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Biomedical subjects

S Hashimoto

Publications and source records attributed to S Hashimoto.

At least 1,639 records · Page 91Linked to original sources
PubMedDate not supplied

Histochemical study of human cremaster in varicocele patients.

Despite the cremaster's important role in thermoregulation, few morphological and biochemical studies of this muscle in humans have been reported, probably due to limitation of sampling. To gain further insight into the pathology of varicocele, the authors studied the histochemical changes of the cremaster from patients with varicocele. Cremaster was obtained from patients with male infertility and varicocele, grades 1-3. The samples were studied using routine histochemical stains. Fiber size variability and type I predominance were observed in all varicocele cases regardless of the grade, and also in control specimens. Muscle from patients with grades 2 and 3 varicocele showed small group atrophy. It would appear that the hemostasis associated with local tissue edema and hypoxemia may lead to nerve damage and denervation of the cremaster. If denervation of the cremaster persists despite the correction of varicocele, thermoregulation would remain disrupted.

Abdominal Muscles↗
PubMedDate not supplied

Extramedullary plasmacytoma of the sinonasal cavities: CT evaluation.

Computed tomography was performed in four patients with solitary extramedullary plasmacytoma of the nasal cavity and paranasal sinuses. Two tumors originated in the nasal cavity, one in the maxillary sinus, and one in the frontal sinus. Soft tissue mass(es) was seen in all patients. Bone destruction was apparent in only two patients. It seems possible to rule out carcinomas in such patients with no or subtle bony destruction. Computed tomography was also helpful for planning radiation therapy.

Adult↗
PubMedDate not supplied

Holography of 3D surface reconstructed CT images.

A multiplex hologram (cylindrical holographic stereogram) was successfully made from three-dimensional (3D) surface reconstruction CT images of a child with plagiocephaly. This method appears to be suitable as one of the projectional aids of 3D surface reconstruction CT images that are proving useful in plastic and reconstructive surgery. The principle of the method is described. Also discussed is the possibility of developing a computer-aided hologram synthesizing system that could be used for images obtained with U-arm X-ray equipment (by either cinefilm, or videotape, or digital subtraction angiography) or by CT as well as MR. For practical use, it is necessary for the hologram to be synthesized in a short time. One of the key problems in developing such a machine is the need for an incoherent-to-coherent image converter.

Child↗
PubMedDate not supplied

Electrophysiological effects of amiodarone on isolated rabbit heart muscles.

We studied the electrophysiological effects of amiodarone on isolated rabbit heart muscles by conventional microelectrode techniques. It significantly suppressed not only sinus node functions (basic cycle length, sinus recovery time, and corrected sinus recovery time) but also atrioventricular node functions (AH interval, effective refractory period, and functional refractory period) by both superfusion (10 micrograms/ml amiodarone in Tyrode solution) and long-term oral administration (50 mg/day for 2 weeks, then 25 mg/day for 4-6 weeks). On the other hand, oral administration significantly lengthened the action potential duration and effective refractory period of the left atrium and the right ventricle, while superfusion did not. The maximum rate of depolarization, action potential amplitude, and diastolic resting potential were not changed by either route of administration. It is thought that the action of amiodarone on the sinus node and on the atrioventricular node is mainly due to its noncompetitive sympathetic inhibition, and that its action on the left atrium and on the right ventricle is mainly due to reduction of serum triiodothyronine, which requires long-term administration of amiodarone.

Action Potentials↗
PubMedDate not supplied

Simultaneous determinations of Fe, Cu, Zn, and Br concentrations in human tissue sections.

Proton-induced x-ray fluorescence has been used to determine the concentration of trace elements in human prostate and liver tissue samples. Ca, Fe, Cu, and Zn were observed in all specimens. Small amounts of Br were detected in most of the prostates, and in nearly half of the livers. The data indicate that the Fe content decreases in malignant liver tissues and the quantities of Cu and Zn are also decreased, but to a lesser extent.

Adenoma, Bile Duct↗
PubMedDate not supplied

Pineal effects on adrenal medulla, area postrema and brain water content in relation to intracranial surgery.

