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Biomedical subjects

S H Li

Publications and source records attributed to S H Li.

At least 145 records · Page 8Linked to original sources
PubMed1990

Consumer product-related tooth injuries treated in hospital emergency rooms: United States, 1979-87.

The database of the National Electronic Injury Surveillance System was used to analyze episodes of consumer product-related traumatic injuries to teeth treated in hospital emergency room in the United States from 1979 through 1987. Results showed a slight but consistent increase in episodes of such injuries during this 9-yr period. Over 75% of such episodes occurred in persons under 15 yr of age. Over 60% of the tooth injuries in such episodes could be crudely classified into the following types by descending rank order: avulsed-, broken-, loosened-, chipped-, intruded-teeth and soft tissue injuries. The most common categories of consumer products and activities associated with such episodes were sports and play, followed by falls on floors, stairs or showers, and bicycles and other wheeled vehicles. The age composition of specific episodes of dental injuries varied considerably for different products and activities, suggesting a need for specific strategies for prevention of episodes of consumer product-related injuries to teeth for different age categories of the population.

Adolescent↗
PubMed1990

Evaluation of the comparative effectiveness of fluoride mouthrinsing, fluoride tablets, and both procedures in combination: interim findings after five years.

This article presents five-year interim findings of an eight-year clinical trial designed to compare the relative caries-preventive benefits of weekly fluoride mouthrinsing, daily fluoride tablet administration, and both procedures combined. Children in kindergarten and first grade residing in Springfield, Ohio, a nonfluoridated community, were assigned randomly in school to one of three groups that (1) rinses once a week in school with a 0.2 percent neutral NaF solution; (2) chews, rinses with, and then swallows daily in school a neutral 2.2 mg NaF tablet; or (3) carries out both procedures. At baseline (1981), 1,640 participants were examined clinically using the DMF surface index. After five years, 789 children were available for reexamination. Findings show that subjects in the combination group experienced a mean caries increment of 1.47 DMFS, 16.5 percent lower than the mean score of 1.76 DMFS for children in the tablet group and 31.3 percent lower than the 2.14 DMFS for those in the rinse group. Only the difference in incremental caries scores between the combined fluoride procedure and the fluoride rinse was statistically significant (P less than .05). Despite the finding of an additive caries-preventive benefit among children who followed the combined regimen, it would be premature to judge which procedure is best before results of the final examinations become known.

Child↗
PubMed1990

A method for measuring the flow of saliva from the minor salivary glands.

This investigation evaluated a procedure to measure the quantity of secretion by the minor salivary glands from various locations in the mouth before and after citric acid stimulation. Fourteen healthy non-medicated adults were assessed on each of two morning visits at the same specific areas of the mucosa (labial, buccal, and palatal). During each assessment, an absorbent paper strip was placed on each designated location for 30 s, removed, and its moisture content determined with a calibrated Periotron. Calibration procedures indicated that readings were linearly associated with known saliva volumes and were negligibly influenced by differences in salt concentration and viscosity. At each visit, the buccal flow was significantly greater than those from the lip and palate. The flow from glands in each area was unaffected by a single application of the gustatory stimulant. The mean flow rates at each specified site were similar during the two visits.

Adult↗
PubMed1990

Effects of platelet-activating factor on rat mesenteric microcirculation.

The actions of platelet-activating factor (PAF) on rat mesenteric microcirculation were studied by laser Doppler microscopy in vivo. PAF 0.2 -0.6 micrograms/kg iv produced a dose-related decrease in the blood flow velocity and an increase in the diameters of the mesenteric arterioles and venules. These responses were completely reversed by pretreatment with PAF receptor antagonist SRI 63441. The results suggest that PAF may be a mediator of microcirculatory disturbances in the disease conditions associated with excessive PAF release.

Animals↗
PubMed1990

[Clinicopathological and immunohistochemical study of 118 cases of rhabdomyosarcoma].

118 cases of rhabdomyosarcoma are reported. Specimens from 30 of these cases were stained with Masson Trichrome and phosphotunstic acid haemotoxylin. 36 cases were studied immunohistochemically by PAP, and ABC methods. Specific antibodies against myoglobin, desmin and vimentim were used. Positive immunostaining for myoglobin and desmin was found in 72.7% and 55.5% of the cases studied respectively. The positivity was dependent on the degree of cell differentiation. Results suggest that immunohistochemistry is a useful tool for the diagnosis of poorly differentiated rhabdomyosarcomas. Cross--striations were found in only 6 of the thirty cases (20%). It is now generally accepted that demonstration of cross--striations is not essential for the diagnosis; nevertheless, the characteristic features of fibrillary material arranged in whorls around the nucleus are of diagnostic significance. Histologically, it is also believed that searching for early differentiated rhabdomyoblasts combined with the histological pattern is of vital importance for an accurate diagnosis.

