Galactosemic neuropathy in transgenic mice for human aldose reductase

We studied the functional consequences of an enhanced polyol pathway activity, elicited with galactose feeding, on the peripheral nerve of transgenic mice expressing human aldose reductase. Nontransgenic littermate mice were used as controls. With a quantitative immunoassay, the expression level of human aldose reductase in the sciatic nerve was 791 +/- 44 ng/mg protein (mean +/- SE), about 25% of that in human sural nerve. When the transgenic mice were fed food containing 30% galactose, significant levels of galactitol accumulated in the sciatic nerve. Galactose feeding of nontransgenic littermate mice led to a 10-fold lower accumulation of galactitol. Galactose feeding for 16 weeks caused a significant and progressive decrease in motor nerve conduction velocity in transgenic mice to 80% of the level of galactose-fed littermate mice, which was not significantly different from that of galactose-free littermate mice. A morphometric analysis of sciatic nerve detected > 10% reduction of mean myelinated fiber size but no alterations of myelinated fiber density in galactose-fed transgenic mice compared with other groups. The functional and structural changes that develop in galactose-fed transgenic mice are similar to those previously reported in diabetic animals. The results of these studies suggest that transgenic mice expressing human aldose reductase may be a useful model not only for defining the role of the polyol pathway in diabetic neuropathy but also for identifying and characterizing effective inhibitors specific for human aldose reductase.

Mechanism of selective inhibition of human immunodeficiency virus by ingenol triacetate

Ingenol 3,5,20-triacetate (ITA), one of the ingenol derivatives, is a selective inhibitor of human immunodeficiency virus (HIV) replication in vitro. ITA inhibited the replication of HIV strains in MT-4 cells at concentrations of 0.051 to 0.65 microM. This concentration was approximately 10(3)-fold lower than its cytotoxic threshold. The mechanism of action of ITA is primarily attributed to the inhibition of viral adsorption to the host cells, but it is distinct from the mechanism of inhibition by other adsorption inhibitors.

The induction of cytotoxicity by a bispecific antibody against CEA positive cell line, in vitro

A mouse anti-human carcinoembryonic antigen (CEA) x anti-human CD3 bispecific antibody, AB5C10*UCHT1, was developed. This antibody-heteroconjugate was chemically prepared by cross-linking the AB5C10 monoclonal antibody reactive with human CEA with the monoclonal antibody, UCHT1, which binds to CD3 on human T-lymphocytes. The AB5C10*UCHT1 recognized both CEA expressed on the KATOIII cell line and CD3 expressed on T-lymphocytes, as determined using flowcytometry. Next, AB5C10*UCHT1-mediated cytolysis was analyzed by 51Cr-release assay. When 51Cr-labeled target KATOIII cells were incubated for 6 h with effector cells that had been pretreated with AB5C10*UCHT1 for 60 min at 4 degrees C, the percentage specific lysis was significantly increased compared to that of untreated effector cells. Using peripheral blood mononuclear cells (PBMC) and lymphokine-activated killer (LAK) cells pretreated with AB5C10*UCHT1 for effector cells, the percentage specific lysis was determined to be 16.3% and 57.4% at effector: target (E:T) ratios of 100:1 and 12.5:1, respectively. On the other hand, the percentage specific lysis of untreated PBMC and LAK cells determined to be 3.0% and 35.8% at E:T ratios of 100:1 and 12.5:1, respectively. The minimum effective dose of AB5C10*UCHT1 required for antibody-mediated cytotoxicity was 0.1 mu g/ml. The results of this study suggest that AB5C10*UCHT1 could be useful for augmenting the cytotoxicity of CD3-positive T-cells against CEA-positive target cells in vitro.

The unusual presentation of mucinous carcinoma in the colon making preoperative diagnosis difficult: report of a case

A 51-year-old man was admitted to our hospital for investigation of fever, lower abdominal pain, and pain on micturition. Barium enema and endoscopic findings revealed an extracanal large cavity of the rectosigmoid colon, which suggested an abscess caused by penetration. Histological examination of the endoscopic biopsy specimen demonstrated no malignancy. A preoperative diagnosis of malignant lymphoma was strongly suspected from the imaging findings; however, intraoperative inspection revealed a large tumor invading the urinary bladder. An intraoperative incisional biopsy was performed and histological examination demonstrated mucinous carcinoma. The patient subsequently underwent pelvic exenteration about 1 week later followed by adjuvant chemotherapy and radiotherapy.

