Age-specific characteristics of nocturnal blood pressure in a general population in a community of northern Japan

The age- and gender-specific profile of circadian blood pressure variation was examined by monitoring ambulatory blood pressure (ABP) in 477 untreated subjects in a rural community of northern Japan. Autoregressive spectral analysis demonstrated three major peaks at around 24, 12, and 8 h. We fitted a truncated Fourier series with three harmonics to the blood pressure (BP) data using least squares regression. More than half of the BP and pulse rate periodic curves were bimodal, one-third were trimodal, and the remainder were unimodal. The nadir of BP appeared between 00:00 and 01:30, and that of pulse rate occurred between 00:30 and 02:00. The nadir of systolic and diastolic BP, as well as pulse rate, appeared earlier with increasing age, and the difference between subjects in their 20s and those in their 70s was about 1 h. The amplitude of 24 h BP decreased with increasing age in men, but not in women. This type of information on the circadian BP profile of a general population is useful for the diagnosis and treatment of hypertension.

Effects of EXP3174, a non-peptide angiotensin II receptor antagonist, on renal hemodynamics and renal function in dogs

We examined the effects of intrarenal infusion of EXP3174, a non-peptide angiotensin II receptor antagonist, in order to evaluate the physiological role of endogenous angiotensin II in regulating renal hemodynamics and urine formation and to assess the possibility of a tubular site(s) of action of endogenous angiotensin II in anesthetized dogs. Intrarenal infusion of EXP3174 at 15 micrograms/kg per min caused increases in renal blood flow (RBF), glomerular filtration rate (GFR), urine, flow and urinary electrolyte excretion. The lower dose of EXP3174 (0.5 micrograms/kg per min) did not change mean arterial pressure, RBF and GFR, but did increase urine flow. The fractional excretion of sodium, the fractional proximal excretion of sodium and the fractional distal excretion of sodium increased with lower doses of EXP3174 infusion. EXP3174 did not affect the linear relationship between the free water reabsorption rate and osmolar clearance. These data suggest that endogenous angiotensin II plays a significant role in regulating renal hemodynamics and urine formation and endogenous angiotensin II stimulates sodium reabsorption in the proximal and the distal portions of the tubules, with the exception of the medullary portion of the ascending limb of Henle.

Effects of right ventricular pacing on QRST isointegral maps in patients with and without myocardial infarction: body surface distribution of significant changes in QRST area compared to supraventricular complex

To assess the effects of right ventricular (RV) pacing on body surface QRST distributions, we recorded QRST isointegral maps (I-maps) during sinus rhythm and RV pacing in 25 patients with anterior myocardial infarction (MI), 19 with inferior MI, and 14 without MI. The QRST values at each lead point recorded during sinus rhythm and RV pacing with an 87-lead system were analyzed with a paired t-test in each patient. An abnormal decrease in the QRST value of the I-map was assessed by the difference map, which indicated a "-2SD area," where the QRST integral value was less than the normal range (mean - 2SD) calculated from 608 normal individuals. The I-maps were similar during the two activation sequences in patients with and without MI. However, during RV pacing, QRST values significantly decreased over the upper right anterior chest and increased over the lower left anterior chest and back. The sigma DMs (sum of QRST integral values below the normal range) for both activation sequences were strongly correlated in patients with anterior MI and with inferior MI (r = 0.91 and r = 0.92, respectively; P < 0.001). Although small but significant changes in QRST values were detected, the distribution of the "-2SD area" and the sigma DM were similar during both activation sequences in patients with prior MI. Thus, these findings demonstrate that an altered activation sequence produces small but significant changes in QRST values but that I-maps still provide information that is useful for the diagnosis of MI during RV pacing.

