[Simultaneous ambulatory electrocardiography and pulse oximetry]

We developed a system for 24-hour ambulatory recording of blood oxygenation (SpO2) and electrocardiography (ECG). Using this system, we studied 10 healthy volunteers and 7 patients with chronic pulmonary diseases. The system incorporated a portable pulse oximeter (SM50) manufactured by Fukuda Denshi KK; the first and second channels were used to record ECG data and the third was used to record SpO2 data. An SpO2 sensor (Dispo-sensor D-25; Nellcor Inc.) was applied to the fourth of fifth finger. The SpO2 data (MicrO2; Siemens AG) were digitized and stored in the ambulatory recording device; the ECG was recorded simultaneously. The data were analyzed with a model DMW-9000H analyzer (Fukuda Denshi KK). A custom-designed program was also used, to remove noise errors. In the healty volunteers, SpO2 was at least 90% for the entire 24 hours. In all the patients, SpO2 fell below 90% at rest during the night or after a 15-minute walk. Transient atrial tachycardia was observed in 3 patients, and during the tachycardia the SpO2 was low. The number of extra ventricular beats divided by the total number of beats increased more in the patients than in the healthy volunteers (1.21 +/- 0.89 vs 0.6 +/- 0.3%, p < 0.05). SpO2 did not change significantly in the patients. In outpatients and in patients receiving home health care, the present system facilitates simultaneous diagnosis of respiratory failure an arrhythmias. In patients with chronic pulmonary diseases desaturation may cause transient atrial tachycardia.

Granule cell disinhibition in dentate gyrus of genetically seizure susceptible El mice

Paired-pulse inhibition was investigated electrophysiologically in the dentate gyrus using hippocampal slices from epileptic El mice. At short interpulse intervals (IPIs), the inhibition was 30% in the El, and 90% in the control ddY mice at the ages of 10 and 15 weeks. No difference in inhibition was observed at the age of 5 weeks. Bicuculline, a GABAA receptor antagonists, attenuated the inhibition during short IPIs n the ddY mice, while in the El mice, phenobarbital and flunitrazepam, which enhance GABAA receptor function, restored the inhibitory activity comparable to that of the ddY. The disinhibition progressed with growth, closely correlating with seizure development in El mice. These results suggest that decrease in the GABAergic inhibition occurs in the dentate gyrus of the El mice with growth. GABA concentration in the hippocampus was also quantified using HPLC. In El mice, GABA level was significantly lower than that in ddY mice at the ages of 5 and 15 weeks. Thus, the disinhibition observed in the El dentate gyrus at 15 weeks of age does not appear to be directly related to the content of GABA. GABAergic disinhibition suggests possible loss of unknown inhibition control factor(s) in the El dentate gyrus as growth progresses. The growth-dependent disinhibition in the granule cells may be prerequisite for epileptogenesis in El mice.

[Preparation and evaluation of solid dispersions of pilocarpine hydrochloride for alleviation of xerostomia]

This investigation was carried out to try the application of pilocarpine hydrochloride (PC) solid dispersion as sustained release dosage form. Four preparations of PC with ethylcellulose and/or hydroxypropylmethylcellulose phthalate were prepared by the organic solvent method. The preparation D including PC: ethylcellulose: hydroxypropylmethylcellulose phthalate (1:9:10 at weight ratio) showed the best sustained release behavior in dissolution test among four preparations. The preparation D was examined by powder X-ray diffractometry and differential scanning calorimetry, and confirmed to be solid dispersion. Saliva secretory effect of preparation D was examined in healthy male volunteers, and its effect for Xerostomia was showed.

