Shingo Hiruma

A MORPHOLOGICAL STUDY ON THE EFFECTS OF COLLAGEN GEL MATRIX ON REGENERATION OF SEVERED RAT SCIATIC NERVE IN SILICONE TUBES

The present study is a chronological morphological examination on the effects of collagen gel matrix on regeneration of severed sciatic nerves. The nerves (5 mm length) were resected, and both the distal and proximal stumps were inserted into a silicone tube with 5 mm gap in between. In the test side, the gap in the tube was then injected with liquid collagen which gells in the tissue when reconstructed with a certain buffer solution. The gap space in the tube of the control side was left empty. In a chronological examination of the tissue in the tube, considerably more rapid growth of sprouting axons toward the distal stump in the test side was revealed in comparison with the control side. The cells, including both fibroblasts and larger Schwann cells, were less in number. More orderly directions were observed in the collagen matrix than in the control tube. The result indicates that regeneration of the peripheral nerves in the silicone tube can be improved, by using appropriate exogenous fine materials, collagen matrix.

Sensorimotor polyneuropathy associated with chronic lymphocytic leukemia, IgM antigangliosides antibody and human T-cell leukemia virus I infection.

A 65‐year‐old man presented with a sensorimotor polyneuropathy associated with B‐cell chronic lymphocytic leukemia (CLL) and immunoglobulin M (IgM) antibody to various gangliosides. Electrophysiological studies denoted significant abnormalities of motor and sensory nerve conduction. Although the pathology of sural nerve biopsy looked minimally affected, immunohistochemical studies showed specific binding of IgM to the human peripheral nerve. Our patient also had high titer of antibody to human T‐cell leukemia virus I (HTLV‐I) in both serum and cerebrospinal fluid (CSF), which might activate B‐cell–mediated immunity and facilitate the production of IgM antibody. The other unique feature is the reactivity of antibody to gangliosides. The patient had IgM antibody reactivities to gangliosides with disialosyl residue such as GT1b, GQ1b and GD3, but not to GD1b. IgM antibody to gangliosides with disialosyl residue has been reported in ataxic symptoms, but our patient failed to demonstrate ataxia. Without reactivity to GD1b, sensory ataxic neuropathy might not develop even in the presence of antibody reactive to other gangliosides with disialosyl residue.

Nemaline bodies of skeletal muscle fibers of the neck in a case of pharyngeal cancer

Nemaline bodiea were found in the regenerating muscle fibers of the neck of a 74‐year‐old Japanese male with pharyngeal cancer. Histologically, the nemaline bodies were needie‐shaped structure and hematoxophllic with phospho‐tungstic acid‐hematoxyiin stain. Electron microscopic examination suggested that they arise as extensions of the 2 bands. Although nemaline bodies occur in a variety of pathological conditions other than nemaiine myopathy, their occurrence in regenerating skeletal muscle fibers Invaded by cancer has not been reported previously. The pathogenesis of the nemaline body formation in the present case is discussed.

HISTOCHEMICAL STUDY OF HUMAN CREMASTER IN VARICOCELE PATIENTS

Despite the cremasters 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.Despite the cremasters 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.

Simple and reproducible model of rat spinal cord injury induced by a controlled cortical impact device

Consistently reproducible experimental trauma was inflicted on the rat spinal cord (L3-L4) employing a controlled cortical impact device. The spinal cord was injured with one of three sizes of chips; thick (3 mm diameter), medium (2 mm diameter), thin (1 mm diameter). Each chip was applied at 1, 2 and 3 mm deformation depths. The correlations of the magnitude of the primary trauma were examined histopathologically. It was found that the extent and intensity of the trauma could be changed by altering the depth of deformation and the chip diameter at a fixed velocity of 4.6 m per sec. The injury caused by the 2 mm diameter chip at 0.5 mm-deformation damaged one to two segments of the perifocal spinal cord. In the surviving animals, the histological changes could be classified as primary, secondary, and late phase changes, and finally the lesion became a cavity. This study reports the application of a controlled cortical impact device to morphological research on a spinal cord injury. We found that the injury by the 2 mm chip at 0.5 mm deformation was the most advantageous and reproducible model for further investigations.

Malignant Gastrointestinal Stromal Tumor Showing Remarkable Whorl Formations

A case of malignant gastrointestinal stromal tumor (GIST) is reported. Histologically, spindle cell proliferation with remarkable whorl formations was predominant in the tumor. Immunohistochemically, the tumor cells were diffusely positive for CD117 (c-Kit) and vimentin and partially positive for CD34. Ultrastructurally, the desmosome-like structures and interdigitations occurred much more frequently in the areas with whorl formations. These organelles were considered to be closely associated with the whorl formations. Various kinds of cellular arrangements are revealed in GISTs, but remarkable whorl formations, such as in our case, are a rare variant pattern. Herein, we discuss the histopathologic differences between this and other tumors showing whorl formations and describe the meaning of this unique arrangement. GISTs are thought to be immature tumors, and, therefore, variations in histopathologic findings are recognized. Finally, the ultrastructural study of GISTs is useful for understanding the mechanisms forming whorl formations and the differentiation or pathogenesis of GISTs.

