Biomedical subjects

Weimin Hu

Publications and source records attributed to Weimin Hu.

14 recordsLinked to original sources

PubMed2006

Aggressive histiocytic disorders that can involve the skin.

Histiocytoses are a heterogeneous group of disorders that are characterized by the proliferation and accumulation of reactive or neoplastic histiocytes. Three classes of histiocytoses have been defined: class I, Langerhans cell disease; class II, non-Langerhans cell histiocytic disease without features of malignancy; and class III, malignant histiocytic disorders. Although the disorders in classes I and II usually have a benign appearance on histology and are commonly non-aggressive and self-healing, some can cause debilitating or even fatal outcomes. Such cases beg the question: what stimulates aggressive behavior of a classically benign disease? New molecular information may now provide insight into the driving force behind many of the aggressive histiocytoses. In this article, we review Langerhans cell disease and seven aggressive histiocytoses that can involve skin, discuss histologic features that may forecast a poor prognosis, and discuss the molecular findings that help to explain the pathophysiology of these aggressive histiocytic disorders.

Histiocytosis↗

PubMed2006

Suppression of carrageenan- and collagen II-induced inflammation in mice by geranium oil.

To obtain experimental evidence on the therapeutic efficacy of essential oils in aromatherapy for inflammatory diseases, we examined the effects of geranium oil on carrageenan-induced and collagen II-induced inflammation in mice, to assess acute and chronic anti-inflammatory activities of the oil. Single intraperitoneal injection of 5 mu L of geranium oil clearly suppressed the carrageenan-induced footpaw edema and increase in tissue myeloperoxidase activity, and repeated administration of the oil suppressed collagen-induced arthritis. These results revealed that geranium oil suppressed both acute and chronic inflammatory responses in mice.

Animals↗

PubMed2005

The Population Health Approach: health GIS as a bridge from theory to practice.

BACKGROUND: The Population Health Approach, proposed by Health Canada, is the articulation of a long advocated model of human health. This approach strives to ensure that the health system is appropriately oriented to improve health status by applying evidence based practices across the continuum from health determinants to service interventions. Although conceptually appealing, it has been difficult to implement widely in the existing program-based health care system. The Population Health Surveillance Unit (PHSU) of the Vancouver Island Health Authority (VIHA) has developed a health geographical information system (HGIS), where GIS is used as both platform for information integration and as an analytical tool supporting comprehensive data analysis. With the assistance of the HGIS, the theory of the population health approach can be transformed into a practical, stepwise process supporting health services and program planning. RESULTS: Three important components of a health service planning and evaluation framework grounded in population health theory are described in this article. In particular, a stepwise methodological process to enable the incorporation of the principles of a population health into practical applications is presented; the technical functionality to integrate multiple sources of information, with different levels and scales is discussed; and sources of information about the health of the population at the appropriate level to populate this frame are proposed. An application of the methodology in the planning of health services for a high needs neighbourhood is presented as an illustrative example. CONCLUSION: The population health approach incorporates the consideration of health determinants and the context within which the health conditions arise in communities. The complexity of these relationships requires the application of innovative methodologies such as Health GIS to frame the issues practically. A population health based foundation for the planning and evaluation of health services can now move from theory to practice.

Journal Article↗

PubMed2005

Terminal complement components mediate release of von Willebrand factor and adhesion of platelets in arteries of allografts.

