Biomedical subjects

R Chin

Publications and source records attributed to R Chin.

At least 37 records · Page 2Linked to original sources

PubMed2000

Increasing use of bronchoscopic needle aspiration to diagnose small cell lung cancer.

OBJECTIVE: To review pathology reports to determine whether a temporal change in diagnostic procedures that included bronchoscopic needle aspiration (BNA) in evaluation of small cell lung cancer (SCLC) had occurred. METHODS: A retrospective review of the computerized pathology database of the Wake Forest University Baptist Medical Center from 1990 to 1998 was performed. All pathology reports of patients newly diagnosed with SCLC were reviewed and abstracted. RESULTS: The number of patients newly diagnosed with SCLC during the 9-year study period totaled 277. Of these, 173 underwent bronchoscopy. From January 1990 to December 1991, 32% (8/25) of bronchoscopies done in patients with SCLC included BNA compared with 81% (120/148) (P < .001) from January 1992 to December 1998. In addition to the increased use of BNA in patients with SCLC undergoing bronchoscopy, the overall diagnostic yield for BNA in SCLC significantly increased over the 9-year study period from 50% (4/8) in 1990 and 1991 to 88% (106/120) thereafter (P = .001). Overall sensitivity of BNA during bronchoscopy was 86% for SCLC with only a small increase in sensitivity with use of all procedures (including BNA) to 91%. The use of forceps biopsy and bronchial brushings decreased over this period. CONCLUSION: With progressive experience with BNA, the frequency of its performance and its diagnostic yield in patients with SCLC increased markedly. The SCLC yield may be a worthwhile marker of BNA program development.

Biopsy, Needle↗

PubMed2000

The Internet: another facet to the paradigm shift in healthcare.

The Internet is an extremely powerful innovation that has and will continue to shape the healthcare industry in the years to come. Albeit a little too slowly, doctors are starting to catch onto this new wave of digital empowerment and creating niches that will enhance their ability to care for their patients and ultimately add value to their practices. The challenge is to encourage every doctor to come on board. The paradigm shift in healthcare delivery is that the Internet brings about the power of information to the patient. This balances the power in the doctor patient relationship. Taken positively, the doctor too can benefit from Internet technology. The biggest contribution of the Internet in the area of electronic medical records is the web-based display environment that is operating-system independent. The Internet can therefore be exploited to provide a supra system that can draw personal medical information together from anywhere to create a virtual electronic medical record. The Internet can also be used to shape up an Internet-based healthcare delivery system. The healthcare delivery paradigm shift brought about by the Internet calls for an eHealth strategy.

Delivery of Health Care↗

PubMed1999

A dose-finding study of nedaplatin and cyclophosphamide for patients with gynecological malignancies.

BACKGROUND: Nedaplatin is a new analogue of cisplatin with similar efficacy but less renal toxicity. We investigated the appropriate dose of nedaplatin in combination with cyclophosphamide for patients with gynecological malignancies. METHODS: Nine patients (five with ovarian cancer and four with uterine cervical cancer) were studied. Three patients received 60 mg/m2 of nedaplatin combined with 500 mg/m2 of cyclophosphamide every 4 weeks. Another three patients were each administered 80 or 100 mg/m2 of nedaplatin with the same dose of cyclophosphamide. A total of 27 courses was given. RESULTS: No patient needed dose reduction due to myelosuppression and no severe adverse events were observed. CONCLUSIONS: Treatment with 100 mg/m2 of nedaplatin and 500 mg/m2 of cyclophosphamide is feasible for patients with gynecological malignancies. However, phase II studies are needed to clarify the efficacy of this combination chemotherapy.

Adult↗

PubMed1998

Sustained expression of high levels of human factor IX from human cells implanted within an immunoisolation device into athymic rodents.

