Biomedical subjects

K Otani

Publications and source records attributed to K Otani.

At least 55 records · Page 3Linked to original sources

PubMed2000

Causes of death in elderly prostate cancer patients and in a comparison nonprostate cancer cohort.

BACKGROUND: Prostate cancer tends to affect older men and to progress relatively slowly. Since the prevalence of comorbidity increases with advancing age, competing causes of death are important contributors to death rates among prostate cancer patients. Accurate determination of the underlying causes of death in older men dying with prostate cancer may thus also be more difficult. METHODS: We compared the distribution of underlying causes of death in decedents from a population-based cohort of elderly prostate cancer patients to that from a population-based comparison cohort of elderly men without prostate cancer. Among decedents from the prostate cancer patient cohort, we examined associations of patient demographics, disease stage, and initial treatment, with assignment of a prostate cancer underlying cause of death (versus any other cause) by use of multivariable logistic regression. In the subgroup of prostate cancer patient decedents having underlying causes of death other than prostate cancer, the underlying cause distribution was compared with that in nonprostate cancer cohort decedents. RESULTS: Prostate cancer was the underlying cause for 39% (95% confidence interval [CI] = 36.3-41.9) of the decedents in the prostate cancer cohort. Causes of death among prostate cancer patients not dying of prostate cancer were similar to those among the nonprostate cancer cohort decedents. However, in those who were aggressively treated, the adjusted odds of other cancer causes of death were 51% higher (odds ratio [OR] = 1.51; 95% CI = 1.08-2.10) than that in nonprostate cancer patient decedents, while in those treated with watchful waiting the adjusted odds were 34% lower (OR = 0.66; 95% CI = 0.47-0.93). CONCLUSIONS: Initial treatment may influence the underlying cause of death reported in vital statistics for prostate cancer patients.

Aged↗

PubMed2000

Methylprednisolone reduces the early vascular permeability increase in spinal nerve roots induced by epidural nucleus pulposus application.

Autologous nucleus pulposus is known to have injurious effects on spinal nerve roots when applied epidurally. Both inflammatory and immunological mechanisms have been implicated in this regard. Various proinflammatory substances might be released or activated by nucleus pulposus and might affect the endoneural nerve root vessels. The present study assessed nucleus pulposus-induced early vascular reactions and the possibility of blocking these reactions with intravenous, high-dose, methylprednisolone pretreatment. In 25 pigs, the S2 and S3 nerve roots were exposed. In five pigs (control group), retroperitoneal fat was applied epidurally on the nerve roots, and the other 20 pigs had nucleus pulposus applied. This group was sub-divided into the treatment group (n = 8), in which the pigs were pretreated with intravenous high-dose methylprednisolone (30 mg/kg body weight), and the nontreatment group (n = 12), in which the pigs received a corresponding volume of saline solution. After 2 hours, Evans blue labeled albumin was injected intravenously 5 minutes before death. Endoneural extravasation of Evans blue labeled albumin was evaluated with fluorescence microscopy. A marked albumin leakage was found in 67% of the nontreated animals, in 25% of those in the treatment group, and in none of the control animals. These results demonstrate that nucleus pulposus can induce a rapid increase in endoneural vascular permeability in spinal nerve roots after epidural application. This increase can be partially prevented by pretreatment with high-dose methylprednisolone.

Animals↗

PubMed2000

Effects of repeated ingestion of grapefruit juice on the single and multiple oral-dose pharmacokinetics and pharmacodynamics of alprazolam.

The effects of repeated ingestion of grapefruit juice, an inhibitor of cytochrome P450 3A4 (CYP3A4), on the pharmacokinetics and pharmacodynamics of both single and multiple oral doses of alprazolam, a substrate of CYP3A4, were examined. In study 1, eight healthy volunteers ingesting 600 ml/day water or grapefruit juice for 10 days took a single oral 0.8-mg dose of alprazolam on the eighth day. Plasma drug concentrations were monitored up to 48 h after alprazolam dosing together with evaluation of psychomotor function. Grapefruit juice altered neither the plasma concentrations of alprazolam at any time points, any pharmacokinetic parameters, nor the majority of psychomotor function parameters in subjects. In study 2, 11 patients with anxiety disorders receiving alprazolam (0.8-2.4 mg/day) ingested grapefruit juice (600 ml/day) for 7 days. Blood samples were collected before and during grapefruit juice ingestion and 1 week after its discontinuation together with an assessment of clinical status. Grapefruit juice altered neither the steady-state plasma concentration of alprazolam nor the clinical status in patients. The present study shows that grapefruit juice is unlikely to affect pharmacokinetics or pharmacodynamics of alprazolam due to its high bioavailability.

