Purification and properties of bacteriolytic enzymes from Bacillus licheniformis YS-1005 against Streptococcus mutans

To find a novel lytic enzyme against cariogenic Streptococci, strains showing strong lytic activity have been screened from soil using Streptococcus mutans. A strain identified as Bacillus licheniformis secreted two kinds of lytic enzymes, which were purified by methanol precipitation, CM-cellulose chromatography, gel filtration, and hydroxyapatite chromatography. The molecular weights of these two enzymes, L27 and L45, were 27,000 and 45,000, respectively. Optimum pH and temperature of both enzymes for lytic activity were pH 8 and 37 degrees C. L27 and L45 digest the peptide linkage between L-Ala and D-Glu in peptidoglycan of Streptococcus mutans. The lytic activity was highly specific for Streptococcus mutans, suggesting their potential use as a dental care product.

Extragenic suppressors of loss-of-function mutations in the aspergillus FlbA regulator of G-protein signaling domain protein

We showed previously that two genes, fl bA and fadA, have a major role in determining the balance between growth, sporulation, and mycotoxin (sterigmatocystin; ST) production by the filamentous fungus Aspergillus nidulans. fadA encodes the alpha subunit for a heterotrimeric G-protein, and continuous activation of FadA blocks sporulation and ST production while stimulating growth. fl bA encodes an A. nidulans regulator of G-protein signaling (RGS) domain protein that antagonizes FadA-mediated signaling to allow development. To better understand FlbA function and other aspects of FadA-mediated growth control, we have isolated and characterized mutations in four previously undefined genes designated as sfaA, sfaC, sfaD, and sfaE (suppressors of flbA), and a new allele of fadA (fadAR205H), all of which suppress a fl bA loss-of-function mutation ( fl bA98). These suppressors overcome fl bA losses of function in both sporulation and ST biosynthesis. fadAR205H, sfaC67, sfaD82, and sfaE83 mutations are dominant to wild type whereas sfaA1 is semidominant. sfaA1 also differs from other suppressor mutations in that it cannot suppress a fl bA deletion mutation (and is therefore allele specific) whereas all the dominant suppressors can bypass complete loss of fl bA. Only sfaE83 suppressed dominant activating mutations in fadA, indicating that sfaE may have a unique role in fadA- fl bA interactions. Finally, none of these suppressor mutations bypassed fl uG loss-of-function mutations in development-specific activation.

Induction of quinone reductase by a methanol extract of Scutellaria baicalensis and its flavonoids in murine Hepa 1c1c7 cells

The effect of extracts of scutellariae radix (Scutellaria baicalensis Georgi) and its flavonoids, baicalin, baicalein and wogonin, on induction of quinone reductase (QR) in the Hepa 1c1c7 murine hepatoma cell line was examined. A significant and dose-dependent induction of QR activity was observed in the methanol extract of scutellariae radix and baicalin. HPCL analysis showed that baicalin was contained as a main component in the methanol extract of scutellariae radix, indicating that baicalin may be the major active principle of QR induction mediated by scutellariae radix extract. To elucidate the mechanism of baicalin-mediated induction of QR enzyme activity, the effect on QR mRNA levels in Hepa 1c1c7 cell cultures was investigated. Using reverse transcriptase-polymerase chain reaction techniques, time- and dose-dependent induction of QR mRNA levels by baicalin were demonstrated in Hepa 1c1c7 cells. On the basis of these results, the scutellariae radix extract or baicalin can be regarded as a readily available, promising, novel cancer chemopreventive agent.

Coordinate control of secondary metabolite production and asexual sporulation in Aspergillus nidulans

Microbial secondary metabolite production is frequently associated with developmental processes such as sporulation, but there are few cases where this correlation is understood. Recent work with the filamentous fungus Aspergillus nidulans has provided new insights into the mechanisms coordinating production of the toxic secondary metabolite sterigmatocystin with asexual sporulation. These processes have been shown to be linked through a common need to inactivate a heterotrimeric G protein dependent signaling pathway that, when active, serves to stimulate growth while blocking both sporulation and sterigmatocystin biosynthesis.

Topographic localization of neuropeptide Y mRNA in the monkey brainstem

Neuropeptide Y (NPY) modulates cardiovascular, feeding and reproductive functions. Peripheral neurohumoral inputs from these systems are integrated and transformed into efferent signals in the brainstem. Detailed mapping of NPY-expressing cells in the brainstem has not been established in primates. In this report we utilized the in situ hybridization (ISH) method to identify brainstem areas that contain NPY mRNA in four ovariectomized rhesus macaques treated with estradiol-17beta. A 35S-labeled human NPY cRNA probe was used for ISH in paraformaldehyde-fixed brainstem blocks that were sectioned at 20 microm thickness. In the upper cervical spinal cord, NPY mRNA signals were confined to the substantia gelatinosa along the spinal tract of the trigeminal nerve. In the medulla, NPY images were found in the nucleus of solitary tract, dorsal motor nucleus of vagus nerve, nucleus of the spinal tract of trigeminal nerve, lateral reticular nucleus and the reticular formation. In the pons, NPY mRNA was confined to cells in the locus coeruleus and the nucleus of raphe. NPY signals were observed in the ventral portion of the periaqueductal grey, the dorsal nucleus of raphe and the reticular formation of mesencephalon in the midbrain. Whereas the brainstem distribution of NPY-containing cells in the rhesus macaque overlap those regions that are rich in catecholamines, NPY perikarya were also present in 'noncatecholaminergic' areas. For example, the reticular formation of both the medulla and mesencephalon abundantly expressed NPY mRNA. The functional significance of, and the effects of estrogen on, these patterns in NPY expression is unknown.

Transcription factor MSY-1 regulates expression of the murine growth hormone receptor gene

Previous studies identified and partially characterized a 42-base pair regulatory element in the 5'-flanking region of the L1 transcript of the murine growth hormone (GH) receptor gene that interacted with both double- and single-stranded DNA-binding proteins. We present evidence that the double-stranded DNA-binding protein is NF-Y, a CCAAT box-binding protein. Experiments with a dominant negative form of NF-Y indicate that NF-Y does not play a direct role in regulating the activity of the FP42 element. A cDNA clone that specifically interacts with the upper (coding) strand of the regulatory element was isolated by screening a cDNA expression library using the Southwestern technique. DNA sequencing, electrophoretic mobility shift assay, Southwestern blot analysis, and supershift EMSA confirm the identity of the single-stranded binding protein to be MSY-1, a DNA-binding protein that is evolutionary conserved from prokaryotes to eukaryotes. Mapping of single-stranded DNA configurations reveals that MSY-1 can facilitate the formation of single-stranded DNA regions in the GH receptor 5'-flanking region. Transient transfection experiments support the role of MSY-1 as a repressor of GH receptor gene activation. Southwestern blot analysis indicates that the levels of nuclear MSY-1 are decreased in the livers of pregnant mice, suggesting a role for MSY-1 in the increased expression of the GH receptor during pregnancy.

