The treatment of periprosthetic fractures of the femur using cortical onlay allograft struts

Periprosthetic fractures of the femur are a complex problem to treat. Careful planning is essential before embarking on such a technically demanding procedure. There are many factors to be considered, including the premorbid condition of the patient and previous experience and training of the surgeon. Important factors relating directly to the fracture include the site, stability of the implant, and the state of the surrounding bone stock.     

Digital image capture and automated analysis of posterior capsular opacification.

PURPOSE: To develop and validate a digital imaging and analysis technique for assessing the extent of posterior capsular opacification after cataract surgery. METHODS: Retroillumination images of the posterior capsule were obtained by using a digital camera mounted on a slit lamp. The images were analyzed using an available image analysis software program. The image acquisition and analysis techniques were tested for face validity, reproducibility, and the ability to detect progression of capsular opacity over time. RESULTS: Digital retroillumination images were obtained without patient discomfort. Automated analysis of images correlated well with clinical grading both at slit lamp examination and when looking at the images themselves (Spearman's correlation coefficient >0.7). Analysis of images taken at different times showed high reproducibility (intraclass correlation >0.9), and the system was able to identify progression of capsular opacity over a 2-year period with a mean increase of 15.8% in progressors versus an increase of 0.6% in nonprogressors (P < 0.05). CONCLUSIONS: Digital retroillumination images of the posterior capsule can be obtained reliably, and automated analyses correlate well with clinical assessment. The system presented here uses commercially available instruments and software, and it is practical for use in longitudinal studies of posterior capsule opacification. It is reliable, easy to use, and can detect small changes in the percentage area covered by posterior capsule opacification over time.     

In utero arterial embolism from renal vein thrombosis with successful postnatal thrombolytic therapy

Thromboembolic events in the pediatric age group occur most commonly in neonates, and newborns of diabetic mothers are particularly at risk. We report a newborn with right renal vein and inferior vena cava thrombosis who apparently embolized across the foramen ovale antenatally with resultant right brachial artery occlusion. The baby was delivered by cesarean section from an insulin-dependent diabetic mother. At the time of birth, there was severe right arm ischemia with absent brachial and radial pulses. There was clinical evidence of distal embolization with a "trash" lesion of the distal right middle finger as well as a midforearm area of full-thickness skin loss. Ultrasound demonstrated a right renal vein thrombosis and a 95% occlusion of the inferior vena cava. Regional urokinase therapy was instituted through a lower extremity vein with a 5,000 U/kg bolus and then 5,000 U/kg/h continuous infusion. Twelve hours of infusion of urokinase led to clinical resolution of the right arm ischemia, with return of pulses. Follow-up ultrasound showed the right renal vein thrombosis and inferior vena cava clot to be completely resolved. The right middle finger and forearm lesions subsequently have healed primarily. We report this as a case of in utero arterial embolization with successful postnatal therapy using regional urokinase infusion.     

Pulse oximetry and capnography in anaesthetic practice: an epidemiological appraisal

In the evaluation of any medical technology the efficacy, effectiveness, and efficiency must each be considered before routine deployment is recommended. Since the widespread practice of patient monitoring by pulse oximetry and capnography has occurred before the performance of rigorously controlled trials, definitive proof of worth is lacking. The purpose of this review is to appraise critically the effectiveness of this technology. The assessment was performed using concepts developed in epidemiology and community medicine to establish a given factor to be causative to a given outcome. The current literature pertaining to anaesthetic adverse outcomes was reviewed, and the use of monitors evaluated against the criteria of a causal relationship. While the conclusions are based more on the absence of positive data (owing to low frequency of adverse anaesthetic occurrences) rather than negative results, it must be concluded that the effectiveness of such monitoring has yet to be demonstrated. Such a conclusion should not detract from their use, for the role of an individual factor in the complex chain of accident evolution will seldom be demonstrable. Rather, such an appraisal should encourage a clear perspective of the depth of our clinical science, and encourage more rigorous critical evaluation in the future.     

"Satellite" haemodialysis.

Thirty of the 39 patients treated at the Blacktown Dialysis Centre, the first "satellite" dialysis centre in the greater metropolitan Sydney, had been referred from four Sydney renal units for long-term dialysis therapy. The move save approximately 150 kilometres in travelling and eight hours time each week for each of these patients. The cost of running the unit was approximately $10,000 per patient per year in the first year--no greater than that of home dialysis, and less than that of dialysis in a teaching hospital. The advantages of establishing satellite dialysis centre, the method of operation, and the results of the first year of operation of the Blacktown Dialysis Centre are described.     

