A highly efficient synthesis of cyclaradine and its behaviour towards adenosine deaminase

(+)-, (-)-, and (+/-)-Cyclaradines were efficiently synthesized from 2-aza-bicyclo[2.2.1]hept-5-en-3-one (ABH). (+)- and (+/-)-Cyclaradines were deaminated by adenosine deaminase whereas (-)-cyclaradine was not hydrolyzed under the same conditions.

Confirmation that a T-to-C mutation at 9176 in mitochondrial DNA is an additional candidate mutation for Leigh's syndrome

Among 80 patients with the clinical and brain imaging characteristics of Leigh's syndrome, 11 patients had a well-known mutation at nucleotide position (nt) 8993 in mitochondrial DNA. In addition, three patients had a T-to-C mutation at nt 9176 which had been described previously in only two brothers with bilateral striatal necrosis and one patient with Leigh's syndrome. In our three patients, one had the typical clinical characteristics of Leigh's syndrome from early infancy, and two had the later onset of neurological deficits. All had a slowly progressive course and basal ganglia abnormalities by neuroimaging. As nt 8993 and 9176 are located in the ATPase 6 coding region, altered ATPase function may be one of the enzyme abnormalities in Leigh's syndrome and other similar conditions with bilateral striatal necrosis.

Detection of kanamycin-resistant Mycobacterium tuberculosis by identifying mutations in the 16S rRNA gene

In Mycobacterium smegmatis and a limited number of Mycobacterium tuberculosis strains, the involvement of alterations of the 16S rRNA gene (rrs) in resistance to kanamycin has been shown. To investigate the extent to which mutations in a specific region of the rrs gene and the kanamycin-resistant phenotype in clinically isolated M. tuberculosis strains were correlated, 43 kanamycin-resistant strains (MICs, > or =200 microg/ml), 71 kanamycin-susceptible strains, and 4 type strains were examined. The 300-bp DNA fragments carrying the rrs gene and the intervening sequence between the rrs gene and 23S rRNA (rrl) gene fragments were amplified by PCR and were subjected to PCR-based direct sequencing. By comparing the nucleotide sequences, substitutions were found in 29 of 43 (67.4%) kanamycin-resistant clinical isolates at positions 1400, 1401, and 1483 but in none of the 71 sensitive isolates or the 4 type strains. The most frequent substitution, from A to G, occurred at position 1400. A substitution from C to T at position 1401 was found once. Two clinical isolates carried the double mutation from C to A at position 1401 and from G to T at position 1483. In addition, we found that these mutants can be distinguished from wild-type strains by digestion with the restriction endonucleases TaiI and Tsp45I. Furthermore, we found that the genotypes of kanamycin-resistant strains can be discriminated from each other by digestion with a restriction endonuclease, BstUI or DdeI.

Apoptosis as a prognostic factor in colorectal carcinoma

We investigated the occurrence of apoptotic cell death in 104 colorectal carcinomas by terminal-deoxynucleotidyl-transferase-mediated dUTP-diotin nick end-labeling (TUNEL) to determine whether apoptosis could be a useful prognostic factor. The apoptotic index (AI) was calculated as the percentage of positive cancer cells per 1,000 cancer cells, the median AI being 4.1, with a range of 1.9-4.7. Apoptosis was less frequently observed in tumors with higher malignant potential, such as those at advanced stages Dukes B, C and D, than those at Dukes stage A (P < 0.05); in tumors showing evidence of moderate differentiation than in well-differentiated tumors (P < 0.05); and in tumors with venous invasion or lymph node metastasis than in those without these features (P < 0.05). Moreover, the subgroup of patients with a low AI of < 4.1 had a significantly poorer survival rate than the subgroup with a high AI in tumors at Dukes stage C, the 5-year survival rates being 33% vs 68% (P < 0.05; Cox-Mantel). Our findings suggest that less apoptosis might result in a greater progression of colorectal carcinoma, and that the rate of apoptosis might be an indicator of the degree of malignancy. Thus it would appear that the frequency of apoptosis in tumor cells could be a useful prognostic factor in colorectal carcinoma.

