Glutamate N-methyl-D-aspartate (NMDA) and non-NMDA receptor antagonists administered into the brain stem depress the renal sympathetic reflex discharges evoked by single shock of somatic afferents in anesthetized rats

The involvement of glutamate receptors in the central transmission of somatosympathetic reflexes was studied by examining, in anesthetized rats, the effects of MK-801, an N-methyl-D-aspartate (NMDA) receptor antagonist, and CNQX, a non-NMDA receptor antagonist, on two reflex components, the A- and C-reflexes evoked in the left sympathetic renal nerve by a single shock to the left tibial nerve. The A-reflex elicited by myelinated A fiber stimulation and the C-reflex elicited by unmyelinated C fiber stimulation were depressed, in a dose-dependent manner, following administration of either MK-801 or CNQX into the cisterna magna (i.c.m.). Intrathecal (i.t.) administration of MK-801 did not have any effect on either A- or C-reflexes, while i.t. administration of CNQX had a slight effect on the A-reflex (significantly on the A-reflex only when treated with the highest dose of 100 ng) and the C-reflex. These results indicate that both NMDA and non-NMDA receptors, stimulated by glutamate released possibly as a neurotransmitter, are involved in the central transmission pathways of somatosympathetic reflexes at the level of the brain stem, but not the spinal cord.

Adrenomedullin induces expression of c-fos and AP-1 activity in rat vascular smooth muscle cells and cardiomyocytes

The recently described hypotensive peptide adrenomedullin has been shown to activate various second messenger pathways in cells of the cardiovascular system though no genomic actions have yet been described. In cultured rat vascular smooth muscle cells, cardiomyocytes, and cardiac fibroblasts, adrenomedullin caused a rapid, but transient induction of c-fos mRNA expression in all three cell types that varied in magnitude. Adrenomedullin increased AP-1 DNA binding activities in vascular smooth muscle cells and cardiomyocytes, but not in cardiac fibroblasts. These data suggest that cardiomyocytes and vascular smooth muscle cells may be important genomic targets for this novel hormone.

Targeting of chrolamphenicol acetyltransferase to human immunodeficiency virus particles via Vpr and Vpx

Vpr and Vpx are the auxiliary proteins of human immunodeficiency viruses (HIVs) selectively incorporated into mature viral particles. We showed that the bacterial chloramphenicol acetyltransferase (CAT) fused to the N-terminus of HIV-1 Vpr, HIV-2 Vpr, or HIV-2 Vpx was incorporated into mature virions in a type-selective manner. By using chimeric proteins between HIV-1 Vpr and HIV-2 Vpx, we found that the N-terminal side of these proteins was mainly important for type-selective virion incorporation. The C-terminal arginine-rich region of HIV-1 Vpr was also found to transport CAT fusion proteins into virions but without any type selectivity. Furthermore, the corresponding regions of HIV-2 Vpr and HIV-2 Vpx had no such activity. This region of HIV-1 Vpr may interact nonspecifically with viral genomic RNA. Collectively, Vpr and Vpx may provide a means to introduce foreign proteins and other molecules into HIV virions for therapeutic purposes.

[Clinical and immunological study of airway disease in collagen vascular disease]

We studied the clinical and immunological characteristics of patients with bronchiolar diseases associated with collagen vascular disease (15 patients with rheumatoid arthritis and 1 primary Sjögren's syndrome). Histological examinations showed that 9 patients had follicular bronchiolitis and 7 had bronchiolitis obliterans. Follicular bronchiolitis was characterized by hyperplasia of bronchus-associated lymphoid tissue, and immunohistochemical studies revealed that the pattern of distribution of T cells and B cells in bronchus-associated lymphoid tissue from patients with follicular bronchiolitis was similar to that in diffuse panbronchiolitis, which may be used as a representative model of chronic respiratory infection. In addition, bacterial cultures of sputum samples were positive in 44% of patients with follicular bronchiolitis and in 71% of patients with bronchiolitis obliterans. These results suggest that antigen stimulation is involved in the development of bronchiolar diseases associated with collagen vascular disease.

