Effects of adenosine 3',5'-monophosphate, dibutyryl adenosine 3',5'-monophosphate, aminophylline, and imidazole on renal cellular calcium metabolism.

The effects of cAMP, dibutyryl cAMP (DBcAMP), aminophylline, and imidazole on total cell calcium, calcium transport, and distribution were studied in cultured kidney cells by kinetic analysis of 45Ca uptake and desaturation curves. Low concentrations of the cyclic nucleotides (10(-7) and 10(-5) M) increase the total cell calcium, all intracellular exchangeable pools, and calcium transport between all cellular compartments. Aminophylline (1 mM) has effects qualitatively similar to cAMP and DBcAMP, while imidazole has opposite effects. At concentrations of 15 and 40 mM, imidazole depresses the total cell calcium and the cellular exchangeable calcium. Compared to the effects of parathyroid hormone (PTH), the changes obtained with 10(-7) and 10(-5) M cAMP are relatively modest, but higher concentrations (10(-3) M) of both cAMP and DBcAMP produce stimulations as marked as with 15 ng/ml PTH. The most dramatic changes are seen in the mitochondrial calcium pool and in the mitochondrial calcium exchange, which increase between 20- and 40-fold. These experiments show that cAMP mimics the effect of PTH on kidney cells and support the theory that cAMP is the mediator of PTH action on renal cell calcium transport.

Effects of parathyroid hormone on the distribution and transport of calcium in cultured kidney cells.

The effects of parathyroid hormone (PTH) on the transport and distribution of calcium in isolated kidney cells were studied by kinetic analysis of 45Ca desaturation curves. The results show that PTH (15 ng/ml) increases the total cell calcium content, every exchangeable pool, and all exchange rates. The greatest effect is observed in the slowest kinetic phase which reflects a mitochondrial pool. The effects of PTH occur even in the absence of magnesium and of phosphate and the larger effect is again obtained in the mitochondrial pool. These results suggest that PTH stimulates calcium transport in kidney cells by affecting the intracellular distribution of calcium or by stimulating calcium influx.

Clinical features and viral excretion in an infant with primary human herpesvirus 7 infection.

OBJECTIVE: To find clinical features of a virologically-confirmed patient with primary human herpesvirus 7 (HHV-7) infection and a relationship of the excretion of viruses between HHV-7 and human herpes-virus 6 (HHV-6). PATIENT AND METHODS: A 13-month-old boy who had a known prior history of exanthem subitum at 6 months of age developed fever for 3 days and a skin rash appeared as the fever was resolving. The course was accompanying with nonspecific signs and symptoms such as anorexia, irritability, mild diarrhea, palpebral edema, mild inflammation of pharynx, and mild occipital and cervical lymphadenopathy. Heparinized blood samples were used for isolation of HHV-6 and HHV-7 and detection of both virus DNA sequences by a nested polymerase chain reaction (PCR) amplification. Samples from other body sites were also tested for their DNA sequences using the PCR. Both virus antibody activity was measured by an indirect immunofluorescent assay or a neutralization test. RESULTS: Cultured mononuclear cells from the patient at the acute stage of the disease produced morphologic changes, which reacted only with the monoclonal antibody to HHV-7 but not with the antibody to HHV-6. Both viruses were not isolated from blood obtained at the convalescent stage. An antibody response of the patient indicated a seroconversion to HHV-7 but not to other microbial agents including HHV-6 and Mycoplasma pneumoniae. Both virus DNA sequences were detected in peripheral blood mononuclear cells at acute and convalescent stages. HHV-7 DNA was excreted into saliva and transiently into stool at an early convalescent stage followed by HHV-6 excretion into saliva. No HHV-7 and HHV-6 was excreted into urine. CONCLUSIONS: Clinical features of a virologically confirmed patient with primary HHV-7 infection were comparable with those of primary HHV-6 infection and HHV-7 infection may reactivate HHV-6.

Possible involvement of calmodulin-dependent kinases in Ca(2+)-dependent enhancement of [3H]5-hydroxytryptamine uptake in rat cortex.

Effects of Ca2+ on [3H]5-hydroxytryptamine (5-HT) uptake into rat cortical synaptosomes were studied. The uptake was enhanced in the presence of Ca2+ in Krebs-Ringer medium and the uptake at 0.3-5 mM Ca2+ was 2.4-2.7 times greater than that observed in the absence of Ca2+. The maximal increase at the concentration of 1 mM Ca2+ was achieved after 2 min preincubation. Ca(2+)-dependent enhancement of the [3H]5-HT uptake reflected an increase in Vmax of the uptake process. However, Kd and Bmax values for [3H]paroxetine were not significantly changed in the presence of 1 mM Ca2+ compared with Ca(2+)-free condition. On the other hand, uptake was still enhanced after synaptosomes were washed with Ca(2+)-free after preincubation with 1 mM Ca2+. Staurosporine (a protein kinase C inhibitor) and wortmannin (a myosin light chain kinase inhibitor) did not affect Ca(2+)-dependent enhancement of the uptake, whereas 1-[N,O-bis(5-isoquinolinesulfonyl)-N-methyl-L-tyrosyl]-4-phenylpiperazin e (KN-62, an inhibitor of Ca2+ /calmodulin-dependent kinase II) and N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide hydrochloride (W-7, a calmodulin antagonist) significantly reduced it. Moreover, L-type, but not P- or N-type, voltage-dependent Ca(2+)-channel blockers suppressed enhancement of the uptake. These results indicate that Ca(2+)-dependent enhancement of [3H]5-HT uptake is mediated by activation of calmodulin-dependent protein kinases, suggesting a possibility of calmodulin-dependent regulation of in vivo 5-HT uptake.

