NMDA receptor antagonist felbamate reduces behavioral deficits and blood-brain barrier permeability changes after experimental subarachnoid hemorrhage in the rat

Increased levels of glutamate and aspartate have been detected after subarachnoid hemorrhage (SAH) that correlate with neurological status. The NMDA receptor antagonist felbamate (FBM; 2-phenyl-1,3-propanediol dicarbamate) is an anti-epileptic drug that elicits neuroprotective effects in different experimental models of hypoxia-ischemia. The aim of this dose-response study was to evaluate the effect of FBM after experimental SAH in rats on (1) behavioral deficits (employing a battery of assessment tasks days 1-5 post-injury) and (2) blood-brain barrier (BBB) permeability changes (quantifying microvascular alterations according to the extravasation of protein-bound Evans Blue by a spectrophotofluorimetric technique 2 days post-injury). Animals were injected with 400 muL of autologous blood into the cisterna magna. Within 5 min, rats received daily oral administration of FBM (15, 30, or 45 mg/kg) for 2 or 5 days. Results were compared with sham-injured controls treated with oral saline or FBM (15, 30, or 45 mg/kg). FBM administration significantly ameliorated SAH-related changes in Beam Balance scores on days 1 and 2 and Beam Balance time on days 1-3, Beam Walking performance on days 1 and 2, and Body Weight on days 3-5. FBM also decreased BBB permeability changes in frontal, temporal, parietal, occipital, and cerebellar cortices; subcortical and cerebellar gray matter; and brainstem. This study demonstrates that, in terms of behavioral and microvascular effects, FBM is beneficial in a dose-dependent manner after experimental SAH in rats. These results reinforce the concept that NMDA excitotoxicity is involved in the cerebral dysfunction that follows SAH.

The role of erythropoietin in neuroprotection: Therapeutic perspectives

Nervous system diseases are very complex conditions comprising a large variety of local and systemic responses. Several therapeutic agents interfering with all or in part the biochemical steps that ultimately cause neuronal death have been demonstrated to be neuroprotective in preclinical models. However, all the agents so far investigated have inexorably failed in the phase III trials carried out. A large body of evidence suggests that the hormone erythropoietin (EPO), besides its well-known hematopoietic action, exerts beneficial effects in the central nervous system. EPO's effect has been assessed in several experimental models of brain and spinal cord injury thus becoming a serious candidate for neuroprotection. The use of EPO as neuroprotectant raises several questions. Besides dosage and therapeutic time window, the safety of recombinant EPO administration in the setting of nervous system diseases takes priority over all other questions. Although recombinant EPO seems to be potentially safe at the neuroprotective proved doses, cardiovascular or cerebrovascular events can occur as a result of its bone marrow stimulating activities. The successful trial using EPO in patients with ischemic stroke and the large body of experimental evidence encourages intensive evaluation of this cytokine to support safe and larger clinical trials in the near future.

CD68 and CR3/43 immunohistochemical expression in secretory meningiomas

OBJECTIVE

Secretory meningiomas (SMs) are unusual benign meningiomas. SMs are highly vascularized lesions, with angiomatous features and a perivascular arrangement, and they are accompanied frequently by massive peritumoral edema. Microglia have been called the brain's immune system, although the specific role and prognostic significance of microglia remain uncertain. The objective of this study was to analyze the expression of CD68, a macrophage marker specific for resting microglia, and the expression of major histocompatibility complex Class II CR3/43 in SMs.

METHODS

From 1995 to 2002, six patients with SMs were treated surgically at our institution. Immunohistochemistry was used to analyze the expression of CD68 and CR3/43 in tumor specimens. The intensity of expression was graded semiquantitatively. A correlation between immunohistochemical expression and the occurrence of brain edema was studied.

