Biomedical subjects

D L Cheng

Publications and source records attributed to D L Cheng.

At least 19 recordsLinked to original sources

PubMed2002

Self-organized nanoscale pattern formation on vicinal Si(111) surfaces via a two-stage faceting transition.

We demonstrate a self-organized pattern formation on vicinal Si(111) surfaces that are miscut toward the [2;11] direction. All the patterns, consisting of a periodic array of alternating (7 x 7) reconstructed terraces and step-bunched facets, have the same periodicity and facet structure, independent of the miscut angle, while the width of the facets increases linearly with miscut angle. We attribute such unique pattern formation to a surface faceting transition that involves two transition stages: the first stage forms a stress-domain structure defining the universal periodicity; the second stage forms the low-energy facets controlling the facet width.

Journal Article↗

PubMed2001

Iridoids from Phlomis umbrosa.

Two epimeric pairs of iridoid aglycones, named shanzhigenin methyl ester and 1-epishanzhigenin methyl ester, and 8-acetylshanzhigenin methyl ester and 8-acetyl-1-epishanzhigenin methyl ester, were isolated from Phlomis umbrosa roots, along with five known iridoid glucosides. The four iridoid aglycones are reported for the first time from a natural source. Their structures were established by spectroscopic methods, mainly 1D- and 2D-NMR spectroscopic experiments, and chemical methods.

Acetylation↗

PubMed2001

[Study on application of CODIS loci to excluding paternity].

OBJECTIVE: The study was carried out on application of CODIS loci (FGA, vWA, CSF1PO, TH01, TPOX, D3S1358, D5S818, D7S820, D8S1179, D13S317, D16S539, D18S51 and D21S11) in 100 cases of excluding paternity. METHODS: The PCR amplified products of Profiler Plus and Cofiler amplification kit were injected into a capillary on the ABI PRISM 310 Genetic Analyzer. GeneScan software analyzed the collected data, which can then be imported into Genotyper software for genotyping of alleles. RESULTS: In the group of Mother-Child-Alleged Father, more than 3 STR loci incompatibilities between alleged father and child were found in all observed cases, the mean incompatibility was 6.63; In the group of Alleged Father-Child, 94.0% of all cases observed was found more than 3 STR loci incompatibilities, the mean incompatibility was 5.01. CONCLUSION: The results showed that CODIS loci had good application to excluding paternity, and the choice of hyperpolymorphic markers in investigation, which were valued by DP, H and PE, had direct relation with the augmentation of incompatibilities in excluding paternity.

Adult↗

PubMed2000

Iridoid glucosides from Caryopteris mongholica.

Two new iridoid glucosides, 8-acetyl-6'-O-(p-coumaroyl) harpagide and 6'-O-(p-coumaroyl) antirrinoside, were isolated from the Caryopteris mongholica, together with two known iridoid glucosides, 8-acetylharpagide and harpagide. Their structures were elucidated, mainly by interpretation of their spectroscopic data (UV, IR, MASS, 1H, 13C, 1H/1H-COSY, HMQC, HMBC and NOESY NMR) and chemical methods.

China↗

PubMed1999

[The phenomenon of gene linkage and recombination in the paternity test].

The phenomenon of gene linkage and recombination may nearly be overlooked in paternity test of one single child, but it is likely encountered in paternity test of twin or more. In a case of paternity test, the results of 17 items including eight DNA loci were analyzed and the phenomenon of gene linkage and recombination was discussed in detail. This phenomenon should be brought into necessary attention in the paternity test.

Blood Group Antigens↗

PubMed1997

Role of benzathine penicillin G in prophylaxis for recurrent streptococcal cellulitis of the lower legs.

