Early ultrastructural changes in the dorsal mucosa of rat tongue after irradiation, with special reference to the microvasculature

PURPOSE

To clarify the acute effects of irradiation on the ultrastructural conformation of the dorsal mucosa of the rat tongue, with special reference to the changes in microvasculature.

METHODS

The proboscis of seventy rats were irradiated. The animals were then perfusion-fixed, followed by India ink-injection or resin casting at 3 to 7 days after irradiation. The bulk, frozen sections, or plastic embedded sections of the treated rat tongues were examined by light and electron microscopy.

RESULTS

In the dorsal epithelium of the rat tongue, multi-nucleated cells appeared in the basal layer at 3 days after irradiation. At day 5, the thickness of the epithelial layer and connective tissue papillae decreased dramatically, concomitant with the shortening of the capillary loops. At day 7, lingual papillae and connective tissue papillae disappeared, leaving dissociated epithelial cells and numerous neutrophils migrating throughout the tissue. Subepithelial blood vessels displayed drastic dilation with a number of neutrophils adhering to the endothelial surface, but without ultrastructural abnormalities in its cellular components.

CONCLUSION

Early changes in the dorsal mucosa of the irradiated rat tongue were limited to the basal epithelial cells, leading to a total disruption of the epithelial layer. Atrophic changes of the capillary loops is due to the loss of the connective tissue papillae. Dilation and conformational changes of the subepithelial capillaries appear to result from the inflammatory reaction, taking place secondarily to the loss of the epithelial barrier of the irradiated tongue. A difference in radiosensitivity among the epithelial, endothelial, and mesenchymal cell components of the rat tongue in vivo is suggested.

"Pseudoocclusion" of the internal carotid artery: a pitfall on intracranial MRA

We report a case showing "pseudoocclusion" of the internal carotid artery as a pitfall on intracranial MRA. Pseudoocclusion was attributed to magnetic susceptibility artifacts with metallic substances located proximal to a slab. The same finding could be reproduced on experimental MRA with a small steel coil applied on the anterior neck of a volunteer at the level of the carotid bifurcation.

Temporal bone pathology of a patient with cochlear implant

A 66-year-old man with profound total deafness received a 22-channel cochlear implant. After surgery, his hearing improved and the postoperative course was uneventful except transient vertigo. The patient died of lung cancer after 2.5 years. Twelve hours after death, the temporal bone was harvested for histological and electron microscopic examination. The mastoid air cells were preserved, although a few mucosal folds were present. The Dacron mesh tie had largely been absorbed, but part remained embedded in fibrous tissue. No inflammation was noted in the tympanic cavity or the round window through which the electrodes were inserted. In the cochlea, the scala tympani was filled with fibrous tissue at the site of electrode insertion. The scala media had collapsed, while the organ of Corti and stria vascularis showed degeneration. Osseous spiral bundles and spiral ganglion cells were noted, though reduced in number.

Neuroradiological assessment of visuoperceptual disturbance in children with spina bifida and hydrocephalus

The intellectual status of twelve children with spina bifida and hydrocephalus was evaluated. Seven children were considered to have verbal and non-verbal skill discrepancies. It was considered that the Verbal IQ-Performance IQ score by WISC-R could be used as an index of their visuoperceptual disturbance. The disturbance was closely related to the morphological characteristics of the lateral ventricles on cerebral MRI. The ratio of the areas of the posterior horns to the anterior horns (P:A) showed a negative correlation with visuoperceptual ability. The visual pathway, visual cortex, and the ventral system were thus considered to be the sites of the affected lesions. From P:A changes with time, it was evident that adequate shunting would prevent the perceptual disturbance.

Improvement of hypertonus after treatment for sleep disturbances in three patients with severe brain damage

Treatment for sleep disturbance was given to three patients with severe brain damage (a 14-year-old boy, an 8-year-old girl and a 9-year-old boy), and changes in their muscle tone were estimated using F-wave analysis. In all patients, F-wave analysis was performed in the ulnar nerve before and 2 weeks after treatment with flunitrazepam or melatonin. From 16 recordings of F-waves, the mean amplitude and latency, the ratio of F-wave amplitude to M-wave amplitude (F/M ratio), the mean F-wave conduction velocity and the F-wave occurrence were evaluated. All patients showed at least one significant decrement of mean F-wave amplitude, the F-wave occurrence and mean F/M ratio, which suggests a reduction in muscle tone after treatment for sleep disturbance. It is concluded that treatment for sleep disturbance occurring in brain damage is important in view of the improvement of increased muscle tone.