RESULTS

CD68-positive mononuclear cells were observed in neoplastic tissue or around pseudopsammoma bodies and in perivascular areas, with minimal expression in one patient and moderate expression in three patients. CR3/43-positive complexes were detected in mononuclear elongated elements with ameboid extensions, presumably referable to cells at different stages of immunological activation phenomena, with minimal expression in two patients, moderate expression in one patient, and marked expression in one patient. Edema was severe in all patients. Therefore, it may be indirectly hypothesized that edema may not be correlated with the CD68 and CR3/43 immunohistochemical expression.

CONCLUSION

Macrophage infiltration and major histocompatibility complex Class II immunoreactivity in this subtype of meningioma suggest the occurrence of an immune response in the presence of SM.

Amelioration of spinal cord compressive injury by pharmacological preconditioning with erythropoietin and a nonerythropoietic erythropoietin derivative

OBJECT

Spinal cord injury (SCI) is a devastating clinical syndrome for which no truly efficacious therapy has yet been identified. In preclinical studies, erythropoietin (EPO) and its nonerythropoietic derivatives asialoEPO and carbamylated EPO have markedly improved functional outcome when administered after compressive SCI. However, an optimum treatment paradigm is currently unknown. Because the uninjured spinal cord expresses a high density of EPO receptor (EPOR) in the basal state, signaling through these existing receptors in advance of injury (pharmacological preconditioning) might confer neuroprotection and therefore be potentially useful in situations of anticipated damage.

METHODS

The authors compared asialoEPO, a molecule that binds to the EPOR with high affinity but with a brief serum half-life (t1/2 < 2 minutes), to EPO to determine whether a single dose (10 microg/kg of body weight) administered by intravenous injection 24 hours before 1 minute of spinal cord compression provides benefit as determined by a 6-week assessment of neurological outcome and by histopathological analysis. Rats pretreated with asialoEPO or EPO and then subjected to a compressive injury exhibited improved motor function over 42 days, compared with animals treated with saline solution. However, pretreatment efficacy was substantially poorer than efficacy of treatment initiated at the time of injury. Serum samples drawn immediately before compression confirmed that no detectable asialoEPO remained within the systemic circulation. Western blot and immunohistochemical analyses performed using uninjured spinal cord 24 hours after a dose of asialoEPO exhibited a marked increase in glial fibrillary acidic protein, suggesting a glial response to EPO administration.

CONCLUSIONS

These results demonstrate that EPO and its analog do not need to be present at the time of injury to provide tissue protection and that tissue protection is markedly effective when either agent is administered immediately after injury. Furthermore, the findings suggest that asialoEPO is a useful reagent with which to study the dynamics of EPO-mediated neuroprotection. In addition, the findings support the concept of using a nonerythropoietic EPO derivative to provide tissue protection without activating the undesirable effects of EPO.

Methylenetetrahydrofolate reductase mutation in subjects with abdominal aortic aneurysm subdivided for age

The aim of the study was to verify the association between abdominal aortic aneurysms (AAA) and methylenetetrahydrofolate reductase (MTHFR) mutation, in relation to age. We studied the frequency of the MTHFR 677T allele in two groups of AAA patients, over and under 60 years. The first AAA group included 42 patients (30 men and 12 women) aged between 65 and 75 years; the second AAA group included 46 patients (32 men and 14 women) aged between 49 and 59 years; the control group included 44 healthy controls (29 men and 15 women) aged between 49 and 75 years. We examined MTHFR allele frequency and MTHFR genotype using Nuclear Laser Medicine. MTHFR allele frequency was significantly increased in AAA patients >60 compared to healthy controls and in AAA patients <60 compared to those >60. The genotype study showed a difference between controls and AAA patients and between AAA patients >60 and those <60. The frequency of MTHFR mutation was more elevated in both AAA groups vs controls, but it was more elevated in younger patients than in the older ones. This mutation might induce an early elastin degradation in the aortic wall.

A case of ovarian hyperstimulation syndrome associated with the methylenetetrahydrofolate reductase mutation gene

OBJECTIVE

To report a case of ovarian hyperstimulation syndrome with methylenetetrahydrofolate reductase (MTHFR) gene 677T homozygosis mutation and A1298C gene heterozygosis mutation.