Cellulitis of the lower leg is an infection caused by streptococci or, less commonly, Staphylococcus aureus and other gram-negative rods. Recurrence of cellulitis is a common problem. In the present study, we evaluated the use of monthly intramuscular injections of benzathine penicillin G to prevent recurrences of cellulitis. A total of 115 patients with definite or presumptive cases of streptococcal cellulitis were enrolled in this study. Eighty-four of these patients who declined follow-up or received incomplete prophylaxis were considered controls. Recurrence occurred in four (12.9%) of 31 cases who received prophylaxis and 16 (19%) of the 84 cases who did not receive prophylaxis. The difference was not statistically significant. Predisposing factors for cellulitis were found in 57 (49.6%) of the 115 enrolled cases and were mostly related to the impairment of local circulation. Administration of prophylaxis successfully reduced the recurrence rate to zero among patients without predisposing factors but failed to prevent recurrence in those with predisposing factors (20%). We conclude that monthly benzathine penicillin G prophylaxis benefits only patients without predisposing factors for cellulitis.

Cellulitis↗

PubMed1997

Skin and soft-tissue manifestations of Shewanella putrefaciens infection.

Shewanella putrefaciens, a saprophytic gram-negative rod, is infrequently recovered from clinical specimens. Although a number of clinical syndromes have been attributed to S. putrefaciens, the pathogenic role of this agent remains largely undefined. We report 16 cases of S. putrefaciens infection that occurred at the Veterans General Hospital-Kaohsiung in Taiwan between 1990 and 1995. S. putrefaciens infection was associated with a wide clinical spectrum including bacteremia/septicemia, skin and soft-tissue infection, biliary tract infection, peritonitis, and empyema. Five of our patients had skin and soft-tissue manifestations, including fulminant periorbitofacial cellulitis, dacryocystitis, perineal abscess, finger abscess, and postcholecystectomy wound infection. These clinical features deviated from the chronic ulcers or infected burns of the lower extremities that have been described in previous reports. Seven (44%) of our 16 patients had bacteremia/septicemia, and all seven had underlying hepatobiliary diseases. S. putrefaciens was isolated in mixed cultures of specimens from 14 patients; Escherichia coli was the most common coisolate. Hepatobiliary diseases and malignancy were the major predisposing factors for S. putrefaciens infection of the biliary tract and S. putrefaciens bacteremia/septicemia.

Aged↗

PubMed1996

New pentapeptides from Aster tataricus.

Three pentapeptides have been isolated from the roots of Aster tataricus and their structures elucidated on the basis of spectroscopic analysis as well as chemical and enzymatic methods.

Amino Acid Sequence↗

PubMed1996

Conservative management of penetrating and blunt Type III renal injuries.

OBJECTIVE: To determine the optimal management, conservative or surgical, of patients with penetrating or blunt Type III renal injuries. PATIENTS AND METHODS: This retrospective study comprised 122 patients with blunt abdominal or penetrating trauma with suspected significant renal injuries. Forty-five patients (32 penetrating and 13 blunt trauma) with Type III injury were identified. Of these patients, 28 (17 penetrating and 11 blunt trauma) had their renal injuries treated conservatively while 14 patients, all with penetrating injuries, underwent immediate surgical repair. Three patients died from multiple trauma shortly after arrival in the emergency room. RESULTS: In the 42 surviving patients with Type III renal injuries, four required delayed intervention. These included two of those managed conservatively and two of the 14 who underwent initial surgical intervention. Three renal units were lost, all of which were in those treated surgically. Thus, of the 42 surviving patients with Type III renal trauma, 28 (67%) were successfully managed conservatively without renal loss. CONCLUSION: This study suggests that Type III penetrating trauma may be successfully managed conservatively with a similar outcome to those patients with Type III blunt injuries. Initial surgical intervention may only be necessary in those with associated intra-abdominal injuries or haemodynamic instability.

Clinical Protocols↗

PubMed1996

Mycotic aneurysm due to non-typhi salmonella: report of 16 cases.