Pyruvate dehydrogenase complex deficiency with multiple minor anomalies

Pyruvate dehydrogenase complex (PDHC) deficiency is known to cause congenital lactic acidosis. The case of a 9-month-old female infant with PDHC deficiency caused by a mutation in exon 11 of the pyruvate dehydrogenase (PDH) E1 alpha gene is described. Her facial features were as follows: frontal bossing, upslanting palpebral fissures, a short upturned nose, a long philtrum and low set ears. These anomalies are characteristic not only of a malformation syndrome or chromosomal aberration, but also of PDHC deficiency. Because PDHC deficiency requires early treatment, metabolic disorders should be kept in mind in a patient with dysmorphic features. Further, she had multiple minor anomalies including bilateral inguinal herniae, an umbilical hernia and small hands and feet, which have not been described in previous reports.

Event-related potentials (ERPs) associated with omitted somatosensory stimuli

Late positive ERP components elicited by omitted somatosensory stimuli in passive paradigm (passive MSPP) and in active time-estimation paradigm (active MSPP) were studied in healthy subjects with single-trial analysis and conventional averages. The active MSPP was also compared with P3 component elicited by somatosensory target stimuli (target P3). Single-trial analysis showed clearly discernible passive MSPP in response to omitted stimuli of the median nerve, whereas passive MSPP was hardly detected in response to omitted stimuli of the index finger. The subjects might pay passive attention to absence of somatosensory stimuli together with absence of the thumb muscle twitches. Single-trial analysis revealed a significantly greater latency fluctuation in passive MSPP than in active MSPP. The active MSPP showed a greater latency fluctuation than the target P3. The active MSPP showed a significantly longer latency and a smaller amplitude than the target P3 in conventional averages. Topography of active MSPP showed a symmetric central-parietal maximal distribution similar to that of target P3.

Large vestibular aqueduct syndrome with high CT density and high MR signal intensity

We report a case of large vestibular aqueduct syndrome with a markedly dilated endolymphatic sac bilaterally. The density and signal intensity of the extraosseous portion of the sac were higher than those of cerebrospinal fluid on CT and MR studies. The findings may represent protein-rich and hyperosmolar fluid within the endolymphatic sac.

Apoptosis in retinal ganglion cell decrease in human glaucomatous eyes

Hematoxylin-eosin staining, the TUNEL method for in situ detection of the intranuclear DNA fragmentation, which indicates apoptosis, and electron microscopy were used to study the morphologic changes in specimens from the eyes of 8 patients with secondary glaucoma and 2 normal control eyes to evaluate our hypothesis that apoptosis causes a decrease in retinal ganglion cells in human glaucomatous eyes. The TUNEL method permits identification of intranuclear DNA fragmentation. Apoptosis was found in the ganglion cells of 2 glaucomatous eyes with recent sight loss, and in the ganglion cells of a control eye from a 95-year-old subject, taken at autopsy. Results of our study indicate that a decrease in retinal ganglion cells in glaucomatous eyes is caused by apoptosis. In addition, apoptosis resulting from aging must be considered in order to understand the reduction of retinal ganglion cells in the glaucomatous eyes of elderly patients.

Evolution of dnaQ, the gene encoding the editing 3' to 5' exonuclease subunit of DNA polymerase III holoenzyme in Gram-negative bacteria

The nucleotide sequences of the dnaQ genes from Salmonella typhimurium and Buchnera aphidicola, encoding the epsilon-subunit of the DNA polymerase III holoenzyme, have been determined. The Salmonella typhimurium dnaQ protein consists of 243 amino acid residues with a calculated molecular weight of 27224. The Buchnera aphidicola dnaQ protein contains 233 amino acid residues with a calculated molecular weight of 27170. A multiple sequence alignment of the amino acid sequences of the dnaQ proteins and those of DNA polymerase IIIs from Gram-positive bacteria produced six homologous segments. These homologous segments contain highly conserved amino acid sequence motifs involved in catalytically important metal ion bindings (ligands 1, 2 and 3). However, metal ligand 4 is found to be altered in the 3'-5' exonuclease domain of the family C DNA polymerases and dnaQ proteins in Gram-negative bacteria. From these results, we propose that the last common ancestor of the dnaQ gene of Gram-negative bacteria and the DNA polymerase III gene (pol C gene) of Gram-positive bacteria was a single gene containing both 3'-5' exonuclease and DNA polymerase domains and then the dnaQ gene separated from the polymerase gene in Gram-negative bacteria.