[Long-term effects of a selective alpha 1-adrenergic inhibitor on right and left ventricular masses in patients with chronic pulmonary disease]

We examined the effect of one year of treatment with the selective alpha 1-adrenergic inhibitor doxazosin on right ventricular mass (RV mass), left ventricular mass (LV mass), and arterial blood gases. The subjects were 24 outpatients (18 men and 6 women, mean age 68.3 +/- 9.4 years) with chronic pulmonary disease complicated by hypertension who were clinically stable. One year of drug therapy was associated with significant decreases both in systolic pressure (159 +/- 15.2 vs 125.8 +/- 14.1 mmHg, p < 0.05, n = 24), and in LV mass index (101.0 +/- 13.4 vs 97.6 +/- 11.8 gm-2, p < 0.05), n = 24). We obtained the RV mass index by multiplying the thallium score RV/LV count and the LV mass index obtained by echocardiography. One year of drug therapy was associated with a significant increase in RV mass index (42.9 +/- 31.2 vs 53.6 +/- 30.5 gm-2, p < 0.05, n = 8). Vital capacity decreased (2.18 +/- 1.95 vs 1.95 +/- 0.57 l, p < 0.05, n = 24), but PaO2 improved (77.3 +/- 17.2 vs 82.2 +/- 2.4 mmHg, p < 0.05, n = 24). These data indicate that doxazosin can decrease blood pressure and can depress the left ventricle with no adverse effect on oxygenation in patients with chronic pulmonary disease complicated by hypertension. The worsening of RV hypertrophy may have been caused by a mechanism different from the one that caused LV hypertrophy, and by an increase in the work load on the right ventricles secondary to lung deterioration.

[A case of enlarging rounded atelectasis difficult to distinguish from a pulmonary neoplasm]

A 55-year-old man with occupational exposure to asbestos presented with a chest roentgenographic abnormality that was found during a physical check-up. Computed tomography disclosed pleural thickening and a pulmonary mass in the left lower lobe. A fine-needle biopsy was done, but the presence of a malignant lesion was not confirmed. The patient was asymptomatic. He was observed closely, and 10 months later computed tomography showed that the mass had enlarged. A fine-needle biopsy was done again, but no evidence of malignancy was found. We suspected that it was rounded atelectasis, but could not rule out a neoplasm. An exploratory thoracotomy was done, and the histopathological findings showed that the mass was lung tissue with alveolar wall fibrosis that had resulted in thickening of the wall. The mass was diagnosed as rounded atelectasis. Rounded atelectasis requires no special treatment, but if the mass increases in size as in the case of this patient, an exploratory thoracotomy is required.

Apoptosis involved in density-dependent regulation of rat fibroblastic 3Y1 cell culture

When rat 3Y1 fibroblastic cells are cultured toward confluency, the cells go through maximum cell density (overshoot) before reaching post-confluence stationary cell density. After overshooting, a number of floating cells are found in the medium. In a long-term culture, a cyclic change in cell number, an increase after each medium refreshment and subsequent cell loss within a few days has been observed so that the cell populations in the monolayer maintain post-confluence stationary cell density at a constant level. The floating cells excluded trypan blue, but they had no ability to attach to the substrate and to form colonies after being reseeded in fresh medium. They had condensed and uniformly electron-dense chromatin with sharply circumscribed edges. Their DNA contained a laddering pattern in harmony with internucleosomal cleavage. The features were those of apoptosis. When floating cells appeared, apoptotic bodies were also observed in the monolayer. Most of them were found within the cytoplasm of intact cells, suggesting that apoptotic bodies were also faded away from the culture by being rapidly engulfed by neighboring intact cells. These suggest that apoptosis and subsequent detachment from the monolayer or engulfment by neighboring intact cells, in addition to inhibition of cell division, are basic mechanisms on the process of density-dependent regulation in monolayer culture of rat 3Y1 cells.

Analysis of the articulation after glossectomy

Rehabilitation of the oral cancer patient should aim to achieve not only morphological restoration but also post-operative functions. However, there are few reports describing quantitative evaluation of the latter. The authors have attempted quantitative evaluation of post-operative articulatory function after glossectomy, and report the evaluation of it by speech intelligibility, electropalatography (EPG), and acoustical analysis. Subjects were five directly sutured patients and five patients reconstructed with forearm flap, all after glossectomy. The target syllable was /ta/ from among speech intelligibility test samples. The speech intelligibility and acoustical analysis were investigated pre-operation, and 1,6 and 12 months post-operation. EPG data were collected by DP-01(RION) at 6 months post-operation. Acoustical analyses were carried out by consonant frequency characteristics and formant variance from consonant to vowel transitions. As a result, subjects reconstructed with a forearm flap showed higher restorative tendency than directly sutured subjects. Articulatory characteristics expected from acoustical analysis were more in agreement with the results of EPG than with the results of the speech intelligibility test. From the results, it was suggested that the acoustical analysis used for this research could reveal changes in articulatory movement and will be useful for quantitatively evaluating post-operative articulatory functions.