DESIGN

Case report.

SETTING

A pregnant woman in an academic hospital.

PATIENT(S)

A woman with ovarian hyperstimulation syndrome.

INTERVENTION(S)

Nadroparin was administered for 2 weeks at a dosage of 200 IU/kg twice per day and then once per day; also administered once per day were folates, 5 mg; B6 vitamin, 15 mg; and B12 vitamin, 1 mg.

MAIN OUTCOME MEASURE(S)

Clinical follow-up.

RESULT(S)

Delivery was regular within the set time limits, and the fetus was born alive and in good health.

CONCLUSION(S)

We believe that MTHFR mutation research could be executed in women before ovarian stimulation treatment, but other observations are necessary to support this recommendation.

An immunohistochemical study of extracellular matrix proteins laminin, fibronectin and type IV collagen in paediatric glioblastoma multiforme

AIMS

In the recent decades many studies have been addressed in the literature to assess specific factors related to glioblastoma multiforme (GBM) invasion. However, few studies have evaluated tumour cell's interaction with specific extracellular matrix (ECM) components, and, moreover, there is a lack of information regarding the occurrence of these phenomena in paediatric GBM.

METHODS AND RESULTS

ECM proteins were evaluated in six cases of paediatric GBM assessing the immunohistochemical expression of laminin, fibronectin, and type IV collagen. We used a semiquantitative scale, ranging from not detected (zero) to marked (3). Laminin expression was minimal in three cases, moderate in one case, marked and generalised in one patient and marked and focal in the last case. Fibronectin expression was minimal in three patients; moderate immunoreactivity was documented in one case. Conversely, one case was classified as marked with generalised distribution and the remaining case as marked with focal immunostaining. Type IV collagen expression was minimal in three cases, moderate in one, marked with focal reaction in one and marked with generalised reaction in the remaining case.

CONCLUSIONS

This study provides additional insights into tumour invasion features of paediatric GBM, as ECM plays a pivotal role in numerous cellular functions during normal and pathological processes. Although based on a limited number of patients, this investigation may serve as a challenge for the management of paediatric GBM, stimulating trials with larger patient numbers aimed at documenting specific factors influencing GBM prognosis.

Growing skull fracture of the posterior cranial fossa and of the orbital roof

BACKGROUND

Growing Skull Fractures (GSF) are rare complications of head trauma, primarily reported in infancy and early childhood. GSF are commonly located on calvaria, and rarely in other locations, including the skull base.

METHOD

In this study, we report two cases of GSF occurring in unusual locations. The first, a 8-month old girl, with a GSF of the suboccipital posterior fossa region, and the second, a 4-year old boy with a GSF of the right orbital roof. Both cases underwent operative treatment of the GSF, with microsurgical dissection and excision of the protruding gliotic brain tissue, watertight duraplasty and autologous bone cranial repair. The authors conducted a Medline search of the relevant English literature from 1966 to 2002.

FINDINGS

From the search, three cases of suboccipital posterior fossa region GSF and twelve series of orbital GSF, describing a total of 22 cases, have been found.

INTERPRETATION

A survey of the pathogenic mechanisms underlying this entity in these locations is reported. A review of suboccipital posterior fossa and orbital roof GSF cases, of nosological, ophthalmological and neurological data, neuroradiological and operative findings, and results of different treatment strategies are described.

The treatment of large supratentorial arachnoid cysts in infants with cyst-peritoneal shunting and Hakim programmable valve

OBJECTIVE

This retrospective case series examines 7 infants with large supratentorial arachnoid cysts who underwent cyst-peritoneal shunting and insertion of a Hakim programmable valve. Comparing pre- and postoperative clinical data, neuroradiological and regional cerebral blood flow (rCBF) findings we evaluated the efficacy of the surgical procedure.

