[Effect of antral gastritis and cytokines on Helicobacter pylori associated duodenal ulcer]

OBJECTIVE

To investigate the role of cytokines and antral gastritis in the development of duodenal ulcer that associated with Helicobacter pylori (H. pylori) infection.

METHOD

48 cases of duodenal ulcer with different degrees of H. pylori infection (35 cases with H. pylori infection and 13 patients without H. pylori infection,) were investigated by measuring the level of gastric mucosal cytokines and the degree of antral gastritis.

RESULTS

Compared with H. pylori negative cases, the patients with H. pylori positive duodenal ulcer had higher level of gastric mucosal IL-8, TNF alpha, MPO, MDA and severer antral gastritis. IL-8, TNF alpha, MPO and MDA were positirely correlated with H. pylori density and they were highly correlated with each other. However IL-6 did not have such specific properties.

CONCLUSION

Cytokines may be an important factor that links gastritis and duodenal ulcer associated with H. pylori infection.

[Relationship of cytokines and cold-heat syndrome differentiation in patients of duodenal ulcer]

OBJECTIVE

To explore the relationship of cytokines and Cold-Heat Syndrome in patients of duodenal ulcer.

METHODS

Cold-Heat Syndrome Differentiation was done in 48 patients of duodenal ulcer, and the levels of interleukin-8 (IL-8), interleukin-6 (IL-6), tumor necrosis factor (TNF), malonyldialdehyde (MDA), marrow peroxidase (MPO) in gastric mucosa biopsy were measured and compared with those of 10 normal subjects.

RESULTS

Levels of IL-8, TNF, MPO and MDA in Heat Syndrome were higher than those in Cold Syndrome (P < 0.05), while IL-6 level showed no significant relationship with Cold-Heat Syndrome.

CONCLUSION

Cytokines IL-8, TNF, MPO and MDA are correlated with Cold-Heat Syndrome in duodenal ulcer patients and which might be one of the molecular mechanisms of Cold-Heat Syndrome Differentiation.

[Clinical and laboratory studies with typhoid fever 178 patients]

One hundred and seventy-eight cases of typhoid patients were studied on clinical and bacteriological aspects. The main clinical findings were as follows: (1) Most of the cases had sustained fever (66.3%). (2) Gastroenterial symptoms developed as the disesase progressed. (3) Rose spots were found in 32.6% of them. (4) Liver and spleen were enlarged in 69.5% of the cases. (5) Blood eosinophil disappeared in most of the patients and leukopenia was noted in 94.3%. (6) There were toxic hepatitis (47.1%), toxic myocarditis (22.4%) and intestinal hemorrhage (19.7%) as complications. In the drug sensitivity test, the number of ampicillin-resistant and chloramphenicol-resistant strains of salmonella typhi was increased more than that seen 5 years ago (P < 0.05), however 100% of the strains were sensitive to amikacin, tobramycin, norflexacin, oflexacin and the third generation of the cephalosporin. For the time being, norflexacin and oflexacin were good and suitable drugs for the treatment of typhoid fever.

In vitro and in vivo activities of moxifloxacin and clinafloxacin against Mycobacterium tuberculosis

On 10% oleic acid-albumin-dextrose-catalase-enriched 7H11 agar medium, the MIC at which 90% of the isolates are inhibited for 20 strains of Mycobacterium tuberculosis was 0.5 microg of sparfloxacin (SPFX) or moxifloxacin (MXFX) per ml and 1.0 microg of clinafloxacin (CNFX) per ml, indicating that the in vitro activities of SPFX and MXFX were virtually identical and were slightly greater than that of CNFX. However, the in vivo activities of these drugs in a murine tuberculosis model differed considerably. Female Swiss mice were infected intravenously with 6.2 x 10(6) CFU of the H37Rv strain and treated for 4 weeks, beginning the next day after infection, with isoniazid (INH) serving as the positive control. By the criteria of 30-day survival rate, spleen weight, gross lung lesion, and mean number of CFU in the spleen, treatment with CNFX at up to 100 mg/kg of body weight six times weekly displayed no measurable effect against M. tuberculosis, whereas both SPFX and MXFX were effective; administration six times weekly of either of the latter two drugs demonstrated dosage-dependent bactericidal effects, as measured by enumeration of CFU in the spleens, and MXFX appeared more bactericidal than the same dosage of SPFX. Of the three fluoroquinolones, only MXFX at 100 mg/kg six times weekly appeared as bactericidal as INH at 25 mg/kg six times weekly. Thus, MXFX may be an important component of the newer combined regimens for treatment of tuberculosis.

