Impact of Vessel Suppressed-CT on Diagnostic Accuracy in Detection of Pulmonary Metastasis and Reading Time.

RATIONALE AND OBJECTIVES: To assess if vessel suppression (VS) improves nodule detection rate, interreader agreement, and reduces reading time in oncologic chest computed tomography (CT). MATERIAL AND METHODS: One-hundred consecutive oncologic patients (65 male; median age 60y) who underwent contrast-enhanced chest CT were retrospectively included. For all exams, additional VS series (ClearRead CT, Riverrain Technologies, Miamisburg) were reconstructed. Two groups of three radiologists each with matched experience were defined. Each group evaluated the SD-CT as well as VS-CT. Each reader marked the presence, size, and position of pulmonary nodules and documented reading time. In addition, for the VS-CT the presence of false positive nodules had to be stated. Cohen's Kappa (k) was used to calculate the interreader-agreement between groups. Reading time was compared using paired t test. RESULTS: Nodule detection rate was significantly higher in VS-CT compared to the SD-CT (+21%; p <0.001). Interreader-agreement was higher in the VS-CT (k = 0.431, moderate agreement) compared to SD-CT (k = 0.209, fair agreement). Almost all VS-CT series had false positive findings (97-99 out of 100). Average reading time was significantly shorter in the VS-CT compared to the SD-CT (154 ± 134vs. 194 ± 126; 21%, p<0.001). CONCLUSIONS: Vessel suppression increases nodule detection rate, improves interreader agreement, and reduces reading time in chest CT of oncologic patients. Due to false positive results a consensus reading with the SD-CT is essential.

GFAP expression of human Schwann cells in tissue culture.

We have studied the expression of the intermediate filament (IF) proteins, vimentin and glial fibrillary acidic protein (GFAP), in cultured human Schwann cells (SC) from patients with different neuropathies and normal control cases. SC cultures from sural nerve biopsies of 8 subjects with axonal neuropathies, 8 with demyelinating neuropathies and 3 normal controls were included in this study and processed with double immunofluorescence technique, using anti-vimentin and anti-GFAP antibodies, during the 2nd, 4th and 6th week of culture. Five cultures incubated with anti-GFAP antibodies were also processed for immunoelectron microscopy. Specificity tests of the used antibodies were performed. We have found that: (1) cultured human SC constantly express vimentin; (2) SC from normal controls are GFAP-negative in the first period of culture; (3) SC from pathologic nerves can contain GFAP-immunoreactive IF and the percentage of GFAP-positive SC is higher in axonal than in demyelinating neuropathies; (4) during the permanence in culture human SC from both normal and pathologic cases acquire the ability to synthesize GFAP. The obtained data suggest that the removal from axonal contact and the resulting loss of myelinating function induce a cytoskeletal cellular response in human SC characterized by the cytoplasmic accumulation of GFAP-immunoreactive IF.

Schwann cell GFAP expression increases in axonal neuropathies.

We studied the Schwann cell (SC) GFAP immunoreactivity in normal human peripheral nerves and in neuropathies of different origin. Immunofluorescence and immunocytochemistry were carried out on serial frozen sections of 58 peripheral nerve biopsies using monoclonal antibodies (mabs) antivimentin and anti GFAP, and antiserum anti S-100 and anti GFAP. To test the specificity of the mabs and antiserum used, proper competition controls on tissue sections of 2 selected cases, tissue cultures studies of human fibroblasts and immunoblotting of homogenates of human fibroblasts, 3 normal and 5 pathologic nerves were carried out. In order to evaluate a possible correlation between SC GFAP positivity and neuropathologic findings a quantitative study was performed, evaluating the SC GFAP reactivity in all the 58 cases, and relating the SC GFAP positivity to the index of nerve pathology (IP) in 9 selected cases, and to the percentage of teased fibers showing axonal degeneration or demyelination and remyelination in 25 representative cases. We demonstrate that in normal human sural nerves and in demyelinating neuropathies only a few scattered SC are recognized by the mabs or antiserum anti GFAP. On the contrary in axonal neuropathies the majority of SC gain the property to express intermediate filaments which show common antigenic properties with GFAP.

