bluuebunny/crossref_metadata_2025 huggingface dataset:
A Case Of Paraneoplastic Neuropathy (PN) And Anti‐Glycolipid Antibodies (GLA)
Authors: Agazzi P , Polo A , Ferrari S , Cavallaro T , Rizzuto N , Nardelli E.
Published: March 2003

Subacute sensory neuronopathy (SSN) is most commonly seen in association with small cell carcinoma of the lung (SCLC), however lower motor neuron syndrome with or without upper motor neuron involvement may occur. Anti‐neuronal antibodies, called “anti‐Hu”, can be frequently demonstrated. Other antibodies that react with the carbohydrate epitope of ganglioside GM1, associated with primary motor PN, are not frequent. We describe a 73‐year‐old man with subacute onset of paraesthesiae starting in his finger and toes and spreading proximally. A few months later he developed generalized muscle weakness and was admitted to another hospital. On examination he was unable to write, as well as to stand or walk without support. Tendon reflexes were absent. He had no cranial nerve involvement and had no complain of pain. Pinprick, vibration and four limb positions were impaired distally. CSF study revealed increased protein (90 mg/dl) and lymphocytes (14/mm3). SCLC was identified in paratracheal lymphnodes and treated with chemotherapy (Carboplatinum and Etopoxide) and mediastinum irradiation (36 Gray). No clinical improvement was observed after i.v. immunoglobulins (400 mg/kg/day for 5 days). He was wheelchair‐bound and unable to feed himself or to recognize the four limb position when he was admitted in the Neurological Department, University of Verona. Eye movements and winking were markedly reduced. Median (48.6 m/s) and ulnar (46 m/s) nerve study revealed slow conductions. ESP were undetectable. SSEP could not be evoked from the four limbs. Cyclophosphamide (250 mg/day for 5 days), monthly plasma exchange associated with prednisone for six months, and Azatioprine were used. Ambigous low titre of antibodies against neuronal nuclei was identified but anti‐Hu antibodies were not detected. The serum antibody titres against glycolipids (GM1, GM2, GM3, GQ1b, GD1a, GD1b, sulfatides) were elevated (>1:720) and had no substantial change at the bimonthly controls in the last 36 months. As negative control case for GLa, we used the Hu‐negative serum from a patient who had electrophysiologically confirmed selective sensory involvement associated with SCLC and long survival (29 months). We hypothesized that the neurological course with prominent motor deficit is probably related to serum anti‐GL antibody specificities. The presence of ganglioside mimicry in the SCLC (Fuentes et al., Lung Cancer, 1997) appears to be determinant for the induction of anti‐GLa. However the anti‐neural immune‐response may be related to host factors.
Microvasculitis In Non‐Diabetic Lumbosacral Radiculoplexus Neuropathy (LSRPN): Similarity To The Diabetic Variety (DLSRPN)
Authors: Dyck Pjb , Engelstad J , Norell J , Dyck Pj
Published: March 2003

Diabetic lumbosacral radiculoplexus neuropathy (DLSRPN) has been shown to be due to ischemic injury from microvasculitis. The present study tests whether ischemic injury and microvasculitis are the pathologic cause of non‐diabetic lumbosacral radiculoplexus neuropathy (LSRPN), and whether the pathologic alterations are different between LSRPN and DLSRPN. We studied distal cutaneous nerve biopsies of 47 patients with LSRPN and compared findings with those of 14 age‐matched healthy controls and 33 DLSRPN patients. In both disease conditions, we found evidence of ischemic injury (multifocal fiber degeneration and loss, perineurial degeneration and scarring, characteristic fiber alterations, neovascularization, and injury neuroma) that we attribute to microvasculitis (mural and perivascular mononuclear inflammation of microvessels, inflammatory separation, fragmentation and destruction of mural smooth muscle, and previous microscopic bleeding [hemosiderin]). Teased nerve fibers in LSRPN showed significantly increased frequencies of axonal degeneration, segmental demyelination, and empty nerve strands. The segmental demyelination appeared to be clustered on fibers with axonal dystrophy. The nerves with abnormal frequencies of demyelination were significantly associated with nerves showing multifocal fiber loss. We reached the following conclusions: 1) LSRPN is a serious condition with much morbidity that mirrors DLSRPN. 2) Ischemic injury from microvasculitis appears to be the cause of LSRPN. 3) Axonal degeneration and segmental demyelination appear to be linked and due to ischemia. 4) The pathologic alterations in LSRPN and DLSRPN are indistinguishable, raising the question whether these 2 conditions have a common underlying mechanism, and whether diabetes mellitus contributes to the pathology or is a risk factor in DLSRPN. 5) Both LSRPN and DLSRPN are potentially treatable conditions.
IL‐1β and Interferon‐γ Induce Schwann Cell Proliferation And Death
Authors: Conti G , Scarpini E , De Pol A , Bava L , Vaccina F , Bussini S , Baron PL , Scarlato G.
Published: March 2003

Schwann cell apoptosis (programmed cell death) has been recently observed during the development and in rare pathological conditions of the peripheral nervous system (PNS) characterized by demyelination‐remyelination. However, the relevance of the phenomenon, and the characterization of the involved molecules are still controversial. This study has been designed to detect in Schwann cell tissue culture whether the administration of different doses of the two pro‐inflammatory cytokines IL‐1β and IFN‐γ, singly or in combination, can induce Schwann cell proliferation and/or death via apoptosis. Our results indicate that the administration of IL‐1β and IFN‐γ induced cell proliferation and concomitant apoptosis in Schwann cells that is numerically related to the different type and dosage of the two pro‐inflammatory cytokines. Moreover, Schwann cell apoptosis was maximal within 24 hours following the administration of 50 U/mL of IFN‐γ, and we did not observe any synergistic action of the two pro‐inflammatory molecules. These findings provide further “in vitro” evidence that cytokines can interact with Schwann cells through a mechanism that is probably mediated by the modulation in time and concentrations of these different pro‐inflammatory molecules.
Experimental Lead Neuropathy: Ultrastructural And Molecular Changes In The Rat Sciatic Nerve
Authors: Baron PL , Bianchi R , Livraghi S , Bussini S , Bava L , Scarpini E , Conti G , Scarlato G , Tacconi MT , Oggioni N , Petruccioli Mg , Cavaletti G , Tredici G.
Published: March 2003

