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Biomedical subjects

M Suehiro

Publications and source records attributed to M Suehiro.

At least 19 recordsLinked to original sources
PubMed1992

Myocardial uptake of antimyosin antibody compared with serum myosin light chain I levels in patients with myocardial infarction.

Myocardial accumulation of In-111-antimyosin (InAM) was evaluated in comparison with circulating serum myosin light chain I (LCI) level at the time of InAM injection. Seventeen consecutive patients were studied at various stages ranging from 6 days to 34 days after myocardial infarction (MI). The infarct area was positive for InAM uptake in all patients (100%), and significant myocardial uptake was observed in 14 patients (82.4%). The intensity of InAM uptake correlated with the infarct location shown by ECG and CAG. In contrast, 12 patients (70.6%) had normal or undetectable serum myosin LCI levels, with 5 being normal (0.42-2.5 ng/ml) and 7 undetectable (0.42 ng/ml or less). Only 5 patients (29.4%) had elevated serum myosin LCI levels at the time of InAM injection, and this elevation was slight, ranging from 3.4 to 4.5 ng/ml (mean: 3.75 ng/ml). Among patients with undetectable, normal, and elevated serum myosin LCI levels, there was no significant correlation between InAM uptake and the serum myosin LCI level. Thus, even after the serum myosin LCI level has decreased to normal, InAM can still bind to cardiac myosin in patients with MI, presumably until there is complete recovery from the hibernating myocardium due to ischemic damage.

Adult↗
PubMed1992

Serum thymidine kinase, a possible marker for monitoring the effect of bone marrow transplant treatment in early recovery phase.

We measured serum thymidine kinase (TK) activity with a radioenzyme assay system employing [I-125]-iododeoxyuridine as the tracer on serial specimens from five bone marrow transplant (BMT) patients before and after transplantation. The serum level of TK activity in the 4 patients with effective BMT treatment ranged from 3.0 to 16.9 U/L (mean, 7.80 U/L) before transplantation and from 27.3 to 236.1 U/L (mean, 82.95 U/L) after the BMT treatment. Mean serum TK activity increased 13.17-fold (range, 1.68 to 29.14-fold). In contrast, the activity in the patient with ineffective BMT treatment was not significantly different during, before, or after BMT treatment. In addition, serum TK activity in BMT patients was well correlated with the change in the number of leukocytes before and after BMT treatment [r = +0.709 (p less than 0.01), y = 0.012 x +0.87]. We conclude that the determination of serum TK activity in BMT patients is very useful in monitoring the course of bone marrow transplantation in the early recovery phase.

Adolescent↗
PubMed1992

Localization of hyperfunctioning parathyroid glands by means of thallium-201 and iodine-131 subtraction scintigraphy in patients with primary and secondary hyperparathyroidism.

The accuracy of the preoperative localization of hyperfunctioning parathyroid glands by subtraction scintigraphy with 201Tl and 131I was evaluated by comparison with the operative findings. The subjects were 67 consecutive patients with hyperparathyroidism (HPT), including 24 with primary and 43 with secondary HPT. In primary HPT, surgery revealed 26 adenomas weighing 0.26-15.80 g (mean +/- SD; 3.01 +/- 3.04 g). Two patients had double adenomas. Scintigraphy correctly localized 25/26 adenomas (96.2%) in primary HPT for a sensitivity, specificity, and accuracy of 96.2%, 98.5%, and 97.9%, respectively. In secondary HPT, 163 hyperplastic glands weighing 0.03-5.08 g (0.85 +/- 0.93 g) were found. Scintigraphy correctly localized 79 glands (48.5%) weighing 0.03-5.08 g (1.19 +/- 1.10 g), but 84 glands (51.5%) weighing 0.04-2.70 g (0.51 +/- 0.50 g) were not detected. Thus, the sensitivity, specificity, and accuracy of scintigraphy were respectively 48.5%, 100%, and 51.2%, in secondary HPT. These results show that scintigraphy with 201Tl and 131I can be used to locate abnormal parathyroid glands with an efficacy equal to or better than that of the conventional methods with 201Tl and 99mTc or 201Tl and 123I.