Bactericidal activity of a single-dose combination of ofloxacin plus minocycline, with or without rifampin, against Mycobacterium leprae in mice and in lepromatous patients

To develop a fully supervisable, monthly administered regimen for treatment of leprosy, the bactericidal effect of a single-dose combination of ofloxacin (OFLO) and minocycline (MINO), with or without rifampin (RMP), against Mycobacterium leprae was studied in the mouse footpad system and in previously untreated lepromatous leprosy patients. Bactericidal activity was measured by the proportional bactericidal method. In mouse experiments, the activity of a single dose of the combination OFLO-MINO was dosage related; the higher dosage of the combination displayed bactericidal activity which was significantly inferior to that of a single dose of RMP, whereas the lower dosage did not exhibit a bactericidal effect. In the clinical trial, 20 patients with previously untreated lepromatous leprosy were treated with a single dose consisting of either 600 mg of RMP plus 400 mg of OFLO and 100 mg of MINO or 400 mg of OFLO plus 100 mg of MINO. The OFLO-MINO combination exhibited definite bactericidal activity in 7 of 10 patients but was less bactericidal than the RMP-OFLO-MINO combination. Both combinations were well tolerated. Because of these promising results, a test of the efficacy of multiple doses of ROM in a larger clinical trial appears justified.

Once-weekly rifapentine-containing regimens for treatment of tuberculosis in mice

The bactericidal activities of several once-weekly rifapentine (P)-containing combination regimens against Mycobacterium tuberculosis, and their ability to prevent the selection of rifampin (R)-resistant mutants, were compared with those of the standard six-times-weekly regimen consisting of R, isoniazid (H), and pyrazinamide (Z) in a mouse experiment. Mice were infected intravenously with 1.3 x 10(7) cfu of M. tuberculosis strain H37Rv, and 8 wk of treatment began on Day 14 after infection, when mice were randomly allocated to an untreated control group and nine treatment groups of 30 mice each. At the end of 8 wk of treatment, all the tested regimens showed promising bactericidal activities. Once-weekly P alone was less bactericidal than six-times-weekly R alone; likewise, the once-weekly P-containing combined regimens were less bactericidal than the six-times-weekly standard regimen. However, the difference in killing was about 1 log10, which represented only a fraction of the overall 4 log10 to 5 log10 magnitude of killing effects. The addition of streptomycin (S) improved the bactericidal effect of once-weekly PHZ, and the effect of once-weekly PHZS was further enhanced when it was preceded by 2 wk of daily HZS. The latter regimen achieved the same level of activity as the standard six-times-weekly regimen. All of the once-weekly P-containing combined regimens were able to prevent the selection of R-resistant mutants, whereas monotherapy with R or P selected resistant mutants in approximately 50% of animals.

Laser Frequency-Modulated Spectroscopy of a Laser-Guided Plasma in Sodium Vapor: Line Positions for NaH (A1Sigma+-X1Sigma+), Na (9-13d and 11-14s), and Ar (5p-4s)

Laser frequency-modulated (FM) spectroscopy has been used as an axial probe of a laser-guided electric discharge in sodium-argon vapor contained in an optically accessible metal heat pipe oven. Absorption measurements in the region 23 106-23 881 cm-1 provided accurate line positions (&plusmn;<0.006 cm-1) for 141 transitions in the v' = 3-8 <-- v" = 0 and v' = 5-9 <-- v" = 1 bands of NaH (A1Sigma+-X1Sigma+). In addition, 18 transitions of Na (3p to 9-13d and 11-14s) and 10 of argon (5p-4s) were measured. Analysis of the spectrum indicates that perhaps all absorption signals are due to neutrals NaH, Na, and Ar and are observed via "population" modulation. Copyright 1997 Academic Press. Copyright 1997Academic Press

Prevention of the selection of clarithromycin-resistant Mycobacterium avium-intracellulare complex

The prevalence of clarithromycin-resistant mutants in untreated bacterial populations of Mycobacterium avium-intracellulare complex (MAC) has been demonstrated to be between 10(-7) and 10(-8) colony-forming units (CFUs) in the beige mouse model. Selection of these mutants occurred during clarithromycin monotherapy if treatment was initiated when the bacterial population size reached approximately 10(8) CFUs per spleen. Likewise, selection of clarithromycin-resistant MAC was induced in AIDS patients during therapy with clarithromycin alone or in combination with drugs that were ineffective for the treatment or prevention of MAC infection. Because the emergence of clarithromycin resistance during preventive therapy was observed exclusively in AIDS patients with CD4+ cell counts < or = 25 cells/microliter, clarithromycin monotherapy can be recommended for the prevention of MAC infection in AIDS patients with CD4+ cell counts of > or = 50 cells/microliter. However, a clarithromycin-containing combination regimen is recommended for patients with CD4+ cell counts < 50 cells/microliter. Since preliminary animal experiments and clinical trials indicate that amikacin, ethambutol or rifabutin in combination with clarithromycin may prevent, or at least delay, the selection of clarithromycin-resistant mutants, further preventive trials are urgently needed to confirm these observations.

