Exaggerated responses to chronic nociceptive stimuli and enhancement of N-methyl-D-aspartate receptor-mediated synaptic transmission in mutant mice lacking D-amino-acid oxidase.

Formalin-induced nociceptive behaviors and N-methyl-D-aspartate (NMDA) subtype glutamate receptor-mediated excitatory synaptic transmission were analyzed in mutant mice lacking D-amino-acid oxidase, which catalyzes the oxidative deamination of D-amino acids. The second phase of the formalin-induced licking response, a part of which is known to be mediated by NMDA receptors in the spinal cord, was significantly augmented in mutant mice. NMDA receptor-mediated excitatory postsynaptic currents recorded from spinal cord dorsal horn neurons by tight-seal whole-cell methods were significantly potentiated in mutant mice. The present observations provide another line of evidence that D-serine functions as an endogenous coagonist at the glycine site of NMDA receptors, and raise the possibility that D-amino-acid oxidase exerts a neuromodulatory function by controlling the concentration of D-serine in the central nervous system.

[A case of amphetamine-induced down-regulation of beta-adrenoceptor].

A 29-year-old man with severe pyloric stenosis confessed that he had been a chronic amphetamine abuser just after awakening from anesthesia for partial gastrectomy. Anesthesia was maintained with thoracic epidural bupivacaine combined with continuous i.v. infusion of propofol. Decreased arterial blood pressure was observed 10 min after starting epidural anesthesia, and remained stable at 80-90 mmHg of systolic blood pressure in spite of massive fluid resuscitation in addition to repeated i.v. administration of ephedrine/methoxamine and continuous i.v. infusion of dopamine at a rate of 8 micrograms.kg-1.min-1. Finally, arterial blood pressure rose gradually after i.v. administration of methylpredonisolone 500 mg. We speculate that the down-regulation of beta-adrenoceptor induced by the sympathomimetic action of amphetamine, might be a major cause of refractory hypotension.

Effects of hemoglobin on pulmonary arterial pressure and pulmonary vascular resistance in patients with chronic emphysema.

BACKGROUND: The increase in viscosity caused by secondary polycythemia is thought to be one of the major causes of pulmonary hypertension secondary to chronic emphysema. However, very few clinical studies considered the relation between pulmonary hypertension and polycythemia in the case of chronic obstructive pulmonary disease. OBJECTIVE: The purpose of this study is to elucidate the relative contribution of an increase in hemoglobin level (Hb) to mean pulmonary arterial pressure (mPAP) and pulmonary vascular resistance (PVR). METHODS: We retrospectively investigated 41 patients with chronic emphysema who had undergone a right heart catheterization. Multiple-regression analysis and F test were performed to investigate both direct effects of Hb and PaO(2) as independent variables on mPAP and PVR as dependent variables. RESULTS: Significant correlations were found between PaO(2) and mPAP (or PVR), or Hb and mPAP (or PVR), indicating that both Hb and PaO(2) are contributory to mPAP and PVR. The F test demonstrated that Hb and PaO(2) could directly affect the level of either mPAP or PVR. CONCLUSIONS: It was concluded that Hb had a direct effect on mPAP and PVR, independently of hypoxia in patients with chronic emphysema.

[Midazolam presynaptically inhibits excitatory synaptic transmission in the superficial dorsal horn of the rat spinal cord].

Whole-cell voltage-clamp recordings were made from superficial dorsal horn neurons in thin slices of neonatal rat spinal cord. Spontaneously occurring glutaminergic miniature excitatory postsynaptic currents (mEPSCs) were recorded in the presence of tetrodotoxin, strychnine and bicuculline. Bath-application of midazolam (5-60 microM) reduced the frequency of mEPSCs dose-dependently and this depression was antagonized by flumazenil 15 microM. In 8 neurons studied, midazolam 15 microM affected neither the amplitude profiles nor the mean amplitudes of the mEPSCs, suggesting a presynaptic site of action. In a nominally Ca(2+)-free solution, midazolam still reduced the frequency of mEPSCs, but to a lesser extent than in a standard solution. We conclude that midazolam may presynaptically inhibit excitatory synaptic transmission in the superficial dorsal horn by affecting both Ca2+ entry into the nerve terminals and transmitter release mechanisms downstream to Ca2+ entry.

Single-point amino acid substitutions at the 119th residue of thermolysin and their pressure-induced activation.

