II), those with disease for over six months (secondary prevention). The follow-up of risk factors or medical advice concerning prevention (dietary and/or treatment) was more common, and compliance to the advice was better, in secondary prevention. However, in both groups, with the exception of hypertension, the diagnosis and follow-up of the risk factors were incomplete with 19% vs 41% (p < or = 0.001) of serum cholesterol levels unmeasured before the onset of clinical disease; during the last 5 years, 41% vs 12% (cholesterol, p < or = 0.001) and 27% vs 9% (serum glucose, p < or = 0.001) were not checked. At least one measure of prevention had been advised to 66% vs 80% (p < or = 0.001) of patients and the measures taken concern 53 vs 75% (p < or = 0.001) of patients: serum cholesterol 27% vs 51% (p < or = 0.001), hypertension 32% vs 36% (NS) and serum glucose 14% vs 21% (p < or = 0.05). Compliance with advice was mediocre with regards to diet and cholesterol lowering drugs. A large proportion of patients in both groups had higher than recommended levels, including those on diet or treatment. These observations, confirmed in France and abroad, suggest that cardiovascular prevention should be better organised.     

Differential immunological aberrations in patients with primary and secondary Sj?gren''s syndrome

PURPOSE: To evaluate the dependence of fine particle dose charge (FPD charge) generated from powder inhalers on physico-chemical properties of the inhalation powder, inhaler type, deaggregation mechanism, dose number and/or retained powder. METHODS: Electrostatic charges were determined on micronized powders and aerosolized fine particle doses withdrawn from two, high efficiency, multidose powder inhalers, Turbohaler and prototype Dryhaler. The behavior of terbutaline sulfate, budesonide, albuterol (sulfate and base), beclomethasone dipropionate and lactose was assessed before and after aerosolization. RESULTS: Both inhalers conferred triboelectric FPD charges during aerosolization in the range -400 pC through +200 pC. Specific charges (charge/unit mass) on the fine particle doses of budesonide from Dryhaler were significantly less than those from Turbohaler (p < 0.01). Electrostatic charges on the potentially respirable cloud of terbutaline sulfate generated by Bricanyl Turbohaler were positive and/or negative and unpredictable. With Pulmicort Turbohaler, FPD charges on budesonide were always positive. Dryhaler was used to determine the chemical dependence of fine particle triboelectrification during the aerosolization of pure materials. A triboelectric series was constructed from the Dryhaler results ranking the powders from positive to negative as budesonide > lactose > albuterol sulfate > terbutaline sulfate > or = albuterol > or = beclomethasone dipropionate. CONCLUSIONS: While there was no evidence of FPD charge dependence upon dose number with either inhaler, FPD charges were dependent upon the powder under investigation, as well as the construction and deaggregation mechanism of the inhaler. The specific charge on the fine particle dose of budesonide from Turbohaler corresponded to approximately 200 electronic charges per particle, a value which is known to affect both total and regional aerosol deposition in the human lung. Electrostatic charge effects may be important determinants of aerosol behavior and should not be neglected.     

Genetic alterations in primary and secondary hyperparathyroidism

OBJECTIVE: To evaluate treatment of patients with primary liver cancer. DESIGN: Prospective protocol including subsets of randomised studies. SETTING: University hospital, Sweden. SUBJECTS: 123 patients with primary liver cancer. INTERVENTIONS: 64 patients underwent hepatic resection, 25 were included in a trial of adjuvant chemotherapy. 24 further patients whose tumours were not resectable were included in a trial of intra-arterial infusion of doxorubicin. MAIN OUTCOME MEASURES: Survival and postoperative morbidity. RESULTS: The median survival time for patients who had had resections was 11 months (range 0-111). Twelve per cent survived more than 5 years. No prognostic factor had any significant effect on outcome. The postoperative mortality was 11% (7/64). The patients allocated to adjuvant chemotherapy survived a median of 10 months (range 1-47) and the controls 29 months (range 8-111) (p=0.04). Patients with unresectable liver cancer treated with intra-arterial doxorubicin lived no longer than untreated controls (median 8 months (range 1-56) compared with 7 months (range 1-28)). CONCLUSIONS: Treatment of patients with primary liver cancer is still an unsolved problem. Adjuvant chemotherapy with doxorubicin had no beneficial effect on survival.     

Diagnostic laparoscopy in primary and secondary infertility

PURPOSE: Our purpose was to compare the diagnostic efficacy of laparoscopy between primary and secondary infertility and to define a subgroup in which the positive findings are low. METHODS: A retrospective review of the cases of 206 infertile women who underwent laparoscopy was conducted. RESULTS: Eighty-two (39.8%) patients were found to have evidence of pelvic disease--20 (22.2%) with primary infertility and 62 (54.3%) with secondary infertility. The ratio of positive findings in secondary infertility was significant in comparison with the positive findings in primary infertility. In only 3 of the 20 patients with primary infertility was there no history of an abdominal operation, pelvic inflammatory disease, or an abnormal hysterosalpingography. Of the 62 women who suffered secondary infertility and had positive findings in laparoscopy, 15 had no history of suspect findings. CONCLUSIONS: The diagnostic yield of laparoscopy for primary infertility in the absence of indications of mechanical factors is low. Therefore the need for diagnostic laparoscopy in these cases should be reconsidered.     