High relapse rate among lepromatous leprosy patients treated with rifampin plus ofloxacin daily for 4 weeks

Fifty-one lepromatous leprosy patients, all of whom had relapsed after previous dapsone (DDS) monotherapy, were treated between 1990 and 1991 with 600 mg of rifampin (RMP) plus 400 mg of ofloxacin (OFLO) daily for 4 weeks, and the great majority of the patients were followed up at least once a year after completion of the treatment. After only 173 patient-years of follow-up, 5 relapses had been detected; the overall relapse rate was 10.0% (confidence limits, 1.7 and 18.3%), or 2.9 relapses (confidence limits, 0.4 and 5.4) per 100 patient-years. The unacceptably high relapse rate indicated that 4 weeks of treatment with daily RMP-OFLO was unable to reduce the number of viable Mycobacterium leprae organisms to a negligible level. In addition, the M. leprae from one of the relapses were proved to have multiple resistance to DDS, RMP, and OFLO. To avoid further relapses, the follow-up was terminated and the great majority of the patients were retreated with the standard 2-year multidrug therapy from 1994. No further relapse has been diagnosed since the beginning of retreatment.

[Preliminary study on erythrocyte immunity during sensorineural hearing loss of unknown etiology]

Red cell immune function was determined in 50 patients with sensorineural deafness and 30 healthy persons as control. The results showed that in patients with sensorineural deafness, the red cell C3b receptor (RBC-C3bR) rosette formation rate (15.10 +/- 1.66) was lowered markedly than controls (18.95 +/- 1.16, P < 0.001) and the red cell surface immune complex (RBC-IC 9.94 +/- 1.68) was elevated markedly than controls (7.44 +/- 1.17, P < 0.001). The results indicate that the red cell immunity in the patients with sensorineural deafness of unknown etiology is lowered.

Comparative activities of amikacin against Mycobacterium avium complex in nude and beige mice

After 4 weeks of treatment, clarithromycin (CLAR) and amikacin showed similar antimicrobial activities against the Mycobacterium avium complex in mice. There was a difference, however, in the effectiveness of the drugs in different types of mice: both drugs displayed bactericidal effects in beige mice but only bacteriostatic effects in nude mice. Because the effectiveness of CLAR is less in nude mice than in beige mice, the predictive value of the nude mouse model for the efficacy of chemotherapy is less than that of the beige mouse model.

[The study of mutation in exon 17 of insulin receptor gene in essential hypertensive pedigrees]

Using the molecular scanning technique of single-stranded conformational polymorphism, we examined the exon 17 of the insulin receptor (INSR) gene in 44 subjects of 6 essential hypertensive pedigrees and 2 normotensive pedigrees. In addition the serum levels of glucose and insulin during an oral glucose tolerance test (OGTT); blood lipid, and plasma angiotension II and angiotensinogen were done on these pedigrees. Upon direct sequence analysis, 5 individuals were found a single nucleotide substitution at the codon 1058 (CAC-->CAT), which didn't change the amino acid sequence. Among the five individuals 4 of them were from the families with history of hypertension, only one was from normotensive pedigree. Compared with those without the mutation, the individuals with the mutation had a lower ratio of fasting blood glucose to fasting serum insulin level (P < 0.01) and an elevated plasma Ang II concentration. (There was no significant difference, P > 0.05, probably due to the mutant cases which we studied were small). Thus, we conjectured that the mutation in codon 1,058 of the INSR gene might be related with the insulin resistance in hypertensive patients and subjects with the positive hypertensive history.

Which aminoglycoside or fluoroquinolone is more active against Mycobacterium tuberculosis in mice?

To identify the most active aminoglycoside or fluoroquinolone for the treatment of tuberculosis, the in vivo activities of four different aminoglycosides and three different fluoroquinolones were compared with that of isoniazid (INH) in a murine tuberculosis model. Mice were each inoculated intravenously with 2.3 x 10(7) CFU of Mycobacterium tuberculosis H37Rv. Treatment began the next day (D1) after inoculation and continued for 4 weeks, at the frequency of six times weekly with one of the following regimens: INH, 25 mg/kg; ofloxacin, 200 mg/kg; levofloxacin, 100 or 200 mg/kg; sparfloxacin (SPFX), 50 mg/kg; and streptomycin, kanamycin, amikacin (AMIKA), and isepamicin, all at 200 mg/kg. The dosages of the treatments were presumably equivalent to their clinically tolerated dosages. The severity of infection and effectiveness of the treatment were assessed by the survival rate, spleen weights, gross lung lesions, and the numbers of CFU in the spleens. The results indicate that INH is more bactericidal than any of the aminoglycosides or fluoroquinolones tested, that AMIKA is the most active aminoglycoside, and that SPFX at 50 mg/kg is far more bactericidal than the treatment with other fluoroquinolones.

Bactericidal activity of single dose of clarithromycin plus minocycline, with or without ofloxacin, against Mycobacterium leprae in patients

