Mechanism of 7,12-dimethylbenz[a]anthracene-induced immunotoxicity: role of metabolic activation at the target organ

The polycyclic aromatic hydrocarbon, 7,12-dimethylbenz[a]anthracene (DMBA), is an immunosuppressor as well as a potent organ-specific carcinogen. To understand the organ-specific mechanism of DMBA-induced lymphoid toxicity, aryl hydrocarbon-nonresponsive mice and microsomal epoxide hydrolase (mEH)-null mice were analyzed. DMBA caused a dose-dependent decrease in spleen weights, but not the thymus weights in aryl hydrocarbon-nonresponsive mice. On the other hand, both spleen and thymus weights were decreased to less than a half in wild-type mice exposed to 30 mg/kg of DMBA. In contrast, no decrease was detected in spleen weights of mEH-null mice exposed to up to 100 mg/kg of DMBA, while thymus weights were markedly lower. Responses to the B-cell mitogen lipopolysaccharide and to T-cell mitogen phytohemagglutinin were nearly completely abolished in splenocytes isolated from wild-type mice treated with 100 mg/kg of DMBA. These responses were decreased, but maintained in splenocytes isolated from mEH-null mice treated with DMBA. Two DMBA metabolites dependent on mEH including DMBA-3,4-diol were detected in an HPLC chromatogram of spleen microsomes isolated from wild-type mice, but not those from mEH-null mice. These results suggest the involvement of mEH in splenic activation of DMBA for immunotoxicity and the difference for the DMBA-induced lymphoid toxicity between spleen and thymus.

Diurnal variation in the biliary excretion of flomoxef in patients with percutaneous transhepatic biliary drainage

AIMS

To examine diurnal variation in biliary excretion of flomoxef.

METHODS

Flomoxef (1 g) was injected intravenously in eight patients with percutaneous transhepatic cholangiography with drainage at 09.00 h and 21.00 h by a cross-over design with a 36 h washout period. Drained biliary fluid was collected for 6 h after each dosing. These patients still had mild to moderate hepatic dysfunction.

RESULTS

Bile flow and bile acid excretion for 6 h after dosing did not differ significantly between the 09.00 h and 21.00 h treatments. The maximum concentration of biliary flomoxef was significantly greater and its total excretion for 6 h tended to be greater after the 21.00 h dose [maximum concentration (microg ml(-1)): 34.2 +/- 29.9 (09.00 h dose) vs 43.5 +/- 28.3 (21.00 h dose) (95% confidence interval for difference: 2.6 approximately 15.9, P = 0.013); total excretion (mg 6 h(-1)): 1.4 +/- 1.3 (09.00 h dose) vs 1.6 +/- 1.2 (21.00 h dose) (95% confidence interval for difference: -26.8, 313.7, P = 0.087)]. The period that biliary flomoxef remained above the minimal inhibitory concentration did not differ significantly between the two treatment times.

CONCLUSIONS

These results suggest that biliary excretion of flomoxef shows diurnal variation. However, as the difference was relatively small, flomoxef could be given at any time of day without any dosage adjustments.

CpG-DNA derived from sera in systemic lupus erythematosus enhances ICAM-1 expression on endothelial cells

OBJECTIVE

To examine the effect of transfection of oligodeoxynucleotides (ODNs) containing a CpG motif (CpG-ODN), of which the sequence was derived from circulating DNA in the sera of patients with systemic lupus erythematosus (SLE), on the expression of intercellular adhesion molecule-1 (ICAM-1) and synthesis of mRNA for proinflammatory cytokines and ICAM-1 in human umbilical vein endothelial cells (EC).

METHODS

A CpG-ODN or a control analogue, GpC-ODN, was transfected into EC. ICAM-1 expression was examined by flow cytometry, and expression of mRNA in EC encoding interleukin 1 (IL1), IL6, IL8, tumour necrosis factor alpha (TNFalpha), interferon gamma (IFNgamma), and ICAM-1 was examined by semiquantitative reverse transcriptase-polymerase chain reaction.

RESULTS

The CpG-ODN augmented the expression of ICAM-1 on EC determined by flow cytometry and increased mRNA levels of IL6, IL8, TNFalpha, IFNgamma, and ICAM-1, but the GpC-ODN did not.

