Randomized placebo-controlled trial assessing the effect of bifidobacteria-fermented milk on active ulcerative colitis

BACKGROUND

Probiotics are efficacious for treating and maintaining remission of ulcerative colitis.

AIM

To conduct a randomized placebo-controlled trial of bifidobacteria-fermented milk supplementation as a dietary adjunct in treating active ulcerative colitis.

METHODS

Twenty patients with mild to moderate, active, ulcerative colitis randomly received 100 mL/day of bifidobacteria-fermented milk or placebo for 12 weeks with conventional treatment.

RESULTS

Clinical and endoscopic activity indices and histological scores were similar in the two groups before treatment. Although improvements were significant in both groups, the clinical activity index was significantly lower in the bifidobacteria-fermented milk than in the placebo group after treatment. The post-treatment endoscopic activity index and histological score were significantly reduced in the bifidobacteria-fermented milk, but not the placebo group. Increases in faecal butyrate, propionate and short-chain fatty acid concentrations were significant in the bifidobacteria-fermented milk, but not the placebo group. No adverse effects were observed in either group.

CONCLUSION

Supplementation with this bifidobacteria-fermented milk product is safe and more effective than conventional treatment alone, suggesting possible beneficial effects in managing active ulcerative colitis. This is a pilot study and further larger studies are required to confirm the result these preliminary results.

Huge IgD plasmacytoma in the abdomen presenting coagulation necrosis

A 65-year-old Japanese woman was diagnosed in 1996 with a pathological fracture of the left femur caused by immunoglobulin D-type myeloma (IgD myeloma). She responded well to combination chemotherapy followed by irradiation. The patient experienced renal failure and became dependent on haemodialysis. In 1999, large plasmacytomas developed in the abdomen and left humerus. The abdominal tumour appeared to induce gastroduodenal ulcers and jejunal obstruction. We initiated irradiation therapy without chemotherapy to prevent further growth of the plasmacytoma, although treatment-resistant gastroduodenal ulcers developed. Continued blood loss from the gastroduodenal ulcers resulted in a deterioration in the patient's health, which prevented successful haemodialysis. An autopsy showed that the plasmacytoma had undergone coagulation necrosis. We conclude that the use of combination chemotherapy with topical irradiation was an acceptable treatment measure against IgD plasmacytoma; irradiation without chemotherapy was the most likely cause of the coagulation necrosis seen in the plasmacytoma at autopsy.

A case of secondary diabetes mellitus with acromegaly improved by pioglitazone

AIM

The acromegaly patient was diagnosed with Type 2 diabetes mellitus. His HbA1c was 10.6% and fasting blood glucose (FBG) 15.3 mmol/l. We prescribed glibenclamide (10 mg/day), but his HbA1c and FBG remained high. At this stage, treatment with short-acting insulin was instigated at a dose of 20 U/day. However, the patient's blood glucose level remained unsatisfactory. We tried using pioglitazone.

METHOD

Pioglitazone was prescribed at 30 mg/day in combination with the insulin.

RESULTS

The FBG and HbA1c value decreased to 7.2 mmol/l and 7.3%, respectively, within 2 months and insulin was discontinued. Pioglitazone alone was able to control the FBG level.

CONCLUSIONS

Pioglitazone treatment might be considered as a choice for similar cases of diabetes secondary to acromegaly.

Benefit of interferon therapy in hepatocellular carcinoma prevention for individual patients with chronic hepatitis C

BACKGROUND

An increase in the incidence of hepatocellular carcinoma (HCC) in Japan since the 1980s suggests an imminent outbreak in other countries where viral spread occurred more recently. Interferon therapy for chronic hepatitis C, in general, has been shown to prevent HCC.

AIMS

To determine the scale of benefit in individual patients.

SUBJECTS

Histologically proven chronic hepatitis C patients in the Inhibition of Hepatocarcinogenesis by Interferon Therapy (IHIT) cohort (Ann Intern Med 1999;131:174), as updated in March 2003.

METHODS

The lifetime risk for HCC was calculated based on HCC incidence rates, stratified by sex, age, fibrosis stage, and outcome of interferon therapy. The gain in HCC free survival was defined as the difference between expected HCC free survival with sustained virological response and that without.