Fifty patients with newly diagnosed lepromatous leprosy were allocated randomly to one of five groups and treated with either a month-long standard regimen of multidrug therapy (MDT) for multibacillary leprosy, a single dose of 600 mg of rifampin, a month-long regimen with the dapsone (DDS) and clofazimine (CLO) components of the standard MDT, or a single dose of 2,000 mg of clarithromycin (CLARI) plus 200 mg of minocycline (MINO), with or without the addition of 800 mg of ofloxacin (OFLO). At the end of 1 month, clinical improvement accompanied by significant decreases of morphological indexes in skin smears was observed in about half of the patients of each group. A significant bactericidal effect was demonstrated in the great majority of patients in all five groups by inoculating the footpads of mice with organisms recovered from biopsy samples obtained before and after treatment. Rifampin proved to be a bactericidal drug against Mycobacterium leprae more potent than any combination of the other drugs. A single dose of CLARI-MINO, with or without OFLO, displayed a degree of bactericidal activity similar to that of a regimen daily of doses of DDS-CLO for 1 month, suggesting that it may be possible to replace the DDS and CLO components of the MDT with a monthly dose of CLARI-MINO, with or without OFLO. However, gastrointestinal adverse events were quite frequent among patients treated with CLARI-MINO, with or without OFLO, and may be attributed to the higher dosage of CLARI or MINO or to the combination of CLARI-MINO plus OFLO. In future trials, therefore, we propose to reduce the dosages of the drugs to 1,000 mg of CLARI, 100 mg of MINO, and 400 mg of OFLO.

Determination of the minimal effective dosages of ofloxacin and sparfloxacin against M. leprae in the mouse foot pad system

The minimal effective dosages (MEDs) of ofloxacin (OFLO) and sparfloxacin (SPFX) against 10 isolates of Mycobacterium leprae were measured in the mouse foot pad system. The drugs were administered either by gavage or by incorporation into the mouse diet in a range of concentrations. The results demonstrated that the MEDs of OFLO were 4 to 5 times higher than those of SPFX, thus confirming that, on a weight-to-weight basis, the anti-M. leprae activity of SPFX was significantly greater than that of OFLO. The MEDs of OFLO/SPFX measured by gavage were 20 times lower than those measured by incorporating the drug into the mouse diet.

How effective is KRM-1648 in treatment of disseminated Mycobacterium avium complex infections in beige mice?

Although the MICs of 3'-hydroxy-5'-(4-isobutyl-1-piperazinyl)benzoxazinorifamycin, or KRM-1648 (KRM), for Mycobacterium avium complex (MAC) were significantly lower than those of other drugs, its in vivo activity was very weak. Beginning 28 days after inoculation, beige mice that had been infected intravenously with 1.87 x 10(7) CFU of MAC 101 were administered KRM alone, clarithromycin (CLARI) alone, or CLARI plus KRM six times weekly for 16 weeks. In contrast to the mice treated with CLARI-containing regimens, the mortality and the mean spleen weights of mice treated with KRM alone (either 10 or 20 mg/kg of body weight per dose) did not differ significantly from those of untreated mice, their numbers of CFU were very much greater than pretreatment values, and multiplication of MAC was only slightly inhibited. Although monotherapy by KRM selected KRM-resistant mutants, the selection was very weak; the mean number of CFU and the frequency of KRM-resistant mutants increased by no more than 1 order of magnitude after 16 weeks of treatment with KRM at 20 mg/kg per dose. Selection of CLARI-resistant mutants was inhibited but not completely prevented by treatment of the mice with CLARI plus KRM. These results indicate that KRM displayed only a weak bacteriostatic effect against the isolate tested in the beige mouse model; its ability to enhance the antimicrobial effect of CLARI or to prevent emergence of CLARI-resistant mutants was very limited.

Bactericidal activities of combinations of new drugs against Mycobacterium leprae in nude mice

The bactericidal activities of 12 regimens with various combinations of new drugs (clarithromycin [CLARI], minocycline [MINO], and ofloxacin [OFLO]) and the standard antileprosy drugs, especially rifampin (RMP), were compared in nude mice with established Mycobacterium leprae infection. The longest duration of treatment was 24 weeks for intermittent (once every 4 weeks) therapy and 8 weeks for daily therapy. Bactericidal effects were monitored by titrating the proportion of viable M. leprae isolates by subinoculating the organisms into the footpads of immunocompetent and nude mice. The results indicate that RMP was more bactericidal than any combination of the new drugs. A single dose of CLARI-MINO, with or without OFLO, displayed bactericidal activity as great as that of 4 weeks of daily treatment with dapsone (DDS) plus clofazimine (CLO); thus, intermittent CLARI-MINO, with or without OFLO, may replace DDS and CLO of the standard multidrug regimen, and these will become regimens that can be administered monthly and under full supervision. Additional evidence that this may be the case is provided by the finding that intermittent RMP-CLARI-MINO or RMP-CLARI-MINO-OFLO administered for 12 or 24 weeks was as active as the standard multidrug regimen. While the intermittent treatment always displayed significantly greater bactericidal activity than the same number of doses of daily treatment, daily treatment with CLARI-MINO and CLARI-MINO-OFLO were more active than the drugs given as intermittent treatment for the same duration; therefore, unless these combinations are to be administered together with intermittent RMP, they should be given daily, especially for the treatment of RMP-resistant cases of infection. Finally, 12 weeks of daily treatment with DDS-CLO was more bactericidal than had been expected, suggesting that it may not be necessary to administer the standard multidrug regimen for multibacillary leprosy for as long as 24 months in order to minimize the risk of developing RMP resistance.

