Production of organometallic polymers by the interfacial technique. XVIII. A study of some associated reaction variables in the synthesis of silicon polyesters

Silicon containing reactants are condensed with diacid salts using the interfacial technique to give low molecular weight products. Infrared frequency band assignments are given. The following reaction variables were studied and reported on: Stirring rate, stirring time, and nature of silane.     

Production of organometallic polymers by the interfacial technique. XI. Synthesis of poly(organotin esters) and a study of some associated reaction variables

Polyesters of the form below are prepared by the interfacial method. Isolation procedures are presented and discussed. Polymer yield is constant as stirring rate, stirring time and nature of the organic solvent are varied. Molecular weight is constant as stirring rate and organic solvent nature are varied. Molecular weight increases as reaction time increases. No correlation is found between polymer molecular weight and polymer softening range.     

Identification and characterization of secreted effector proteins of Chlamydophila pneumoniae TW183

We report the expression of several chlamydial effector proteins in Chlamydophila pneumoniae, as well as their time-dependent secretion into the inclusion membrane. Localization of the respective genes within type III secretion gene clusters as well as bioinformatic analysis suggest that the identified proteins are type III-secreted effector proteins. Immunocytochemistry with antisera raised against CpMip (C. pneumoniae macrophage infectivity potentiator, Cpn0661), Pkn5 (Cpn0703), Cpn0709, Cpn0712 and Cpn0827 showed secretion of the respective proteins into the inclusion membrane at 20 h postinfection (hpi). CpMip was detected within the inclusion membrane from 20 to 72 hpi, whereas Cpn0324 (CopN) was located in this compartment at 72 hpi only. This was confirmed by co-localization of the respective proteins with IncA, an inclusion membrane marker protein. These data illustrate the fact that different effectors are being expressed and secreted during different time intervals of the infection cycle. Proteins Cpn0706 and Cpn0808 were not secreted by C. pneumoniae. The immunophilin FK506, known to inhibit the activity of Legionella, C. trachomatis and C. psittaci Mip proteins, was shown to interfere with chlamydial infection. Here we report the putatively type III-dependent secretion of CpMip into the inclusion membrane as well as the effect of its inhibition on C. pneumoniae infection of HEp-2 cells.     

Anuria during pneumoperitoneum in infants and children: a prospective study

Introduction

Transient oliguria during laparoscopic surgery is a known phenomenon. Currently, no data on the impact of pneumoperitoneum on renal function in children are available.

Patients and Methods

Thirty children with normal kidney function, who underwent laparoscopic surgery, were included in a prospective study. A transurethral catheter was placed to measure urine output during and 6 hours after operation. Renal blood flow (resistive index) was evaluated by Doppler ultrasound of a segmental renal artery before surgery, every 15 minutes during laparoscopy, and after 24 hours. Blood and urine samples were studied before and 24 hours after surgery. Hemodynamic parameters were monitored continuously during standardized anesthesia, including a standardized intravenous infusion regimen.

Results

Urine output decreased within 45 minutes of pneumoperitoneum in all patients. Of 8 children younger than 1 year, 7 (88%) developed anuria vs 3 of 22 (14%) children aged 1 to 15 years (P < .001). Nine children 1 year and older (32%) developed oliguria. There was a significant recovering in the mean urine output until 5 to 6 hours after pneumoperitoneum in both age groups. No significant alterations of the renal blood flow (resistive index) and the serum and urine levels of cystatin C, creatinine, and urea nitrogen were evident until 24 hours postoperatively. The volume of infusion during pneumoperitoneum did not correlate with urine output.

Conclusion

Pneumoperitoneum leads to anuria in most children younger than 1 year and to oliguria in about one third of older children. This is a completely reversible phenomenon. Urine output should not be taken into consideration for calculating intravenous fluid administration during pneumoperitoneum in children.     

A look inside the nerve – Morphology of nerve fascicles in healthy controls and patients with polyneuropathy

Objective

Polyneuropathies are increasingly analyzed by ultrasound. Summarizing, diffuse enlargement is typical in Charcot-Marie Tooth type 1 (CMT1a), regional enlargement occurs in inflammatory neuropathies. However, a distinction of subtypes is still challenging. Therefore, this study focused on fascicle size and pattern in controls and distinct neuropathies.

Vision and touch are automatically integrated for the perception of sequences of events

The purpose of the present experiment was to investigate the integration of sequences of visual and tactile events. Subjects were presented with sequences of visual flashes and tactile taps simultaneously and instructed to count either the flashes (Session 1) or the taps (Session 2). The number of flashes could differ from the number of taps by +/-1. For both sessions, the perceived number of events was significantly influenced by the number of events presented in the task-irrelevant modality. Touch had a stronger influence on vision than vision on touch. Interestingly, touch was the more reliable of the two modalities-less variable estimates when presented alone. For both sessions, the perceptual estimates were less variable when stimuli were presented in both modalities than when the task-relevant modality was presented alone. These results indicate that even when one signal is explicitly task irrelevant, sensory information tends to be automatically integrated across modalities. They also suggest that the relative weight of each sensory channel in the integration process depends on its relative reliability. The results are described using a Bayesian probabilistic model for multimodal integration that accounts for the coupling between the sensory estimates.     

Mesenchymal hamartoma of the liver--new insight into histogenesis.

BACKGROUND/PURPOSE: Mesenchymal hamartoma (MH) of the liver is thought to develop from the ductal plates of the prenatal liver. This immunohistochemical study was performed to gain insight into the pathophysiology of its development. METHODS: Specimens from four MHs with adjacent liver, in one case from a biopsy and from the resected lesion after 6 years follow-up, were investigated with immunostaining on cryostatsectionswith antibodies against cytokeratins, vimentin, desmin and alpha-actin, as well as von Willebrand factor (factor VIII), fibroblast growth factor (FGF) receptors, FGF-1 (acidic FGF), FGF-2 (basic FGF), and the proliferation-associated Ki67 antigen. RESULTS: Fibrous tissue of MH stained positive not only for vimentin, but also for desmin and alpha-actin, whereas cytokeratins and factor VIII showed specific staining in biliary cysts and endothelial cells, respectively. All mesenchymal cells expressed proteins of the FGF receptor family. Although FGF-1 was only scarcely detectable, there was an accumulation of FGF-2 in borderline areas of liver to MH. Multiple Ki67-positive mesenchymal cells could be identified in these regions in all three MHs. However, we could not detect any proliferative activity in the MHs after follow-up. CONCLUSIONS: The proliferative process in MH is still active during early childhood. FGF-2 may have a role in promoting this process. The positivity for desmin and alpha-actin of the lesions suggests that fat-storing (Ito) cells of the immature liver may be involved in the development of MH.