Single-fiber electromyography improvement with 3,4-diaminopyridine in Lambert-Eaton myasthenic syndrome.
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4-Aminopyridine↗
Biomedical subjects
S J Oh
Publications and source records attributed to S J Oh.
Immunohistochemical and molecular studies of serotonin, substance P, galanin, pituitary adenylyl cyclase-activating polypeptide, and secretoneurin in fibromyalgic muscle tissue.
OBJECTIVE: Because former investigations have reported abnormal changes in the expression of serotonin (5-hydroxytryptamine [5-HT]) and substance P (SP) in serum and cerebrospinal fluid, this study sought to determine whether 5-HT and pain-modulating neuropeptides (SP, galanin [GA], pituitary adenylyl cyclase-activating polypeptide, and secretoneurin) were expressed abnormally in the muscle tissue of patients with fibromyalgia (FM). METHODS: Snap-frozen muscle tissue specimens (deltoid muscles) from 10 patients with FM (mean disease duration 15 years) and from 10 healthy control subjects were examined by reverse transcriptase-polymerase chain reaction (RT-PCR) of RNA preparations from muscle cells, and by immunohistochemistry methods (alkaline phosphatase-anti-alkaline phosphatase and immunogold-silver) using specific primers as well as antibodies. When specific messenger RNA (mRNA) was detected by RT-PCR, in situ RT-PCR was performed for mRNA localization. RESULTS: Specific mRNA for the examined substances was absent in 9 of 10 FM patients and in 10 of 10 controls. No differences between the FM patients and controls could be detected in the muscle tissue by immunohistochemistry. In 1 FM patient, mRNA for the GA receptor could be shown. CONCLUSION: This study showed that 5-HT and neuropeptides are not produced in the muscle of patients with FM, and therefore do not appear to be involved in the peripheral induction of pain in this chronic, painful disorder.
Adult↗
NOS-like immunoreactive neurons express GABA-like immunoreactivity in rabbit and rat retinae.
In rabbit and rat retinae, wholemounted preparations and 40 microm thick vibratome sections were processed for nitric oxide synthase (NOS) immunoreactivity and consecutive semithin sections were immunostained with anti-NOS and anti-GABA antisera, respectively. Two types of NOS-labelled amacrine cells were identified: type 1 cells with larger somata were intensely stained, and type 2 cells with smaller somata were weakly stained. A few displaced amacrine cells also showed NOS-like immunoreactivity. All these NOS-like immunoreactive neurons also expressed GABA-like immunoreactivity. Thus, nitric-oxide-containing neurons might constitute a subpopulation of GABAergic neurons in rabbit and rat retinae.
Animals↗
Reaction of Müller cells after increased intraocular pressure in the rat retina.
Using light microscopy and immunocytochemistry, we investigated the morphological changes of retinal tissues and the reaction of Müller cells in the ischemic rat retina induced by increasing intraocular pressure. At early stages (from 1 h to 24 h after reperfusion), cells in the ganglion cell layer and in the inner nuclear layer showed some degenerative changes, but at later stages (from 72 h to 4 weeks) marked degenerative changes occurred in the outer nuclear layer (ONL). At 4 weeks after reperfusion, the ONL was reduced to 1 or 2 cell layers. Immunoreactivity for glial fibrillary acidic protein (GFAP) appeared in the endfeet and distal processes of Müller cells as of 1 h after reperfusion. GFAP immunoreactivity in Müller cells increased up to 2 weeks and then decreased at 4 weeks after reperfusion. Our findings suggest that Müller cells are involved in the pathophysiology of retinal ischemia through the expression of GFAP. The degree of GFAP expression in Müller cells closely correlated with that of the degeneration of retinal neurons.
Animals↗
Platelet-derived growth factor-B induces transformation of fibrocytes into spindle-shaped myofibroblasts in vivo.