Vitamin E and coenzyme Q concentrations in the thyroid tissues of patients with various thyroid disorders

To clarify the different roles of free radical scavenging systems in various thyroid disorders, we measured the levels of alpha-, beta-, and gamma-tocopherols and coenzyme Q in the thyroid tissues of patients with thyroid tumors and Graves' disease using high-performance liquid chromatography. The levels of alpha-tocopherols and gamma-tocopherols in the thyroid tissue of patients with papillary carcinoma and the level of gamma-tocopherol in the thyroid tissue of patients with malignant lymphoma were elevated compared with those in normal thyroid tissues. The level of coenzyme Q was reduced in the thyroid tissue of patients with Graves' disease and follicular and papillary thyroid carcinomas. These findings imply that vitamin E and coenzyme Q as scavengers play some role in thyroid follicular cell hyperfunction or dysfunction.

Ratio of motor nerve conduction velocity to F-wave conduction velocity in diabetic neuropathy

OBJECTIVE

To investigate the usefulness of a new parameter, the ratio of motor nerve conduction velocity to F-wave conduction velocity (M/F ratio), for the differential diagnosis of diabetic neuropathy.

RESEARCH DESIGN AND METHODS

Nerve conduction studies were conducted in 95 patients with diabetic neuropathy, 44 nondiabetic patients with peripheral neuropathy, and 24 normal control subjects. Nondiabetic patients with neuropathy were grouped by clinical diagnosis as follows: segmental demyelination (n = 15), axonal neuropathy (n = 11), alcoholic polyneuropathy (n = 4), and other polyneuropathy (n = 14). Motor nerve conduction velocity (MCV) of post-tibial nerves, sensory nerve conduction velocity (SCV) of sural nerves, and F-wave conduction velocity (FWCV) of post-tibial nerves were measured by standardized techniques. The M/F ratio was calculated from these measurements.

RESULTS

The MCV and SCV of diabetic patients were significantly slower and the M/F ratio was significantly lower than those of normal subjects: MCV, 43.7 +/- 5.4 vs. 47.1 +/- 2.9 m/s, P < 0.001; SCV, 44.7 +/- 11.1 vs. 48.3 +/- 5.7 m/s, P < 0.05; M/F ratio, 0.84 +/- 0.09 vs. 0.90 +/- 0.06, P < 0.001. The FWCV of nondiabetic patients with neuropathy was significantly slower (40.0 +/- 6.3 vs. 48.3 +/- 4.0 m/s, P < 0.001) and the M/F ratio was significantly higher (1.04 +/- 0.12, P < 0.001) than that of normal subjects, respectively. Although MCV, SCV, and FWCV were correlated with age in normal control subjects, the M/F ratio was independent of age in the diabetic as well as the nondiabetic patients with neuropathy.

CONCLUSIONS

Results suggest that the M/F ratio, which is influenced by the neuronal damages in the distal segment of peripheral nerves, is useful in the differential diagnosis of diabetic neuropathy.

[Enhanced induction of apoptosis of human colorectal cancer cells after preoperative treatment with 5-fluorouracil its relationship to DNA ploidy pattern]

We examined the relationship between apoptosis induced by 5-fluorouracil (5-FU) that was given preoperatively to colorectal cancer patients and DNA ploidy pattern, and investigated the cell cycle changes, and the expression of Ki-67. Twenty-nine patients with advanced colorectal cancer were divided into four groups, 3 days, 5 days, 7 days, and 10 days. Groups received continuous intravenous 5-FU at 500 mg/body/day preoperatively. Then, patients were divided into two groups by DNA ploidy pattern, diploid(D) and aneuploid(A). Apoptotic cells were stained by the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) method. The expression of Ki-67 was examined by immunohistochemical staining. We used flow cytometry (FCM) for analysis of cell cycle distribution. Apoptosis of cancer cells was mostly increased in 7 days 5-FU administration in both D and A groups. The expression of Ki-67 was reduced according to the prolongation of the term of 5-FU administration in both D and A groups. We assessed S-phase fraction (SPF) to evaluate the cell cycle changes by 5-FU. Tumor samples of all patients after injection of 5-FU showed S-phase accumulation. The ratio of SPF (after 5-FU/before 5-FU) was the highest in the 5-day 5-FU administration group in both D and A groups. We concluded that apoptosis and S-phase accumulation were increased, and proliferative activity was decreased by preoperative 5-FU administration in colorectal cancer patients. However, there was no clear correlation between DNA ploidy pattern and these changes.

