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Biomedical subjects

Y Kitahara

Publications and source records attributed to Y Kitahara.

At least 37 records · Page 2Linked to original sources
PubMed1999

[Anesthetic management of an infant with pulmonary atresia and ventricular septal defect accompanied by excess pulmonary blood flow for systemic-pulmonary shunt operation].

A 6-month-old infant had pulmonary atresia with ventricular septal defect (PA + VSD) accompanied by excess pulmonary artery flow via major aortopulmonary collateral artery, underwent aortopulmonary shunt with artificial graft under midazolam-fentanyl anesthesia. After the administration of protamine, arterial oxygen saturation gradually decreased. We suspected that hypotension and decrease in cardiac output induced by protamine caused the decrease in pulmonary blood flow via central shunt. It is suggested that pulmonary blood flow should be maintained by using an inotropic agent and a selective pulmonary arterial dilator such as prostaglandin E1 in a patient with PA + VSD after the institution of aorto-pulmonary shunt, because the patient with excess pulmonary flow has been reported to have high pulmonary resistance due to pulmonary abnormalities such as stenosis and thrombosis.

Anesthesia, Intravenous↗
PubMed1998

[Diagnostic usefulness of the tuberculin reaction by PPD-B in Mycobacterium avium complex disease].

This study was carried out to clarify the diagnostic usefulness of the skin tests of purified protein derivatives from M. intracellulare (PPD-B) and M. tuberculosis (PPDs). Study subjects consisted of 41 patients with primary infection type of M. avium complex (MAC) disease, 36 patients with pulmonary tuberculosis (TB) and 29 patients with other bacterial respiratory infections including COPD (OB). The patients were sorted out to middle (50-69 y.o.) and old (70-89 y.o.) age groups of each disease. The size of skin redness elicited 48 hours after the PPD-B and PPDs intradermal injections were compared among them. The results were as follows. 1) Both PPD-B and PPDs skin reactions were larger in the middle age group than in the old one for each disease. 2) In PPDs skin tests, the reaction of TB group was the largest among the three diseases. In PPD-B skin tests, that of MAC was the largest. 3) In TB group, PPDs skin reaction was significantly larger than that of PPD-B, while in MAC and OB groups there was no significant difference between the skin reactions of PPDs and PPD-B. 4) Defining significant positive reaction to PPD-B as PPD-B skin reaction exceeding 10 mm and larger than that of PPDs skin reaction, the rate of significant positive reaction to PPD-B was significantly higher in MAC than TB in both age groups. These results showed that the simultaneous skin tests of PPD-B and PPDs were a useful aid in the diagnosis of MAC infection disease when mycobacterial infection diseases were clinically suspected by bacteriological or chest radiographic examinations.

Age Factors↗
PubMed1997

Development of degenerative muscle weakness by chronic administration of beta,beta'-iminodipropionitrile in the drinking water to rats: a model for motorneuropathy.

Progressive muscle weakness accompanied by progressive muscle atrophy was investigated in rats administered beta,beta'-iminodipropionitrile (IDPN) chronically in the drinking water. Spontaneous running wheel activity declined slowly and reached a constant low level before postural muscle weakness was apparent. The rats being offered IDPN in the drinking water showed definite postural muscle weakness about 25 weeks after first being given IDPN, and muscle strength declined gradually throughout the remainder of the experiment (to 66 weeks). Flaccid paralysis became apparent in the hind limbs in the later stages of the experiment. Neurogenic muscle atrophy, measured by group atrophy of the muscle fibers, also progressed slowly, almost in parallel with the loss of muscle strength. At the end of the experiment, muscle weight of the gastrocnemius had decreased to about 20% that of control [F(2, 12) = 40.4, p < 0.05]. Plasma creatinine in the rats given IDPN in the drinking water for 66 weeks was significantly elevated over that of controls [F(2, 12) = 20.1, p < 0.05]. On the other hand, in rats given IDPN intraperitoneally, postural muscle weakness and muscle atrophy were less apparent, and plasma creatinine was normal. However, in these animals, abnormal behaviors, such as hyperexcitement, circling, and choreic movement (ECC syndrome), were apparent. These results suggest that the present model, which administers IDPN chronically in the drinking water ad lib and does not show involuntary movements and ECC syndrome, is of potential importance for investigation of chronic diseases of progressive muscle weakness with progressive muscle atrophy, and for assessing the efficacy of drugs and therapies for treating chronic neuromuscular diseases.

Animals↗
PubMed1997

Effect of dietary supplementation with branched-chain amino acids on spontaneous motor activity and muscle function in beta,beta'-iminodipropionitrile-treated rats: a model for motorneuropathy.

