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Biomedical subjects

Y C Chuang

Publications and source records attributed to Y C Chuang.

At least 55 records · Page 3Linked to original sources
PubMed1999

Unusual dilatation of Virchow-Robin spaces: case report.

Virchow-Robin spaces normally surround the perforating arteries that enter the brain. These spaces are a well-defined sites where immunological reactions take place and they may have implications in the pathogenesis of a number of neuropathological conditions. We present the case of a 52-year-old woman who had a history of complex partial seizures for 30 years. Her routine neurological examinations and mini-mental tests had normal results. Magnetic resonance images of this patient revealed unusual widening of the Virchow-Robin spaces up to 1.5 cm in diameter along the perforating medullary arteries in the white matter, more so in the left hemisphere. Although it has been concluded that these large spaces are a phenomenon of the normal aging brain and are unrelated to neurological diseases, our patient had had epileptic seizures for 30 years. The large Virchow-Robin spaces of our patient might have been an incidental radiologic finding. Their pathogenesis remains unclear, and their possible clinical relationship to epilepsy deserves further pathological studies.

Blood Vessels↗
PubMed1998

The prognostic factors of adult gram-negative bacillary meningitis.

Seventy-seven patients with Gram-negative bacillary meningitis (GNBM), 57 males and 20 females, aged 17-86 years, were identified at Kaohsiung Chang Gung Memorial Hospital, over an 11-year period. Fifty-four infections were community-acquired, and 23 were nosocomial; 49 were spontaneous and 28 occurred after head surgery or neurosurgery. The organisms most frequently involved were Klebsiella pneumoniae, Pseudomonas aeruginosa, Escherichia coli, and Acinetobacter. Rarer pathogens included Citrobacter species, Serratia marcescens, Enterobacter cloacae, and Proteus mirabilis. All patients who did not receive appropriate antibiotic therapy died. The mortality in those treated with appropriate antibiotics was 28%. Other statistically significant prognostic factors included septic shock, initial level of consciousness, hyperosmolar hyperglycemic nonketotic coma, disseminated intravascular coagulation, high cerebrospinal fluid lactate levels and leucocytosis. In the multiple logistic regression analysis, only appropriate antimicrobial therapy and septic shock were strongly associated with mortality even after adjusting for other potentially confounding factors. Despite the high mortality, management can be improved by early diagnosis, early use of appropriate antibiotics, and correction of underlying and associated medical derangement.

Adult↗
PubMed1998

Invasive group A streptococcal disease in Taiwan is not associated with the presence of streptococcal pyrogenic exotoxin genes.

We reviewed the clinical features of 44 patients with invasive group A streptococcal (GAS) disease who were treated at two teaching hospitals in southern Taiwan from 1991 to 1994. Genes encoding streptococcal pyrogenic exotoxin types A (speA), B (speB), C (speC), and F (speF) and serotypes of M1, M6, and M12 were determined by polymerase chain reaction to target specific sequences in the 44 isolates recovered from these patients and in 28 isolates recovered from upper respiratory sites in 28 additional patients during the study period. The protease activity of these isolates was tested by using the casein plate method. Of the 44 patients with invasive diseases, 25 (57%) had no obvious underlying diseases, and 14 (32%) had preexisting neoplastic diseases or had previously used steroids. Twenty-five patients (57%) presented with cellulitis or necrotizing fasciitis, 24 (55%) had bacteremia, and eight (18%) had streptococcal toxic shock syndrome (STSS). Eight patients (18%) died of invasive GAS disease; seven had STSS, and seven had underlying diseases. All eight patients died within 48 hours after hospitalization. The presence of speA, speC, or speF was not implicated in any particular clinical syndrome in patients with invasive GAS disease. High-level protease activity and the M1 serotype of the isolates were significantly associated with the clinical signs of STSS and with mortality. M1 serotype and protease activity, as well as host immune status, might play significant roles in the pathogenesis of invasive GAS disease in Taiwan.

Aged↗
PubMed1998

Infections due to non-O1 Vibrio cholerae in southern Taiwan: predominance in cirrhotic patients.