Effects of thyroid hormone on catecholamine and its metabolite concentrations in rat cardiac muscle and cerebral cortex

Clinical and experimental data suggest that thyroid hormone affects the actions of catecholamine (CA). However, the serum or tissue levels of CA during thyroid disorders have not been well defined. Accordingly, we investigated the levels of CA and their metabolites in the cardiac muscle, the cerebral cortex, and the plasma of rats with hyperthyroidism and hypothyroidism versus euthyroid animals. The Neurochem analyzer system (ESA, Inc., Bedford, MA) was used in such determinations. The cardiac muscles of hyperthyroid rats exhibited a 16% decrease in the levels of 1-dopa, 3-methoxytyramine (3-MT) and homovanillic acid (HVA) as compared with those in euthyroid rats. The levels of norepinephrine (NE) in cardiac muscle of these rats increased significantly (5.2-fold) relative to the levels in euthyroid rats. NE was undetectable in the cardiac muscles of the hypothyroid rats. Epinephrine (E) and dopamine (DA) were not detected in the cardiac muscles of the rats with either thyroid disorder. Levels of E and 3,4-dihydroxymandelic acid (DOPEG) were detected only in the cerebral cortex of hyperthyroid rats. The cerebral cortex levels of 3-methyoxytyramine (3-MT), 3,4-dihydroxyphenylacetic acid (DOPAC), metanephrine (MN), and homovanillic acid (HVA) were all significantly increased in the hyperthyroid versus the euthyroid rats. The cerebral cortex levels of DA, NE, normetanephrine (NMN), and VMA in the hyperthyroid rats all showed a significant decrease. Levels of NE, NMN, and DOPAC in the cerebral cortex increased significantly in the hypothyroid rats. The level of VMA was undetectable in cerebral cortex of such animals. Data from studies on cardiac muscle and cerebral cortex indicate that the changes in CA and CA metabolites are responsible in part for the cardiovascular and the central nervous system symptoms observed in hyperthyroidism and hypothyroidism.

Serial changes of sensory nerve conduction velocity and minimal F-wave latency in streptozotocin-induced diabetic rats

We studied the serial changes of sensory nerve conduction velocity (SNCV) in the caudal nerve of streptozotocin (STZ)-induced diabetic rats using a new technical method. Minimal F-wave latency was also studied by stimulating the tibial nerve. The SNCV in the diabetic rats was slower than that in the normal rats 2 weeks after STZ injection, and minimal F-wave latency was prolonged compared to normal rats 4 weeks after STZ injection. Treatment of the diabetic rats with insulin for 14 days inhibited SNCV slowing and minimal F-wave latency prolongation. This new method to measure SNCV is useful for various studies, and improvement of diabetic neuropathy with insulin treatment is indicated by recovery from SNCV slowing and minimal F-wave latency prolongation.

Randomized comparison of two preoperative methods for preparation of the colon: oral administration of a solution of polyethylene glycol plus electrolytes and total parenteral nutrition

BACKGROUNDS/AIMS

Two colon preparation methods were compared for their efficacy. The comparison was carried out between whole bowel irrigation using polyethylene glycol-electrolyte lavage solution (PEG-ELS) and total parenteral nutrition (TPN).

METHODOLOGY

Twenty-six consecutive patients suffering from colorectal cancer without apparent obstruction were randomly divided into two groups. Twelve patients received 2 litres of PEG-ELS one day before the operation following two tablets of sennoside (24 mg) two days before the operation without restriction of food until PEG-ELS. Fourteen patients received magnesium citrate (34 g) and sennoside (24 mg) on the day before the operation with 7 days' TPN and fasting.