Adenoma↗
PubMed1992

Synthesis and biodistribution of a new radiotracer for in vivo labeling of serotonin uptake sites by PET, cis-N,N-[11C]dimethyl-3-(2',4'-dichlorophenyl)-indanamine (cis-[11C]DDPI).

A new PET radiotracer for in vivo labeling of serotonin (5-HT) uptake sites, cis-N,N-[11C]dimethyl-3-(2',4'-dichlorophenyl)-indanamine, cis-[11C]DDPI, was synthesized and its biological behavior was studied. The radiosynthesis of cis-[11C]DDPI was performed by N-methylation of cis-N-methyl-3-(2',4'-dichlorophenyl)-indanamine with [11C]iodomethane. The average radiochemical yield was approx. 8%, with an average specific activity of 600 mCi/mumol. Following intravenous administration, cis-[11C]DDPI accumulated in mouse brain regions rich in 5-HT uptake sites, such as olfactory tubercles, hypothalamus and frontal cortex. Following pre-injection of 1 mg/kg of paroxetine, a high affinity 5-HT uptake blocker, the binding of cis-[11C]DDPI in the olfactory tubercles, hypothalamus and frontal cortex was decreased by 23, 25 and 16%; this corresponds to 73, 82 and 59% of the specific binding in these regions. These results suggest that the accumulation of cis-[11C]DDPI in the tissues rich in 5-HT sites is a result of specific binding of cis-[11C]DDPI to 5-HT uptake sites. Due to the relatively high non-specific uptake and slow clearance of this compound from non-specific binding sites, the ratio between specific and non-specific binding increased slowly with time, reaching 1.5:1 at 60 min after injection.

Animals↗
PubMed1992

[Fundamental evaluation of ELSA.F-beta HCG kit as an immunoradiometric assay specific for serum beta HCG].

We evaluated ELSA.F-beta HCG kit as an immunoradiometric assay (IRMA) specific for serum beta human chorionic gonadotropin (beta hCG). This IRMA was found to be highly sensitive to serum beta hCG; the minimum detectable concentration of beta hCG was 0.05 ng/ml. No significant effects on the standard curves were observed when first and second incubation time and temperature were varied from 30 min to 240 min and from 4 degrees C to 37 degrees C, respectively. Commercial LH, FSH, and TSH had little effect on the assay system; the cross-reactivity of commercial hCG was 2.5%, and 0.14% after unconjugated beta hCG with alpha-subunit was absorbed with ELSA-tube. Multiple dilutions of sera of pregnancy resulted in curves paralleling that obtained using standard beta hCG; the recovery of beta hCG added to the serum was 98.1 +/- 2.5% (mean +/- SD), and mean coefficient of variation of the interassay reproducibility of serum beta hCG (n = 10) was 6.7 +/- 2.8 (SD)%. Serum beta hCG concentration measured using ELSA.F-beta HCG kit was well correlated with that measured using conventional beta hCG RIA kit (r = +0.961, p less than 0.01), although values were lower than those measured with the latter (y = 0.35x + 0.26). Our results suggest that ELSA.F-beta HCG kit is a useful assay system for serum beta hCG.

Chorionic Gonadotropin↗
PubMed1991

Detection of bile leakage into the thoracic cavity by hepatobiliary scintigraphy.

We report early detection of bile leakage into the thoracic cavity by hepatobiliary scintigraphy in a rare case of spontaneous withdrawal of the catheter for percutaneous transhepatic cholangiographic drainage (PTCD). An 81-year-old man with inoperable carcinoma of the common bile duct was readmitted with a 38 degrees C fever and suspected bile leakage from the hepatic biliary tree following withdrawal of the catheter for PTCD. While plain X-ray immediately after readmission revealed no abnormality in the chest or abdomen, hepatobiliary scintigraphy revealed not only bile leakage into the right thoracic cavity but also the site of laceration. We conclude that hepatobiliary scintigraphy is a simple, non-invasive procedure useful in the early detection and localization of bile leakage following spontaneous withdrawal of the catheter for PTCD.

