PubMed Health⌕ Search

Biomedical subjects

Q Chu

Publications and source records attributed to Q Chu.

At least 37 records · Page 2Linked to original sources
PubMed2000

[Analysis on the intervention effect of HIV/AIDS cases].

OBJECTIVE: To study the effect of a comprehensive intervention strategy on the HIV infected individuals and their families. METHODS: Eleven HIV positive persons and their families were included to a comprehensive intervention strategy including routine surveillance, safer sex education and improving the status of hygiene. The outcome was compared with 2 fully developed AIDS cases who were not included to the intervention strategy. RESULTS: Of those HIV positive persons, that subjected to the intervention strategy, none had developed to AIDS, with only 1 transmitted HIV to his spouse among the 6 married individuals. All of their families were stable. Of those that not had been subjected, 2 individuals developed to AIDS and transmission in family was confirmed. CONCLUSION: The comprehensive intervention strategy on HIV/AIDS was effective which could the possibility of HIV in-family transmission and enhance the quality of life and the stability of their families.

Acquired Immunodeficiency Syndrome↗
PubMed1999

Binding and uptake of cationic lipid:pDNA complexes by polarized airway epithelial cells.

To better understand the barriers associated with cationic lipid-mediated gene transfer to polarized epithelial cells, Fischer rat thyroid (FRT) cells and polarized normal human bronchial epithelial (NHBE) cells grown on filter supports at an air-liquid interface were used to study the binding and uptake of cationic lipid:plasmid DNA (pDNA) complexes. The efficiencies of binding and uptake of cationic lipid:pDNA complexes by these cell systems were monitored using fluorescence microscopy of fluorescently tagged lipid or pDNA probes. Fluorescent probe bound to the cell surface was differentiated from internalized probe by adding trypan blue, which quenched the fluorescence of bound but not internalized probes. For proliferating cells, binding and internalization of the cationic lipid:pDNA complexes were determined to be efficient. In contrast, little binding or internalization of the complexes was observed using polarized epithelial cells. However, after aspirating a small area of cells from the filter support, virtually all of the cells adjoining this newly formed edge bound and internalized the cationic lipid:pDNA complexes. To determine if their uptake in edge cells was related to the ability of the complexes to access the basolateral membranes of these cells, the binding and uptake of complexes was monitored in polarized NHBE cells that had been pretreated with EGTA or Ca2+-free media, strategies known to disrupt tight junctions. Cells treated in this manner bound and internalized cationic lipid:pDNA complexes efficiently and also expressed significant levels of transgene product. Control cells with intact tight junctions neither bound complexes nor expressed significant transgene product. These data confirm and extend earlier observations that the polarized apical membranes of airway epithelial cells are resistant to transfection by lipid:pDNA complexes. Further, in contrast to previous studies that have shown the entry step of complexes is not an important barrier for COS and HeLa cells, binding and entry of complexes in polarized NHBE cells appear to be rate limiting. These findings suggest that strategies designed to open the tight junctions of polarized epithelial cells may improve gene delivery to these cells for diseases such as cystic fibrosis (CF).

Alkaline Phosphatase↗
PubMed1999

Capillary electrophoretic determination of cathepsin D activity using Oregon Green-labeled hemoglobin.

Cathepsin D is an aspartyl protease of lysosomal origin and functions in a variety of roles including protein turnover, catabolism of peptide hormones, antigen processing and presentation, and neoplastic disease. In breast cancer, the level of cathepsin D has been linked to metastasis and prognosis for survivability. Many of these studies concerning the role of cathepsin D in cancer have used immunological detection methods to determine the level of enzyme. These indirect methods to assess the cathepsin D level may not reflect enzyme activity accurately. The significance of cathepsin D to physiological and pathophysiological processes suggests that rapid and sensitive methods for determining cathepsin D activity would contribute to a more complete assessment of this enzyme in its various roles. This work describes a procedure to determine cathepsin D activity based on hydrolysis of fluorescently labeled hemoglobin and employs capillary electrophoresis to separate and measure the products of reaction. A single major cleavage product, representing the first 32 residues of the hemoglobin alpha-chain, appeared after a very short incubation time (less than 10 min) and was used to determine activity. The procedure described here requires very small sample volumes, has a low detection limit (approximately 10(-9) M) and thus represents an additional approach to determine cathepsin D activity in biological samples.