End-plate acetylcholine receptor deficiency due to nonsense mutations in the epsilon subunit

We describe a congenital myasthenic syndrome associated with severe end-plate (EP) acetylcholine receptor (AChR) deficiency not associated with an EP myopathy, and with evidence of immature AChR, containing the gamma instead of the epsilon subunit (gamma-AChR) at the EPs. Molecular genetic analysis of AChR-subunit genes revealed two mutations in the epsilon-subunit gene: insertion of a thymine after epsilon nucleotide 1101 (epsilon 11O1insT) that generates a nonsense codon directly, and insertion of a guanine after epsilon nucleotide 1293 (epsilon 1293insG) that generates three missense codons followed by a nonsense codon. Each mutation predicts truncation of the epsilon subunit at the level of the long cytoplasmic loop, between the third (M3) and fourth (M4) membrane spanning domains. The propositus' asymptomatic son carries epsilon 1293G, indicating that the two mutations are heteroallelic. Expression of AChR harboring either mutation in human embryonic kidney (HEK) fibroblasts was markedly reduced. Single-channel activity recorded from HEK cells expressing epsilon 11O1insT-AChR was infrequent but resembled activity of wild-type AChR channels in amplitude and open duration. No channel activity could be recorded from HEK cells expressing epsilon 1293insG-AChR. Expression of gamma-AChR at the EPs may serve as the means of phenotypic rescue from potentially fatal nonsense mutations in the epsilon-subunit gene.

Transcriptional regulation of the Drosophila CycA gene by the DNA replication-related element (DRE) and DRE binding factor (DREF)

The Drosophila gene for cyclin A is expressed in dividing cells throughout development. This expression pattern is similar to those of genes related to DNA replication, suggesting involvement of some common control mechanism(s). In the upstream region (-71 to -64 with respect to the transcription initiation site) of the CycA gene, we found a sequence identical to the DNA replication-related element (DRE; 5'-TATCGATA), which is important for high level expression of replication-related genes such as those encoding DNA polymerase alpha and proliferating cell nuclear antigen. Transient expression assays with chloramphenicol acetyltransferase (CAT) were carried out to examine the function of the DRE sequence of the CycA gene. Deletion or base substitution mutations resulted in an extensive reduction in CAT expression. Furthermore, monoclonal antibodies against DRE binding factor (DREF) diminished or supershifted the complex of the DREF and DRE-containing fragment. The results indicate that the Drosophila CycA gene is under the control of a DRE/DREF system, as are DNA replication-related genes.

Genetic profiles of three inbred strains derived from wild rats (Rattus norvegicus) trapped in Japan

In order to establish the genetic profiles of three inbred strains of rats (MITB/Yag, MITC/Yag and MITE/Yag; commonly designated as Mitake strains), which were derived from wild specimens of the Rattus norvegicus trapped in Mitake-cho, Gifu, Japan, 63 microsatellite markers were typed in these strains as well as nine other laboratory inbred strains. The data indicate that the MITB and MITC strains are very closely related (3% polymorphism between these strains), whereas the third strain MITE/Yag is relatively different from the other two strains (36% with the MITB, 39% with the MITC). Eighty-three to 58% of polymorphic loci had different alleles between the Mitake strains and the other strains, but 65-35% between the latter strains. In addition, 14 new alleles were found in the Mitake strains. These results suggest that the Mitake strains are useful for linkage analysis.