A new nitric oxide (NO) releaser: spontaneous NO release from FK409

The remarkable vasorelaxant and anti-platelet effects of FK409 have been reported to be due to nitric oxide (NO) release. The purpose of the present study is to investigate the spontaneous NO-releasing pathway of FK409 in aqueous solutions. 1H-NMR spectra of FK409 suggested that the compound underwent a time-dependent elimination of the hydrogen atom at alpha-position of the nitro moiety (at the 5-position) in weakly alkaline solutions. In addition, the degradation of FK409 monitored by HPLC showed a pH-dependency accelerating with an increase of pH. These results revealed that the first step in the degradation of FK409 might be the hydroxyl ion-dependent subtraction of the hydrogen atom at the 5-position. On the other hand, NO release from FK409 also exhibited a pH-dependency, and the velocity of NO liberation was markedly enhanced above pH 6. Furthermore, a linear relationship between the rate of FK409 degradation and that of NO formation was observed, indicating that the rate-limiting step for NO formation is the same as that for degradation. Thus, the rate-limiting process of NO formation from FK409 is due to the deprotonation reaction of the hydrogen atom at the 5-position by hydroxyl ions. The deprotonation process appears to be an essential step for both FK409 degradation and NO release. On the basis of the results, a possible kinetic scheme for NO release from FK409 is proposed.

Somatovisceral reflexes

In experimental animals, both noxious and innocuous stimulation of somatic afferents have been shown to evoke reflex changes in sympathetic efferent activity and, thereby, effector organ function. These phenomena have been demonstrated in such sites as the gastrointestinal tract, urinary bladder, adrenal medulla, lymphatic tissues, heart and vessels of the brain and peripheral nerves. Most often, reflexes have been elicited experimentally by stimulation of cutaneous afferents, although some work has also been conducted on muscle and articular afferents, including those of spinal tissues. The ultimate responses may represent the integration of multiple tonic and reflex influences and may exhibit laterality and segmental tendencies as well as variable excitability according to the afferents involved. Given the complexity and multiplicity of mechanisms involved in the final expression of the reflex response, attempts to extrapolate to clinical situations should probably be eschewed in favor of further systematic physiological studies.

Liver scarring associated with congenital absence of the right hepatic lobe: CT and MR findings

We describe a patient with liver scarring associated with congenital absence of the right lobe of the liver. Computed tomography demonstrated a low density zone at the periphery of the liver that appeared hyperintense on T2-weighted MRI and markedly enhanced on contrast-enhanced T1-weighted imaging. Computed tomography during both arteriography and arterial portography demonstrated a differential blood supply to the low density zone, suggesting the diagnosis of liver scarring. Histological examination of a biopsy from this region disclosed periportal fibrosis and sinusoidal dilatation, confirming the diagnosis of liver scarring.

[Effect of inhaled vancomycin hydrochloride on elimination of methicillin-resistant Staphylococcus aureus]

Vancomycin hydrochloride (VCM) is one of the most useful drugs in treating methicillin-resistant Staphylococcus aureus (MRSA) infections. Intravenous administration of the drug is, however, not appropriate in patients with impaired renal or liver function. Thus, we studied the effect of inhaled VCM on MRSA. Fifty-one patients with MRSA in their sputum (35 men and 16 women 21, in the "infected" group and 30 in the "colonized" group, mean age 76.4 years) were studied. MRSA was eliminated in 84.3% of the patients (43 of 51 patients), and the average time required for elimination was 14.7 days. MRSA colonization or infection recurred in 46.5% of the patients (20 of 43 patients), and the duration from elimination until recurrence of MRSA averaged 28 days. Eight patients in whom MRSA was not eliminated by inhaled VCM were not clinically distinguishable from other patients, but their performance status was worse. Two hours after VCM was inhaled, serum VCM concentrations were unmeasurable in 7 patients. The VCM level in sputum peaked at 262.5 micrograms/g just after inhalation, and then gradually decreased. No side effects of this treatment were observed. These results suggest that inhaled VCM can be used to eliminate MRSA.

