Basic assessment on adding platelet measurement to legal health checkup in Japan: A cross-sectional and 20-year longitudinal study

Background

In Japan, health checkups for workers are legally compulsory. Considering legal health checkup items are important for Japanese workers' health problems. To date, the legal health checkup items for blood cell counts include only red blood cell counts and hemoglobin but not platelet counts. This study aimed to investigate the significance of measuring platelets in workers by showing the association between the FIB-4 index (FIB-4), which can be easily calculated from factors including platelet counts and viral hepatitis infection.

Method

Both cross-sectional and longitudinal analyses were conducted on the comprehensive medical examinations of male workers. In fiscal year (FY) 2019, a logistic regression model was applied to 12,918 examinees. For 13,459 examinees (mean age = 47.5 ± 9.3 SD), FY2000 was set to be followed until FY2019. A total of 149,956 records between FY2000 and FY2019 were analyzed cross-sectionally, and 8,038 men who were consecutively examined to FY2019 at the longest were analyzed longitudinally. Receiver operating characteristic (ROC) curve–area under the ROC curve (ROC–AUC) and Cox proportional methods were used to examine the association between platelet-related indices and viral hepatitis infection.

Results

Logistic regression showed that the risk of FIB-4 ≥ 2.67 was mostly associated with hepatitis C virus antibody (HCVAb) positivity [odds ratio (OR) = 2.51, 95% confidence interval (CI) = 1.08–5.86], while negatively associated with body mass index (BMI) (OR = 0.54, 95% CI = 0.30–0.97), and not associated with the presence of fatty liver. To detect HVC Ab positivity, ROC–AUC showed more effectiveness in FIB-4 than in the AST/ALT ratio (0.776, 95% CI = 0.747–0.773 vs. 0.552; 95% CI = 0.543–0.561). The Cox analysis showed that the risk of FIB-4 ≥ 2.67 was closely associated with hepatitis B virus surface antigen (HBsAg) [hazard ratio (HR) = 3.1, 95% CI = 2.0–4.6] and HCV Ab positivity (HR = 3.2, 95% CI = 2.0–5.0).

Conclusion

Our results suggest that it might be worth considering that usage of information on platelets in legal health checkups could be some help not to overlook workers with hepatitis virus carriers as a complementary countermeasure, although further investigations are needed into its practical application.

Significance of Fib4 index as an indicator of alcoholic hepatotoxicity in health examinations among Japanese male workers: a cross-sectional and retrospectively longitudinal study

BACKGROUND

Fib4 index (Fib4) is clinically used as a noninvasive marker of liver fibrosis. In this study, we aimed to preliminarily investigate whether Fib4 can be used to detect individuals who need assessment for alcoholic liver disease (ALD) in the general population by clarifying the detailed association of Fib4 with alcohol consumption and gamma-glutamyl transferase (GGT) among male workers.

METHODS

We analyzed data sets on the comprehensive medical examinations of male workers as cross-sectional and retrospectively longitudinal studies. We enrolled 10 782 males (mean age: 52.2 ± 10.2 years) in FY2019 and 7845 males (mean follow-up: 12.6 ± 6.7 years) who could be consecutively followed up for 20 years from FY2000 to FY2019. Data were evaluated using logistic regression and COX proportional analysis.

RESULTS

In the cross-sectional setting, the rate of Fib4 ≥ 2.67 in heavy drinkers (≥ 40 g of ethanol/day) was increased dose dependently in those over 65 years old, and that of body mass index ≥ 30 kg/m² was increased in those over 60 years old, but not in those with fatty liver. The odds ratio (OR) (95% confidence interval [CI]) for heavy drinking was 4.30 (95% CI = 1.90-9.72), and GGT ≥ 200 IU/L was considerably high (OR = 29.05 [95% CI = 17.03-49.56]). In the longitudinal setting, heavy drinkers and those with GGT ≥ 200 IU/L at 10 years after the baseline showed an increased risk for Fib4 ≥ 2.67 (hazard ratio = 2.17 [95% CI = 1.58-2.98] and 7.65 [95% CI 5.26-11.12], respectively).

CONCLUSIONS

The development of Fib4 ≥ 2.67 after 10 years was associated with heavy alcohol drinking and GGT level ≥ 200 IU/L. Therefore, Fib4 combined with GGT could indicate high risk of ALD. However, clinical examinations and course observations are essentially needed.

Efficacy and Safety of Ramucirumab in Patients with Unresectable Hepatocellular Carcinoma with Progression after Treatment with Lenvatinib

Objective A survival benefit was demonstrated for ramucirumab (RAM) in patients with unresectable hepatocellular carcinoma (uHCC) and α-fetoprotein (AFP) concentrations ≥400 ng/mL who had previously received sorafenib (SOR). However, it is unclear whether RAM has a similar efficacy in patients with uHCC that progresses after lenvatinib (LEN) treatment. This study aimed to evaluate the early anti-tumor response to RAM as a second-line treatment for advanced uHCC after LEN treatment. Methods We retrospectively assessed the efficacy and safety of RAM at 6 weeks after initiation. The therapeutic effects were evaluated according to the Response Evaluation Criteria in Solid Tumors version 1.1. Patients We evaluated 7 patients with uHCC who received RAM as a second- or third-line treatment after LEN failure. Results The disease control rate (DCR) was 28.6% (2 of 7 patients). After the initiation of RAM, a rapid disease progression resulted in 1 patient death after 19 days. The median progression-free survival (PFS) was 41 days. There were no grade 3 or 4 treatment-related adverse events. At 6 weeks, there was no deterioration in the modified albumin-bilirubin (mALBI) grade. In patients with an imaging response of stable disease (SD), the rate of AFP production decreased from the baseline. Conclusion RAM may have a therapeutic potential for the suppression of uHCC progression in patients previously treated with LEN, as well as for maintaining the liver function during treatment. Evaluating the AFP trends may therefore be useful for predicting RAM effectiveness.

Lenvatinib-Transarterial Chemoembolization Sequential Therapy as an Effective Treatment at Progression during Lenvatinib Therapy for Advanced Hepatocellular Carcinoma

BACKGROUND

The aims of this study were to evaluate the efficacy of additional treatment, especially lenvatinib-transarterial chemoembolization (TACE) sequential therapy, for unresectable hepatocellular carcinoma (HCC).

METHODS

Consecutive 56 patients who underwent lenvatinib treatment were reviewed. Oncological aggressiveness of tumor was estimated using a dynamic CT enhancement pattern classification, and clinical impact of subsequent treatment was investigated through analysis of progression-free survival (PFS), post-progression survival (PPS), and multivariate analysis of potential confounders for survival after progression during lenvatinib therapy.