Adult↗

PubMed2000

Prolactin response to nemonapride, a selective antagonist for D2 like dopamine receptors, in schizophrenic patients in relation to Taq1A polymorphism of DRD2 gene.

The dopamine D2 receptor (DRD2) gene has a Taq1A restriction fragment length polymorphism yielding two alleles, A1 and A2. It has been shown that the subjects with less frequent allele, the A1 allele, have lower density and diminished function of DRD2 in the striatum, compared to those with no A1 allele. In the present study, the relationship between this polymorphism and prolactin response to nemonapride, an antipsychotic drug with selective and potent DRD2 antagonistic property, was investigated in 25 Japanese schizophrenic inpatients (13 males, 12 females). The daily dose of nemonapride was fixed at 18 mg, and the duration of treatment was 3 weeks. Taq1A genotypes were determined by the polymerase chain reaction method. Plasma prolactin concentrations were measured by enzyme immunoassay. The subjects were divided into four subgroups by gender and Taq1A genotypes, i.e., six males and eight females with the A1 allele, seven males and four females with no A1 allele. The (delta)prolactin (change from the pretreatment concentration) at 1 week was significantly (P<0.05) higher in females with the A1 allele (78.0 +/- 47.1 ng/ml) than in males with the A1 allele (33.4 +/- 14.0 ng/ml) or with no A1 allele (29.5+/-24.8 ng/ml). In addition, (delta)prolactin at 3 weeks was significantly (P<0.05) higher in females with the A1 allele (98.1+/-67.9 ng/ml) than in females with no A1 allele (33.4+/-24.6 ng/ml), males with the A1 allele (29.1+/-17.3 ng/ml) or males with no A1 allele (28.6+/-22.0 ng/ml). The present study thus suggests that female patients with the A1 allele show a greater prolactin response to nemonapride, who may have a high risk for adverse effects associated with neuroleptic-induced hyperprolactinemia.

Adolescent↗

PubMed2000

Association between Taq1 a dopamine D2 receptor polymorphism and psychopathology of schizophrenia in Japanese patients.

1. Previous reports showed that the A1 allele of Taq1 A dopamine D2 receptor polymorphism was associated with lowered density and diminished function of dopamine D2 receptor. In this study, association between Taq1 A dopamine D2 receptor polymorphism and psychopathology of schizophrenia was investigated. 2. The subjects were 61 acutely exacerbated schizophrenic patients who were all Japanese descent and had received no medication for at least one month before this study. Pretreatment psychotic symptoms were assessed by the Brief Psychiatric Rating Scale (BPRS). The Taq1 A genotypes, the A1 and A2 alleles, were determined by polymerase chain reaction method. 3. The patients were divided into three genotype groups; i.e., the patients with A1/A1 allele (n=6), those with A1/A2 allele (n=32) and those with A2/A2 allele (n=23). 4. There was no significant difference in total BPRS, subgrouped symptoms (positive, negative, anxiety-depression, excitement and cognitive symptoms) or any scores of BPRS items among the three Taq1 A genotype groups. 5. The present study suggests that Taq1 A dopamine D2 receptor polymorphism does not play an important role in psychopathological symptoms of schizophrenia.

Adult↗

PubMed2000

Administration of bacterial lipopolysaccharide to rats induces heme oxygenase-1 and formation of antioxidant bilirubin in the intestinal mucosa.

Heme oxygenase (HO)-1, the rate-limiting enzyme in heme degradation, is induced by oxidative stress and its major end product, bilirubin, is a potent physiological antioxidant. We studied the induction of HO-1 and bilirubin production in intestinal mucosa using a rat model of sepsis. E. coli lipopolysaccharide was administered intraperitonealy to male Wistar rats and intestinal mucosa was harvested. Intestinal lipid peroxides increased significantly at 1 hr and peaked at 170% of the control value at 5 hr. GSH significantly decreased at 3 hr, reaching the nadir of 50% of the control value at 5 hr. HO-1 mRNA was maximally induced fivefold at 3 hr and HO-1 protein maximally increased to 10 times the control value at 7.5 hr. Both bilirubin and bilirubin oxidative metabolites were maximally increased at 10 hr, to 4.3 and 3.7 times the control value, respectively. These data suggest that oxidative stress in sepsis quickly induces HO-1 in intestinal mucosa and that subsequent production of bilirubin works as an antioxidant. The small intestinal mucosa is an active participant in the general response to sepsis.

