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Biomedical subjects

M Tan

Publications and source records attributed to M Tan.

At least 163 records · Page 9Linked to original sources

Chronic pain.

Explore the source record for details and available documents.

Attitude of Health Personnel↗

[Textual study and resource investigation on traditional Chinese drugs duhuo, jiuyanduhuo and qianghuo].

By means of Bencaological study on traditional Chinese drugs Duhuo, Jiuyanduhuo and Qianghuo, it has been found out that the Duhuo recorded in earlier Bencao works should be Qianghuo, and Duhuo was first used medically in the South-North Dynasty period, whereas Jiuy-anduhuo's medical use started in the Ming Dynasty. Resources of the three drugs were investigated and their main species were found out.

Drug Contamination↗

Endobronchial radiation therapy with or without neodymium yttrium aluminum garnet laser resection for managing malignant airway obstruction.

BACKGROUND: Previous reports have shown low-dose-rate (LDR) afterloading Ir-192 endobronchial radiation therapy (EnBRT) to effectively palliate symptoms in patients with malignant airway obstruction. The authors retrospectively assessed the consequences of LDR EnBRT with or without neodymium yttrium aluminum garnet (Nd:YAG) laser resection in 37 patients. METHODS: Between February 1986 and June 1991, 37 patients with malignant airway obstruction were treated with LDR EnBRT at The Cleveland Clinic Foundation. Inclusion criteria for LDR EnBRT with or without Nd:YAG laser resection were patients with recurrent, symptomatic endobronchial lesions treated previously with external beam irradiation. Of the 37 patients, 21 patients with endobronchial lesions underwent Nd:YAG laser resection; 16 patients with mainly extrinsic lesions received EnBRT only. Before EnBRT, selected patients (7 of 16 in the nonlaser-treatment group and 14 of 21 in the laser-treatment group) received additional external beam treatments of 2000 cGy/10 fractions. The LDR afterloading Ir-192 technique was used to deliver approximately 30 Gy to a 1.0-cm radius target. RESULTS: All patients had one or more of the following symptoms: 1) dyspnea, 2) fever, 3) cough, and 4) hemoptysis. Good-to-excellent symptom relief was apparent in 16 of 21 (76.2%) laser-treated patients and in 12 of 16 (75%) nonlaser-treated patients. Follow-up bronchoscopy in 28 patients revealed tumor regression in 22 (79%). Median survival time was 16.3 weeks in the laser group and 11.7 weeks in the nonlaser group (P = 0.36). Longer median survival times were noted in laser-treated (22.8 weeks) and nonlaser-treated (16.4 weeks) patients receiving additional external beam treatments. Exsanguination occurred in 7 of 21 (33.3%) laser-treated patients and in 4 of 16 (25%) nonlaser-treated patients. The only factor affecting the exsanguination rate was implant location: 6 of 11 (54.5%) patients had lesions in the right or left upper lobe. CONCLUSIONS: EnBRT alone or with Nd:YAG laser resection provided good-to-excellent symptom palliation in these patients although a high rate of exsanguination occurred in both groups.

Adult↗

Independent impact of thrombolytic therapy and vessel patency on left ventricular dilation after myocardial infarction. Serial echocardiographic follow-up.