A randomized placebo-controlled double-blind trial of lipid-lowering strategies in patients with renal insufficiency: diet modification with or without fenofibrate

BACKGROUND: Renal insufficiency is characterized by lipoprotein abnormalities including elevated triglyceride levels. PATIENTS AND METHODS: The safety and efficacy of micronized fenofibrate as a treatment for dyslipidemia in patients with progressive renal insufficiency was evaluated in a randomized, placebo-controlled double-blind study comparing fenofibrate and dietary modification to dietary modification alone. Patients were evaluated following a 3-month pre-randomization period of dietary counseling. Twenty-eight patients with moderate renal insufficiency and triglyceride levels 2.3 mmol/l or LDL/HDL ratio 5 were randomized to placebo (n = 12) or fenofibrate (n = 16) therapy. Treatment and dietary counseling continued for 6 months. RESULTS: Ten of 16 patients (63%) treated with fenofibrate achieved a 30% reduction in triglyceride levels or LDL/HDL ratio reduction < 5 compared to 2 of 17% in the placebo group (p = 0.015). Triglyceride levels were significantly reduced in the fenofibrate group (-31%) versus placebo (+1.3%, p = 0.003). In compliant patients (n = 25) there was also a significantly greater increase in HDL cholesterol levels in the fenofibrate group (+19.9%) compared to placebo (-4.7%, p = 0.001). Changes in measured creatinine clearance were not significantly different between the groups and there were no serious adverse effects of treatment. CONCLUSION: Fenofibrate therapy combined with dietary modification effectively reduced triglyceride levels in renal insufficiency patients without serious adverse effects.     

Pilot study evaluating the pharmacokinetics, pharmacodynamics, and safety of the combination of exemestane and tamoxifen.

PURPOSE: We conducted a pilot study assessing the effects of the selective estrogen receptor modulator, tamoxifen, on the pharmacokinetics, pharmacodynamics, and safety of the steroidal, irreversible aromatase inhibitor (AI), exemestane, when the two were coadministered in postmenopausal women with metastatic breast cancer. EXPERIMENTAL DESIGN: Patients with documented or unknown hormone receptor sensitivity were eligible. Patients received oral exemestane at 25-mg once daily. Starting day 15, oral tamoxifen at 20-mg once daily, was added. We measured plasma concentrations of exemestane, estrone, estrone sulfate, and estradiol after 14 days of exemestane monotherapy and after approximately 4 weeks of combination therapy. The incidence and severity of adverse events were assessed by physical examination and patient reporting. RESULTS: We treated 18 patients. All had received prior chemotherapy and/or hormonal therapy, eight and six, respectively, with single-agent selective estrogen receptor modulators or irreversible aromatase inhibitors; no hormonal therapy was given within 30 days of study entry. Plasma exemestane concentrations and estrone, estrone sulfate, and estradiol suppression were unchanged after approximately 4 weeks of tamoxifen coadministration. All drug-related adverse events were grades 1 or 2; none was unexpected. Although not a formal study end point, antitumor activity was noted, with two partial responses and four cases of stable disease among 17 evaluable patients after a 9-month median follow-up (range, 2.5-19 months). CONCLUSIONS: This pilot study provides evidence that coadministration of tamoxifen does not affect exemestane pharmacokinetics or pharmacodynamics and that the combination is well-tolerated and active. Further clinical investigation is warranted.     

Aging regulates 5-HT(1B) receptors and serotonin reuptake sites in the SCN

Middle age is associated with changes in circadian rhythms (e.g., alterations in the timing of the circadian wheel running rhythm) which resemble changes induced by selective destruction of the serotonergic input to the suprachiasmatic nucleus (SCN), the principal mammalian circadian pacemaker. We hypothesized that serotonergic neurotransmission in the SCN is decreased in middle-aged hamsters, as compared to young adults. This hypothesis was tested indirectly by investigating the effect of aging on two markers of serotonin neurotransmission, 5-HT(1B) receptors and serotonin reuptake sites, which are regulated by serotonin. Previous studies have shown that experimentally induced decreases in serotonergic neurotransmission increase 5-HT(1B) receptors but decrease serotonin reuptake sites. Quantitative autoradiography was conducted using [125I]iodocyanopindolol ([125I]ICYP) and [3H]paroxetine, selective radioligands for the 5-HT(1B) receptors and the serotonin reuptake sites, respectively. Consistent with the hypothesis, specific ([125I]ICYP binding was significantly elevated in the SCN of middle-aged hamsters, as compared to young hamsters. The results also showed that serotonin reuptake sites in the SCN were significantly increased in both middle-aged and old hamsters, as compared to young controls. This result could not have been caused by decreased serotonin release. Alternatively, increased serotonin reuptake, which would reduce serotonin levels in the synaptic cleft, may cause or contribute to the increase in 5-HT(1B) receptor binding in the SCN in middle aged animals. These results show that the SCN exhibits changes in serotonergic function during middle age, which has been characterized by changes in the expression of circadian rhythms. Because these changes occur during middle age, they probably reflect the aging process, rather than senescence or disease.