Platelet-derived growth factor (PDGF) has a targeted activity on mesenchymal cells, but the in vivo effects of PDGF are not well understood. We have applied about 3 microg of PDGF-A and PDGF-B on the differentiated chorioallantoic membrane (CAM) of 13-day-old chick embryos. After 1-3 days, specimens were evaluated macroscopically, histologically with semi- and ultrathin sections, and immunohistologically with antibodies against smooth muscle alpha-actin (alphaSMA), desmin, and fibronectin (FN). Proliferation studies were performed according to the 5-bromo-2-deoxyuridine (BrdU)/anti-BrdU method. We did not observe effects of PDGF-A. PDGF-B induced proliferation of fibrocytes and their transformation into myofibroblasts. Bundles of spindle-shaped myofibroblasts accumulated beneath the chorionic epithelium. These cells were strongly positive for alphaSMA and FN, but negative for desmin. They possessed a well developed rough endoplasmic reticulum and bundles of microfilaments anchoring in the cell membrane. Our results suggest that PDGF-B is a "transforming" growth factor with important functions during formation of granulation tissue which are closely comparable to the effects of the PDGF-B-like protein of simian sarcoma virus. PDGF-B also induced vascular alterations in the CAM, which, however, appeared to be a secondary effect. While the intra-chorionic capillaries were lost, an accumulation of small vessels positive for alphaSMA was observed. This indicates a function for PDGF-B during segregation of main vessels from a primary vascular plexus.
Actins↗
Squamous cell carcinoma of the renal pelvis with invasion of the infradiaphragmatic inferior vena cava.
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Aged↗
Indirect open reduction through intercartilaginous incision and intranasal Kirschner wire splinting of comminuted nasal fractures.
The majority of nasal fractures have been managed by using closed reduction and intranasal packing. In comminuted nasal fractures, open reduction and internal fixation may be indicated for accurate reduction and rigid fixation, but it is a very aggressive procedure. We developed a new technique for comminuted nasal fractures: indirect open reduction and intranasal Kirschner wire splinting. A periosteal elevator is used to elevate the mucoperiosteum posterior to the nasal bone through intercartilaginous incision and to reduce accurately the nasal bone, at the same time detecting the fracture lines. The Kirschner wire is used to insert between the nasal bone and the mucoperiosteum and to splint rigidly the nasal bone. During the follow-up period of 5 weeks to 4 months, 23 of 27 patients (85 percent) had successful cosmetic results. Four patients had slight cosmetic deformity but did not request a late rhinoplasty. Nineteen patients had accurate reduction on a computed tomography scan. Ten patients had undercorrection of the nasal septum on a computed tomography scan, and three patients had significant septal deviation with airway obstruction. Indirect open reduction through intercartilaginous incision and intranasal Kirschner wire splinting is a reliable and useful method for the treatment of comminuted nasal fractures because it achieves accurate reduction and rigid, long intranasal support, can be done comfortably under local anesthesia, permits early nasal breathing postoperatively, has no external scar, and minimizes complications such as nasal bleeding, soft-tissue injury, infection, and recurrent displacement.
Adolescent↗
Activity-dependent conduction velocity changes of A(delta) fibers in a rat model of neuropathy.
Activity-dependent changes of conduction velocity (CV) and conduction block in single A(delta) fibers of primary afferent neurons were characterized in a rat model of neuropathy (NP). Injured dorsal root (DR) fiber in NP rats exhibited profoundly greater decreases of CV following impulse activity than did DR fiber in normal rats. Activity-dependent conduction block was absent up to 100 Hz of activity rate in DR fiber of NP rats, but was present above 25 Hz in normal rats. Profiles of activity dependence in sciatic fibers were similar in both NP and normal rats. These results suggest that nerve injury may alter activity-dependent hypoexcitability of A(delta) DR fibers. Furthermore, this excitability change may be responsible for the elevated pain perception in neuropathy.
Animals↗
Activity-dependent conduction latency changes in A beta fibers of neuropathic rats.
Activity-dependent changes of the conduction latency of single A beta fibers of primary afferent neurons were characterized in both neuropathic (L4 and L6 ligated) and normal rats. Activity-dependent increases in conduction latency of dorsal root fibers in neuropathic rats were significantly stronger than those in normal rats. Different profiles of activity dependence were also observed between injured and adjacent intact dorsal root fibers of neuropathic rats. However, activity-dependent latency changes in sciatic nerves distal to the dorsal root ganglion were not different between neuropathic and normal rats. These results suggest that partial nerve injury induces activity-dependent excitability changes in the dorsal root fibers of neuropathic rat and that these changes may be responsible for the altered sensory processing such as those seen in allodynia.
Action Potentials↗
VEGF and VEGF-C: specific induction of angiogenesis and lymphangiogenesis in the differentiated avian chorioallantoic membrane.