Relationship between the states of spinal impact injuries and magnetically evoked EMGs in rats.

Abstract The relationship between the states of spinal Impact injuries and magnetically evoked electromyograms (EMGs) were studied in rats. Impact injuries to the spinal cord were induced at a depth of 0.25-2.0 mm by insertion of a cylinder tip measuring 2 mm in diameter into the lumbar vertebrae L1-L2. Magnetically induced electromyograms for the brain and lumbar vertebrae L4-L5 were recorded from the tibialis anticus and the gastrocnemius muscles. H-reflex was not induced by the spinal cord injury (SCI) at a depth of 0.25 mm, although motor evoked potential (MEP) was observed. Continuous waves following the M- response were observed in the SCI at a depth of 0.25 mm. Elevation of the threshold, reduction of its latency and decrease in amplitude of the M-responses were observed at an injury depth of 0.5 mm or deeper. With SCI magnitude from mild (0.5 mm depth) to severe (1.0 mm depth), the amplitudes of the M-response were decreased, and the latency of the M-response was shorter than that of the control. The F-response was accelerated in severe SCI. Our results indicated that there was a relationship between extensive injury legions and the H-reflex F- and M-responses in magtnetically evoked EMGs. Magnetically evoked EMGs are useful for monitoring the states of SCI. [Neurol Res 2000; 22: 727-732]

Neuronal changes of hypokalemic myopathy: A light- and electron-microscopic study on muscle biopsy

Hypokalemic myopathy has been observed in various clinical conditions. There are many studies of the pathomorphological changes of muscle fibers but alterations in intramuscular nerves and motor end-plates are seldom mentioned. The present authors observed biopsied muscle from a 51-year-old housewife who had suffered from gradually increasing muscle weakness. Laboratory examinations revealed a severe hypokalemia of 1.5 mEq/1, 18304 U/1 of CPK, 1300 U/1 of LDH, 343 U/1 of SGOT and 297 IU/1 of adolase. Light-microscopic examination showed changes previously described, including twin-peaked distribution in the histogram of type I, IIA and IIB fibers, ballooning and thickening of terminal axon, and 2 or 3 end-plates closely spaced along the length of muscle fibers. The electron-microscopic examination revealed empty folds of basement membrane in end-plate regions, reduced secondary synaptic clefts, interposition of Schwann cell processes between nerve ending and primary synaptic cleft, and an increase of disarranged microtubules and neurofilaments in terminal axons. The findings suggest that severe hypokalemia primarily produces structural alterations of intramuscular peripheral nerves and motor end-plates as well as of muscle fibers.

Changes in spinal cord function caused by injuries at different levels of the lumbar spinal cord

We examined the impact of spinal cord injury to a depth of 0.5 mm at L1–L2 (upper lumbar cord injury) and in L6-S1 (lower cord injury) in Wistar rats. Upper lumbar cord injury resulted in the disappearance of the motor evoked potential (MEP) of the gastrocnemius muscle during transcranial magnetic stimulation, while the threshold was decreased in rats with lower cord injury. During magnetic stimulation of L4–L5, the M-response threshold was decreased in rats with upper lumbar cord injury, while the amplitude was increased. In lower cord injury, the pattern of H-response recruitment curves differed from that in controls. Our results indicated that MEP and the spinal reflex are influenced not only by upper lumbar cord injury but also by lower cord injury.

A case in which cytodiagnosis was useful for evaluation of aspergillus.

脾カンジダ症を伴った気管支肺アスペルギルス症の1剖検例を報告し, それを用いて, 内臓真菌症の中でも原因菌属としてカンジダに次いで最も多いアスペルギルスの同定を, 菌糸のみの形態的特徴から試みた.症例は43歳, 女性. 急性前骨髄球性白血病の再燃例で右肺中・下葉および左上葉にアスペルギルスによる肺炎をきたし, 右中・下葉の一部は横隔膜に癒着し, 右出血性胸膜炎を呈していた.左上葉では空洞を形成していた. 脾には結節状のカンジダ感染が認められた. 剖検時に右肺・横隔膜癒着部および左上葉空洞内の壊死物の塗抹標本を作製したところ, アスペルギルスの菌糸の特徴すなわち, Y字状に2分岐しながら一方向へ向かって増殖するようすがきわめて明瞭に見い出され, 組織標本で観察できた菌糸形態よりも真菌の同定に役立つと考えられた.