PubMed Health⌕ Search

Biomedical subjects

Z Shi

Publications and source records attributed to Z Shi.

At least 127 records · Page 7Linked to original sources
PubMed1996

Field studies on the preventive effect of oral artemether against schistosomal infection.

OBJECTIVE: To study the preventive effect of oral artemether (Art) against schistosomal infection in the field. METHODS: In Minglang District of Yiyang City, Hunan Province, there is an islet with embankment type endemic area in the southern Dongting Lake region. From August to October 1994 the residents who frequently contacted the infested water were selected for study and allocated to the Art group and the control group. About one month before the preventive Art administration, all the residents understudied were examined by stool hatching technique, and then treated orally with praziquantel at a single dose of 40 mg/kg in stool egg-negative residents and 50 mg/kg in stool egg-positive ones. In the Art group, the first dose of 6 mg/kg was given at the end of August, followed by 3 repeated doses every 15 days. Placebo (starch) was given to the control group at the same time as in the Art group. The preventive efficacy was evaluated by stool examination 25-32 days after the last medication. RESULTS: In the Art group, 20 out of 365 studied residents became stool positive with an infection rate of 5.5%, while in the control group, 51 out of 376 studied residents were stool positive with an infection rate of 13.6%. The egg count per gram of feces (EPG) determined by the Kato-Katz method was 122 +/- 79 in the Art group and 681 +/- 909 in the control group. Meanwhile, two cases of acute schistosomiasis were found in the control group, but none was observed in the Art group. No apparent adverse side effect was seen during the treatment with Art. CONCLUSION: Oral Art exhibited apparent preventive effect on the residents who contacted the infested water in schistosomiasis endemic area.

Administration, Oral↗
PubMed1996

[The prevalence and risk factors of carotid atherosclerosis in elderly patients].

To assess the prevalence of extracranial carotid artery atherosclerosis and its relation to principal cardiovascular risk factors in Chinese elderly patients, 100 cases aged from 54 to 94 were investigated with B-mode ultrasonography. Arterial intima-media thickening, plaque, mild stenosis (defined as a plaque that obstructed > 20% of the lumen diameter), and clinically significant stenosis (> 50% in cross-sectional area) were found in 79, 49, 40 and 3 patients, respectively. There was no significant correlation between carotid atherosclerosis and coronary heart disease, cerebral infarction, hypertension, hyperlipidemia or diabetes. In contrast, the prevalence of carotid atherosclerosis was increased with age (P < 0.05), so did the severity. Thus, age is a major risk factor for carotid atherosclerosis in the elderly.

Age Factors↗
PubMed1996

[Repair of skin defects on the anterior portion of the foot with reversed dorsalis pedis flap].

Based on anatomical observations of the course of skin arteries and venous drainage of the reversed dorsalis pedis flap in 30 adult cadaversmretrograde dorsalis pedis flaps have been performed on six patients to repair their skin defects on the anterior portion of the foot. All the flaps survived without severe swelling or any necrosis. Clinical applications indicated that the blood supply and venous drainage of the flap were satisfactory. The advantages and key points of the operation were discussed in this paper.

Adolescent↗
PubMed1995

Mechanism of adenylate kinase. The "essential lysine" helps to orient the phosphates and the active site residues to proper conformations.

Although how Lys21 interacts with the substrate MgATP of muscle adenylate kinase (AK) can now be deduced from the crystal structure of Escherichia coli AK.MgAP5A [P1,P5-bis(5'-adenosyl) pentaphosphate] [Müller, C. W., & Schulz, G. E. (1992) J. Mol. Biol. 224, 159-177], its contribution to catalysis has not yet been demonstrated by functional studies since the proton NMR of the K21M mutant was shown to be perturbed significantly [Tian, G., Yan., H., Jiang, R.-T., Kishi, F., Nakazawa, A., & Tsai, M.-D. (1990) Biochemistry 29, 4296-4304]. We therefore undertook further structural and functional analyses of a conservative mutant K21R and a nonconservative mutant K21A. In addition to kinetic analyses, the structures of the mutants were analyzed by one- and two-dimensional proton NMR spectroscopy and (1H, 15N) heteronuclear multiple-quantum coherence (HMQC) experiments. Detailed assignments were performed in reference to the total backbone assignments of the WT AK.MgAP5A complex [Byeon, I.-J. L., Yan, H., Edison, A. S., Mooberry, E. S., Abildgaard, F., Markley, J. L., & Tsai, M.-D. (1993) Biochemistry 32, 12508-12521]. The analysis showed that the residues located near the active site (Gly15, Thr23, Arg97, Gln101, Arg128, Arg132, Asp140, Asp141, and Tyr153) exhibit greater changes in 1H-15N chemical shifts. Finally, two-dimensional 31P-31P COSY experiments were used to examine the effects of the lysine side chain on the phosphate groups in the bound AP5A. Our data have led to the following conclusions independent of the crystal structure: (i) Because the perturbations in the conformation of the mutants are not global and are mainly localized at active site residues and Tyr153, the side chain of Lys21 can be concluded to stabilize the transition state in the catalysis of AK by up to 7 kcal/mol on the basis of the 10(5)-fold decreases in the kcat/Km of mutants. (ii) The results of 31P NMR analyses suggest that Lys21 functions by orienting the triphosphate chain of MgATP to a proper conformation required for catalysis. (iii) The interaction between Lys21 and the phosphate chain in turn dictates the interactions between the substrates and the active site residues. In the K21R.MgATP complex, the NH chemical shifts of many of the active site residues are perturbed. (iv) The catalytic functions of Lys21 cannot be replaced by a conservative residue arginine. In addition, since K21A and K21R behave similarly, the catalytic function of Lys21 should not be merely a charge effect.

