Biomedical subjects

S Ji

Publications and source records attributed to S Ji.

At least 55 records · Page 3Linked to original sources

PubMed1998

Partial cloning and expression of the bovine leptin gene.

The product of the leptin (i.e., obese) gene may be an important regulator of energy metabolism, adiposity, and reproduction, and is perhaps linked to meat quality determinants such as marbling. Molecular probes were developed using polymerase chain reaction (PCR) technology to evaluate leptin expression in adipose depots and to evaluate the tissue-dependent nature of expression reported in other species. A 438 bp fragment representing the coding region of the bovine leptin gene excluding the N-terminal secretory signal was amplified, cloned into a plasmid vector (pASK75), and expressed in E. coli. Sequence analysis of the cDNA and the corresponding polypeptide indicate that, overall, both share approximately 87% homology with the mouse and human leptin genes and polypeptides. Amino terminal sequencing (30 amino acid residues) of the recombinant bovine leptin (rBL) protein revealed 100% homology with mouse and human leptin. The bovine leptin gene is expressed as a 3,090 nt mRNA which is detected in adipose tissue, but is not found in brain (despite the appreciable fat content and lipid metabolism) or other tissues. Leptin gene expression in several adipose depots (subcutaneous, renal, and omental) was similar (P = .73) in finished cattle.

Adipose Tissue↗

PubMed1998

Leptin expression in porcine adipose tissue is not increased by endotoxin but is reduced by growth hormone.

The physiologic response to infection includes reductions in tissue concentrations of anabolic growth factors as a means of reducing growth and conserving nutrients for immunologic processes. This repartitioning of nutrients is accompanied by anorexia, which has been linked to increased leptin expression. Furthermore, leptin and growth hormone (GH) concentrations are inversely related, with leptin being required for normal GH release. The objective of this study was to determine if pretreatment with GH would influence endotoxin-induced changes in leptin expression or attenuate endotoxin-induced reductions in serum insulin-like growth factor-1 (IGF-1) and IGF-1 expression in liver and longissimus muscle. In experiment 1, 40 pigs were assigned to four treatments (n = 10 per treatment) arranged as a 2x2 factorial with GH (s.c. injection, 2 mg 1 h before challenge and 2 mg 2 h after challenge) and endotoxin (single i.m. injection, 25 microg/kg body weight) as main effect variables. Pretreatment with GH resulted in a marked increase (p<0.001) in serum GH within 1 h that was sustained throughout the study. Endotoxin challenge reduced (p<0.003) serum IGF-1 independent of GH (GH x endotoxin, p>0.682), and reduced (p<0.05) IGF-1 expression in longissimus muscle but not liver. Leptin mRNA abundance was reduced 56% (p<0.005) by GH but was not affected by endotoxin (p>0.81). In experiment 2, 36 pigs (n = 12 per treatment) were either allowed ad libitum feed consumption with no injection or deprived of feed and injected twice with either saline or endotoxin 24 h apart. Feed deprivation reduced leptin expression (p<0.05). However, endotoxin did not change leptin expression but markedly increased (p<0.05) serum haptoglobin. These data indicate that changes in IGF-1 status in endotoxin-challenged pigs are independent of serum GH and that leptin expression is not increased by endotoxin challenge in the pig. These data also indicate a regulatory linkage between GH and leptin in vivo.

Adipose Tissue↗

PubMed1998

Obese gene expression in porcine adipose tissue is reduced by food deprivation but not by maintenance or submaintenance intake.