Experimental lead intoxication is an important model for the study of cellular and molecular mechanisms of segmental demyelination in peripheral nerve. In this report we have compared pathological changes with the molecular and immunohistochemical expression of the proteins of compact and non‐compact myelin in the demyelinating neuropathy induced in Sprague‐Dawley rats after chronic administration (3 and 6 months) of lead acetate in drinking water. All the rats underwent the neurophysiological determination of the conduction velocity in the tail nerve at baseline and 3, 4.5 and 6 months after the beginning of the lead acetate administration. At the end of the treatment period the rats were sacrificed and sciatic nerve specimens were obtained. The neurophysiological study demonstrated a significant decrease in the nerve conduction velocity, which was already evident at the first determination (3 months) and persisted along the entire experiment. The neurophysiological results were in agreement with the pathological observations performed in the sciatic nerve, where several large demyelinated fibers were observed in the lead‐intoxicated rats. Northern and Western blot analysis demonstrated that steady state mRNA and protein levels for P0, MBP, PMP22 and PLP were not changed comparing treated and control rats. Immunohistochemistry on teased fibers revealed that those proteins were distributed in areas of compact myelin along the internodes. In control fibers, as expected, MAG was found in the periaxonal cytoplasm, at nodes of Ranvier, and in the Schmidt‐Lanterman incisures. In lead neuropathy, MAG was still limited to discrete regions, but the intensity of staining was reduced, in accordance with changes of paranodal structures. Immunohistochemical localization of other proteins of non‐compacted myelin, including connexin‐32, E‐cadherin and β‐catenin was also examined. Our data further suggest that chronic lead intoxication in the rat produces segmental demyelination due primarily to Schwann cell dysfunction.
The D355V Mutation Decreases EGR2 Binding To An Element Within The CX32 Promoter
Authors: Musso M , Balestra P , Bellone E , Cassandrini D , Di Maria E , Lamba Doria L , Grandis M , Mancardi GL , Schenone A , Levi G , Ajmar F , Mandich P.
Published: March 2003

Mutations in the early growth response 2 (EGR2) gene are associated with some forms of Charcot‐Marie‐Tooth disease (CMT) and other demyelinating neuropathies. These mutations modify the EGR2 binding to specific DNA sequences suggesting a role in the transcriptional control of myelination‐specific genes. In this study we demonstrated that the D355V mutation, associated with a CMT case combining axonal and demyelinating abnormalities, reduces three times the affinity of EGR2 to its consensus sequence and ten times its affinity to a responsive element present in the human connexin 32 promoter. These findings could indicate that this EGR2 mutation leads to the development of CMT1 through the transcriptional deregulation of connexin 32. This research was partially supported by a MURST grant to FA, by a Ministero della Sanità grant to PM. Our laboratory is a member of the European Charcot‐Marie‐Tooth Consortium co‐ordinated by Prof. Christine Van Broeckhoven.
Neurotrophin Effect On The SH‐SY5Y Human Neuroblastoma (HN) MODEL Of Cddp‐Induced Neurotoxicity
Authors: Nicolini G , Cavaletti G , Miloso M , Donzelli E , Galbiati S , Di Silvestro A , Braga M , Marmiroli P , Tredici G.
Published: March 2003

Neurotrophins (NGF, BDNF, NT‐3, NT‐4/5) have several pharmacological effects on adult neurons, and it has been proposed that they may play a role in sustaining the reparative mechanisms following peripheral nerve injuries. In this study we evaluated the effect of recombinant human (rh) neurotrophins (rhNGF, gifted by Boehringer Mannheim, Germany; rhBDNF and rhNT‐3 gifted by Amgen Co, USA) on cisplatin (CDDP)‐induced neurotoxicity in HN SH‐SY5Y neurotoxicity model. The cells were differentiated with RA 10 μM and exposed for 4 hours to 2.5 μg/ml CDDP with 50 ng/ml rhNGF, rhBDNF or rhNT‐3. Then the cells were maintained in DMEM, 10 μM RA and 50 ng/ml rhNGF, rhBDNF or rhNT‐3 and assessed for neurotoxicity 48, 72 and 96 hours after the first treatment with RA. Cells were considered “differentiated” when their neurite was longer than 50 μm. At each time point the neurite length was measured on at least 200 randomly selected cells/dish and the percentage of differentiated cells per culture was calculated. Exposure of RA‐differentiated SH‐SY5Y cells to CDDP 2.5 μg/ml induced a reduction of the neurite length and of the percentage of differentiated cells. The co‐treatment of RA‐differentiated SH‐SY5Y neuroblastoma cells with CDDP and rhBDNF restored the neurite length and the percentage of differentiated cells to values similar to those of cells treated with RA 10 μM alone. On the contrary, exposure of RA‐differentiated SH‐SY5Y neuroblastoma cells to rhNT‐3/CDDP combination did not significantly modify the neurite length nor the percentage of differentiated cells in comparison to the cells treated with CDDP alone. The effect of rhNGF was intermediate between that of rhBDNF and the absence of any protection observed with rhNT‐3. Our results are in agreement with the observation that RA treatment induces the expression of functional trkB receptors in SH‐SY5Y cells, which results in BDNF‐mediated neuronal differentiation of SH‐SY5Y cells and explains the BDNF neuroprotective effect observed, while trkA receptors are expressed at a lower level and trkC receptors are not expressed even after RA‐induced differentiation.
Axonal Neuropathy Associated With Cold Agglutinins: A Vasculitic‐Ischaemic Neuropathy
Authors: Bezzi G , Previtali S , Nemni R , Epis R , Compagnoni V , Canal N , Quattrini A.
Published: March 2003