CONCLUSION

Synthesised DNA, with a sequence corresponding to that of the fragment containing the CpG motif, in sera of patients with SLE was found to enhance ICAM-1 expression on EC, suggesting the participation of circulating DNA fragments in the pathogenesis of vasculitis in SLE.

Anti-cathepsin G antibodies in the sera of patients with ulcerative colitis

The presence of perinuclear anti-neutrophil cytoplasmic antibodies (P-ANCAs) and that of antibodies against cathepsin G, a target antigen for P-ANCAs, was determined in the sera of patients with ulcerative colitis (UC), relative to the endoscopic severity and disease activity. P-ANCAs were detected by indirect immunofluorescent assay (IIF) on ethanol-fixed human neutrophils. Antibodies to cathepsin G were detected by an enzyme-linked immunosorbent assay (ELISA) and Western blotting. P-ANCAs were detected by IIF in 62.5% of 32 patients with active UC. Anti-cathepsin G antibodies were detected in 40.6% of 32 patients with active UC, and their prevalence was significantly higher in patients with severe colitis, as determined by endoscopy, than in those with mild or moderate colitis (P < 0.05). The prevalence and titers of anti-cathepsin G antibodies were significantly higher during the active than the inactive phase of the disease (P < 0.05). Measurement of titers of anti-cathepsin G antibodies by ELISA in the serum is useful for evaluating the activity of UC.

Controlled expansion of a molecular cavity in a steroid host compound

Expansion of a molecular cavity is described by using elongation of the side chain of a bile acid host compound. Bishomocholic acid (2), which has a side chain that is longer by two methylene unit than cholic acid (1), includes many organic substances at 1:1 host:guest ratios. X-ray crystallographic studies revealed that 2 has two types of open host frameworks: a bilayer type and a crossing type. Both of them are isostructural to those of 1, indicating that they are robust against the elongation of the side chain. In the former type, the increment of the width of the host channel corresponds to that of the length of the molecular structures. Larger aromatic guest components such as 1-methylnaphthalene and 1-tetralone, are included in 2, but not in 1.

Deficient long-term synaptic depression in the rostral cerebellum correlated with impaired motor learning in phospholipase C beta4 mutant mice

Long-term depression (LTD) at parallel fibre-Purkinje cell synapse of the cerebellum is thought to be a cellular substrate for motor learning. LTD requires activation of metabotropic glutamate receptor subtype 1 (mGluR1) and its downstream signalling pathways, which invariably involves phospholipase Cbetas (PLCbetas). PLCbetas consist of four isoforms (PLCbeta1-4) among which PLCbeta4 is the major isoform in most Purkinje cells in the rostral cerebellum (lobule 1 to the rostral half of lobule 6). We studied mutant mice deficient in PLCbeta4, and found that LTD was deficient in the rostral but not in the caudal cerebellum of the mutant. Basic properties of parallel fibre-Purkinje cell synapses and voltage-gated Ca2+ channel currents appeared normal. The mGluR1-mediated Ca2+ release induced by repetitive parallel fibre stimulation was absent in the rostral cerebellum of the mutant, suggesting that their LTD lesion was due to the defect in the mGluR1-mediated signalling in Purkinje cells. Importantly, the eyeblink conditioning, a simple form of discrete motor learning, was severely impaired in PLCbeta4 mutant mice. Wild-type mice developed the conditioned eyeblink response, when pairs of the conditioned stimulus (tone) and the unconditioned stimulus (periorbital shock) were repeatedly applied. In contrast, PLCbeta4 mutant mice could not learn the association between the conditioned and unconditioned stimuli, although their behavioural responses to the tone or to the periorbital shock appeared normal. These results strongly suggest that PLCbeta4 is essential for LTD in the rostral cerebellum, which may be required for the acuisition of the conditioned eyeblink response.

