Lateral supraorbital approach as an alternative to the classical pterional approach

OBJECTIVE

The standard pterional approach has been used to approach aneurysms of the anterior circulation and the basilar tip, suprasellar tumors, cavernous lesions. The senior author (JH) established a lateral supraorbital approach as an alternative to the pterional approach after continuous trial and error. We describe the techniques of this approach based on clinical experiences.

METHODS

The lateral supraorbital approach is more subfrontal and anterior than the pterional approach. This approach has been regularly used by the senior author (JH) in the last decade in more than 2000 operations for mostly aneurysms of anterior circulation, but also for tumors of the anterior fossa and parasellar area as well as the sphenoid wing area.

RESULTS

This approach can be used to operate on most cases, in which the classical pterional approach would be used. There are almost no craniotomy-related complications with this approach. This approach is not suitable in certain lesions which need to be exposed from a more temporal perspective.

CONCLUSION

This approach is simpler, faster, safer and less invasive than the classical pterional approach.

Human parvovirus B19 as a causative agent for rheumatoid arthritis

Human parvovirus B19 (B19) DNA was detected in the synovial tissues in 30 of 39 patients with rheumatoid arthritis (RA), and infrequently in those with osteoarthritis and traumatic joints. On the other hand, the expression of the B19 antigen VP-1 was specific (27/27) in RA synovium with active synovial lesions, but not in osteoarthritis and controls. The target cells of B19 were macrophages, follicular dendritic cells, T cells, and B cells, but not synovial lining cells in the synovium. B19-negative bone marrow cells, tonsil cells, and macrophage cell line U-937 cells became positive for the expression of VP-1, and more productive for interleukin 6 and tumor necrosis factor alpha when cocultured with RA synovial cells. The expression of VP-1 and the production of interleukin 6 and tumor necrosis factor alpha was significantly inhibited by the addition of neutralizing antibody for B19, suggesting that B19 detected in RA synovial cells is infective. B19 is involved in the initiation and perpetuation of RA synovitis, leading to joint lesions.

Regional cerebral blood volume and hematocrit measured in normal human volunteers by single-photon emission computed tomography

Single-photon emission computed tomography (SPECT) was used for the measurement of regional cerebral blood volume (CBV) and hematocrit (Hct) in normal healthy human volunteers (mean age 30 +/- 8 years). Regional cerebral red blood cell (RBC) volume and plasma volume were determined separately and their responses to carbon dioxide were investigated. Ten right-handed healthy volunteers were the subjects studied. SPECT scans were performed following intravenous injection of the RBC tracer (99mTc-labeled RBC) and plasma tracer (99mTc-labeled human serum albumin) with an interval of 48 h. Regional cerebral Hct was calculated as the regional ratio between RBC and plasma volumes and then was used for calculating CBV. Mean regional CBV in the resting state was 4.81 +/- 0.37 ml/100 g brain, significantly greater in the left hemisphere compared with the right by 3.8% (p less than 0.01). Mean regional RBC volumes (1.50 +/- 0.09 ml/100 g brain) were less than mean regional plasma volumes (3.34 +/- 0.28 ml/100 g brain), and mean regional cerebral Hcts were 31.3 +/- 1.8%, which was 75.9 +/- 2.1% of the large-vessel Hct. During 5% CO2 inhalation, increases in plasma volume (2.48 +/- 0.82%/mmHg PaCO2) were significantly greater than for RBC volume (1.46 +/- 0.48%/mmHg PaCO2). Consequently, the cerebral-to-large-vessel Hct ratio was reduced to 72.4 +/- 2.2%. Results emphasize the importance of cerebral Hct for the measurement of CBV and indicate that regional cerebral Hcts are not constant when shifted from one physiological state to another.