RESULTS

The average time of defecation was 9 in the PEG-ELS group and 5 in the TPN group (p < 0.001), with little difference between the necessary times to complete defecation (PEG-ELS: 280 min. vs. TPN: 260 min.). However, although half of the PEG-ELS group complained of side effects of abdominal fullness the overall incidence of side effects in both groups were the same of 50%. There were no significant changes between the data of blood test and routine chemistry before and after the bowel preparation in both groups. The purity of the colorectum judged at operation in both groups were excellent, no residue at all, except in one patient of the TPN group. The total bacterial counts of the rectal samples obtained at operation of PEG-ELS group were fewer than that of TPN group but not statistically significant.

CONCLUSION

Colon preparation using PEG-ELS is just as good as the 7-days' TPN treatment and fasting, and exceeds from the standpoint of saving time.

[Auditory evoked magnetic fields in patients of pure word deafness]

Auditory evoked magnetic fields (AEF) were recorded in 2 cases with pure word deafness. AEF examination were performed with a novel 129-channel vector neuromagnetic imaging system (SBI 100). The latency and the location of equivalent current dipole (ECD) of N100 m after 1,000 Hz tone burst stimulation, one of the most prominent peak of AEF, were evaluated. One patient, 59-year-old man, suffered from left putaminal hemorrhage and the other, 59-year-old man, had a history of bilateral putaminal hemorrhage. There was no N100 m detected in the left temporal lobe with the right ear stimulation in both patients. However normal N100 m was obtained in the right hemisphere with the left ear stimulation in both cases. And the position of ECD of N100 m in the right hemisphere were correctly superimposed on the Heschl gyrus in brain MRI. The pathophysiology of pure word deafness has been postulated that a disconnection between Wernicke area and bilateral auditory inputs played one of important roles in progression of pure word deafness. Because there was no pathological lesion in temporal lobe verified by MRI study in both patients, N100 m in the left could not be evoked due to interception of the auditory pathway to the Heschl gyrus, but not due to destruction of Heschl gyrus. AEF test is one of the most useful tools in order to estimate central auditory function in patients with pure word deafness.

Myositis ossificans in the tip of the thumb: a case report

A case of a myositis ossificans occurring in the distal portion of the finger is reported. An 18-year-old female noticed a small nodule in the tip of the left thumb for 11 months. Plain radiographs showed calcified shadow and there was a radiolucent zone between the mass and the distal phalanx. The excised mass was diagnosed as myositis ossificans. To our best knowledge, there has been no report of a myositis ossificans in the tip of the finger in literature.

Deamination of cyclaradine by adenosine deaminase under high pressure

The deamination of cyclaradine corresponding to a carbocyclic analogue of ara-A having anti-HSV activity by adenosine deaminase was examined under various pressure. The deamination of (+)- and (+/-)-cyclaradine was remarkably facilitated by high pressure, and the rate was increased with increasing of pressure. However, (-)-cyclaradine was not deaminated even under high pressure.

An expression of anaplastic large cell lymphoma-associated antigens on HTLV-I-infected CD4+ T cells

We investigated tumor-associated antigens induced by infection with human T-lymphotropic virus type I(HTLV-I). Anaplastic large cell lymphoma (APLL) antigens were found to be expressed on interleukin 2 (IL-2)-dependent, HTLV-I-infected CD4+ T-cell lines established from patients with adult T-cell leukemia and HTLV-I-associated myelopathy/tropical spastic paraparesis. However, APLL antigens were not detected on unstimulated lymphocytes, mitogen-activated T lymphocytes, or Epstein-Barr virus-infected B cells. Furthermore, APLL antigens were not found on IL-2-independent HTLV-I-transformed cells such as MT-I or MT-2. When naive CD4+ T cells were infected with HTLV-I in vitro in the presence of IL-2, the APLL antigens were detected on them 4 weeks after infection. The expression level increased in a time-dependent fashion. These results indicate that HTLV-I infection induces a unique category of tumor-associated antigens on CD4+ T cells.