Arachnoid granulations of the posterior fossa: CT and MR findings

The radiological appearance of typically located arachnoid granulations on craniograms is well known. Arachnoid granulations of unusual size and location should be distinguished from pathological processes. We analyzed six patients with arachnoid granulations in the posterior fossa. Characteristic findings of arachnoid granulations were disclosed by computed tomography (CT) and magnetic resonance (MR) imaging; a punched out-like bone defect from the inner table into the outer table on CT scans and intensity similar to that of the cerebrospinal fluid in all pulse sequences on MR images.

Solitary plasmacytomas of the occipital bone: a report of two cases

The radiological appearances of two cases of solitary plasmacytoma in the occipital bone are described. One arose in the lateral part and the other in the squama. They showed characteristic radiological features on CT, MRI and angiography. Bone scintigraphy and gallium scintigraphy were also available. Solitary plasmacytoma of the skull is a rare condition and usually occurs in the calvarium. The skull base is an extremely rare site and only four cases have been reported. The literature of solitary plasmacytoma of the skull is reviewed.

Atrophy of bilateral extraocular muscles. CT and clinical features of seven patients

Swelling of the extraocular muscles is a common orbital abnormality that is easily demonstrated by computed tomography (CT). However, muscle atrophy is more difficult to identify and is rarely reported in the literature. Bilateral atrophy is extremely rare. We report the CT and clinical features of seven patients showing bilateral extraocular muscle atrophy: four with mitochondrial myopathy (MM) and three with myasthenia gravis (MG). Six patients had clinical histories of muscle involvement > 20 years. An incorrect diagnosis of MG was made initially in two patients with MM because of mildly positive Tensilon testing. The ocular motor abnormalities failed to improve after thymectomy in the myasthenic patients. Orbital appearance on neuroimaging is similar in these disorders. Differentiation between these two disorders is impossible with orbital CT and magnetic resonance imaging (MR) alone.

Morphological analysis of the human lower extremity based on the relative muscle weight

Morphological study of the muscles of the lower extremity is necessary for the analysis of the muscular function and its relation with locomotion. In this study, the muscle weight of the lower extremities from 11 adult Japanese cadavers (6 males and 5 females, aged from 50 to 91 years old) were measured. The morphological characteristic of the human lower extremity is discussed based on the relative muscular weight. The largest muscles were the gluteus maximus (the extensor at the hip joint), the vasti muscles (the extensor at the knee joint) and the soleus (the plantarflexor at the ankle joint). These results reveal that the muscles acting on one joint are developed in the human lower extremity and that these muscles have important roles in human locomotion.

Promotion of microfilament polymerization by depolymerized glia filament preparation through interaction of vimentin with actin

We investigated the in vitro interaction between microfilaments and glia filaments in the presence of alpha-sialosylcholesterol (SC). The depolymerized glia filament preparation (GF) that had been extracted from a crude cytoskeletal fraction of cultured rat astrocytes promoted markedly the polymerization of the depolymerized microfilament preparation (MF) in the presence of SC. The ability of GF to promote the MF polymerization was highest in the concentration range 7.5-15 microM SC. The polymerization of MF at the concentration of 10 micrograms protein/200 microliters was enhanced to the highest level by 4 micrograms protein/200 microliters of GF in the presence of 15 microM SC. The MF polymerization was promoted more efficiently by GF than by MF: for example, the polymerization of actin in MF (7.5 micrograms/200 microliters) was enhanced by the addition of 5 micrograms GF protein/200 microliters to a twice greater extent than by the addition of 5 micrograms MF protein/200 microliters in the presence of 15 microM SC. GF enhanced the MF polymerization by over three-fold at 4-37 degrees C, and the GF activity became greater with an increase in incubation temperature. Vimentin promoted the G-actin polymerization in the presence of 11.3 microM alpha-SC. The finding suggested that the interaction between vimentin and actin was one of the factors to cause GF to promote the MF polymerization.

