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Biomedical subjects

A Wu

Publications and source records attributed to A Wu.

At least 163 records · Page 9Linked to original sources
PubMed1990

Verification of electron beam therapy with storage phosphor images: precision of field placement.

Portal verification images were generated from the photon contamination in electron beams produced by a linear accelerator during treatment of patients receiving high-energy electron radiation therapy (8-14 MeV). An experimental storage phosphor system was used to record the images and display them on laser-printed film. Images were obtained from four or more treatment fractions from 21 cases of head and neck cancer. Precision in field placement was estimated by determining the position of a selected anatomic landmark relative to the center of the field for each series of images. The average standard deviation in the field-position measurements was 3.8 mm. Several procedural problems were also detected and corrected after review of the verification images. The results indicate that the emphasis placed on monitoring and control of field-positioning error in high-energy electron treatments should be similar to the emphasis placed on this aspect of error in photon treatment.

Electrons↗
PubMed1990

Detection of HPV-16 DNA in cervical carcinoma by paraffin section in situ hybridization.

Thirty-eight cervical carcinomas and 1 cervical condyloma were examined for the presence of human papillomavirus (HPV) type 16 DNA using 3H-dCTP-labelled HPV-16 DNA probe in paraffin section in situ hybridization and 32P-dCTP-labelled probe in dot blot hybridization (Tm-17). The results showed an HPV-16 DNA positive rate in our series of about 74.4% (29/39) as determined by paraffin section in situ hybridization and about 71.8% (28/29) by dot blot hybridization. There was no significant difference between the two methods. We thus confirmed that paraffin section in situ hybridization is an informative, reliable, and sensitive method for the diagnosis of cervical HPV infection.

Condylomata Acuminata↗
PubMed1990

[Extraction rate of trace elements in wuling san in simulated gastric fluid].

The present paper reports the determination of twelve trace elements in Wuling San and its extracts in simulated gastric fluid by atomic absorption spectroscopy. The experimental result shows that among these elements the extraction rate of K, Na and Mn is higher in extracts of Wuling San, and that of the other nine elements differs greatly from each other between 4-89%.

Drugs, Chinese Herbal↗
PubMed1989

Smoking, air pollution, and the high rates of lung cancer in Shenyang, China.

A case-control study involving interviews with 1,249 patients with lung cancer and 1,345 population-based controls was conducted in Shenyang, an industrial city in northeastern China, where mortality rates are high among men and women. Cigarette smoking was found to be the principal cause of lung cancer in this population, accounting for 55% of the lung cancers in males and 37% in females. The attributable risk percentage among females is high compared to elsewhere in China, largely because of a higher prevalence of smoking among women. After adjustment for smoking, there were also significant increases in lung cancer risk associated with several measures of exposure to air pollutants. Risks were twice as high among those who reported smoky outdoor environments, and increased in proportion to years of sleeping on beds heated by coal-burning stoves (kang), and to an overall index of indoor air pollution. Threefold increases in lung cancer risk were found among men who worked in the nonferrous smelting industry, where heavy exposures to inorganic arsenic have been reported. The associations with both smoking and indoor air pollution were stronger for squamous cell and small cell carcinomas than for adenocarcinoma of the lung. Risks due to smoking or air pollution were not greatly altered by adjustment for consumption of fresh vegetables or sources of beta carotene or retinol, prior chronic lung diseases, or education level. The findings suggest that smoking and environmental pollution combine to account for the elevated rates of lung cancer mortality in Shenyang.

Adenocarcinoma↗
PubMed1989

Improved early results of elective hepatic resection for liver tumors. One hundred consecutive hepatectomies in cirrhotic and noncirrhotic patients.

Liver resection for a neoplasm was performed in 100 patients between 1979 and 1987. There were 43 hepatocellular carcinomas (70% of them arising in patients with cirrhosis), 28 metastases from colorectal cancers, 20 benign tumors, and 9 miscellaneous tumors. Forty-nine patients had a major liver resection, 36 a segmentectomy, and 15 a nonanatomic liver resection. Great care was taken to avoid intraoperative and postoperative bleeding, including late ligation of the hepatic vein, the use of Kelly fracture and resorbable clips for hemostasis of transection planes in 74 patients, and temporary clamping of the portal pedicle in 22. Drainage of the abdomen was avoided in 21 patients to prevent ascitic leakage to decrease the postoperative hospital stay. Operative mortality was 1%. There were eight major complications, including one bile leak, one subphrenic abscess, and three subphrenic hematomas. The use of resorbable clips significantly reduced operative time and transfusion requirements. In patients with cirrhosis, temporary clamping of the hepatic pedicle significantly decreased blood loss. Avoiding drainage significantly decreased the postoperative hospital stay.