The relationship between obese gene expression and energy intake was determined in pigs of various body weights. With ad libitum consumption, expression increased (P < 0.001) with body weight from 55 to 163 kg. Obese mRNA relative abundance was correlated with fat mass (r = 0.74, P < 0.0001) and percentage of fat (r = 0.72, P < 0. 0001). Obese expression was also evaluated at 159 kg (initial weight) and ad libitum, maintenance or 23% of maintenance intake for 28 d. Obese mRNA was independent of treatment (P > 0.78) despite considerable weight differences. Obese mRNA abundance was then compared at 136 kg (initial weight) and ad libitum or maintenance intake for 3 or 28 d. Abundance was not influenced by either duration of treatment or intake, despite a small increase (P < 0.01) in serum nonesterified fatty acids (NEFA) and a reduction (P < 0.02) in insulin attributable to maintenance intake. Finally, mRNA abundance was determined at 60 and 136 kg and conditions of food deprivation or ad libitum intake for 3 d. Food deprivation reduced (P < 0.01) serum insulin and increased (4- to 5-fold) NEFA concentrations. Obese mRNA abundance was greater (P < 0.01) in the heavier pigs and was reduced (P < 0.01) by food deprivation. We conclude that obese mRNA abundance in pigs correlates with fat mass and percentage of body fat under conditions of ad libitum intake. Furthermore, obese mRNA abundance is reduced by food deprivation, whereas lesser degrees of intake restriction do not change obese mRNA abundance, even when accompanied by appreciable weight loss.

Adipose Tissue↗

PubMed1998

Elongation factor-1 alpha occurs as two copies in bees: implications for phylogenetic analysis of EF-1 alpha sequences in insects.

We report the complete sequence of a paralogous copy of elongation factor-1 alpha (EF-1 alpha) in the honeybee, Apis mellifera (Hymenoptera: Apidae). This copy differs from a previously described copy in the positions of five introns and in 25% of the nucleotide sites in the coding regions. The existence of two paralogous copies of EF-1 alpha in Drosophila and Apis suggests that two copies of EF-1 alpha may be widespread in the holometabolous insect orders. To distinguish between a single, ancient gene duplication and parallel, independent fly and bee gene duplications, we performed a phylogenetic analysis of hexapod EF-1 alpha sequences. Unweighted parsimony analysis of nucleotide sequences suggests an ancient gene duplication event, whereas weighted parsimony analysis of nucleotides and unweighted parsimony analysis of amino acids suggests the contrary: that EF-1 alpha underwent parallel gene duplications in the Diptera and the Hymenoptera. The hypothesis of parallel gene duplication is supported both by congruence among nucleotide and amino acid data sets and by topology-dependent permutation tail probability (T-PTP) tests. The resulting tree topologies are also congruent with current views on the relationships among the holometabolous orders included in this study (Diptera, Hymenoptera, and Lepidoptera). More sequences, from diverse orders of holometabolous insects, will be needed to more accurately assess the historical patterns of gene duplication in EF-1 alpha.

Animals↗

PubMed1998

Myostatin expression in porcine tissues: tissue specificity and developmental and postnatal regulation.

The objective of this study was to establish the developmental pattern and tissue specificity of porcine myostatin expression and to evaluate expression in skeletal muscle during circumstances in which muscle growth was altered. Northern blot analysis revealed two transcripts (1.5 and 0.8 kb). Myostatin mRNA was detected in whole fetuses at 21 and 35 days and was markedly increased (P < 0.05) by 49 days. At birth, mRNA abundance in longissimus muscle had declined significantly (P < 0.05) from that at day 105 of gestation and continued to decrease (P < 0.05) to its lowest level 2 wk postnatally (4 kg body wt). Myostatin expression was higher (P < 0. 05) at 55, 107, and 162 kg body wt than at 4 kg body wt. Postnatally, myostatin mRNA was detected in skeletal muscle and mammary gland. Expression at birth was 65% higher (P < 0.04) in longissimus muscle of low-birth-weight piglets (0.57 +/- 0.052 kg body wt) vs. normal (1.37 +/- 0.077 kg body wt) littermates, irrespective of gender. However, suppression of longissimus muscle growth by food deprivation (3 days) did not alter (P > 0.15) myostatin expression in either 4- or 7-wk-old piglets. Additionally, myostatin mRNA abundance was not changed by porcine growth hormone administration in growing animals. These data indicate that myostatin expression in skeletal muscle peaks prenatally and that greater expression is associated with low birth weight. Expression in mammary gland indicates a possible role for myostatin in mammary gland development and/or lactation.

Aging↗

PubMed1998

[A novel rotavirus causing large scale of adult diarrhea in Shi Jiazhuang].

