Release of cholecystokinin from rat cerebral cortex in vivo: role of GABA and glutamate receptor systems

Using cortical cups in chloralose-urethanized rats, the in vivo release of cholecystokinin-like immunoreactivity (CCK-LI) from cerebral cortex was examined. Resting levels of cholecystokinin-like immunoreactivity ranged from 20 to 30 pg/20 min sample. The addition of potassium (40 mM) in excess, resulted in a highly significant elevation in the levels of CCK-LI in the cortical superfusate. Deletion of calcium and the substitution of cobalt (10 mM), resulted in a significant reduction in both resting release and the release otherwise evoked by the addition of potassium. Focal electrical stimulation of the cortex (20 Hz), resulted in a significant (1.9 +/- 0.2-fold, n = 8) increase in the levels of CCK-LI. The addition of glutamate (10(-6)-10(-4) M) of kainic acid (10(-8)-10(-6) M), also resulted in significant elevations in the levels of CCK-LI. The co-administration of a putative glutamate receptor antagonist, kynurenic acid (10(-4) M) resulted in a significant reduction in the levels of release otherwise evoked by the addition of glutamate, but not by electrical stimulation. The addition of GABA (10(-5)-10(-3) M) resulted in a dose-dependent decrease in the resting release of CCK-LI, and the release evoked by glutamate. Picrotoxin (10(-6)-10(-4) M), resulted in a highly significant increase in the levels of CCK-LI in the cortical effluent. These results are consistent with a tonic GABAergic inhibition of CCK-releasing neurons. The treatment of the animal with diazepam (30 mg/kg, i.p.) also resulted in a significant reduction in resting release and the release otherwise evoked by focal cortical stimulation.     

Diagnosis of deep vein thrombosis by high resolution ultrasonography

Using high resolution ultrasonography (US), diagnostic accuracy of thrombi in each venous segment of lower limbs and qualitative evaluation of thrombi in deep vein thrombosis (DVT) were investigated. The subjects were 106 lower limbs in 81 patients. The thrombi in common femoral vein (CFV), were diagnosed by compression technique and, were qualitatively analysed by echogenicity and consistency. Venography was performed in 18 limbs and histologic tests of thrombi were made in 6 limbs. The total accuracy of US was 100% for diagnosis of DVT, but was 83% for diagnosis of its extent. The total accuracy of US in each segment was greater than 90%, but the sensitivity of iliac veins was less than 90%. The thrombi in CFV were divided into 3 types and 8 sub-types. Type A was homogenous, type B was heterogenous, and type C was contracted echo. The types of us were consistent with results of histologic tests. We concluded that high resolution US is available for screening test for diagnosis of DVT and that qualitative evaluation of thrombi by US is a useful clinical test for selection of more adequate treatments.     

A case of autoimmune hepatitis needed to be differentiated from EBV hepatitis, in that the histology of liver biopsy specimen was useful for diagnosis]

A 10-year-old girl with autoimmune hepatitis (AIH) was reported. She was admitted to our hospital because of cholestasis and elevation of liver enzymes for 2 months. Laboratory examination revealed that EBV-DNA copy number in the PBMNC (peripheral mononuclear cells) was 1.2 x 10(3) copies/microg of DNA, hypergammaglobulinemia, and positive antinuclear antibody, positive anti-smooth muscle antibody. The histology of her liver biopsy specimen revealed interface hepatitis, dense mononuclear cell infiltrates, mild fibrosis, and negative for EBV in situ hybridization assay indicating AIH and not EBV-associated hepatitis. She was treated firstly with methylprednisolone pulses, then will prednisolone p.o.+azathioprine p.o.. Intravenous cyclophosphamide pulse therapy was introduced because of her abnormal immune pathology. All abnormal laboratory parameters improved to normal levels within 2 months, and EBV-DNA copy number in the PBMNC became negative after 4 months. The histology of liver biopsy specimen was useful for the diagnosis of AIH in such a difficult case needed to be differentiated from EBV hepatitis.     

99mTc(V)-DMSA and99mTc-MDP uptake and no67Ga-citrate uptake in a case of primary pulmonary leiomyosarcoma

Tumor scintigraphy with 67Ga-citrate, 99mTc(V)-DMSA and 99mTc-MDP were performed on a patient with rare primary pulmonary leiomyosarcoma. While 67Ga-citrate accumulation to the tumor was not recognized, 99mTc(V)-DMSA and 99mTc-MDP scintigraphy showed relatively intense localization of the tracers in the lesion, and were very useful in suggesting the characteristics of the tumor.     

