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K Sim

Publications and source records attributed to K Sim.

10 recordsLinked to original sources
PubMed2005

Testing models of thalamic dysfunction in schizophrenia using neuroimaging.

Neural models of schizophrenia have implicated the thalamus in deficits of early sensory processing and multimodal integration. We have reviewed the existing neuroimaging literature for evidence in support of models that propose abnormalities of thalamic relay nuclei, the mediodorsal thalamic nucleus, and large-scale cortico-thalamic networks. Thalamic volume reduction was found in some but not all studies. Studies of the early stages of schizophrenia suggest that thalamic volume reduction is present early in the course of the illness. Functional imaging studies have revealed task related abnormalities in several cortical and subcortical areas including the thalamus, suggesting a disruption of distributed thalamocortical networks. Chemical imaging studies have provided evidence for a loss of thalamic neuronal integrity in schizophrenia. There is, at present, inadequate data to support the hypothesis that schizophrenia is associated with abnormalities of sensory relay or association nuclei. There is evidence for a perturbation of cortico-thalamic networks, but further research is needed to elucidate the underlying mechanisms at the cellular and systems levels. The challenges ahead include better delineation of thalamic structure and function in vivo, the combination of genetic and imaging techniques to elucidate the genetic contributions to a thalamic phenotype of schizophrenia, and longitudinal studies of thalamic structure and function.

Animals↗
PubMed2004

High dose antipsychotic use in schizophrenia: findings of the REAP (research on east Asia psychotropic prescriptions) study.

BACKGROUND: High-dose antipsychotic regimes (defined as the prescription of more than 1000 chlorpromazine-equivalents milligrams of antipsychotic per day) in the management of patients with schizophrenia are not uncommon, but most reports are from western countries. Recent functional neuroimaging studies have found that the previous notion concerning the use of antipsychotic medication, especially in high doses, was unsupported and untenable. METHODS: This international study examined the use of high dose antipsychotic medication and its clinical correlates in schizophrenia patients within six East Asian countries/territories. RESULTS: Within the study group (n = 2399), 430 patients (17.9%) were prescribed high dose antipsychotics. Antipsychotic use varied significantly between countries, with Japan, Korea, and Singapore using higher doses than the other countries. High dose antipsychotic use was associated with younger age in Japan (p < 0.001), longer duration of admission (p < 0.001), duration of illness (p < 0.001, particularly in Korea and Taiwan), positive psychotic symptoms (p < 0.001, particularly in Japan and Korea), and aggression (p < 0.05, particularly in Japan), and also with a higher likelihood of extrapyramidal and autonomic adverse effects (p < 0.05, particularly in China). Country, younger age, the presence of delusions and disorganized speech, polypharmacy, and receiving depot medication but not atypical antipsychotic drugs were important predictors of high antipsychotic use. CONCLUSIONS: This survey revealed that high antipsychotic dosing is not an uncommon practice in East Asia. It behooves the prescribing clinicians to constantly reevaluate the rationale for such a practice.

Adult↗
PubMed2004

Psychiatric comorbidity in first episode psychosis: the Early Psychosis Intervention Program (EPIP) experience.

OBJECTIVE: To determine the prevalence rates of psychiatric comorbidity in a hospitalized Asian patient group with first episode psychosis and examine its clinical correlates. METHOD: Seventy-nine consecutively admitted patients with first episode psychosis were assessed using the Structured Clinical Interview for DSM-IV-axis I disorders (patient edition), Positive and Negative Symptom Scale (PANSS), Scale to assess Unawareness of Mental Disorders (SUMD) and Global Assessment of Functioning (GAF) scales. RESULTS: Psychiatric comorbidity was present in 36.7% (n = 29) of the patients. Patients with psychiatric comorbidity were younger (P < 0.05), had an earlier onset of illness (P < 0.05) and better insight on social consequences and flat affect items (P < 0.05) on the SUMD. No significant differences were found between the two groups with and without psychiatric comorbidity in gender, ethnicity, marital status, length of education, employment status, living arrangements, duration of hospitalization and untreated psychosis as well as total PANSS and GAF scores. CONCLUSION: Psychiatric comorbidity is common thus calling for a greater awareness in clinicians of these conditions, which are often under-recognized, under-diagnosed and untreated.

Adult↗
PubMed2003

Individual and familial characteristics of youths involved in street corner gangs in Singapore.

Thirty-six youths involved in street corner gangs in Singapore were compared with 91 age-matched controls on measures of self-esteem, aggression, dysfunctional parenting and parent-adolescent communication. Results revealed that gang youths had lower self-esteem and higher levels of aggression than controls. Of note were the findings that gang youths reported a relative absence of parental abuse and indifference, and experienced less open communication and higher levels of over-control with their mothers, but not fathers. These findings diverge from anticipated familial correlates of antisocial activity in youths and were discussed with reference to cultural factors and their implications on prevention and intervention.

Adolescent↗
PubMed2002

Thyroid dysfunction in chronic schizophrenia within a state psychiatric hospital.

