Acute sodium deficiency reduces gustatory responsiveness to NaCl in the parabrachial nucleus of rats

Sodium-deprived rats ingest excessive amounts of salt solutions at high concentrations which are normally avoided. This phenomenon, salt appetite, is known to be controlled by the sense of taste. In the present study, a possible involvement of the parabrachial nucleus (PBN) in sodium appetite was examined by recording PBN neuron responses to 12 different taste stimuli in sodium-deprived and control groups of urethane anesthetized rats. Sodium deficiency was induced by two injections of furosemide 24 and 22 h before the recording. Taste responses to 0.3 and 0.5 M solutions of NaCl were significantly lower in the sodium-deprived rats than in controls. In gustatory responses to other taste solutions except for quinine hydrochloride solution, no differences were detected between the two groups of the rats. Correlation coefficients of responses among sodium salts and those between 0.5 M NaCl and sweeteners were larger in the sodium-deprived rats than in controls. The results indicate that PBN neurons in sodium-deprived rats are critically implicated in induction of quantitative and qualitative changes of gustatory sense to sodium salts.

The effect of L-menthol stimulation of the major palatine nerve on subjective and objective nasal patency

To determine whether L-menthol stimulation of the major palatine nerve can affect nasal patency, we noted subjective and measured objective nasal patency before and after L-menthol stimulation of the palatal mucosa. L-Menthol stimulation of the palatal mucosa enhanced nasal sensation of airflow but nasal resistance was unaffected. By contrast, L-menthol stimulation after local anesthesia of the palatine nerve or of the nasal mucosa substantially diminished the subjective response of increased nasal patency but without affecting objective nasal patency. It is suggested that the effect of both direct stimulation by L-menthol of the major palatine nerve and its vapor action on the sensory nerve endings of the nasal mucosa produce an increase in the sensation of nasal patency without an increase in objective nasal patency.

The effect of ulinastatin on cutaneous microcirculation during inhalation of 100% oxygen in a rabbit ear chamber

This study aims to investigate the effects of ulinastatin, a human urinary trypsin inhibitor, on the cutaneous microcirculation during inhalation of 100% oxygen in the rabbit. Twenty-one rabbits having a rabbit ear chamber (REC), were divided into 2 groups: 11 rabbits without ulinastain treatment (Group C) and 10 rabbits with ulinastatin (Group U). After air inhalation, the inspired gas was changed to 100% oxygen. In Group U, 50,000 units of ulinastatin were administered before changing the concentration of inspired gas. The results suggests that ulinastatin may be useful for maintaining the cutaneous microcirculation during inhalation of 100% oxygen.

Expression of prolactin gene in mouse placenta during late pregnancy: detection of mRNA and its translation product

To examine the existence of PRL messenger ribonucleic acid (mRNA) in the mouse placenta during late pregnancy, reverse transcriptase-polymerase chain reaction (RT-PCR) and Southern blot analysis were carried out followed by nucleotide sequence analysis of cDNA. Total RNA extracted from each tissue was reverse-transcribed, followed by PCR with two oligonucleotide primers specific or a part of mouse PRL (mPRL) cDNA. An amplified RT-PCR product of predicted size was detected in all samples from the placenta of days 16 and 18 pregnant mice. This product was specifically hybridized with a probe overlapping an entire sequence of mPRL cDNA in Southern blot analysis. Nucleotide sequence analysis also provided evidence that the amplified cDNA had a nucleotide sequence completely identical to the mPRL cDNA sequence reported previously. Furthermore, mPRL with a slightly bigger molecular weight than that of pituitary PRL was detected in the placenta of days 12, 14, 16 and 18 pregnancy by immunoblot analysis. These results suggest that PRL mRNA and its translation product are synthesized in mouse placenta during late pregnancy.

