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Biomedical subjects

M Shimoda

Publications and source records attributed to M Shimoda.

At least 145 records · Page 8Linked to original sources
PubMed1992

[Problems in general management during barbiturate therapy].

Sixty-three patients (aged from 4 to 75 years) who had suffered severe head injury or cerebrovascular disease were placed on barbiturate regimens in which intravenous administration was given in amounts of 1-4 mg/kg/hr. Dobutamine and dopamine were also administered to prevent cardiac failure and renal failure. Immediate and delayed complications caused by barbiturate therapy were investigated and analyzed. Immediate complications included tachycardia which was seen in 16 cases (25%), and hypotension in 14 cases (22%), respectively. Higher incidence of those complications was noted among the patients who underwent surgery. Delayed complications included hypokalemia (41 cases, 65%), liver dysfunction hypernatremia (24 cases, 38%), infection (21 cases, 33%), cardiac failure (8 cases, 13%) and renal failure (1 case, 2%), respectively. Therefore, in patients treated under barbiturate regimens great care should be taken in order to avoid above mentioned complications.

Adolescent↗
PubMed1992

[A case of bilateral panophthalmoplegia caused by paranasal malignant lymphoma extending into the skull base].

A case of bilateral panophthalmoplegia developed after paranasal malignant lymphoma is described, and previously reported cases are reviewed. A 74-year-old female was hospitalized with the chief complaints of bilateral ptosis and bilateral deep orbital pain that had developed over a 10-day period. Neurological examination revealed bilateral dilated pupils, panophthalmoplegia, and hypalgesia in the area of the ophthalmic nerve on both sides. Laboratory studies and endocrinological examination were free from abnormal findings. Skull X-ray films showed a soft tissue lesion in the sphenoidal and ethmoidal sinus and this was associated with bony structure destruction in the surrounding area. Computed tomography demonstrated a heterogeneously enhanced mass lesion in the paranasal sinus extending into the intrasellar region and bilateral cavernous sinus. Meticulous investigation has so far revealed no distant lesions either in the thoracic or abdominal lesions. Subtotal tumor resection was undergone via the transsphenoidal route at which time tumor extension into the nasal cavity and sellar floor destruction were confirmed. Diffuse and mixed B-cell type malignant lymphoma was the pathological diagnosis. Postoperatively, improvement of abnormalities of pupils, panophthalmoplegia, and ptosis was achieved but this was only transient. Despite focal radiation therapy and repeated chemotherapy, the patient died 14-months after the diagnosis was made. On reviewing the literature, it is shown that the incidence of bilateral panophthalmoplegia among patients who develop disturbance of ocular movement is extremely low (0.4%).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1991

Adaptation of hybridoma cells to higher ammonia concentration.

Using two mouse-mouse hybridoma cell lines, the response to ammonia step and serial changes was investigated in batch and continuous cultures with serum-free medium. The inhibitory effect of ammonia on cell growth depended on the cultivation mode, and differed markedly between cell lines. The cell line, 4C10B6 producing IgG monoclonal antibody against Pseudomonas, showed a high adaptation ability to ammonia. The 4C10B6 cells could grow under ammonia concentration as high as 21 mmol/l NH4Cl with a viability of 80% in the continuous culture with serial increase in ammonia concentration. Whereas, in the batch culture with ammonia step change the cell growth completely ceased at 12 mmol/l NH4Cl. The other cell line, TO-405 producing IgG monoclonal antibody against hepatitis B surface antigen, could not adapt to ammonia, and the cell growth did not occur at 9 mmol/l NH4Cl even under the ammonia serial change.

Ammonium Chloride↗
PubMed1991

Tetrahydrofolic acid as the principal congener of plasma folates in pigs.

Concentrations of pig plasma folates were determined by a high-performance liquid chromatography with an electrochemical detector (HPLC-ECD). Tetrahydrofolic acid (THF) and 5-methyltetrahydrofolic acid (5-MF) were found to be the plasma folates. The concentration of THF (10.3 +/- 4.3 ng/ml) was significantly higher than that of 5-MF (3.5 +/- 1.0 ng/ml). The sum of the THF and 5-MF concentrations determined by the HPLC-ECD analysis in Göttingen miniature pigs was comparable to the total folate concentration of the same plasma sample determined by a radioligand assay. No or only trace amounts of THF were found in the plasma of the rats, mice, rabbits, dogs, cows, horses, or humans. Although 5-MF is generally recognized as the only principal plasma folate in many species, THF may be the principal congener with 5-MF as a secondary congener in the pig.

