HIV type 1 env subtype A variants in Taiwan.
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Biomedical subjects
Publications and source records attributed to M Y Chen.
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OBJECTIVE: In the setting of blunt trauma, abdominal CT, which routinely includes images of the lower thorax, frequently reveals pneumothoraces that have not been detected on routine supine chest radiographs. Proper management of these occult pneumothoraces remains controversial. The purpose of this study was to test the hypothesis that small (minuscule) to moderate (anterior) radiographically occult pneumothoraces can be safely managed without chest tube placement for patients in whom the need for positive pressure ventilation is not anticipated. SUBJECTS AND METHODS: We undertook a prospective study in which 44 occult pneumothoraces were classified into three groups, minuscule, anterior, or anterolateral, according to size and location on CT scans. Choice of initial management (tube thoracostomy versus close observation) was based in part on this classification system and in part on individual circumstances of a surgeon's decision. RESULTS: Of the 44 pneumothoraces found in 36 patients, 16 pneumothoraces were minuscule, 20 were anterior, and eight were anterolateral. Thirteen minuscule pneumothoraces and 11 anterior pneumothoraces initially managed with observation did not require subsequent tube thoracostomy. All eight patients with anterolateral pneumothoraces underwent tube thoracostomy. CONCLUSION: Most small (minuscule) occult pneumothoraces can successfully be managed with close observation. The risk that the pneumothorax will progress is slight. Moderate-sized (anterior) pneumothoraces may also be successfully managed without initial placement of a chest tube if the patient is not to undergo positive pressure ventilation.
OBJECTIVE: The purpose of this investigation was to determine the prevalence of lower esophageal mucosal rings and to correlate the relationship between these mucosal rings and the presence and anatomic level of symptoms evoked using a marshmallow bolus. SUBJECTS AND METHODS: Our prospective study included 130 patients who underwent barium examination of the esophagus. All patients completed a questionnaire regarding the anatomic location of their symptoms of dysphagia. In addition to a multiphasic examination of the esophagus, all patients also underwent fluoroscopic observation and videotaping while swallowing a marshmallow bolus; any symptoms that were provoked were recorded. RESULTS: Lower esophageal mucosal rings were shown in 26 (20%) of the 130 patients. The diameter of the rings was 9-12 mm in six patients, 13-20 mm in 18 patients, and larger than 20 mm in two patients. In 16 (62%) of the 26 patients, a marshmallow bolus became impacted at the ring; the impaction caused dysphagia in 12 (75%) of the 16 patients. In these 12 patients, dysphagia was referred to the neck in seven, the sternal angle in two, the mid chest in two, and the lower chest in one patient. None of the 12 patients had a pharyngeal or cervical esophageal abnormality that would account for their symptoms. CONCLUSION: Because proximal referral of symptoms is common in patients with lower esophageal mucosal rings, a thorough radiographic examination of the entire esophagus and esophagogastric region is required regardless of the level of their swallowing complaints.
Treatment with a low daily dose of amphotericin B (0.4 mg/kg) in AIDS patients with cryptococcal meningitis has been associated with low efficacy and high mortality. We report our successful clinical experiences on a higher daily dose of amphotericin B (0.8-1.0 mg/kg) monotherapy in treating cryptococcal meningitis from June 1994 to August 1997 in 13 cases of advanced HIV infection. Most of them (12/13) had at least one of several poor prognostic factors. The mean duration of amphotericin B administration was 26 days (range, 3 to 58 days). Both microbiologically and clinically successful rates of treatment at the end of amphotericin B therapy were high (85%, 11/13). The median duration of negative CSF culture post therapy was 17 days (range, 8 to 33 days). Bone marrow toxicities were; thrombocytopenia (46%) and significant anemia (92%) after a mean of 9 days of treatment. Both, impaired renal function and hypokalemia, were seen in 10 cases (77%), while elevation of amylase and lipase values were present in 6 cases (46%). Our report reveals that a higher daily dose of amphotericin B can achieve a high efficacy in treatment of cryptococcal meningitis in AIDS patients, even though most cases had poor prognostic factors and were in severe immunocompromised states. However, clinicians should monitor higher dose-related adverse effects carefully.
Gastrointestinal histoplasmosis complicated by intestinal obstruction and peritonitis has not been reported. We report a case of gastrointestinal histoplasmosis in a 27-year-old patient with acquired immunodeficiency syndrome (AIDS). The patient was a Chinese man from Thailand with a history of intravenous drug use and unprotected sex with female prostitutes. He was admitted for prolonged fever, abdominal pain, and diarrhea. Colonoscopy revealed volcano-like ulcers and tumors, while computed tomography of the abdomen showed a colon tumor and hypoattenuated lymphadenopathy of the retroperitoneum. Histopathologic examination as well as cultures of colon biopsy specimens and an aspirate from the retroperitoneal lymphadenopathy revealed Histoplasma capsulatum. Intestinal obstruction and peritonitis requiring surgical intervention developed, despite amphotericin B therapy. Histoplasmosis should be included in the differential diagnosis in AIDS patients who present with colon tumors, retroperitoneal lymphadenopathy, and peritonitis.