Cloning of the thermostable phytase gene (phy) from Bacillus sp. DS11 and its overexpression in Escherichia coli

Phytase hydrolyzes phytate to release inorganic phosphate, which would decrease the addition of phosphorus to feedstuffs for monogastric animals and thus reduce environmental pollution. The gene encoding phytase from Bacillus sp. DS11 was cloned in Escherichia coli and its sequence determined. A 560-bp DNA fragment was used as a probe to screen the genomic library. It was obtained through PCR of Bacillus sp. DS11 chromosomal DNA and two oligonucleotide primers based on N-terminal amino acid sequences of the purified protein and the cyanogen bromide-cleaved 21-kDa fragment. The phy cloned was encoded by a 2.2-kb fragment. This gene comprises 1152 nucleotides and encodes a polypeptide of 383 amino acids with a deduced molecular mass of 41,808 Da. Phytase was produced to 20% content of total soluble proteins in E. coli BL21 (DE3) using the pET22b(+) vector with the inducible T7 promoter. This is the first nucleic sequence report on phytase from a bacterial strain.

Isolation and sequence analysis of metalloprotease gene from Vibrio mimicus

The vmc gene encoding a metalloprotease of Vibrio mimicus (ATCC 33653) was cloned in Escherichia coli and sequenced. The vmc gene contained 1884 nt sequence which codes a polypeptide of 628 amino acids with a predicted molecular mass of 71,275 Da. The deduced amino acid sequence had the similarity of 68.5% with V. parahaemolyticus metalloprotease. The consensus sequence of a zinc binding motif (HEXXH) was identified to be HEYTH. The zymography analysis showed a gelatinolytic protein band around molecular mass of 61 kDa, and this result suggested that the cloned metalloprotease may undergo processing during secretion.

Asexual sporulation in Aspergillus nidulans

The formation of mitotically derived spores, called conidia, is a common reproductive mode in filamentous fungi, particularly among the large fungal class Ascomycetes. Asexual sporulation strategies are nearly as varied as fungal species; however, the formation of conidiophores, specialized multicellular reproductive structures, by the filamentous fungus Aspergillus nidulans has emerged as the leading model for understanding the mechanisms that control fungal sporulation. Initiation of A. nidulans conidiophore formation can occur either as a programmed event in the life cycle in response to intrinsic signals or to environmental stresses such as nutrient deprivation. In either case, a development-specific set of transcription factors is activated and these control the expression of each other as well as genes required for conidiophore morphogenesis. Recent progress has identified many of the earliest-acting genes needed for initiating conidiophore development and shown that there are at least two antagonistic signaling pathways that control this process. One pathway is modulated by a heterotrimeric G protein that when activated stimulates growth and represses both asexual and sexual sporulation as well as production of the toxic secondary metabolite, sterigmatocystin. The second pathway apparently requires an extracellular signal to induce sporulation-specific events and to direct the inactivation of the first pathway, removing developmental repression. A working model is presented in which the regulatory interactions between these two pathways during the fungal life cycle determine whether cells grow or develop.

Topographic comparison of the expression of norepinephrine transporter, tyrosine hydroxylase and neuropeptide Y mRNA in association with dopamine beta-hydroxylase neurons in the rabbit brainstem

In mammalian species, ovulation occurs following a massive release of hypothalamic gonadotropin-releasing hormone (GnRH). Several chemicals, including norepinephrine (NE) and neuropeptide Y (NPY), are responsible for the initiation and/or magnitude and duration of this pre-ovulatory GnRH surge. In the central nervous system, NE neural cell bodies are located in the brainstem; some are co-localized with NPY neurons and/or co-express the NE transporter (NET) gene which dictates NET protein production. The activity of NET at NE terminals is critical for synaptic NE function. In the rabbit, coitus induces a hypothalamic NE release which precedes the GnRH surge. We hypothesize that the coital stimulus is transmitted to the brainstem and transformed and integrated into GnRH-stimulating signals via NE, NET and/or NPY. However, very little is known about the distribution of cells expressing NET, NPY and tyrosine hydroxylase (TH, the rate-limiting enzyme of NE synthesis) in this species. Therefore, we utilized the sensitive in situ hybridization technique to identify the presence of these messages in conjunction with the location of NE cells, the latter being marked by dopamine beta-hydroxylase (DBH), the specific enzyme for NE synthesis. Three non-mated New Zealand White does were perfused with 4% paraformaldehyde and their brainstems were sectioned at 20-micron thick between 2 mm caudal to the obex and the rostral pons. Serial sections were immunohistochemically stained for DBH and hybridized with rabbit-specific TH and NET cRNAs and a human NPY probe. The data suggest that several DBH-positive areas in the medulla expressed one or more messages, i.e. the lateral tegmentum (A1) and the nucleus of the solitary tract (A2) expressed all three mRNAs, the area postrema (AP) contained NET and TH mRNAs but not NPY cells. In the pons, the locus coeruleus (LC), subnucleus of coeruleus (LCs) and lateral tegmental nuclei (A5) expressed NET and TH mRNAs but contained little or no NPY message. The distribution patterns of TH and NET appeared to be similar in the LC, LCs, A2 and AP.

Dominant mutations affecting both sporulation and sterigmatocystin biosynthesis in Aspergillus nidulans

The initiation of conidiophore development in the filamentous fungus Aspergillus nidulans is a complex process requiring the activities of several genes including fluG, flbA, flbB, flbC, flbD, and flbE. Recessive mutations in any one of these genes result in greatly reduced expression of the brlA developmental regulatory gene and a colony morphology described as fluffy. These fluffy mutants have somewhat diverse phenotypes but generally grow as undifferentiated masses of vegetative hyphae to form large cotton-like colonies. In this paper we describe a genetic screen to identify dominant mutations resulting in similar fluffy colony morphologies. We have identified 36 dominant fluffy mutant strains and shown that 29 of these mutants have greatly reduced brlA expression as compared to wild-type. In addition, we have found that 19 of these mutants are not only developmentally altered but also fail to produce the toxic, carcinogenic, secondary metabolite sterigmatocystin. At least three of the mutants isolated result from dominant activating mutations in fadA which encodes the G alpha subunit of a heterotrimeric G-protein. Another of the mutants results from a dominant interfering mutation in brlA. We discuss the approaches taken to characterize these potentially important regulators of growth, development and secondary metabolism.