Clarithromycin is inactive against Mycobacterium tuberculosis

When 10% oleic acid-albumin-dextrose-catalase-enriched Mueller-Hinton agar medium was employed, the MICs of clarithromycin (CLARI) at which 50 and 90% of 12 strains of Mycobacterium tuberculosis were inhibited were 64 and > 128 micrograms/ml, respectively, which are significantly greater than the achievable peak CLARI concentrations in serum and in lung tissue in humans. In two different mouse experiments, 4 to 6 weeks of treatment with CLARI at 200 mg/kg of body weight six times weekly produced neither bactericidal nor bacteriostatic effects against M. tuberculosis. Therefore, we conclude that CLARI as a single drug is inactive against M. tuberculosis.

Relapse after long-term follow up of multibacillary patients treated by WHO multidrug regimen. Marchoux Chemotherapy Study Group

Thirty-five multibacillary (MB) leprosy patients were treated with 2 years of multidrug therapy (MDT) and followed up regularly for relapse. Relapse was defined as: a) an increase of the bacterial index (BI) by 2+ over the previous value from any single site of old lesions and b) the occurrence of definite new skin lesion(s) which demonstrated a higher BI than any pre-existing lesion. After a mean duration of 72.7 +/- 17.3 months of follow up per patient, seven relapses were diagnosed; the mean incubation period of relapse was 62.7 +/- 18.7 months. The overall relapse rate was 20.0% (or 3.3 per 100 patient-years), very significantly higher than the figures obtained from the same group of patients analyzed 2 1/2 years earlier, indicating that relapses occurred late (at least 5 +/- 2 years) after stopping MDT. Further analysis indicated that the relapse rate was closely correlated with the bacterial load of the patient, occurring far more frequently among patients with a BI of > or = 4.0 before MDT or with a BI of > or = 3.0 at the end of MDT. To avoid the alarmingly high relapse rate, it is proposed that the duration of MDT be doubled to 4 years in patients with an average BI of > or = 4.0 before MDT.

Selection of clarithromycin-resistant Mycobacterium avium complex during combined therapy using the beige mouse model

Sixteen weeks of treatment with clarithromycin (CLARI) alone displayed significant bactericidal activity against Mycobacterium avium complex infection in beige mice. Only two combined regimens, CLARI combined with an initial 4 or 8 weeks of amikacin (AMIKA), displayed activity greater than that displayed by CLARI alone. Four other combined regimens, CLARI combined with ethambutol (EMB), rifabutin (RBT), or both EMB and RBT during the entire 16 weeks of treatment or with AMIKA administered in an initial 2-week course showed bactericidal activity not significantly greater than that of CLARI alone. After 16 weeks of treatment, CLARI-resistant mutants were isolated from the majority of mice that had been treated with CLARI alone, CLARI-RBT, CLARI-EMB, or CLARI-EMB-RBT, as was the case for untreated controls, but the frequencies of occurrence of mutants were significantly greater in the groups treated with these combinations or CLARI alone. On the other hand, no CLARI-resistant mutants were isolated from the mice that had been treated with the combination of CLARI plus an initial 4 or 8 weeks of AMIKA and were isolated from only a tiny proportion of mice that had been treated with CLARI plus an initial 2 weeks of AMIKA. Therefore, only treatment with CLARI combined with an initial 4 or 8 weeks of AMIKA but not combined with RBT or EMB or both, could enhance the activity of the drug treatment and prevent the selection of CLARI-resistant mutants.

Effectiveness of various antimicrobial agents against Mycobacterium avium complex in the beige mouse model

The results of five chemotherapeutic experiments in beige mice infected with organisms of the Mycobacterium avium complex are presented. After monotherapy with various antimicrobial agents for 4 weeks, only clarithromycin, amikacin, and ethambutol displayed definite bactericidal effects; sparfloxacin and clofazimine showed modest bacteriostatic effects; and rifampin and rifabutin were totally inactive against the isolate tested. After treatment for 4 weeks, the large quantities of clofazimine that had accumulated in the organs of mice seriously interfered with the enumeration of the CFU and assessment of the efficacy of the treatment. The in vitro synergistic effects of drug combinations against M. avium complex were not confirmed in beige mice. In combination with clarithromycin, amikacin could prevent the selection of clarithromycin-resistant mutants, whereas minocycline could not.

Preventive therapy of tuberculosis with rifapentine in immunocompetent and nude mice

The effectiveness of intermittent administration of rifapentine (RPT), with or without isoniazid (INH), for preventive therapy of tuberculosis was evaluated in immunocompetent (normal) and nude mice. After infection with a small inoculum of Mycobacterium tuberculosis H37Rv, normal mice developed a chronic and nonfatal infection, and the bacterial population became relatively stable after an initial period of limited multiplication. On the other hand, nude mice developed an acute and fatal infection, and all untreated mice died within 5 wk, with very high colony-forming-unit (CFU) counts in their organs. Various degrees of bactericidal activity were shown in normal mice after daily treatment with rifampin (RMP) plus pyrazinamide (PZA) for 13 wk, INH daily for 26 wk, or RPT once weekly for 13 or 26 wk or once fortnightly for 26 wk. The activity of RPT was significantly enhanced when INH was added at the same dosing frequency. In nude mice the response of M. tuberculosis infection to certain regimens was less favorable than that in normal mice, suggesting that preventive therapy may be less effective in severely immunodeficient hosts even during treatment. After chemotherapy was stopped, virtually all nude mice relapsed within 12 wk regardless of the regimen administered, whereas no or very few relapses were observed in normal mice that had been treated with RMP+PZA daily for 13 wk, or RPT alone or RPT+INH once weekly for 26 wk. The latter three regimens and RPT+INH once weekly for 13 wk may be applied for fixed-duration preventive therapy in human immunodeficiency virus (HIV)-negative subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

