In vivo electrochemical studies of dopamine overflow and clearance in the striatum of normal and MPTP-treated rhesus monkeys

Translational recruitment of maternal mRNAs is an essential process in early metazoan development. To identify genes required for this regulatory pathway, we have examined a collection of Drosophila female-sterile mutants for defects in translation of maternal mRNAs. This strategy has revealed that maternal-effect mutations in the cortex and grauzone genes impair translational activation and cytoplasmic polyadenylation of bicoid and Toll mRNAs. Cortex embryos contain a bicoid mRNA indistinguishable in amount, localization, and structure from that in wild-type embryos. However, the bicoid mRNA in cortex embryos contains a shorter than normal polyadenosine (poly(A)) tail. Injection of polyadenylated bicoid mRNA into cortex embryos allows translation demonstrating that insufficient polyadenylation prevents endogenous bicoid mRNA translation. In contrast nanos mRNA, which is activated by a poly(A)-independent mechanism, is translated in cortex embryos, indicating that the block in maternal mRNA activation is specific to a class of mRNAs. Cortex embryos are fertilized, but arrest at the onset of embryogenesis. Characterization of grauzone mutations indicates that the phenotype of these embryos is similar to cortex. These results identify a fundamental pathway that serves a vital role in the initiation of development.     

Delay in administering the first dose of antibiotics in patients admitted to hospital with serious infections

A 66-year old female was admitted to our ICU in septic shock with accompanying signs of gastroenteritis and diabetic-related hyperglycemia. Computer tomography of the abdomen revealed the rare diagnosis of emphysematous pyelonephritis. Immediate nephrectomy led to a favourable outcome in this dramatic case. Although abscess drainage and broad-based antibiotic therapy are generally the first-line therapy today, emergency surgery would seem to be indicated in selected cases.     

Diagnosis and treatment of sphincter of Oddi dysfunction

BACKGROUND Sphincter of Oddi dysfunction is a challenge from both the diagnostic and therapeutic point of view. There is much ongoing debate about the accuracy and usefulness of various diagnostic tests, as there is about the effectiveness of proposed therapeutic alternatives. METHODS: A comprehensive review of the past 15 years' literature was undertaken, using the Medline database and cross-referencing of major articles on the subject. RESULTS AND CONCLUSION: Endoscopic and surgical treatments result in similar outcomes, with considerable failure rates. The latter reflect the difficulties in accurate diagnosis and a lack of sound objective criteria for selecting patients for intervention. In addition, in some patients sphincter of Oddi dysfunction may be only part of a generalized motility disorder of the gastrointestinal tract.     

Diet choice by dairy cows. 2. Selection for metabolizable protein or for ruminally degradable protein?

Diet choice, expressed as grams of high protein feed selected per kilogram of intake, was measured for lactating cows with ad libitum access to two feeds. First, cows were given a choice between a low protein feed and a high protein feed for 9 wk while feeds were alternated between feeders. The proportion of feed chosen from a feeder depended on the feed it contained, which showed that cows selected for feed characteristics. Diet choice was then measured over six periods during which cows had access to either a low protein feed and a high protein feed or to these feeds plus added urea. Diet choice was lower when urea was added, suggesting a substantial effect of the content of ruminally degradable protein (RDP) in feeds on diet selection. All feeds had equal RDP contents in Experiment 3 when early and late lactating cows had access first to two feeds with a low and high yield of metabolizable protein and then to two feeds with a low and medium yield of metabolizable protein. Diet choice did not differ from what was considered to be random and was not affected by milk yield or stage of lactation. No evidence suggests that cows selected for metabolizable protein when both feeds contained adequate RDP.     

Attenuation of neomycin ototoxicity by iron chelation

Increasing evidence suggests that aminoglycoside ototoxicity is mediated by the formation of an aminoglycoside-iron complex and that the creation of this complex is a preliminary step in generation of free radical species and subsequent hair cell death. In this study we have assessed the ability of the iron chelator deferoxamine to attenuate the hearing loss induced by an ototoxic dose of the aminoglycoside neomycin (100 mg/kg per day for 14 days). Experiments were carried out on pigmented guinea pigs weighing 250 to 300 g. Changes in auditory sensitivity were characterized by monitoring shifts in compound action potential (CAP) thresholds, recorded through indwelling electrodes implanted at the round window, vertex, and contralateral mastoid. Results show that animals receiving neomycin alone suffered a mean threshold shift exceeding 35 dB at all test frequencies (2.0, 4.0, and 8.0 kHz) 30 days after initiation of treatment. In comparison, all animals receiving cotherapy of neomycin and deferoxamine (150 mg/kg twice daily for 14 days) maintained their CAP threshold, suggesting significant protection from neomycin ototoxicity. A statistical comparison of treatment groups showed that in the animals receiving cotherapy with neomycin and deferoxamine, deferoxamine produced a significant protective effect against neomycin-induced ototoxicity (P < 0.001). These results provide further evidence of the intrinsic role of iron in aminoglycoside ototoxicity and suggest that deferoxamine may have a therapeutic role in attenuating the cytotoxic action of aminoglycoside antibiotics.     

Magnetic resonance imaging of elephantiasis neuromatosa

We present the case of a 43-year-old man with neurofibromatosis type 1 who developed elephantiasis neuromatosa of his left leg. The gross limb enlargement was extremely disfiguring, and resulted in such severe disability that he was only able to walk a very short distance using crutches. Previous debulking procedures had resulted in massive blood loss, and prior to attempting further surgical intervention MRI studies were requested. Taking advantage of the excellent tissue characterisation and multiplanar imaging capabilities of MRI, we were able to assess the extent of soft tissue and osseous involvement. The use of recently developed MR angiographic sequences enabled us to non-invasively provide detailed images to assess the relationship of the lesions to the major vessels, as well as the vascular supply and angiographic features of the lesions themselves. This article describes our MRI-based findings, which precluded debulking surgery in this unusual manifestation of neurofibromatosis.     

Dental luting agents: A review of the current literature

STATEMENT OF PROBLEM: The practice of fixed prosthodontic has changed dramatically with the introduction of innovative techniques and materials. Adhesive resin systems are examples of these changes that have led to the popularity of bonded ceramics and resin-retained fixed partial dentures. Today's dentist has the choice of a water-based luting agent (zinc phosphate, zinc polycarboxylate, glass ionomer, or reinforced zinc oxide-eugenol) or a resin system with or without an adhesive. Recent formulations of glass ionomer luting agents include resin components (resin-modified glass ionomers), which are increasingly popular in clinical practice. PURPOSE: This review summarizes the research on these systems with the goal of providing information that will help the reader choose the most suitable material. MATERIAL: The scientific studies have been evaluated in relation to the following categories: (1) biocompatibility, (2) caries or plaque inhibition, (3) microleakage, (4) strength and other mechanical properties, (5) solubility, (6) water sorption, (7) adhesion, (8) setting stresses, (9) wear resistance, (10) color stability, (11) radiopacity, (12) film thickness or viscosity, and (13) working and setting times. In addition, guidelines on luting-agent manipulation are related to available literature and include: (1) temporary cement removal, (2) smear layer removal, (3) powder/liquid ratio, (4) mixing temperature and speed, (5) seating force and vibration, and (6) moisture control. Tables of available products and their properties are also presented together with current recommendations by the authors with a rationale.