Aspergillus sporulation and mycotoxin production both require inactivation of the FadA G alpha protein-dependent signaling pathway

The filamentous fungus Aspergillus nidulans contains a cluster of 25 genes that encode enzymes required to synthesize a toxic and carcinogenic secondary metabolite called sterigmatocystin (ST), a precursor of the better known fungal toxin aflatoxin (AF). One ST Cluster (stc) gene, aflR, functions as a pathway-specific transcriptional regulator for activation of other genes in the ST pathway. However, the mechanisms controlling activation of aflR and synthesis of ST and AF are not understood. Here we show that one important level for control of stc gene expression requires genes that were first identified as early acting regulators of asexual sporulation. Specifically, we found that loss-of-function mutations in flbA, which encodes a RGS domain protein, or dominant activating mutations in fadA, which encodes the alpha subunit of a heterotrimeric G protein, block both ST production and asexual sporulation. Moreover, overexpression of flbA or dominant interfering fadA mutations cause precocious stc gene expression and ST accumulation, as well as unscheduled sporulation. The requirement for flbA in sporulation and ST production could be suppressed by loss-of-function fadA mutations. The ability of flbA to activate stc gene expression was dependent upon another early acting developmental regulator, fluG, and AflR, the stc gene-specific transcription factor. These results are consistent with a model in which both asexual sporulation and ST production require inactivation of proliferative growth through inhibition of FadA-dependent signaling. This regulatory mechanism is conserved in AF-producing fungi and could therefore provide a means of controlling AF contamination.

beta-Agarase from Pseudomonas sp. W7: purification of the recombinant enzyme from Escherichia coli and the effects of salt on its activity

The recombinant plasmid (pJAI), harbouring the agarase gene (pjaA) of Pseudomonas sp. W7, was introduced and expressed in Escherichia coli JM83. The agarase was purified using a combination of acetone precipitation and anion-exchange, gel-filtration and affinity chromatographies, with overall yield of 10% from the culture supernatant of E. coli JM83 (pJAI). The purified agarase migrated as a single band (molecular mass 59 kDa) on SDS/PAGE and was found to be beta-agarase, which could hydrolyse the beta-1,4 linkage of agarose to yield neoagarotetraose as the main product. Optimal enzyme activity was at pH 7.8 and the temperature optimum spanned the broad range 20-40 degrees C. The recombinant agarase was halophilic, maximum activity being exhibited at 0.9 M NaCl. This halophilic property could improve the production of neoagaro-oligosaccharides available in a marine environment.

Nucleotide sequence of the vmhA gene encoding hemolysin from Vibrio mimicus

The structural gene (vmhA) of hemolysin from Vibrio mimicus (ATCC33653) was cloned and sequenced. The vmhA gene contains an open reading frame consisting of 2232 nucleotides which can code for a protein of 744 amino acids with a predicted molecular mass of 83,059. The similarity of amino acid sequence shows 81.6% identity with Vibrio cholerae El Tor hemolysin.

The Aspergillus FlbA RGS domain protein antagonizes G protein signaling to block proliferation and allow development

flbA encodes an Aspergillus nidulans RGS (regulator of G protein signaling) domain protein that is required for control of mycelial proliferation and activation of asexual sporulation. We identified a dominant mutation in a second gene, fadA, that resulted in a very similar phenotype to flbA loss-of-function mutants. Analysis of fadA showed that it encodes the alpha-subunit of a heterotrimeric G protein, and the dominant phenotype resulted from conversion of glycine 42 to arginine (fadA(G42R)). This mutation is predicted to result in a loss of intrinsic GTPase activity leading to constitutive signaling, indicating that activation of this pathway leads to proliferation and blocks sporulation. By contrast, a fadA deletion and a fadA dominant-interfering mutation (fadA(G203R)) resulted in reduced growth without impairing sporulation. In fact, the fadA(G203R) mutant was a hyperactive asexual sporulator and produced elaborate sporulation structures, called conidiophores, under environmental conditions that blocked wild-type sporulation. Both the fadA(G203R) and the fadA deletion mutations suppressed the flbA mutant phenotype as predicted if the primary role of FlbA in sporulation is in blocking activation of FadA signaling. Because overexpression of flbA could not suppress the fadA(G42R) mutant phenotype, we propose that FlbA's role in modulating the FadA proliferation signal is dependent upon the intrinsic GTPase activity of wild-type FadA.

Specific domains of beta-amyloid from Alzheimer plaque elicit neuron killing in human microglia

Alzheimer's disease (AD) is found to have striking brain inflammation characterized by clusters of reactive microglia that surround senile plaques. A recent study has shown that microglia placed in contact with isolated plaque fragments release neurotoxins. To explore further this process of immunoactivation in AD, we fractionated plaque proteins and tested for the ability to stimulate microglia. Three plaque-derived fractions, each containing full-length native A beta 1-40 or A beta 1-42 peptides, elicited neurotoxin release from microglia. Screening of various synthetic peptides (A beta 1-16, A beta 1-28, A beta 12-28, A beta 25-35, A beta 17-43, A beta 1-40, and A beta 1-42) confirmed that microglia killed neurons only after exposure to nanomolar concentrations of human A beta 1-40 or human A beta 1-42, whereas the rodent A beta 1-40 (5Arg-->Gly, 10Tyr-->Phe 13His-->Arg) was not active. These findings suggested that specific portions of human A beta were necessary for microglia-plaque interactions. When coupled to microspheres, N-terminal portions of human A beta (A beta 1-16, A beta 1-28, A beta 12-28) provided anchoring sites for microglial adherence whereas C-terminal regions did not. Although itself not toxic, the 10-16 domain of human A beta was necessary for both microglial binding and activation. Peptide blockade of microglia-plaque interactions that occur in AD might prevent the immune-driven injury to neurons.

Conservation of structure and function of the aflatoxin regulatory gene aflR from Aspergillus nidulans and A. flavus

Under limiting growth conditions, Aspergillus nidulans produces a carcinogenic secondary metabolite related to aflatoxin and called sterigmatocystin (ST). The genes for ST biosynthesis are co-ordinately regulated and are all found within an approximately 60-kilobase segment of DNA. One of the genes within this region is predicted to encode a CX2CX6CX6CX2CX6CX2 zinc binuclear cluster DNA-binding protein that is related to the Aspergillus flavus and Aspergillus parasiticus aflatoxin regulatory gene aflR. Deletion of the A. nidulans aflR homolog resulted in an inability to induce expression of genes within the ST gene cluster and a loss of ST production. Because A. nidulans aflR mRNA accumulates specifically under conditions that favor ST production we expect that activation of ST biosynthetic genes is determined by A. nidulans aflR. In support of this hypothesis, we demonstrated that induced expression of the A. flavus aflR gene in A. nidulans, under conditions that normally suppress ST gene expression, resulted in activation of genes in the ST biosynthetic pathway. This result demonstrates that AflR function is conserved between Aspergillus spp. and that aflR expression is sufficient to activate genes in the ST pathway.

Excimer laser photorefractive keratectomy for myopia

To evaluate the safety, effectiveness and stability of excimer laser photorefractive keratectomy (PRK) treatment, we studied its posttreatment results in 44 normal-sighted myopic eyes where a 193-nm emission wavelength excimer laser was used to correct myopia. The eyes were divided into three groups according to the preoperative refractive error and attempted correction: group I, preoperative myopia < or = 6.00 diopters (D), full correction; group II, preoperative myopia between 6.00 and 8.00 D, full correction; group III, preoperative myopia > 8.00 D, attempted correction of 8.00 D. Percentages of relative spherical equivalents (ie, observed spherical equivalent -- expected spherical equivalent) within +/- 1.0 D 3 months after treatment were 95% in group I, 64% in group II and 67% in group III. Uncorrected visual acuity of 20/40, or better, was achieved in 100% of eyes in group I, and 92% in group II at 6 months. Initial overcorrection followed by myopic regression was observed in all groups. The refractive outcome in our study was stable 3 months after surgery. Anterior stromal haze was mild and disappeared gradually 3 months postoperatively. The greater the diopter correction needed, the higher the grade of corneal haze (p < 0.01). There were no significant complications. The results of this study demonstrated that excimer laser PRK appears to be a reasonably predictable and stable procedure to correct low to moderate myopia.

