HTLV-II non-integrated malignant lymphoma induction in Japanese white rabbits following intravenous inoculation of HTLV-II-infected simian leukocyte cell line (Si-IIA)

Lymphoma induction in rabbits by an unknown factor derived from an HTLV-II-producing simian (Cynomolgus) leukocyte cell line (Si-IIA) is reported. Thirteen of 17 male Japanese white rabbits (76%) inoculated intravenously with Si-IIA cells developed malignant lymphoma including Hodgkin-like lymphoma between 62 and 167 days after inoculation. Histologically, there was extensive diffuse or nodular infiltration of either large cell type or mixed type lymphoma cells in many organs, frequently involving the spleen, liver, lymph nodes and kidneys, and less frequently the thymus, bone marrow, lungs, heart, skin and gastrointestinal tract. Hodgkin-like lymphoma was also observed in two rabbits. Chromosomal analysis of five cell lines established from tumor-bearing rabbits revealed the male rabbit karyotype. The immunophenotype of these tumor cells was usually T-cell (CD5+ or -, RT1+, RT2+ or -, CD45+, CD4-, RABELA- and MHC class II-DQ+) except for Hodgkin-like lymphoma cells which expressed only CD45. However, integration of the HTLV-II provirus genome could not be demonstrated in the tumor tissues or any of the rabbit cell lines by polymerase chain reaction or Southern blot analysis. Moreover, no lymphoma was induced by inoculation of HTLV-IIC, MOT (other HTLV-II-producing human cell lines) or TALL-1 (control). Two of four rabbits injected with cell-free pellets from Si-IIA cultures died of malignant lymphoma (15-20 days). Five irradiated rabbit cell lines were inoculated but only one (Ra-SLN) induced lymphoma in 1 of 3 rabbits at 27 days. Neither Herpesvirus saimiri nor Herpesvirus ateles (simian oncogenic viruses) was detected in Si-IIA cells by immunofluorescence testing. These data suggest that the high rate of lymphoma induction in rabbits may be caused not by only HTLV-II or well known simian oncogenic viruses, but rather by an unknown passenger agent derived from Si-IIA or HTLV-IIA, with which Si-IIA was established.

Angiotensin II receptors: cloning and expression

To identify the mechanisms of action of isoforms angiotensin II receptors (AT1A, AT1B, and AT2) and to overcome the difficulties encountered in attempts to purify the receptors, we have expression-cloned their cDNAs from bovine and rat sources and isolated human cDNA and rat and human genomic DNA. The AT1A and AT1B cDNAs were found to encode respective receptor proteins with 359 amino acid residues, whereas, AT2 encodes a 363 amino acid residue receptor protein. Both AT1 and AT2 were found to conform with the seven transmembrane receptor structural motif, but showed only 32% amino acid residue identity to each other. The AT1 receptor was shown to be coupled to, at least, three different G proteins activating phospholipase C, inhibiting adenylyl cyclase and opening an L-type Ca(2+)-channel, whereas, AT2 was found to inhibit a phosphotyrosine phosphatase activity without affecting guanylyl cyclase by a pertussis-toxin-sensitive, presumably G-protein-mediated mechanism.

Adhesion of NFS-60 myeloid leukemia cells to MC3T3-G2/PA6 stromal cells induces granulocyte colony-stimulating factor production

To examine the interaction between immature myeloid cells and stromal cells in the induction of granulocyte colony-stimulating factor (G-CSF) production, stromal cells of the MC3T3-G2/PA6 (PA6) murine cell line, which has preadipocyte characteristics and can support hematopoiesis, were cocultured with various myeloid cell lines and G-CSF mRNA expression was examined by Northern and reverse transcriptase-polymerase chain reaction analyses. A significant amount of G-CSF mRNA was induced by the culture of an interleukin-3/G-CSF-dependent murine myeloid leukemia cell line, NFS-60, on PA6 stromal cells for 16 hours. Using a G-CSF-dependent subline of DA-1 (DA-1N), the biologic activity of G-CSF was also detected in PA6/NFS-60 coculture supernatants, but not in the culture supernatant of PA6 or NFS-60 alone. Direct contact of NFS-60 cells with the PA6 stromal layer was essential for the induction of G-CSF mRNA, as indicated by the following observations: (1) NFS-60 cells efficiently adhered to PA6 cells; (2) medium conditioned by NFS-60 cells did not contain the activity to induce G-CSF mRNA in PA6 cells; and (3) induction of G-CSF mRNA was not observed when NFS-60 cells were separated from PA6 cells by a microporous membrane (0.45-microns pore size). Several other myeloid cell lines, including FDC-P2, 32Dcl3, WEHI-3, and DA-1, did not induce G-CSF mRNA expression after the coculture with PA6 cells, although significant numbers of these cells adhered to PA6 cells. Therefore, NFS-60 cells may express or overexpress a molecule that is involved in adhesion-mediated induction of G-CSF production.

