Molecular surveillance detects high prevalence of the neglected parasite Mansonella ozzardi in the Colombian Amazon.

Mansonellosis is an undermapped insect-transmitted disease caused by filarial nematodes that are estimated to infect hundreds of millions of people globally. Despite their prevalence, there are many outstanding questions regarding the general biology and health impacts of the responsible parasites. Historical reports suggest that the Colombian Amazon is endemic for mansonellosis and may serve as an ideal location to pursue these questions in the backdrop of other endemic and emerging pathogens. We deployed molecular and classical diagnostic approaches to survey Mansonella prevalence among adults belonging to indigenous communities along the Amazon River and its tributaries near Leticia, Colombia. Deployment of a loop-mediated isothermal amplification (LAMP) assay on blood samples revealed an infection prevalence of ∼40% for Mansonella ozzardi . This assay identified significantly more infections than blood smear microscopy or LAMP assays performed using plasma, likely reflecting greater sensitivity and the ability to detect low microfilaremias or occult infections. Mansonella infection rates increased with age and were higher among males compared to females. Genomic analysis confirmed the presence of M. ozzardi that clusters closely with strains sequenced in neighboring countries. We successfully cryopreserved and revitalized M. ozzardi microfilariae, advancing the prospects of rearing infective larvae in controlled settings. These data suggest an underestimation of true mansonellosis prevalence, and we expect that these methods will help facilitate the study of mansonellosis in endemic and laboratory settings.

The Added Value of SPECT/CT in Sentinel Lymph Nodes Mapping for Endometrial Carcinoma.

OBJECTIVES: This study was designed to evaluate the detection rate (DR) and sensitivity of sentinel lymph node (SLN) mapping in patients with endometrial cancer using TC99m colloid and blue dye and to evaluate the contribution of preoperative planar lymphoscintigraphy (PLSG) and SPECT/CT. METHODS: A retrospective analysis of patients who underwent SLN mapping as part of their primary surgery for endometrial cancer. Patients underwent preoperative PLSG and later with additional SPECT/CT. Intraoperative detection was performed using TC99m colloid and blue dye by cervical injections. SLNs were sent separately for pathologic evaluation with ultrastaging. RESULTS: Fifty-three patients were included in this study. Successful preoperative mapping was achieved in 31 of 37 patients (84 %) who underwent SPECT/CT compared with only 30 of 45 patients (67 %) who underwent PLSG. SPECT/CT localizations of SLNs were anatomically accurate in 91 % of cases. Intraoperative DR of at least one SLN was 77 %, whilst the bilateral DR was 49 %. DR was significantly better using combined blue dye and TC99m colloid injections compared with blue dye alone: 81 versus 57 % for unilateral and 54 versus 28 % for bilateral mapping (P = 0.01, 0.009, respectively). Six cases of nodal metastasis were diagnosed: four by positive SLNs, and two cases were diagnosed using side-specific full dissection according to the SLN algorithm when SLN detection failed. There were no cases of false-negative results. CONCLUSIONS: SLN detection using cervical injections of TC99m colloid and blue dye is feasible and sensitive for patients with endometrial cancer. SPECT/CT aids to accurate locating of the SLN.

Use of naturally growing aquatic plants for wastewater purification.

This paper examines potential uses of naturally growing aquatic plants for wastewater purification. These plants enhance the removal of pollutants by consuming part of them in the form of plant nutrients. This applies to urban and agricultural wastewater, in particular, where treatment units of different sizes can be applied at the pollution source. The effectiveness of wastewater purification by different plants was tested on laboratory and pilot scales. The growth rate of the plants was related to the wastewater content in the water. Batch and semicontinuous experiments verified that the plants are capable of decreasing all tested indicators for water quality to levels that permit the use of the purified water for irrigation. This applies to biochemical oxygen demand (BOD), chemical oxygen demand, total suspended solids. pH, and turbidity. In specific cases, the turbidity reached the level of drinking water. Comparison of BOD concentrations with typical levels in water treatment facilities across the country indicates the effectiveness of water purification with plants. A major effect of treatment with plants was elimination of the disturbing smell from the wastewater. It is shown that mixtures of wastewater and polluted water from the Kishon River are amenable in varying degrees to treatment by the plants. The higher the wastewater content in the mixture, the more effective the treatment by the plants. In this context, a scheme for rehabilitation and restoration of the Kishon River is presented and technical and economical aspects of the purification technology are considered.

