[Changes in contents of chromium, zinc and copper in the blood, liver and kidney of diabetic rats]

Contents of chromium, zinc and copper in the blood (or serum), liver and kidney of diabetic rats induced by streptozotocin were determined for three weeks by graphite stove and flame atom absorption spectrophotometry to study the changes in trace elements in diabetics. Results showed liver chromium level increased significantly and kidney chromium level lowered significantly in diabetic rats, as compared with normal ones. Zinc and copper in liver and kidney and serum copper also increased to various extent during three-week observation period. No changes in chromium, zinc and copper levels in blood (or serum), liver and kidney, with the course of the disease, were observed. But, contents of trace elements in rats correlated with their blood sugar levels closely, and chromium, zinc and copper contents in the liver correlated with those in the kidney directly, and with chromium content in the kidney inversely. Therefore, improvement of blood sugar level in diabetic rats may, to a certain extent, improve the disturbance of trace elements in the body.

Hairpin loops consisting of single adenine residues closed by sheared A.A and G.G pairs formed by the DNA triplets AAA and GAG: solution structure of the d(GTACAAAGTAC) hairpin

The DNA undecamers GTACAAAGTAC (AAA 11-mer) and GTACGAGGTAC (GAG 11-mer) have been studied in solution by high-resolution NMR spectroscopy. Both duplexes form stable hairpins containing single deoxyadenosine loops and stems containing five base-pairs that are closed at the loop end by sheared AxA and GxC pairs, respectively. These molecules thus contain new AAA and GAG loop turn motifs. All protons, including the chiral H5'/H5" protons of the loop residues, were assigned using NOESY, DQF-COSY and heteronuclear 1H-31P COSY experiments. The backbone torsion angles were constrained using experimental data from NOE crosspeaks, three-bond 1H-1H coupling constants and four-bond 1H-31P coupling constants and four-bond 1H-31P coupling constants. The AAA and GAG 11-mers form similar structures in solution. The detailed structure of the AAA 11-mer was determined by the combined use of NMR, distance geometry and energy minimization methods. This structure exhibits good stacking of the loop adenosine base on the closing 5Ax7A sheared pair, with the 6A base stacking on the 5A base and the 6A deoxyribose stacking with the 7A base. All sugars in the AAA 11-mer hairpin adopt the typical DNA C2'-endo conformation and a sharp backbone turn occurs between residues 6A and 7A. This loop turn is brought about mainly by a change in the backbone phosphate torsion angles from zeta(g-) alpha(g-) to zeta(g+) alphat(g+) at the turn. The gamma torsion angle of residue 7A in the closing sheared pair also changes from gauche+ to trans. In Pu1NPu2 loop turns of the GCA, AAA and GAG types, the chemical shift of the H4' proton of the loop deoxyribose depends on the nature of Pu2; this reflects the stacking of the loop sugar on the Pu2 base and the different ring current effects of A or G in this position.

A replication function associated with the activation domain of the Epstein-Barr virus Zta transactivator

The Zta transactivator is crucial for both Epstein-Barr virus (EBV) lytic gene expression and lytic DNA replication. We have used a cotransfection-replication assay to examine the effect of mutations in the Zta activation domain (amino acids [aa] 1 to 167) on Zta replication activity. Deletion of Zta aa 25 to 86, which are critical for transcriptional activation of ori-Lyt, or aa 93 to 141 did not adversely affect replication of an ori-Lyt-containing target plasmid. However, removal of aa 2 to 25 (delta2-25) abolished replication activity. Within this subdomain, deletion of aa 2 to 10 (delta2-10) or mutation of codons 18 and 19 (m18/19) or 22 and 26 (m22/26) did not affect replication competency, while deletion of codons 13 to 19 (delta13-19) or mutation at codons 12 and 13 (m12/13) impaired Zta replication function. Each of the replication-negative Zta variants was capable of transactivating expression from both BHLF1 promoter-chloramphenicol acetyltransferase constructions and the BMRF1 promoter on endogenous EBV genomes in Raji cells with efficiency comparable to that of the wild-type polypeptide. Thus, a replication contribution of Zta was functionally separable from its transactivation activity and was supplied by the N-terminal region encompassing aa 11 to 25. Replication by a subset of the impaired Zta mutants was partially rescued upon the addition of Rta to the replication assay. The contribution of Rta mapped to domain II of the Rta activation domain and was specific for this region. A chimeric Rta-EBNA-2 transactivation domain fusion, which retains the DNA-binding and transactivation properties associated with wild-type Rta, failed to rescue replication-deficient Zta. Our data suggest that Rta may act as an ancillary replication factor in EBV ori-Lyt DNA synthesis by stabilizing Zta-replisome interactions.

[Analysis of types of P53 gene mutation in gastric cancer tissues]

To study etiology of gastric cancer, polymerase chain reaction-single sequence configuration polymorphism (PCR-SSCP) method was used to analyze the changes of P53 gene in gastric cancer tissues derived from areas with high prevalence of it. Changes in P53 gene occurreds in 45 of 90 specimens of gastric cancer tissues, and 39 of them showed focal mutation and six were deletion and insertion. Among the point mutation, 66.7% were substitution of A to G (G-A) or G to A (A-G), and only 15.5% were substitution of T to G (G-T) or G to T (T-G). These results suggest that there is a close relationship between P53 gene mutation and occurrence of gastric cancer. Based on the characteristics of base pair mutation, it is postulated that methylating carcinogen and polycyclic aromatic hydrocarbon from environment contributed to the above results.