Aged↗
PubMed1991

Radiosynthesis and evaluation of N-(3-[18F]fluoropropyl)paroxetine as a radiotracer for in vivo labeling of serotonin uptake sites by PET.

To visualize serotonin uptake sites by positron emission tomography (PET), N-(3-[18F]fluoropropyl)-paroxetine ([18F]FPP), a derivative of the selective serotonin uptake blocker paroxetine, was synthesized from 3-[18F]fluoropropyltosylate and paroxetine via a one-pot procedure. The rate of formation of [18F]FPP was a function of the ratio of the initial amount of paroxetine to that of 1,3-propanediol bistosylate with which [18F]fluoropropyltosylate was synthesized. When the reaction mixture contained an excess amount of paroxetine over that of the propyl-bistosylate, the radiosynthesis followed by HPLC purification, which took approx. 90 min, gave [18F]FPP in a radiochemical yield of approx. 8%, and in high radiochemical and chemical purity. The specific activity was 2640 +/- 360 mCi/mumol. The brain biodistribution of [18F]FPP showed no distinguishable localization in regions with high density of serotonin uptake sites such as hypothalamus or olfactory tubercles. In vitro binding assays revealed that N-fluoropropylation of paroxetine reduced the affinity for the serotonin uptake site by three orders of magnitude.

Animals↗
PubMed1990

Bromination, no-carrier-added radiobromination and simultaneously-occurring chlorination by chloramine T.

Factors regulating initial rates of bromination, no-carrier-added radiobromination and simultaneously-occurring chlorination by chloramine T were studied using a neuroleptic drug spiperone as the substrate. Besides the factors such as initial concentrations of chloramine T, substrate and bromide ions, upon which the rates were dependent in first, second or zero-order, the water-acetic acid composition or the hydrogen ion concentration of the solutions, where the reactions took place, was found to play a key role. By controlling these factors, optimal radiobromination conditions, where radiobromination proceeds effectively whilst simultaneously-occurring chlorination is kept from proceeding at a high rate, thus resulting in radiobrominated radiopharmaceuticals of high specific activity (10 Ci/mumol) and high radiochemical and chemical purity, could be fulfilled.

Bromine↗
PubMed1990

[Effects of an increase or decrease in the middle ear pressure on tympanic membrane vibrations (experimental study by holographic interferometry)].

The effects of positive and negative pressure in the middle ear on tympanic membrane (TM) vibrations were studied in twenty canine temporal bones by holographic interferometry. The displacement of the TM was measured by moiré topography. 1) When pressure was applied to the tympanic cavity, the curvature of the TM became small under negative pressure and large under positive pressure, with the displacement being greater under positive pressure. 2) Without pressure load, the vibration pattern below 2 kHz was simple and there were peak displacement regions in the posterior and anterior parts of the membrane and the peaks occurred approximately halfway along the manubrium. The TM vibrations showed sectional patterns, above 3 kHz in the posterior and above 4 kHz in the anterior. The amplitude of the anterior peak was larger than that of the mallear tip, but smaller than that of the posterior. 3) At frequencies below 2 kHz, the vibration pattern was not affected by negative pressure load. At frequencies of 3 kHz or higher, the sectional patterns changed into the simpler patterns and the sectional vibrations diminished as the pressure increased. 4) Below 2 kHz, the TM amplitude decreased with increasing negative pressure. Above 3 kH, the amplitude showed an initial increase but decreased at higher negative pressure loading. With the amplitude of the mallear tip, the same tendency was observed. The resonance frequency shifted to a higher frequency range with pressure loading. 5) Under positive pressure, the vibration pattern remained unchanged below 2 kHz, and above 3 kH, sectional vibrations changed to the simple vibrations.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

In vivo labeling of the dopamine D2 receptor with N-11C-methyl-benperidol.

