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M Zhang

Publications and source records attributed to M Zhang.

At least 1,009 records · Page 56Linked to original sources
PubMed1991

[Comparison of several screening instruments for dementia].

Both evidences of cognitive and functional impairments are necessary for the diagnosis of dementia. Following instruments: Mini-Mental State Examination (MMSE), Blessed Dementia Scale (BDS) and Hasegawa Dementia Scale (HDS) for cognitive assessment, and Activity of Daily Living (ADL) and Pffefer's Social Function Questionnaire (POD) for function measurement, were used in a survey sample of 5055 aged persons. It was found that the scores of both categories of tests were significantly correlated. The scores of MMSE, BDS and HDS were highly education-related, thus the education-dependent cutoff point should be decided. Among the cognitive assessment scales, MMSE and HDS seems better than BDS, while in functional scales, POD was more suitable for community survey. Sensory and motor disturbances, emotional and health problem were also interfered with both cognitive and daily or social function, it should be taken account in the diagnostic process for dementia.

Activities of Daily Living↗
PubMed1991

[A preliminary report of evoked potential marker study of pattern shift visual evoked potentials (PS-VEP) and auditory evoked potentials (AEP) on schizophrenic twins].

This paper reports the result of electroneurophysiological study of the pattern shift visual evoked potentials (PS-VEP) and auditory evoked potentials (AEP) on six pairs of schizophrenic twins. The result indicated that there were significant differences in the inter-pair variance between MZ and DZ in latency P2, amplitude P2-N2 and P2 of using PS-VEP. AEP was also used for this group cases, and the result showed the presence of statistical differences in the inter-pair variance of latency N2, amplitude N1-P2 and P2. The authors speculated upon that the above six electrophysiological markers may be related to genetic factors, which had been proved by the blood group, character, clinical symptoms and treatment response of those patients.

Adolescent↗
PubMed1990

Factor IX Chongqing: a new mutation in the calcium-binding domain of factor IX resulting in severe hemophilia B.

A Chinese patient with sporadic, severe hemophilia B was found to have a low level of total factor IX antigen (3.5 U/dl), but less apparent antigen in an assay using a calcium-dependent antibody fraction (1.1 U/dl). This suggested a defect in the factor IX Gla domain coded mainly by exon 2 of the factor IX gene. Exon 2 was therefore amplified and sequenced. An A to T substitution was found at nucleotide 6455 of the patient's factor IX gene. This transversion changes the codon for Glu 27 in normal factor IX to a codon for Val. Since Glu 27 becomes an essential Gla residue, the defect should result in altered calcium-binding or calcium-dependent conformation of the patient's factor IX. The introduction of a hydrophobic side chain also appears to affect the hemophilic protein's stability. In leukocyte DNA from the patient's mother, the nucleotide sequence of exon 2 was entirely normal. Thus, barring somatic mosaicism within her germ cells, the new mutation occurred in oogenesis of her ovary.

Amino Acid Sequence↗
PubMed1990

Coordinate occupancy of AP-1 sites in the vitamin D-responsive and CCAAT box elements by Fos-Jun in the osteocalcin gene: model for phenotype suppression of transcription.

Osteocalcin, a bone-specific protein and marker of the mature osteoblast, is expressed only in nonproliferating osteoblasts in a mineralizing extracellular matrix, while type I collagen is expressed in proliferating cells. The nuclear proteins encoded by the c-fos and c-jun protooncogenes are expressed during the proliferation period of osteoblast phenotype development. We present evidence that AP-1 (HeLa cell-activating protein 1) sites residing within two promoter elements of the osteocalcin gene bind the Fos-Jun protein complex: the osteocalcin box (OC box; nucleotides -99 to -76), which contains a CCAAT motif as a central element and influences tissue-specific basal levels of osteocalcin gene transcription, and the vitamin D-responsive element (VDRE; nucleotides -462 to -440), which mediates enhancement of osteocalcin gene transcription. Gel electrophoretic mobility-shift analysis demonstrated high AP-1 binding activity in proliferating osteoblasts and dramatic changes in this activity after the down-regulation of proliferation and the initiation of extracellular-matrix mineralization in primary cultures of normal diploid osteoblasts. Methylation interference analysis established at single nucleotide resolution that purified recombinant Fos and Jun proteins bind in a sequence-specific manner to the AP-1 sites within the VDRE and OC box. Similarly, an AP-1 motif within a putative VDRE of the alkaline phosphatase gene, which is also expressed after the completion of proliferation, binds the Fos-Jun complex. These results support a model in which coordinate occupancy of the AP-1 sites in the VDRE and OC box in proliferating osteoblasts may suppress both basal level and vitamin D-enhanced osteocalcin gene transcription as well as transcription of other genes associated with osteoblast differentiation--a phenomenon we describe as phenotype suppression. This model is further supported by binding of the Fos-Jun complex at an AP-1 site in the type alpha I collagen promoter that is contiguous with, but not overlapping, the VDRE. Such a sequence organization in the collagen VDRE motif is compatible with vitamin D modulation of collagen but not with osteocalcin and alkaline phosphatase expression in proliferating osteoblasts.