Protein-losing enteropathy exacerbated with the appearance of symptoms of systemic lupus erythematosus

A 38-year-old woman visited our hospital with edema on her face and conjunctivae. The underlying disease was not clarified, and she did not visit the hospital afterwards. She suffered from diarrhea, polyarthralgia, Raynaud's phenomenon, malar rash and hair loss in the subsequent two years, and was hospitalized because of hypoproteinemia. Her urine, liver and heart test results did not account for her hypoproteinemia. She was diagnosed as having protein-losing enteropathy (PLE) associated with SLE based on the 99mtechnetium-labeled human serum albumin scintigraphy findings, clinical findings and laboratory results of antinuclear and anti-Sm antibodies. This case report demonstrates a strong association between PLE and SLE because PLE was aggravated along with the appearance of SLE symptoms and PLE subsided with prednisolone treatment along with improvement of SLE.

Expression of corticotropin-releasing hormone type 1 receptor in paraventricular nucleus after acute stress

We have previously proposed the existence of ultrashort loop-positive feedback regulation of corticotropin-releasing hormone (CRH) in the hypothalamus. To gain a better understanding of this effect, we performed double-label in situ hybridization to identify the neurons in the paraventricular nucleus (PVN) that express CRH type 1 receptor (CRH-R1) following stress. We also conducted immunohistochemistry to determine whether CRH-R1 mRNA was translated to CRH-R1 protein in the PVN. Thirty-minute restraint stress given to male Wistar rats increased c-fos mRNA expression primarily in the CRH-producing neurons of the parvocellular PVN. Small numbers of vasopressin and oxytoxin-producing cells were also labeled by c-fos probes. Approximately 70% of CRH-R1 positive neurons exhibited CRH mRNA 2 h after the beginning of stress, while only a small percentage of the vasopressin and oxytocin-producing cells coexpressed CRH-R1 mRNA. CRH-R1 immunoreactivity, which was detected in the perikarya and fibers of PVN neurons, appeared to increase in response to stress, though this was not statistically significant. Pretreatment with a selective CRH-R1 antagonist, CP-154,526, significantly attenuated stress-induced corticotropin (ACTH) secretion as well as c-fos mRNA expression in the PVN. These results demonstrate that acute stress increases neuronal activation and CRH-R1 mRNA expression primarily in CRH-producing neurons of the parvocellular PVN, that CRH-R1 message is translated to CRH-R1 protein, and that PVN neurons are activated at least in part through CRH-R1 under acute stress. The data further support the possibility of feedback regulation of CRH itself in CRH-producing neurons.

Surgical results of skull base surgery for the treatment of head and neck malignancies involving skull base: multi-institutional studies on 143 cases in Japan

We analyzed 143 cases of skull base surgery collected from the eight institutions of the Study Group supported by the Grant-in-Aid for Cancer Research from the Ministry of Health and Welfare of Japan. Histologically, the most common type was squamous cell carcinoma (n = 78), which was followed by olfactory neuroblastoma (n = 16) and adenoid cystic carcinoma (n = 16). The most frequent surgical approach was frontal craniotomy (n = 66), followed by front-temporal craniotomy (n = 54) and infratemporal fossa approach (n = 8). For repair of dura matter, fascia lata was used in 37 cases. galeopericranial flap in 35 and temporal muscle fascia in 16. The 5-year survival rate by Kaplan-Meier method of nose and paranasal sinus carcinoma (n = 119) was 48%. As for histological classification, the survival rates were both 65%) in adenoid cystic carcinoma (n = 12) and bone soft tissue malignancy (n = 10), 62% in olfactory neuroblastoma (n = 16), 46% in squamous cell carcinoma (n = 62) and 33% in adenocarcinoma (n = 11). All the three cases of malignant melanoma died within 1 year, so we considered skull base surgery to be contraindicated for this disease. Complications were observed in 62 out of the 143 cases (43%); local infection was most frequent in 29 cases. liquorrhea in 18, abscess in 16, necrosis of the flap and meningitis in ten cases, DIC in four, rupture of the internal carotid artery in two and cerebral thrombosis in one. Death caused directly by surgery was in ten cases (7%). It is important that a multi-center registry be maintained to have a large enough database for comparison of results, and prognosis for each histological entity and further define the role of multidisciplinary treatment.

Genome sequence of a VP2/NS junction region of pillar cell necrosis virus (PCNV) in cultured Japanese eel Anguilla japonica

Pillar cell necrosis virus (PCNV) is an aquatic birnavirus that was isolated from farmed Japanese eel experiencing mass mortality. In this study, a VP2/NS junction region in genome segment A of PCNV was amplified by reverse transcriptase polymerase chain reaction (RT-PCR) and sequenced. The VP2/NS region in PCNV had the highest homology with that of a strain Ab of infectious pancreatic necrosis virus (IPNV). This result revealed that PCNV belongs to birnavirus genogroup II.