[Dietary factors and cancer of the colon and rectum in a population based case-control study in Shanghai]

The study was a population-based case control one, to compare possible difference in the risk factors between colonic and rectal cancer. This study showed that: (1) High intake of pork and saturated fat was an important risk factor for colon cancer, and only slightly related to rectal cancer. (2) Low consumption of vegetables especially cruciferous vegetables, rhizome vegetables, sea weeds, legume vegetables, dietary fiber and some vitamins mainly derived from vegetables, e.g. vitamin c and carotene, was associated with an increased risk for both colonic and rectal cancer, and these factors were closer relationship with rectal cancer than colon cancer. (3) High intake of the fried and pickled foods significantly increase the risk of occurrence of these cancers. (4) The ratio of bowel cancer in first degree relatives of colon cancer cases was 2.9 times of control group (P < 0.01), but the ratio for rectal cancer was only 1.6 times (P > 0.05) compared with control group.

Seroepidemiologic survey of Borrelia burgdorferi exposure of dairy cattle in Wisconsin

An ELISA, using purified flagellin of Borrelia burgdorferi as the solid-phase antigen, was used to measure antibody concentrations to B burgdorferi in dairy cattle in Wisconsin. Serum obtained from 5,060 cows in 160 randomly selected herds in the state were tested. Serum from an additional 2,600 cattle in Barron County, Wis, a county with a high annual incidence of B burgdorferi infections in human beings, was also tested. Only 7% of the cows that were tested, but 66% of the herds that were tested, were seropositive for B burgdorferi. Sixteen percent of the herds had a prevalence of > or = 15% seropositive cows, whereas 50% of the herds had a prevalence of 1 to 14% seropositive cows. Seropositive herds were concentrated in the west-central part of Wisconsin. An association existed between the geographic location of seropositive herds and counties in which B burgdorferi infection of human beings was acquired (P < 0.05) as well as the geographic location of seropositive herds and the geographic distribution of Ixodes scapularis (P < 0.05). Barron County, in which B burgdorferi infection is endemic, had a significantly (P < 0.05) higher percentage of seropositive cows (17%) than did the state of Wisconsin (7%).

Evaluation of an enzyme-linked immunosorbent assay that uses the 41-kd flagellin as the antigen for detection of antibodies to Borrelia burgdorferi in cattle

An ELISA was developed to detect antibodies to the 41-kd flagellin (P41) of Borrelia burgdorferi in serum obtained from cattle. Absorption studies, immunoblot analysis, immunoelectron microscopy, and correlation of results of the P41-ELISA and the P39-ELISA as well as measurement of the antibody to P41 in calves challenge-exposed with Borrelia theileri were used to assess the specificity of the P41-ELISA. Antigens derived from Escherichia coli, Leptospira interrogans serovar hardjo, and B burgdorferi were used for absorption studies and immunoblot analysis. Antibodies to P41 of B burgdorferi cross-reacted with antigens of E coli, but were not cross-reactive with L hardjo. A value 3 SD higher than the mean of the negative-control population of cattle was defined as the minimum value (cutoff value) for a positive result by the P41-ELISA. Use of this value for classification of test results reduced the predicted rate of false-positive results attributable to E coli cross-reactivity to 1%. Immunoblot analysis revealed that test-positive serum from cattle reacted mainly with 41-, 39-, 34-, and 31-kd proteins of B burgdorferi, as well as several smaller proteins. Immunoelectron microscopy revealed that serum from cattle that was test-positive by the P41-ELISA bound to the flagellin and outer membrane of B burgdorferi. Results of absorption studies, immunoblot analysis, and immunoelectron microscopy were correlated and indicated that serum from cattle that was test-positive by P41-ELISA had stronger reactivity to B burgdorferi antigens than to antigens of E coli or L hardjo.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical trial of ofloxacin alone and in combination with dapsone plus clofazimine for treatment of lepromatous leprosy

Twenty-four patients with newly diagnosed lepromatous leprosy were allocated randomly to three groups and treated for 56 days with 400 mg of ofloxacin daily, 800 mg of ofloxacin daily, or 400 mg of ofloxacin, 100 mg of dapsone, and 50 mg of clofazimine daily plus 300 mg of clofazimine once every 28 days. The patients in all three groups demonstrated remarkable clinical improvements, accompanied by rapid decline of the morphological index in skin smears during treatment. More than 99, > 99.99, and > 99.99% of the viable Mycobacterium leprae organisms had been killed by 14, 28, and 56 days of treatment, respectively, as measured by inoculation into the footpads of immunocompetent and nude mice of organisms recovered from skin biopsy specimens obtained before and during treatment. Mild to moderate elevations of the serum glutamic pyruvic transaminase level were observed in four patients, all after 28 days of treatment, which returned to normal after the trial had been completed. Clinical improvement, bactericidal activity, and hepatotoxicity did not differ significantly among the three groups. Ofloxacin displayed powerful bactericidal activity against M. leprae in leprosy patients and may be an important component of new multidrug regimens for the treatment of leprosy. Its optimal dosage appears to be 400 mg daily, and combination with dapsone and clofazimine does not enhance its activity.