We aimed to explore whether and how the pineal influences the adrenal medulla, the area postrema and the brain water content; and is influenced by sham pinealectomy (SPX) in its structures and melatonin secretion. Quantitative morphological methods were mainly used in rats and golden hamsters. Experimental results showed: (1) Pineal effects on the A cell system of the adrenal medulla were inhibitory to the synthesis and secretion of epinephrine into the perivascular space and stimulatory to the opioid synthesis, and augmented by SPX. Time-of-day changes were also influenced by SPX and PX. (2) The sizes of a part of the nuclei of nerve and glia cells in the area postrema and the brain water content increased by SPX depending on the presence of the pineal, suggesting the pineal's stimulatory effects on these following SPX. (3) SPX caused morphological changes suggesting an increased activity of pinealocytes. However, corresponding consistent increases in plasma melatonin levels were not seen following SPX. Possible interpretations of these observations were discussed.

Adrenal Medulla↗
PubMedDate not supplied

Light and plasma melatonin rhythm in humans.

Plasma melatonin rhythm in humans was investigated: its stability, relationship to the sleep-wake rhythm, and response to light. The so-called day-to-day variation of reference phases of plasma melatonin rhythm was within 1.4 h when blood was sampled at 1-hour intervals. Therefore, a change in phase beyond this value is regarded as a phase shift of melatonin rhythm in individuals. Plasma melatonin rhythm was spontaneously desynchronized from the sleep-wake rhythm and probably regulated by the common circadian pacemaker which drives the rhythm in rectal temperature. When a bright-light pulse was applied, the melatonin rhythm produced a phase shift, but the amount of phase shift seems to be different for the ascending and descending phases of nocturnal melatonin rise. Finally, a partial entrainment was observed in a subject who developed a non-24-hour sleep-wake syndrome later, in which the plasma melatonin rhythm was free-running whereas the sleep-wake rhythm was apparently entrained by a 24-hour day-night alternation. It is concluded that the plasma melatonin rhythm is the best marker of the human circadian pacemaker so far available.

Circadian Rhythm↗
PubMedDate not supplied

Expression of c-fms proto-oncogene product by ovarian cancer cell lines with effects of macrophage colony-stimulating factor on proliferation.

We studied the production of macrophage colony-stimulating factor (M-CSF) and the expression of c-fms mRNA, an M-CSF receptor, in four human ovarian cancer cell lines. All four cell lines expressed c-fms mRNA while three secreted M-CSF into the culture medium. The exogenous administration of M-CSF caused no significant enhancement of cellular proliferation in any cell line. Interestingly, the proliferation of KK cells was not affected by anti-M-CSF antibody. These results, taken together with the fact that ovarian cancer cells simultaneously produce M-CSF and c-fms, suggest that an autocrine mechanism may modulate cellular proliferation.

Adenocarcinoma↗
PubMedDate not supplied

Accumulation of cholesteryl ester and lipid droplets in macrophages after uptake of cholesterol-rich necrotic products.

The prevalence of degenerated cells in the thickened intima of cholesterol-fed animals suggested that necrotic regions might become a focus for lesion development by attracting histiocytes or monocytes. We propose that cholesterol-rich necrotic products scavenged by macrophages incite the accumulation of cholesteryl ester and the formation of cholesteryl ester droplets. The feasibility of this hypothesis was tested with readily available materials, namely, lung macrophages and plasma membrane vesicles (PMV) released from dying cholesterol-rich and normal hepatocytes. PMV from cholesterol-rich hepatocytes contained 30-fold more cholesteryl ester than PMV from normal hepatocytes. Degradation of 125I-PMV to trichloroacetic acid-soluble products by macrophages was fourfold higher than that of 125I-acetylated low density lipoprotein (acetyl-LDL) at 100 micrograms/ml of ligand in the incubation medium. Within this concentration range, degradation of PMV increased almost linearly with increasing concentrations of PMV, while the degradation of acetyl-LDL followed a saturation curve. Cholesterol-rich PMV increased the cholesteryl ester content of macrophages fourfold and augmented the incorporation of oleate threefold relative to normal PMV. These studies were extended to aortic smooth muscle cells. As with hepatocyte-PMV, smooth muscle cell-PMV was internalized and degraded by macrophages. The results suggested that cholesterol-rich necrotic materials could play a significant role in atherogenesis.