A new dopamine D2 receptor radiotracer, N-11C-methyl-benperidol (11C-NMB), was prepared and its in vivo biologic behavior in mice and a baboon was studied. Carbon-11-NMB was determined to bind to specific sites characterized as dopamine D2 receptors. The binding was saturable, reversible, and stereospecific. Kinetic studies in the dopamine D2 receptor-rich striatum showed that 11C-NMB was retained five times longer than in receptor-devoid regions, resulting in a high maximum striatal-to-cerebellar ratio of 11:1 at 60 min after injection. From frontal cortex and cortex, on the other hand, the tracer washed out as rapidly as it did from cerebellum, resulting in tissue-to-cerebellar ratios close to one in these regions at any time after injection. Blocking studies confirmed the specificity and selectivity of the 11C-NMB binding to the dopamine D2 receptor. A PET study with 11C-NMB of the baboon brain revealed highly selective labeling of dopamine D2 receptor sites which was blocked by preinjection of raclopride.

Animals↗
PubMed1988

Abnormal 13C-fatty acid breath tests in patients treated with valproic acid.

Breath tests using fatty acids labeled with a stable isotope (carbon 13) were carried out on epileptic patients treated with valproic acid in order to detect abnormal fatty acid metabolism. The patients were given 13C-octanoic acid or 13C-palmitic acid orally, and expired air was collected at appropriate intervals for the analysis of 13CO2 content by a mass spectrometer. Eight patients were tested in the palmitic acid breath test and nine patients in the octanoic acid breath test. Controls for these tests were patients treated with antiepileptic drugs other than valproic acid and unmedicated cerebral palsy patients. In the valproic acid-treated group, 13C recovery was reduced by 56% in seven hours on the 13C-palmitic acid breath test, while the octanoic acid breath test showed a 52% reduction in one hour. This suppression of fatty acid oxidation was significantly correlated with dose of valproic acid in both tests. No influence of other drugs was detected, and the effect of administered carnitine was not conclusive. This study demonstrates the usefulness of 13C-labeled fatty acid breath tests in clinical practice.

Adolescent↗
PubMed1987

[13C]methacetin breath test for evaluation of liver damage.

Methacetin undergoes rapid O-dealkylation by hepatic microsomal enzyme systems, and the resultant CO2 is present in the expired air. The rate of O-dealkylation of methacetin was assessed by the [13C]methacetin breath test in seven healthy volunteers and 30 patients with histologically proven chronic liver diseases. The 30-min recovery of orally administered [13C]methacetin as 13CO2 in the exhaled air was significantly reduced in patients with chronic aggressive hepatitis and in those with liver cirrhosis but not in patients with chronic persistent hepatitis or healthy controls. Patients with either advanced cirrhosis or hepatocellular carcinoma showed significantly lower values than those with well-compensated cirrhosis. The levels in two patients with late primary biliary cirrhosis were reduced. These results show that the severity of liver damage can be effectively evaluated by [13C]methacetin breath test. In addition, this test is simple, safe, and time efficient.

Acetamides↗
PubMed1987

Automated 13CO2 analyzing system for the 13C breath test.

An automated 13CO2 analyzing system for the 13C breath test was designed, built and evaluated. The system, which was designed to be controlled by a micro-computer, includes CO2 purification, 13CO2 abundance measurement, data processing and data filing. This article gives the description of the whole system with flow charts. This system has proved to work well and it has become feasible to dispose of 5 to 6 CO2 samples per hour. With such a system, the 13C breath test will be carried out much more easily and will obtain much greater popularity.

Autoanalysis↗
PubMed1984

Somatostatin-like immunoreactivity in rat thyroid. Age-associated S-cell hyperplasia.

Somatostatin-like immunoreactive cells of the rat thyroid gland at various ages were investigated immunohistochemically. The number of cells per lobe in 5 micron sections increased with age. Immunopositive cells were evident as small clusters in the older age group (8 to 24 months old) but not clustered in the younger age group (3 to 5 months old). This type of proliferation was termed S-cell hyperplasia in a manner similar to C-cell hyperplasia observed in the aged rat thyroid.

Aging↗