Beta,beta'-iminodipropionitrile (IDPN)-induced muscle weakness in rats is a model for motorneuropathy diseases. The effects of oral administration of branched-chain amino acids on the progression of muscle weakness and muscle atrophy induced by the administration of IDPN in the drinking water, were investigated in this study. The spontaneous motor activity of the animals, as measured with a running wheel, slowly declined after IDPN administration, reaching a steady and low level at approximately week 15. Progressive muscle weakness and muscle atrophy were observed beginning at approximately 15 weeks after the initiation of administration of IDPN. Administration of branched-chain amino acids (BCAA) as a dietary supplement did not improve the lowered spontaneous motor activity seen in IDPN animals, but it did significantly improve measures of postural weakness and muscle strength [range of F values (2, 24) = 4.1-9.5, p < 0.05]. Plasma creatinine of the IDPN-treated rats was markedly elevated, and BCAA administration also significantly suppressed this elevation [F(2, 24) = 41.2, p < 0.05]. Moreover, although BCAA in plasma were elevated in the rats administered BCAA [range of F values (2, 21) = 25.7-29.7, p < 0.05], skeletal muscle showed no differences (at the p < 0.05 level) in the amounts of BCAA, whether or not BCAA were administered. These data suggest that the BCAA taken up in the skeletal muscle were utilized in the muscle of motorneuropathic rats and improved muscle function, such as energy metabolism, and that the BCAA treatment is one important therapeutic approach for retarding the progression of muscle weakness seen in certain neuromuscular disorders.

Amino Acids, Branched-Chain↗
PubMed1997

[The distribution and the characteristics in computed tomography (CT) of the lungs in primary Mycobacterium avium complex (MAC) infection].

We investigated the distribution and the characteristics of the lung lesions of patients with primary Mycobacterium avium complex (MAC) infections mainly by computed tomography (CT). They admitted to our hospital during the period from 1984 to 1995 and none of them had a medical history of tuberculosis or other lung diseases. The subjects consisted of fifty patients: fourteen male (average age +/- SD was 66.4 +/- 14.0 year old) and thirty six female (69.0 +/- 11.9 year old). Of 50 patients 24 were M. intracellulare infection, 10 were M. avium infection and others were not identified. First, by using the ratio of slices with lesions on CT to all CT slices from the apex to the base of the lungs, all the patients were divided into two groups; a slight group with less than 15.0% (n = 19) and a severe group with 15.0% or more (n = 31). Next, the density of abnormal shadows in each segment as divided into 5 grades; none (-), minimal (+/-), slight (+), moderate (+2) and severe (+3). The grading was done by taking into account the grade of distribution, density of lesions and destruction of lung parenchym found mainly on CT, and in addition by a standard roentogenographic and tomographic features supplemental. The characteristics frequently observed findings on CT in primary MAC infection patients were nodular (94%), cavitary (74%), bronchiectatic (62%), infiltrative (74%), atelectatic (56%), and pleural-thickened (36%) shadows. Comparing the incidence of segmental lesions in MAC infection patients by segment, it was higher in right and in left lung, but the difference was statistically not significant. As to the number of segments with lesions graded from (+/-) to (+3), many segments were infected unexpectedly: the mean value was 7.7 +/- 1.5 even in the slight group. The proportion of segments with relatively severe lesions graded from (+2) to (+3) in each segment was observed, and the rate in the slight group was 52.6% in S5, 28.9% in S4, 16.7% in S1 (S1 + 2a, b), and 16.7% in S2 (S1 + 2c). In severe group, it was 54.8% in S5, 45.2% in S4, 46.8% in S1 (S1 + 2a, b) 54% in S2 (S1 + 2c), 27.4% in S3 and 26.2% in S6, respectively. The rate of segments with lesions in the lower lobes were less frequent especially in the slight group while it was slightly higher in the severe group. Speculating the initial lesions in the slight group, it was assumed that there might be two types of foci; the one is relatively localized in the beginning and the other is a diffuse type with lesions in many segments even from its early stage. As to the location of initial lesions, the middle lobe and lingula were the most important sites, and the right upper lobe and the left upper division were the next.

Aged↗
PubMed1996

Nonpeptide angiotensin II receptor antagonists: synthesis, biological activities, and structure-activity relationships of imidazole-5-carboxylic acids bearing alkyl, alkenyl, and hydroxyalkyl substituents at the 4-position and their related compounds.