A progressive postoperative increase in the serum level of soluble receptors for interleukin-2 is an indicator of a poor prognosis in patients with gastric cancer

Activated T lymphocytes release a soluble form of IL-2R (SoIL-2R) into the bloodstream, which can be detected by CD25 monoclonal antibody. Perioperative changes of serum levels of SoIL-2R and the number of CD25-positive cells were monitored simultaneously to clarify the clinical implications of SoIL-2R in patients with gastric cancer (n=91). Preoperative levels of SoIL-2R were significantly higher than in normal controls and levels were a useful indicator of possible lymph node involvement. Postoperative levels of SoIL-2R increased independently of the number of CD25-positive cells. Patients with progressive postoperative increases in levels of SoIL-2R had both a significantly high frequency of postoperative relapse and a poor prognosis. Increased SoIL-2R may reduce the availability of IL-2 by binding to it. Postoperative progressive increases in SoIL-2R appear to be a good indicator for a poor prognosis in patients with gastric cancer.

Sho-saiko-to, a traditional Kampo medicine, enhances the anti-HIV-1 activity of lamivudine (3TC) in vitro

Sho-saiko-to (SST), a traditional Kampo medicine, has been examined for its inhibitory effect on human immunodeficiency virus type 1 (HIV-1) replication in peripheral blood mononuclear cells (PBMCs). SST alone moderately inhibited HIV-1 replication at a concentration of 25 microg/ml. When SST was combined with zidovudine (AZT), lamivudine (3TC) or AZT plus 3TC, SST enhanced the anti-HIV-1 activity of 3TC. In contrast, SST slightly enhanced the anti-HIV-1 activity of AZT plus 3TC but did not enhance the activity of AZT alone. These results suggest that the combination of SST and 3TC has potential as a chemotherapeutic modality of HIV-1 infection.

Characterization of the rpsL and rrs genes of streptomycin-resistant clinical isolates of Mycobacterium tuberculosis in Japan

Mutations in the rpsL and rrs genes associated with streptomycin resistance in Mycobacterium tuberculosis clinically isolated in Japan were characterized. The rpsL genes of 172 clinical isolates were amplified by PCR and classified into two groups on the basis of MboII restriction digestion. Thirty-three out of 54 (61.1%) streptomycin-highly resistant isolates (MIC > 200 micrograms ml-1) were not digested by MboII. By contrast, the remaining 21 of 54 (38.9%) streptomycin-highly resistant isolates, all of 41 isolates with streptomycin resistance at a lower level (20 micrograms ml-1 < MIC < or = 200 micrograms ml-1), and all of 77 streptomycin-sensitive isolates, were restricted. Thus, all isolates resistant for MboII digestion showed a high level of resistance to streptomycin. Subsequently, the sequence for the rpsL and rrs genes from the 46 isolates were analysed. Eighteen out of 19 (94.7%) streptomycin-highly resistant isolates carried a mutation in any rpsL gene at position 43 or 88, or the rrs gene; 10 out of 17 (58.8%) streptomycin-resistant isolates at a lower level were confirmed to exhibit the mutation of either the mutated rpsL gene at position 88, or the rrs gene. In the total 36 streptomycin-resistant isolates, the mutation of the rpsL or rrs gene was observed in 28 streptomycin-resistant isolates, corresponding to 77.8%, whereas none of the streptomycin-sensitive isolates had mutations in either the rpsL or rrs gene.

Protective effects of granulocyte colony-stimulating factor on endotoxin shock in mice with retrovirus-induced immunodeficiency syndrome

Mice with retrovirus-induced murine acquired immunodeficiency syndrome (MAIDS) were hypersensitive to lipopolysaccharide (LPS)-induced lethal shock accompanied by marked elevations of systematic interleukin 1beta (IL-beta) and interferon gamma (IFN-gamma) after LPS challenge. Pretreatment with 10 microg of recombinant human granulocyte colony-stimulating factor (rhG-CSF) protected MAIDS mice from hypersensitivity to LPS-induced lethal shock and this protection was concomitant with suppression of IFN-gamma production.

Circadian rhythms of cardiovascular functions are modulated by the baroreflex and the autonomic nervous system in the rat

BACKGROUND

We assessed the hypothesis that the baroreflex and the autonomic nervous system are important in the control of the circadian rhythms of cardiovascular functions.

