Relationship between serum cholesterol levels and meta-chlorophenylpiperazine-induced cortisol responses in healthy men and women

We investigated the effect of cholesterol on serotonergic receptor function in 20 healthy male and 10 healthy female subjects using cortisol responses to meta-chlorophenylpiperazine (m-CPP) neuroendocrine challenge tests. M-CPP, a metabolite of the antidepressant trazodone, has been widely used in psychopharmacology research as a probe of serotonin function. In the human brain, m-CPP binds both to various serotonergic receptors, mainly 5-HT(2C), and to alpha(2)-adrenoceptors. After an overnight fast, the subjects received m-CPP (0.5 mg/kg) or identical placebo capsules orally in a randomized, double blind, crossover design. Blood was obtained for measurement of cholesterol and cortisol. In some analyses, especially in males, there were significant positive correlations between serum cholesterol levels and cortisol responses. These findings suggest the possibility that serum cholesterol levels may be positively associated with serotonergic receptor function. The existence of such an association may provide an explanation for reported increases in depression, suicide and violence in individuals with low or lowered cholesterol.

Comparative study of transurethral laser prostatectomy versus transurethral electroresection for benign prostatic hyperplasia

BACKGROUND

Transurethral resection of the prostate (TURP) is the gold standard treatment for benign prostatic hyperplasia (BPH). Recently, less invasive transurethral laser prostatectomy, such as visual laser ablation (VLAP) or interstitial laser coagulation (ILCP), have been developed. Herein, we investigated the efficacy of VLAP and ILCP compared to TURP.

METHODS

A total of 80 patients with BPH were treated: 20 patients by VLAP, 30 patients by ILCP and 30 patients by TURP. All patients were followed up for 12 months after their operations. Treatment outcomes were evaluated by four different criteria: (i) the International Prostatic Symptom Score (I-PSS), (ii) the maximum flow rate (Qmax), (iii) postvoided residual urine volume before treatment and one, three, six and 12 months after treatment, and (iv) prostatic volume before operation and three and six months postoperatively.

RESULTS

The I-PSS, Qmax and residual urine volume were significantly improved compared to baseline levels and the improvement continued for 12 months in the three groups: for I-PSS (P<0.001 in the VLAP group and P<0.0001 in the ILCP and TURP groups), Qmax (P<0.001 in the VLAP and ILCP groups, and P<0.0001 in the TURP group), residual urine volume (P<0.01 in the VLAP group and P<0.0001 in the ILCP and TURP groups). Significant reduction of the prostatic volume was recorded only in the ILCP and TURP groups (P<0.001).

CONCLUSION

Visual laser ablation and ILCP can be good alternative treatments for BPH. Visual laser ablation provides good outcomes in patients with small-sized BPH and with risk factors such as heart disease or anticoagulation therapy.

Expression of cyclooxygenase-2 in prostate carcinoma

BACKGROUND

Nonsteroidal antiinflammatory drugs inhibiting cyclooxygenase (COX) enzyme activity in both its constitutive (COX-1) and inducible (COX-2) isoforms were shown also to inhibit the development of colon carcinoma in animal models. COX-2 is an inducer of angiogenesis of new blood vessels. The expression of COX-1 and COX-2 in prostate tissues from patients with prostate carcinoma was investigated using reverse transcriptase-polymerase chain reaction (RT-PCR) and immunohistochemistry.

METHODS

Tumor specimens were obtained from 28 prostate carcinoma (PC) patients, 8 benign prostatic hyperplasia (BPH) patients, 1 prostatic intraepithelial neoplasia (PIN) patient, and 8 specimens of normal prostate tissue (NP). Affinity-purified COX-1 and COX-2 antibodies were used in immunochemistry.

RESULTS

Very weak expression of COX-1 and marked expression of immunoreactive COX-2 in tumor cells was obtained. In contrast, expression of both isoforms was very weak in all cases of BPH and in the NP tissues. Immunoreactive COX-1 also was very weak in all cases of benign tissues. The extent and intensity of immunoreactive COX-2 polypeptides in tumor cells was statistically much greater than those of cells from BPH. Immunostaining with normal rabbit immunoglobulin G was completely negative. By RT-PCR analysis, enhanced expression of COX-2, but not COX-1, was observed in PC tissue. BPH displayed faint expression of COX-2.

CONCLUSIONS

The results of the current study demonstrated that human prostate carcinoma cells generated COX-2, and that COX-2 might play an important role in the proliferation of prostate carcinoma cells. These findings suggest that inhibition of COX-2 development may lead not only to inhibition of the proliferation and metastasis of prostate carcinoma but also to the inhibition of prostate carcinogenesis.

Low dosage of levomepromazine did not increase plasma concentrations of fluvoxamine

The cytochrome enzyme P450 2D6 (CYP2D6) is thought to play a role in the human metabolism of fluvoxamine. Levomepromazine is a potent inhibitor of CYP2D6. We coadministered a low dosage of levomepromazine and fluvoxamine in 15 patients and found that the low dosage of levomepromazine was effective in counteracting the fluvoxamine-induced insomnia and did not increase plasma fluvoxamine levels. These results suggest that the inhibition of CYP2D6 by levomepromazine has little effect on fluvoxamine metabolism. Therefore, a low dosage of levomepromazine, used as a hypnotic agent, appears to be effective and safe when coadministered with fluvoxamine. Since this was a pilot study without a placebo control, a double-blind placebo-controlled study is needed to confirm our preliminary findings.

