Effect of acute renal failure on neurotoxicity of cimetidine in rats

PURPOSE

We investigated the effect of acute renal failure on the neurotoxicity of cimetidine in rats.

METHODS

Experimental acute renal failure was produced by bilateral ureteral ligation. Cimetidine was intravenously infused to ureter ligated (UL) and control rats, and cimetidine concentration in plasma, brain and cerebrospinal fluid (CSF) were compared.

RESULTS

The cimetidine concentration in plasma was rapidly increased in UL rats as compared to control rats. The cimetidine concentration in CSF at the onset of convulsion did not depend on the infusion rate, suggesting that cimetidine in CSF equilibrates rapidly with the site of action for clonic convulsion. The cimetidine concentration in CSF of UL rats at the onset of clonic convulsion was lower than those of control rats.

CONCLUSIONS

Increased sensitivity to the drug on the central nervous system may contribute to increased toxicity of cimetidine with renal failure.

Myosin from alga Chara: unique structure revealed by electron microscopy

Cytoplasmic streaming is a fundamental process for the transport of molecules and organelles in plant cells. A myosin-like protein responsible for cytoplasmic streaming in fresh water alga, Chara corallina, has been purified. Electron micrographs of this protein revealed that it has two heads with similar size and shape to those of muscle myosin (myosin II) but its tail was shorter than that of muscle myosin with a globular structure at its distal end like that of myosin V. The myosin cosedimented with vesicles composed of phosphatidyl serine like other non-muscle myosin species involved in intracellular transport.

A role for phosphorylation in the proteolytic processing of the human NF-kappa B1 precursor

A precursor, p105, for one of the subunits (p50) of the NF-kappa B transcription factor, plays an important role in inducible expression of diverse cellular genes. p105 also functions as a cytoplasmic inhibitor for NF-kappa B, and the proteolytic processing of its inhibitory C-terminal region is required for generation of active NF-kappa B. Here, it is reported that the human p105 C-terminal region is phosphorylated in vivo on Ser894 and Ser908, which are potential phosphorylation sites in vitro for proline-directed serine/threonine kinases such as cyclin-dependent kinase. Furthermore, the mutation of these in vivo phosphorylation sites retards p105 processing in vivo, suggesting that p105 processing is regulated in a phosphorylation-dependent manner.

Allelotype of neuroblastoma

Although relatively high incidence of loss of heterozygosity (LOH) on chromosomes 1p, 11q, and 14q have been reported in neuroblastoma, it is still unclear whether or not LOH occurs specifically on these chromosome arms in neuroblastoma since only a few chromosomal arms have been examined for LOH in previous studies. Therefore, we screened 81 cases of tumors for LOH on all 22 autosomes and chromosome X using 35 restriction fragment length polymorphism markers and eight microsatellite markers. High incidence of LOH (> 20%) was observed on six chromosome arms; 1p (26%), 2q (30%), 9p (36%), 11q (24%), 14q (22%), and 18q (31%). Frequencies of LOH on other chromosome arms were less than 13%. Patients with 9p LOH in the tumors showed statistically significant association with advanced stage of the disease and poor prognosis (P = 0.037 and P = 0.003, respectively) independently from N-myc amplification, while LOH on other chromosomes did not show association with stage, prognosis, and N-myc amplification. Thus, besides LOH on chromosomes 1p, 11q, and 14q, LOH on chromosomes 2q, 9p, and 18q also occurs relatively frequently in neuroblastoma, indicating the involvement of multiple tumor suppressor genes in the development of neuroblastoma. It is possible that there is a novel tumor suppressor gene on chromosome 9p which is involved in the progression of neuroblastoma.

Area of paresthesia as determinant of sensory block in axillary brachial plexus block

BACKGROUND AND OBJECTIVES

Paresthesia is widely considered a useful indicator for locating components of the brachial plexus using the axillary approach. While establishing axillary brachial plexus blocks, the authors attempted to correlate the area of paresthesia with the effectiveness of the sensory block.

METHODS

Axillary brachial plexus blocks were established in 222 consecutive adult patients scheduled for elective surgery of the hand or forearm. After paresthesia was elicited in the distribution of one of the three terminal nerves of the hand (median, radial, or ulnar nerve), 30 microliters 1.5% mepivacaine without epinephrine was injected after advancing an indwelling catheter. Sensory block of each terminal nerve was assessed 20 minutes after the injection.