Although Taiwan is not an area where cholera is endemic, from October 1988 to October 1997 30 episodes of non-O1, non-O139 Vibrio cholerae infection were noted at the National Cheng Kung University Hospital in Taiwan. Infections generally occurred in hot seasons, and two episodes were concomitant with Vibrio vulnificus infection. Three major clinical presentations were found: bacteremia with concurrent spontaneous bacterial peritonitis or invasive soft-tissue infections that occurred solely in cirrhotic patients; self-limited acute febrile gastroenteritis that occurred in patients with no underlying medical disease; and necrotizing fasciitis or cellulitis that often resulted from a wound on extremities. Other manifestations included fatal pneumonitis in a drowned man and acute pyosalpinx. The differential diagnosis of invasive infections in cirrhotic patients should include infections due to non-O1 V. cholerae or V. vulnificus, and a third-generation cephalosporin and a tetracycline analogue or a fluoroquinolone alone is recommended for treatment of severe vibrio infections.

Acute Disease↗
PubMed1998

Suppurative Acinetobacter baumanii thyroiditis with bacteremic pneumonia: case report and review.

Suppurative thyroiditis is rare, and the major pathogens are Staphylococcus and Streptococcus species. We present a case caused by Acinetobacter baumanii, which has never before been reported. We review another 191 cases from the English-language literature (1980 to April 1997) and make a comparison with a review of 224 cases (1900-1980). As the numbers of immunocompromised patients increase, cases of suppurative thyroiditis are increasing. Pneumocystis carinii has become an important pathogen. Most patients (83.1%) with bacterial infections were euthyroid, whereas those with fungal or mycobacterial infections tended to be hypothyroid (62.5%) and hyperthyroid (50%), respectively.

Acinetobacter↗
PubMed1998

Minocycline and cefotaxime in the treatment of experimental murine Vibrio vulnificus infection.

We conducted an in vivo study with the mouse model of Vibrio vulnificus infection to evaluate the efficacies of therapy with minocycline or cefotaxime alone and in combination. V. vulnificus was introduced subcutaneously into the area over the right thigh. The inoculum size ranged from 1.0 x 10(3) to 1.2 x 10(8) CFU from experiment to experiment but was constant for all animals in the same experiment. Antibiotics were given intraperitoneally 2 h after the bacteria were inoculated. In experiments 1 to 4, the standard dose for humans was used to treat the infection, while in experiment 5, five times the standard dose for humans was used to treat the infection. In experiment 1, with a small inoculum of 5 x 10(3) CFU, all mice in the saline-treated control group and the cefotaxime-, minocycline-, and combined antibiotic-treated groups survived. In experiment 2, with a moderate inoculum of 1.2 x 10(5) CFU, all the mice in the three antibiotic-treated groups survived, while only two of nine mice in the control group survived. In experiment 3, with a large inoculum of 8.0 x 10(7) CFU, six of nine mice in the combined antibiotic-treated group survived, while only one of nine mice in the cefotaxime-treated group and none of the mice in the control and minocycline-treated groups survived. In experiment 4, with a large inoculum of 1.2 x 10(8) CFU, 8 of 20 mice in the combined antibiotic-treated group survived, while none of the 20 mice in the control group, the group treated with cefotaxime alone, and the group treated with minocycline alone survived. In experiment 5, in which mice were infected with a large inoculum of 6.6 x 10(7) CFU and treated with five times the standard human dose of antibiotics, 10 of 12 mice in the combined antibiotic-treated group survived, while only 4 of 12 mice in the minocycline-treated group, 1 of 12 mice in the cefotaxime-treated group, and none of the mice in the control group survived. In experiments 3 to 5, the difference in the survival rates between the combined antibiotic-treated and minocycline-treated groups was statistically significant (P < 0.05). These results indicate that combination therapy with cefotaxime and minocycline is distinctly more advantageous than therapy with the single antibiotic regimen for the treatment of severe experimental V. vulnificus infections.

Animals↗
PubMed1998

Osmotic demyelination syndrome with two-phase movement disorders: case report.

Osmotic demyelination syndrome (ODS) is characterized by regions of demyelination throughout the brain, which are most prominent in the pons. This demyelinating disease is associated with electrolyte disturbances and typically occurs in patients who are alcoholic or malnourished. Movement disorders are not frequently recognized in patients with ODS. This report describes a 22-year-old woman with ODS after correction of profound hyponatremia. The main neurologic symptom was two-phase movement disorder. First, she had acute onset dystonia, then the movement disorder transformed to generalized rigidity and tremors in the delayed second phase. Magnetic resonance imaging in the first phase revealed demyelinating lesions in the central pons, bilateral thalami and basal ganglia. In the second phase, the previous myelinolysis had been partially resolved. The clinical course of the two-phase movement disorder did not correlate with the resolving feature of neuroradiologic findings. During the second-phase movement disorder, the patient had a good response to propranolol and trihexyphenidyl.

