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T Duong

Publications and source records attributed to T Duong.

49 records · Page 3Linked to original sources
PubMed1989

Immunodetection of the amyloid P component in Alzheimer's disease.

Amyloid P component (AP), a plasma constituent normally not found in brain parenchyma, has been immunohistochemically determined in brains from patients with Alzheimer's disease (AD). Tissue came from 11 clinically diagnosed and neuropathologically verified AD patients and from 6 normal aged controls. Positive labeling for AP was observed in amyloidotic blood vessels, senile plaques (SP) and neurofibrillary tangles (NFT). The immunoreactivity was specific for these AD-associated lesions and clearly revealed their morphological appearance. Affected blood vessels appeared to be mainly of the arteriolar type and were labeled abluminally in short segments. SP constituents such as amyloid fibrils, amyloid core and degenerative axonal and dendritic processes were positive for AP antiserum; the morphology and distribution of immunoreactive SP corresponded to previous descriptions. Labeling of NFT revealed the morphology of paired helical and straight filaments. In all cerebral areas studied, tangle-bearing neurons were immunoreactive to AP antiserum, suggesting that AP is involved in early cellular development of NFT. Given the large molecular weight of AP (about 220,000), these results point to a potential impairment of the blood-brain barrier in AD. Since AP is always present in systemic amyloidosis, its detection in cerebral amyloidosis associated with AD may suggest mechanisms common to the two disorders.

Aged↗
PubMed1989

A reexamination of aluminum in Alzheimer's disease: analysis by energy dispersive X-ray microprobe and flameless atomic absorption spectrophotometry.

We have attempted to verify the presence of increased aluminum (Al) levels in Alzheimer's disease (AD) brains by energy dispersive X-ray microanalysis (EDX) and flameless atomic absorption spectrophotometry (AAS). Tissue from seven AD brains, mounted on carbon polymerized coverslips, were stained with Congo-red or treated immunohistochemically to allow optical localization of AD-associated lesions during EDX. Despite a demonstrated sensitivity of 20-25 ppm, we were unable to detect Al in either plaque cores or neurons containing neurofibrillary tangles. For AAS, wet weight samples (ranging from 48-144 mg) from six of the seven AD brains and four controls were selected from regions similar to those studied under EDX, i.e., Brodmann areas 9, 11, 28, 46, 47, and the hippocampus. The tissue surrounding each sample site was sectioned and stained for thioflavin S. Both controls and AD samples revealed similar levels of Al ranging from undetectable to 1.80 ng/mg wet wt. (mean AD: 0.28 +/- 0.39 (SD), control: 0.54 +/- 0.58 (SD], independent of degree of histopathology or age of the case. We conclude that the combined strengths of these two techniques on similar tissue specimens demonstrate that abnormal Al levels are not required to produce the histologic findings of AD and that this element may not accumulate in the aging brain. It is unlikely, therefore, that Al is essential in the etiology of pathogenesis of plaques and tangles in AD. Al's role as a primary or secondarily associated event, when present, needs further delineation.

Aged↗
PubMed1989

Cutaneous cryptococcosis resembling molluscum contagiosum: a first manifestation of AIDS.

A 30-year-old homosexual man developed multiple skin umbilicated lesions resembling molluscum contagiosum. Initially the lesions were on his face but they rapidly spread. Histopathology and mycologic cultures of a skin biopsy revealed cryptococcus neoformans which was also identified in cerebrospinal fluid and in bronchoalveolar washings. The patient had fever, weight loss, generalized lymph node enlargement, depletion of the T helper subpopulation and positive HIV-1 serology. During treatment with flucytosine and amphotericin B, the skin lesions regressed in 3 months (cryptococcus neoformans disappeared in the cerebrospinal fluid and skin within one and five weeks, respectively). Our case demonstrates that molluscum contagiosum-like skin manifestations may be caused by cryptococcal infections. So it is necessary to perform skin biopsy in HIV seropositive patients with skin lesions resembling molluscum contagiosum, to diagnose mycotic infections, and especially cryptococcosis. Cutaneous cryptococcosis was, in this case, the first symptom of AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1986

Lower Purkinje cell counts in the cerebella of four autistic subjects: initial findings of the UCLA-NSAC Autopsy Research Report.

As part of an autopsy research project, the brains of four autistic subjects were examined and compared with those of three comparison subjects without CNS pathology and one with phenytoin toxicity. The cerebellum was selected for initial investigation because pathognomonic symptoms and neurophysiological measures suggest that pathology may exist in the cerebellar-vestibular axis in certain patients. Total Purkinje cell counts were significantly lower in the cerebellar hemisphere and vermis of each autistic subject than in the comparison subjects.

Adolescent↗
PubMed1983

Schistosomiasis mekongi diagnosed by rectal biopsy.

