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Biomedical subjects

S Shi

Publications and source records attributed to S Shi.

At least 109 records · Page 6Linked to original sources
PubMed1995

[Surgical treatment of avascular necrosis of the femoral head].

71 patients (83 hips) with avascular necrosis of the femoral head were followed up. The patients had bilateral necrosis (12), and unilateral (59). Their ages ranged from 19 to 71 years. Ficat classification showed stage I for 1 hip, stage II 19 hips, stage III 35 hips, and stage IV hips. According to the severity, the range of motion, the age, and the X-ray appearances, 6 kinds of procedures were used including decompression with bone grafting (32 hips), surface arthroplasty with cartilage (4), surface arthroplasty with fascia (4), replacement of femoral head (7), THA (20), and obturator neuroetomy (16). The follow-up period ranged from 2 years and 3 months to 10 years and 5 months. Postoperative improvement included pain (39.7%), range of motion (21.7%), and walking (33.7%). Among the procedures, decompression with bone grafting showed best results. Treatment revealed better results in stage I, II than in stage III, IV. We emphysize the early diagnosis and management, and choice of procedure should base on the clinical classification.

Adult↗
PubMed1995

[Effects of lead on neurobehavior and neurochemistry in rats].

Effects of exposure to lead on neurobehavioral function, content of monoamine neurotransmitter in hippocampus, and brain level of lipid peroxide were studied in 45 SD rats. Results showed learning and memory abilities of the rats were affected in exposure to lead of 1333.3 mg/kg (with their blood lead level of 6.23 mumol/L), their motor activities changed and emotional status became unsteady with 266.7 mg/kg of lead (with blood lead of 4.20 mumol/L) and 1333.3 mg/kg of lead, respectively, and levels of dopamine neurotransmitter and its metabolites declined and those of lipid peroxide increased with increasing exposure to lead. It is postulated changes in levels of neurotransmitter, such as monoamine and lipid peroxide, could explain the mechanism for damage in neurobehavioral function caused by lead exposure.

Animals↗
PubMed1995

[Mammaplasty immediately after mastectomy for breast cancer].

From March 1990 to March 1994, 7 cases of one stage breast reconstruction with silicone prosthesis after mastectomy for breast cancer were performed in our hospital. All the operations were successful and no operative complication observed. They were followed up for three months to four years. The contour was good, symmetrical, soft to touch and the patients did not complain uncomfortable sensation. The authors propose that immediate reconstruction of the breast be recommended. In this paper, the indications, methods, selection of opportune time for operation and precautions are discussed.

Adenocarcinoma↗
PubMed1994

Abnormal expression of aldose reductase mRNA in fiber cells of cataractous rat lens. Analysis by in situ hybridization.

Aldose reductase (AR), an enzyme of the polyol pathway, has been implicated in the pathogenesis of diabetic and galactosemic cataracts. AR mRNA is a specific transcript of the lens epithelial cells. However, in addition to its presence at high levels in the epithelial cells at the equator, it is also found at significant concentrations in fiber cells at the lens bow. In this study we extended our previous work, and examined the distribution of AR mRNA by in situ hybridization in lens of rats maintained on a 50% galactose diet for up to 20 days, then reversed to a normal diet for an additional 20 days. It was found that within 8 days on galactose the posterior AR mRNA dissipated, with no clear increase in this transcript in the lens epithelial cells. By 16 to 17 days on galactose, the surviving fiber cells in the equatorial region appeared to express AR mRNA; these cells in the normal lens contain insignificant amounts of AR mRNA, as we have previously demonstrated. AR mRNA in the fiber cells of the cataractous lens appears to be of the same base length as that found in the control, indicating that the AR mRNA in these cells may not represent a degraded transcript. Upon reversal of the cataracts, the posterior AR mRNA re-accumulates, and the fiber cells at the equator appear to have lost the AR mRNA that accumulated during the period of exposure to galactose. The data demonstrate that during formation of galactose-cataract, surviving cortical fiber cells express significant levels of AR mRNA, while following withdrawal from galactose these fiber cells lose that activity.

Aldehyde Reductase↗
PubMed1994

Levels of expression of the genes for glutathione reductase, glutathione peroxidase, catalase and CuZn-superoxide dismutase in rat lens and liver.

