The rat brachial plexus and its terminal branches: An experimental model for the study of peripheral nerve regeneration

Despite the introduction of microsurgical techniques into clinical practice, the results of surgical procedures involving the brachial plexus and peripheral nerves are still far from spectacular. We therefore studied the rat brachial plexus and its terminal branches in 203 rats. Detailed anatomic and morphologic analyses of the biceps brachii and musculocutaneous nerve, finger flexors, flexor carpi radialis, and the median nerve were performed. Various sources of conventional and vascularized nerve grafts were explored. After musculocutaneous nerve section or median nerve section, there were no articular contractures or automutilations, which constitutes an advantage for these experimental models over the sciatic nerve model. The brachial plexus and its terminal branches provide a good experimental model which can be used to assess the development and normal control of muscle function, examine the mechanisms underlying functional recovery, and test the effects of treatments to enhance recovery. © 1995 Wiley-Liss, Inc.     

Glycosaminoglycan mimetics (RGTA) modulate adult skeletal muscle satellite cell proliferation in vitro

Confocal Raman microspectroscopy (CRM) provides an important and novel means of analyzing the chemical composition of the adhesive/dentin (a/d) interface. The purpose of this study was to develop a method for quantitative determination of the degree of adhesive penetration at the a/d interface using CRM. Three commercial dentin adhesive systems [Scotchbond Multipurpose Plus (SBMP+), Single Bond (SB), and Primer Bond NT (PBNT)] based on the total etch and "wet" bonding technique were examined in this study. Human dentin specimens treated with these adhesives were analyzed with CRM mapping across the a/d interface. Also, Raman spectra were collected on model mixtures of adhesive and type I collagen, and the ratios of the relative intensities of the Raman bands corresponding to adhesive and collagen were used for the construction of calibration curves. By comparing the Raman band ratios of interface specimens to the calibration curves, the percent of adhesive as a function of spatial position across the a/d interface was determined. The results show that there is a gradual decrease in penetration as a function of position for all three adhesive systems while the adhesive concentration gradient decreases in the order of SBMP+ > SB > PBNT. These differences in penetration of the three adhesives at the a/d interface also are discussed relative to the composition and phase segregation in adhesives. Additionally, our results indicate that confocal Raman microspectroscopy is a reliable in situ analytical technique for simple and rapid quantitative determination of adhesive penetration at its interface with prepared dentin.     

Neutrophil Migration in Opposing Chemoattractant Gradients Using Microfluidic Chemotaxis Devices

Neutrophils migrating in tissue respond to complex overlapping signals generated by a variety of chemotactic factors (CFs). Previous studies suggested a hierarchy between bacteria-derived CFs and host-derived CFs but could not differentiate neutrophil response to potentially equal host-derived CFs (IL-8 and LTB₄). This paper reports neutrophil migration in conflicting gradients of IL-8 and LTB₄ using a microfluidic chemotaxis device that can generate stable and well-defined gradients. We quantitatively characterized the movement of cells from time-lapse images. Neutrophils migrate more efficiently toward single IL-8 gradients than single LTB₄ gradients as measured by the effective chemotactic index (ECI). In opposing gradients of IL-8 and LTB₄, neutrophils show obvious chemotaxis toward a distant gradient, consistent with previous reports. When an opposing gradient of LTB₄ is present, neutrophils show less effective chemotaxis toward IL-8 than when they are in a gradient of IL-8 alone. In contrast, the chemotactic response of neutrophils to LTB₄ is not reduced in opposing gradients as compared to that in a single LTB₄ gradient. These results indicate that the presence of one host-derived CF modifies the response of neutrophils to a second CF suggesting a subtle hierarchy between them.This revised version was published online in May 2005 with corrected author affiliations     

Universal Collection Medium (UCM) is as suitable as the Standard Transport Medium (STM) for Hybrid Capture II (HC-2) assay.

BACKGROUND: Collection of cervical-vaginal material in liquid media enables simultaneous evaluation of both oncologic cytology and molecular tests for the detection of Human papillomavirus (HPV), Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG). Universal Collection Medium (UCM) has been developed to fulfill this objective. OBJECTIVES: To compare Hybrid Capture II (HC-2) to diagnose HPV, NG and CT in specimens collected in UCM and in the current Digene Standard Transport Medium (STM). STUDY DESIGN: The study was cross-sectional. Three collections of endocervical and ectocervical material were performed in each of 893 women referred for colposcopy in the following order: (1) to prepare a conventional Pap smear slide using the accompanying brush of the STM kit and with Ayre spatula; (2) for HC-2 test and liquid-based cytology using a 1 ml UCM vial as transport medium; material was collected with another similar brush; (3) for HC-2 test using a 1 ml STM vial as transport medium; material was collected with the same brush that we used in the procedure no. (1) (conventional Pap smear). HC-2 results from samples taken from STM and UCM media were compared by using simple linear regression analysis and Kappa statistic. RESULTS AND CONCLUSIONS: HC-2 results from the two media were highly correlated: high-risk HPV (kappa=0.92; r(2)=0.92), low-risk HPV (kappa=0.85; r(2)=0.86) and NG/CT (kappa=0.96; r(2)=0.81). Despite being obtained from a second specimen, the UCM HC-2 results were equivalent to those obtained with the standard medium STM and the UCM medium.     

