Strategies for improving performance in long duration events: Olympic distance triathlon

This review focuses on strategic aspects that may affect performance in a long-duration Olympic event, the Olympic distance triathlon. Given the variety of races during the Olympic Games triathlon, strategic aspects include improving technological features as well as energetics factors affecting overall triathlon performance. During the last decade, many studies have attempted to identify factors reducing the metabolic load associated (or not) with the development of fatigue process by analysing the relationship between metabolic and biomechanical factors with exercise duration. To date, a consensus exists about the benefit of adopting a drafting position during the swimming or the cycling part of the triathlon. Other potential strategic factors, such as the production of power output or the selection of cadence during the cycling or the running leg, are likely to affect the overall triathlon performance. Within this approach, pacing strategies are observed by elite athletes who swim or cycle in a sheltered position, inducing several changes of pace, intensity or stochastic shifts in the amplitude of the physiological responses. The analysis of these parameters appears to arouse some experimental and practical interest from researchers and coachers, especially for long-distance Olympic events.     

Endoscopic calcaneoplasty combined with Achilles tendon repair

Endoscopic calcaneoplasty is a minimally invasive technique for resection of inflamed retrocalcaneal bursa as well as the posterosuperior part of the calcaneus. A relative contra-indication for this technique is a tear of the Achilles tendon. In this report, we describe the treatment of a patient with Haglund’s deformity associated with a tear of the Achilles tendon. Both the lesions are treated endoscopically. The technique is described and the pitfalls are discussed.     

The role of ultrasonography in the assessment of renal function in the elderly

BACKGROUND: Ageing is associated with a progressive loss of renal mass and kidney length and a decline in glomerular filtration rate (GFR). This study evaluated a possible correlation between renal function and kidney size measured by ultrasonography (US), and whether the latter helps estimate GFR in the elderly. METHODS: Twenty-five medically stable elderly patients (mean age 85 +/- 5 yrs) were examined in a geriatric ward at a university hospital. Blood samples were taken to determine serum creatinine (Cr) levels. On the same day, 51chromium ethylenediamine tetraacetic acid (51Cr-EDTA) clearance was performed as the gold standard of GFR. US measured kidney length, transverse and anteroposterior dimensions. RESULTS: Serum Cr (r=-0.67; p=0.0002), Cockcroft-Gault formula (r=0.82; p<0.0001), absolute length (r=0.51; p=0.008) and volume kidney (r=0.46; p=0.02) correlated significantly with GFR. After receiver operating curve (ROC) analysis, length was less specific than sensitive in detecting renal impairment. Adding length to the Cockcroft-Gault formula did not improve GFR estimation (p=0.44). In contrast, adding length to serum Cr levels improved GFR estimation (p=0.015). CONCLUSION: In the elderly, kidney length and volume significantly correlated with GFR. However, length has a low specificity in predicting renal impairment. Therefore, in clinical practice, serum Cr levels and calculated Cr clearance are more useful in predicting renal impairment. However, normal kidney length can help to exclude renal impairment in the elderly at risk of GFR underestimation by a calculated Cr clearance.     

Efficacy and safety of lowering immunosuppression to treat CMV infection in renal transplant recipients on valaciclovir prophylaxis: a pilot study.

BACKGROUND: Routine cytomegalovirus (CMV)-pp65 antigenaemia monitoring shows that some patients will develop pp65 antigenaemia during valaciclovir prophylaxis or after cessation of treatment. The aim of this pilot study was to evaluate the safety and efficacy of lowering immunosuppression in kidney transplant recipients who exhibit mildly symptomatic CMV infections while on valaciclovir prophylaxis. METHODS: We selected 12 patients who experienced mildly symptomatic CMV infections defined as a positive CMV-pp65 antigenaemia test associated with either neutropenia, asthenia or arthralgia, but no fever. All of them received prophylaxis with valaciclovir for at least 3 months. Testing for CMV-pp65 antigenaemia was performed weekly for 6 months. RESULTS: The mildly symptomatic infections occurred at a median interval of 69 days after transplantation-during prophylaxis in eight cases and after valaciclovir discontinuation in the other four cases. All of them were effectively managed by lowering immunosuppressive therapy, leading to the disappearance of symptoms and CMV antigenaemia reduction. No immunological complication or recurrence of CMV infection or disease was noted. I.v. ganciclovir never became necessary. CONCLUSION: The mildly symptomatic CMV infections occurring in valaciclovir-treated patients may be managed efficiently and without immunologic complication by lowering immunosuppressive therapy.     