The effect of amino acid substitution at the 119th site of thermolysin (TLN) on the pressure activation behavior of this enzyme was studied for four mutants at pressures < 300 MPa. For Q119Q, Q119N and Q119R, the highest activation was observed to be over 30 times that at atmospheric pressure and the activation volumes (deltaV++) were about -75 ml/mol. However, we obtained only 10 times higher activation for Q119E and Q119D (deltaV++ approximately -60 ml/mol). The intrinsic fluorescence of TLN changed at pressures > 300 MPa, and the latter two mutants showed a smaller deltaGapp and deltaVapp of transition than the wild type. These results are discussed with respect to the hydration change in the enzyme protein around the substituted region.

Preparative-scale Enzyme-catalyzed Synthesis of (R)-α-Fluorophenylacetic Acid.

A preparative-scale asymmetric synthesis of (R)-α-fluorophenylacetic acid, a useful chiral derivatizing reagent, is described. Starting from ethyl α-bromophenylacetate, α-fluorophenylmalonic acid dipotassium salt was prepared in three steps (54% yield), including nucleophilic substitution by the fluoride ion as the keystep. Both the purified form and crude preparation of arylmalonate decarboxylase in E. coli worked well on this substrate, and (R)-α-flurophenylacetic acid (>99% e.e.) was prepared in a quantitative yield.

[A case of Bence-Jones protein-lambda positive multiple myeloma complicated by abnormal plasma cells in pleural effusion].

A 53-year-old woman was admitted to this institution with chest pain and dyspnea. Chest roentgenogram showed pleural effusion and multiple tumor shadows, bilaterally which represented extrapleural signs. Numerous atypical plasma cells were found in the pleural effusion. Bone marrow biopsy showed atypical plasma cells. Immunoelectrophoresis revealed monoclonal Bence-Jones protein-lambda in serum and urine. Myeloma was subsequently diagnosed and chemotherapy was started. Multiple myeloma is a plasmacytoma, and myeloma cells proliferate in the bone marrow. The incidence of myeloma associated with malignant pleural effusion is rare with only 33 cases previously reported in Japan, to the best of our knowledge.

[A case of pneumoconiosis (welder's lung) suspected to be lung cancer].

A 60-year-old man, employed as a welder for 25 years, was admitted with an abnormal shadow on chest X-ray. An ill-defined and solitary mass shadow 3 cm in diameter was subsequently detected in the left upper lung field. The mass shadow exhibited high attenuation on chest CT scan. Transbronchial lung biopsy (TBLB) revealed an organized lesion possessing a large quantity of iron. Although pneumoconiosis was suspected, the possibility of lung cancer could not be dismissed. Pneumoconiosis (welder's lung) was diagnosed after thoracotomy and examination of the resected mass. Pneumoconiosis (welder's lung) rarely presents as a solitary mass lesion.

[Allergic bronchopulmonary mycosis caused by Schizophyllum commune].

In December 1989, a 72-year-old woman was hospitalized with atelectasis in the left lower lobe. The atelectasis resolved after bronchoscopic removal of impacted mucous plugs. Histopathological examination showed pulmonary mycosis. Microscopy suggested that a species of Aspergillus was responsible, but no definite diagnosis was made. After treatment with flucytosine and nebulized amphotericin, the patient's condition improved and she was discharged. In the middle of August 1994, she visited a local hospital complaining of fatigue. Eosinophilia (22%) was detected, and a few days later she visited that hospital again due to sudden dyspnea. A chest X-ray examination showed an abnormal shadow, and she was referred to our hospital. Atelectasis was seen in the left upper lobe. This finding, together with eosinophilia, suggested recurrence of pulmonary mycosis, and therefore bronchoscopy was performed. White mucous plugs obstructing the left upper lobe were observed and were bronchoscopically removed. Microscopical examination of the mucous plugs showed marked eosinophil infiltration and hyphae. Cultures of specimens obtained during bronchoscopy showed Schizophyllum commune, and allergic bronchopulmonary mycosis due to this microorganism was diagnosed. Identification of this microorganism as a cause of deep-seated pulmonary mycosis is very rare.

The structure of subtilisin ALP I from alkalophilic Bacillus sp. NKS-21.