Regional hemodynamic effects of betaxolol, a new selective beta 1-blocker, and atenolol in conscious spontaneously hypertensive rats

Betaxolol is a new beta-blocker that has been reported to have beta 1-selectivity, and it is devoid of both membrane stabilizing action and intrinsic sympathomimetic action. The effects of betaxolol on systemic and regional hemodynamics were examined in conscious spontaneously hypertensive rats (SHR) by a microsphere method and compared with the effects of atenolol. A single oral administration of betaxolol at 1 and 10 mg/kg decreased the mean arterial pressure in a dose-dependent manner. At the same doses, atenolol also showed a similar but weak hypotensive effect. Both of these drugs at the high dose decreased cardiac output and heart rate and at the low dose, did not. Total peripheral resistance decreased by only betaxolol at the low dose. Betaxolol showed a tendency to normalize the hemodynamic abnormalities which were observed in the kidney, spleen and gastrointestinal tract of SHR, while atenolol did not. It should be noted that betaxolol increased the flow rate in the kidney, which may be explained by its direct vasodilatory action on renal blood vessels. In conclusion, betaxolol showed an antihypertensive action at the doses of 1 and 10 mg/kg, exhibited the characteristics of a beta 1-blocker and produced preferable effects on regional hemodynamics in SHR.

Membrane potential measurement in isolated outer hair cells of the guinea pig cochlea using conventional microelectrodes

Membrane potential of the isolated outer hair cells (OHCs) from the guinea pig cochlea was measured using conventional microelectrodes filled with 200 mM KCl. The resting membrane potential during superfusion with the standard physiological saline solution containing 3.5 mM K+ was -47.3 +/- 1.4 mV (N = 72), which was higher than those previously reported for isolated OHCs studied by using microelectrodes. Addition of ouabain (10(-5)-10(-3) M), the specific Na+, K+ ATPase inhibitor, depolarized the cell slowly and progressively, indicating the presence of low but definite Na+, K+ ATPase activity in the plasma membrane of OHCs. The magnitude of membrane potential was mainly dependent on the extracellular K+ concentration ([K+]O). A ten-fold increase of [K+]O depolarized the membrane potential by 49.6 +/- 1.0 mV (N = 58). A decrease of [Na+]O to one tenth of the control hyperpolarized the membrane potential by about 2 mV. Decreasing extracellular Cl- from 131.3 mM to 27.5 mM did not cause a significant change in the membrane potential. Using the Goldman-Hodgkin-Katz equation, assuming a negligible contribution of Cl- to the membrane potential and total monovalent cat ion concentration of the cytosol similar to the extracellular fluid, we calculated the permeability ratio of K+ versus Na+ to 131 +/- 19 and intracellular K+ concentration to 33.3 +/- 1.9 mM.

Clinical significance of residual collaterals immediately after successful coronary angioplasty

The clinical significance of collaterals visible on angiography immediately after successful percutaneous transluminal coronary angioplasty (PTCA) was analyzed in 221 patients who underwent successful PTCA for coronary arteries receiving collaterals. Filling of the collaterals was classified as good; filling the entire epicardial segment of the stenosed site, fair; partially filling the epicardial segments distal to the stenosed site, and faint; visible but not filling the epicardial segments of the diseased vessel. Fifteen of 41 good collaterals remained good or fair on angiography immediately after PTCA. Among the 114 fair collaterals, 26 remained fair and 20 of 66 faint collaterals remained visible on the angiogram immediately after PTCA. There was no relationship between the degree of residual stenosis after PTCA and the degree of residual collaterals. Repeat coronary angiography was obtained in 156 patients. There was no correlation between the presence, absence or degree of collaterals observed on angiography immediately after successful PTCA and the rate of restenosis. Thus, collaterals to the vessels dilated by PTCA often remain on the angiogram immediately after PTCA and are dependent primarily on their degree before dilation. They do not indicate inadequate dilation or predict restenosis.

Expression of the F84.1 glycoprotein in the spinal cord and cranial nerves of the developing rat

The monoclonal antibody designated as F84.1 was used for an immunohistochemical study of the developing rat nervous system. The most prominent neural components recognized by F84.1 are motor and sensory components of the spinal cord and cranial nerves. F84.1 is first detected in the dorsal root ganglia of embryonic day 11 spinal cord. The expression in the dorsal roots persists in the adult. In contrast, a more transient expression of F84.1 is found in the spinal motor system. F84.1 labels primary neurons of cranial nerves V, VIII, IX and X. F84.1 is also expressed by the non-neuronal cells of the notochord and the floor plate. Immunoprecipitation experiments from several types of cells in culture show that the F84.1 antigen is a cell-surface glycoprotein with a molecular weight of 90-105 kDa. An analysis of the amino terminal sequence demonstrates that the F84.1 antigen is similar to the chick cell adhesion molecule SC1/DM-GRASP, a member of the immunoglobulin superfamily. The pattern of expression of F84.1 in the rat differs in several aspects from that of the chick molecules, leaving a possibility that F84.1 may be a variant of SC1/DM-GRASP.

