Evaluation of clinical criteria for diagnosis of bullous pemphigoid. French Bullous Study Group

OBJECTIVE

To check the potential usefulness of clinical criteria for the diagnosis of bullous pemphigoid when state-of-the-art techniques such as Western immunoblotting, immunoprecipitation, and indirect immunofluorescence on salt-split skin or direct immunoelectron microscopy are not available.

DESIGN

Comparison of the clinical criteria between 2 groups (with and without bullous pemphigoid) as defined by immunoelectron microscopy used as standard criterion, in a prospective study. Multivariate logistic regression analysis was carried out by including all items that were statistically significant (at P < .05 level) in univariate analysis.

SETTING

Five dermatology departments in teaching hospitals.

PATIENTS

The 231 patients studied had subepidermal autoimmune bullous diseases with linear IgG or C3 deposits in the basement membrane zone (157 with bullous pemphigoid, 33 with cicatricial pemphigoid, 30 with epidermolysis bullous acquisita, 5 with lupus erythematosus, and 6 others). A second set of patients was used to calculate predictive values.

RESULTS

The multivariate logistic stepwise analysis resulted in a final set of predictors that included only 4 items: absence of atrophic scars, absence of head and neck involvement, absence of mucosal involvement, and age greater than 70 years. No additional variables met the .05 significance level to enter into the model. If 3 of these 4 characteristics were present, a diagnosis of bullous pemphigoid could be made with a sensitivity of 90% and a specificity of 83%; these predictive values were calculated on a sample of 70 new cases.

CONCLUSIONS

With and estimated incidence of bullous pemphigoid among subepidermal autoimmune bullous diseases of 80%, the presence of 3 of the 4 significant criteria allows the diagnosis of bullous pemphigoid, with a positive predictive value of 95%. Our set of clinical criteria thus allows the diagnosis of bullous pemphigoid with good validity for both clinical practice and therapeutic trials.

Adhesion of mammalian cells to polymer surfaces: from physical chemistry of surfaces to selective adhesion on defined patterns

The study of the adsorption of type I collagen from a solution containing Pluronic F68 has shown that the latter prevents collagen adsorption on polystyrene and does not prevent it on surface-oxidized polystyrene. This explains the control of mammalian cell adhesion by substrate surface hydrophobicity and composition of pre-conditioning solution. On that basis, selective adhesion of different types of mammalian cells (PC12 pheochromocytoma, MSC80 schwannoma, Hep G2 hepatoblastoma, rat hepatocytes) on patterned surfaces was achieved. Therefore tracks (width in the range of a few tens of microm) of reduced hydrophobicity were produced on polystyrene by photolithography and oxygen plasma treatment. After conditioning by a solution containing both Pluronic F68 and extracellular matrix protein (collagen, fibronectin), the latter adsorbed selectively on these paths thus allowing selective adhesion of the cells.

Fibronectin adsorption, conformation, and orientation on polystyrene substrates studied by radiolabeling, XPS, and ToF SIMS

Protein adsorption is widely studied by a variety of techniques, but there still is little known about protein orientation and conformation after adsorption. This probably is due to the large number of parameters involved, such as the characteristics of the surface and the structure of the protein. In this study, the adsorption of fibronectin was investigated with three different techniques: radiolabeling, X-ray photoelectron spectroscopy (XPS), and time-of-flight secondary ion mass spectrometry (ToF SIMS) on polystyrene and oxidized polystyrene. The first two techniques have been widely used to study protein adsorption, allowing us to determine the amount of protein adsorbed on each surface. The ToF SIMS, however, is a technique just emerging for the study of protein adsorption. This study confirms its utility since ToF SIMS is found to be sensitive to the protein orientation and/or conformation at the surface. Indeed, the ToF SIMS peaks characteristic of the protein show differences in their reduced intensity between the two substrates. These differences, which are not detected by XPS, are attributed to different orientations and/or conformations of the protein.

Molybdenum cofactor properties and [Fe-S] cluster coordination in Escherichia coli nitrate reductase A: investigation by site-directed mutagenesis of the conserved his-50 residue in the NarG subunit

Most of the molybdoenzymes contain, in the amino-terminal region of their catalytic subunits, a conserved Cys group that in some cases binds an [Fe-S] cluster. In dissimilatory nitrate reductases, the first Cys residue of this motif is replaced by a conserved His residue. Site-directed mutagenesis of this residue (His-50) was performed on the NarG subunit from Escherichia coli nitrate reductase A. The results obtained by EPR spectroscopy enable us to exclude the implication of this residue in [Fe-S] binding. Additionally, we showed that the His-50 residue does not coordinate the molybdenum atom, but its substitution by Cys or Ser introduces a perturbation of the hydrogen bonding network around the molybdenum cofactor. From potentiometric studies, it is proposed that the high-pH and the low-pH forms of the Mo(V) are both involved during the redox turnover of the enzyme. Perturbation of the Mo(V) pKV value might be responsible for the low activity reported in the His-50-Cys mutant enzyme. A catalytic model is proposed in which the protonation/deprotonation of the Mo(V) species is an essential step. Thus, one of the two protons involved in the catalytic cycle could be the one coupled to the molybdenum atom in the dissimilatory nitrate reductase of E. coli.

