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Biomedical subjects

M T Wong

Publications and source records attributed to M T Wong.

At least 19 recordsLinked to original sources
PubMed1997

Positron emission tomography in male violent offenders with schizophrenia.

The FDG PET brain scans from 31 offenders with schizophrenia and schizoaffective disorder from a maximum security mental hospital were compared with those of normal controls (N = 6) in terms of relative FDG uptake in a range of regions covering frontal and temporal regions. The patient sample was divided into those who had a history of repetitive violent offending (RVO, N = 17) and those without a repetitive violent history (NRVO, N = 14) according to the violence rating of their pre-admission convictions. Reduced FDG uptake was noted at both the right and left anterior inferior temporal (R and L AIT) regions in NRVOs but only at LAIT in RVOs. NRVOs had significantly lower FDG uptake at RAIT than RVOs. The findings suggest that metabolic changes at AIT may be related to different patterns of violent offending in patients with schizophrenia.

Adult↗
PubMed1996

Pulp management in dens evaginatus.

A 12-yr-old Guamanian girl presented with seven premolars displaying dens evaginatus. The pulp of one tooth was necrotic secondary to fracture of the evagination. Calcium hydroxide treatment was used to induce closure of this root apex, and subsequent routine canal obturation resulted in clinical success. Three teeth had fractured evaginations and compromised coronal pulps, but the radicular pulp tissue was vital. Coronal calcium hydroxide pulpotomy procedures were performed, and root development continued on all three teeth. In one of these teeth, endodontic treatment was completed, and in the other two the radicular pulp remained vital. Three teeth had intact evaginations and vital pulps. In an attempt to protect these evaginations from trauma, composite reinforcements were placed around the evaginations. These pulps remained vital and the roots completed normal development. Early diagnosis and treatment should be sought in cases of dens evaginatus to provide the greatest opportunity for complete root development.

Bicuspid↗
PubMed1996

Patterns of virus burden and T cell phenotype are established early and are correlated with the rate of disease progression in human immunodeficiency virus type 1-infected persons.

Human immunodeficiency virus (HIV)-1 DNA and RNA levels and T lymphocyte cell surface markers were measured in blood serum and cell fractions from asymptomatic infected patients to find novel virologic and immunologic features in early disease predictive of subsequent clinical disease course. Thirty-two patients with rapid disease progression (rapid CD4+ cell loss and progression to clinical AIDS) were compared with 25 patients with stable infections (constant or rising CD4+ cell counts, no clinical disease manifestations). All HIV-1 burdens measured by polymerase chain reaction were consistently higher in specimens from rapid progressors than slow progressors. For each patient, virus burden remained relatively constant throughout the study period (mean, 42-44 months). Flow cytometry also disclosed stable lymphocyte immunophenotype patterns that correlated strongly with subsequent rapid progression to clinical disease. Thus, in early HIV-1 infection, a constellation of high virus burden and in vivo costimulatory antigen and lymphocyte activation abnormalities is predictive of rapid disease course.

Adult↗
PubMed1995

Neuroretinitis, aseptic meningitis, and lymphadenitis associated with Bartonella (Rochalimaea) henselae infection in immunocompetent patients and patients infected with human immunodeficiency virus type 1.

Bartonella (Rochalimaea) henselae causes a variety of diseases, including bacillary angiomatosis, peliosis hepatis, lymphadenitis, aseptic meningitis with bacteremia, and cat-scratch disease (CSD). Cases of B. henselae-related disease were collected from September 1991 through November 1993. Patients with suspected CSD, unexplained fever and lymphadenitis, or suspected B. henselae infection who were seen in the Infectious Diseases Clinic at Wilford Hall Medical Center (Lackland Air Force Base, TX) underwent physical and laboratory examinations. In addition to three previously described cases, 23 patients with R. henselae-related infection were identified. The patients included 19 immunocompetent individuals presenting with lymphadenitis (11), stellate neuroretinitis (5), Parinaud's oculoglandular syndrome with retinitis (1), chronic fatigue syndrome-like disease (1), and microbiologically proven adenitis without the presence of immunofluorescent antibodies to B. henselae (1) and four patients infected with human immunodeficiency virus type 1 presenting with isolated lymphadenitis (1), diffuse upper-extremity adenitis (1), neuroretinitis (1), and aseptic meningitis (1). A couple with neuroretinitis and their pet cat, a persistently fatigued patient, and a patient with Parinaud's oculoglandular syndrome were shown to have bacteremia. Tissue cultures were positive for B. henselae in three recent cases of adenitis. Twenty-two patients were exposed to cats. This series further demonstrates the similarities between B. henselae-related diseases and CSD and identifies several new syndromes due to B. henselae.