OBJECTIVES: This study seeks to determine the prevalence and pattern of thyroid dysfunction in a group of adult psychiatric inpatients with chronic schizophrenia. We also hypothesize that raised thyroid hormones are associated with more severe psychopathology. METHODS: Thyroid function tests were performed on 189 patients and the Brief Psychiatric Rating Scale (BPRS) was administered by a single rater on all patients. RESULTS: There was a high prevalence of (36.4%) thyroid function test abnormalities but all patients except 1 were assessed to be clinically euthyroid. Free thyroxine (fT4) and triiodothyronine (fT3) were significantly higher in patients with mild (BPRS score, 10-20) and major syndrome (BPRS score, equal or above 21) compared to no syndrome (BPRS score, 0-9). No correlation was found between thyroid hormones and neuroleptic use. CONCLUSION: Although thyroid function test abnormalities are common in patients with chronic schizophrenia, clinical thyroid illness was absent. This calls for caution in the use and interpretation of thyroid function tests in patients with chronic schizophrenia.

Adult↗
PubMed2001

High prevalence of psychiatric morbidity in a medical intensive care unit.

This study seeks to determine the prevalence of psychiatric morbidity within a medical intensive care unit, examine its correlation with the various physiological parameters and delineate any clinical predictors for psychiatric morbidity. Seventy-seven patients who gave informed consent were administered the General Health Questionnaire (GHQ), Acute Physiological And Chronic Health Evaluation II (APACHE II) and thyroid function tests were performed. A high prevalence of psychiatric morbidity was found (36.4%). However, no statistically significant association was found between psychiatric morbidity and gender, age, APACHE II scores and thyroid function indices. Nevertheless, it is hoped that the index of suspicion for psychiatric morbidity can be raised in order to optimise the clinical management of patients within this setting.

APACHE↗
PubMed1999

Identification of differentially expressed mRNAs in human fetal liver across gestation.

Differential gene expression, with its precise start and stop times, is believed to be critical for the programmed development of new cells and tissues. Within the developing fetus, one tissue of particular interest is fetal liver. This organ undergoes rapid changes in the pathway toward liver development in utero since it is also the major site of hematopoiesis, until bone marrow hematopoiesis predominates. Believing that patterns would emerge from the bi-weekly large-scale inspection of expressed genes in the fetal liver, we employed differential display reverse transcription-polymerase chain reaction (DDRT-PCR) as ourprimary inspection tool. Using DDRT-PCR, we isolated cDNAs differentially expressed throughout fetal liver development and in adult liver. We displayed approximately 25 000 cDNAs from 10 and 24 week fetal liver and adult liver. From this initial screen, we determined that approximately 0.1-1% of the mRNA population undergoes expression changes. We extracted, purified and sequenced 25 differentially displayed cDNA bands. Fourteen cDNAs had similarities to known genes, while 11 cDNAs were not similar to any characterized gene. The differentially expressed cDNAs from known genes present in fetal liver include alpha-fetoprotein, stem cell factor, erythroid alpha-spectrin, 2,3-bisphosphoglycerate mutase, insulin-like growth factor-2, porphobilinogen deaminase and Mac30. The differentially expressed cDNAs present in adult liver but not in 10 week fetal liver were nicotinamide deaminase, human fibrinogen-related protein and alpha-acid glycoprotein. The majority of differentially expressed genes found during this effort appear to be turned on during organogenesis, however, some genes were found that are apparently turned off completely.

Adult↗
PubMed1990

Mesenchymal hamartoma of the liver. A 35-year review.

Mesenchymal hamartoma of the liver occurs almost exclusively in infancy and childhood, with approximately 140 total cases reported. We report the experience with 18 patients at the Childrens Hospital of Los Angeles (Calif) during the past 35 years. The charts of all patients with mesenchymal hamartoma were retrospectively reviewed. The mean age at presentation was 16 months. Thirteen patients were symptomatic, presenting with increasing abdominal distention. Physical examination revealed an abdominal mass or hepatomegaly. Ultrasonography and computed tomography were the most useful diagnostic tests. Fourteen patients underwent resection; 9 underwent hepatic resection and 5 underwent excision of the tumor only. One patient had marsupialization, 1 underwent a biopsy only, and 2 died of unrelated causes and the hamartoma was found incidentally at autopsy. In all instances, a large cystic mass with well-demarcated margins was found. Three patients were unavailable for follow-up and 13 patients were alive and well 1 month to 24 years (mean, 5 years) after diagnosis. Recurrence or malignant transformation was not noted. A presumptive diagnosis can be made preoperatively by normal laboratory values and a combination of ultrasonography and computed tomography. We recommend excision of the tumor in all patients once the diagnosis is made, with the expectation of complete recovery.

California↗
PubMed1984

[Ultrastructural observations of human pancreatic duct cell carcinoma].

The great majority of human pancreatic duct cell carcinoma are thought to be of ductal origin and acinar cell carcinoma has been reported to be very rare. This paper reports electron microscopic observations of human pancreatic duct call carcinoma. The results were as follows. In the cases which were diagnosed as well or moderate differentiated adenocarcinoma of the pancreas by light microscope, three different types of tumor cells were observed by electron microscope. Two of them had characters of ductal cells. The origin of these tumor cells were considered to be originated from the relative large and small pancreatic ducts. Third type was a little different from cell types mentioned above. Some of these cells had swollen mitochondria and well developed rough endoplasmic reticulum with a various distribution of zymogen granules. Microvilli and cellular projects were scant. These findings were considered to be the dedifferentiation of the acinar cells and this type belonged to be acinar cell carcinoma.

Aged↗