Animals↗

PubMed2000

Therapeutic spectrum of nemonapride and its relationship with plasma concentrations of the drug and prolactin.

The therapeutic spectrum of nemonapride, a new substituted benzamide, and its relationship with plasma concentrations of the drug and prolactin were investigated by a fixed-dose study (18 mg/day for 3 weeks) in 31 patients with acutely exacerbated schizophrenia. Of 31 patients, 25 (80.6%) were responders who showed a reduction in symptoms (percentage of improvement) of 50% or more after 3 weeks. The mean values of percentage of improvement in scores on the total Brief Psychiatric Rating Scale (BPRS) and the five subscale symptoms were 71.5% for total, 73.2% for Positive, 86.0% for Excitement, 53.9% for Negative, 84.2% for Cognitive, and 67.5% for Anxiety-Depression. Responders had higher percentage of improvement in positive (84.6 +/- 17.0% vs. 25.9 +/- 15.7%; p < 0.001) and anxiety-depression (76.9 +/- 18.8% vs. 28.5 +/- 39.9%; p < 0.005) symptoms than did nonresponders after 3 weeks. The percentage of improvement in total BPRS after 2 weeks was well correlated with that after 3 weeks (Spearman rank correlation coefficient: r(s) = 0.711; p < 0.01). There was an inverted U-shaped relationship between plasma drug concentrations (nemonapride plus desmethylnemonapride) and percentage of improvement in total BPRS symptoms after a 3-week treatment (y = 46.9 + 73.9x - 44.2x2; p < 0.001). These findings suggest that nemonapride has a broad therapeutic spectrum in the treatment of acute schizophrenia. The improvements in scores for the Positive and Anxiety-Depression subscale symptoms are regarded as determinant factors for total response to nemonapride. An assessment of clinical status after 2 weeks and plasma drug monitoring may be useful for the prediction of the final outcome for patients.

Adolescent↗

PubMed2000

Pharmacogenetics of classical and new antipsychotic drugs.

Several classical antipsychotic drugs, i.e., chlorpromazine, haloperidol, perphenazine, thioridazine and zuclopenthixol; and some new neuroleptic drugs, i.e., risperidone and sertindole, are metabolized predominantly by cytochrome P450 (CYP) 2D6. Significant relationships have been reported between the steady state plasma concentrations (Css) of some classical neuroleptics and the CYP2D6 activity or genotype. Several of these drugs also potently inhibit the CYP2D6 activity. These facts explain several drug metabolic interactions of the classical drugs. Two studies failed to show that the CYP2D6 activity predicts the therapeutic effects of haloperidol or perphenazine. Some studies have suggested that the poor metabolizer phenotype is associated with the development of oversedation during treatment with the classical drugs, but other studies have been inconsistent or negative. The CYP2D6 phenotyping and genotyping appear to be useful in predicting the Css of some classical drugs, but their usefulness in predicting clinical effects must be further explored.

Antipsychotic Agents↗

PubMed2000

Effect of a genetic polymorphism of CYP1A2 inducibility on the steady state plasma concentrations of haloperidol and reduced haloperidol in Japanese patients with schizophrenia.

The effect of a genetic polymorphism of inducibility of cytochrome P450 (CYP) 1A2 on the steady state plasma concentrations (Css) of haloperidol and reduced haloperidol was studied to clarify if these Css are dependent on the CYP1A2 activity. The subjects were 101 Japanese schizophrenic inpatients receiving oral haloperidol 12 mg/d. The Css of haloperidol and reduced haloperidol were measured in duplicate by high performance liquid chromatographic method, and were corrected to the mean body weight. A point mutation from guanine (wild-type) to adenine (mutated-type) at position -2964 in the 5'-flanking region of CYP1A2 gene was identified by polymerase chain reaction (PCR)-fragment length polymorphism method. Based on the present results, i.e., significant effects of CYP2D6 genotypes on the Css of haloperidol and reduced haloperidol, analyses were separately performed in two groups, i.e., patients with 0 mutated allele of the CYP2D6 (41 cases) and those with 1 or 2 mutated alleles (60 cases). Subjects in each CYP2D6 genotype group consisted of 4 subgroups according to smoking habit and the presence of the mutated allele of the CYP1A2. Neither the Css of haloperidol nor that of reduced haloperidol significantly differed among the 4 subgroups in either CYP2D6 genotype group. The present study thus suggests that the CYP1A2 activity does not play an important role in controlling the Css of haloperidol or reduced haloperidol.

