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Biomedical subjects

J Lam

Publications and source records attributed to J Lam.

At least 37 records · Page 2Linked to original sources
PubMed2001

Service delivery and community: social capital, service systems integration, and outcomes among homeless persons with severe mental illness.

OBJECTIVES: This study evaluated the influence of features of community social environment and service system integration on service use, housing, and clinical outcomes among homeless people with serious mental illness. STUDY SETTING: A one-year observational outcome study was conducted of homeless people with serious mental illness at 18 sites. DATA SOURCES: Measures of community social environment (e.g., social capital) were based on local surveys and voting records. Housing affordability was assessed with housing survey data. Service system integration was assessed through interviews with key informants at each site to document interorganizational transactions. Standardized clinical measures were used to assess clinical and housing outcomes in face-to-face interviews. RESEARCH DESIGN: Structural equation modeling was used to determine the relationship between (1) characteristics of the social environment (social capital, housing affordability); (2) the level of integration of the service system for persons who are homeless in each community; (3) access to and use of services by individual clients; and (4) successful exit from homelessness or clinical improvement. PRINCIPAL FINDINGS: Social capital was associated with greater service systems integration, which was associated in turn with greater access to assistance from a public housing agency and to a greater probability of exiting from homelessness at 12 months. Housing affordability also predicted exit from homelessness. Neither environmental factors nor systems integration predicted outcomes for psychiatric problems, substance abuse, employment, physical health, or income support. CONCLUSION: Community social capital and service system integration are related through a series of direct and indirect pathways with better housing outcomes but not with superior clinical outcomes for homeless people with mental illness. Implications for designing improved service systems are discussed.

Case Management↗
PubMed2000

Target velocity effects on manual interception kinematics.

Participants generated manual interception movements toward a target cursor that moved across a computer screen. The target reached its peak velocity either during the first third, at the midpoint, or during the last third of the movement. In Experiment 1 the view of the target was available for either the first 316, 633, 950, or 1267 ms, after which it disappeared. Results showed that for all viewing conditions, the timing of the interception velocity was related to the temporal properties of the target's trajectory. In Experiment 2, when the portion of the target trajectory that was viewed was reversed (such that participants did not see the first 316, 633, 950, or 1267 ms of the trajectory, but instead saw only the later portions of the trajectory), there was no clear relationship between the target trajectory and the timing of the aiming trajectory. These results suggest that participants use visual information early in the target's trajectory to form a representation of the target motion that is used to facilitate manual interception.

Adult↗
PubMed2000

On impulsive autoassociative neural networks.

Many systems existing in physics, chemistry, biology, engineering, and information science can be characterized by impulsive dynamics caused by abrupt jumps at certain instants during the process. These complex dynamical behaviors can be modeled by impulsive differential systems or impulsive neural networks. This paper formulates and studies a new model of impulsive autoassociative neural networks. Several fundamental issues, such as global exponential stability and existence and uniqueness of equilibria of such neural networks, are established.

Models, Neurological↗
PubMed2000

Childhood risk factors for criminal justice involvement in a sample of homeless people with serious mental illness.

It has been suggested that criminal justice involvement among the homeless, particularly those with mental illness, is largely situational. The objective of this study was to assess, in a sample of homeless seriously mentally ill people, the prevalence of childhood conduct disorder behaviors as a risk factor for adult criminal activity as well as the extent and types of adult criminal justice contact. Data were taken from the national ACCESS program, which conducted extensive baseline interviews with 7,222 homeless seriously mentally ill adults. The interview assessed demographics, childhood risk factors for criminal activity such as conduct disorder behaviors, foster care, and parental abuse, as well as current illness severity and recent criminal justice contact. The 2-month arrest rate in this sample was much higher than national rates (11% compared with 1% annually in the general population). Although most arrests were for minor crimes (10.8%), there were also substantial rates of arrest for major (2.7%) and substance-related charges (2.0%). The prevalence of a history of conduct disorder behavior was also substantial (55% in male subjects, 40% in female subjects), and conduct disorder was a strong predictor of recent criminal justice involvement, even after controlling for other predictors of arrest (odds ratio = 1.76 for major crimes, 1.49 for minor crimes, and 1.98 for substance-related crimes). Recent literature has criticized a trend to criminalize homeless mentally ill persons for attempting to get needed food, shelter, or medical attention. However, these data indicate that at least some proportion of arrests in this population are of people who have been exhibiting antisocial behavior since early adolescence, and that early antisocial behavior is a strong predictor of all types of recent arrests in this population.