METHODS

Infants, ranging in age from 1 to 55 days (mean age 29.5 days), were assessed pre- and postoperatively by neurological examination, developmental profile and neuroimaging.

RESULTS

Post procedure, all patients showed a significant reduction in the cyst/brain ratio on neuroimaging (p<0.001), 6 had a normal developmental profile (p<0.001) and 5 cases showed a significant amelioration of clinical symptoms and neurological signs. Two patients underwent preoperative SPECT scans, which showed hypoperfusion in the area surrounding the cyst; this decreased rCBF also improved post shunting.

CONCLUSIONS

Large supratentorial arachnoid cysts in infants can be successfully treated with cyst-peritoneal shunting and insertion of a Hakim programmable valve. This is the first study specifically aimed at evaluating the long-term results of these conditions.

Cardiovascular and respiratory consequences of bilateral involvement of the medullary intermediate reticular formation in syringobulbia

We studied five patients with clinical and radiological evidence of syringobulbia (SB) to determine whether the distribution of lesions in relationship to the cardiorespiratory control networks in the medullary intermediate reticular zone (IRt) correlates with the presence of abnormalities in autonomic cardiovascular and respiratory control in these patients. All patients underwent high resolution MRI to characterize the size, volume and distribution of the SB lesions, cardiovascular autonomic function testing and polysomnography. One patient with bilateral IRt involvement at both the rostral and caudal medulla had orthostatic hypotension (OH), absent HR(DB), abnormal Valsalva ratio, exaggerated fall of BP during phase II and absent phase IV during VM, and a dramatic fall of BP during head up tilt; this patient also had severe obstructive sleep apnea (OSA) and exhibited BP drops during each respiratory effort. A second patient, with bilateral IRt involvement restricted to the caudal medulla, had less severe cardiovascular autonomic dysfunction but also exhibited severe OSA. The other three patients had small SB cavities sparing the IRt and had sleep apnea but no autonomic dysfunction. Autonomic dysfunction could not be related to the size of the syrinx or the degree of atrophy in the cervical spinal cord in any of the five patients. Bilateral involvement of the IRt by SB produces cardiovascular autonomic failure and sleep apnea. In patients with more restricted lesions, autonomic and respiratory dysfunction may be dissociated. Clinico-radiological correlations using high resolution MRI assessment of medullary lesions can provide insight into the central organization of cardiovascular and respiratory control in humans.

Merosin-positive congenital muscular dystrophy with mental retardation, microcephaly and central nervous system abnormalities unlinked to the Fukuyama muscular dystrophy and muscular-eye-brain loci: report of three siblings

Classical merosin (2 laminin)-positive congenital muscular dystrophy is a heterogeneous subgroup of disorders; a few cases characterized by severe mental retardation, brain involvement and no ocular abnormalities were called Fukuyama-like congenital muscular dystrophy. We report a family of healthy non-consanguineous parents, with four affected siblings, of which one died at the age of 7 months due to an intercurrent illness, who presented congenital hypotonia, severe mental retardation, microcephaly, delayed psychomotor development, generalized muscular wasting and weakness with mild facial involvement, calf pseudohypertrophy, joint contractures and areflexia. Muscle biopsy disclosed severe muscular dystrophy. Immunostaining for laminin 2 80 kDa and clone Mer3/22B2 monoclonal antibodies, 1 and 1 chain was preserved. Magnetic resonance imaging findings were consistent with pontocerebellar hypoplasia, bilateral opercular abnormalities and focal cortical dysplasia as well as minute periventricular white matter changes. Clusters of small T2-weighted focal hyperintensities in both cerebellar hemispheres consistent with cysts were observed in two of the three siblings studied with magnetic resonance imaging. Ophthalmologic and cardiologic examination was normal. Haplotype analysis using microsatellite markers excluded the Fukuyama congenital muscular dystrophy, LAMA2 and muscle-eye-brain disease loci. Thus, a wider spectrum of phenotypes, gene defects and protein deficiencies might be involved in congenital muscular dystrophy with brain abnormalities.