Animals↗
PubMed1990

Molecular characterization of immune inhibitor A, a secreted virulence protease from Bacillus thuringiensis.

The gene for the secreted neutral metalloprotease, immune inhibitor A (InA), from Bacillus thuringiensis var. alesti has been cloned and sequenced. The deduced amino acid sequence has been confirmed by partial amino acid sequencing. The central part of the amino acid sequence showed similarity to the active site in thermolysin. Southern and Western blots show that InA-related sequences are common among other B. thuringiensis subspecies. In Western blots, 17 out of 25 tested species gave a positive signal. Culture filtrates from subspecies expressing InA were toxic when injected in Trichoplusia ni larvae, whereas filtrate from a strain negative in Western blot had no effect when injected. The LD50 dose of purified InA protein injected in T. ni larvae was 12.5 +/- 2.5 ng per mg of larval body weight.

Amino Acid Sequence↗
PubMed1990

Does single-amino-acid replacement work in favor of or against improvement of the thermostability of immobilized enzyme?

Thermostabilities of kanamycin nucleotidyltransferase and of its mutants that became thermostable, in the free state, because of single-amino-acid replacements were studied after immobilization of the enzymes on cyanogen bromide-activated Sephadex G-200 particles. Lys in place of Gln at position 102 decreased the thermostability of the immobilized enzyme, whereas replacement with other amino acids enhanced it.

Amino Acid Sequence↗
PubMed1990

The myelin-deficient rat mutant: partial recovery of oligodendrocyte maturation in vitro.

The morphological and immunocytochemical identification and characterization of the myelin-forming cell, the oligodendrocyte, have defined a model system for developmental studies. The myelin-deficient (md) rat mutant lacks myelin in the central nervous system and fails to express the normal developmental increase in oligodendroglial and myelin markers, apparently as a consequence of a point mutation in the proteolipid protein gene. In the present work, we compared the developmental pattern of primary glial cultures derived from newborn md rat brains to those derived from wild-type animals. Brain cell suspensions were prepared from each rat pup and cultured separately. We found by immunocytochemical and enzymatic analyses for the various markers that the developmental cascade of oligodendroglial marker expression is delayed, oligodendrocytes failing to mature compared to normal cultures. However, a partial recovery of marker expression was observed in md-derived cultures as compared to development previously reported in the intact md animals. We suggest that the partial recovery of the sequential expression of oligodendroglial markers may be due to a supportive environment provided to the oligodendrocyte progenitor cell (1) by tissue culture conditions or (2) by the absence of the blood-brain barrier in contrast to its presence in the intact animal.

Animals↗
PubMed1990

Budd-Chiari syndrome. Surgical treatment of 45 cases.

Fourty-five patients with Budd-Chiari syndrome were treated surgically from December 1985 to May 1988. The procedures consisted of cavoatrial shunt, mesoatrial shunt, transcardiac membranotomy, splenopneumopexy, portal vein-systemic vein shunt and re-opened umbilical vein-right auricle shunt, etc. Two of the patients died postoperatively. Others showed improvement after follow-up for 3-24 months. Recurrent hemorrhage from varices did not occur after operation in all patients. The diagnosis, surgical indications, and various methods of surgery for Budd-Chiari syndrome were discussed.

Adolescent↗
PubMed1990

Clinical effects of rheum and captopril on preventing progression of chronic renal failure.

A clinical trial, to evaluate the effects of a Chinese herbal drug, Rheum E and angiotensin converting enzyme inhibitor, Captopril on chronic renal failure (CRF), was conducted. Thirty cases with initial serum creatinine (Scr) levels of 344.8 +/- 114.0 mumol/L were allocated randomly to 3 groups: Rheum E treated group, Captopril treated group and Rheum E + Captopril group. A control group of 12 cases were on dietary therapy alone. During the 6-22 months of treatment, all the patients were kept on low-protein (0.6g/kg/d), and low-phosphorus (10mg/kg/d) diet. The results showed that the progression rate of renal failure, calculated by regression analysis of 1/Scr vs time, was found to be retarded after treatment with the increased regression coefficient (b value). Scr levels and blood urea nitrogen were kept stable or fell slightly. Albumin rose during the follow-up period (P less than 0.05) in the treated patients, being more marked in both Rheum E and Rheum E + Captopril groups. Uremic symptoms of nausea, anorexia improved in most of the treated patients. It is concluded that long-term low-dose Rheum E taken orally is beneficial to CRF. Its effect is better than that of Captopril. The regime of Rheum E and Captopril is a preferable choice in the long-term treatment for preventing progression of CRF.

Adult↗
PubMed1990

[The study of effect of pain in the change of respiration by stimulating "renzhong" acupoint].

