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Biomedical subjects

S C Chang

Publications and source records attributed to S C Chang.

At least 253 records · Page 14Linked to original sources
PubMed1992

Primary malignant melanoma of the vagina and cervix uteri: case report and literature review.

Malignant melanoma of vagina is rare. Malignant melanoma of the cervix is even rare. To date, only 96 cases of the former and 26 cases of the latter have been reported. We report here a very rare case of primary malignant melanoma involving both vagina and cervix in a 70-year-old woman. The clinical, cytologic, light microscopic and ultrastructural findings are presented, and the pertinent literature is reviewed and discussed.

Aged↗
PubMed1992

In vitro antibacterial activities of ticarcillin alone and ticarcillin plus clavulanic acid against beta-lactamase producing and non-producing microorganisms.

A total of 818 clinical bacterial isolates were tested for the production of beta-lactamase by rapid chromogenic cephalosporin method and for the susceptibility to ticarcillin alone and in combination with clavulanic acid (2 micrograms/mL) by agar dilution method. These included 83 strains of methicillin-sensitive Staphylococcus aureus (MSSA), 31 of methicillin-resistant S. aureus (MRSA), 49 of Neisseria gonorrhoeae, 58 of Haemophilus influenzae, 112 of Escherichia coli, 118 of Klebsiella pneumoniae, 58 of Proteus mirabilis, 30 of Proteus vulgaris, 60 of Serratia marcescens, 113 of Enterobacter cloacae, 60 of Pseudomonas aeruginosa and 46 of Bacteroides fragilis. The results revealed that 46.6% of P. mirabilis, 53.4% of H. influenzae, 57.1% of N. gonorrhoeae, 80% of P. vulgaris, 83.9% of MRSA, 85.6% of MSSA, 87.5% of E. coli, 91.7% of S. marcescens, 95.7% of B. fragilis, 98.2% of E. cloacae, and 100% of K. pneumoniae and P. aeruginosa strains produced beta-lactamase. In general, beta-lactamase nonproducers were more susceptible to ticarcillin than beta-lactamase producers. The ranges of minimum inhibitory concentrations (MICs) of ticarcillin for beta-lactamase nonproducers of MSSA, MRSA, H. influenzae, E. coli, P. vulgaris, S. marcescens, E. cloacae, B. fragilis and beta-lactamase producers of MSSA, H. influenzae strains were all within the in vitro susceptible range. The presence of clavulanic acid resulted in a significant enhancement of the antibacterial activity of ticarcillin against beta-lactamase producers of MRSA, N. gonorrhoeae, E. coli, K. pneumoniae, P. mirabilis, P. vulgaris and B. fragilis strains. Clavulanic acid had no synergistic activity for ticarcillin against S. marcescens, P. aeruginosa and E. cloacae.

Bacteria↗
PubMed1992

Urodynamic findings in interstitial cystitis.

Fifty patients with irritative voiding symptoms and a painful bladder when full were engaged in this study to clarify the role of urodynamics in the diagnosis of interstitial cystitis (IC). Patients underwent urodynamic study, cystoscopic hydrodilatation of the bladder under general anesthesia and bladder biopsy. Twenty-eight women and two men who presented with signs of glomerulations or petechial hemorrhage of the bladder mucosa were classified as having IC, while 20 women without this characteristic were classified as having non-IC. A hypersensitive urge sensation, a small bladder capacity, a lower maximal flow rate and an abnormal flow pattern were observed in both groups of patients, but no significant difference was noted. More IC patients had a lower bladder compliance than non-IC patients (p < 0.025), and the maximal bladder capacity under anesthesia was smaller in IC patients (p < 0.05). However, there does not seem to be any definite correlation to the pathologic findings, except in patients with marked bladder inflammation, in whom a small capacity and severe clinical symptomatology were found.

Adult↗
PubMed1992

Epidemiologic investigation of nosocomial outbreak of methicillin-resistant Staphylococcus aureus by plasmid pattern analysis.