Animals↗
PubMedDate not supplied

Progressive hearing loss from strial dysplasia.

An otherwise healthy male patient had a bilateral, slowly progressive hearing loss first noticed in early childhood and possibly present at birth. Audiometric studies at the age of 32 showed a moderately severe, bilateral, mixed type hearing loss. He died of unrelated causes at the age of 34. Studies of the temporal bones showed bilateral hypoplasia and atrophy of the striae vascularis as the cause of hearing loss. The history and findings are consistent with a genetically determined hypoplasia and atrophy of this structure.

Adult↗
PubMedDate not supplied

[Studies on early changes in myocardial electrolytes and histological reaction in isoproterenol-induced myocardial injury].

To determine morphological changes in the very early stage of damage and recovery of myocardial fibers in relation to electrolytes and water content in the myocardium, experimental myocardial infarcts were produced after injection of 75 mg/kg isoproterenol (Isp) to rats weighing 270 +/- 10 g. Electrolytes were examined by an atomic absorption spectrophotometer, and histologic examination was performed by light and electron microscopy. At 30 min after Isp injection, Ca and water contents of myocardium increased, but Mg decreased. These myocardial damages showed a maximum level from 6 to 12 h after injection of Isp. It consisted of reversible injury of muscle fibers represented by eosinophilic and fatty degeneration, intermingled with coagulation necrosis of fibers which was irreversible. Most of these eosinophilic degeneration fibers recovered to normal fibers between 12 h and 3 d after the injection. The chronological changes of Ca, Mg, and water contents were well correlated to the morphological early changes of myocardial fibers, and this experimental model by using Isp may be useful for examining the recovery of damaged myocardial tissue and estimating the effects of therapeutics.

Animals↗
PubMedDate not supplied

Computer-aided three-dimensional reconstruction and morphometry of the outer hair cells of the guinea pig cochlea.

The outer hair cells and their nerve endings in the basal and third turns of the guinea pig cochlea were reconstructed three-dimensionally from serial thin sections by means of computer graphics, and morphometric data were obtained. The number of nerve endings in the third turn was two to three times greater than that in the basal turn. Many afferent and efferent terminals in the third turn did not demonstrate synaptic specialization. Presynaptic dense bodies were missing in the majority of outer hair cells in both basal and third turns. The morphologic arrangement of the subsurface cisternae and efferent fiber synapses on the side and base of the outer hair cells suggests a close functional relationship. The nerve fibers and cisternae may be involved in the contractile process of the cells. The volume of the outer hair cells in the first row of the basal turn was about 656 micron 3, and third turn, 1358 micron 3. The total count of mitochondria in the outer hair cells of the first row in the basal turn was 1425, and 1963 in the third turn. The density of mitochondria in the sensory cell in the basal turn was higher. The highest density was seen in the infranuclear region. The mitochondrial distribution patterns suggest that metabolic activity of the outer hair cells is higher in the basal turn than in the third turn and the energy requirement is greatest in the region close to nerve endings.

Animals↗
PubMedDate not supplied

Anatomy of the cerebello-pontine angle visualized through the translabyrinthine approach.

The anatomical situations of the cerebello-pontine angle were studied in cadavers via the translabyrinthine approach. A series of black and white photographs are presented showing the exit zones and intracranial courses of the IV-XI cranial nerves, as seen observed through the translabyrinthine approach in different directions. In order to popularize this procedure and to publish the technical details involved, it is necessary that the anatomy and patho-anatomy of the cerebello-pontine angle and its surroundings are studied systematically as they appear through the translabyrinthine approach.

Cadaver↗
PubMedDate not supplied

Computer-aided serial section reconstruction of nerve endings on the outer hair cells of the cochlea. Semithin sections vs. ultrathin sections.