Temporal lobe volume determined by magnetic resonance imaging in schizotypal personality disorder and schizophrenia.

The volumes of the whole temporal lobe, the superior temporal gyrus and the corpus callosum were measured on magnetic resonance images from 13 patients with schizotypal personality disorder (SPD), 27 patients with schizophrenia, and 31 age- and sex-matched controls. Temporal lobe structures were traced on consecutive 1.2mm thick SPGR images. Both patient groups had smaller temporal lobes than normal volunteers, a difference that was more marked for the area outside the superior temporal gyrus than for the STG. Correcting for brain volume diminished differences between normal subjects and schizophrenia patients, but the differences between normal subjects and SPD patients remained. Normal volunteers and SPD patients showed significant correlations between the sagittal section area of the posterior portion of the corpus callosum, which carries temporal interhemispheric connections, and the white matter volume of the temporal lobe. While the sample size is modest, taken together, these results suggest that the psychopathological symptoms of SPD may be related to temporal gray matter loss with relatively intact white matter connectivity, while the cognitive and psychotic symptoms of schizophrenia may be related to temporal gray loss combined with disruption of normal patterns of white matter development.

Visuospatial working memory in schizotypal personality disorder patients.

BACKGROUND: Cognitive processing deficits have been identified as an abnormality that schizotypal personality disorder (SPD) individuals share with schizophrenic patients. It has been hypothesized that impaired working memory may be a critical component of several of the more complex cognitive deficits found in schizophrenia spectrum patients. METHOD: 18 DSM-III-R SPD patients, and 17 normal comparison subjects were compared on a pen and paper visuospatial working memory task. Moreover, we identified a second psychiatric comparison group comprised of nine patients with other, non-odd cluster personality disorder diagnoses who met no more than one of the SPD criteria and were also tested on the same task. Each person was given 14 immediate recall trials and 10 trials using a 10 s delay. RESULTS: SPD patients performed significantly worse than normal control subjects on the working memory task. SPD patients also performed significantly worse compared to the non-schizophrenia-related personality disorder psychiatric comparison group. CONCLUSIONS: Like schizophrenic patients, SPD patients demonstrate working memory impairment compared to normal controls. This impairment may be specific to the schizophrenia-related personality disorders.

The effect of long-term antipsychotic treatment on the body weight of patients suffering from chronic schizophrenia: clozapine versus classical antipsychotic agents.

The aim of this study was to evaluate the effect of long-term clozapine treatment on body weight changes in neuroleptic-resistant chronic schizophrenic patients and to compare it with that of classical antipsychotic agents. The body mass index (BMI) of 96 neuroleptic-resistant chronic schizophrenic patients was calculated before the beginning and after long-term (mean +/- SD 1.7 +/- 1.3 years) clozapine treatment. These data were compared to the BMI of 98 chronic schizophrenic patients maintained on classical antipsychotic agents for a similar duration (mean +/- SD 1.9 +/- 1.6 years). A significant elevation in BMI was detected in both groups during these periods (P < 0.0001 versus baseline, for both groups). The change in BMI (delta BMI) was similar in both groups (P < 0.9). We conclude that the increase in body weight caused by long-term (> 6 months) clozapine treatment is comparable to that obtained following long-term classical antipsychotic agents treatment.

Verbal learning and memory in schizotypal personality disorder.