Animals↗
PubMed1991

Functional imaging of cerebral blood volume using simultaneous measurements of dynamic and xenon computerized tomography (CT).

This report describes a method for measuring regional cerebral blood volume (r-CBV), by simultaneously using dynamic computerized tomography (DCT) and stable Xenon-enhanced CT (Xe CT). Local cerebral blood flow (CBF) was measured using a Xe CT blood sampling method, and mean transit time (MTT) was calculated using DCT after a rapid injection of iodinated contrast material. A functional image of r-CBV was obtained from multiplication of CBF and MTT on each pixel using the formula: CBF x MTT = CBV. This calculated value is not suitable to indicate a r-CBV which directly reflects cerebral microcirculation. Accordingly, only a comparative estimation of relative r-CBV images is applicable. However, laterality of image and comparison of serial studies are useful in hemodynamic evaluations, especially in ischemic cerebrovascular diseases, because they indicate hemodynamic reserve within the hypoperfused region.

Adult↗
PubMed1991

[Optimal hypervolemic therapy for symptomatic vasospasm].

Thirty-five patients with symptomatic vasospasm (SV) following aneurysmal subarachnoid hemorrhage (SAH) were managed according to a method based on hemodynamic manipulation, monitored by Swan-Ganz catheter. Nine out of these had delayed surgery. For those who developed SV, the pulmonary wedge pressure (Pcwp) and/or central venous pressure (CVP) were immediately increased up to the point at which neurological deficit was reversed by rapid injection of fresh frozen plasma, albuminates, low molecular dextrose, and glycerol. On this regimen, patients were closely observed for any neurological change. Then the hemodynamic parameters were maintained as optimal values until they could be reduced below optimal values without reappearance of neurological deficit. In inoperable patients, special attention was given in making a decision about discontinuing the regimen. The results were compared with thirty-seven patients with SV who were treated with conventional hypervolemic therapy (CHT) by continuous administration of albuminates. In the treatment of CHT, optimal values could hardly be established, so the same hemodynamic parameters were applied in all the cases. From this study, in the majority of the cases optimal values were found as follows: Pcwp up to 10-15 mmHg, and CVP below 11 cmH2O. On the contrary, in 20% of patients, neurological deficit was reversed by increasing CVP to a point not above 7 cmH2O. Correlation between neurological reversal and systemic blood pressure was not statistically significant. After this regimen (OHT), 74% of patients showed immediate improvement after volume expansion, and, in 80%, outcome was good, while 20% died. The motor function at the time of discharge was more than 3 on the manual test in all cases.(ABSTRACT TRUNCATED AT 250 WORDS)

Central Venous Pressure↗
PubMed1991

[A case report: abscess of the cavum septi pellucidi].

A rare case of an abscess in the cavum septi pellucidi (CSP) is described and previously reported cases are reviewed. A 60-year-old male was admitted to the hospital because a diagnosis of cerebellar hemisphere infarction was made on CT scan. Seven years earlier, the patient had undergone a craniotomy for aneurysm clipping, and a ventriculo-peritoneal shunt was installed for normal pressure hydrocephalus 14 days after the aneurysmal rupture. On his second hospitalization CT scan also demonstrated CSP but this was not associated with ventriculomegaly. He was placed on a rehabilitation regimen and his hospital course was uneventful. Two months later, however, he developed hyponatremia due to the syndrome of inappropriate secretion of antidiuretic hormone. After analysis of CSF obtained from the shunting device, a diagnosis of meningitis was made and CSF culture revealed E. coli infection. A part of the peritoneal tubing was torn and missing when the tube was removed from the peritoneal cavity and converted to outer drainage. Being treated with intrathecal and intravenous antibiotics administration, the meningitis subsided. However, CT scan taken twelve days after the onset of the infection showed an abscess in CSP which showed ring enhancement after contrast media. Therefore, the patient continued to receive intravenous antibiotics to counter the mass effect due to the abscess. The abscess had disappeared on follow-up CT scan obtained ten days later. The patient, however, eventually expired after iatrogenic hypernatremia associated with acute renal failure. The patient was submitted to an autopsy. The authors speculate that the abscess developed through a retrograde cisternal route after infection which had originated from bowel perforation by the peritoneal shunt tube.

