[An electron microscopic histochemical study on proteoglycans in salivary gland myoepithelioma]

Four myoepitheliomas and four parotid gland were studied histochemically be electron microscopy after stain with ruthenium red. It was found that the normal myoepithelial cells of parotid gland had no secretion function, whereas the myoepithelioma cells were capable of secreting proteoglycans and might form the myxoid region in this tumor. The authors propose that in the pathological diagnosis and differentiat diagnosis of salivary gland epithelial tumors, the appearance of the myxoid region is not only the pathological feature of pleomorphic adenoma, but also the pathological change of myoepithelioma.

CEDIA for screening drugs of abuse in urine and the effect of adulterants

The performance of the Microgenics CEDIA DAU assays for screening amphetamines, barbiturates, benzodiazepines, cocaine, opiates, phencylidine (PCP), and tetrahydrocannabinol (THC) was evaluated on the Boehringer Mannheim/Hitachi 717 in urine. Limits of detection ranged from 0.6 ng/mL for PCP, to 34.1 ng/mL for benzodiazepines. The average within run and total precision for these assays ranged from 1.3 to 7.3% for controls at cutoff concentrations, and control values at -25% and +25% of cutoffs. The rate separations by CEDIA between the negative and cutoff calibrators for all drugs were greater than corresponding EMIT II (Syva Co.) assays. The relative sensitivity and specificity of CEDIA as compared to EMIT II were 95.6 and 98.8%, respectively, on 13,535 urine samples. All positive samples, and those samples producing discordant results between the assays were confirmed by quantitative gas chromatography/mass spectrometry (GC/MS). Using SAMHSA cutoff limits (and including barbiturates and benzodiazepines at 300 ng/mL), the relative sensitivity and specificity of CEDIA vs. EMIT II were 96.7 and 98.8%, respectively. The overall sensitivity of CEDIA vs. GC/MS was 98.9% with 179 false positives, as compared to 96.2% with 189 false positives for EMIT II vs. GC/MS. The effect of adulterants added to urine to potentially invalidate screening results was also tested. CEDIA produced strong interferences for most drug assays in the presence of glutaraldehyde, detergent, and high concentrations of bleach and Drano. Minimal or selective interferences were seen with golden seal tea lemon juice, Visine, and low concentrations of bleach and Drano. Essentially no interference was observed with bicarbonate, sodium chloride, and vinegar.

[Clinical study on the feasibility of preserving vagal trunks in the surgical treatment of carcinoma of the thoracic esophagus]

The results of preserving vagal trunks in the surgical treatment of 47 patients with the carcinoma of the thoracic esophagus were discussed through a controlled study. There were 20 patients in the test group with vagus nerve being preserved (PG) and 27 in the control group (CG) with vagus nerve being routinely severed. Eighteen patients in PG and 26 in CG underwent radical resections, the remaining patients received palliative surgery. Pathological findings showed that 3 cases (15.0%) in PG and 3 cases (11.1%) in CG had cancerous invasion near the vagal trunks and/or their main branchs close to the primary cancer; and 1 case (5.0%) in PG and 3 (11.1%) in CG the vagal nerves were actually invaded by cancer cells. Determinations of basal gastric acid output (BAO) and half gastric emptying time (T 1/2) revealed that the mean value of BAO (1.93mmol/h) and T 1/2(63.51min.) of the PG were statistically different from those of 0.75mmol/h and > 105min. in CG, but similar to those of the healthy group and the preoperative control values. We consider that it is feasible to preserve vagal trunks in the operation and is beneficial in minimizing of postoperative disturbances of gastric acid output and gastric motility; but the indications of this procedure should only be limited to T1-T2 lesions in order not to jeopardize the radicality of tumor resection.

Effect of acute and long-term smoking on myocardial blood flow and flow reserve

BACKGROUND

Cigarette smoking is a major preventable risk factor for coronary artery disease and sudden cardiac death. However, the effect of acute and long-term cigarette smoking on coronary vasodilatory capacity and myocardial flow reserve has not been quantified in humans.