The investigation of cognitive deficits in patients with schizotypal personality disorder (SPD) is important both to establish commonalities between SPD and schizophrenia and to clarify the significance of these cognitive deficits for schizophrenic disorders. The purpose of this study was to examine verbal learning and memory with the California Verbal Learning Test (CVLT) in a group of patients with SPD (n=24) and a group of patients with personality disorders other than SPD (OPD; n=25). The results indicated that SPD patients learned significantly fewer words with practice on the CVLT than OPD patients (F=4.32, df=1,47, p < 0.05), and their rate of learning was reduced relative to normative standards. These findings suggest that SPD patients have a deficit in verbal learning that is similar to, although not as severe as, the impairments seen in schizophrenia.

Diminished suicidal and aggressive behavior, high plasma norepinephrine levels, and serum triglyceride levels in chronic neuroleptic-resistant schizophrenic patients maintained on clozapine.

Impulsiveness and aggressiveness may be the most common behavioral correlates of central serotonergic dysfunction. The aim of this study was to determine whether clozapine, an atypical antipsychotic agent with a potent serotonergic antagonistic activity, affects impulsiveness and aggression. Its effects on serum lipids, platelet-poor plasma serotonin (5-HT), and norepinephrine (NE) levels were also studied. Thirty neuroleptic-resistant chronic schizophrenic patients, maintained on clozapine for 1 year, were evaluated for aggressiveness, impulsiveness, and suicidality in comparison with 30 chronic schizophrenic patients maintained on classical antipsychotic agents for the same period of time. Clozapine treatment was associated with less impulsiveness (p < 0.05), aggressiveness (p < 0.01) and fewer suicidal attempts (p < 0.05). Serum triglycerides and plasma NE levels were significantly higher (p < 0.01 and p < 0.0001, respectively) in the patients treated with clozapine, as compared with patients treated with classical neuroleptic drugs. The authors conclude that long-term clozapine treatment may be effective in controlling aggressive, impulsive, and suicidal behavior in neuroleptic-resistant chronic schizophrenic patients. The elevated plasma NE levels in patients treated with clozapine as compared to those treated with classical neuroleptic drugs may be relevant for the anti-aggressive/antisuicidal activity of clozapine.

Attentional and eye tracking deficits correlate with negative symptoms in schizophrenia.

Thirty patients with a DSM-III-R diagnosis of schizophrenia were assessed for severity of schizophrenic symptoms using the Brief Psychiatric Rating Scale (BPRS) and were tested on a Continuous Performance Test (CPT) and a smooth pursuit eye tracking task. Negative symptoms were significantly correlated with eye tracking impairment (r = 0.43, p < 0.01) and CPT deficits (r = 0.67, p < 0.001), but performance on neither task was correlated with positive symptoms. CPT performance and eye tracking performance were modestly correlated with each other (r = 0.39, p < 0.01) and CPT performance was found to be a stronger predictor of negative symptoms than eye tracking performance. These data indicate that neurocognitive markers of vulnerability to schizophrenia are associated with negative rather than positive symptoms.

Performance of patients with schizophrenia on a pen and paper visuospatial working memory task with short delay.

Human and nonhuman primate data suggest that visuospatial working memory is mediated by a neural network that includes the prefrontal cortex. Simple working memory tasks are less complex than standard neuropsychological tests of frontal dysfunction. As such, they are less vulnerable to general performance factors such as amotivation and uncooperativeness in schizophrenic patients. These tasks thus hold promise as potential measures of frontal dysfunction in schizophrenia. However, the specific parameters of visuospatial working memory deficit in schizophrenia have not been established. This study assessed working memory functions in 18 schizophrenic patients and 28 controls using a pen-and-paper analogue of a monkey prefrontal cortex activation task. Schizophrenic patients and controls performed similarly on a sensory-guided task that did not require working memory functions, yet schizophrenic patients performed significantly worse than controls on tasks that required subjects to retain visuospatial information for delay periods of 10 and 20 s. These data suggest that the working memory deficits in patients with schizophrenia begin to appear less than 10 s following encoding of visuospatial information and that these working memory deficits can be assessed with easily administered pen-and-paper tasks.

