Fixations extra-osseuses du Tc MDP dans le cas d’un cancer du sein métastatique à l’os

Aim

To report and discuss an unusual visceral uptake on bone scan in a case of breast cancer with bone metastases.

Patient and methods

A 40-year-old woman, with untreated bilateral breast cancer was referred to our department for a bone scan.

Results

The bone scan evidenced multiple metastases over the axial skeleton. Uncommonly, visceral uptake was noted associating diffuse bilateral lung uptake and intense myocardium, stomach and kidneys uptakes. Serum calcium level was high: 4.08 mmol/L (normal: 2.38–2.70 mmol/L).

Conclusion

The incidental observation of metastasic calcifications on bone scan is often related to severe hypercalcemia. Such pattern should alert the physician on the existence and the severity of calcium metabolism disturbances that had not been suggested before.     

Glucose-6-phosphate dehydrogenase deficiency in Tunisia: molecular data and phenotype-genotype association

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common human enzyme defect. In this study, we aimed to perform a molecular investigation of G6PD deficiency in Tunisia and to associate clinical manifestations and the degree of deficiency with the genotype. A total of 161 Tunisian subjects of both sexes were screened by spectrophotometric assay for enzyme activity. Out of these, 54 unrelated subjects were selected for screening of the most frequent mutations in Tunisia by PCR/RFLP, followed by size-based separation of double-stranded fragments under non-denaturing conditions on a denaturing high performance liquid chromatography system. Of the 56 altered chromosomes examined, 75 % had the GdA^? mutation, 14.28 % showed the GdB^? mutation and no mutations were identified in 10.72 % of cases. Hemizygous males with GdA^? mutation were mostly of class III, while those with GdB^? mutation were mainly of class II. The principal clinical manifestation encountered was favism. Acute hemolytic crises induced by drugs or infections and neonatal jaundice were also noted. Less severe clinical features such as low back pain were present in heterozygous females and in one homozygous female. Asymptomatic individuals were in majority heterozygote females and strangely one hemizygous male. The spectrum of mutations seems to be homogeneous and similar to that of Mediterranean countries; nevertheless 10.72 % of cases remain with undetermined mutation thus suggesting a potential heterogeneity of the deficiency at the molecular level. On the other hand, we note a better association of the molecular defects with the severity of the deficiency than with clinical manifestations.     

Microsatellite allele frequencies in humans and chimpanzees, with implications for constraints on allele size

The distributions of allele sizes at eight simple-sequence repeat (SSR) or microsatellite loci in chimpanzees are found and compared with the distributions previously obtained from several human populations. At several loci, the differences in average allele size between chimpanzees and humans are sufficiently small that there might be a constraint on the evolution of average allele size. Furthermore, a model that allows for a bias in the mutation process shows that for some loci a weak bias can account for the observations. Several alleles at one of the loci (Mfd 59) were sequenced. Differences between alleles of different lengths were found to be more complex than previously assumed. An 8-base-pair deletion was present in the nonvariable region of the chimpanzee locus. This locus contains a previously unrecognized repeated region, which is imperfect in humans and perfect in chimpanzees. The apparently greater opportunity for mutation conferred by the two perfect repeat regions in chimpanzees is reflected in the higher variance in repeat number at Mfd 59 in chimpanzees than in humans. These data indicate that interspecific differences in allele length are not always attributable to simple changes in the number of repeats.      

A novel deconvolution method for modeling UDP-N-acetyl-D-glucosamine biosynthetic pathways based on 13C mass isotopologue profiles under non-steady-state conditions

This article is a response to Wang and Luo. See correspondence article http://www.biomedcentral.com/1741-7007/10/30/ [WEBCITE] and the original research article http://www.biomedcentral.com/1741-7007/9/24 [WEBCITE].     

Intérêt de la scintigraphie parathyroïdienne de soustraction dans la prise en charge de l’hyperparathyroïdie secondaire. À propos de 33 cas

Aim^99mTc-Sestamibi is used in the imaging of hyperparathyroidism in order to guide the surgical procedure and to propose methods of less invasive surgery. The aim of our study was to evaluate the efficiency of preoperative subtraction parathyroid scintigraphy (Sestamibi-^99mTc/Pertechnetate) in the management of secondary hyperparathyroidism.Patients and methodsThe records of 33 patients with renal impairment consecutively operated from 2009 to 2011 for secondary hyperparathyroidism were retrospectively reviewed. We collected data on parathyroid function, results of parathyroid scintigraphy, intraoperative findings and pathological findings.ResultsScintigraphy was positive in 32 patients by disclosing a total of 75 hyperplastic parathyroid glands. The surgical exploration of all parathyroid glands revealed 99 hyperplastic glands confirmed by histological analysis. The sensitivity of parathyroid scintigraphy was 70.7% with a specificity of 85%. Positive predictive value was 93.3%, while negative predictive value was 50%. No correlation was found between the values of parathyroid hormone (PTH) and calcemia measured preoperatively and scintigraphic results.Discussion and conclusionIn our study, the correlation of scintigraphic data with PTH and serum calcium is not statistically significant. However, owing to a high positive predictive value, the parathyroid scan should be indicated. Value of parathyroid scintigraphy extends to searching ectopic or supernumerary glands and especially in cases of persistent or recurrent hyperparathyroidism.     

Monoclonal antibodies against chicken type V collagen: production, specificity, and use for immunocytochemical localization in embryonic cornea and other organs

Two monoclonal antibodies have been produced against chick type V collagen and shown to be highly specific for separate, conformational dependent determinants within this molecule. When used for immunocytochemical tissue localization, these antibodies show that a major site for the in situ deposition of type V is within the extracellular matrices of many dense connective tissues. In these, however, it is largely in a form unavailable to the antibodies, thus requiring a specific “unmasking” treatment to obtain successful immunocytochemical staining. The specificity of these two IgG antibodies was determined by inhibition ELISA, in which only type V and no other known collagen shows inhibition. In ELISA, mixtures of the two antibodies give an additive binding reaction to the collagen, suggesting that each is against a different antigenic determinant. That both antigenic determinants are conformational dependent, being either in, or closely associated with, the collagen helix is demonstrated by the loss of antibody binding to molecules that have been thermally denatured. The temperature at which this occurs, as assayed by inhibition ELISA, is very similar to that at which the collagen helix melts, as determined by optical rotation. This gives strong additional evidence that the antibodies are directed against the collagen. The antibodies were used for indirect immunofluorescence analyses of cryostat sections of corneas and other organs from 17 to 18-day-old chick embryos. Of all tissues examined only Bowman’s membrane gave a strong staining reaction with cryostat sections of unfixed material. Staining in other areas of the cornea and in other tissues was very light or nonexistent. When, however, sections were pretreated with pepsin dissolved in dilute HAc or, surprisingly, with the dilute HAc itself dramatic new staining by the antibodies was observed in most tissues examined. The staining, which was specific for the anti-type V collagen antibodies, was largely confined to extracellular matrices of dense connective tissues. Experiments using protease inhibitors suggested that the “unmasking” did not involve proteolysis. We do not yet know the mechanism of this unmasking; however, one possibility is that the dilute acid causes swelling or conformational changes in a type-V collagen-containing supramolecular structure. Further studies should allow us to determine whether this is the case.