BACKGROUND: It has been shown that successful reperfusion of the infarct-related artery by thrombolysis can prevent left ventricular dilation after acute myocardial infarction; these beneficial effects were detected from several days to several months after infarction. To date, however, no study has shown that these effects can be demonstrated within hours after the onset of infarction. Furthermore, data are scarce on the independent impact of thrombolytic therapy and late vessel patency on ventricular volume and function. The aim of this study was to assess separate effects of thrombolysis and patency of the infarct-related artery on left ventricular size and function by serial two-dimensional echocardiographic examinations. METHODS AND RESULTS: We evaluated 131 consecutive patients with first acute myocardial infarction by two-dimensional echocardiography in the following sequence: days 1, 2, 3, 7, and after 3 and 6 weeks. Intravenous streptokinase was administered in 81 patients, and 50 patients were treated without thrombolysis. Left ventricular end-diastolic volume, end-systolic volume, and ejection fraction were determined from apical two- and four-chamber views using the Simpson biplane formula and normalized to body surface area. Coronary angiography was performed in 107 patients after a mean of 26.0 +/- 20.2 (mean +/- SD) days after infarction. Patency of the infarct-related artery was assessed using TIMI criteria, with 54 considered patent (TIMI 3) and 53 with TIMI grade < 3. On day 1, end-systolic volume was significantly higher in patients not receiving thrombolysis (37.7 +/- 15.3 versus 33.0 +/- 10.6 mL/m2, P = .045). End-systolic volume (ESVi) was significantly higher in patients treated without thrombolysis throughout the study, whereas significant differences in end-diastolic volume (EDVi) were detected from day 3 (P = .041) onward and in ejection fraction (EF) from day 2 (P = .025) onward, all differences becoming progressively more significant with time (6-week values: EDVi, 78.8 +/- 25.4 versus 65.9 +/- 15.7 mL/m2, P = .001; ESVi, 45.4 +/- 22.6 versus 33.9 +/- 15.1 mL/m2, P = .002; EF, 45.1 +/- 11.6% versus 50.2 +/- 10.1%, P = .018). Patients with an occluded infarct-related artery (TIMI < 3) demonstrated highly significant differences at 6 weeks compared with patients with patent vessels (EDVi, 76.8 +/- 24.7 versus 65.2 +/- 15.6 mL/m2, P = .006; ESVi, 44.6 +/- 23.3 versus 31.9 +/- 12.2 mL/m2, P = .001; EF, 45.0 +/- 11.6% versus 52.1 +/- 9.0%, P < .001), but these differences developed more slowly than that seen among the thrombolytic subgroups. Indeed, multivariate analysis demonstrated that thrombolysis was the major determinant of initial volumes (P = .08, .02, and .08 for EDVi, ESVi, and EF, respectively), while vessel patency was the overwhelming determinant of subsequent changes (P = .0033, .0002, and .0024 for EDVi, ESVi, and EF, respectively). Additionally, ventricular volumes were significantly higher and ejection fractions lower in patients with anterior versus inferior infarction, but even adjusting for these differences as well as those associated with age, sex, and initial ventricular volume, the additive and independent impact of thrombolysis and infarct vessel patency persisted. CONCLUSIONS: These data indicate that the beneficial effect of thrombolysis on left ventricular size and function can be demonstrated in the earliest phases of acute myocardial infarction and that subsequent changes are mediated primarily through patency of the infarct-related artery. Thrombolytic therapy and late vessel patency thus have an additive and complementary impact in reducing ventricular dilation after myocardial infarction.

Coronary Vessels↗

Patent foramen ovale and brain infarct. Echocardiographic predictors, recurrence, and prevention.

BACKGROUND AND PURPOSE: Paradoxical embolism through a patent foramen ovale is a recognized cause of stroke, but clinical predictors, recurrence rate, and prevention of brain infarcts in patients with patent foramen ovale have not been determined. We reviewed transesophageal echocardiographic records to ascertain echocardiographic predictors and optimal prophylaxis for patent foramen ovale-related infarcts. METHODS: A patent foramen ovale was identified in 74 patients during 615 transesophageal echocardiograms by color Doppler or saline contrast during a 60-month period. On the basis of final clinical situation, the patients were divided into the following groups: group 1, infarct with patent foramen ovale a likely cause (n = 16); group 2, infarct with patent foramen ovale an unlikely cause (n = 23); and group 3, no infarct (n = 35). Transesophageal echocardiograms were reviewed to assess patent foramen ovale characteristics and associated cardio-embolic sources without knowledge of clinical details or group assignment. Follow-up after a patent foramen ovale-related infarct was obtained by telephone or written correspondence in 15 of 16 group 1 patients. RESULTS: Atrial septal aneurysms were more common in group 1 (38%) compared with group 2 (10%) and group 3 (8%) (P = .02). Contrast right-to-left shunting occurred in 88% of group 1 (P = .06) and 86% of group 2 (P = .07) compared with 60% of group 3. Prevention of recurrence in subjects with presumed patent foramen ovale-related brain infarcts varied. Aspirin was usually chosen after initial brain ischemia. Warfarin and patent foramen ovale closure were usually reserved for subjects with symptoms of brain ischemia while taking aspirin or those who required warfarin or cardiac surgery for other indications. No recurrent infarcts occurred in 15 patients during a mean follow-up period of 28 months. CONCLUSIONS: Atrial septal aneurysm and right-to-left shunt may be predictive of a patent foramen ovale that predisposes a patient to stroke. Aspirin may provide sufficient infarct prophylaxis after initial ischemia. Warfarin and surgical correction should likely be reserved for those in whom aspirin is not effective or those who require warfarin or cardiac surgery for other reasons until prospective studies are available.

Adult↗

[Home chemotherapy for peritoneal carcinomatosis].