[Mediastinal thoracic duct cyst--a case report]

The patient, a 55-year-old asymptomatic man, was referred to our hospital in October 1995 for further investigation of a chest ++roentogenographic abnormality found during a "physical check-up". His chest X-ray showed a round shadow over the hilus of the left lung. Computed tomography revealed a homogeneous, low density mass bordering the esophagus, vertebral column, left lower pulmonary vein and descending aorta. Roentogenography after swallowing barium sulfate showed that the esophagus was compressed and displaced to the right in the anterior direction. Endoscopic ultrasound scan demonstrated a cystic mass. The preoperative findings were suggestive of an esophageal cyst or a thoracic duct cyst. On December 12, 1995, the patient was operated on. The mass was 2 x 3 x 6 cm in size, and was easily separated from the left pulmonary vein, esophagus and vertebral column by blunt and sharp dissection, but it was strongly adhered to the aorta. The wall of the cyst was incised and a chylous fluid was found inside. The mass was diagnosed as a thoracic duct cyst and was removed after clipping and cutting the thoracic duct above and below the cyst. Histopathological features of the wall of the cyst was that the luminal surface was lined by a monolayer of flat endothelium and composed of loose fibrous tissue with scattered bundles of smooth muscle. It differed from that of veins. The postoperative course was uneventful and he was discharged on the 12th postoperative day. Mediastinal thoracic duct cysts are rare and only 25 operated cases have been reported in the literature. We review and discuss these cases.

Molecular characterization of feline immunodeficiency virus genome obtained directly from organs of a naturally infected cat with marked neurological symptoms and encephalitis

Feline immunodeficiency virus (FIV) was first isolated from cats with immunodeficiency syndrome. Recently, neurological abnormalities and brain lesions were shown in cats infected with FIV. To investigate the FIV genome associated with central nervous system (CNS) lesions, proviral DNA sequences from the V3-V6 region of the FIV env gene were directly amplified from uncultured necropsy tissues of a 2-year-old naturally FIV-infected cat with marked neurological symptoms and encephalitis. By in situ hybridization, FIV RNA was detected mainly in the astrocytes. Fifteen clones isolated from cerebrum, bone marrow and lymph node samples showed only a small number of mutations or deletions in this region. A representative clone, JN-BR1, was distantly related to the previous Japanese strain (TM2) belonging to the subtype B. However, it was relatively close to the Petaluma strain which is known to infect feline brain-derived culture cells and induce brain lesions in inoculated cats. By phylogenetic analysis, the JN-BR1 strain was placed in subtype A that included Petaluma strain and several other American and European strains. The JN-BR1 strain derived from brain with encephalitis in this study and the Petaluma strain may share a common genetic structure that is related to their neuropathogenicity.

An anatomical study on the forearm vascular system

The purpose of the present study was to establish the clinicoanatomical basis for the radial forearm flap. We conducted a morphometric investigation on 52 Japanese cadavers, of forearm vessels, for use in free forearm flaps. The mean inner diameter of the cephalic and median cubital veins at the interepicondylar line was 1.9 +/- 1.2 mm and 1.8 +/- 1.1 mm, respectively. Mean inner diameter of the radial artery and venae comitantes 1 cm distal to the origins of the radial and ulnar arteries was 2.3 +/- 0.5 mm and 1.6 +/- 0.5 mm, respectively. The longest segment of a superficial vein was 28.7 +/- 4.6 cm, it was measured between the basilic vein 5 cm proximal to the interepicondylar line and the cephalic vein at Lister's tubercle. The length of the radial artery was 18.1 +/- 1.7 cm. There were fewer valves in the basilic vein and cephalic vein proximal to the median cubital vein and in the brachial veins than in the distal antebrachial veins. From these results some of the clinicoanatomical considerations of forearm vessels which will form the clinicoanatomical basis of the free forearm flap should be clarified.

Detection of apoptosis induced in peripheral blood lymphocytes from cats infected with feline immunodeficiency virus

Peripheral blood lymphocytes (PBL) from cats infected with feline immunodeficiency virus (FIV) were examined for the occurrence of apoptosis after short-term culture. In the PBL from FIV-infected cats, changes in flow-cytometry scattergram, morphological characteristics of apoptosis and nucleosomal DNA fragmentation were observed. Percentages of apoptotic cells by flowcytometry analysis in PBL from FIV-infected cats (22.4% +/- 9.4%) were significantly higher than those in PBL from uninfected control cats (9.2% +/- 3.5%). The lymphocytes which underwent apoptosis included CD5+, CD4+ and sIgM+ cells, indicating that induction of apoptosis was not restricted to a special subset of lymphocytes. These findings provide evidence of the apoptotic state of PBL in cats with FIV infection.