Alleles↗

PubMed2000

The relationship between dopamine D2 receptor polymorphism at the Taq1 A locus and therapeutic response to nemonapride, a selective dopamine antagonist, in schizophrenic patients.

Previous studies have demonstrated that subjects with one or two A1 alleles of dopamine D2 receptor (DRD2) polymorphism at the Taq1 A locus have lower DRD2 density than those with no A1 allele. The present study aimed to examine whether the Taq1 A DRD2 genotypes are related to therapeutic response to nemonapride, a selective dopamine antagonist, in schizophrenic patients. The subjects were 25 acutely exacerbated schizophrenic inpatients who had received no medication for at least 1 month before the study. The fixed dose (18 mg/day) of nemonapride was administered to each patient for 3 weeks. The clinical status was prospectively monitored by the Brief Psychiatric Rating Scale (BPRS) before, and 3 weeks after, the treatment. The Taq1 A genotypes (A1 and A2 alleles) were determined by the polymerase chain reaction method. Three patients were homozygous for the A1 allele, 11 were heterozygous for the A1 and A2 alleles, and 11 were homozygous for the A2 allele. The patients with one or two A1 alleles (n = 14) showed significantly higher percentage improvement in total BPRS and positive symptoms than those with no A1 allele (n = 11) after 3-week treatment while the percentage improvement in other subgrouped symptoms (negative, anxiety-depression, excitement and cognitive symptoms) was similar between the two genotype groups. The present results suggest that the Taq1 A DRD2 polymorphism is related to early therapeutic response to nemonapride in schizophrenic patients, possibly by modifying the efficiency of DRD2 antagonism of the drug in the central nervous system.

Adult↗

PubMed1999

Protein markers in cerebrospinal fluid in experimental nerve root injury. A study of slow-onset chronic compression effects or the biochemical effects of nucleus pulposus on sacral nerve roots.

STUDY DESIGN: Measurement of changes in cerebrospinal fluid concentrations of nerve tissue markers, total proteins, and immunoglobulin after compression of nerve root or application of nucleus pulposus in a pig model. OBJECTIVES: To assess whether compression or application of nucleus pulposus to spinal nerve roots may cause increased levels of cerebrospinal fluid markers of nerve tissue damage and total proteins, and whether synthesis of immunoglobulins may be induced in cerebrospinal fluid. SUMMARY OF BACKGROUND DATA: Previous studies have reported that there seems to be a relationship between elevated cerebrospinal fluid total protein concentrations, nerve tissue markers, clinical findings, and compression of the nerve root evaluated by radiologic changes in patients with sciatica. METHODS: Subjects included 41 pigs, including 5 control animals. In two groups of experimental animals (n = 7; n = 5), an ameroid constrictor was slid onto the S1 nerve root. In two other groups (n = 7; n = 5), nucleus pulposus harvested from the L2-L3 disc was applied to the S1 nerve root. Two sham animal groups (n = 7; n = 5) underwent the same laminectomy. Twenty-one pigs underwent reoperation after 1 week, and 15 pigs after 4 weeks. A syringe was used to remove 3 mL of cerebrospinal fluid at L4-L5. Concentrations of total proteins, the light subunit of the neurofilament protein, S-100 protein, neuron-specific enolase, and glial fibrillary acidic protein were measured, and the presence of oligoclonal bands (immunoglobulins) were assayed in cerebrospinal fluid. RESULTS: The pigs with compressed S1 nerve root had considerably higher neurofilament protein and total protein concentrations in their cerebrospinal fluid than the-control animals (P < 0.001 and P < 0.01, respectively) or the sham animals (P < 0.001 and P < 0.05) in the 1-week experiment. Nucleus pulposus did not induce a significant increase in concentrations of the different protein markers. The presence of oligoclonal bands in cerebrospinal fluid in the experimental groups did not differ between the control and sham animals. CONCLUSIONS: The neurofilament protein and total protein concentrations in cerebrospinal fluid may have diagnostic importance in cases wherein clinical findings are not clearly related to the radiologic changes and vice versa. These protein markers also may be useful tools in different experimental models.