Expression of keratinocyte growth factor in periapical lesions

The epithelial proliferation associated with inflammatory periapical lesions and with periapical cyst formation represents an interesting but poorly understood pathological change. Keratinocyte growth factor (KGF) is a recently identified growth factor that is produced by stromal fibroblasts and acts specifically to stimulate epithelial growth and differentiation. To investigate its possible role in the activation of the normally quiescent rests of Malassez, we examined the expression of KGF by in situ hybridization of sections of normal periodontal ligament (PDL) and of 12 periapical granulomas or cysts. Normal PDL and periapical granulomas with scant inflammatory infiltration showed few cells expressing message for KGF. However, KGF-expressing cells were found in the connective tissue stroma close to dense foci of inflammatory cells and to proliferating epithelial elements and cystic epithelial linings. Examination of tissues by the reverse-transcription polymerase chain reaction (RT-PCR) showed KGF expression in 4 specimens of periapical lesions but low or undetectable levels in normal PDL. These observations suggest that the induction of KGF expression in the stromal cells of periapical lesions may play an important role in stimulating the epithelial proliferation associated with cyst formation.

[Burn bacteremia in children]

214 cases of burn children with bacteremia accounting for 6.4% of the total number of admission were treated in our hospital from 1981 through 1993, and the mortality was 29.44%. All the patients were classified according to their age, burn area, and complications such as inhalation injury and shock, agents causing the bacteremia or type of bacteria invasion, time for developing bacteremia. The inducing causes and prognosis of bacteremia were analysed, aiming at eruditing the regular pattern of bacteremia and providing means for preventive measures in treatment.

Wortmannin inhibits insulin secretion in pancreatic islets and beta-TC3 cells independent of its inhibition of phosphatidylinositol 3-kinase

Glucose is the primary stimulus for insulin secretion by pancreatic beta-cells, and it triggers membrane depolarization and influx of extracellular Ca2+. Cholinergic agonists amplify insulin release by several pathways, including activation of phospholipase C, which hydrolyzes membrane polyphosphoinositides. A novel phospholipid, phosphatidylinositol 3,4,5- trisphosphate [PtdIns(3,4,5)P3], a product of phosphatidylinositol 3-kinase (PI 3-kinase), has recently been found in various cell types. We demonstrate by immunoblotting that PI 3-kinase is present in both cytosolic and membrane fractions of insulin-secreting beta-TC3 cells and in rat islets. The catalytic activity of PI 3-kinase in immunoprecipitates of islets and beta-TC3 cells was measured by the production of radioactive phosphatidylinositol 3-monophosphate from phosphatidylinositol (PtdIns) in the presence of [gamma-32P]ATP. Wortmannin, a fungal metabolite, dose dependently inhibited PI 3-kinase activity of both islets and beta-TC3 cells, with an IC50 of 1 nmol/l and a maximally effective concentration of 100 nmol/l, when it was added directly to the kinase assay. However, if intact islets were incubated with wortmannin and PI 3-kinase subsequently was determined in islet immunoprecipitates, approximately 50% inhibition of PI 3-kinase activity (but no inhibition of glucose- and carbachol-stimulated insulin secretion) from intact islets was obtained at wortmannin concentrations of 100 nmol/l. Wortmannin, at higher concentrations (1 and 10 micromol/l), inhibited glucose- and carbachol-induced insulin secretion of Intact rat islets by 58 and 92%, respectively. Wortmannin had no effect on the basal insulin release from rat islets. A similar dose curve of inhibition of glucose- and carbachol-induced insulin secretion by wortmannin was obtained when beta-TC3 cells were used. Cellular metabolism was, not changed by any wortmannin concentrations tested (0.01-10 micromol/l). Both basal cytosolic [Ca2+]i and carbamyl choline-induced increases of [Ca2]i were unaffected by wortmannin in the presence of 2.5 mmol/l Ca2+, while Ca2+ mobilization from intracellular stores was partially decreased by wortmannin. Together, these data suggest that wortmannin at concentrations that inhibit PI 3-kinase does not affect insulin secretion. PI 3-kinase is unlikely to have a major role in insulin secretion induced by glucose and carbachol.

[Analysis of changes in human embryo fibroblasts with long-term exposure to drinking water in gastric cancer prevalent areas by flow cytometry]

Cell cycle distribution, cell proliferation index (PI) and DNA index (DI) were analyzed with flow cytometry (FCM) to study changes in human embryo fibroblast exposed to drinking water in gastric cancer prevalent areas for a long time. Results showed both proportion of cells in S and G2M phases and PI increased significantly, DI were beyond its normal range, and cells revealed morphologically abnormal. It suggests drinking water in gastric cancer prevalent areas may contain carcinogenic substances, and correlate closely to high incidence of gastric cancer.