Nosocomial infections caused by methicillin-resistant Staphylococcus aureus (MRSA) have become an important problem with increasing frequency. In order to learn if plasmid pattern analysis can be used in epidemiologic investigations of MRSA infections, the authors did plasmid extractions of 70 MRSA stock isolates using a rapid lysostaphin lysis method. All isolates carried at least one plasmid. Most of the isolates had one large plasmid of 24-28 megadaltons (Md). Many also carried one or two small plasmids. Accordingly, 12 different patterns were identified. From these background results, we applied this method to the investigation of two small nosocomial outbreaks of MRSA infection. It was found that the analysis of plasmid pattern and restriction endonuclease analysis are more discriminative than antibiograms. Strains with the same antibiograms can be different by plasmid analysis. It is concluded that the plasmid pattern with a restriction endonuclease analysis study is a reliable method for epidemiologic study of MRSA infections.

Cross Infection↗
PubMed1992

Staging of cervical cancer: comparison between magnetic resonance imaging, computed tomography and pelvic examination under anesthesia.

A prospective study was undertaken to compare magnetic resonance imaging (MRI) with computed tomography (CT) and examination under anesthesia (EUA) in staging cervical carcinoma, with special emphasis on parametrial status. Twenty patients with carcinoma of the cervix, in whom the extent of the disease was surgically confirmed, were analyzed by MRI, CT and EUA. The tumor size estimated by MRI correlated well (r = 0.79, p < 0.001) with those obtained by histopathologic measurement of the surgical specimen. Neither clinical examination nor CT could precisely estimate tumor size. The overall accuracy rate of MRI in staging carcinoma of the cervix was 75%, compared with 32% for CT staging and 55% for clinical staging. The accuracy rate of these modalities for parametrial status was 90% for MRI, 55% for CT and 82.5% for EUA. MRI accurately excluded all 20 patients with pelvic side wall, bladder and rectal involvement. In conclusion, MRI is superior to CT and EUA in assessment of the parametrium (90% vs 55% vs 82.5%, p < 0.005). From MRI, tumor size can be estimated precisely. Although a larger scale study comparing MRI and CT is needed to determine their roles, both should help in the diagnosis and selection of proper treatment for cervical carcinoma. Our preliminary report agrees with previous reports that MRI is promising and indispensable. MRI should be routinely used in conjunction with clinical staging to determine appropriate therapy in patients with cervical carcinoma.

Adult↗
PubMed1992

Successful treatment of cytomegalovirus pneumonitis with ganciclovir and high-dose intravenous immunoglobulin in a bone marrow transplant recipient.

A 35-year-old man with acute lymphoblastic leukemia in second remission received an allogeneic bone marrow transplant from an HLA-compatible sibling donor. Unfortunately, cytomegalovirus (CMV) pneumonitis was histologically documented on Day +72. Combination therapy with ganciclovir (9-[2-hydroxy-1-(hydroxy-methyl) ethoxymethyl] guanine) and high-dose intravenous immunoglobulin (IVIG) was started immediately. The treatment comprised a three-week induction course (ganciclovir, 2.5 mg/kg q8h and IVIG, 500 mg/kg qod) and a seven-week fixed-dose maintenance course (ganciclovir 5 mg/kg thrice a week for 20 doses and IVIG 500 mg/kg twice a week for eight doses). The pneumonia resolved gradually, and he was free from symptoms within two weeks. The only significant side effect was moderately severe myelosuppression which was reversible after discontinuation of ganciclovir. The patient had a relapse of leukemia on Day +186, but there was no recurrence of CMV pneumonitis. This result confirms that such combination therapy is effective in the treatment of CMV pneumonitis in a patient with a bone marrow transplant.

Adult↗
PubMed1992

[Identification and typing of Pseudomonas pickettii during an episode of nosocomial outbreak].