The gene for an alkaline serine protease from alkalophilic Bacillus sp. NKS-21 (subtilisin ALP I) was cloned, and its nucleotide sequence was determined. The gene (aprQ) contained an open reading frame of 1125 bp, encoding a primary product of 374 amino acids. The mature protease, composed of 272 amino acids, was preceded by a putative signal sequence of 37 amino acids and a pro-sequence of 65 amino acids. The mature protease conserved the catalytic triad, Asp, His, and Ser, as subtilisin BPN' or other subtilisins, and the subtilisin ALP I might belong to the subtilisin super family. The primary structure of subtilisin ALP I was compared and discussed with those of 13 subtilisins, 5 subtilisins from alkalophilic Bacillus, and 8 from neutrophiles. Low homology was shown between subtilisin ALP I and subtilisins from alkalophiles or subtilisins from neutrophiles. Forty-five amino acid residues of the mature protein of subtilisin ALP I were entirely independent of other subtilisins. According to the homology of ALP I with other subtilisins, subtilisin ALP I might be in the middle point between alkaline subtilisins and neutral ones.

Molecular and enzymatic properties of an aspartic proteinase from Rhizopus hangchow.

An aspartic proteinase, rhizopuspepsin (EC 3.4.23.21), from Rhizopus hangchow was purified. The M(r) and isoelectric point were determined as ca 37,000 and 4.5, respectively. The first 19 amino acids in the N-terminal region were SGSGVVPMTDYEYDIEYYG. The contents of the alpha-helix, beta-structure and random coil were calculated to be ca 7.5, 88.9 and 2.7%, respectively. The enzyme can activate trypsinogen at pH 3.0. The activity was completely inactivated by pepstatin A. The specificity and mode of action of the enzyme were investigated with oxidized insulin B-chain at pH 3. The enzyme hydrolysed primarily two peptide bonds, the Leu15-Tyr16 bond and the Tyr16-Leu17 bond, while additional cleavage of the bonds, Ala14-Leu15 and Phe24-Phe25 was also noted.

[An autopsy case of lung cancer metastasizing to renal cell cancer and rectal villous adenoma].

A 67-year-old woman with bloody stool was admitted to our hospital. Chest radiograph on admission showed a tumor shadow in the right lower lung field. Lung adenocarcinoma of right S6 and villous adenoma of the rectum were detected. Although she was treated with chemotherapy and radiotherapy, she died of respiratory failure. At autopsy, moderately differentiated adenocarcinoma of the right lung, renal cell carcinoma, and villous adenoma of the rectum were confirmed. Lung adenocarcinomas were detected in the focus of the renal cell carcinoma and in the villous adenoma. Metastasis of a cancer into another coexisting tumor in the same individual is extremely rare, and a satisfactory explanation for this phenomenon has not yet been offered.

Henoch-Schönlein purpura associated with pregnancy in a patient with chronic thyroiditis.

A case of Henoch-Schönlein purpura with chronic thyroiditis associated with pregnancy is reported. A 27-year-old woman had a struma since age 14. She felt easily fatigable along with enlargement of the struma after the delivery of her first child, and was diagnosed as having chronic thyroiditis. She developed hematuria between the first delivery and the second pregnancy. The hematuria continued during the second pregnancy and in the postpartum period. Immediately after the delivery of her second child, she developed purpura followed by arthralgia and melena. Renal biopsy revealed focal segmental and global type Henoch-Schönlein nephritis. We reviewed five cases of Henoch-Schönlein purpura associated with pregnancy and found that our case is the first in which purpura developed immediately after delivery. Our patient would have developed Henoch-Schönlein nephritis between the first delivery and the second pregnancy. She developed Henoch-Schönlein purpura possibly due to rebound activation of immune response in the postpartum period after the disappearance of dramatic suppression of both humoral and cell-mediated immunity in the pregnant period.

[A case of traumatic hernia of diaphragm showing prolapse of liver with abnormal lobulation into pleural cavity].

A 48-year-old male was admitted to our hospital in 1988 with injury by a traffic accident, resulting in fracture of the right rib, right clavicle, and pelvic. The patient came to us again with a chief complaint of abdominal pain in May, 1991 when digestive tract gas was observed in the right pleural cavity casting a doubt of diaphragmatic hernia. Chest CT scan and liver scintigraphy disclosed prolapse of the colon into the pleural cavity together with a picture on the diaphragm being supposed as parenchyma of the liver. Operation findings showed prolapses of the colon and the omentum through the opening of diaphragm into the pleural cavity and also exhibited prolapse of hepatic parenchyma, supposedly S4, together with gallbladder into the pleural cavity. The case, which had showed no abnormality in the Chest X-ray film before the injury, was conceivably an extremely rate case of traumatic hernia with the right diaphragm showing; abnormality of hepatic lobulation accompanied by diaphragmatic rupture, and prolapse of the liver with abnormal lobulation.

