[Malignant melanoma of external ear: 14 cases report]

OBJECTIVE

To improve the diagnosis and treatment level of malignant melanoma in external ear.

METHOD

14 cases with malignant melanoma of external ear were reported. All patients were treated by surgical excision.

RESULT

13(in 14) cases were followed up. 7 patients were survival with no tumor, the others died. The 5-year survival rate for the whole series was 50.0%.

CONCLUSION

The malignant melanoma of external ear has rapid progress and poor prognosis, early detection and treatment are necessary. Extensive excision of malignant melanoma was principle method of the treatment. Recurrent tumor should be treated by combined operation with radiation.

Gross anatomy of the pancreatic lobes and ducts in six breeds of domestic ducks and six species of wild ducks in China

A previously unreported pancreatic duct was found by Liu (1989) in Pekin ducks. This duct has now been consistently found in six breeds of domestic ducks and six species of wild ducks in China. For purposes of Nomina Anatomica Avium it is hereby called the 'first pancreatic duct' (Ductus pancreaticus primus) since it enters the duodenum at or near the flexure where the descending duodenum becomes the ascending duodenum. All other pancreatic ducts enter the duodenum later, closer to where it joins the jejunum. This first pancreatic duct drains the caudal extremity of the dorsal lobe of the pancreas and can be easily exteriorized for experimental purposes. Within the parenchyma of the dorsal lobe of the pancreas this duct communicates with the dorsal pancreatic duct. In the present study of the gross anatomy of the pancreatic lobes of domestic and wild Chinese ducks we describe and illustrate variations in position and number of all biliary and pancreatic ducts.

[A study of the expression of c-myc onoprotein in laryngeal cancer and different distant adjacent mucosa]

Using citric-LSAB-microwave immunohistochemical technique, the expression of c-myc was studied in different regions of larynx including laryngeal squamous cell carcinoma (LSCC), border area, adjacent mucosa which was 0.5, 1.0, 1.5 and 2.0 cm away from cancer 30 cases and four cases of normal laryngeal mucosa. The results showed that over-expression of c-myc in LSCC was found in 29 of 30 (96.7%), which was higher than that in normal laryngeal mucosa (P < 0.01). A significant different expression of c-myc can be seen at the regions of 2.0 and 1.5 cm distant from the tumor (P < 0.05). The expression of c-myc increased as tissue progressed in sequence from normal mucosa, adjacent mucosa to carcinoma. The c-myc expression did not correlate with site of tumor, stage and histological grade (P > 0.05). The results indicate that over-expression of c-myc is involved in genesis of LSCC, and may be an early event in the development of human squamous-cell carcinoma of the larynx. The tissue adjacent to the tumor may have a potential malignancy.

[Cloning and expression of leptospiral protective antigen gene OmpL1 in BCG]

This study was intended to produce a new living vaccine against leptospirosis using BCG as vector. Leptospiral outer envelop antigen gene OmpL1 was amplified from the genome of pathogenic leptopira serova Lai 017 by PCR, and cloned in E. coli-BCG shuttle plasmid pY6002. Recombinant plasmids were isolated by dot blotting with Digoxigeninlabeled OmpL1 gene. After transforming the recombinant plasmids in BCG (Shanghai strain) by electroporation, the genomic DNA of all 21 transformants were prepared and hybridized with OmpL1. It showed that 6 of the 21 transformants were recombinants in which the OmpL1 gene had been integrated into the genome of BCG. By immunoblotting with OmpL1 infected rabbit antiserum, which was preabsorbed to remove antibody against E. coli and SPA-HRP, three recombinants, pLI1, pLI2 and pLI3, were detected to express OmpL1 protein. The ability of expression is in the order of pLI2 > pLI1 >> plI3. These studies provide the possibility of further research on the development of highly efficient recombinant vaccines against leptospirosis.

[Analysis on speciems of serum and urine in 66 cases of early leptospirosis by PCR and biotin-AMPPD hybridization]

We used polymerase chain reaction (PCR) and Biotin-AMPPD hybridization to detect leptospiral DNA in blood and urine samples in 66 patients at the early stage of leptospirosis. The results showed that PCR and Biotin-AMPPD hybridization not only ruled out the non-specific PCR amplification and increased the reliability for clinical specineus of leptospirosis but also raised the detecting sensibility (from 71.3% to 86.1%). The positive rates of PCR resulted from serum and urine showed no statistical difference; therefore urine sample is worthy of application and dissemination for detecting leptospires at the early stage of leptospirosis. Urine sample is easier for one to collect, preserve and has less intervention. The primers G1, G2 are optimal opplication of PCR in epdemic areas in China.