Cathepsin D↗
PubMed1999

Epithelial-myoepithelial carcinoma arising in the nasal cavity: a case report and review of literature.

Epithelial-myoepithelial carcinoma is an uncommon, low-grade, malignant epithelial neoplasm composed of variable proportions of ductular cells and large, clear staining, myoepithelial cells arranged around the periphery of the ducts. About 120 cases have been reported in the world literature, most of which were located in salivary glands, except for a few cases occurring in unusual locations such as breast, lacrimal gland, nose, paranasal sinus, trachea, bronchus, and lung. We here reported the second case of epithelial-myoepithelial carcinoma of the nasal cavity with extension to the nasopharynx. The patient was a 61 year old Chinese female with two month's history of progressive nasal obstruction. Histopathologically, the tumor showed typical myoepithelial and ductal cells biphasic differentiation, duct-like structure and infiltrating growth pattern. Some ductal cells showed the characteristics of oxyphilic cell, which had never been reported before. Recurrence and metastasis rates of epithelial-myoepithelial carcinoma varied from 35% to 50% and 8.1% to 25% respectively in different reports. The present case had neither recurrence nor metastasis twenty months after operation. When epithelial-myoepithelial carcinoma is mainly composed of spindle myoepithelial cells, the differential diagnosis should include myoepithelioma, neurofibroma, leiomyoma and hemangiopericytoma.

Biomarkers, Tumor↗
PubMed1999

Markers of severe appendicitis.

Appendicitis is a common surgical disease that often presents with vague, inconclusive symptoms. Despite the development of technologically advanced diagnostic modalities, perforation has usually occurred before the surgeon sees the patient. Morbidity, length of stay, and hospital costs associated with appendiceal perforation have not changed markedly in the past 50 years. To evaluate prognostic markers for severe appendicitis, we reviewed 18 years' worth of records of patients with appendicitis who were admitted to St. Elizabeth's Medical Center of Boston and found that the combination of history and physical examination has withstood the test of time. We found that advancing age, duration of symptoms for 36 or more hours, white blood cell count, shift left in white blood cell count, and fever were significantly related to severe appendicitis. An abnormal plain film was a marker if fever coexisted.

Adolescent↗
PubMed1999

[A case report of heterosexual transmission of HIV infection between spouses with persistent condom use].

OBJECTIVE: To report a case of heterosexual transmission of HIV infection between spouses with consistent condom use. METHODS: The first case with HIV infection was detected in the contracted male workers returned from abroad in Qingdao in 1992 and both he and his spouse were given health education for AIDS/HIV prevention and instructions on condom use. And, his wife was followed-up every six months by detecting her serum anti-HIV. RESULTS: The wife of the index case was negative for anti-HIV in the first 12 blood tests before December 1996. But, she was found suspect of positive for anti-HIV an July 1997 and definitely positive for anti-HIV-1 in August 1997 during her 14th test. In the period of 1992 to 1997, they persisted in condom use during intercourse. Recall of the wife showed that she had low fever in May 1997, suggesting at the window phase of her acute HIV infection. It postulated that she infected with HIV curing March to April 1997. CONCLUSION: The case report indicated that incorrect use of condom could not prevent from HIV transmission between spouses.

Acquired Immunodeficiency Syndrome↗
PubMed1999

[A clinico-pathological and immunohistochemical study on anaplastic large cell lymphoma].