Adolescent↗
PubMed1990

[Morphological and histological studies of Chinese Ephedra, ma huang. II. Species produced in southwestern China and other species].

In this paper, the morphological and histological characters of crude drugs derived from Ephedra likiangensis Florin, E. likiangensis f. mairei (Florin) C. Y. Cheng, E. saxatilis Royle ex Florin, E. gerardiana Wall, E. gerardiana var. congesta C. Y. Cheng, E. minuta Florin, E. minuta var. dioeca C. Y. Cheng, E. lepidosperma C. Y. Cheng, E. lomatolepis Schrenk and E. intermedia var. tibetica Stapf are described, compared and illustrated with line drawings. It was found that all the Ephedra spp. growing in southwester nChina possess the following features in common, viz. (1) numerous distinct longitudinal ridges are present on the stem; (2) xylem fibres and tracheids possess steep, tertiary spiral thickenings; (3) stone cells (sclereids) are absent from the nodes. According to the above characters, the drugs produced in southwestern China can be differentiated from those produced in northern China. The results also show that the histological characters of E. intermedia var tibetica Stapf produced in southeast ern Xizang (Tibet) are different from those produced in north western Xizang. The former possesses the xylem fibres and tracheids with steep, tertiary spiral thickenings, while the latter possesses sclereids at stem-nodes. It may be related to their habitat factors and interspecies hybridization. A key for identification of all the crude drugs derived from Chinese Ephedra spp. studied in this series of paper, including thirteen species, three varieties and one form is presented.

China↗
PubMed1990

Developmental incompatibility between cell nucleus and cytoplasm as revealed by nuclear transplantation experiments in teleost of different families and orders.

Teleosts from different families and orders were used as materials for nuclear transplantation experiments. (1) The nuclei of goldfish (Carassius auratus, family Cyprinidae, order Cypriniformes) were transplanted into the enucleated egg cytoplasm of loach (Paramisgurnus dabryanus, family Cobitidae, order Cypriniformes) and vice-versa. (2) The nuclei of Tilapia (oreochromis nilotica, order Perciformes) were transplanted into the enucleated egg cytoplasm of goldfish (Carassius auratus, order Cypriniformes). The chromosome number of the nucleus donor fish is different from that of the cytoplasmic recipient fish in each of the two combinations. In the first case, only a few early nucleo-cytoplasmic hybrid (NCH) larval fish were obtained in each combination. In second case, even though a high percentage of NCH blastulas were also obtained, the majority of them died at the same developmental stage, except a few which survived until early gastrula stage. The examination of the metaphase chromosome figures of the NCH blastulas or embryos obtained in all three combinations indicated that they were of nucleus-donor type. The developmental rates of all the NCH eggs were similar to those of cytoplasmic-recipient type. Scanning electronmicroscopy examination showed that the morphology of NCH blastula cells, which were obtained from the combination of Tilapia nucleus and goldfish cytoplasm, manifested obviously abnormal features and the cells were arrested at different stages of cell disintegration. Two-dimension polyacrylamide gel electrophoretograms of the homogenates of Tilapia, goldfish and their NCH blastula cells showed that the protein synthetic pattern of NCH blastula was similar to that of Tilapia nucleus type. The results of experiments which failed to obtain NCH adult fish in all three combinations can be explained as a result of developmental incompatibility between the donor nucleus and the enucleated recipient egg cytoplasm, which were from distantly related fish species. And the chromosome numbers of all the component fish of the three combinations which were examined in the experiment and shown to be quite different from each other in the tested fish, should not be overlooked as one of the essential factors causing the developmental incompatibility in NCH fish in this experiment.

Animals↗
PubMed1989

[Clinico-pathologic comparison between early gastric cancer and early cancriform progressive cancer].

Clinico-pathologic comparison between 36 cases of early gastric cancer (EGC) and 34 cases of early cancriform progressive cancer (ECPC) were made. It was found that there was no difference in the average age and sex. Epigastric pain occurred in most of the cases. Weight loss, hematemesis and melena occurred more frequently in patients with ECPC than those with EGC. Pathologically, the cancers were located in gastric antrum in most of the cases in both groups. The lesions 1-2 cm across accounted for half in each. Lesions over 4 cm (19.4%) was obviously more common in EGC than in ECPC (2.9%). Macroscopic classification showed that though pouch-type predominated in both groups, it was more frequent in ECPC (88.2%) than in EGC (72.2%). Histologically, there were more highly differentiated types in EGC (52.7%) and more poorly differentiated types in ECPC (52.9%). The Pm depth of ECPC was high. The prognosis of ECPC was favorable, second only to EGC. ECPC belongs to Type 5.

Adenocarcinoma↗
PubMed1989

Analysis of 4628 cases in the genetic counselling clinic of PUMC Hospital.