RESULTS

The median and radial nerves were blocked with the highest reliability (87% and 93%, respectively) after paresthesia was elicited in the areas supplied by the corresponding nerves. The ulnar nerve was blocked most reliably ( > 85%) after the elicitation of paresthesia in its area of distribution as well as when no paresthesia was induced. The most reliable block of the musculocutaneous nerve (72%) was achieved after paresthesia was induced in the area supplied by the median nerve.

CONCLUSION

Eliciting paresthesia at the nerve supplying the area of a planned surgical incision is a reliable determinant of successful axillary brachial plexus block.

Formation of lyso-glycosphingolipids by Streptomyces sp

The actinomycete strain Streptomyces sp. H37 produces a novel glycosphingolipid-degrading enzyme. This strain was capable of converting ganglioside GM1 to lyso-GM1. After cultivation for 5 days in medium containing GM1, peptone, and detergent, GM1 was found to be almost completely converted to lyso-GM1. The product was purified on a DEAE-Sephadex A-25 column and thin layer chromatographies. The purified lyso-GM1 was hydrolyzed by endoglycoceramidase, and the released oligosaccharide moiety was identified as that of GM1 by HPLC using the pyridylaminoderivative method. The counterpart sphingosine moiety was confirmed with TLC. Moreover, the structure of lyso-GM1 was ascertained by 1H-NMR analysis. The maximum formation of lyso-GM1 was found in 50 mM potassium phosphate buffer (pH 7.5) containing 0.1% glycodeoxycholate. Various lyso-glycoshingolipids, including those of ganglio-, neolacto-, and globo-types, were formed from their parent glycosphingolipids using this strain.

Neurotropin inhibits accumulation of eosinophils induced by allergen through the suppression of sensitized T-cells

A non-protein extract isolated from the inflamed dermis of rabbits inoculated with vaccinia virus (Neurotropin) has been clinically used in Japan as an analgesic and anti-allergic drug. To clarify its anti-allergic mechanism, the effect of Neurotropin on eosinophil accumulation induced by ragweed pollen extract or platelet-activating factor (PAF) was examined in BALB/c mice. Neurotropin inhibited the T-cell-dependent accumulation of eosinophils induced by allergen in a dose-dependent manner when administered during sensitization. However, Neurotropin was unable to inhibit the T-cell-independent accumulation of eosinophils induced by PAF. A T-cell transfer experiment was performed to address the inhibitory mechanism. A marked accumulation of eosinophils was observed when recipients were injected i.p. with allergen and Nylon wool column-passed splenic T-cells from the sensitized donor mice. However, significant accumulation of eosinophils was not observed when sensitized donor mice were administered with Neurotropin but not saline. Taken together, these results suggest that Neurotropin inhibits the accumulation of eosinophils induced by allergen via the suppression of sensitized T-cell induction, or alternatively by interfering with T-cell function.

[Three-dimensional helical CT angiography of the abdomen]

To evaluate the quality of three-dimensional (3D) images of the abdominal vasculature acquired using enhanced helical CT, 3D reconstructions were performed for 43 examinations (38 patients). Twenty-one of 43 examinations were also reconstructed by Maximum Intensity Projection (MIP). The CT scanner employed was the Toshiba Xforce. Helical CT data were acquired using up to 20 continuous 1.5-sec rotations with an X-ray beam width of 5 mm and a couchtop movement speed of 5 to 10 mm/1.5 sec. Axial images were reconstructed at a section interval of 2 mm. Optimal protocol on enhanced helical CT was as follows: Iopamidol 300 mg I/ml was administered intravenously using a biphasic technique (3-4 ml/sec for the initial 100 ml, followed by 0.7-1.5 ml for the remaining 50 ml), and delay times of the early and late phases were 25-35 and 90 sec, respectively. Aortic branches were clearly demonstrated on early phase, while portal branches were well defined on late phase. In the visualization of abdominal vessels, 3D images were nearly equal to MIP images. However, for anteroposterior images, MIP images were superior to 3D images in quality, because 3D images had some longitudinal direction artifacts. Three-dimensional images were considered to be useful for correctly evaluating overlapping abdominal vasculatures. From the above results, 3D and MIP images of the abdominal vasculature obtained using enhanced helical CT were considered to compensate for each other.