Evaluation of three commercially available hepatitis C virus antibody detection assays under the conditions of a clinical virology laboratory.

BACKGROUND: Most studies evaluating antibody detection assays are conducted on samples from healthy blood donors but not on samples of hospitalized patients which can show non-specific reactions. OBJECTIVES: To compare the performance of three commercial automated assays for the detection of hepatitis C virus (HCV) antibodies, Monolisa anti-HCV Plus version 2, Axsym anti-HCV 3.0 and Vitros anti-HCV, on a population of hospitalized patients. STUDY DESIGN: The specificity of the assays was prospectively evaluated in 2020 routine serum samples. In order to assign the serostatus of each sample, those giving positive or discordant results were further tested by three immunoblots and by RT-PCR (Roche). Moreover, the sensitivity was evaluated on eight commercial HCV seroconversion panels. RESULTS: The Monolisa, Axsym and Vitros assays showed specificities of 99.64%, 99.12% and 99.33%, respectively. Concerning the sensitivity, among 49 samples, the number of positive results was 21, 24 and 24 for the Monolisa, Axsym and Vitros kits, respectively. The differences were not statistically significant at an alpha risk of 5%. CONCLUSIONS: All assays appeared to be reliable for routine screening, but there were a surprising number of indeterminate samples that could not be resolved by confirmatory tests.     

Triploidy syndrome: A report on two live-born (69, XXY) and one still-born (69, XXX) infants

Two live-born cases, 69,XXY and one stillbirth, 69,XXX are reported. Further evidence is presented to delineate the triploidy syndrome. Common external and internal features which characterize the triploidy syndrome are low-set ears, hypertelorism, colobomata, syndactyly, simian creases, microphallus, undescended testes, scrotal aplasia, anomalous heart and hypoplasia of kidneys and adrenals. The triploidy syndrome encompasses features found in trisomies 13, 18 and 21. We suggest that the abnormal development of the triploidy infants is the result of the mentioned trisomies and their subsequent effect on the remaining genome.     

Osteolytic potential of triphenyl bismuth as an alternative contrast medium in acrylic bone cement

Radiopaque cement containing barium sulfate causes significantly more bone resorption in vivo and in vitro than radiolucent cement. The aim of this study was to investigate the osteolytic potential of an alternative radiopaque agent, triphenyl bismuth (TPB). Bone cement particles containing various concentration of TPB (15 and 25 wt %) prepared by two methods, blending and dissolution, were added to monocytes in a bone resorption assay and the extent of lacunar resorption on dentine slices was determined. The results clearly show that cement particles containing TPB cause less bone resorption than cement particles containing barium sulfate. In addition, our results suggest that TPB prepared by dissolution in bone cement induces less osteolytic response than TPB-cement prepared by blending. The osteolysis in response to bone cement wear particles may therefore be reduced with TPB prepared using the blending technique.     

Merkel cell tumour: case reports and review

Merkel cell carcinoma, a small-cell undifferentiated/neuroendocrine carcinoma, is a highly invasive primary malignant neoplasm of the skin that may arise from Merkel cells or an epithelial precursor cell. One tenth of all cases affect the eyelids and periocular region, typically in the elderly population. The presentation is generally as a painless erythematous nodule with telangiectatic blood vessels and often intact overlying skin. The rarity of Merkel cell carcinoma of the eyelid can lead to delay in diagnosis and treatment of this tumour. In the present paper, the authors illustrate the aggressive nature of Merkel cell carcinoma, and the importance of early and wide surgical treatment and close follow-up. They discuss the role of rapid paraffin histology compared to frozen section. METHODS: Three cases are described, discussing the clinical presentation, diagnosis and treatment, with a review of the pathology. RESULTS: All three patients were female, presenting with rapidly growing upper eyelid tumours 20 mm in size; one case had paraffin sections suggesting incomplete clearance when frozen section had appeared clear; exenteration was required. The other two cases had lymph node involvement at one and two months post wide local excision. All patients remain alive at follow-up of 6, 4.6, and 2 years, respectively. DISCUSSION: The cases illustrate the aggressive nature of the tumour, the unusual tarsal involvement and the typical pathology. Sampling errors associated with limited frozen section control of excision may be avoidable by the use of rapid paraffin histology. The highly invasive nature of this tumour requires close follow-up following resection.