To understand the characteristic clinical features of human immunodeficiency virus (HIV)-related oral lesions and determine the prevalence of various oral lesions in HIV-infected patients in Taiwan, we conducted a cross-sectional study of 207 HIV-infected patients at the Taipei Municipal Institute for Venereal Disease Control. Overall, 108 (52.2%) patients had at least one oral lesion. The most common oral manifestation of HIV infection among these 207 patients was oral hairy leukoplakia (OHL, 29.5%), followed by candidiasis (12.1%), xerostomia (10.6%), aphthous ulcers (8.7%), and linear gingival erythema (5.8%). Less frequently encountered oral lesions included leukoplakia (1.9%), papilloma (1.4%), necrotizing ulcerative periodontitis (1.0%), Kaposi's sarcoma (1.0%), herpes simplex (0.5%), Burkitt's lymphoma (0.5%), and parotid gland enlargement (0.5%). Thirty-one (15%) patients had multiple oral lesions. Patients with oral candidiasis or multiple oral lesions had significantly lower mean CD4 lymphocyte counts and CD4/CD8 lymphocyte ratios than those without any oral lesions (p < 0.05). Chi-square analysis revealed that patients with CD4 lymphocyte counts below 200 cells/mm3 were more prone to have OHL (p < 0.002), oral candidiasis (p < 0.001) and multiple oral lesions (p < 0.001). Those with CD4/CD8 lymphocyte ratios below 0.4 were more likely to have OHL (p < 0.02), oral candidiasis (p < 0.01) and multiple oral lesions (p < 0.02) than those with higher counts. In conclusion, the occurrence of oral lesions, especially OHL and oral candidiasis, is fairly common in Taiwanese HIV-infected patients.
The cause of laryngeal and pharyngeal carcinomas is likely multifactorial. Smoking is an important factor, but mucosal damage from gastroesophageal reflux may also contribute. The purpose of this study was to determine whether gastroesophageal reflux is more common in patients with laryngeal or pharyngeal carcinomas than in those without these malignancies. Over an 8-year period, we correlated the results of clinical and radiographic examinations of the pharynx and esophagus to pH monitoring results in 798 patients with a variety of upper aerodigestive tract symptoms and who underwent both pH monitoring and barium esophagography. In this group, 63 patients (52 men, 11 women) had laryngeal or pharyngeal carcinomas, and 735 patients (319 men, 416 women) had neither malignancy. Abnormal pH findings were defined as a total percentage of esophageal acid exposure time of 6% or more as determined with the esophageal probe, or any reflux event detected with the pharyngeal probe. Thirty-four of 63 patients with carcinomas (54%) had abnormal pH-monitoring results: Esophageal acid exposure was abnormal in 10 patients, pharyngeal acid exposure was abnormal in 7 patients, and acid exposure was abnormal in both areas in 17 patients. Of the 735 patients without malignancies, 365 (50%) had abnormal pH-monitoring results (p > 0.05). In this population of patients, abnormal results of pH monitoring were common, occurring in 399 (50%) of 798 patients, but no significant difference was found between results in those with and without laryngeal or pharyngeal carcinomas. Therefore, our study found that gastroesophageal reflux as shown by pH monitoring was not more common in patients with these malignancies.
To understand the etiology and clinical outcome of bacterial and fungal sepsis in patients with advanced human immunodeficiency virus (HIV) infection in Taiwan, we conducted a prospective study of nonmycobacterial bacteremia and fungemia in HIV-infected patients with fever who were admitted to a university hospital in Taiwan during a 42-month period. Of 210 patients, 41 (19.5%) had a total of 52 episodes of sepsis due to nonmycobacterial bacteria or fungi, or both (15.5% of 336 episodes of fever). All but one patient had acquired immunodeficiency syndrome (AIDS), and the mean CD4 lymphocyte count was 29/microL (range, 0-321/microL). A total of 57 pathogens (39 bacteria and 18 fungi) were isolated from blood; polymicrobial sepsis due to both bacteria and fungi occurred in four episodes. Nontyphoid Salmonella (NTS) was the most common cause of community-acquired bacteremia (24/30, 80%). Staphylococcus aureus bacteremia was diagnosed in three episodes while Streptococcus pneumoniae bacteremia was found in only one. Cryptococcus neoformans was the most common cause of fungemia and was responsible for 12 episodes, while fungemia due to Penicillium marneffei and Histoplasma capsulatum, two emerging fungi in Taiwan, were diagnosed in four cases and one case, respectively. Nine episodes, eight of bacteremia and one of candidemia, were nosocomial. The overall in-hospital mortality was 29%, and nosocomial sepsis was associated with a higher mortality rate (56%, p = 0.02). The mean duration of survival after recovery from initial sepsis was 426 days. We conclude that NTS bacteremia was the most common cause of sepsis in patients with advanced HIV infection in Taiwan and clinicians caring for such patients should watch for emerging fungal infections. Nosocomial sepsis was associated with a high mortality rate. The mean survival duration after recovery from sepsis of our patients was short.