Oxidative mechanisms are thought to play a major role in several biological phenomena, including cataract formation. In the following studies we determined the relative levels of expression of the genes for the mRNAs for glutathione peroxidase (GPx), glutathione reductase (GR), CuZn-superoxide dismutase (CuZn-SOD) and catalase, in both the rat lens and liver. Northern blot hybridization methods were used to determine the mRNA size. The RNase protection method was used to determine levels of expression for these mRNAs plus levels of expression for alpha A-crystallin and gamma-crystallin mRNAs in the lens, and gamma-actin mRNAs in both the lens and the liver; using [32P]-labeled specific cRNA probes transcribed from the various cDNA clones for the mRNAs being studied. The data was normalized relative to the level of expression of alpha A-crystallin and gamma-actin mRNAs in the lens, and to gamma-actin mRNA in the liver. We find the levels of the mRNAs in the lens fall in the following descending order: GPx > GR > CuZn-SOD > catalase, in the same order as has been reported for the activities of the enzymes in the lens. In the liver, levels of these mRNAs were as follows: GPx > CuZn-SOD > GR > catalase. In the liver, CuZn-SOD mRNA was expressed at about four times the level found in the lens, GPx at three times, catalase at three times and GR at about the same level.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

cDNA cloning, sequencing and in situ localization of a transcript specific to both sublingual demilune cells and parotid intercalated duct cells in mouse salivary glands.

A cDNA clone derived from mouse sublingual gland was isolated from lambda-phage cDNA library. Northern blot hybridization indicated that the transcript from which it was derived was approx. 700 nucleotides in length. This mRNA encoded a protein of about 20 kDa, as determined by hybrid selection and cell-free translation. Conceptual translation of the cDNA clones showed that p20 is 170 amino acids in length. The putative protein is hydrophobic in nature, is neither a mucin-like protein nor does its amino acid sequence or composition resemble the other known mouse proteins. However, the amino acid sequence of p20 suggests that it may be from a gene or gene family homologous to rat common salivary protein 1. The p20 mRNA also appears to share a non-random degree of sequence homology with the cysteine-rich domains of bovine and porcine submandibular mucins. The p20 mRNA is abundant in the mouse sublingual gland, and its expression is approx. nine times greater than in the parotid gland. In situ hybridizations localized the p20 mRNA exclusively in the demilune cells of the sublingual gland and in the intercalated duct cells of the parotid gland. It is detectable in the neonatal and adult submandibular gland at very low levels, but is absent from liver, heart, brain, thymus, spleen, lens and lacrimal glands.

Amino Acid Sequence↗
PubMed1994

[Correction of severe epicanthus using the square-flap method].

The square-flap method has been adopted gradually in plastic surgery because of lengthening effectively the distance between two points on the skin surface. Good results have been obtained in the treatment of severe epicanthus in 14 cases of 26 eyes by using modified square flap since 1990. This paper describes the operation design, advantages and key points of the surgery.

Adolescent↗
PubMed1994

[The trend of mortality of lung cancer and its association with air pollution].

A death retrospective survey of all causes from 1985 to 1989 was carried out in thirteen districts of Shandong Province in 1990. The total population investigated was 8.10 million that accounted for nearly ten percent of the whole population of Shandong. The death rate of lung cancer (adjusted by Chinese population in 1964) was 12.0 per 100,000 population. As compared with that in 1970-1974, it increased by 96.7%, of which 102.5% for male and 85.7% for female. In each district the mortality of lung cancer also went up. In Qingtao, Jinan, and Zibo with high-mortality in 1970-1974, the rates of lung cancer death increased by 213%, 291%, and 260%, respectively. At the same time, in Zhaozhuang, Jining, Hezie with low-mortality in 1970-1974, the mortality rates of lung cancer increased by 303%, 284% and 285%, respectively. The results of correlational analysis showed that the increasing rate of lung cancer was related to the air pollution.

Air Pollutants↗
PubMed1993

Water distributions of hydrated biological specimens by valence electron energy loss spectroscopy.

A technique has been developed for measuring the water distribution in thin frozen hydrated biological specimens by means of electron energy loss spectroscopy (EELS). The method depends on the quantification of subtle changes in the valence electron excitation spectrum as a function of composition. It involves determining the single-scattering intensities, calculating oscillator strengths and applying a multiple-least-squares fitting procedure to reference spectra for water and the organic constituents. The direct EELS approach has an important advantage over other indirect methods that are based on X-ray generation or elastic scattering measurements since these are applied to freeze-dried specimens where differential shrinkage between compartments may produce errors. Precision and accuracy of the EELS method have been tested on cryosectioned solution of bovine serum albumin; data have also been obtained from cryosections of rapidly frozen erythrocytes. Results suggest that a precision of better than +/- 5% (s.d.) is attainable from a single measurement and the accuracy may be as high as +/- 2% if repeated measurements are made. The lateral spatial resolution of the water determinations is limited by radiation damage to approximately 100 nm which is of the same order as the specimen thickness.

Body Water↗
PubMed1992

Transient elevation of aldose reductase mRNA in lens of rats developing galactose cataracts.