Effects of semotiadil fumarate (SD-3211) on renal hemodynamics and function in dogs

Studies were carried out to define the effect of semotiadil on renal hemodynamics, renal function and renin release in pentobarbital-anesthetized dogs. Intrarenal arterial infusion of semotiadil resulted in a significant increase in renal blood flow (RBF), glomerular filtration rate (GFR), urine flow, urinary excretion of electrolytes and renin release. Semotiadil did not affect the linear relationship between osmolar clearance and the free water reabsorption rate, and increased the urinary excretion of sodium and calcium to the same extent. These results suggest that the main tubular site of action of semotiadil is the proximal tubule. Intrarenal infusion of a potent non-peptide angiotensin II antagonist, DuP753 (15 micrograms/kg per min), resulted in an increase in RBF, GFR, urine flow and UNaV. In spite of the blockade of the intrarenal renin angiotensin system(RAS) with DuP753, semotiadil caused almost the same effects as it did in the absence of DuP753. These results suggest that the renal effects of semotiadil are independent of the intrarenal RAS.

Human glial fibrillary acidic protein (GFAP): molecular cloning of the complete cDNA sequence and chromosomal localization (chromosome 17) of the GFAP gene

We isolated three glial fibrillary acidic protein (GFAP) cDNA clones from a glioma cell line, U-251 MG. One clone isolated from a U-251 MG cDNA library was long, but lacked both ends. Using poly(A)+ RNA and primers synthesized according to the sequence of this clone, we used the polymerase chain reaction-assisted rapid amplification of cDNA ends (PCR-RACE) method, which is a strategy to isolate cDNA ends, and obtained cDNA clones for the 5' and 3' ends. From the sequences of these overlapping clones, the complete nucleotide sequence of human GFAP cDNA was established. The start (ATG) and the stop (TGA) signals were seen at nucleotide positions 15 and 1311, respectively, and divided the entire sequence of 3027 bp into 14 bp of 5' non-coding, 1296 bp of coding and 1717 bp of 3' non-coding regions. Using cDNA probes made from both the coding and the 3' non-coding regions, Northern blot hybridization was performed with two different stringencies on RNAs from human and rodent brains and human GFAP-positive and -negative cells. It was shown that the 3' non-coding region probe was more specific for human GFAP than the coding region probe which was specific only under higher stringency conditions. This was also suggested by homology analysis of the sequence with those of various intermediate filament proteins. Based on these findings, we performed spot blot hybridization of sorted human chromosomes and Southern blot hybridization of PCR-amplified DNAs of a panel of hamster-human somatic cell hybrids and localized the human GFAP gene to chromosome 17.

Na(+)-Ca2+ exchange in the isolated cochlear outer hair cells of the guinea-pig studied by fluorescence image microscopy

The outer hair cell isolated from the guinea-pig was superfused in vitro and the cytosolic calcium concentration ([Ca2+]i) and sodium concentration ([Na+]i) were measured using fluorescence indicators. Under the resting condition, [Ca2+]i and [Na+]i were 91 +/- 9 nM (n = 51) and 110 +/- 5 mM (n = 12), respectively. Removal of external Na+ by replacing with N-methyl-D-glucamine (NMDG+) increased [Ca2+]i by 270 +/- 79% (n = 27) and decreased [Na+]i by 23 +/- 4 mM (n = 6). Both changes in [Ca2+]i and [Na+]i were totally reversible on returning external Na+ to the initial value and were inhibited by addition of 0.1 mM La3+ or 100 microM amiloride 5-(N,N-dimethyl) hydrochloride. Elevation of external Ca2+ ions to 20 mM reversibly decreased [Na+]i by 8 +/- 6 mM (n = 5). Moreover, the chelation of the intracellular Ca2+ with 1,2-bis (2-aminophenoxy) ethane-N,N,N',N'-tetraacetic acid (BAPTA) exerted an inhibitory action on the NMDG(+)-induced reduction in [Na+]i. Exposure to 5 mM NaCN for 2 min significantly and reversibly increased [Ca2+]i by 290 +/- 37% (n = 5), but did not affect the [Ca2+]i elevation induced by the NMDG+ solution. The rise in [Ca2+]i induced by the NMDG+ solution was not enhanced by ouabain pretreatment. Addition of ouabain did not alter the [Na+]i. The present results are best explained by the presence of an Na(+)-Ca2+ exchanger in cell membrane and indicate that the activity of Na+/K+ pump is poor in outer hair cells.