Sexual dysfunction in male schizophrenic patients

BACKGROUND: Neuroleptic treatment in schizophrenic patients is associated with sexual dysfunction. However, it is not clear to what extent the psychiatric disorder and/or the pharmacologic treatment are responsible for the sexual impairment. The aim of the present study was to evaluate the sexual function of untreated and treated male schizophrenic patients in comparison with healthy subjects. METHOD: Participants included 122 male subjects: 20 drug-free schizophrenic patients, 51 neuroleptic-treated (depot form) schizophrenic patients, and 51 normal controls. A detailed structured interview was used to quantitatively and qualitatively assess sexual function. RESULTS: A high frequency of sexual dysfunction was reported by both schizophrenic groups of patients. Impairments in arousal items (erection) and orgasm during sex were reported mainly by the treated patients. Desire parameters were reduced in both schizophrenic groups, but reduction in the frequency of sexual thoughts was confined to the untreated one. The schizophrenic patients were more involved in masturbatory activity in comparison with the control subjects. Treated patients disclosed dissatisfaction with their sexual function. CONCLUSION: Untreated schizophrenic patients exhibit decreased sexual desire. Neuroleptic treatment is associated with restoration of sexual desire yet it entails erectile, orgasmic, and sexual satisfaction problems. Clinicians' awareness and open discussion of sexual problems with patients may improve comprehension and compliance.     

Brain evoked potential in schizophrenic patients

The authors reviewed the literature on evoked potentials in mentally ill patients, with particular emphasis on schizphreniacs. The commonly observed abnormalities were as follows: 1) higher SEPs amplitudes with less waveshape variability during first 100 ms in non-depressed chronic, paranoid or undifferentiated patients with florid psychotic symptoms; normal SEPs amplitudes in acute or latent schizophrenics and in chronic depressed schizophrenics but without florid psychotic symptoms; 2) reduced SEPs and VEPs amplitude recovery and faster latency recovery; 3) reduced AEPs amplitude and latency; 4) greater VEPs waveshape variability and tendency to be "reducers" in hallucinating patients; reduced amplitude and latency recovery; prolonged latencies in patients with positive family history (schizophrenia or affective disorders in close relatives); prolonged N2 latency in motor responses to "easy" and "difficult" stimuli; reduced activity of "late potentials"; 5) greater waveshape variability in all modalities in chronic schizophrenics, abnormal P300 (reduced amplitude, lack of P300 or negative "effect of uncertainty") and abnormal CNV (less "readiness" potential, prolonged negativity with motor responses).     

Shape constancy in schizophrenic patients.

Shape constancy in visual perception of schizophrenic patients was studied. 40 chronic schizophrenic, 40 acute schizophrenic, 40 nonschizophrenic mental patients, and 40 normal controls were used as Ss. Ss matched the shape of a standard object (circle) inclined at an angle. 2 angles of inclination, 30° and 60°, were used. It was found that shape constancy was lower in schizophrenic patients than in controls when the stimulus object was inclined 60° from the horizontal plane. When the angle of inclination was 30° there was no difference between the groups. The chronic schizophrenic patients displayed greater response variability than the other groups. The relation of these findings to the theory of assimilation of percepts to the perceptual schemata in schizophrenic patients was discussed. (23 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Overinclusive thinking and delusions in schizophrenic patients.

15 schizophrenics with paranoid delusions, 15 schizophrenics with no delusions, and a control group of 15 nonschizophrenic hospitalized patients were given the Benjamin Proverbs test, the Mill Hill Vocabulary Scale, and 3 of Babcock's psychomotor speed tests. As predicted, there was a significant relationship between the presence or absence of delusions, and overinclusive thinking, as assessed by the average number of words needed to explain the proverbs and 2 time scores. Overinclusive patients tend to have paranoid delusions. There was no significant relationship between retardation, as assessed by the Babcock tests, and the presence of delusions. This finding complements an earlier finding of Harris and Metcalfe (see 32: 719) that slowness in schizophrenic patients is specifically associated with inappropriate affect and a poor prognosis, and Payne's (see 37: 5499) finding that a group of chronic schizophrenics was not overinclusive. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Clozapine in long-term treatment of schizophrenic patients

Clozapine has advantages over standard antipsychotics in refractory schizophrenia. Studies on the efficacy of clozapine in the maintenance treatment are sparse and suffer from methodological limitations. Despite this fact clozapine ranked second in a survey dealing with the preference of this antipsychotic in the long-term treatment of schizophrenia. Doctors report on using a mean of 130 mg/d in this indication which is considerably less than the doses used in most of the published long-term trials. The discrepancy between the popularity of clozapine and the lack of sound empirical data on its long-term efficacy is discussed.     

The future of protein secondary structure prediction accuracy

In order to investigate the path of medical education in Iran, indicators of medical education were searched from 1970 to 1994. There have been rises in the number of educational institutions from 10 to 46; student admissions in programmes of medical sciences from 1387 to 18,141; medical student admissions from 632 to 3630; teaching staff from 1573 to 7979; and teaching-bed to student ratio from 1.05 to 2.08. The numbers of students in clinical specialty and MS degrees have increased, and various programmes in clinical sub-specialty and PhD degrees have been initiated. The quality of medical education has improved with increasing field and ambulatory care training, with more emphasis on teaching preventive medicine and a significant rise in the research activities. Most qualitative and quantitative progress has been achieved following the establishment of a joint Ministry of Health and Medical Education in 1985. The results of this review demonstrate the success of Iran in upgrading medical education by the unification of health services and medical education in one ministry.     

Plasma levels of adrenomedullin in primary and secondary pulmonary hypertension in patients <20 years of age

To elucidate the pathophysiologic significance of adrenomedullin in pulmonary hypertension, we measured plasma adrenomedullin-like immunoreactivity (AM-LI) concentrations in blood samples obtained from various sites during cardiac catheterization by using radioimmunoassay in patients with pulmonary hypertension in comparison with patients without pulmonary hypertension. In patients with pulmonary hypertension, plasma AM-LI concentrations were significantly elevated and there was a significant uptake of AM-LI in pulmonary circulation, indicating the involvement of adrenomedullin in the cardiovascular regulation of pulmonary circulation in pulmonary hypertension.