Further study of the effectiveness of single doses of clarithromycin and minocycline against Mycobacterium leprae in mice

The anti-Mycobacterium leprae activities of single doses of rifampin (RMP), clarithromycin (CLARI), or minocycline (MINO) alone, and various combinations of CLARI + MINO were determined in immunocompetent mice by the kinetic method. A single dose of RMP 10 mg/kg, CLARI 100 mg/kg or 200 mg/kg, MINO 25 mg/kg or 50 mg/kg alone, or various combinations of CLARI & MINO were active. RMP was more active than the other treatments; the activity of CLARI 100 mg/kg was greater than that of 50 mg/kg, but did not differ significantly from that of 200 mg/kg; MINO 50 mg/kg was more active than 25 mg/kg; and none of the combinations of CLARI + MINO was more active than any of the stronger components administered alone. Therefore, both CLARI and MINO may be applied, either alone or in combination, as components of monthly administered, fully supervised, multidrug regimens for the treatment of multibacillary leprosy. Taking into account the effectiveness of the drugs and the comparative pharmacokinetic data, we propose that the optimal dosage in human trials is CLARI 1000 mg per month or MINO 200 mg per month.

[Comparison of risk factors between left and right-sided colon cancer]

To compare differences of risk factors between left-sided and right-sided colon cancer, a population-based comparative case-control study involving 267 patients with left colon cancer, 247 with right colon cancer and 1451 population controls matched by age (+/- 5 yrs) and sex was carried out in Shanghai. The major causes in the two cancer groups were dietary and nutritional factors. Vegetables, ascorbic acid, riboflavin, tocopherol and carotenes played a protective role in the two groups, but various other foods and some vitamins displayed different relations with the two types of cancer. A negative association was observed between dietary fiber and right colon cancer. Animal fat and some fatty acids (e.g. saturated fatty acids, mono-unsaturated fatty acids and oleic acid) significantly elevated the risk for left colon cancer, but only slightly for right colon cancer. Physical activity and familial history of colorectal cancer in first degree relatives showed a more remarkable relationship with left- than right-sided colon cancers.

Effectiveness of rifampin, rifabutin, and rifapentine for preventive therapy of tuberculosis in mice

To identify alternative regimens for preventive therapy of tuberculosis, the pharmacokinetics and antimicrobial activities of rifampin (RMP), rifabutin (RBT), and rifapentine (RPT) were compared in BCG-vaccinated and M. tuberculosis-infected immunocompetent mice. RPT showed the highest serum peak level (Cmax) and the longest half-life (t1/2), whereas RBT displayed the lowest Cmax and the shortest t1/2. On weight-to-weight basis, both RPT and RBT were more bactericidal than RMP. The activity of RMP was significantly reduced when the frequency of administration was reduced from six to three times weekly, whereas significant bactericidal activity was still observed in mice treated with RPT, 10 mg/kg up to once fortnightly, or RBT, 10 mg/kg twice weekly. Because the bactericidal activity of RBT, 10 mg/kg six times/wk for 6 wk, or RPT, 10 mg/kg two times/wk for 12 wk, was comparable to that of RMP, 10 mg/kg six times/wk for 12 wk in mice, the two regimens are appropriate for clinical trials of preventive therapy of tuberculosis.

Powerful bactericidal activities of clarithromycin and minocycline against Mycobacterium leprae in lepromatous leprosy

Thirty-six patients with newly diagnosed lepromatous leprosy were allocated randomly to three groups and treated for 56 days with minocycline (100 mg daily), clarithromycin (500 mg daily), or clarithromycin (500 mg) plus minocycline (100 mg daily). All groups had rapid and remarkable clinical improvement and significant decline of the bacterial and morphologic indices in skin smears during treatment. More than 99% and > 99.9% of the viable Mycobacterium leprae had been killed by 28 and 56 days of treatment, respectively, as measured by inoculation of organisms recovered from skin samples, taken before and during treatment, into the footpads of immunocompetent and nude mice. Clinical improvement and bactericidal activity did not differ significantly among the three groups. Adverse reactions were rare and mild, and no laboratory abnormality was detected during the trial. Both clarithromycin and minocycline displayed powerful bactericidal activities against M. leprae in leprosy patients and may be considered important components of new multidrug regimens for the treatment of multibacillary leprosy.