Twenty-five coregulated transcripts define a sterigmatocystin gene cluster in Aspergillus nidulans

Sterigmatocystin (ST) and the aflatoxins (AFs), related fungal secondary metabolites, are among the most toxic, mutagenic, and carcinogenic natural products known. The ST biosynthetic pathway in Aspergillus nidulans is estimated to involve at least 15 enzymatic activities, while certain Aspergillus parasiticus, Aspergillus flavus, and Aspergillus nomius strains contain additional activities that convert ST to AF. We have characterized a 60-kb region in the A. nidulans genome and find it contains many, if not all, of the genes needed for ST biosynthesis. This region includes verA, a structural gene previously shown to be required for ST biosynthesis, and 24 additional closely spaced transcripts ranging in size from 0.6 to 7.2 kb that are coordinately induced only under ST-producing conditions. Each end of this gene cluster is demarcated by transcripts that are expressed under both ST-inducing and non-ST-inducing conditions. Deduced polypeptide sequences of regions within this cluster had a high percentage of identity with enzymes that have activities predicted for ST/AF biosynthesis, including a polyketide synthase, a fatty acid synthase (alpha and beta subunits), five monooxygenases, four dehydrogenases, an esterase, an 0-methyltransferase, a reductase, an oxidase, and a zinc cluster DNA binding protein. A revised system for naming the genes of the ST pathway is presented.

Genetic mapping indicates that VP4 is the rotavirus cell attachment protein in vitro and in vivo

To identify the rotavirus protein which mediates attachment to cells in culture, viral reassortants between the simian rotavirus strain RRV and the murine strains EHP and EW or between the simian strain SA-11 and the human strain DS-1 were isolated. These parental strains differ in the requirement for sialic acid to bind and infect cells in culture. Infectivity and binding assays with the parental and reassortant rotaviruses indicate that gene 4 encodes the rotavirus protein which mediates attachment to cells in culture for both sialic acid-dependent and -independent strains. Using ligated intestinal segments of newborn mice and reassortants obtained between the murine strain EW and RRV, we developed an in vivo infectivity assay. In this system, the infectivity of EW was not affected by prior treatment of the enterocytes with neuraminidase, while neuraminidase treatment reduced the infectivity of a reassortant carrying gene 4 from RRV on an EW background more than 80% relative to the controls. Thus, VP4 appears to function as the cell attachment protein in vivo as well as in vitro.

Cloning of a novel crystal protein gene cry1K from Bacillus thuringiensis subsp. morrisoni

A novel crystal protein gene cry1K has been cloned and sequenced from a Bacillus thuringiensis subsp. morrisoni BF190 isolated from phylloplane. The upstream promoter region of cry1K was almost identical with that of cry1B. The deduced amino acid sequence of Cry1K contains 1215 amino acid residues with an estimated molecular mass of 137 kDa. Comparison of the amino acid sequence of the Cry1K with that of Cry proteins revealed that Cry1K is most closely related to Cry1B and Cry1I. Cry1K has a high degree of identity with Cry1B in the region between initiator codon and conserved sequence block 1, and with Cry1F in the region between conserved block 3 and 5. Protein inclusion purified from a recombinant strain of B. thuringiensis expressing the cry1K gene was found to have a different insect-host specificity from Cry1B, Cry1I and Cry1F, Cry1K was found to be selectively toxic to Artogeia rapae and not active to Plutella xylostella.

Insulin secretory defect in Zucker fa/fa rats is improved by ameliorating insulin resistance

The role of insulin resistance in the impaired glucose-stimulated insulin release of Zucker fatty rats was investigated using the insulin-sensitizing thiazolidinedione drug pioglitazone. Fatty rats had fasting hyperinsulinemia yet a blunted secretory response to intravenous glucose compared with lean age-matched controls. Islets from fatty rats secreted less insulin (based on islet DNA) in response to high glucose than islets from lean rats but secreted normal amounts of insulin when tolbutamide or alpha-ketoisocaproic acid (alpha-KIC) was the stimulus. Administering pioglitazone for 9 days diminished basal hyperinsulinemia and increased the insulin response to high glucose by fatty rats but not by lean controls. Pioglitazone pretreatment augmented the secretory response by isolated islets to high glucose, alpha-KIC, and tolbutamide. Augmentation of islet insulin release was not associated with reduced plasma glucose concentration, suggesting that altered glycemia was not involved. Pancreas and islet insulin content was greater in fatty rats than in lean controls and was decreased by pioglitazone; hence, insulin stores and glucose-stimulated insulin release did not correlate. Pioglitazone treatment did not affect the rate of islet glucose usage or ATP/ADP in the presence of 2.75 or 16 mmol/l glucose. These data indicate that ameliorating insulin resistance reverses defective glucose-stimulated insulin release by Zucker fa/fa rats. After pioglitazone administration, insulin secretion may be augmented by increased generation of a metabolic coupling factor from glucose or at a later step in the secretory process that is common to both glucose and nonglucose secretagogues.

Sterigmatocystin biosynthesis in Aspergillus nidulans requires a novel type I polyketide synthase

A filamentous fungus, Aspergillus nidulans, produces the carcinogenic mycotoxin sterigmatocystin (ST), which is a polyketide-derived secondary metabolite. A gene (pksST) encoding the ST polyketide synthase (PKSst) in A. nidulans was cloned, sequenced, and characterized. Large induced deletion mutants, which did not make ST or any ST intermediates, were used to identify genes associated with ST biosynthesis. Among the transcripts detected within the deletion region, which showed developmental expression with ST production, was a 7.2-kb transcript. Functional inactivation of the gene encoding the 7.2-kb transcript blocked production of ST and all ST intermediate substrates but did not affect transcription of the pathway genes, indicating that this gene was involved in a very early step of ST biosynthesis. These results also indicate that PKSst was not associated with activation of other ST genes. Sequencing of the region spanning this gene revealed that it encoded a polypeptide with a deduced length of 2,181 amino acids that had high levels of similarity to many of the known polyketide synthases and FASs. This gene, pksST, encodes a multifunctional novel type I polyketide synthase which has as active sites a beta-ketoacyl acyl carrier protein synthase, an acyltransferase, duplicated acyl carrier proteins, and a thioesterase, all of these catalytic sites may be multiply used. In addition, a 1.9-kb transcript, which also showed developmental expression, was mapped adjacent to pksST, and the sequence of this gene revealed that it encoded a cytochrome P-450 monooxygenase-like peptide.