Adenosine Triphosphate↗
PubMed1995

The measurement and application of TSH-IRMA levels among different age groups in areas with iodine deficiency disorders.

Using immunoradiometric TSH assay (TSH-IRMA) to measure whole blood TSH levels spotted onto filter paper, we compared TSH levels among different age groups (neonates, < 1 yr infants, schoolchildren aged 7 to 14 yrs, adults, pregnant women and reproductive-age women) in Guiyang, where iodine deficiency has long been a problem. The results showed: 1) The percentage of subjects with TSH levels equal to or greater than 5 mIU/L in the neonate group was 38.9% while the percentages in the other groups were 0-3.3% (P < 0.01); 2) The TSH levels of the neonates were inversely related to the urinary iodine values of their mothers (pregnant women). (r = -0.5, P < 0.01); 3) 97.6% of the inhabitants in Guiyang ingested salt with less than 20 mg/kg iodine. The results indicate that iodine deficiency remains a problem in Guiyang. Neonates are the only ideal population for monitoring iodine deficiency.

Adolescent↗
PubMed1995

[Field studies on preventive effect of artemether against infection with Schistosoma japonicum].

From August to October 1994, a field trial of preventive treatment with artemether (Art) was carried out in Minglang District of Yiyang City, Hunan Province, an islet with embankment type endemic area nearby southern Donting Lake region. The residents who frequently contacted with the infested water were selected for study and allocated to the Art group and the control group in reference to paired methods of randomization table. About one month before administration of Art, all residents under study were examined by stool hatching technique after nylon-bag concentration to determine the infection rate of each group, and then treated with praziquantel at a single dose of 40 mg/kg in stool egg-negative residents and 50 mg/kg in stool egg-positive ones. In Art group, the first dose of 6 mg/kg was given in late August, followed by repeated dosing every 15 days for 3 times. Placebo (starch) was given to the study residents in the control group at the same time as in Art group. The efficacy was evaluated by stool examination 25-32 days after the last medication. The results showed that after the preventive administration of Art, 20 out of 365 study residents in Art group revealed stool positive with an infection rate of 5.5%, while in the control group 51 out of 376 study residents showed stool positive with an infection rate of 13.6%. The difference between the two groups was statistically significant. Meantime, two cases of acute schistosomiasis were seen in the control group, but none was observed in Art group. The egg per gram of feces (EPG) determined with the Kato-Katz method was 122 +/- 79 (range 12-192) in Art group and 681 +/- 909 (range 12-2,760) in the control group. No apparent adverse side effect was seen during the treatment with Art, and no abnormal change in liver and renal function was detected after the last medication. The preliminary study indicates that application of the preventive administration of Art in the endemic area during the transmission season may effectively reduce both the infection rate and intensity of schistosomiasis.

Adolescent↗
PubMed1995

[Cost-benefit analysis on Malayan filariasis control in Miaoxi Township, Huzhou City, Zhejiang Province during 1964-1987].

The methods adopted in this paper were as follows: (1) The cost of the filariasis control was estimated to be direct cost and indirect cost; (2) Using the reduction rate of acute inflammatory attack as the measurable indicator of control effectiveness; (3) Estimating the case number of acute inflammatory attack occurred after control year by year basing on the goodness by fitting in the reduction trend of acute inflammatory attack with hyperbola formula; (4) Assuming that the case number of acute inflammatory attack would be relatively stable at the same level of pre-control if filariasis control measures were not implemented; (5) The benefit from the filariasis control was estimated by transforming the increasing man-working day and saving the medicine expenses of patients due to the reduction of acute inflammatory attack. By allowing seven percent discount on cost and benefit, the total cost was 21,182 Yuan, the total benefit was 119,859 Yuan, the ratio of cost-benefit was 1:5.7, implying that putting in one Yuan to filariasis control in this township may gain benefit 5.7 Yuan.