An outbreak of adult diarrhea causing more than 1,000 hospitalized cases among graduates in a university in Shi Jiazhuang city (Hebei province), occurred in 10-28, April, 1997. The non-bacterial pathogenic agent is confirmed as Rotavirus first by PAGE. Forteen samples have been demonstrated sharing the same nucleic acid electrophoresis pattern of 4-2-1-1-1-1-1. The positive rate was 47% (thirty samples have been checked) with no other RV pattern. Dada showed that RV with this kind of nucleic acid electrophoresis pattern were responsible for the outbreaks acute diarrhea in adults. The novel RV and known ADRV was RT-PCR with end-primers 5, 9 of typical ADRV, the positive control typical ADRV's results are positive, the novel RV's are negative. Experimental results showed that the novel RV did not belong to group B RV, totally different from all the known ARDV. This case was the first reported one in Hebei province with an outbreak of adult diarrhea not by any known ADRV.

Adult↗

PubMed1998

Clinical features of the femoral head necrosis caused by gross teres ligament after reduction for the developmental dislocation of the hip.

OBJECTIVE: To observe the clinical features of the femoral head necrosis caused by a gross teres ligament after reduction of developmental dislocation of the hip and study its pathological causes. METHODS: Ten hips with necrosis of the femoral head after reduction of developmental dislocation of the hip were observed. X-ray images of the hip were retrospectively reviewed with regard to the acetabular index, the acetabular-head index, the shapes and the development of the femoral heads. The operative findings were analyzed. RESULTS: No growth or delayed growth of the femoral head and the acetabular index was found after reduction. The recovery of acetabulum was very slow. All of the cases showed the same features: femoral head necrosis, subluxation, and acetabular dysplasia. A gross teres ligament was proved during surgical operation. The femoral head recovered gradually after the operation. CONCLUSIONS: The gross tissue interposed (a gross teres ligament) is another important pathogenesis of femoral head necrosis after the reduction of developmental dislocation of the hip. It is necessary to recognize it before reduction by imaging examinations.

Acetabulum↗

PubMed1998

24-hour gastroesophageal double pH monitoring acid and alkaline gastroesophageal and duodenogastric refluxes in pediatric patients.

OBJECTIVE: To study the pathophysiologic significance of gastroesophageal and duodenogastric-esophageal refluxes in pediatric patients. METHODS: Gastroesophageal double pH monitoring was performed on 68 children with gastroesophageal reflux (GER) diseases and 39 normal children. The pH shifts in the intra-gastric and esophageal lumina were recorded for a total of 24 hour period (P1) and for the period of gastric empty (P2) in supine and upright body postures. RESULTS: The following reflux types were identified: acid GER in 40 cases (58.8%), alkaline GER (AGER) in 8 cases (11.8%), mixed GER (MGER) in 14 cases (20.6%) and silent GER (SGER, i.e., reflux with normal pH values in P1) in 6 cases (8.8%) as well as duodenogastric reflux (DGR). The results showed a number of transient GER and DGR (19 of 39 children) in the control group, recorded mainly in the upright position at meal times and 2 hours postprandially. All pH variables for acid reflux were higher in the acid GER and MGER groups than those in the control group (P < 0.01). The alkaline episode was significantly noted in cases with AGER and MGER in the supine position during P2. There was no significant difference in terms of incidence of esophagitis between GER groups. The gastroesophageal double pH monitoring produces the higher positive diagnostic rate of 91.2% than single esophageal pH testing (79.4%). CONCLUSIONS: Transitory GER and DGR at meal times and 2 hours later might be a physiologic phenomenon. Acid and alkaline reflux occurring in the supine position during P2 should be considered of pathologic significance. This combined gastroesophageal pH monitoring is used not only to improve the diagnostic rate but also to guide clinicians to choose efficient anti-reflux therapy based on the type of reflux as well as to provide refined information for the further study of the pathophysiology of duodenogastroesophageal reflux.

Adolescent↗

PubMed1998

[Analysis of lobar pneumonic tuberculosis].