Pitfalls in the use of random amplified polymorphic DNA (RAPD) for fingerprinting of gram negative organisms

Two arbitrary PCR primers for random amplified polymorphic DNA (RAPD) bacterial fingerprinting were used to test factors which may affect RAPD PCR results. These primers have been used in previously published RAPD fingerprinting studies. As expected, the MgCl2 concentration and template concentration in the reaction mixture may affect the RAPD banding patterns. The results obtained were not comparable between runs when using the Hybaid thermal cycler when all other conditions were kept constant. Addition of DMSO, gelatin and repeated subculturing did not appear to affect the banding patterns. A second set of primers directed against known repetitive sequences in Gram negative bacteria (REP1/REP2 and ERIC2) were examined to compare with RAPD as a means of fingerprinting organisms. The reproducibility was excellent. The results suggest RAPD primers can provide some useful comparative information on suspected related strains when tested on the same day and under the same conditions. PCR using REP1/REP2 and ERIC2 primers may provide a more reliable and reproducible alternative method for fingerprinting Gram negative bacteria.

DNA fingerprint variability within and among parental lines and its correlation with performance of F1 laying hens

Genetic diversity within and among nine pure lines of Beijing White Leghorn chickens was determined by DNA fingerprinting using human ministatellite probes 33.6 and α-globin 3'HVR, as well as bacteriophage M13. Within lines similarity coefficients ranged from 0.497 to 0.628, significantly higher than that within a sample of white chicken from a local market. Relationships among lines were established by clustering analysis based on inter-line coefficients of difference calculated from DNA fingerprints of pooled DNA. A complete diallel crossing among the nine pure lines was conducted. By using linear correlation analysis, it was found that the maximum distance between parental lines was positively correlated with egg number, egg production, survival rate and their corresponding heterosis percentages within a pair of reciprocal crosses. Similar relationships were found where only the higher of the reciprocal crosses were used in the analysis. It was also shown that similarity coefficients within a sire line or dam line were positively correlated with 40-week egg number and its heterosis percentage and the heterosis percentage for 40-week egg production, but negatively correlated with the 40-week survival rate of the cross-bred populations.

[Mycethemia: an analysis of 56 cases]

Mycethemia was diagnosed in 56 burn patients between 1958 and 1992. The overall incidence was 0.39% and the mortality rate was 39.29%. Candida albicans, constituting for 75% of cases, was most common encountered. The incidence was 0.26% and the mortality 72.73% in years before 1985, while that in the years after 1985 were 0.58% and 17.65%, respectively. The differences are of significance (P < 0.01) predisposing. The clinical characteristics were summed up, and the causes, clinical diagnosis and treatment were studied and discussed.

Influence of retinoic acid on the expression of cytokeratins, vimentin and ICAM-1 in human gingival epithelia in vitro

Phenotypic differences exist in vivo between junctional (JE) and oral gingival (OGE) epithelia and an in vitro system has been developed that maintains phenotypic differences. This system, which permits in vitro studies of factors that may influence the epithelial phenotype, was used to investigate the effects of retinoic acid (RA) on epithelial expression of various markers known to distinguish JE from OGE. Primary cultures of JE and OGE were initiated from defined gingival regions and were subcultured and grown for 48 h in 96-well plates or on multiple-well slides. Control cultures were grown in medium supplemented with delipidized serum and all-trans RA was added to experimental groups. Other cultures were grown in a defined RA-free medium. Cultures were examined using monoclonal antibodies against cytokeratins, vimentin, and ICAM-1 and binding displayed by indirect immunocytochemical staining. Staining reactions were assessed by direct microscopic observation and assayed by spectrophotometric quantitation. The results showed that RA had minor effects on the marker expression of JE but markedly enhanced expression of cytokeratins 8, 18, 19, vimentin and ICAM-1 in OGE. These markers, which normally distinguish JE from OGE, were expressed at levels approaching or exceeding those of control JE cultures. These observations indicate that RA responsive mechanisms affect the phenotypes expressed by epithelia in vitro and suggest that such mechanisms may be related to the different phenotypic patterns expressed by gingival epithelia in vivo.

[Studies of aetiology and management about iatrogenic injuries of bile duct]

74 patients with iatrogenic injuries of bile duct were treated from June 1965 to October 1994 in our hospital. Iatragenic extrahepatic bile duct injuries may be caused by some errors during cholecystectomy. The operator did not realize that cholecystectomy itself is a procedure with inherent and potential risks. The operator was careless, rude and arrogant in operating. The operator lacked experience and skill, and was unable to deal with difficult situation during operation. Also we discussed the management of bile duct injuries, and suggested that intraoperative injuries of extrahepatic bile duct should be reconstructed immediately including repair of or end to end anastomoses of the injuries of bile duct. Cholecystojejunostomy (Roux-en-Y technique) is the best reconstruction procedure for patients with the injuries of bile duct after operation or failure of repetitional repaired and reconstructive operations of bile duct. Satisfactory result could be obtained.