Intravenous leiomyomatosis with caval involvement: report of a case with radical resection and venous replacement

Intravenous leiomyomatosis is a rare, histologically benign neoplasm that may be malignant in its specific tendency to intravascular extension. A case of intravenous leiomyomatosis with extension into the entire inferior vena cava in a 41-year-old woman is described. The patient was diagnosed with syncope 3 years after hysterectomy and was treated with a 1-stage procedure including venous replacement.

[Home oxygen therapy in children with chronic respiratory failure]

BACKGROUND

Home oxygen therapy improves survival and quality of life in adults with chronic obstructive airways disease. The few studies about home oxygen therapy in children show improvements in weight gain, school performance and decreases in hospitalization expenses.

AIM

To report our experience in home oxygen therapy in children followed for six months to four years.

PATIENTS AND METHODS

Fifty five children, less than 15 years old, discharged from a University hospital with the diagnosis of chronic respiratory failure, were followed up at their homes.

RESULTS

Discharge diagnoses were bronchopulmonary dysplasia in 36% of children, postinfectious pulmonary damage in 22%, neonatal distress in 13%, chronic aspiration in 9%, cystic fibrosis in 7% and miscellaneous in 13%. Forty six completed at least 6 months of follow up, five moved to other hospitals, three required ventilatory support and one died. Oxygen was discontinued in 33 patients, and this occurred before the ninth month of follow up in 88% of those children. Neonatal distress and bronchopulmonary dysplasia had the best prognoses, and oxygen was discontinued at 4 +/- 1 and 5.7 +/- 3 months respectively. Patients with postinfectious pulmonary disease had a higher incidence of bronchoneumoniae, and those with bronchopulmonary dysplasia a higher incidence of acute bronchiolitis, that motivated hospital admissions. Expenses due to home oxygen were lower than hospitalization costs. No adverse effects were detected.

CONCLUSIONS

Infants and newborns on home oxygen therapy have a good prognosis, specially those with reversible diseases. This type of therapy allows an earlier hospital discharge with considerable cost reductions.

[Comparative efficacy and risks of low molecular weight heparins and thrombolysis in massive pulmonary embolism without cardiogenic shock]

The aim of this retrospective study was to assess pulmonary reperfusion by scintigraphy, the risks of recurrent embolism and of bleeding complications at the 7th day and 3rd month in 2 groups of patients admitted to hospital for massive pulmonary embolism without cardiogenic shock treated by intravenous thrombolysis (Group I) and by subcutaneous low molecular weight heparin (Group II) paired by Miller's index. The basal characteristics of the two groups, each comprising 31 patients, were comparable with respect to the severity of the pulmonary embolism with an average global scintigraphic defect of 40.6 +/- 13.5% in Group I and 39 +/- 13.7% in Group II. The scintigraphic changes at the 7th day were comparable with a relative improvement of 55 and 51% respectively and at 3 months of 74% in both groups. There was no significant difference in terms of recurrence of embolism (3 versus 0% at the 7th day and 3% in each group at 3 months) or of bleeding complications (13 and 10% at the 7th day and 10 and 6% at 3 months respectively). Low molecular weight heparin seems to be as effective as intravenous thrombolysis for the treatment of massive pulmonary embolism without shock. This result requires confirmation by a large scale prospective randomised trial.

[MRI diagnosis of sinus cavernous invasion by pituitary adenomas]

PURPOSE

To evaluate the preoperative MRI criteria of a sinus cavernous invasion by a pituitary adenoma.

MATERIAL AND METHODS

Study of 102 cavernous sinuses among 51 patients who had had a surgical cure of pituitary adenoma. Thirteen patients had a surgical invasion of the cavernous sinus.

RESULTS

A certain number of signs eliminated cavernous sinus invasion. The best means consisted in not crossing the intercarotid line (Sensitivity-Se = 100%, Specificity-Sp = 85% and Negative Predictive Value-NPV = 100%). The others means implied: not going past twelve o'clock on the internal carotid artery-ICA (NPV = 97.1%), symmetrical size of the cavernous sinus (NPV = 92.5%), non-convexity of the lateral wall (NPV = 90.2%), visualization of at least two venous groups of the laterosellar space (NPV = 90.2%) and finally, non-displacement of the ICA (NPV = 89.2%). The best criteria for diagnosis were passing by the intra and supracavernous ICA lateral tangent (Se = 84.6%, Sp = 95%) and the percentage of ICA encasement by the adenoma exceeding 25% (Se = 92.3%, Sp = 85%).

CONCLUSION

Except the total encasement of the intracavernous ICA, the cavernous sinus can be invaded when the lateral tangent of the supra and the intracavernous ICA is crossed, and also when the percentage of ICA encasement exceeds 25%.