Cold agglutinin (CA) disease is an autoimmune hemolytic process characterized by chronic anemia, hemoglobinuria, cold induced rash, and acrocyanosis of exposed body parts. Although few cases of peripheral neuropathies have been observed in patients with CA, the mechanism of peripheral nervous system involvement is still uncertain. However, similar to other neuropathies due to IgM paraproteinaemia, such as anti‐myelin associated glycoprotein, or anti‐acidic glycolipid sulphate‐3‐glucuronyl paragloboside, the direct effect of the antibody on nerve constituents is considered the pathogenetic mechanism causing the demyelinating neuropathy. We report a patient with CA and sensorimotor peripheral neuropathy with electrophysiological and histological findings of a severe acute axonal neuropathy. Pathological findings show vascular damage in the nerve, suggesting a major role for ischaemic/vasculitic pathogenetic mechanism of the peripheral neuropathy in CA.
HNPP Associated With An Alternatively‐Sized Deletion At Chromosome 17p11.2‐p12
Authors: Taioli F , Fabrizi GM , Rigatelli F , Rizzuto N.
Published: March 2003

Chromosome 17p11.2‐p12 is prone to unequal crossing‐over events associated with inherited neuropathies (17p12) and with forms of mental retardation known as Smith Magenis Syndrome (SMS) (17p11.2). A 1.5 megabase (Mb) duplication or deletion encompassing the PMP22 gene causes respectively Charcot‐Marie‐Tooth neuropathy type 1A (CMT1A) and Hereditary Neuropathy with liability to Pressure Palsies (HNPP); the unequal crossing over is caused by misalignment of two low‐copy repeat elements named CMT1A‐REP which flank the duplicated/deleted region. HNPP is genetically homogenous; only exceptional cases have been associated with non‐sense mutations of PMP22. In a four‐generation pedigree five individuals were affected with a clinically and pathologically typical HNPP (tomaculous neuropathy). PFGE analysis with SacII endonuclease and probe pNEA101, which maps to the proximal CMT1A‐REP, failed to detect the 770 and 820 kb junction fragments associated with the 1.5‐Mb deletion. Restriction by SacII and NotI showed respectively two novel junction fragments of ≅1.1 and 1.25 Mb, suggesting the presence of a shorter deletion. Nucleotide sequencing of PMP22 was normal. Linkage analysis using the markers D17S1921, D17S839, D17S1357, D17S12, D17S261, D17S953 and D17S1843 confirmed the results of PFGE by demonstrating loss of heterozygosity for D17S1357 and D17S122. The report underlines the high instability of chromosome 17p11.2‐p12 and prompts to investigate other mechanisms of genetic rearrangement in that region.
Serum Antibodies To Campylobacter Jejuni In Multifocal Motor Neuropathy
Authors: Terenghi F , Allaria S , Carpo M , Scarlato G , Nobile‐Orazio E.
Published: March 2003

Multifocal motor neuropathy (MMN) has been frequently associated with high titers of anti‐ganglioside antibodies but the cause of this immune response is not known. Recently a possible association with an antecedent Campylobacter jejuni (CJ) infection has been reported in three patients who developed MMN and high titers of anti‐GM1 antibodies after CJ enteritis. Furthermore reactivity with the lipopolysaccharides (LPS) of CJ have been reported in some patients with chronic motor neuropathies and high anti‐ganglioside antibodies. To determine whether CJ may be involved in the pathogenesis of MMN we examined 22 patients with MMN, including 6 with anti‐ganglioside reactivity (2 GM1, 2 GD1a, 1 GM1+GD1a, 1 GM1+GM2), for the presence of anti‐CJ antibodies by Covalink ELISA and immunoblot, and correlated their presence with that of anti‐ganglioside antibodies. As controls we examined 17 patients with chronic inflammatory demyelinating polyneuropathy (CIDP), 23 with amyotrophic lateral sclerosis (ALS), 43 with other neurological diseases (OND) and 23 normal subjects (NS). By ELISA we found high titers (1/640) of anti‐CJ in 8 patients (36%) with MMN (4 IgM, 2 IgA, 1 IgM+IgA, 1 IgM+IgG+IgA), 2 each with CIDP (12%; 1 IgA and 1 IgM) and ALS (9%; 1 IgM and 1 IgG), one with OND (2%; IgG) and none in NS (MMN vs. neurological controls p < 0.0005; MMN vs. NS p < 0.005). By immunoblot, 5 patients with MMN (23%), one of whom was also positive by ELISA, had a very intense reactivity (3 IgG, 1 IgA, 1 IgG+IgA) with a 14 kD band corresponding to the lipopolysaccharides (LPS) of CJ, as compared to two patients with ALS (9%; 1 IgG and 1 IgM), one each with CIDP (6%; IgG) and NS (4%), while no reactivity was found in OND (MMN vs. neurological controls p < 0.01). Overall anti‐CJ antibodies were detected by at least one method in 12 MMN patients (55%), 3 CIDP (18%), 4 SLA (17%), 1 OND (2%) and 1 NS (4%) (MMN vs. neurological controls p < 0.0005; MMN vs. NS p < 0.0005). Anti‐ganglioside antibodies were similarly frequent in patients with (33%) or without (20%) anti‐CJ reactivity. The high frequency of anti‐CJ antibodies in MMN patients supports the hypothesis of an association between MMN and CJ even if it is still unclear whether this reflects a concurrent or previous CJ infection possibly involved in the pathogenesis of MMN. If this is the case, the lack of association with anti‐ganglioside antibodies suggests that these antibodies might not be the only anti‐neuronal antigens induced by CJ.
Overexpression Of GPR7 In Schwann Cells From Patients With Peripheral Neuropathies
Authors: Zaratin PF , Quattrini A , Previtali S , Hervieu G , Scheideler MA
Published: March 2003