Safety and Efficacy of Hyperthermic Intraperitoneal Chemoperfusion with High-Dose Oxaliplatin in Patients with Peritoneal Carcinomatosis

Background Cytoreduction with hyperthermic intraperitoneal chemoperfusion (HIPEC) has an established role in selected patients with peritoneal carcinomatosis (PC). We analyzed the safety and efficacy of HIPEC using high-dose oxaliplatin, a cytotoxic agent commonly used in metastatic colorectal cancer and showing promising activity in ovarian cancer and mesothelioma. Methods Following complete cytoreduction, HIPEC was performed using 460 mg/m² oxaliplatin in 5% dextrose for 30 min at a temperature of 41–42°C. Open perfusion (coliseum technique) was performed in all patients. Metabolic, electrolyte, and hemodynamic changes were recorded during chemoperfusion as well as postoperative morbidity, mortality, late toxicity, and survival. Results From July 2005 to January 2007, 52 patients were treated. Chemoperfusion with 5% dextrose resulted in temporary significant hyperglycemia, hyponatremia, and metabolic acidosis. Major morbidity developed in 24% of patients, while 30-day mortality did not occur. One patient developed unexplained repeated episodes of hemoperitoneum. Chemoperfusion with oxaliplatin resulted in mild hepatic toxicity evidenced by persistent elevation of glutamyl transferase and alkaline phosphatase 1 month after surgery. After a mean follow-up time of 14.5 months, nine patients died from disease progression. In colorectal cancer patients, actuarial overall survival was 80% at 1 year. Conclusion Cytoreduction with HIPEC using high-dose oxaliplatin leads to manageable metabolic and electrolyte disturbances and frequent mild hepatic toxicity without discernible impact on postoperative morbidity. Longer follow-up in a larger patient cohort will be required to assess the real risk of unexplained hemoperitoneum observed in one patient, and to establish the long-term effect on local relapse and survival.     

Infected urocolpos and generalized peritonitis secondary to labia minora adhesions

Introduction

Labia minora adhesions (LMA) are a common finding in young girls. Usually, this condition is asymptomatic and spontaneously disappears during adolescence. We report on a case revealed by infected urocolpos and peritonitis and whose treatment finally required surgical reduction labioplasty.

Case report

A 9-year-old girl presented with a 2-day history of abdominal pain and fever. Urinary continence had never been obtained, with diurnal leaks. Physical examination showed signs of peritoneal irritation and a subtotal vulvar obstruction due to LMA. At surgery, after LMA lysis, a large amount of cloudy urine-like fluid emptied under pressure from the vagina. Laparoscopy showed generalized peritonitis without any intraabdominal cause. The same Escherichia coli was identified in the infected urocolpos and the abdominal fluid. Postoperative course was uneventful.Because of recurrent LMA, the patient underwent several courses of local estrogen therapy. Labia minora hypertrophy with LMA developed 2 years after peritonitis, requiring surgical reduction labioplasty. We used a new technique with interposition of skin flaps. The girl is now well, without LMA or infection, 4 years after labioplasty.

Conclusion

Although rare, subtotal vulvar obstruction because of LMA may lead to infected hydrocolpos and peritonitis. Recurrent LMA may necessitate surgical labioplasty.     