Adult↗
PubMed1997

Cloning and characterization of the gene (empV) encoding extracellular metalloprotease from Vibrio vulnificus.

A gene (empV) encoding the extracellular metalloprotease of Vibrio vulnificus CKM-1 has been cloned and sequenced. When the empV gene was expressed in minicells, a unique peptide of approx. 46 kDa was identified. Protease activity staining experiments also indicated a similar M(r) for the protease. The empV gene product (EmpV) is secreted into the periplasm of Escherichia coli, but not out of it. The crude enzyme prepared from the periplasmic fraction of recombinant E. coli was inhibited by a metalloprotease inhibitor and Zn2+ is essential for its protease activity. Nucleotide sequence analysis predicted a single open reading frame (ORF) of 1818 bp encoding a 606 amino acid (aa) polypeptide, with a potential 24 aa signal peptide followed by a long 'pro' sequence consisting of 172 aa. The N-terminal 20 aa sequence for the elastolytic protease (EepV), purified from the culture supernatant of V. vulnificus ATCC 29307, completely identified the beginning of the predicted mature protein within the deduced aa sequence except for 1 aa residue difference. The estimated pI and molecular weight of the predicted mature protein were 5.86 and 44.3 kDa, respectively, which are nearly identical to those of V. vulnificus L-180 extracellular neutral metalloprotease (EnmV) and of strain ATCC 29307 EepV. The estimated molecular weight also closely matches that determined by SDS-PAGE analysis of the minicells and by protease activity staining. The deduced aa sequence of EmpV showed high homology to V. anguillarum metalloprotease (EmpA), V. cholerae HA/protease (HprC), and V proteolyticus neutral protease (NprP), particularly with respect to active-site residues, zinc-binding residues, and cysteine residues.

Amino Acid Sequence↗
PubMed1997

Paraneoplastic elevation of serum alkaline phosphatase in renal cell carcinoma: incidence and implication on prognosis.

PURPOSE: We investigated the incidence and prognostic significance of paraneoplastic elevation of serum alkaline phosphatase in patients with renal cell carcinoma. MATERIALS AND METHODS: Clinical data of 365 pathologically proved renal cell carcinoma cases were reviewed. Serum alkaline phosphatase level greater than 100 units per 1., but without obvious conditions that may cause phosphatase elevation, including metastasis to or disease of liver or bone and pregnancy, was regarded as paraneoplastic serum alkaline phosphatase elevation. Survival was evaluated using the Kaplan-Meier method. RESULTS: Of 365 patients 77 (21.1%) had paraneoplastic serum alkaline phosphatase elevation. The respective incidence from stage I to IV cases was 9.9% (16 of 161), 31.9% (15 of 47), 34.3% (23 of 67) and 25.6% (23 of 90). Patients with stage I disease had the lowest incidence but there were no statistically significant differences among stages II, III and IV disease. Of 77 patients with elevated serum alkaline phosphatase 48 had additional paraneoplastic manifestations. The disease specific 5-year survival rate in patients with normal serum alkaline phosphatase was significantly better than in patients with isolated phosphatase elevation, which in turn was better than in patients with multiple paraneoplastic syndromes (70.7 versus 50.5 versus 30.8%). Patients with persistent or recurrent elevation of serum alkaline phosphatase after radical nephrectomy had metastatic lesion or local recurrence. In some patients serum alkaline phosphatase returned to normal after nephrectomy but metastasis developed later without recurrent phosphatase elevation. CONCLUSIONS: Paraneoplastic serum alkaline phosphatase elevation in renal cell carcinoma patients implies an unfavorable prognosis, and additional paraneoplastic syndromes further worsen the prognosis. Recurrent or persistent serum alkaline phosphatase elevation after radical nephrectomy suggests distant metastasis or residual tumor. However, the return of serum alkaline phosphatase to normal does not guarantee cure of the disease. Identification of paraneoplastic serum alkaline phosphatase elevation is valuable in the prediction of outcome and postoperative followup of renal cell carcinoma patients.

Alkaline Phosphatase↗
PubMed1997

In vitro synergism between cefotaxime and minocycline against Vibrio vulnificus.

