Urea protects from the proapoptotic effect of NaCl in renal medullary cells

Hypertonic NaCl upregulated two sensitive and specific biochemical indices of apoptosis, caspase-3 activation and annexin V binding, in a time- and dose-dependent fashion in renal medullary mIMCD3 cells. Pretreatment with urea (200 mM for 30 min) protected from the proapoptotic effect of hypertonic stress (200 mosmol/kgH(2)O) in this model. The protective effect of urea was dose dependent and was effective even when applied a short time (< or =1 h) following NaCl exposure; this protective effect was not observed in the nonrenal 3T3 cell line. In both mIMCD3 and 3T3 cells, urea failed to protect from the proapoptotic stressor, ultraviolet (UV)-B irradiation. The ability of urea to protect from hypertonic stress was approximately comparable to the protective effect of peptide mitogens epidermal growth factor and insulin-like growth factor (IGF), but it potentiated the IGF effect. Interestingly, the tyrosine kinase inhibitor, genistein, potentiated the proapoptotic effect of urea yet abrogated the proapoptotic effect of hypertonic stress. In aggregate, these data indicate that urea protects from the proapoptotic effect of hypertonic stress in a potentially cell type-specific and stimulus-specific fashion.

[Molecular cytogenetics of bone tumors]

OBJECTIVE

To study alterations of molecular cytogenetics of bone tumor serially.

METHODS

Chromosomal analysis, immunohistochemistry, molecular hybridization, nested-PCR/SSCP, DNA sequence analysis, and gene transfection techniques were used to investigate the common bone tumors.

RESULTS

Chromosomal aberrations were found in 50 cases of aggressive bone tumors, with a chromosome number aberration rate of 86.96% and a structure aberration rate of 93.94%. However, there were differences among different kinds of bone tumors. The incidence of chromosomal instability in 53 patients with bone tumors was higher than that in normal controls. Meanwhile, the fragile sites of chromosomes of the patients were closely correlated with the high nonrandom chromosome breakpoints of tumor cells and related oncogene loci. The data on p53 and Rb from 305 cases and 89 cases, respectively, indicated that abnormalities of p53 and Rb were common events in bone tumors. The accumulation of p53 protein and loss of Rb protein were more common in aggressive bone tumors. Structures and their products of related proto-oncogenes (ras, myc, fos, bcl-2, met) were studied in 124 cases. Bone tumors presented multi-oncogenes abnormalities with differences in different pathological kinds. Exogenous wild-type p53 gene transfected into osteosarcoma cell line induced growth inhibition and apoptosis of tumor cells.

CONCLUSIONS

Abnormalities of chromosomes, proto-oncogenes, and tumor suppressor genes frequently exist in bone tumor cells and are correlated with oncogenesis.

[Allelic polymorphism of HLA-DQA1 locus in Han nationality in Hunan province]

OBJECTIVE

To explore the genetic polymorphism of HLA-DQA1 locus in Han nationality in Hunan province.

METHOD

Sixty samples randomly selected from healthy individuals of Han nationality in Hunan province were typed for HLA-DQA1 by PCR/SSP in combination with silver-staining PCR/SSCP.

RESULTS

Ten types of HLA-DQA1 alleles were found in all 60 samples, HLA-DQA1*0302, *0501, *0102 were the common alleles with gene frequencies of 0.2254, 0.2254, and 0.2041 respectively. Twenty-six kinds of genotypes were found, and the genotype distribution fitted the Hardy-Weinberg equilibrium test (P > 0.05). Five samples which had ambiguity in their PCR/SSP typing were further clarified with PCR/SSCP analysis.

CONCLUSIONS

Normal gene frequency values of HLA-DQA1 alleles in Han nationality in Hunan province are provided; PCR/SSCP can be used to eliminate the ambiguity which might exist in PCR/SSP typing for HLA-DQA1 locus.

[Correlative study on HLA-DR2 allelic polymorphism and systemic lupus erythematosus in the Han nationality in Hunan province]

Fifty-eight systemic lupus erythematosus (SLE) patients and 59 normal controls of the Han nationality in Hunan province were involved in this study to analyze the correlation between HLA-DR2 group specific amplification in combination with HLA-DRB generic amplification PCR/SSCP technique to detect the sequence variation within exon 2 of HLA-DR2 alleles outside the sequence specific primer matching positions. The results were that HLA-DR2 was strongly correlated with SLE (RR = 2.71, P < 0.01); and HLA-DRB1 * 1501 was the allele correlated with disease (RR = 3.01, Pc < 0.05). In addition, PCR/SSCP showed that there was not any novel sequence variation in exon 2 of HLA-DR2 alleles in the Han nationality in Hunan province.

Ras signaling in the inner medullary cell response to urea and NaCl

The small guanine nucleotide-binding protein Ras, activated by peptide mitogens and other stimuli, regulates downstream signaling events to influence transcription. The role of Ras in solute signaling to gene regulation was investigated in the murine inner medullary collecting duct (mIMCD3) cell line. Urea treatment (100-200 mM), but not sham treatment, increased Ras activation 124% at 2 min; the effect of NaCl did not achieve statistical significance. To determine the contribution of Ras activation to urea-inducible signal transduction, mIMCD3 cells were stably transfected with an expression plasmid encoding a dominant negative-acting N17Ras mutant driven by a dexamethasone-inducible (murine mammary tumor virus) promoter. After 24 h of induction, selected cell lines exhibited sufficient N17Ras overexpression to abolish epidermal growth factor- and hypotonicity-mediated signaling to extracellular signal-regulated kinase (ERK) phosphorylation, as determined by immunoblotting. Conditional N17Ras overexpression inhibited urea- and NaCl-inducible ERK phosphorylation by 40-50%, but only at 15 min, and not 5 min, of treatment. N17Ras induction, however, almost completely inhibited urea-inducible Egr-1 transcription, as quantitated by luciferase reporter gene assay, but failed to influence tonicity-inducible (TonE-mediated) transcription. N17Ras overexpression also blocked urea-inducible expression of the transcription factor Gadd153 but did not influence osmotic or urea-inducible apoptosis. In addition, urea treatment induced recruitment of the Ras activator Sos to the plasma membrane. Taken together, these observations suggest a role for Ras signaling in the IMCD cell response to urea stress.