[Clinical evaluation of cervical esophageal reconstruction after resection of thoracic esophageal carcinoma]

From Apr. 1979 to Dec. 1994, a total of 3,714 patients with thoracic esophageal carcinoma were surgically treated. As a standard operative procedure for thoracic esophageal cancer, cervical esophagogastrostomy was performed. While this operative procedure was rarely used (accounting for only 8.8% the treated cases) in early years, it has been recently carried out in the overwhelming majority of our patients (94.1%). This technic offers the advantages of resecting the lesions radically, dissecting the regional lymph nodes in both the neck and the mediastinum, reducing the incidence of postoperative complications and improving the quality of life after operation. In this paper the operative indication, approach and the surgical efficacy are discussed.

[Changes in blood gas in burned patients in Xining]

The changes in arterial blood gas were observed and analysed in twenty-seven burned patients at high altitude. It was showed that a serious hypoxemia existed in burn patients, both in survivors and dead cases, and that hypoxemia occurred earlier in the cases with inhalation injury or dead cases than without inhalation injury. These results suggest that patients with inhalation injury should undergo tracheostomy as early as possible to ensure oxygen supply, and patients without inhalation injury should be give oxygen therapy routinely. ARDS occurred in all inhalation injury cases, and high frequency jet ventilation was effective in improving hypoxemia in such cases.

[A comparative study on the chemical constituents of cultivated and wild fructus Gardeniae]

Studies have been made on the preliminary tests of the chemical constituents of cultivated and wild Fructus Gardeniae on the comparative analysis of the thin-layer chromatograms, IR and UV spectra of 95% ethanolic extracts as well as extracts obtained with four different solvents, and on the content determination of gardenosides. The results reveal that the cultivated and wild Fructus Gardeniae have similar chemical constituents, but differ in the contents of some constituents.

[Surgical treatment of gastric cardia cancer with fundoplication--a report of 193 cases]

From December 1987 to 1994, a total of 193 patients with carcinoma of the gastric cardia were surgically treated by partial esophagectomy, partial gastrectony and end-to-side esophagogastric anastomosis with fundoplication. When compared to those patients during the same time period similarly treated but with end-to-end esophagogastrostomy, the incidences of anastomotic leakage, anastomotic stricture and esophageal reflux were all significantly decreased (P < 0.01). It is a novel surgical treatment of choice for cancer of the gastric cardia.

High-performance liquid chromatographic determination of (-)-beta-D-2,6-diaminopurine dioxolane and its metabolite, dioxolane guanosine, using ultraviolet and on-line radiochemical detection

(-)-beta-D-2,6-Diaminopurine dioxolane (DAPD) and its metabolite dioxolane guanosine (DXG) have potent activity against hepatitis B virus and HIV, in vitro. A reversed-phase HPLC analytical method using UV and on-line radiochemical detection for the determination of DAPD and DXG in monkey serum and urine is described in this report. Retention times for DXG, DAPD and internal standard (2',3'-didehydro-2'deoxythymidine, D4T) were 5.0, 6.0 and 13.0 min, respectively. The extraction recovery was greater than 97% for DAPD and 94% for DXG. The limit of quantitation for UV detection was 100 ng/ml and 125 ng/ml for DXG and DAPD in monkey serum. The standard curves were linear from 0.1 microgram/ml to 5 micrograms/ml for DXG and 0.125 microgram/ml to 5 micrograms/ml for DAPD. For radiochemical detection, calibration curves of standard solutions of DAPD and DXG were linear in the range of 3500 Bq to 32,000 Bq and 7500 Bq to 60,000 Bq. The intra- and inter-day relative standard deviations were less than 7.2% using UV and less than 8.6% using on-line radiochemical detection. The HPLC method was applied to serum and urine samples collected from a male rhesus monkey that was administered 33.3 mg/kg DAPD with 200 microCi of [3H]DAPD intravenously.

Hearing loss and trace elements Fe2+ and Zn2+ in the perilymph

Fe2+ and Zn2+ levels in perilymph of guinea pigs injected with gentamicin (GM) were examined and compared with the corresponding concentrations in CSF, serum and hairs. We observed a preventive and therapeutic action of sea buckthorn oil and injectio gastrodini to hearing loss. The results showed that: (1) the Fe2+ content in GM-injected guinea pigs was increased in perilymph and hairs; it was decreased after prevention and treatment, but there was no obvious change in CSF and serum; (2) the Zn2+ content in perilymph and CSF was increased in GM-injected guinea pigs. It rose further after prevention, but in serum and hairs it decreased. The results indicate that the ototoxic reaction to GM is related to the rise of the Fe2+ content in perilymph. The elevation of Zn2+ is a compensatory reaction. The changes in the chemical composition of perilymph are more important than those in CSF, serum and hairs for pathological changes of the cochlea. Sea buckthorn oil can prevent GM ototoxicity.