A series of imidazole-5-carboxylic acids bearing alkyl, alkenyl, and hydroxyalkyl substituents at the 4-position and their related compounds were prepared and evaluated for their antagonistic activities to the angiotensin II (AII) receptor. Among them, the 4-(1-hydroxyalkyl)-imidazole derivatives had strong binding affinity to the AII receptor and potently inhibited the AII-induced pressor response by intravenous administration. Various esters of these acids showed potent and long-lasting antagonistic activity by oral administration. The most promising compounds were (5-methyl-2-oxo-1,3-dioxol-4-yl)methyl (CS-866) and (pivaloyloxy)-methyl esters of 4-(1-hydroxy-1-methylethyl)-2-propyl-1-[(2'-1H-tetrazol-5- ylbiphenyl-4-yl)-methyl]imidazole-5-carboxylic acid (26c). A study involving stereochemical comparison of 26c with the acetylated C-terminal pentapeptide of AII was also undertaken.

Acetylation↗
PubMed1996

[Promotive factors of chronic subdural hematoma in relation to age].

To reveal the pathogenesis of chronic subdural hematoma (CSDH), 256 patients with CSDH over 1 year of age were studied in relation to various traumatic or nontraumatic promotive factors of CSDH including arachnoid cyst, implantation of a cerebrospinal fluid shunt, secondary cerebral atrophy, coagulopathies and past history of acute subdural hematoma or effusion. All patients were grouped according to decade of age. The incidences of associated promotive factors were individually analyzed in each group. The incidences of associated promotive factors in the 1st, 2nd, 3rd, 4th, 5th, 6th, 7th, 8th, 9th decades of life were 71%, 89%, 56%, 33%, 9%, 11%, 8%, 8% and 5%, respectively. Thus, they were divided into two groups; youth (1st to 4th decade: n = 34) and elder (5th to 9th decade: n = 222). The incidences of associated promotive factors were 62% and 8%, respectively (P < 0.001). Severity of head injury received was also evaluated in these two groups. In the youth group, 15 out of 34 patients (44.1%) had received severe head injuries with loss of consciousness, while in the elder group, only 22 out of 222 patients (9.9%) had received severe head injuries (P < 0.001). The analysis was repeated after each group was divided into two subgroups regarding the coexistence of promotive factors. Among the youth group, 13 patients had no promotive factors and 21 had one or more promotive factors. In those without any promotive factor, 9 out of 13 had received severe head injuries with loss of consciousness, while in those with promotive factors, 6 out of 21 had received severe head injuries. On the other hand, majority of the elder group had not received severe head injuries irrespective of whether patients had promotive factors or not. The present study revealed that majority of young CSDH patient had some promotive factors or severe head injuries with loss of consciousness, and that majority of patients aged over 40 years had no promotive factors and did not receive severe head injuries.

Adolescent↗
PubMed1996

[Lumbar and thoracic epidural anesthesia in children's hospitals in Japan].

A retrospective study of the lumbar and thoracic epidural anesthesia (catheterization) in infants and children younger than 12 years was undertaken in children's hospitals in Japan. Seventeen institutions replied to our questionnaire and 10 institutions experienced these procedures in the year preceding September 1994. The total number of the lumbar and thoracic epidural anesthesia performed was 324, with average of 32.4 +/- 31.1, and maximum of 113 and the minimum of 2. The number of thoracic epidural anesthesia performed was 56 a much smaller figure than that of lumbar anesthesia. Infants younger than 12 months were 23 in both groups. No major complications occurred except a case of infection at the insertion site. The patient had herpes zoster. On the other hand, several institutions cast doubt on the necessity of epidural anesthesia in infants and children. The long-term influence on the developing nervous system should be investigated.

Anesthesia, Epidural↗
PubMed1995

Effect of spinal cord stretching due to head flexion on intramedullary pressure.

The effect of the longitudinal stretching force of the spinal cord on intramedullary pressure was investigated using our method for measuring intramedullary pressure of the spinal cord with implanted balloons. The transverse compressive force against the posterior wall of the spinal column was excluded by measuring the intramedullary pressure during flexion of the head with the middle and lower cervical spine in the neutral position. The intramedullary pressure of the cervical spinal cord was measured simultaneously at the C-2, C-4, and C-6 levels in 10 mongrel dogs, in three head positions: neutral, and head extension and flexion. Head flexion caused significant increases in the intramedullary pressure at C-2, C-4, and C-6. The pressure increase in the middle to lower cervical cord must have been due to the transmission of the longitudinal stretching force of the cord itself, and may be a factor in the development of intramedullary disorders such as syringomyelia and intramedullary neoplasms.