Sugar interaction with metal ions. Crystal structure and FT-IR spectroscopic study of strontium galactarate mono-hydrate

The crystal structure of strontium galactarate mono-hydrate, Sr2+ x C6H8O8(2-) x H2O, Mr = 313.76, monoclinic, P2(1)/c, a = 10.268(2), b = 10.333(2), c = 10.194(2) A, beta = 117.87(3) degrees, lambda(Mo K alpha) = 0.71073 A, Z = 4, Dx = 2.180 Mg m(-3), V = 956.1(3) A3, mu = 5.676 mm(-1), F(000) = 624, T = 293(2) K, R = 0.0260 for 1690 observed reflections and 145 parameters refined, has been determined. The galactarate ion is centro-symmetrical in the crystal structure, although it contains independent half-ions. The Sr2+ ion is nine-coordinated (tricapped trigonal prism) with five Sr-O bonds from carboxylic groups, and four from hydroxyl groups. The water molecule does not take part in the coordination. Six hydrogen bonds are formed, three of them related to the water molecule. The spectroscopic evidence shows that the carboxylic acid dimers of the free acid dissociate. The asymmetric stretching vibrations of the anionic COO groups in the salt are observed at 1609 and 1548, and 1581 cm(-1), assigned to a mono-dentate and a tetra-dentate coordination, respectively. The symmetric stretching vibration is located at 1397 cm(-1). The hydroxyl groups of the galactarate skeleton take part in the metal-oxygen interaction, and the hydrogen-bonding network is rearranged upon sugar metalation.

Sugar interaction with metal ions. FT-IR study on the structure of crystalline galactaric acid and its K+, NH4+, Ca2+, Ba2+, and La3+ complexes

The FT-IR spectra of galactaric acid and its K+, NH4+, Ca2+, Ba2+, and La3+ salts have been recorded and interpreted. Spectroscopic evidence shows that the dimeric carboxylic groups of the free acid are dissociated upon formation of the salt, and the asymmetric and symmetric stretching vibrations of the anionic COO- group in these salts are observed at about 1600 and 1400 cm-1, respectively. The two carboxylic groups of the galactarate coordinate with Ca2+ ions in a monodentate form. One of the carboxylic groups in the Ba2+ salt coordinates in a monodentate state; another group interacts with three cations in a tetradentate form. In the K+, NH4+, and La3+ salts, the COO- groups coordinate in a polydentate manner with the cations. By comparison of the spectra of the salts with that of the free acid, it is concluded that the hydroxyl groups of the galactarate skeleton take part in metal-oxygen interaction, and the hydrogen-bonding network is rearranged upon sugar metalation. The degree of participation of the sugar OH groups in metal-galactarate interaction is varied from the K+ and NH4+ salts to the Ca2+, Ba2+, and La3+ salts.

Production of polyesters consisting of medium chain length 3-hydroxyalkanoic acids by Pseudomonas mendocina 0806 from various carbon sources

Pseudomonas mendocina strain 0806 was isolated from oil-contaminated soil and found to produce polyesters consisting of medium chain length 3-hydroxyalkanoates (mclPHAs). The monomers of mclPHAs contained even numbers of carbon atoms, such as 3-hydroxyhexanoate (HHx or C6), 3-hydroxyoctanoate (HO or C8), and/or 3-hydroxydecanoate (HD or C10) as major components when grown on many carbon sources unrelated to their monomeric structures, such as glucose, citric acid, and carbon sources related to their monomeric structures, such as myristic acid, octanoate, or oleic acid. On the other hand, PHA containing both even and odd numbers of hydroxyalkanoates (HA) monomers was synthesized when the strain was grown on tridecanoic acid. The molar ratio of carbon to nitrogen (C/N) had a significant effect on PHA composition: the strain produced PHAs containing 97-99% of HD monomer when grown in a glucose ammonium sulfate medium of C/N<20, and 20% HO, and 80% of the HD monomer when growth was conducted in media containing C/N>40. It was demonstrated that the HO/HD ratio in the polymers remained constant in media with a constant C/N ratio, regardless of the glucose concentration. Up to 3.6 g/L cell dry weight containing 45% of PHAs was produced when the strain was grown for 48 h in a medium containing 20 g/L glucose with a C/N ratio of 40.

Transcriptional control of development, protein synthesis, and heat-induced heat shock protein 70 synthesis in 2-cell bovine embryos

Experiments were performed to evaluate the role of transcription in early development of bovine embryos. Two transcription inhibitors-5, 6-dichloro-1-beta-D-ribofuranosylbenzimidazole (DRB) and actinomycin D-were used to test whether 1) the inhibitors alter the rate of early embryonic development and protein synthesis, 2) heat shock increases the steady-state amounts of mRNA for the inducible form of heat shock protein 70 (HSP70) in embryos, and 3) this latter effect is blocked by transcription inhibitors. Addition of either DRB or actinomycin D to culture medium beginning 8 h postinsemination (hpi) reduced the proportion of oocytes that had undergone cleavage by 32-34 hpi. Both transcription inhibitors also reduced the proportion of cleaved embryos that reached the 4-cell stage by 32-34 hpi. Incorporation of (35)S-labeled amino acids into de novo synthesized protein by bovine 2-cell embryos was lower for embryos cultured with DRB. Using reverse transcription-polymerase chain reaction, HSP70 mRNA in 2- and 4-cell embryos was increased by exposure to 42 degrees C. Both inhibitors reduced amounts of HSP70 mRNA at 42 degrees C. Results indicate that bovine embryos can undergo transcription in response to heat shock as early as the 2-cell stage. Moreover, the observations that transcription inhibitors reduce rates of cleavage and early development point out the importance of transcription for development from the earliest period of embryonic life.