Adult↗
PubMed1989

Morphological and histological features of resected hepatocellular carcinoma in cirrhotic patients in the West.

The pathological findings of 26 consecutive resections for hepatocellular carcinomas developing in cirrhotic patients were analyzed morphologically with a special interest in the presence of a capsule, vascular extension and satellite nodules. Tumor sizes varied from 2 to 11 cm. There were 20 expanding (76.9%) and six infiltrating tumors. Infiltrating tumors were significantly larger than expanding tumors (p less than 0.01). Histologically, the most common subgroups were the trabeculated pattern (65.4%) and the Edmonson-Steiner Type II (53.9%). Of the 20 expanding tumors, only six had direct spread in the liver parenchyma adjacent to the tumor (p less than 0.02). There was a significant relationship between the presence of a tumor extension in the distal portal branches and the presence of satellite nodules around the tumor (p less than 0.01). Survival at 6 months was significantly lower in patients with infiltrating (16.7%) than in those with expanding tumors (75%), (p less than 0.05). The present results indicate that pathological features of hepatocellular carcinomas in cirrhotic patients in Western countries are similar to those encountered in the East: (a) tumors are frequently encapsulated; (b) the propensity for the tumor to spread is closely related to the presence of a tumor capsule. This study suggests that a thorough preoperative search for the capsule should be made whenever resection of a hepatocellular carcinoma in a cirrhotic patient is contemplated.

Carcinoma, Hepatocellular↗
PubMed1989

Improved neonatal heart preservation with an intracellular cardioplegia and storage solution.

The optimal conditions for preservation of the neonatal heart for transplantation remain uncertain. An isolated, working neonatal piglet heart model was used to compare a standard extracellular-like cardioplegic solution followed by storage at 4 degrees C in normal saline for 12 hr (n = 8) to cardioplegia and storage at 4 degrees C for 24 hr in an intracellular-like solution (n = 7). Seven of eight hearts in the 12-hr Extracellular Group failed to regain function, with a maximum stroke work index (SWI), developed at a left ventricular end-diastolic pressure (LVEDP) of 9 mm Hg of 0.91 +/- 0.30 x 10(3) erg/g (mean +/- standard error of the mean), 7.1% of nonpreserved control hearts. In contrast, all hearts arrested and stored for 24 hr in the intracellular solution regained function with a maximum SWI, again at a LVEDP of 9 mm Hg of 9.51 +/- 1.98 X 10(3) erg/g, 73.7% of control (P less than 0.05). Ultrastructural changes seen by electron microscopy paralleled the functional results. We conclude that an intracellular arrest and storage solution may be superior to conventional solutions for extended preservation of the neonatal heart.

Animals↗
PubMed1989

Pharmacokinetics of ketorolac and p-hydroxyketorolac following oral and intramuscular administration of ketorolac tromethamine.

Ketorolac tromethamine (KT), a potent analgesic with cyclooxygenase inhibitory activity, was administered in an open, randomized, single-dose study of Latin-square design to 12 healthy male volunteers. Doses of 30 mg oral (po) and 30, 60, and 90 mg intramuscular (im) KT were administered in solution. Plasma samples were analyzed for ketorolac (K) and its inactive metabolite, p-hydroxyketorolac (PHK), by reversed-phase high-performance liquid chromatography (HPLC). The 30-mg im dose was found to be similar to the 30-mg po dose with respect to total AUC values for both K and PHK. The amount of PHK circulating in plasma was very low as judged by AUC ratios (PHK/K x 100) of 1.9 and 1.5% for the 30-mg po and im doses, respectively. The rate of absorption of K and formation of PHK, as determined by Cmax and Tmax values, was significantly slower following the im doses. Total AUC and Cmax for K and PHK increased linearly with dose after im administration of 30, 60, and 90 mg of KT. The mean plasma half-life of K was remarkably consistent between po and im administration and was independent of dose, ranging from 5.21 to 5.56 hr. The plasma metabolic profile was similar following both routes of administration and graded im doses.

Administration, Oral↗
PubMed1989

Long term results (greater than 5 years) in patients with peritoneovenous shunting for intractable ascites: liver function and cancer mortality.