UNLABELLED: It had been reported that the stimulation of the "Renzhong" starts respiratory activity in rabbits whose respiration has been suspended. This action was caused by stimulating Renzhong. Those signals transmit to the nucleus of trigeminal spinal, and go to influence the nucleus of respiration. Those signals include of pain and other sense. This study investigated whether this stimulation of "Renzhong" is caused by pain or another stimulus. Phrenic nerve discharges and respiratory rates of 7 anesthetized rabbits, each weighing 1.5 to 2.0 kg were recorded. Stimulation of the "Renzhong" by electrical impulses (10 ms pulse, 20 Hz, 0.4-4 mA, duration 3-5 seconds). RESULTS: 1. Stimulating the "Renzhong", resulted in an 83 +/- 16% increase in the amplitude of phrenic nerve discharges, and a 31 +/- 6% decrease in respiratory rate. 2. morphine was then injected into the rabbits (5 mg/kg). After 8 minutes, the amplitude of phrenic nerve discharges had decreased by 22 +/- 9% and the respiratory rate had decreased by 16 +/- 6%. 3. At this acupoint, stimulation of the "Renzhong" resulted in a 43 +/- 8% increase of the amplitude of phrenic nerve discharges and a 20 +/- 6% decrease in respiratory rate. These results suggest that in the effect of the stimulation of "Renzhong" on the respiration pain sensation is one factor among the rest.

Acupuncture Points↗
PubMed1990

[Study on the variation of relaxation time in diabetic cataractous lenses of rats by using NMRA].

Nuclear magnetic resonance analysis (NMRA) was used to measure the relaxation time T1 and T2 of the protons in the different-stage-diseased lenses of rats with diabetic cataract caused by the streptozotocin, and the results were put in comparison with those obtained from the control group, showing that after one month of medication the values of T1 and T2 in the cataractous lenses are greater than those gained from the control group. The variation, as time goes on, becomes greater and greater. T1 and T2 indicate the speed of the free induction decay (FID) signals, and the variation of the FID signals are in direct proportion to that of the proton content of the samples. This shows that an increase in T1 and T2 indicates an increase in the water content in the diseased lenses, and the changes in ratio of "bound" water to free water. Such changes may be explained that the space for "bound" water is occupied by some other macromolecules, causing the alteration of the macromolecular structure, and consequently the aggregation of protein and the degeneration or dehydration or dehydration of the membrane occur, which may give rise to another scattering centre. So the scattering of the lens increases and its transparency decreases. This result is in agreement with some reports in the medical literature. As T1 and T2 are quite different in the normal and pathological tissues, and the protons are the most extensive nucleus in all biological tissues, NMR is a very important method to determine the proton relaxation time in the biological tissue and to judge if it is normal or not.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

[Preparation on monoclonal antibodies against laminin receptors and their inhibitory effects on attachment and spreading of tumor cells].

Monoclonal antibodies against laminin receptors (LN) isolated from a highly metastatic human giant cell carcinoma of lung (PG) were prepared by routine hybridoma technique. Two positive clones secreted monoclonal antibodies against laminin receptors, one of which was named McB1. McB1 was bound more efficiently to LN-R of cultured PG tumor cells immunohistochemically. McB1 could markedly inhibit the attachment and spreading of S-180 mouse ascitic tumor cells and PG tumor cells on laminin substrate. Monoclonal antibody against LN-R is definitely useful in studying the interaction between tumor cells and extracellular matrix and the molecular mechanisms of invasion and metastases of tumor cells.

Animals↗
PubMed1990

[Prevalence study on dementia and Alzheimer disease].

An epidemiological survey on dementia and Alzheimer disease (AD) was carried out in a community of 5055 persons over the age of 55 at Jingan district of Shanghai. Diagnoses were made according to the diagnostic criteria of dementia of DSM-III-R and of AD of NINCDS-ADRDA. It was found that dementia is not uncommon in the aged, and AD was the leading category of dementia. The age and sex adjusted prevalence rate of dementia was 2.57% in those over 55, 3.46% in those over 60, and 4.61% in those over 65, and that of AD was 1.50%, 2.05% and 2.90% respectively. Beside age, the other risk factors were female sex, bereavement of spouse, low education and unfavorable socio-economic status.

Aged↗
PubMed1990

[Changes of the microcirculating blood volume in the reproductive axis during estrous cycle of the rats].

The microcirculating blood volume of the hypothalamic-pituitary-ovarian axis in the female rats was measured using radiobiomicrosphere method during the estrous cycle. The blood flow volume of the hypothalamus and the pituitary was not significantly different between each phase of the estrous cycle. The ovarian blood flow volume was the highest in metestrus and the lowest in estrus. The difference between them was significant (P less than 0.02). The uterine blood flow volume was the highest in metestrus and remained at higher level in diestrus and then changed to the lowest in estrus. The values in metestrus and diestrus were significantly higher than that in estrus (P less than 0.01, P less than 0.05, respectively). The blood flow volume of the oviduct in proestrus was significantly lower than that in estrus (P less than 0.05). The above results suggest that the cyclic changes of the blood volume of the ovary, uterus and oviduct are closely related to their functional state and the hormonal changes.

Animals↗