Purification, characterization, and localization of follipsin, a novel serine proteinase from the fluid of porcine ovarian follicles

Follipsin, an enzyme that accumulates in the follicular fluid of porcine ovaries during follicular maturation, was purified to apparent homogeneity. The purified enzyme consists of two different polypeptide chains having M(r) = 45,000 and 32,000 each, associated covalently. The enzyme activity was strongly inhibited by diisopropyl fluorophosphate, benzamidine, leupeptin, and antipain, indicating that follipsin is a serine proteinase. Using synthetic peptide substrates containing 4-methylcoumaryl-7-amide, follipsin was shown to preferentially hydrolyze Arg-X bonds but not Lys-X bonds. The NH2-terminal amino acid sequences of the 45- and 32-kDa polypeptides were highly homologous with those of the heavy and light chains, respectively, of human plasma kallikrein and human factor XIa. Immunological analyses and substrate specificity studies, together with other existing evidence, indicated that follipsin is distinct from kallikrein and factor XIa, thus being a novel type of serine proteinase. Follipsin is immunohistochemically localized in follicular fluid as well as in stroma cells of porcine ovaries. The results strongly suggest that follipsin originates from interstitial cells of the ovarian stroma.

Transvaginal ultrasound imaging, histopathology and endocrinopathy in patients with polycystic ovarian syndrome

In order to investigate the pathological characteristics of polycystic ovaries diagnosed by transvaginal ultrasound (TVS) in patients with polycystic ovarian syndrome (PCOS) and to investigate the relationship between morphological and endocrine changes in the ovaries, 32 PCOS patients with bilateral polycystic ovaries (> 10 cysts) detected by TVS were studied; 20 ovulatory women served as controls. Ovarian tissues from wedge resection were examined histologically. A comparative histological and TVS study of ovarian morphology was made, and the relationship between the number of small cysts and the endocrine profile was examined. The position and size of small cysts on TVS agreed with those observed histologically. There was a significant correlation between the number of small cysts on TVS and the number of atretic follicles with hypertrophied and luteinized inner theca cells, and thickened ovarian capsules. Numerous atretic follicles and thickened ovarian capsules were observed in 97 and 64% of ovaries respectively, from PCOS patients. In patients with PCOS, a significant positive correlation was noted both between the number of small cysts and delta 4-androstenedione (ASD), and between ASD and the luteinizing hormone/follicle-stimulating hormone (LH/FSH) ratio. Furthermore, testosterone, ASD and the number of small cysts on TVS were significantly higher in PCOS patients with ovarian thickened tunica compared to PCOS patients without ovarian thickened tunica. TVS images of ovaries in patients with PCOS correlated with the histopathological and endocrine features. It is suggested that an increase in intra-ovarian small cysts leads to increased production of ovarian androgen, in turn influencing the secretion of gonadotrophin, and is correlated with ovarian capsular thickness.

Analysis of T cell antigen receptors of myelin basic protein specific T cells in SJL/J mice demonstrates an alpha chain CDR3 motif associated with encephalitogenic T cells