Aberrant progenitors common to megakaryocytic and myeloid cells in a Down's infant with transient abnormal myelopoiesis

Phenotypic characteristics of blasts were studied in a Down's infant with transient abnormal myelopoiesis (TAM). Two major subpopulations were identified: (1) CD33+CD42b+ cells with platelet peroxidase activity, the commitment of which to megakaryocytic lineage was supported by an increased expression of GATA-1 mRNA; (2) CD33+CD34+CD7+CD4+ cells with immature ultrastructure, which could be either immature megakaryocytic or myeloid cells with aberrant differentiation. Mixed colonies containing megakaryocytes and monocyte/macrophages in the peripheral blood suggested the presence of progenitors common to these subpopulations. These results may indicate that subpopulations of blasts with phenotypic diversity could be derived from aberrant common progenitors to megakaryocytic and myeloid lineages in this patient.

Diagnostic usefulness of postexercise systolic blood pressure response for detection of coronary artery disease in patients with electrocardiographic left ventricular hypertrophy

Patients with left ventricular (LV) hypertrophy often have a positive result on exercise testing despite a normal coronary arteriogram. This indicates that exercise-induced ST depression is not always an accurate indicator of the presence of coronary artery disease (CAD) in such patients. We evaluated the usefulness of the postexercise systolic blood pressure (BP) response for detection of CAD in 51 patients with both electrocardiographic evidence of LV hypertrophy and positive ST depression on treadmill exercise testing. Coronary cineangiograms showed normal coronary arteries in 23 patients (45%) (group 1) and significant CAD in 28 patients (55%) (group 2). The systolic BP ratio (systolic BP at 3 minutes of recovery divided by systolic BP at peak exercise) was significantly higher in group 2 than in group 1 (1.01 +/- 0.19 vs 0.80 +/- 0.09; p < 0.001). Analysis of the relative cumulative frequency revealed that a systolic BP ratio of 0.86 was the cutoff point for distinguishing a patient with CAD from one with normal coronary arteries. The sensitivity, specificity, and accuracy of a systolic BP ratio > or = 0.86 for detection of CAD in patients with LV hypertrophy were 79%, 83%, and 82%, respectively. Our results suggest that the use of an abnormal BP ratio, in combination with ST depression, improves the accuracy of treadmill exercise testing for detecting CAD in patients with electrocardiographic evidence of LV hypertrophy.

Dose- and route-dependent alteration of metabolism and toxicity of chloroform in fed and fasting rats

Effects of overnight food deprivation on the metabolism and toxicity of chloroform (CHCl3) administered to rats per os (po), intraperitoneally (ip), or by inhalation (inh) at different doses were investigated. Rats that had been either deprived of food overnight or normally fed were challenged with CHCl3 either po (0, 100, 200, or 400 mg/kg), ip (0, 100, 200, or 400 mg/kg), or inh (0, 50, 100, or 500 ppm for 6 hr). Overnight fasting increased CHCl3 metabolism in vitro about threefold with a decrease of liver glutathione content to 67%. The fasting caused route- and dose-dependent alteration in the metabolism and toxicity of CHCl3. The area-under-the-curve (AUC) of blood CHCl3 concentration was invariably smaller following po than ip administration, and CHCl3 administered po caused more severe hepatic damage than did the same amount of CHCl3 administered ip. With po administration, the AUC (toxicity) of CHCl3 in fasting rats was significantly smaller (higher) than that of fed rats at a dose as small as 100 mg/kg, whereas, with ip administration at such a small dose, fasting caused no significant alteration in the AUC (toxicity). When rats were exposed by inhalation to CHCl3 vapor, food deprivation had little or no effect on either the blood concentration or the toxicity until the exposure concentration was raised to 500 ppm. The present study indicates that po administration is different from both ip and inh administration with regard to the effect of enzyme induction on the toxicokinetics of CHCl3, mainly due to the first-pass metabolism unique to po administration.

