A novel reconstruction technique for chronic lateral ankle instability: comparison to primary repair.

Twenty patients with lateral ankle instability were treated by a novel anatomical reconstruction technique (group A) and the results compared with 20 patients (group B) who, during the same period of time, underwent primary repair of ruptured lateral ligaments of the ankle. We reviewed 15 patients from group A and 17 patients from group B at a mean follow-up of between 2 and 4 years. The mean functional scores were good in both groups without significant difference, and there was no difference in the mean anterior talar translation between the two groups. We therefore conclude that chronic lateral instability of the ankle may be successfully treated, even in the presence of severely damaged, attenuated or absent ligament tissue.

Perioperative cardiac complications.

Although infrequent, perioperative cardiac complications are a source of major morbidity and mortality. As the population ages, the prevalence of cardiovascular disease is increasing. For physicians who refer patients for surgery as well as for clinicians directly involved in perioperative medical care, an understanding of perioperative cardiac complications, reduction of such complications, and treatment of complications is essential. This article summarizes the approach to perioperative hypertension, hypotension, myocardial ischemia, myocardial infarction, and congestive heart failure.

Postoperative arrhythmias and conduction disorders.

Cardiac arrhythmias are common in the perioperative period. Most arrhythmias are clinically benign. Occasionally, cardiac arrhythmias and conduction disturbances can pose a major additional risk to the patient in the perioperative and postoperative periods. The current availability of a wide array of techniques for controlling serious arrhythmias--pharmacologic, electrical, and interventional--enable the physician to manage most arrhythmias and conduction disturbances successfully. The added risks posed by arrhythmias and conduction disturbances in the perioperative period now can be minimized.

The effect of culture conditions on the mycelial growth and luminescence of naturally bioluminescent fungi.

The effects of temperature, light and pH on mycelial growth and luminescence of four naturally bioluminescent fungi were investigated. Cultures of Armillaria mellea, Mycena citricolor, Omphalotus olearius and Panellus stipticus were grown at 5 degrees C, 15 degrees C, 22 degrees C and 30 degrees C, under 24 h light, 12 h light/12 h dark and 24 h dark, and at a pH ranging from 3.5 to 7 in three separate experiments. Temperature and pH had a significant effect on mycelial growth and bioluminescence, however light did not. Bioluminescence and mycelial growth were optimum at 22 degrees C and pH 3-3.5, the exception being M. citricolor for which bioluminescence and growth were optimum at pH 5-6 and pH 4, respectively. With the exception of M. citricolor, bioluminescence and mycelial growth were greater under 24 h darkness. An understanding of the effect of culture conditions on mycelial growth and luminescence is necessary for the future application of bioluminescent fungi as biosensors.

Construction of a modified mini-Tn5 luxCDABE transposon for the development of bacterial biosensors for ecotoxicity testing.

A mini-Tn5 transposon was modified to introduce a promoterless luxCDABE cassette from Vibrio fischeri into environmentally relevant bacterial strains in order to develop bioluminescence-based biosensors for toxicity testing. The mini-Tn5 luxCDABE transposon was chromosomally integrated downstream from an active promoter into two Pseudomonas strains (Pseudomonas fluorescens 8866 and Pseudomonas putida F1). Characterisation of the bioluminescent transconjugants demonstrated that the transposon integration was stable and had no effect on growth rate. Both P. fluorescens 8866 Tn5 luxCDABE and P. putida F1 Tn5 luxCDABE were used to assess the toxicity of standard solutions (Cu, Zn and 3,5-DCP) as well as Cu- and 3,5-DCP-spiked groundwater samples. They were successfully used for bioluminescence-based bioassays and the potential value of using different bacterial biosensors for ecotoxicity testing was shown.

Use of enoxaparin for the chronically anticoagulated patient before and after procedures.

Patients who require chronic anticoagulation and a procedure have been traditionally managed either by stopping warfarin and starting intravenous standard heparin or by adjusted dose subcutaneous standard heparin or taken off all anticoagulation for a week before the procedure. Enoxaparin may be useful as an alternative method of anticoagulation, avoiding hospitalization and the need for frequent monitoring.

Feasibility of using prokaryote biosensors to assess acute toxicity of polycyclic aromatic hydrocarbons.

The aim of this study was to assess the acute toxicity of polycyclic aromatic hydrocarbons using lux-marked bacterial biosensors. Standard solutions of phenanthrene, pyrene and benzo[a]pyrene were produced using 50 mM hydroxpropyl-beta-cyclodextrin solution which contained each respective polycyclic aromatic hydrocarbon at 6.25 times the aqueous solubility limit of the compound. The polycyclic aromatic hydrocarbon solutions were incubated with each of the biosensors for 280 min and the bioluminescence monitored every 20 min. Over the incubation time period, there was no significant decrease in bioluminescence in any of the biosensors tested with the exception of Rhizobium leguminosarum biovar trifolii TA1 luxAB. In this series of incubations, there was a dramatic increase in bioluminescence in the presence of phenanthrene (2.5 times) and benzo[a]pyrene (3 times) above that of the background control (biosensor without polycyclic aromatic hydrocarbon) after 20 min. Over the next 3 h, bioluminescence decreased to that of the control. An ATP assay was carried out on the biosensors to assess if uncoupling of the oxidative phosphorylation mechanisms in the respiratory chain of the cells had occurred. However, it was found that the polycyclic aromatic hydrocarbons had no effect on the organisms indicating that there was no uncoupling. Additionally, mineralisation studies using 14C-labelled polycyclic aromatic hydrocarbons showed that the biosensors could not mineralise the compounds. This study has shown that the three polycyclic aromatic hydrocarbons tested are not acutely toxic to the prokaryotic biosensors tested, although acute toxicity has been shown in other bioassays. These results question the rationale for using prokaryote biosensors to assess the toxicity of hydrophobic chemicals, such as polycyclic aromatic hydrocarbons.