Anticancer activity of beta-L-dioxolane-cytidine, a novel nucleoside analogue with the unnatural L configuration

Naturally occurring nucleosides and all anticancer nucleoside analogue drugs are in the beta-D configuration. L-(-)-dioxolane-cytidine [(-)-OddC] is the first L-nucleoside analogue ever shown to have anticancer activity. This compound was converted within cells to its mono-, di-, and triphosphate metabolites and was incorporated into DNA. As with cytosine arabinoside, conversion to the monophosphate was catalyzed by cellular deoxycytidine kinase, which was essential for cytotoxicity. However, unlike cytosine arabinoside, (-)-OddC was not susceptible to degradation by deoxycytidine deaminase. Because (-)-OddC inhibited the growth of hepatocellular and prostate tumors that are generally difficult to treat, it is a promising candidate for additional testing. Our results indicate that there is a great deal of variability in the chiral specificities of cellular enzymes and demonstrate how these differences can be exploited in the design of better anti-viral and anticancer drugs.

[Intrapleural administration of LAK cells combined with rIL2 in the treatment of advanced lung cancer with malignant pleural effusion]

Thirty-three patients with malignant pleural effusions due to advanced lung cancer were treated by intrapleural administration of LAK cells combined with rIL2. The pleural effusions disappeared in 18 patients and significantly decreased in 12. Three patients did not respond to the treatment. No serious side effect was found in 33 patients. The results indicate that transfer of LAK cells combined with rIL2 in the treatment of patients with malignant pleural effusions due to advanced lung cancer is effective and safe.

[An epidemiologic study of glaucoma in Tongcheng county, Anhui province]

An epidemiologic survey of glaucoma was conducted in Tongcheng County of Anhui Province in April, 1987. The results revealed that the prevalence of primary glaucoma was 0.38% consisting of angle-closure glaucoma 0.31% and open-angle glaucoma 0.07%, the prevalence of primary glaucoma was 0.71% in persons over 40 years of age and the rates of the blind and low-vision were 14.28% and 21.42%, respectively in primary glaucoma.

[Effects of alveolar macrophage conditioned media from interstitial lung disease patients on the procollagen mRNA expression in human lung fibroblasts]

We investigated the effects of alveolar macrophage (Am) conditioned media from interstitial lung disease (ILD) patients on lung fibroblast proliferation and procollagen mRNA expression in cells. 13 patients with ILD and 8 patients with bronchial carcinoma (BC) received bronchoalveolar lavage (BAL). The BAL fluid was collected and centrifuged to obtain cells of two groups. The cells were washed and incubated at 37 degrees C and 5% CO2 for 2 hours in DMEM with 10% FCS. Then the adherent Am was added with DMEM with 0.1% FCS. (2ml/10(6) cells), and cultured at 37 degrees C and 5% CO2 for 24 hours. The supernatant was obtained by centrifugation and stored in -20 degrees C for experiment. Lung fibroblasts were planted in 96 well microtitle plate and cultured to confluence. Each well was added 100 microliters Am conditioned medium and incubated for 16 hours, then added 5 uci 3H-TdR for measuring the fibroblast proliferation and incubated till 24 hours. The cells were collected and counted. The DMEM with 0.1% FCS was used as control. When stimulated with Am conditioned media from ILD patients, fibroblast proliferation increased 71%, but for media from BC patients, it just increased 14% (P < 0.05). After stimulated with conditioned media for 24 hours, the cells were trypzied, collected, ashed and isolated total RNA with guanine method. Several samples' total RNA was subjected to electrophoresis in 1% agaroseformaldehyde gel to test specificity of procollagen al (I) and al (III) cDNA probes. 10 micrograms total RNA of each sample was bloted to nitrit membrane and baked at 80 degrees C for 2 hours.

[Human parathyroid allotransplantation: comparison of donor grafts]

The authors compared the degrees of cell maturity, antigenicity and secretory function of parathyroid (PTG) tissues from cadavers (C-PTG), 20-28 wk fetus (F-PTG) and PTG adenoma (A-PTG). In A-PTG tissues, clustered or scattered immature cells were observed, but there were none in F-PTG and C-PTG. C-PTG and A-PTG tissues revealed better secretory function than F-PTG. No clear difference was found in HLA class I (ABC) antigen quantity among the three donor PTG tissues, but the amount of HLA class II (DR) antigen in A-PTG and F-PTG were significantly lower than that in C-PTG. The results demonstrate that C-PTG, with better function, and F-PTG, with lower antigenicity, can be used in clinical transplantation. A-PTG is not suitable for clinical transplantation due to their immaturity and possibility of carcinomatous change.

Comparison of dopexamine hydrochloride, fenoldopam, and procaterol on myocardial nutritional flow in rats

Myocardial nutritional flow (MNF) was determined using 99mTechnetium-methoxy-isobutyl-isonitrile (99mTc-MIBI) in rats. At 25 nmol.kg-1, dopexamine hydrochloride (DH), fenoldopam, and procaterol increased the uptake rate of 99mTc-MIBI/g myocardium by 80.8 +/- 10.2% (P < 0.01), 44.9 +/- 6.3% (P < 0.05), and 30.2 +/- 5.4% (P < 0.05) respectively. These findings suggested the potential advantages of DH over other dopaminergic agonists in the treatment of coronary disease.