[Characterication of reference strains of L. interrogans in China by ISSP-PCR]

The gene polymorphism of the DNAs extracted from reference strains of L. interrogans in China was characterized by LSSP-PCR primered by G1 or G2, which were a pair of specific primers for L. interrogans. The fingerprinting produced by LSSP-PCR showed that serovar lai, serovar canicola, serovar pyrogens, serovar autumnalis, serovar australis, serovar linhai, serovar wolffi and serovar haemolytic have similar patterns, but serovar hebdomadis, serovar javanica, serovar ballum, serovar pomona, serovar spaidjin, serovar tarassov and serovar manahao I have different profiles. This result agreed with the classification of genetic species by Yasuda. The utilization of LSSP-PCR banding patterns in the identification of leptospries in blood samples also gained encouraging results. Compared with the routine methods in genetic species classification, LSSP-PCR has the advantages of rapidity, simplicity and low-cost. It appears to be a promising tool in studying such slowly growing bacteria as leptospires. Further exploration of LSSP-PCR in classification and identification of Leptospires is worthwhile.

[The sawtooth oscillation phenomenon of visible spectral signal in HT-6M Tokamak]

The sawtooth oscillation phenomenon of visible spectral signal in HT-6M Tokamak is presented. The influences of electron temperature, electron density and atomic ground density on the spectral signal discussed. This phenomenon results mainly from the change of electron temperature at the edge.

[16S rRNA gene PCR-SSCP analysis of the reference strains from 15 serovars (14 serogroups) of pathogenic leptospires in China]

The DNAs of reference strains from 15 serovars (14 serogroups) of pathogenic leptospires in China were amplified with 16S rRNA gene primers, and then single-strand conformation polymorphism (SSCP) of the products were analyzed in 12.5% nondenaturing mini polyacrylamide gel (containing 5% glycerol) combining with silver-staining. All products showed two bands on electrophoresis at different parameters of voltage or current and concentration of gel. It proved that serovar lai, serovar canicola, serovar pyrogenes, serovar autumnalis, serovar australis, serovar pomona, serovar linhai, serovar hebdomadis, serovar haemolytica, serovar wolffi and serovar paidjan have the identical pattern (Leptospira interrogans), while serovar javanica, serovar ballum, serovar tarassovi and serovar manhao I belong to another pattern (L. borgpetersenii). The result was consistent with the classification of genetic species by Yasuda et al (1987) and Ramadass et al (1992).

Structural characterization and regulatory element analysis of the heart isoform of cytochrome c oxidase VIa

In order to investigate the mechanism(s) governing the striated muscle-specific expression of cytochrome c oxidase VIaH we have characterized the murine gene and analyzed its transcriptional regulatory elements in skeletal myogenic cell lines. The gene is single copy, spans 689 base pairs (bp), and is comprised of three exons. The 5'-ends of transcripts from the gene are heterogeneous, but the most abundant transcript includes a 5'-untranslated region of 30 nucleotides. When fused to the luciferase reporter gene, the 3.5-kilobase 5'-flanking region of the gene directed the expression of the heterologous protein selectively in differentiated Sol8 cells and transgenic mice, recapitulating the pattern of expression of the endogenous gene. Deletion analysis identified a 300-bp fragment sufficient to direct the myotube-specific expression of luciferase in Sol8 cells. The region lacks an apparent TATA element, and sequence motifs predicted to bind NRF-1, NRF-2, ox-box, or PPAR factors known to regulate other nuclear genes encoding mitochondrial proteins are not evident. Mutational analysis, however, identified two cis-elements necessary for the high level expression of the reporter protein: a MEF2 consensus element at -90 to -81 bp and an E-box element at -147 to -142 bp. Additional E-box motifs at closely located positions were mutated without loss of transcriptional activity. The dependence of transcriptional activation of cytochrome c oxidase VIaH on cis-elements similar to those found in contractile protein genes suggests that the striated muscle-specific expression is coregulated by mechanisms that control the lineage-specific expression of several contractile and cytosolic proteins.

[Dynamics of blood lead level in exposed workers and its effects on fetal constitutional development]

Levels of blood lead (Pb-B) and zinc protoporphyrin (ZPP) in exposed women of a storage battery plant during their early gestation and delivery stage were determined and compared with those in control women. Pb-B in exposed women kept in a consistently high level of 0.98 mumol/L and ZPP of 1.35 mumol/L. Pb-B level in umbilical cord of their neonates reached 0.90 mumol/L and ZPP 1.11 mumol/L, both of which were significantly higher than those in control women (0.26 mumol/L and 0.34 mumol/L of Pb-B and 0.51 mumol/L and 0.78 mumol/L of ZPP in women's blood and umbilical cord blood, respectively). The significance of consistent increase in Pb-B and ZPP and their effects on fetal development were discussed in the paper.