From 1990 through 1994, we collected information on all cases of mycotic aneurysms due to non-typhi Salmonella that occurred at the Veterans General Hospital in Kaohsiung, Taiwan. All cases of salmonella bacteremia were reviewed to find any additional cases. A total of 16 cases of salmonella mycotic aneurysms occurred. The mortality rate was 100% among the three patients treated with medical therapy alone. Nine (70%) of the 13 patients who received surgical and medical therapy survived. Ten of the 16 cases were due to Salmonella choleraesuis. Diagnosis was established by computed tomography or aortography. Gallium scans were of no diagnostic utility. A culture of blood from a patient with underlying atherosclerosis that is positive for invasive Salmonella should prompt a search for a mycotic aneurysm. Treatment with a third-generation cephalosporin and resection of the infected vessel is usually successful.

Aged↗

PubMed1996

Comparison of the Roche AMPLICOR MYCOBACTERIUM assay and Digene SHARP Signal System with in-house PCR and culture for detection of Mycobacterium tuberculosis in respiratory specimens.

Two commercial primer kits and detection systems, the Roche AMPLICOR MYCOBACTERIUM test and the Digene primer-probe kit with the SHARP Signal System, were compared to in-house PCR as well as standard culture techniques. For the 27 culture-positive specimens, the Roche AMPLICOR MYCOBACTERIUM test detected 20 specimens, the Digene system detected 19, and in-house PCR detected 21. Of the 86 culture-negative specimens, 13 were positive by the Roche AMPLICOR MYCOBACTERIUM test, 16 were positive by the Digene system, and 21 were positive by in-house PCR. When clinical situations were evaluated, 11 of 13 culture-negative Roche AMPLICOR MYCOBACTERIUM test-positive specimens, 10 of 16 culture-negative Digene system-positive specimens, and 13 of 21 culture-negative-in-house PCR-positive specimens were diagnosed as true-positive specimens. The sensitivities of Roche AMPLICOR MYCOBACTERIUM test, the Digene system, and in-house PCR were 73.81, 69.05, and 80.95%, and the specificities were 97.18, 91.55 and 88.73%, respectively. The positive predictive values were 93.94, 82.86, and 80.95%, and the negative predictive values were 86.25, 83.33, and 88.73%, respectively. For the commercial kits, the Roche AMPLICOR MYCOBACTERIUM test seems to be more sensitive and specific than the Digene system. However, the Roche AMPLICOR MYCOBACTERIUM test cannot be used on nonrespiratory specimens.

Bacteriological Techniques↗

PubMed1996

Endogenous Escherichia coli endophthalmitis.

Metastatic bacterial endophthalmitis caused by Klebsiella pneumoniae is a unique but well-known phenomenon in Taiwan, where most cases occur in diabetic patients with pyogenic liver abscesses. However, endogenous Escherichia coli endophthalmitis is quite rare. The most common primary site of this infection is the urinary tract and the incidence of concurrent systemic infections, such as abscess formation and infective endocarditis, is high. This illness has a rapidly progressive clinical course associated with a poor prognosis for recovery of visual acuity. This is a report of a case of endogenous E. coli endophthalmitis originating from a renal abscess in a diabetic woman. Despite aggressive local and systemic treatment, evisceration was required to prevent the infection from spreading.

Abscess↗

PubMed1996

Evaluation of polymerase chain reaction-restriction enzyme analysis of mycobacteria cultured in BACTEC 12B bottles.

Polymerase chain reaction with restriction enzyme analysis (PRA) was first tested on 15 reference strains and 50 subcultured clinical isolates of mycobacteria according to the reference algorithm by Telenti et al [1]. Next, we evaluated the application of this method to 108 isolates from liquid media (BACTEC 12B). Of them, 15 M. tuberculosis complex and 81 mycobacteria other than tuberculosis (MOTT) had comparable results with both PRA and the BACTEC 460 TB systems. However, seven M. tuberculosis complex and three potentially pathogenic MOTT were identified by PRA rather than the BACTEC TB system. PRA seems to be an efficient method for the identification of mycobacteria to the species level and a good aid to detect potentially pathogenic mycobacteria, especially in mixed mycobacterial cultures.

Humans↗

PubMed1996

Melioidosis: two indigenous cases in Taiwan.