Cytokine mRNA expression patterns in human esophageal cancer cell lines

The mRNA expression for 21 kinds of cytokines was measured in six human esophageal cancer cell lines using RT-PCR. More than moderate levels of RNA for IL-1 alpha were expressed in six of six cell lines, IL-1 beta in four, IL-6 in six, IL-7 in five, IL-10 in six, G-CSF in six, GM-CSF in six, SCF in six, MIP-2 beta in two, and LIF in six. None of the tumors expressed detectable message for IL-2, 3, 4, 5, 8, 11, 13, or IRAP after 30 cycles of PCR amplification. IL-1 alpha, IL-6, M-CSF, and GM-CSF levels in the culture supernatants were detectable using ELISA in three of six, four of six, one of six, and six of six ECCs, respectively. IL-1 beta, IL-2, TNF-alpha, and G-CSF were not detectable in all ECCs. There was no correlation between cytokine mRNA expression and production. These results suggest the existence of a complicated cytokine network around esophageal carcinomas that may affect their growth and proliferation.

Thromboxane A2 receptor-mediated signal transduction in rabbit aortic smooth muscle cells

1. 9,11-Epithio-11,12-methenothromboxane A2 (STA2), a stable analogue of thromboxane A2 (TXA2), contracted rabbit aortic smooth muscles (RASM) and accumulated [3H]inositol phosphates in cultured RASM cells. The contraction and phosphoinositide hydrolysis were competitively inhibited by TXA2 receptor antagonists, including ONO NT-126, S-145, SQ29548, KW3635, GR32191B and ONO3708. 2. STA2 inhibited [3H]ONO NT-126 binding in a concentration-dependent manner in membranes derived from cultured aortic smooth muscle cells, but GTP gamma S, a stable GTP analogue, did not affect STA2-induced inhibition of [3H]ONO NT-126 binding. 3. The time course analysis revealed that STA2 rapidly decreased inositol phosphate level and therefter increased. Pertussis toxin did not attenuate but rather increased STA2-induced phosphoinositide hydrolysis. 4. TXA2 receptor stimulation results in at least two signaling pathways in RASM cells: stimulation and inhibition of phosphoinositide hydrolysis.

Long-term spatial cognitive impairment after middle cerebral artery occlusion in rats: no involvement of the hippocampus

The behavioral and neurochemical changes in the chronic phase of permanent occlusion of the right middle cerebral artery (MCA) in rats were investigated. One month after MCA occlusion, 23 rats were unable to solve a radial eight-arm maze task during an entire 1-month period, whereas seven rats were able to solve this task. Three months after occlusion, 19 MCA-occluded rats failed to solve the task successfully again for at least 1 month (the cognitively impaired rats), whereas 11 MCA-occluded rats were able to solve it (the cognitively unimpaired rats). The rats that underwent behavioral testing were examined for any changes in the acetylcholine (ACh) levels in the hippocampus using HPLC with electrochemical detection or the formation of long-term potentiation (LTP) in the population spike of the hippocampal CA1 field. The immunohistochemical distribution of either the microtubule-associated protein 2 (MAP2) or glial fibrillary acidic protein (GFAP) in the hippocampus of the cognitively impaired rats was also studied. In the cognitively impaired rats, neither the suppression of the induction of LTP, nor the degradation of MAP2, nor the increase in the GFAP immunoreactivity was observed in the hippocampus. The levels of ACh in the hippocampus did not change significantly among the cognitively impaired, unimpaired, and the sham-operated rats. These results suggest that MCA occlusion is capable of producing long-term spatial cognitive disturbance in rats without any evidence of neurobiological damage in the hippocampus.