Isolation and structural elucidation of new cyclotetrapeptides, trapoxins A and B, having detransformation activities as antitumor agents

New cyclotetrapeptides, trapoxins A and B were isolated from the culture broth of Helicoma ambiens RF-1023. These compounds exhibit detransformation activities against v-sis oncogene-transformed NIH3T3 cells (sis/NIH3T3) as antitumor agents. The structures were found to be new cyclotetrapeptides, cyclo[(S)-phenylalanyl-(S)-phenylalanyl-(R)-pipecolinyl- (2S,9S)-2-amino-8-oxo-9,10-epoxydecanoyl-] for trapoxin A and cyclo[(S)-phenylalanyl-(S)-phenylalanyl-(R)-prolyl-2- amino-8-oxo-9,10-epoxydecanoyl-] for trapoxin B, by X-ray analysis, mass spectrometric, NMR and chemical studies.

Cloned platelet thrombin receptor is necessary for thrombin-induced platelet activation

Platelet activation by thrombin is critical for hemostasis and thrombosis. Structure-function studies with a recently cloned platelet thrombin receptor suggest that a hirudin-like domain in the receptor's extracellular amino terminal extension is a thrombin-binding determinant important for receptor activation. We now report that a peptide antiserum to this domain is a potent and specific antagonist of thrombin-induced platelet activation. This study demonstrates that the cloned platelet thrombin receptor is necessary for platelet activation by thrombin, and provides a strategy for developing blocking monoclonal antibodies of potential therapeutic value.

Role of the nondominant hemisphere and undamaged area during word repetition in poststroke aphasics. A PET activation study

BACKGROUND AND PURPOSE

Although the resting regional cerebral blood flow (rCBF) in aphasic patients has been thoroughly investigated with positron emission tomography (PET) and single-photon emission CT, and PET studies in normal subjects have elucidated the functional localization of language processing, little is known about the activation pattern of language processing in aphasic patients.

METHODS

We measured the changes in rCBF during a repetition task (hearing a single word and repeating it aloud) and the resting state using the H2(15)O PET activation technique in 6 normal subjects (mean +/- SD age, 58.3 +/- 8.1 years) and 16 aphasic patients: 10 fluent aphasics (age, 60.3 +/- 12.5 years) and 6 nonfluent aphasics (age, 50.5 +/- 8.3 years).

RESULTS

In normal subjects, the posteroinferofrontal area (PIF) including Broca's area, the posterosuperotemporal area (PST) including Wernicke's area, the rolandic areas, and a few other areas were activated with left side dominance by the repetition task. In the resting state, the rCBF in the left PIF and the left posterotemporal area was reduced in both fluent and nonfluent aphasics. In aphasic patients, the magnitude of activation in the right PIF and PST by the repetition task was greater than in normal subjects. The increase in rCBF during the repetition task in the left PIF correlated with the Western Aphasia Battery score of spontaneous speech in the nonfluent aphasics with a left inferofrontal lesion.

CONCLUSIONS

This study shows the importance in aphasic patients of the mirror regions of the left PIF and PST in the nondominant (right) hemisphere for performing the word repetition task. The results also show the importance for nonfluent aphasic patients of the recruitment of the undamaged PIF for spontaneous speech.

The bifunctional plant receptor, OsCERK1, regulates both chitin-triggered immunity and arbuscular mycorrhizal symbiosis in rice

Plants are constantly exposed to threats from pathogenic microbes and thus developed an innate immune system to protect themselves. On the other hand, many plants also have the ability to establish endosymbiosis with beneficial microbes such as arbuscular mycorrhizal (AM) fungi or rhizobial bacteria, which improves the growth of host plants. How plants evolved these systems managing such opposite plant-microbe interactions is unclear. We show here that knockout (KO) mutants of OsCERK1, a rice receptor kinase essential for chitin signaling, were impaired not only for chitin-triggered defense responses but also for AM symbiosis, indicating the bifunctionality of OsCERK1 in defense and symbiosis. On the other hand, a KO mutant of OsCEBiP, which forms a receptor complex with OsCERK1 and is essential for chitin-triggered immunity, established mycorrhizal symbiosis normally. Therefore, OsCERK1 but not chitin-triggered immunity is required for AM symbiosis. Furthermore, experiments with chimeric receptors showed that the kinase domains of OsCERK1 and homologs from non-leguminous, mycorrhizal plants could trigger nodulation signaling in legume-rhizobium interactions as the kinase domain of Nod factor receptor1 (NFR1), which is essential for triggering the nodulation program in leguminous plants, did. Because leguminous plants are believed to have developed the rhizobial symbiosis on the basis of AM symbiosis, our results suggest that the symbiotic function of ancestral CERK1 in AM symbiosis enabled the molecular evolution to leguminous NFR1 and resulted in the establishment of legume-rhizobia symbiosis. These results also suggest that OsCERK1 and homologs serve as a molecular switch that activates defense or symbiotic responses depending on the infecting microbes.