From January to April 1989, Pseudomonas pickettii was isolated from clinical specimens of 24 hospitalized patients at the National Taiwan University Hospital in Taipei. The source of the organism was the 0.9% NaCl solution prepared by the hospital pharmacy. A total of 39 isolates of P. pickettii were collected, including 28 from clinical specimens and 11 from 0.9% saline and distilled water during the outbreak. These microorganisms were studied by using four methods, namely, conventional biochemical method, Vitek Auto-Microbic System (Vitek AMS), gas-liquid chromatographic analysis of cellular fatty acids composition and determination of the minimum inhibitory concentrations of 10 different antimicrobial agents. By conventional biochemical method, 16 isolates were typed as biovar 1 and 23 strains were biovar 3. Strains of both biovars were recovered from clinical specimens and 0.9% saline. Vitek AMS was able to identify P. pickettii correctly, but the result of biotyping was not satisfactory. Analysis of cellular fatty acids could rapidly identify P. pickettii to the species level, but could not distinguish the different biovars. By determination of the MICs, the antibiogram could be classified into 9 patterns. Of 16 isolates of P. pickettii biovar 1, 7 (44%) belonged to pattern I, and 9 (56%) pattern II. Strains of both patterns were found in cultures of clinical specimens and 0.9% saline. Of 23 isolates of P. pickettii biovar 3, 11 (48%) belonged to pattern III, 4 (17%) pattern IV and 8 (35%) pattern V to IX. Pattern III and pattern IV were seen in isolates from clinical specimens and 0.9% saline, while pattern V to IX were only seen in isolates from clinical specimens.(ABSTRACT TRUNCATED AT 250 WORDS)

Cross Infection↗
PubMed1992

Primary lung cancer complicated with pneumothorax.

Eighteen lung cancer patients with a pneumothorax complication were studied. Pneumothorax appears rarely in lung cancer patients, having been found in 18 out of 5567 (0.32%) at our hospital over a period of ten years. Of the 18 patients, eight had adenocarcinoma, seven epidermoid carcinoma and three alveolar cell carcinoma. Unlike those of previous reports, our results showed pneumothorax not to be found exclusively on the same side as the lung cancer. It was contralateral in five cases. Pneumothorax was the initial manifestation of lung cancer in three cases and occurred as a complication in another 15. Of these 15 patients, 11 were described as developing pneumothorax between one and twelve months after completion of radiation therapy for lung cancer. Another two patients developed pneumothorax following cytotoxic chemotherapy. Pneumothorax occurred prior to any treatment for lung cancer in the remaining two patients. The factors contributing to pneumothorax in the lung cancer patients were the rupture of the necrotic neoplastic tissue into the pleural cavity, the rupture of a subpleural bleb or the formation of interstitial air due to partial bronchial obstruction by the tumor, complications arising from radiation therapy and cytotoxic chemotherapy, or any combination of such factors. Pneumothorax was an ominous sign for the lung cancer patients. Most (12/14) died within six months of the onset of pneumothorax.

Aged↗
PubMed1991

Modification of morphine-induced analgesia and toxicity by pertussis toxin.

The present study evaluates the effect of pertussis toxin (PTX) on morphine-induced analgesia and lethality. Mice were injected with 0.2 microgram PTX intracerebroventricularly (i.c.v.) and 0.2 micrograms PTX intrathecally (i.t.) or saline. Mice were tested for morphine-induced analgesia (tail flick) and lethality 16 days later; mice were also examined for pentobarbital-induced mortality. Morphine analgesic potency was decreased by approximately 4-fold in PTX-treated mice compared to controls. Conversely, the lethal potency of morphine was increased by 10-fold in PTX-treated mice compared to controls. PTX treatment did not alter the lethal potency of pentobarbital. Morphine-induced analgesia and lethality were dose-dependently antagonized by naloxone in both PTX and saline-treated groups. The results of this study suggest that morphine analgesia is mediated through PTX-sensitive G proteins. On the other hand, morphine-induced lethality appears to be limited by PTX-sensitive factor(s) since PTX treatment enhanced morphine's lethal potency. The increase in lethal potency of morphine may be due to unmasking of an excitatory opioid receptor mediated effect by PTX.

Analgesia↗
PubMed1991

Dissociation of opioid receptor upregulation and functional supersensitivity.

Alterations in brain opioid binding and opioid pharmacodynamics following chronic (8-day) naltrexone (NTX) treatment were determined in pertussis toxin (PTX)-treated mice. Intrathecal (IT) and intracerebroventricular (ICV) PTX produced a time-dependent, long-lasting inhibition of morphine (SC) analgesia without modifying basal nociception. Inhibition was maximal 16 days following PTX treatment, and was still observed at 40 days. Relative to placebo controls, NTX treatment produced supersensitivity to morphine analgesia in all control mice and in mice pretreated with PTX 1 day before NTX. Supersensitivity was not observed in 7-day PTX-pretreated mice. [3H][D-Ala2-D-Leu5]enkephalin ([3H]DADLE) and [3H][D-Ala2-MePhe4-Gly(ol)5]enkephalin ([3H]DAMGO) binding sites were increased by NTX treatment in saline- and PTX-pretreated groups. KDs were unchanged. These results indicate that PTX does not alter opioid antagonist-induced receptor upregulation. However, PTX treatment can diminish morphine potency in upregulated and control mice. Therefore, opioid analgesia in control and upregulated mice appears to be mediated by receptors linked to a common PTX-sensitive G-protein. Furthermore, in 7-day PTX-pretreated mice, NTX increased binding sites without altering morphine potency, which suggests that new binding sites can appear without being functionally coupled.