[Changes of F-actin in neutrophils under fluid shear stress]

Neutrophils are the main defender in the body, and their physiological characters are associated with functions. Because the environments of neutrophils maturation and storage are different from their function environment, they have to adapt thess changes. Filamentous actin (F-actin), as one of the important cytoskeleton components of neutrophils, has different quantity and distribution under different physiological conditions. Previous researches are all focused on static activation of neutrophils using various stimulants such as formyl-methionyl-leucyl-phenylalanine (f-MLP) and tumor necrosis factor(TNF). In our study, Low-Shear 30 and NXE-1 rheometers were used to provide steady or sinusoidaloscillatory fluid shear stress on separated neutrophils. Fluorescent agent Tritc-Phalloidin was added to label F-actin and the mean fluorescent intensity tested by flow cytometry was used as the indication of F-actin quantity and confocal laser scan microscope was used to detect the distribution of F-actin in neutrophils. We found that F-actin polymerization was significantly decreased under both steady and sinusoidal-oscillatory shear stress when the shear stress was below certain level. The density of the cortex F-actin near cell membrane in cells sheared became thinner than in that without shear stress. f-MLP and TNF both could increase actin polymerization in neutophils due to activation. When neutorphils were activated with f-MLP or TNF under shear stress, the quantity of F-actin in the cells was also decreased, but it was still higher than that in the cells absent of f-MLP or TNF. We concluded that neutrophils had different mechanical properties in different fluid environments. F-actin content and distribution would change according to the shear stress values to play their determinant role in neutrophils mechanical adaptation. The mechanism of actin polymerization in neutrophils for mechanical action is probably different from that for chemoattractants and cytokine activation.

Outcomes among African-Americans and Caucasians in colon cancer adjuvant therapy trials: findings from the National Surgical Adjuvant Breast and Bowel Project

BACKGROUND

African-Americans generally have lower survival rates from colon cancer than Caucasian Americans. This disparity has been attributed to many sources, including diagnosis at later disease stage and other unfavorable disease features, inadequate treatment, and socioeconomic factors. The randomized clinical trial setting ensures similarity in disease stage and a uniform treatment plan between blacks and whites. In this study, we evaluated survival and related end points for African-American and Caucasian patients with colon cancer participating in randomized clinical trials of the National Surgical Adjuvant Breast and Bowel Project (NSABP) to determine whether outcomes were less favorable for African-Americans.

METHODS

The study included African-American (n = 663) or Caucasian (n = 5969) patients from five serially conducted, randomized clinical trials of the NSABP. We compared recurrence-free survival, disease-free survival (recurrence, new primary cancer, or death), and survival (death from any cause) between blacks and whites by using statistical modeling to account for differences in patient and disease characteristics between the groups. Statistical tests were two-sided.

RESULTS

Dukes' stage and number of positive lymph nodes were remarkably similar between African-American and Caucasian patients in each trial. Over all trials combined, an 8% (95% confidence interval [CI] = -6% to 25%; P =.27) excess risk of colon cancer recurrence that was not statistically significant was observed for blacks. A greater disparity in survival was seen, with blacks experiencing a statistically significant 21% (95% CI = 6%-37%; P =.004) greater risk of death. Treatment efficacy appeared similar between the groups.

CONCLUSIONS

While the overall survival prognosis was less favorable for African-Americans compared with Caucasians in these trials, other outcomes measured were considerably more similar than those seen in the population at large, suggesting that earlier detection and adjuvant therapy could appreciably improve colon cancer prognosis for African-Americans. Continued investigations into causes of the deficits noted are warranted.

Further evaluation of intensified and increased total dose of cyclophosphamide for the treatment of primary breast cancer: findings from National Surgical Adjuvant Breast and Bowel Project B-25

PURPOSE

In 1989, the National Surgical Adjuvant Breast and Bowel Project initiated the B-22 trial to determine whether intensifying or intensifying and increasing the total dose of cyclophosphamide in a doxorubicin-cyclophosphamide combination would benefit women with primary breast cancer and positive axillary nodes. B-25 was initiated to determine whether further intensifying and increasing the cyclophosphamide dose would yield more favorable results.

PATIENTS AND METHODS

Patients (n = 2,548) were randomly assigned to three groups. The dose and intensity of doxorubicin were similar in all groups. Group 1 received four courses, ie, double the dose and intensity of cyclophosphamide given in the B-22 standard therapy group; group 2 received the same dose of cyclophosphamide as in group 1, administered in two courses (intensified); group 3 received double the dose of cyclophosphamide (intensified and increased) given in group 1. All patients received recombinant human granulocyte colony-stimulating factor. Life-table estimates were used to determine disease-free survival (DFS) and overall survival.

RESULTS

No significant difference was observed in DFS (P =.20), distant DFS (P =.31), or survival (P =.76) among the three groups. At 5 years, the DFS in groups 1 and 2 (61% v 64%, respectively; P =. 29) was similar to but slightly lower than that in group 3 (61% v 66%, respectively; P = 08). Survival in group 1 was concordant with that in groups 2 (78% v 77%, respectively; P =.71) and 3 (78% v 79%, respectively; P =.86). Grade 4 toxicity was 20%, 34%, and 49% in groups 1, 2, and 3, respectively. Severe infection and septic episodes increased in group 3. The decrease in the amount and intensity of cyclophosphamide and delays in therapy were greatest in courses 3 and 4 in group 3. The incidence of acute myeloid leukemia increased in all groups.

CONCLUSION

Because intensifying and increasing cyclophosphamide two or four times that given in standard clinical practice did not substantively improve outcome, such therapy should be reserved for the clinical trial setting.

