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Biomedical subjects

M Ohi

Publications and source records attributed to M Ohi.

At least 91 records · Page 5Linked to original sources
PubMed1992

[Application of nasal intermittent positive pressure ventilation to a case of limb-girdle muscular dystrophy].

We applied nocturnal ventilation (NV) with nasal intermittent positive pressure ventilation with custom molded mask (NIPPV-C Mclermott, 1989), as well as NV with tracheostomy intermittent positive pressure ventilation (TIPPV) to a male patient with limb-girdle muscular dystrophy who had developed chronic respiratory failure at the age of 47. NV with both methods successfully corrected nocturnal hypoxemia, improved daytime arterial blood gas values, and achieved a stable clinical course without marked deterioration for four years. Daytime PaO2 higher than 60 Torr and PaCO2 lower than 70 Torr while breathing room air were maintained with both methods, whereas PaO2 was lower than 50 Torr and PaCO2 higher than 70 Torr before the implementation of NV. TIPPV was safely suspended repeatedly for as long as two weeks, maintaining daytime PaO2 higher than 50 Torr. NIPPV-C was also repeatedly suspended for two weeks. Occasionally PaO2 dropped as low as 40 Torr after periods without NV; however, it was restored to higher than 60 Torr after one or two nights' NIPPV-C. These facts suggest that NV had a restorative effect on respiratory muscle fatigue in the present case. While on NIPPV-C, nighttime SaO2 was higher than 90% for 94% of the total time, and between 80% and 90% for the remaining 6% of the time. Desaturation for short periods was thought to be due to oral air leakage, which made the method slightly less effective than TIPPV. However, the overall clinical effectiveness of NIPPV-C was comparable to that of TIPPV.(ABSTRACT TRUNCATED AT 250 WORDS)

Chronic Disease↗
PubMed1991

Diagnostic value of Lipiodol injection in focal nodular hyperplasia of the liver.

We encountered a case of small focal nodular hyperplasia (FNH) of the liver. It was difficult to distinguish FNH from hepatocellular carcinoma by means of sonography, computed tomography (CT), and angiography. After the injection of Lipiodol, it accumulated densely on FNH, but was washed away after a short time, as observed on the follow-up CT. This progress was different from that in hepatocellular carcinoma.

Adult↗
PubMed1990

[Tuberculosis sequelae: pathophysiological aspect (ventilation)].

The percentage of the patients with PaCO2 more than 60 Torr and PaO2 more than 50 Torr were 13% in the patients with tuberculosis sequela (N = 502) and 4% in the patients with chronic obstructive lung disease (COLD, N = 727), who were treated with home oxygen therapy in the western region of Japan. Patients with chronic respiratory failure caused by tuberculosis sequela have higher PaCO2 than patients with COLD. Although the prognosis of patients with hypercapnia and moderate hypoxemia is not necessarily poor, some patients may need treatment for severe hypoventilation to prevent respiratory muscle fatigue and abnormal breathing during sleep. In this study, nine patients with hypercapnic chronic respiratory failure caused by tuberculosis sequela were ventilated by Chest Negative Pressure Ventilation (CNPV). The patients were monitored as in polysomnography by transcutaneous PCO2 (PtcCO2) electrode and Respiratory Inductance Plethysmography (RIP). Tidal volume induced by CNPV was larger during mouth breathing (504 +/- 128 ml, mean +/- s.d.) than during nose breathing (438 +/- 109 ml) calculated from RIP in awake state (N = 7). Oxygen saturation measured by ear oximeter and PtcCO2 were 94.4 +/- 2.9% and 57.8 +/- 12.2 Torr in awake state. Following CNPV SaO2 and PtcCO2 were 95.7 +/- 3.0%, 42.7 +/- 12.1 Torr in awake state (N = 9) and 93.0 +/- 4.4%, 57.0 +/- 15.7 Torr in Non-REM sleep (N = 5), respectively. CNPV is effective in these patients in awake state. During Non-REM sleep, CNPV maintains the PtcCO2 level only in awake state.

Aged↗
PubMed1990

[Upper airway function and non-intubated, assisted ventilation].