Renal cell carcinoma in an L-shaped kidney

A 64-year-old man with a chief complaint of an asymptomatic abdominal mass was diagnosed as having a renal cell carcinoma in his L-shaped kidney. He was successfully treated with partial nephrectomy following selective embolization of the feeder artery. It is thought to be the first reported case of renal cell carcinoma occurring in an L-shaped kidney.

Effect of risperidone on plasma free 3-methoxy-4-hydroxyphenylglycol (pMHPG) levels in schizophrenic patients: relationship among plasma concentrations of risperidone and 9-hydroxyrisperidone, pMHPG levels, and clinical improvement

We examined the relationships among the clinical efficacies of risperidone, plasma concentrations of risperidone and its active metabolite, 9-hydroxyrisperidone, and changes in plasma free MHPG (pMHPG) in 14 schizophrenic patients. Clinical improvement in negative symptoms of schizophrenia treated with risperidone has been associated with increased pMHPG and, in the present study, there were positive correlations between plasma 9-hydroxyrisperidone concentrations and increased pMHPG levels. These results suggest that risperidone might improve negative symptoms in schizophrenia by influencing noradrenergic neurons.

Induction of hyperacute rejection of skin allografts by CD8+ lymphocytes

BACKGROUND

Second-set rejection is generally regarded as a phenomenon mainly mediated by humoral cytotoxic antibodies, although a few discordant data have been presented. In the reported experiments, we have taken advantage of the absence of production of specific cytotoxic alloantibodies contrasting with the normal development of transplantation cellular immunity, in two murine models: chimeric mice and RAG mice.

METHODS

Chimeras (BALB/c-->CBA) were obtained by transplantation of 2x10(7) fetal liver cells from BALB/c (H-2d) mice to lethally irradiated CBA (H-2k) mice. After hyperimmunization with third-party C57/ BL6 (B6) (H-2b) skin transplants and with injections of 2x10(7) B6 spleen cells, antibody production, and skin graft survival were analyzed. To identify further the factors or cells responsible for accelerated rejection of B6 skin transplants in hyperimmunized chimeras, transfer experiments were carried out involving the injection of serum, whole spleen cells, spleen T cells, spleen CD8+ T cells or spleen CD4+ T cells from chimeras into BALB/c mice that had received 6 Gy irradiation. The recipient mice were then grafted with B6 skin. Similarly, the immunodeficient RAG mice were used to construct a model of recipient animals with anti-H-2d hyperimmunized B6 T cells in the total absence of antibody.

RESULTS

In chimeras, anti-B6 cytotoxic antibodies were not detectable in any of hyperimmunized chimeric mice, yet accelerated rejection of B6 skin transplant occurred: a graft survival of 8.6+/-0.5 days (d), comparable to 8.9+/-0.8 d survival in CBA control mice subjected to the same hyperimmunization procedure, and significantly shorter than that in nonhyperimmunized (BALB/c-->CBA) chimeras (11.6+/-0.5 d) or in non-hyperimmunized CBA control mice (12.1+/-0.6 d). High titers of anti-B6 cytotoxic antibodies were present in the serum of hyperimmunized CBA control mice. In transfer experiments, the graft survival was over 14 d in mice treated with irradiation alone, with irradiation + serum or with irradiation + CD4+ T cells. It was significantly shorter in mice treated with irradiation + whole spleen cells, with irradiation + T cells or with irradiation + CD8+ T cells (8.9+/-0.8 d). Similarly, in immunodeficient RAG mice, reconstitution of the T cell compartment with T cells from hyperimmunized B6 mice led to accelerated rejection of BALB/c skin allografts (11.4+/-1.1 d vs. 18.8+/-0.8 d when T cells were provided by nonimmunized mice). In a second transfer of cells from these reconstituted RAG mice into naive RAG mice, CD8+ T cells were shown to induce accelerated rejection of skin allografts (12.0+/-0.6 d) whereas CD4+ T cells were much less efficient (16.5+/-0.1 d).

CONCLUSION

These data indicate that T cells, and especially the CD8+ subset, can be responsible for second-set rejection in the absence of anti-donor antibodies in chimeric and RAG mouse models. These sensitized CD8+ T cells are also likely to play an important role in normal mice, in addition to that of cytotoxic antibodies.

A novel servo-control system that imposes desired aortic input impedance on in situ rat heart

To clarify the pathophysiological role of dynamic arterial properties in cardiovascular diseases, we attempted to develop a new control system that imposes desired aortic impedance on in situ rat left ventricle. In 38 anesthetized open-chest rats, ascending aortic pressure and flow waveforms were continuously sampled (1,000 Hz). Desired flow waveforms were calculated from measured aortic pressure waveforms and target impedance. To minimize the difference between measured and desired aortic flow waveforms, the computer generated commands to the servo-pump, connected to a side branch of the aorta. By iterating the process, we could successfully control aortic impedance in such a way as to manipulate compliance and characteristic impedance between 60 and 160% of their respective native values. The error between desired and measured aortic flow waveforms was 70 +/- 34 microl/s (root mean square; 4.4 +/- 1.4% of peak flow), indicating reasonable accuracy in controlling aortic impedance. This system enables us to examine the importance of dynamic arterial properties independently of other hemodynamic and neurohumoral factors in physiological and clinical settings.

Increased brain angiotensin receptor in rats with chronic high-output heart failure

BACKGROUND

The renin-angiotensin system (RAS) plays a key role in the pathophysiology of chronic heart failure (CHF). In rats, we reported that CHF enhances dipsogenic responses to centrally administered angiotensin I, and central inhibition of the angiotensin-converting enzyme (ACE) prevents cardiac hypertrophy in CHF. This suggests that the brain RAS is activated in CHF. To clarify the mechanism of the central RAS activation in CHF, we examined brain ACE and the angiotensin receptor (AT) among rats with CHF.