Afferent and efferent nerve endings on several outer hair cells in different turns and rows of the guinea pig cochlea were three-dimensionally reconstructed from serial semithin sections or ultrathin sections by means of a new computer system. In the basal turn, a single afferent ending was sometimes isolated from the others and surrounded by efferent endings, suggesting that this type of afferent ending may have properties different from the others. The advantages and disadvantages of semithin sections and ultrathin sections in computer-aided reconstruction were discussed and it was concluded that the semithin section technique will be useful in reconstructions of specimens from a wide range, whereas the ultrathin section technique will be better for reproducing fine structures such as the distribution of cell organelles as well as synaptic membrane specializations.

Animals↗
PubMedDate not supplied

Computer-aided three-dimensional reconstruction of the inner hair cells and their nerve endings in the guinea pig cochlea.

The inner hair cells and their nerve endings in the basal and third turns of the guinea pig cochlea were reconstructed three-dimensionally from serial thin sections by means of computer graphics. The inner hair cells showed narrowing below the cuticular plate and gradual increase in size toward the base where the surface was indented by nerve attachments. The sizes of the afferent nerve endings were in the range of 0.9 to 3.2 microns in cross section. Large endings were fewer and were located mainly on the pillar cell side, whereas small endings were numerous and were located on the modiolar side. The number of afferent nerve endings on a single cell in the basal turn averaged 26 and in the third turn, 17. All the afferent fibers were unbranched, most of them innervated a single cell, and 81% of them formed synapses with distinct synaptic bodies in the inner hair cells. A few afferent endings formed membrane specializations with two adjacent inner hair cells but the synaptic body was seen in only one cell. The number of efferent endings, from 0.08 to 2.0 micron in diameter, was about nine in the basal turn and was seven in the third turn. No significant difference was seen between the basal and third turns in cell shape, proportion of afferent to efferent endings, nor in morphology of synapses.

Animals↗
PubMedDate not supplied

Prognostic factors in stage I and II non-Hodgkin's lymphoma of Waldeyer's ring.

Sixty-nine stage I and II patients treated for non-Hodgkin's lymphoma of Waldeyer's ring were retrospectively analysed. Diffuse histiocytic lymphoma (Rappaport's classification) was the most common histology (67%). Staging without laparotomy revealed 31 patients in stage I and 38 in stage II. Sixty-five patients received radiation therapy against involved or extended fields. In 43 patients adjuvant chemotherapy with single or multiple agents was given and 4 patients received only chemotherapy. A relapse occurred in 34 (49%) patients. The 5-year relapse-free survival was 67 per cent and 36 per cent in stage I and stage II, respectively. Radiation doses of 50 Gy gave no recurrence within treated volumes. However, since relapse below the clavicles and especially below the diaphragm was common, the radiation doses did not seem important for reduction of the overall failure rate. In stage II, patients with a single neck node less than 5 cm in diameter seemed to have a better prognosis than patients with large or multiple neck nodes. In this non-randomized study adjuvant chemotherapy seemed to reduce the risk of relapse, especially in stage II patients.

Adolescent↗
PubMedDate not supplied

Squamous cell carcinoma of the nasopharynx. An analysis of failure patterns after radiation therapy.

Seventy-seven patients with nasopharyngeal squamous cell carcinoma were treated with irradiation, with or without chemotherapy. Sixty-three (82%) developed a relapse in some part of the body; the first relapse appeared at primary, cervical and distant sites in 45 (71%), 30 (48%) and 12 (19%) of the 63 relapsing patients, respectively. In 22 of the 63 relapsing patients, the first relapse occurred simultaneously in two or more sites. Local recurrence-free survival was higher for the T1 + T2 group than for the T3 + T4 group (p less than 0.02). Cervical relapse-free survival was higher for N0 patients than for N+ patients (p less than 0.02). Distant metastases frequently developed as a component of the first relapse. Distant metastases were more common in N+ patients than in N0 patients. Forty-two patients received adjuvant chemotherapy. Although local recurrence-free survival tended to be higher in patients with chemotherapy than without chemotherapy, survival rates and relapse-free survival rates did not differ in the two groups.

Adolescent↗