METHODS AND RESULTS

We continuously measured blood pressure (BP), heart rate (HR), and locomotor activity in sinoaortic denervated (SAD), sympathectomized, and atropine-injected rats by use of a radiotelemetry system. The circadian rhythm of mean blood pressure (MBP) was selectively disrupted in SAD rats under 12-hour light-dark (LD12:12) cycles as a result of an increase in MBP during the light period and disappeared under constant darkness (DD). The locomotor activity and HR were not remarkably affected by SAD. The circadian rhythm of MBP was suppressed in sympathectomized rats by a decrease in the MBP during the dark period, and the abrupt changes in MBP when the lighting was altered were not seen under LD. Under DD, an MBP rhythm similar to that observed under LD was obtained. Sympathectomized rats also showed lower HR levels during the dark period than intact rats under LD cycles. In atropine-injected rats, the MBP and HR increased, especially during the light period, resulting in a reduction of light-dark differences in MBP and HR. The locomotor activity showed an apparent 24-hour variation in the sympathectomized and atropine-injected rats.

CONCLUSIONS

The disruption of the baroreflex selectively eliminates the circadian rhythm of BP, and the circadian rhythms of BP and HR are modulated by the autonomic nervous system in rats. The circadian rhythms of BP and HR are regulated by different mechanisms involving the autonomic nervous system.

Body-surface distribution of changes in activation-recovery intervals before and after catheter ablation in patients with Wolff-Parkinson-White syndrome: clinical evidence for ventricular 'electrical remodeling' with prolongation of action-potential duration over a preexcited area

BACKGROUND

T-wave abnormalities after catheter ablation in patients with manifest Wolff-Parkinson-White (WPW) syndrome have been attributed to a continuation of repolarization abnormalities induced by preexcitation (cardiac memory).

METHODS AND RESULTS

To clarify changes in repolarization properties, we analyzed the activation-recovery interval (ARI) obtained from body-surface maps and the relationship between the activation time (AT) and ARI in 30 patients with WPW syndrome (group A, 18 patients with manifest left-sided accessory pathway; group B, 7 patients with manifest right-sided accessory pathway; and group C, 5 patients with concealed left-sided accessory pathway) before, 1 day after, and 1 week after ablation. The ARI significantly decreased 1 week after ablation compared with before and 1 day after ablation over the preexcited area in groups A and B. Correlation coefficients between the AT and ARI showed a significantly (P<.01) stronger inverse relationship before (r=-.58) and 1 week after (r=-.64) ablation than 1 day after ablation (r=-.46) in groups A and B. In group C, the ARI and correlation coefficients between the AT and ARI showed no significant changes.

CONCLUSIONS

These findings suggest a prolongation of the action-potential duration over the preexcited area before and just after ablation as ventricular "electrical remodeling," a decrease in the inverse relationship between the AT and action-potential duration 1 day after ablation, and a gradual recovery of the action-potential duration over the preexcited area and inverse relationship 1 week after ablation.

Strontium-89 therapy and imaging with bremsstrahlung in bone metastases

The bone-seeking radiopharmaceutical Sr-89 has been used as a palliative treatment for patients with bone pain caused by bone metastases. The authors report the results of nine patients (three with prostate cancer, four with breast cancer, one with thyroid cancer, and one with lung cancer) who underwent therapy with Sr-89 chloride for painful bone metastases, and evaluate Sr-89 imaging with bremsstrahlung. Two levels of dosage (1.5 and 2.2 MBq/kg) were used. Sr-89 imaging was performed in seven patients 1 week after injection. Abnormal uptake was seen in all and was consistent with the results of Tc-99m HMDP imaging. Six patients were assessed at 3 months and three patients toward the time they were terminal; 78% (seven of nine) derived some benefit. Two patients had a favorable clinical response and showed improvement on Tc-99m HMDP imaging.

Induction of intestinal lesions in nu/nu mice induced by transfer of lymphocytes from syngeneic mice infected with murine retrovirus

BACKGROUND

Murine leukemia virus, LP-BM5, induces severe immunodeficiency with abnormal lymphoproliferation in susceptible C57BL/6 mice. In a previous study, it was shown that a Sjögren's syndrome-like systemic exocrinopathy is induced in the virus infected mice.

AIMS

To examine lymphocyte functions of the virus infected mice.