Experimental autoimmune encephalomyelitis (EAE) is an animal autoimmune disease mediated by CD4+ T cells. Analysis of TCR expression revealed that limited TCR elements (V beta 8.2, V alpha 2 or 4) were utilized by myelin basic protein (MBP) specific T cells in mice with H-2u haplotype and Lewis rats. The usage of a particular beta chain complementarity determining region 3 (CDR3) motif has also been shown. However, it remains unclear to what extent these observations can be extrapolated. Here we studied the TCR sequences of MBP 89-101/I-A(s) specific T cell clones derived from SJL/J mice, using the polymerase chain reaction on reverse transcribed mRNA. Although the V beta usage was less restricted than in H-2u mice, they predominantly utilized V beta 17a and expressed LGG or related motifs in the V beta-D beta-J beta junctions. Furthermore, a single alpha chain rearrangement between V alpha 1.1 and J alpha BBM142 with no N region diversity was preferentially used. Concordantly, immunization with a peptide corresponding to the alpha chain CDR3 was found to significantly alter the clinical course of EAE. Comparison of the published TCR junctional regions demonstrates that the CDR3 motifs (LGG in beta chain, CA*R*NY motif in alpha chains) are expressed by other encephalitogenic clones. Notably, the CA*R*NY was conserved in PL/J mice clones that recognize a distinct MBP-MHC determinant. It suggests that an antigen-independent mechanism may contribute to conserving the alpha chain motif. The implications of these observations are discussed.

Transvaginal ultrasonic assessment of the response to clomiphene citrate in polycystic ovarian syndrome

OBJECTIVE

To study the relationship between some ovarian morphological findings based on transvaginal ultrasound (US) and the clomiphene citrate (CC) responsiveness in patients with polycystic ovarian syndrome (PCOS).

DESIGN

A comparative study of ovarian US features between the CC responders and the CC nonresponders.

SETTING

Infertility and Endocrine Clinic, Department of Obstetrics Gynecology, Shimane Medical University Hospital, Izumo, Japan.

PATIENTS

Forty-seven infertile patients with PCOS and 30 healthy volunteers.

INTERVENTIONS

A dose of 50 to 200 mg/d CC was given for ovulation induction in patients with PCOS.

MAIN OUTCOME MEASURES

Ovarian volume and number of follicles; serum LH, FSH, T, delta 4 androstenedione, and DHEAS.

RESULTS

The mean ovarian volume (11.9 mL) and the number of small follicles (13.0) were significantly larger in the CC nonresponders compared with those of the CC responders (7.9 mL and 7.0, respectively). Only 47% of the CC responders and 79% of the CC nonresponders had bilaterally enlarged ovaries (> 6.2 mL). Considerable overlap existed between the different groups. However, 96% of the CC nonresponders had a significantly increased number of follicles (> or = 10 follicles) in each ovary compared with that (16%) of the CC responders. Furthermore, with the combination of these parameters, none of the CC nonresponders had bilaterally normal ovaries, and 96% of patients with PCOS with bilaterally abnormal ovaries were CC nonresponsive.

CONCLUSIONS

Small multiple follicles (> or = 10) and enlarged ovarian volume (> 6.2 mL) were the most prominent transvaginal US features of ovaries in patients with PCOS with CC nonresponsiveness. These US features could be clinically useful for distinguishing clearly a CC nonresponder from a CC responder.

Regulation by GTP of a Ca(2+)-activated K+ channel in the apical membrane of rabbit cortical collecting duct cells

Ca(2+)-activated K+ channels play an important role in Ca2+ signal transduction and may be regulated by mechanisms other than a direct effect of Ca2+. Inside-out patches of the apical membrane of confluent transformed rabbit cortical collecting duct cells cultured on collagen were subjected to patch clamp analysis. Two types of K+ channel, of medium and high conductance, were observed. The latter channel was characterized by a K+/Na+ permeability ratio of 10, an inwardly rectified current, a conductance of 80 pS at 0 mV, and an open probability dependent on both voltage and Ca2+. Guanosine 5'-triphosphate (GTP) but not a guanosine 5'-diphosphate (GDP) analogue, adenosine 5'-triphosphate (ATP), cytidine 5'-triphosphate (CTP), or inosine 5'-triphosphate (ITP), inhibited the activity of this Ca(2+)-activated K+ channel. The inhibitory effect of GTP was dose dependent, with a 50% inhibitory concentration of 10(-5) M in the absence of Mg2+. In the presence of Mg2+ (1 mM), which is required for the binding of GTP to G proteins, the 50% inhibitory concentration decreased to 3 x 10(-12) M. Pertussis toxin or cholera toxin (each at 10 ng/ml) did not prevent the inhibitory effect of GTP. After removal of GTP from the medium bathing an inhibited channel, subsequent application of Ca2+ failed to activate the channel. Ca(2+)-activated K+ channels of smooth muscle cells and proximal tubule cells did not respond to GTP. Thus, the Ca(2+)-activated K+ channel in the apical membrane of collecting duct cells is inhibited by GTP, which appears to exert its effect via a G protein that is insensitive to both cholera and pertussis toxins.