Ossifying fibromyxoid tumor of soft parts: a morphological and immunohistochemical study

A case is presented of ossifying fibromyxoid tumor of soft parts (OFMTSP) which occurred in the left cheek of a 59 year old Chinese woman. Histologically, the tumor was located in the subcutis with a fibrous pseudocapsule that contained discontinuous rims of mature trabecular bone. The tumor cells were small, round to ovoid with a uniform, round nucleus and a pale or slightly eosinophilic cytoplasm. Most of the cells were arranged in a random manner, some in a vague lace-like pattern. Mitotic figures were extremely rare. The stroma appeared fibromyxoid with scattered foci of mucinous lakes. Immunohistochemically, most of the neoplastic cells displayed immunoreactivities for S-100 protein, S-100 protein alpha, vimentin and alpha-smooth muscle actin; many tumor cells were positive for desmin. The tumor also showed stromal immunoreactivity for type IV collagen and was negative for cytokeratins, epithelial membrane antigen, glial fibrillary acidic protein, neurofilaments, muscle-specific actin, Leu-7, myelin-basic protein, osteocalcin and melanoma-specific antigen. The immunophenotypes expressed by the present OFMTSP seem to reflect two lineages of neoplastic cell differentiation, that is of nerve sheath and of smooth muscle; at the present stage, it is premature to diagnose this lesion as either nerve sheath or smooth muscle tumor.

[The excitation site of MEP on facial nerve by transcranial magnetic stimulation]

A magnetic stimulator was used for direct transcutaneous stimulation of the intracranial portion of the facial nerve in 30 normal subjects. Compound muscle action potentials (CMAPs) thus elicited in the frontal muscle of controls were of similar amplitude but of longer latency (1.3 +/- 0.6ms) as compare with CMAPs produced by conventional electrical stimulation at the stylomastoid foramen. Because the measured distal facial nerve motor conduction velocity was 50-60 mm/ms, the locus of impulse generation induced by magnetic coil stimulation was estimated to be approximately 65mm proximal to the site of electrical stimulation at the stylomastoid foramen, i.e., closer to the exit of the facial nerve from the brain stem than to its entrance into the internal auditory meatus.

[Alteration of human leukocyte antigens in human parathyroid tissues after transplantation into nude mice]

Human parathyroid (PTG) tissues from cadaver (C-PTG), 20-28 wk fetus (F-PTG) and PTG adenoma (A-PTG) were transplanted into the kidney subcapsular spaces of Balb/C nude mice as interim host. Dynamic changes in the amount of human leukocyte antigens (HLA) in human PTG grafts within the transplantation period were observed. The results showed that during 100 days of interim hosting, no obvious changes in the amount of tissue HLA class I antigens occurred, but the amount of tissue HLA class II antigens were significantly reduced, The changes of HLA antigens in the different types of donor human PTG tissues were compared.

Voltammetric determination of dopamine in the presence of ascorbic acid at over-oxidized polypyrrole-indigo carmine film-coated electrodes

Over-oxidized polypyrrole films doped with indigo carmine (PPy-IC) offer substantial improvements in voltammetric sensitivity and selectivity towards dopamine. This polymer coating attenuates the voltammetric response of ascorbic acid while the oxidation peak current of dopamine is enhanced by over one order of magnitude compared with that at the bare electrode. The high sensitivity and selectivity for dopamine appears to be mainly due to the charge discrimination and the analyte accumulation. The detection limit is dependent on both film thickness and preconcentration time. At a 0.25 micron thick PPy-IC film-coated electrode, for a 2 min preconcentration time, the detection limit is 10(-8) mol l-1, over two orders of magnitude lower than at a bare glassy carbon electrode. The concomitant ascorbic acid shows no interference although its concentration is as high as 0.1 mmol l-1. The effects of various experimental parameters on the voltammetric response of dopamine were also investigated. The attractive permselective and preconcentrating properties of the PPy-IC films make them valuable for in vivo electrochemistry.

Reinfection with Schistosoma japonicum after treatment with praziquantel in Poyang lake region, China

The study on reinfection with Schistosoma japonicum after treatment was carried out in a cohort of subjects in a heavy endemic village of Poyang lake region, China. After mass treatment with praziquantel in non-transmission time, detailed observations of water contact were estimated using the mean area of skin exposed daily. One year after treatment, the prevalence of infection in study subjects was 54.48%, returning to 83% of initial prevalence. The peak prevalence occurred the 11-15 year age class, but intensity of exposure also varies with age and that age group supporting the higher prevalence of reinfection had high levels of exposure. Among groups of subjects with a similar exposure stratum, young subjects under the age of 21 years were more heavily reinfected, while no heavy reinfection was observed in adults (> or = 25 years). These observations suggest that subjects in this area slowly acquire an increasing degree of immunity to lighten the intensity of infection with S. japonicum.

[Nude mouse interim host model for human parathyroid grafts]

Human parathyroid (PTG) tissues from cadaver (C-PTG), fetus (F-PTG) and PTG adenoma (A-PTG) were transplanted into the subcapsular space of Balb/C nude mouse kidney as interim host. The tissue structure and secretory function were examined 30, 60, 90, 120 and 150 days after operation. The results showed that PTG tissues from all three donors can retain their tissue structure and secretory function for more than 100 days in the nude mouse. The growth and function of PTG tissues from the three types of donors in the nude mice were compared.

