Spectral opponency of on-type ganglion cells and the blue preference of Rana pipiens

Spectrally opponent processes of ON-type retinal ganglion cells and the blue preference behavior were identified by parallel physiological and behavioral experiments in Rana pipiens. Spectral opponency of retinal ON-units was measured by recording from optic nerve terminals in the anterior thalamus, while the retina was stimulated by combinations of monochromatic stimuli. Spectral opponency of the blue preference was determined in a Y-maze, using similar combinations of monochromatic stimuli. The opponent processes of the ON-units and blue preference are similar in the spectral ranges of excitatory and inhibitory effects. In both cases the spectral opponency can be described as short wavelength excitation and long wavelength inhibition. The data suggest that the short wavelength excitation is based, at least in part, on the green rod (P432) channel, while the long wavelength inhibition is caused, at least in part, by stimulation of the principal and/or single cone (P580) channel. A model is presented to show how receptor interactions may encode this spectrally opponent process. The results support the hypothesis that the blue preference is dependent on information supplied to the anterior thalamus by ON-type retinal ganglion cells.     

Properties of X- and Y-type retinal ganglion cells in Siamese cats

There is ample evidence that the visual system of the Siamese cat is different from common cats. These abnormalities suggest possible retinal origins, although no documentation exists. In the present study, single unit recordings were made from 91 misrouted and 209 normally-routed optic tract fibers in Siamese cats. Electrophysiological responses of the misrouted fibers did not differ from those found in the normally-routed fibers of the Siamese cat with the exception of depressed responses to contrast reversal stimuli. X/Y classification of units and experiments on receptive field center sizes, intensity-response functions, and responses to flicker failed to demonstrate significant differences between the misrouted and normally-routed fibers in Siamese cats. These results were not affected by different degrees of interocular misalignment exhibited by the Siamese cat studied. Response properties of retinal ganglion cells in Siamese cats, however, were found to be quite abnormal when compared with common cats. Only 14% (42/300) of all units studied were Y-cells in Siamese cats in comparison to 35% (60/170) in common cats. The percentage of Y-units also was correlated with the severity of interocular misalignment in Siamese cats, i.e. the greater the misalignment of the eyes, the lower the percentage of Y-cells. Experiments on response to contrast reversal stimuli, intensity-response functions and responses to flicker revealed that the ganglion cells in Siamese cats are not as responsive as those in common cats.     

Pathogen occurrence and antimicrobial susceptibility of urinary tract infection cases during a 20-year period (1983-2002) at a single institution in Japan

Urinary tract infections are one of the most common infectious diseases diagnosed in outpatients as well as in hospitalized patients. Recently, urinary tract infections have become more complicated and difficult to treat. Therefore, the present study analyzed the occurrence and antimicrobial susceptibility of uropathogens isolated at Kobe University Hospital between 1983 and 2002. This study was performed with three patient groups: urology inpatients, urology outpatients, and inpatients of other departments. During the 20-year study period, we studied 15,925 urine isolates obtained from those patients who were diagnosed with urinary tract infection. Overall, Enterococcus faecalis was the most frequently isolated pathogen, followed by Pseudomonas aeruginosa and Escherichia coli. The frequency of Staphylococcus aureus increased over time, corresponding to an increase in the occurrence of methicillin-resistant S. aureus (MRSA). In addition, the rate of isolation of Serratia marcescens also increased over time, especially among patients with urinary tract catheters. Our results demonstrate that the uropathogens isolated at a single institution have shown a trend of increasing resistance to various classes of antimicrobial agents. In addition, serious problems should be anticipated in the treatment of multidrug-resistant P. aeruginosa, fluoroquinolone-resistant E. coli, and arbekacin-resistant MRSA.     

Episodic hyponatremia in mitochondrial encephalomyopathy, lactic acidosis, and strokelike episodes (MELAS)

Various organ involvements and endocrinologic abnormalities associated with electrolyte imbalance, including hyponatremia, are seen in patients with mitochondrial encephalomyopathy, lactic acidosis, and strokelike episodes (MELAS); however, the clinical significance of hyponatremia in these patients is rarely reported. We analyzed the serum sodium concentration profiles and clinical and laboratory data of seven patients with MELAS. We found that hyponatremia occurred episodically in four of the seven patients from an early stage of the disease. We identified excessive sodium loss in urine to be associated with the hyponatremic episodes and the causes of hyponatremia in two patients as relative adrenal insufficiency, acute renal failure, and serious paralytic ileus. However, even extensive examinations failed to reveal the cause in other patients. Because severe hyponatremia can cause serious complications, clinicians should pay attention to serum sodium levels and maintain them properly in patients with MELAS.     