OBJECTIVE: To study the clinicopathological characteristics, immunophenotype and biologic behavior of anaplastic large cell lymphoma (ALCL). METHODS: Clinicopathological and immunohistochemical methods (ABC method) were used to analyse 8 cases of ALCL and followed for 6 to 25 months. RESULTS: Eight ALCL patients (4 male and 4 female) accounted for 4.1% of the 195 lymphomas seen from 1994 to 1997. Average age was 40 years. Two tumors were located in the skin, the remainder were systemic. Clinical stage: stage I, 2 cases; stage II, 1 case; stage III, 5 cases. Histopathology: Tumor cells exhibited high pleomorphism and a large amount of mitotic figures. Reactive components (cells) often observed in the background. Immunohistochemical studies found that all tumors reacted positively with CD30 and negatively with CD15. Five cases expressed T-cell's markers (CD3, UCHL-1, CD43) and three expressed B-cell markers (CD79a, L26). After chemotherapy, two patients with cutaneous type ALCL had complete remission and survived 14 and 25 months respectively. Of the six systemic cases, three survived for 6-8 months, the remaining three died at 2 days, 20 days and 18 months after diagnosis. CONCLUSIONS: This study found that ALCL was a group of lymphomas showing similarity in morphology but diversity in clinical presentation and immunophenotype. Even if the tumor is very responsive to chemotherapy, ALCL remains a high grade malignant lymphoma.

Adolescent↗
PubMed1999

Extraperitoneal rectal perforation due to retroflexion fiberoptic proctoscopy.

The increasing use of retroflexion proctoscopy to evaluate the distal rectum is not without complications. We report a series of three patients who experienced extraperitoneal rectal perforation secondary to retroflexion proctoscopy and discuss our success with conservative management. By evaluating each clinical situation individually and following certain principles, successful outcome can be achieved without surgical intervention. Success depends on several factors: 1) the injury must be below the peritoneal reflection; 2) the patient must have undergone a complete bowel preparation before endoscopy; 3) postinjury, the patient must continue to show no evidence of peritonitis or hemodynamic instability; and 4) the patient must be given nothing by mouth, started on intravenous antibiotics and possibly parenteral nutrition, and closely monitored with serial abdominal examinations. The presence of comorbid conditions does not necessarily diminish the chance that conservative therapy will succeed.

Aged↗
PubMed1998

Direct Analysis of Resveratrol in Wine by Micellar Electrokinetic Capillary Electrophoresis.

Resveratrol is an antioxidant found in grapes and other plants. It has been reported to have health benefits including anticarcinogenic activity and protection against coronary heart disease. Previous methods for its quantification in wines have relied on HPLC and GC. However, an alternative method utilizing capillary electrophoresis (CE) has been developed in our laboratory. The CE procedure resolves cis- and trans-resveratrol isomers, using a micellar mode of separation. The detection limit for resveratrol was 1.25 µM using UV detection at 310 nm. This procedure was employed for the direct analysis of trans-resveratrol in wines. The direct analysis method used was advantageous because the analysis time was greatly reduced and sample preparation procedures that might result in resveratrol isomerization were avoided. The CE procedure was used to determine the level of trans-resveratrol in several California red wines, and the values obtained were in close agreement with those reported using other methods.

Journal Article↗
PubMed1998

Aerosolization of cationic lipid:pDNA complexes--in vitro optimization of nebulizer parameters for human clinical studies.