METHODS AND RESULTS

We created high-output heart failure in 22 male Sprague-Dawley rats by aortocaval shunt. Four weeks after surgery, we examined ACE mRNA by reverse transcriptase polymerase chain reaction (RT-PCR) and AT by binding autoradiography. ACE mRNA levels were not significantly increased in the subfornical organ (SFO), the hypothalamus, or in the lower brainstem of CHF rats (n = 5) compared with sham-operated rats (SHM) (n = 6). Binding densities for type 1 AT (AT1) in the SFO (P < .05), paraventricular hypothalamic nuclei (P < .05), and solitary tract nuclei (P < .05) were higher in rats with CHF (n = 5) than in SHM rats (n = 6). Thus, in rats with CHF, AT1 expression is increased in brain regions that are closely related to water intake, vasopressin release, and hemodynamic regulation.

CONCLUSIONS

The fact that AT1 expression was upregulated in important brain regions related to body fluid control in CHF rats indicates that the brain is a major site of RAS action in CHF rats and, therefore, a possible target site of ACE-inhibitors in the treatment of CHF.

Inhibitory effects of clozapine and other antipsychotic drugs on noradrenaline transporter in cultured bovine adrenal medullary cells

The effects of clozapine and other antipsychotic drugs on noradrenaline (NA) transport were examined in cultured bovine adrenal medullary cells and in transfected Xenopus laevis oocytes expressing the bovine NA transporter. Incubation of adrenal medullary cells with clozapine (30-1000 ng/ml) inhibited desipramine (DMI)-sensitive uptake of [3H]NA in a concentration-dependent manner (IC50=110 ng/ml or 336 nM). Other antipsychotic drugs such as haloperidol, chlorpromazine, and risperidone also decreased [3H]NA uptake (IC50= 144, 220, and 210 ng/ml or 383, 690, and 512 nM, respectively). Eadie-Hofstee analysis showed that clozapine reduced V(max) of uptake of [3H]NA and increased K(m). Furthermore, clozapine inhibited specific binding of [3H]DMI to plasma membranes isolated from bovine adrenal medulla (IC50=48 ng/ml or 146 nM). Scatchard plot analysis of [3H]DMI binding revealed that clozapine decreased both B(max) and K(d). Other antipsychotic drugs, including haloperidol, chlorpromazine, and risperidone, also reduced [3H]DMI binding to the membranes. In transfected Xenopus oocytes expressing the bovine NA transporter, clozapine inhibited [3H]NA uptake in a concentration-dependent manner similar to that observed in adrenal medullary cells. These results suggest that clozapine and haloperidol directly inhibit transport of NA by acting on the site of an NA transporter that influences both substrate transport and binding of tricyclic antidepressants.

p53 status in multiple human urothelial cancers: assessment for clonality by the yeast p53 functional assay in combination with p53 immunohistochemistry

Multifocal synchronous or metachronous tumor development is a common observation in human urothelial cancer cases. However, the underlying mechanism has remained obscure. We have employed a new tool to investigate the p53 gene status, the yeast p53 functional assay, in combination with immunohistochemistry in a total of 50 tumor samples from 32 cases with urothelial cancers, including 8 with multiple synchronous tumor development and 2 demonstrating metachronous tumors. p53 mutations were found in 13 cases (9 with missense mutations, 3 with deletion, 1 with splicing mutation) by the yeast p53 functional assay. p53 protein overexpression was seen in all 9 cases with missense mutations, but in only one of the 4 cases with nonsense mutations. Two tumors without p53 mutation also showed positive p53 immunoreactivity. Overall, p53 abnormalities including mutations and/or protein overexpression were found in 15 (47%) cases. p53 abnormalities were significantly more frequent in non-papillary and in high grade tumors. Loss of the wild type allele in addition to a p53 mutation was suggested in 8 of the 15 (53%) cases. All 4 cases with mutations in multiple synchronous tumors had identical p53 mutations in the separate urothelial cancers, strongly suggestive of monoclonality. The one case with multiple metachronous tumors, in contrast, was characterized by variation in the p53 status, indicative of different clonal origins. In conclusion, combined assessment for p53 status as used here (yeast p53 functional assay plus immunohistochemistry) may provide insights into the molecular mechanisms of urothelial carcinogenesis.

Local epinephrine release in the rabbit myocardial interstitium in vivo

Although several investigations have suggested cardiac epinephrine (Epi) release, local Epi release in the myocardial interstitium in vivo has not been measured. Using cardiac microdialysis in the rabbit, we measured dialysate Epi and norepinephrine (NE) concentrations as indices of myocardial interstitial Epi and NE levels, respectively. Exocytotic release induced by local administration of KCl (100 mM) through the dialysis probe increased Epi to 24.2 +/- 13.2 pg/ml from a control value of 3.2 +/- 3.6 pg/ml (P < 0.01, n = 6). Non-exocytotic release induced by the local administration of tyramine (10 microg/ml) also increased Epi to 34.6 +/- 15.3 pg/ml (p < 0.05 from control, n = 6). We conclude that Epi can be released via both exocytotic and non-exocytotic release mechanisms from the heart.