Nineteen patients diagnosed with peritoneal carcinomatosis were treated by in-home chemotherapy over a period of four years from August, 1990 to July, 1994. Primary diagnoses of the four male and 15 female patients included 12 cases gastric cancer (four males, eight females), five cases of ovarian cancer, one case (female) of appendicular cancer, and one case (female) of breast cancer. In addition to oral administration of UFT-E and 5'-DFUR, chemotherapy included weekly intravenous injection of a massive dose of 5-FU (1,000 mg/m2), subselective intraaortic infusion and intraperitoneal infusion using a reservoir. These methods were used individually and in combination. The drugs used included 5-FU, CBDCA, CPA, THP, and EPIR. Subselective intraaortic infusion was performed by low dose continuous infusion using the Baxter infusor multiday type. Six gastric cancer patients lived normally for over one year, while four died in less than a year. All ovarian and appendicular cancer patients were CR, the breast cancer patient was PR. Ten patients continued working at their jobs while receiving at home chemotherapy treatments. Diuretics were used to alleviats ascites. Although there were no side effects on digestive organs, 5-FU and CBDCA were mixed with 100 mg hydrocortisone in the infusor to improve cachexia, and promote appetite and activity. Bone marrow suppression was very slight at these dosages, and weekly checkups were adequate. The at-home rate (number of days at home/entire period since onset) of all patients was 78%.

Adult↗

Using POSTDOC to recognize biomedical concepts in medical school curricular documents.

Recognition of the biomedical concepts in a document is prerequisite to further processing of the document: medical educators examine curricular documents to discover the coverage of certain topics, detect unwanted redundancies, integrate new content, and delete old content; and clinicians are concerned with terms in patient medical records for purposes ranging from creation of an electronic medical record to identification of medical literature relevant to a particular case. POSTDOC (POSTprocessor of DOCuments) is a computer application that (1) accepts as input a free-text, ASCII-formatted document and uses the Unified Medical Language System (UMLS) Metathesaurus to recognize relevant main concept terms; (2) provides term co-occurrence data and thus is able to identify potentially increasing correlations among concepts within the document; and (3) retrieves references from MEDLINE files based on user identification of relevant subjects. This paper describes a formative evaluation of POSTDOC's ability to recognize UMLS Metathesaurus biomedical concepts in medical school lecture outlines. The "precision" and "recall" varied over a wide range and were deemed not yet acceptable for automated creation of a database of concepts from curricular documents. However, results were good enough to warrant further study and continued system development.

Curriculum↗

[Application of ORM1 phenotyping in forensic science].

ORM1 is an important genetic marker for both parentage testing and personal identification in forensic science. We have examined the ORM1 phenotypes in the human serum and dried bloodstains using the ULPAGIF method. ORM1 phenotypes were successfully demonstrated from dried bloodstains stored at 4 degrees C and room temperature for up to twenty-four weeks. In bloodstains stored at 37 degrees C, the 100% of ORM1 phenotyping was no longer possible after 12 weeks. We examined 9 bloodstains stored at room temperature for one, two and three years, respectively. For the one-year-old bloodstains, all of the samples could be phenotyped correctly, for the two-year-old bloodstains 8 out of the 9 and for the three-year-old bloodstains 7 out of the 9 samples could be phenotyped correctly. The results have indicated that ORM1 is relatively stable, for it is tolerable toward high temperature and long duration. It was suggested that the bloodstains should be ultrasonicated before ULPAGIF, because the ultrasonication could elevate the detectable rate of ORM1 phenotypes from bloodstains. ORM1 phenotypes was performed in five disputed parentage cases. One of the alleged fathers was excluded.

Blood Stains↗

Cloning and characterization of the RNA polymerase alpha-subunit operon of Chlamydia trachomatis.

We have cloned the chlamydial operon that encodes the initiation factor IF1, the ribosomal proteins L36, S13, and S11, and the alpha subunit of RNA polymerase. The genes for S11 and alpha are closely linked in Escherichia coli, Bacillus subtilis, and plant chloroplast genomes, and this arrangement is conserved in Chlamydia spp. The S11 ribosomal protein gene potentially encodes a protein of 125 amino acids with 41 to 42% identity over its entire length to its E. coli and B. subtilis homologs; the gene encoding the alpha subunit specifies a protein of 322 amino acids with 25 to 30% identity over its entire length to its E. coli and B. subtilis homologs. In a T7-based expression system in E. coli, the chlamydial alpha gene directed the synthesis of a 36-kDa protein. Mapping of the chlamydial mRNA transcript by RNase protection studies and by a combination of reverse transcription and the polymerase chain reaction demonstrates that IF1, L36, S13, S11, and alpha are transcribed as a polycistronic transcript.

Amino Acid Sequence↗

Extra G positive band on the long arm of chromosome 9.