Immunoisolation of allogeneic cells within a membrane-bound device is a unique approach for gene therapy. We employed an immunoisolation device that protects allograft, but not xenograft, cells from destruction, to implant a human fibroblast line (MSU 1.2) in athymic rodents. Cells, transduced with the MFG-human factor IX retroviral vector, and expressing 0.9 microg/10(6) cells/day in vitro, were implanted in rats (four 40-microl devices, each containing 2 x 10(7) cells, two subcutaneously, two in epididymal fat) and in mice (two 20-microl devices, each containing 2 x 10(6) cells, subcutaneously). Plasma factor IX levels increased for 50 days, reaching maxima of 203 ng/ml (rat) and 597 ng/ml (mouse), and both continued at greater than 100 ng/ml for more than 140 days. A clone derived from the transduced cells, making 5 microg of factor IX/10(6) cells/day, was implanted within a device (one 20-microl device containing 2.5 x 10(6) cells), or without a device (1 x 10(7) cells implanted freely), either subcutaneously or in epididymal fat. The freely implanted cells expressed transiently, reaching more than 100 ng/ml in each site by day 4, but dropped to zero by day 20 (subcutaneous) or day 90 (epididymal fat). In devices, levels gradually increased to 100 ng/ml (subcutaneous) or 300 ng/ml (epididymal fat), remaining high for more than 100 days. These results show long-term, high-level expression of a human protein: (1) when cells are implanted within a cell transplantation device, but not when the cells are freely implanted, and (2) from a transgene driven by a viral promoter. An alloprotective device will enable the use of cloned cell lines that can be subjected to stringent quality control assessment that is impossible to achieve with autologous approaches.

Animals↗

PubMed1998

New therapies for the treatment of chronic hepatitis B infection.

Persistent hepatitis B virus infection can lead to the development of chronic liver disease, cirrhosis and primary hepatocellular carcinoma. The only therapy of confirmed benefit in chronic hepatitis B is interferon alpha, which can lead to long-term benefit in only a third of highly selected patients. A number of new therapeutic approaches are being actively developed for treating chronic hepatitis B, including the use of nucleoside analogues, cytokines, antisense oligonucleotides, ribozymes, dominant negative mutants and DNA-based vaccines. Recent clinical trials with the nucleoside analogues have identified several important challenges for future drug development, in which the gene therapy-based approach may prove useful either alone or most probably in various combinations. Future clinical trials should aim to address these challenges using the new therapies so that the goal of substantial and sustained inhibition of viral replication with the accompanying improvement in the underlying liver disease can be achieved.

Journal Article↗

PubMed1998

Fiberoptic bronchoscopy in coronary care unit patients: indications, safety, and clinical implications.

STUDY OBJECTIVES: To evaluate the indications, safety, therapeutic impact, and outcome of fiberoptic bronchoscopy (FOB) in coronary care unit (CCU) patients. DESIGN: Retrospective review of all CCU patients undergoing FOB during a 6-year period. SETTING: Tertiary care university hospital. RESULTS: Among 8,330 patients admitted to the CCU; 40 (0.5%) patients underwent FOB to evaluate pulmonary abnormalities, most often (78%) to appraise clinically suspected pneumonia. Thirty-five (88%) patients were intubated and 21 (53%) had acute myocardial infarction (MI) before FOB. There were two major complications (bleeding, intubation) occurring within 24 h of FOB, one of which appeared due to the procedure. No episodes of chest pain or ischemic events were recorded and no significant increase in major complications was noted in MI patients (3% vs 5%). Patients having FOB within 10 days of MI had higher survival (79%) than those undergoing FOB later (29%) (p = 0.05). Seven different bacterial pathogens were isolated in 6 (15%) patients, probably reflecting prior empiric antibiotics in 32 (80%) patients. Therapy was changed in 64% of patients in whom a potential pathogen was identified. Despite alterations in treatment, patients with clinically suspected pneumonia and any organisms isolated by FOB had greater mortality (79% vs 31%, p = 0.003) than those with sterile FOB cultures. CONCLUSION: FOB may be diagnostically useful in the evaluation of pulmonary abnormalities in selected patients with acute cardiac disease, can be performed safely, and may influence management decisions. Positive bronchoscopy cultures often influence therapy but are associated with higher mortality, suggesting a lethal effect of nosocomial pneumonia in this subset of CCU patients. The risks of FOB must be weighed with the impact of FOB results on patient outcome, and its role requires further investigation.