Powerful bactericidal activity of sparfloxacin (AT-4140) against Mycobacterium tuberculosis in mice

The bactericidal activities of various monotherapies and combined regimens were compared in mice at different stages after infection with Mycobacterium tuberculosis. These therapies mimicked the initial and continuation phases of chemotherapy for human tuberculosis. As monotherapy, the bactericidal activity of sparfloxacin (SPFX) was dose related; the activity of SPFX at 100 mg/kg of body weight was comparable to that of rifampin (RMP) and was significantly greater than those of isoniazid (INH), pyrazinamide (PZA), or ofloxacin (OFLO) during both the initial and continuation phases of chemotherapy. During the initial phase, the addition of SPFX did not enhance or diminish the activities of the combinations INH-RMP-PZA or RMP-PZA; the combinations SPFX-PZA-streptomycin (SM) and SPFX-PZA-kanamycin (KANA) displayed powerful bactericidal activity. Because the area under the plasma concentration-time curve of SPFX (100 mg/kg) in mice is similar to that of SPFX (400 mg) in humans, the promising bactericidal activity displayed by SPFX in mice might be achieved in humans by administration of the drug in a clinically tolerated dosage. In addition, the combinations SPFX-PZA-SM and SPFX-PZA-KANA may be useful for the treatment of multidrug-resistant tuberculosis.

Bactericidal activities of single or multiple doses of various combinations of new antileprosy drugs and/or rifampin against M. leprae in mice

The bactericidal activities against Mycobacterium leprae of single or multiple doses of various combinations of new antileprosy drugs [minocycline (MINO), clarithromycin (CLARI), ofloxacin (OFLO), and sparfloxacin (SPFX)] and/or rifampin (RMP) were titrated in immunocompetent mice by the proportional bactericidal method. Drugs were administered by gavage at the following dosages (mg/kg) per dose: RMP 10, MINO 25, CLARI 100, OFLO 150, and SPFX 50. All 15 regimens exerted significant bactericidal activities, at least 96% of viables were killed. The activity of a single dose MINO + CLARI was only slightly inferior to that of RMP, and the activities of a single dose OFLO/SPFX + MINO + CLARI were similar to that of RMP. This suggests that either MINO + CLARI or OFLO/SPFX + MINO + CLARI may be administered once monthly together with RMP 600 mg for the treatment of multibacillary (MB) leprosy, and monthly administration of MINO + CLARI or OFLO/SPFX + MINO + CLARI may also be employed for the treatment of RMP-resistant MB leprosy. Because the killing effects of multiple doses of the combinations were so powerful, comparison of the bactericidal activities of these regimens was beyond the sensitivity of the immunocompetent mouse model, and are being tested in the nude mouse model. Although SPFX is more active against M. leprae than OFLO on a weight-to-weight basis, when both drugs were administered in mice at dosages equivalent to clinically tolerated dosages in humans, SPFX did not show more superiority than OFLO, and its real advantage over OFLO in the treatment of leprosy remains unclear.

Short-term trial of clofazimine in previously untreated lepromatous leprosy

Forty-five previously untreated lepromatous leprosy patients were allocated randomly to three groups and treated, respectively, with Regimen A, standard dosage of clofazimine (CLO) in multidrug therapy (MDT) regimen; Regimen B, CLO 600 mg once every 4 weeks; and Regimen C, CLO 1200 mg once every 4 weeks. The duration of the trial was 24 weeks. By the end of the trial, although a few patients in each group did not improve at all clinically, the majority of patients showed clinical amelioration but the responses were slow. While the mean morphological index dropped to the baseline after 24 weeks of treatment, the mean bacterial index did not change significantly. About 80% of the patients in each group remained nasal-smear positive at the end of the trial, but the bacterial loads steadily declined. No significant difference has been detected in these parameters among the three groups. The patients tolerated the regimens very well and the side effects were mild. The results of serial mouse foot pad inoculation demonstrated that the positivity rates of multiplication of Mycobacterium leprae in mice and the proportions of viable organisms reduced gradually in all groups. Because the positivity rate at week 24 in Group C did not differ significantly from Group A, but was significantly smaller than that of Group B, we conclude that Regimen C was as active as Regimen A and could be applied for monthly supervised treatment along with rifampin; Regimen B is less effective and should not be used for the treatment of leprosy.

Selection of resistant mutants of Mycobacterium avium in beige mice by clarithromycin monotherapy

Beige mice were inoculated intravenously with 10(7.90) CFU of Mycobacterium avium 101. Among the untreated control mice, when the mean CFU per spleen increased to a level greater than 10(8), small numbers of organisms resistant to clarithromycin (CLARI) were isolated from some of the spleens; the frequency of CLARI-resistant mutants was estimated to be between 10(-8) and 10(-9). In mice treated with 200 mg of CLARI per kg of body weight six times weekly, however, CLARI-resistant organisms were isolated from the spleens of all mice examined after treatment for 8 weeks; the mean CFU per spleen and the frequency of resistant mutants were significantly greater than those of control mice and increased further after treatment for 16 weeks. The MICs of CLARI against the resistant organisms isolated from both control and treated mice were > or = 512 micrograms/ml.