Fallacies of CT based component size prediction in total knee arthroplasty – Are patient specific instruments the answer?

Background

The purpose of the study was to assess the accuracy of tibial and femoral component size prediction using computerised tomography (CT) based patient specific instruments in total knee arthroplasty.

Villous adenoma of female urethra

Villous adenoma of the female urethra is extremely rare. We present one such case and compare with only other case reported in the literature.     

Intravenous morphine attenuates pain induced changes in skin blood flow in newborn infants

Abstract

In a previous study we found that pain and discomfort caused a marked increase in skin blood flow, in newborn infants, and that skin blood flow decreased after morphine. In this study we tested morphine effect on the skin blood flow response to pain more systematically. Skin blood flow was measured using a laser Doppler technique during 19 percutaneous central venous catheter placements in 18 infants, 10 of whom received intravenous morphine premedication. The mean ± SD baseline skin blood flow was similar between the two groups: 22.5±9.5 ml 100 g-7 m/n-7 in the morphine group, and 23.7± 8.0 ml TOO g~1 min~1 in the no-morphine group, respectively (p = n.s.). During PCVC placement in the morphine treated group, skin blood flow remained low with minimal variability. The mean value was 22.6 ±7.7 ml 100 g~1 min(p = n.s. compared to baseline). In 7/9 infants not treated with morphine skin blood flow increased dramatically during PCVC placement; while in two it did not. But the mean skin blood flow in this group of 9 infants during PCVC placement was 45.3 ±34 ml 100 g~1 min~ \ an overall change of 97% increase from the baseline. This was statistically significant compared with the baseline and the morphine group value during PCVC insertion (p< 0.04). During the 45 min time period after PCVC placement, skin blood flow values between groups again were similar. We conclude that morphine pretreatment for PCVC placement minimizes pain-associated increases in skin blood flow. The issue of whether skin blood flow changes could serve as measures of adequate analgesia needs to be evaluated with further studies. [Neurol Res 1996; 18: 440-444]     

Human brain imaging of nicotinic acetylcholine α4β2* receptors using [18F]Nifene: Selectivity,functional activity,toxicity, aging effects,gender effects,and extrathalamic pathways

Nicotinic acetylcholinergic receptors (nAChR's) have been implicated in several brain disorders, including addiction, Parkinson's disease, Alzheimer's disease and schizophrenia. Here we report in vitro selectivity and functional properties, toxicity in rats, in vivo evaluation in humans, and comparison across species of [¹⁸F]Nifene, a fast acting PET imaging agent for α4β2* nAChRs. Nifene had subnanomolar affinities for hα2β2 (0.34 nM), hα3β2 (0.80 nM) and hα4β2 (0.83 nM) nAChR but weaker (27–219 nM) for hβ4 nAChR subtypes and 169 nM for hα7 nAChR. In functional assays, Nifene (100 μM) exhibited 14% agonist and >50% antagonist characteristics. In 14‐day acute toxicity in rats, the maximum tolerated dose (MTD) and the no observed adverse effect level (NOAEL) were estimated to exceed 40 μg/kg/day (278 μg/m²/day). In human PET studies, [¹⁸F]Nifene (185 MBq; <0.10 μg) was well tolerated with no adverse effects. Distribution volume ratios (DVR) of [¹⁸F]Nifene in white matter thalamic radiations were ～1.6 (anterior) and ～1.5 (superior longitudinal fasciculus). Habenula known to contain α3β2 nAChR exhibited low levels of [¹⁸F]Nifene binding while the red nucleus with α2β2 nAChR had DVR ～1.6–1.7. Females had higher [¹⁸F]Nifene binding in all brain regions, with thalamus showing >15% than males. No significant aging effect was observed in [¹⁸F]Nifene binding over 5 decades. In all species (mice, rats, monkeys, and humans) thalamus showed highest [¹⁸F]Nifene binding with reference region ratios >2 compared to extrathalamic regions. Our findings suggest that [¹⁸F]Nifene PET may be used to study α4β2* nAChRs in various CNS disorders and for translational research.     

Long term results of endoscopic dilatation for corrosive oesophageal strictures.

Although dilatation is the treatment of choice for most patients with benign oesophageal strictures, there is little information on its efficacy and safety in corrosive oesophageal strictures. Of 123 adults with benign oesophageal strictures treated by endoscopic dilatation, 52 (42.3%) had strictures after corrosive ingestion and 39 (31.7%) had peptic strictures. Treatment was considered adequate if the oesophageal lumen could be dilated to 15 mm and there was complete relief of dysphagia. If dysphagia recurred after adequate initial dilatation, the stricture was dilated again up to 15 mm. Initial dilatation was adequate in 93.6% of patients with corrosive strictures and this success rate was comparable with that of the peptic stricture group (100%, p > 0.05). Long term success after adequate initial dilatation was studied in 36 patients with corrosive strictures (mean follow up 32.36 (17.12) months, range 6-60) and 33 patients with peptic strictures (mean follow up 36.32 (17.9) months, range 6-60). The mean (SEM) number of symptomatic recurrences per patient month during the total follow up period in the corrosive group was significantly higher than that in the peptic group (0.27 (0.04) v 0.07 (0.02), p < 0.001). The recurrence rate in the corrosive group, however, decreased over time, and after 12 months it was significantly (p < 0.001) lower than the recurrence rate in the first six months. After 36 months, the difference in the recurrence rate in the two groups was not significant (p > 0.05). Only nine oesophageal perforations occurred during a total of 1373 dilatation treatments (procedure related incidence 0.66%), and eight of these were in the corrosive stricture group. These patients were managed conservatively and subsequently strictures were dilated adequately in all. Endoscopic dilatation is safe and effective for short and long term relief of dysphagia in patients with corrosive oesophageal strictures.