Long-term changes of infarct-related lesions. Comparison of angiograms in recent and remote phases

Coronary angiograms recorded in the recent phase of an acute myocardial infarction in 73 patients were compared with those taken in the remote phase at least 12 months from the onset of the infarction. The infarct-related lesions of 23 patients (32%) showed a regression of 20% or more. Analysis of recent-phase angiograms proved that any one of several features (long-segment narrowing, intraluminal thrombus, flap-like structure or atheromatous ulceration) was present more frequently in the lesions showing a marked regression (18/23, 78%) than in the lesions without regression (15/40, 38%) (p less than 0.01). Thus, the narrowings of infarct-related lesions seen on the recent-phase angiograms regress frequently. The possibility of regression can be predicted from the angiographic features.

Intracellular pH regulation in isolated cochlear outer hair cells of the guinea-pig

1. The intracellular pH (pHi) regulation mechanisms of the outer hair cell (OHC) isolated from the guinea-pig were studied using fluorescence ratio imaging microscopy. 2. The OHC pHi in the resting condition was 7.26 +/- 0.08 (mean +/- S.D., n = 49) when the standard solution buffered with HEPES-Tris was superfused. 3. Exposure to 25 mM-NH4+ in the absence of HCO3- caused biphasic changes in pHi; a transient increase (7.89 +/- 0.14, n = 22) followed by a slow decrease (7.57 +/- 0.12; mean +/- S.D.). Removal of external NH4+ by introducing the N-methyl-D-glucamine (NMDG+) solution in the absence of HCO3- markedly acidified the pHi to 6.38 +/- 0.12 with little pHi recovery. Subsequent application of the standard Na+ solution restored the pHi to the initial value. The recovery was inhibited by 0.5 mM-amiloride but not by 0.3 mM-DIDS (4,4'-diisothiocyanatostilbene-2,2'-disulphonic acid). 4. In the presence of HCO3-, removal of both external NH4+ and Na+ promptly caused an intracellular acidification followed by a pHi recovery. The pHi recovery from an acid load was inhibited by 0.3 mM-DIDS or 10 microM-NPPB (5-nitro-2-(3-phenylpropyl-amino)-benzoate). However, the pHi in the steady state in the presence or absence of HCO3- was not altered by addition of 0.5 mM-amiloride or NMDG+ solution. 5. The intracellular buffering power obtained from the NH4+ exposure and withdrawal was -15.1 +/- 8.7 mM (pH unit)-1 (n = 6) and -14.3 +/- 5.8 mM (pH unit)-1, respectively. 6. Replacement of external Cl- with gluconate in the HCO3- solution increased the pHi from 7.22 +/- 0.12 to 7.51 +/- 0.20 (n = 6), which was inhibited by 0.3 mM-DIDS. Moreover, addition of DIDS to the HCO3- solution increased the pHi by 0.13 +/- 0.08 (n = 8). 7. When the external standard solution buffered with HEPES-Tris was replaced with the HCO3- solution, the basal pHi (7.27 +/- 0.10) was promptly acidified to 6.87 +/- 0.10 then relaxed slowly to 7.00 +/- 0.15 (n = 16). 8. The pHi showed an initial alkalinization and a subsequent slow acidification after the HCO3(-)-free standard solution replaced the HCO3- solution. The slow acidification was inhibited by low external Cl- concentration or by addition of 0.3 mM-DIDS.(ABSTRACT TRUNCATED AT 400 WORDS)

In situ hybridization histochemistry of Spot 35 protein, a calcium-binding protein, in the rat brain