The identification of regulated gene products that play a role in Schwann cell‐axon contact after nerve injuries may have important implications for pain mechanisms and nerve repair processes. Schwann cell‐intrinsic defects have been recently shown to cause neuropathies associated with pain (Gillespie et al., 2000). The 7TM GPR7, originally described by O'Dowd et al. (1995) as a likely G‐protein coupled receptor, is a human orphan receptor expressed in the nervous system with sequence similarity to both somatostatin and opioid receptors. Using real time quantitative PCRTM we evaluated the expression of GPR7 in sural nerve biopsies from patients with different kinds of peripheral neuropathies. We observed that GPR7 expression was significantly (p < 0.001) increased in sural nerves when an epineurial and endoneurial perivascular inflammatory infiltration was present. The overexpression was particularly noted in patients with painful peripheral neuropathies with an inflammatory, immuno and vasculitic etiology. In order to confirm changes in GPR7 expression at the protein level, we performed immunofluorescence staining on sections of neuropathic human sural nerves. A comparative analysis of rat injured sciatic nerves was also performed. We observed that GPR7 receptor is expressed by Schwann cells and that the amount of Schwann cell‐staining in both human and rat nerve is increased in conditions of inflammatory neuropathy. In addition, we observed that the expression of GPR7 was significantly decreased in severe axonal neuropathies, suggesting that GPR7 expression is axon dependent. Immunofluorescence staining in rat cultured Schwann cells suggested that the expression GPR7 increased during Schwann‐axon interaction. Taken together these results suggest that molecules such as GPR7 whose expression in Schwann cells varies under pathological conditions may play a role in the pathogenesis of human neuropathies. Altered GPR7 expression may disrupt myelination leading to progression of the neuropathy. Alternatively, GPR7 may play a role in Schwann cell‐axon signaling and thereby influence axonal function in neuropathies leading to a painful phenotype.
Focal Amyotrophy In Neurofibromatosis 2
Authors: Trivedi R , Byrne J , Huson SM , Donaghy M
Published: March 2003

Neurofibromatosis type 2 (NF2) is an autosomal dominant disorder characterised by bilateral vestibular schwannomas and other CNS tumours including meningiomas and spinal schwannomas. Occasionally, peripheral neuropathy occurs in these patients but this is the first report of focal amyotrophy. Clinical, electrophysiological, and imaging data from four NF2 patients seen at a specialist neurofibromatosis clinic over a 4 year period are described in whom symptomatic focal amyotrophy preceded the diagnosis of NF2. Two presented with wasting and weakness of a single muscle group, several years before NF2 was diagnosed. In one patient a mononeuritis multiplex was the presenting feature of NF2, and in one patient focal wasting and weakness developed after the diagnosis of NF2 was made. In none of the four cases could a focal peripheral nerve or root neurofibroma be identified despite extensive imaging with MRI, and the limitations of neuroimaging for identifying a structural cause in patients with NF2 with a focal peripheral nerve lesion is discussed. It is likely that NF2 may affect peripheral nerve structures in a manner distinct from a compressive schwannoma.
Antibody recognition of amyloidogenic transthyretin variants in serum of patients with familial amyloidotic polyneuropathy
Authors: Palha JA , Moreira P , Olofsson A , Lundgren E , Saraiva MJ
Published: March 2003

Familial amyloidotic polyneuropathy (FAP) is a late‐onset inherited disease characterized by the deposition of amyloid fibrils. FAP is associated with mutations on the transthyretin (TTR) gene. A monoclonal antibody, MAb 39‐44, reacting with high molecular weight aggregates of TTR but not with tetrameric TTR has recently been generated and characterized. This antibody recognizes a cryptic epitope that is expressed in isolated recombinant amyloidogenic mutants and in ex vivo amyloid. In the present work we show that this amyloid‐specific antibody specifically recognizes in a direct enzyme‐linked immunoassay (ELISA) plasma TTR from carriers of various mutations associated with FAP, both in asymptomatic individuals and in patients. In contrast, it does not react with plasma TTR from healthy individuals or that from carriers of nonpathogenic mutations. Using the ELISA developed in this study we identified three different TTR mutations in Portuguese patients with neuropathy of unknown cause, later shown to have amyloid tissue deposition. This antibody recognizes conformations that express cryptic epitopes shared by amyloidogenic TTR variants associated with FAP, not present among nonpathogenic TTR molecules. This antibody will contribute to further identify and characterize intermediates of the amyloidogenic cascade. In addition, it will also be useful for screening amyloidogenic TTR mutations in patients with neuropathy of unknown cause, prior to precise molecular diagnosis using protein and/or DNA analysis.
The current state of diabetes management in Taiwan
Authors: Chuang LM , Tsai ST , Huang BY , Tai TY
Published: March 2003