RESULTS

Heterogeneous enhancement patterns (Type-3 and -4), which are reportedly associated with higher oncological aggressiveness of HCC, were associated with better objective response to lenvatinib compared to homogeneous enhancement pattern (Type-2) (86 and 85% vs. 53% in modified Response Evaluation Criteria in Solid Tumors), resulting in similar PFS (p = 0.313). Because of significantly worse PPS, overall survival of Type-4 tumor was poor compared to Type-2 or -3 tumors (p = 0.009). However, subgroup of patients who achieved subsequent treatment showed significantly better PPS, regardless of CT enhancement pattern. Multivariate analysis confirmed that use of lenvatinib-TACE sequential treatment after progression during lenvatinib therapy was associated with better PPS (hazard ratio [HR], 0.08; 95% CI, 0.01-0.71; p = 0.023), while Type-4 enhancement pattern was correlated with worse PPS (HR, 2.92; 95% CI, 1.06-8.05; p = 0.039).

CONCLUSION

Oncological aggressiveness of HCC estimated by CT enhancement pattern was predictive of PPS after progression during lenvatinib. Successful subsequent treatment with lenvatinib-TACE sequential therapy may offer survival benefit regardless of CT enhancement pattern of HCC.

Non-invasive predictors of prognosis of Asian patients with histopathologically-confirmed lean nonalcoholic fatty liver disease

BACKGROUND

The prognostic factors of morbidity and mortality in patients with lean NAFLD (body mass index < 25.0 kg/m2) are unknown.

METHODS

In this retrospective study, 446 Japanese patients with histopathologically-confirmed NAFLD (lean NAFLD, n = 170) were followed for liver events, cardiovascular events, type 2 diabetes mellitus, and non-liver malignancies. The median observation period was 4.6 years. We also investigated the predictors of severe fibrosis (stage 3-4) and mortality in lean NAFLD patients.

RESULTS

Glycolipid metabolic markers, liver function tests, NAFLD fibrosis score (NFS), and histological scoring were significantly lower in lean NAFLD patients than in non-lean NAFLD. The incidence of liver cancer was higher while that of T2DM was lower in lean NAFLD. Kaplan-Meier analysis showed no significant difference in overall survival between the lean and non-lean NAFLD. Multivariate analysis of data of lean NAFLD identified NFS ≥ - 1.455 as significant independent predictor of severe fibrosis, while history of liver cancer and NFS ≥ - 1.455 were predictors of overall survival.

CONCLUSIONS

Although patients with lean NAFLD have better histopathological and biochemical profile compared to patients with non-lean NAFLD, the prognosis is not different between the two groups. Lean NAFLD patients with NFS ≥ - 1.455 or history of liver cancer should be monitored carefully during follow-up.

Diagnosis and Resection Treatment of Triplet Hepatocellular Carcinomas with a non-B non-C Background in a Middle Aged Man over a Period of 6-years

We report a 71-year-old man with non-B non-C chronic liver damage who had been regularly visiting our hospital since he was 38 years of age. He underwent three partial hepatectomies for hepatocellular carcinoma (HCC) diagnosed at 65, 67, and 71 years of age, respectively. A histopathological examination showed moderately-differentiated HCC, and chronic hepatitis with mild fibrosis stage in non-tumor areas. alpha-fetoprotein (AFP) and PIVKAII were not useful for the early prediction of HCC, but TERT promotor mutation (C228T) in serum cell-free DNA was useful. This is the first report on the importance of long-term follow-up in non-B non-C chronic liver damage, regardless of the fibrosis stage.

Pretreatment Heterogeneous Enhancement Pattern of Hepatocellular Carcinoma May Be a Useful New Predictor of Early Response to Lenvatinib and Overall Prognosis

OBJECTIVE

The aim of this study was to evaluate the performance of pretreatment computed tomography (CT) enhancement of hepatocellular carcinoma (HCC) as a potential predictor of response to lenvatinib and its relevance to survival outcomes.

METHODS

We evaluated 51 consecutive patients who received lenvatinib treatment for unresectable HCC. On imaging analysis, pretreatment arterial/portal phase dynamic CT images were classified as follows: type 2, homogeneous enhancement pattern with increased arterial blood flow; type 3, heterogeneous enhancement pattern with a septum-like structure; and type 4, heterogeneous enhancement pattern with irregularly shaped ring structures. Treatment response was evaluated using modified Response Evaluation Criteria in Solid Tumors at 2-12 weeks after initiation of lenvatinib, and the correlations between the CT enhancement patterns and response to lenvatinib or survival outcomes were investigated.

RESULTS

Of the 51 patients, 38 (75%) experienced an objective response (OR). ORs were significantly more common in heterogeneously enhanced HCC (types 3 and 4) than in homogeneous HCC (type 2) (83 vs. 53%, respectively; p = 0.037). Multivariate analysis revealed that pretreatment heterogeneous enhancement pattern is an independent predictor for response to lenvatinib (odds ratio, 4.75; p = 0.042). Presence of OR was associated with longer progression-free survival (PFS) (hazard ratio, 0.36; p = 0.017), and patients with oncologically aggressive type 3 and 4 tumors showed similar PFS to those harboring type 2 tumors (p = 0.455), reflecting that OR was more common in type 3 or 4 tumors compared with type 2 tumors. Although postprogression survival was extremely poor in patients with type 4 tumors (p = 0.064), overall survival after introduction of lenvatinib was not statistically different among the three groups of patients (p = 0.053).

CONCLUSION

The CT enhancement pattern of HCC may predict response to lenvatinib. OR seems to occur more frequently in HCC with oncologically aggressive features and may contribute to prolonged survival through a prolonged progression-free interval, even in an oncologically poor-risk group of patients.

18F-Fluorodeoxyglucose Uptake in Hepatocellular Carcinoma as a Useful Predictor of an Extremely Rapid Response to Lenvatinib

BACKGROUND AND AIMS

This study aimed to identify the utility of ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG-PET/CT) as a predictor of the response of hepatocellular carcinoma (HCC) to lenvatinib.

METHODS

We evaluated 28 consecutive patients with HCC diagnosed by dynamic CT or magnetic resonance imaging combined with ¹⁸F-FDG-PET/CT. The tumor-to-normal liver standardized uptake value ratio (TLR) of the target tumor was measured before treatment using ¹⁸F-FDG-PET/CT, with a TLR ≥2 classified as a high potential for malignant HCC. The treatment response was evaluated 2 weeks after the initiation of lenvatinib using modified Response Evaluation Criteria in Solid Tumors.

RESULTS

Of the 28 patients, 12 (43%) presented with a TLR ≥2. Evaluation of the treatment response at 2 weeks in these 12 patients revealed that 2 (17%) exhibited a complete response, 8 (67%) a partial response, 2 (17%) stable disease, and none with progressive disease. Therefore, 10 of the 12 patients (83%) experienced an objective response to lenvatinib. On the other hand, 7 of the 16 patients with a TLR <2 (44%) experienced an objective response. Thus, the objective response rate was higher in patients with a TLR ≥2 than in those with a TLR <2. Multivariate logistic regression analysis revealed that a TLR ≥2 (odds ratio 10.53; p = 0.028) is a useful predictor of an early objective response at 2 weeks.

CONCLUSION

Patients with unresectable HCC showed a good early treatment response to lenvatinib. High TLR (≥2) may be a useful predictor of an extremely rapid treatment response.