Prediction of lithium response using. m-chlorophenylpiperazine challenge test: A preliminary finding

It is important to be able to predict a response to lithium before lithium administration because it usually takes 2 or 3 weeks for lithium to manifest its effect sufficiently. We hypothesized that lithium responders have a high post-synaptic serotonergic receptor function, whereas non-responders have low one. This is because it has been suggested that lithium's primary actions on the serotonergic neuron may be presynaptic and several reports have shown that lithium enhances serotonin synthesis and secretion at the presynaptic serotonergic neuron. As a preliminary study, we investigated the relationship between several responses to meta-chlorophenylpiperazine (a serotonergic agonist) reflecting the serotonergic receptor function and the clinical lithium response of 10 patients. No significant relationship between hormone responses and improvement ratios was found. However, there were significant relationships found between 'anger' during the challenge test and the improvement ratio and between 'tension' during the test and the improvement ratio. Thus, it seems that the hormone response to a serotonergic agonist is not useful for predicting lithium response. However, subjective responses such as anger and tension to a serotonergic agonist are possible candidates for predicting lithium response. In any case, further studies with larger numbers of participants are required to investigate whether subjective responses to a serotonergic agonist are useful for predicting lithium response.

Immunocytochemical localization of taurine in the developing retina of the lefteye flounder Paralichthys olivaceus

Light microscopic immunolocalization of taurine, a sulfur-containing free amino acid, was investigated in the developing retina of a lefteye flounder, Paralichthys olivaceus, which exhibits metamorphic changes with rod cell addition for 3-5 weeks after hatching. This immunocytochemical study of the developing retina revealed: 1) From 3 to 13 days after hatching, intense immunostaining was shifted from the surroundings of neural cells to the neural somata and processes in the inner retina. 2) Intense immunoreactivity appeared also in the outer and inner segments and basal processes (pedicles) of cone cells within 6 days or 13 days after hatching. 3) Lack of immunoreactivity was found in the outer segment of rod cells from their appearance during metamorphosis. These findings are discussed with the possible functional roles of taurine in the fish retina: 1) involvement in cell differentiation and/or development; 2) protection of the outer segments against light stimuli; and 3) regulation of neural transmission.

Clinical results of total cystectomy for 92 patients with bladder cancer

The survival rate of 92 patients with primary bladder cancer who had undergone total cystectomy during a 13-year period from 1984 to 1996 was examined. The mean follow-up period was 1,886 days. The 5-year survival rate was 67.9% and the 10-year survival rate was 55.1%. When survival rates were compared pathohistologically, with 81 patients with transitional cell carcinoma divided into two groups, a high-stage group including T3 and T4 patients and a low-stage group with all other patients, the cancer-specific 5-year survival rate of the low-stage group was 88.9% while that of the high-stage group was 45.4%; this difference was significant (p = 0.0002). There were also significant differences in survival rate between those with and those without regional lymph node metastasis, those with and those without lymphatic infiltration, and those with and those without vascular infiltration. However, there was no significant difference in survival rate for the 34 patients with T3 or T4 disease when those with or without chemotherapy and/or radiation therapy were compared.

Can quinolones cause hemorrhagic colitis of late onset? Report of three cases

PURPOSE

This study was undertaken to demonstrate that quinolones may cause acute colitis resembling penicillin-induced hemorrhagic colitis.

METHODS

We reviewed the medical records of patients with acute colitis in our institutes. Twenty-eight patients with acute hemorrhagic colitis in which no pathogenic microorganisms were identified were the subjects of this study. Pseudomembranous colitis caused by Clostridium difficile was excluded. Ulcerative colitis, Crohn's disease, and radiation proctocolitis were also excluded.

RESULTS

Among these patients, 25 had a history of recent administration of penicillin derivatives. The remaining three patients had never been given any penicillin derivatives, but had ingested quinolones approximately four weeks before the developing colitis had been identified. Klebsiella oxytoca was also isolated in these three patients.

CONCLUSIONS

Quinolones may cause acute hemorrhagic colitis. The time interval from antibiotic ingestion to onset of the condition may be much longer in quinolones than in penicillin derivatives.

Why the flexible cystoscope has not yet been widely introduced?: A questionnaire to Japanese urologists

BACKGROUND

The flexible cystoscope has not been as widely accepted in the field of urology as in other fields. The results of this investigation provided implications for determining the reasons for the under-use of flexible cystoscopy as well as for the drawbacks of the flexible cystoscope.

METHODS

We performed an investigation by sending a questionnaire to urologists asking them to compare the flexible cystoscope with the rigid cystoscope in order to determine why use of the former lags behind that of the latter.

RESULTS

We received answers from 420 urologists. We classified the urologist into four groups according to their years of experience. We also classified patients, for whom flexible cystoscopy was carried out, into four groups. The majority of the urologists in all groups thought that the flexible cystoscope provided a small field of vision and rough images. Urologists thought that the flexible cystoscope was inferior to the rigid cystoscope in terms of manipulability in biopsy. However, doctors who examined many patients using flexible cystoscopy believed that it was advantageous in terms of decreasing the patients' pain and they have experienced no problem in clinical practice.

CONCLUSIONS

Lack of experience in using the flexible cystoscope appears to be the main reason for the negative impression it generates. The flexible cystoscope can be routinely used in place of the rigid counterpart for urological investigations and it is recommended that it be used more widely for the benefit of the patients.