[The effects of combined use of multiple growth factors on proliferation and differentiation of human osteoblast-like cells]

Four growth factors PDGF, bFGF, IGF-II and TGF-beta, which is believed to have biological effects on bone cells, were examined in this study. The aim was to assess the effects of combinations of three and four growth factors on the proliferation and differentiation of osteoblast-like cells. The incorporation of 3H-TdR, 3H-Proline of osteoblast-like cells and alkaline phosphatase content of the cells were tested. The results showed the combinations of three and four growth factors stimulated the synthesis of DNA, collagen and ALP of osteoblast-like cells. These four growth factors interacted synergistically. The combinations of three and four growth factors showed stronger promoting effect on osteoblast-like cells, compared with the combinations of two growth factors. These findings suggest that the combined use of growth factors be a potential way of bone defect reconstruction and treatment of human bone disease.

[Effects of fluid shear stress on neutrophil surface expression of adhesion molecules]

Fluid shear is a physiological and functional environment for circulating neutrophils where various chemoattractants and cytokines have different effects on neutrophils, activating them or evoking inflammation. So far there have been abundant in vitro researches demonstrating that while neutrophils are activated, some adhesion molecules, which are expressed on the surface of neutrophils, are necessary to cell-to-cell adhesion, and the quantity or quality of these molecules will be changed. The above results were all obtained under static fluid which is quite different from physiological condition. Recently, we used Low-Shear 30 to provide steady or sinusoidal-oscillated fluid shear stress on separated neutrophils with or without f-MLP/TNF stimulation. FITC-anti CD18 monoclonal antibody and PE-anti CD62L monoclonal antibody were added to label CD18 and CD62L on neutrophils suface respectively. Flow cytometry was used to quantify surface expression and positive cell percentage of these two adhesion molecules. The results demonstrat that fluid shear stress increases the expression of CD18 significantly and decreases the CD62L positive cell percentage, but it does not influence the CD62L expression on the CD62L positive cells. The effects of the different patterns of fluid shear stress are not much different, f-MLP or TNF can slightly decrease the expression of CD18 and make CD62L shedding respectively. When one of the two activators and the fluid shear stress act together, the expression of the two adherent molecules can be added. This indicates that the mechanical and biochemical stiumlative action can produce different effects through different receptors and different signal transduction pathways. So the mechanical environment should be considered in the research of activation and adhesion of neutrophils.

Anatomic variation of the extensor tendons to the ring and little fingers: a cadaver dissection study

We found an anatomic variation of the extensor digiti minimi (EDM) and extensor digitorum communis (EDC) in a cadaveric dissection. The EDM had three tendon slips; two slips to the little finger and one to the ring finger metacarpophalangeal (MP) joint. The ring finger slip inserted in the extensor hood with the EDC. The EDC had a separate tendon to the little finger extensor hood. The EDM had an additional pulley distal to the extensor retinaculum. The MP joints of the little and ring fingers extended simultaneously upon pulling the EDM or the EDC. The third slip of the EDM could provide an extra donor site and possibly poses a unique clinical presentation.

[Separation and determination of morphine, pethidine and diazepam by high performance liquid chromatography]

Morphine, penthidine and diazepam in blood were determined by high performance liquid chromatography (HPLC). The HPLC system was consisted of 10 microns particle size C18 column and UV detector set at 254 nm. The mobile phase was V(CH3OH):V(25 mmol/L KH2PO4) = 90:10 with a flow rate of 1.0 mL/min. The average recoveries of morphine, penthidine and diazepam were 93.27%, 90.23% and 93.29% respectively. The linear range was between 0.05-50 mg/L. The detection limit was 0.05 mg/L and CV was less than 6%.

The Posterior Interosseous Nerve Anatomical Variation and Surgical Consideration - A Case Report of Cadaver Study

We found an anatomical variation of the posterior interosseous nerve (PIN) in a cadaver. The PIN entered the supinator muscle 3 cm distal to the radiohumeral joint, but exited from two sites. 50% of the nerve exited under the distal edge of the supinator muscle. The other half of the nerve pierced through the supinator muscle, 4.2 cm distal to the articular surface of the radial head and then joined the remaining PIN as it emerged from the supinator muscle distally. We did not find variations concerning the order and the manner of branches to the muscles. This variation in the PIN could be an additional compression site for this nerve; and therefore responsible for some of the atypical presentations of symptoms and for partial recovery after surgical decompression. A careful surgical dissection should be recommended to avoid injury to this branch.

[Determination of pericarpium papaveris(yingsuqiao) in bottom material of chafing dish by high performance liquid chromatography(HPLC)]

Morphine, codeine and papaverine in bottom material of chafing dish were determined by HPLC. The conditions were as follows: C18 column, mobile phase V(CH3OH):V(25 mmol/L KH2PO4) = 90:10, the flow rate 1 mL/min and the wavelength 254 nm. These three compounds were entirely separated. The blank and positive comtrasts were being done simultaneously. The detection limit was 0.1 mg/L. The experiment showed that this method is sensiuve, accurate and reliable.

[Surgical reduction and rigid internal fixation of midface fractures]

OBJECTIVE

To determine the cause, clinical characteristics and treatment of midface fractures.

METHODS

A retrospective review of 98 patient records was conducted. Data regarding age, cause of fracture, anatomic site, treatment modalities and clinical results were reviewed.

RESULTS

Of the 98 patients, 78.6% were male, with the peak incidence occurring in the age group from 21 to 40 years old. Of the fractures, 32.6% were due to traffic accidents, 24.5% to assaults, and 17.3% to accidental falls. Most patients (87.8%) were treated by open reduction surgery and rigid internal fixation. Only 12.2% of patients were treated by closed reduction fixation. Almost all of the patients regained normal face appearance and functional occlusion.

CONCLUSION

Surgical reduction and rigid internal fixation of midface fractures is a satisfactory method of treatment.