Fulminant Hepatitis due to de novo Hepatitis B after Cord Blood Transplantation Rescued by Medical Treatment

A 53-year-old man presented with fulminant hepatitis due to de novo hepatitis B. He had been diagnosed previously with adult T-cell leukemia (ATL) and previously resolved hepatitis B virus infection. The ATL had been treated with cord blood transplantation (CBT). He developed fulminant hepatitis 18 months after CBT, 15 months after the withdrawal of immunosuppressants, and 10 months after vitreous injections of methotrexate for ATL-related retinal infiltration. The aggressive medical protocol included entecavir, prednisolone, plasma exchange, hemodialysis, and bilirubin adsorption. We herein report successful medical treatment for fulminant de novo hepatitis B in a patient considered unsuitable for liver transplantation.

Real-world effects of long-term rifaximin treatment for Japanese patients with hepatic encephalopathy

AIM

Rifaximin (RFX) improves hepatic encephalopathy (HE). However, information on long-term treatment with RFX is limited. In this study, we aimed to investigate the effect of long-term treatment with RFX on HE and liver function. Moreover, we investigated factors associated with the recurrence of HE under RFX treatment.

METHODS

In this retrospective cohort study, we consecutively enrolled 65 patients with HE who initiated RFX treatment (1200 mg/day) in our hospital from January 2017 to June 2018. We evaluated liver function test results, including blood ammonia levels, and the recurrence rate of HE after RFX treatment.

RESULTS

The median follow-up duration was 41.6 weeks (range, 1.4-96.7 weeks). The blood ammonia level significantly declined from 157 to 86 μg/dL at 4 weeks after RFX treatment (P < 0.01), and the effect was prolonged. Furthermore, Child-Pugh score decreased in 51% (26/51) of the patients at 12 weeks during RFX treatment. The recurrence rate of HE after RFX treatment was 26.2% (17/65), and presence of ascites at baseline was identified as the only independent risk factor for HE recurrence (hazard ratio 4.71; 95% confidence interval, 1.27-17.5; P = 0.02). The cumulative recurrence rate of HE was significantly lower in patients without ascites than in patients with ascites at baseline (13.8% vs. 50.8%, P = 0.001).

CONCLUSIONS

Long-term treatment with RFX was beneficial for HE and liver function in patients with HE. Furthermore, the recurrence rate of HE was low in RFX-treated patients without ascites. Thus, long-term treatment with RFX could be effective for the management of Japanese patients with HE.

Role of NS5A-L31/Y93 Double Wild-type in Failure of Glecaprevir/Pibrentasvir Double Therapy in Two Patients with a History of Direct-acting Antiviral Agent Failure: An Ultra-deep Sequencing Analysis

We experienced two cases of hepatitis C virus (HCV) eradication failure in patients with a history of non-responsiveness to previous treatments with direct-acting antiviral agents (DAAs) who were subsequently treated with the combination of glecaprevir and pibrentasvir (GLE/PIB). Direct sequencing at commencement of GLE/PIB therapy showed non-structural protein (NS) 5A-P32 deletion in the first patient and NS5A-R30E/Q54H/A92K in the second patient (both genotype 1b). The common point was that L31/Y93 was double wild-type, and the IL28B polymorphism was non-TT type. Even when L31/Y93 is double wild-type, other NS5A mutations may affect the DAA re-treatment outcome. We analyzed the transition of amino acid mutations at NS5A by ultra-deep sequencing.

The Lack of Hepatocyte Steatosis in Adult-onset Type II Citrullinemia Patients as Assessed by 7-year Interval Paired Biopsies

Adult-onset type II citrullinemia (CTLN2) is a urea cycle disease characterized by neurological and psychiatric abnormalities associated with hyperammonemia. One of the pathological features of CTLN2 is the presence of hepatocyte steatosis. The condition progresses in almost all CTLN2 patients to nonalcoholic fatty liver disease (NAFLD). We herein report a 74-year-old woman who developed CTLN2 without hepatocyte steatosis. The diagnosis was based on clinical and laboratory findings and confirmed by two liver biopsies conducted within 7 years, as well as by a DNA analysis, which demonstrated mutations in the SLC25A13 gene. We describe a rare CTLN2 case without hepatocyte steatosis in an elderly woman who responded well to a low-carbohydrate diet.

No-touch ablation in hepatocellular carcinoma has the potential to prevent intrasubsegmental recurrence to the same degree as surgical resection

AIM

The aim of this study was to clarify the utility of a no-touch pincer ablation procedure that uses bipolar electrodes to prevent intrasubsegmental tumor recurrence after radiofrequency ablation (RFA) for patients with hepatocellular carcinoma (HCC) compared to surgical resection.

METHODS

We evaluated 175 consecutive patients with HCC (single nodule, tumor diameter ≤ 30 mm) who underwent surgical resection (146 received partial resection) and 313 patients who received RFA; 277 patients received touch ablation using a monopolar or bipolar RFA device, and 36 received no-touch ablation using a bipolar RFA device. Pretreatment arterial and portal phase dynamic computed tomography (CT) or magnetic resonance imaging (MRI) images were classified into four enhancement patterns: Type 1 and Type 2 are homogeneous enhancement patterns without or with increased arterial blood flow, respectively; Type 3 is a heterogeneous enhancement pattern with a septum-like structure; and Type 4 is an irregularly shaped ring structure enhancement pattern.

RESULTS

Cumulative recurrence rates significantly differed between procedures (surgical resection, 7.5%; no-touch ablation, 2.9%; and touch ablation, 17.7% at the third year; P = 0.005). Multivariate Cox proportional hazards analysis revealed that enhancement pattern type (Type 3: hazard ratio [HR], 2.95; P = 0.002; and Type 4: HR, 3.88, P = 0.002), treatment procedure (touch ablation: HR, 3.36; P < 0.001), and serum α-fetoprotein level (≥30 μg/L: HR, 1.87; P = 0.009) were significant predictors of intrasubsegmental recurrence. No significant differences between no-touch ablation and surgical resection were observed.

CONCLUSION

The no-touch pincer ablation procedure has the potential to prevent intrasubsegmental recurrence after RFA for patients with HCC to the same degree as partial resection.

Trends in the quality assurance process indicators for Japanese colorectal cancer screening during 2003-13

Background

Recently, the importance of quality assurance (QA) for cancer screening has gained increasing attention in Japan. This study aimed to evaluate QA process indicators for population-based colorectal cancer screening during 2003-13.

Methods

A national cancer screening database was used to evaluate the following process indicators: the positivity rate, diagnostic follow-up rate, unidentified results rate, non-compliance with diagnostic follow-up rate, cancer detection rate and positive predictive value (PPV).

Results

The positivity rate remained constant at 6.5% until 2011, and then increased slightly thereafter. During 2003-13, the cancer detection rate increased from 0.15% to 0.21%, and the PPV increased from 2.2% to 3.1%. Although the diagnostic follow-up rate increased from 58% to 67%, the non-compliance with diagnostic follow-up rate decreased from 24% to 16% and the unidentified results rate decreased from 18% to 17%.

Conclusions

During the study period, the QA process indicators for colorectal cancer screening in Japan generally improved. However, the recent increase in the positivity rate requires careful observation. Innovative solutions are needed to increase the diagnostic follow-up rate.