Complete nucleotide sequences of 93-kb and 3.3-kb plasmids of an enterohemorrhagic Escherichia coli O157:H7 derived from Sakai outbreak

Enterohemorrhagic Escherichia coli (EHEC) O157:H7, derived from an outbreak in Sakai city, Japan in 1996, possesses two kinds of plasmids: a 93-kb plasmid termed pO157, found in clinical EHEC isolates world-wide and a 3.3-kb plasmid termed pOSAK1, prevalent in EHEC strains isolated in Japan. Complete nucleotide sequences of both plasmids have been determined, and the putative functions of the encoded proteins and the cis-acting DNA sequences have been analyzed. pO157 shares strikingly similar genes and DNA sequences with F-factor and the transmissible drug-resistant plasmid R100 for DNA replication, copy number control, plasmid segregation, conjugative functions and stable maintenance in the host, although it is defective in DNA transfer by conjugation due to the truncation and deletion of the required genes and DNA sequences. In addition, it encodes several proteins implicated in EHEC pathogenicity such as an EHEC hemolysin (HlyA), a catalase-peroxidase (KatP), a serine protease (EspP) and type II secretion system. pOSAK1 possesses a ColE1-like replication system, and the DNA sequence is extremely similar to that of a drug-resistant plasmid, NTP16, derived from Salmonella typhimurium except that it lacks drug resistance transposons.

Power spectral analysis of heart rate variability as a new method for assessing autonomic activity in the rat

The authors studied power spectral analysis of heart rate variability in the rat, hypothesizing that the quantitative information provided by this analysis reflects the interaction between sympathetic and parasympathetic regulatory activities. For this purpose, an electrocardiogram was recorded from conscious and unrestrained Wistar rats (Nippon, Shizuoka) (12-16 weeks old) by a telemetry system and analyzed by a power spectrum. Because it was thought that the electrocardiogram recorded by the telemetry system could provide more reliable data to assess autonomic nervous activity than the tethering system, the telemetry recording system was used. There were two major spectral components in the power spectrum at low frequency (LF) (0.6 Hz) and high frequency (HF) (approximately 1.4 Hz). On the basis of these data, the authors defined two frequency bands of interest: LF (0.04-1.0 Hz) and HF (1.0-3.0 Hz). The power of LF was higher than that of HF in the normal rat. Atropine (2 mg/kg intraperitoneally) significantly reduced both HF and LF power. Propranolol (4 mg/kg intraperitoneally) also significantly reduced LF power; however, it had no significant effect on HF power. Thus, this study in the rat confirmed earlier observations in the conscious dog and human. Furthermore, the decrease in the parasympathetic mechanism produced by atropine was reflected by a slight increase in the LF/HF ratio. The LF/HF ratio appeared to follow the reductions of sympathetic activity produced by propranolol. From these results, the LF/HF ratio seemed to be a convenient index of parasympathetic and sympathetic interactions in the rat.(ABSTRACT TRUNCATED AT 250 WORDS)

Inhibitory effects of ginsenoside Rh2 on tumor growth in nude mice bearing human ovarian cancer cells