[Investigation on invasion of preepiglottic space by supraglottic carcinoma]

This study, based on analysis of 100 whole-organ serial sections of the larynx, concluded that preepiglottic space invasion is involved in 60% of supraglottic carcinoma. The preepiglottic space is involved either by invasion through the adjacent structures of the epiglottis, or more frequently by destroying the epiglottic cartilage and the thyro-epiglottic ligament. The preepiglottic space is involved mainly by epiglottic and epiglottic-ventricular carcinomas, accounting for 95% of carcinomas which invade the space. The involvement of preepiglottic space by supraglottic carcinoma is intimately related to the morphologic features, marginal growth patterns, and T classification. Ulcerative carcinoma is the commonest, accounting for 65%. The incidence of the infiltrative carcinomas is the highest. With increase in T stage, the percentage of invasion of preepiglottic space is increased. We believe that the easy invasion of the preepiglottic space by the supraglottic carcinoma is due to the fact that the epiglottic and epiglttic-ventricular carcinomas which account for 83% of supraglottic carcinomas are located in front of the larynx. In addition, the carcinoma easily destroys the epiglottic, cartilage and enters the preepiglottic space because the embryonic barrier which exists below the glottis and the perichondrium of the epiglottic cartilage is quite fragile.

Polymeric 6-aminoquinoline, an activated carbamate reagent for derivatization of amines and amino acids by high-performance liquid chromatography

A new polymeric reagent containing the 6-aminoquinoline (6-AQ) tag was developed and applied for the off-line derivatization of amines and amino acids in high-performance liquid chromatography (HPLC). The synthesis and characterization of this polymeric reagent are described. An authentic external standard of a typical amine was synthesized and characterized for the determination of the derivatization efficiency. All amines had a derivatization efficiency higher than 50%; the derivatization of amino acids was performed under optimized phase-transfer catalysis reaction conditions. Derivatized amines and amino acids were separated under conventional reversed-phase conditions and determined by UV and FL detectors. To investigate the practical applications, this polymeric reagent was also used to derivatize protein hydrolysates.

[The inhibitory effect and its mechanism of transferrin on FSH-induced differentiation of granulosa cells]

Transferrins are a class of related metal-binding transport glycoproteins for transporting iron to various organs and tissues of the body. In recent years, it has been reported that the transferrin can play an important role in the local regulation of ovarian function, apart from its iron-binding characteristic. Transferrin could attenuate FSH-induced differentiation of rat and human granulosa cells and its mechanisms were considered as follows: (1) Transferrins partially blocked the binding of FSH with its receptors on granulosa cells and reduced the formation of intracellular cAMP, and therefore inhibited the expression of FSH receptors. (2) Acting sites beyond cAMP formation also existed for the inhibitory effect of transferrin on inhibin and estradiol production. (3) The inhibitory effect of transferrin seemed not to be involved in the changes of protein kinase C activity, the calcium release and "proliferation-differentiation reversed mechanism" in granulosa cells.

Nucleotide sequence of the gene encoding the Corynebacterium glutamicum mannose enzyme II and analyses of the deduced protein sequence

The complete nucleotide sequence of the gene encoding the Corynebacterium glutamicum mannose enzyme II (EIIMan) was determined. The gene consisted of 2052 base pairs encoding a protein of 683 amino acid residues; the molecular mass of the protein subunit was calculated to be 72570 Da. The N-terminal hydrophilic domain of EIIMan showed 39.7% homology with a C-terminal hydrophilic domain of Escherichia coli glucose-specific enzyme II (EIIGlc). Similar homology was shown between the C-terminal sequence of EIIMan and the E. coli glucose-specific enzyme III (EIIIGlc), or the EIII-like domain of Streptococcus mutans sucrose-specific enzyme II. Sequence comparison with other EIIs showed that EIIMan contained residues His-602 and Cys-28 which were homologous to the potential phosphorylation sites of EIIIGlc, or EIII-like domains, and hydrophilic domains (IIB) of several EIIs, respectively.

Nucleotide sequence of the pectate lyase gene from alkali-tolerant Bacillus sp. YA-14

The nucleotide sequence of the pectate lyase gene (pe lK) from alkali-tolerant Bacillus sp. was identified and analyzed. A 1,260-base pair open reading frame for the pe lK gene was observed and encoded for a protein of 420 amino acids. The signal peptide was composed of 21 amino acid residues. In the deduced primary structure of this enzyme, the three conserved regions of several pectate lyases were found and showed high homologies.

Purification and characterization of alkaline serine protease from an alkalophilic Streptomyces sp

SAP, an extracellular alkaline serine protease produced by Streptomyces sp. YSA-130, was purified to homogeneity by CM-Sephadex column chromatography and crystallization. The enzyme was a monomeric protein with a molecular weight of 19,000 as estimated by SDS-PAGE and gel filtration. The amino acid composition and amino-terminal sequence of SAP were similar to those of other bacterial serine proteases, i.e., Streptomyces griseus proteases A and B, Lysobacter enzymogenes alpha-lytic protease and Nocardiopsis dassonvillei subsp. prasina OPC-210 alkaline serine protease NDP-I. The optimum temperature and pH for the enzyme activity were 60 degrees C and 11.5. The enzyme was stable up 50 degrees C, and between pHs 4 and 12. The activity was inhibited by Ag+, Hg2+, Co2+, sodium dodecyl sulfate. N-bromosuccinimide, diisopropyl phosphorofluoridate (DFP), 2,3-butanedione, 5,5'-dithiobis-(2-nitrobenzoic acid) (DTNB), iodoacetate, N-ethylmaleimide (NEM), phenylmethanesulfonyl fluoride (PMSF), and phenylglyoxal.

[Haemorrheological effects of different processed products of radix Aconiti Kusnezoffii on animal model with syndrome of "accumulation of cold and blood stasis"]

The effects of Radix Aconiti Kusnezoffii processed by moistening in combination with steaming method and by pharmacopoeial method as well as of the crude drug on haemorrheological nature and the plasma fibronogen content and platelet aggregation rate in the rat model with syndrome of "accumulation of cold and blood stasis" were studied, the result shows that the product processed by moistening in combination with steaming works best.