[The culturing of human Schwann cells: a new contribution to the study of polyneuropathy]. / La coltura delle cellule di Schwann umane: un nuovo apporto per lo studio delle polineuropatie.

We have established 44 Schwann cell cultures from human peripheral nerves that underwent biopsy for diagnostic purposes using a new "sandwich" connective tissue and cut into 1 mm cubic explants which were placed between two glass coverslips coated with D-poly-L-lysine, in HAM-F10 medium, 15% FCS, 600 mg/dl glucose and antibiotics. In the first 3 weeks this new sandwich technique yields a fairly great and homogeneous amount of Schwann cell growth, with only a few fibroblasts and virtually no macrophages and provides a suitable substrate on which immuno cytochemical studies could be performed.

Amyloid neuropathy in light chain multiple myeloma.

We describe a 73-year-old man with peripheral neuropathy and light chain lambda-type myeloma. A sural nerve biopsy showed the typical neuropathological picture of amyloid neuropathy. With the present case we first demonstrate amyloid deposits in peripheral nerves during light chain multiple myeloma and stress the importance of amyloidosis in the development of peripheral neuropathy.

Class II antigen expression on human cultured Schwann cells from patients with Charcot-Marie-Tooth disease.

T lymphocytes control the extent of the immune reaction by recognizing the antigen in connection with class II histocompatibility surface molecules, coded by genes located on the HLA-D locus. The expression of HLA-DR antigens is confined to a few antigen presenting cells, like lymphocytes and macrophages, which can therefore induce the initial phase of the immune reaction. We report that also Schwann cells (SC) from patients with Charcot-Marie-Tooth disease (CMT), an hereditary disorder of the peripheral nervous system, are able to express HLA-DR antigens. Human SC cultures were carried out from sural nerve biopsies of CMT and normal control cases. Cultures were tested on day 7, 14, 21 and 28, with double immunofluorescence technique using rabbit antiserum anti-S-100 and mouse anti-HLA-DR monoclonal antibody. SC from CMT were HLA-DR positive since the first few days, continuing to express class II antigens for all the duration of the culture. The presence of class II antigens on cultured SC from CMT disease suggests that immune-mediated mechanisms may be relevant in the pathogenesis of this degenerative disorder of the peripheral nervous system.

[Hereditary sensory motor neuropathy: degenerative disease or a disease with an immune-mediated pathogenesis?]. / Le neuropatie ereditarie sensitivo motorie: malattie degenerative o malattie a patogenesi immuno-mediata?

The clinical data proving that some hereditary motor-sensory neuropathies (HMSN type 1) are steroid sensitive may indicate inflammatory or immunomediated mechanisms as cofactors contributing to the clinical course of these disorders. The finding of HLA-DR positivity of Schwann cells in HMSN type I along with the presence in some cases of inflammatory infiltrates in nerve sections provides further evidence for this hypothesis.

HLA-DR Schwann cell reactivity in peripheral neuropathies of different origins.

HLA-DR antigens have been found on Schwann cells in peripheral neuropathies of different origins but not in normal control cases. Class II antigen reactivity was more intense in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and hereditary motor and sensory neuropathy type 1 (HMSN), but was also observed in toxic or metabolic neuropathies. The expression of HLA-DR antigen on Schwann cells does not appear to be related to the inflammatory or autoimmune origin of the disease.

Direct immunofluorescence in sural nerve biopsies.

Direct immunofluorescence (DIF) has been carried out in 66 sural nerve biopsies using antibodies against human IgG, IgA, IgM, C3, C4, albumin, fibrinogen, and kappa- and lambda-chains. In 37 out of 63 (59%) different neuropathies immunoglobulins or other plasma proteins were found within the peripheral nerves. IgM along the myelin sheaths were found in monoclonal IgM-K-associated demyelinating peripheral neuropathy and chronic inflammatory demyelinating peripheral neuropathy. IgM within the perineurium were detected in hereditary, diabetic, paraneoplastic, paraproteinemic and neuropathies of unknown cause. In inflammatory, vasculitic, hereditary and toxic neuropathies fibrinogen, albumin, IgG and IgA were variably observed in endoneurium, endoneurial vessels, perineurium and epineurial vessels. In our experience DIF appears to be just an unspecific marker of sural nerve pathology. In selected cases however DIF may be helpful in the diagnosis or in better understanding the pathogenetic mechanisms of the disease.