Quantitation of anti-hepatitic C virus antibodies in interferon-treated patients by S29-1/S4 ELISA

In 23 patients with chronic hepatitis C who have undergone interferon (IFN) treatment, quantitation of anti-hepatitis C virus IgG antibodies by a second-generation assay S29-1/S4 ELISA [Sato et al. (1993): Microbiology and Immunology 37: 295-304]. (anti-S29-1/S4) was compared with that of anti-HCV core IgG antibodies (C22-3, anticore) and the presence of viral RNA confirmed by the reverse transcription-nested polymerase chain reaction (RT-nested PCR). In 12 complete responders with loss of HCV-RNA and normal alanine aminotransferase (ALT) levels at 6 months after therapy, IgG antibodies quantified by a second-generation assay have decreased significantly at the end of treatment (P < 0.05). Further significant reduction of anti-S29-1/S4 titers was observed at 6 months after therapy (P < 0.01) as well as anti-core antibodies (P < 0.01). On the other hand, in 11 non-responders with persistent or intermittent viremia at 6 months after therapy, no significant change in the level of anti-S29-1/S4 titers was observed, whereas anti-core titers have decreased at the end of therapy (P < 0.01). In contrast, both levels of anti-S29-1/S4 and anti-core have increased at 6 months after treatment (P < 0.05). It is concluded that, although it appears difficult to monitor the effect of virus clearance during IFN therapy, changes in anti-S29-1/S4 titers after IFN treatment correlate with virus clearance and with anti-core titers.

[A clinical study of non-tuberculous pulmonary mycobacteriosis]

We studied the clinical features of sixty-one patients with non-tuberculous pulmonary mycobacteriosis (NTM), who were newly diagnosed at five national hospitals in Kinki area during 1993. The study subjects were composed of 31 patients with M. avium complex (MAC) disease (20 males and 15 females), 21 with M. kansasii (MK) disease (19 males and 3 females), 2 males with M. szulgai (MS) disease and 2 females with M. chelonae (MC) disease. The rate of NTM to all culture proven mycobacteriosis was 20.2% and the rate of NTM to all culture proven, newly discovered mycobacteriosis was 18.2% and the rates were higher than Sakatani's report in 1994 (14% in 1991). The ratio of MK to MAC was 22:35, and the ratio of MK was higher than the report of Sakatani. The mean age of patients with MK was 57.9 in male and 76.7 in female, that with MAC was 71.0 in male and 70.1 in female, that with MS was 57.0 in male and that 72.5 with MC in female. The proportion of elderly patients was higher than the former reports in Japan, especially in female with MK. The main lesions on chest X-ray was found in bilateral S1, 2(S1+2), particularly in the cases with cavitary lesions, but right middle lobe and left lingular lobe were mainly affected in some patients with MAC and S6 was often affected in elderly patients with MK. The chemotherapy with isoniazid, rifampicin, ethambutol and/or streptomycin (or kanamycin) w as highly effective in case with MK and MS disease, the efficacy was similar to pulmonary tuberculosis. Some patients with MAC were treated with combination of anti-tuberculosis drugs and new quinolons and/or clarythromycin, but the efficacy was not yet revealed.