RESULTS

The gain in HCC free survival was greater when a patient was younger and fibrosis was more advanced. For example, a 30 year old male with F3 fibrosis gained 12.4 years by attaining sustained response while a patient with F1 fibrosis older than 60 years gained less than one year. For a treatment protocol with a given sustained response rate, prior estimation of the gain can be obtained by multiplying the calculated HCC free survival for responders by the response rate.

CONCLUSIONS

The gain in HCC free survival may serve as an indicator of the benefit of interferon therapy in terms of HCC prevention and be useful in the consideration of indication and selection of treatment protocol for individual patients.

X-chromosomal localization of mammalian Y-linked genes in two XO species of the Ryukyu spiny rat

Ryukyu spiny rats (genus Tokudaia), which are endemic to the central part of the Nansei Shoto archipelago in Japan, have unique karyotypes with odd numbers of chromosomes and no cytologically recognizable Y chromosome. The chromosome numbers of Tokudaia osimensis from Amamioshima and of Tokudaia sp. from Tokunoshima are 2n = 25 and 2n = 45, respectively, with a putative single X chromosome. The mouse X probe hybridized to the unpaired X chromosome, except for the distal part of the short arm in a female specimen of T. osimensis and in one male and one female of Tokudaia sp. Fluorescence in situ hybridization with the Tspy (testis-specific protein, Y-encoded) gene from both male and female cells of Tokudaia sp. by PCR localized Tspy to the distal part of the long arm of the X chromosome. Another Y-related gene, Zfy, from Tokudaia sp. was also localized to the same region in both species. Although the Sry gene is absent in this species, the present results suggest that the Y-chromosome segment carrying functional Y-linked genes, such as Tspy and Zfy, is translocated onto the distal part of the long arm of the X chromosome.

Ectopically expressed PDX-1 in liver initiates endocrine and exocrine pancreas differentiation but causes dysmorphogenesis

To date, the potency of pancreatic and duodenal homeobox gene 1 (PDX-1) in inducing differentiation into insulin-producing cells has been demonstrated in some cells and tissues. In order to carry out efficient screening of somatic tissues and cells that can transdifferentiate into beta-cell-like cells in response to PDX-1, we generated CAG-CAT-PDX1 transgenic mice carrying a transgene cassette composed of the chicken beta-actin gene (CAG) promoter and a floxed stuffer DNA sequence (CAT) linked to PDX-1 cDNA. When the mice were crossed with Alb-Cre mice, which express the Cre recombinase driven by the rat albumin gene promoter, PDX-1 was expressed in more than 50% of hepatocytes and cholangiocytes. The PDX-1 (+) livers expressed a variety of endocrine hormone genes such as insulin, glucagon, somatostatin, and pancreatic polypeptide. In addition, they expressed exocrine genes such as elastase-1 and chymotrypsinogen 1B. However, the mice exhibited marked jaundice due to conjugated hyperbilirubinemia, and the liver tissue displayed abnormal lobe structures and multiple cystic lesions. Thus, the in vivo ectopic expression of PDX-1 in albumin-producing cells was able to initiate but not complete the differentiation of liver cells into pancreatic cells. The conditional PDX-1 transgenic mouse system developed in this study appeared to be useful for efficient screening of PDX-1 responsive somatic tissues and cells.

High frequency of antibiotic-associated diarrhea due to toxin A-negative, toxin B-positive Clostridium difficile in a hospital in Japan and risk factors for infection