Multifocal granulomatous jejunitis associated with an argyrophilic gram-positive segmented filamentous bacterium in a Holstein cow

Multifocal, raised, ulcerated firm nodules accompanied by an intussuscepted area were detected in the jejunum of an 8-year-old Holstein cow. The cut surfaces of the nodules were yellow-white. Microscopically, the lamina propria was expanded by an intense infiltration of epithelioid cells, multinucleate giant cells, macrophages, lymphocytes and neutrophils. Numerous bacteria were found within the granulomatous lesions. These were argyrophilic, gram-positive, periodic acid-Schiff-positive, segmented, rarely branched, elongate filamentous bacteria (2-28 μm in length, 0.2-0.35 μm in diameter). Ultrastructurally, a cell wall with an electron-transparent zone was detected. The present pathogen was clearly different from the argyrophilic, gram-negative, non-segmented, filamentous bacterium previously reported in a Holstein cow with jejunal granuloma. Comparative 16S rDNA gene sequencing analysis revealed that the organism was an unpublished species (GenBank accession number AB539875). This is the first report of bovine jejunal granuloma associated with an argyrophilic gram-positive segmented filamentous bacterium.

Lawsonia intracellularis and virulent Rhodococcus equi infection in a thoroughbred colt

A 26-month-old thoroughbred colt with a 4-month history of continuous diarrhoea and weight loss was subject to necropsy examination. The small intestinal mucosa was thickened and this change particularly affected the terminal ileum. Microscopical examination revealed multifocal epithelial hyperplasia, with multifocal granulomas and marked lymphocytic infiltration of the lamina propria. Numerous gram-negative argyrophilic curved bacilli were observed within the cytoplasm of affected enterocytes. Macrophages and epithelioid cells forming the granulomas had abundant, lightly eosinophilic, foamy cytoplasm, with occasional large, clear vacuoles containing gram-positive coccobacilli. Immunohistochemical studies suggested that the argyrophilic bacilli were Lawsonia intracellularis and the gram-positive coccobacilli were Rhodococcus equi. L. intracellularis-specific DNA fragments were amplified from the affected ileocaecal mucosa by polymerase chain reaction. Virulent R. equi (VapA positive) was isolated in pure culture from the liver and mesenteric lymph nodes. These results suggested that the two intracytoplasmic organisms had induced multifocal proliferative and granulomatous enteritis accompanied by severe and extensive lymphocytic infiltration.

Enzymatic degradation of atactic poly(R,S-3-hydroxybutyrate) induced by amorphous polymers and the enzymatic degradation temperature window of an amorphous polymer system

The phase structure and biodegradability were investigated for amorphous blends of chemosynthetic fully amorphous atactic poly(R,S-3-hydroxybutyrate) (a-PHB) with atactic poly(methyl methacrylate) (PMMA) and atactic poly(R,S-lactide) (a-PLA). The differential scanning calorimetry thermal analysis indicated that a-PHB/PMMA blends were partially miscible while a-PHB/a-PLA blends were miscible in the studied composition range. The biodegradations of the blends were carried out in phosphate buffer solution in the presence of bacterial poly(R-3-hydroxybutyrate) extracellular depolymerases purified from Alcaligenes faecalis T1 and P. stutzeri. Although a-PHB in the pure state was not degraded by these depolymerase, it was degraded by blending with PMMA and a-PLA. The results demonstrated that the enzymatic degradation of a-PHB can be induced by amorphous polymers such as PMMA and a-PLA. Also, the biodegradation rate of a-PHB in the blends decreased drastically when the degradation temperature is too much away from the polymer glass transition temperatures. On the basis of these results, a temperature window of the enzymatic degradation was first proposed for the blend and the essence of induced degradation was discussed.

Identification of a marine benthic P(3HB)-degrading bacterium isolate and characterization of its P(3HB) depolymerase

A poly[(R)-3-hydroxybutyrate] (P(3HB))-degrading marine bacterium (strain NK-1, JCM10458) was isolated from the Pacific Ocean deep-sea floor (1165 m in depth) in Japan. The organism was a motile and Gram negative, aerobic, and rod-shaped bacterium, and its DNA had a guanine-plus-cytosine content of 57.7 mol%. On the basis of several phenotypic characters and a phylogenetic analysis of the gene coding for 16S rRNA, this strain was identified as Marinobacter sp. The strain required sodium salt for growth in the medium and secreted a P(3HB) depolymerase into the supernatant when it was cultivated on (S)-3-hydroxybutyric acid or P(3HB) as the sole carbon source. The P(3HB) depolymerase (PhaZMsp) was purified to homogeneity from the culture supernatant of Marinobacter sp. by hydrophobic and ion exchange column chromatography and showed a molecular mass of 70 kDa. PhaZMsp was stable at temperatures below 37 degrees C and at pH values of 7.5-10.0. The N-terminal amino acid sequences of both the purified enzyme and the truncated one shared high homologies to the N-terminal and internal sequences of Pseudomonas stutzeri depolymerase, respectively. High-performance liquid chromatography analysis revealed that the enzymatic products of P(3HB) yielded monomer, dimer, and trimer of 3-hydroxybutyric acid. PhaZMsp was capable of hydrolyzing P(3HB), poly(3-hydroxypropionate), and poly(4-hydroxybutyrate).

Function of the catalytic domain of poly(3-hydroxybutyrate) depolymerase from Pseudomonas stutzeri

The mechanism of enzymatic hydrolysis for (R)-3-hydroxybutyrate (3HB) oligomers with poly[(R)-3-hydroxybutyrate] [P(3HB)] depolymerase (PhaZpst) from Pseudomonas stutzeri was investigated by two deletion mutants lacking the substrate-binding domain and linker region, PhaZpst delta sbd and PhaZpstcore. The two deletion mutants had no ability for hydrolysis of water-insoluble P(3HB), while the hydrolysis activities of two deletion mutants for water-soluble 3HB oligomer and its derivatives (dimer, trimer, and tetramer) were identical with those of the wild type, indicating that the function of catalytic domain is independent of its substrate-binding domain and linker region. The hydrolyzed products analysis of 3HB oligomers by HPLC showed that the active site of catalytic domain recognizes at least two 3HB units for hydrolysis. The initial rates of hydrolysis of dimer derivative were lower by 2 orders of magnitude than those of trimer and tetramer derivatives, suggesting that 3HB oligomer derivatives larger than trimer are favorite substrates for PhaZpst.

Is frozen section effective for diagnosis of unsuspected gallbladder cancer during laparoscopic cholecystectomy?

BACKGROUND

Although frozen section is recommended to prevent tumor dissemination following laparoscopic cholecystectomy (LC) for unsuspected gallbladder cancer, there are no reports concretely demonstrating its effectiveness and outcome.

METHODS

Frozen section during LC was performed in 990 patients with gallstones. The sensitivity, specificity of frozen section, and false-negative cases were evaluated in comparison with postoperative entire cross sections.

RESULTS

In frozen section, 983 cases were diagnosed as benign and 7 cases as malignant. Of the benign cases, cancer was discovered in 4 patients postoperatively in which frozen section was diagnosed as regenerative epithelial severe atypia. Sensitivity was 64% and specificity was 100%. Concerning the results of frozen section by p-TNM classification, cancer was diagnosed in 40% of Tis lesions, whereas it was found in 83% of T2 or T3 lesions.