METHODS

Four-week old mice were inoculated with the virus and their spleen cells were transferred into syngeneic nu/nu mice. Their organs were examined by light and electron microscopy. Phenotypes of the colon infiltrating cells were examined by flow cytometry.

RESULTS

All nu/nu recipients had died by six weeks after cell transfer, showing runting disease like cachexia with diarrhoea and anal bleeding. Histopathological examination revealed that systemic exocrinopathy was adoptively transferable and that the colon became thickened due to mononuclear cell infiltration into the mucosal and submucosal layer with hyperplasia of intestinal epithelial cells. No virus particles were found in the colon. Flow cytometric analyses revealed that most of the infiltrating CD4+ T cells showed CD45RBlow. No intestinal lesions were observed in the virus infected mice nor in nu/nu mice inoculated with normal lymphocytes.

CONCLUSION

Lymphocytes of the virus infected mice induced colitis and hyperplasia of intestinal epithelial cells as well as systemic exocrinopathy in nu/nu mice. Our experimental system may give some insight into intestinal lesions associated with virus infection.

HTLV-I-infected T cells activate autologous CD4+ T cells susceptible to HTLV-I infection in a costimulatory molecule-dependent fashion

A vigorous production of human T lymphotropic virus type I (HTLV-I)-infected CD4+ T cells is closely associated with the development of adult T cell leukemia (ATL) and neurological disease. However, the immunological mechanisms leading to generation of the HTLV-I-infected cells are not fully clarified. The modulation of CD80 and CD86 expression on the HTLV-I-infected cells and its physiological role in the interaction of infected CD4+ T cells with uninfected CD4+ T cells was examined. The HTLV-I-infected CD4+ T cell lines established from ATL patients and normal donors by infecting their CD4+ T cells with the virus expressed CD80, CD86, and HLA-DR, and induced a proliferation of autologous and allogenic CD4+ T cells. While the CD4+ T cells stimulated with the autologous HTLV-I-infected cells for 7 days expressed CD80 and CD86 but not HTLV-I gene products, they expressed HTLV-I gag antigen after 4 weeks. The interaction of HTLV-I-infected and -uninfected CD4+ T cells was profoundly suppressed by a combination of CD80 and CD86 monoclonal antibodies. These results suggest that the induction of CD80 and CD86 on HTLV-I-infected CD4+ T cells participates actively in the generation of the virus-infected progenitor cells.

HIV-1-infected myelomonocytic cells are resistant to Fas-mediated apoptosis: effect of tumor necrosis factor-alpha on their Fas expression and apoptosis

To get insight into the involvement of tumor necrosis factor-alpha (TNF-alpha) and Fas (CD95) ligand in apoptosis (programmed cell death) of monocyte/macrophages in HIV-1-infected individuals, various T cell and myelomonocytic cell lines, including the HIV-1-infected clones OM-10.1 and U1 cells, were cultured in the presence of either TNF-alpha alone, anti-Fas agonist monoclonal antibody (Fas-mAb) alone, or their combinations. TNF-alpha moderately decreased the viability of myelomonocytic cell lines in a dose-dependent fashion (1-100 ng/ml). Unlike HIV-1-infected T cell lines, the viability of OM-10.1 and U1 cells was not affected by the treatment with Fas-mAb alone at concentrations up to 1,000 ng/ml. However, the viability of OM-10.1 cells further decreased with increasing concentrations of Fas-mAb when exposed simultaneously to TNF-alpha, suggesting that TNF-alpha sensitizes the cells to Fas-mAb-induced cell death. FACScan analysis and DNA gel electrophoresis revealed that the cell death was due to apoptosis. Such an effect of Fas-mAb was not identified in U1 cells. TNF-alpha but not Fas-mAb activated latent HIV-1 in OM-10.1 and U1 cells. Although all myelomonocytic cell lines expressed Fas on their cell surface, TNF-alpha significantly up-regulated the expression of Fas in only OM-10.1 cells. These results indicate that, unlike T cells, HIV-1-infected myelomonocytic cells are generally resistant to the Fas-mediated apoptosis. However, they would become sensitive to the apoptosis if the expression of Fas could be up-regulated by TNF-alpha or other factors.