The effect of immunosuppressive agents (FK-506, rapamycin) on renal P450 systems in rat models

It is well known that cyclosporin, rapamycin and FK-506 (tacrolimus) are metabolized by the liver microsomal cytochrome P450 enzyme system. Although there have been reports of interaction between these drugs and the renal P450 enzyme system, differences among these immunosuppressants has not been comprehensively demonstrated. We have studied the individual capacities of these immunosuppressants to induce renal microsomal P450 enzymes similar to CYP2B4 and CYP4A2 by examining renal function in treated rats, and have correlated the results by means of biochemical, immunological and immunohistochemical assays of renal P450 enzymes. Cyclosporin caused impairment of renal function with an increase in renal-specific P450 content, but FK-506 and rapamycin did not. Laurate omega- and (omega-1)-hydroxylase activity increased in rats treated with rapamycin but decreased in those treated with FK-506. Prostaglandin A1 (PGA1) omega-hydroxylase activity increased in rats treated with FK-506 but was reduced by treatment with cyclosporin. Aminopyrine N-demethylase activity increased in rats treated with cyclosporin or FK-506, but not in those treated with rapamycin. Western-blot analysis revealed significant induction of P450, (similar to CYP2B4 of the rabbit P450 isozyme) in kidneys from rats treated with cyclosporin but not in those from rats receiving FK-506 or rapamycin. Histochemical studies clearly demonstrated a form of P450 such as CYP4A2 in the proximal tubules of rats treated with cyclosporin, but not in those of rats treated with FK-506 or rapamycin. These results show that although cyclosporin has a strong effect on renal P450 systems and induces such a system in kidney cortex (microsomal P450), FK-506 and rapamycin have no substantial effect on the induction of renal P450. These findings might clarify the nephrotoxicity induced by these immunosuppressive drugs.

Successful interstitial treatment for bilateral tongue cancer

We report three cases of bilateral tongue cancer who received interstitial brachytherapy successively for each tumour. Tumour control following treatment are as good as that for unilateral tongue cancer and there have been no severe complications in, or around, the tumour area after using a mandibular protective spacer and dose reduction for the second treatment.

A simpler and more accurate equation to predict daily lithium dose

Recently, the authors suggested that the lithium dose prediction equation created by Zetin and associates cannot always accurately predict a required lithium dose and that the inclusion of renal function data may improve the accuracy of the equation. The charts of 70 patients were reviewed to obtain data regarding factors thought to affect serum lithium concentrations, including renal function, and an equation to estimate the dose intended to achieve an expected concentration was derived by stepwise multiple linear regression. The equation was also applied to 30 other patients to evaluate its accuracy. The authors obtained the following equation: daily lithium carbonate dose (in milligrams) = 100.5 + 752.7 x (expected lithium concentration in millimoles per liter) - 3.6 x (age in years) + 7.2 x (weight in kilograms) - 13.7 x (blood urea nitrogen [BUN] in milligrams per deciliter). When the equation was applied to 30 patients, the mean +/- SD of deviations from the expected concentration was 0.15 +/- 0.30 mmol/L, and 19 patients (63%) had deviations of less than 0.20 mmol/L. On the other hand, when the equation set forth by Zetin and associates was applied to the same patients, the mean +/- SD of deviations from the expected concentration was 0.52 +/- 0.42 mmol/L, and only 6 patients (20%) had deviations of less than 0.20 mmol/L. Although it is necessary to measure BUN levels before starting lithium, this equation may be simpler and more accurate than that offered by Zetin and associates.

The influence of chronic sympathectomy on cutaneous blood flow in the rat tail

Tail blood flow (TBF) in the rat markedly increases during sympathetic withdrawal such as hyperthermia or lumbar sympathetic blockade. However, a long-term alteration of TBF after chronic sympathetic denervation is not well understood. In the present study, TBF following lumbar sympathectomy (LSX) was observed to ascertain whether subsequent changes in TBF occur in the absence of the sympathetic nervous activity in the rat tail. Assessed by recording tail and rectal temperature, the LSX immediately caused an increase in TBF. TBF was gradually decreased along with time and returned to the sham operated (SO) control level within 4 days. About a week after the surgery, a rapid increase in TBF in response to whole body heating was almost abolished in denervated animals. Neither hexamethonium (20 mg/kg, i.v.) for ganglion blockade nor intra-arterial infusion of alpha-receptor antagonist, phentolamine (10, 100 microg) produced vasodilation in LSX animals. Nitroprusside, a donor of nitric oxide, produced an increase in TBF in both LSX and SO animals. These results indicate that the tail vasculature after LSX constricts with capability to be vasodilated independent of sympathetic reinnervation. Quantification of the tail vascular mRNA expression by reverse transcriptase-polymerase chain reaction showed less endothelial nitric oxide synthetase in LSX group than that in SO group whereas endothelin-1 was not significantly different in both groups. It is suggested that functional changes in tail vascular endothelium takes at least a part in the reduction in TBF after LSX.

Neuronal uptake affects dynamic characteristics of heart rate response to sympathetic stimulation

Recently, studies in our laboratory involving the use of a Gaussian white noise technique demonstrated that the transfer function from sympathetic stimulation frequency to heart rate (HR) response showed dynamic characteristics of a second-order low-pass filter. However, determinants for the characteristics remain to be established. We examined the effect of an increase in mean sympathetic stimulation frequency and that of a blockade of the neuronal uptake mechanism on the transfer function in anesthetized rabbits. We found that increasing mean sympathetic stimulation frequency from 1 to 4 Hz significantly (P < 0.01) decreased the dynamic gain of the transfer function without affecting other parameters, such as the natural frequency, lag time, or damping coefficient. In contrast, the administration of desipramine (0.3 mg/kg iv), a neuronal uptake blocking agent, significantly (P < 0.01) decreased both the dynamic gain and the natural frequency and prolonged the lag time. These results suggest that the removal rate of norepinephrine at the neuroeffector junction, rather than the amount of available norepinephrine, plays an important role in determining the low-pass filter characteristics of the HR response to sympathetic stimulation.