CONCLUSION

Frozen section is effective in cases with T2 or greater lesions for which conversion to radical surgery should be required.

Dye-staining stereomicroscopic examinations for fine mucosal structures of the gallbladder

BACKGROUND

In order to diagnose an unsuspected gallbladder carcinoma and to examine whether a differential diagnosis could be made between cancer and noncancerous lesions during surgery, we evaluated the findings of fine structures of various types of gallbladder mucosa.

METHODS

We used stereomicroscopy with a dye-contrast technique under water and measured the maximum blood vessel diameters of the gallbladder mucosa: normal gallbladder, chronic cholecystitis, and carcinoma.

RESULTS

All normal gallbladders showed fine-reticular-type findings. In chronic cholecystitis, 5.8% of the specimens (n = 69) had fine reticular type, 87.0% had rough reticular type, and 7.2% had atrophic type. All the cases of adenomyomatosis (n = 16) showed rough reticular type. In eight specimens of pancreaticobiliary maljunction, 75% of them showed high reticular type, and the other 25% showed papillary type. The two adenoma specimens showed fine granular type. In five gallbladder carcinomas, the lattice-like pattern completely disappeared and showed rough granular type. The average of maximum vessel diameters in the gallbladder mucosa were 41.0 microm in normal gallbladders, 99.1 microm in patients with chronic cholecystitis, and 614.8 microm in patients with a carcinoma. There were significant differences among them (p < 0.05).

CONCLUSION

This study showed that differential diagnosis between cancer and noncancerous lesion is possible by dye-staining mucosal pattern and measurement of maximum vessel diameters by stereoscopic examination.

Macrophages are present not only in atretic mature follicles but also in the growing follicles of the guinea pig ovary

In atretic ovarian follicles, massive groups of apoptotically dead granulosa cells are eliminated by two kinds of phagocytic cells: intact granulosa cells and macrophages. Using mature guinea pig ovaries, this study further examined whether or not phagocytic cells are present in the growing follicles by means of light and electron microscopy. Within healthily growing follicles, small numbers of large round cells were found among the granulosa cells. By electron microscopy, the nucleus of the large cells appeared to be pushed aside by prominently expanded large cytoplasmic vacuoles together with abundant large and small lysosomes. These cells were identified as macrophages. This is the first report to demonstrate macrophages within the growing follicles of the guinea pig. The importance of the intrafollicular macrophages is suggested in connection with the dynamics of the follicle, such as its development and atresia.

Is preventive resection of the extrahepatic bile duct necessary in cases of pancreaticobiliary maljunction without dilatation of the bile duct?

BACKGROUND

No consensus has been reached on whether preventive resection of the extrahepatic bile duct is necessary in cases of pancreaticobiliary maljunction (PBM) without dilatation of the extrahepatic bile duct (undilated type).

METHODS

Sixty-eight patients with PBM underwent corrective surgery and several clinical characteristics and pathological findings including K-ras point mutation were evaluated.

RESULTS

Unlike dilated bile duct, none of the patients with undilated type duct had clinical symptoms in early childhood. In patients with either cystic or spindle type duct, amylase levels in the bile duct were >10(4) U/l, whereas those in patients with undilated type duct were <10(4) U/l. Postoperative scintigraphy of the biliary system of undilated type revealed no evidence of cholestasis. After surgery, eight patients with undilated type duct, in whom the bile duct had been preserved, had no further clinical symptoms and no evidence of malignancy. Bile duct tissue specimens revealed no hyperplasia, dysplasia or cancerous lesions and they had no K-ras mutation in undilated type.

CONCLUSION

The results showed that there was little bile stasis, injury to the mucosa was mild and less genetic changes could be seen in patients with undilated type duct. Therefore, in patients without dilatation of bile duct and advanced cancer, cholecystectomy alone is sufficient.

Relation between K-ras codon 12 mutation and p53 protein overexpression in gallbladder cancer and biliary ductal epithelia in patients with pancreaticobiliary maljunction

It is well known that the incidence of biliary cancer is higher in patients with pancreaticobiliary maljunction (PBM) than in individuals without PBM. However, the relationship between PBM and the carcinogenesis remains unclear. The purpose of the present study was to examine histopathologic changes in the mucosa of the gallbladder and bile duct in patients with PBM, and to investigate K-ras oncogene mutation and overexpression of p53 protein in the mucosa. We examined 47 surgical specimens of gallbladder and 36 surgical specimens of bile duct obtained from 48 patients with PBM. The 48 patients were divided into three age groups: group A (0-3 years), group B (4-39 years), and group C (40 years or more). Investigation of K-ras mutation and overexpression of p53 protein was performed using an enriched polymerase chain reaction (PCR) and enzyme-linked mini-sequence assay (ELMA), and by the streptavidin-biotin (SAB) method, using DO-7 antibodies, respectively. Hyperplastic changes in the gallbladder mucosa were observed in patients in the three groups. However, metaplastic or dysplastic changes were observed in the mucosa of only groups B and C. K-ras gene mutation in the gallbladder mucosa was found in 18.8% of the hyperplastic mucosae in group B and in 20% in group C. The mutation was found in 33.3% of lesions with metaplastic change associated with hyperplastic changes and in 25% of lesions with dysplastic changes in group C. No mutation was observed in the non-cancerous mucosae of gallbladders and bile ducts without congenital dilatation of the bile duct. Overexpression of p53 protein was observed only in carcinoma of the gallbladder; in seven of nine advanced carcinomas and in two of three carcinomas in situ. We concluded that the mucosal epithelia of the biliary system in patients with PBM showed a high frequency of gene mutations and the carcinogenesis appeared in involve a multistage process of mutation in the K-ras gene and the p53 suppressor gene.

Relation between K-ras codon 12 mutation and p53 protein overexpression in gallbladder cancer and biliary ductal epithelia in patients with pancreaticobiliary maljunction

It is well known that the incidence of biliary cancer is higher in patients with pancreaticobiliary maljunction (PBM) than in individuals without PBM. However, the relationship between PBM and the carcinogenesis remains unclear. The purpose of the present study was to examine histopathologic changes in the mucosa of the gallbladder and bile duct in patients with PBM, and to investigate K-ras oncogene mutation and overexpression of p53 protein in the mucosa. We examined 47 surgical specimens of gallbladder and 36 surgical specimens of bile duct obtained from 48 patients with PBM. The 48 patients were divided into three age groups: group A (0-3 years), group B (4-39 years), and group C (40 years or more). Investigation of K-ras mutation and overexpression of p53 protein was performed using an enriched polymerase chain reaction (PCR) and enzyme-linked mini-sequence assay (ELMA), and by the streptavidin-biotin (SAB) method, using DO-7 antibodies, respectively. Hyperplastic changes in the gallbladder mucosa were observed in patients in the three groups. However, metaplastic or dysplastic changes were observed in the mucosa of only groups B and C. K-ras gene mutation in the gallbladder mucosa was found in 18.8% of the hyperplastic mucosae in group B and in 20% in group C. The mutation was found in 33.3% of lesions with metaplastic change associated with hyperplastic changes and in 25% of lesions with dysplastic changes in group C. No mutation was observed in the non-cancerous mucosae of gallbladders and bile ducts without congenital dilatation of the bile duct. Overexpression of p53 protein was observed only in carcinoma of the gallbladder; in seven of nine advanced carcinomas and in two of three carcinomas in situ. We concluded that the mucosal epithelia of the biliary system in patients with PBM showed a high frequency of gene mutations and the carcinogenesis appeared in involve a multistage process of mutation in the K-ras gene and the p53 suppressor gene.