Adolescent↗
PubMed1995

Presence of neutralizing antibodies to heterologous human immunodeficiency virus type 1 isolates in sera of infected individuals is not predictive of rate of disease progression.

These studies were undertaken to examine whether the presence of human immunodeficiency virus type 1 (HIV-1)-neutralizing antibodies in sera of infected individuals would alter the rate of disease progression. HIV-1-infected individuals (n = 87) were initially examined for neutralizing activity in vitro against both laboratory and tissue culture-adapted clinical heterologous HIV-1 isolates. The neutralizing activities of sera were determined by a 90% or greater reduction in HIV-1 p24 levels in vitro. In a cross-sectional analysis of all infected individuals, we observed that sera from asymptomatic individuals neutralized a significantly greater number of heterologous HIV-1 isolates than sera from symptomatic patients. Patients who could be followed up longitudinally (n = 24) were then studied to determine the impact of neutralizing antibodies on the rate of disease progression. We observed no significant difference between the numbers of HIV-1 isolates neutralized in vitro by sera from patients who remained clinically stable and by those from patients who progressed rapidly. Our data indicated that the presence or absence of neutralizing antibodies to heterologous HIV-1 isolates was not associated with the rate of disease progression.

Adult↗
PubMed1995

Serologic evaluation of human immunodeficiency virus type 1-infected individuals from Argentina and the United States indicates a similar distribution of subgroup B isolates.

Utilizing peptides based on the V3 region of gp120, we undertook a serologic examination of human immunodeficiency virus type 1 (HIV-1)-infected individuals from Argentina to determine if prevalent HIV-1 isolates could be identified in this population. Our findings suggest that a similar pool of HIV-1 subgroup B isolates exists in both Argentina and the United States.

Amino Acid Sequence↗
PubMed1995

A chemically defined liquid medium that supports primary isolation of Rochalimaea (Bartonella) henselae from blood and tissue specimens.

Rochalimaea (Bartonella) henselae is a fastidious, slowly growing, gram-negative bacillus that is an etiologic agent of bacillary angiomatosis, cat scratch disease, and related syndromes. Accumulation of direct microbiologic evidence of the relationship between the organism and the syndromes compatible with cat scratch disease has been hindered by the difficulties in the primary isolation of the organism from infected tissue specimens. A chemically defined liquid medium was developed to support the growth of Rochalimaea species to facilitate study of the organism. This medium was also used successfully to isolate R. henselae from clinical specimens from infected patients and a domestic cat. Recovery of R. henselae in this was more successful than when recovery was attempted on solid agar. This cell-free, extract-free, defined medium additionally supported the growth of Rochalimaea quintana and Afipia felis.

Angiomatosis, Bacillary↗
PubMed1995

DNA analysis of Huntington's disease in southern Chinese.

Allelic frequencies of RFLPs at loci closely linked to the HD gene, D4S95, D4S91, D4S141, and D4S90, were determined in 13 Huntington's disease (HD) patients from nine Chinese families and 129 normal subjects. These were similar for non-HD and HD chromosomes and the HD gene in Chinese is associated with multiple haplotypes. Hence the HD gene probably arose independently in the background haplotypes of the Chinese population. The heterozygosity rates for the two most useful RFLP sites are 0.659 for D4S95-AccI VNTR and 0.494 for D4S141-HindIII. (CAG)n repeat numbers ranged from 12 to 27 in 174 normal chromosomes. In 52 meiotic recombinations, the (CAG)n repeats were stably inherited in normal families. In HD families, 12 of 13 HD patients had expanded (CAG)n repeats of 40 to 58. Additionally, 10 asymptomatic family members had expanded (CAG)n repeats and the inheritance of the expanded repeat was unstable in these families.