Animals↗

PubMed1999

Bacteriological investigation of an outbreak of Clostridium perfringens food poisoning caused by Japanese food without animal protein.

An outbreak of Clostridium perfringens food poisoning occurred in a senior citizen's home in Japan. Japanese food, spinach boiled with fried bean curd, was considered to be the causative food as a result of the detection of the C. perfringens enterotoxin gene by nested PCR. The number of enterotoxin-positive C. perfringens was enumerated as 4.3 x 10(5)/g in the causative food by the MPN method combined with nested PCR. By cultivation, enterotoxin-positive C. perfringens was isolated from all the fecal specimens of patients tested and the causative food. The isolates from patients were serotypable, heat-resistant and the majority produced enterotoxin, however most isolates from the causative food were nonserotypable, enterotoxin-negative and heat-sensitive.

Aged↗

PubMed1999

Effects of itraconazole on the steady-state plasma concentrations of bromperidol and reduced bromperidol in schizophrenic patients.

RATIONALE: A previously reported pharmacokinetic interaction between bromperidol and carbamazepine, an inducer of cytochrome P450 (CYP) 3A4, suggests possible involvement of CYP3A4 in the metabolism of bromperidol. OBJECTIVE: We investigated pharmacokinetic interaction between bromperidol and itraconazole, a potent inhibitor of CYP3A4, to clarify the involvement of CYP3A4 in the metabolism of bromperidol and its reduced metabolite. METHODS: Itraconazole 200 mg/day for 7 days was coadministered to eight schizophrenic patients treated with a fixed dose of bromperidol 12 or 24 mg/day for at least 2 weeks. Blood samples were taken before and 1 week after itraconazole coadministration and 1 week after its discontinuation, together with clinical assessments using the Brief Psychiatric Rating Scale (BPRS) and the Udvalg for Kliniske Undersøgelser (UKU) Side Effect Rating Scale. RESULTS: Plasma concentrations of bromperidol during itraconazole coadministration (16.7+/-4.9 ng/ml) were significantly higher (P<0.01) than before itraconazole coadministration (8.9+/-4.4 ng/ml) and 1 week after its discontinuation (9.9+/-4.3 ng/ml). Plasma concentrations of reduced bromperidol during itraconazole coadministration (3.6+/-2.9 ng/ml) were significantly higher (P<0.01) than before itraconazole coadministration (1.8+/-1.3 ng/ml). No changes were observed in BPRS and UKU scores throughout the study. CONCLUSIONS: The pharmacokinetic interaction between bromperidol and itraconazole is probably due to the inhibitory effect of itraconazole on the metabolism of bromperidol. This study provides in vivo evidence of involvement of CYP3A4 in the metabolism of bromperidol and reduced bromperidol.

Adult↗

PubMed1999

Effects of the CYP2D6*10 allele on the steady-state plasma concentrations of haloperidol and reduced haloperidol in Japanese patients with schizophrenia.

BACKGROUND: The CYP2D6*10 (*10) allele that causes decreased CYP2D6 activity is present in Asians with a high frequency of about 50%. In this study we studied the effects of the *10 allele on the steady-state plasma concentrations (Css) of haloperidol and reduced haloperidol. METHODS: The subjects were 67 Japanese inpatients with schizophrenia who had only the wild-type or *10 alleles. Thirty-four patients were homozygous for the wild-type allele, and 26 were heterozygous and 7 were homozygous for the *10 allele. All patients had been receiving 12 mg/day haloperidol for at least 2 weeks. Plasma concentrations of haloperidol and reduced haloperidol were measured by HPLC. RESULTS: The mean +/- SD values of haloperidol Css in the patients with 0, 1, and 2 *10 alleles were 22.8+/-11.0, 30.1+/-10.6, and 31.2+/-21.2 nmol/L, respectively, and those values for reduced haloperidol were 6.1+/-2.9, 9.5+/-3.7, and 9.9+/-6.2 nmol/L, respectively. The mean haloperidol Css was significantly (P < .05) higher in the patients with 1 *10 allele than in those with no *10 alleles. The mean Css of reduced haloperidol was significantly (P < .05) higher in the patients with 1 and 2 *10 alleles than in those with no *10 alleles. CONCLUSION: This study suggests that the *10 allele plays an important role in controlling the Css of both haloperidol and reduced haloperidol, especially in Asian subjects.

