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Biomedical subjects

H Fukuda

Publications and source records attributed to H Fukuda.

At least 1,351 records · Page 75Linked to original sources
PubMedDate not supplied

Results of surgical treatment for squamous carcinoma of the lower alveolus: segmental vs. marginal resection.

The records of 53 patients treated surgically for squamous cell carcinoma of the lower alveolar ridge were reviewed and the results of segmental and marginal resections of the mandible were compared. Analysis of these 2 treatment modalities disclosed that marginal resection was effective in controlling lower gingival cancers, with and without apparent bone involvement, if erosive bone defects that did not extend beyond the inferior alveolar canal, or invasive bone defects confined to a superficial area of the alveolar bone, were detected radiologically.

Adult↗
PubMedDate not supplied

Thyroid nodules: clinical effect of ultrasound-guided fine-needle aspiration biopsy.

Ultrasound (US)-guided fine-needle aspiration biopsy (FNA) was performed on 268 thyroid nodules (135 palpable, 133 nonpalpable) in 210 patients with various thyroid conditions; 62 nodules also had palpation-guided FNA. Surgical pathology was obtained in 67 malignant nodules and 32 benign nodules. Although the initial failure rate for palpation-guided FNA (12 of 62) was significantly higher than that for US-guided FNA (10 of 268) (p < 0.001), sensitivity (96%), specificity (91%), accuracy (94%), and positive (96%) and negative predictive values (91%) of US-guided FNA for malignancy (n = 99) were not significantly different from those (88%, 90%, 88%, 95%, and 75%, respectively) of palpation-guided FNA (n = 34) for those nodules where an adequate biopsy was obtained. US-guided FNA established a correct diagnosis in 20 of 22 patients with nonpalpable malignancy and in another nodule in the opposite thyroid lobe in 16 of 17 patients with thyroid malignancy. This procedure determined the correct cancer staging in 19 of 21 patients. US-guided FNA can reliably (1) select a patient who needs surgery and (2) avoid unnecessary surgery. This technique will help determine a cancer staging and institute an appropriate treatment.

Adolescent↗
PubMedDate not supplied

Thyroid nodules: re-evaluation with ultrasound.

The purpose of this study was to clarify ultrasound (US) evaluation of microcalcifications and determine whether the calcifications seen in US scans can reliably predict malignant thyroid tumors. Diagnostic accuracy of microcalcification and other various signs seen in US scans for predicting malignancy was evaluated prospectively in 259 pathologically verified thyroid nodules. Sonographic and pathologic correlation of calcifications was performed on 69 of 99 surgically removed nodules. Pathologic studies revealed that hyperechoic areas with acoustic shadowing represented mostly amorphous dense calcifications and sometimes microcalcifications, but small particles without acoustic shadowing mainly reflected microcalcifications and sometimes large amount of fibrous bands and condensed colloids. Of the various sonographic signs, microcalcification showed the highest accuracy (76%), specificity (93%), and positive predictive value (70%) for malignancy as a single sonographic sign, but its sensitivity (36%) was poor. Although sonographic microcalcification showed relatively high specificity, the accuracy of this finding for malignancy was insufficient.

Adenoma↗
PubMedDate not supplied

The role of central serotoninergic and noradrenergic neurons in the regulation of nyctohemeral rhythm of plasma thyrotropin.

A possible participation of central serotoninergic or noradrenergic neurons on nyctohemeral periodicity of plasma TSH concentration was studied in the rat. Control rats exhibited normal nyctohemeral fluctuations of plasma TSH characterized by high AM (09:30) and low PM (18:30) values (397 +/- 45 vs. 207 +/- 28 ng/ml, p < 0.01). The daily ip administration of p-chlorophenylalanine (p-CPA, 100 mg/kg body weight) for 7 days produced significant decreases in plasma TSH concentration and hypothalamic TRH content in the AM. However, these parameters in the PM were unaffected by p-CPA administration. An inhibition of serotoninergic activity thus abolished nyctohemeral periodicity in plasma TSH by lowering only AM values (AM:253 +/- 32 vs. PM:236 +/- 30 ng/ml, p > 0.1). On the other hand, intraventricular administration of 6-hydroxydopamine (6-OHDA, 250 micrograms/rat), a drug able to deplete noradrenaline and possibly dopamine, had no appreciable effect on AM-PM fluctuations of either plasma TSH or hypothalamic TRH content. The rate of elevation of plasma TSH after thyroidectomy was not significantly different in p-CPA or 6-OHDA treated rats compared to the respective controls, suggesting that there is no significant contribution of these biogenic amines to feedback control of TSH secretion by thyroid hormones. The present study suggests that the nyctohemeral periodicity of pituitary TSH secretion can be produced by cyclic activation of hypothalamus brought about by the increased input of serotoninergic neurons in response to the periodicity of certain environmental cues and that central noradrenergic or dopaminergic neurons are not involved in this system.