Brain glucagon-like peptide-1 regulates arterial blood flow, heart rate, and insulin sensitivity

OBJECTIVE— To ascertain the importance and mechanisms underlying the role of brain glucagon-like peptide (GLP)-1 in the control of metabolic and cardiovascular function. GLP-1 is a gut hormone secreted in response to oral glucose absorption that regulates glucose metabolism and cardiovascular function. GLP-1 is also produced in the brain, where its contribution to central regulation of metabolic and cardiovascular homeostasis remains incompletely understood.RESEARCH DESIGN AND METHODS— Awake free-moving mice were infused with the GLP-1 receptor agonist exendin-4 (Ex4) into the lateral ventricle of the brain in the basal state or during hyperinsulinemic eu-/hyperglycemic clamps. Arterial femoral blood flow, whole-body insulin-stimulated glucose utilization, and heart rates were continuously recorded.RESULTS— A continuous 3-h brain infusion of Ex4 decreased femoral arterial blood flow and whole-body glucose utilization in the awake free-moving mouse clamped in a hyperinsulinemic-hyperglycemic condition, only demonstrating that this effect was strictly glucose dependent. However, the heart rate remained unchanged. The metabolic and vascular effects of Ex4 were markedly attenuated by central infusion of the GLP-1 receptor (GLP-1R) antagonist exendin-9 (Ex9) and totally abolished in GLP-1 receptor knockout mice. A correlation was observed between the metabolic rate and the vascular flow in control and Ex4-infused mice, which disappeared in Ex9 and GLP-1R knockout mice. Moreover, hypothalamic nitric oxide synthase activity and the concentration of reactive oxygen species (ROS) were also reduced in a GLP-1R–dependent manner, whereas the glutathione antioxidant capacity was increased. Central GLP-1 activated vagus nerve activity, and complementation with ROS donor dose-dependently reversed the effect of brain GLP-1 signaling on peripheral blood flow.CONCLUSIONS— Our data demonstrate that central GLP-1 signaling is an essential component of circuits integrating cardiovascular and metabolic responses to hyperglycemia.There is now compelling evidence supporting the interplay between metabolic and vascular diseases (1,2) in which neuronal circuits in the central nervous system seem to play a critical role in orchestrating the control of glucose homeostasis (3). We recently demonstrated that the central infusion of insulin decreased blood pressure and increased arterial blood flow and heart rate through a molecular mechanism depending on the synthesis of nitric oxide in the hypothalamus (4). Importantly, the central regulation of nitric oxide (NO) metabolism affected whole-body glucose utilization (5). This mechanism was impaired during high-fat diet–induced insulin resistance and diabetes and reverted upon central NO supplementation (4). These findings raise the possibility that signals from peripheral tissues, which act on the brain to control glucose metabolism, could also regulate vascular function.Enteroendocrine cells have important roles in regulating energy intake and glucose homeostasis through their actions on peripheral target organs, including the endocrine pancreas. Enteroendocrine cells secrete multiple hormones, including glucagon-like peptide (GLP)-1, which controls pancreatic endocrine secretion (6). GLP-1 is also a neuropeptide synthesized by neurons in the caudal regions of the nucleus of the solitary tract (NTS) (7,8). GLP-1 is released into the hypothalamus and controls food intake, blood pressure, and heart rate (9,10). Whereas most of the glucose-lowering actions of GLP-1 have been attributed to the direct effect of the hormone on the endocrine pancreas, i.e., to stimulation of insulin and inhibition of glucagon secretion, we demonstrated the importance of extra-pancreatic GLP-1 receptor–dependent control of insulin secretion (11) and whole-body glucose distribution (12). The infusion into the brain of the GLP-1 receptor antagonist exendin-9 (Ex9) inhibited insulin secretion induced by gut glucose (11). Conversely, central administration of the GLP-1 receptor agonist exendin-4 (Ex4) augmented intravenous glucose-stimulated insulin secretion to a level similar to that obtained during an intragastric glucose infusion (11). Our data suggested that the absorptive state was associated with the stimulation of the gut-to-brain axis leading to the activation of brain GLP-1 signaling and, consequently, to hyperinsulinemia. During the absorptive state, blood flow redistribution toward mesenteric organs is also observed, which has been proposed to favor nutrient redistribution into the liver (13). Importantly, stimulation of the central GLP-1 receptor increases blood pressure and heart rate and activates autonomic regulatory neurons (8,14,15). However, recently it has been shown that GLP-1 reduced islet blood flow after glucose administration (16). Therefore, the role of brain GLP-1 signaling also in the control of cardiovascular homeostasis remains incompletely understood.We have now pursued the importance of GLP-1 action in the central nervous system for control of cardiovascular function using studies in conscious free-moving mice. After central GLP-1 infusion, we simultaneously recorded femoral arterial blood flow, heart rate, and insulin and glucose sensitivity during hyperinsulinemic-euglycemic or hyperglycemic clamps. We now demonstrate that hypothalamic reactive oxygen and nitrogen species are controlled by brain GLP-1 and are essential for the coordinated regulation of metabolic and cardiovascular function.     