Various heteromorphisms of the 9q heterochromatic area have been reported. In most instances, the extra G positive band is accompanied by an extra C band. We describe a family where the extra G band is totally euchromatic and does not include an extra C band. It is not clear whether these two types of variant chromosome 9 arose from a similar mechanism.

Adult↗

[Research on hemostatic mechanism of extracts from carbonized Schizonepeta tenuifolia Brig].

It has been shown that StE can significantly shorten PT, TT, KPTT and RT of experimental animals and has an antiheparin function in the body. Meanwhile, it can significantly shorten ELT and strengthen FA. Its hemostatic action is accomplished through promoting coagulation and inhibiting fibrinolysis. 3P test and EG test were negative, it is thus impossible for a large dosage of StE to lead to DIC.

Animals↗

Variation of perfluoropropane disappearance after vitrectomy.

In complex cases of retinal detachment, perfluoropropane (C3F8) is frequently used after vitrectomy for tamponade of retinal breaks. Results of previous studies of C3F8 disappearance using 10% C3F8 after vitrectomy in human eyes have differed significantly. A wide variation in the decay rate and half life of C3F8 after vitrectomy was observed in eyes that had similar clinical settings and received the same C3F8 concentration (15%, 20%, or 25%). This occurred even in those eyes where there was no change in the geometric contour of the eye after a repeat vitrectomy.

Eye↗

Cell-mediated immunity in patients on hemodialysis: relationship with hepatitis B carrier status.

We compared cell-mediated immune responses in two groups of patients on hemodialysis. One group of patients were chronic carriers of hepatitis B virus (HBV), and the patients of the other group were HBV antigen negative. Our results show that despite the presence of normal numbers of T cells and an increased CD4/CD8 ratio in both groups of patients compared to healthy controls (p less than 0.0001), only the group of patients who were chronic HBV carriers showed depressed lymphoproliferative responses to phytohemagglutinin (p less than 0.001) and concanavalin A (p less than 0.0001). In contrast, a control group of healthy adult HBV carriers showed normal T cell subsets and lymphoproliferative responses to mitogens, indicating that HBV infection per se did not result in depressed lymphoproliferative responses. These results further substantiate the notion that depressed cell-mediated immunity in chronic renal failure is an important factor in predisposing patients to HBV infection with subsequent development of the chronic carrier state.

Adult↗

[The relationship between hepatitis B and renin-angiotensin-aldosterone system].

The angiotensin II (AT II) levels in plasma were measured 68 times by using radio-immunoassay in 30 patients with viral hepatitis B (HB) and in 35 healthy persons as the control group. The results showed that the AT II levels of patients with HB were much higher than those of the control group (P less than 0.001). They were 219.25 +/- 91.31 ng/L and 60.70 +/- 10.73 ng/L, respectively. These indicated that the renin-angiotensin-aldosterone system (RAAS) of the patients was in exciting state. The levels of 8 cases of severe chronic active hepatitis (SCAH) (AT II = 270.40 +/- 106.55 ng/L, 6 cases of subacute fulminant hepatitis (SFH) (AT II = 332.80 +/- 140.12 ng/L), and 4 cases of hepatocirrhosis (HC) (AT II = 218.50 +/- 97.64 pg/ml) were all higher than those of 8 cases of chronic active hepatitis (CAH) (100.50 +/- 83.81 ng/L) and those of 4 cases of acute icteric hepatitis (A1H) (123.33 +/- 64.97 ng/L). These findings showed that the levels of AT II were directly related with the severity of the illness. The AT II levels of 8 cases of HRS (270.50 +/- 66.31 ng/L) were higher that those without HRS (174.50 +/- 78.48 ng/L). After treatment with captopril (CPT), the renal function of the patients returned to normal and the patients got better, while the AT II levels decreased greatly. The results suggested that high AT II levels in plasma may be one of the causes aggressing the HRS. The CPT may inhibit the produce of AT II and there are some therapeutic effects for the HRS.

Adult↗

Use of enzyme-developed immunoblots scanned by densitometry to compare lot-to-lot variability of Russian-thistle extracts.

Two different lots of Russian-thistle extracts from five commercial sources were evaluated by isoelectric focusing, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and immunoblots of Immobilon transfers from these separations. The immunoblots were developed by an enzyme-linked method and scanned with a densitometer. The two lots of a standardized extracts produced scans that suggested uniformity in allergenic components. Several of the nonstandarized extract lots also appeared quite comparable. With further refinement, immunoblotting with densitometric analysis appears to offer an attractive way to standardize allergen extracts.

Allergens↗