Acute ischemic stroke : polymorphonuclear leukocyte membrane fluidity and cytosolic Ca(2+) concentration at baseline and after chemotactic activation

BACKGROUND AND PURPOSE

Several reports have considered the role of systemic leukocytes in acute ischemic stroke (AIS). Initially, greater attention was focused on the leukocyte count and subsequently on their adhesiveness, aggregation, rheology, and activation. The aim of this study was the evaluation of certain polymorphonuclear leukocyte (PMN) parameters, reflecting their rheology and activation, in subjects with AIS.

METHODS

In a group of 19 subjects with AIS and in a control group of 18 subjects with asymptomatic vascular atherosclerotic disease, we evaluated the PMN membrane fluidity and cytosolic Ca(2+) concentration at baseline and after in vitro chemotactic activation with 4-phorbol 12-myristate 13-acetate (PMA) and N-formyl-methionyl-leucyl-phenylalanine (fMLP).

RESULTS

From the obtained data, it is evident that at baseline only PMN membrane fluidity distinguishes control subjects from AIS subjects. After PMN activation with PMA and fMLP, prolonged for 5 and 15 minutes, we found an increase in PMN cytosolic Ca(2+) concentration and a decrease in PMN membrane fluidity only in subjects with AIS.

CONCLUSIONS

These findings emphasize that in subjects with AIS a functional alteration of systemic PMN cells is clearly expressed during chemotactic activation, although the mechanism of this abnormality is not yet explained.

Type II diabetics with macrovascular complications: polymorphonuclear leukocyte (PMN) filtration, PMN membrane fluidity and cytosolic Ca2+ content after activation

We evaluated polymorphonuclear (PMN) filtration parameters, membrane fluidity and cytosolic Ca2+ content in 21 normal subjects and in 18 type II diabetics with macrovascular complications (MVC). Evaluations were carried out at baseline and after in vitro activation prolonged for 5 and 15 min. PMA (4-phorbol 12-myristate 13-acetate) and fMLP (N-formyl-methionyl-leucyl-phenylalanine) were used as stimulating agents. TMA-DPH (1-[4-(trimethylamino)phenyl]-6-phenyl-1,3,5-hexatriene) was used as fluorescent probe for the membrane fluidity tests and Fura 2-AM for the cytosolic Ca2+ content. A significant variation was evident in PMN filtration parameters at 5 and 15 min. No variation was present in PMN membrane fluidity and cytosolic Ca2+ content in normals. In type II diabetics with MVC, we found an increase solely in PMN cytosolic Ca2+ content after PMA activation and an early decrease in PMN membrane fluidity and a late increase in PMN cytosolic Ca2+ content after fMLP activation. After PMA activation alone (at 15 min), PMN filtration distinguishes normals from type II diabetics with MVC. The PMN filtration parameters behave similarly in the two groups, but PMN membrane fluidity and cytosolic Ca2+ content behave differently.

Behavior of the polymorphonuclear leukocyte membrane fluidity and cystolic Ca2+ content in vascular atherosclerotic disease with and without non-insulin-dependent diabetes mellitus

In 71 subjects with vascular atherosclerotic disease (VAD), in 32 VAD subjects with non-insulin-dependent diabetes mellitus (NIDDM) and in 31 normal controls, we evaluated polymorphonuclear leukocyte (PMN) membrane fluidity and PMN cytosolic Ca2+ content. The PMN membrane fluidity was obtained by marking intact and unstimulated PMN cells with fluorescent probe 1-[4-(trimethylamino)phenyl]-6-phenyl-1,3,5-hexatriene (TMA-DPH) and the PMN cytosolic Ca2+ content was obtained by marking intact and unstimulated PMN cells with the fluorescent probe Fura 2-AM. From the obtained results, it is evident that PMN membrane fluidity does not differentiate normals from VAD subjects and VAD subjects with NIDDM, and normals from subjects with monovascular disease (MVAD) and polyvascular disease (PVAD) with and without NIDDM. The PMN cytosolic Ca2+ content is significantly increased in VAD subjects and VAD subjects with NIDDM, and also in MVAD and PVAD subjects with and without NIDDM. A positive correlation is present between PMN membrane fluidity and PMN cytosolic Ca2+ content in normals and VAD subjects, but not in VAD subjects with NIDDM. In conclusion, in VAD subjects with and without NIDDM, an increase of the PMN cytosolic Ca2+ content is present; this increase might be related to the PMN spontaneous activation.