The diagnosis and treatment of esophageal perforations resulting from nonmalignant causes

Esophageal perforations are extremely difficult to diagnose and treat. We report herein our results of a review of 26 patients with esophageal perforation which were spontaneous in 11, iatrogenic in 11, and caused by a foreign body in 4. Surgical treatment was performed in 7 of the patients with spontaneous rupture, but the remaining 19 patients were treated conservatively. The abnormality was found by plain radiography (X-ray) in 22 (85%) of the 26 patients, and by computed tomography (CT) in all 13 patients who underwent this procedure. The detection rates by esophagography and esophagoscopy were 100%, or all of 25 patients examined, and 60%, or 9 of 15 patients examined, respectively. Of 12 patients with underlying diseases, 4 (33%) died after the perforation, whereas only 1 (7%) of 14 patients without any underlying disease died. Postoperative empyema developed in all of 3 patients treated by intraoperative unfixed intrathoracic drainage (UID), but in none of the 4 treated by fixed intrathoracic drainage (FID). Conservative treatment achieved satisfactory results for spontaneous esophageal ruptures confined to the mediastinum, and for iatrogenic perforations and esophageal perforations caused by foreign bodies, provided there was no serious underlying disease such as advanced cirrhosis. Moreover, intraoperative FID proved useful in helping to prevent postoperative empyema.     

Error-prone bypass of certain DNA lesions by the human DNA polymerase kappa

The Escherichia coli protein DinB is a newly identified error-prone DNA polymerase. Recently, a human homolog of DinB was identified and named DINB1. We report that the DINB1 gene encodes a DNA polymerase (designated polkappa), which incorporates mismatched bases on a nondamaged template with a high frequency. Moreover, polkappa bypasses an abasic site and N-2-acetylaminofluorene (AAF)-adduct in an error-prone manner but does not bypass a cis-syn or (6-4) thymine-thymine dimer or a cisplatin-adduct. Therefore, our results implicate an important role for polkappa in the mutagenic bypass of certain types of DNA lesions.     

Immunohistochemical detection of hepatocellular carcinoma in the setting of ongoing necrosis after radiofrequency ablation.

After radiofrequency ablation (RFA), hepatocellular carcinoma undergoes complete necrosis and an ongoing necrosis that is irreversible and characterized histologically by disrupted cell outlines, homogenous cytoplasmic eosinophilia, and preserved nuclear staining, with the cells appearing quite distinct from viable cancer cells. Antibody to detect single-stranded DNA (ssDNA) specifically labeled nuclei in the setting of ongoing necrosis, but not viable tumor cells, whereas human mitochondrial antibody labeled the cytoplasm of viable cells but not cells of ongoing necrosis. The results demonstrate that RFA causes denaturation of both DNA and proteins and that the immunohistochemistry of ssDNA and mitochondrial protein is useful in detection of ongoing necrosis after RFA and provides pathological information on the validity of this procedure.     

The absence of DNA polymerase kappa does not affect somatic hypermutation of the mouse immunoglobulin heavy chain gene

During the immune response to T cell-dependent antigen, somatic hypermutation (SHM) is introduced into immunoglobulin (Ig) genes. The variable region is the target for SHM and it is here that DNA lesions are introduced and mutations are generated. It has been suggested that error-prone DNA polymerase(s) may play an important role in this mutagenesis phase. Recently, DNA polymerase kappa (Polkappa), which belongs to the Y-family of DNA polymerases, was identified. Since a hot spot of SHMs (RGYW motif) is also a hot spot of mutations by human Polkappa, this enzyme was suggested to be an SHM instigator. In order to address the question whether Polkappa is involved in SHM, we immunized Polkappa-deficient mice and analyzed the SHM of the Ig heavy chain gene. We found that the SHM frequency and spectrum were indistinguishable between the Polkappa knockout mice and control mice. These results suggested that Polkappa is not essential for this process.     

Synthesis and ion-coupling reactions of telechelic polystyrene having cyclic onium salt groups

A series of mono- and bifunctional polystyrenes ( 1 c and 1 ′ c ) having 1-methylpyrrolidinium salt end groups were prepared through sequential derivatization, i.e., tosylation and quaternization reactions, of prepolymers having 3-hydroxypropyl groups ( 1 a and 1 ′ a ) produced by end-capping reactions of the relevant living polymers. The 1-methylpyrrolidinium salt end group was found to undergo a selective ring-opening reaction at 100°C by nucleophilic attack of a benzoate counter anion introduced by ion-exchange reaction. The ion-coupling reaction of 1 c and 1 ′ c with poly(styrene-co-acrylate salt) was found to take place upon coprecipitation of an equimolar mixture into methanol to afford ionically linked pseudo-graft and network products, respectively. The subsequent heat treatment, converting the ionic bond into a covalent one, results in branched and crosslinked polystyrene with predetermined structural parameters.     

HLA antigens are candidate markers for prediction of lymph node metastasis in gastric cancer

We investigated the association between human leucocyte antigen (HLA) antigens and lymph node metastasis in 724 gastric cancer patients. Among patients who had poorly differentiated adenocarcinoma with or without HLA-DR4 antigen, lymph node metastasis was detected in 80.8 and 54.9%, respectively (relative risk (RR)=3.5, P = 0.0005, corrected P = 0.0285). It was more common in patients with a family history of cancer death (RR = 7.7). Among signet ring cell carcinoma patients with or without HLA-1152 antigen, lymph node metastasis was detected in 57.7 and 19.7%, respectively (RR =5.6, P=0.0001, corrected P=0.0086). It was more common in patients who were smokers (RR = 8.3). Our findings suggest that HLA-DR4 and HLA-1152 antigens are associated with lymph node metastasis in gastric cancer.