Nuclear cyclin D1 overexpression is a critical event associated with cell proliferation and invasive growth in gallbladder carcinogenesis

Cyclin D1 overexpression is remarkably frequent in several human carcinomas and is believed to be a critical event in oncogenesis. We examined cyclin D1 expression, p53 expression, and the Ki-67 labeling index by immunostaining in human gallbladder mucosa in conditions varying from normal to malignant tissue. We also examined K-ras codon 12 mutations in these tissues with a two-step polymerase chain reaction. Nuclear cyclin D1 overexpression was observed in 48% of carcinomas occurring independently of adenoma, but not in adenomas, carcinomas arising in adenomas, or nonneoplastic lesions. Cytoplasmic cyclin D1 overexpression was observed in about 15% of abnormal specimens, irrespective of the type of epithelial abnormality. Carcinomas showing nuclear cyclin D1 overexpression had significantly higher Ki-67 labeling indexes than those with no overexpression. Moderately to poorly differentiated adenocarcinomas showed a higher incidence of nuclear cyclin D1 overexpression than papillary to well differentiated carcinomas. Specimens with cyclin D1 overexpression showed a high incidence of lymph permeation, venous permeation, and lymph node metastasis. We conclude that nuclear cyclin D1 overexpression is a critical event importantly associated with cell proliferation and invasive growth in gallbladder carcinogenesis, and that cyclin D1 immunostaining may become a useful marker for evaluating gallbladder carcinomas.

Assessment of cerebrospinal fluid levels of serum amyloid P component in patients with Alzheimer's disease

Serum amyloid P component (SAP) is a normal plasma constituent that is observed both in senile plaque and in neurofibrillary tangle in brains of patients with Alzheimer's disease (AD). In this study, we evaluated the SAP levels in cerebrospinal fluid (CSF) of 72 patients with AD, 11 frontotemporal dementia and nine normal control subjects. There was no significant difference in the SAP levels between the AD group and other groups. However, among AD patients, cognitive function was rated using the Mini-Mental State Examination and was correlated with the SAP level (R = 0.38, P < 0.05). Our results suggest that measurement of the SAP levels in CSF can be useful for assessing the degree of cognitive impairment in AD patients.

[Percutaneous ethanol injection therapy with hepatic arterial infusion chemotherapy for liver metastases from gastric cancer]

Ten patients with liver metastases from advanced gastric cancer received percutaneous ethanol injection therapy (PEI) and chemotherapy by hepatic arterial infusion (HAI) via implantable reservoir. A 90% ethanol solution including 10%. Lipiodol was injected in the liver as PEI.5-FU, EPIR and MMC were used as the regimen for HAI chemotherapy. We have performed this therapy (PEI + HAI) for ten patients with liver metastases since February, 1997. These patients have received this therapy for 4-36 months and three patients died within 16 months. However, three patients did not develop any liver failure after this therapy. The median survival rate was 25.2 months. There are statistically significant differences between upto ss and over se of invasion, and between INF alpha and gamma (p = 0.005).

Malignant paraganglioma metachronously recurring at short duration in different paraganglions: report of a case

We report the rare case of a 57-year-old man with retroperitoneal malignant paraganglioma. He was referred to our hospital complaining of left lower abdominal dull pain. Computer tomography (CT), magnetic resonance imaging, and aortography showed a mass measuring 5 x 4 cm in size on the left side of the abdominal aorta below the renal artery. The resected tumor was confirmed histologically to be malignant paraganglioma. Irradiation of the resected area was performed. Four months after the operation, an abdominal CT scan showed a 5.5 x 3.0 cm mass on the right side of the aorta below the diaphragm. This tumor was thereafter also resected. Three months after the second operation, a soft subcutaneous nodule measuring 4.5 x 2.0 cm in size was palpable above the left clavicle and was visible on a CT scan. A resection was again performed. All tumors showed the same histological findings. This is the first case reported in the Japanese literature with such a short-term demonstration of multiple metachronous recurrences in different paraganglions.

Substrate and binding specificities of bacterial polyhydroxybutyrate depolymerases

The substrate specificities of three extracellular polyhydroxybutyrate (PHB) depolymerases from Alcaligenes faecalis (PhaZ Afa), Pseudomonas stutzeri (PhaZ Pst), and Comamonas acidovorans (PhaZ Cac), which are grouped into types A and B based on the position of a lipase box sequence in the catalytic domain, were examined for films of 12 different aliphatic polyesters. Each of these PHB depolymerases used was capable of hydrolyzing poly(3-hydroxybutyrate) (P(3HB)), poly(3-hydroxypropionate) (P(3HP)), poly(4-hydroxybutyrate) (P(4HB)), poly(ethylene succinate) (PESU), and poly(ethylene adipate) (PEA) but could not hydrolyze another seven polyesters. In addition, the binding characteristics of substrate binding domains from PhaZ Afa, PhaZ Cac, and PHB depolymerase from Comamonas testosteroni (PhaZ Cte) were studied by using fusions with glutathione S-transferase (GST). All of fusion proteins adsorbed strongly on the surfaces of polyester granules of P(3HB), P(3HP), and poly(2-hydroxypropionate) (P(2HP)) which was not hydrolyzed by the PHB depolymerases used in this study, while they did not bind on Avicel and chitin granules. The adsorption kinetics of the fusion proteins to the surface of P(3HB) and P(2HP) granules were found to obey the Langmuir isotherm. The cross-area per molecule of fusion protein bound to P(3HB) granules was estimated to be 12+/-4 nm2/molecule. It has been suggested that the active sites in catalytic domains of PHB depolymerases have a similar conformational structure, and that several amino acids in substrate-binding domains of PHB depolymerases interact specifically with the surface of polyesters.

An enzyme-linked immunosorbent assay and reference ranges for bisphosphoglycerate mutase in human erythrocytes

We established an enzyme-linked immunosorbent assay (ELISA) system for the determination of human bisphosphoglycerate mutase (BPGM) protein content in human erythrocytes using a polyclonal anti-BPGM antibody, we determined reference ranges for BPGM protein content, synthase activity, and specific activity in human erythrocytes. We produced a recombinant human BPGM (rBPGM) by gene manipulation using E. coli and then obtained the polyclonal antibody by immunizing rabbits with purified rBPGM. The reproducibility of the ELISA was in an acceptable range with a coefficient of variation under 1.5%. The ELISA was reliable in the range of 0.1 to 10 ng/mL. The polyclonal anti-rBPGM antibody did not show any cross-reaction with recombinant human B type phosphoglycerate mutase, which is highly homologous to rBPGM. The ELISA was found to be practical for the determination of BPGM protein content in human erythrocytes. The mean BPGM protein content was 56.3+/-9.7 microg/mL in whole blood (mean+/-SD, n = 50). The ELISA can be used to examine various hematologic disorders with abnormal red cell size and cell counts, and to detect BPGM enzymopathy in human erythrocytes.