Patients hospitalized in a hospital with a high incidence of antibiotic-associated diarrhea due to toxin A-negative, toxin B-positive (A-/B+) Clostridium difficile were retrospectively investigated to determine the clinical manifestations and risk factors for infection. Of 77 Clostridium difficile isolates obtained from 77 patients during the 1-year investigation period, 30 were A-/B+ and 47 were toxin A-positive, toxin B-positive (A+/B+). By pulsed-field gel electrophoresis analysis, 23 of the 30 A-/B+ strains were outbreak-related, suggesting nosocomial spread of a single type of bacterium, which mainly affected patients in the wards of respiratory medicine, hematology and neurology. Using regression analysis, three factors were found to be associated with infection by A-/B+ isolates: (i) exposure to antineoplastic agents ( P=0.01, odds ratio [OR]=5.1), (ii) the use of nasal feeding tubes ( P=0.008, OR=5.2), and (iii) assignment to a certain internal medicine ward ( P=0.05, OR=3.0). Between patients with Clostridium difficile-associated diarrhea caused by A-/B+ strains and those with A+/B+ strains, no statistically significant difference was found in body temperature, serum concentration of C-reactive protein, leukocyte count in whole blood, frequency of diarrhea, or type of underlying disease. These results indicate that A-/B+ strains of Clostridium difficile can cause intestinal infection in humans and they spread nosocomially in the same manner as A+/B+ strains.

Prevalence of Helicobacter pylori in NSAID users with gastric ulcer

OBJECTIVE

Regarding the interaction of Helicobacter pylori and non-steroidal anti-inflammatory drugs (NSAIDs), we cannot accept unanimous conclusions in inducing gastric ulcer. We therefore evaluated the role of Helicobacter pylori and NSAIDs in inducing gastric ulcer.

METHODS

Dyspeptic patients receiving NSAIDs underwent endoscopic examination. Gastric ulcer formation and H. pylori status were investigated. Biopsy specimens from the antrum and lower body of the stomach were prepared for the rapid urease test and pathological evaluation. Anti-H. pylori antibody was measured by enzyme-linked immunosorbent assay.

RESULTS

Two hundred and twenty-six patients receiving NSAIDs (220 chronic and six on-demand users) underwent gastrofibrescopic examination. There were 110 patients with gastric ulcer and 111 non-ulcer patients with gastritis. The remaining five patients had neither. NSAID users with gastric ulcer showed a low prevalence of H. pylori compared with those without them [55/110 (50.0%) vs 79/111 (71.2%), P < 0.01]. The same tendency was seen when patients receiving low-dose aspirin and those with rheumatoid arthritis were analysed separately [13/29 (44.8%) vs 50/62 (80.6%), P < 0.01, and 11/33 (33.3%) vs 16/26 (61.5%), P < 0.06 with Yates' correction, respectively].

CONCLUSION

Helicobacter pylori infection appeared to be a risk factor for developing gastritis, but we found no evidence that it increases gastric ulcer formation in NSAID users with dyspepsia.

Characterization of the portal signal in a nonsteady hyperglycemic state in conscious dogs

To characterize the "portal signal" in a nonsteady hyperglycemic state, the kinetic relationship between net hepatic glucose balance (NHGB) and either hepatic glucose load (HGL) or plasma insulin level was determined during glucose infusion using a catheter technique in 36 conscious dogs. Glucose was infused intraportally (Po group) and peripherally (Pe group) at 39, 56, and 83 micromol x kg(-1) x min(-1) over 2 h. There was a linear relationship between mean NHGB and either mean HGL or plasma insulin levels at each rate in either delivery (HGL: Po r = 0.99, Pe r = 0.95; insulin: Po r = 99, Pe r = 0.79). The threshold levels for net hepatic glucose uptake were 3.8 and 11.7 mmol/l for plasma glucose and 65 and 392 pmol/l for plasma insulin, respectively. The slope of the regression line against the abscissa was four times larger in portal than in peripheral delivery (HGL: Po 0.20 vs. Pe 0.05, P < 0.05; insulin: Po 0.19 vs. Pe 0.04, P < 0.05). These results suggest that the portal signal overrules the threshold of glucose for hepatic uptake by increasing hepatic extraction rate in a nonsteady hyperglycemic state.