Ginsenoside Rh2 (Rh2), isolated from an ethanol extract of the processed root of Panax ginseng CA Meyer, inhibits the growth of B16 melanoma cells. This study was designed to evaluate the ability of Rh2 to inhibit growth of human ovarian cancer cells (HRA) in vitro and in nude mouse. Rh2 inhibited proliferations of various established human ovarian cancer cell lines in a dose-dependent manner between 10 and 60 microM in vitro and induced apoptosis at around the IC50 dose. When HRA cells were inoculated s.c. into the right flank of nude mice, all mice formed a palpable tumor within 14 days. Although i.p. administration of Rh2 alone hardly inhibited the tumor growth, when Rh2 was combined with cis-diamminedichloroplatinum(II) (CDDP) the tumor growth was significantly inhibited, compared to treatment with CDDP alone. When mice were treated p.o. with Rh2 daily (but not weekly), the tumor growth was significantly (P<0.01) inhibited, compared to CDDP treatment alone. When Rh2 was combined with CDDP, the degree of tumor growth retardation was not potentiated. The survival time was significantly (P<0.05) longer than that of medium alone-treated controls or the group treated with CDDP alone. Then, we examined whether p.o. administration of Rh2 has a dose-dependent inhibitory effect on the tumor growth. I.p. and weekly administration of CDDP had more potent antitumor activity in the order of 1 mg/kg, 2 mg/kg and 4 mg/kg, whereas p.o. and daily administration of Rh, (0.4 to 1.6 mg/kg) not only had antitumor activity comparable to that of 4 mg/kg CDDP, but also resulted in a significant increase of the survival. Doses of Rh2 used in this study did not result in any adverse side-effects as confirmed by monitoring hematocrit values and body weight, unlike 4 mg/kg CDDP, which had severe side-effects. It is noteworthy that p.o. but not i.p. treatment with Rh2 resulted in induction of apoptotic cells in the tumor in addition to augmentation of the natural killer activity in spleen cells from tumor-hearing nude mice. Thus, particularly in view of the toxicity of CDDP, Rh2 alone would seem to warrant further evaluation for treatment of recurrent or refractory ovarian tumor.

Human desmocollin 1 (Dsc1) is an autoantigen for the subcorneal pustular dermatosis type of IgA pemphigus

IgA pemphigus showing IgA anti-keratinocyte cell surface autoantibodies is divided into subcorneal pustular dermatosis (SPD) and intraepidermal neutrophilic IgA dermatosis (IEN) types. We previously showed by immunoblotting that IgA from some IgA pemphigus patients reacted with bovine desmocollins (Dsc), but not human Dsc. To determine the antigen for IgA pemphigus, we focused on conformation-dependent epitopes of Dsc, because sera of patients with classical pemphigus recognize conformation-sensitive epitopes of desmogleins. We constructed mammalian expression vectors containing the entire coding sequences of human Dsc1, Dsc2, and Dsc3 and transiently transfected them into COS7 cells by lipofection. Immunofluorescence of COS7 cells transfected with single human Dscs showed that IgA antibodies of all six SPD-type IgA pemphigus cases reacted with the surface of cells expressing Dsc1, but not with cells expressing Dsc2 or Dsc3. In contrast, none of seven IEN-type IgA pemphigus cases reacted with cells transfected with any Dscs. These results convincingly indicate that human Dsc1 is an autoantigen for SPD-type IgA pemphigus, suggesting the possibility of an important role for Dsc1 in the pathogenesis of this disease. This study shows that a Dsc can be an autoimmune target in human skin disease.

Optimization of annealing temperature to reduce bias caused by a primer mismatch in multitemplate PCR

To reduce PCR bias derived from a primer mismatch, the effect of the annealing temperature on the product ratio was investigated by denaturing gradient gel electrophoresis analysis of PCR products from a mixture of perfect-match and one-mismatch templates. These templates were generated by PCR from Pediococcus acidilactici for one mismatch and Micrococcus luteus for the perfect match. PCRs showed that the bias was reduced at lower temperatures. An environmental sample was also examined.

Function of sigma1 receptors in Parkinson's disease

OBJECTIVE

The objective of this study was to investigate the mapping of sigma1 receptors in Parkinson's disease (PD) using [11C]SA4503 and positron emission tomography (PET), and to assess whether sigma1 receptors are involved in the damaged dopaminergic system in PD patients.

MATERIALS AND METHODS

We studied seven normal volunteers and six PD patients. The low density of dopamine transporters and the normal or high density of dopamine receptors were confirmed in the putamen of all patients using [11C]CFT and [11C]RAC PET. A dynamic series of PET data acquisition was performed with arterial blood sampling. We computed the binding potential (BP) of [11C]SA4503.