Effects of Goshajinkigan on insulin resistance in patients with type 2 diabetes

We investigated the effects of Goshajinkigan (GJG), a Chinese herbal medicine, on insulin sensitivity in patients with type 2 diabetes using the homeostasis model assessment of insulin resistance (HOMA-R) and the euglycemic insulin clamp procedure. Daily oral administration of GJG (7.5 g/day) was performed for 1 month in 71 type 2 diabetes patients: the GJG treatment group. HOMA-Rs were calculated before and after 1 month of GJG treatment and compared with those of 44 controls who were matched in terms of sex, age, body mass index (BMI) and HbA1c levels with the experimental group. In 64 patients out of the GJG treatment group, HOMA-R was calculated 1 month after discontinuation of treatment. In addition, euglycemic clamp was conducted in eight patients before and after the GJG treatment. HOMA-R was 4.78+/-0.37 (means+/-S.E.) before GJG treatment and significantly decreased to 4.02+/-0.25 after GJG treatment (P=0.019). No significant change was observed in the control group. HOMA-R returned to the pre-treatment level (P=0.018) 1 month after GJG treatment discontinuation. Glucose infusion rates and metabolic clearance rates determined by the high-dose euglycemic clamp increased after 1 month of GJG treatment (from 9.6+/-1.1 to 11.1+/-0.7 mg/kg/min, P=0.045 and from 7.9+/-0.8 to 9.1+/-0.8 ml/kg/min, P=0.046, respectively). These results indicate that GJG administration might be useful for improving insulin resistance in patients with type 2 diabetes.     

In vivo insulin action in adrenodemedullated rats after voluntary running

The purpose of this study was to estimate the influence of epinephrine on in vivo insulin sensitivity and responsiveness after voluntary running. Wistar rats that had previously undergone adrenodemedullation or sham-operation were kept in a sedentary state or trained over a 4 week period. An euglycemic insulin clamp study was performed on adrenodemedullated sedentary rats (ADMX), adrenodemedullated voluntary running rats (ADMX-T), sham-operated voluntary running rats (SHAM-T), and control rats (C) at 18 h after the last bout of exercise. The insulin infusion rate was 3.0, 6.0, and 303.0 mU/(kg min), respectively. The blood glucose concentration was maintained constant at basal levels. Metabolic clearance rate of glucose (MCR) was calculated as an index of whole-body insulin action. In the presence of physiological hyperinsulinemia (an insulin infusion rate of 6.0 mU/(kg min)), MCR (ml/(kg min)) was significantly higher in ADMX-T rats (31.2 +/- 2.0) than in ADMX rats (19.8 +/- 0.8, P<0.001) and SHAM-T rats (23.8 +/- 0.8, P<0.05). Also, the MCR values of SHAM-T and ADMX rats were significantly (P<0.001, and P<0.05, respectively) greater than that of C rats (12.7 +/- 0.4). At maximal hyperinsulinemia (an insulin infusion rate of 303.0 mU/(kg min)), there was no difference of MCR between ADMX-T rats (49.8 +/- 4.3) and C rats (38.2 +/- 2.2). The GDR values of SHAM-T rats (43.5 +/- 3.7) and ADMX rats (43.5 +/- 2.1) were also not different from that of C rats. These results provide indirect evidence that epinephrine is one of factors that suppresses increased insulin sensitivity after physical training, although it seems to have no significant influence on insulin responsiveness.     

Ovarian vessel dilatation with ovarian mass on MR images: influence of pelvic venous plexus dilatation