The aim of this study was to provide an overview of diabetes management and complication status in Taiwan. A cohort of 2446 patients (from 25 diabetic centers) with more than 12 months of diabetes management participated and data were collected by interviews and reviewing the medical records. Overall, 97% were diagnosed as type 2 diabetes, with a mean age (+/−S.D.) of 61.6 +/− 11.3 years, duration of diabetes of 10.3 +/− 7.3 years and age at onset of diabetes of 51.5 +/− 11.8 years. Mean BMI was 25.1 +/− 3.6 kg/m(2) and about 50% had BMI> 25 kg/m(2). Majority (75%) were treated with oral hypoglycemic agents (OHAs), 14% with insulin and 10% with combination of insulin and OHA. Mean HbA(1c) was 8.1 +/− 1.6% and 59% had HbA(1c)> 7.4% (1% above the upper limit of normal range, 4.7‐6.4%). Mean FBG was 9.0 +/− 3.3 mmol/l and 59% had FBG> 7.8 mmol/l. Of all the patients who had screening for complications, cataract (38%), neuropathy (30%), proteinuria (17%) and stroke (6%) were the most frequently reported eye, feet, kidney and late complications. We conclude that the majority of patients involved in this study had unsatisfactory glycaemic control which may lead to diabetes complications.
Enhanced in situ expression of aldose reductase in peripheral nerve and renal glomeruli in diabetic patients
Authors: Kasajima H , Yamagishi SI , Sugai S , Yagihashi N , Yagihashi S
Published: March 2003

To explore the relationships between polyol pathway‐related enzymes and pathologic features, we examined the immunohistochemical expression of aldose reductase (AR) and sorbitol dehydrogenase (SDH) in the peripheral nerve and kidney tissues collected postmortem from diabetic patients and compared it with those from non‐diabetic patients. Tissue AR protein concentrations were also quantified. In non‐diabetic patients, AR distributed in pericytes, smooth muscle cells of endo‐and epi‐neurial microvessels, Schwann cells in the sciatic nerve, and tubular cells of the renal medulla. By contrast, positive SDH reactions were observed in tubular cells of the renal cortex but were faint in the sciatic nerve. Diabetic patients frequently showed dense AR expressions in the sciatic nerve. In nephropathic diabetic patients, the glomerular mesangial area showed diffuse positive reactions for AR. The severity of structural changes in glomeruli correlated with the intensity of immunoreactive AR (r(2)=0.626. P <0.01). AR contents in the renal cortex and sciatic nerve from diabetic patients were 1.5‐ and 1.8‐fold greater than those from non‐diabetic patients, respectively (P <0.05 for both). These findings are the first to demonstrate enhanced AR expressions in peripheral nerve and renal glomeruli in diabetic patients and its relevance to the characteristic pathology.
Impaired inhibitory G‐protein function contributes to increased calcium currents in rats with diabetic neuropathy
Authors: Hall KE , Liu J , Sima AAF , Wiley JW
Published: March 2003

There is a growing body of evidence that sensory neuropathy in diabetes is associated with abnormal calcium signaling in dorsal root ganglion (DRG) neurons. Enhanced influx of calcium via multiple high‐threshold calcium currents is present in sensory neurons of several models of diabetes mellitus, including the spontaneously diabetic BioBred/Worchester (BB/W) rat and the chemical streptozotocin (STZ)‐induced rat. We believe that abnormal calcium signaling in diabetes has pathologic significance as elevation of calcium influx and cytosolic calcium release has been implicated in other neurodegenerative conditions characterized by neuronal dysfunction and death. Using electrophysiologic and pharmacologic techniques, the present study provides evidence that significant impairment of G‐protein‐coupled modulation of calcium channel function may underlie the enhanced calcium entry in diabetes. N‐ and P‐type voltage‐activated, high‐threshold calcium channels in DRGs are coupled to mu opiate receptors via inhibitory G(o)‐type G proteins. The responsiveness of this receptor coupled model was tested in dorsal root ganglion (DRG) neurons from spontaneously‐diabetic BB/W rats, and streptozotocin‐induced (STZ) diabetic rats. Intracellular dialysis with GTPgammaS decreased calcium current amplitude in diabetic BB/W DRG neurons compared with those of age‐matched, nondiabetic controls, suggesting that inhibitory G‐protein activity was diminished in diabetes, resulting in larger calcium currents. Facilitation of calcium current density (I(DCa)) by large‐amplitude depolarizing prepulses (proposed to transiently inactivate G proteins), was significantly less effective in neurons from BB/W and STZ‐induced diabetic DRGs. Facilitation was enhanced by intracellular dialysis with GTPgammaS, decreased by pertussis toxin, and abolished by GDPbetaS within 5 min. Direct measurement of GTPase activity using opiate‐mediated GTPgamma[(35)S] binding, confirmed that G‐protein activity was significantly diminished in STZ‐induced diabetic neurons compared with age‐matched nondiabetic controls. Diabetes did not alter the level of expression of mu opiate receptors and G‐protein alpha subunits. These studies indicate that impaired regulation of calcium channels by G proteins is an important mechanism contributing to enhanced calcium influx in diabetes.
Methylprednisolone exacerbates axonal loss following optic nerve trauma in rats
Authors: Steinsapir KD , Goldberg RA , Sinha S , Hovda DA
Published: March 2003