Previously, we have described the optimization of the aerosol delivery of a nonviral gene therapy vector to the lungs of rodents (Eastman et al., 1997b). Although aerosolizing cationic lipid:pDNA complexes into a whole-body exposure chamber resulted in high levels of reporter gene expression in the lungs of BALB/c mice, the conditions employed were not optimal for the delivery of lipid:pDNA complexes to the lungs of human patients. That is, the consumption rate of the material in the nebulizer, and thus the delivery time, were very slow and the aerosol was delivered in a continuous flow. Here we describe in vitro experiments used to develop a cationic lipid:pDNA aerosol with characteristics more suitable for delivery to the lungs of humans, as a necessary prerequisite for conducting a clinical study with human cystic fibrosis patients. Using cascade impactors and all-glass impingers, we have screened several commercially available nebulizers for their ability to deliver intact, respirable, active lipid:pDNA complexes in the shortest time possible, and have identified the Pari LC Jet Plus nebulizer as the optimal nebulizer that meets these criteria. Using this nebulizer in an intermittent mode to mimic breath actuation, consumption rates of approximately 0.6 ml/min of the cationic lipid:pDNA complexes (6 mM cationic lipid:8 mM pDNA) were obtained. The plasmid DNA remained intact and the complexes were shown to maintain activity throughout the nebulization run. Based on measurements of the nebulized dose and the mass median aerodynamic diameter, we calculate a delivered dose of approximately 22 micromol (7.2 mg) of pDNA for each 8 ml of cationic lipid:pDNA complex aerosolized to the lungs of a human patient. This dose should be sufficient to test the clinical efficacy of cationic lipid-mediated gene delivery for the treatment of cystic fibrosis.

Aerosols↗
PubMed1998

Delayed hemothorax after blunt thoracic trauma: an uncommon entity with significant morbidity.

OBJECTIVE: To describe the nature of delayed hemothorax occurring after blunt thoracic trauma and to identify the population at risk for this complication. METHODS: A retrospective review was conducted of 36 consecutive patients with hemothorax consequent to blunt trauma. Criteria for the definition of delayed hemothorax were established involving normal interval chest radiographs or computed tomographic scans during hospitalization. RESULTS: Twelve cases of delayed development of hemothorax were identified. Ninety-two percent of cases occurred in patients with multiple or displaced rib fractures. Presentation occurred from 18 hours to 6 days after injury. Eleven of the 12 cases were heralded by a prodrome of new pleuritic chest pain and dyspnea that occurred from 4 to 19 hours before treatment. CONCLUSION: Delayed hemothorax after blunt trauma is a unique entity occurring in patients with multiple or displaced rib fractures. Vigilance for the recognizable prodrome in the high-risk population should allow early remediation of this complication.

Aged↗
PubMed1998

[Epidemiological analysis of HIV infection status in the population at high risk].

In order to understand the status of HIV infection in the population under high risk, we conducted an epidemiological investigation among 396 persons from 1992 to 1995. The research sample included 55 female prostitutes, 159 labourers who had finished labour services abroad upon returning, 88 professional blood donors, 88 STD patients, 3 spouses and 3 children of the HIV infected people. Six cases of HIV positive were identified in four years. Among these, two were blood donors with one male and one female, the other four cases were all male labourers returned from abroad.

Adolescent↗
PubMed1998

[Research on risk factors of 5 types of viral hepatities among population with high risk behaviors].

Epidemiological and serological survey on five types of viral hepatities (hepatitis A-hepatitis E) was conducted from October 1994 to December 1996 among 119 labourers returned from abroad, including 55 female prostitutes, 86 medical workers, 88 STD patients and 88 paid blood donors. HAV infection rates for all of the 5 groups were above 83%. HBV infection rate showed significantly different (chi 2 = 3.86, P < 0.05) between medical workers (53.49%) and the control group (30.43%). A significant difference (chi 2 = 5.36, P < 0.05) between HBV infection among prostitutes (52.73%) and control group (26.67%) was also noticed. In all the five groups, none was found to be anti-HDV positive. The HEV infection rates for the medical workers, prostitutes, blood donors, returned labourers and STD patients were 1.16%, 3.64%, 2.27%, 5.88% and 6.82%, whereas the anti-HCV positive rates were 1.16%, 3.64%, 0.00%, 0.00% and 1.14%, among them respectively.

Adult↗
PubMed1997

Quantitative separation of 4-hydroxyproline from skeletal muscle collagen by micellar electrokinetic capillary electrophoresis.