Effect of BDM, verapamil, and cardiac work on mitochondrial membrane potential in perfused rat hearts

The biochemical link providing effective coordination between the mitochondrial ATP synthetic machinery and the contractile apparatus following transitions in cardiac work remains enigmatic. Studies were designed to determine whether activation of the actomyosin adenosinetriphosphatase (ATPase) is a necessary part of the signaling mechanism to the mitochondrial ATP synthase or whether a rise in cytosolic free Ca2+ is sufficient to activate the synthase. With the use of Langendorff-perfused rat hearts, cardiac work was varied via changes in perfusion pressure and by the inclusion of a beta-adrenergic agent. Furthermore, 2,3-butanedione monoxime and verapamil were used to vary independently either the activity of the actomyosin ATPase or the level of cytosolic free Ca2+. Determinations of the in vivo mitochondrial membrane potential [delta psi m; see Wan et al. Am. J. Physiol. 265 (Heart Circ. Physiol. 34): H445-H452, 1993] and its vectorial displacement during work transitions provide valuable information concerning direct activation of the ATP synthase and proton movement through the membrane domain of the synthase. Increased cardiac work in the presence of the beta-adrenergic agent resulted in a decrease in delta psi m. Addition of 2,3-butanedione monoxime decreased cardiac work but did not change delta psi m. The inclusion of verapamil resulted in similar decreases in cardiac work. However, delta psi m reversed back to a value observed under control, low-work conditions. These results in conjunction with data regarding levels of high-energy phosphates, free Mg2+, and adenosine 3',5'-cyclic monophosphate suggest a Ca(2+)-mediated increase in the activity of the ATP synthase.

[Effect of bee pollen on maternal nutrition and fetal growth]

Plant pollen collected by the honeybee is called bee pollen, which is a natural nutrient. We studied the effects of the bee pollen of Brassia campestres L. on maternal nutrition and fetal growth. Pregnant Sprague-Dawley rats at O-d were divided randomly into three groups. The control group (C) was fed with a diet. The other two groups (A) and (B) were fed with the diet plus bee pollen 20 g/kg.d-1 and 10 g/kg.d-1, respectively. All the dams in each group took a diet and drank water and libitm. Pollen-fed dams in both groups (A) and (B) had greater body weight and higher levels of haemoglobin, total protein, serum iron and albumin (P < 0.01, P < 0.05). Fetuses of pollen-fed dams had greater body weight (P < 0.01) and lower death rate (P < 0.005). No gross external, visceral and skeletal malformations were observed in the fetuses. These results suggested that bee pollen could improve maternal nutrition without affecting normal fetal development. It is a practical and effective nutrient during pregnancy.

[Biochemical effects of maternal intravenous and intra-amniotic infusion of amino-acids on fetal blood]

Before elective cesarean section, 58 normal term's pregnant women were randomly divided into three groups: intravenous (25 women), intra-amniotic (8 women) and control (25 women) groups. The first two groups received maternal intravenous and intra-amniotic infusion of amino acids respectively. The results showed that maternal intravenous administration of amino-acids led to increased levels of amino acids in maternal venous blood and fetal umbilical cord blood plasma (P < 0.05). There was no increase in fetal uptake of amino acids (P > 0.05). The levels of amino acids in fetal umbilical cord blood plasma of the intra-amniotic group were higher than those of the control group (P < 0.05) and intravenous group (P < 0.05). In the intra-amniotic group, the fetal uptake of amino acids increased (P < 0.05). There were no significant differences in fetal umbilical arterious pH, PO2 and PCO2 among the three groups (P > 0.2). Intra-amniotic infusion of 250ml amino-acids did not change the pressure of amniotic cavity (P > 0.2). The authors suggested that intra-amniotic infusion of amino acids, as a paraplacental nutritional route, should be more effective in the treatment for cases of intrauterine fetal growth retardation particularly for those accompanied by severe placental lesions.

A method of determining electrical potential gradient across mitochondrial membrane in perfused rat hearts

