Martin-Gruber anastomosis revisited

Based on a study of 70 human cadavers (31 male, 39 female) and on cases described previously, we propose a new classification of the Martin-Gruber anastomosis, a neural connection between the median and ulnar nerves in the forearm. The anastomosis was found in 16 (22.9%) cadavers, being bilateral in three (18.7%) and unilateral in 13 (81.3%), five right and eight left. It occurred in eight (25.8%) of the 31 male cadavers and in eight (20.5%) of the 39 females. Therefore, the anastomosis was found in 19 (13.6%) of the 140 forearms. In Pattern I (89.5%) the anastomosis was made by only one branch, whereas in Pattern II (10.5%) it was made by two. The individual branches were classified as Types a, b, and c based on the nature of their origin from the median nerve. Type a (47.3%) arose from the branch to the superficial forearm flexor muscles, Type b (10.6%) from the common trunk, and Type c (31.6%) from the anterior interosseous nerve. Pattern II was a duplication of Type c (10.5%). The anastomotic branch took an oblique or arched course before joining the ulnar nerve, undivided in 15 cases, but divided into two branches in four cases. The anastomosis passed in front of the ulnar artery in four cases, behind it in six, and in nine cases it was related to the anterior ulnar recurrent artery.     

Feeding NOD mice with pig splenocytes induces transferable mechanisms that modulate cellular and humoral xenogeneic reactions against pig spleen or islet cells

We have reported previously that oral administration of pig cells to NOD mice modified xenogeneic cellular response against pig islet cells (PICs), and hypothesized that it may have induced active suppression. This preliminary report evaluated only the effect of feeding pig cells by 'primary' proliferation, i.e. when splenocytes from fed mice are confronted with pig cells in vitro. The present study also considered 'secondary' proliferation and cytokine production after feeding and subsequent in vivo graft of pig cells. Additionally, serum IgM and IgG isotypes were quantified by ELISA using pig target cells. Induction of active mechanism by feeding was hypothetical, which led us here to transfer splenocytes from mice fed pig spleen cells (PSC) and evaluate 'primary' (after transfer) and 'secondary' (after transfer and subsequent graft of pig cells) proliferations and cytokine secretions in recipient mice. We also determined whether the effects of feeding pig cells persisted after depression of suppressor mechanisms by cyclophosphamide. Mice fed with PSC displayed increased 'primary' splenocyte proliferation to PSC or PIC (P < 0.0001), while 'secondary' responses were decreased (P < 0.03) in those fed PSC and subsequently grafted with PSC. The increased 'primary' and decreased 'secondary' proliferations were reduced (P < 0.04) by pretreatment with cyclophosphamide. The IL-10/ and IL-4/IFNgamma ratios produced in response to PSC increased (P < 0.04) in mice fed and grafted with PSC compared to those grafted only with PSC. IgM and IgG levels against pig cells were, respectively, increased (P < 0.04) and decreased (P < 0.04) in mice fed and grafted with PSC. IgG2a and IgG2b, but not IgG1, levels were lower (P < 0.01). These effects of feeding PSC on 'secondary' proliferation, cytokine and antibody productions, were not detected when mice were fed PSC only after graft with PSC. Transfer with splenocytes from mice fed PSC increased 'primary' proliferation of splenocytes from recipient mice in response to PSC (P < 0.02) or PIC (P < 0.05). After transfer with splenocytes from PSC-fed mice and graft with PSC, 'secondary' proliferation to pig cells were reduced (P < 0.04), and the IL-10/IFNgamma ratio produced in response to PSC was increased fourfold. Thus, oral administration of PSC induces active transferable mechanisms, characterized by a biphasic pattern with early increased 'primary' xenogeneic cellular reactions to both PSC and PIC, followed by decreased 'secondary' responsiveness and a concomitant shift of the Th1/Th2 balance towards greater Th2 influence. Decreased responsiveness may be due to active suppression, even though induction of anergy or deletion cannot be excluded.     