PURPOSE: This study investigates the clinical dogma that very high doses of methylprednisolone helpful in spinal cord injury are also helpful in optic nerve trauma. Methods: The right optic nerve of 29 male rats received a 5 second traumatic crush followed 30 minutes later by one of five intravenous treatments (methylprednisolone 30 mg/kg, 60 mg/kg, 90 mg/kg, 120 mg/kg, or saline). Treatment was continued for three additional administrations at 6 hour intervals. Untreated sham controls (n = 7) were also prepared. Six weeks after injury, animals were sacrificed, perfused and optic nerves systematically counted. RESULTS: Axon counts (means +/− s.e.m.) were as follows: Saline = 16,670 +/− 8,900 (n = 5); Methylprednisolone: 30 mg/kg = 8,098 +/− 4,741 (n = 5); 60 mg/kg = 6,925 +/− 6,517 (n = 4); 90 mg/kg = 2,663 +/− 2,653 (n = 4); 120 mg/kg = 6,149 +/− 3,487 (n = 6). Consequently, the data revealed that saline treated animals retained more axons than those that were administered methylprednisolone (p < 0.02). CONCLUSIONS: We conclude that methylprednisolone exacerbates axonal loss following crush injury in the rat optic nerve. Based on the results of this study, clinical studies of traumatic optic neuropathy in the future should also examine the possibility that corticosteroid treatment may have an adverse effect on visual outcome following optic nerve trauma.
Congenital hypomyelination neuropathy in a newborn infant: unusual cause of diaphragmatic and vocal cord paralyses
Authors: Hahn JS , Henry M , Hudgins L , Madan A
Published: March 2003

We report a case of congenital hypomyelination neuropathy presenting at birth. The infant had generalized hypotonia and weakness. There was decreased respiratory effort along with a right phrenic nerve and left vocal cord paralyses. Tongue fasciculations were present. Deep tendon reflexes were absent in the upper extremities and hypoactive (1+) in the lower extremities. Magnetic resonance imaging of the head revealed no intracranial abnormalities, including normal cerebral myelination. Nerve conduction study showed absence of motor and sensory action potentials in the hands when the nerves in the upper limbs were stimulated. A motor response could be elicited only in the proximal leg muscles. Needle electromyography study was normal in the proximal limb muscles, but showed active denervation in the distal muscles of the arm and leg. These findings were thought to be consistent with a length‐dependent sensorimotor peripheral polyneuropathy of axonal type with greater denervation of the distal muscles. A biopsy of the quadriceps muscle showed mild variability in fiber diameter, but no group typing or group atrophy. The muscle fibers showed no intrinsic abnormalities. Biopsy of the sural nerve showed scattered axons with very thin myelin sheaths. There was also a nearly complete loss of large diameter myelinated fibers. No onion bulb formations were noted. These findings were thought to be consistent with congenital hypomyelination neuropathy with a component of axonopathy. DNA analysis for identification of previously characterized mutations in the genes MPZ, PMP22, and EGR2 was negative. Several attempts at extubation failed and the infant became increasingly ventilator‐dependent with increasing episodes of desaturation and hypercapnea. He also developed increasing weakness and decreased movement of all extremities. He underwent surgery at 2 months of age for placement of a gastrostomy tube and a tracheostomy. He was discharged from the hospital on a ventilator at 6 months of age. The infant was 13 months old at the time of submission of this report. Although he appears cognitively normal, he remains profoundly hypotonic and is on a home ventilator. There was no evidence of progressive weakness. Congenital hypomyelination neuropathy is a rare form of neonatal neuropathy that should be considered in the differential diagnosis of a newborn with profound hypotonia and weakness. It appears to be a heterogeneous disorder with some of the cases being caused by specific genetic mutations.
SEQUENCE TYPING CONFIRMS THAT CAMPYLOBACTER JEJUNI STRAINS ASSOCIATED WITH GUILLAIN‐BARRÉ AND MILLER‐FISHER SYNDROMES ARE OF DIVERSE GENETIC LINEAGE, SEROTYPE, AND FLAGELLA TYPE
Authors: Dingle KE , Van den Braak N  , Colles FM , Price LJ , Woodward DL , Rodgers FG , Endtz HP , Van Belkum A , Maiden MCJ.
Published: March 2003

Guillain‐Barré syndrome (GBS) and Miller‐Fisher syndrome (MFS) are correlated with prior infection by Campylobacter jejuni in up to 40% of cases. Nucleotide sequence‐based typing of 25 C. jejuni isolates associated with neuropathy permitted robust comparisons with equivalent data from approximately 800 C. jejuni isolates not associated with neuropathy. A total of 13 genetic lineages and 20 flaA short variable region nucleotide sequences were present among the 25 isolates. A minority of isolates (4 of 25) had the flaA short variable region nucleotide sequences that were previously proposed as a marker for GBS‐associated isolates. These 4 isolates probably represented the Penner serotype 19 lineage, which has been proposed to have an association with GBS.
ALLOXANTHIN IN DINOPHYSIS NORVEGICA (DINOPHYSIALES, DINOPHYCEAE) FROM THE BALTIC SEA
Authors: Meyer‐Harms Bettina , Pollehne Falk
Published: March 2003

The pigment composition of Dinophysis norvegica Ehrenberg from the central Baltic Sea differs from the normal pigment pattern found in dinoflagellates, which contain peridinin as a typical marker pigment. In D. norvegica isolated by cell fractionation of field samples, the major carotenoid was alloxanthin, a typical cryptomonad pigment. No evidence was found that the presence of alloxanthin was due to a recent phagotrophic uptake of cryptomonads, so the presence of alloxanthin in D. norvegica may be a consistent feature of a permanent endosymbiosis.
PHYLOGENETIC RELATIONSHIPS OF THE FRESHWATER ALGA BOLDIA ERYTHROSIPHON (COMPSOPOGONALES, RHODOPHYTA) BASED ON 18S rRNA GENE SEQUENCES
Authors: Holton Raymond W. , Boele‐Bos Stella A. , Stam Wytze T.
Published: March 2003