Expression of corticotropin releasing factor (CRF), urocortin and CRF type 1 receptors in hypothalamic-hypophyseal systems under osmotic stimulation

The expression of corticotropin releasing factor (CRF) and urocortin in hypothalamic magnocellular neurones increases in response to osmotic challenge. To gain a better understanding of the physiological roles of CRF and urocortin in fluid homeostasis, CRF, urocortin and CRF type 1 receptor (CRFR-1) gene expression was examined in the hypothalamic-hypophyseal system usingin situ and double-label in situ hybridization following chronic salt loading. CRFR-1 expression was further examined by immunohistochemistry and receptor binding. Ingestion of hypertonic saline by Sprague-Dawley rats for 7 days induced CRF mRNA exclusively in the oxytocin neurones of the magnocellular paraventricular nucleus (PVN) and the supraoptic nucleus (SON), but induced CRFR-1 mRNA in both oxytocin and vasopressin-containing magnocellular neurones. Hypertonic saline treatment also increased urocortin mRNA expression in the PVN and the SON. In the SON, urocortin was localized to vasopressin and oxytocin neurones but was rarely seen in CRF-positive cells. Changes in CRFR-1 mRNA expression in magnocellular neurones by hypertonic saline treatment were accompanied by changes in CRFR-1 protein levels and receptor binding. Hypertonic saline treatment increased CRFR-1-like immunoreactivity in the magnocellular PVN and SON, and decreased it in the parvocellular PVN. CRF receptor binding in the PVN and SON was also increased in response to osmotic stimulation. Finally, hypertonic saline treatment increased CRFR-1 mRNA, CRFR-1-like immunoreactivity and CRF receptor binding in the intermediate pituitary. These results demonstrate that the increase in the expression of CRF and urocortin message in magnocellular neurones induced by salt loading is accompanied by an increase in CRF receptor levels and binding in the hypothalamus and intermediate pituitary. Thus, CRF and urocortin may exert modulatory effects locally within magnocellular neurones as well as at the pituitary gland in response to osmotic stimulation.

[The medical team approach to the suicide--attempted patients by taking drugs or chemicals--participation of the medical social workers]

There are many suicide-attempted patients admitted to the critical care medical center of the Kitakyushu General Hospital. Suicide-attempted patients need psychosocial intervention from the beginning of their hospitalization, because they have their own psychosocial problems. Accordingly, medical social workers (MSW) give psychosocial assistance to the patients in our critical care medical center. In 1997, we participated in the treatment of 53 patients out of 64 suicide-attempted patients. Forty-four patients committed suicide by ingesting some drugs or poisons, and 9 patients committed suicide by jumping from a height or by self-burning. Kinds of drugs or chemicals used for suicide were medicinal drugs (55.3%), household medicines (14.9%), agricultural chemicals (10.7%), insecticides (8.5%), detergents (4.3%), household chemicals (4.3%) and others (2.0%). The largest number of male patients was in their fifties (6 out of 15 male patients). Patients with alcoholism held the first place in male patients. The largest number of female patients was in their twenties (11 out of 29 female patients). There were many female patients with mood disorder, drug dependence or psychopathy. If the patients are discharged without receiving psychosocial measures, it may be every possibility that the patients commit suicide again. MSW make the cause of suicide clear and assess the mental status, and also have interview with patient's families. If both MSW and the doctors in charge judge that there is high possibility of repeated suicide, MSW introduce the patient to the special hospital under the consent of the patient and families. Thirty-five patients out of 44 patients transferred to the psychiatric hospitals. It is important that MSW join the treatment of suicide-attempted patients in order to prevent repeated suicide.