Genetic analysis was applied to identify novel genes involved in G protein-linked pathways controlling development. Using restriction enzyme-mediated integration (REMI), we have identified a new gene, Pianissimo (PiaA), involved in cAMP signaling in Dictyostelium discoideum. PiaA encodes a 130-kD cytosolic protein required for chemoattractant receptor and G protein-mediated activation of the 12 transmembrane domain adenylyl cyclase. In piaA- null mutants, neither chemoattractant stimulation of intact cells nor GTPgammaS treatment of lysates activates the enzyme; constitutive expression of PiaA reverses these defects. Cytosols of wild-type cells that contain Pia protein reconstitute the GTPgammaS stimulation of adenylyl cyclase activity in piaA- lysates, indicating that Pia is directly involved in the activation. Pia and CRAC, a previously identified cytosolic regulator, are both essential for activation of the enzyme as lysates of crac- piaA- double mutants require both proteins for reconstitution. Homologs of PiaA are found in Saccharomyces cerevisiae and Schizosaccaromyces pombe; disruption of the S. cerevisiae homolog results in lethality. We propose that homologs of Pia and similar modes of regulation of these ubiquitous G protein-linked pathways are likely to exist in higher eukaryotes.
OBJECTIVE: To determine the effects of sinus surgery on the production and perception of speech. DESIGN: Vocal recordings were performed before, 1 week after, and at least 1 month after sinus surgery. Acoustic spectra were analyzed for nasal consonants /m/ and /n/, nasalized vowels, and nonnasalized vowels. Results for nasal consonants were compared with similar recordings obtained from a group of normal subjects with no history of sinus disease. Perceptual analysis of nasalized vowels was conducted by trained phoneticians. SETTING: Private practice at an academic medical center. SUBJECTS: Five patients who underwent endoscopic sinus surgery and 3 normal subjects. MAIN OUTCOME MEASURES: The spectral characteristics and perceptual attributes of nasal sounds. RESULTS: Significant differences in spectral properties were observed for the consonants and nasalized vowels recorded before and after surgery (P < .001). Perceptual experiments for nasalized vowels demonstrated a postoperative decrease in nasality for the high vowel /i/, as in "beep," and an increase in nasality for the non-high vowel /ae/, as in "bad." These perceived changes correlated well with acoustic measures of nasal peak amplitudes and the lowest resonance peak amplitude of the vocal tract. CONCLUSIONS: Sinus surgery results in measurable effects on the produced acoustic signal and the perceived nasality of a patient's speech. The identified acoustic correlates may be useful for preoperative counseling of patients concerning expected changes in speech quality following surgery.
BACKGROUND: The preoperative assessment of depth of invasion of rectal carcinoma is increasingly important as new treatment methodologies are developed. Accuracy of preoperative endorectal MR imaging was therefore compared with that of the endoscopic rectal sonography in determining depth of invasion of rectal carcinomas. METHOD: From March 1993 to April 1994, 10 consecutive patients with biopsy-proven rectal carcinomas were imaged with both endorectal MR imaging and endoscopic rectal sonography. These two studies were performed an average of 2.7 days apart in each patient. All 10 patients had surgical resection of the rectal carcinoma within days of imaging studies. TNM staging of each malignant lesion was correlated with the imaging reports. RESULT: Staging accuracy was 80% for endorectal MR imaging and 70% for endoscopic rectal sonography. With MR imaging, one T2 lesion was overstaged and one T3 lesion was understaged. With sonography, two T2 lesions were overstaged and one T3 lesion was understaged. One MR error resulted from misinterpretation. All other staging errors occurred in patients with tumor spread into, but not through, the muscularis propria or with microscopic spread through this layer. CONCLUSIONS: Endorectal MR imaging and endoscopic rectal sonography have similar accuracy for assessing depth of invasion of rectal carcinoma.