[Recovery from descending necrotizing mediastinitis and multiple organic failure after seven months of mechanical ventilation]

A 61-year-old man with a history of hypertension and diabetes mellitus had a tooth extracted. Nine days later, he was admitted to the hospital with complaints of high fever, dyspnea, and anterior chest pain. Physical examination revealed a drowsy man with a fever of 38.2 degrees C, blood pressure of 66/44 mmHg, and marked redness and swelling from the neck to anterior part of the chest. Laboratory examination indicated severe infection and multiple organ failure, consisting of cardiac, respiratory, renal, and hepatic failure, with disseminated intravascular coagulation. Chest X-ray and CT-scan films showed abscesses extending from the neck to the mediastinum, and bilateral pleural effusion. Immediately, he was treated with catecholamines, furosemide, mechanical ventilation with a high concentration of oxygen, continuous drainage, repeated skin incisions, and broad-spectrum antibiotics. In addition, steroid pulse therapy was administered for persistent respiratory failure. On the 28th hospital day, a fistula developed between the trachea and the mediastinum, and an intratracheal tube had to be inserted through the fistula. On the 212 th hospital day, after intravenous hyperalimentation, continuous intravenous insulin infusion, and administration of broad-spectrum antibiotics, catecholamines, and furosemide, the patient was weaned from mechanical ventilation. A restrictive ventilatory defect due to ankylosis and atrophy of underused muscles was noted after weaning, but the PaO2 was high with a low dose of oxygen (1 to 2 l/min), and 21 months later, the blood gases were normal while the patient was breathing room air. As of January, 1996, he was undergoing rehabilitation to promote his recovery from ankylosis, muscle atrophy, and speech dysfunction.

Magnetic resonance imaging and pathologic studies on lateral fluid percussion injury as a model of focal brain injury in rats

In this study, morphologic changes in brain lesions initiated by moderate lateral fluid percussion injury in rats were investigated chronologically using high-resolution magnetic resonance imaging (MRI) and histopathologic methods. Rats were subjected to moderate fluid percussion injury (average 2.80 +/- 0.48 atmospheres) over the exposed dura overlying the right parietal cortex. MRI obtained in vivo were compared with corresponding pathologic findings at 1, 6, and 24 h and at 3, 6, 14 and 80 days after injury. T2-weighted images showed scattered low-signal intensity in the injured cortex within a few hours after injury, whereas histologic findings revealed intraparenchymal hemorrhages. T2-weighted images of the ipsilateral cerebral cortex and/or corpus callosum showed a high-signal-intensity area 4 h after injury. The high-signal-intensity area became largest in size between 6 and 24 h, then declined gradually, and almost disappeared 14 days after injury. Histologic examination revealed pyknosis, retraction of the cell body of neurons with vacuolated neuropil in the corresponding regions 6 and 24 h after injury, and cystic necrosis 14 days after injury. The location and extent of these pathologic changes were depicted accurately by MRI in vivo. In the hippocampus, pyknosis and retraction of the cell body of pyramidal neurons were observed on the injured side 24 h after injury, and the number of neurons in the CA1 and CA2-CA3 regions decreased significantly on the same side by 14 days after injury. It is concluded that morphologic changes in the brain following experimental traumatic brain injury in rats are detectable in vivo by high-resolution MRI, and that MRI may be useful for the evaluation of treatment effects in experimental brain injury.

New mutations in acetylcholine receptor subunit genes reveal heterogeneity in the slow-channel congenital myasthenic syndrome

Mutations in genes encoding the epsilon, delta, beta and alpha subunits of the end plate acetylcholine (ACh) receptor (AChR) are described and functionally characterized in three slow-channel congenital myasthenic syndrome patients. All three had prolonged end plate currents and AChR channel opening episodes and an end plate myopathy with loss of AChR from degenerating junctional folds. Genetic analysis revealed heterozygous mutations: epsilon L269F and delta Q267E in Patient 1, beta V266M in Patient 2, and alpha N217K in Patient 3 that were not detected in 100 normal controls. Patients 1 and 2 have no similarly affected relatives; in Patient 3, the mutation cosegregates with the disease in three generations. epsilon L269F, delta Q267E and beta V266M occur in the second and alpha N217K in the first transmembrane domain of AChR subunits; all have been postulated to contribute to the lining of the upper half of the channel lumen and all but delta Q267E are positioned toward the channel lumen, and introduce an enlarged side chain. Expression studies in HEK cells indicate that all of the mutations express normal amounts of AChR. epsilon L269F, beta V266M, and alpha N217K slow the rate of channel closure in the presence of ACh and increase apparent affinity for ACh; epsilon L269F and alpha N217K enhance desensitization, and epsilon L269F and beta V266M cause pathologic channel openings in the absence of ACh, rendering the channel leaky, delta Q267E has none of these effects and is therefore a rare polymorphism or a benign mutation. The end plate myopathy stems from cationic overloading of the postsynaptic region. The safety margin of neuromuscular transmission is compromised by AChR loss from the junctional folds and by a depolarization block owing to temporal summation of prolonged end plate potentials at physiologic rates of stimulation.