Significance of low mRNA levels of interleukin-4 and -10 in mononuclear cells of the synovial fluid of patients with rheumatoid arthritis

Our objective was to investigate the clinical significance of Th1 and Th2-type cytokines, such as interferon-gamma (IFNgamma) interleukin (IL)-12, IL-4 and IL-10, in the mononuclear cells (MNC) of the synovial fluid (SF) in patients with rheumatoid arthritis (RA). The cytokine production in the MNC obtained from the SF (SF-MNC) in 30 patients with RA and 10 with gout was examined by measuring the mRNA levels of IFNgamma, IL-12, IL-4 and IL-10 by semiquantitative RT-PCR. The mRNA levels of IFNgamma, IL-4 and IL-10 were significantly higher in the SF-MNC of RA patients than in those of gout patients (p<0.001, p<0.01 and p<0.001, respectively). Correlations between mRNA levels were significant for IL-12 and IL-4, IL-12 and IL-10, and IL-4 and IL-10 (p<0.05). The mRNA levels of IL-4 and IL-10 were very low compared to those of IL-12 in seven of the 30 patients with RA; all of these patients were in stage 4, and serum levels of CRP, ESR and blood platelet count which are considered as indices of the severity of inflammation, were significantly elevated in these seven patients compared to the other 23 RA patients. The markedly reduced synthesis of both IL-4 and IL-10 mRNA could be considered to be related to the progression and/or activity of RA. The results of this study therefore indicate an imbalance in the levels of Th1 and Th2 cytokines at the site of inflammation in RA, and draw attention to the possibility of treatment of progressive or intractable RA with IL-4 and/or IL-10.

Relationships between perceived workload, stress and oxidative DNA damage

OBJECTIVES

The present study was performed to investigate the relationship between work-related factors, including psychological stress, and the formation of a type of oxidative DNA damage, 8-hydroxydeoxyguanosine (8-OH-dG), in order to examine their possible risk factor for occupational carcinogenesis.

METHODS

A total of 54 healthy workers (27 male and 27 female, aged 41.2 +/- 12.5 years) in a company were investigated for 8-OH-dG levels in the peripheral blood leukocytes at the time of a questionnaire survey regarding several factors, such as working hours, workload, fatigue, sleep, psychological stress and the prospect of alleviating it. Subjects were limited to non-smoking and non-drinking workers to exclude the influence of cigarette smoking and alcohol drinking, which have been reported to have associations with the formation of 8-OH-dG.

RESULTS

The levels of 8-OH-dG in female subjects were significantly related to the perceived workload (F = 5.56, P = 0.010), the perceived psychological stress (F = 6.15, P = 0.007), and the impossibility of alleviating stress (F = 3.82, P = 0.048). No associations were observed in male subjects.

CONCLUSIONS

Psychological stress and perceived over-work appear to be related to the pathogenesis of cancer via the formation of 8-OH-dG, particularly in female workers.

Psychosocial factors as a potential trigger of oxidative DNA damage in human leukocytes

Although numerous studies have been carried out on the stress-cancer linkage, the results are still inconclusive. One of the useful, but rarely applied, methods to assess this linkage is to examine the relationship between psychosocial stress and cancer-predisposing genetic alterations simultaneously. We investigated whether various psychosocial factors can be associated with the levels of 8-hydroxydeoxyguanosine (8-OH-dG), a biomarker of cancer-related oxidative DNA damage, in peripheral blood leukocytes in 362 healthy workers (276 males and 86 females). After adjustments for age, body mass index, cigarette smoking, and alcohol use, female subjects showed positive relationships between the amount of 8-OH-dG and the Tension-Anxiety, Depression-Rejection, Anger-Hostility, Fatigue, and Confusion scores of the Profile of Mood States, respectively. The levels of 8-OH-dG also increased reliably in the female subjects who had poor stress-coping behaviors, particularly wishful thinking strategy, in the NIOSH general job stress instrument. There were positive relationships of the 8-OH-dG levels to average working hours, a self-blame coping strategy, and recent loss of a close family member in male subjects. These findings in a nonclinical sample of healthy adults not only provide evidence of a stress-cancer linkage, but also suggest possible sex differences in the mechanisms of stress-related cancer initiation.