OBJECTIVE: To heighten the awareness of lobar pneumonic tuberculosis(or tuberculous pneumonia or acute pneumonic tuberculosis). METHOD: 10 cases with lobar pneumonic tuberculosis were reviewed. RESULT: All the patients showed acute onsets and 9 of them had a continuous high fever, and their WBC was not found higher than 10 x 10(9)/L. All of the patients' chest radiographs showed a consolidation in one or two lobars, and in 30% of the patients pleural effusions were found. Significant roent genographic changes could occur in short duration. All the patients were not sensitive to common antibiotics, and the shadow could enlarge in short time. Exudative foci could be absorbed shortly after antituberculosis chemotherapy, and no cavitation was found. CONCLUSION: An early transbroncho-lung biopsy (TBLB) and (or) brushing smear may be advantageous to early diagnosis and treatment of this illness.

Adolescent↗

PubMed1998

[Preliminary study on determination methods of respiratory muscle functions].

Attention has been paid to the research of respiratory muscle functions recently. In this paper some lung function indices concerning respiratory muscle functions, such as maximal inspiratory and expiratory pressure at mouth, inspiratory and expiratory tolerance time, transdiaphragmatic pressure and maximal transdiaphragmatic pressure and diaphragmatic electromyogram etc, were determined in 24 healthy young men and the normal values were obtained. They were important in the study of respiratory muscle functions in hard physical labours, especially in divers, pilots and sportsmen etc. These indices were also useful for evaluating convalescent therapy chronic lung diseases, respiratory muscles training programs or the drug effects on respiratory muscle fatigue etc.

Adult↗

PubMed1998

Sensitization of acnu killing effects on HeLa S3 cells by MGMT antisense RNA transfection.

O6-methylguanine-DNA-methyltransferase (MGMT) plays a very important role in the cellular resistance to nitrosoureas drugs. Inhibition of MGMT might be a useful approach in tumor chemotherapy. In this study, the depletion of MGMT activity by retroviral-mediated antisense RNA transfection were reported. Three retroviral vectors expressing MGMT antisense RNA were constructed and transfected into HeLa S3 cells. The difference of MGMT mRNA, MGMT activity as well as cellular resistance to ACNU before and after transfection were observed. It was found that antisense RNA targeting 5' region and whole length of MGMT mRNA could partially deplete MGMT activity and enhance killing effects of ACNU. However, 3' region antisense RNA had no effect on MGMT modulation.

Antineoplastic Agents↗

PubMed1998

[Studies on infrared spectra of Schiff base ligands and Mn(III) complexes with methylene bridge].

The FTIR spectra (3800-150cm(-1)) of Schiff base ligands and Mn(III) complexes with methylene bridge were measured and investigated. The major bands have been empirically assigned in comparison with a large number of previous results. The characteristic absorption bands of intra-molecular hydrogen bond of ligands were found at ca. 3438cm(-1). The vC=N of ligands and complexes were found at ca. 1630cm(-1). The characteristic absorption bands of the phenyl ring of ligands and complexes were found at ca. 1630cm(-1). The characteristic absorptin bands of the phenyl ring of ligands and complexes were found at ac. 1598, 1469 and 755cm(-1). The vibrations coupling between the M-N stretching modes and the phenyl ring deformation were found at ca. 369cm(-1). The vibrations coupling between the M-N deformation modes and the phenyl ring deformation modes were found at ca. 247cm(-1). The vibrations coupling between the M-O stretching modes and the phenyl ring deformation were found at ca. 329cm(-1). The vibrations coupling between the M-N deformation modes and the phenyl ring deformation modes were found at ca. 275cm(-1). The vMn-Cl of the complexes were found at ca. 303cm(-1). The vMn-N of the complexes shift to higher wavenumbers and the vMn-Cl shift to lower wavenumbers than of the phenylporphyrin Mn(III) complexes.

English Abstract↗

PubMed1997

Functional differentiation of T cells in the intestine of T cell receptor transgenic mice.