The Hansenula polymorpha PEX14 gene encodes a novel peroxisomal membrane protein essential for peroxisome biogenesis

We have cloned the Hansenula polymorpha PEX14 gene by functional complementation of the chemically induced pex14-1 mutant, which lacked normal peroxisomes. The sequence of the PEX14 gene predicts a novel protein product (Pex14p) of 39 kDa which showed no similarity to any known protein and lacked either of the two known peroxisomal targeting signals. Biochemical and electron microscopical analysis indicated that Pex14p is a component of the peroxisomal membrane. The synthesis of Pex14p is induced by peroxisome-inducing growth conditions. In cells of both pex14-1 and a PEX14 disruption mutant, peroxisomal membrane remnants were evident; these contained the H.polymorpha peroxisomal membrane protein Pex3p together with a small amount of the major peroxisomal matrix proteins alcohol oxidase, catalase and dihydroxyacetone synthase, the bulk of which resided in the cytosol. Unexpectedly, overproduction of Pex14p in wild-type H. polymorpha cells resulted in a peroxisome-deficient phenotype typified by the presence of numerous small vesicles which lacked matrix proteins; these were localized in the cytosol. Apparently, the stoichiometry of Pex14p relative to one or more other components of the peroxisome biogenesis machinery appears to be critical for protein import.

Another interpretation of burst imaging as a variation of line projection imaging

Burst imaging and DUFIS realize fast imaging without rapid switching of magnetic field gradients. In this paper, some new aspects of burst imaging are explored. Interestingly, when one-dimensional Fourier transform is applied, Burst imaging becomes similar to line projection scanning, a concept proposed earlier by Mansfield and Maudsley (P. Mansfield, A. A. Maudsley, Planar spin imaging by NMR. J. Magn. Reson. 27, 101-119 (1977)). The line scanning interpretation is applied to two-dimensional Burst imaging, and the relationship between its two-dimensional k-space trajectory and line scanning interpretation is discussed.

An international comparison of characteristics of the sensation of nasal obstruction between Canadian and Japanese patients

To determine differences in perception of nasal obstruction in Canadians and Japanese, we assessed subjective and objective nasal patency of 48 patients in Canada and 43 patients in Japan. Mean severity of the sensation of nasal obstruction in Canadian patients was significantly higher than in Japanese patients, while no significant differences in nasal resistances were found. Complaints of nasal obstruction in Canadian patients were directly concerned with nasal breathing, while Japanese patients complained of indirect matters, such as "unable to concentrate on job or study" or "nasal obstruction or nasal speech pointed out by other persons." The differences might be due to national characteristics.

Peroxisomal remnants in peroxisome-deficient mutants of the yeast Hansenula polymorpha [corrected]

We have analyzed the presence of peroxisomal remnants ('ghosts') in three peroxisome-deficient (per) mutants of the yeast Hansenula polymorpha, namely delta per4, delta per5 and delta per10. Under peroxisome-inducing growth conditions peroxisomal membrane proteins (PMPs) were normally synthesized in cells of these mutants. In addition, these cells contained clusters of small membraneous vesicles, which were absent in cells grown under peroxisome-repressing growth conditions. These structures displayed typical peroxisomal properties in that they proliferated upon overproduction of Per8p, the H. polymorpha peroxisome proliferation factor. Moreover, in delta per4 and delta per5 these vesicles were susceptible to glucose-induced proteolytic degradation.

Heterologous complementation of peroxisome function in yeast: the Saccharomyces cerevisiae PAS3 gene restores peroxisome biogenesis in a Hansenula polymorpha per9 disruption mutant

PER genes are essential for the biogenesis of peroxisomes in the yeast Hansenula polymorpha. Here we describe the functional complementation of a H. polymorpha per9 disruption strain (delta per9) by a heterologous gene. The Saccharomyces cerevisiae Pas3p, a homologue of per9p, restored peroxisome biogenesis and peroxisomal protein import in the delta per9 mutant, allowing it to grow again on methanol as sole carbon and energy source. This result shows that heterologous complementation of peroxisome function in yeast is indeed feasible and furthermore suggests that H. polymorpha delta per9 may be the candidate of choice to attempt the isolation of Per9p homologues from higher eukaryotes by functional complementation.

[Antihypertensive effects of repeated oral administration of cilnidipine, a novel calcium antagonist, in 2K1C renal hypertensive dogs]

Antihypertensive effects of repeated oral administration of cilnidipine in 2K1C renal hypertensive dogs were compared with those of nicardipine. On the first day, oral administration of cilnidipine (3 mg/kg) or nicardipine (3 mg/kg) markedly lowered both systolic and diastolic blood pressure 1 hr after administration. The hypotensive effects of cilnidipine were longer compared with those of nicardipine. Both drugs elevated the heart rate and plasma renin activity. On the 8th and 15th days, similar responses were obtained by repeated administrations of cilnidipine and nicardipine. After withdrawal of these drugs, no rebound phenomena in blood pressure were observed. The changes in mean blood pressure were correlated with plasma cilnidipine or nicardipine concentrations that were obtained at each time of blood pressure measurement (r = -0.598; P < 0.001 and r = -0.594; P < 0.001, respectively). These results suggest that stable and long-acting antihypertensive effects of cilnidipine for 15 consecutive days in renal hypertensive dogs are related to the change in plasma drug concentrations.