Visualization of the attachment organelle and cytadherence proteins of Mycoplasma pneumoniae by immunofluorescence microscopy

A method was developed for protein localization in Mycoplasma pneumoniae by immunofluorescence microscopy. The P1 adhesin protein was revealed to be located at least at one cell pole in all adhesive cells, as has been observed by immunoelectron microscopy. Cell images were classified according to P1 localization and assigned by DNA content. Cells with a single P1 focus at one cell pole had a lower DNA content than cells with two foci, at least one of which was positioned at a cell pole. Those with one focus at each cell pole had the highest DNA content, suggesting that the nascent attachment organelle is formed next to the old one and migrates to the opposite cell pole before cell division. Double staining revealed that the accessory proteins for cytadherence-HMW1, HMW3, P30, P90, P40, and P65-colocalized with the P1 adhesin in all cells. The localization of cytadherence proteins was also examined in cytadherence-deficient mutant cells with a branched morphology. In M5 mutant cells, which lack the P90 and P40 proteins, HMW1, HMW3, P1, and P30 were focused at the cell poles of short branches, and P65 showed no signal. In M7 mutant cells, which produce a truncated P30 protein, HMW1, HMW3, P1, P90, and P40 were focused, and P65 showed no signal. In M6 mutant cells, which express no HMW1 and a truncated P30 protein, the P1 adhesin was distributed throughout the entire cell body, and no signal was detected for the other proteins. These results suggest that the cytadherence proteins are sequentially assembled to the attachment organelle with HMW1 first, HMW3, P1, P30, P90, and P40 next, and P65 last.

Hepatic lymphocyte transplantation in hyperbilirubinemic gunn rats

Hepatic lymphomyeloid cells (HLCs) are thought to contain liver stem cells. We investigated whether HLCs generated enzyme-producing cells in vivo. HLCs from normal Wistar/Shi rats and rats in which liver ischemia was induced using a portal clamp 4 days previously were studied histopathologically and characterized using flow cytometry. Splenic lymphocytes obtained from these animals were compared as a control. The proliferative activity of HLCs and splenic cells from both groups was also tested by stimulation with concanavalin A. HLCs contained a significantly higher number of NK-T cells and OV6+ cells compared with the splenic cells. The HLCs from rats in which liver ischemia was induced tended to have greater proliferative activity than those from normal rats, while the proliferative activity of splenic lymphocytes was impaired by liver ischemia. The HLCs obtained from Wistar/Shi rats with liver ischemia were then injected into hereditary hyperbilirubinemic Gunn rats to determine whether the HLCs generated enzyme-producing cells. After injection of these stimulated HLCs, the titer of serum bilirubin in the recipient rats was markedly reduced over a long time course (6.80+/-0.93 to 4.87+/-0.22 mg/dl after 1 month and 3.52+/-1.33 mg/dl after 6 months). The results of the present study indicate that HLCs have different populations than splenic cells, and ischemia-reperfusion of the liver increased their proliferative activity. HLC transplantation successfully reduced high bilirubin levels over a long time course.

Acid stimulates E-cadherin surface expression on gastric epithelial cells to stabilize barrier functions via influx of calcium

BACKGROUND AND AIMS

E-cadherin, which is a [Ca2+]-dependent, homotypic cell-cell adhesion molecule, is expressed in gastrointestinal epithelial cells. Much has been learned about the down-regulation of E-cadherin expression in gastrointestinal tumours, Barrett's oesophageal dysplasia, and Crohn's disease, but the functions of this molecule in normal gastrointestinal mucosa are less known.

METHODS

In this study, we investigated the relationship between E-cadherin expression and permeability using rat cultured gastric and intestinal epithelial cells following a 30-min exposure to various pH solutions. We also investigated the participation of [Ca2+] in these events.

RESULTS

E-cadherin expression increased under acid (pH 4) but not alkali (pH 10 or 11) exposure only for gastric epithelial cells. Gastric epithelial permeability was maintained only against acid exposure while intestinal permeability increased under both conditions. Transient influx of [Ca2+] was only observed for gastric epithelial cells just after acid exposure.

CONCLUSIONS

These findings suggest that E-cadherin expression on gastric epithelium stabilizes the epithelial barrier against acid, probably through influx of [Ca2+]. This event is thought to be one of the protective mechanisms in gastric mucosa against acid back-diffusion, which is one of the causes of peptic ulcer formation.