Brain Abscess↗
PubMed1991

[Rapid deterioration of renal function in minimal change nephrotic syndrome].

This report concerns two boys with minimal change nephrotic syndrome progressed to renal failure. The first case aged 17 being a steroid sensitive infrequent relapse developed acute renal failure at his third relapse and recovered soon after the treatment with diuretics and corticosteroids. The second case aged 15 being a steroid dependent frequent relapse became steroid resistant at his 11th relapse and progressed to renal failure seven months later. As the causes of renal failure, acute tubular necrosis and tubular obstruction by casts were suspected in the former. Renal vein thrombosis, morphological transition of renal histology, hemodynamic change and change in glomerular permeability might be occurred in the latter. Renal failure is a rare complication of minimal change nephrotic syndrome and the cause is variable. Precise diagnosis and prompt treatment should be needed to improve the prognosis.

Acute Kidney Injury↗
PubMed1990

Pharmacokinetics, N1-glucuronidation and N4-acetylation of sulfadimethoxine in man.

Sulfadimethoxine is metabolized by O-dealkylation, N4-acetylation and N1-glucuronidation. In man, only N1-glucuronidation and N4-acetylation takes place, leading to the final double conjugate N4-acetylsulfadimethoxine-N1-glucuronide. The N1-glucuronides are directly measured by high pressure liquid chromatography. When N4-acetylsulfadimethoxine is administered as parent drug, 30% of the dose is N1-glucuronidated and excreted. Fast acetylators show a shorter half-life for sulfadimethoxine than slow acetylators (27.8 +/- 4.2 h versus 36.3 +/- 5.4 h; P = 0.013), similarly the half-life of the N4-acetyl conjugate is also shorter in fast acetylators (41.3 +/- 5.2 h versus 53.5 +/- 8.5 h, P = 0.036). No measurable plasma concentrations of the N1-glucuronides from sulfadimethoxine are found in plasma. N1-glucuronidation results in a 75% decrease in protein binding of sulfadimethoxine. N4-acetylsulfadimethoxine and its N1-glucuronide showed the same high protein binding of 99%. Approximately 50-60% of the oral dose of sulfadimethoxine is excreted in the urine, leaving 40-50% for excretion into bile and faeces.

Acetylation↗
PubMed1990

High-performance liquid chromatography of sulphadimethoxine and its N1-glucuronide, N4-acetyl and N4-acetyl-N1-glucuronide metabolites in human plasma and urine.

Sulphadimethoxine is metabolized in humans by N1-glucuronidation and by N4-acetylation. Sulphadimethoxine-N1-glucuronide can be measured by the direct high-performance liquid chromatographic analysis and without enzymic deglucuronidation. The N1-glucuronide can be measured by an isocratic as well as by a gradient mobile phase. The group contribution of the N1-glucuronide moiety to the capacity factor is a reduction of 0.24 in the isocratic system and 0.55 in the gradient system. N4-Acetylation increases the capacity factor by a factor 1.4 in the isocratic system and by 1.06 in the gradient system.

Chromatography, High Pressure Liquid↗
PubMed1990

Oral dosage regimen in the nonlinear pharmacokinetics of sulphadimethoxine in pigs.

An oral high dosage regimen of sulphadimethoxine (SDM) was examined in pigs. The dose (50 mg/kg) in the therapeutic range, showed nonlinear pharmacokinetics, and administered by drench once a day for 4 days. The unbound plasma concentration-time profile was compared with that of the dosage regimen based on nonlinear pharmacokinetics, where a pharmacokinetic model and parameters were used except for the first order absorption rate constant (ka) and bioavailability (F). F and ka were obtained from oral and intravenous administration of 20 and 10 mg/kg of SDM. The unbound plasma concentration was observed almost within the setting range by the dosage regimen through the experimental period. This result suggested that the dosage regimen, based on the nonlinear pharmacokinetic model, resulted in an appropriate effect in the clinical use.

Absorption↗
PubMed1990

The role of plasma protein binding on the metabolism and renal excretion of sulphadimethoxine and its metabolite N4-acetylsulphadimethoxine in pigs.