Schistosoma mekongi, a parasite of the dog which is endemic in small foci along the Mikong river, is rarely seen in Europe. A case of schistosomiasis caused by S mekongi was recently seen in France, in a native of Laos who had been living in Thailand. He was admitted for treatment of previous diagnosed tuberculoid leprosy but was found to have hepatosplenomegaly, with a high eosinophil count and high bilirubin concentrations. Serological examination suggested schistosomiasis, but there were no parasites in the urine and the rectal mucosa looked normal on endoscopy. Nevertheless, rectal biopsy showed schistosomal proctitis and many ova of S mekongi. Two courses of praziquantel cleared the ova from his rectal mucosa. Although serological examination using S mansoni antigen suggested schistosomiasis, only biopsy of normal looking rectal mucosa allowed the diagnosis to established.

Adult↗
PubMed1983

An improved gas chromatographic determination of urinary catecholamine metabolites.

We describe an improved gas chromatographic method for the determination of 3-methoxy-4-hydroxymandelic acid (vanilmandelic acid), 3-methoxy-4-hydroxyphenyacetic-acid (homovanillic acid), and 3-methoxy-4-hydroxyphenylethylene glycol. By incorporating slight modifications to established procedures, this method allows the urinary metabolites to be measured more rapidly and with better resolution. The procedure uses an internal standard and involves ethyl acetate extraction, silylation, and chromatography using a combination of two different stationary phases. The technique is simple and reliable and may be easily incorporated as a routine laboratory procedure.

Catecholamines↗
PubMed1976

Occupation and Hodgkin's disease.

An incidence survey of Hodgkin's disease (HD) was conducted in the Boston Standard Metropolitan Statistical Area for 1959-73. Information on affected persons, 20 to 64 years old, was related to the 1960 and 1970 U.S. decennial censuses to evaluate the rates of HD in several occupational groups of special interest. No excess HD risk was found for two groups with high exposure to persons with the disease: Physicians had a relative risk (RR) of 1.2(0.4-2.6, 95% confidence interval) and nurses had an RR of 0.9 (0.4-1.8). Teachers, a group suggested to be at high risk due to exposure to "carriers" or contacts, had an RR of 1.1 (0.7-1.6). A high sex ratio, 1.9:1, at 35-64 years of age suggested that occupational exposures might increase disease risk. However, no difference in HD incidence was seen between employed and unemployed women in this age group. As in previous studies, woodworkers had an excess risk of HD [RR=1.6(0.9-2.6-a)], but the reason for this is obscure.

Adolescent↗
PubMedDate not supplied

[Extensive cutaneous candidiasis revealing cutaneous T-cell lymphoma: 2 cases].

BACKGROUND: During the course of immunodeficiency diseases, severe candidiasis can occur with extensive cutaneous and mucous membrane lesions. However, blood dyscrasias are very rarely revealed by diffuse candidiasis. We report two case of cutaneous T-cell lymphoma revealed by extensive and atypical cutaneous candidiasis. PATIENTS AND METHODS: Case No. 1:A 72-year-old woman presented a pruritic rash of circinate, serpiginous patches on glabrous skin and skinfolds with multiple intertrigo and rapidly worsening palmoplantar keratoderma. All mycological skin specimens tested positive for Candida albicans. Histological examination of a biopsy sample from a serpiginous patch revealed the presence of fungal elements while palmoplantar keratoderma biopsy showed an epidermotropic lymphocytic infiltrate in the superficial dermis evocative of mycosis fungoides. Blood tests showed a white cell count of 28 600/mm3 with 14% circulating Sezary cells and a T-cell clone. The T-cell lymphoma was treated with methotrexate, but the disease worsened a few months later, progressing to CD30- large T-cell pleomorphic lymphoma. The patient died of severe sepsis. Case No 2:A 60-year-old man presented a macular rash over the face, trunk and skinfolds as well as erythematous scaly annular plaques of the glabrous skin with lymphadenopathy. Cultures of skin scrapings were all positive for Candida albicans. Blood tests showed a white cell count of 15 000/mm3 with 30% circulating Sezary cells. A trunk patch biopsy revealed the histological appearance of mycosis fungoides. There was a T-cell clone in the peripheral blood and skin. DISCUSSION: In both cases, the patients presented with widespread annular and erythematous scaly lesions of the glabrous skin and skinfolds with evidence of Candida albicans on fungal tests of all skin scrapings. The discovery of circulating Sezary cells on a systematic smear for hyperleukocytosis led us to suspect underlying cutaneous T-cell lymphoma, which was confirmed by biopsy of the skin lesions accompanying the mycoses. Widespread cutaneous candidiasis can occur in patients with cell-mediated immunodepression. Cutaneous T-cell lymphoma can enhance such candidiasis through interference with skin integrity and impairment of cell-mediated immunity, with large amounts of IL10 and TGF-B, increased secretion of soluble interleukin-2 receptors (CD25) and impaired CD8 suppressor cell function.

Aged↗
PubMedDate not supplied

On the possible relationship of cortical microvascular pathology to blood brain barrier changes in Alzheimer's disease.

A group of alterations in the structure of cortical microvessels is described in the brain tissue of neuropathologically confirmed patients with Alzheimer's disease. These changes include irregular thickening of the vessel walls, infiltration with amyloid and the serum P component of amyloid, loss of the perivascular neural plexus and the frequent occurrence of pits and lacunae in vessel walls. The possibility that these alterations may be related to blood brain barrier defects is suggested.

Alzheimer Disease↗