Using in situ hybridization, we analyzed the localization of mRNA for Spot 35 protein (Spot 35), a calcium-binding protein of the EF-hand type, in the rat cerebellum at various developmental stages. A cDNA fragment corresponding to part of the 3'-noncoding region was 35S-labeled and used as a hybridization probe. Autoradiographic signals for Spot 35 mRNA were detected in all the Purkinje cells, but not in any other neurons or glial cells in the adult rat cerebellum. There was no significant difference in signal intensity among individual cells. The signals were observed exclusively in Purkinje cell bodies, but not in their processes, in striking contrast to previous immunohistochemical studies in which Spot 35 protein was demonstrated in both cell bodies and processes. In the time-course study, signals for Spot 35 mRNA were detected in Purkinje cell bodies weakly at embryonic day 19, thereafter more intensely at more developed stages and most intensely at postnatal days 30 and 60 (adulthood). The signal intensities of individual cells were similar at each of these developmental stages except for the very early stages at which signals were weak and slightly variable among cells. These findings, especially that of the characteristic coordinated expression of Spot 35 mRNA at given stages, should prove useful in studies of degenerative diseases in the cerebellum in experimental animals and man. A weak expression of Spot 35 mRNA in some of non-Purkinje cells was also noted.

Microfluorimetric imaging study of the mechanism of activation of the Na+/H+ antiport by muscarinic agonist in rat mandibular acinar cells

The mechanism of regulation of intracellular pH (pHi) in dispersed acini from the rat mandibular salivary gland has been studied with a microfluorimetric imaging method and the pH probe 2',7'-bis(2-carboxyethyl)-5(and -6)-carboxyfluorescein. The pHi in the TRIS/HEPES-buffered standard solution was 7.29 +/- 0.01. Addition of 1 mumol/l acetylcholine (ACh) or ionomycin caused a sustained increase in the pHi. These agents decreased pHi in the absence of external Na+ or in the presence of amiloride. The rate of pHi recovery from an acid load after NH+4 prepulse was a linear function of pHi and increased as pHi became more acidic. Addition of ACh shifted the relationship towards a more alkaline pHi range. The increase in pHi induced by ACh or ionomycin was not inhibited by the protein kinase C inhibitors staurosporine (10 nM) and 1-(5-isoquinolinesulfonyl)-1-methylpiperazine (50 mumol/l). Addition of 0.1-1 mumol/l phorbol 12-myristate 13-acetate (TPA) had little effect on pHi within 10 min; however, exposure to TPA for 120 min resulted in a significant rise in pHi. In Ca(2+)-free solution with 50 mumol/l 8-(diethylamino)-octyl-3,4,5-trimethoxybenzoate, the ACh-induced rise in both pHi and cytosolic Ca2+ concentration was suppressed. ACh and ionomycin caused an increment of amiloride-sensitive acid output into the extracellular fluid, while 20 mumol/l 1-oleoyl-2-acetylglycerol had little effect on it. It was concluded that (a) stimulation with ACh activated the Na+/H+ antiport in the plasma membrane, (b) ACh also stimulated the intracellular acid production but acid extrusion by the Na+/H+ antiport prevented the cell from intracellular acidification, and (c) the major route of signal transduction for the ACh-induced activation of the Na+/H+ antiport was independent of protein kinase C but was dependent on the rise in cytosolic Ca2+ concentration. The implication of the cytosolic acidification and cell volume change in pHi regulation is discussed.

Effects of pH on intracellular calcium levels in isolated cochlear outer hair cells of guinea pigs