Sequence characteristics of natural populations of tomato spotted wilt tospovirus infecting flue-cured tobacco in Georgia

Using primers from conserved regions, the nucleocapsid (Nc) gene sequences of naturally occurring tomato spotted wilt tospovirus (TSWV) isolates from flue-cured tobacco (Nicotiana tabacum) grown in several Georgia counties were amplified by immunocapture-reverse transcription-polymerase chain reaction. The resulting amplicons were cloned and sequenced. Sequence analyses showed a high degree of sequence conservation among the Nc genes of the tobacco isolates, and those reported from other parts of the world. However, distinct differences that were unique to these tobacco isolates as well as the previously studied peanut, tomato and pepper isolates from Georgia were present. The Georgia isolates formed a distinct cluster that was clearly resolved from the rest of the TSWV isolates based on sequence phylograms.

Hyaluronectin is produced by oligodendrocytes and Schwann cells in vitro

A hyaluronectin (HN)-like antigen was found in rat O-2A progenitors and oligodendrocytes, as well as in Schwann cells and in their culture medium. The HN-like antigen secreted in culture supernatants had a higher molecular mass than HN extracted from rat brain at acidic pH. In vitro the secreted HN-like antigen was spontaneously and slowly degraded into species whose Mr was close to that of HN found in acidic brain extract. In brain or nerve neutral pH extracts, both HN-like antigen and HN were present. The high Mr of the secreted antigen, the homology in amino acid sequences between HN and N-terminal domain of PG-M/versican, in addition to a positive hybridization between Schwann cell RNAs and a probe obtained with primers derived from HN sequences also found in versican suggested that HN is closely related to the large proteoglycan PG-M/versican. The presence in Schwann cell extract of a HN mRNA whose Mr was compatible with the size expected for HN showed that HN may be directly secreted by cells and not only the consequence of a proteolytic cleavage. The similarity of HN with PG-M (V3) suggested that HN found in vivo could be the result of an alternative splicing of a single gene. We conclude that HN as other members of the PG-M/versican family is a marker of oligodendrocytes and Schwann cells in culture.

Reading ability and processing in Duchenne muscular dystrophy and spinal muscular atrophy

We analysed the reading abilities and processing of 21 children with Duchenne muscular dystrophy (DMD), 11 matched children suffering from spinal muscular atrophy (SMA) and 42 children receiving normal education. The principal result observed was that the DMD children exhibited a reading age which was significantly lower than the SMA children compared with their chronological age. These learning disabilities were not related to a deficit in non-verbal performance intelligence, but psycholinguistic evaluation showed a deficit in verbal intelligence, especially in the Similarities and Arithmetic WISC-R subtests, in phonological abilities, oral word repetition, and in digit span score. The results for the DMD children were heterogeneous, and ranged from normal to greater or lesser involvement. In an attempt to clarify the nature of this reading impairment in DMD children, the three groups (DMD, SMA, and normal control children) were tested by reading aloud a list of single words and non-words. The DMD children were significantly impaired in reading non-words, suggesting reading disability similar to dysphonetic dyslexia, the most frequent subtype of developmental dyslexia. These results are discussed in the light of psychometric data available for our DMD population and in the light of previous studies. The practical consequences of diagnosis on rehabilitation are very important. The precise description of the cognitive deficits seen in DMD is of value for future clinical and genetic studies.

Hyaluronectin blocks the stimulatory effect of hyaluronan-derived fragments on endothelial cells during angiogenesis in vitro

Hyaluronic acid (HA) is a glycosaminoglycan of the extracellular matrix. Its fragmentation by the hyaluronidase, secreted by tumor cells, facilitates tumor invasion and the HA degradation products generated stimulate angiogenesis. We report here that the HA-binding protein hyaluronectin (HN) inhibits the stimulatory effect of HA-derived fragments on the proliferation and migration of endothelial cells in vitro, and hampers the organization of endothelial cells into capillary-like structures. Since HN strongly inhibits endothelial cell adhesion to immobilized HA, it is postulated that HN acts by impairing the binding to endothelial cells of HA fragments generated by hyaluronidase, thereby neutralizing the effect of HA degradation products on angiogenesis. Our results reveal a new mechanism by which the angiogenesis induced by HA fragments is modulated by HN.

Increased hyaluronidase levels in breast tumor metastases

Hyaluronidase, a matrix-degrading enzyme, was assayed in extracts from breast primary tumors and regional metastases using a pool of human sera as a standard. Optimal activities of tumor extracts and serum were found for concentrations of 0.15-0.20 M NaCl in pH 3.8-4.0 buffer. In evaluating contamination by serum due to vascular proliferation, we expressed our results as the ratio of the entire activity (mU/l extract) on serum albumin content of tumors (g/l). Median (interquartile range) activities were 9.02 (6.04-14.34) for primary tumors and 37.36 (24.06-99.63) mU/g albumin for metastases. The difference was significant. Zymographic analysis showed that 3 bands of activity were detected which corresponded to 68, 53 and 49 kDa for tumoral hyaluronidase. The same pattern was observed for cellular extracts of breast cancer cell line CAL51, demonstrating that hyaluronidase detected in tumor extracts had mainly a cellular origin. Our results suggest that hyaluronidase may be involved in the metastatic process.