Sequencing and chromosomal localization of the RA138 gene encoding a rice allergenic protein

A cDNA clone (RA138) encoding a rice allergenic (RA) protein has been isolated during a large-scale random sequencing of a cDNA library prepared from developing seeds. The nucleotide sequence of the RA138 gene contained an open reading frame (ORF, 477 bp) encoding a 17 kDa protein. The amino acid sequence deduced from the ORF was composed of 159 amino acid residues and was highly homologous to those from RA genes previously isolated, such as RA5 (92% identity), RA14 (73%), and RA17 (68%). The protein contained 10 cysteine residues that were conserved in the alpha-amylase/trypsin inhibitor family including RA proteins. Excluding a putative signal peptide consisting of 26 amino acid residues, the mature protein would be 14.4 kDa in size and have a pI of 7.0. DNA gel blot analysis under high stringency conditions indicated that multiple copies of the RA138 gene were present in the rice genome. The chromosomal location of the RA138 gene has been identified on chromosome 7 in a segregation analysis using a population of 164 recombinant inbred lines derived from a cross between Milyang 23 and Gihobyeo. The locus that may contain multiple copies of the RA138 was located between RFLP markers RG477A and C492 with genetic distances of 10.7 cM and 6.7 cM, respectively.

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.

Immunocytochemical localization of aquaporin 1 in the rat retina

Aquaporins transport water through membranes of various tissues, thereby playing crucial roles in a number of physiological processes. Aquaporin 1 (AQP1, also known as CHIP, channel forming integral membrane protein of 28 kDa) is the first identified protein to function as a water channel and has been recently shown to be present in the rat retina. This study was conducted to examine the cellular localization of AQP1 in the rat retina by immunocytochemistry using antisera against AQP1. The AQP1-like immunoreactivity was present in a certain population of amacrine cells and in the proximal processes of Müller cells. Thus, AQP1 appears to be important in the retinal homeostasis.

[18F]fluoromethylbenzylsulfonate ester: a rapid and efficient synthetic method for the N-[18F]fluoromethylbenzylation of amides and amines

We have prepared 4-[18F]fluoromethylbenzylsulfonate esters as fluoromethylbenzylating agents. These agents are readily prepared by an [18F]fluoride ion displacement of the corresponding bissulfonate esters. The application of these 4-[18F]fluoromethylbenzylsulfonate esters to N-alkylation reaction of spiperone and 1-phenylpiperazine shows that the products 3-N-(4-[18F]fluoromethylbenzyl)spiperone and 1-N-(4-[18F]fluoromethylbenzyl)-4-phenylpiperazine are rapidly produced with high radiochemical yields under a no-carrier-added condition.

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.

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.

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.

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.

Relationship between skin phototype and MED in Korean, brown skin

The Fitzpatrick skin classification has been a useful method to categorize cutaneous sensitivity to ultraviolet radiation (UVR), although it was based originally on responses in white skin. Because the relevance of this phototype in brown skin is in question, we investigated skin phototypes of university students by a self-reporting questionnaire and measured their MEDs in Korean, brown skin. After studying our explanation of the definition of Fitzpatrick skin types, 707 Korean university students answered the questionnaire. We then measured UVB MEDs in 156 randomly selected male students. The order of frequency of skin type was type III (55.0%), IV (29.0%), and V (12.3%) by the questionnaire, with the sun sensitive categories (types I and II) reported only for 3.7%. There was no significant difference in MEDs between types IV and V, and the mean MED of each skin type did not show a monotonic increase with increasing skin type. Subjects with MEDs of 70-90 mJ/cm2 (corresponding to the MED of skin type V, as proposed by Pathak & Fitzpatrick) represented about half or more of the subjects in all categories, even types II and III. Subjects with MEDs lower than 60 mJ/cm2 were more prevalent in types II and III compared with types IV and V. We suggest that there is at best a weak relationship between the skin types, by the Fitzpatrick method, and MEDs in Korean, brown skin.

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.

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.

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.