Analgesia↗
PubMed1991

Usefulness of bronchoalveolar cell profile in early detection of canine lung allograft rejection.

To evaluate the value of a bronchoalveolar cell profile in the early detection of canine lung allograft rejection, bronchoalveolar lavages were done serially in mongrel dogs before and after single lung transplantation. The dogs were divided into 3 groups. In group 1, neither donor nor recipient dogs were treated with cyclosporine. In group 2, only donors were treated with cyclosporine, orally at a single dose of 20 mg/kg/day for 3 days prior to single lung transplantation. In group 3, only recipients were treated with cyclosporine (20 mg/kg/day) for 9 days after single lung transplantation. A marked increase in the number of bronchoalveolar cells and their cell differentials, and of major histocompatibility complex (MHC) class II-positive cells obtained from the grafted lungs after lung transplantation, was seen in groups 1 and 2. The changes in bronchoalveolar cell profile obtained from the rejecting grafted lungs were significantly different from those obtained from the normal and native lungs (P less than 0.05). In group 3, the bronchoalveolar cell profile obtained from the grafted lungs did not significantly differ from those present in normal and native lungs during the period of cyclosporine treatment after lung transplantation. On various days after withdrawal of cyclosporine treatment, bronchoalveolar cell profiles obtained from the grafted lungs showed similar changes to those observed in groups 1 and 2. Abnormal changes in bronchoalveolar cell profiles obtained from the grafted lungs heralded the appearance of abnormalities detected by chest X-ray films. Our results indicate that serial measurements of bronchoalveolar cell profile may serve as a useful means for early detection of canine lung allograft rejection.

Animals↗
PubMed1991

Significance of biochemical markers in early detection of canine lung allograft rejection.

To evaluate the significance of bronchoalveolar lavage fluid, levels of tumor necrosis factor-alpha (TNF), gamma-interferon, interleukin 2, and soluble IL-2 receptor in early detection of canine lung allograft rejection, bronchoalveolar lavages were performed serially in mongrel dogs before and after single lung transplantation. The dogs were divided into three groups. Group 1 (control group) consisted of one in which neither donor nor recipient dogs were treated with cyclosporine. In group 2 (CsA-pretreated group) only donors were treated with CsA orally at a single dose of 20 mg/kg/day for 3 days prior to single lung transplantation. In group 3 only recipients were treated with CsA orally at a single dose of 20 mg/kg/day for a short period of 9 days after single-lung transplantation. Marked elevation was found of TNF, IFN-gamma, IL-2, and IL-2R in BALF obtained from the grafted lungs in group 1 and group 2 dogs. The levels of these markers were significantly higher than those obtained from the normal, native lungs (P less than 0.05). Two of three recipients in group 2 had pneumonia in the native lungs on day 10 after single-lung transplantation. All markers except IFN-gamma in BALF obtained from the infected native lungs were also increased, but the titers were less than those obtained from the grafted lungs at the same time. There were significantly higher levels of TNF, IL-2, and IL-2R present in the BALF of grafted lungs of dogs in group 1 than group 2 (P less than 0.05). In group 3, BALF levels of these markers from the grafted lungs were not significantly different from those of the normal and native lungs during the period of CsA treatment after single-lung transplantation. On various days after discontinuation of CsA treatment, BALF levels of all markers began to rise. Abnormal levels of BALF markers obtained from the grafted lungs heralded the appearance of abnormalities detected by chest x-ray films. Our study suggests that serially measuring BALF levels of TNF, IFN-gamma, IL-2, and IL-2R may serve as a useful means in monitoring the immunologic status of canine lung allografts and in the early detection of lung allograft rejection. The role of BALF IFN-gamma in distinguishing lung allograft rejection from pulmonary infection needs further studies.