The electrical potential gradient across the mitochondrial membrane (delta psi m) in perfused rat hearts was estimated by calculating the equilibrium distribution of the lipophilic cation tetraphenylphosphonium (TPP+), using measured kinetic constants of uptake and release of TPP+. First-order rate constants of TPP+ uptake were measured during 30-min perfusions of intact rat hearts with tracer amounts (5.0 nM) of tritium-labeled TPP+ ([3H]TPP+) in the perfusate. This was followed by a 30-min washout, during which the first-order rate constant of efflux was estimated. Values of [3H]TPP+ outside the heart and total [3H]TPP+ inside the heart at equilibrium were calculated. From this information and separately estimated time-averaged plasma membrane potentials (delta psi c) it was possible to calculate free cytosolic [3H]TPP+ at equilibrium. It was also possible to calculate free intramitochondrial [3H]TPP+ at equilibrium as the difference between total tissue [3H]TPP+ minus free cytosolic TPP+ and the sum of all the bound [3H]TPP+. Bound [3H]TPP+ was determined from [3H]TPP+ binding constants measured in separate experiments, using both isolated mitochondria and isolated cardiac myocytes under conditions where both delta psi m and delta psi c were zero. Delta psi m was calculated from the intramitochondrial and cytosolic free TPP+ concentrations using the Nernst equation. Values of delta psi m were 144.9 +/- 2.0 mV in hearts perfused with 5 mM pyruvate and 118.2 +/- 1.4 mV in hearts perfused with 11 mM glucose, in good agreement with delta psi m obtained from isolated rat heart mitochondria.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of cardiac work on electrical potential gradient across mitochondrial membrane in perfused rat hearts

The myocardium responds to alterations in cardiac work by changing its rate of O2 consumption. This reflects an increase in the oxidative synthesis of ATP to meet the contractile demand for ATP. However, the biochemical mechanisms responsible for increased ATP synthesis are not fully understood. To localize the flux-controlling reaction(s) in the pathway of ATP synthesis, the effects of substrates and cardiac work on mitochondrial membrane potential (delta psi m), total tissue NADH-to-NAD+ ratio, and high-energy phosphate metabolites were examined in perfused rat hearts. Delta psi m was measured using the equilibrium distribution of tetraphenylphosphonium (33). Cytosolic phosphorylation potential, total tissue NADH-to-NAD+ ratio, and delta psi m were higher in hearts perfused with pyruvate than in those perfused with glucose. Increasing cardiac work induced a four-fold increase in O2 consumption, which was accompanied by 1) decreased or unaltered cytosolic ADP concentration, 2) increased tissue NADH-to-NAD+ ratio, and 3) decreased delta psi m. The results indicate that both NADH-generating reactions and the ATP synthase-catalyzed reaction are important in causing the increase in respiration that accompanies increased work. Because the activation of ATP synthase by cardiac work occurred in the absence of increases in delta psi m, ADP, and Pi, it is possible that the work-related acceleration in ATP synthesis may be due to modification of the kinetic properties of the ATP synthase.

Regulation of citric acid cycle by calcium

The relationship of extramitochondrial Ca2+ to intramitochondrial Ca2+ and the influence of intramitochondrial free Ca2+ concentrations on various steps of the citric acid cycle were evaluated. Ca2+ was measured using the Ca2+ sensitive fluorescent dye fura-2 trapped inside the rat heart mitochondria. The rate of utilization of specific substrates and the rate of accumulation of citric acid cycle intermediates were measured at matrix free Ca2+ ranging from 0 to 1.2 microM. A change in matrix free Ca2+ from 0 to 0.3 microM caused a 135% increase in ADP stimulated oxidation of 0.6 mM alpha-ketoglutarate (K0.5 = 0.15 microM). In the absence of ADP and the presence of 0.6 mM alpha-ketoglutarate, Ca2+ (0.3 microM) increased NAD(H) reduction from 0 to 40%. On the other hand, when pyruvate (10 microM to 5 mM) was substrate, pyruvate dehydrogenase flux was insensitive to Ca2+ and isocitrate dehydrogenase was sensitive to Ca2+ only in the presence of added ADP. In separate experiments pyruvate dehydrogenase activation (dephosphorylation) was measured. Under the conditions of the present study, pyruvate dehydrogenase was found to be almost 100% activated at all levels of Ca2+, thus explaining the Ca2+ insensitivity of the flux measurements. However, if the mitochondria were incubated in the absence of pyruvate, with excess alpha-ketoglutarate and excess ATP, the pyruvate dehydrogenase complex was only 20% active in the absence of added Ca2+ and activity increased to 100% at 2 microM Ca2+. Activation by Ca2+ required more Ca2+ (K0.5 = 1 microM) than for alpha-ketoglutarate dehydrogenase. The data suggest that in heart mitochondria alpha-ketoglutarate dehydrogenase may be a more physiologically relevant target of Ca2+ action than pyruvate dehydrogenase.

Studies of cytogenetic effects of sodium arsenicals on mammalian cells in vitro

The cytotoxic and cytogenetic effect of sodium arsenite and sodium arsenate on Chinese hamster ovary (CHO) cells is reported. Chromosome aberrations were induced with both arsenic compounds. Trivalent arsenic was more clastogenic than pentavalent arsenic. Sodium arsenite was also shown to produce increased sister chromatid exchange in CHO cells and increased chromosome breakage in human lymphocytes.