Plasma alpha 1-acid glycoprotein concentration in broilers: influence of age, sex and injection of Escherichia coli lipopolysaccharide

1. The influence of age, sex and injection of Escherichia coli lipopolysaccharide (LPS) on the plasma concentration of alpha-1 acid glycoprotein (AGP) was determined in broilers using the single radial immunodiffusion method. 2. Plasma AGP concentration increased in the 3 d after hatching, and then stabilised at 240 +/- 33 micrograms/ml up to 14 d of age. 3. No sex-related differences in plasma AGP concentration were observed up to 6 weeks of age. 4. A single injection of 900 micrograms LPS per chick resulted in a 5-fold increase in AGP concentration compared with that in saline-injected chicks. Multiple injections of LPS (200 micrograms/chick every 2 d for 14 d) caused only a 50% increase in AGP concentration.

Hair analysis for drugs of abuse. VIII. Effective extraction and determination of 6-acetylmorphine and morphine in hair with trifluoroacetic acid-methanol for the confirmation of retrospective heroin use by gas chromatography-mass spectrometry

A procedure for the detection and determination of 6-acetylmorphine (6AM) and morphine in rat and human hair is described. The efficiency of extraction of 6AM and morphine from hair was compared between five extraction methods using methanol, 0.1 M hydrochloric acid, methanol-5 M hydrochloric acid (20:1), helicase and methanol-trifluoroacetic acid (TFA) (9:1). Methanol-TFA was found to be the best solvent for extracting 6AM and morphine with minimum hydrolysis and maximum extraction efficiency of 6AM. The extraction rates of 6AM and morphine from heroin abuser's hair with methanol-TFA reached a plateau after 8-10 h. After the extraction from hair with deuterated internal standards added, the extract was purified by Bond Elut Certify in the usual manner. The 6AM and morphine were then derivatized with bis(trimethylsilyl)acetamide, which were characterized by GC-MS with electron impact ionization. Confirmation was accomplished by comparing their retention times and the relative abundances of major four selected ions with those of the standards. Quantification was based on the deuterated internal standards. Linearity was obtained in the concentration range 0.1-50 ng/mg. The overall recoveries after solvent extraction and solid-phase purification were 95% for 6AM and 97% for morphine. The limit of detection for confirmation was 0.2 ng/mg. The coefficients of variations for 6AM and morphine at concentrations of 4 ng/mg were generally less than 8%. 6AM was stable during extraction with methanol-TFA (9:1) at room temperature. This method was applied to the elucidation of heroin drug history by using hair sectional analysis.

Relation between lung asbestos fibre burden and exposure indices based on job history

Lung asbestos burden was compared with exposure indices derived from job history interviews in 42 male subjects originating from the Montréal Case-Control Study project, 12 of whom had documented asbestos exposed job histories. Job interview data consisting of a chronological timetable of job histories were translated into detailed exposure indices by an expert group of hygienists and chemists. Total and individual asbestos fibre type concentrations were quantified by transmission electron microscopy with fibre identification by energy dispersive chi ray spectrometry after deparaffinisation of tissue blocks and low temperature plasma ashing. Geometric mean or median asbestos content was higher in subjects with an asbestos exposed job history than those without for retained dose of amosite, total commercial amphiboles, and total asbestos fibre. Except for crocidolite fibre diameter, which was significantly less in the lungs of exposed workers, no consistent differences were found in measurements of fibre dimension for any fibre type. Subgroups of subjects exposed to silica, metals, or smokers and non-smokers without significant occupational exposure showed varying patterns of lung asbestos fibre type deficit compared with the asbestos exposed subgroup. There was an overall trend for higher lung asbestos content proportional to higher exposure indices for asbestos representing concentration, frequency, and reliability. These exposure indices as well as duration of exposure (in years) were independent predictors of total asbestos content in regression analyses when combined in a model with age. Stepwise regression indicated that exposure concentration was the most important variable, explaining 32% of the total variation in total asbestos content. Smoking, whether expressed in ever or never smoked dichotomy or in smoked-years, had no relation to lung asbestos content in this model.