Mutagenic activation of 3-methoxy-4-aminoazobenzene by mouse renal cytochrome P450 CYP4B1: cloning and characterization of mouse CYP4B1

A new P450 responsible for mutagenic activation of 3-methoxy-4-aminoazobenzene (3-MeO-AAB) which is a potent procarcinogen was purified from renal microsomes of male mice using an index of umu gene expression. The purified P450 had high bioactivation toward 3-MeO-AAB and also 2-aminofluorene and 2-aminoanthracene. The antibody against this P450 completely inhibited mutagenic activation of 3-MeO-AAB of mouse renal microsomes. With immunoblotting, this form was present abundantly in renal microsomes of male mice but not in those of female mice. This P450 was also present in pulmonary microsomes of male and female mice but not in hepatic microsomes. The NH2-terminal amino acid sequence analysis indicated that this form belonged to the CYP4B subfamily. Thus, mouse kidney cDNA library was screened with rat CYP4B1 probe. The cDNA-deduced amino acid sequence of isolated cDNA consisted of 511 amino acids and bore 90, 86, and 84% similarities to rat, rabbit, and human CYP4B1, respectively. The NH2-terminal amino acid sequence of the purified renal P450 and amino acid sequence of BrCN-digested peptides from the purified P450 agreed with the cDNA-deduced amino acid sequence. These results suggest that CYP4B1 is a major form in renal microsomes of male mice and plays a major role in mutagenic activation of 3-MeO-AAB. In extrahepatic tissue, CYP4B1 may contribute to chemical carcinogenesis.

[Computerized three-dimensional reconstruction of human embryos and their organs using the "NIH image" software]

Three-dimensional structures of human embryos and their internal organs were reconstructed on a CRT from their serial histological sections using a free computer software system "NIH Image." It was possible to rotate the computer images on CRT and to make cut models on any desired plane. In addition, various developmental changes could be animated by artificial "morphing" between the models at different stages. Computer graphic modeling should be of great value in the study of normal and abnormal morphogenesis. The "NIH Image" software is freely available via computer networks and has a lot of advantages over previously developed software programs used for three-dimensional reconstruction.

Effect of iron as a new type of phosphate binder in hemodialysis patients

Hyperphosphatemia is one of the major problems requiring management in the majority of hemodialysis patients and they require phosphate-binding agents to control the hyperphosphatemia. Aluminum hydroxide and calcium compounds are used currently as phosphate-binding agents to treat hyperphosphatemia, but these compounds can cause undesirable side effects. Therefore, the development of new phosphate-binding agents is imperative. It is well known that oral and intravenous administration of iron causes hypophosphatemia. We hypothesized that this side effect of iron may be beneficial for the treatment of hyperphosphatemia in hemodialysis patients. Consequently, we conducted a fundamental and clinical investigation of the effects of iron administration. Membrane permeability of phosphorus in a mixture of sodium ferrous citrate and dessicated aluminium hydroxide in the presence of hydrogenated lecithin as a phosporic compound was examined. Fifteen patients undergoing hemodialysis were treated with 150 mg of sodium ferrous citrate given orally for eight weeks. The permeability of the filtering membrane to phosphorus decreased in accordance with the dosage of sodium ferrous citrate and dessicated aluminum hydroxide. The degree of phosphate-binding effect of sodium ferrous citrate was larger than that of dessicated aluminum hydroxide. Serum phosphorus decreased significantly during the experiment. These results suggest that the oral administration of sodium ferrous citrate as a new phosphate binder is a useful therapeutic method for hemodialysis in patients with hyperphosphatemia.