[Hypertension and peripheral arterial hemodynamics]

Sixty uncomplicated hypertensive patients (40 stable and 20 borderline) were studied, by strain gauge plethysmography, in comparison with 25 normotensive subjects, in order to evaluate the arterial hemodynamics of the lower limbs in essential hypertension and to verify the different pattern in borderline and in stable hypertensives. Resting blood flow, even if lightly decreased in hypertensive groups, didn't show significant differences in its mean values; Peak Flow, instead, was reduced proportionally to the severity of hypertension in all the hypertensive patients, but only in the stable hypertensives did it prove statistically significant. Minimal Vascular Resistances showed a similar behaviour; they were significantly increased only in the stable hypertensives, whereas Basal Vascular Resistances, were raised in all hypertensive patients, in the borderline group too. Finally, half time and total hyperemic time, which indicate vascular reactivity, were significantly decreased in all hypertensives. These results suggest that the stable hypertensive patients principally develop arterial structural changes, while the borderline hypertensive patients have only functional modifications, such as a reduced compliance and a hyperdynamic condition.

Somatosensory and visual evoked potentials study in young insulin-dependent diabetic patients

To evaluate central nervous system involvement in diabetes, somatosensory (SEPs) and visual (VEPs) evoked potentials were investigated in a group of 35 patients and 20 sex, age-matched controls. In order to avoid methodological biases due to different type and duration of disease, we studied an omogeneous group of young insulin-dependent diabetics with ten or more year duration of disease. In our results VEP and SEP parameters were found abnormal in 10 (28%) patients, all of whom presenting clear signs of peripheral neuropathy. In diabetic patients median and tibial SEPs showed significant increase in absolute latency mean values of several components except interpeak intervals, as well as mean P 100 latencies were significantly increased in both eyes at 15' check size stimulation pattern. VEP and SEP components were not generally significantly associated with the indices of peripheral function. In contrast, in diabetics significant correlations were found between P 100 latencies and median SEP parameters including interpeak intervals. No major associations related VEP and SEP latencies to duration of diabetes and prevailing glycaemic control. In conclusion the central nervous system involvement in young insulin-dependent diabetics, even though diffusely present, seems unequivocally concomitant to peripheral conduction impairment.

[Pulmonary hypertension caused by a severe scoliosis. Description of a case]

BACKGROUND

Pulmonary hypertension in childhood is uncommon. It can be idiopathic or secondary to other pathologies (cardiovascular, skeletric,...).

CASE DESCRIPTION

We report on a 9 year old girl suffering from pulmonary hypertension due to severe dorso-lumbar scoliosis.

CONCLUSIONS

We discuss the etiopathogenetic relationship between scoliosis and pulmonary hypertension, with particular reference to the role of the treatment with Milwaukee's corset in the evolution of the disease.