We conducted time-kill studies to evaluate the inhibitory activities of either cefotaxime or minocycline alone and the two drugs in combination against a clinical strain of Vibrio vulnificus. The MICs of cefotaxime and minocycline were 0.03 and 0.06 microg/ml, respectively. When approximately 5 x 10(5) CFU of V. vulnificus per ml was incubated with cefotaxime at 0.03 or 0.05 microg/ml, the bacterial growth was inhibited during the initial 2 and 8 h, respectively. Thereafter, V. vulnificus regrew and the level of growth reached that of the control. Within the dose range of less than five times the MIC, the duration of the inhibitory effect of cefotaxime was proportional to its concentration. When minocycline at 0.015, 0.03, 0.045, and 0.06 microg/ml was used to evaluate the inhibitory effect, a similar trend was observed. Either antibiotic at a concentration of five times the MIC or greater prevented the regrowth of V. vulnificus for at least 48 h. When cefotaxime at 0.05 microg/ml and minocycline at 0.045 microg/ml were combined in the same culture, the inhibitory effect against V. vulnificus persisted for more than 48 h, with no regrowth noted. The use of a combination of these two antibiotics resulted in the reduction of growth by 6 orders of magnitude compared to the use of either of the two antibiotics alone, and the number of surviving organisms in the presence of the antibiotics combined was approximately 3 orders of magnitude less than that in the starting inoculum. We conclude that cefotaxime and minocycline acted synergistically in inhibiting V. vulnificus in vitro.

Anti-Bacterial Agents↗
PubMed1997

Cloning and sequence analysis of a novel hemolysin gene (vllY) from Vibrio vulnificus.

A gene (vllY) encoding a novel hemolysin of Vibrio vulnificus CKM-1 has been cloned and sequenced. When the vllY gene was expressed in minicells, a unique peptide of approximately 40 kDa was identified. Subcellular fractionation of Escherichia coli cells carrying the vllY gene indicated that the VllY protein was distributed in both the cytoplasmic and the periplasmic fractions, with the notable ability to appear in the latter compartment. Nucleotide sequence analysis predicted a single open reading frame of 1,071 bp encoding a 357-amino acid polypeptide with an estimated pI of 5.02. The deduced amino acid sequence of VllY showed high similarity to the sequence of legiolysin, responsible for hemolysis, pigment production, and fluorescence in Legionella pneumophila. The enzyme also exhibited sequence homology to the MelA protein sequence of Shewanella colwelliana and the sequences of 4-hydroxyphenylpyruvate dioxygenase family proteins from various organisms. PCR screening and Southern blotting of V. vulnificus strains revealed that all of the 41 V. vulnificus clinical isolates contained vllY-like genes.

Amino Acid Sequence↗
PubMed1997

Use of the transurethral prostatectomy clinical path to monitor health outcomes.

PURPOSE: We evaluated the effect on cost and medical care quality of use of the transurethral prostatectomy clinical path. MATERIALS AND METHODS: Results in 100 patients treated when the transurethral prostatectomy clinical path was used were compared to those of 100 treated by the same physicians before implementation of this path. RESULTS: After implementation of the transurethral prostatectomy clinical path the length of hospital stay was significantly decreased from 5.9 to 5.0 days (p < 0.01) and Foley catheterization time was significantly decreased from 3.13 to 2.84 days (p < 0.01). Antibiotics were routinely used from the day before surgery to the day of hospital discharge as required by patient conditions. Therefore, a shorter hospital stay will significantly decrease the use of antibiotics. After implementation of the clinical path the average admission charges were decreased significantly by 17% (p < 0.01). Although some results from use of this path will not significantly affect costs, they will reflect some quality improvement. The effect of clinical path implementation on length of hospital stay between patients treated by junior and senior attending physicians was not significant. However, there was a statistically significant difference (p < 0.01) between results obtained by junior and senior attending physicians regarding average admission charges. CONCLUSIONS: Implementation of the transurethral prostatectomy clinical path can improve health care outcome by decreasing length of stay and admission charges, and improving quality of medical care, particularly for patients treated by junior attending physicians.

Aged↗
PubMed1997

Acute Q fever as a cause of acute febrile illness of unknown origin in Taiwan: report of seven cases.

Acute Q fever, caused by Coxiella burnetii has been well documented in Western countries, but only recently identified in Taiwan. Seven cases diagnosed by indirect fluorescent antibodies to phase II antigens of C. burnetii are reported. The patients were all men and a history of animal contact could be traced in most cases. Clinical manifestations were high fever, chills, relative bradycardia and elevated serum aminotransferases. Therapy with tetracycline or clarithromycin resulted in defervescence within 96 hours. Combining the knowledge on the prevalence of Q fever in Taiwan, the typical exposure history and clinical features in acute Q fever infection, primary care physicians may be able to avoid invasive but futile diagnostic intervention for patients with prolonged febrile illness. Prior to results from serologic testing, empiric therapy with tetracycline or its analogs may be considered for patients with typical clinical manifestations.