Alterations of quantitative EEG and mini-mental state examination in interferon-alpha-treated hepatitis C

We have recently observed a diffuse slowing of brain waves using serial quantitative electroencephalographic (qEEG) examinations in interferon (IFN)-alpha-treated chronic hepatitis C patients. However, it remains unclear how this alteration could be assessed. We evaluated the correlation between the qEEG changes and three tests of mental status, including the Mini-Mental State Examination (MMSE), in such patients. This is the first study to undertake a clinical evaluation of the adverse effects on brain function due to IFN. We undertook blind, prospective and serial qEEG examinations on 56 chronic hepatitis C patients at three independent hospitals. IFN-alpha was administered intramuscularly at a dose of 9 x 10(6) IU daily for the first 4 weeks and then 3 times/week for the next 20 weeks. Serial EEGs were obtained before, at 2 and 4 weeks of treatment, and after the IFN-alpha treatment. The absolute power values of each frequency band in each patient at different stages of treatment were recorded by qEEG. Each patient was assessed by the MMSE, Hamilton Rating Scale for Depression (HSD), and Hamilton Rating Scale for Anxiety (HSA). We statistically evaluated the correlations between the changes in power values and alterations of scores on the mental status tests during IFN-alpha treatment. The decreased scores observed on the MMSE ranged from 2 to 5 points at both 2 and 4 weeks of IFN-alpha treatment. There were no significant differences in age distribution for each decreased score on the MMSE. As the alteration in MMSE score during IFN treatment increased, the alteration in absolute power values for the slow waves during IFN treatment increased significantly, while that for the alpha 2 and fast waves during treatment decreased significantly. However, the changes in the HDS and HSA revealed no significant correlations. The alteration of the qEEG was reversible after the treatment. MMSE scores represent one screening method for the clinical assessment of IFN-alpha-induced alterations of brain function.

Comparison of insulinotrophic actions of nateglinide with glibenclamide dissociated from absorption in conscious dogs

Nateglinide is more rapidly absorbed than glibenclamide. Therefore, the different absorption kinetics of both drugs were eliminated by intraportal administration in conscious fasted dogs. The plasma insulin profiles were compared under similar kinetic changes in plasma drug concentrations. After a priming dose of nateglinide (1 mg/kg. 5 min) or glibenclamide (40 microg/kg. 5 min), plasma drug concentrations reached a peak at 4 minutes (nateglinide, 80 +/- 5 micromol/L, n = 6 and glibenclamide, 263 +/- 60 nmol/L, n = 6) followed by a sustained level at approximately 30% of the peak concentration at 30 minutes. Nateglinide led to a rapid and constant reduction in arterial glucose of approximately 30% basal, while glibenclamide promoted a gradual decrease to approximately 50% basal at 120 minutes. An increase in plasma insulin level by nateglinide of 4 times basal (218 +/- 58 pmol/L v 47 +/- 3 pmol/L, P <.05, n = 6) occurred at 6 to 10 minutes followed by sustained release of 1.4 times basal (67 +/- 15 pmol/L, n = 6). The insulin surge was more than doubled (484 +/- 209 pmol/L, n = 6) under a euglycemic clamp. Insulin release by glibenclamide increased gradually reaching 10-fold basal (449 +/- 166 pmol/L, n = 6) at 60 minutes. This was not enhanced during a euglycemic clamp. Lowering the primed doses of nateglinide resulted in a diminished peak plasma insulin concentration. In contrast, glibenclamide caused only a slower increase, but eventually reaching a similar peak. By increasing the continuous infusion of nateglinide, the sustained insulin release was not altered. Glibenclamide, but not nateglinide, evoked prompt and sustained insulin release in the continuing presence of the other. These results are consistent with the concept that nateglinide produces a quick, but very short-lived, interaction with sulfonylurea (SU)-receptors on plasma membrane by free access of the drug from the cell exterior. In contrast, glibenclamide promotes a slow and longer interaction with the receptor by distribution of the drug into the cell inferior. We conclude, therefore, that not only the different kinetics of gastrointestinal (GI) absorption, but also the inherent difference in the interaction with beta cells is attributed to the different insulin release characteristics between nateglinide and glibenclamide in vivo.

Circadian rhythm of melatonin and prostaglandin in modulation of stress-induced gastric mucosal lesions in rats

BACKGROUND

We previously demonstrated the circadian variation of water-immersion restraint stress (WRS)-induced gastric mucosal lesions in rats.

AIM

To investigate the roles of melatonin and prostaglandin in the gastric mucosa in circadian modulation of WRS.