The phenylthiohydantoin (PTH) derivatives of 3- and 4-hydroxyproline (Hyp) were separated using micellar electrokinetic capillary electrophoresis (MEKC). The separation protocol was also used to determine Hyp content of bovine skeletal perimysial collagen preparations and whole muscle samples. Amino acids from hydrolyzed tissues were labeled using a two step procedure that involved initial reaction with o-phthalaldehyde (OPA) to modify primary amines followed by their precipitation under acidic conditions. In the second step, imino acids were reacted with phenyl isothiocyanate (PITC). This labeling method was rapid and the Hyp values determined in these biological samples were found to be in close agreement with conventional methods and other published reports.

Animals↗
PubMed1997

Synovial fluid interleukin 6, tumor necrosis factor, and nitric oxide values in dogs with osteoarthritis secondary to cranial cruciate ligament rupture.

OBJECTIVE: To measure and compare values of interleukin 6 (IL-6), tumor necrosis factor (TNF), and nitric oxide (NO) metabolites in synovial fluid from canine joints with osteoarthritis (OA) secondary to naturally acquired cranial cruciate ligament (CCL) rupture and experimental CCL transection. ANIMALS: 57 dogs (clinical group) with OA secondary to CCL rupture; 5 dogs (experimental group) with OA secondary to CCL transection; 19 control dogs with normal joints. PROCEDURE: Joints were radiographed and graded for seventy of OA. Synovial fluid was collected from dogs: at surgery from the clinical group, at 90 days after surgery from the experimental group, and at necropsy from the control group. Activities of IL-6 and TNF, as well as concentration of the NO metabolites (NO2-/NO3-) were measured, and results were reported as mean +/- SEM. RESULTS: IL-6 activity in dogs of the clinical (290 +/- 40 U/ml) and experimental (494 +/- 165 U/ml) groups was greater than that in control dogs (6 +/- 1.6 U/ml; P < 0.05). The TNF values in dogs of the clinical (3.0 +/- 0.5 pg/ml) and experimental (2.0 +/- 0.9 pg/ml) groups were lower than those in control dogs (8.6 +/- 2.3 pg/ml; P < 0.05). The IL-6 values were negatively associated with radiographic score of OA and were positively associated with age (R2 = 26.5%, P < 0.05). CONCLUSION: Dogs with OA secondary to naturally acquired CCL rupture and experimental CCL transection had significantly different alterations in synovial fluid IL-6 and TNF values. The decrease in IL-6 activity with advancing OA was independent of the increase in IL-6 activity with aging. CLINICAL RELEVANCE: IL-6 and TNF may be involved in pathogenesis of OA secondary to naturally acquired and experimentally induced CCL rupture.

Age Factors↗
PubMed1996

In vivo dynamics of myosin II in Dictyostelium by fluorescent analogue cytochemistry.

We used fluorescent analogue cytochemistry to study in vivo dynamics of myosin II in Dictyostelium discoideum. We labeled myosin with biotin or tetramethyl-rhodamine iodoacetamide (IATR). The labeled myosin shows normal activities as reversible filament assembly and Ca2+ and actin-activatable Mg(2+)-ATPase. We used the biotin-myosin as a probe examining the effects of microinjection on the amoebae and the ability to associate with endogenous actin cytoskeleton. The biotin-myosin incorporates into certain actin populations and localizes to the cortex with the highest accumulation in the posterior end of polarized amoebae. The dynamics in live amoebae were probed by TR-myosin. We monitored the dynamics for a long period to determined the dynamic reorganization corresponding specific cellular behaviors. The TR-myosin converges into a discrete actin- and myosin-rich structure located at the posterior end ("myosin-organizing center"). The rod-shaped TR-myosin exhibits linear orderly arrays emanating from the organizing center which extend about two-thirds of the cell length. The myosin arrays show a dynamic reorganization when the amoebae move. To examine if the observed myosin dynamics are related to filamentous (F-) actin, we disrupted the F-actin by cytochalasin D. The ratioed image of TR-myosin (vs. FITC-dextran) demonstrates that myosin in these cells accumulates in the cortex but does not form the organizing center. Overall, the results suggest that the filamentous myosin organizes into orderly arrays in the live cytoplasm and its translocation occurs by means of F-actin cables, converging into the organizing center.

Animals↗