[The effect of age on the regional blood flow of neck of femur in normal Chinese]

This study aimed to assess the effect of age on the regional blood flow of neck of femur in normal Chinese. 133Xe washout method was adopted. The result showed that the femur regional blood flow of normal Chinese decreased slowly with the increase of their age. The relation between age and femur blood flow might be expressed as F = -0.042Y + 9.01(F refers to blood flow, Y refers to age). The average femur regional blood flow of normal Chinese was 7.37 +/- 0.62 ml.(100 g.min)-1 for 21-40 years old. The authors suggest this result can be considered to stand for regional femur blood flow of young healthy adults.

[Effects of two growth factors combination on the proliferation and differentiation of human osteoblast-like cells]

OBJECTIVE

To examine the effects of platelet-derived growth factor (PDGF), basic fibroblast growth factor (bFGF), insulin-like growth factor (IGF-II) and type beta transforming growth factor(TGF-beta) which were believed to have biological effects on bone cells on human osteoblast-like cells.

METHODS

3H-TdR, 3H-Proline and alkaline phosphatase of the osteoblast-like cells were tested to study the combinating effects of different growth factors on the proliferation and differentiation of osteoblast-like cells.

RESULTS

The combination of different growth factors had promotive effect and synergic interact on proliferation and differentiation of osteoblast-like cells.

CONCLUSION

The phenomena indicate that the combination of two growth factors will enhance the biological effects of bone formation.

[Analysis of 413 cases of mandibular fractures]

OBJECTIVE

To investigate the characteristics of mandibular fracture.

METHODS

413 patients with mandibular fracture were chosen from patients who received treatment at the department of oral and maxillofacial surgery, College of Stomatology, West China University of Medical Sciences from 1986 to 1995, and a retrospective study was carried out. Chi-square test, t-test and linear regression were used to analyzed age, sex, causes, anatomic site, complicated injury, and treatment of jaw fracture.

RESULTS

Fracture of Mandible occurred mainly in male, and during 20 to 29 years old. Mental fracture was common in mandibular fracture, and fracture of central craniofacial bone and craniocerebral injury were often complicated with jaw fracture.

CONCLUSION

Mandibular fractures are caused mainly by traffic ever since 1990, and rigid intrafixation is a satisfactory treatment which has been accepted by surgeons.

[Glutathione S-transferase GSTM1 and GSTT1 genotypes and susceptibility to lung cancer]

A 1:1 matched population-based case-control study was conducted in Xuanwei City, Yunnan Province, where the lung cancer mortality is among China's highest. In this study there were 86 newly diagnosed lung cancer cases and 86 matched control subjects with the same sex, fuel type used, and age(+/- 2 years). Buccal cells were collected from each subject to determine the genotypes of GSTM1 and GSTT1. It was found that the rate of GSTM1 null genotype was higher in the case group than in the control group, and its odds ratio was 2.39(95% CI: 1.25-4.56). The odds ratio became 2.62(95% CI: 1.33-5.15) when other possible confounding factors such as smoking, COPD, and the lifetime exposure to unvented fuel combustion (tons) were adjusted. No association was found between GSTT1 null genotype and lung cancer. The rate of GSTM1 null genotype in Xuanwei City was found to be similar to those of other Chinese populations.

Study on air pollution in Beijing's major industrial areas using multielements in biomonitors and NAA techniques

Three kinds of plant leaves, Chinese white aspen, arborvitae, and pine needles, have been sampled from the Yanshan Oil refinery complex, the Capital Iron and Steel Factory, and Badachu, a control area in Beijing, as biomonitors for air-pollution studies. Each sample was divided into two parts, washed, and unwashed. Thirty-one trace elements (As, Au, Br, Ca, Cd, K, La, Lu, Mo, Na, Sb, Sm, U, W, Yb, Ba, Ce, Co, Cr, Cs, Eu, Fe, Hf, Hg, Rb, Sc, Se, Sr, Ta, Tb, Th, and Zn) have been determined by using the relative and the K0 methods of instrumental neutron activation analysis (NAA) techniques. The results indicated the following: (1) The concentration of trace elements in unwashed samples are much higher than these in washed samples; (2) the area around Capital Iron and Steel Factory is heavily polluted, and the Yanshan Oil refinery complex area is moderately polluted; (3) Chinese white aspen is a good biomonitor in particular seasons and pine needles are better than arborvitae for yearly monitoring; (4) elements As, Cd, Hg, Co, Rb, Sb, W, and Zn are highly absorbed by Chinese white aspen. Pine needles are sensitive for the absorption the elements Br, Cr, Cd, Fe, Sc, Cs and rare earth elements, but arborvitae is very sensitive for the absorption of Sr.

Clinical significance of an extensor tendon anomaly to the little finger--a new finding

A new anatomical variation of extensor digiti minimi (EDM) was discovered during our anatomical studies. The EDM usually gives one tendon to the little finger to extend the metacarpophalangeal joint (MPJ) independently from the other fingers. The EDM in our cadaver had three tendon slips. It supplied the MPJ of the little finger with two tendon slips. Along with the extensor digitorum communis (EDC), the EDM also had an additional slip to the ring finger MPJ extensor hood apparatus. The little finger also received a separate tendon from EDC.