Evidence for an increased intracellular free calcium concentration in platelets of bronchial asthma patients

The pathogenesis of bronchial asthma is not yet fully understood. Recently much attention has been given to the hypothesis that intracellular free calcium ([Ca2+]i) metabolism is abnormal in various diseases. In this study we investigated whether [Ca2+]i exists abnormally in subjects with bronchial asthma. The [Ca2+]i in 32 treated or untreated subjects with bronchial asthma were compared with 63 normal subjects. Resting levels of [Ca2+]i were estimated by loading the fluorescent indicator Fura-2 in washed platelets. The [Ca2+]i level in the control subjects was 129.7 +/- 18.0 nM (mean +/- SD). However, in that of the bronchial asthma patients was 152.7 +/- 44.1 nM, significantly higher than that of the control subjects (p < 0.05). It is well recognized that an increase of [Ca2+]i in vascular smooth muscle involves contraction. The findings suggest that the same phenomenon is quite possible in the tracheal smooth muscle and that it plays an important role in the pathogenesis of bronchial asthma.

New aerodynamic aspects of nasal patency

In considering possible aerodynamic indicators of subjective nasal stuffiness, we measured nasal resistance, acceleration change of nasal airflow, and alteration of differential pressure and compared those with the degree of severity of sensation of nasal obstruction in 75 patients. The acceleration change of airflow and alteration of differential pressure are presented as an equation: y = ax2 + bx + c, in which "a" represents the approximate shape of the curve. Nasal resistance, on either inspiration or expiration, and coefficient "a" of acceleration change the rapid phase from inspiration to expiration correlated well with subjective nasal patency, while coefficient "a" of acceleration change the rapid phase from expiration to inspiration and alteration of differential pressure either the rapid phase from inspiration to expiration or from expiration to inspiration did not correlate well with perception of nasal blockage. It seems that measurement of respiratory acceleration of airflow of quiet nasal breathing is a useful indicator of subjective nasal patency.

A case of acquired petrous cholesteatoma associated with insidious middle ear infection treated by staging the surgical procedures

Surgical treatment of petrous cholesteatoma is difficult, especially in infected cases, since it often involves vital structures. We report the case of a patient successfully treated for an infected petrous cholesteatoma by staging the surgical procedures to reduce the risk of intracranial complications. The patient, a 53-year-old man, was referred to our hospital because of vertigo during coughing or strenuous effort. The left side mastoid cavity was open to the external ear canal and wholly covered with cholesteatoma epithelium with purulent discharge. The superior basal turn of the cochlea, superior and posterior semicircular canals, and roof of the internal auditory canal were eroded. Conservative treatment was not effective in eradicating the otorrhea. Four weeks after the first operation (radical mastoidectomy), the second operation was conducted following a combined middle cranial fossa and transmastoid approach. The postoperative course was uneventful. Normal facial nerve function was preserved and unsteadiness disappeared, but hearing could not be preserved. The MRI examination, performed one year after surgery, did not reveal any evidence of residual cholesteatoma.

Comparison of heme environment at the putative distal region of P-450s utilizing their external and internal nitrogenous ligand bound forms

Thr-303 to Lys-mutated P-450 2E1, as well as Thr-301 to Lys-mutated P-450 2C2, had absorption spectra characteristic of a nitrogenous ligand-bound form of P-450, such as the pyridine complex of P-450 2E1; (i) in the ferric state, the red-shifted Soret band, compared with the typical low-spin type spectrum of P-450, and the more intense beta band than the alpha band and (ii) in the ferrous state, two Soret peaks at around 447 and 422 nm, the relative intensities of which depended on pH, indicating the existence of two interconvertible states. The equilibrium between the two states of the mutated P-450 2E1 appeared to be shifted toward the 422 nm state, compared with the mutated P-450 2C2. The corresponding mutant of P-450 2C14 had similar spectral properties to those of both mutated P-450s except that the shorter of the two Soret bands of its ferrous form was relatively broad and appeared at 418 nm. These findings suggest that the epsilon-amino-nitrogen of the Lys of the mutated P-450s is located in the appropriate position to occupy the sixth coordination position with the heme iron and spatial differences exist in the essentially conserved structure of the distal heme domain among the three ferrous Lys-mutated P-450s.