Effect of a serotonin receptor antagonist on interleukin-6-induced pulmonary hypertension in rats

STUDY OBJECTIVES

To determine the significance of serotonin in the pathogenesis of interleukin (IL) 6-induced pulmonary hypertension (IL-6-PH) in rats, the plasma serotonin concentrations, and the effects of a specific antagonist of the serotonin (5-hydroxytryptamine [5-HT]) receptor, 1-[o-(m-methoxyphenyl)ethyl]phenoxy]-3-(dimethylamino)-2-propyl hydrogen succinate hydrochloride (MCI) on the degree of pulmonary hypertension (PH) were investigated in MCI-treated IL-6-PH (IL-6-MCI-PH) rats.

MEASUREMENTS

The thickness of the media of small pulmonary arteries and the ratio of the weight of the right ventricle free wall (RV) to that of the left ventricle with the septum (LV + S) were measured as indexes of the degree of PH. Serotonin concentrations in plasma and in supernatants of cultured vascular smooth muscle cells (VSMCs) stimulated by IL-6 were measured by high-performance liquid chromatography. The amplification of DNA encoding the 5-HT receptor in the lung specimen and VSMCs was performed by polymerase chain reaction.

RESULTS

The degree of PH, as determined by the medial thickness of small pulmonary arteries, was significantly increased in IL-6-PH rats as compared with normal control rats (p<0.05), and that in IL-6-MCI-PH rats was not significantly different from that in normal control rats. The RV/LV + S weight ratio in the IL-6-PH rats was significantly higher than that in normal control rats (p < 0.01). The RV/LV + S weight ratio in IL-6-MCI-PH rats was significantly lower than that in IL-6-PH rats (p < 0.01) and was not significantly different from that in normal control rats. The serotonin concentration was significantly higher in IL-6-PH rats than in normal control rats (p < 0.02), and the serotonin concentration in IL-6-MCI-PH rats was not significantly different from that in the normal control rats. The expression levels of the 5-HT receptor messenger RNA in the lung tissue tended to increase in IL-6-PH rats but was suppressed in IL-6-MCI-PH rats. IL-6 significantly increased the amount of serotonin released from VSMCs (p < 0.02). The expression of the 5-HT receptor messenger RNA was observed with IL-6 stimulation as was observed with serotonin stimulation in VSMCs.

CONCLUSIONS

Serotonin receptor antagonists could be considered as potentially useful agents for the treatment of chronic thromboembolic PH, as well as for that of primary PH and PH associated with collagen vascular diseases.

Roles of phospholipase Cbeta4 in synapse elimination and plasticity in developing and mature cerebellum

The beta isoforms of phospholipase C (PLCbetas) are thought to mediate signals from metabotropic glutamate receptor subtype 1 (mGluR1) that is crucial for the modulation of synaptic transmission and plasticity. Among four PLCbeta isoforms, PLCbeta4 is one of the two major isoforms expressed in cerebellar Purkinje cells. The authors have studied the roles of PLCbeta4 by analyzing PLCbeta4 knockout mice, which are viable, but exhibit locomotor ataxia. Their cerebellar histology, parallel fiber synapse formation, and basic electrophysiology appear normal. However, developmental elimination of multiple climbing fiber innervation is clearly impaired in the rostral portion of the cerebellar vermis, where PLCbeta4 mRNA is predominantly expressed in the wild-type mice. In the adult, long-term depression is deficient at parallel fiber to Purkinje cell synapses in the rostral cerebellum of the PLCbeta4 knockout mice. The impairment of climbing fiber synapse elimination and the loss of long-term depression are similar to those seen in mice defective in mGluR1, Galphaq, or protein kinase C. Thus, the authors' results strongly suggest that PLCbeta4 is part of a signaling pathway, including the mGluR1, Galphaq and protein kinase C, which is crucial for both climbing fiber synapse elimination in the developing cerebellum and long-term depression induction in the mature cerebellum.