Antihyperglycemic action of guanidinoalkanoic acids: 3-guanidinopropionic acid ameliorates hyperglycemia in diabetic KKAy and C57BL6Job/ob mice and increases glucose disappearance in rhesus monkeys

To evaluate the long-held concept that acidic guanidines lack glycemic effects, guanidinoalkanoic acids and the biguanide metformin (positive control) were administered to KKAy mice, a model of noninsulin-dependent diabetes. Two acidic guanidines, 3-guanidinopropionic acid (3-GPA) and guanidinoacetic acid, decreased the plasma glucose level; other compounds were ineffective. 3-GPA was more potent than even metformin. Insulin suppression tests in KKAy mice indicated that improved insulin sensitivity was the mode of action for 3-GPA. Glycemic effects in KKAy mice resulted from increased glucose disposal whereas gluconeogenesis, hepatic glycogen content and intestinal glucose absorption were unchanged. 3-GPA's glycemic effect was corroborated in two other models of noninsulin-dependent diabetes. In ob/ob mice, the compound reduced hyperglycemia, polyuria, glycosuria and hyperinsulinemia. In insulin-resistant rhesus monkeys, it increased the disappearance of i.v. glucose. The glycemic action of 3-GPA required the presence of some circulating insulin as well as hyperglycemia because the compound was ineffective in normoglycemic mice, insulinopenic Chinese hamsters and streptozotocin-diabetic rats. These data indicate that acidic guanidine derivatives can ameliorate hyperglycemia in animal models of noninsulin-dependent diabetes. Because acidic derivatives uniquely lack the propensity of guanidine compounds for inducing lactic acidosis, our finding suggests a new approach for developing improved antidiabetes compounds from this chemical class.

An insert of seven amino acids confers functional differences between smooth muscle myosins from the intestines and vasculature

The molecular mechanisms underlying the heterogeneity in contractile properties observed among smooth muscle tissues are unknown. We examined whether part of this diversity might be intrinsic to myosin by comparing structural and enzymatic properties of myosins from two physiologically diverse tissues. Using the reverse transcriptase polymerase chain reaction, we compared avian intestinal smooth muscle and vascular smooth muscle myosin heavy chain (MHC) mRNA. We found that intestinal, but not vascular, MHC mRNA contains an insert of 21 nucleotides, encoding 7 amino acids, in a region near the ATP binding site in the myosin head. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of purified myosin revealed that the relative mobilities of the previously described intestinal MHC isoforms SM1 (204 kDa) and SM2 (200 kDa) were slower than the corresponding vascular SM1 and SM2 isoforms. Furthermore, antibodies raised against a synthetic peptide corresponding to the deduced amino acid sequence of the intestinal insert strongly recognized intestinal SM1 and SM2 but only weakly recognized the vascular isoforms. The presence of the insert in intestinal myosin correlated with a higher velocity of movement of actin filaments in vitro and a higher actin-activated Mg(2+)-ATPase activity, compared with vascular myosin. Other than the MHC insert, one other structural difference distinguished intestinal and vascular myosins: two isoforms of the 17-kDa myosin light chain were found in vascular myosin, whereas a single isoform was found in intestinal myosin. Exchange of the intestinal myosin light chains onto the vascular MHC did not alter its activity in the in vitro motility assay, suggesting that the 7-amino acid MHC insert is responsible for the different enzymatic activities of vascular and intestinal myosins.

Effects of clonidine on the calcium content and morphology of rat salivary glands

These effects were examined with and without pretreatment of animals with reserpine and the adrenergic antagonists prazosin (alpha 1), yohimbine (alpha 2) and propranolol (beta). The effects of clonidine on glandular concentrations of norepinephrine and dopamine also were examined. These effects were compared with those of xylazine, a presynaptic alpha 2-adrenergic agonist. A single, high dose of clonidine followed by an overnight fast caused marked increases in calcium content and acinar secretory granules in the submandibular and sublingual glands, similar to those caused by reserpine. However, the calcium content of the parotid gland was not altered by clonidine, although there seemed to be a modest increase in acinar secretory granules. The clonidine-induced increase in submandibular calcium content could not be attributed to any adrenergic receptor activity since it was not blocked by either alpha- or beta-adrenergic antagonists. Unlike reserpine, clonidine did not affect catecholamine concentrations in the parotid and submandibular glands. Pretreatment with reserpine did not significantly alter the clonidine-induced increase in submandibular calcium content. It is likely that the greater accumulation of acinar secretory granules is related to the increased calcium stores of the glands in clonidine- and/or reserpine-treated rats. The large differences in calcium content among the three glands might be attributable, in part, to differences in the calcium-binding capacity of their secretory granules. Possible mechanisms for the clonidine effects on salivary-gland calcium include disturbances in membrane-associated pools or gating mechanisms for calcium, which need further study.

[Inhibitory effect of transferrin on the binding and maintenance of FSH receptors in rat granulosa cells]

It has been recently demonstrated that transferrin (TRF) can inhibit the functional differentiation of rat granulosa cells, but the mechanism remains unknown. In present experiment, the effect of TRF on the binding of 125I-rFSH to receptors and on the maintenance of FSH receptors in granulosa cells from immature, diethylstilbestrol treated rats were studied. The results show that the physiological range of TRF partially blocked the binding of 125I-rFSH to granulosa cells in a dose-dependent manner. TRF also dose-dependently inhibited the maintenance of FSH receptors in accordance with the reduced production of progesterone and estradiol. In view of the present and our previous investigation, it could be concluded that mechanisms of the inhibitory effect of TRF on the functional differentiation of granulosa cells mainly involve blockade of FSH binding to its receptors and inhibition of FSH receptor maintenance by FSH.

Chemical modification of the neutral amino acid transport system L of Chinese hamster ovary cells with p-chloromercuribenzene sulfonate

Branched-chain and aromatic neutral amino acids enter mammalian cells predominantly through a Na(+)-independent transport agency called System L. The sulfhydryl specific reagent p-chloromercuribenzene sulfonate (pCMBS) has been shown to be a potent inactivator of System L transport activity in Chinese hamster ovary cells, however, inactivation by pCMBS can be prevented by the presence of System L-specific substrate amino acids during the inactivation reaction. In addition, the presence of amino acids that are not substrates for System L have no effect on pCMBS inactivation of System L. Inactivation of System L activity by pCMBS was sensitive to pH and reversible by incubation with dithiothreitol. These findings suggest that there is a sulfhydryl group in, or very near, the amino acid-binding site of the System L transporter of CHO cells. Substrate protection, however, could be explained by conformational changes in the transporter associated with substrate binding. The presence of a substrate protectable sulfhydryl group on the System L transporter would aid in the attempt to identify this transporter using the technique of differential labeling.

[Analysis of 526 cases of trigeminal neuralgia treated by radiofrequency thermal coagulation of temperature]

In 526 cases of trigeminal neuralgia,254 cases were male,272 were female.The age from 17-90,average age is 58.8. The shortest course of disease is 2 months,but the longest one is 39 yrs,with a mean course of 6.8 yrs.Pain in right side is more than in left side.Pain was more often involved simultaneously on first and second branch of trigeminal nerve.505 cases (96%)got the complete response after radiofrequency thermal coagulation therapy,13 cases (2.47%) were obviously advanced,while 8 cases (1.52%) were failed.The total effective rate was 98.47%.After follow up of 1-5yrs,in 518 efficacious cases,65 recurred cases (12.54%) were treated again by the same method,pain was then stopped.