Adult↗

PubMed1997

Mastication of verruca vulgaris associated with esophageal papilloma: HPV-45 sequences detected in oral and cutaneous tissues.

Human papillomaviruses (HPVs) are double-stranded, circular, epitheliotropic DNA viruses of which nearly 70 types have been identified. Specific HPV types exhibit a predilection to infect certain sites; however, occurrence is not unique or restricted to these sites. HPV typing may also be helpful in determining the oncogenic potential of HPV lesions. The most common HPV types, 6 and 11, are associated with benign mucosal lesions, whereas types 18, 16, 31, and 33 are thought to confer a high rate of malignant transformation. We describe a patient with both palmar verrucae and esophageal papillomatosis that proved to be HPV type 45 by polymerase chain reaction. HPV 45 has a high homology to HPV 18 and is a member of the relatively new "high-risk" mucosal HPV family in terms of cervical oncogenic potential. To our knowledge, HPV 45 has never been reported in cutaneous warts or esophageal lesions.

DNA, Viral↗

PubMed1996

Sexual behavior in pregnancy among Hong Kong Chinese women.

Sexual behavior during pregnancy was examined in a retrospective study of 150 Hong Kong Chinese women interviewed in the immediate postpartum period. Sexual activity was found to decline abruptly during the first trimester of pregnancy, and continued to decrease in frequency as the pregnancy advanced. The frequency of intercourse was lower both before and during pregnancy than has been reported in similar studies among Western populations. There was no consistent relationship between age, parity, level of education, or employment status and sexual behavior either before or during pregnancy. These results suggest that a relatively conservative attitude toward sexual activity persists within this population.

Adolescent↗

PubMed1996

Thoracobiliary fistula.

Thoracobiliary communications in the form of either pleurobiliary or bronchobiliary fistulas are reported complications of many diseases. A strong suspicion in the appropriate clinical setting is necessary to recognize this problem. Bilioptysis is the sine qua non of a bronchobiliary fistula. Diagnostic imaging studies are useful to identify the communication and to delineate its location. Although surgery is the optimal intervention, percutaneous drainage and intravenous antimicrobial therapy may offer the best therapeutic option in patients with metastatic cancer and limited physiologic reserve. We report a unique case of bronchobiliary fistula complicating a uterine leiomyosarcoma with hepatic metastases. Long-term palliation was achieved with percutaneous drainage and appropriate fluid and electrolyte replacement therapy.

Biliary Fistula↗

PubMed1996

Pulmonary section development influences general medical house officer interests and ABIM certifying examination performance.

To determine whether sectional development in pulmonary and critical care medicine influences medical house officers' (HO) interests and knowledge about respiratory medicine, we reviewed HO performance on the American Board of Internal Medicine (ABIM) certifying examination during 4 years before and 5 years after reorganization of our section. After major changes in the program and introduction of new educational opportunities, HOs more often selected pulmonary consultation electives (68.6% vs 47.8%; p = 0.009) and entered pulmonary fellowships after completion of residency training (12% vs 3%; p = 0.047). Total ABIM examination score did not change, but performance on its respiratory disease component improved from a median national percentile score of 48.5% (1986 to 1989) to 80.0% (1990 to 1994) (p = 0.0365). In relation to other specialty component scores, the rank of the respiratory disease percentile improved from the lowest specialty score to the highest. ABIM examination scores correlated with the cumulative faculty effort directed toward HO teaching (r = 0.70; p = 0.04) and the total number of clinical teachers (faculty and fellows) interacting with HOs (r = 0.73; p = 0.02). Academic development in pulmonary/critical care faculty has an important influence on medical HO interests in and knowledge of that discipline. Plans for the future structure of academic pulmonary/critical care sections must take into account this impact on the training of generalists. Although institutional priorities, resources, and shifting external forces will define how, where, and by whom respiratory medicine will be taught, an appropriate number of faculty members and sufficient commitment of their time to HO education must be preserved.

Attitude↗

PubMed1995

Oropharyngeal cancer in the elderly.

