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Biomedical subjects

C Park

Publications and source records attributed to C Park.

302 records · Page 17Linked to original sources
PubMedDate not supplied

Experience with the microbiologic diagnosis of Campylobacter enteritis in an office laboratory.

Campylobacter jejuni has been recognized as a frequent cause of bacterial diarrhea in infants and children. C. jejuni is a fastidious, Gram-negative, comma-shaped or sea gull-shaped, curved rod which is capable, particularly during the summer months, of causing slimy mucoid, blood diarrhea, abdominal pain and fever. In our pediatric office laboratory we found over a 12-month period that 14 (10%) of 126 stool specimens contained this pathogen. All but two children were diagnosed during the late spring and summer. There was no common source for Campylobacter infections in the patients. In 8 (66%) of 12 patients, C. jejuni infection was immediately detected by examining a 1% aqueous basic fuchsin-stained stool smear. Uncontrolled observations from this study suggest that erythromycin therapy, if started within 2 to 3 days of the onset of illness, is clinically effective.

Adolescent↗
PubMedDate not supplied

Comparison of sequence differences in a variable 23S rRNA domain among sets of cryptic species of ciliated protozoa.

Studies were undertaken to discover the relative molecular distances separating some familiar forms of ciliated protozoa, and the genetic species they include. Sequences of 190 bases of the D2 domain of the large ribosomal nucleic acid molecule were obtained by polymerase chain reaction from protists of three distinctive groups of ciliated protozoa-Colpoda, Paramecium and Tetrahymena. Evolutionary trees were constructed for each set of sequences using the PHYLOGEN 1.0 string programs. All three groups of ciliates manifested large molecular diversity among strains difficult or impossible to distinguish morphologically. The largest single evolutionary distance within a group was the 75 differences separating Tetrahymena paravorax from the other tetrahymenids. The largest mean distance for a group was the 21.2 for the colpodids. In all the protist groups the large molecular diversity is obscured by morphological conservatism associated with constraints of ancient designs. The molecular diversity within morphotypes argues for long evolutionary coexistence of species differentiated from each other in significant physiological, ecological, or nutritional ways.

Animals↗
PubMedDate not supplied

Comparison of superior oblique tendon expander to superior oblique tenotomy for the management of superior oblique overaction and Brown syndrome.

We compared surgical results of superior oblique tenotomy to the superior oblique silicone expander for the treatment of superior oblique overaction and Brown syndrome. Of 24 patients with bilateral superior oblique overaction, 13 underwent tenotomy and 11 had the silicone expander procedure. Reduction of A-pattern to within 10 prism diopters was achieved in 12/13 (92.3%) tenotomy patients and in 10/11 (90.9%) patients undergoing silicone expander (P greater than .05). Correction of superior oblique overaction on versions to within +/- 1 dysfunction was achieved in 22/26 (84.6%) of the tenotomies, and 21/22 (95.5%) silicone expander procedures (P greater than .05). Zero superior oblique dysfunction was found after 14/26 (53.8%) tenotomy procedures versus 18/22 (81.8%) silicone expander operations (P = .041). Superior oblique paresis occurred postoperatively in 4/13 (30.8%) tenotomy patients, whereas none of the 11 patients in the silicone expander group had superior oblique paresis (P = .044). Six patients who underwent superior oblique tenotomy for superior oblique overaction had preoperative stereopsis; following surgery, only two maintained the same level of stereopsis, and three patients totally lost all stereo acuity. All patients in the silicone expander group either maintained or had improved stereo acuity postoperatively. Seven patients with true Brown syndrome were operated on: three underwent the silicone expander procedure and four had a superior oblique tenotomy with an ipsilateral inferior oblique recession. The combination of superior oblique tenotomy with simultaneous ipsilateral inferior oblique recession resulted in an undercorrection in two of the four patients, whereas all three patients in the silicone expander group showed excellent ocular motility postoperatively, with two having normal versions and one a -1 residual limitation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMedDate not supplied

Reduced transforming growth factor-beta type II receptor (TGF-beta RII) expression in adenocarcinoma of the lung.