The influence of upper airway patency on ventilation assisted by chest negative pressure ventilation (CNPV) or nasal intermittent positive pressure ventilation (nIPPV) was studied as follows. 1) In seven patients with chronic respiratory failure (PaCO2 more than 50 Torr), the increase in tidal volume (VT) induced by CNPV was larger during mouth breathing than during nose breathing in the awake state. On CNPV transcutaneous PCO2 (PtcCO2) decreased during awake state, but increased during NREM sleep. 2) In four patients with chronic respiratory failure (PaCO2 more than 60 Torr), nIPPV induced the leakage of air from mouth in more than 20 cmH2O of nasal mask pressure during sleep. PtcCO2 increased during sleep, especially during REM sleep in spite of nIPPV. The change in PtcCO2 during REM sleep on nIPPV comparing awake state was 16.1 +/- 1.4 torr and comparing REM sleep in usual sleep was -6.0 +/- 1.4 Torr. 3) Upper airway resistance (UAR) was measured in two patients with tracheostomy. An increase in UAR was associated with a linear decrease in VT during nIPPV, although associated with a curvilinear decrease in VT during CNPV. These results indicate that the efficiency of CNPV and nIPPV depends on the patency of upper airway.

Adult↗
PubMed1989

Breathing during sleep with mild hypoxia.

To investigate ventilatory response to mild hypoxia during non-rapid-eye-movement sleep, we administered approximately 16% O2 (which corresponds to concentrations found in commercial high altitude air craft) to 12 normal subjects by using a Venturi mask, which did not alter the breathing pattern during this study. Under mild hypoxia, inspiratory minute ventilation during sleep showed an initial rapid increase (P less than 0.001) but then declined significantly (P less than 0.001) and stabilized. Stable levels differed among individuals and, compared with those measured before hypoxia, were significantly lower in some subjects, higher in one, and essentially unchanged in the others. The initial rapid increase in minute ventilation after mild hypoxia during sleep correlated with the respective values of hypoxic ventilatory response during the awake state (P less than 0.01), but the final lowered levels did not. We conclude that the ventilatory response after mild hypoxia during sleep is biphasic and hypoxic depression exerts considerable influence on ventilation under mild hypoxia during sleep. So we should take hypoxic depression into consideration to evaluate the response to hypoxia during sleep.

Adult↗
PubMed1989

Nerve regeneration in the dorsal funiculus of the rat spinal cord: a light and electron microscopic study.

In an attempt to identify regenerating axons in the central nervous system, a partial transection of the dorsal funiculus in the rat spinal cord was carried out with a pair of microdissection scissors, and a nylon thread loop was inserted into the lesion to demarcate the severed tissue. Nerve regeneration through the demarcated lesion was observed 4-20 days after the operation by light and electron microscopy. In the early stage, many naked axons appeared from the caudal part of the lesion, and some of these further extended into the demarcated space. They contained an accumulation of mitochondria, smooth-surfaced endoplasmic reticulum and vesicles in the axoplasm; this axoplasmic feature indicated that they were regenerating axons. They gradually increased in number, and took highly irregular courses exhibiting various fluctuations in diameter throughout their lengths. Immature Schwann cells as well as glial cells including oligodendrocytes and astrocytes appeared in close association with these regenerating axons. Oligodendrocytes eventually formed thin myelin sheaths. On the other hand, naked axons were present deflecting outside the thread loop; they showed no axoplasmic characteristics as described above. These axons could be regarded as uninjured ones merely undergoing demyelination due to the surgery. Thus, regenerating axons were clearly distinguished from merely demyelinated ones, and some of them were shown to grow through the traumatic lesion in the dorsal funiculus of the rat spinal cord.

Animals↗
PubMed1989

[Noninvasive ventilatory support on chronic respiratory failure with hypoventilation].

Chest negative pressure ventilation (CNPV) and intermittent positive pressure ventilation (IPPV) through a nose mask were used for ventilatory support of 4 patients with chronic respiratory failure due to old tuberculosis (2 patients), chronic pulmonary emphysema, and kyphoscoliosis (VC, 0.91 +/- 0.16 L; %VC 31.2 +/- 3.2; FEV1.0, 0.62 +/- 0.19 L). These ventilatory supports were used for relief of chronic arterial CO2 retention, weaning from the mechanical ventilation, therapy for the acute exacerbation on the chronic respiratory failure, and the relief of the respiratory muscle fatigue. After CNPV and IPPV through a nose mask, PaCO2 showed a significant fall from 75.7 +/- 14.8 Torr to 60.2 +/- 12.3 Torr (p less than 0.01). All patients showed improvement of clinical symptoms. Two patients have continued CNPV at home on a regular basis. We conclude that CNPV and IPPV through a nose mask significantly improve hypoventilation and quality of life in some patients with chronic respiratory failure.