Rapid neointima formation with elastic laminae similar to the natural arterial wall on an adipose tissue fragmented vascular prosthesis

A vascular prosthesis that can induce a neointima similar to a natural arterial wall is reported. The authors have developed a sealing method using autologous tissue fragments. The sealed graft showed many advantages, with characteristic neointima formation in an animal study. The grafts were implanted in the thoracic descending aortae of 40 dogs and were removed from 1 hour to 608 days after implantation. Another 40 dogs, used as controls, had a fabric graft implanted using the preclotting method. The luminal surface of the sealed graft was completely endothelialized and the original adipose tissue fragments were absorbed within 1 month. Smooth muscle cells infiltrated and proliferated at the same time as endothelialization took place. Most of the smooth muscle cells were arranged in parallel rows and oriented circumferentially within the graft. At 1 month, elastic fibers appeared around the smooth muscle cells near the anastomotic sites. In the long-term specimens, these elastic fibers constituted a fine lamina in the neointima. Intimal hyperplasia and degenerative changes in the neointima were not observed. These results indicated that the sealing method could induce a very stable neointima with a smooth muscle cell layer and elastic laminae similar to a natural arterial wall within a short period of time throughout the graft wall, with maintenance of the neointima for a long period of time after implantation.

Effects of basic fibroblast growth factor in retinal ischemia

PURPOSE

Basic fibroblast growth factor (bFGF), a 17- to 24-kDa protein known to be essential for the survival of neurons, induced fiber outgrowth of ganglion cells in cultures of rat retina and rescued photoreceptor cell loss in the retina of Royal College of Surgeon rats. The authors evaluated the efficacy of bFGF in rescuing the neuronal loss in rat retina after retinal ischemia.

METHODS

Retinal ischemia was induced in 29 eyes of 17 albino Lewis rats by increasing the intraocular pressure to 110 mm Hg for 45 minutes via an intracameral catheter. A total of 800 ng of bFGF was delivered into the anterior chamber at the time of induction of ischemia. Sixteen eyes of nine rats received bFGF, and 13 eyes of eight rats received heparin in phosphate-buffered saline as vehicle control. The animals were euthanized 7 or 14 days after reperfusion.

RESULTS

Morphologic examination of the retinas at both time points showed that necrosis of the retinal ganglion cells (RGCs) and thinning of the inner plexiform and inner nuclear layers were less severe in the bFGF-treated eyes than in the vehicle-treated eyes. On morphometric examination, 7 days after reperfusion, the mean thickness of the inner retinal layers and the RGC counts on flat preparations of retina in both the posterior and the peripheral portions of the retina were significantly higher in the bFGF-treated eyes than in the vehicle-treated eyes (P < 0.02). At 14 days, similar beneficial effects were noted in all morphometric parameters, except RGC counts in the posterior pole.

CONCLUSIONS

These results demonstrate that bFGF partially protects the RGCs and other inner retinal elements from ischemic injury.

A case of viral encephalitis with hyperthermia and status epilepticus: efficacy of dantrolene treatment

A case of viral encephalitis is described. A 55-year-old female developed hyperthermia and status epilepticus. Herpes simplex virus was regarded as a factor since viral complex titres were elevated and decreased. In addition to acyclovir and anticonvulsive agents, dantrolene (150 mg/day) was administered orally through a nasogastric tube for heat stroke. Convulsions and hyperthermia gradually decreased and intravenous agents were replaced by oral agents. Dantrolene may be a useful adjuvant in hyperthermia and convulsions associated with encephalitis.