A polydiagnostic study of depressive disorders according to DSM-IV and 23 classical diagnostic systems

The classification of mood disorders is one of the most highly debated topics in modern psychiatry. The introduction of DSM-III (and its followers) has set a new standard in this controversy but little empirical evidence is available as to how the various classical diagnostic categories of mood disorders by Kraepelin, Schneider, Leonhard, Hamilton, Kielholz, Winokur and others compare with this new standard. The Intensive Prospective Study arm of the Group for Longitudinal Affective Disorders Study has studied a broad spectrum of mood disorders in 23 participating centres from all over Japan with a polydiagnostic semistructured interview called Comprehensive Assessment List of Affective disorders. In this paper we examined how the various classical diagnostic systems of depressive disorders correspond to the DSM-IV diagnoses, and found the following: (1) The classical 'neurotic' or 'psychogenic' depressions are diagnosed as major depression and not as dysthymia in DSM-IV; although dysthymia was dubbed as 'depressive neurosis' in DSM-III, its criteria were not true to the traditional usage of the term. Viewed from the other side of the coin, DSM-IV can be said to stand in the unitary tradition. (2) Some of the classical diagnostic categories such as Schneider's depressive psychopathy and Klein's acute dysphoria as well as modern ones such as Akiskal's subaffective dysthymia and Angst's recurrent brief depression were rarely seen in traditional psychiatric treatment settings. (3) Comparisons of the unique diagnostic systems such as those by Leonhard, Winokur and Berner warrant further studies on their validity.

Effects of ethanol on the stress-induced expression of NGFI-A mRNA in the rat brain

We investigated expression of NGFI-A/zif268 mRNA, reliable marker for neuronal activation in response to stress in the brain of rats pretreated with ethanol. The rats were orally administrated with either 25% sucrose or 20% ethanol (20 ml of kg body weight) 10 min before the onset of the stress. The rats were exposed to immobilization stress for 20 min and quickly decapitated. The brains were extracted and immediately frozen. The level of NGFI-A mRNA was evaluated by in situ hybridization histochemistry. Prior ethanol administration attenuated the immobilization stress-induced upregulation of NGFI-A mRNA level in the neocortex and hippocampus. However, in the paraventricular hypothalamic nucleus, prior administration of ethanol did not affect the upregulation of this gene. These data suggest that ethanol abolishes the forebrain component of the stress response while it fails to attenuate the stress response on a region of the brain that regulates the autonomic nervous system and the hypothalamo-pituitary-adrenal axis. Regional differences in the expression of NGFI-A mRNA may be important for the complex interactions between ethanol and stress.

[Intrascrotal epidermoid cyst: report of two cases]

A 41-year-old man and a 47-year-old man presented with an intrascrotal mass. The routine studies and ultrasonography showed that the mass was not associated with the testis, epididymis or spermatic cord, but the magnetic resonance imaging was the most useful for making a preoperative diagnosis. Both patients received transscrotal resection of the mass, the histopathological diagnosis of which was epidermoid cyst. A total of 24 cases of epidermoid cyst have been reported in the Japanese literature.

Simultaneous identification of static and dynamic vagosympathetic interactions in regulating heart rate

We earlier reported that stimulation of either one of the sympathetic and vagal nerves augments the dynamic heart rate (HR) response to concurrent stimulation of its counterpart. We explained this phenomenon by assuming a sigmoidal static relationship between nerve activity and HR. To confirm this assumption, we stimulated the sympathetic and/or vagal nerve in anesthetized rabbits using large-amplitude Gaussian white noise and determined the static and dynamic characteristics of HR regulation by a neural network analysis. The static characteristics approximated a sigmoidal relationship between the linearly predicted and the measured HRs (response range: 212.4 +/- 46.3 beats/min, minimum HR: 96.0 +/- 28.4 beats/min, midpoint of operation: 196.7 +/- 31.3 beats/min, maximum slope: 1.65 +/- 0.51). The maximum step responses determined from the dynamic characteristics were 7.9 +/- 2.9 and -14.0 +/- 4.9 beats. min-1. Hz-1 for the sympathetic and the vagal system, respectively. Because of these characteristics, changes in sympathetic or vagal tone alone can alter the dynamic HR response to stimulation of the other nerve.

New simple methods for isolating baroreceptor regions of carotid sinus and aortic depressor nerves in rats

We developed new methods for isolating in situ baroreceptor regions of carotid sinus and aortic depressor nerves in halothane-anesthetized rats. After ligation of the root of the external carotid artery, the internal carotid and pterygopalatine arteries were embolized with two ball bearings of 0.8 mm in diameter. Bilateral carotid sinus pressures were changed between 60 and 180 mmHg in 20-mmHg steps lasting 1 min each. The sigmoidal steady-state relationship between aortic and carotid sinus pressures in 11 rats indicated the maximum gain of the carotid sinus baroreflex to be -2. 99 +/- 0.75 at 120 +/- 5 mmHg. An in situ isolation of the baroreceptor area of the right aortic depressor nerve could be made by ligation of the innominate, common carotid, and subclavian arteries in 9 rats. Pressure imposed on the subclavian baroreceptor was altered between 40 and 180 mmHg in 20-mmHg steps lasting 1 min each. The sigmoidal steady-state relationship between the aortic depressor nerve activity and imposed pressure showed that the baroreceptor gain peaked at 118 +/- 4 mmHg. We established an easy approach to the rat baroreflex and baroreceptor research.