Animals↗
PubMedDate not supplied

The chloride-dependent depression by GABA in the frog spinal cord.

Spontaneous activities from ventral and dorsal roots of the isolated perfused spinal cord of the bullfrog were inhibited by GABA. beta-Alanine showed a strong and glycine a weaker inhibitory effect. The inhibitory effect of GABA was markedly reduced in a chloride-free medium, whereas glycine and beta-alanine still showed an inhibitory effect similar to that seen in normal medium. Employing the sucrose-gap method, a marked depolarization in the dorsal root and a small but obvious hyperpolarization in the ventral root were found by the application of GABA. These results support the view that GABA is one of the transmitters involved in pre- and postsynaptic inhibition of the spinal cord. The postsynaptic hyperpolarizing effect of GABA on motoneurones would be caused directly through increased permeability of the membrane to chloride ion. The depolarizing effect of GABA on primary afferent terminals is discussed in connection with chloride dependency.

Alanine↗
PubMedDate not supplied

Oral hygiene reduces respiratory infections in elderly bed-bound nursing home patients.

In the elderly, aspiration is a common and serious problem. A procedure to minimize respiratory infections caused by silent aspiration was conducted on elderly bed-bound nursing home patients who suffered mainly from cerebral infarction and dementia. Oral care was provided by a dentist and a dental hygienist once a day and the mouth cleansed with povidone iodine by nurses after each meal to restrict respiratory bacterial infection caused by silent aspiration. In period I, neither group of patients received particular care. In period II, the A group was orally cared for and the B group was not cared for. In period III, the A group was not cared for and B group was cared for. During oral treatment for 6 months, febrile days did not improve but degradation of febrile days were prevented by oral care in a limited number of patients. We suggest that oral care may be useful to some extent in elderly patients to prevent respiratory infections.

Journal Article↗
PubMedDate not supplied

The P300 event-related potentials in dementia of the Alzheimer type. Correlations between P300 and monoamine metabolites.

We studied auditory event-related potentials (ERPs) in 40 patients with dementia of the Alzheimer type (DAT). Peak latencies and amplitudes of N100, P200 and P300 components were measured. To study the possible relationships between the ERPs and monoaminergic neurotransmitter functions, CSF neurotransmitter metabolites were also analyzed. In patients with DAT, the P300 amplitude was significantly reduced and the P300 latency was prolonged. CSF concentrations of 5-hydroxyindoleacetic acid (5-HIAA) and homovanillic acid (HVA) were decreased. The P300 amplitude was significantly correlated with the 5-HIAA concentration. There were no correlations between the P300 components and the HVA concentration. These findings suggest that the serotonergic system modulates the P300 component of ERPs in patients with DAT.

Adult↗
PubMedDate not supplied

Response of the human larynx to silicone.

This report is concerned with tissue reaction to silicone and, in particular, long-term foreign body reaction. A histopathologic study was done on the larynx of a patient who had been injected 12 years before in the right vocal fold with room temperature vulcanizing silicone. The examination revealed particles of silicone encapsulated by thin fibrous tissue. There were few giant cells of the foreign body type and little cell infiltration. In addition, a questionnaire was returned by 54 of 90 patients who had vocal fold injected with less than 1.5 mL of either silicone fluid or room temperature vulcanizing silicone in the vocal fold from 1977 to 1984. Of these 54 patients, there was no occurrence of laryngeal disease, carcinoma, and/or connective tissue disease after the silicone injection. These findings attest to the safety of silicone in the small amounts used to treat vocal cord paralysis.