BACKGROUND: Both humoral and cellular immune responses can cause arterial injury in organ transplants, but the manifestations of these different inflammatory mechanisms have not been dissected fully. The present study was designed to define the effects of the terminal complement components on arterial injury in vivo. METHODS: The authors have developed congenic rat strains with a C6 deficiency. The absence of C6 terminates the cascade of complement after C5 cleavage and prevents the assembly of the membrane attack complex. Hearts were transplanted from PVG.1A (RT1) rats to major histocompatibility complex-incompatible C6-deficient (C6-) or C6-sufficient (C6+) PVG.1U (RT1) rats. RESULTS: PVG.1A (C6-) cardiac grafts were rejected acutely (6-7 days) by untreated PVG.1U (C6+) recipients but survived significantly longer in PVG.1U (C6-) recipients (8 to >30 days). Arteries of cardiac allografts in C6+ recipients demonstrated extensive endothelial injury evidenced by release of von Willebrand factor (vWF) and accompanied by platelet aggregation. In contrast, vWF was retained in Weibel-Palade storage granules of arterial endothelial cells in cardiac allografts that were rejected by C6- recipients. In the absence of C6, intimal alterations were limited to lifting of endothelial cells from supporting stroma by infiltrating mononuclear cells, duplicating the clinical lesion described as endotheliitis or intimal arteritis. Delaying graft rejection with a short course of cyclosporine did not decrease vWF release and platelet aggregation in PVG.1U (C6+) recipients. CONCLUSIONS: Mononuclear cell infiltration of the arterial intima occurs in the absence of C6, but C6 deficiency limits the release of vWF from arterial endothelial cells.

Animals↗

PubMed2004

Augmented inhibition of Candida albicans growth by murine neutrophils in the presence of a tryptophan metabolite, picolinic acid.

The effects of picolinic acid (PLA), a product of tryptophan catabolism, on anti- Candida activity of neutrophils were studied. Casein-induced peritoneal neutrophils of C3H/He mice partially inhibited mycelial growth of Candida albicans when cultured with C. albicans for 16 h in vitro. The growth inhibition of Candida was augmented by a combination of neutrophils and more than 4 mM picolinic acid. Especially in the presence of 200 U/ml murine interferon-gamma (IFN-gamma), 2 mM picolinic acid augmented the anti- Candida activity of neutrophils. The physiological significance of the augmenting effects of picolinic acid is discussed.

Animals↗

PubMed2004

Malignant melanoma arising in a pregnant African American woman with a congenital blue nevus.

BACKGROUND: The incidence of cutaneous melanoma in African-Americans is relatively low. Despite the slightly greater occurrence of congenital melanocytic nevi in black persons compared with white persons, the cumulative risk of melanoma arising in these lesions is very small. In addition, the overwhelming majority of melanomas in black persons occur on nonglaborous skin where congenital melanocytic nevi are rare. OBJECTIVE: The objective was to describe and an unusual case of melanoma arising in a congenital nevus with combined features of a blue nevus on the scalp of a pregnant African-American woman. RESULTS: Histologic examination revealed a polypoid malignant melanoma arising in association with a congenital blue nevus in a young African-American woman. The lesion was located on the right parietal scalp and had been enlarging over the course of her pregnancy. Pathology from parotidectomy and neck dissection confirmed metastatic melanoma involving two intraparotid lymph nodes and 3 of 26 cervical lymph nodes. Despite aggressive chemotherapy, she died in 1 year after the diagnosis. METHODS: A case is reported and the literature is reviewed. CONCLUSION: Clinicians must take great care in documenting and following pigmented lesions in all patients including African-American persons. Excision is indicated for lesions that undergo significant change during pregnancy.

Adult↗

PubMed2003

The ethanol metabolite, linolenic acid ethyl ester, stimulates mitogen-activated protein kinase and cyclin signaling in hepatic stellate cells.

Chronic ethanol consumption can result in hepatic fibrosis and cirrhosis. In addition to oxidative metabolism, ethanol can be metabolized by esterification with fatty acids to form fatty acid ethyl esters (FAEE) such as linolenic acid ethyl ester (LAEE). We have previously demonstrated that LAEE has promitogeinc and activating effects on hepatic stellate cells (HSC), but the mechanisms of these actions are not known. Intracellular signaling through MAP kinase pathways, including extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) can influence the activity of the transcription factor AP-1, while cell-cycle regulatory proteins such as cyclin E and cyclin-dependent kinase (CDK), play an important role in cell proliferation. In this study, we demonstrate that treatment of HSC with LAEE increases cyclin E expression and cyclin E/CDK2 activity, which may underlie the promitogenic effects of this compound. In addition, LAEE increases ERK and JNK activity, and these pathways play an important role in the activation of AP-1-dependent gene expression by LAEE. The stimulation of intracellular signaling pathways in HSC by this well-characterized ethanol metabolite may contribute to ethanol-induced hepatic fibrogenesis.