This report is based on twenty-eight (26%) of 107 patients included in a protocol for prospective evaluation of elective peritoneo-venous shunting for intractable ascites in cirrhosis. These patients had no other procedures and survived more than 5 years after the operation. All patients were free of ascites except one in whom it was mild. One patient refused follow-up. Shunt patency was assessed in 23 patients In 14 patients (60.9%), the shunt was obstructed and the superior vena cava was occluded in 5 of them. In 9 patients (39.1%), the shunt was still functioning. No clinical or biological parameters differentiated these two groups of patients. Of the 24 patients who were alcoholics, 2 abstained completely and 20 significantly reduced their drinking habits. In 25 patients, the Pugh's score improved and was A at the time of the study. Seven patients (25.9%) developed a malignant tumor of the oro-pharynx or digestive tract, all other patients were alive and in good health. This study suggests that patients with intractable ascites treated by a peritoneo-venous shunt may survive for a long period. In patients abstaining from heavy drinking, it may function as a therapeutic bridge permitting spontaneous improvement of liver function. The risk of supervening neoplasms suggests that a continuous follow-up of these patients is warranted.

Adult↗
PubMed1989

Interstitial iridium-192 implantation for malignant brain tumours. Part II: Clinical experience.

The treatment results of 37 patients with malignant brain neoplasms treated with a computed-tomography-guided stereotactic iridium-192 implant are reviewed. Of these, 29 patients with high-grade gliomas (20 with glioblastoma multiforme (GBM), nine with anaplastic astrocytoma (AA] received an implant as part of their initial management. The median survival was 14.5 and 15.5 months in the patients with previously untreated GBM and AA, respectively. In those patients with recurrent tumour after external-beam irradiation, durable local control over a year was achieved with implantation. Increasing the total tumour dose from 120 to 160 Gy did not improve survival or local control. Karnofsky Performance Status (KPS) was used as an indicator of quality of life and was seen to decrease with a median interval of 8.5 months following treatment. No severe complications were noted in the entire group of patients treated with this implant procedure.

Adult↗
PubMed1989

Dental insurance and its effects among the elderly in Ontario.

This paper examines the association between dental insurance, dental utilization and oral health outcomes among elderly people living independently in two communities in Ontario. Dental insurance had no independent effect on use of dental services, dissatisfaction with oral health status or clinically defined treatment needs. However, dentate attenders were less likely to be dissatisfied with their oral health and less likely to need dental treatment than those defined as non-attenders. One unexpected finding was that the dentate elderly had higher levels of utilization than is often reported in the literature but still had high levels of treatment need.

Aged↗
PubMed1989

Ethnic distribution of amyloidosis: an autopsy study.

We examined the ethnic heritage of 467 patients with amyloidosis and related it to the type of amyloid (secondary versus other types) found among 52,370 autopsies at Los Angeles County-University of Southern California Medical Center. Classification of amyloidosis by type was accomplished by using the potassium permanganate Congo red staining method and a specific anti-AA antiserum, supplemented by the anatomical distribution of the amyloid in some instances. We discovered a statistically significant increase in amyloidosis among patients with hispanic surnames as compared with other Caucasians. The overall rate for Hispanics in our total autopsy population was 2.3% as compared with 0.6% for other Caucasians (P less than or equal to 0.001). The increase was mostly among those whose amyloid was negative to tests for secondary (AA) amyloidosis and not anatomically compatible with senile cardiac (senile systemic) amyloidosis. Hispanics accounted for 76% of these cases as compared with 18.5% for Caucasians (P less than or equal to 0.001). Our findings, along with previously published reports, suggest that the frequency of amyloidosis may vary significantly in different ethnic groups.

Adult↗
PubMed1988

T-cell-rich lymphoproliferative disorders. Morphologic and immunologic differential diagnoses.