Alleles↗
PubMed1994

Patterns of psychogeriatric referral and attendance at three different settings in Hong Kong.

In order to analyze whether the referral system and nature of care exert any effect on the characteristics of patients, subjects aged 60 or above attending three medical centers on the Hong Kong Island between August and December 1990 were studied with respect to their age, sex, and psychiatric diagnosis. Psychiatric diagnoses were made in 98% of subjects at the psychogeriatric assessment service (PAC) (predominantly chronic organic brain syndrome), in 79.6% at the university psychiatric unit (mainly acute psychiatric problems, substance abuse, and deliberate self-harm), and in 20% at the general outpatient clinic (largely sleep and anxiety-related disorders). There was overrepresentation of the very old (above 80) and underutilization of counseling service at PAC. In Hong Kong, the psychogeriatric needs of the very old and of those with minor emotional disturbances associated with aging, retirement, and bereavement deserve reassessment.

Aged↗
PubMed1994

Psychosocial impact of Huntington's disease on Hong Kong Chinese families.

Twenty-eight asymptomatic relatives from 7 Chinese families with Huntington's disease (HD) received psychosocial assessment. One third of these subjects (n = 9) had symptoms of anxiety and depression that warranted a Present State Examination (PSE) diagnosis. One quarter of these subjects (n = 8) would contemplate suicide if their predictive testing indicated a high risk of having the disease. This suicidal risk was associated with a PSE diagnosis of depression and a stress-coping repertoire with a high proportion of coping strategies of the avoidance type at the time of interview. Early and close liaison with these subjects for the detection of mental symptoms and provision of counselling on a balanced and positive coping style is essential.

Adaptation, Psychological↗
PubMed1994

Electroencephalography, computed tomography and violence ratings of male patients in a maximum-security mental hospital.

A retrospective study of brain investigations of 372 male patients in a maximum-security mental hospital patients is described. All computed tomography (CT) scan and electroencephalography (EEG) reports were collected and rated blind; patients were subsequently divided into 3 groups according to the violence rating of their pre-admission offending behaviour. The 3 groups were similar in their mean age, psychiatric diagnosis, Wechsler Adult Intelligence Scale score and proportions of patients investigated with EEG and CT. In the most violent group, 20% had focal temporal electrical abnormalities on EEG (slowing and/or sharp waves) and 41% had structural abnormalities localised to temporal lobe on CT (dilated temporal horn and/or reduced size of temporal lobe). The corresponding figures for the least violent group are 2.4% and 6.7% respectively. These results suggest that high violence rating scores are associated with temporal lobe abnormalities on CT and abnormal temporal electrical discharges on EEG.

Adult↗
PubMed1994

Huntington's disease in Hong Kong Chinese: epidemiology and clinical picture.

In a territory-wide survey of Huntington's disease (HD) in the Chinese population of Hong Kong, 20 patients from 11 families were identified from 1984 to 1991, giving a low period prevalence of 3.7 per 10(6) population. Six patients had died by 1991, hence the point prevalence was even lower, being 2.5 per 10(6) population. The male to female ratio was 3:1. No paternal transmission effect on the age of onset was observed. Apart from these differences, the clinical and pathological features were similar to those seen in the West.

Adult↗
PubMed1993

Syndrome of Rochalimaea henselae adenitis suggesting cat scratch disease.