Factors influencing the levels of fatty acid synthase complex activity in fowl

There is a notable discrepancy between the FAS (fatty acid synthase) activity of four types of fowl (egg chicken, meat chicken, egg duck, and meat duck) with distinctively different body fat levels. There is a 14.8 fold difference per unit body weight between the maximum and minimum FAS activities. The three major factors affecting this discrepancy are liver weight per unit body weight, which is 2.3 times greater in meat ducks than in egg chickens, the amount of FAS protein per gram of liver, which is 1.85 times greater in meat ducks than in egg chickens, and the FAS specific activity in meat ducks, which is 3.5 times greater in meat ducks than in egg chickens. Within the same species of egg chickens, the abdomen fat per kg of body weight at 470 days after egg production is 66 times greater than 90 days before egg production and the liver FAS activity is increased 9.6 fold. The 9.6 fold FAS activity increase resulted from an increase in the specific activity, since the liver weight per kilogram of body weight remained constant at approx. 20 grams and the FAS weight per gram of liver also remained constant at approx. 4.5 mg. This shows that the control of the basic FAS activity level which is closely related to the level of body fat does not mainly arise from genetic control. For the same kind of fowl, the control of the basic FAS activity level occurs after gene expression. It is suggested that control may be imposed in the folding phase when new peptides give rise to functional proteins.

Preliminary study on the relationship between osteoporosis and trace elements with rat models

Thirty rats were divided randomly into five groups and fed with different feeds. They were killed after 2 mo. Right thighs of these rats were taken as samples. Bone mineral densities of these samples were measured by the double-energy x-ray bone mineral densitometer, and trace elements contents of the samples were analyzed by neutron activation analysis. Results of the experiments showed that some elements were well correlated with others, and there were obvious variances between some elements of the normal group and those of other four groups.

Characterization of a rat Na+-dicarboxylate cotransporter

The metabolism of Krebs cycle intermediates is of fundamental importance for eukaryotic cells. In the kidney, these intermediates are transported actively into epithelial cells. Because citrate is a potent inhibitor for calcium stone formation, excessive uptake results in nephrolithiasis due to hypocitraturia. We report the cloning and characterization of a rat kidney dicarboxylate transporter (SDCT1). In situ hybridization revealed that SDCT1 mRNA is localized in S3 segments of kidney proximal tubules and in enterocytes lining the intestinal villi. Signals were also detected in lung bronchioli, the epididymis, and liver. When expressed in Xenopus oocytes, SDCT1 mediated electrogenic, sodium-dependent transport of most Krebs cycle intermediates (Km = 20-60 microM), including citrate, succinate, alpha-ketoglutarate, and oxaloacetate. Of note, the acidic amino acids L- and D-glutamate and aspartate were also transported, although with lower affinity (Km = 2-18 mM). Transport of citrate was pH-sensitive. At pH 7.5, the Km for citrate was high (0.64 mM), whereas at pH 5.5, the Km was low (57 microM). This is consistent with the concept that the -2 form of citrate is the transported species. In addition, maximal currents at pH 5.5 were 70% higher than those at pH 7.5, and our data show that the -3 form acts as a competitive inhibitor. Simultaneous measurements of substrate-evoked currents and tracer uptakes under voltage-clamp condition, as well as a thermodynamic approach, gave a Na+ to citrate or a Na+ to succinate stoichiometry of 3 to 1. SDCT1-mediated currents were inhibited by phloretin. This plant glycoside also inhibited the SDCT1-specific sodium leak in the absence of substrate, indicating that at least one Na+ binds to the transporter before the substrate. The data presented provide new insights into the biophysical characteristics and physiological implications of a cloned dicarboxylate transporter.

A practical synthesis of 3-substituted delta 3,5(6)-steroids as new potential 5 alpha-reductase inhibitor

A new and practical synthetic approach to 3-substituted delta 3,5(6)-Steroids, as potential 5 alpha-reductase inhibitor, is described. The key step involves Pd-catalyzed coupling reaction of steroid 3-enol 5H-3-oxo-octafluoropentanosulfonates. 3-Phenylacetylenyl substituted delta 3,5(6)-steroid 3g and 3-phosphate substituted delta 3,5(6)-steroid 3f in our synthesized compounds exhibited high 5 alpha-reductase inhibitory activity in vitro assay.

[The manifestations of 496 cases with thyroid-related immune orbitopathy and normal thyroid function]

OBJECTIVE

To observe the clinical manifestations of thyroid-related immune orbitopathy (TRIO) with normal thyroid function.

METHODS

496 cases with TRIO were collected from 1973 to 1994 and their clinical manifestations were analyzed.

RESULTS

The clinical manifestations showed that males are more than females. The disease occurred in middle aged persons with unilateral exophthalmos as the primary early manifestation. Most of the cases had the signs of eyelids and extraocular muscle involvement.

CONCLUSIONS

The thyroid-related immune orbitopathy with normal thyroid function can be named thyroid-related immune orbitopathy-II. The clinical characteristics of this disease are unilateral, of signs of eyelids, exophthalmos and enlargement of eye muscles. The pseudo-tumors of the orbit are mainly considered for differential diagnosis.

Influence of IFN-beta1b (Betaferon) on cytokine mRNA profiles in blood mononuclear cells and plasma levels of soluble VCAM-1 in multiple sclerosis

Inflammatory cell infiltration within the central nervous system (CNS) and upregulation of both pro- and anti-inflammatory cytokines are characteristic for multiple sclerosis (MS). Treatment with interferon-beta 1b (IFN-beta1b) reduces the number and severity of MS relapses. To examine whether treatment with IFN-beta1b affects levels of cytokine mRNA expressing blood mononuclear cells (MNC) we employed in-situ hybridization with synthetic oligonucleotide probes to detect and enumerate IFN-gamma, TNF-alpha, IL-10, TGF-beta and perforin mRNA expressing cells in MS patients before treatment with IFN-beta1b and during treatment for 3-6 weeks and for 3-6 months. Numbers of blood MNC spontaneously expressing TNF-alpha and IL-10 mRNA were lower after 3-6 months of treatment, while numbers of IFN-gamma, TGF-beta and perforin mRNA expressing MNC were not affected by treatment. IFN-beta1b had no influence on levels of MBP-reactive IFN-gamma, TNF-alpha, TGF-beta, IL-10 or perforin mRNA expressing blood MNC determined after 3-6 weeks or 3-6 months of treatment. Parallel measurements of plasma concentrations of soluble vascular cell adhesion molecule-1 (sVCAM-1) revealed elevated levels after 3-6 weeks of treatment and these levels remained higher after 3-6 months of treatment. The results suggest that IFN-beta1b treatment upregulates plasma levels of sVCAM-1, but has little effects on numbers of blood MNC expressing mRNA of the pro- and anti-inflammatory cytokines under study.Copyright Lippincott-Raven Publishers

[Reoperative treatment of recurrent retroperitoneal tumor]

OBJECTIVE

To improve the resection rate and survival rate for recurrent retroperitoneal tumor (RRT).