A major glucocorticoid-inducible P450 in rat liver is not P450 3A1

A new P450 3A cDNA (RL33) has been cloned from a liver cDNA library of untreated male rat. RL33 is 2032 nucleotides in length and has an open reading frame of 502 amino acid residues. The nucleotide sequence of its 5'-noncoding region is completely identical with that of a genomic clone of P450 3A1 isolated by Burger et al. [Proc. Natl. Acad. Sci. USA 89, 2145-2149 (1992)]. Compared with rat P450 3A1, P450 RL33 showed 98 and 97% identities in the nucleotide and deduced amino acid sequences, respectively, with the deletion of 2 amino acids and substitution of 12 amino acids. These residues were localized around amino acids 107-230. Recently Kirita and Matsubara have isolated the same P450 3A cDNA (cDEX) from dexamethasone (DEX)-treated rat liver [Arch. Biochem. Biophys. 307, 253-258 (1993)]. Northern blot analysis using an oligonucleotide probe specific for P450 RL33/cDEX revealed that P450 RL33/cDEX mRNA was induced strongly by pregnenolone 16 alpha-carbonitrile and DEX and weakly by phenobarbital (PB) and triacetyloleandomycin. We constructed a P450 3A cDNA library by the reverse transcriptase-polymerase chain reaction using common primers to P450 RL33/cDEX, 3A1, and 3A2, and subcloned the cDNAs into pUC119. The expression level of P450 RL33/cDEX mRNA was investigated by identifying each clone with the above oligonucleotide probe. P450 RL33/cDEX mRNA represented over 70% of the total P450 3A mRNA from untreated, PB-, and DEX-treated rat liver. These results indicated that the major DEX-inducible form of P450 3A is P450 RL33/cDEX and not P450 3A1.

[Monocular indirect argon laser photocoagulation for advanced retinopathy of prematurity]

A retrospective study of monocular indirect argon laser retinal photocoagulation for retinopathy of prematurity (ROP) was performed on 53 eyes of 36 premature infants, admitted to the neonatal intensive care unit (NICU) of Juntendo hospital from Jan. 1988 to Dec. 1990. The argon laser beam was delivered from an argon laser source located in the outpatient clinic to the NICU through a 50-meter fiber-optic cable. Thirty-eight eyes of 27 infants showing stage 3 middle substage of ROP retained a mild grade of cicatrical ROP. Fifteen eyes of 8 infants showed "Plus disease". Five eyes of these retained a severe grade of cicatrical ROP. The success rate of ROP treatment by laser photocoagulation was more satisfactory than in xenon are photocoagulation with cryotherapy. This method has slight technical difficulties, but the infants could be treated in a supine position in the incubators. Thus, monocular indirect argon laser retinal photocoagulation is a useful method in the treatment of ROP.

Different mechanisms of regioselection of fatty acid hydroxylation by laurate (omega-1)-hydroxylating P450s, P450 2C2 and P450 2E1

P450 2C2 as well as P450 2E1 [Fukuda, T. et al. (1993) J. Biochem. 113, 7-12] catalyzed the hydroxylation of medium chain fatty acids, although the regioselectivity of substrates of the former contrasted with that of the latter. Whereas P450 2E1 hydroxylated C9-C18 fatty acids at the omega-1 position and to a much lesser extent at the omega and omega-2 positions, P450 2C2 hydroxylated C9-C13 fatty acids at different positions dependent on the chain length of fatty acids. Among the fatty acids used as the substrate, undecanoate was hydroxylated at the omega-1 position almost exclusively by P450 2C2. The proportion of omega-hydroxylated products produced by P450 2C2 was markedly increased with decreasing chain length of fatty acids, while the hydroxylation positions were enlarged to the omega-3 position with tridecanoate. When the conserved Thr at the putative distal helix was replaced with Ser, the substrate regioselectivity of the two P450s was affected in different manners. The mutation of P450 2C2 did not change the hydroxylation positions of C9-C12 fatty acids, but caused a significant decrease in the proportion of the omega-1 hydroxy analog in the total products. In sharp contrast to P450 2C2, the mutated P450 2E1 gave additional products to those with the wild-type P450, and the number of different products increased with increasing chain length of the fatty acids. Thus, the products of palmitate hydroxylation were identified as omega-1, omega-2, omega-3, omega-4, omega-5, omega-6, and omega-7 monohydroxy isomers using gas chromatography-electron impact mass spectrometry.(ABSTRACT TRUNCATED AT 250 WORDS)