Analysis of the membrane structures involved in autophagy in yeast by freeze-replica method

Under starvation conditions, the yeast S. cerevisiae sequesters its own cytoplasmic components by forming autophagosomes with double membrane in the cytoplasm. The autophagosome then fuses with the vacuolar membrane and delivers its own cytoplasmic components into the vacuole in the form of an autophagic body with a single membrane (Baba, M., Takeshige, K., Baba, N., and Ohsumi, Y. 1994. J. Cell Biol., 124: 903-913). We examined membrane structures involved in the autophagy induced by nitrogen-starvation by using freeze-replica method. The most conspicuous characteristic of the autophagic body is that the intramembrane particles were rarely detected on either the protoplasmic or exoplasmic face of its fracture membrane. This morphological feature of the fractured face was clearly different from other intracellular organelles. Next we examined the autophagosomal membrane. The inner membrane of autophagosome was also intramembrane particle-free, and its morphological feature was identical to the membrane of autophagic body. At the fusion site between autophagosome and vacuole we obtained direct evidence that two different membranes, the outer membrane of autophagosome and vacuolar membrane, became continuous by using freeze-etching technique. From these results we concluded that the autophagic body originated from the inner membrane of the autophagosome, and its membrane reflects an intrinsic feature of autophagosomal membrane. The outer membrane of autophagosome had only a few intramembrane particles and may be differentiated from the inner membrane. In cells under nitrogen-starvation condition, the density of intramembrane particles of vacuolar membrane decreased beyond that in control cells.

Investigation of Culicoides (Diptera: Ceratopogonidae) in relation to the transmission of bovine Onchocerca and other filariae in central Kyushu, Japan

In Kyushu, Japan, where a human case of zoonotic onchocerciasis was found, a survey was conducted to know if the bovine Onchocerca species of this region, O. gutturosa, O. lienalis and O. sp., which develop in local Simulium spp., were also transmitted by Culicoides. A total of 17,006 out of 42,582 females of eight Culicoides species captured by light-traps from May to November in 1989 and 1990 at two cattle sheds, one in Oita and one in Kumamoto, were dissected and examine for Onchocerca infection. Overall results showed that none of the species had filarial infections except 4 of 946 C. arakawae, an ornithophilic species, collected in Oita which harboured filarial larvae with a short tail, belonging to Lemdaninae. Unsheathed microfilariae indistinguishable from O. lienalis or O. gutturosa were found in the midgut of only one blood-fed C. matsuzawai collected in Oita. It is concluded that Culicoides species would not be vectors of these three bovine Onchocerca species. Additional collections of Culicoides in a residential area of Oita showed that several filarial species, Lemdaninae and Splendidofilarinae, probably from birds, are transmitted by C. arakawae.

Superantigen toxic shock syndrome toxin-1 (TSST-1) enhances the replication of HIV-1 in peripheral blood mononuclear cells through selective activation of CD4+ T lymphocytes

Staphylococcus aureus has been recognized as a common cause of bacteremia of such infections in human immunodeficiency virus type 1 (HIV-1)-seropositive patients. Some staphylococcal exotoxins are recognized as superantigens. We have found that superantigen toxic shock syndrome toxin-1 (TSST-1) brings about a high level of viral production in HIV-1-infected peripheral blood mononuclear cells (PBMCs) through their activation in vitro. The p24 antigen level in the culture supernatant markedly increased in the presence of TSST-1 at a concentration of 1 pg/ml or higher. Fluorescent-activated cell sorter analysis revealed that TSST-1 specifically activated CD4+ T lymphocytes. Although significant production of tumor necrosis factor alpha (TNF-alpha) was observed in uninfected PBMCs treated with TSST-1 after 96 h of incubation, much earlier (after 12 h of incubation) production of TNF-alpha was identified in HIV-1 infected PBMCs with or without TSST-1 treatment. The addition of anti-TNF-alpha antibody to the culture medium resulted in a dramatic decrease in HIV-1 replication. These results suggest that the enhanced replication of HIV-1 by TSST-1 in PBMCs is attributable mainly to the activation of CD4+ T lymphocytes and that the induction of TNF-alpha further enhances replication. Since the enhancement of HIV-1 replication by TSST-1 occurs in a concentration range of picograms per milliliter, the superantigen TSST-1 may play an important role in the pathogenesis and clinical course of HIV-1 infections.