METHOD

We analysed 34 patients with RRT who were treated in our hospital from 1987 to 1995. One patient had benign tumor, the others malignant. Because 7 patients were operated on over one time, we performed 53 operations including complete resection in 42 patients, palliative resection 8 and biopsy 3.

RESULT

The 1-and 2-year survival rates for complete resection cases were 71.2% and 65.3%. The patients who received palliative resection and biopsy died within one year.

CONCLUSION

The diagnosis, preoperative preparation and intraoperative management of RRT are important to operative safety and survival rate. We emphasize the importance of reoperation and complete resection for RRT.

Detection of Borrelia burgdorferi from ticks (Acari) in Hebei Province, China

From May 1992 to August 1993, 1,196 ticks were collected by flagging vegetation and from domestic animals in Chengde, Zhangjiakou, Shijiazhuang, and Handan districts of Hebei Province. Of those ticks collected, 954 were Haemaphysalis japonicum Warburton and H. longicornis Neumann, 205 were Ixodes persulcatus Schulze, and 37 were Dermacentor silvarum Olenev. Four strains of Borrelia burgdorferi were isolated from 135 I. persulcatus collected in Weichang and Zhuolu counties. Three of 574 Haemaphysalis spp. (collected in Laishui, Pingshan, and Xinglong counties) were positive for B. burgdorferi by direct immunofluorescent assay. One of 24 H. japonicum and 1 of 1 I. persulcatus (collected in Zhuolu) were positive for B. burgdorferi by polymerase chain reaction. This is the 1st report of a B. burgdorferi isolation from H. japonicum.

[The effects of TGF-beta on the proliferation and differentiation of human osteoblast-like cells]

Osteoblast-like cells were isolated from embryonic human calvarium with modified enzyme digestion method. TGF-beta which is believed having biological effects on bone cells was added into the culture medium with separate concentrations. The incorporation of 3H-TdR, 3H-Proline of osteoblast-like cells and alkaline phosphatase(ALP) content of the cells were tested to study the effects of the TGF-beta on the proliferation of osteoblasts. The results showed that TGF-beta increased ALP activity and the synthesis of collagen, and the cell proliferation was inhibited. It affected the proliferation and differentiation of osteoblast-like cells with the best 1 ng/ml among four concentration of 0.01-10 ng/ml. These findings suggested that function of TGF-beta might be modified by other local growth factors.

[The effects of IGF-II on the proliferation and differentiation of human osteoblast-like cells]

Biological regulatory mechanism which supports bone cell development within the context of proliferation/differentiation relationship serves as a viable basis for addressing skeletal disorders and provides experiment and theoretic basis for selection and utilization of growth factors to reconstruct bone defect. Osteoblast-like cells isolated from human calvarium were used in this study. IGF-II were investigated by adding in the culture medium with different concentration. The results showed that IGF-II stimulated DNA, collagen synthesis and ALP activity of human osteoblast-like cells. Its effects were strong for proliferation and differentiation of osteoblast cells, when 10 ng/ml of four different concentrations (0.1, 1, 10 and 100 ng/ml) were used. IGF-II was proved to be important factor in bone regeneration.

Optic neuritis and cytokines: no relation to MRI abnormalities and oligoclonal bands

Acute unilateral monosymptomatic optic neuritis (ON) is a common first manifestation of MS if associated with multiple MS-like lesions on brain MRI and oligoclonal IgG bands (OB) in the CSF, whereas ON patients lacking these laboratory abnormalities are considered to have a good prognosis regarding future MS development. Several cytokines involved in immune regulation are upregulated in blood and even more noticeable in CSF in MS. To study a possible relation between cytokine profiles and presence versus absence of MS-like brain MRI lesions and CSF OB, we used in situ hybridization to examine mRNA expression of the proinflammatory interleukin-12 (IL-12), interferon-gamma, and tumor necrosis factor-alpha and the immune response downregulating IL-10, transforming growth factor-beta, and IL-4 in blood and CSF mononuclear cells (MNC) from 59 patients with untreated ON. There were no differences in numbers of MNC in blood or CSF expressing any of the cytokines under study, upon subgrouping the ON patients regarding presence (n = 31) versus absence (n = 28) of MRI lesions, presence (n = 45) versus absence (n = 14) of OB, or duration after onset of ON (<1 month, n = 30, versus >1 month, n = 29). Similarly, no differences were observed for numbers of myelin basic protein-reactive blood MNC expressing any of these cytokines after subgrouping according to these variables. Our findings suggest that the cytokine profile, as examined in this study, is less useful to determine the risk of future development of clinically definite MS in ON patients or as indicator for therapeutic interventions in ON. An upregulation of both pro- and anti-inflammatory cytokines in ON patients seems to be more related to the CNS disease per se, whether limited to the optic nerve or not, than to the inflammatory process characteristic for MS.

[Diagnosis and treatment of blowout fracture of the orbit]

OBJECTIVE

To analyze the diagnosis and treatment of blowout fracture of the orbit.

METHODS

78 cases with blowout fracture of the orbit seen in 20 years were retrospectively analyzed. In different years, different methods of examinations were used. There were 16 cases who had undertaken X-ray examinations, 31 cases, ultrasonographic examinations and 72 cases, CT.