Leukocyte flow properties, polymorphonuclear membrane fluidity, and cytosolic Ca2+ content in subjects with vascular atherosclerotic disease with and without noninsulin-dependent diabetes mellitus

The aim of this research was the evaluation of white blood cell (WBC) filtration, reflecting WBC flow properties, polymorphonuclear cell membrane fluidity, and cytosolic Ca2+ content in subjects with vascular atherosclerotic disease (VAD) and in VAD subjects with noninsulin-dependent diabetes mellitus (NIDDM), in good hemodynamic balance. The authors examined WBC filtration (unfractionated, mononuclear [MN], polymorphonuclear [PMN] cells), using the St. George Filtrometer and considering, respectively, the initial relative flow rate (IRFR) and the clogging rate (CR); the PMN membrane fluidity, employing the fluorescent probe TMA-DPH and calculating the fluorescence polarization degree; and the PMN cytosolic Ca2+ content, adopting the fluorescent probe Fura 2-AM and considering the ratio between the Fura 2-Ca2+ complex and the unchelated Fura 2 fluorescence intensity. The obtained data showed that only the filtration parameters (IRFR, CR) of unfractionated WBCs discriminated normal subjects from VAD groups, whereas the filtration parameters of MN and PMN cells did not demonstrate any distinction. PMN membrane fluidity did not distinguish normal subjects from VAD groups, whereas PMN cytosolic Ca2+ content was significantly increased in VAD groups in comparison with normal subjects. No relationship was evident between WBC filtration and plasma metabolic parameters; the correlations obtained between PMN filtration and other PMN parameters need further investigation.

Regulation of p21WAF1/CIP1 expression through mitogen-activated protein kinase signaling pathway

p21WAF1/CIP1 is a cyclin-dependent kinase inhibitor whose expression in mammalian tissues is highly induced in response to stress as well as during normal development and differentiation. Induction of p21WAF1/CIP1 in response to DNA damage occurs through a transcriptional mechanism that is dependent on the activation of the tumor suppressor protein p53. Recent evidence indicates that p21WAF1/CIP1 can also be induced independently of p53, but the signal transduction mechanisms involved in regulating p21WAF1/CIP1 expression in these situations have not been elucidated. In this study, we have addressed the role of the mitogen-activated protein kinase signaling pathway in the induction of p21WAF1/CIP1 in response to growth factor treatment. Using an experimental approach involving cotransfection of a p21WAF1/CIP1 promoter-luciferase construct with a variety of plasmids expressing dominant positive or dominant negative mutant proteins involved in this signaling pathway, we provide evidence to support a role for mitogen-activated protein kinase in the transcriptional activation of p21WAF1/CIP1 by growth factor stimulation.

Nerve conduction velocity and circulating immunocomplexes in type 1 diabetic children

There is evidence from several laboratories of an increased prevalence of circulating immuno-complexes (CIC) in diabetic patients. It has also been suggested that CIC are pathogenetically related to chronic diabetic complications. The aim of this study was to assess peripheral nerve function in children with Type 1 diabetes and to evaluate the relationship between the neurophysiological abnormalities and the possible presence of CIC. The investigation was carried out in 25 Type 1 diabetic patients ranging in age from 7-19 years and in 20 normal controls. Neurophysiological assessment was performed to evaluate motor and sensory conduction velocity on median and tibial nerves. IgG-CIC were detected by the solid-phase C1q-binding and anti-C3 enzyme immuno-assay. The results of this study showed a greater slowing of median motor and sensory and tibial sensory conduction velocities in patients with CIC with respect to the patients without CIC, suggesting a possible role of immunological factors in the pathogenesis of diabetic neuropathy.

Conduction velocity study in type 1 diabetic patients

The role of metabolic abnormalities in the development of diabetic neuropathy is controversial. To investigate the peripheral nerve function and the influence of hyperglycemia on nerve conduction in insulin-dependent diabetes, a one-year neurophysiological study was carried out in 30 type 1 diabetic patients ranging in age from 2-16 years. During the 12-month follow-up period the glycosylated hemoglobin determination, motor conduction velocity of the peroneal nerve and the motor and sensory conduction of the tibial nerve were assessed 3 times, at the beginning of the study and every 6 months thereafter. The sensory latency was found significantly delayed in these patients as compared with the controls. The degree of sensory conduction slowing correlated well with the glycosylated hemoglobin concentrations and improved with the reduction in hyperglycemia.