The nuclear small‐subunit ribosomal DNA sequence from the freshwater red alga Boldia erythrosiphon Herndon emend Howard et Parker was determined. Phylogenetic analysis confirms the positioning of this species within the bangiophycidean order of the Compsopogonales. The results strongly suggest that occupation of freshwater habitats by marine red algae has happened at least twice during red algal evolution.
ENHANCED GROWTH RATES OF THE GERMLINGS OF CYANOBACTERIAL RESTING SPORES (AKINETES)
Authors: Jameson I. , Thompson P.A. , Blackburn S.
Published: March 2003

In experiments with the toxic cyanobacterium, Anabaena circinalis, we investigated the nature of cyst formation and germination under different environmental conditions (variation in light quality and quantity, temperature, nutrient limitation). We consistently found that germlings up to about 5 days old had greater growth rates than those of vegetative cells grown under similar saturating irradiance and excess nutrient conditions in batch culture. Averaging the results from 4 experiments, the specific growth rate (K′) fell from 1.9 d‐1, 24 hours after germination to 1.17, 1.04, 0.8, and to 0.45 d−1 after 48, 72, 120 and 144 hours, respectively. This equates to an increase in generation time from 0.37 to 1.54 days over this 6 day period. To investigate the implications of these results we modelled two hypothetical populations, A & B, with an initial akinete or resting cyst concentration of 10/mL each, but with population A having a standard growth rate of 0.45 and B with the 6 day early enhanced growth rate as determined in our laboratory experiments. The model indicates that population B quickly establishes dominance over population A. In this modeling exercise we have assumed a germination frequency of 100% for both populations but our laboratory results indicate that even given optimum germination conditions this factor may vary between 5% and 90% depending on the age of akinetes and the conditions experienced during dormancy (senescence). Some conditions that determine germination frequency were also investigated.
PHYLOGENETIC ANALYSIS OF THE MARINE AND FRESHWATER THALAS‐SIOSIROID DIATOMS
Authors: Julius M.L. , Theriot E.C.
Published: March 2003

The thalassiosiroid centric diatoms are distinguished by at least one synapomorphy, the strutted process or fultoportula. Variously classified as a family (Thalassiosiraceae) or an order (Thalassiosirales) among centric diatoms, it is generally conceded that the group of several hundred fossil and living species is monophyletic as a whole. There are two ecological groups of thalassiosiroids, marine and freshwater. It has been hypothesized, based on an ecletic, non‐rigorous, evolutionary taxonomy perspective that both the marine and freshwater ecological groups are also monophyletic, but this hypothesis has never been tested in a rigorous framework. Likewise, the freshwater thalassiosiroid species have been grouped into several genera and subgenera using an evolutionary taxonomic approach, but these hypotheses have not fully been tested using cladistic analysis. Focusing mainly on freshwater species, but including at least one representative of each marine genus and one representative from each of several proposed subgeneric groupings of the genus Thalassiosira, we scored morphological characters for fossil and living marine and freshwater Thalassiosiraceae to test these hypotheses. Our cladistic results provide strong support for monophyly for the freshwater group, but it seems unlikely that the marine group is monophyletic. The cladistic results are corroborated to greater or lesser degrees by the fossil record. The implications for evolution in the group and for taxon sampling in molecular studies we are conducting will be discussed.
VERTICAL MIGRATION OF EUGLENA SP. ON THE SAND BANKS OF A NORTH CAROLINA PIEDMONT STREAM
Authors: Kingston
Published: March 2003

On summer days, visible patches of green appeared on the aerially‐exposed sand banks of a small tributary of Mays Lake in Burlington, North Carolina. These green patches became visible approximately 3 hours after sunrise and disappeared 2 hours prior to sunset. Microscopic examination of sediment samples revealed that the appearance of color was due to the upward migration of Euglena sp. that attained densities of 2200 cells per square millimeter around solar noon. Triplicate sediment cores revealed the presence of live Euglena cells as deep as 6 cm below the sediment surface. During the day, over 80% of the population was located between the surface and a depth of 2 mm. During the night, 75% of the population was found between 2 and 6 cm below the surface. Artificially darkening the sediment surface during the day stimulated downward migration of the population. Controlled experiments with neutral density filters indicated that the number of cells on the sediment surface was directly related to incident irradiance. The results of these experiments on Euglena sp. living on the banks of a freshwater stream in central North Carolina will be contrasted with those of previous experiments conducted on Euglena proxima living on the intertidal sand flats of the Newport River estuary in coastal North Carolina.
FIELD STUDY OF ALGAL RECRUITMENT BY CLEARING EXPERIMENT IN PING CHAU, HONG KONG SAR, CHINA
Authors: Kong S. L. , Ang P.O.
Published: March 2003

Recruitment, the entry of new individuals into a population, was investigated by a clearing experiment along the shore of A Ma Wan (AMW) in Ping Chau, Hong Kong SAR, China. Two types of clearing, with all the existing vegetation removed (cleared) and with the top 2 to three mm of the rock surface removed (hammered), were carried out monthly in AMW from November 1997 to June 1999. Observations were made one month after clearing and on a monthly basis thereafter. The number of algal species present on the cleared areas and their percentage cover were recorded. The experimental results showed that more algal species were recruited during March and April in 1998 (n=10) but in 1999, the number of species was found higher in February and March (n=8). Species richness dropped after May (more obvious in 1998), indicating that recruitment greatly declined in summer. A tuft complex composed of several filamentous algal species dominated over the others in all clearing areas (coverage mostly over 90%) but recruits of Caulerpa peltata, Colpomenia sinuosa, Enteromorpha sp., Hypnea charoides, Padina spp., Sargassum sp., Spyridia filamentosa, Ulva sp., etc. also were observed during the study period. Generally, there were no significant differences in terms of species richness and composition of the recruits between the two treatments (cleared vs. hammered) as well as with the controls. This implied that algae in AMW were more likely to be recruited de novo from elsewhere rather than regenerated from remnants of the previous year's growth.
GENETIC STRUCTURE VARIABILITY OF KELP ALARIA MARGINATA OVER SPACE AND TIME
Authors: Kusumo H.T. , Druehl L.D.
Published: March 2003