The lymphangiogenic potency of endothelial growth factors has not been studied to date. This is partially due to the lack of in vivo lymphangiogenesis assays. We have studied the lymphatics of differentiated avian chorioallantoic membrane (CAM) using microinjection of Mercox resin, semi- and ultrathin sectioning, immunohistochemical detection of fibronectin and alpha-smooth muscle actin, and in situ hybridization with VEGFR-2 and VEGFR-3 probes. CAM is drained by lymphatic vessels which are arranged in a regular pattern. Arterioles and arteries are accompanied by a pair of interconnected lymphatics and form a plexus around bigger arteries. Veins are also associated with lymphatics, particularly larger veins, which are surrounded by a lymphatic plexus. The lymphatics are characterized by an extremely thin endothelial lining, pores, and the absence of a basal lamina. Patches of the extracellular matrix can be stained with an antibody against fibronectin. Lymphatic endothelial cells of differentiated CAM show ultrastructural features of this cell type. CAM lymphatics do not possess mediae. In contrast, the lymphatic trunks of the umbilical stalk are invested by a single but discontinuous layer of smooth muscle cells. CAM lymphatics express VEGFR-2 and VEGFR-3. Both the regular pattern and the typical structure of these lymphatics suggest that CAM is a suitable site to study the in vivo effects of potential lymphangiogenic factors. We have studied the effects of VEGF homo- and heterodimers, VEGF/PlGF heterodimers, and PlGF and VEGF-C homodimers on Day 13 CAM. All the growth factors containing at least one VEGF chain are angiogenic but do not induce lymphangiogenesis. PlGF-1 and PlGF-2 are neither angiogenic nor lymphangiogenic. VEGF-C is the first lymphangiogenic factor and seems to be highly chemoattractive for lymphatic endothelial cells. It induces proliferation of lymphatic endothelial cells and development of new lymphatic sinuses which are directed immediately beneath the chorionic epithelium. Our studies show that VEGF and VEGF-C are specific angiogenic and lymphangiogenic growth factors, respectively.
Actins↗
Stiff-persons' syndrome associated with thymoma and subsequent myasthenia gravis.
We report the first case of stiff-persons' (-man) syndrome in the setting of a histologically proven thymoma. Muscular hyperactivity was abolished under general anesthesia and the symptoms of stiffness resolved after thymectomy and three courses of intravenous immunoglobulins. After thymectomy, the patient developed ocular myasthenia gravis which later resolved spontaneously. We suggest that thymoma be sought for in cases with neuromuscular hyperactivity syndromes. Myasthenia gravis may develop subsequently in these cases.
Electromyography↗
Low-dose guanidine and pyridostigmine: relatively safe and effective long-term symptomatic therapy in Lambert-Eaton myasthenic syndrome.
Guanidine hydrochloride is known to be highly effective in the symptomatic treatment of the Lambert-Eaton myasthenic syndrome (LEMS). However, because of its potentially dangerous side reactions of hematologic abnormalities and renal insufficiency, 3,4-diaminopyridine, which is not readily available in the United States, is recommended as the preferred drug for LEMS. We used low-dose guanidine and pyridostigmine combination therapy in 9 patients with LEMS and analyzed its long-term safety and effectiveness. In all patients, a liberal amount of pyridostigmine was used, while daily guanidine dose was kept below 1000 mg a day, and guanidine was given between pyridostigmine dosings. This combination therapy was used for 3-102 months (mean: 34.1 months) and improved clinical status in all patients. Although guanidine had to be discontinued due to severe gastrointestinal symptoms in 3 cases, no serious side reactions such as bone marrow suppressions or signs of renal insufficiency developed in any case. Thus, we conclude that low-dose guanidine therapy is relatively safe and effective for long-term symptomatic treatment of LEMS when it is combined with pyridostigmine.
Adult↗
Paraneoplastic vasculitis of the peripheral nervous system.
Paraneoplastic vasculitic neuropathy (PVN) is a rare paraneoplastic syndrome characterized by non-systemic subacute vasculitic neuropathy. The two cancers most commonly associated with PVN are small cell lung cancer (SCLC) and lymphomas. Neuropathy varies from mononeurotherapy multiplex to symmetrical polyneuropathy. Two helpful laboratory abnormalities are a high erythrocyte sedimentation rate (ESR) and high cerebro spinal fluid (CSF) protein content. Axonal neuropathy is the characteristic finding in electrophysiological studies. Nerve biopsy is crucial to document microvasculitis. Recognition of this entity is important because of its potential treatability. Unlike other paraneoplastic syndromes, anti-cancer chemotherapy and immunotherapy for vasculitis are both effective in this disorder.
Aged↗
A case of prostate cancer in 34 year old man presenting with generalized lymphadenopathy mimicking malignant lymphoma.