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.

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.

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.

Isaacs' syndrome associated with chronic inflammatory demyelinating polyneuropathy

We report the first case of Isaacs' syndrome in which an inflammatory demyelinating neuropathy was documented histologically. For 9 months, the patient developed slowly progressive weakness, muscle spasms and stiffness, fasciculations, and myokymia in the arms, which were unmodified by sleep. Nerve conduction studies showed multifocal motor conduction block, abnormal dispersion phenomenon, and abnormal sensory and mixed nerve conduction. Needle electromyogram showed continuous motor unit potentials at rest with bursts of rapid-firing discharges which were unaffected by spinal anesthesia but diminished by peripheral nerve block and completely abolished by local curarization. Sural nerve biopsy demonstrated an inflammatory demyelinating neuropathy. Muscle cramping, twitching, and stiffness responded to phenytoin. The patient's weakness gradually responded to prednisone and azathioprine. Over a 17-year period, the patient had three relapses which were well controlled with prednisone and azathioprine. At this time, the patient is symptom-free without any medication.

Multifocal demyelinating motor neuropathy: pathologic evidence of 'inflammatory demyelinating polyradiculoneuropathy'

We report a case of multifocal demyelinating motor neuropathy in a patient with a 5-year history of progressive, asymmetric, predominantly motor weakness characterized by multifocal progression, multifocal conduction block, and lack of response to steroid therapy. Neuropathologic findings at autopsy showed an "inflammatory demyelinating polyradiculoneuropathy" in the motor cranial nerves and motor roots of peripheral nerves, an extensive deposition of IgG and focal accumulations of IgM in the peripheral nerve motor roots, and loss of motor neurons. These findings clearly document an inflammatory demyelinating polyradiculoneuropathy in multifocal demyelinating motor neuropathy, suggesting a close relation with chronic inflammatory demyelinating polyneuropathy.

Peroneal nerve repetitive nerve stimulation test: its value in diagnosis of myasthenia gravis and Lambert-Eaton myasthenic syndrome

We have developed a repetitive nerve stimulation (RNS) technique for the peroneal nerve. Normal limits for the decremental responses for the anterior tibialis and extensor digitorum brevis muscles are 6-21% at the low rate of stimulation and 44-70% at the high rate of stimulation. These values exceed the normal limits for other commonly tested muscles. This may be due to the lower safety factor for neuromuscular transmission for the anterior tibialis and extensor digitorum brevis muscles. We present 4 cases in which the peroneal nerve RNS test was crucial for the diagnosis of the limb-girdle form of MG or LEMS. Thus, we conclude that, in a small number of patients with neuromuscular transmission disorders, the peroneal nerve RNS test is needed for confirmation of disease.

Light- and electron-microscopic study of substance P-immunoreactive neurons in the guinea pig retina

Substance P (SP) immunoreactivity in the guinea pig retina was studied by light and electron microscopy. The morphology and distribution of SP-immunoreactive neurons was defined by light microscopy. The SP-immunoreactive neurons formed one population of amacrine cells whose cell bodies were located in the proximal row of the inner nuclear layer. A single dendrite emerged from each soma and descended through the inner plexiform layer toward the ganglion cell layer. SP-immunoreactive processes ramified mainly in strata 4 and 5 of the inner plexiform layer. SP-immunoreactive amacrine cells were present at a higher density in the central region around the optic nerve head and at a lower density in the peripheral region of the retina. The synaptic connectivity of SP-immunoreactive amacrine cells was identified by electron microscopy. SP-labeled amacrine cell processes received synaptic inputs from other amacrine cell processes in all strata of the inner plexiform layer and from bipolar cell axon terminals in sublamina b of the same layer. The most frequent postsynaptic targets of SP-immunoreactive amacrine cells were the somata of ganglion cells and their dendrites in sublamina b of the inner plexiform layer. Amacrine cell processes were also postsynaptic to SP-immunoreactive neurons in this sublamina. No synaptic outputs onto the bipolar cells were observed.