METHODS AND RESULTS

To examine the effect of short-term and long-term smoking, myocardial blood flow was quantified at rest and during dipyridamole-induced hyperemia (0.56 mg/kg) in 12 smokers (10 males and 2 females; mean age, 27 +/- 4 years) under baseline conditions (reflecting the effect of long-term smoking) and during short-term cigarette smoking with 13N ammonia, positron emission tomography, and a two-compartment model. Twelve sex- and age-matched nonsmokers served as control subjects. Smoking significantly increased the rate-pressure product at rest from 7525 +/- 1290 to 9160 +/- 1125 (P < .001 versus baseline), which was paralleled by a proportional increase in myocardial blood flow at rest (0.70 +/- 0.17 versus 0.88 +/- 0.17 mL.g-1.min-1; P < .05 versus baseline). In contrast, hyperemic blood flow declined from 2.23 +/- 0.35 at baseline (P = NS versus control) to 1.98 +/- 0.32 mL.g-1.min-1 during smoking (P < .01 versus baseline). Accordingly, the myocardial flow reserve declined from 3.36 +/- 0.83 in smokers at baseline to only 2.28 +/- 0.28 during smoking (P < .0001 versus baseline). Thus, myocardial blood flow and flow reserve were similar in young, long-term smokers and young, healthy nonsmokers.

CONCLUSIONS

Short-term smoking increases the coronary vasomotor tone during dipyridamole-induced hyperemia and markedly reduces the myocardial flow reserve. In contrast, long-term smoking does not attenuate the coronary vasodilatory capacity in young individuals with a relatively short smoking history. It might be speculated that the short-term reduction in the coronary vasodilatory capacity during smoking could lower the ischemic threshold in smokers with coronary artery disease and contribute to the increased risk for sudden cardiac death.

Structural and ultrastructural studies of the synovial membrane in temporomandibular joint disturbance syndrome

To gain further knowledge on temporomandibular joint disturbance syndrome (TMJDS), the synovial membranes of 7 patients and 3 cadavers were examined with light microscope and transmission electron microscope. The results showed that the synoviocytes degenerated or disappeared in TMJDS. The cytoplasm contained numerous fibrils, while the organelles diminished in number. The surface of the synovial membrane was covered with a fibrinoid material. The surface of the synovial membrane was covered with a fibrinoid material. The authors consider that these pathological changes reduce or eliminate the normal functions of the synovial membrane, which may lead to damage to the articular cartilage. The articular adhesion found sometimes in TMJDS may be related to the changes in the synovial membrane.

[The ultrastructure study of white sponge nevus in oral mucosa]

Biopsies from 7 patients with white sponge nevus were examined histologically. Two of them had family history. Light microscopic observation reveals that the epithelium was thickened; the spinous cell layers had enlarged and oedematous cells and ballon-like degeneration; the keratohyalin granules were increased in upper spinous cells; the superficial layers of epithelium exhibited parakeratosis and thickening. 3 specimens were examined by electron microscopy. The basal and parabasal cells were cylindrical. The cytoplasmic tonofilaments were aggregated into boundles. It was characteristics of keratinized epithelium. In middle and superficial stratum spinosum the tonofilaments were homogeneously distributed in the cell plasma and the electron-dense granulars were located near the cell boundary and attached to desmosomes by tonofilaments, unlike normal non-keratinized oral mucosa. Many Odland bodies with a lamellar structure and irregular in both size and shape were seen. It is concluded that this leasion have a dyskeratinized process. The characteristic features of keratinized oral mucosa in non-keratinized mucosa is appeared. The thickening of superficial layer is due to shedding disturbance relating to dysfunction of Odland bodies.

[The prognostic significance of lymph node metastasis in surgical resection of esophageal cancer]

The metastatic rate and degree of lymph node (LN) were evaluated and the relation between prognostic significance and LN metastasis (M) was analysed through a retrospective study of 474 patients undergoing resections of non-irradiated esophageal carcinoma. In patients with LNM, the LNM rate was 44.5%. A total of 5382 LNs were resected and examined pathologically. 690 of them were metastatic ones with a LNM degree of 12.8%. The 5-year survival rate of this series was 30.6% (145/474), and was 12.8% (27/211) in patients with LNM and 44.9% (118/263) in those without LNM. We concluded that surgery remains the first choice of treatment for carcinoma of esophagus, and that meticulous LN dissection is an important part of surgical oncology. This is especially true when the cancer process is reasonably localized. However, in more advanced cases of this disease, surgery alone is of limited value in eradicating all cancer compromized tissue, and therefore the routine practice of extensive LN dissection in such cases may not be rewarding.