Adult↗
PubMed2000

TNF-alpha induces osteoclastogenesis by direct stimulation of macrophages exposed to permissive levels of RANK ligand.

While TNF-alpha is pivotal to the pathogenesis of inflammatory osteolysis, the means by which it recruits osteoclasts and promotes bone destruction are unknown. We find that a pure population of murine osteoclast precursors fails to undergo osteoclastogenesis when treated with TNF-alpha alone. In contrast, the cytokine dramatically stimulates differentiation in macrophages primed by less than one percent of the amount of RANKL (ligand for the receptor activator of NF-kappaB) required to induce osteoclast formation. Mirroring their synergistic effects on osteoclast differentiation, TNF-alpha and RANKL markedly potentiate NF-kappaB and stress-activated protein kinase/c-Jun NH(2)-terminal kinase activity, two signaling pathways essential for osteoclastogenesis. In vivo administration of TNF-alpha prompts robust osteoclast formation in chimeric animals in which ss-galactosidase positive, TNF-responsive macrophages develop within a TNF-nonresponsive stromal environment. Thus, while TNF-alpha alone does not induce osteoclastogenesis, it does so both in vitro and in vivo by directly targeting macrophages within a stromal environment that expresses permissive levels of RANKL. Given the minuscule amount of RANKL sufficient to synergize with TNF-alpha to promote osteoclastogenesis, TNF-alpha appears to be a more convenient target in arresting inflammatory osteolysis.

Animals↗
PubMed2000

Mice lacking beta3 integrins are osteosclerotic because of dysfunctional osteoclasts.

Osteoclasts express the alphavbeta3 integrin, an adhesion receptor that has been implicated in bone resorption and that is therefore a potential therapeutic target. To assess the role of this heterodimer in skeletal development in vivo, we engineered mice in which the gene for the beta3 integrin subunit was deleted. Bone marrow macrophages derived from these mutants differentiate in vitro into numerous osteoclasts, thus establishing that alphavbeta3 is not necessary for osteoclast recruitment. Furthermore, the closely related integrin, alphavbeta5, does not substitute for alphavbeta3 during cytokine stimulation or authentic osteoclastogenesis. beta3 knockout mice, but not their heterozygous littermates, develop histologically and radiographically evident osteosclerosis with age. Despite their increased bone mass, beta3-null mice contain 3.5-fold more osteoclasts than do heterozygotes. These mutant osteoclasts are, however, dysfunctional, as evidenced by their reduced ability to resorb whale dentin in vitro and the significant hypocalcemia seen in the knockout mice. The resorptive defect in beta3-deficient osteoclasts may reflect absence of matrix-derived intracellular signals, since their cytoskeleton is distinctly abnormal and they fail to spread in vitro, to form actin rings ex vivo, or to form normal ruffled membranes in vivo. Thus, although it is not required for osteoclastogenesis, the integrin alphavbeta3 is essential for normal osteoclast function.

Animals↗
PubMed1999

Pulse methylprednisolone therapy for impending cardiac tamponade in immunoglobulin-resistant Kawasaki disease.

We describe a boy with Kawasaki disease (KD) whose clinical course was marked by a rapid improvement upon treatment with intravenous immunoglobulin (IVIG) and oral aspirin, which - within 14 days - was followed by the development of a large pericardial effusion with symptoms of impending cardiac tamponade as part of a polyserositis syndrome (pleural effusions, ascites). Upon treatment with pulsed methylprednisolone, the pericardial and pleural effusions and ascites rapidly disappeared within 48 h. This is the first case reported with a polyserositis syndrome and impending cardiac tamponade during KD.

Acute Disease↗
PubMed1999

Disseminating information using an anesthesiology consultant report: impact on patient perceptions of quality of care.