RESULTS

In PD patients, the BP was significantly lower on the more affected than the less affected side of the anterior putamen, although there was no significant difference with respect to the BP between patients and controls.

CONCLUSIONS

Release of dopamine is reduced asymmetrically in the putamen of early PD. [11C]SA4503 PET is an indicator of presynaptic dopaminergic damage in PD.

Characterization of pseudotype VSV possessing HCV envelope proteins

The genome of hepatitis C virus (HCV) encodes two envelope glycoproteins (E1 and E2), which are thought to be responsible for receptor binding and membrane fusion resulting in virus penetration. To investigate cell surface determinants important for HCV infection, we used a recombinant vesicular stomatitis virus (VSV) in which the glycoprotein gene was replaced with a reporter gene encoding green fluorescent protein (GFP) and produced HCV-VSV pseudotypes possessing chimeric HCV E1 or E2 glycoproteins, either individually or together. The infectivity of the pseudotypes was determined by quantifying the number of cells expressing the GFP reporter gene. Pseudotypes that contained both of the chimeric E1 and E2 proteins exhibited 10--20 times higher infectivity on HepG2 cells than the viruses possessing either of the glycoproteins individually. These results indicated that both E1 and E2 envelope proteins are required for maximal infection by HCV. The infectivity of the pseudotype virus was not neutralized by anti-VSV polyclonal antibodies. Bovine lactoferrin specifically inhibited the infection of the pseudotype virus. Treatment of HepG2 cells with Pronase, heparinase, and heparitinase but not with phospholipase C and sodium periodate reduced the infectivity. Therefore, cell surface proteins and some glycosaminoglycans play an important role in binding or entry of HCV into susceptible cells. The pseudotype VSV possessing the chimeric HCV glycoproteins might offer an efficient tool for future research on cellular receptors for HCV and for the development of prophylactics and therapeutics for hepatitis C.

Evolutionarily stable mutation rate in a periodically changing environment

Evolution of mutation rate controlled by a neutral modifier is studied for a locus with two alleles under temporally fluctuating selection pressure. A general formula is derived to calculate the evolutionarily stable mutation rate mu(ess) in an infinitely large haploid population, and following results are obtained. (I) For any fluctuation, periodic or random: (1) if the recombination rate r per generation between the modifier and the main locus is 0, mu(ess) is the same as the optimal mutation rate mu(op) which maximizes the long-term geometric average of population fitness; and (2) for any r, if the strength s of selection per generation is very large, mu(ess) is equal to the reciprocal of the average number T of generations (duration time) during which one allele is persistently favored than the other. (II) For a periodic fluctuation in the limit of small s and r, mu(ess)T is a function of sT and rT with properties: (1) for a given sT, mu(ess)T decreases with increasing rT; (2) for sT &lt;/= 1, mu(ess)T is almost independent of sT, and depends on rT as mu(ess)T & 1.6 for rT &lt; 1 and mu(ess)T & 6/rT for rT &gt; 1; and (3) for sT &gt;/= 1, and for a given rT, mu(ess)T decreases with increasing sT to a certain minimum less than 1, and then increases to 1 asymptotically in the limit of large sT. (III) For a fluctuation consisting of multiple Fourier components (i.e., sine wave components), the component with the longest period is the most effective in determining mu(ess) (low pass filter effect). (IV) When the cost c of preventing mutation is positive, the modifier is nonneutral, and mu(ess) becomes larger than in the case of neutral modifier under the same selection pressure acting at the main locus. The value of c which makes mu(ess) equal to mu(op) of the neutral modifier case is calculated. It is argued that this value gives a critical cost such that, so long as the actual cost exceeds this value, the evolution rate at the main locus must be smaller than its mutation rate mu(ess).