Effects of intracellular pH (pHi) on intracellular Ca2+ (Cai2+) in the outer hair cell (OHC) were investigated using fluorescence ratio imaging microscopy. Cai2+ and pHi were determined with fluorescence indicators fura-2 and 2,7-bis(2-carboxyethyl)- 5,6-carboxyfluorescein, respectively. Intracellular alkalinization from the basal pHi of 7.22 +/- 0.03 to 7.82 +/- 0.09 (n = 7) induced by 25 mM NH4+ caused a rise in Cai2+ from 102 +/- 15 to 195 +/- 28 nM (n = 8). The elevation of Cai2+ was inhibited by removing external Ca2+ or by 50 microM nifedipine. On the other hand, the cytosolic acidification produced by the removal of NH4+ (delta pHi = 0.53 +/- 0.06, n = 7) and the admission of 5% CO2 (delta pHi = 0.72 +/- 0.05, n = 4) elicited a slight reduction in Cai2+. The depolarization of the membrane potential by exposure to 100 mM K+ induced an increase in Cai2+ that was susceptible to nifedipine, indicating the presence of voltage-sensitive Ca2+ channels. The elevation in Cai2+ induced by 100 mM K(+)-containing solution was increased by 138 +/- 6% (n = 4) by external alkalinization to pH 8.4 and was decreased by 87 +/- 3% (n = 4) by external acidification to pH 6.4. These results demonstrate that both internal and external alkalinization of OHCs facilitate the influx of Ca2+ through the Ca2+ channel, leading to a rise of Cai2+. Thus pH, extra- and intracellular, may modulate the OHC motility by regulating the Cai2+.

The primary structure of NG2, a novel membrane-spanning proteoglycan

The complete primary structure of the core protein of rat NG2, a large, chondroitin sulfate proteoglycan expressed on O2A progenitor cells, has been determined from cDNA clones. These cDNAs hybridize to an mRNA species of 8.9 kbp from rat neural cell lines. The total contiguous cDNA spans 8,071 nucleotides and contains an open reading frame for 2,325 amino acids. The predicted protein is an integral membrane protein with a large extracellular domain (2,224 amino acids), a single transmembrane domain (25 amino acids), and a short cytoplasmic tail (76 amino acids). Based on the deduced amino acid sequence and immunochemical analysis of proteolytic fragments of NG2, the extracellular region can be divided into three domains: an amino terminal cysteine-containing domain which is stabilized by intrachain disulfide bonds, a serine-glycine-containing domain to which chondroitin sulfate chains are attached, and another cysteine-containing domain. Four internal repeats, each consisting of 200 amino acids, are found in the extracellular domain of NG2. These repeats contain a short sequence that resembles the putative Ca(++)-binding region of the cadherins. The sequence of NG2 does not show significant homology with any other known proteins, suggesting that NG2 is a novel species of integral membrane proteoglycan.

The expression of NG2 proteoglycan in the developing rat limb

NG2 is a chondroitin sulfate proteoglycan previously found to be expressed by glial progenitor cells of the O2A lineage. We have examined the expression of NG2 in the developing rat limb by immunohistochemistry and northern blot analysis. Staining of embryonic day 14 (E14) rat limb bud sections with polyclonal and monoclonal anti-NG2 antibodies reveals reactivity in the precartilaginous mesenchymal condensation. The staining intensity increases with the differentiation of chondrocytes until E16. NG2 staining is not detected in the mature hypertrophic chondrocytes of E17 and postnatal day 3 (P3) limbs even after treatment of the sections with hyaluronidase or collagenase. Immuno-precipitations with anti-NG2 antibody using 125I-labeled limb cells in culture showed a 400 to 800 × 10(3) Mr proteoglycan species with a core protein size of 300 × 10(3) Mr, comparable to NG2 from O2A cells and neural cell lines. Northern blot analysis reveals the expression of an 8.9 kb mRNA in E16 limbs and at a lower level in P1 cartilage. The northern blot analyses also show that NG2 is distinct from the large aggregating proteoglycan of the cartilage. Our results indicate that in the developing limb cartilage, as in the differentiating oligodendrocytes, NG2 is present on immature cells in the process of differentiating, but its expression is downregulated as terminal differentiation of chondrocytes takes place.

Effect of neuroregulators on the intracellular calcium level in the outer hair cell isolated from the guinea pig

The cytosolic calcium concentration [( Ca2+]i) of the isolated outer hair cell of the guinea pig was measured using fluorescence imaging microscopy and the effects of efferent neuroregulators such as acetylcholine, ATP, GABA, substance P, enkephalin, calcitonin gene-related peptide, serotonin, dopamine, norepinephrine, and glutamate were investigated. Among the drugs tested only ATP induced an elevation of the [Ca2+]i of the outer hair cell. In the resting condition, [Ca2+]i averaged 104.5 +/- 31.1 nM (n = 27), while 100 microM ATP significantly increased [Ca2+]i to 146.3 +/- 43.5 nM (n = 19). Superfusion with Ca2(+)-free solution (pCa = 7.5) abolished the increase in [Ca2+]i induced by ATP, suggesting that ATP causes an entry of external Ca2+. The relevance of [Ca2+]i to the inhibitory actions of efferent neuroregulators is discussed.