We report the first two indigenously acquired cases of melioidosis in Taiwan, diagnosed by positive culture and biochemically identified using the ID 32 GN system (BioMerieux Vitek Inc, Hazelwood, MO, USA). The first patient was a 75-year-old Chinese woman who had not travelled abroad since her arrival from mainland China (San-Tung province) 47 years ago. She presented with spontaneous bacterial peritonitis and hepatitis C-related liver cirrhosis with septic shock. Burkholderia pseudomallei (formerly Pseudomonas pseudomallei) was isolated from cultures of both blood and ascites fluid. The second patient, a 70-year-old Chinese man, presented with right lower lobar pneumonia complicated with empyema and septic shock. Blood cultures grew B. pseudomallei. Both patients had underlying diabetes mellitus; one also had liver cirrhosis and chronic renal failure, while the other had a renal stone. The first patient died of refractory septic shock prior to diagnosis. The second patient survived with the use of intravenous ceftazidime for 30 days, followed by oral amoxicillin-clavulanic acid for a further 3 months. These cases serve as a reminder to clinical physicians that melioidosis is now no longer exclusive to patients with a history of travel to endemic areas. A high index of clinical suspicion is required for early diagnosis and treatment in order to reduce the mortality and improve clinical outcome.

Aged↗

PubMed1996

Pentapeptides from the roots of Aster tataricus.

Asterinin D and E, pentapeptides, have been isolated from the roots of Aster tataricus L.f. (Compositae, syn. Asteraceae, subtribe Asteroideae) and their structures have been elucidated on the basis of spectroscopic analysis, as well as chemical and enzymatic methods.

Amino Acid Sequence↗

PubMed1996

Group a streptococcal meningitis.

Meningitis due to group A Streptococcus is uncommon. Only a few cases have been reported in the literature. In this paper, we report a case of a 19-year-old man who presented with fever, headache, nausea, vomiting and a decrease in level of consciousness. Five days prior to admission, he had an episode of acute pharyngitis. Group A Streptococcus was isolated from both the cerebrospinal fluid and blood. He recovered without sequelae after therapy with penicillin G for 2 weeks. Physicians should be aware that group A streptococcal infection may cause meningitis.

Adult↗

PubMed1995

Successful treatment of metastatic small cell carcinoma of the bladder with methotrexate, vinblastine, doxorubicin and cisplatin therapy.

A man with metastatic small cell carcinoma of the bladder who was treated with methotrexate, vinblastine, doxorubicin and cisplatin therapy achieved complete remission with disease-free survival of more than 9 years. The nature of this unusual form of bladder carcinoma and the course of the disease in our case are discussed.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1995

Streptococcal toxic shock syndrome in southern Taiwan.

This report outlines our experience with streptococcal toxic shock syndrome (STSS) at the Veterans General Hospital-Kaohsiung during the period October 1990 to November 1993. Group A streptococci were isolated from blood or normally sterile tissue in association with hypotension and multi-organ failure in the eight cases studied. A primary focus of infection was identified in seven cases, including pneumonia (1), septic arthritis (1) and soft-tissue infections (5). The remaining patient suffered from hyperglycemic hyperosmolar non-ketotic coma and Group A streptococcal bacteremia, without an obvious focus of infection. There were four cases of bacteremia. Clinical complications included acute renal failure in all eight cases, disseminated intravascular coagulation in five cases, liver involvement in two cases, adult respiratory distress syndrome in one case and soft-tissue necrosis in five cases. All isolates were sensitive to penicillin, and most patients were treated with intravenous penicillin G, with or without other antibiotics (gentamicin or clindamycin). Of the six patients with soft-tissue infection, two underwent amputation of the infected limb, and one patient underwent sono-guided pigtail drainage of psoas muscle abscess. Three of the patients died. STSS may be uncommon in Taiwan, but it is not rare. Early recognition of STSS (facilitated by Gram stain and culture), prompt debridement and drainage, and adequate antibiotic treatment with penicillin or clindamycin, or both, are necessary for control of such lethal infections.

Adult↗