Gliclazide directly suppresses arginine-induced glucagon secretion

To clarify whether the effect of sulfonylurea on glucagon secretion is directly on the pancreatic A cell, we examined changes produced by gliclazide in glucagon (IRG), insulin (IRI) and somatostatin (IRS) release from the isolated perfused rat pancreas. Under 5 mM glucose infusion, IRI and IRS were increased by gliclazide in a dose-dependent manner, but IRG was unchanged. When 20 mM arginine was infused to stimulate glucagon secretion, both IRI and IRG increased markedly in a biphasic fashion and IRS increased slightly. The administration of gliclazide at the time of second phase response of IRG, IRI and IRS increased further and IRG decreased at every dose used. Insulin administration to the control and streptozotocin-treated rat pancreas did not change arginine-induced IRG secretion. Gliclazide-induced glucagon suppression was also observed in streptozotocin-diabetic rat pancreas. The amount of administered somatostatin required for inhibiting glucagon secretion was higher than the maximal level obtained from endogenous secretion of somatostatin after gliclazide. Neither cysteamine treatment alone (somatostatin-depleted) nor combined with streptozotocin-treatment (combined depletion of somatostatin and insulin) changed gliclazide-induced glucagon suppression. Thus, it is concluded that suppression of glucagon is induced by sulfonylurea itself.

[Clinical significance of serum ferritin H and L subunit determination in various diseases--evaluation by enzyme-linked immunosorbent assay]

Serum ferritin H and L subunit levels and H/L ratios were evaluated in normal subjects and patients with various diseases by means of enzyme-linked immunosorbent assay using monoclonal antibody against ferritin H or L subunits. In normal subjects, serum levels of H subunit were significantly lower than those of L subunit, as previously reported by Cazzola and coworkers. Although the serum levels of L subunit were elevated and the values of H/L ratios were decreased in inflammatory diseases, serum levels of H subunit were remarkably high in patients with infectious mononucleosis. In liver disease, elevation of mean values of L subunit was observed. However, in liver cirrhosis and severe acute hepatitis, the serum levels of H subunit were often elevated as well as those of L subunit, and so it was suggested that the elevation of H subunit was related to the degree of hepatocellular injury. In hepatocellular carcinoma and pancreatic cancer, since the levels of H/L ratio were higher than controls and no correlation was observed between H and L subunits, it was suggested that the production of H subunit was increased in these cancers. However, the result of H/L ratio determination in serum ferritin did not appear enough to be important for tumor marker, because of a few instances demonstrated over the cut off limit of H/L ratio in neoplastic diseases. The rate of the patients whose H or L subunit levels were over the cut off point was higher in leukemia than in solid cancer, and so it was likely that the measurement of H and L subunit at the same time was clinically useful in leukemic patients. In acute myeloblastic leukemia, relatively high levels of serum L subunits and low H/L ratio were shown. It was suggested that the measurement of H and L subunits in patients with neoplastic diseases would also be useful for monitoring the effect of the therapy.

A new cardiac wall substitute with high affinity for fibroblasts that can induce an endothelial cell lining

A new cardiac wall substitute (PC graft) was developed using equine pericardium cross-linked with a polyepoxy compound. Compared with glutaraldehyde cross-linked pericardium (GA graft), the PC graft showed an approximately 10 times higher affinity for fibroblasts as measured by our in vitro cell migration and proliferation test. Six PC grafts (5 x 3 cm) were implanted into the right ventricular-pulmonary outflow tract position as a cardiac wall patch. Three GA grafts were used as controls. The PC grafts showed excellent handling during surgery because of their softness and elasticity. These grafts were explanted at 2 and 7-8 weeks after implantation. All PC grafts showed a white and glistening surface without any thrombus formation except in one case where thrombus deposition was observed in the center of the graft. In the GA grafts, thrombus adhered to the luminal surface. Light microscopic observation showed that the PC graft surface was covered with a connective tissue layer and significant fibroblast infiltration. Approximately 60% of the area infiltrated by these fibroblasts was endothelialized, whereas in the GA graft, endothelialization was limited to within 2-5 mm of the suture line. Other areas were covered with a thrombus layer without any endothelial cells or fibroblast infiltration. PC cross-linking can maintain the biologic and mechanical properties of the original materials. The PC graft offered excellent affinity for fibroblast migration and proliferation, which induced an endothelial cell lining on the surface. The results of this experiment indicated that the PC graft, which obtained the natural antithrombogenic property, was superior to a GA graft in terms of safety as well as mechanical, physiologic, and biologic properties as a cardiac wall substitute.