BACKGROUND: TGF-beta type II receptor is considered as one of the tumor suppressor genes, and altered expression of TGF-beta RII has been found in many kinds of cancers. MATERIALS AND METHODS: Seven NSCLC cell lines and 21 surgically resected NSCLC tissues were obtained. The growth inhibition by TGF-beta 1 was examined by MTT assay. Northern blot and Southern blot analysis were performed for TGF-beta 1 and TGF-beta RII in NSCLC cell lines. TGF-beta 1 and TGF-beta RII expression were analyzed by immunohistochemistry (IHC) in 21 surgically resected NSCLC tissues. RESULTS: Six of 7 NSCLC cell lines were resistant to TGF-beta 1. Southern blot analysis for TGF-beta 1 and TGF-beta RII showed no genetic changes. However, mRNAs of TGF-beta RII were barely detectable in 3 of 7 cell lines, and mRNAs of TGF-beta 1 were almost undetectable in 2 of 7. IHC revealed decreased TGF-beta RII expression in 6 of 21 surgically resected NSCLC tissues (5 adenocarcinomas, 1 sarcomatoid carcinoma). Being analyzed by the histologic subtypes, TGF-beta RII decreased in 5 of 8 adenocarcinomas but in only 1 of 13 non-adenocarcinomas (p = 0.0139). On the other hand, TGF-beta 1 was expressed at a higher level in 20 of 21 tumors. CONCLUSION: These results suggest that decreased TGF-beta RII expression may play a role in human lung carcinogenesis, especially in adenocarcinoma.

Adenocarcinoma↗
PubMedDate not supplied

Microsatellite instability(MSI) in non-small cell lung cancer(NSCLC) is highly associated with transforming growth factor-beta type II receptor(TGF-beta RII) frameshift mutation.

BACKGROUND: TGF-beta type II receptor (TGF-beta RII) mutations associated with microsatellite instability(MSI) are characteristically frameshift mutations within a 10 bp poly-A tract. These frameshift mutations have been reported to be common in colorectal and gastric cancers with MSI, though, rarely reported in non-small cell lung cancer (NSCLC). MATERIALS AND METHOD: In this study, we analysed MSI and TGF-beta RII frameshift mutations in 7 NSCLC cell lines and 21 surgically resected NSCLC tissues. Determination of MSI in NSCLC was performed using primer sets for BAT-25, BAT-26 and BAT-40. In order to examine the presence of the frameshift mutations of TGF-beta RII in samples with MSI, sequencing for TGF-beta RII poly-A tract was performed. RESULTS: MSI was observed in 5 out of 7 NSCLC cell lines and 3 out of 21 NSCLC tissues. Six out of 8 samples with MSI(75%) showed frameshift mutations in TGF-beta RII poly-A tract. CONCLUSION: These results suggest that MSI is highly associated with TGF-beta RII frameshift mutations in NSCLC and further support the hypothesis that TGF-beta RII plays an important role in NSCLC carcinogenesis.

Carcinoma, Non-Small-Cell Lung↗
PubMedDate not supplied

New nursing graduates: a key factor in nursing supply.

The Canadian nursing education system is the most significant contributor to the country's supply of registered nurses. This article provides current data on the numbers of nursing graduates produced in each province in 1994. The authors highlight some of the differences in the numbers produced and use the national average of new graduates as the percentage of the population of Canada as one method to arrive at the numbers of new graduates per year which each province could attempt to produce. This article provides a national perspective on current and future nursing human resources and will assist nursing administrators in their staffing plans related to registered nurses.

Canada↗
PubMedDate not supplied

Differential effects and transport kinetics of ascorbate derivatives in leukemic cell lines.

In order to investigate the differential effects of ascorbate derivatives on leukemic cell growth, we examined their stabilities and transmembrane transport efficiencies. The growth of HL-60 and U937 cells was dose-dependently inhibited by ascorbic acid and sodium ascorbate, but not by dehydroascorbic acid and magnesium ascorbyl 2-phosphate up to 200 microM. The growth-suppression by ascorbic acid was dependent on its redox state, showing a complete or partial reversion by ascorbate oxidase or FeCl3 addition, respectively. Three different patterns of intracellular ascorbic acid accumulation were observed by HPLC according to the species of ascorbate derivative applied for the incubation. Compared with the reduced form of ascorbic acid, the oxidized forms (dehydroascorbic acid, ascorbic acid plus ascorbate oxidase or FeCl3) were rapidly transported into cells and readily degraded, while magnesium ascorbyl 2-phosphate, a stable derivative of ascorbic acid, slowly elevated the intracellular level of ascorbic acid, reaching a plateau at 24 hours. We also measured the differential kinetics of ascorbic acid levels In culture supernatants following the addition of ascorbate derivatives. Ascorbic acid at 40, 10, or 1 microM was observed 3 hours following treatment with 100 microM of ascorbic acid, ascorbic acid plus FeCl3, or magnesium ascorbyl 2-phosphate, respectively. No ascorbic acid was found in the culture supernatant treated with dehydroascorbic acid. This order of ascorbic acid concentrations in culture supernatant reflects their growth-inhibitory effects. Thus the growth inhibitory effect of ascorbic acid appears to be dependent on its concentration in culture medium rather than its intracellular concentration. In conclusion, the results in this study indicate that the differential effects of ascorbate derivatives appear to be due to the actual concentration differences of the reduced form of ascorbic acid in culture medium following their addition, which is determined by their stability and efficiency of cellular uptake.

Ascorbate Oxidase↗