Ex vivo expansion and differentiation of unselected peripheral blood progenitor cells in serum-free media

The ability to expand and differentiate unselected PBPC was investigated. Cells were grown in serum-free media containing stem cell factor, GCSF and megakaryocyte growth and development factor (pegylated PEG-rHuMGDF) with or without supplemental serum. Optimal proliferation occurred when PBPC were cultured without prior Ficoll-Paque separation in serum-free media. Cell yields after 17 days of culture were proportional to the percentage of CD34+ cells in the starting population and were 1170+/-302-fold higher than the starting numbers of CD34+ cells. Granulocyte-macrophage colony-forming units increased over 12 days of culture, whereas the numbers of erythroid colony-forming cells peaked between 4 and 7 days. Elimination of PEG-rHuMGDF from cell cultures resulted in significantly lower yields of myeloid and erythroid colony-forming cells and total cell numbers. Cell differentiation into neutrophils was indicated by progressive increases in CD11b, CD15, and CD66b expression. Expanded neutrophils phagocytosed and killed bacteria as efficiently as neutrophils from normal donors. Large-scale expansion studies yielded similar proliferation and differentiation results as parallel small-scale cultures. Therefore, unselected PBPC can be efficiently expanded and differentiated into large numbers of functional mature neutrophils.

Carbamazepine-induced up-regulation of voltage-dependent Na+ channels in bovine adrenal medullary cells in culture

Treatment of cultured bovine adrenal medullary cells with carbamazepine (CBZ) for 5 days caused an increase in catecholamine secretion induced by veratridine, an activator of voltage-dependent Na+ channels. However, no increase was stimulated by carbachol, an agonist of nicotinic receptors, or by 56 mM K+, a depolarizing agent that activates voltage-dependent Ca++ channels. CBZ (30 microg/ml) treatment enhanced veratridine-induced catecholamine secretion in a time-dependent manner (increases of 25%, 65% and 70% for 3, 5 and 7 days of treatment, respectively). CBZ treatment (5 days) increased veratridine-induced catecholamine secretion in a concentration-dependent manner (increases of 27%, 36%, 45% and 55% at 10, 15, 20 and 30 microgram/ml of CBZ, respectively). CBZ treatment also increased 22Na+ influx and 45Ca++ influx stimulated by veratridine. The stimulatory effect of CBZ treatment on catecholamine secretion was blocked by either actinomycin D or cycloheximide, an inhibitor of protein synthesis. Additive responses of catecholamine secretion and 22Na+ influx induced by veratridine were associated with combined exposure of the cells to CBZ and dibutyryl cyclic AMP. CBZ treatment (30 microg/ml, 5 days) significantly increased the specific binding of [3H]saxitoxin to cell membranes. A Scatchard analysis of [3H]saxitoxin binding revealed that CBZ increased the Bmax value without any change in the dissociation constant. These findings suggest that CBZ up-regulates the density and activity of voltage-dependent Na+ channels.

Accumulation of cAMP augments dynamic vagal control of heart rate

Recent investigations in our laboratory using a Gaussian white noise perturbation technique have shown that simultaneous sympathetic stimulation augmented the gain of the transfer function from vagal stimulation frequency to heart rate response. However, the mechanism of that augmentation remains to be elucidated. In this study, we examined in anesthetized rabbits how three pharmacological interventions known to cause intracellular accumulation of cAMP affected the transfer function. Isoproterenol (0.3 microg . kg-1 . min-1 iv) increased the dynamic gain of transfer function from 7.12 +/- 0.67 to 12.4 +/- 1.21 beats . min-1 . Hz-1 (P < 0.05) without changing the corner frequency or the lag time. Similar augmentations were observed when forskolin (5 microg . kg-1 . min-1 iv) or theophylline (20 mg/kg iv) was administered under conditions of beta-adrenergic blockade. These results suggest that the accumulation of cAMP at postjunctional effector sites contributes, at least in part, to the sympathetic augmentation of the dynamic vagal control of heart rate.

Cholinesterase affects dynamic transduction properties from vagal stimulation to heart rate

Recent investigations in our laboratory using a Gaussian white noise technique showed that the transfer function representing the dynamic properties of transduction from vagus nerve activity to heart rate had characteristics of a first-order low-pass filter. However, the physiological determinants of those characteristics remain to be elucidated. In this study, we stimulated the vagus nerve according to a Gaussian white noise pattern to estimate the transfer function from vagal stimulation to the heart rate response in anesthetized rabbits and examined how changes in acetylcholine kinetics affected the transfer function. We found that although increases in the mean frequency of vagal stimulation from 5 to 10 Hz did not change the characteristics of the transfer function, administration of neostigmine (30 microg . kg-1 . h-1 iv), a cholinesterase inhibitor, increased the dynamic gain from 8.19 +/- 3.66 to 11.7 +/- 4.88 beats . min-1 . Hz-1 (P < 0.05), decreased the corner frequency from 0.12 +/- 0.05 to 0.04 +/- 0.01 Hz (P < 0.01), and increased the lag time from 0.17 +/- 0.12 to 0.27 +/- 0.08 s (P < 0.05). These results suggest that the rate of acetylcholine degradation at the neuroeffector junction, rather than the amount of available acetylcholine, plays a key role in determining the dynamic properties of transduction from vagus nerve activity to heart rate.

The brain is a possible target for an angiotensin-converting enzyme inhibitor in the treatment of chronic heart failure

BACKGROUND

Although many lines of evidence have shown beneficial effects of angiotensin-converting enzyme (ACE) inhibitors on patients with chronic heart failure (CHF) after myocardial infarction (MI), the target of ACE inhibitors still remains unclear. The objectives of the present study were to evaluate the dipsogenic response to centrally administered angiotensin and to examine the effect of central administration of an ACE inhibitor on cardiac remodeling in rats with CHF after large MI.