Relationship between morphological diversity and AgNORs or cathepsin B expression in colorectal cancers.

The biological characteristics associated with the morphological diversity of colorectal cancers were investigated to elucidate the causes of this diversity. We examined the proliferative and infiltrating activity of tumor cells, indicated by the mean number of Ag nucleolar organizer region associated proteins (NORs) per nucleus (MNA) and the immunohistochemical response to cathepsin B(CB), in various morphological types of early and advanced colorectal cancers. We examined 73 colorectal cancers obtained by endoscopic and surgical resection. MNA values for sessile and flat-elevated cancers were greater than the values for pedunculate, subpedunculate, and flat-or-depressed early cancers (sessile, P < 0.05). In advanced cancers invading the muscularis propria, protruding cancers showed significantly higher MNA values than small ulcerative cancers (P < 0.01). CB expression increased significantly with the progression of colorectal cancers (P < 0.01), but was not related to morphological diversity in early and advanced cancers. In both sessile and flat cancers, CB expression was higher in moderately differentiated than in well differentiated adenocarcinomas. These results indicate that, in colorectal cancers, protruding early cancers without stalks and protruding advanced cancers have higher proliferative activity than pedunculate or flat early cancers and small ulcerative advanced cancers, respectively, and that CB expression is not associated with morphological diversity, but with depth of invasion and histological differentiation.

Effect of glycyrrhizine on hyperkalemia due to hyporeninemic hypoaldosteronism in diabetes mellitus.

Liquorice extract has been claimed to induce inhibition of the activity of 11 beta-hydroxysteroid dehydrogenase which converts cortisol to cortisone. This enzyme is thought to protect the mineralocorticoid receptor from being occupied by endogeneous glucocorticoids in the kidney. Based on these hypotheses, we investigated the effect of low-dose glycyrrhizine on hyperkalemia due to hyporeninemic hypoaldosteronism in eight subjects with NIDDM. The mean serum potassium concentration decreased from 5.3 +/- 0.3 (SD) mEq/1 to 4.9 +/- 0.2 mEq/1 when 15 g of calcium polystyrene sulfonate, a potassium-binding resin, was given per day, and it decreased significantly to 4.4 +/- 0.4 mEq/1 with 150 mg/day of glycyrrhizine therapy. Changes in fasting plasma glucose and hemoglobin A1c were not significant. These data support the assumption that liquorice extract can be used safely in the therapy for treating hyperkalemia due to selective hypoaldosteronism in diabetes mellitus subjects.

Emphysematous pyelonephritis successfully treated with nephrectomy and granulocyte colony-stimulating factor.

A 58-year-old woman developed diabetic ketoacidosis and emphysematous pyelonephritis caused by Escherichia coli. She was successfully treated with nephrectomy, antibiotics, and recombinant human granulocyte colony-stimulating factor (rhG-CSF). RhG-CSF therapy may be an effective adjunct for diabetic patients with severe infection, even when neutropenia is not present.

Piezoelectric ultrasonic motor using longitudinal-torsional composite resonance vibration.

A piezoelectric ultrasonic motor, which uses longitudinal and torsional composite vibration, is examined in order to obtain high torque characteristics with small diameter. Piezoelectric ceramic elements, oscillating in both longitudinal and torsional modes, respectively, are used as piezoelectric stiffened modes having high electromechanical coupling factors k(33) and k(15), respectively. It is found that the resonant frequencies for longitudinal mode and torsional mode could coincide with each other in the ultrasonic motor, according to finite element method analysis and experimental measurement. The motor operating in both resonant vibrations indicated good performance. The 20-mm diameter motor exhibited 4 kgfcm maximum torque, 450 r/min maximum rotational speed, 40% maximum efficiency, and quick responsiveness, within 2.5 ms.

[Pharmacokinetics of cisplatin and vindesine in a patient with chronic renal failure undergoing hemodialysis].

Plasma total platinum and vindesine levels were monitored in a patient with chronic renal failure undergoing hemodialysis. Plasma levels of cisplatin were determined as platinum by atomic absorption spectrophotometry, and plasma vindesine levels were measured by radioimmunoassay. Fifty mg. of cisplatin in combination with 3 mg. of vindesine were infused for 60 minutes before dialysis. During dialysis, plasma total platinum levels decreased rapidly in a biphasic fashion and 1.76 at 30 hours after infusion. Plasma vindesine levels declined with higher concentration. In conclusion, it is considered that cisplatin and vindesine can be given to anuric patients undergoing hemodialysis. However, it is suggested that smaller doses should be given to prevent side effects.