We report a case of prostate cancer in 34 year old man presenting with generalized lymphadenopathy mimicking malignant lymphoma without any urinary symptoms. Lymph node biopsy revealed metastatic adenocarcinoma and immunohistochemical stain was strongly positive to prostate antigen (PSA). Serum PSA level was also markedly elevated. Transrectal ultrasonogram showed mild enlargement in right lobe of prostate. Needle biopsy finding of prostate also was consistent with adenocarcinoma. Bone scan revealed multiple metastatic lesions including vertebrae, ribs, pelvis, and both femurs. Generalized lymphadenopathy and elevated PSA level was decreased after bilateral orchiectomy.
Adult↗
Pulmonary asbestosis: radiologic-pathologic brief report.
Pulmonary asbestosis is defined as bilateral diffuse interstitial fibrosis of the lungs caused by exposure to asbestos. Many occupations are at risk for asbestos exposure, particularly in the mining, milling, manufacturing, construction, shipbuilding, and automotive industries. Therefore, the prevalence of asbestosis should be fairly widespread. The diagnosis of asbestosis can be made on either clinical or pathological grounds. We recently encountered one case of asbestosis which was confirmed histologically. On HRCT, there was ground-glass opacity with irregular linear shadows, subpleural curvilinear lines and parenchymal bands. Neither plaque nor calcification were noted. The histologic findings observed on open-lung biopsy specimen were well in accord with those in HRCT. Many asbestos-coated bodies were present along with black dust.
Asbestosis↗
Motor and sensory demyelinating mononeuropathy multiplex (multifocal motor and sensory demyelinating neuropathy): a separate entity or a variant of chronic inflammatory demyelinating polyneuropathy?
We report 16 patients with motor and sensory demyelinating mononeuropathy multiplex (MSDMM) or multifocal motor and sensory demyelinating neuropathy (MMSDN). These patients had the clinical pattern of motor and sensory mononeuropathy multiplex, electrophysiological evidence of demyelination including conduction block, and segmental demyelination in the sural nerve biopsy. Sixty per cent of patients had high CSF protein. Eighty per cent of patients showed good responsiveness to steroid treatment. Unlike multifocal motor neuropathy (MMN), MSDMM is characterized by a shorter course, sensory deficits and sensory nerve conduction abnormalities, absence of GM1 antibody in most patients tested, and a good response to steroid therapy. We believe that MSDMM represents a variant of chronic inflammatory demyelinating polyneuropathy (CIDP) and an intermediate link between CIDP and MMN.
Adolescent↗
Anti-Hu-associated paraneoplastic sensory neuropathy responding to early aggressive immunotherapy: report of two cases and review of literature.
Anti-Hu-associated paraneoplastic sensory neuropathy (PSN) has been reported to be nonresponsive to immunotherapy or cancer therapy. We report 2 patients with anti-Hu-associated PSN who achieved sustained clinical improvement with early and aggressive immunotherapy 10-15 months before the diagnosis of small-cell lung carcinoma. Both had chronic "sensory neuronopathy plus"; in addition to sensory neuronopathy, case 1 had a motor-autonomic dysfunction with encephalopathy, and case 2 had a motor-autonomic dysfunction with swallowing difficulty. These two cases were unusual in that sustained clinical improvement was achieved with early aggressive immunotherapy before the detection of cancer and without any concomitant anticancer therapy or lowering of anti-Hu antibody titer. We believe that early and aggressive immunotherapy should be tried in any patient with anti-Hu-associated PSN, as it may induce sustained clinical improvement.
Aged↗
Augmentation of tumor metastasis by platelet-activating factor.
The effect of platelet-activating factor (PAF) on experimental pulmonary metastasis by the B16F10 murine melanoma and the possible involvement of PAF in the activities of tumor necrosis factor alpha (TNF-alpha) and interleukin 1alpha (IL-1alpha) in tumor metastasis were investigated. i.p. injection of PAF enhanced the lung colonization in a dose- and time-dependent manner. PAF enhanced lung colonization when it was administered after, but not before, B16F10 inoculation. Multiple injections of PAF were more effective than a single injection. Neutralization of endogenous PAF with PAF antagonist BN50739 decreased lung colonization, suggesting that endogenous PAF plays an important role in pulmonary metastases. A single i.p. injection of TNF-alpha or IL-1alpha caused a marked enhancement in lung colonization. TNF-alpha- and IL-1alpha-mediated enhancement in lung colonies was significantly inhibited by BN50739. These results demonstrate that PAF has a metastasis-enhancing effect and is a mediator of the metastatic activities of TNF-alpha and IL-1alpha.
Animals↗