Animals↗
PubMed1995

[Effect of sevoflurane and nitrous oxide anesthesia on auditory brainstem responses in children].

The effect of sevoflurane and nitrous oxide anesthesia on the auditory brainstem response (ABR) was studied in 70 infants and children ranging in age between 1 month and 15 years. The latencies in ABR under a non-anesthetic state are no longer in the waves originating from the central portion in younger subjects. This tendency was recognized under ketamine anesthesia as control and sevoflurane and nitrous oxide anesthesia as well. Although nitrous oxide 60% and sevoflurane 2.5% increased the latency of wave V and the interpeak interval I-V significantly in all age groups, the changes were small (0.26 +/- 0.16 msec and 0.23 +/- 0.19 msec). The changes in infants were relatively large compared with elder subjects. These concentrations did not decrease the amplitude of waves I, III and V significantly in any age group. Sevoflurane exerted little influence on ABR, and it would be useful for ABR testing in children.

Adolescent↗
PubMed1994

Spinal cord intramedullary pressure. A possible factor in syrinx growth.

STUDY DESIGN: This study analyzed biomechanical characteristics of the cervical spinal cord, especially in relation to neck flexion. Intramedullary pressure was measured in different neck positions. OBJECTIVES: The results provided a rationale for dynamic changes in intramedullary pressure, with the flexed neck position playing a role in syrinx growth. SUMMARY OF BACKGROUND DATA: Dynamic changes in intramedullary pressure in the flexed position have been postulated to play an important role in syrinx growth. However, intramedullary pressure of the spinal cord has not been measured. METHODS: The authors designed a balloon method to assess, experimentally, intramedullary pressure dynamics of the spinal cord. A system was incorporated to examine the reliability of the balloons. Using 15 mongrel dogs, two balloons were embedded in the cervical spinal cord. Intramedullary pressure of the spinal cord was measured in several neck positions. In 5 of them, the same measurements were repeated when the spinal cord and roots were transected. RESULTS: When filled with a suitable volume of water, the balloons faithfully transmitted the pressure of the environment. No pressure differences were observed with the neck in the extended or neutral positions. However, when the neck was flexed, intramedullary pressure significantly increased. This increase in intramedullary pressure in the flexed neck position was not observed after spinal cord and roots were transected. CONCLUSION: The results indicated that the intramedullary pressure of the cervical spinal cord increases when the neck is flexed. This phenomenon might play an important role in syrinx growth.

Animals↗
PubMed1994

Pharmacokinetics and pharmacodynamics of serum glycerol in patients with brain edema: comparison of oral and intravenous administration.

To clarify the pharmacokinetics and effect of ICP reduction of glycerol administered orally, the serum concentration of glycerol was measured by the enzymatic method and ICP was measured by the subdural balloon method in severe head injured patients with brain edema and increased ICP. Sequential change of serum glycerol concentration and its relationship to the reduction of ICP were analyzed. The results showed that the pharmacokinetics of glycerol through oral administration were similar to that of intravenous glycerol administration and the changes of ICP were also similar to that of intravenous glycerol administration. We determined that glycerol can be administered either per oral or per venous to obtain the same results for treatment of brain edema with raised ICP.

Administration, Oral↗
PubMed1994

Dural arteriovenous malformation involving the inferior petrosal sinus--case report.

A 59-year-old male presented with a dural arteriovenous malformation involving the inferior petrosal sinus manifesting as false-localizing ocular symptoms. Occlusion between the right inferior petrosal sinus and the right jugular bulb caused an unusual retrograde venous outflow from the inferior petrosal sinus to the cavernous sinus, thought to have been responsible for the chemosis, abducens nerve paresis, and orbital bruit. He was treated successfully with transarterial embolization and radiotherapy.

Cerebral Angiography↗
PubMed1994

[A study on drug resistance of newly admitted pulmonary tuberculosis patients with special reference to the resistance to SM, INH, EB and RFP].

Previously untreated 347 tuberculosis patients newly admitted to our hospital from 1980 to 1991 with positive bacilli and the full record of the drug sensitivity tests were analysed in this study. Among them, 49 cases showed primary resistance to either of major 4 anti-tuberculosis drugs (SM, INH, EB, RFP). The results obtained were as follows: 1. The number of patients with positive bacilli increased with age. The rate of primary drug resistance in patients of age group below 49 were significantly higher than that of age group over 50. 2. The rate of resistance was 8.6% to SM, 4.0% to INH, 1.4% to RFP and 0.6% to EB. These results are consistent with the results of studies of the Tuberculosis Research Committee, Ryoken. EB was frequently substituted to resistant drugs. 3. There was no significant difference between a group with primary resistance and a sensitive group in the various risk and intractable factors, laboratory data as a indicator of risk factors, and in the results of tuberculin skin test. There was also no significant difference in the rate of culture negative conversion of tubercle bacilli and the improvement in radiological findings. 4. We could rarely find the source of infection in 49 cases with primary resistance. In only 5 cases, family contacts were suspected and in another 1 case, the contact in a work place was suspected.