OBJECTIVE: To describe a clinical syndrome of cat scratch disease caused by Rochalimaea henselae, including methods for isolation of the organism from tissue and for identification. DESIGN: Case series. SETTING: U.S. Air Force referral hospital infectious diseases clinic. PATIENTS: Two previously healthy patients. MAIN MEASUREMENTS AND RESULTS: Two immunocompetent patients who had handled cats developed unilateral upper-extremity adenitis associated with a distal papular lesion and fever. The adenitis and distal lesions persisted and progressively worsened. Cultures of the involved lymph nodes from both patients grew R. henselae, a recently described organism associated with bacillary angiomatosis and peliosis hepatis in human immunodeficiency virus-infected patients and with bacteremia in immunocompromised and immunocompetent hosts. The organism was characterized as oxidase negative and X-factor dependent and had a characteristic pattern in analysis of whole-cell fatty acids differing from Afipia felis, a bacterium that has been associated with cat scratch disease. The identity of the isolate was confirmed by analysis of whole-cell fatty acids using gas chromatography and by amplification of the citrate synthetase gene sequence and analysis of the polymerase chain reaction-amplified product. The organisms were broadly susceptible to a variety of antimicrobials by broth microdilution; however in-vitro resistance to first-generation cephalosporins correlated with clinical failure of therapy. CONCLUSION: Rochalimaea henselae can be a cause of cat scratch disease in immunocompetent patients.

Adult↗
PubMed1993

Removable partial denture framework try-in.

Removable partial denture frameworks must fit accurately to function properly and not cause injury to remaining teeth or soft tissue. This article presents a logical method and rationale for seating a removable partial denture framework and a review of several disclosing media used in the try-in procedure.

Acrylic Resins↗
PubMed1993

Longitudinal analysis of the humoral immune response to human immunodeficiency virus type 1 (HIV-1) gp160 epitopes in rapidly progressing and nonprogressing HIV-1-infected subjects.

Antibody response to conserved human immunodeficiency virus type 1 (HIV-1)IIIB gp160 epitopes was longitudinally examined in HIV-1-infected persons. Twelve hundred individuals were evaluated, and sequential sera from 25 rapidly progressing (RP) and 30 nonprogressing (NP) subjects collected over an average of 4 years were examined. Initial sera from the RP group contained greater reactivity to a gp120 epitope defined by peptide 503-528 than did sera from the NP group (P < .001). Reactivity declined with sequential sera for the RP group, paralleling disease progression. Conversely, antibody recognition to this site developed in 23% of the NP group with time. However, 60% of the NP group never developed a response to this epitope. This suggests sequential examination of antibody response to an epitope within the gp120 carboxyl-terminus may have prognostic significance. No association between antibodies directed against the gp160 epitopes and in vitro neutralizing activity against HIV-1IIIB was observed.

Adult↗
PubMed1993

Litigation, sleep, symptoms and disabilities in postaccident pain (fibromyalgia)

Twenty-four patients with chronic postaccident pain were studied with self-rating symptom checklists, polysomnography and disability questionnaires. All except one had fibromyalgia. Eight had litigation resolved (R) while 16 had medicolegal claims still unresolved (UR). Patients from the R group were older, with a longer duration of symptoms and more occupation handicap compared to those from the UR group. There were no significant differences between the 2 groups in other demographic data, nature of accident, symptoms, polysomnographic findings and disability. Medicolegal claim status in these patients did not differentiate the outcome of their symptoms. Implications for litigation, treatment and further studies are discussed.

Accidents↗
PubMed1992

Significant infections due to Bacillus species following abrasions associated with motor vehicle-related trauma.

Non-anthracis Bacillus species are ubiquitous gram-positive spore-forming organisms that were once believed to be nonpathogenic but are now recognized as causing a variety of infections. We report a new aspect of trauma associated with bacillus infection: clinically significant infection by Bacillus species in patients who are involved in motor vehicle accidents and sustain injury related to road contact. Cases were evaluated retrospectively from May 1990 through December 1991. Four patients who had documented infections with Bacillus species and who were involved in motor vehicle accidents associated with road trauma were identified during this period. The antibiotic susceptibility profile of the Bacillus species consistently demonstrated resistance to beta-lactam antibiotics. This series of cases illustrates an additional aspect of disease associated with bacteria of the Bacillus species that should be considered for patients who have sustained injuries from motor vehicle accidents associated with road trauma.

Accidents, Traffic↗