c-Src phosphorylates epidermal growth factor receptor on tyrosine 845

In the previous study [Sato et al. (1995) Biochem. Biophys. Res. Commun. 210, 844-851], we found that c-Src was associated with epidermal growth factor (EGF) receptor and activated upon EGF treatment in A431 cells. In the present study, we investigated the phosphorylation of EGF receptor by c-Src in the c-Src-EGF receptor complex. We have focused our attention to tyrosine residue 845 (Y845) of EGF receptor as a candidate for the phosphorylation site. A synthetic peptide containing Y845, named Y845 peptide, which corresponds to residue 837 to 856 of EGF receptor, was found to be phosphorylated by c-Src and used to provide the standard phosphopeptide. In addition to the autophosphorylated peptide of 25 kDa, a phosphopeptide of 7 kDa was detected in the cyanogen bromide-digested fragments of the c-Src-associated EGF receptor phosphorylated in vitro in an EGF-dependent manner. In phosphopeptide mapping, tryptic digest of the 7-kDa phosphopeptide was shown to co-migrate with that of the phosphorylated Y845 peptide. The 7-kDa phosphopeptide was found to be phosphorylated exclusively on tyrosine. These results suggest that c-Src can phosphorylate EGF receptor on Y845 in an EGF-dependent manner. Furthermore, we confirmed that the same site of the c-Src-associated EGF receptor was phosphorylated in EGF-treated A431 cells.

[Chronic necrotizing pulmonary aspergillosis treated with itraconazole and inhaled amphotericin B]

A 52-year-old man with chronic necrotizing pulmonary aspergillosis complicated by a residual tuberculous cavity was admitted to the hospital because of fever and a new infiltration shadow in the right lower lobe. Aspergillus was isolated repeatedly from his sputum, though he had been treated with itraconazol for 9 months. Combination therapy with itraconazol (200 mg) and inhaled amphotericin B (AMPC, 10 mg, 4 times a day) was begun. The infiltration shadow gradually resolved. The concentration of AMPC in serum was measured by high-performance liquid chromatography, and was found to be 0.09 micrograms/ml, which is equal to the AMPC concentration obtained with daily oral administration of 2400 mg. This case shows that, contrary to previous opinion, AMPC can be effectively administered by inhalation. We know of no previous reports of similar cases. In addition, itraconazol and inhaled AMPC may have had a synergistic effect in this case.

Expanding intracerebral hematoma from pituitary adenoma: case report

We report the case of a 53-year-old man presenting with a headache of sudden onset and blurred vision secondary to hemorrhage from a nonfunctioning pituitary adenoma, which had been treated 25 years previously by transcranial surgery and postoperative irradiation. The intratumoral and intracerebral hematoma expanded to three times its initial size because of a recurrent hemorrhage that occurred during a 2-day period while the patient awaited surgery. The mechanisms of hematoma expansion and the management strategy in such a case are discussed, and a review of the pertinent literature is presented.

Enhanced migration of fibroblasts derived from lungs with fibrotic lesions

BACKGROUND

The migration and proliferation of fibroblasts may be important in the pathogenesis of pulmonary fibrosis. Considerable data are available on the proliferation of fibroblasts, but very few on their migration.

METHODS

The migratory activity of fibroblasts obtained from lung biopsy specimens from 11 patients with idiopathic pulmonary fibrosis (IPF) was studied using a 96-well chemotaxis chamber. Fibroblasts from eight normal controls, seven patients with interstitial fibrosis associated with a collagen vascular disease (IP-CVD), and 13 patients with sarcoidosis were also examined. Migratory activity was tested in a serum-free medium in the presence and absence of platelet derived growth factor (PDGF), 30 ng/ml, as a chemoattractant.

RESULTS

Migration of fibroblasts from patients with IPF was enhanced in serum-free maintenance medium alone (mean (SD) controls v IPF: 183 (86) v 689 (491) cells/field), and was also enhanced when cells were stimulated by PDGF (controls v IPF: 829 (222) v 1928 (600) cells/field). Fibroblasts from tissues with dense fibrosis had a greater capacity for migration than those from an earlier stage of fibrosis. No correlation was found between migratory activity and proliferative capacity of the individual cells.

CONCLUSIONS

The fact that fibroblasts from fibrotic lungs migrate faster than those from controls suggests that migration is related to the initiation of the pulmonary fibrotic process. These in vitro studies suggest that fibroblasts derived from the lungs of patients with pulmonary fibrosis have a migratory phenotype. Such a change in fibroblast phenotype, if it occurred in vivo, may be important in the context of the pathogenesis of pulmonary fibrosis.