Coexistence of a pectoralis quartus muscle and an unusual axillary arch: case report and review

A pectoralis quartus muscle and an unusual axillary arch were found on the left side of a female cadaver. The axillary arch was a musculoaponeurotic complex continuous with the iliacal fibers of the latissimus dorsi. The muscular part, together with the tendon of pectoralis major, inserted into the lateral lip of the bicipital groove of the humerus, whereas the aponeurotic part was formed by a fibrous band that extended deep to the pectoralis major to insert into the coracoid process between the attachments of the coracobrachialis and pectoralis minor. The pectoralis quartus originated from the rectus sheath, and joined the inferior medial border of the fibrous band of the axillary arch, at the lateral edge of the pectoralis major. The axillary arch muscle crossed anteriorly the axillary vessels and the brachial plexus. The clinical importance of these muscles is reviewed.     

Iron and marine nitrogen fixation: progress and future directions

A synthesis of the current understanding of potential iron limitation of pelagic nitrogen fixation is given, considering biochemical bases of Fe requirements and empirical observations of growth and Fe quotas of cultures and field populations of Trichodesmium. The potential for iron limitation of heterotrophic diazotrophy in the marine environment is also evaluated.     

Slow crack growth behaviour of hydroxyapatite ceramics

Among materials for medical applications, hydroxyapatite is one of the best candidates in orthopedics, since it exhibits a composition similar to the mineral part of bone. Double torsion technique was here performed to investigate slow crack growth behaviour of dense hydroxyapatite materials. Crack rate, V, versus stress intensity factor, K(I), laws were obtained for different environments and processing conditions. Stress assisted corrosion by water molecules in oxide ceramics is generally responsible for slow crack growth. The different propagation stages obtained here could be analyzed in relation to this process. The presence of a threshold defining a safety range of use was also observed. Hydroxyapatite ceramics appear to be very sensitive to slow crack growth, crack propagation occurring even at very low K(I). This can be explained by the fact that they contain hydroxyl groups (HAP: Ca(10)(PO(4))(6)(OH)(2)), favouring water adsorption on the crack surface and thus a strong decrease of surface energy in the presence of water. This study demonstrates that processing conditions must be carefully controlled, specially sintering temperature, which plays a key role on V-K(I) laws. Sintering at 50 degrees C above or below the optimal temperature, for example, may shift the V-K(I) law towards very low stress intensity factors. The influence of ageing is finally discussed.     

高功率脉冲微波和电磁脉冲辐照对心肌细胞膜电穿孔效应及机理的研究

电磁辐射可造成人体多器官系统的损伤。对其损伤的病理机制至今尚未完全阐明。心脏是电磁辐射损伤的敏感器官之一。本实验拟通过研究HPPM和EMP对心肌细胞的影响,探讨电磁辐射致伤的关键机制,解释脉冲电磁场致心肌细胞损伤的发展规律。本实验采用HPPM和EMP辐照原代培养心肌细胞的方法,用原子力显微镜、激光扫描共聚焦显微镜、流式细胞仪和全自动生化检测仪等多种实验手段,检测辐照对细胞膜形态、结构和功能的影响。结果发现HPPM和EMP辐照后,心肌细胞搏动减慢,形态异常,活力下降,凋亡和坏死率明显增加。细胞膜出现数量不等、大小不一的电穿孔,细胞膜通透性丧失,结构破坏,细胞培养液中Na 、K 、Ca2 、Cl-、Mg2 、Ca2 和无机磷离子浓度显著升高(P<0.01),细胞内Ca2 浓度显著降低(P<0.01)。结果提示心肌细胞是电磁辐射损伤的敏感细胞,脉冲电磁场可致心肌细胞膜电穿孔,细胞形态、结构和功能均受到严重损伤。电穿孔效应是解释电磁辐射非热效应的关键机制之一。电穿孔导致的细胞膜通透性和膜结构改变存在一定发展规律。     

The importance of cyclin D1 and Ki67 expression on the biological behavior of pancreatic adenocarcinomas