Mutagenicity of isomeric alkanediazotates, precursors for ultimate alkylating species of carcinogenic N-nitroso compounds

Alkanediazohydroxides are common key intermediates in carcinogenesis and mutagenesis of N-nitroso compounds, which are widely found in human environment. Mutagenicity of (E)- and (Z)-potassium alkanediazotates, as precursors of corresponding alkanediazohydroxides were evaluated to investigate the effect of geometric isomerism and also the effect of alkyl groups on their biological activity. Mutagenicity of N-nitroso-N-alkylureas which spontaneously produce alkanediazohydroxides after non-enzymatic hydrolysis were also tested in comparison to that of the corresponding diazotates and other activated chemical species of N-nitrosamines. When the mutagenicity was assayed in three microbial strains, Salmonella typhimurium TA1535, and Escherichia coli WP2 and WP2 uvrA, the order of mutagenic potency of the compounds with the same alkyl group was as follows; (E)-diazotates > (Z)-diazotates > nitrosoureas. The effect of alkyl groups on the mutagenic potency was different in Salmonella strain and in E. coli strains, and this result could be explained by the efficiency of O6-alkylguanine-DNA alkyltransferase. In each bacterial strain, this effect of alkyl groups was similar in mutagenicity induced by (E)- and (Z)-diazotates, N-nitroso-N-alkylureas and other activated N-nitrosodialkylamines such as alpha-hydroxy nitrosamines. The geometrical isomerism affected the mutagenicity of (E)- and (Z)-potassium alkanediazotates, and the result suggested that alkanediazohydroxides react through diazonium ions in a cage rather than through free alkyldiazonium ions which have no geometrical isomerism. Our results confirmed that (E)-potassium alkanediazotates, (Z)-potassium alkanediazotates and N-nitroso-N-alkylureas all decomposed through diazohydroxides, and that alkanediazohydroxides are the active alkylating species of N-nitroso compounds, and also that the geometrical isomerism is important for carcinogenic N-nitroso compounds to show their biological activity.

[Aortic stop flow and hypoxic perfusion chemotherapy for unresectable gallbladder cancer]

We performed the aortic stop flow and hypoxic perfusion chemotherapy for unresectable gallbladder cancer under general anesthesia and made the perfusion only in the abdominal cavity by clamping the abdominal aorta and inferior vena cava near the site of diaphragma. Although temporary hypertension occurred just after clamping the aorta, no severe problem could be seen during operation. After surgery the patient had no abnormalities such as liver or kidney dysfunction, and tumor markers gradually came to decrease. Furthermore, the effectiveness of this therapy is greatly anticipated for the unresectable abdominal cancer, evaluating the selection of anti-cancer drugs and their administration dosage etc.

Biochemical and molecular characterization of the polyhydroxybutyrate depolymerase of Comamonas acidovorans YM1609, isolated from freshwater

Comamonas acidovorans YM1609 secreted a polyhydroxybutyrate (PHB) depolymerase into the culture supernatant when it was cultivated on poly(3-hydroxybutyrate) [P(3HB)] or poly(3-hydroxybutyrate-co-3-hydroxyvalerate) [P(3HB-co-3HV)] as the sole carbon source. The PHB depolymerase was purified from culture supernatant of C. acidovorans by two chromatographic methods, and its molecular mass was determined as 45,000 Da by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. The enzyme was stable at temperatures below 37 degrees C and at pH values of 6 to 10, and its activity was inhibited by diisopropyl fluorophosphonate. The liquid chromatography analysis of water-soluble products revealed that the primary product of enzymatic hydrolysis of P(3HB) was a dimer of 3-hydroxybutyric acid. Kinetics of enzymatic hydrolysis of P(3HB) film were studied. In addition, a gene encoding the PHB depolymerase was cloned from the C. acidovorans genomic library. The nucleotide sequence of this gene was found to encode a protein of 494 amino acids (M(r), 51,018 Da). Furthermore, by analysis of the N-terminal amino acid sequence of the purified enzyme, the molecular mass of the mature enzyme was calculated to be 48,628 Da. Analysis of the deduced amino acid sequence suggested a domain structure of the protein containing a catalytic domain, fibronectin type III module as linker, and a putative substrate-binding domain. Electron microscopic visualization of the mixture of P(3HB) single crystals and a fusion protein of putative substrate-binding domain with glutathione S-transferase demonstrated that the fusion protein adsorbed strongly and homogeneously to the surfaces of P(3HB) single crystals.

Cloning of the gene for poly(3-hydroxybutyric acid) depolymerase of Comamonas testosteroni and functional analysis of its substrate-binding domain

A poly(3-hydroxybutyric acid) (PHB) depolymerase gene of Comamonas testosteroni YM1004 was cloned on Sau3AI fragment from genomic DNA into Escherichia coli DH5. Nucleotide sequence analysis dedicated a 1539 bp open reading frame encoding a protein 513 amino acid with a putative 25 residue signal peptide for secretion. The deduced amino acid sequence was very similar to that of PHB depolymerase of Comamonas sp. In order to understand the characteristics of substrate-binding domain of the depolymerase, we constructed its glutathione S-transferase (GST) fusion protein and investigated the ability of adsorption on PHB single crystals by using gold-conjugated antibody and transmission electron microscopy. The fusion protein adsorbed on PHB single crystals tightly and homogeneously, suggesting that binding domain contributes to the adsorption of enzyme on solid PHB without site specificity.

p53 protein overexpression and K-ras codon 12 mutation in pancreatic ductal carcinoma: correlation with histologic factors

The correlation of p53 protein overexpression and the K-ras codon 12 mutation with histologic type, grade of cytologic atypia, depth of invasion and other histologic prognostic factors was studied in paraffin sections from 43 ductectatic- and 70 solid-type pancreatic ductal carcinomas. Overexpression of p53 was found in 23.3% (10/43) of ductectatic carcinomas (17.2% of intraductal and 35.7% of invasive carcinomas) and in 61.4% (43/70) of solid carcinomas. In ductectatic cancers, p53 overexpression was detected in 14.8% (4/27) of carcinomas with low-grade atypia (CAL), 50.0% (5/10) of carcinomas with high-grade atypia (CAH) and in 16.7% (1/6) of mixed low- and high-grade cancers. In the last group, expression was restricted to an area of CAH. In solid cancers, p53 overexpression did not differ by histologic type or grade. Overexpression of p53 and K-ras mutations did not correlate with histologic prognostic factors (lymphatic, venous and perineural invasion, and lymph node metastasis) in ductectatic and solid cancers or depth of invasion of solid carcinomas. Our data suggest that p53 alteration occurs at an early intraductal stage of solid carcinoma, irrespective of cellular atypia, but is low in ductectatic CAL and becomes higher in ductectatic CAH. K-ras mutation, present in a high percentage of tumors of all groups and not correlating with the factors above, showed no changes in frequency with tumor progression.