Estimation of acute toxicity by fitting a dose-time-response surface

In acute toxicity testing, organisms are continuously exposed to progressively increasing concentrations of a chemical and deaths of test organisms are recorded at several selected times. The results of the test are traditionally summarized by a dose-response curve, and the time course of effect is usually ignored for lack of a suitable model. A model which integrates the combined effects of dose and exposure duration on response is derived from the biological mechanisms of aquatic toxicity, and a statistically efficient approach for estimating acute toxicity by fitting the proposed model is developed in this paper. The proposed procedure has been computerized as software and a typical data set is used to illustrate the theory and procedure. The new statistical technique is also tested by a data base of a variety of chemical and fish species.

Quantitative multivariate analysis of myoepithelioma and myoepithelial carcinoma

The nuclear DNA content and morphologic data of 30 surgical samples (eight normal parotid gland, 12 myoepithelioma, and 10 myoepithelial carcinoma) were analyzed by the IBAS II analysis system. The results suggest that there are relationships between tumor ploidy distribution and prognosis, and that correct pathologic diagnosis can be obtained by the IBAS image system.

[Histogenesis of pleomorphic adenoma of the salivary gland]

Six parotid pleomorphic adenomas were studied histochemically by electron microscopy after staining with ruthenium red. It was found that the myxoid region was filled with ruthenium red granules. Similar positive ruthenium red-stained intracellular granules were observed within the Golgi-derived vacuoles of the neoplastic myoepithelial cells in the myxoid region. Some cells located at the periphery of the double-layer ductal structure had the features of myoepithelial cell, they also showed similar positive ruthenium red-stained granules in the intracellular vacuoles and intercellular space. No ruthenium red-stained granules was obtained in neoplastic ductal epithelium and the mucus in ductal cavities were negative for ruthenium red stain. The observations indicate that the neoplastic myoepithelial cells in the myxoid region probably derive from the periphery of the double-layer ductal structure, they secrete the proteoglycans forming the myxoid region and play an important role in the histogenesis of pleomorphic adenoma.

Genomic structure and chromosomal localization of processed pseudogenes for human RBP-Jk

The functional gene for human recombination signal sequence-binding protein (RBP-Jk) and corresponding processed psudogenes have been isolated from various species, such as Drosophila, Xenopus, mouse, and human. Here we report the isolation of another two genomic pseudogenes of human RBP-Jk, named K2 and K7, from a cosmid library of Hela cells. The nucleotide sequences of both genes exhibited more than 95% homology to the functional human gene for RBP-Jk. Moreover, they did not contain any intron sequences and were interrupted by several stop codons in all frames. In situ hybridization demonstrated that the pseudogenes, K2 and K7, were localized at chromosomes 9p13 and 9q13, respectively. Their physical maps differed from those of the true functional gene and of the pseudogenes reported previously by Amakawa et al. (1993).

Omega-3 and omega-6 fatty acids and PGE2 stimulate the growth of normal but not tumor mouse mammary epithelial cells: evidence for alterations in the signaling pathways in tumor cells

The direct effect of omega-3 and omega-6 fatty acids on the proliferation of mouse mammary tumor cells (MTC) was examined in a serum-free cell culture system. While the EGF-induced proliferation of normal mammary epithelial cells was shown to be enhanced by omega-3 and omega-6 fatty acids and prostaglandins (PGs), a majority (75-80%) of primary mammary tumors were not stimulated by these agents. Compared to normal cells, some MTC cultures showed a higher susceptibility to inhibition by omega-3 fatty acids. The general lack of response of MTC cultures to PGE2 and cyclic adenosine monophosphate (cAMP) suggests some alterations in the cAMP-mediated pathway. However, the PGE2-induced cAMP levels and cAMP-dependent protein kinase (PKA) activities in the tumor cells were comparable to normal cells. We conclude that the proliferation of mammary tumor cells either follow a cAMP-PKA-independent pathway or have some alterations in the serine/threonine kinase mediated signaling pathway.