Adult↗
PubMed1989

[Evaluation of respiratory disability in patients of respiratory diseases using relationships between ventilatory drive, ventilation and thoracic pump function during exercise].

We studied the parameters of breathing control during exercise in patients with respiratory diseases for the evaluation of respiratory disability. The ventilatory drive during the same load exercise was increased in patients with respiratory diseases compared with that in normal subjects. In addition, the ratio of ventilation to ventilatory drive during exercise was decreased in patients with respiratory diseases. Impairment of rapid thoracic movement was suggested to be one of the mechanical limitations for ventilation in these patients, based on the findings of smaller esophageal pressure fluctuation during maximum ventilation of 40 respirations per minute than that in normal subjects. Flow at 0.1 sec after initiation of inspiration was designated V0.1. The increase of the ratio of V0.1 at rest to that at maximum voluntary inspiration (V0.0 (rest)/V0.1 (max)) indicate the grade of respiratory disability showing the impossibility of rapid movement of thorax as a parameter of thoracic pump function. It was recognized that the decrease of VE/P0.1 during incremental exercise indicated ventilatory insufficiency.

Exercise Test↗
PubMed1988

[Huge jugular foramen neurinoma extending to the pharyngeal region: a case report].

The authors report a rare case of a huge jugular foramen neurinoma extending to pharyngeal region in a 64 year-old woman who visited an otolaryngologist with complaints of dysphagia, hoarseness and headache in 1984. At that time a submucosal lump was noted in her left pharyngeal region. Biopsy of the tumor proved it to be neurinoma. A CT scan disclosed a dumbell shaped jugular foramen neurinoma and noncommunicating hydrocephalus. Because her symptoms slowly progressed and cerebellar signs as well as signs of increased intracranial pressure was noted, she was referred to our hospital in 1986. She had shown typical sings of left Vernet syndrome, VIIth, VIIIth cranial nerve impairment as well as cerebellar, long tract and increased ICP signs. A subtotal removal was performed from the extracranial and posterior fossa in one stage. The tumor seemed to originate from the Xth cranial nerve. The histological diagnosis of neurinoma was confirmed. Postoperatively, although her dysphagia increased for several weeks, a tracheostomy was not necessary. She was discharged 2 months later and returned to her usual occupation as a house wife. Slight dysphagia and hoarseness were her only chronic symptoms. So far, 88 cases of jugular foramen neurinoma have been reported, 15 of them including our case from Japan. Our case is probably the largest of these reported tumors. Tumors in jugular foramen often masquerade as an acoustic neurinoma or other tumor. However, recently this can usually be diagnosed preoperatively with a careful neurological examination and by means of neuroradiological investigations such as jugular venography, CT scan and MRI.

Cerebral Angiography↗
PubMed1987

Noninvasive method to assess cor pulmonale in patients with chronic obstructive pulmonary disease.

In our study of 15 patients with chronic obstructive pulmonary disease, we performed myocardial perfusion single-photon-emission computerized tomography (SPECT) with thallium-201 to quantitatively assess right ventricular hypertrophy. On the SPECT images, we determined the ratio of activity in the right-to-left ventricular wall as the thallium score. Right ventricular ejection fraction (RVEF) was measured by multigated equilibrium radionuclide ventriculography with krypton-81m. Both the thallium scores and RVEF values correlated well with pulmonary arterial pressure (r = 0.65 and r = -0.86, respectively) and permitted the structural and functional assessment of cor pulmonale. When the patients were classified according to the thallium scores and RVEF values, those who had both a high thallium score and reduced RVEF had a significantly high pulmonary arterial pressure and vice versa. The combined evaluation of the thallium score and RVEF enabled accurate noninvasive assessment of cor pulmonale.

Adult↗