BACKGROUND: The purpose of this study was to determine the incidence and severity of thoracic reactions in patients undergoing intraperitoneal heated chemotherapy (IPHC). METHODS: Forty-two patients who had intraperitoneal disseminated malignancies were treated with cytoreductive surgery (CS) and IPHC. The primary malignancies included carcinoma of the colon (n = 17), stomach (n = 6), appendix (n = 6), pseudomyxoma peritonei (n = 3), mesothelium (n = 2), ovaries (n = 2), jejunum (n = 2), gallbladder (n = 1), urachus (n = 1), and peritoneal carcinomatosis (n = 2). After CS, IPHC with mitomycin (MMC) was administered by perfusion at 40.5 degrees C. After IPHC, multiple radiographs of the chest were reviewed in comparison to the control group. RESULTS: Thoracic complications occurred in 36 patients (86%), including atelectasis in 32 patients (76%), pleural effusions in 27 (64%), pulmonary edema in 10 (24%), pneumonia in 2 (5%), and pneumothorax in 2 (5%). The incidence of thoracic complications in the IPHC group was significantly higher than that of patients in the control group (P < .05). Correlations between the prevalence of pleural effusion and the dose of MMC, duration of procedure, and presence of thrombocytopenia were not significant (P > .05). CONCLUSIONS: Bibasilar atelectasis and pleural effusions are common findings after IPHC with MMC, but most of them do not necessarily warrant intervention.
Because of the high morbidity and mortality in patients with bacterial arthritis, rapidly and correctly diagnosing this critical condition is a challenge to emergency clinicians. Synovial fluid samples were obtained from 75 patients with arthritis disorders who presented to an emergency service, and levels of tumor necrosis factor-alpha (TNF-alpha), interleukin-1 beta (IL-1 beta), and interleukin-6 (IL-6) were measured. Twenty patients with culture-proven bacterial arthritis had higher levels of synovial TNF-alpha than patients with osteoarthritis or with inflammatory arthritis, including gouty arthritis, rheumatoid arthritis, reactive arthritis, and lupus arthritis. There was a good sensitivity for synovial TNF-alpha level in diagnosing patients with bacterial arthritis. Nearly 100% of patients with bacterial arthritis had elevated synovial TNF-alpha levels. However, synovial IL-1 beta and IL-6 levels failed to discriminate bacterial arthritis from other inflammatory arthritis. Measurement of synovial TNF-alpha level may be useful as a diagnostic aid in emergency patients with bacterial arthritis disorders.
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RATIONALE AND OBJECTIVES: To determine whether a standard computed tomographic (CT) protocol is used in the staging of lung cancer. MATERIALS AND METHODS: A questionnaire was designed to determine what type of CT scanner is used, whether intravenous contrast material is used, how often the abdomen is scanned and at what level, and the section thicknesses used in scanning the chest and abdomen in patients with lung cancer. A total of 1,118 survey forms were mailed to members of the Society of Thoracic Radiology and to all community hospitals in the United States with at least 300 beds. RESULTS: The authors received 520 responses (47%) to the 1,118 questionnaires mailed. Of these 520 responses, 140 were from society members, 256 were from hospitals with 300-500 beds, and 124 were from hospitals with more than 500 beds. One-half of hospital respondents used helical CT scanners. Significantly more society members used helical CT scanners (P < .001). Intravenous contrast material was used to opacify mediastinal blood vessels at 449 (86%) of 520 hospitals. Intravenous contrast material was used for liver scanning at 363 (82%) of 444 hospitals, but it was used less often at hospitals in the northeast region and by society members than at hospitals in other regions (P < .001). A mixture of section thicknesses was commonly used (252 [48%] of 520 responses) for scanning the chest; a thickness of 8-10 mm was used in scanning the abdomen at most hospitals (348 [78%] of 445 responses). CONCLUSION: No CT protocol is consistently used for the examination of patients with lung cancer. Use of intravenous contrast material during chest or liver CT also is not uniform.
Acoustic analysis of nasalized vowels in the frequency domain indicates the presence of extra peaks: one between the first two formants with amplitude P1 and one at lower frequencies, often below the first formant, with amplitude P0. The first-formant amplitude A1 is also reduced relative to its amplitude for an oral vowel. These acoustic characteristics can be explained by speech production theory. The objective of this study was to determine the values for the acoustic correlates A1-P1 and A1-P0 (dB) for quantifying nasalization. They were tested as measures of nasalization by comparing vowels between nasal consonants and those between stop consonants for English speakers. Also, portions of nasal vowels following a stop consonant were compared for speakers of French, which makes a linguistic distinction between oral and nasal vowels. In the analysis of English, the mean difference of A1-P1 measured in oral vowels and nasalized vowels had a range of 10 dB-15 dB; the difference of A1-P0 had a range of 6 dB-8 dB. In the study of French, the difference of A1-P1 measured between the least-nasalized portion and the most-nasalized portion of the vowel had a range of 9 dB-12 dB; for A1-P0, the difference ranged between 3 dB and 9 dB. In order to obtain an absolute acoustic measure of nasalization that was independent of vowel type, normalized parameters were calculated by adjusting for the influence of the vowel formant frequencies.