Basal and KCl-stimulated corticotropin-releasing hormone release from human placental syncytiotrophoblasts is inhibited by sodium nitroprusside

Human placenta synthesizes and secretes large amounts of CRH during the second and third trimesters. In the hypothalamus, nitric oxide (NO) has been reported to affect CRH release. We studied the effect of NO on the regulation of placental CRH secretion. The effect of the NO donor sodium nitroprusside (SNP) on basal and KCl-stimulated CRH release was examined in cultured human syncytiotrophoblasts. CRH secretion and intracellular concentrations of cGMP, calmodulin-dependent protein kinase (CaM-PK), protein kinase-G (PKG), protein kinase-C, and cAMP-dependent protein kinase holoenzyme were measured under basal conditions and after treatment with a depolarizing concentration of KCl and with SNP. The results showed that depolarization (3 h) increased CRH release 4-fold (from basal value of 5.16 +/- 0.65 to 19.31 +/- 4.46 fmol/10(6) cells); SNP (100 mumol/L) decreased both basal (0.42 +/- 0.21 fmol/10(6) cells) and KCl-stimulated CRH release (0.94 +/- 0.32 fmol/10(6) cells). KCl also increased the activity of CaM-PK in the cell membrane and both cytosolic and membrane PKG activity, whereas the activities of protein kinase-C and cAMP-dependent protein kinase holoenzyme were unchanged. SNP increased intracellular cGMP concentrations after 10, 60, and 180 min. Methylene blue (100 mumol/L), a guanylate cyclase inhibitor, blocked the inhibitory effects of SNP on CRH release. These results suggest that NO exerts inhibitory effects on both basal and KCl-stimulated CRH release from placental syncytiotrophoblasts through a cGMP-mediated pathway. In addition, as KCl-induced changes in the cell membrane were blocked by SNP, CaM-PK may be involved in KCl-stimulated CRH release. KCl may also sensitize the inhibitory pathway involved in the regulation of CRH release by increasing cellular PKG levels. The effects of KCl and SNP on CRH release are more complex than simple activation of CaM-PK and PKG activity, as other cellular signal transduction pathways are also modulated.

Effect of exercise supplementation during adenosine infusion on hyperemic blood flow and flow reserve

Physical stress might modulate myocardial blood flow in near-maximally dilated coronary arteries by increasing coronary perfusion pressure, myocardial contractility, and heart rate. The net effect of these changes on hyperemic blood flows has not yet been defined in humans. To quantify the effect of physical exercise on pharmacologically induced hyperemia, myocardial blood flow was measured in 11 healthy volunteers. Measurements were performed with positron emission tomographic imaging with nitrogen-13 ammonia at rest, during intravenous (i.v.) adenosine administration (140 micrograms.kg-1.min-1 over 6 minutes), and during i.v. adenosine administration plus supine bicycle exercise with a maximal workload of 125 W. Myocardial blood flow was quantified by using a previously validated graphic analysis. Heart rate, systolic blood pressure, rate-pressure product, and mean aortic blood pressures were significantly higher during combined physical and pharmacologic stress than during pharmacologic stress alone. However, myocardial blood flow decreased from 2.6 +/- 0.4 to 2.2 +/- 0.4 ml.min-1.gm-1 with the addition of physical stress (p < 0.05). This decline was associated with a significant increase in coronary vascular resistance (35 +/- 6 vs 52 +/- 13 mm Hg.ml-1.gm.min; p < 0.05). Accordingly, myocardial flow reserve declined, from 5.0 +/- 0.9 to 4.3 +/- 1.0, with exercise supplementation (p < 0.05). Exercise in addition to pharmacologic stress increases coronary vascular resistance and thus significantly decreases hyperemic myocardial blood flow and flow reserve. This decrease results most likely from an increase in extravascular restrictive forces caused by higher ventricular pressures and contractility during physical stress.