The prognosis and the treatment of patients with a C3/4 spinal cord injury

Twenty patients with a C3/4 spinal cord injury have been treated in our hospital since 1974. There were 15 new patients. The average follow up period was 68 months, ranging from 7 to 162 months. The 15 new cases were classified as Frankel A in nine cases, B in one, and C in five. Frankel A or B were usually accompanied by either an unstable spinal fracture or by spinal canal stenosis at the C3/4 level. Twelve patients received surgery. At the most recent follow up, eight of the 15 patients (53.3%) had improved according to Frankel's classification. Five, all Frankel A on remission, have died between 2 and 156 months after injury. Seven patients required tracheotomy on account of severe respiratory disturbance.

Kindling induces neuropsin mRNA in the mouse brain

Neuropsin mRNA expression was analyzed and mapped in the mouse brains after kindling epileptogenesis by using in situ hybridization histochemistry. Dynamic increases of the neuropsin mRNA were observed in the layer II of prelimbic, somatosensory, auditory, perirhinal, entorhinal, and piriform cortices in an activity-dependent manner, though no neuropsin gene was expressed in these areas in control mice. In addition to the confirmation of our previous studies showing increases of mRNA in the hippocampus and amygdaloid complex, there were also remarkable increases of the neuropsin mRNA in the limbic areas, such as the accessory olfactory nucleus, the medial and lateral septal nucleus, the nucleus of diagonal band, the substantia innominata and the zona incerta. The dynamic activity-dependent changes of the gene expression and the site-specificity of neuropsin localization are suggesting that this molecule is implicated in cortical- and limbic-specific neuronal reorganization.

Muscle histopathology in spastic cerebral palsy

We studied the histopathology of spastic muscles in patients with spastic cerebral palsy using specimens obtained from the gastrocnemius muscles during orthopedic operations. Though there was no disease-specific abnormality, we found changes in fiber type distribution, i.e., type-1 fiber predominance and type-2B fiber deficiency. These changes were not found in the patient with brain infarction at age 1 year 5 months. Variation in fiber size, especially in type-1 fibers, was also detected in older patients and at the more severely affected sides. We speculated that the influence on the spinal motor unit from upper motor cortex might be applicable to the muscle histological findings and the time of the onset of the brain damage might be important.

Effects of fructose ingestion on sorbitol and fructose 3-phosphate contents of erythrocytes from healthy men

To investigate the effect of fructose ingestion on sorbitol and fructose 3-phosphate (F3P) in erythrocytes, we administered 50 g fructose with and without treatment with an aldose reductase inhibitor, epalrestat, to seven healthy, normal-glucose-tolerant, male volunteers aged 20-43 years. The same subjects were given 50 g glucose on another day. The sorbitol and F3P contents in their erythrocytes increased significantly, reaching peak levels at 60 min and 180 min, respectively, following fructose in gestion. On the other hand, glucose ingestion did not cause any statistically significant change in sorbitol content in their erythrocytes, although it significantly elevated their F3P content. Treatment with epalrestat had no significant effect on incremental changes in erythrocyte sorbitol and F3P content following fructose ingestion. This suggests that oral fructose may be converted directly to sorbitol and F3P in erythrocytes instead of being converted via glucose. Thus, the dietary intake of fructose may affect the concentrations of sorbitol and F3P in erythrocytes in normal men.

Cystic Hypersecretory Duct Carcinoma of the Breast:A Case Reprot Describing the Cytologic Features

We report the clinical, cytological and pathological features of so-called cystic hypersecretory duct carcinoma occurring in a 60-year-old Japanese woman. The tumor mainfested a multicystic mass ultrasonographically, and aspiration biopsy cytology revealed atypical ductal epithelial cells with vacuolar cytoplasm. A modified radical mastectomy was performed. Histologically, the lesion was charcterized by many dilated ducts containing eosinophilic secretions, which resembled thyroid colloid. The ducts were lined by an intraductal micropapillary carcinoma with hobnail-shaped cells, and were positive for lactalbumin immunohistochemically. Additionally, a so-called cystic hypersecretory hyperplasia was seen in the surrounding breast parenchyma. Although a direct transition from the hyperplasia to the carcinoma was not proved, a close relationship between the two lesions was suggested.