PURPOSE: We assessed the value of analyzing visualization of the ovarian vessels in relation to the features of ovarian masses using MR images. MATERIALS AND METHODS: 74 patients with 91 masses (61 benign lesions and 30 malignant lesions) were evaluated. Ovarian masses were classified using the following features: 1) benignancy, 2) characterization, and 3) maximum diameter. We assessed the relationship between visualization and the diameter of the ipsilateral ovarian vessels and the features of ovarian masses. In addition, we assessed the relationship between visualization and the diameter of ovarian vessels and pelvic venous plexus (PVP) dilatation. RESULTS: Regardless of tumor laterality, 82% of ovarian vessels were visualized (121/148 vessels) on MR images. There was a significant relationship between the average diameter of ovarian vessels and dilatation of PVP (p<0.001). In patients without dilatation, there was a stronger relationship between ovarian vessel average diameter and benignancy (p=0.007), and the character of ovarian mass (solid versus cystic; p<0.05, mixed versus cystic; p<0.01). CONCLUSION: We confirmed a strong relationship between the diameter of ovarian vessels and dilatation of PVP. If ovarian vessels are dilated in patients without dilatation of PVP, we could suggest the possibility of malignant ovarian tumor.     

Treatment of traditional Chinese medicine for idiopathic male infertility

Several Chinese herbal medicines have been used to treat patients with idiopathic male infertility and have been reported to improve semen quality. The clinical efficacy of these medicines was reviewed. The therapeutic effect of Hochu-ekki-to based on the pretreatment traditional diagnosis (Sho) was examined. Three months after the administration of Hochu-ekki-to, the semen count and motility significantly increased in comparison with pretreatment values. When the patients were classified into 3 categories based on "Sho", Hochu-ekki-to was effective in semen motility in patients with vacuity pattern (Kyo-Sho). Seminal plasma soluble Fas (sFas) levels before and three months after the administration of drug were analyzed. Seminal plasma sFas level elevated significantly after the administration of Hochu-ekki-to. After the administration of Hochu-ekki-to, seminal plasma sFas levels significantly correlated with sperm concentration. To make the best use of traditional medicine, it is important to give medication according to the traditional diagnosis (Sho).     

Results of adjuvant intravesical Bacillus Calmette-Guérin therapy for grade 3 superficial bladder cancer

To examine the incidence of recurrence, progression and survival in patients with grade 3 superficial bladder cancer after transurethral resection (TUR) and adjuvant intravesical instillation of Bacillus Calmette-Guérin (BCG), we retrospectively studied 39 patients with grade 3 superficial bladder cancer. Nineteen patients with high-grade superficial bladder cancer (pTa, pT1) and 5 patients with grade 3 carcinoma in situ (CIS) received intravesical instillation of BCG after transurethral resection of the bladder tumor (BCG group and CIS-BCG group). The Tokyo 172 strain BCG was given for 8 weeks, as a rule, in a dose of 80 mg in 40 ml of saline instilled into the bladder. As a control, 15 patients with grade 3 superficial bladder cancer who did not receive BCG therapy after TUR were compared (non-BCG group). Of the BCG group (n=19), 4 patients (21.1%) had recurrent tumor and 3 had invasive progression after BCG therapy and died as a result of tumor progression, while in the non-BCG group (n=15), 8 cases (53.3%) developed recurrence, only one case had progression and died of cancer. In the CIS-BCG group (n=5), 3 patients (60.0%) had recurrent tumor and 2 had invasive progression. Univariate analysis (Logrank test) demonstrated that tumor size and adjuvant instillation of BCG were associated with tumor recurrence except for carcinoma in situ, but tumor progression and survival did not differ significantly. Our results suggest that BCG therapy prevents grade 3 superficial bladder cancer (pT1, pTa) recurrence.     

Expression of dentin matrix protein 1 (DMP1) in nonmineralized tissues

Dentin matrix protein 1 (DMP1) is an Arg-Gly-Asp-containing acidic phosphoprotein that was originally identified from a rat incisor cDNA library and was thought to be a dentin-specific protein. DMP1 was later shown to express in a number of hard tissue-forming cells, including osteoblasts, osteocytes, ameloblasts, and cementoblasts, and was considered to play important roles in mineralization. Further, DMP1 gene expression was also detected in fetal bovine brain and in newborn mouse brain. These findings indicate the possibility of DMP1 expression in other soft tissues. In the present study, to clarify the significance of DMP1 expression in nonmineralized tissues, we made a specific antibody to mouse DMP1 peptides and demonstrated that DMP1 protein was localized in mouse brain, pancreas, and kidney by immunohistochemistry. Further DMP1 mRNA was detected in nonmineralized mouse tissues including liver, muscle, brain, pancreas, and kidney by RT-PCR. Based on the evidence that the localization and the expression of DMP1 are not restricted to mineralized tissues, we assume that DMP1 may have functions other than the regulation of mineralization.