STUDY OBJECTIVE: To determine if providing an Anesthesiology Consultant Report (ACR) to patients would result in enhanced patients' perceptions of their knowledge about their care and improve their perception of the quality of their care. DESIGN: Randomized, unblinded study. SETTING: Outpatient center associated with tertiary care center. PATIENTS: 371 outpatients without adverse anesthetic events. INTERVENTIONS: Patients were randomized to receive either routine discharge instructions or routine instructions and an anesthesia discharge summary (ACR). MEASUREMENTS AND MAIN RESULTS: Short questionnaire with discharge packet regarding knowledge of anesthetic and questions regarding satisfaction and perceptions of quality of care was distributed. The patients in the group that received an ACR were more satisfied with the management of their pain and other symptoms (p < 0.05, by Wilcoxon rank sums) and were more satisfied overall with the quality of the anesthesia care (p < 0.01, by Wilcoxon rank sums). Taken another way, significantly more patients deemed the quality of their anesthetic care as excellent in the ACR group compared to control (83% vs. 67%, p < 0.01). CONCLUSIONS: Providing patients, with uneventful anesthetic courses, with information regarding their anesthetic care, in the form of the ACR, results in improved perceptions of the quality of care.

Anesthesia↗
PubMed1999

X-linked cardioskeletal myopathy and neutropenia (Barth syndrome) (MIM 302060).

X-linked cardioskeletal myopathy, neutropenia and abnormal mitochondria (MIM 302060) (synonyms: Barth syndrome, 3-methylglutaconic acid-uria type II, endocardial fibroelastosis type 2) has been reported in patients and families from Europe, North America and Australia. Previous studies characterized the main components of the disease: dilated cardiomyopathy, skeletal myopathy, neutropenia, 3-methylglutaconic aciduria and diminished statural growth. Respiratory chain impairments have been found in several studies, without pinpointing a single enzyme complex. 3-Methylglutaconic aciduria is shared with several other disorders that affect the respiratory chain. Previous studies excluded a block in the major pathway of leucine catabolism. We performed leucine loading, accompanied by fasting, in patients and observed a significant rise of 3-methylglutaconic acid and 3-methylglutaric acid. Taken together with the absence of an enzymatic block in the major leucine catabolic route, the possibility remains that the increased basal excretion of 3-methylglutaconic acid and other products of branched-chain amino acids is the result of overload of this pathway or--more likely--mitochondrial leakage. Linkage studies have localized the gene to the Xq28 region. The associated tafazzin gene (TAZ), has been fully characterized recently, and mutations located in conserved regions have been reported. Carrier detection and prenatal diagnosis have now become possible through mutation analysis. Sequence homology of the TAZ gene to a highly conserved superclass of acyltransferases (Neuwald's hypothesis) predicts a glycerophospholipid as the missing end product. This points to the (lipid) structure of the inner mitochondrial membrane as a promising new area of research.

Cardiomyopathy, Dilated↗
PubMed1999

Patient preferences for early discharge after laparoscopic cholecystectomy.

UNLABELLED: Patients may have concerns about their ability to manage postoperative symptoms at home after ambulatory surgery. We assessed patients' attitudes toward postoperative care at home or in the hospital after laparoscopic cholecystectomy. Thirty-eight patients undergoing elective laparoscopic cholecystectomy were pre- and postoperatively (within a week each) presented with scenarios describing symptoms of differing severity in either a home or hospital setting and were asked to rank and rate the relative desirability of the scenarios using rating scale, standard gamble, and willingness-to-pay techniques. Preoperatively, 16 (42%), 21 (55%), and 30 (79%) patients ranked pain of mild, moderate, and severe levels, respectively, as worse than the respective levels of nausea and vomiting. Of 24 patients, 19 (79%) preferred home care to hospital care for mild symptoms, and 12 of 22 patients (55%) preferred home care to hospital care for moderate symptoms. The average ratings were 20, 53, and 90 for mild, moderate, and severe symptoms, respectively, where 0 = no symptoms and 100 = the worst symptoms possible. Patients who preferred care outside the home indicated that they were willing to pay a mean of $142 (maximum $410) as a maximal copayment to have postoperative care in the hospital and a mean of $255 to receive care in a medical hotel-like facility. Postoperative assessment correlated highly with the preoperative assessment (correlation coefficient >0.6 for rating, standard gamble, and willingness-to-pay assessments). We conclude that patients vary in their attitudes toward where they would like to receive postoperative care. Attitudes assessed preoperatively may predict their attitudes postoperatively. IMPLICATIONS: Patients preferred to be at home for mild postoperative symptoms but in the hospital for worse postoperative symptoms. Preferences did not change with different methods of asking and were the same pre- and postoperatively. If patients made choices for their care before their procedure, they would still be happy with those decisions postoperatively.