The effects of plasma protein binding on the elimination of sulphadimethoxine (SDM) were examined after intravenous administration of 6.25, 12.5, 25, 50, 100 and 150 mg/kg to pigs. At an early stage of the experiment, the animals were anaesthetised by inhalation of enflurane to obtain a more exact relationship between plasma concentration and the renal excretion. SDM and its acetylated conjugate, N4-acetylsulphadimethoxine (N4-SDM) were detected in plasma and urine of all animals, and the recovery of the doses was almost complete in two animals with negligible renal excretion of SDM. The percentages of plasma protein binding of SDM and N4-SDM were almost similar, and ranged from 30 to 95%, depending on the plasma concentration. The metabolic clearance of SDM by acetylation increased when the plasma protein binding decreased. These results suggested that the main elimination route of SDM in pigs is acetylation, and that the plasma protein binding can have a large effect on the elimination of SDM in pigs. The effect of plasma protein binding on the renal clearance of SDM was not so evident, because urine pH had a much greater effect on it. The deacetylation of N4-SDM was detected after 25 mg/kg intravenous administration of N4-SDM, which suggests that the metabolic clearance of SDM is part of an acetylation-deacetylation equilibrium. Saturation of the active tubular reabsorption of SDM and of the active tubular secretion of N4-SDM was also suggested after higher doses of SDM.

Acetylation↗
PubMed1990

Use of a chronic ureter cannula in the pig for the determination of renal clearance.

The surgical implantation of chronic ureter cannula to determine the renal clearance was evaluated using 24 pigs. The silicon tubing was surgically implanted into both ureters of each pigs. Two types of thick tubing (the inside diameter 1.0 or 2.5 mm and the outside diameter 4.0 mm) were used for these cannulas. The tubing was exposed out of the pig's body on the flank, on the hypogastric zone near the umbilicus, or near the groin. The following steps were effective to minimize the opportunity of a bacterial infection in the kidney and to maintain the functional integrity of the chronic ureter cannula for as longer period as possible: 1) to use the tubing of larger opening as the ureter cannula, 2) to expose the tubing from the hypogastric zone near the groin, and 3) to apply the disinfectant frequently to the incision sites, cannula outlets and pig's metabolic cage. The oral ingestion of the GGES solution increased the urinary volume, which might in turn have resulted in the effective rinsing of the kidney and the chronic ureter cannula. The cannula served satisfactorily for more than 3 weeks in 13 of the pigs, up to a maximum of 7 weeks. The PSP clearances values were low during the first week of the postoperative period, which may be attributed to surgical stress. The chronic ureter cannula, associated with the postoperative period of more than 1 week, can be recommended for the evaluation of the renal clearance of drugs in the pig.

Animals↗
PubMed1990

Severe glomerulonephritis and tubulo-interstitial nephritis accompanied with urticaria and vasculitis.

We report a 9-year-old girl who developed recurrent urticaria, arthritis and serious renal involvement. She was treated by prednisolone with considerable improvement. Biopsy examinations revealed cutaneous vasculitis and moderate mesangial proliferation with crescents and tubulo-interstitial nephritis on light microscopy. Immunofluorescence study showed IgG, IgM and complement deposits in the mesangium and along the capillary wall. On electron microscopy, electron-dense deposits were identified in the mesangium and paramesangium. Her disease resembled the hypocomplementemic vasculitis syndrome, but her serum complement values were normal throughout the course of the illness. The pathogenesis of her disease is unknown, but it seems to be a sort of systemic immune-complex disease.

Child, Preschool↗
PubMed1989

Effect of albumin distribution. A simulation analysis of the effect of altered albumin distribution on the apparent volume of distribution and apparent elimination rate constant of drugs.

The effects of altered albumin distribution on the apparent volume of distribution (V) and the apparent elimination rate constant (kappa) of drugs were investigated by a simulation analysis. The Equations derived by Oie et al. were modified for this purpose. Within the range observed in normal healthy subjects and patients, the change in albumin distribution significantly affected V of drugs but, in general, not kappa. For drugs with more than 90% plasma-protein binding, V changed by more than 100%. The change in plasma-protein binding caused by an altered albumin distribution produced a greater effect on V than that caused by an altered albumin amount. These results suggest that albumin distribution is an important factor in controlling the kinetics of drugs which are highly bound to plasma protein. This is illustrated using midazolam as an example.

Blood Proteins↗