Animals↗
PubMed1995

[Treating steroids dependent asthmatic patients with high dose beclomethasone dipropionate aerosol].

In order to provide a more effective alternative therapy for the steroid dependent asthmatic (SDA) patients, 23 SDA patients replaced their oral steroids with high dose beclomethasone dipropionate (1500 micrograms/d) inhalation were investigated. The changes of clinical features, pulmonary function and the Synacthen test were recorded. The results showed that about 82% of the patients replaced their oral steroids completely or partially with the inhalation therapy, the clinical features were improved in 13% of the patients and the failure rate was only 4.4%, the results also revealed that, after replacement, the pulmonary function of the patients were improved (P < 0.05); according to the results of Synacthen test, after alternative therapy for 3-6 months, the damaged reserve power and secretive ability of adrenal cortex of the patients were also partially improved (P < 0.01).

Administration, Inhalation↗
PubMed1995

[Prognosis of hypopharyngeal and esophageal cancers treated with different surgical procedures].

Thirty-nine cases of hypopharyngeal and 21 cases of cervical esophageal carcinomas were resected and different organs and tissues were used for reconstruction. Among them, the stomach was used as substitute for the esophagus in 33 cases the colon in 20, the myocutaneous flap in 4 and the gastric tube in 3. Three-year and 5-year survival rates were 61.2% and 37.9% respectively. Of the post-operative deaths within 5 years, 40.5% was due to local recurrence and 35.1% due to metastasis to cervical lymphnode. In patients who had negative lymphnode findings before operation, positive results were obtained in 42.1% of the cervical lymphnodes and in 27.2% of the tracheoesophageal groove and superior mediastinal lymphnodes resected. Reoperation was performed in 5 cases with local recurrence and 8 cases with cervical lymphnode metastasis and the resectabilities were 40.1% and 37.9% respectively. The authors consider that among these operative procedures, the colonic interposition with pharyngocolonic anastomosis had the following advantages: (1) excellent physiological function; (2) higher successful rate; (3) lower local recurrence incidence; and (4) good living quality.

Adult↗
PubMed1994

A small, high-copy-number vector suitable for both in vitro and in vivo gene expression.

A 2433-bp, high-copy-number expression vector, pUK, was constructed from pUC19 and pKK223-3. The genes encoding chicken adenylate kinase (AK) and phospholipase A2, cloned into pUK, were highly expressed in vitro using the coupled transcription/translation system of Zubay. High-level in vivo expression in Escherichia coli was also demonstrated for the AK gene cloned in this vector. The multiple cloning site (MCS) of pKK223-3 was preserved in pUK. In addition, three more sites in the MCS sequence, AccI, BamHI and SalI, were made unique for the convenience of cloning.

Adenylate Kinase↗
PubMed1994

Isolation and characterization of the gene encoding 2,3-oxidosqualene-lanosterol cyclase from Saccharomyces cerevisiae.

The ERG7 gene encoding oxidosqualene-lanosterol cyclase [(S)-2,3-epoxysqualene mutase (cyclizing, lanosterol forming), EC 5.4.99.7] from Saccharomyces cerevisiae has been cloned by genetic complementation of a cyclase-deficient erg7 strain. The DNA sequence of this gene has been determined and found to contain an open reading frame of 2196 nt (including stop codon) that encodes a predicted protein of 731 amino acids. The predicted molecular mass of the S. cerevisiae cyclase, 83.4 kDa, is similar to the predicted molecular masses of the oxidosqualene-lanosterol cyclase from Candida albicans and the oxidosqualene-cycloartenol cyclase from Arabidopsis thaliana, as well as to the molecular masses assigned to vertebrate oxidosqualene-lanosterol cyclases; however, it is substantially larger than the molecular mass assigned to purified S. cerevisiae cyclase. At the level of DNA and predicted amino acid sequences, the S. cerevisiae and C. albicans cyclases share 56% and 63% identity, respectively. Tryptophan and tyrosine residues are unusually abundant in the predicted amino acid sequences of (oxido)-squalene cyclases, leading to a hypothesis that electron-rich aromatic side chains from these residues are essential features of cyclase active sites.

Amino Acid Sequence↗