The aim of this study was to evaluate the role of cyclin D1 and Ki67 proteins involved in cell-cycle control as a prognostic factor in pancreatic carcinomas. We examined formalin-fixed, paraffin-embedded material from 59 pancreatic adenocarcinomas, for which appropriate clinical and prognostic data were available. The standard streptavidin biotin immunoperoxidase method was used for immunostaining with cyclin D1 and Ki67. The extent of positive nuclear and cytoplasmic cyclin D1 staining was graded semiquantitatively. Ki67 reactivity was quantified and expressed as the percentage of stained nuclei. Staining with cyclin D1 and Ki67 was compared with histopathological prognostic features, and their relation with survival was also tested statistically. Patients whose tumors were cyclin D1-positive showed perineural invasion significantly more frequently than did patients with cyclin D1-negative tumors at the immunohistochemical level. In addition, tumors with lymphatic vessel invasion and without showed a significant difference in terms of cytoplasmic cyclin D1 staining. Ki67 indices were statistically different in stage groups. There was a significant and direct correlation between Ki67 index and nuclear cyclin D1 staining scores. No relation with survival was found. Our results suggest that cell-cycle proteins do not directly affect the prognosis of patients with pancreatic adenocarcinoma. Conversely, cyclin D1-positive tumors tend to have perineural invasion more frequently. In addition, lymph vessel invasion is another factor related to cyclin D1 reactivity of the cells. Ki67 indices differ statistically in stage groups.     

Chemolithoautotrophic oxidation of thiosulfate and phylogenetic distribution of sulfur oxidation gene (soxB) in rhizobacteria isolated from crop plants

Twenty-one thiosulfate-oxidizing bacteria were isolated from rhizosphere soils and 16S rRNA analysis revealed that the isolates were affiliated with seven different phylogenetic groups within the Beta and Gamma subclasses of Proteobacteria and Actinobacteria. Among these, five genera, including Dyella, Burkholderia, Alcaligenes, Microbacterium and Leifsonia sp., represented new sulfur oxidizers in rhizosphere soils. The thiosulfate-oxidizing Dyella, Burkholderia, Alcaligenes, Microbacterium, Leifsonia and Pandoraea were able to grow chemolithotrophically with a medium containing thiosulfate and exhibited growth coupled with thiosulfate oxidation. They accumulated intermediate products such as sulfur, sulfite and trithionate in the spent medium during the time course of thiosulfate oxidation, and these products were finally oxidized into sulfate. Furthermore, they possessed thiosulfate-metabolizing enzymes such as rhodanese, thiosulfate oxidase, sulfite oxidase and trithionate hydrolase, suggesting that these bacteria use the 'S4 intermediate' (S4I) pathway for thiosulfate oxidation. Phylogenetic analysis of the soxB gene revealed that Pandoraea sp. and Pandoraea pnomenusa strains formed a separate lineage within Betaproteobacteria.     

Asymptomatic carriage of Leishmania in family members of patients with visceral leishmaniasis in Central Tunisia

Introduction

In Tunisia, asymptomatic carriage of Leishmania is poorly documented.

Objective

The aim of the present study was to estimate the frequency of asymptomatic infection among the family members of patients with patent visceral leishmaniasis by using the Western blotting kit based on 14 and 16 kDa bands.

Material and methods

We tested 94 sera collected from 24 patients with patent visceral leishmaniasis and 70 from their families’ members.

Results

The rate of seropositivity was 100% in the group of patients and 54.3% in the group of families’ members. The analysis of the Western blotting patterns showed that the 33 kDa, 24 kDa and to a lesser extent the 22 kDa band were very indicative of patent visceral leishmaniasis in contrast to asymptomatic infection where these bands were very rarely detected.

Conclusion

The results reported herein showed the high frequency of asymptomatic carriers of Leishmania among the families’ members of visceral leishmaniasis cases and the usefulness of the Western blotting as a screening technique and in distinguishing between patent visceral leishmaniasis and the asymptomatic carriage of Leishmania.