[Electrodiagnostic features in inflammatory demyelinating polyneuropathy]

Demyelinating conduction block is an important hallmark to distinguish chronic inflammatory demyelinating polyneuropathy (CIDP) from hereditary neuropathies, motor neuron disease and other axonal type neuropathies. The electrodiagnostic criteria of partial conduction block proposed by Asbury and Cornblath, more than 20% drop in CMAP amplitude between proximal and distal sites (e.g. elbow and wrist), may be inadequate, because 20% to 30% drop sometimes occurs in cases with hereditary demyelinating neuropathies. Rhee et al showed that pure temporal dispersion can produce amplitude reduction up to 50% without conduction block. This reduction between elbow and wrist is equivalent to 2% drop/cm. Since lesions are multifocal in CIDP, more than 2% drop/cm in relatively short segments could be a convincing finding of conduction block of CIDP or multifocal motor neuropathy. Our inching study has revealed that chance of lesion is equal from distal to proximal along the nerves of CIDP. However, it is not true in AIDP; most distal sites, roots, and physiological entrapment sites are more fragile, and early demyelination and secondary axonal degeneration start there. Axonal degeneration easily makes demyelinating conduction changes; therefore, in diagnosis of axonal form of AIDP, the possibility of early Wallerian degeneration has to be ruled out by careful follow-up, and delayed F-wave or long-latency units definitely go against the primary axonal pathology.

Suppression by amiloride of bombesin-enhanced peritoneal metastasis of intestinal adenocarcinomas induced by azoxymethane

The effects of concomitant administration of bombesin and of the diuretic drug amiloride on the development of large and small intestinal tumors induced by azoxymethane (AOM), the incidence of their metastasis to the peritoneum and the labeling index of intestinal adenocarcinomas were investigated in inbred Wistar rats. From the start of the experiment, rats were given weekly s.c. injections of AOM for 10 weeks and s.c. injections of bombesin and/or a higher or lower dose of amiloride hydrochloride (amiloride) every other day until the end of the experiment in week 45. Administration of bombesin significantly increased the incidence of intestinal tumors and cancer metastasis to the peritoneum in week 45. It also significantly increased the labeling index of intestinal adenocarcinomas. Although administration of both doses of amiloride with bombesin had little or no influence on the enhancement of intestinal tumorigenesis by bombesin, the location, histological type, depth of involvement or labeling index of intestinal adenocarcinomas, a higher dose of amiloride significantly reduced the incidence of cancer metastasis to the peritoneum. Our findings indicate that amiloride possesses an anti-metastatic activity.

Anti-Tat MTT assay: a novel anti-HIV drug screening system using the viral regulatory network of replication

Since the recognition of its pivotal role in viral replication, Tat activity has become an interesting target for chemotherapeutic intervention of HIV infection. Here, we report a sensitive and simple colorimetric assay for the screening of Tat inhibitors. We have constructed a plasmid that contains the hygromycin B phosphotransferase gene under the control of the HIV-1 long terminal repeat (LTR) and HIV-1 tat gene constitutively expressed from the cytomegalovirus promoter. This plasmid has been stably transfected to the CD4+ T cell line CEM, which is rendered resistant to hygromycin B through the action of Tat. The inhibitory activity of the anti-Tat drugs was assessed by the extent of cytotoxicity in the presence of hygromycin B as a consequence of the suppressed expression of the hygromycin B phosphotransferase gene. Spectrophotometric quantitation of cell viability was done utilizing 3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide (MTT) dye as the indicator. Using this assay system, we have confirmed that known anti-Tat compound Ro5-3335 and its derivative Ro24-7429 could inhibit Tat-mediated gene expression although their selectivities (anti-Tat activity versus nonselective cytotoxicity) were narrow. Since this method offers the advantage of not handling infectious particles or radioactive materials, it can offer wide applicability as a screening system for anti-Tat compounds.