Adult↗

PubMed1999

Possible association between delusional disorder, somatic type and reduced regional cerebral blood flow.

1. A 78-year-old female with DDST and pain disorder was treated by clomipramine 20-100 mg/day. The hypochondriacal delusion was completely resolved, while the pains were partially resolved. 2. The SPECT using Xe-133 taken at the early stage of clomipramine treatment, when she still had hypochondriacal delusions, showed markedly reduced rCBF in the temporal and parietal lobes, with predominance on the left hemisphere. Meanwhile, the SPECT taken after resolution of the hypochondriacal delusions showed a marked improvement in the reduced rCBF. 3. This report suggests that DDST has some association with reduced rCBF in the temporal and parietal lobes.

Aged↗

PubMed1999

Ring chromosome 14 complicated with complex partial seizures and hypoplastic corpus callosum.

A Japanese male with mosaicism of ring chromosome 14 and chromosome 14 monosomy is described. He demonstrated the characteristic morphologic features of ring chromosome 14, in addition to mental retardation and epileptic seizures. Clusters of complex partial seizures, one of which originated in the left frontocentral region on electroencephalographic monitoring, were evident. His seizures responded to phenobarbital, and his mental and motor development was only mildly retarded. Magnetic resonance imaging revealed a hypoplastic corpus callosum, previously unknown in association with this syndrome.

Agenesis of Corpus Callosum↗

PubMed1999

Comparison of treatments for hepatolithiasis: hepatic resection versus cholangioscopic lithotomy.

BACKGROUND: Hepatic resection and percutaneous transhepatic cholangioscopic lithotomy (PTCSL) are the two main approaches to the treatment of hepatolithiasis, but comparisons of longterm followup results have not been adequately reported. STUDY DESIGN: Of 86 patients with hepatolithiasis admitted to our institution between 1980 and 1996, we reviewed 54 patients: 26 who underwent hepatic resection and 28 who underwent PTCSL. Five patients who underwent postoperative cholangioscopic lithotomy were included in the former group. The remainder of the hepatolithiasis patients were not treated by hepatic resection or PTCSL and, therefore, were excluded from this study. Hepatic resections were mainly indicated for left-sided localized intrahepatic calculi, atrophic liver, and possible presence of cholangiocellular carcinoma. PTCSL was performed for right-sided, bilateral or recurrent stones at an average of 6 treatments (range 1 to 20 treatments) for each patient. There were no differences between the two groups in terms of gender or age. The recurrence rate of stones and longterm prognosis were analyzed using the Kaplan-Meier method, and other clinical factors listed below were statistically compared. RESULTS: The rate of complete removal of stones was similarly high in each group (96.2% in the hepatic resection group versus 96.4% in the PTCSL group). The complication (38.5% versus 21.4%) and 5-year survival (85.6% versus 100%) rates were comparable. Remaining bile duct stricture (18.2% versus 60.9%, p < 0.01) and 5-year recurrence rates (5.6% versus 31.5%, p < 0.05) were statistically lower in the hepatic resection group than in the PTCSL group. CONCLUSIONS: Hepatic resection, when combined with postoperative cholangioscopic lithotomy, is a preferable treatment for left-sided stones with strictures and bilateral stones.

Adult↗

PubMed1999

Inhibition by 16,16-dimethyl prostaglandin E2 of tumor necrosis factor-alpha and interleukin-1beta production and messenger RNA expression in human monocytes stimulated by Helicobacter pylori.

We investigated the effects of 16,16-dimethyl prostaglandin E2 on the production of tumor necrosis factor-alpha and interleukin-1beta in human monocytes stimulated with Helicobacter pylori. Monocytes isolated from human peripheral blood were incubated for 24 hr with the extract of H. pylori diluted 1:100 to 1:100,000 by volume, a combination of the extract and 16,16-dimethyl prostaglandin E2, or a vehicle alone. The extract stimulated the production of tumor necrosis factor-alpha and interleukin-1beta and the expression of their messenger RNA in a dose-dependent manner. 16,16-Dimethyl prostaglandin E2 inhibited the production of these cytokines and their messenger RNA in the presence of H. pylori at doses higher than 10(-6) M, predominantly with tumor necrosis factor-alpha. These data suggest that antiinflammatory effects of prostaglandins on gastric mucosa are in part related to their effects on inhibition of production of proinflammatory cytokines by monocytes.

16,16-Dimethylprostaglandin E2↗