PURPOSE: The poor prognosis of elderly patients in many cancers may be due to less thorough investigation and less aggressive treatment because of the perception that radical treatment will be poorly tolerated and that elderly patients have a limited life expectancy. We wished to assess whether older age is associated with (a) less radical treatment, (b) poorer outcome, or (c) greater toxicity, after adjusting for other possible contributing factors. METHODS AND MATERIALS: A retrospective study of patients with loco-regional oropharyngeal cancer treated between January 1980 and December 1985 was conducted. Patients were treated with radiotherapy, surgery, chemotherapy, or combinations. Cox regression was used to assess age effects while allowing for the influence of other factors. RESULTS: Eighty-eight patients were treated radically and 16 palliatively. Treatment intent (radical or palliative) did not appear to be related to age, before (p = 0.42) or after adjusting for other factors (p = 0.34). In a selected group of 86 radically treated patients ages ranged from 33 to 85 (median 60). There were 35 loco-regional failures and 58 deaths (38 related to oropharyngeal cancer). Older patients were prescribed and received lower doses of radiation. However, older age was not related to the risk of loco-regional recurrence (p = 0.96) or shorter survival (p = 0.67), and was not associated with duration of treatment interruption or severity of toxicity after adjustment for prognostic factors. There was some suggestion of a higher risk of recurrence with increasing age for patients under 70 years but with a risk for patients over 70 at least equal to that of the youngest group. Elderly patients in our study may have been a selected group. CONCLUSION: Older patients with loco-regional oropharyngeal cancer, or at least a subset of them, appear to be able to tolerate radical courses of radiotherapy, and to have similar outcomes as do younger patients.

Adult↗

PubMed1995

Pressure/flow behaviour in collapsible tube subjected to forced downstream pressure fluctuations.

An experimental investigation has been made into the pressure/flow behaviour of a collapsible tube subjected to downstream pressure fluctuations. These downstream pressure waves are observed to be transmitted upstream beyond the point of collapse. The mean flow rate is not significantly affected by the amplitude or frequency of pressure fluctuations. However, the oscillatory flow amplitude is reduced at the higher frequency. The mean flow rate also remains independent of the mean driving pressure.

Hemorheology↗

PubMed1995

Education and experience improve transbronchial needle aspiration performance.

To determine whether the diagnostic yield of transbronchial needle aspiration (TBNA) improves over time and to obtain insights about factors influencing its performance, we reviewed our experience during a 3-yr period. After serial multifaceted educational interventions directed toward bronchoscopists and their technical staff, TBNA yield increased significantly from 21.4 to 47.6% (p < 0.001). More frequent and more detailed notations in bronchoscopy reports (p < 0.05), a lower frequency of cytopathology specimens contaminated by endobronchial material (p < 0.05), and higher yields in patients with small cell carcinoma (p < 0.01) suggested that bronchoscopists' TBNA proficiency had increased. More frequent diagnoses with small cell carcinoma and fewer cytologically unsatisfactory specimens (p < 0.01) suggested that education of bronchoscopy technicians, and use of a direct smear technique for specimen preparation also contributed to improved TBNA yield. Increased experience with TBNA and focused education regarding its performance can enhance the role of this procedure in diagnosis and staging of patients with lung cancer.

Allied Health Personnel↗

PubMed1995

Mediastinal staging of non-small-cell lung cancer with positron emission tomography.

To determine the usefulness of positron emission tomography with fluoro-2-deoxyglucose (PET-FDG) in assessing mediastinal disease in patients with non-small-cell lung cancer (NSCLC) and to compare its yield to that of computed tomography (CT), we performed a prospective consecutive sample investigation in a university hospital and its related clinics. In 30 patients with NSCLC with clinical stage I (T1-2, NO, MO) disease, we compared the results of chest CT and PET-FDG with the findings at surgical exploration of the mediastinum. Seven (77%) of nine patients with surgically proven mediastinal metastasis were identified by the PET-FDG results, with four false-positives in 21 patients with negative lymph node dissections (p = 0.004). Using the results of pathologic examination of mediastinal lymph nodes as the criterion standard, the diagnostic sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) for PET-FDG imaging of mediastinal metastases were 78%, 81%, 80%, 64%, and 89%, respectively. The sensitivity, specificity, accuracy, PPV, and NPV for chest CT in the detection of mediastinal metastasis were 56%, 86%, 77%, 63%, and 87%, respectively. CT and PET-FDG results agreed in 21 patients. The diagnostic accuracy of the combined imaging modalities was 90%. We concluded that mediastinal uptake of FDG correlates with the extent of mediastinal involvement of NSCLC and may contribute to preoperative staging. PET-FDG imaging complements chest CT in the noninvasive evaluation of NSCLC, and strategies for its use merit further investigation.