Initiation of hepatocarcinogenesis by endogenously formed N-nitrosobis(2-hydroxypropyl)amine, N-nitrosodiethanolamine and N-nitroso-2,6-dimethylmorpholine in rats

Initiation activities of endogenously formed N-nitrosobis(2-hydroxypropyl)amine (NBHPA), N-nitrosodiethanolamine (NDELA) and N-nitroso-2,6-dimethylmorpholine (NDMM) were investigated in a modified short-term assay for rat hepatocarcinogenesis. Male Wistar rats were fed 1% bis(2-hydroxypropyl)amine, 0.5% diethanolamine or 0.25% 2,6-dimethylmorpholine in the diet plus 0.3% sodium nitrite in the drinking water. Two weeks after starting the experimental regimen they underwent 2/3 partial hepatectomy and were then maintained on the respective diets for a further week. Following a 2 week recovery period on basal diet rats were subjected to a resistant hepatocyte regimen consisting of 0.02% 2-acetylaminofluorene in the diet for 2 weeks and 1 mg carbon tetrachloride/kg body wt by gavage at the midpoint. Initiation activity was assayed by measuring hepatic foci positive for gamma-glutamyltranspeptidase. Numbers of such foci per cm2 were significantly increased in the groups given the secondary amines together with nitrite compared with values for groups given each precursor or nitrite alone. Further, the numbers of lesions were essentially similar to those found in rats given carcinogenic doses of NBHPA, NDELA and NDMM. The results clearly of demonstrate hepatocyte initiation activities of endogenously formed carcinogens, presumably NBHPA, NDELA and NDMM.

[Changes in plasma cytokine levels during lung surgery]

We studied the changes in plasma cytokine (IL-6 and IL-8) levels during lung surgery in 20 patients. The correlation between the changes in cytokine levels and surgical stress as well as the postoperative complications were examined. The levels of IL-6 and IL-8 increased shortly after the surgical incision and were 326 pg.ml-1 and 61 pg.ml-1 respectively, at the end of surgery. The changes in cytokine levels correlated well with the duration of surgery, blood loss and CPR levels for 2 days after the surgery. However, there were no severe postoperative complications in the present study. We conclude that the cytokines increase shortly after the surgical incision and the changes in cytokine levels correlate well with the surgical stress.

[Phase 3 multicenter clinical study of 111In-DTPA-D-octreotide (MP-1727) in patients with gastrointestinal hormone producing tumors]

A phase 3 multicenter clinical study was performed to investigate the efficacy, safety and usefulness of MP-1727, a novel tumor imaging agent which binds to somatostatin receptors, in 23 patients with gastrointestinal hormone producing tumor. The efficacy was graded effective or very effective in 16 cases (76.2%) out of 21 cases who could be evaluated. Positive predictive accuracy was 77.8% (7/9) for carcinoids, 100% (5/5) for gastrinomas and 40.0% (2/5) for insulinomas. In three cases, tumor lesions which had been unknown were detected by MP-1727 scintigraphy. The consistent ratio between scintigraphically positive sites and preinjection localizations was 82.0% (41/50 sites) in total. Although adverse drug reactions were observed in two cases, the safety was graded 'not problematic at all' in all of 23 cases. These results show that MP-1727 is a very useful radiopharmaceutical for detection and localization of gastrointestinal hormone producing tumors.

Human T-cell leukemia virus type I tax transactivates the interleukin-6 gene in human rheumatoid synovial cells

OBJECTIVE

To determine the effect of the human T cell leukemia virus type I (HTLV-I) tax gene on interleukin-6 (IL-6) production and gene transcription in synovial cells, we established the synovial cell line, E-11, from a patient with rheumatoid arthritis.

METHODS

E-11 cells were transfected with tax expression vector using the calcium phosphate coprecipitation method. IL-6 production and gene expression were investigated by ELISA and Northern blot analysis, respectively. To clarify how tax induces IL-6 gene expression, we used deletion analysis and chloramphenicol acetyltransferase (CAT) assay, and electrophoretic mobility shift assay (EMSA).

RESULTS

Transfection of the tax gene induced markedly high levels of IL-6 mRNA. Furthermore, the tax gene strongly transactivated IL-6 gene promoter activity assayed by CAT assay. By using deletion and site specific mutations, we have identified a nuclear factor (NF)-kappa B sequence (positions -73 to -63) which is essential for tax transaction. EMSA demonstrated the induction of specific binding of nuclear extracts to the NF-kappa B sequence by HTLV-I tax.