Adult↗
PubMed1999

[Neck hydatidosis. Thyroid and submaxillary gland involvement in 2 cases].

Neck located hydatid cysts are of rare occurrence. We report two patients with such condition. A 66 years old male with a slowly progressive painless 4 cm nodule located in the right thyroid. It did not concentrate 131I and a fine needle aspiration cytology was informed as an acute thyroiditis. A 5 years old boy presented with a 5 cm painless right submaxillary cyst. Ultrasound examination showed that it was unilocular, and fine needle aspiration biopsy disclosed unspecific findings. In both cases surgical findings and the pathological study showed hydatid cysts. Both patients had normal chest x ray and abdominal ultrasound examinations. They had an uneventful postoperative evolution. Echinococcosis must be considered in the differential diagnosis of cervical cysts in endemic area.

Aged↗
PubMed1998

Perioperative cost-finding analysis of the routine use of intraoperative forced-air warming during general anesthesia.

BACKGROUND: Despite the well-documented ability of forced-air warming (FAW) to maintain normothermia, it is unclear whether this technique results in a net increase or decrease in costs. The authors did a prospective cost-finding study comparing FAW with routine thermal care in patients at low risk for perioperative complications who were undergoing general anesthesia. METHODS: After institutional review board approval was received, 100 patients were studied who were having elective surgery scheduled for more than 2 h during general endotracheal anesthesia. Patients were randomly assigned to one of two groups: FAW or routine thermal care. All patients received a standardized anesthetic. Anesthesia providers were blinded to core temperatures and the use of FAW. Primary outcomes were those associated with perioperative costs. RESULTS: The time from completion of surgical dressing until tracheal extubation was significantly reduced in the FAW group (10 +/- 1 min compared with 14 +/- 1 min; mean +/- SEM; P < 0.01). There was no demonstrable difference in attainment of postanesthesia care unit discharge criteria between the two groups, although the FAW group used one less cotton blanket there. The net savings related to the use of the FAW depends on the percentage of the intraoperative costs that are fixed rather than variable ($15 additional for FAW if all costs are fixed compared with $29 savings if all costs were variable). CONCLUSIONS: Routine intraoperative FAW significantly reduced time until extubation and use of cotton blankets in the postanesthesia care unit. These results suggest that the influence of FAW on net total perioperative costs depends on patient and surgical characteristics and institutional factors related to cost accounting.

Adolescent↗
PubMed1998

The 15-year outcome of Chinese patients with schizophrenia in Hong Kong.

OBJECTIVE: To explore the differential outcome of schizophrenia in developed and developing countries. The 15-year outcome of patients with schizophrenia in Hong Kong is reported. METHOD: In a 15-year retrospective outcome study, 100 patients with first-onset schizophrenia in 1977-1978 were randomly selected for outcome assessment from a pool of 797 patient files. The patterns of outcome were assessed by the same set of instruments and methodology as in other centres, since Hong Kong is 1 of the World Health Organization (WHO) centres for the International Study of Schizophrenia (ISoS). RESULTS: Nineteen subjects were untraceable, and 10 subjects committed suicide. More than one-half of the subjects had a good symptomatic outcome, while about 20% of the subjects were rated as having a good psychosocial adjustment. Over the entire 15-year period, 96% of the subjects were maintained on medications, and 79% were living with family members. CONCLUSION: Despite Hong Kong's developed economy, its schizophrenia outcome is similar to that in developing countries. The existence of good family support and active follow-up treatment may be important contributory factors to better outcome.

Adult↗