Foreign-Body Reaction↗
PubMedDate not supplied

Voice prognosis after liquid and solid silicone injection.

A study was undertaken to determine the voice prognosis in 51 of the 408 patients with unilateral recurrent laryngeal nerve paralysis who had visited the Department of Ear, Nose and Throat at Keio University between 1977 and 1984. The 51 patients were divided into three groups: 18 patients without silicone injection, 15 with a silicone liquid implant, and 18 with a silicone solid implant. Data are provided to show that (1) both types of silicone implant are tolerated by the body and effective in improving voice and that (2) the liquid implant is ultimately absorbed and therefore useful for temporary voice improvement in patients in whom the prognosis for vocal fold paralysis is not known, whereas the solid implant is not absorbed and is therefore effective in the long term when recovery can be ruled out.

Adult↗
PubMedDate not supplied

S-adenosyl-L-methionine: its effect on aminolevulinate dehydratase and glutathione in acute ethanol intoxication.

The effect of disulfiram and S-adenosyl-L-methionine (SAM) administration to acute ethanol intoxicated mice on the hepatic glutathione (GSH) concentration and aminolevulinic and dehydratase (ALA-D) activity was investigated. It was found that both GSH levels and ALA-D activity were decreased, and evidence suggested that the toxic action of ethanol was due to its conversion into acetaldehyde. Administration of SAM reverses the effects of acute alcohol abuse by increasing liver GSH availability. In vitro, hepatic ALA-D activity was not modified by ethanol; instead it was non-competitively inhibited by acetaldehyde. This inhibition was efficiently reversed by GSH and cysteine (CySH). Therefore, a mechanism for the action of ethanol on ALA-D, based on the inhibitory effect of acetaldehyde, is proposed.

Acetaldehyde↗
PubMedDate not supplied

Age-related changes in cerebral white matter measured by computed cranial tomography.

Changes in the cerebral white matter in relation to aging were studied quantitatively by computed cranial tomography (CT) in 70 healthy subjects aged 30 to 94 years. There were no age-related changes in the CT number of the white matter (WMCT) in 41 younger subjects aged 30 to 65 years. But, there was a significant negative correlation between age and the WMCT in 29 elderly subjects aged 66 to 94 years. Brain atrophy was significantly correlated with the WMCT. The WMCT decreased with aging even in neurologically healthy elderly persons.

Adult↗
PubMedDate not supplied

Acute and chronic intracerebroventricular morphine infusions affect long-term potentiation differently in the lateral perforant path.

Experiments were performed to investigate the effects of acute and chronic intracerebroventricular (icv) morphine infusions via osmotic minipumps on long-term potentiation (LTP) in the lateral perforant path (LPP)-granule cell synapse of the rat dentate gyrus. Although significant antinociceptive activity was observed when morphine was infused (25 nmol/microl/h) for 30 min or 1 h, the activity was not observed in rats receiving morphine chronically for 72 h, and the tail-flick latency of this group was comparable to that of rats receiving saline. LTP induction was significantly attenuated after acute morphine infusion (1 h) in LPP-granule cell synapses of the dentate gyrus. In contrast, LTP induction was augmented after chronic morphine infusion for 72 h. Bath-perfused morphine augmented the baseline population spike (PS) amplitude in rats treated with saline, whereas it attenuated the LTP induced by chronic morphine infusion. Returning the LTP to the level of saline infusion after in vitro morphine perfusion suggests that enhancement of the LTP is a withdrawal-like phenomenon. These results suggest a difference between the effects of acute and chronic intracerebroventricular morphine infusions on synaptic plasticity in the LPP-granule cell synapses of the dentate gyrus.

Analgesics, Opioid↗
PubMedDate not supplied

Reorganization of myosin in surface-activated spreading platelets.