Comparison of whole genome sequences of Chlamydia pneumoniae J138 from Japan and CWL029 from USA

Chlamydia pneumoniae is a widespread pathogen of humans causing pneumonia and bronchitis. There are many reports of an association between C.PNEUMONIAE: infection and atherosclerosis. We determined the whole genome sequence of C.PNEUMONIAE: strain J138 isolated in Japan in 1994 and compared it with the sequence of strain CWL029 isolated in the USA before 1987. The J138 circular chromosome consists of 1 226 565 nt (40.7% G+C) with 1072 likely protein-coding genes that is 3665 nt shorter than the CWL029 genome. Plasmids, phage- or transposon-like sequences were not identified. The overall genomic organization, gene order and predicted proteomes of the two strains are very similar, suggesting a high level of structural and functional conservation between the two unrelated isolates. The most conspicuous differences in the J138 genome relative to the CWL029 genome are the absence of five DNA segments, ranging in size from 89 to 1649 nt, and the presence of three DNA segments, ranging from 27 to 84 nt. The complex organization of these 'different zones' may be attributable to a unique system of recombination.

Molecular cloning of a cDNA coding for 70 kilodalton subunit of soluble guanylate cyclase from rat lung

A complementary DNA clone corresponding to the 70 kDa subunit of soluble guanylate cyclase (EC 4.6.1.2) of rat lung has been isolated. The primary structure of the cDNA consisted of 3063 nucleotides including a 1857-nucleotide coding region for 619 amino acids, and the calculated molecular weight was 70476. Blot hybridization of total poly(A)+RNAs from rat tissues detected a mRNA of about 3.4 kilobases. The amount of mRNA was abundant in lung, cerebrum and cerebellum, moderate in heart and kidney, and low in liver and muscle. Southern blot analysis of high molecular weight genomic DNA from rat liver indicated the presence of one gene in the rat haploid genome. The amino acid sequence of the 70 kDa subunit has partial homology with particulate guanylate cyclase from sea-urchin sperm, and protein phosphatase inhibitor I.

Effect of the leukotriene receptor antagonist pranlukast on cellular infiltration in the bronchial mucosa of patients with asthma

BACKGROUND

It has been reported that pranlukast reduces the antigen induced immediate and late phase asthmatic responses, airway hyperreactivity to acetylcholine, and pulmonary eosinophil accumulation in guinea pigs. A study was undertaken to test the hypothesis that pranlukast may reduce the number of inflammatory cells in the bronchial mucosa of patients with asthma.

METHODS

A double blind, placebo controlled study was performed in 17 mild to moderate asthmatic subjects to examine changes in inflammatory cell infiltration in response to pranlukast (225 mg orally twice per day for four weeks). Comparisons of the mean daily beta 2 agonist use, symptom score, FEV1 percentage predicted, and airway methacholine responsiveness were made before and after treatment. Using fibreoptic bronchoscopy, bronchial biopsy specimens were obtained before and after treatment with either pranlukast (n = 10) or placebo (n = 7). Immunohistology was performed using monoclonal antibodies for CD3, CD4, CD8, CD68, NP57, AA1, EG1, EG2, gamma GTP and CD19.

RESULTS

When the pranlukast and placebo treated groups were compared there were decreases in beta 2 agonist use, symptom score, and airway methacholine responsiveness after pranlukast but no increase in FEV1 was seen. The clinical response in patients treated with pranlukast was accompanied by a reduction in CD3 (median difference -37, 95% confidence interval (CI) -69 to -1; p < 0.05), CD4 (median difference -28, 95% CI -49 to -8; p < 0.01), AA1 (median difference -15, 95% CI -26 to 0; p < 0.05) and EG2 positive cells (95% CI -35 to 0; p < 0.05), but not in EG1 positive eosinophils, gamma GTP positive cells, and CD19 positive plasma cells.

CONCLUSIONS

These results support the view that pranlukast may act by inhibition of bronchial inflammation in patients with asthma.

Regional cerebral blood flow difference between dementia with Lewy bodies and AD

The authors studied 14 patients with dementia with Lewy bodies (DLB), 14 patients with AD, and 14 healthy control subjects with N-isopropyl-p-[123I]iodoamphetamine SPECT. Comparison with the statistical parametric mappings revealed that relative cerebral blood flow was lower in the occipital lobes and higher in the right medial temporal lobe in the DLB group than in the AD group. Decreased occipital perfusion and relatively well preserved medial temporal perfusion are features that distinguish DLB from AD.