RESULTS

The positive rate of the CT examinations with blowout fracture of the orbit was 100%, CT having the tendency to eventually replace the X-ray. Ultrasonography shows only changes of intraorbital tissue, providing an auxiliary method for diagnosis.

CONCLUSION

With the progress of modern photographic methods, blowout fracture of the orbit is known more deeply and the advance helps in the improvement of the treatment of the disease.

[The culture of TMJ condylar cartilage cells and study on their biological behaviors in vitro]

To investigate the behavoir of TMJ condylar cartilage cells in vitro, the mandibular condylar cartilage cells were harvested from a 5-month-old human fetus by dissection and sequential digestion with 0.25% trypsin and 0.2% collagenase (type II). The isolated cells were cultured in DMEM medium and identified by histochemical and immunohistochemical methods. Cell proliferation, morphology and ultrastructure were observed by phase-contrast microscope, cytologic staining and electronic microscope. In primarily cultured cells, polygonal chondroblast-like cells dominated and they were confirmed by the positive result of immunohistochemical examination for type II collagen and Toludin blue staining. In conclusion, the TMJ cells in this culture system kept their phenotype in vivo.

[Molfig, a software for displaying the structure and vibration of molecule]

A Molfig software has been developed for displaying the structure and vibrational mode of molecule in our lab. Various functions and a friendly interface are equipped in the software. The testing results showed that the software may enhance our understanding of the relationship between the vibrational behavior and the structure of molecules.

[Alteration in regional blood flow in minipigs' femur under inadequate decompression studied by isotopes washout method]

We studied the alteration in regional blood flow in minipigs' femur under inadequate decompression after hyperbaric air exposure. The animals were placed in the hyperbaric chamber and exposed to the pressure of 0.5 MPa for 1.5 h, which was reduced to atmosphere at an ascent rate of 0.03-0.04 MPa/min. Regional blood flow in the femur was measured by the isotopes washout method of inhaling 133Xe. The radioactivity was monitored by a multifunctional blood flowmeter interfaced to a minicomputer. Before exposure, the values of average blood flow (F) of femur on the left and right were 15.4 +/- 1.8 and 16.9 +/- 2.0 ml/100 g.min respectively. The values of blood flow (f1) of hematopoietic marrow were 19.1 +/- 2.0 and 21.3 +/- 2.0 ml/100 g.min (n = 7). After inadequate decompression, F values were reduced to 10.3 +/- 1.8 and 11.1 +/- 1.6 ml/100 g.min and f1 values reduced to 13.9 +/- 1.4 and 13.8 +/- 1.0 ml/100 g.min (n = 7), which were obviously lower than those before exposure (P < 0.05). This experiment showed that significant reduction in blood flow in the femur region occurred under inadequate decompression after the exposure of minipigs hyperbaric environment, suggesting that ischemia is a causative factor of osteonecrosis.

The prognosis and the treatment of patients with a C3/4 spinal cord injury

Twenty patients with a C3/4 spinal cord injury have been treated in our hospital since 1974. There were 15 new patients. The average follow up period was 68 months, ranging from 7 to 162 months. The 15 new cases were classified as Frankel A in nine cases, B in one, and C in five. Frankel A or B were usually accompanied by either an unstable spinal fracture or by spinal canal stenosis at the C3/4 level. Twelve patients received surgery. At the most recent follow up, eight of the 15 patients (53.3%) had improved according to Frankel's classification. Five, all Frankel A on remission, have died between 2 and 156 months after injury. Seven patients required tracheotomy on account of severe respiratory disturbance.

[Orbital exenteration associated with cavity reconstruction]

OBJECTIVE

A surgery was designed for the cosmetic improvement after orbital exenteration.

METHODS

Exenteration associated with simultaneous or secondary orbital reconstruction was performed on 22 patients, including transplantation of temporalis muscle in 11 cases, temporoparietal fascia with vascular pedicle in 10 cases and latissimus dorsi myocutaneous free flap in one case.

RESULTS

Except 7 patients who needed palpebral resection and orthopedic operation the second time, all of them were fitted well with ocular prostheses postoperatively and obtained satisfactory cosmetic results.

CONCLUSION

Among the three methods of orbital reconstruction, the temporoparietal fascia transplantation is the best.

A rating instrument for the evaluation of in-patient rehabilitation programmes in China. Results of reliability and validity testing

To objectively evaluate in-patient rehabilitation programmes in China, we developed a new rating scale: the Inpatient Psychiatric Rehabilitation Outcome Scale (IPROS). The scale has five subscales: performance in occupational therapy, daily activities, socialisation, personal hygiene, and level of interest in external events. Evaluators (physicians or nurses) observe patients for one week before coding items on a five-point scale. Comparison of four independent evaluators' results for 32 schizophrenic patients assessed on two separate occasions indicated that the inter-rater and test-retest reliability for the overall IPROS score and for the five subscale scores was excellent (all ICC values > or = 0.973). Validity was evaluated by comparing IPROS results with those of five other independently assessed clinical measures for 101 chronic schizophrenic patients before and after a six-month rehabilitation programme; concurrent validity and longitudinal validity were satisfactory (correlation coefficients 0.37-0.81, all P values < 0.01).

Partial desiccation of mature embryo-derived calli, a simple treatment that dramatically enhances the regeneration ability of indica rice

Regeneration of indica rice varieties remains a limiting factor for researchers undertaking rice Iransformation experiments. As reported for japonica rice and other crops, partial desiccation of indica rice calli dramatically promotes organogenesis and leads to high regeneration ability. We are now able to obtain 66.5%, 61.1% and 73.7% of calli that regenerate plants for the indica varieties TN1, IR72 and IR64 whereas in non desiccated controls only 30.0%, 15.5% and 18.7% of calli regenerated, respectively. Plants obtained were phenotypically normal and 50% were highly fertile. Partial desiccation is a reliable and simple method for improving indica rice regeneration. It also shortens the time of in vitro culture.