CONCLUSION

The HTLV-1 tax gene may transactivate IL-6 gene in the synovial cells through NF-kappa B and may contribute in the pathophysiology of HTLV-I associated arthritis.

Identification of Ro(SSA) 52 kDa reactive T cells in labial salivary glands from patients with Sjögren's syndrome

OBJECTIVE

To identify the self-antigens recognized by autoreactive T cells in labial salivary glands from patients with Sjõgren's syndrome (SS).

METHODS

T cells lines were established from infiltrating T cells in the labial salivary glands from 6 patients with SS, using interleukin 2 and phytohemagglutinin. Bulk cultured T cells and T cell lines were examined for the proliferative response to recombinant Ro(SSA) 52 kDa and SSB proteins. The usage of T cell receptor (TCR) V beta and V alpha genes from Ro(SSA) 52kDa reactive T cells was analyzed by family polymerase chain reaction. The sequences of complementary determining region 3 of TCR V beta genes were also examined.

RESULTS

Three of 6 bulk cultured T cells and 4 of 16 T cell lines showed a significant proliferative response to Ro(SSA) 52 kDa protein. All T cell lines represented CD4+ alpha beta T cells by flow cytometry analysis. All 4 RO(SSA) 52 kDa reactive T cell lines utilized the V beta 2 gene and 3 lines used the V beta 13 gene, suggesting preferential usage of the V beta 2 and the V beta 13 genes in Ro(SSA) 52 kDa reactive T cells. Junctional sequences of TCR V beta genes from Ro(SSA) 52 kDa reactive T cell lines showed the conserved amino acid sequences in CDR3 region.

CONCLUSION

These findings support the notion that Ro(SSA) 52 kDa is a possible autoantigen recognized by autoreactive T cells and that limited epitope is present on the Ro(SSA) 52 kDa antigen.

Aberrant gene for E1 Tor hemolysin from Vibrio cholerae non-O1, N037

Vibrio cholerae non-O1 strain N037 produced a hemolysin (NO37-Hly) which was antigenically similar to E1 Tor hemolysin (E1 Tor-Hly) but different in molecular size, hemolytic activity, and glucose binding capacity. In the gene encoding NO37-Hly, a 4-bp insertion into the structural gene for E1 Tor-Hly (hlyA) was found. The insertion in a shift of codon frames generating a new stop codon in the downstream region. NO37-Hly was a truncated product of E1 Tor-Hly sharing 90% of the N terminal region. This suggested that the 10% C-terminal region of E1 Tor-Hly is needed for the maximal hemolytic activity and glucose binding capacity.

Structure of the gene encoding the mouse pituitary adenylate cyclase-activating polypeptide receptor

The PACAP-R gene, encoding the mouse pituitary adenylate cyclase-activating polypeptide receptor (PACAP-R), has been isolated and its structural organization has been determined. PACAP-R spans more than 50 kb and is divided into 18 exons. PACAP-R contains two alternative exons encoding the putative third intracellular loop, as found in the rat PACAP-R. The proximal promoter region is highly G+C rich and lacks an apparent TATA box, but contains a CCAAT box and two potential Sp1-binding sites.

Construction and characterization of arginine-specific cysteine proteinase (Arg-gingipain)-deficient mutants of Porphyromonas gingivalis. Evidence for significant contribution of Arg-gingipain to virulence

Arginine-specific cysteine proteinase (Arg-gingipain; formerly, argingipain) is one of the major extracellular proteinases produced by the oral anaerobic bacterium Porphyromonas gingivalis. To determine whether Arg-gingipain is important for periodontopathogenicity of the organism, Arg-gingipain-deficient mutants were constructed via gene disruption by use of suicide plasmid systems. First, Southern hybridization analyses suggested that two separate Arg-gingipain-encoding genes designated rgpA and rgpB existed on 12.5- and 7.8-kilobase pair HindIII chromosomal fragments of P. gingivalis ATCC33277, respectively. rgpA and rgpB single mutants were constructed by mobilization of a suicide plasmid. Then, an rgpA rgpB double mutant was isolated by electroporation with a second suicide plasmid. No proteolytic activity for Arg-gingipain was observed in either the cell extract or the culture supernatant of the rgpA rgpB mutant. The chemiluminescence response of polymorphonuclear leukocytes, which is closely related to their bactericidal function, was not inhibited by the culture supernatant of the rgpA rgpA mutant, while the wild type parent showed a significant inhibition of the response. The result suggests that Arg-gingipain is responsible for disruption of the function of polymorphonuclear leukocytes. In addition, the rgpA rgpB double mutations caused a marked decrease in the hemagglutination of P. gingivalis, indicating that a major part of the hemagglutinin activity of the organism is associated with the two genes. These findings demonstrate that Arg-gingipain makes a significant contribution to the virulence of P. gingivalis.