METHODS AND RESULTS

The drinking responses to intracerebroventricular (i.c.v.) injections of saline and angiotensin I (100 ng) were measured in 22 male Sprague-Dawley rats with or without CHF at 2-5 weeks after the ligation of the left coronary artery. The dipsogenic responses to i.c.v. angiotensin I were significantly larger in rats with CHF and large MI (infarct size > 30%) than in sham-operated rats. Pretreatment with losartan abolished the significant difference between the two groups. Left ventricular (LV) weights of 32 surviving rats with CHF were measured after the 3-week subcutaneous infusions of vehicle (s.c.-VEH) and captopril (1 mg x kg(-1) x h(-1), s.c.-CAP) or the 3-week i.c.v. infusions of vehicle (i.c.v.-VEH) and captopril (50 microg x kg(-1) x h(-1), i.c.v.-CAP). The LV weights normalized by body weights of s.c.-CAP rats were significantly smaller than those of s.c.-VEH rats (1.73 +/- 0.04 vs 2.08 +/- 0.09 g x kg(-1); P < .01); those of i.c.v.-CAP rats were also significantly smaller than those of i.c.v.-VEH rats (1.84 +/- 0.08 vs 2.1 +/- 0.10 g x kg(-1); P < .05).

CONCLUSIONS

These results suggest that the brain is a possible target for ACE inhibitors in the treatment of CHF after MI.

An active metabolite of carbamazepine, carbamazepine-10,11-epoxide, inhibits ion channel-mediated catecholamine secretion in cultured bovine adrenal medullary cells

We have recently reported inhibitory effects of carbamazepine (CBZ) on ion channel-mediated secretion of catecholamines in bovine adrenal medullary cells. Here, we report the effects of carbamazepine-10,11-epoxide (CBZ-E), an active metabolite of CBZ, and carbamazepine-10,11-diol (CBZ-D), a non-active metabolite, on 22Na+ influx, 45Ca2+ influx and catecholamine secretion in cultured adrenal medullary cells. CBZ-E, but not CBZ-D inhibited 22Na+ influx, 45Ca2+ influx and catecholamine secretion induced by carbachol or veratridine with a half-maximal inhibitory concentration (IC50) of 0.26 or 0.68 microg/ml, respectively. CBZ-E also inhibited high K+-evoked 45Ca2+ influx and catecholamine secretion (IC50 = 0.3 microg/ml), but CBZ-D did not. These findings suggest that CBZ-E, but not CBZ-D, attenuates catecholamine secretion by inhibiting nicotinic acetylcholine receptor-associated ion channels, voltage-dependent Na+ channels and voltage-dependent Ca2+ channels in the cells. This inhibition of CBZ-E as well as CBZ may be related to the clinical effects in neuropsychiatric disorders.

Closed-loop identification of carotid sinus baroreflex open-loop transfer characteristics in rabbits

In the circulatory system, a change in blood pressure operates through the baroreflex to alter sympathetic efferent nerve activity, which in turn affects blood pressure. Existence of this closed feedback loop makes it difficult to identify the baroreflex open-loop transfer characteristics by means of conventional frequency domain approaches. Although several investigators have demonstrated the advantages of the time domain approach using parametric models such as the autoregressive moving average model, specification of the model structure critically affects their results. Thus we investigated the applicability of a nonparametric closed-loop identification technique to the carotid sinus baroreflex system by using an exogenous perturbation according to a binary white-noise sequence. To validate the identification method, we compared the transfer functions estimated by the closed-loop identification with those estimated by open-loop identification. The transfer functions determined by the two identification methods did not differ statistically in their fitted parameters. We conclude that exogenous perturbation to the baroreflex system enables us to estimate the open-loop baroreflex transfer characteristics under closed-loop conditions.

Impact of natural IRS-1 mutations on insulin signals: mutations of IRS-1 in the PTB domain and near SH2 protein binding sites result in impaired function at different steps of IRS-1 signaling

Insulin receptor substrate-1 (IRS-1) is one of the major substrates of insulin receptor tyrosine kinase and mediates various insulin signals downstream. In this study, we have examined the impact of three natural IRS-1 mutations identified in NIDDM patients (G971R, P170R, and M209T) on insulin signaling. G971R is located near src homology 2 protein binding sites, and P170R and M209T are located in the phosphotyrosine binding domain of IRS-1. 32D-IR cells, stably overexpressing human insulin receptor, were transfected with wild-type human IRS-1 cDNA (WT) or three mutant IRS-1 cDNAs and analyzed. All the cell lines expressing mutant IRS-1 showed a significant reduction in [3H]thymidine incorporation compared with WT. Upon insulin stimulation, cells expressing G971R showed a 39% decrease (P < 0.005) in phosphatidylinositol 3-kinase (PI 3-kinase) activity, a 43% decrease (P < 0.01) in binding of the 85-kDa regulatory subunit of PI 3-kinase, and a 22% decrease (P < 0.05) in mitogen-activated protein kinase activity compared with those expressing WT. Cells expressing P170R and M209T showed slight but significant decreases in PI 3-kinase activity (17 and 14%, respectively; both P < 0.05) and in binding of p85 (22 and 16%, respectively; both P < 0.05) and a greater decrease in mitogen-activated protein kinase activity (41 and 43%, respectively; both P < 0.005) compared with WT. After insulin stimulation, cells expressing P170R and M209T showed significant decreases in IRS-1 phosphorylation (37 and 42%, respectively; both P < 0.05) and in IRS-1 binding to the insulin receptor (48 and 53%, respectively; P < 0.01) compared with WT. G971R showed no changes in IRS-1 phosphorylation and in IRS-1 binding to the insulin receptor compared with WT. These data suggest that the impaired mitogenic response of P170R and M209T was mainly due to reduced binding to the insulin receptor, whereas the impaired response of G971R was mainly due to reduced association with PI 3-kinase p85.