METHODS

Fasted rats were subjected to 4-h WRS during both the diurnal and nocturnal phases of a light/dark cycle. Mucosal lesions, serum melatonin concentrations, mucosal generation of prostaglandin E2 (PGE2) and mucosal gene expressions of cyclooxygenase (COX)-1 and -2 were evaluated.

RESULTS

Lesion area after 4-h stress during the dark phase was significantly smaller than that in light-phase controls. Serum melatonin concentration in control rats during the light phase was significantly increased 4 h after WRS, but PGE2 generation was decreased by 48% as compared to that in intact mucosa before stress. In the dark phase, melatonin concentration after 4-h WRS was significantly depressed as compared with the control level at the corresponding time. PGE2 concentrations after 4-h WRS in the dark phase were not decreased compared with the control level at the corresponding time, although PGE2 level was significantly lower than that in light-phase controls. Expression of COX-1 and COX-2 mRNA was detected after exposure to stress in both the light and dark phases.

CONCLUSION

These results suggest that circadian rhythm has an important role in the formation of stress-induced gastric mucosal lesions in rats. The circadian rhythm of melatonin responses and PGE2 generation may contribute to nocturnal/diurnal rhythmicity of gastric mucosal defences between day and night.

Isotypes of rheumatoid factors in rheumatoid arthritis and chronic liver diseases

Abstract We studied isotype-specific rheumatoid factors (RFs) to clarify their significance in rheumatoid arthritis (RA) and to verify the difference in RF isotypes between RA and chronic liver diseases (CLD). Isotype-specific RFs in RA and in CLD were measured by enzyme-linked immunosorbent assay (ELISA). Most sera (n = 51, 94.1%) from RA patients contained some kind of RF isotypes (92.1% for IgM RF, 76.4% for IgG RF, and 43.1% for IgA RF), and seronegative RA by ELISA was seen in only 11.8% (n = 6). The most characteristic combination of RF isotypes in active RA was IgG, IgA, and IgM. This combination of RF isotypes changed to IgG plus IgM, according to the diminution of RA activity; then, we found only IgM RF in inactive RA. The titers of each RF isotype also decreased in parallel with the activity of RA. IgA RF seemed to be the most sensitive factor for evaluating the activity of RA. In CLD, almost the same high frequency (n = 49, 89.8% for IgM RF, 59.2% for IgG RF), with the same titer levels seen in RA, was observed. On the other hand, IgA RF was significantly lower in frequency (n = 9, 18.4%) and in titer, compared with the finding in RA. Surprisingly, even in CLD, true seronegativity by ELISA was also found in very few patients (n = 4, 8.1%). In CLD, positive RFs detected by agglutination assay were seen more often in chronic hepatitis than in liver cirrhosis. In RA patients, significant associations of IgA RF and the serum concentration of IgA, and IgG RF and the serum concentration of IgG, were observed. On the other hand, in CLD patients, significant associations of IgG RF and the serum IgG concentration, and of IgM RF and the serum IgM concentration, were observed. These results indicated that IgA RF in active RA is the most characteristic RF isotype distinguishing it from other nonrheumatic diseases, as well as from inactive RA. RF isotypes reflected the background polyclonal B-cell activation in different manners in both diseases. In CLD, RF isotypes seemed to be disease-related immunological disorders reflecting disease progression.

Characteristics of macrolide-resistant Mycoplasma pneumoniae strains isolated from patients and induced with erythromycin in vitro

Some patients with Mycoplasma pneumoniae infection are clinically resistant to antibiotics such as erythromycin, clarithromycin, or clindamycin. We isolated M. pneumoniae from such patients and found that one of three isolates showed a point mutation in the 23S rRNA gene. Furthermore, 141 EM-sensitive clinical isolates of M. pneumoniae were cultured in broth medium containing 100 microg/ml of erythromycin (EM). Among 11 EM-resistant strains that grew in the medium, point mutations in the 23S rRNA were found in 3 strains at A2063G, 5 strains at A2064G and 3 strains at A2064C. The relationship between the point mutation pattern of these EM-resistant strains and their resistance phenotypes to several macrolide antibiotics was investigated.