[Length method in evaluating right ventricular volume in children with congenital heart disease: a comparison with two dimensional echocardiographic method]

The accuracy and reliability of two-dimensional echocardiographic length method in right ventricular volume measurement were assessed by three-dimensional echocardiographic method in 10 normal children, 10 patients with atrial septal defect, and 10 patients with pulmonary stenosis. Their age and sex were matched. Right ventricular end diastolic, end systolic, mid-systolic volume, and ejection fraction evaluated by length method were correlated very well with the values obtained by three-dimensional echocardiographic method in normal and pulmonary stenosis group (r = 0.71-0.95, P < 0.01). In atrial septal defect group, right ventricular volume obtained by the two methods was correlated well (r = 0.86-0.95, P < 0.01). Although the correlation in right ventricular ejection fraction was lower, it was still significant. The shortening rate of X, Y, Z parameters required by length method were similar in each group: delta Z % > delta X % > delta Y %. We conclude that right ventricular volume and function could be assessed accurately by two-dimensional echocardiographic length method in children with right ventricular volume or pressor overloaded, and that right ventricular systolic pattern is similar in those situations.

Cognitive performance in a high-functioning community-dwelling elderly population

BACKGROUND

The purpose of this study was to examine the role of demographic factors as predictors of cognitive performance in a high-functioning, community-dwelling elderly population.

METHODS

The study cohort consisted of 1,192 community-dwelling subjects, who were selected to represent the highest third of an elderly population with respect to physical and cognitive functioning. A neuropsychological battery, including 5 cognitive performance subtests (confrontation naming, delayed recognition span, similarities, figure-copying, and incidental delayed recall) was administered to the subjects in their homes.

RESULTS

A summary measure of the 5 neuropsychological subtest scores, the total cognitive score, arrayed the study group across a broad range of difficulty, creating a near-normal distribution. Education, income, and race had statistically significant associations with the total score and the individual subtests. The effect of education was the most striking finding, explaining 30% of the variance in the total score. Education was most strongly related to the abstraction (partial R2 = .11) subtest, and least related to the memory subtests, delayed recognition (R2 = .02) and delayed recall (R2 = .01).

CONCLUSIONS

Demographic factors are important predictors of cognitive performance in this high-functioning cohort. Education had the strongest influence on overall cognitive performance, and particularly notable associations with subtests that depended upon the use of previously learned materials. Longitudinal follow-up, now underway, will help to determine whether high levels of education help to maintain cognitive performance with age.

Technology assessment in diagnostic imaging. A proposal for a phased approach to evaluating radiology research

RATIONALE AND OBJECTIVES

The authors propose an objective basis for critical evaluation of research trends and define and analyze a sample of radiology studies according to research phase.

METHODS

A random sample of 146 original diagnostic studies from two radiology journals was categorized according to phase, modality, and design by three physician reviewers, collated with a microcomputer database, and analyzed using an SAS program.

RESULTS

Phase 1 studies (technical evaluation) constituted 18.5% of publications: phase 2 (standardization and tissue characterization), 10.3%; phase 3 (spectrum of appearances), 40.4%; phase 4 (diagnostic efficacy), 21.2%; and phase 5 (clinical evaluation), 9.6%. Of 48 diagnostic efficacy studies, 42% were prospective (versus 35% for the total sample), 38% were controlled (median sample size, 53 [versus 30 for the total sample]). Only 27% of the 48 diagnostic efficacy studies were externally funded. Research in magnetic resonance imaging (MRI), which comprised 45% of all publications, was oriented toward phase 1 (32%) rather than phase 5 studies (0%). Phase 5 studies were the focus of 18% and 8% of ultrasound (US) and computed tomography (CT) studies, respectively. There were more prospective, controlled efficacy studies in US than in MRI or CT.

CONCLUSIONS

Analyses of research trends will be facilitated by use of a standard taxonomy which adopts a modality-based, phased approach.

[Stability of shuang huanglian aerosol]

The contents of chlorogenic acid and baicalin in shuang huanglian aerosol were determined by HPLC. The process of chemical kinetics of the aerosol was studied by constant temperature acceleration tests, and the stability of the drug predicted. The results appeared close to those from the stored sample method. pH changes during degradation of the drug were also observed.