Identified hair follicle afferent boutons in the spinal cord of the cat are enriched with L-glutamate-like immunoreactivity

Hair follicle afferent boutons in the spinal dorsal horn of the cat were examined for L-glutamate enrichment. Two hair follicle afferent axons were labelled intra-axonally with horseradish peroxidase, and post-embedding immunogold reactions of L-glutamate were performed on thin sections containing horseradish peroxidase-labelled boutons. Quantitative analysis showed that hair follicle boutons were associated with immunogold reactions for L-glutamate which were almost twice as dense as average values for dorsal horn tissue. Further analysis revealed that hair afferent boutons displayed 2.3-times the average gold particle density associated with post-synaptic dendrites and 3-times the average immunogold density for L-glutamate of structures which were known to be immunoreactive for GABA. This enrichment of L-glutamate in identified hair afferent terminals supports the idea that the amino acid is a neurotransmitter of hair follicle primary afferent axons.     

The value of frozen section examination in planning surgery for follicular thyroid neoplasms

Frozen section examination of follicular neoplasms of the thyroid has been claimed to be of little value in planning the extent of surgery. Clinical factors such as age, sex and tumour size are said to be more accurate predictors of malignancy. The aim of this study was to examine the respective value of clinical factors and frozen section in the surgical management of follicular thyroid neoplasms. A retrospective study of 735 patients with follicular neoplasms treated at Royal North Shore Hospital was undertaken. Factors assessed included clinical features, such as age and sex of the patients and tumour size, as well as findings at frozen section examination. No significant difference in sex distribution was demonstrated when comparing follicular adenoma with follicular carcinoma. There was a significant difference with respect to patient age between the two groups, but the large overlap in the distribution made this difference of no clinical value. In addition, there was no significant difference in tumour size when comparing follicular adenoma with carcinoma. On the other hand, review of frozen section results showed that 40% of patients with follicular carcinoma were positively identified by frozen section examination at initial surgery, with a false positive rate of less than 0.2%. It appears that clinical factors, such as age, sex and tumour size, are of little assistance in differentiating benign from malignant follicular neoplasms. Frozen section examination remains the most definitive tool in planning intra-operatively the extent of surgery for follicular neoplasms of the thyroid.     

Enhanced mass resolving power, sensitivity, and selectivity in laser desorption Fourier transform ion cyclotron resonance mass spectrometry by ion axialization and cooling

Ion cooling and axialization produced by azimuthal quadrupolar excitation in the presence of ion-neutral collisions are applied to laser desorption Fourier transform ion cyclotron resonance mass spectrometry (LD/FT/ICR-MS). With this technique, the large kinetic and internal energies of ions generated by laser desorption processes can be cooled effectively by collisions of ions with neutral argon atoms (at > 5 x 10(-7) Torr). After sufficient cooling in the source compartment of a dual ion trap, the axialized ions may be transferred to the analyzer compartment for detection at much lower pressure (and thus much higher mass resolving power). Enhancements in both FT/ICR mass resolving power and sensitivity are observed; moreover, ion isolation with high selectivity at high pressure is also demonstrated.     

Postoperative fatigue after laparoscopic surgery

Postoperative fatigue (POF) appears to be less following laparoscopic surgery but this has not been proven previously. This study compared a group of patients who had undergone open cholecystectomy with a group undergoing laparoscopic cholecystectomy. Postoperative fatigue was found to be decreased in duration in the patients having laparoscopic surgery, returning to pre-operative fatigue levels by 14 days, compared to 28 days for open surgery. Postoperative pain in the first 24 h and the early metabolic response to surgery were similar for both groups. The authors conclude that laparoscopic surgery is associated with decreased POF and that this is unlikely to be accounted for by a decrease in the early metabolic response to surgery.     

Characterization of partially saturated poly(propylene fumarate) for orthopaedic application

Neointimal formation and arterial wall remodeling are pivotal causes of luminal narrowing in atherogenesis and restenosis. Arterial remodeling refers to a series of dynamic structural changes that arteries may undergo in response to various stimuli, including changes in blood flow and pressure, and acute injury. The biological mechanisms involved in arterial remodeling are poorly understood and are currently a main target for research. We have recently focused on the role of the arterial wall microcirculation (ie, vasa vasorum) in arterial remodeling after injury. In the past, a correlation between arterial wall neovascularization and the accumulation of arterial plaque has been documented; however, the dynamic role of these microvessels in arterial repair and luminal narrowing has not been examined. The type of arterial injury, the nature of the lesion that develops, and the arterial compartment in which angiogenesis occurs may determine the role of the vasa vasorum in arterial narrowing. In this review, we highlight the data that link arterial wall neovascularization with lesion formation and the process of arterial remodeling.     

Grading leniency is a removable contaminant of student ratings

It is well established that students' evaluative ratings of instruction correlate positively with expected course grades. The authors identify 4 additional data patterns that, collectively, discriminate among 5 theories of the grades--ratings correlation. The presence of all 4 of these markers in student ratings data (obtained at University of Washington) was most consistent with the theory that the grades--ratings correlation is due to an unwanted influence of instructors' grading leniency on ratings. This conclusion justifies use of a statistical correction--illustrated here with actual ratings data--to remove the unwanted inflation of ratings produced by lenient grading. Additional research can profitably seek other inappropriate influences on ratings to identify more opportunities for validity-enhancing adjustments.     

Spinal anaesthesia with 0.5% hyperbaric bupivacaine in elderly patients: effect of site of injection on spread of analgesia

In this randomized, observer-blind study, we have examined, in elderly patients, the effect of site of injection on analgesia levels after spinal injection of 0.5% hyperbaric bupivacaine solution. Thirty male patients, aged 68-87 yr, undergoing minor urological surgery during spinal anaesthesia received 3 ml of a 0.5% hyperbaric bupivacaine solution at either the L3-4 (n = 15) or L4-5 (n = 15) interspace. The solution was injected with the patient in the sitting position. The patient remained sitting for 2 min and was then placed in the supine horizontal position. Analgesia levels were assessed bilaterally using pin-prick. The highest analgesia levels did not differ between groups (medians were approximately T7). There were no significant differences in the time to maximum cephalad spread of analgesia, maximum degree of motor block or haemodynamic changes. We conclude that injection at the L4-5 interspace has no advantage compared with injection at the L3-4 interspace.