A novel P450 expressed at the high level in rat brain

Only P450 2D mRNA could be detected in Northern blot analysis of rat brain poly(A)+ RNA using probes from eight different P450s involved in drug metabolism. Four cerebral P450 cDNAs were isolated from a rat brain cDNA library using rat P450 2D2 cDNA as a probe, three of which were identified to rat P450 2D4. The expression of 2D4 mRNA was investigated by the reverse transcriptase-polymerase chain reaction and southern blot analysis using an oligonucleotide probe specific for P450 2D4. P450 2D4 mRNA was expressed at the high level in brain. Furthermore, it was detected in all other tissues examined, although to a lesser extent except in the liver and small intestine. However, total mRNAs of other P450 2D members (2D1, 2D2, 2D3, and 2D5) were mainly expressed in liver. The total level of expression of these mRNAs varied markedly among tissues. These results suggest that P450 2D4 may have a specific physiological function in the brain.

Purification and characterization of a form of P450 from horse liver microsomes

A form of P450 [termed P450(h-1)] was purified from the liver microsomes of a male horse to electrophoretic homogeneity. The specific content of the final P450(h-1) preparation was 14.8 nmol/mg of protein and the recovery was 0.38% of the microsomal P450. The apparent molecular weight of P450(h-1) was 52,000 Da. The absorption spectra of P450(h-1) indicated that P450(h-1) was a low- and high-spin mixed type P450 in the oxidized form. The reconstituted system containing P450(h-1) could catalyze benzphetamine N-demethylation, 7-ethoxycoumarin O-deethylation, and testosterone 16 alpha-hydroxylation. In the horse hepatic microsomes, aniline p-hydroxylation and testosterone 6 beta-hydroxylation, in addition to the above reactions, were detected. The N-terminal amino acid sequence of P450(h-1) was highly homologous to that of rat P450 2C11. Western blot analysis using anti-P450(h-1) antibody revealed that this antibody most strongly recognized P450 2C13 among ten rat P450s belonging to eight different subfamilies involved in hepatic drug metabolism. This anti-P450(h-1) antibody inhibited the testosterone 16 alpha-hydroxylase activity in horse liver microsomes. These results suggest that P450(h-1) belongs to the P450 2C subfamily and contributes to the testosterone 16 alpha-hydroxylation in horse liver microsomes.

Transgenic Drosophila carrying mammalian cytochrome P-4501A1: an application to toxicology testing

Transgenic Drosophila which carry a canine cytochrome P-450 were established and evaluated for its value on toxicology testing. Dah1, a cDNA clone for the canine hepatic P-4501A1, was ligated between the promoter of Drosophila heat-shock protein gene and the terminator of actin 5C gene, and then microinjected into Drosophila embryos with a transposon P element. The injected DNA was stably integrated into chromosomal DNA in germ line cells. After heat-shock treatments, transgenic larvae produced mRNA and a detectable amount of protein that cross-reacted with antibodies against rat P-4501A1. The ability of transgenic flies to activate procarcinogens was monitored in the DNA repair test with the endpoint being preadult mortality of repair-defective mei-9a mei-41D5/Y males. Heat-shock treatments of larvae showed that the repair-defective males carrying the P-4501A1 transgene were killed by lower concentrations of 7,12-dimethylbenz[a]anthracene than their non-transgenic or non heat-shocked counterparts. Coadministration of alpha-naphthoflavone, one of the inhibitors of P-4501A subfamily, cancelled the enhanced mortality of transgenic males, supporting that 7,12-dimethylbenz[a]anthracene was metabolized to its genotoxic form by the expressed P-4501A1 enzyme. This study indicates a potential utility of transgenic Drosophila for screening mammalian promutagens and procarcinogens.

Celadon: an eggshell color mutation in Japanese quail

A new eggshell color mutant was discovered in the Japanese quail. This trait was named "celadon" and was shown to be controlled by an autosomal recessive gene. Therefore, the gene symbol ce was proposed. This gene and an autosomal recessive gene we controlling a white eggshell trait were shown to be nonallelic. Also, ce was shown to be hypostatic to we. A spectrophotometric analysis revealed that the celadon eggshell pigments are protoporphyrin and biliverdin as in the wild-type eggshell, but the protoporphyrin content is much lower than that of the wild type. The biliverdin content was 44% of the wild type.