Adult↗
PubMed1994

[An investigation on risk factors relating to the treatment difficulty in originally treated pulmonary tuberculosis cases].

In order to investigate whether so-called risk factors relating to treatment difficulty are true risk or not, treatment results of 520 in-patients originally treated for pulmonary tuberculosis during 12 years' period from 1980 to 1991 in our hospital were analyzed. The proportion of cases with so-called risk factors among total 520 cases was as follows: Aged patients (70 years of age and over) 31.5%. Cases discharging abundant bacilli in sputum (Gaffky scale VII or above or culture, +3 positive) 29.4%. Adverse reactions to drugs 18.1%. Far advanced cavitary lesions (GAKKAI Classification I or II3) 15.6%. Relative risk of various risk factors in cases of group A (died of tuberculosis), group B (showed delay in the negative conversion of bacilli; namely, cases converted to negative only 4th month of treatment or later) and group C (cases of groups A and B) were calculated comparing with cases of the control group (pretreatment negative bacilli cases or cases converted to negative within 3 months). In cases of group A died of tuberculosis, the results were as follows; pretreatment abundant bacilli discharge 3.1, far advanced cavitary lesions 4.6, emaciation and/or malnutrition 5.1. Other risk factors identified were the following; unhealthy life style 4.0, severe gastrointestinal tract disease 3.9, impaired pulmonary function 3.3, complicated infections 3.2, cerebrovascular injuries including psychosis and nervous system diseases 2.3, diabetes mellitus 2.0, and the adverse reactions to drugs 1.9. In cases of group B showing delay in the negative conversion of bacilli, significant risk factors were pretreatment abundant bacilli discharge, far advanced cavitary lesions, emaciation and/or malnutrition and diabetes mellitus.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

[A case of hypogamma-globulinemia with thymoma (Good's syndrome) follow-up for 8 years].

A 58-year-old woman, who had a past history of left upper lobectomy with thoracoplasty for pulmonary tuberculosis and resection of thyroid cancer, was diagnosed as having a mediastinal tumor by chest X-ray examination. It was found to be a malignant thymoma (spindle cell type) after resection. The level of serum gammaglobulin, which had been low before resection, progressively decreased. Afterward, she frequently suffered from airway infections which resulted in severe bronchiecatsis. She died due to respiratory failure 8 years later. In the early stage, though the percentage of pan T cells in peripheral blood lymphocyte subsets was normal, CD4 T cells decreased and CD8 T cells increased. A decrease in helper T cells and an increase in cytotoxic T cells were especially marked. In the late stage, all T cells subsets decreased. In particular, naive T (CD45RA* CD3+ T) cells decreased markedly. However, the percentage of B cells remained normal and that of NK cells was elevated. From the findings of lymphocyte subsets and lymphocyte reactivity to PHA stimulation, it is suggested that T cell dysfunction caused hypogrammaglobulinemia in this case.

Agammaglobulinemia↗
PubMed1993

A new model for infective endocarditis of the mitral valve in rabbits.

To produce an experimental model of infective endocarditis without inserting catheters into the heart, we injected a bacterial suspension into rabbits in which mitral complex lesions had been induced by electrical stimulation of the cervical vagus. Typical infective vegetations grew on the surface of the mitral valves 1 week later. The formation of vegetations was related to the timing of the inoculation. Streptococcus viridans injected just after vagal stimulation produced vegetations in 10 of 17 animals (58.8%), but the same bacteria injected 14 days after vagal stimulation did so in only 2 of 11 animals (18.2%). The incidence of infective endocarditis was significantly higher after early inoculation compared with delayed inoculation (p < 0.01). The susceptibility to infection depended on the species of bacteria injected. Both S. viridans and Pseudomonas pseudoalkaligenes injected just after vagal stimulation produced vegetations in 10 of 17 (58.8%) and 6 of 13 (46.2%) animals, respectively, but Staphylococcus epidermidis injected just after vagal stimulation did not produce vegetations in any of the 10 animals. S. viridans injected into nine normal animals never produced vegetations. These findings indicate that infective endocarditis develops after intravenous injection of bacterial suspensions alone in rabbits with mitral complex lesions.

Animals↗