The intestinal lamina propria (LP) is a major effector site of the mucosal immune system where antigen-specific and antigen-nonspecific factors shape the functional responses of CD4+ T helper cells. To study the functional differentiation of LP T helper cells we utilized DO11.10 T cell receptor (TCR) transgenic (Tg) mice that expressed a clonotypic TCR specific for a class II major histocompatibility complex-restricted peptide of chicken ovalbumin. The majority of cells expressing Tg TCR (Tg+) in peripheral lymphoid tissue expressed naive surface phenotypes whereas nearly all Tg+ T cells in the intestinal LP expressed an activated/ memory-like phenotype. Flow cytometric analysis of Tg+ T cell populations revealed that a small proportion of cells in peripheral lymphoid tissue but nearly all cells in the LP expressed dual (Tg plus non-Tg) TCRs. In Tg x recombinase-activating-gene-1-deficient (Tg x RAG-1(-/-)) mice, splenic and LP T cells expressed naive surface phenotypes and produced cytokines equivalent to naive splenic cells from Tg x RAG-1(+/+) mice. In contrast, Tg LP cells from Tg x RAG-1(+/+) mice produced 35-fold greater levels of interferon-gamma and 5-fold greater levels of interleukin 4 compared with naive splenic cells. These findings suggested that activation of Tg+ T cells through endogenous non-Tg TCR had promoted the localization and differentiation of memory-like effector T helper cells in the intestine.

Animals↗

PubMed1997

Benzene metabolism in the isolated perfused mouse liver.

The hematotoxicity of benzene (BZ) requires its hepatic metabolism, the release of metabolites into the circulation, and the access of metabolites to the bone marrow. Although a range of potentially toxic metabolites produced by the liver was identified using subcellular systems and isolated hepatocytes, these models do not allow identification of the metabolites released from the liver with respect to time and flow through the liver. We developed an isolated perfused mouse liver model to evaluate metabolites released following a single-pass of radiolabeled BZ and after recirculation of single-pass metabolites back through the liver. Reversing the path of flow through the liver changes the orientation of hepatic oxidizing and conjugating enzymes with respect to perfusate flow. Comparison of metabolite production following normal (orthograde, portal vein to hepatic vein) perfusion with reversed (retrograde) perfusion permitted an evaluation of the impact of zonal distributions of these enzymes on BZ metabolism. The major metabolites detected by HPLC, irrespective of the direction of perfusion, were free phenol (P), phenylsulfate (PS), and phenylglucuronide (PG), plus lesser amounts of hydroquinone (HQ) and hydroquinone glucuronide (HQG). Recirculation of the products of single pass orthograde perfusion through the liver yielded P conjugates as well as low levels of free and conjugated HQ. No free P was detected after recirculation. Although no qualitative differences between orthograde and retrograde perfusion were observed, the percentage of free P and P conjugates (PS + PG) found as free P was twice as great following orthograde perfusion as compared to retrograde perfusion. These results suggest that regional differences in the zonation of enzymes involved in oxidation and conjugation may play a critical role in hepatic BZ metabolism.

Animals↗

PubMed1997

Isomorphism between cell and human languages: molecular biological, bioinformatic and linguistic implications.

The concept of cell language has been defined in molecular terms. The molecule-based cell language is shown to be isomorphic with the sound- and visual signal-based human language with respect to ten out of the 13 design features of human language characterized by Hockett. Biocybernetics, a general molecular theory of living systems developed over the past two and a half decades, is found to provide a physical theory underlying the phenomenon of cell language. The concept of cell language integrates bioenergetics and bioinformatics on the one hand and reductionistic and holistic experimental data on the other to account for living processes on the molecular level. The isomorphism between cell and human languages suggests that the DNA of higher eucaryotes contains two classes of genes--structural genes corresponding to the lexicon and 'spatiotemporal genes' corresponding to the grammar of cell language. The former is located in coding regions of DNA and the latter is predicted to reside primarily in noncoding regions. The grammar of cell language is identified with the mapping of the nucleotide sequences of DNA onto its 4-dimensional folding patterns that control the spatiotemporal evolution of gene expression. Such a mapping has been referred to as the second genetic code, in contrast to the first genetic code which maps nucleotide triplets onto amino acids. The cell language theory introduces into biology the linguistic principle of 'rule-governed creativity,' leading to the formulation of the concept of 'rule-governed creative molecules' or 'creations.' This concept sheds new light on molecular biology, bioinformatics, protein folding, and developmental biology. In addition, the cell language theory suggests that human language is ultimately founded on cell language.