Skin fibroblasts in Huntington's disease. An electron microscopic study.

Cultured skin fibroblasts of 3 patients with Huntington's disease (HD) and of 3 normal individuals have been examined by electron microscopy during the log phase of growth and at confluence. Though HD fibroblasts achieve higher maximal densities than controls, this is not associated with abnormal ultrastructural aspects of the cells. In particular, microfilaments and microtubules are identical in HD and normal fibroblasts.

[Mucolipidosis. biologic characteristics (author's transl)]. / Características biológicas de las mucolipidosis II y III.

Mucolipidosis II is a severe inherited lysosomal storage disease characterized by profound psychomotor retardation, severe Hurler-like skeletal changes and normal urinary mucopolysaccharide excretion. Mucolipidosis II is a related disorder distinguished by its milder course, milder to absent mental retardation and survival to adult life. Cultivated fibroblasts from patients with both of these disorders display large inclusions on phase microscopy and reduced levels of many acid hydrolases. However, culture medium fibroblasts out the body fluids of affected patients show enormously elevated levels of these hydrolases. The lysosomal enzyme activities in serum, leukocytes, fibroblasts extracts and culture medium from seven patients with mucolipidosis II are similar to those found in four cases of mucolipidosis III. The findings of excessive excretion of sialyl-oligosaccharide in urine and of increased level of sialic acid compounds in cultured fibroblasts associated with a sialidase deficiency in leukocytes, fibroblasts and serum are discussed.

Tendency to periodic recurrence of EEG changes in Lafora's disease. Case report.

A young male patient affected with Lafora's disease and concomitant mental deterioration, myoclonic jerks and epileptic seizures is reported. A cerebral biopsy showed round PAS-positive myoclonus bodies in nerve cells and neuropile. A tendency to periodic recurrence of paroxysmal activity in the EEG tracings, an unusual finding in Lafora's disease, is briefly discussed.

Dextrothyroxine treatment of phosphorylase-kinase deficiency glycogenosis in four boys.

Four boys, aged 2 years 5 months to 3 years 7 months, with large hepatomegaly due to phosphorylase-kinase deficiency glycogenosis, were given a trial of sodium dextrothyroxine (D-T4) at a mean dose of 0.165 mg/kg/day for an average period of 6 months. Phosphorylase-kinase was undetectable in the haemolysates of erythrocytes (3 patients) or in the liver (one patient) before, and still undetectable in the haemolysates of the four patients during treatment, thus pointing to X-linked phosphorylase-kinase deficiency glycogen storage disease (GSD IXb). D-T4 administration resulted in complete normalization of liver size, decrease of serum GOT (p less than 0.02), GPT (p less than 0.05) and triglycerides (p less than 0.01) to normal values, as well as correction of mild asymptomatic hypoglycemia (p less than 0.01). As long as the outcome of type IXb glycogenosis in adult life remains undefined, dextrothyroxine therapy seems an effective means of reducing liver size and correcting part of the biochemical abnormalities of the disease.

Oculocutaneous tyrosinosis. Report of two cases in the same family.

Clinical and biochemical evidence of oculocutaneous tyrosinosis, a rare disease due to hepatic soluble tyrosine aminotransferase (STAT) deficiency, was found in a 3 1/2-year-old girl and in her maternal aunt. Different expressivity of this disease, resulting in clinical heterogeneity, is shown to occur commonly according to the cases reported in this as well as in previous studies. The metabolic pathways leading to the unexpected excretion of phenolic acids in urine are reviewed, and the need for early diagnosis and dietary treatment, in order to prevent corneal clouding and brain damage is finally stressed.