An analysis of 4628 cases in the genetic counseling clinic of PUMC Hospital is reported. Althogether 966 cases (20.87%) were diagnosed as having genetic diseases, among whom were 436 cases (45.13%) with chromosome aberrations, 161 (16.67%) with inherited metabolic diseases, 111 (11.49%) with constitutional bone diseases, 103 (10.66%) with various kinds of genetic neuromuscular diseases, 109 (11.28%) with different dysmorphic syndromes, and 46 (4.76%) with different kinds of genetic dermatoses and oculopathies. 973 cases (21.02%) were suspected to suffer from some form of genetic disease, but this could not be proved due to a lack of specific diagnostic methods. 2689 cases (58.10%) were found to be unaffected by inherited diseases. Some of the experiences gained and the key role of genetic counselling in family planning are briefly discussed.

Adolescent↗
PubMed1989

[Morphological and histological studies of Chinese Ephedra mahuang. I. Seven species produced in north China].

The Chinese drug Ma Huang, Herba Ephedrae, is well known in the East and West. The botanical origin specified in the Chinese Pharmacopoeia (1985 edition) includes the dried herbaceous stems of Ephedra sinica Stapf, E. equisetina Bunge and E. intermedia Schrenk ex Mey. A survey of the botanical origin of this drug, however, revealed that other Eqhedra spp. are also used in certain districts in China. In order to find means for the identification of drugs derived from different plant origins, it is necessary to make a comparative study of the morphology and histology of all the Eqhedra spp. growing in China. In this paper, the morphological and histological characters of the crude drugs derived from the Eqhedra spp. chiefly growing in north China, viz. E. sinica Stapf, E. equisetina Bunge, E. intermedia Schrenk ex Mey., E. qrzewaskiistaqs E. monosperma Gmel. ex Mey., E. fedtschenkoae Pauls, and E. regeliana Florin are described, compared and illustrated with line drawings. It is discovered that the following characters are useful for their differentiation, viz. (1) the presence, shape and height of cuticular papillae of the stem; (2) the presence, amount and arrangement of sclereids at stem-nodes; (3) vessels and tracheids with bordered pits and spiral thickenings, tracheids with bordered pits and reticulate thickenings, and xylem parenchyma cells with reticulate thickenings, (4) the ratios of longitudinal and transverse diameters of stomata on the epidermis of stem and leaf. Observation with scanning electron microscope (SEM) revealed that the perforations of the end walls of vessel element in Eqherda spp. are bordered. It is also found that the degree of lignification of fibres and medullary cells of the herbaceous stems is related to the positions and diameters of the stems. It is therefore unsuitable as a diagnostic feature for the differentiation of Eqhedrra species.

Medicine, Chinese Traditional↗
PubMed1989

Immunogenicity of highly purified porcine and human insulins in diabetic patients with high titers of insulin antibody.

Twenty-nine non-insulin-dependent diabetic Chinese subjects previously treated with conventional porcine isophane insulin (NPH) for a period of time, whose titer of serum insulin antibody was greater than 40% were changed to either highly purified pork insulin (Nordisk, Denmark) or human insulin of recombinant DNA origin (Eli Lilly, USA) for 1 year in a double-blind and randomized trial. The human (n = 16) and pork insulin (n = 13) groups were carefully matched for age, sex and measures of metabolic control. In highly purified pork-insulin-treated patients, the glycated hemoglobin and fasting blood sugar values began to fall significantly from a mean of 13.2% to 12.3% (p less than 0.05) and 228 mg/dl to 183 mg/dl (p less than 0.005), respectively, 2 months after the commencement of this study, whereas insulin antibody levels began to fall significantly from a mean of 61.8% to 49.5% (p less than 0.01) 6 months after the start of the study. Also, daily insulin doses increased significantly from a mean of 58 units to 70 units (p less than 0.005) 6 months after the start of the study. In human-insulin-treated patients, there were no significant changes in the glycated hemoglobin values. The fasting blood sugar levels fell significantly (p = 0.0515) at the end of the study period but the insulin antibody levels did not show any significant change during the same study period. Daily insulin dose increased significantly from a mean of 51 units to 57 units (p less than 0.01) 4 months after beginning the study.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Measuring fracture toughness of high-impact poly(methyl methacrylate) with the short rod method.

A comparison between the plane strain fracture resistance (Klc) of high-impact PMMA and conventional resins was made. Because microcracks and surface irregularities can be introduced when PMMA is cut, a specially designed sample-forming device that processed specimens with a minimal amount of machining was used. Specimens were made in the final shape of short rods as proposed by Barker and Barker and Baratta. The results showed that the fracture resistance (Klc) values of processed short rod specimens of high-impact Lucitone 199 resin were more than twice those of the control.

Acrylic Resins↗