Aldose reductase (AR), a major enzyme in the polyol pathway, is thought to be responsible for accumulation of polyols in lenses exposed to high doses of galactose or glucose, and it may be linked to some of the complications found in diabetes. In this report we examined the level of expression of AR mRNA in lens epithelia undergoing development of galactose cataracts in vivo. The AR mRNA was quantitated by Northern blot hybridization with a [35S]-RNA transcript from a previously described AR cDNA clone. This was done on normal lens epithelia and on epithelia from lens of rats fed a diet of Purina Chow containing 50% galactose for periods of from 6 hr to 20 days. We found AR mRNA to elevate to about 5-fold the control levels by 12-24 hr on galactose, then decrease to the control levels by day 4. The increase in AR mRNA appears to be transitory. The high abundance in AR mRNA by 24 hr on galactose was confirmed by in situ hybridization. At later periods, from 8 to 20 days on galactose, a slow increase in AR mRNA took effect, as we have previously reported. Changes in the levels of galactose and dulcitol between 0 and 96 hr were also quantitated by gas chromatography, showing that there was a significant increase in both galactose and dulcitol occurring throughout the experimental period.(ABSTRACT TRUNCATED AT 250 WORDS)

Aldehyde Reductase↗
PubMed1992

Profile of messenger RNA decay in the Emory mouse lens in cataractogenesis and in aging.

The Emory mouse is presumed to be a model for studies on human senile cataracts. The cataract develops in 5-8 months after birth, and it does not appear to have an osmotic component. To date, no specific metabolic lesion has been uncovered as a probable cause to this cataract. Several studies have shown that the Emory mouse undergoes accelerated aging changes, possibly leading to development of senile-type cataracts. In this study we quantitated changes that might occur in the population of various mRNAs for proteins presumed to be essential for lens transparency, and for proteins that may contribute to development of cataracts. By Northern blot hybridization analysis we quantitated the mRNAs for: alpha A-crystallin, beta B1-crystallin, gamma-crystallin, the main lens intrinsic membrane protein, MP26, and aldose reductase; all in lenses of Emory mouse early cataract strain (EMEC), and of an age-matched cataract resistant strain (CR). These measurements were done in increments of 1 month over a 6-month period, then at both 9 and 12 months. The results show that all of these mRNAs decrease with age and with development of cataracts; although in some cases the initial concentrations at 1 month appear to be lower in the EMEC than in the CR strain. The most dramatic change occurred with the MP26 mRNA. In the CR strain, MP26 mRNA maintained its high concentration for a period of about 6 months before it began its decline to the 12 month level (about 25% of the 1 month level).(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗
PubMed1992

Inhibitory effects of diallyl sulfide on the metabolism and tumorigenicity of the tobacco-specific carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) in A/J mouse lung.

Diallyl sulfide (DAS), a component of garlic oil, has been shown to inhibit tumorigenesis by several chemical carcinogens. Our previous work demonstrated that DAS inhibited the metabolic activation of carcinogenic nitrosamines, including the tobacco-specific 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), in rat lung and nasal mucosa microsomes. In the present study, the effects of DAS on the tumorigenicity and the metabolism of NNK in A/J mouse lung were examined. Female A/J mice at 7 weeks of age were pretreated with DAS (200 mg/kg body wt in corn oil, p.o) daily for 3 days. Two hours after the final DAS treatment, the mice were either given a single dose of NNK (2 mg/mouse, i.p.) and kept for an additional 16 weeks for determining the production of pulmonary tumors, or were killed immediately so as to measure the microsomal activity in metabolizing NNK. In comparison to the vehicle control group, DAS pretreatment significantly decreased the incidence of NNK-induced lung tumors (37.9 versus 100%) and the tumor multiplicity (0.6 versus 7.2 tumors/mouse). In pulmonary metabolism of NNK, DAS pretreatment reduced the rates of formation of keto aldehyde, keto alcohol, NNAL-N-oxide, and NNK-N-oxide by 70-90%. In addition, the formation of NNK oxidative metabolites from NNK in the liver microsomes from DAS-pretreated mice was remarkably reduced. DAS also inhibited the metabolism of NNK in mouse lung microsomes in vitro. These results demonstrate that DAS is an effective chemopreventive agent against NNK-induced lung tumorigenesis, probably by inhibiting the metabolic activation of NNK.

Allyl Compounds↗
PubMed1992

Equivalent eighteen-hour lung preservation with low-potassium dextran or Euro-Collins solution after prostaglandin E1 infusion.