Complementary DNAs for choline acetyltransferase from spinal cords of rat and mouse: nucleotide sequences, expression in mammalian cells, and in situ hybridization

Complementary DNA clones containing the entire coding region of choline acetyltransferase (ChAT) were isolated from the spinal cords of rat and mouse. The cDNAs of rat and mouse coded for 640 and 641 amino acids, respectively, and showed 95% mutual homology and 80% homology with the cDNA of porcine ChAT. Northern blot analysis revealed a single band of 4.4 kb in the spinal cord and brain in each species. Introduction of the cDNAs into Chinese hamster ovary cells and neuron-derived cell lines, N1E115 and NG108-15, expressed a high ChAT activity, which was inhibited by a specific ChAT inhibitor. In situ hybridization using the rat cRNA probe revealed specific labeling of the motoneurons in the spinal cord and neurons in various forebrain nuclei of the rat where the existence of cholinergic neurons has been demonstrated immunohistochemically.

High titers of antibodies inhibiting the binding of envelope to human cells correlate with natural resolution of chronic hepatitis C

Most cases of hepatitis C virus (HCV) infection result in chronic disease; however, a very small fraction of patients naturally clear the virus and resolve chronic hepatitis. In an attempt to correlate immune response with chronic disease resolution, we compared the antibody response in patients with different outcomes of the infection. Antibody responses to HCV structural proteins were assessed in 34 patients originally diagnosed with acute hepatitis. Five cases resolved acute infection, 22 developed chronic hepatitis, and 7 naturally resolved chronic hepatitis C. To estimate HCV neutralizing antibodies we used the neutralization of binding (NOB) assay, which evaluates inhibition of the envelope-2 protein binding to human cells. Enzyme-linked immunosorbent assay was used for the quantitative assessment of serum antibodies. The presence of HCV RNA was ascertained by reverse transcription-polymerase chain reaction. In 6 of 7 patients naturally recovered from chronic hepatitis C, the emergence and the persistence (for more than 3 months) of high serum titers (>1/600) of NOB antibodies coincided with virus clearance and clinical resolution of hepatitis. NOB antibody activity was observed in only 2 of 5 patients recovered from acute hepatitis C. Chronic patients who did not show any resolution during the course of the study developed low or no NOB antibodies. Because of the correlation between prolonged high NOB titers and natural resolution of chronic hepatitis C, vaccination or passive immunization aimed at high titers of NOB antibodies may be valuable new therapeutic approaches for chronic hepatitis C.

Brain dialysis: in vivo metabolism of dopamine and serotonin by monoamine oxidase A but not B in the striatum of unrestrained rats

A dialysis cannula was implanted into rat striatum while the animals were anesthetized, and the area was perfused with Ringer solution while the animals were unanesthetized after at least 3 days following surgery. Concentrations of the metabolites of 3,4-dihydroxyphenylethylamine (DA) and 5-hydroxytryptamine (5-HT) in the perfusate were determined by HPLC with electrochemical detection. Levels of the DA metabolites 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) in the perfusate significantly decreased after pargyline administration (50 mg/kg i.p.), which may inhibit not only monoamine oxidase (MAO)-B but also MAO-A in these high doses. The level of the 5-HT metabolite 5-hydroxyindoleacetic acid (5-HIAA) also decreased after pargyline treatment, although change in the relative level of 5-HIAA was less than that of DOPAC or HVA. To clarify the mechanisms for the metabolism of monoamines in rat striatum, highly specific MAO-A and -B inhibitors were used in the following experiments. Treatment with l-deprenyl (10 mg/kg), a specific inhibitor for MAO-B, did not cause any statistically significant change in DOPAC, HVA, and 5-HIAA levels. No significant change was found in rat striatal homogenates at 2 h after the same treatment with l-deprenyl. In contrast, low-dose treatment (1 mg/kg) with clorgyline, a specific inhibitor for MAO-A, caused a significant decrease in levels of these three metabolites in both the perfusates and tissue homogenates. In addition to the above three metabolites, the level of 3-methoxytyramine, which is an indicator of the amount of DA released, greatly increased after treatment with a low dose (1 mg/kg) of clorgyline.(ABSTRACT TRUNCATED AT 250 WORDS)