Cell Biology↗

PubMed1997

[Studies on peripheral blood stem cells mobilization by short course and high-dose G-CSF].

OBJECTIVE: To explore the effect of short-course, high dose granulocyte-colony stimulating factor (G-CSF) on peripheral blood stem cell (PBSC) mobolization. METHODS: G-CSF 5microg/kg was injected subcutaneously twice daily for 3 consecutive days. On the first day and the fourth day the peripheral blood and bone marrow were collected for CFU-GM, BFU-E, CFU-mix assays and CD34/CD38 detection. A single apheresis of over 8000ml blood processing was performed with CS-3000 blood cell separator. The mononuclear cells were prepared for hematopoietic colony assays and CD34/CD38 detection before and after freezing. RESULTS: After adminitration of G-CSF, the white blood cell count increased significantly. The CFU-GM, BFU-E, CFU-mix yields and CD34+ CD38+ cell and CD34+ CD38- cells also increased significantly (P<0.05). The median of mononuclear cells was 1.56 x 10(8)/kg. After one week freezing, the recovery of mononuclear cells, CFU-GM, BFU-E yields and CD34+ CD38+ cells were about 80% (P>0.05) and CFU-mix yields was 60%; The CD34+ CD38- cells were decreased compared with that of pre-freezing (P<0.05). The median of the reinfused mononuclear cells was 1.27 x 10(8)/kg,CFU-GM 6. 7 x 10(4)/kg, BFU-E 1.6 x 10(4)/kg, CFU-mix 0.32 x 10(4)/kg, CD34- CD38+ cells 1.6 x 10(6)/kg and CD34+ CD38- cells 0.23 x 10(6)/kg. CONCLUSION: Short course and high-dose G-CSF can effectively mobilize the peripheral stem cells. The mononuclear cells, hematopoietic colonies and CD34/CD38 cells were satisfied for the peripheral stem cells rescue.

ADP-ribosyl Cyclase 1↗

PubMed1997

Pathological classification and diagnosis of intestinal duplication.

OBJECTIVE: To determine the pathological classification and the clinical characteristics of intestinal duplication. METHODS: Eighty-four pediatric patients with intestinal duplication were proved on operation in the last 20 years in the Second Hospital of Harbin Medical University and Harbin Children's Hospital. The pathological classifications were as follows: enteral septum type (2), parietal cyst type (9), parenteral canal type (31), parenteral cyst type (35), and solitary type (1). The clinical presentations and complications included: abdominal mass (24), illius (41), hemorrhage of digestive tract (15) and intestinal perforation with peritonitis (3). Two asymptomatic cases were discovered incidentally. RESULTS: Among the 84 patients, 82 healed, 1 newborn complicated by intestinal fistula died of septicemia, and the other one died of toxic shock. CONCLUSIONS: Recognizing the pathological types, common presentations and complications, and applying the corresponding examination methods timely, doctors may improve the diagnostic accuracy.

Adolescent↗

PubMed1997

Evolutionary regularity of acetabular dysplasia after reduction of developmental dislocation of the hip.

OBJECTIVE: To observe the developmental changes of the acetabulum after reduction of developmental dislocation of the hip and require evolutionary regularity of acetabular dysplasia. METHODS: A follow-up in an average of 7.4 years was carried out in 117 patients (161 hips) with developmental dislocation of the hip after reduction. By the series of X-ray films, acetabular index, acetabular-head index, Sharp's angle, ACM angle (Idelberger's angle) and anteversion were observed. At the same time, centre-head distance discrepancy was measured. RESULTS: Acetabular index returned to normal gradually as the time went by and significantly within one year after the reduction of developmental dislocation of the hip. The process of recovery was nearly stable three years later. Acetabular index in the dysplasia group was above 39 degrees before reduction and decreased slowly after the reduction. However, it was still up to 30 degrees after 3 years observation. The value of centre-head distance discrepancy decreased gradually as the years went by after reduction. CONCLUSIONS: If acetabular index before reduction is above 39 degrees and is still up to 30 degrees three years after reduction, acetabular dysplasia can be diagnosed.

Acetabulum↗