Effects of chronic amitriptyline administration on saliva from the parotid and submandibular glands of the rat

The effect of prolonged treatment with amitriptyline on the secretory activity of rat salivary glands evoked by parasympathetic nerve stimulation and isoprenaline administration has been studied. Low doses of amitriptyline (10 mg/kg per day for 2 or 4 weeks), did not significantly affect salivary flow evoked by either parasympathetic nerve or isoprenaline stimulation. Higher doses of amitriptyline (50 mg/kg/day for 2 or 4 weeks) however, markedly decreased parasympathetic-evoked salivary secretion (flow and volume) from both parotid and submandibular glands, while isoprenaline-evoked secretions were unaffected. Sodium, potassium, and calcium concentrations of nerve-elicited or isoprenaline-evoked saliva were not significantly altered by amitriptyline treatment. Protein concentration and amylase activity of nerve-elicited parotid saliva were, however, greatly increased by chronic amitriptyline administration. Possible mechanisms for drug-induced increase in nerve-elicited salivary protein concentration include changes in cholinergic receptor binding, release of neuropeptides and variations in phosphatidylinositol turnover, which need further study.

Effects of chronic clonidine administration on parasympathetic-evoked rat saliva

Effects of chronic administration of clonidine on parasympathetic-evoked saliva from both parotid and submandibular glands were investigated. Clonidine at 1 mg/kg/day for 5 or 7 days caused a significant reduction in the salivary secretion (flow rate and total volume) evoked by parasympathetic nerve stimulation of parotid but not submandibular glands. Ion concentrations (Na, K and Ca) of parasympathetically nerve-evoked parotid saliva were not altered. However, the total protein concentration as well as output, amylase activity, and output of such saliva were markedly increased. Possible mechanisms for clonidine-induced increase in nerve-elicited salivary protein concentration include release of neuropeptides, and changes in adrenergic receptor binding which need further study.

Immunochromatography of fusarochromanone mycotoxins

The present paper describes an enzyme-linked immunoassay (ELISA) used in combination with thin-layer chromatography (TLC) and liquid chromatography (LC) for determination of fusarochromanone (TDP) mycotoxins in barley, wheat, and a Fusarium culture grown in rice and corn. The mycotoxins were first extracted from the sample with 100% methanol and subjected to TLC or LC without additional cleanup treatment. Individual fractions eluted from TLC or LC were acetylated, then analyzed by ELISA. Determinations of TDP toxins at levels as low as 0.1 and 0.5 ng were achieved by ELISA in combination with LC and TLC, respectively. The detection limit for TDP-1 in barley and wheat was about 20 ppb by ELISA alone as compared with a detection limit of 5 ppb by a combination of ELISA with either TLC or LC. Overall analytical recovery (% of added) of TDP-1 added to barley and wheat at 5, 10, and 20 ppb of TDP-1 was 106.9 +/- 15.3 and 113.2 +/- 11.6 by LC-ELISA and 108.8 +/- 9.1 and 110.4 +/- 4.9 by TLC-ELISA, respectively. Analysis of extracts obtained from Fusarium equiseti R6137 grown in corn and rice by the combination of TLC and ELISA revealed that diacetyl-TDP was also produced by this fungus in addition to TDP-1 and TDP-2. Comparable results were obtained when fungal extracts were subjected to ELISA, LC, and immunochromatography (i.e., combination of ELISA with either TLC or LC).

An inhibitory effect of transferrin on differentiation of rat granulosa cells in vitro

The effects of human transferrin (TRF) on granulosa cell function were examined using serum-free cultures of rat granulosa cells obtained from immature, diethylstilbestrol-treated rats. The results show that TRF had dose- and time-dependent inhibitory effects on FSH-induced inhibin and progesterone production with the half-maximal inhibitory dose of 6.1-6.3 micrograms/ml. The inhibitory effect of TRF on FSH-induced inhibin and progesterone production was not reversed by removing TRF and changing medium after 48 h of treatment. TRF also inhibited insulin- and insulin-like growth factor-I (IGF-I)-induced inhibin production in a dose-dependent manner. TRF did not inhibit forskolin- and 8-bromo-cAMP-induced progesterone production but did inhibit inhibin production induced by these agents. TRF had no effect on basal production of inhibin and progesterone. On the other hand, high concentrations of insulin and cortisol completely counteracted the inhibitory effect of TRF on FSH-induced progesterone production but only partially counteracted the inhibitory effect of TRF on FSH-induced inhibin production. Our data suggest that: 1) TRF may be an important negative modulator of the stimulatory actions of FSH or IGF-I and other factors acting on granulosa cells; 2) the inhibitory effects of TRF require the presence of FSH or other factors such as IGF-I or insulin, which facilitate granulosa cell differentiation; and 3) different mechanisms are involved in the modulating effects of TRF on inhibin and progesterone production.

Effects of changes in pattern of LHRH pulse on LH secretion by perfused anterior pituitary cells of male rats

In the present study, a perfusion system of dispersed cells was used to investigate the effects of LHRH pulse amplitude and frequency, and LHRH continuous stimulation on LH secretion by anterior pituitary cells of adult male rats. The results have shown that, in the range of LHRH concentrations from 1 X 10(-10) to 1 X 10(-6) mol/L, the dose-response curve of LH secretion was linear. LHRH pulse frequency generated a biphasic LH response: increasing LHRH pulse frequency increased the basal LH secretion and decreased LH/pulse. When 1 X 10(-9) mol/L or greater LHRH was given at frequencies of 3 pulses/h or higher, it was observed that a maximal LH peak was induced and then the LH release declined progressively to its LH basal level, i.e. LHRH self-priming effect and LH desensitization occurred. Enhancement of amplitude of LHRH pulses could reduce pulse frequency required for priming. Increases in frequency of LHRH pulses with high amplitude would provoke the priming effect more quickly. In addition, continuous perfusion of LHRH with different concentrations could also elicit the LHRH self-priming effect and lH desensitization. LHRH with low concentration (1 X 10(-10) mol/L) would take much longer to evoke a self-priming effect. These results indicate that the LH secretion pattern is dependent on LHRH pulsatile amplitude and frequency, and will help to clarify the kinetics mechanisms by which LH pulses fluctuate in vivo.

An analysis of thin-rod flexural acoustic wave gravimetric sensors immersed in liquid

A perturbation analysis of acoustic wave propagation properties for a stiff thin rod surrounded by a liquid is presented. A study is made of the velocity sensitivity of the lowest flexural acoustic mode, F(11), along a thin rod due to mass changes in the rod and variations in the surrounding liquid density. It is shown that the presence of the liquid decreases the velocity of the F(11 ) mode and also the mass sensitivity.