Traumatic pancreatic duct injury in children: minimally invasive approach to management

Background

The management of children with main pancreatic duct injuries is controversial. We report a series of patients with pancreatic trauma who were treated using minimally invasive techniques.

Methods

Retrospective review of children with pancreatic trauma treated at a UK tertiary referral institution between 1999 and 2004.

Results

Fifteen children (11 boys) were admitted with pancreatic trauma. Twelve (80%) were less than 50th centile for body weight. Contrast-enhanced computed tomography (CT) scans were used to define organ injury, supplemented by magnetic resonance cholangiopancreatography (MRCP) in 7. Twelve (80%) underwent diagnostic endoscopic retrograde cholangiopancreatography (ERCP) with a median time after injury of 11 (range, 6-29) days. The degree of pancreatic injury was defined by ERCP and CT/MRCP as grade II (n = 2), grade III (n = 4), grade IV (n = 9) (American Association for the Surgery of Trauma grades). Nine children had a transductal pancreatic stent inserted endoscopically. Computed tomography/ultrasound-guided drainage was performed in 4 children for acute fluid collections. Two children later underwent endoscopic cyst-gastrostomy, one of whom later required conversion to an open cyst-gastrostomy.

Conclusion

Body habitus may predispose to pancreatic duct trauma. Contrast-enhanced CT scan (and MRCP) should dictate the need for ERCP. Transductal pancreatic stenting allows internal drainage of peripancreatic collections and may reestablish duct continuity, although a proportion still requires percutaneous or endoscopic cyst-gastrostomy drainage. Open surgery for pancreatic trauma should now be an exception.     

Living-related liver transplantation and vena cava reconstruction after total hepatectomy including the vena cava for hepatoblastoma.

BACKGROUND: In most cases of total hepatectomy (TH) required for hepatoblastoma (HB), the retrohepatic inferior vena cava (IVC) has to be removed with the native liver for complete tumor excision. Because the liver graft procured by living donation has no IVC, a reconstruction of the recipient IVC is needed. We report our experience with living-related liver transplantation (LRLT) and IVC replacement in such cases. METHODS: Between May 1998 and December 1999, four children underwent TH, including IVC and LRLT with IVC replacement for otherwise irresectable HB after chemotherapy (SIOPEL 2 and 3 protocols). IVC reconstruction used an allogenic iliac vein procured from a cadaveric donor (bank graft) in two cases and an internal jugular vein procured from the donor parent in two cases. Median age and weight at surgery were 17 months (range 10-60) and 9.6 kg (range 8.3-17.9). RESULTS: In the living donors, there were two complications of the procurement: one intra-abdominal biliary collection and one subcutaneous abscess. In all four children, complete excision of the tumor could be achieved without any intra-operative complication. One patient died 5 months after LRLT due to lung metastases. Three patients were alive and well with no evidence of tumor recurrence 13-24 months after surgery. Reconstructed IVC was patent in two patients, and asymptomatic thrombosis occurred 2 years after operation in one patient. CONCLUSION: Total hepatectomy including the retrohepatic IVC is not a technical obstacle to LRLT. Therefore, scheduled surgery, at the best time after chemotherapy, can be considered in all patients with otherwise irresectable HBs.