To differentiate peripheral T-cell lymphomas (PTCL), the authors evaluated the results of T11 monoclonal antibody studies on consecutive cell suspensions prepared from 509 lymph nodes from various lymphoproliferative disorders (LPD). They used T11 (CD2) positivity to identify those LPD in which the content of T cells was high. There were 266 (52%) cell suspensions which contained more than 50% T11-positive cells. More than 75% of the following non-Hodgkin's lymphomas had over 50% T11-positive cells: diffuse mixed cell (DM), diffuse atypical poorly differentiated lymphocytic and lymphoblastic lymphomas; mycosis fungoides; and true histiocytic lymphoma. Eleven cell suspensions had more than 90% T11-positive cells; four were involved by B-cell lymphomas. The cell suspensions prepared from nine of 14 diffuse large cell lymphomas of the T-cell type had more than 50% T11-positive cells. Of these, three of five cases of the polymorphous subtype had fewer than 50% T11 cells, but six of seven lymph nodes of the clear-cell type had more than 50% T11-positive cells. Each of seven DM samples of the T-cell type contained over 50% T11 cells; none had a polymorphous appearance. In the 112 cases of reactive LPD studied, more than 75% of cases of necrotizing lymphadenitis, dermatopathic lymphadenitis, angioimmunoblastic lymphadenopathy, and those with lymph nodes with no specific reactive pattern had more than 50% T11-positive cells. The authors' findings indicate that T11 positivity is a reliable T-cell marker in reactive and neoplastic LPD except for those cases of PTCL with a polymorphous appearance; these tend to lose T11-expression. A multi-parameter diagnostic approach is required in the following LPD: (1) PTCL which are T11-negative; (2) PTCL of small lymphocytic type having an unremarkable T-cell phenotype; (3) SIg-negative B-cell lymphomas which are rich in nonneoplastic T cells; (4) non-Hodgkin's lymphomas with minimal disease which are rich in reactive T cells; and (5) polymorphous large cell proliferations.

Antigens, Differentiation, T-Lymphocyte↗
PubMed1988

Hashimoto's thyroiditis lacks detectable clonal immunoglobulin and T cell receptor gene rearrangements.

The development of B cell lymphoma, predominantly of the large-cell type, in patients with autoimmune diseases such as Hashimoto's thyroiditis or Sjogren's syndrome is well known. In Sjogren's syndrome, it has been recently shown that the benign-appearing lymphocytic infiltrates of the lymphoepithelial lesions in the salivary glands have clonal rearrangements of immunoglobulin genes in their DNA, even in the absence of malignant lymphoma. To investigate whether a similar situation occurs in Hashimoto's thyroiditis, we studied the thyroid glands from four patients with this disease. In all four cases, there was a benign-appearing lymphocytic infiltrate in the thyroid, with eosinophilic changes in the Hurthle cells. In immunologic studies, we determined that the lymphocytes were polyclonal in each case. We extracted DNA from the frozen tissue blocks of these four patients and analyzed it by molecular hybridization for the presence of clonal immunoglobulin (IgH, kappa, and lambda) and T cell receptor beta chain gene rearrangements, and detected none in any case. Therefore, we conclude that the lymphocytes in Hashimoto's thyroiditis are immunologically and immunogenetically polyclonal proliferations of cells, and that the initial lesion of Hashimoto's thyroiditis does not contain a detectable clone of cells that may eventually develop into malignant lymphoma.

Gene Rearrangement, B-Lymphocyte↗
PubMed1988

Cardiolipin from ethanol-fed rats confers tolerance to ethanol in liver mitochondrial membranes.

In rats chronically consuming ethanol, the liver mitochondrial membranes develop resistance to the disordering effects of ethanol in vitro, so-called "membrane tolerance". To investigate the molecular basis of this tolerance in the inner mitochondrial membrane, multilamellar vesicles were produced by recombining the mitoplast phospholipids (quantitatively separated by preparative HPLC) from control and ethanol-fed animals in various combinations. The effect of in vitro ethanol on the physical properties of these vesicles was determined by electron spin resonance. Vesicles composed of all mitoplast phospholipids from control rats were disordered by 50-100 mM ethanol, whereas those made of the phospholipids from ethanol-fed animals were resistant. When phosphatidylcholine (46 mol %) or phosphatidylethanolamine (42 mol %) from ethanol-fed rats replaced the corresponding phospholipids of control rats, the vesicles were disordered by ethanol. By contrast, when as little as 2.5 mol % of cardiolipin (one-fourth the naturally occurring amount) from ethanol-fed rats replaced that phospholipid from control rats, vesicles were rendered entirely resistant to disordering by ethanol. The same amount of cardiolipin from ethanol-fed rats also conferred membrane tolerance to vesicles composed of bovine phospholipids, demonstrating that this effect is not restricted to rat mitoplast phospholipids. In vesicles composed of a single mitoplast-phospholipid class, only vesicles composed of cardiolipin from ethanol-fed rats resisted disordering. Phosphatidylinositol from liver microsomes of ethanol-fed rats also confers membrane tolerance and was the only microsomal phospholipid that formed tolerant vesicles. Thus, in livers of rats chronically fed ethanol, anionic phospholipids are selectively converted into potent promoters of membrane tolerance in both mitochondrial and microsomal membranes.

Alcoholism↗