Aged↗

PubMed1995

Digital clubbing. Demonstration with positron emission tomography.

Digital clubbing is a classic cutaneous manifestation of pulmonary disease, but its mechanism is unknown. We describe a patient with lung cancer and clubbing in whom positron emission tomography (PET) demonstrated, for the first time, that increased glucose metabolism occurs at the nailbed. PET may contribute to future investigations of digital clubbing.

Carcinoma, Squamous Cell↗

PubMed1994

Evidence for the production and action of interleukin-10 in pituitary cells.

1. Interleukin-10 (IL-10) has a wide range of activities in the immune system such as modulation of interferon-gamma (IFN-gamma) and antibody production. The neuropeptide hormone corticotropin (ACTH) has similar activities, suggesting that a bidirectional communication mechanism operates between the immune and the neuroendocrine system involving these two substances. 2. Murine pituitary tumor cells (AtT-20) were found to produce up to 3 ng/ml of IL-10. 3. Pituitary cell corticotropin production was enhanced by IL-10 treatment. 4. IL-10 induced the production of ACTH in mouse splenocytes. 5. Authenticity of pituitary-derived IL-10 was shown by the demonstration of identical nucleic acid sequences of reverse-transcribed, polymerase chain reaction amplified fragments of cDNA obtained from murine splenocytes, a murine pituitary tumor cell line, and freshly isolated murine pituitaries.

Adrenocorticotropic Hormone↗

PubMed1994

Distinction of mouse interferon-alpha subtypes by polymerase chain reaction utilizing consensus primers and type-specific oligonucleotide probes.

We have developed a novel method to study the subtype-specific expression of interferon-alpha (IFN-alpha) in the mouse system: we synthesized and used consensus oligonucleotide primers to allow simultaneous polymerase chain reaction (PCR) amplification of multiple murine IFN-alpha gene sequences. In addition, a set of subtype-specific oligomer probes were designed and used to distinguish between IFN-alpha genes that differ by only a few bases. The consensus primers, corresponding to two regions highly conserved among murine IFN-alpha subtypes, were used in reverse transcription and PCR amplification of total cellular RNA, isolated from IFN-gamma-treated murine L-929 cells, to yield a fragment of the anticipated approximately 520-bp size. Southern analysis of the amplified product using an internal consensus oligomer probe confirmed specific amplification of murine IFN-alpha gene(s). Subtype-specific oligonucleotide probes indicate that IFNs-alpha 1, -alpha 2, and -alpha 5 are present following IFN-gamma treatment, whereas IFN-alpha 4 remains virtually absent. Our results indicate that the expression of specific IFN-alpha subtypes may be subject to complex regulation, dependent upon inducing agents and cell types involved, and countless other factors. The procedure described here represents a novel method for studying the subtleties of the murine IFN-alpha mRNA expression.

Animals↗

PubMed1994

Endobronchial needle aspiration in the diagnosis of small-cell carcinoma.

Endobronchial biopsy specimens of small-cell carcinoma often exhibit extensive crush artifact that precludes definitive diagnosis. Occasionally, cytologic study from the brushings and washings is also nondiagnostic, contributing to the frustration of the bronchoscopist. We reviewed our experience with this problem over the past 4 years. We identified five cases in which an endobronchial needle aspirate proved critical in establishing the diagnosis of small-cell carcinoma. We believe endobronchial needle aspiration is a valuable adjunct in the diagnosis of endobronchial small-cell carcinoma.

Aged↗