Combined radionuclide and radiocontrast arthrography for evaluating hip arthroplasty

Twenty-two patients had combined radiographic and radiocolloid arthrography. The two procedures were in agreement in 86% of the patients as to whether the femoral component was loose or not. Fourteen patients has surgical revision of the prosthesis and in 3 (23%) radiographic arthrography was falsely negative. No false negative results were obtained with radiocolloid arthrography thus far. The radionuclide method cannot be used to assess the acetabular component.     

Radiophosphate evaluation of loose hip prostheses

There were 23 patients who had revisions of their failed hip arthroplasties and a prior radiophosphate assessment of the joint components. In this selected group of patients the true positive incidence of abnormal scintigraphic findings for femoral component loosening was 19 out of 20 (95%) and the true negative incidence was two out of two by the criteria adopted. The true positive incidence of such findings, indicating acetabular component loosening, was seven out of seven, and the true negative was nine out of 10. Some of these patients also had contrast arthrography and the incidences of true positive and true negative findings for femoral component loosening were seven out of 15 (47%) and one out of one, respectively. Prediction of the status of the acetabulum was poorer using this technique with true positive and true negative incidences of four out of nine and two out of five, respectively.     

Expectant treatment of ectopic pregnancies: clinical and sonographic predictors

OBJECTIVE. We identified the potential clinical and sonographic predictors of the spontaneous resolution of ectopic pregnancies. SUBJECTS AND METHODS. We performed a prospective study of 78 consecutive patients with a transvaginal sonographic diagnosis of ectopic pregnancy who had either two consecutive quantitative measurements of their beta subunit of human chorionic gonadotropin (beta-hCG) more than 24 hrs apart or an embryo with a heart beat. We evaluated the patient's age, time from the last menstrual period, beta-hCG level, size of ectopic pregnancy, presence of a gestational sac or embryonic elements, vascularity on color Doppler sonography, peak systolic velocity, and resistive index of ectopic pregnancy at the time of presentation as potential independent predictors of the final outcome. Logistic regression was performed to identify the independent predictors. RESULTS. Forty-six patients had declining beta-hCG levels, and 32 ectopic pregnancies showed an embryo with a heart beat or had steady or rising beta-hCG levels. Univariate analysis indicated that a longer time from the last menstrual period (older ectopic pregnancies), lower beta-hCG levels, and the absence of gestational sac are statistically more significantly seen in ectopic pregnancies with declining beta-hCG levels (p < 0.05). Resistive index of ectopic pregnancy reached borderline significance (p = 0.05). In a multiple logistic model, the same variables were independent predictors of outcome (p < 0.05). Resistive index was also a predictor (p = 0.09). CONCLUSION. Longer times from the last menstrual period, lower beta-hCG levels, absence of gestational sacs, and higher resistive indexes of ectopic pregnancy at the time of presentation appear to be independent predictors of the spontaneous resolution of ectopic pregnancy.     

Variants of the heavy neurofilament subunit are associated with the development of amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorderprimarily affecting motor neurons. The etiology of the majorityof cases remains unknown. Recent findings from several laboratoriessuggest a role for neurofilaments in the development of motorneuron disorders. The C-terminal region of the human neurofilamentheavy subunit (NEFH) contains a unique functional domain consistingof 43 repeat motifs of the amino acids Lys-Ser-Pro (KSP). ThisC-terminal region of NEFH forms the sidearm projections whichcross-link the neurofilaments. Previously, we have demonstratedpolymorphism in the C-terminal region of the human NEFH: anallelic variant of a slightly larger molecular size, containingan additional KSP phosphorylation motif. Novel mutations inthis region were found in five ALS patients. We propose thatchanges in the KSP-repeat domain may affect the cross-linkingproperties of the heavy neurofilament subunit and perhaps contributeto the development of neurofilamentous swellings in motor neurons,a hallmark of ALS.     

Diode laser and microvascular carotid anastomosis: A preliminary study

A crossed carotid end-to-end anastomosis was performed in 20 Wistar rats by means of a diode laser device (wavelength 830 nm and power output 3 W in continuous wave). The diode laser energy was delivered into a micromanipulator coupled to an OPMI 1 Zeiss operating microscope with a focused spot of 300 μm diameter. The vessel sealing was effected on common carotids (0.8–1.2 mm) using laser shots (average 9) of 680 mW power and 4.5 s duration and 962 W cm⁻² irradiance each. The good vascular flow was confirmed by Doppler spectral analysis and angiography performed on days 0, 10 and 30. Light and scanning electron microscopy showed that reendothelialization was complete on day 10 whilst collagenous fusion of media and adventitia was obvious. The patency rate was 90% impaired by a lethal thrombosis. The efficiency of the diode laser was compared to that of other types of LAVA and to manual microanastomosis.     

Neural correlates of long-term object memory in the mouse anterior cingulate cortex

Damage to the hippocampal formation results in a profound temporally graded retrograde amnesia, implying that it is necessary for memory acquisition but not its long-term storage. It is therefore thought that memories are transferred from the hippocampus to the cortex for long-term storage in a process called systems consolidation (Dudai and Morris, 2000). Where in the cortex this occurs remains an open question. Recent work (Frankland et al., 2005; Vetere et al., 2011) suggests the anterior cingulate cortex (ACC) as a likely candidate area, but there is little direct electrophysiological evidence to support this claim. Previously, we demonstrated object-associated firing correlates in caudal ACC during tests of recognition memory and described evidence of neuronal responses to where an object had been following a brief delay. However, long-term memory requires evidence of more durable representations. Here we examined the activity of ACC neurons while testing for long-term memory of an absent object. Mice explored two objects in an arena and then were returned 6 h later with one of the objects removed. Mice continued to explore where the object had been, demonstrating memory for that object. Remarkably, some ACC neurons continued to respond where the object had been, while others developed new responses in the absent object's location. The incidence of absent-object responses by ACC neurons was greatly increased with increased familiarization to the objects, and such responses were still evident 1 month later. These data strongly suggest that the ACC contains neural correlates of consolidated object/place association memory.     

Accuracy of ultrasound in counting and measuring gallstones

A prospective study of accuracy of ultrasound in measuring and counting gallstones was undertaken in 30 patients undergoing cholecystectomy. Stones were correctly counted (up to five) in 27 of 30 patients. Ninety-three of 106 stones (88%) examined were measured accurately (with a 2 mm error margin). The size of the smaller stones tended to be overestimated, whereas the size of the larger stones tended to be underestimated. When nonoperative treatment of gallstones is considered, ultrasound can be used as the first examination to identify patients who will not be eligible for one or another protocol on the basis of size or number of stones.