The biphasic modulation of inhibin mRNA levels and secretion by PMSG in rat granulosa cells in vitro

Granulosa cell cultures derived from diethylstilboestrol-treated immature rats were used to study the in vitro effect of pregnant mare serum gonadotrophin (PMSG) on steady state mRNA levels for the inhibin alpha and beta A subunits and the secretion of immunoreactive inhibin and progesterone. After 48 h treatment the dose-response curve of PMSG revealed a maximum stimulation (2.5-3.5 fold) of cytosolic alpha and beta A mRNAs over the range of 1 to 10 mU PMSG mL-1, with corresponding stimulation of inhibin secretion. A high dose of PMSG (160-500 mU mL-1) clearly suppressed inhibin alpha mRNA levels as well as inhibin secretion, whereas progesterone (P) was maximally stimulated (up to 600 fold). Although the level of cytosolic inhibin beta A subunit mRNA was also down-regulated by a high concentration of PMSG in the culture medium, the doses required to suppress its mRNA level to less than those of the control varied. These data demonstrate that low doses of follicle stimulating hormone/luteinizing hormone (FSH/LH)-like (PMSG) activity enhances and high doses decrease the steady-state mRNA levels of inhibin in rat granulosa cells in vitro; this biphasic regulation in vitro reflects the differential regulation of inhibin secretion observed during the rat oestrous cycle.

Autologous perfusion of an isolated rabbit gastrointestinal tract

Most perfusion techniques rely on mechanical means to provide blood flow to the isolated organ for maintaining its physiological conditions. The approach usually requires a complicated mechanical system with the associated problems of blood type matching and prevention of blood cell damage. This paper describes a gastrointestinal tract perfusion technique that uses the rabbit's own cardiopulmonary system as the autologous blood supply source. The technique allows for the removal of the complete intestinal loop from the abdominal cavity of the rabbit, and maintains its blood circulation through silastic tubing connections of the catheterized portal vein and cranial and caudal mesenteric arteries. An alternative perfusion site that uses the aorta as the arterial blood supply and the vena cava as the venous return also is described. The isolated perfused GI tract may then be placed in a separate test environment for controlled experiments. For an acute animal test, the approach was found to be a convenient alternative to conventional approaches.

Isolation and amino acid sequences of squirrel monkey (Saimiri sciurea) insulin and glucagon

It was reported two decades ago that insulin was not detectable in the glucose-stimulated state in Saimiri sciurea, the New World squirrel monkey, by a radioimmunoassay system developed with guinea pig anti-pork insulin antibody and labeled pork insulin. With the same system, reasonable levels were observed in rhesus monkeys and chimpanzees. This suggested that New World monkeys, like the New World hystricomorph rodents such as the guinea pig and the coypu, might have insulins whose sequences differ markedly from those of Old World mammals. In this report we describe the purification and amino acid sequences of squirrel monkey insulin and glucagon. We demonstrate that the substitutions at B29, B27, A2, A4, and A17 of squirrel monkey insulin are identical with those previously found in another New World primate, the owl monkey (Aotus trivirgatus). The immunologic cross-reactivity of this insulin in our immunoassay system is only a few percent of that of human insulin. Squirrel monkey glucagon is identical with the usual glucagon found in Old World mammals, which predicts that the glucagons of other New World monkeys would not differ from the usual Old World mammalian glucagon. It appears that the peptides of the New World monkeys have diverged less from those of the Old World mammals than have those of the New World hystricomorph rodents. The striking improvements in peptide purification and sequencing have the potential for adding new information concerning the evolutionary divergence of species.

An innovated treatment for intra-articular fracture of calcaneus

An innovated composite treatment for intra-articular fracture of the calcaneus has been developed. A Steinmann's pin is introduced into the calcaneus percutaneously to release the impaction of the fragments and to lift the compressed subtalar joint facet, which forms a potential cavity in the calcaneal body facilitating restoration of Bohler's angle and correction of widening of the calcaneus by manual reduction. A new type external fixation device, the calcaneus fixation boot, is used to substitute for the traditional plaster immobilization. The boot can exert continuous centripetal pressure on both sides of the calcaneus to control transverse displacement and to maintain the normal height of the heel. The patient is allowed to do functional exercises 24 hours after reduction with the aid of the spring stepping roller, which not only helps dissipate swelling in the early stage but also remold the articular facet. Biomechanical determination showed that the power of triceps surae muscles returned to nearly normal in 4-5 weeks. The patients were allowed to bear weight with crutches in 6-7 weeks. In this series, 94 (87.8%) of 107 cases with an average follow-up period of 2 years and 9 months attained excellent and good results.

[Continuous perfusion of dispersed anterior pituitary cells: a model for LHRH regulation of LH secretion]

The anterior pituitary (AP) tissues were removed from adult male Sprague-Dawley rats by decapitation. The dispersed cells with high viability (greater than or equal to 95%) were prepared using trypsin digestion and mechanical dissociation, and then mixed with Bio-Gel P2, packed into the columns, and perfused continuously with M199 medium for more than 24 hours. Different doses of LHRH were administered by 6-min pulses at one hour intervals. A steady and detectable basal LH secretion was present in all columns during the experiment. LHRH stimulation pulse could induce LH secretion rapidly, and repeated LHRH pulses of same dose produced statistically equal LH pulses. The dose-response curve of LH secretion was linear within the range of 1 X 10(-10) to 1 X 10(-7) mol/L LHRH. These results indicate that continuous perfusion system of dispersed AP cells which offers significant advantages over other methodologies provides a very useful in vitro model for studying the mechanisms on LHRH regulation of LH secretion.

Physostigmine-induced salivary secretion in the rat

The purpose of this study was to see if physostigmine, a reversible cholinesterase inhibitor, affects the secretion and composition of saliva of the major salivary glands of the rat. Low doses of physostigmine did not elicit secretion. At higher doses there was significant flow from the parotid and submandibular glands within 5 min; however, no sublingual secretion was observed. The submandibular flow rate was highest for the first 5 min, then declined rapidly. The parotid flow rate initially was one-fifth of the maximum submandibular rate and then gradually decreased. The concentrations of Ca, Na and K of physostigmine-induced parotid saliva, and the Na of submandibular saliva, were similar to those with carbachol stimulation. The Ca and K concentrations of submandibular saliva were significantly higher than with carbachol or parasympathetic stimulation, and resembled those of alpha-adrenergic stimulation. The protein concentrations of physostigmine-evoked saliva from both glands were similar. The amylase activity of physostigmine-evoked parotid saliva was much higher than that of carbachol or parasympathetic stimulation. Physostigmine-evoked secretion was completely blocked by atropine, a cholinergic antagonist, and by reserpine, partially blocked by phentolamine, an alpha-adrenergic antagonist and not affected by surgical sympathectomy. Morphologically, physostigmine resulted in a moderate decrease in the number of acinar, but not ductal, secretory granules of both the parotid and submandibular glands, while the sublingual gland was unaffected. Numerous patches of parotid acini also developed vacuoles or vesicles. These results suggest that physostigmine-induced salivary secretion is mediated primarily by direct effects on cholinergic and alpha-adrenergic receptors.

Reference values of indicators for WHO neurobehavioral core test battery

The reference values of the indicators for WHO neurobehavioral core test battery (NCTB) and the factors of age and sex on the performance preliminarily were analyzed. The results showed that there was a significant interference with the performance of behavior involved in hand movement and hand operation, a slight interference with the performance of behavior in simple reaction time, digit span and Benton visual retention, and almost no interference with the performance of behavior in mood due to age. It seemed that sex had hardly any effect on the indicators for WHO NCTB.