Specificity and molecular properties of penicillolysin, a metalloproteinase from Penicillium citrinum.

The specificity and mode of action of penicillolysin, a metalloproteinase from Penicillium citrinum, were investigated with several bioactive-oligopeptides. The enzyme showed a high affinity toward the Pro-X (X = Gln, Lys, Leu or Arg) bonds of substance P, dynorphin A (1-13), neurotensin and chicken brain pentapeptide, and the R-R bonds in dynorphin A and neurotensin. Preferential cleavage of bonds by the enzyme with hydrophobic amino acid residues at the P1 position were observed on the peptides used. The specificity of penicillolysin differs from that of other metalloproteinases. The M(r) and pI were determined as 18,000 and 9.6, respectively. The first 50 amino acids in the N-terminal region were TKETCSNASRKSALEKALSNTVKLANAAATAARSGSASKFSEYEKTTSSS. CD spectra on the hollo- and apo-enzymes of penicillolysin were studied.

Amino Acid Requirements of Two Hyperthermophilic Archaeal Isolates from Deep-Sea Vents, Desulfurococcus Strain SY and Pyrococcus Strain GB-D.

Two sulfur-dependent hyperthermophilic archaea, Desulfurococcus strain SY and Pyrococcus strain GB-D, which were isolated from deep-sea hydrothermal vents, utilized free amino acids and peptides obtained from various molecular size fractions of yeast extract. It was found that 11 amino acids were essential for growth. The metabolic products were acetate, i-butyrate, and i-valerate.

[A case of pulmonary actinomycosis that was difficult to distinguish from pulmonary carcinoma].

A 45-year-old male was admitted with chief complaint of hemoptysis. Prior to admission, a tumor in the S3 segment of the right lung had been detected by chest radiography. Despite a detailed examination after admission, no definite diagnosis was made, and right upper lobectomy was performed. Histopathological examination of the surgically resected tissue led to the diagnosis of pulmonary actinomycosis. In Japan, 52 cases of this condition were reported between 1964 and 1991. This paper discusses the epidemiology, diagnosis and diagnostic imaging of the condition, with reference to the literature.

[Endoscopic Nd-YAG laser treatment of tracheobronchial lesions].

Eight cases treated with Nd-YAG laser via fiberoptic bronchoscopy were studied. Four of them were primary lung cancer, one was tracheal invasion of thyroid cancer and three were postintubation lesions of trachea. In six cases, Nd-YAG laser treatment was effective for enlargement of the airway lumen and improvement of their symptoms. In the cases of advanced lung cancer, not only local findings of the tumor but also clinical stage and possibility of adjuvant therapy must be considered to apply this procedure. In the cases of postintubation tracheal stenosis (except polypoid lesions), T-tube stenting or surgical reconstruction must be followed after laser treatment. Nd-YAG laser treatment can be useful for the tracheobronchial lesions such as primary tracheal tumors, lung cancer, metastatic tumors, postintubation tracheal stenosis and so on if applied precisely.

[A case of Pryce's type I intralobar pulmonary sequestration diagnosed by noninvasive techniques].

The patient was a female who came to our hospital with a chief complaint of hemoptysis. Radiography of the chest demonstrated a funicular shadow, and CT of the chest also revealed a similar shadow in contact with the thoracic aorta enhanced by the contrast material. Pulmonary arteriography and aortography showed that the left S8, S9 and S10 areas were supplied by abnormal blood vessels bifurcating from the thoracic aorta, rather than the pulmonary artery. This finding was supported by scintigraphy of the pulmonary blood flow and pulmonary RI angiography. Since bronchography revealed no obvious abnormality in the bronchial system, the diagnosis of Pryce's type I intralobar pulmonary sequestration was established, and left lower lobectomy was carried out. While the evidence of abnormal blood vessels is important for the definitive diagnosis of pulmonary sequestration, concurrent image processing of the results of scintigraphy of the pulmonary blood flow and pulmonary RI angiography permits noninvasive demonstration of the fact that the sequestral pulmonary tissue is regulated by the systemic circulatory system, rather than the pulmonary circulatory system and thus is a useful technique.