Effects of intra- and extracellular H+ and Na+ concentrations on Na(+)-H+ antiport activity in the lacrimal gland acinar cells

Kinetic properties of the Na(+)-H+ antiport in the acinar cells of the isolated, superfused mouse lacrimal gland were studied by measuring intracellular pH (pHi) and Na+ activity (aNai) with the aid of double-barreled H(+)- and Na(+)-selective microelectrodes, respectively. Bicarbonate-free solutions were used throughout. Under untreated control conditions, pHi was 7.12 +/- 0.01 and aNai was 6.7 +/- 0.6 mmol/l. The cells were acid-loaded by exposure to an NH4+ solution followed by an Na(+)-free N-methyl-D-glucamine (NMDG+) solution. Intracellular Na+ and H+ concentrations were manipulated by changing the duration of exposure to the above solutions. Subsequent addition of the standard Na+ solution rapidly increased pHi. This Na(+)-induced increase in pHi was almost completely inhibited by 0.5 mmol/l amiloride and was associated with a rapid, amiloride-sensitive increase in aNai. The rate of pHi recovery induced by the standard Na+ solution increased in a saturable manner as pHi decreased, and was negligible at pHi 7.2-7.3, indicating an inactivation of the Na(+)-H+ antiport. The apparent Km for intracellular H+ concentration was 105 nmol/l (pH 6.98). The rate of acid extrusion from the acid-loaded cells increased proportionally to the increase in extracellular pH. Depletion of aNai to less than 1 mmol/l by prolonged exposure to NMDG+ solution significantly increased the rate of Na(+)-dependent acid extrusion. The rate of acid extrusion increased as the extracellular Na+ concentration increased following Michaelis-Menten kinetics (Vmax was 0.55 pH/min and the apparent Km was 75 mmol/l at pHi 6.88).(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of surfactant on bioelectric properties of canine tracheal epithelium

The functional significance of pulmonary surfactant in the airways is not well known and the effects of surfactant on bioelectrical properties of airway epithelium have not been investigated. In the present study, we examined the effect of synthetic surfactant (TR-14) or calf lung surfactant extract (surfactant TA) on transepithelial potential difference (PD) and short circuit current (SCC) in canine trachea. The conductance (G) was calculated as the ratio of SCC per open-circuited PD. The posterior membrane without muscular layer from canine trachea was mounted in an Ussing-type chamber, bathed with Krebs-Ringer buffer solution at 37 degrees C and gassed with 95% O2-5% CO2, pH 7.4. Treatment with mucosal surfactant produced an increase in both PD and SCC in a dose-dependent fashion. PD and SCC reached 132% and 124% of before control at 0.25 mg/ml after the addition of each surfactant respectively, whereas G remained unchanged. Both ouabain and furosemide abolished surfactant-evoked increases in PD and SCC, whereas amiloride did not alter the surfactant-evoked increases. No significant differences in the effect on bioelectric parameters were observed between TR-14 and surfactant TA. These findings suggest that lung surfactant affects bioelectrical properties and changes ion transport (Cl- secretion) across airway epithelium, probably through the activity of ion pumps in the cellular membrane.

Leucocyte function in rats with naturally occurring gingivitis

The severity of gingivitis in relation to abnormal macrophage chemotaxis and superoxide (O2-) production was investigated in rats with naturally occurring gingivitis (plaque-susceptible rats). Macrophage chemotaxis was measured by the membrane filter method; zymosan-activated serum was used as a chemo-attractant. O2- production was measured by the reduction of cytochrome c method. Opsonized zymosan, phorbol myristate acetate and calcium ionophore A23187 were used as stimulants. The macrophage chemotaxis and O2- production in the plaque-susceptible rats with deep pockets were significantly lower than those in the susceptible rats with shallow pockets or the normal group. In addition, there was a negative correlation between the severity of gingivitis in plaque-susceptible rats and macrophage chemotaxis or O2- production. These findings suggest that impairement of the host defence mechanisms due to the reduction in macrophage chemotaxis and O2- production is related to the progression of periodontal disease in plaque-susceptible rats.