The genetic variability of Alaria marginata Postels & Ruprecht was investigated spatially and seasonally using the finger printing technique of amplified fragment length polymorphism (AFLP). Using 206 scoreable bands generated by one primer pair, individual plants that were separated by as little as a few decimeters to> 100 km could be distinguished, and followed an isolation‐by‐distance model. Genetic similarity ranged from 76% for patches (a few decimeters in diameter), to 71% for individual kelp stands (15 m across) and 67% for a group of stands separated by 185 km. Greater genetic similarity of patches occurred at the wave‐sheltered site than at wave‐exposed site. The influence of wave to genetic variability and the ability to predict gene flow on small stretch of beach were discussed. In one stand, genetic similarities were markedly different between seasons. This seasonal pattern may be the result of different age groups dominating the sampled stands over time. The genetic structure of A. marginata comprises local scale (patch and within stand) heterogeneity and larger scale (between stands) homogeneity.
MOLECULAR ANALYSES OF LINEAR CHLOROPLAST PLASMIDS FROM ERNODESMIS VERTICILLATA
Authors: La Claire J.W. , Wang J.
Published: March 2003

Ernodesmis verticillata contains novel, linear plasmid‐like DNA molecules in its chloroplasts, whose function remains unclear. Their molecular architecture is putatively a “hairpin,” wherein every molecule consists of a long inverted repeat folded back on itself. Thus, each molecule is composed of a terminal (telomeric) domain, a central inverted repeat, and a “loop” domain. Cloning strategies have been devised for characterizing the terminal and loop regions, since they might contain landmark features like replication origins. Polymerase chain reaction (PCR) was used to amplify loop domains of native molecules, and ligation of the PCR products with commercial cloning vectors initially yielded 11 clones. So far, no recognizable sequences have turned up in the loop domains of the molecules. Unlike what has been reported for most linear plasmids, we have been unable to verify that any proteins are associated with either the 5′‐ or 3′‐ends of the Ernodesmis plasmids. In fact, the 5′‐end of each molecule contains a terminal phosphate that is accessible to alkaline phosphatase and subsequently to T4 polynucleotide kinase in vitro. It is also possible to modify the 3'‐end with terminal deoxynucleotidyl transferase (TdT) for homopolymeric tailing. Poly‐(C) tailing of native molecules promotes their annealing to poly‐(G) tailed vectors, for cloning of the terminal domains. An initial library of 14 TdT clones (10 unique) indicates that short (11–28 bp) direct repeats occur near the termini of the plasmids. Shorter (4–6 bp) inverted repeats at the very ends may lead to terminal foldbacks that might serve to protect the termini.
PHENOLOGY OF SCINAIA LATIFRONS (NEMALIALES; RHODOPHYTA) IN THE SOUTHWESTERN GULF OF CALIFORNIA, MEXICO
Authors: León‐Cisneros K. , Riosmena‐Rodriguez R.
Published: March 2003

Scinaia latifrons Howe is one of the main species in rhodolith beds between 30 and 90 feet; however, little known about the morphological changes of this species. Consequently, we investigated the phenological changes of the species at San Lorenzo channel from December 1998 to December 1999 (based on bi‐weekly sampling during the first 6 months and monthly sampling during the last part of the study). The gametophyte phase of the species is present from December to late May and the sporophyte potentially is present the rest of the year. The peak of the development occurs in April and reproduction occurs in small size plants with two cohorts in the period. This species presents an allometric growth pattern due to the lack of correlation between size and width of the plant or branching patterns. Our data suggest that temperature and light control the development of the plant. Furthermore, we found the spermatagonial structure in the same thallus as the female/carposporophyte plant indicating that this species is monoeious (contrary to what was considered previously). This suggests that some taxonomic problems are present in this species in relation with S. cottoni.
CHEMICALLY INDUCED ECDYSIS AND ISOLATION OF NUCLEI FROM THE DINOFLAGELLATES GONYAULAX POLYEDRA AND GONYAULAX TAMERENSIS
Authors: Morris R. L. , Rizzo P.J.
Published: March 2003

Armored dinoflagellates such as Gonyaulax sp. are not good candidates for isolation of intact clean nuclei, due to difficulty in breaking the cells. Previously, isolation of nuclei from Gonyaulax was achieved using vigorous cell disruption by ultrasonication (Rizzo & Hastings, unpublished observations). A detergent method for production of spheroplasts from Gonyaulax was published some time ago (Adamich & Sweeney, 1976), but was not reproducible (Rizzo & Hastings, Morris & Rizzo, unpublished observations). We describe here a modification of the method described by Adamich & Sweeney that is highly reproducible. Ecdysis and production of intact dinoflagellate spheroplasts with a yield of virtually 100% within 5 minutes, has been achieved through the use of anionic and nonionic detergents in hypotonic buffers. This method of ecdysis followed by a gentle spheroplast breakage in a hypotonic buffer allowed the release of nuclei for later biochemical analysis with minimal damage or breakage. The nuclei are subsequently purified by centrifugation in a Ficoll discontinuous gradient.