[Morphological and clinical study of acoustic tumor with respect to enlargement of internal auditory canal: mechanism of bone destruction]

The mechanism of widening of the internal auditory canal (IAC) by an acoustic tumor is still unknown. Degree of IAC enlargement was expressed as "IAC ratio' calculated from the measurement of bilateral horizontal diameters from bone-imaging CT. Comparing IAC ratio to radiological findings of tumors, such as size, solidity, mode of attachment to pyramidal bone and the presence of ventricular dilatation, we found a positive correlation between the ratio and the volume of solid tumors (especially of smaller ones) and more marked destruction of IAC in association with ventricular dilatation. Preoperative degrees of hearing ability or facial nerve function didn't correlate with that of IAC enlargement. It is our hypothesis that the mechanism involved in the destruction of IAC is as follows: (1) The repeated strokes of the tumor caused by brain pulsation gradually erode the bony wall of IAC (especially, that of the posterior wall). The apparently less destruction of IAC in cases with mostly cystic large tumors might be due to the restriction of this pulsatile movement. (2) Increased CSF pressure on the site has some influence on the mechanism of bone erosion as also does solidity of the tumor.

A computerized method for evaluating balance of occlusal load

In order to undertake a quantitative evaluation of balance occlusal load, the use of the Dental Prescale System was investigated. The method uses a test sheet that undergoes a colour-developing chemical reaction, for detecting contact area, and a computerized analysis system, for evaluating the balance of occlusal load. Twenty natural dentate subjects and 10 hemimaxillectomy patients participated in the study. Each subject bit a test sheet as hard as possible for 3 s. The balance of occlusal load was expressed as a percentage of the load on the side with the lesser occlusive load (%OLR). The %OLR ranged from 39.7% to 49.4% in the natural dentate subjects, and from 0% to 31.3% in the hemimaxillectomy patients at their resection site. The patients' low %OLRs were attributed to loss of sustaining structure and subjective occlusal adjustment by clinicians. Combining technical simplicity, relatively high reproducibility, and diverse analysis capability, this system is useful for quantitative evaluation of balance of occlusal load in clinical situations.

Cell-specific, multidrug delivery system using streptavidin-protein A fusion protein

Tissue-specific delivery of variety of molecules has been a valuable technique for biological and medical research and for the diagnosis and therapy of cancer. We have therefore examined the ability of streptavidin-protein A (ST-PA) fusion protein complexed with monoclonal antibodies (mAbs) to transfer biotinylated proteins into specific type of cells. ST-PA/mAbs complexes could efficiently deliver biotinylated beta-galactosidase into a variety of cancer cell lines through molecules expressed on their surface. In addition, ST-PA/mAb complexed with either biotinylated glucose oxidase or biotinylated ribonuclease A could be transferred to specific cell types and made to display cytotoxic activity against the transduced cell. The flexibility of the system was enhanced by the fact that the cell-targeting specificity could be altered by just changing the mAb used and the "payload" molecule could be replaced by substituting one biotinylated protein or enzyme with another. This flexibility was achieved without the need to generate a covalent chemical link or engineering new recombinant molecules. Results obtained to date suggest that the ST-PA fusion protein may be used as a nearly "universal carrier" to transfer a variety of effector molecules into target cells with a high degree of specificity. Essentially, the ST-PA fusion protein effectively serves as a high-efficiency, modular "molecular bridge" for the transfer into cells of a wide variety of effector molecules.