Elimination of apoptotic granulosa cells by intact granulosa cells and macrophages in atretic mature follicles of the guinea pig ovary

Phagocytic cells disposing of dying granulosa cells in the atretic ovarian follicles were morphologically studied in guinea pig ovaries at various stages of estrous cycle. Epon embedded semithin sections stained with toluidine blue were observed with a light microscope, and ultrathin sections were examined under a transmission electron microscope. Frozen sections were processed for acid phosphatase histochemistry and MR-1 (a monoclonal antibody against guinea pig macrophages) immunohistochemistry. In animals during the estrus period (days 1 and 2) as well as the second half of the estrous cycle (days 11 and 16), there were numerous mature follicles in which massive groups of granulosa cells were undergoing apoptosis. Two kinds of phagocytic cells were identified in these follicles of the initial stage of atresia: one was intact granulosa cells ingesting neighboring dead granulosa cells, and the other was large round cells identified as macrophages due to their strong acid phosphatase activity and MR-1 immunoreactivity. Mature follicles of the advanced stage of atresia were frequently recognized during the metestrus period (days 4 and 5). Small stellate cells were regarded as surviving granulosa cells, while large round cells showing intense reactions for acid phosphatase and MR-1 were identified as macrophages. This study demonstrates that both intact granulosa cells and macrophages participate in the elimination of apoptotic granulosa cells in atretic mature follicles of the guinea pig ovary, and remain even in the advanced stages of atresia.

Adsorption kinetics of bacterial PHB depolymerase on the surface of polyhydroxyalkanoate films

The kinetics of adsorption and hydrolysis by an extracellular PHB depolymerase from Alcaligenes faecalis were studied at 37 degrees C on the surface of five types of polyhydroxyalkanoate (PHA) films. The films of poly[(R)-3-hydroxybutyrate] (P(3HP)), poly(3-hydroxypropionate) (P(3HP)), and poly(4-hydroxybutyrate)(P(4HB)) were hydrolyzed by the enzyme, while the films of poly[(S)-2-hydroxypropionate)(P(2HP)) and poly(6-hydroxyhexanoate)(P(6HH)) were not eroded. The PHB depolymerase with binding and catalytic domains adsorbed on the surface of all PHA films used, and the adsorption kinetics were found to obey the Langmuir isotherm. The cross-area per one molecule of enzyme binding to the surface of PHA film was estimated to be 17 +/- 8 (nm2/molecule). It has been concluded that the binding domain of enzyme is non-specific for the binding to the surface of PHA film, while the active site in a catalytic domain is specific for the hydrolysis of PHA molecules.

Perinatal changes in bovine SEGI's caps with special reference to their endocrine cells migrating into the lamina propria

Large aggregations of endocrine cells at the top of villi in the upper small intestine, discovered by SEGI (1935) in human fetuses and hence called SEGI's caps, have been known to occur also in bovine and porcine fetuses. Using bovine fetuses and newborns, this study aimed to clarify the fate of and changes in the SEGI's cap during the perinatal period. Immunocytochemistry was performed for CgA and PGP 9.5 as markers of the endocrine and nervous elements concerned. In the second trimester in bovine fetuses, numerous endocrine cells were confirmed, by CgA immunocytochemistry, to gather in the epithelium on the top of almost every duodenal villus, either in a single layer or accumulating in a rounded cell mass. They persisted until birth, though decreasing in number during the third trimester. In these fetal periods the endocrine cells came to be invaginated into the lamina propria, and to be separated from the epithelium. They were attached by nerve fibers and shifted to the base of the villi and to the intercryptal tissue. The endocrine cell aggregations at the villous tips rapidly disappeared within three days after birth. The intraepithelial endocrine cells (paraneurons) decreased in their immunoreactivity for CgA after they shifted into the lamina propria, whereas they increased in their immunoreactivity for PGP 9.5 while descending the villous interstitium. Using immunocytochemistry for PGP 9.5, we were able to trace the descent of the endocrine cells in association with nerve fibers. Microscopic images were obtained supporting the possibility that the endocrine-type cells eventually might be taken up by the intramural plexuses of Meissner and Auerbach. Furthermore, the fetal and perinatal intestine revealed enlarged solitary endocrine cells and authentic neurons, as well as their intermediate types, in the villous and intercryptal interstitium. The present results indicate that the SEGI's caps in cattle are best developed in the second trimester of the fetal life, and do not support a hypothesis that the endocrine sensor cells in the caps principally function at the time of birth, especially for responding to the advent of colostrum. The endocrine or paraneuronal elements of the SEGI's cap appear to migrate into the interstitium to obtain more neuron-like features. A possibility that they may be incorporated in the intramural ganglia and further be transformed into neurons awaits further investigation.

Microdialysis measurement of intracerebral somatostatin in the goat

A microdialysis sampling technique for the intracerebral measurement of somatostatin (SS) in extracellular fluid was examined in the goat. The microdialysis probe (70-mm shaft, 0.5 mm outer diameter) contained at its tip a 4-mm length of copolymer dialysis membrane (20 kDa cut-off). Artificial cerebrospinal fluid (artificial CSF) was pumped through the probe tip at a rate of 4 microliters/min with a batter-driven syringe pump, and effluent fractions of dialysate (120 microliters) were collected every 30 min. An in vitro recovery test showed that changes in the SS concentration in dialysate were highly correlated (r = 0.95, P < 0.01) with those in the external medium, and the relative recovery averaged 2.0%. As a validation for in vivo microdialysis, trails were conducted with conscious behaving goats wherein the inflow dialysate was changed transiently from artificial CSF with low potassium (2.5 mM) to a solution of 300 mM KCl. Potassium-induced depolarization around the probe tip located in the preoptic area and in the hypothalamus induced an increase in SS concentrations in dialysate at each location. In the most remarkable response, the concentrations of SS were increased 6-fold and 11-fold in the first and second 30-min fractions, respectively, compared with prepotassium concentrations. These results suggest that intracerebral SS levels in extracellular fluid could be estimated from conscious behaving goats by the use of our intracerebral microdialysis system.

The process of apoptosis in follicular epithelial cells in the rabbit ovary, with special reference to involvement by macrophages

Using rabbit ovaries, this study investigated the fate of follicular epithelial cells undergoing apoptosis in follicle atresia, especially in atretic Graafian follicles. This is the first report to apply the TUNEL method and histochemistry for acid phosphatase in order to demonstrate macrophages immigrating into the follicles to eliminate the apoptotically dead epithelial cells. At initial stages of atresia, a few epithelial cells solitarily revealed the condensation of nuclear chromatin characteristic of apoptosis, simultaneously reacting positive to the TUNEL method. At advanced stages, chromatin condensation and separation as well as cytoplasmic fragmentation spread to the entire follicular epithelium. In such an advanced atretic follicle, large round cells appeared in the follicular lumen; these could be identified as macrophages by their morphologies and positive reactions for acid phosphatase. These macrophages were adhering to and internalizing apoptotic epithelial cells and their fragments until the lumen became completely free of dead cells and fragments.