Catecholamine-induced cAMP response in streptozotocin-induced diabetic rat liver

The effect of prolonged diabetic state on catecholamine-induced adenosine 3',5'-monophosphate (cAMP) response in the rat liver was examined using isolated liver perfusion. Epinephrine- or isoproterenol-induced cAMP production was enhanced (10-fold of the control) in the liver from extremely emaciated (intraperitoneal adipose tissue was absent completely) diabetic rats 4 weeks after streptozotocin-injection kept without insulin, but not from adipose tissue-present diabetic rats. Glucagon-induced cAMP production was decreased in the diabetic rat liver 4 weeks after streptozotocin regardless of the presence or absence of adipose tissue. Secretin-induced cAMP production was also decreased in the adipose tissue-absent diabetic rat liver. Plasma levels of glucose or insulin were not different between adipose tissue-present and -absent diabetic rats. Liver dysfunction (elevated AST and ALT levels) was observed 1 week after streptozotocin-injection, and worsened at 4 weeks. Forskolin-induced production of cAMP, and oxymetazoline (an alpha 2-adrenergic agonist)-induced suppression of it were not different among the control, newly diabetic (1 week after streptozotocin-injection), and the adipose tissue-absent diabetic rat liver.

IN CONCLUSION

1) enhanced beta-adrenergic, and decreased glucagon- or secretin-induced cAMP production seems to be caused by different mechanisms; 2) the prolonged severe diabetic state losing adipose tissue may cause a considerable change in metabolism and the characteristics of hepatocyte, and lead to enhanced beta-adrenergic cAMP production.

Colonization pattern of Pasteurella pneumotropica in mice with latent pasteurellosis

Colonization pattern of Pasteurella pneumotropica (P. pneumotropica) in mice with latent pasteurellosis was examined with the original selective media, NKBT medium and TGN broth. In the mice of 0 to 15 weeks old, the organism was mainly isolated from the upper respiratory tract, lower intestinal tract, feces and vagina, with the highest isolation rate in the pharyngolarynx. In the pregnant and lactating mice, the organism was isolated from the same sites, but not from the uterus, fetus or mammary gland. In the neonates, the organism was isolated from the respiratory and intestinal tracts within 24hr after birth. The organism was constantly detected in the feces of the 0- to 20-week-old mice, with the highest viable count one week after birth. Through the monitoring of mouse colonies, the pharyngolarynx always showed higher isolation rate than the feces in several mouse strains. These results reveal that the pharyngolarynx is the primary colonization site of P. pneumotropica in mice, and the lower intestinal tract and vagina are also the main sites. Further, frequent isolation of the organism from the feces and vagina, and the results in neonates suggest the mode of the transmission to newborn mice in the colony, i.e., intravaginal infection at the partition, and oro-nasal infection through the maternal feces and saliva.

A new antithrombogenic RV-PA valved conduit

A new antithrombogenic right ventricular (RV)-pulmonary artery (PA) valved conduit was developed using a bovine jugular vein containing a natural valve. To maintain the natural and mechanical properties of the venous tissue, a hydrophilic cross-linking reagent, glycerol polyglycidyl ether polyepoxy compound (PC) was used instead of glutaraldehyde (GA). Moreover, to induce antithrombogenicity, heparin was bonded to the inner surface of the bovine jugular vein cross-linked with PC. Conduits of 18 to 20 mm inner diameter (ID) were implanted between the RV and PA in nine dogs weighing 7-17 kg, with the native main PA being ligated proximally. The handling and suturing of the graft was easy and adaptable, and the anastomosis was completed with excellent coaptation and no blood leakage at the suture lines. All animals were chronic survivors, but one animal died of hematemesis on the 438th postoperative day. Grafts were explanted from 182 to 385 days after implantation. The luminal surface of the conduits were white, glistening, and smooth with good coaptation of the cusps, without calcification or degenerative changes except for one cusp that showed a minimal deformation with a small thrombus. Macroscopic and microscopic observation showed that there were no thrombi at the anastomotic lines, but small thrombi on the luminal surface of the conduits near the cusps and in some cusps. Endothelium-like cells were noticed on the luminal surface of the graft, except in the area near the cusps, and on one cusp at 196 days after surgery. These results indicated that the new RV-PA valved conduit provided adequate antithrombogenicity by temporary slow heparin release, followed later by endothelialization of the graft in a low pressure system at 1 year after implantation.