Animals↗

PubMed2003

Positron emission tomography for basal cell carcinoma of the head and neck.

OBJECTIVE: To determine the ability of fluorodeoxyglucose F 18 positron emission tomography (FDG-PET) to image basal cell carcinoma (BCC). DESIGN: Case series study. SETTING: Mohs surgery practice in a tertiary university hospital. PATIENTS: Six patients with BCC larger than 1.0 cm of the head and neck region were identified. RESULTS: Patients were imaged using FDG-PET before surgery. In 3 patients, PET imaging correlated well with the size and extent of the soft tissue invasion. Histologically, all 3 tumors were of the nodular subtype. The remaining 3 patients failed to demonstrate identifiable tumor activity on PET. Two of these 3 tumors were of the infiltrative histologic subtype, and 1 was of the nodular subtype. Perineural spread was detected by tissue biopsy in 1 infiltrative tumor, but not by FDG-PET imaging. CONCLUSIONS: In our study, FDG-PET imaging was able to image and identify BCC in the head and neck region in 3 of 6 patients. In some cases, anatomic accuracy and the extent of soft tissue invasion were observed. The histologic subtype of the BCC appears to affect the ability of FDG-PET detection, with the nodular histologic subtype more likely to test positive on PET. This is a preliminary study, and future investigation is needed to evaluate the role of PET imaging in the management of patients with BCC.

Aged↗

PubMed2003

SMTP-4D, -5D, -6D, -7D and -8D, a new series of the non-lysine-analog plasminogen modulators with a D-amino acid moiety.

Staplabin and SMTPs, triprenyl phenol metabolites of the fungus Stachybotrys microspora, are a family of non-lysine-analog plasminogen modulators that enhance both activation and fibrin binding of plasminogen by modulating plasminogen conformation. These compounds, including SMTP-4, -5, -6, -7 and -8, have an amino acid or an amino alcohol moiety in their structure, and precursor amine feeding greatly increases the biosynthesis of a metabolite of interest. In the present study, we have isolated five novel SMTPs (designated SMTP-4D, -5D, -6D, -7D and -8D) from precursor D-amino acid-fed cultures. Physico-chemical properties as well as chromatographic behavior were distinct from those of the corresponding L-amino acid analogs, which are selectively accumulated in L-amino acid-fed cultures and share common properties with corresponding natural products. The D-series SMTPs enhanced urokinase-catalyzed plasminogen activation by 10-fold at 80 approximately 180 microM.

Benzopyrans↗

PubMed2003

[Preliminary identification of up-regulated genes after the interaction of human peripheral blood mononuclear cell and porcine endothelial cell].

OBJECTIVE: To investigate the change of gene expression after the interactions of human peripheral blood mononuclear cell (PBMC) and porcine endothelial cell. METHODS: Human PBMC were co-cultured with porcine vascular endothelial cell line PIEC for 18 h. The mixed un-co-cultured PBMC and PIEC were used as controls. The cDNAs of both groups were prepared and subtracted by suppression subtractive hybridization (SSH). The up-regulated cDNAs were cloned into pGEM-T Easy vector to be sequenced. Nucleic acid homology searches were performed using the BLAST program. RESULTS: A subtracted cDNA library was obtained through SSH and cloning, which included about 300 clones corresponding to up-regulated genes. We randomly selected 24 of these clones for sequencing tests and analysis of homology in the GenBank. Four of the 24 clones were part of known human genes, 8 were known porcines expressed sequence tag (EST), and 9 held similar homology with known human genes. Three clones were not matched. CONCLUSION: Many genes are up-regulated after the interaction of human PBMC and porcine endothelial cell.

Animals↗

PubMed2002

Product-related emphasis of skin disease information online.