Adenosine radionuclide perfusion imaging in the preoperative evaluation of patients undergoing peripheral vascular surgery.

To define the clinical and adenosine test variables that predicted perioperative cardiac events, 122 patients who received adenosine radionuclide perfusion imaging before peripheral vascular surgery were reviewed. Events included pulmonary edema, an ischemic end point of acute myocardial infarction (AMI) or cardiac death. Five patients underwent coronary revascularization before the surgical procedure. Of the 117 remaining patients, 19 had pulmonary edema, 10 had an AMI, and 2 died after peripheral vascular surgery. Most of the patients (78%) were in an intermediate-risk group as indicated by the presence of > or = 1 clinical risk factor as defined by the Eagle criteria. The only predictor of perioperative pulmonary edema was a history of congestive heart failure (33% vs 4%; p = 0.002). No clinical variables predicted AMI or death. The adenosine variables that were univariate predictors of AMI and death were the number of reversible perfusion defects (1.75 +/- 1.84 vs 0.75 +/- 0.90; p = 0.001) and the number of coronary artery distributions with a radionuclide perfusion defect (1.33 +/- 0.64 vs 0.85 +/- 0.67; p = 0.022). The number of reversible perfusion defects was the only multivariate predictor of ischemic events (p = 0.017). The presence of > 1 reversible defect was associated with an increased frequency of ischemic events (68% vs 28%; p = 0.045). The sensitivity and specificity of > 1 reversible defect was 58% and 73%, respectively, with a positive and negative predictive value of 19% and 94%.(ABSTRACT TRUNCATED AT 250 WORDS)

Approach to the patient with palpitations.

Palpitations are a common complaint present in up to 16% of outpatients. They are nonspecific and in only 15% of patients do they correlate with a cardiac arrhythmia. The significance of palpitations is related to the presence or absence of underlying cardiac disease, the clinical setting in which palpitations occur, and the characteristics and severity of symptoms. This article presents a concise approach to the evaluation of the ambulatory patient with palpitations.

Approaching the surgical patient. Role of the medical consultant.

Medical consultants will no longer "clear patients" but will "prepare them" for surgery instead. They will be required to possess the expertise in assessing a patient's risk for surgery, managing perioperative medications, caring for postoperative complications, maintaining appropriate conduct in the role as consultant, and recording accurate documentation of level of service for third party reimbursement.

Cardiac risk stratification prior to vascular surgery.

A cardiac etiology is the cause of death in approximately 40% to 60% of patients who die in the early postoperative period following vascular surgery. A variety of modalities has been proposed to identify the patient at risk before the surgical procedure. This article puts these modalities in perspective and discusses the increased risk of cardiac complication for the vascular surgery patient, identifies the patient at risk, and defines methods to decrease patient risk.

Noncardiac surgery in the elderly patient with cardiovascular disease.

The elderly patient with cardiovascular disease who undergoes noncardiac surgery presents a challenge to the medical-surgical team. A high prevalence of cardiac disease necessitates a preoperative in-depth search for the presence of cardiovascular risk factors and their reversal if possible. Aging is associated with an altered physiologic response to the stress of surgery as well as to anesthetic agents and perioperative medications, requiring that the elderly patient often be treated quite differently than the younger surgical patient. This article provides guidelines for the estimation of the risk of cardiac complication due to noncardiac surgery and discusses the identification and management of acute and chronic cardiovascular problems in the perioperative period.

Spatial and temporal variability of blood flow in stimulated dog gastrocnemius muscle.

The distribution of blood flow in skeletal muscle stimulated to rhythmic isotonic contractions was studied by injections of radioactive microspheres into the arterial supply of gastrocnemius muscles (mean weight 88 g) subsequently cut into 0.5 g pieces for determination of radioactivity. The coefficient of variation (CV = SD/mean) of the ratio of simultaneously injected 10 microns and 15 microns microspheres, 0.12, was taken as the inherent scatter of the method. The average spatial distribution inequality of 10-15 microns microspheres corresponded to a CV of 0.45 and the specific local blood flow inhomogeneity to a CV = 0.43 (= square root of 0.45(2) - 0.12(2)), but there were marked differences between muscles. The temporal variability of blood flow in individual muscle pieces was obtained from the comparison of fractional trapping of 4 to 5 differently labeled microspheres injected at intervals of 2 minutes into steadily stimulated muscles. The mean CV for the variations in time was 0.23 and that corrected for methodological scatter, 0.19. There were large differences between muscle pieces within a muscle and between muscles. The presence of considerable spatial and temporal variations of blood flow in exercising muscle during apparent steady state may be important in limiting and/or modulating tissue O2 supply.