Anxiety and depressive states in multiple chemical sensitivity

Cases with multiple chemical sensitivity (MCS) frequently present mental symptoms. This study discusses the characteristics of the anxiety and depressive state of MCS by comparing patients of MCS with a gender and age-matched control group. In this investigation, MCS cases were selected among those satisfying the diagnostic criteria of Cullen after ruling out other physical diseases. Patients visiting ophthalmologists with other diseases were designated as the control. Evaluation of the anxiety and depressive state was performed in 48 cases of MCS and 48 controls using the Japanese version of the State-Trait Anxiety Inventory, the Self-rating Depression Scale (SDS), and the Hamilton Rating Scale for Depression. Significantly higher mean values of subjective anxiety and a depressive state were obtained in 18 MCS cases than in 18 controls for the follow-up patients, while no significant difference was observed between MCS and controls of 30 new patients for each group. Therefore, anxiety in MCS is characterized by the continuous high anxiety level. MCS is also characterized by a continuance of depressive state at a "neurotic level" category by SDS. The anxiety scores and depressive levels were highly correlated in MCS and controls at the first and subsequent appearances, except those in the follow-up control cases. In conclusion, both anxiety and a depressive state in MCS remained at high level until the subsequent examination, when those in controls decreased to a normal level.

Importance of packing coefficients of host cavities in the isomerization of open host frameworks: guest-size-dependent isomerization in cholic acid inclusion crystals with monosubstituted benzenes

The crystal structures of inclusion compounds of cholic acid (CA) with 28 monosubstituted benzenes have been systematically investigated. All of the crystals belong to the monoclinic space group P2(1) and have bilayer structures with one-dimensional molecular channels that can include guest compounds. They are classified into four types of host frameworks that depend on the conformations and stacking modes of the host compound. The host frameworks and the host-guest ratios depend primarily on the molecular volumes of the guest compounds. The packing coefficient of the host cavity (PCcavity), which is the volume ratio of the guest compound to the host cavity, is used to clarify the relationship between the guest volume and isomerization of the host frameworks. The value of PCcavity, for stable inclusion compounds lies in the range of 55-70%. Compounds out of this range induce isomerization of the host frameworks. The packing coefficients of other host-guest compounds, in which the guest components are included in the host cavities through steric dimensions and van der Waals forces, are also in this range. These results indicate that PCcavity is a useful parameter correlation for guest recognition and isomerization of the host frameworks.

Haemangiopericytoma of infratemporal fossa

Haemangiopericytomas (HPCs) are rare vascular tumours that commonly involve the soft tissues of the trunk and lower extremities. In the head and neck, the most common sites are the nasal cavity and the paranasal sinuses, and unusually, the orbital region, the parotid gland, and the neck. We report a patient with HPC that originated in the infratemporal fossa and involved the pterygopalatine and the middle cranial fossae, apparently the first such case to be reported. Although the patient has undergone resection on three separate occasions, the tumour recurred. We then performed an extended resection using the infratemporal fossa approach type D. The patient has shown no recurrence in the past five years. Although histopathologic confirmation of this malignancy may be difficult, extensive resection remains the most effective treatment in such cases.

Mechanical vibratory stimulation of feline forepaw skin induces long-lasting potentiation in the secondary somatosensory cortex

We investigated the long-lasting effects of mechanical vibratory stimulation of the skin on the excitability of feline cortical neurons in the forelimb areas of the primary (SI) and secondary (SII) somatosensory cortices. Conditioning mechanical stimuli were 300 bursts of 10 pulses at 200 Hz delivered with a 10-s interburst interval from a mechanical stimulator. Test field potentials and unit discharges were evoked by electrical stimulation to the ventral posterolateral thalamic nucleus (VPL) or by single mechanical stimuli applied to the skin. In SII, the mechanical burst stimulation to the skin increased the amplitudes of field potentials and the frequency of unit discharges elicited by single mechanical stimuli applied to the skin. The vibratory conditioning stimulus also produced a similar potentiation of the VPL-evoked field potentials (126-139% increase in amplitude, P < 0.05) with an associated increase in firing rates of extracellularly recorded neuronal activity (117%, P < 0.001). These potentiations persisted through the entire experimental period of 120 min. The translaminar current source density analysis calculated from the VPL-evoked field potentials increased to 127% of the control value (P < 0.01). In contrast, in SI we observed no significant changes in the field potential amplitudes or in the currents generated in superficial layers (91-117%). Taken together with the previous finding that tetanic electrical stimulation of VPL induces long-lasting potentiation of the VPL-evoked cortical responses in SII but not of those in SI, the present results suggest that SII has a large capacity for the rapid functional plasticity involved in the learning that occurs during repeated tactile experiences.