Improved techniques of pulmonary preservation would help alleviate the critical shortage of donor organs in lung transplantation and would improve early graft function. A previous study demonstrated that cold pulmonary artery flush with low-potassium dextran solution was superior to Euro-Collins solution in preservation of canine lung allografts stored for 12 hours when no pulmonary vasodilator was used before donor lung flush. The present study was designed to determine whether donor pretreatment with prostaglandin E1 would affect the superiority of low-potassium dextran as a preservation solution. Prostaglandin E1 was infused (50 micrograms/min) in 12 donor dogs until potent vasodilation was demonstrated. Low-pressure pulmonary artery flush (50 ml/kg) with either Euro-Collins or low-potassium dextran solution (n = 6 for each group) was performed at 4 degrees C in a randomized, blinded fashion. Heart-lung blocks were extracted and stored at 4 degrees C for 18 hours before left lung allografting. Inflatable cuffs were placed around each pulmonary artery, allowing independent study of the native and transplanted lungs. All 12 recipient dogs survived the 3-day assessment period. Lungs flushed and stored in Euro-Collins or low-potassium dextran solution provided equivalent gas exchange function on day 0 (arterial oxygen tension: Euro-Collins 289 +/- 105 mm Hg versus low-potassium dextran 265 +/- 111 mm Hg; mean +/- standard error of the mean) and on day 3 (Euro-Collins 516 +/- 45 mm Hg versus low-potassium dextran 354 +/- 77 mm Hg; p = 0.10). Mean pulmonary artery pressures in the transplanted lung were not significantly different in the Euro-Collins and low-potassium dextran groups on day 0 (21.4 +/- 2 mm Hg versus 33.7 +/- 5 mm Hg, respectively; p = 0.09) or on day 3 (20.2 +/- 2.7 mm Hg versus 24.2 +/- 5.1 mm Hg, respectively; p = 0.50). We conclude that there was no advantage of low-potassium dextran over Euro-Collins as a flush solution in this 18-hour canine single lung allograft model in which prostaglandin E1 was administered before pulmonary artery flush.

Alprostadil↗
PubMed1992

Reliable eighteen-hour lung preservation at 4 degrees and 10 degrees C by pulmonary artery flush after high-dose prostaglandin E1 administration.

Pulmonary preservation is improved by hypothermia, but the optimal preservation temperature is not known. The effects of two different preservation temperatures, 4 degrees and 10 degrees C, on lung function were studied in a canine left lung allograft survival model allowing selective perfusion of either lung. After donor treatment with high-dose prostaglandin E1, (25 micrograms/kg), lungs were flushed with modified Euro-Collins solution (50 ml/kg) and stored in Euro-Collins solution for 18 hours at 4 degrees C in group I (n = 8) and 10 degrees C in group II (n = 6). Pulmonary gas exchange and hemodynamics were compared on the day of transplantation (day 0) and 3 days later (day 3). Rapid, high-flow, low-pressure flush was achieved uniformly in both groups (flush time: group I, 35.1 +/- 2.4 second; group II, 35.3 +/- 3.0 seconds; p = 0.96; flush pressure: group I, 9.8 +/- 0.7 mm Hg; group II, 10.1 +/- 1.1 mm Hg; p = 0.8). Transplanted lungs provided similar excellent oxygenation in both groups on day 0 (arterial oxygen tension, group I, 451 +/- 82 mm Hg; group II, 497 +/- 37 mm Hg; p = 0.61; inspired oxygen fraction = 1.0) and day 3 (arterial oxygen tension, group I, 551 +/- 57 mm Hg; group II, 587 +/- 19 mm Hg; p = 0.55), with a statistically significant improvement from day 0 to day 3 in both groups (group I, p = 0.034; group II, p = 0.038). There was no difference in arterial carbon dioxide tension, base excess, cardiac output, blood pressure or pulmonary artery pressure between the two groups. We conclude that a large bolus of prostaglandin E1 into the pulmonary artery produces a high-flow, low-pressure flush with modified Euro-Collins solution; with this technique, equivalent, reliable 18-hour lung preservation can be achieved at 4 degrees and 10 degrees C flush and storage temperatures.

Alprostadil↗
PubMed1991

Statistical analysis of the extended Hansen method using the bootstrap technique.

In this study, simple bootstrap techniques are combined with the extended Hansen solubility approach to calculate biases, standard errors, and confidence limits of the partial solubility parameters and to obtain bias-corrected values for these solubility parameters. The bootstrap method is rather new in its application to problems in the pharmaceutical sciences and, therefore, is described here in some detail. This method provides measures of the statistical variation of ratios of regression coefficients without making unwarranted assumptions about data variability. The bootstrap can be used in many statistical packages such as MINITAB, SPSS, SAS, BMDP, or GLIM, all of which are widely available, and could be useful in other areas of the pharmaceutical sciences where regression analysis is employed.

Computer Simulation↗