Adult↗
PubMed1997

The route of seminal vesicle involvement in adenocarcinoma of prostate: lymphaticovascular or local extension?

BACKGROUND: Adenocarcinoma of the prostate with seminal vesicle involvement indicates a rather poor prognosis. The aim of this study is to evaluate the route of seminal vesicle involvement via lymphaticovascular or local extension, as a possible way which may determine the extent of disease as systemic or local. METHODS: In a retrospective study of 32 patients who underwent radical prostatectomy for localized cancer of the prostate, medical records and imaging studies were reviewed, and the histopathological slides of the resected specimens were rechecked. RESULTS: Of 32 patients, 12 (37.5%) had seminal vesicle involvement. Seven patients had involvement of bilateral seminal vesicles and five had unilateral involvement. Tumor cells invaded the muscle portion of seminal vesicle from the adjacent prostatic tissues in all 12 patients. Four of the seven patients with involvement of bilateral seminal vesicles developed bony metastasis 7 to 12 months after operation. No patient with unilateral involvement of seminal vesicle was found to have disease progression to bony metastasis during follow-up for as long as 39 months. CONCLUSIONS: The route of seminal vesicle involvement in prostate cancer was through local extension in all of our patients. Involvement of bilateral seminal vesicles may have more chances to develop bony metastasis than unilateral involvement. Further study with a large number of patients is necessary to clarify the issue regarding the route of seminal vesicle involvement in adenocarcinoma of prostate.

Adenocarcinoma↗
PubMed1997

Clinical characteristics and antimicrobial susceptibility of invasive group B streptococcal infections in nonpregnant adults in Taiwan.

To understand group B streptococcal infections other than peripartum events in adults and to provide a regional antimicrobial therapy guide, we conducted a retrospective analysis of invasive diseases caused by group B streptococcus (GBS) in 33 nonpregnant adults treated in a medical center in southern Taiwan, from January 1993 to July 1994. Antimicrobial susceptibility tests were performed using the agar dilution method. The incidence of the disease was 1.6 per 1,000 nonpregnant adult admissions, and the mean age of patients was 58 years (range 17-86 years). Primary bacteremia (13) and soft-tissue infections (11) were the most common manifestations. Nearly all the patients had underlying disease(s) and/or condition(s); the three most common were diabetes mellitus (13), malignancy (5), and liver cirrhosis (5). There were eight nosocomial infections and six patients died. Of 32 GBS strains tested, 27 were susceptible to penicillin G and the rest were intermediately susceptible. All strains were uniformly susceptible to cephalothin, cefotaxime, ofloxacin, and vancomycin; two strains were susceptible to gentamicin and nearly half were intermediately susceptible. Our findings imply a requirement for higher doses of penicillin or combination with an aminoglycoside for treatment of GBS infection. First-generation cephalosporins may be an alternative for the treatment of GBS infections in Taiwan.

Adolescent↗
PubMed1997

Mouse skin damage caused by a recombinant extracellular metalloprotease from Vibrio vulnificus and by V. vulnificus infection.

Vibrio vulnificus wound infection is characterized by an intense acute cellulitis which spreads along the subcutaneous tissue with severe tissue destruction. Toxins produced by the bacteria appear to be involved in the pathogenesis of skin necrosis and to facilitate microbial dissemination in vivo. We report microscopic studies of mouse skin damage caused by a single intradermal injection of V. vulnificus or of an extracellular metalloprotease isolated from this organism. The gene encoding this metalloprotease has been cloned and expressed in Escherichia coli. The crude metalloprotease extract obtained from the periplasmic fraction by osmotic shock was used in this study. Intradermal injection of this preparation resulted in marked edematous changes of the skin, which extended throughout the dermis and subcutaneous tissues and into adjacent muscles. The collagen and elastic fibers degenerated and some muscle cells even appeared necrotic. Blood vessels became congested, with moderate perivascular neutrophil and mononuclear cell infiltration. There was no evidence of necrotic changes in the blood vessel itself. These results show that the damage to the connective tissues caused by V. vulnificus is at least partly attributable to its protease. Therefore, the protease seems to be an important virulence factor of this microbe.

Animals↗