[Unilateral auditory hallucinations due to left temporal lobe ischemia: a case report]

Unilateral auditory hallucinations are a rare lateralization phenomenon experienced in one ear or from one direction. We recently encountered a 63-year-old right-handed man who developed transient unilateral auditory hallucinations associated with pure word deafness. The patient had a past history of myocardial infarction, lung cancer and aortic aneurysm, but no previous psychiatric or convulsive disorders. About six months before admission, he developed right hemiparesis and motor aphasia caused by a hemorrhagic left parietal infarct. These symptoms gradually improved over three weeks. Two days before admission, he suddenly lost the ability to understand spoken words. He concurrently experienced auditory hallucinations arising from the right anterior direction. On admission, he was very embarrassed to simple verbal commands. He was unable to comprehend spoken words and repeat speech, although he could fairly follow written commands. Confrontation naming, reading aloud, comprehension, spontaneous writing remained relatively unaffected, although he occasionally made paraphasic errors. He could distinguish environmental sounds such as a telephone ringing or running water. After gradual improvement of his auditory incomprehension, he began to describe auditory hallucinations of verbal, musical and elementary types. He was fully aware of the hallucinatory nature of his experience, and took some notes. Two days before admission, from the right anterior side of his head he heard a familiar radio announcer reporting news about the earthquake in Osaka Prefecture and the recommended places of refuge. After similar experiences over several days, he repetitively heard a familiar Japanese traditional song from the right side, which was followed by elementary auditory hallucinations such as a car engine and a siren. These symptoms spontaneously disappeared after nine days. Besides his auditory hallucinations, visual hallucinations and illusional emotion were temporarily present. The Wechsler adult intelligence scale revealed a verbal IQ of 91 and a performance IQ of 100. Pure tone audiometry revealed bilateral, mild peripheral sensorineural hearing loss. Brainstem auditory evoked potentials were unrevealing. The EEG showed slow activities in the left temporoparietal region. Magnetic resonance imaging of the brain failed to reveal any relevant abnormalities except for an old hemorrhagic parietal infarct. The SPECT with Tc99m-HMPAO, however, showed reduced blood flow in the left temporal lobe including the first temporal convolution as well as in the left parietal lobe. Based on the SPECT findings, unilateral auditory hallucinations in our patient are considered to have resulted from the left temporal lobe ischemia. Our case indicates that unilateral auditory hallucinations may have a clinicoanatomical correlation with contralateral temporal lobe lesions.

[A clinicopathological study of angiogenesis in breast cancer]

To evaluate the clinicopathological significance and the objective methods for angiogenesis, we immunohistochemically stained all of the regions around the cancer nests with Factor VIII-related antigen staining. We also identified microvessels in the many areas all along the border between cancer nests and the stroma by 200 x power field. We then examined the relationship between the average microvessel count (AC/mm2) and clinicopathological factors and between a 10-year cumulative survival rate in 109 cases of primary breast cancer from 1971 to 1979. There were an average of 35 fields counted among all the cases, and AC was 39.1 +/- 16.1. AC without blood vessel invasion was 36.4 +/- 15.2, while AC with blood vessel invasion was 44.7 +/- 16.6 (p < 0.02). AC without node metastasis or with n1 alpha was 37.6 +/- 15.4, while AC with n1 beta or n2 or n3 was 45.2 +/- 17.4 (p < 0.05). There was no relationship between AC and clinical tumor size, histological classification, lymphatic invasion, nuclear grade, and histological extension. A 10-year cumulative survival rate in AC (> or = 39) was 62.4%, while that in AC (< 39) was 82.7% (p < 0.03). Thus AC was considered a useful prognostic factor.