Attentional functioning in schizotypal personality disorder.

OBJECTIVE: Previous research has shown biological, phenomenological, and cognitive similarities between schizophrenic patients and individuals with schizophrenia-related personality disorders and features. Evidence further suggests that of these common dysfunctions, abnormal attention is one of the most promising indicators of a biological susceptibility to schizophrenia-related disorders. Although attentional dysfunctions have been reliably detected in schizophrenic patients as well as in a variety of populations at risk for schizophrenia, few studies have investigated attention in clinical patients with schizotypal personality disorder. In this study, the extent of attentional impairment was assessed in subjects with schizotypal personality disorder, normal comparison subjects, patients with other personality disorders, and schizophrenic patients. METHOD: Thirty subjects with schizotypal personality disorder, 35 subjects with other personality disorders (i.e., clinic patients with non-odd cluster personality disorders), 36 subjects with schizophrenia, and 20 comparison subjects who did not meet criteria for any axis I or axis II disorder participated in this study. All subjects were diagnosed according to DSM-III criteria. Attention was assessed by using the Continuous Performance Test, Identical Pairs Version. RESULTS: Analyses indicated that subjects with schizotypal personality disorder, like schizophrenic subjects, performed significantly worse than comparison subjects on both the verbal and spatial tasks of the Continuous Performance Test, Identical Pairs Version. In contrast, patients with other personality disorders performed similarly to comparison subjects across conditions. CONCLUSIONS: These results suggest that patients with schizotypal personality disorder are impaired in their attentional functioning relative to normal comparison subjects and that they display deficits that are similar to the pattern characterizing schizophrenic patients.

Eye tracking, attention, and schizotypal symptoms in nonpsychotic relatives of patients with schizophrenia.

BACKGROUND: Biological relatives of patients with schizophrenia demonstrate an increased prevalence of schizotypal personality disorder symptoms, eye tracking deficits, and attentional disturbances. We investigated whether these hypothesized components of a schizophrenia-related phenotype are associated with one another or are independent in nonpsychotic relatives of patients with schizophrenia. METHODS: Eighty-three nonpsychotic first-degree relatives of 38 patients with schizophrenia and 45 control subjects without a psychiatric diagnosis underwent clinical evaluation, eye tracking evaluation, and the Continuous Performance Test (CPT) of visual attention. RESULTS: Eye tracking qualitative rating was more powerful than quantitative eye tracking measures or CPT measures in discriminating relatives of patients with schizophrenia from control subjects. Correlations between neurocognitive variables and DSM-III-R schizotypal personality disorder symptom clusters suggested that CPT errors of omission are associated with positive schizotypal symptoms. Eye tracking measures were not significantly correlated with schizotypal symptoms or CPT errors in relatives of patients with schizophrenia. CONCLUSIONS: Eye tracking deficits in the relatives of patients with schizophrenia are unrelated to CPT deficits and schizotypal symptoms. Eye tracking deficits and disturbances in visual attention may be separate components of a schizophrenia-related phenotype and should be considered as independent factors in genetic studies of schizophrenia.

Cognitive function and biological correlates of cognitive performance in schizotypal personality disorder.

There is evidence that some schizophrenic patients have deficits on tests of cognitive function, particularly tests of executive function, including the Wisconsin Card Sorting Test (WCST) and the Trail-making Test, Part B. This study was conducted to determine the generalizability of these findings across the schizophrenia spectrum to schizotypal personality disorder (SPD). Forty DSM-III SPD patients, 56 nonschizophrenia-related other personality disorder (OPD) patients, and 32 normal volunteers from two medical centers performed tests of executive function such as the WCST, Trail-making Part B, Stroop Word-Color Test, and Verbal Fluency, as well as tests of more general intellectual functioning such as the Wechsler Intelligence Scale-Revised Vocabulary and Block Design subtests, and Trail-making Part A. SPD patients performed more poorly on the WCST and on Trail-making Part B than did OPD patients or normal subjects; the groups did not differ on tests of general intellectual functioning. SPD patients may share some of the cognitive deficits observed in schizophrenia.