BACKGROUND: In 2000, 41 million people searched for medical information online. The quality of that information is unregulated, variable, and not well studied. OBJECTIVE: To quantify and compare the numbers and types of Internet sites matched for 10 diverse skin conditions through different search systems. DESIGN: Search strategies were performed at 6-month intervals via Netscape Navigator, using 3 search engines and 1 directory. Ten skin conditions were chosen to represent common (psoriasis and eczema), cosmetic (wrinkles and cellulite), difficult-to-treat (alopecia, mastocytosis, granuloma annulare, and xanthoma), and uncommon (dermatitis herpetiformis and epidermolysis bullosa) problems. Search strings were designed to generate lists of Web sites that provide educational or product-related information. Results were compared. SETTING: The Saint Louis University information technology server, July 9, 1999, December 16, 1999, and February 5, 2000. MAIN OUTCOME MEASURES: Comparisons of the total number, top 10 ranking, and type (educational vs product-related) of sites that matched through different search systems at 6-month intervals. RESULTS: The total number of matched sites for different skin conditions varied up to 100-fold. This number increased by 30% to 316% between July and December 1999. The largest number of Web sites related to wrinkles, followed by Web sites related to common conditions. Product-related sites outnumbered educational sites, especially for common and cosmetic conditions. Although there were differences in the total number of sites found through different search engines, the ratios of product-related to educational sites were similar. Different search engines yielded different top 10 match lists for the same condition. The top 10 lists included higher proportions of educational sites than the total match lists for all conditions except cellulite. Within the top 10 lists, the rank order of well respected sites varied by search engine used and changed over time. CONCLUSIONS: Patients are increasingly accessing the growing body of data available through the Internet. Most Web sites contain information related to products. Until standards are enacted to govern the distribution of online medical information, consumers are at risk for obtaining misinformation and buying ineffective products. To better guide patients, physicians must become familiar with this ever-changing information.

Female↗

PubMed2002

[Inhibition of constitutively activated Jak3 and induction of apoptosis in NALM-6 cell line].

OBJECTIVE: To investigate the relation of Jak3 constitutive activation and acute lymphoblastic leukemia(ALL). METHODS: NALM-6 cells were treated with varying concentrations of AG490, a Jak3 inhibitor. Apoptosis and proliferation of NALM-6 cells were tested by flow cytometry (FCM) analysis and MTT assay. RESULTS: With the exception of AG490 5 mumol/L, the AG490 10, 15, 20 mumol/L induced a strong apoptotic response in NALM-6 cells by FCM analysis(P < 0.05) and significantly inhibited the proliferation of NALM-6 cells by MTT assay(P < 0.05). All of the effects were dose-dependent. CONCLUSION: Jak3 inhibitor AG490 can inhibit proliferation and induce apoptosis in NALM-6 cells, and Jak3 activation is associated with pre-B ALL.

Antineoplastic Agents↗

PubMedDate not supplied

Epidermodysplasia verruciformis in two half brothers with HIV infection.

BACKGROUND: Epidermodysplasia verruciformis (EV) is a rare disorder characterized by widespread flat and common verrucae. From 25% to 50% of EV cases are inherited, usually with an autosomal recessive pattern. An X-linked inheritance has also been reported. Many EV patients have a cellular immunity defect. HIV-associated lesions have been found to contain HPV-5, HPV-8, and HPV-20. OBJECTIVE: We describe two HIV-positive Hispanic maternal half brothers who presented with asymptomatic polyangular papules and plaques on the face, trunk, and extremities and which first appeared 4-5 years prior. The histopathology is consistent with EV. HPV-8 was detected by in situ hybridization. The patients were treated with topical imiquimod for two months without improvement. CONCLUSION: To our knowledge, this is the first reported case of epidermodysplasia verruciformis in HIV-positive pediatric patients.

Child↗

PubMedDate not supplied

Acrokeratoelastoidosis.

Acrokeratoelastoidosis of Costa is a rare papular palmoplantar keratosis characterized by small round-oval to rhomboid-shaped, yellowish papules most commonly localized to the palmar surface of the hands and sometimes also found on plantar surfaces of the feet. Both autosomal dominant and sporadic forms of the disease have been reported. Histologically acrokeratoelastoidosis is marked by hyperkeratosis and epidermal hypertrophy. Specific stains for elastic tissue reveal characteristic fragmentation and rarefaction of elastic fibers. We report a sporadic case of acrokeratoelastoidosis in a 13-year-old girl and review the etiology, differential diagnosis, and treatment of this disorder.

Adolescent↗