Recurrent Guillain-Barré syndrome in Japan

The clinical profiles of 11 Japanese patients with recurrent episodes of Guillain-Barré syndrome (GBS), including 3 of our cases out of a total of 76 patients (48 males and 28 females), are reviewed. The recurrence rate was estimated as 4%. Among the 11 Japanese patients, 10 were male. Various viral infections had been confirmed in 1 case. No patients showed recurrent ophthalmoplegia. Sensory involvement varied from one episode to the next. These findings suggest the changing distribution of the demyelinating lesions and possibly a different reaction to the unknown pathogens in the recurrence of GBS.

Promotion by substance P of gastric carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine in Wistar rats

The effects of prolonged administration of neuropeptide substance P (SP) on gastric carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and on the labeling index of gastric mucosa were investigated in Wistar rats. Rats received subcutaneous injections of 12 micrograms/kg body weight of SP every other day after 25 weeks of oral treatment with MNNG. Long-term administration of SP significantly increased the incidence of gastric cancers in week 52. However, it did not affect the histological type and depth of involvement of gastric cancers. SP also caused a significant increase in the labeling index of the antral and fundic epithelial cells in week 52. These findings indicate that SP promotes gastric carcinogenesis and suggest that this effect may be related to its stimulation of antral epithelial cell proliferation.

Ornithine decarboxylase inhibitor attenuates NaCl enhancement of gastric carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine

The effects of combined administration of NaCl and the ornithine decarboxylase (ODC) inhibitor 1,3-diaminopropane (DAP) on the incidence and number of gastric cancers induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and on the ODC activity of the gastric wall and the labeling index of the gastric mucosa were investigated in inbred Wistar rats. Rats were given drinking water with or without 2.5 g/l DAP and chow pellets with and without 10% NaCl ad libitum after 25 weeks of oral administration of MNNG. At week 52 feeding 10% NaCl resulted in significant increases in the incidence of gastric cancers, in the ODC activity of the antral portion of the gastric wall and in the labeling index of antral epithelial cells. Administration of both NaCl and DAP significantly reduced the enhancements by NaCl of gastric carcinogenesis, ODC activity of the antral wall and the labeling index of antral epithelial cells. These results suggest that inhibition of ODC attenuates NaCl enhancement of gastric carcinogenesis and that enhancement by NaCl of gastric carcinogenesis is mediated by polyamine biosynthesis.

[Interleukin 1 production by peripheral blood mononuclear cells of children with bronchial asthma in remission]

To analyse the change of the immunological response in the remission state of children with bronchial asthma, we studied the interleukin 1 (IL-1) production of peripheral blood mononuclear cells (PBMC) obtained from children with bronchial asthma sensitized by mite antigen. After PBMC were cultured for 24 hours with Dermatophagoides farinae (Df) or lipopolysaccharide (LPS), the PBMC-derived culture supernatant was estimated for IL-1 alpha and beta by enzyme-linked immunosorbent assay (ELISA). PBMC from some of subjects with active asthma produced IL-1 alpha and beta without any stimulation, but not those from controls or subjects in remission. IL-1 alpha and beta production of PBMC stimulated with Df was observed in all three groups, but IL-1 produced by subjects with active asthma was higher than that produced by subjects in the other two groups. Moreover, when PBMC were incubated with LPS, the secretion of both IL-1 alpha and beta was enhanced. PBMC from patients with active asthma produced both IL-1 alpha and beta in amounts comparable to those produced by PBMC from control subjects, but IL-1 production of PBMC from patients in remission was lower than in the other two groups. IL-1 beta production was about ten times as much as IL-1 alpha. Df-induced IL-1 production of PBMC from asthmatic patients sensitized by mite antigen, which was increased in the active state, was down-regulated in the remission state. Moreover, nonspecific stimuli such as LPS may induce the suppressive factors which down-regulate IL-1 production.(ABSTRACT TRUNCATED AT 250 WORDS)

Pattern of cytokine production by T cells from adolescents with asthma in remission, after stimulation with Dermatophagoides farinae antigen