To study the localization of myosin in platelets, we utilized polyclonal antibody to heavy chain of platelet myosin. Both immunofluorescence and indirect immunogold staining techniques were employed. (1) In the unactivated platelets, myosin was distributed homogeneously throughout the cytosol. The cytosolic myosin was removed after platelets were treated with Triton X-100. The association of myosin with actin microfilaments in unactivated platelets was minimal. (2) In the surface-activated platelets, myosin was unextractable by Triton X-100. The myosin antibody heavily decorated the actin cable-networks which characterized the activated platelets. (3) In the Triton-unextractable cytoskeleton of both unactivated and activated platelets, we found fine fibrils (about 1-nm wide) that were often associated with immunogolds. These fibrils were similar to purified myosin molecules observed in rotary-shadowed metal replicas and ultrathin sections. These results indicate that cytosolic myosin becomes associated with actin cable-networks after the activation of platelets.

Blood Platelets↗
PubMedDate not supplied

Affinity purification of fusion chaperonin Cpn60-(His)(6) from thermophilic bacterium Bacillus strain MS and its use in facilitating protein refolding and preventing heat denaturation.

The cpn60 gene from Bacillus strain MS, which is highly homologous to Bacillus stearothermophilus, was cloned. Cpn60 with a hexahistidine affinity tag (His)(6) fused to its C-terminus (cpn60-(His)(6)) was overproduced in Escherichia coli. Cpn60-(His)(6) was expressed in a soluble form in E. coli. and purified to homogeneity in a single step by nickel chelate affinity chromatography. Cpn60-(His)(6) formed a tetradecamer and had ATPase activity. Cpn60-(His)(6) mediated refolding of guanidine hydrochloride unfolded pig heart malic dehydrogenase (MDH) and Thermus flavus MDH at 25 and 70 degrees C, respectively, in an ATP-dependent manner. In addition, cpn60-(His)(6) prevented heat denaturation of pig heart MDH and T. flavus MDH at 30 and 80 degrees C, respectively, in an ATP-dependent manner. Therefore, cpn60-(His)(6) facilitates protein refolding and prevents heat denaturation of proteins across a wide temperature range.

Bacillus↗
PubMedDate not supplied

Nanometric patterning of zinc by optical near-field photochemical vapour deposition.

A new technique, optical near-field photochemical vapour deposition (NFO-PCVD) enables maskless production of nanometric structures with controllable size, chemical composition and morphology. By placing a near-field optical microscope inside the reaction chamber for photochemical vapour deposition we have deposited nanoscale metal patterns. We demonstrate for the first time, successfully deposited in the near-field region, lines of metallic zinc with the observed stripe width of 20 nm.

Journal Article↗
PubMedDate not supplied

Expression of apoptosis in placentae from mice lacking the prostaglandin F receptor.

This study aimed to investigate the changes in apoptosis in the placenta and decidua of pregnant mice lacking the prostaglandin F receptor. Mouse placentae were removed from fetuses on days 10-23 of pregnancy. Apoptotic cells were examined by a DNA fragmentation assay and the terminal deoxynucleotidyl transferase-mediated dUDP nick end-labelling (TUNEL) technique. The placenta and decidual weight increased before day 18 and 14 of pregnancy, and then decreased with gestational day. After day 19, the fetuses gradually died in the uterus. All fetuses died in the uterus on day 23 of pregnancy. The number of apoptosis was not significantly different between wild type and FP-deficient mice before day 18 of pregnancy by DNA fragmentation and TUNEL staining. The DNA fragmentation was always more pronounced in decidual tissue on each day of pregnancy. DNA laddering on placentae was more extensive on day 22 than day 18. In placenta, most TUNEL-positive cells were detected in trophoblast and stromal cells. A higher intensity of apoptotic cells was in the decidual basalis. The main area was the centre of the decidual basalis, and was in decrease toward to margin of placenta. The index of TUNEL positive cells increased as gestation progressed toward termination. Especially, it was prominent in the placentae on day 22 compared with that day 18 of pregnancy. The increased TUNEL-positive staining in syncytiotrophoblast surface was found in placenta at post-term, compared with those at term. Apoptosis may provide insights into both normal placental development and placental dysfunction during an abnormal pregnancy from post-term pregnancy.

Animals↗