The participation of pharmacists in a team to introduce a clinical pathway to laparoscopic cystectomy in obstetrics and gynecology

In the Department of Obstetrics and Gynecology at our hospital, a team of doctors, pharmacists, nurses, and other medical staff was established to prepare a clinical pathway for laparoscopic cystectomy. Various data on clinical charts including the use of drugs were collected from 57 patients by pharmacists and nurses. Based on the analysis of these data, hospitalization period, method of preoperative bowel preparation, time to initiation of food intake, duration of antibiotic administration, and time and content of pharmaceutical instructions to patients of dosage and administration were determined. Criteria for variances requiring the doctor's directions were determined for fever, wound pain, and vomiting. The clinical pathway established here allows of not only the efficient and uniform care of patients, but also the active exchange of opinions among members of the medical team. Moreover, most patients who replied to a questionnaire said that they were at ease during hospitalization because they had received detailed information about the clinical pathway including the use of drugs before surgery. Thus, the participation of pharmacists on a medical team that is introducing a clinical pathway is particularly important because the use of drugs and pharmaceutical care are an important part of good patient care.

Nationwide survey shows that methicillin-resistant Staphylococcus aureus strains heterogeneously and intermediately resistant to vancomycin are not disseminated throughout Japanese hospitals

A total of 6,625 methicillin-resistant Staphylococcus aureus (MRSA) clinical isolates obtained from 278 hospitals throughout Japan were obtained between November and December 1997 and were examined for their sensitivities to vancomycin using Mueller Hinton (MH), brain heart infusion (BHI), agar plates, or the broth microdilution method. A concentrated inoculum of an MRSA strain or the use of highly enriched medium, such as BHI medium, allows an individual cell to grow on agar plates containing a vancomycin concentration greater than the MIC for the parent strain. However, cells of the colonies which grew on BHI agar plates containing the higher vancomycin concentrations did not acquire a level of vancomycin resistance greater than that of the parent strain and were not subpopulations of heterogeneously vancomycin-resistant MRSA. There was no significance in the fact that these colonies grew on the higher concentration of vancomycin: none showed stable resistance to vancomycin at a concentration above the MIC for the parent strain, and no cell from these colonies showed a relationship between the MIC and the ability of these colonies to grow on higher concentrations of vancomycin. The vancomycin MIC was not above 2 microg/ml for any of the cells originating from these colonies. No Mu3-type heterogeneously resistant MRSA strains, which constitutively produce subpopulations from MRSA clinical isolates with intermediate vancomycin resistance at a high frequency, were detected. There was a unipolar distribution of the MICs ranging from 0.25 to 2 microg of vancomycin/ml among the 6,625 MRSA clinical isolates, indicating that there was no Mu50-type intermediately vancomycin-resistant MRSA (MIC, 8 microg/ml by National Committee for Clinical Laboratory Standards criteria) among the clinical isolates, and there was no evidence of dissemination of Mu3-type MRSA heteroresistant to vancomycin.

Preparation and clinical application of 2% diflunisal oral ointment for painful lesions of the oral mucosa

We previously reported the development and clinical efficacy of a 2% aspirin oral ointment and 2% ethenzamide oral ointment as hospital preparations for painful lesions of the oral mucosa. This study investigated methods of preparing a more stable oral ointment with a more effective analgesic action, using diflunisal, another salicylic acid derivative, with an analgesic effect stronger than that of aspirin. A two-percent diflunisal oral ointment was prepared similarly to the aspirin ointment using plastibase and CMC-Na as the ointment base. From the results of spreadability measurement, a CMC-Na content of 20% was considered appropriate. The stability of diflunisal in 2% diflunisal oral ointment stored at 5 degrees C, 20 degrees C and 30 degrees C, was determined using HPLC, and a high stability of diflunisal at room temperature for more than 100 days was confirmed. We also investigated its antinociceptive effect using the Randall-Selitto paw pressure test in rats, which showed that 2% diflunisal oral ointment was as effective as 2% aspirin oral ointment. On clinical application of 2% diflunisal oral ointment to 8 patients with painful oral mucous diseases, it was found to be significantly (p = 0.014) more effective than 2% aspirin oral ointment. The results of this study demonstrated that 2% diflunisal oral ointment is a clinically useful analgesic for painful oral lesions.