Children with asthma usually become asymptomatic by the time they reach age 20 y. To clarify the immunologic mechanisms responsible for this phenomenon, we studied patients in remission and others who still had frequent asthma attacks. Patients were grouped by clinical status, and three variables were measured: serum levels of IgE, production of IL4 and interferon (IFN)-gamma, and the activation of T cells induced by Dermatophagoides farinae (Df) antigen. Df-induced activation of T cells (as measured by antigen-induced IL2 responsiveness) or IL2 synthesis itself was induced in patients with active asthma but not in normal subjects. These responses were much weaker in patients in remission. When stimulated by Df antigen in vitro, lymphocytes from patients with active asthma produced much more IL4 than did the cells from normal subjects, and cells from patients in remission produced only a small amount. In contrast, under similar conditions lymphocytes from patients with active asthma produced less IFN-gamma than did the cells from normal subjects. Production of IFN-gamma stimulated by Df antigen was high in patients in remission but not in normal subjects. Thus, upregulated IFN-gamma production after exposure to Df antigen might reduce IL4 secretion, which would suppress IgE production and would improve clinical status. Df antigen may suppress Df-induced allergic responses in patients with asthma in remission.

Synthesis and antiviral activity of 6-benzyl analogs of 1-[(2-hydroxyethoxy)methyl]-6-(phenylthio)thymine (HEPT) as potent and selective anti-HIV-1 agents

Several 6-benzyl analogs of 1-[(2-hydroxyethoxy)methyl]-6-(phenylthio)thymine (1; HEPT) were synthesized and evaluated for their anti-HIV-1 activity. LDA (lithium diisopropylamide) lithiation of 5-ethyluracil derivatives 7 and 8 and subsequent reaction with an aryl aldehyde gave 6-(arylhydroxymethyl)-5-ethyluracil derivatives 9-12. 6-(Arylhydroxymethyl)-5-isopropyluracil derivatives 15-18 were prepared from the 5-isopropyl-2-thiouracil derivatives 13 and 14 by the above procedure following oxidative hydrolysis of the thione. Preparation of the target 5-alkyl-1-(alkoxymethyl)-6-benzyluracil derivatives 27-34 was carried out by acetylation of 9-14 followed by Pd-catalyzed hydrogenolysis. The 1-butyl- (37 and 39) and 1-(2-methoxyl)- (38 and 40) 5-alkyl-6-benzyluracils were synthesized by 1-alkylation of the 3-phenacyl derivatives 35 and 36 with alkyl halides followed by deprotection of the 3-phenacyl group. Compounds synthesized in this study inhibited HIV-1 replication in MT-4 cells in the submicromolar to namomolar concentration range. From this series of compounds, 6-benzyl-1-(ethoxymethyl)-5-isopropyluracil (33) was selected for clinical evaluation.

Enhancement by peptide histidine isoleucine of experimental carcinogenesis in the colon of rats induced by azoxymethane

The effects of peptide histidine isoleucine (PHI) on the incidence and histology of colon tumors induced by azoxymethane (AOM), and on the labeling index of colon mucosa were investigated in Wistar rats. Rats received weekly s.c. injections of 7.4 mg/kg body weight of AOM for 10 weeks, and of 1.0 or 4.0 nmol/kg body weight of PHI until the end of the experiment in week 35. Administration of PHI at the higher, but not the lower dosage, significantly increased the incidence of colon tumors. PHI had no influence on the histology of colon tumors or adenocarcinomas. It also caused significant increase in the labeling index of colon epithelial cells. These findings indicate that PHI enhances colon carcinogenesis, and that its effect may be related to increasing proliferation of colon epithelial cells.

Attenuation of vasoactive intestinal peptide enhancement of colon carcinogenesis by ornithine decarboxylase inhibitor

The effects of combined administration of vasoactive intestinal peptide (VIP) and the ornithine decarboxylase (ODC) inhibitor, 1,3-diaminopropane (DAP), on development of colon tumors induced by azoxymethane (AOM), on ODC activity of the colon wall, and on the labelling index of colon epithelial cells were investigated in inbred Wistar rats. Rats received weekly subcutaneous injections of AOM for 10 weeks and subcutaneous injections of VIP every other day and drinking water containing DAP (2.5 milligrams) ad libitum until the end of the experiment at week 45. Administration of VIP significantly increased the incidence of colon tumors at week 45. It also resulted in significant increases in colon ODC activity and in the labelling index during administration of AOM, but not after its cessation. Administration of both DAP and VIP significantly reduced the enhanced colon carcinogenesis by VIP. The DAP significantly attenuated the VIP enhancement of colon ODC activity and of the labelling index during AOM administration. These findings indicate that ODC inhibition attenuated enhancement of colon carcinogenesis, and suggest that enhancement of colon carcinogenesis by VIP may be mediated through its polyamine biosynthesis.