[Detection of chromosomal numerical aberration in early colorectal carcinomas using fluorescence in situ hybridization].

The authors have performed fluorescence in situ hybridization (FISH) in tissue sections of archival paraffin-embedded blocks of seven cases in adenoma and ten cases in carcinoma in order to clarify which chromosomal aberration occurred in association with multi-step carcinogenesis in colorectal carcinomas, using alpha-satellite DNA probes to chromosome 11 and 17, D11Z1 and D17Z1, respectively. Monosomy of chromosome 11 was most frequented (5/7, 71.4%) in adenoma, and trisomy of chromosome 17 was predominant (9/10, 90.0%) in carcinoma. The numerical chromosomal aberrations can be already detected at the stage of adenoma, and monosomy of chromosome 11 was mainly observed in adenoma. Furthermore, malignant transformation arising from adenoma accounted for most of the trisomic change in chromosome 17. Consequently, applying the FISH technique to tissue sections from archival paraffin embedded specimen, it would be possible to distinguish between the cancerous and non-cancerous regions in view of chromosomal numerical aberrations. The authors emphasized that intratumoral heterogeneity could be elucidated at the chromosomal level.

[Increase in extracellular levels of serotonin and amino acids in the rat brain following cyanide-induced energy failure].

We studied the effects of ATP depletion on neurotransmitter release in the rat brain using the microdialysis method. Ringer's solution containing 2 mM sodium cyanide (NaCN) was perfused into the hippocampus and striatum for 60 min via a microdialysis probe, and changes in serotonin (5-HT) and amino acids (glutamate, aspartate and taurine) levels in dialysates were investigated. NaCN perfusion induced a transient 3.9-fold increase in 5-HT levels in the hippocampal dialysate. Amino acid levels in dialysates also increased during NaCN perfusion, but differently in the striatum and hippocampus (glutamate: 1.3- and 2.4-fold, taurine: 2.3- and 1.3-fold, respectively). Perfusion of Ca(2+)-free Ringer's solution remarkably suppressed the NaCN-induced increase in 5-HT but not the increases in amino acid levels. Depolarization by 100 mM KCl perfusion could induce increases in 5-HT and amino acids in dialysates at 3 hr after NaCN perfusion similarly with that of control. These findings indicate that the sensitivity of nerve terminals to energy failure are different between neurons containing different neurotransmitters and also between brain regions, and suggest that this regionally different sensitivity of amino acid neurons might be involved in the underlying mechanism of the localized vulnerability to transient ischemia.

Effects of the anti-platelet agent cilostazol on peripheral vascular disease in patients with diabetes mellitus.

Effects of cilostazol (OPC-13013, CAS 73963-72-1), a selective inhibitor of platelet cAMP-phosphodiesterase, on peripheral vascular disease in diabetes mellitus were studied. Cilostazol in a dose of 200 to 300 mg/d was administered to 5 diabetic patients with arteriosclerosis obliterans. Skin temperature of the finger and the toe, which reflects blood flow to the tissue, was selected as an objective index of cilostazol effects and measured by infra-red thermography at a constant temperature of 26 degrees C. Before administration, digital skin temperatures were low in 9 limbs of 5 patients. 200 mg/d of cilostazol significantly (p less than 0.001) increased the digital skin temperatures of 8 limbs, the increase (mean +/- SD) ranging from 29.9 +/- 1.4 degrees C to 33.2 degrees C +/- 1.2 degrees C for the average skin temperatures and from 28.7 +/- 2.1 degrees C to 33.1 +/- 1.5 degrees C for the lowest ones. An increase in the dose to 300 mg/d resulted in further elevation of skin temperatures of the digits. Cilostazol constantly elicited an increase in blood flow to the digits within the range of its therapeutic dose. This effect was observed about 1 month after initiation of administration and persisted while administration was continued. The measurement of digital skin temperatures by infrared thermography provided a noninvasive means to individualize the dosage of cilostazol and to monitor the cilostazol effect and patient complicance during long-term administration. It is concluded that cilostazol exerts a potent and steady vasodilatory effect on peripheral circulation in patients with diabetes mellitus.

Kinetic analysis of calcium desaturation curves from isolated kidney cells.

This paper provides mathematical solutions for calculating calcium fluxes and compartments in isolated kidney cells from calcium-45 desaturation curves. In contrast to other available methods, these solutions allow the calculation of kinetic parameters even if isotopic equilibrium has not been reached at the beginning of the desaturation period. To test the validity of the method, calcium-45 desaturation experiments were performed in isolated kidney cells after labeling periods of 30, 60, 90, or 120 min. Even though the calcium-45 desaturation curves differ with different labeling times, the respective values of the calculated parameters are practically identical. The optical labeling period was found to lie between 60 and 120 min. Since this new method does not require initial isotopic steady state, it allows a formal kinetic analysis of tracer desaturation curves even after short periods of labeling.