Animals↗
PubMed1991

Factors affecting the production of eremofortin C and PR toxin in Penicillium roqueforti.

Eremofortin C (EC) and PR toxin are secondary metabolites of Penicillium roqueforti. Of 17 strains from the American Type Culture Collection that were studied for their ability to produce EC and PR toxin, 13 produced these metabolites. Toxin production by strains grown in solid media (10 cereals and 8 other agricultural products) was also investigated. Production of EC and PR toxin by fungi grown on cereals was greater than production of EC and PR toxin by fungi grown on legumes; fungi grown on corn produced the greatest amount of PR toxin. Addition of corn extracts to the culture medium greatly increased the production of EC and PR toxin in a coordinated manner, with no significant change in mycelial dry weight. The fungi produced the highest levels of EC and PR toxin at 20 to 24 degrees C depending on the strain. Toxin production was higher in stationary cultures than in cultures that were gently shaken at 120 rpm. The optimum pH for production of both EC and PR toxin was around pH 4.0. With regard to spore age, toxin levels did not change significantly when we used spores obtained from fungi that were grown at 24 degrees C for 3 up to 48 days.

Culture Media↗
PubMed1991

[Age and pulmonary function testing in predicting postoperative morbidity after thoracic surgery].

In order to evaluate whether age and pulmonary function testing may predict postoperative morbidity and mortality in the patients having received thoracic surgery, 203 patients were included in this study. Spirometry, flow volume curve, lung volume determination and arterial blood gas analysis were performed in all of them. Postoperative complications were classified into respiratory complications including pneumonia, purulent bronchitis, atelectasis, respiratory failure and so on; and non-respiratory complications including subcutaneous emphysema, internal bleeding, stump leakage, dysarrythmia and so on. Of the 117 patients over 65 years of age, 27 (23.1%) had postoperative respiratory complications, 27 (23.1%) had non-respiratory complications, and 7 (5.93%) expired postoperatively. Of the 86 patients under 65 years of age, 21 (24.4%) had postoperative respiratory complications and 9 (7.6%) had postoperative non-respiratory complications, but one expired. The incidences of postoperative mortality and non-respiratory complications were both higher in the patients over 65 years of age (p less than 0.05). Our results indicated that age is a risk factor of thoracic surgery, even if the pulmonary function testing meet the surgical criteria.

Age Factors↗
PubMed1991

[The tracing of brain tissue and 3-D imaging display CT image application: 3-D recursive tracing].

The size and the shape of brain tissue offer lots of information for clinical diagnosis and treatment. The commercial imaging systems, such as x-ray computer tomography (CT) and magnetic resonant image (MRI), always display only two dimensional (2-D) image, which makes quantitative diagnosis of the variation of brain tissue very difficult. Furthermore, some tissue may be connected through little vessels, which is also difficult to identify using discrete 2-D image. In this study, we processed CT image data using an general purpose IBM personal computer. A new three dimensional (3-D) recursive tracing algorithm was proposed. This new algorithm can automatically extract the image of brain tissue in each 2-D image. The information obtained was therefore used to reconstruct 3-D image. This system allows user to observe 3-D size and shape of brain tissue from arbitrary view. Such 3-D image can also be used to calculate the volume of tissue. Using overlay projecting method, it can display skin, bone, brain tissue and gray material at the same time. Such display method accurately shows the relative position of each tissue and offer physicians important information for diagnosis and treatment.

Algorithms↗
PubMed1991

A new classification of female stress urinary incontinence--based on transrectal sonographic cystourethrography.

A new classification of female stress urinary incontinence was made according to the results of transrectal ultrasonography of the urinary bladder and urethra (cystourethrography) studied in 67 women with genuine stress urinary incontinence (SUI). This classification is based on the following changes of the bladder and urethra on abdominal straining: hypermobility of the urethra, bladder neck incompetence, urethral sphincter incompetence and presence of a cystocele. Five types of SUI has been classified. We believe that this new classification can provide a better understanding of the anatomical changes as well as the pathophysiology of SUI. In addition, it can serve as a guideline of proper surgical management for SUI.

Adult↗