Nucleotide sequence of the precore/core gene and X gene of hepatitis B virus DNA in asymptomatic hepatitis B virus carriers who are negative for serum hepatitis B core antibody

A hepatitis B virus (HBV) carrier who is positive for hepatitis B surface (HBs) antigen but negative for hepatitis B core (HBc) antibody despite persistent HBV infection, is designated as having hepatitis B virus 2 (HBV2). HBV2 is reported to be induced by mild-grade hepatitis. Patients with HBV2 have been reported in Taiwan and Senegal. In the present study, we determined the nucleotide (nt) sequence of the precore/core gene coding region and X gene region of the HBV DNA sequence in 7 subjects who were positive for HBs antigen and negative for HBc antibody. HBV DNA was detected by nested polymerase chain reaction (PCR). Nested PCR was carried out to amplify the precore/core and X open reading frames (ORFs) of HBV DNA. The second PCR products were sequenced, followed by investigation of nt homology. There were no deletions nor insertions in the nt sequence of the precore/core and X ORFs in the HBV DNA of these 7 patients, and mutations were found only sporadically in the 7 patients. Also, there were no common amino acid substitutions in the examined regions of the amino acid sequence of HBV in the 7 patients, and we could not find a common mutation in the examined regions of HBV DNA that could potentially contribute to the development of negativity for HBc antibody. Thus, it is suggested that negativity for HBc antibody in patients with HBV2 is due to an immune response abnormality in the host.

Homozygous deletion of INK4a/ARF genes and overexpression of bcl-2 in relation with poor prognosis in immunocompetent patients with primary central nervous system lymphoma of the diffuse large B-cell type

Only a few reports have been published on molecular genetic alterations in primary central nervous system lymphomas (PCNSLs) of the diffuse large B-cell type and no reports have addressed the correlation between the genetic alterations and clinical course of the patients with this neoplasm. Thus, the molecular background of the PCNSL and its importance for the clinical course of the patients are still unclear. We investigated a series of 14 patients with PCNSL to determine structural alterations of the INK4a/ARF, MDM2, and TP53 genes, the status of bcl-2 and bcl-6 protein expression, and the clinical course of the patients (i.e. their survival time after diagnosis). No structural alterations of MDM2 and TP53 genes were found. Only INK4a/ARF genes whose expression affects both the p161NK4a-Rb and p14ARF-mdm2-p53 pathways in the regulation for cell cycle and apoptosis, showed an alteration of the homozygous deletions at a high frequency (nine of 14 patients: 64%). This specific alteration was not related with the bcl-6 expression, but a relation was shown with overexpression of the bcl-2 anti-apoptotic protein (p = 0.036, chi-square test), as well as a shorter patient survival (p = 0.044, Wilcoxon test). There was only a tendency, not a significant correlation, in which the patients with bcl-2 overexpression resulted in poor prognosis (p = 0.149). The present study is the first to suggest that the INK4a/ARF gene homozygous deletions and overexpression of the bcl-2 protein may be correlated with each other and together serve as important predictors for the prognosis of patients with PCNSL.

Quality control of diphtheria tetanus acellular pertussis combined (DTaP) vaccines in Japan

Diphtheria tetanus acellular pertussis combined (DTaP) vaccines have been successfully used in Japan by controlling their potencies and toxicities with animal models. In accordance with the recent practical introduction of DTaP vaccines of various formulations, a question has been raised in other nations as to the efficacy of a quality control system based on animal tests and standard preparations. The World Health Organization issued its guidelines on the production and quality control of acellular pertussis vaccines in 1998 along with the concept of quality control by ensuring that production lots were consistent with clinical trial lots, rather than by comparing them with standard preparations in traditional laboratory tests. However, because it is not feasible to evaluate the combined use of vaccines from different manufacturers in a clinical study, the alternative trend of quality control may give rise to a difficulty in rationalizing the practical immunizations to use vaccines of different brands in a mixed consequence. A standardized national regulation system to ensure the equivalence of approved products would be essential for such an immunization practice. The success of the Japanese DTaP vaccination suggests the possibility of an effective quality control of DTaP vaccines by means of standardized test systems.