Preliminary observation of the thymus as a privileged site for parathyroid gland allotransplantation in rats

Twenty Wistar rats were divided into two groups. In the control group parathyroid allografts were transplanted into the kidney subcapsule. In the experimental group parathyroid allografts were transplanted into the thymus. The results showed a statistically significant difference in mean allograft survival times between the two groups.

[Effect of fagopyrum cymosum rootin on clonal formation of four human tumor cells]

The effects of fagopyrum cymosum rootin on four human tumor cells in vitro were observed in comparison with 5-Fu. It was found that the clonal formations of four human tumor cells were markedly inhibited and the inhibition rates were positively proportional to concentration. At the concentration of 12.5 micrograms/ml, inhibition rates were GLC 98.7%, Hela 53.8%, SGC 65.4% and KB 82.1%.

Comparison of parathyroid donor grafts

We compared the degrees of cell maturity, antigenicity and secretory function of parathyroid tissues (PTG) from cadavers (C-PTG), 20-28 week fetuses (F-PTG) and PTG adenomas (A-PTG). In A-PTG, scattered or clustered immature cells were observed, but there were none in F-PTG and C-PTG tissues. A-PTG and C-PTG exhibited better secretory function than did F-PTG. No clear differences were found in HLA class I (ABC) antigen quantity among the three donor PTG tissues, but the amounts of HLA class II (DR) antigen in A-PTG and F-PTG were significantly lower than that in C-PTG. The results demonstrate that C-PTG, with its functional advantages, and F-PTG, with its relatively low antigenicity, can be used in clinical transplantation, while A-PTG tissues are not suitable for clinical transplantation on account of their immaturity and the possibility of carcinomatous change.

[Isolation and purification of a NAD(+)-dependent 15-hydroxyprostaglandin dehydrogenase from human placenta]

A NAD(+)-dependent 15-hydroxyprostaglandin dehydrogenase has been isolated and purified from human placenta. About 9300-fold enrichment was achieved with a yield of 9.3%. The specific activity of the purified enzyme was 6470 nmol/min.mg. 15-OH-PGDH showed a single band on PAGE and two bands on SDS-PAGE. The molecular weights were approximately 26 and 52 kd, respectively. The two bands were recognized by both polycloning and monocloning antibodies of the enzyme. It is suggested that the 15-OH-PGDH be composed of two identical subunits.

Nude mouse interim host model for human parathyroid grafts. Part III. Mechanism of modification of allograft antigenicity

The alterations of number and DR antigen expression of antigen presenting cells (APCs) in human PTG grafts during the interim hosting period were analyzed. The results were as follows: 1) In C-PTG grafts, the APC number was reduced obviously within 100 days in the interim host. In F-PTG and A-PTG grafts, the APC number was increased at 30 d of interim hosting, and then decreased gradually. 2) No obvious change in D-related (DR) antigen expression of individual APCs was seen in C-PTG and F-PTG grafts. In A-PTG grafts, DR antigen expression was increased at 30 d of interim hosting, but then dropped gradually and asynchronously.

Nude mouse interim host model for human parathyroid grafts. Part IV. Human PTG xenograft rejection in a mouse B lymphocyte system

An interim host model for human parathyroid gland (PTG) grafts has been established. In this experiment, the proliferation of mouse blood vessels and infiltration of mouse B lymphocytes into human PTG grafts were successively observed. The results showed that within 10 d of interim hosting, when PTG grafts were still nourished by permeable factors, scattered mouse B lymphocyte infiltration was already apparent. As time went by, B lymphocyte infiltration and IgG secretion became more obvious. At 60-90 d interim hosting, an intact human-mouse tissue "chimera" was formed. Thereafter, human PTG grafts were gradually fragmented and absorbed. The theoretical significance and clinical value of this rejection phenomenon are discussed.

Patterns of cytokeratin expression in the epithelia of inflamed human gingiva and periodontal pockets

Fourteen specimens of periodontal pockets and the associated marginal gingiva were collected and either frozen for examination using antibodies against various defined cytokeratin specificities or processed for 2-dimensional gel electrophoresis. The epithelium forming the pocket lining typically extended into the connective tissue of the pocket wall in the form of a network of finger-like strips. Immunocytological staining indicated that keratins (K) 5, 6, 14 and 19 were expressed by almost all cells of the pocket lining and K13 and K16 by the suprabasal cells. The coronal region of the pocket lining showed some cells staining for K4. Staining for K8 and K18 was seen in the apical region of the pocket lining and in the finger-like extensions of epithelium into the connective tissue. Compared with normal gingiva, the sulcular and the oral gingival epithelia showed a marked increase in staining for K19. Surprisingly, the pattern of keratin expression of the epithelium of the pocket lining was found to be essentially similar to that of normal junctional epithelium and the anatomical position of the boundaries between each epithelial phenotype were not significantly altered. These patterns of keratin expression were confirmed by the 2D electrophoretic analyses of microdissected regions of epithelium. The potential significance of inflammation to the epithelial changes associated with pocket formation is discussed.