A pen-and-paper human analogue of a monkey prefrontal cortex activation task: spatial working memory in patients with schizophrenia.

In order to pursue the hypothesis that the dorsolateral prefrontal cortex is a source of cognitive deficit in schizophrenia, we developed an easily administered pen-and-paper human analogue of a visuospatial working memory task that in non-human primates activates the neurons of Walker area 46 (Goldman-Rakic, 1987). Compared to normal controls, schizophrenic patients made significantly greater errors in identifying where a visuospatial stimulus had been presented to them 30 and 60 seconds earlier, and these differences were significantly greater than in an immediate recall condition. These data suggest that schizophrenic patients have visuospatial working memory deficits that are sensitive to pen-and-paper versions of the tasks that activate the Walker area 46 in non-human primates. The availability of an easily administered test that may be associated with the functioning of the prefrontal cortex may enable more specific assessment of this brain region in humans.

Eye movement impairment and schizotypal psychopathology.

OBJECTIVE: Eye movement dysfunction in relation to a smooth pursuit task has been documented in schizophrenic patients and in patients with the related personality disorder, schizotypal personality disorder. To investigate which quantitative measures are associated with the eye movement dysfunction and whether the dysfunction is more related to the psychotic-like or the deficit-like symptoms of schizotypal personality disorder, ratings of eye movements in several groups of subjects were compared. METHOD: The study groups consisted of 26 patients with schizotypal personality disorder, 42 patients with other personality disorders (22 who also had two or more schizotypal personality traits and 20 who had fewer than two), and 37 normal comparison subjects. Smooth pursuit eye tracking of sinusoidal and constant velocity targets was recorded by an infrared eye tracking system. Two raters evaluated pursuit gain and large and small saccades in the direction of the target and in the direction opposite to that of the target (quantitative ratings) and constant velocity (qualitative rating). RESULTS: Patients with schizotypal personality disorder and patients with other personality disorders and two or more schizotypal traits, but not those with fewer than two schizotypal traits, had significantly poorer qualitative ratings of tracking than the normal comparison subjects. Neither gain nor any of the saccadic measures significantly differed between groups. The number of large saccades in the direction of the target was the only quantitative variable that predicted low qualitative ratings. Qualitatively poor tracking was associated with the deficit-like, but not the psychotic-like, symptoms of schizotypal personality disorder. CONCLUSIONS: Patients with schizotypal personality disorder demonstrate qualitatively poorer tracking than comparison groups, and the impaired tracking is associated with deficit-like symptoms.

Performance of nonpsychotic relatives of schizophrenic patients on cognitive tests.

We tested 54 nonpsychotic first degree relatives of 23 schizophrenic probands and 18 control subjects matched for age and education on several neuropsychological tests. The tests were selected to assess overall intellectual ability or because previous work indicated that they are particularly sensitive measures of cognitive dysfunction in schizophrenic patients. The relatives of schizophrenic patients performed significantly worse than the control subjects on tests of verbal fluency and on Trailmaking, part B. Each of these tests contributed unique variance to the discrimination between groups. The groups did not differ significantly on the number of perseverative errors on the Wisconsin Card Sorting Test, Wechsler Adult Intelligence Scale-Revised block design or vocabulary, or Trailmaking, part A. Eight relatives who met DSM-III-R criteria for schizotypal personality disorder were more impaired than the remaining 46 relatives on letter fluency, but otherwise their performance was similar to that of nonschizotypal relatives. These data suggest that close relatives of schizophrenic patients may have subtle neuropsychological impairments that are not necessarily associated with clinical symptoms of schizophrenia spectrum disorders.