Glomeruloid blood vessels in ethylnitrosourea-induced rat gliomas. Histological and immunohistochemical studies

Glomeruloid blood vessels (GBVs), a characteristic histological feature of most human malignant gliomas, were recognized with high incidence in autochthonous rat gliomas induced by transplacental administration of ethylnitrosourea. To evaluate some of the biological properties of these GBVs, we carried out a study using histological methods and immunohistochemical staining for glial fibrillary acidic protein, factor VIII-related antigen (VIII Ag) and bromodeoxyuridine (BrdUrd). Of 22 animals with large, massively growing gliomas in the CNS, GBVs including conglomerate aggregations of small blood vessels with endothelial hyperplasia and strong VIII Ag expression were observed in 13 large gliomas histologically consisting of primitive neuroepithelial neoplasms (PNN; so called ependymoma) and mixed-type gliomas in combination with astrocytoma and PNN or anaplastic astrocytoma. The anaplastic gliomas in our series were devoid of GBVs. These findings indicate that GBV formation takes place in a histological variety of experimental gliomas. Furthermore, the GBVs were frequently associated with the vasculo-mesenchymal stroma in the parent gliomas, suggesting an intimate relationship with the morphogenesis of GBVs. In addition, it was shown that the GBVs had a higher BrdUrd-labelling index than that of other blood vessels in gliomas and also that of neoplastic cells in most parent gliomas, except for anaplastic gliomas. Based on these results, the possible mechanism of GBV morphogenesis is discussed with regard to the roles of macromolecules in the induction and regulation of GBVs.

[A case of miliary tuberculosis associated with ARDS, DIC and bilateral pneumothorax]

We reported a case of 64 a year-old male patient of miliary tuberculosis associated with ARDS, DIC and pneumothorax, who had a history of gastric ulcer and pulmonary tuberculosis. On admission his chief complaints were fever, fatigue, palpitation, appetite loss and weight loss, and most noticeable abnormalities were bleeding from the gastric ulcer and miliary shadow on the chest x-ray film with hypoxemia. On the day after admission to the hospital he was diagnosed as ARDS as he showed severe hypoxemia due to extensive tuberculous infiltration in bilateral lung fields, and treatment with antituberculous drugs and steroids were started. On the third hospital day DIC appeared on laboratory data, Gabexate mesilate (FOY) for DIC and respirator for ARDS were introduced. Two weeks later pulmonary infiltration, PaO2 and general condition were somewhat improved. On the 15th day after admission pneumothorax occurred on the right side, and on the 20th day on the left. Tube drainage of both pleural cavities, and instillation of OK-432 and Fibrinogen HT into the right pleural cavity were done, but it showed no effect. Two months after admission pouring Fibrinogen HT and thrombin into the left B1+2 and right B1 with cannula washing pipe through the instrument channel of bronchoscope was carried out. A few days later air leakage stopped and collapsed lungs were completely expanded. This method is effective in the case of incurable pneumothorax with pulmonary hypofunction.

An immunohistochemical analysis of T cells in primary B cell malignant lymphoma of the brain

An immunohistochemical study was performed on small lymphoid cells present in frozen tissue sections of seven cases of primary B cell malignant lymphomas of the brain by using monoclonal antibodies to T cell (Leu-1, OKT-11, Leu-3a, and Leu-2a) and B cell (BA-1 and Leu-12) surface markers. In all the seven cases, positive reaction for Leu-1 and OKT-11 was seen in the majority of the small lymphoid cells which were dispersed among the lymphoma cells or clustered around blood vessels. The large neoplastic cells were unstained by these antibodies. Staining for T cell subsets with antibodies to Leu-3a and Leu-2a showed heterogeneous staining in each case. The ratio of Leu-3a+ to Leu-2a+ cells was less than one in six cases, demonstrating a suppressor/cytotoxic phenotype predominance. Most of these small lymphoid cells were negatively stained by antibodies to BA-1 and Leu-12. From these findings, it was shown that the small lymphoid cells observed in primary B cell lymphomas of the brain were of T cell lineage, distinct from the neoplastic cells, and probably reactive in nature. The implications of these findings are discussed.