Secretion of the STA3 heat-stable enterotoxin of Escherichia coli: extracellular delivery of Pro-STA is accomplished by either Pro or STA

The methanol-soluble, heat-stable enterotoxin of Escherichia coli is a protease-resistant extracellular peptide which is synthesized as a 72-amino-acid precursor Pre-Pro-STA3. The specific roles of Pre (19 amino acids), Pro (34 amino acids) and STA3 (19 amino acids) in the secretion process were studied by functionally deleting each of the three domains. Deletion of the Pre signal sequence resulted in a short-lived cell-associated molecule with an M(r) equivalent to that of Pro-STA3. Deletion of Pro (i.e., Pre-STA3) resulted in the rapid extracellular accumulation of STA3; the periplasmic intermediate found in the secretion of the wild-type toxin was undetected. Deletion of the STA3 domain resulted in a cell-associated Pre-Pro peptide; with time this form converted to periplasmic Pro which later became extracellular. When DNA encoding either STA3, by itself, or Pro-STA3 (lacking the signal peptide) was expressed, these peptides were degraded intracellularly, with no periplasmic or extracellular forms detected. The results presented demonstrate that the signal peptide (Pre) is essential even for the export of small peptides to the periplasm, and that its absence causes the STA3 domain to become susceptible to intracellular proteases. The rapid degradation of intracellular STA3 indicates that its proteolytic resistance is acquired in a compartment other than the cytoplasm. The results also show that after the Pre domain is proteolytically cleaved from Pre-STA3 and Pre-Pro, the STA3 and Pro peptides can exit to the culture supernatant.(ABSTRACT TRUNCATED AT 250 WORDS)

Evidence for the interaction between antacid and gastric mucosa using an "artificial stomach" model including gastric mucosa

In light of evidence that certain aluminum-based antacids adhere to the gastric mucosa, we modified our previously described "artificial stomach" (AS) model by including a piece of hog stomach and compared the antacid activity of six aluminum-containing antacid products in the model with and without gastric mucosa. The activity of three of these, Maalox, Riopan and Supralox, was not significantly different in the two systems. In contrast, the activity of the other three, Aludrox, Phosphalugel and Simeco, was significantly greater with mucosa. Antacid activity of one product from each set (Supralox, Phosphalugel) was evaluated in two in vivo methods in human volunteers. For both antacids, results in vivo were similar to those obtained with the AS-containing mucosa. Without mucosa, in vivo and in vitro results were dissimilar for Phosphalugel, thus validating the modified AS. The difference between the two sets of antacids can be explained by 1) the fact that the Al:Mg ratio in the set affected by mucosa is greater than that of unaffected antacids, and 2) a weaker antacid load than in unaffected Supralox. We suggest that in an acid milieu, aluminum ions in antacids like Aludrox, Phosphalugel and Simeco are bound to sialic acid residues in mucus glycoproteins, thus retarding the transit of these antacids through both the AS and the real stomach and prolonging their activity in both situations. When the Al:Mg ratio is low or when the amount of antacid salts is large, aluminum ions tend to be buried in complexes, giving them less chance to interact with gastric mucus, so they transit the stomach more quickly.

Patterns of phenotypic expression of human junctional, gingival and reduced enamel epithelia in vivo and in vitro

Epithelia differ regionally in their patterns of phenotypic expression. The junctional epithelium (JE) that attaches the oral mucosa to the teeth is a unique tissue that shows a pattern of differentiation unlike other oral epithelia and forms basal lamina against the non-vital tooth surface. The mechanisms that establish this unusual phenotype and the developmental origin of this epithelium are both uncertain. The formation of JE by downgrowth of the oral gingival epithelium (OGE) during tooth eruption has been suggested but morphological studies indicate that it may be derived from the reduced enamel epithelium (REE) that covers the crown of the unerupted tooth. These epithelia of potential origin differ in their developmental histories: intrinsic differences between them could thus significantly influence the phenotype of an epithelium formed from them. The patterns of phenotypic expression of specimens of dissected JE, OGE and REE, and of cell cultures of these epithelia grown under standardized conditions, were examined (1) by immunocytochemistry using monoclonal antibodies with specificity for individual cytokeratins, vimentin and ICAM-1, and (2) by two-dimensional SDS-PAGE and immunoblotting. The results indicated that, in vivo, OGE expressed keratin markers typical of differentiating mucosal epithelium; JE and REE, in contrast, lacked expression of most such markers but expressed keratins typical of simple epithelia together with some undefined keratin peptides. All epithelia showed changes in vitro but OGE remained different from JE and REE. OGE lost expression of the differentiation markers K1, K10 and K13; it acquired some expression of K19, but less than JE and REE. Cultures of JE and REE retained some expression of ICAM-1 and K8 and K18, and consistently acquired high levels of vimentin expression. These findings indicate that differences persist in standardized culture conditions and that these are apparently of an intrinsic nature. They support a concept of the origins of JE from REE and suggest that the unusual in vivo phenotype of JE results partly from intrinsic differences acquired during its development.