Kinematic and electromyographic changes during 200 m front crawl at race pace.

The purpose of this study was to analyse eventual kinematic and electromyographic changes during a maximal 200 m front crawl at race pace. 10 male international level swimmers performed a 200 m maximal front crawl test. Images were recorded by 2 above and 4 under water cameras, and electromyographic signals (EMG) of 7 upper and lower limbs muscles were analysed for 1 stroke cycle in each 50 m lap. Capillary blood lactate concentrations were collected before and after the test. The variables of interest were: swimming speed, stroke length, stroke and kick frequency, hand angular velocity, upper limb and foot displacement, elbow angle, shoulder and roll angle, duration of stroke phases, and EMG for each muscle in each stroke phase. Generally, the kinematic parameters decreased, and a relative duration increased for the entry and pull phases and decreased for the recovery phase. Muscle activation of flexor carpi radialis, biceps brachii, triceps brachii, peitoral major and upper trapezius increased during specific stroke phases over the test. Blood lactate concentration increased significantly after the test. These findings suggest the occurrence of fatigue, characterised by changes in kinematic parameters and selective changes in upper limbs muscle activation according to muscle action.

Use of NSAIDs in triathletes: prevalence, level of awareness and reasons for use.

OBJECTIVE: to determine the level of awareness regarding nonsteroidal anti-inflammatory drugs (NSAIDs) and the prevalence and reasons for their consumption among athletes competing at the 2008 Brazil Ironman Triathlon (3.8 km swim, 180 km cycle and 42.2 km run). DESIGN: survey study. SETTING: 2008 Brazil Ironman Triathlon, Florianópolis, Brazil, May 2008. PARTICIPANTS: 327 Of the 1250 athletes competing at the 2008 Brazil Ironman Triathlon were enrolled in the study. MAIN OUTCOME MEASURES: athletes answered a questionnaire about NSAID effects, side effects and consumption at the bike checkout or awards lunch. RESULTS: 196 (59.9%) Athletes reported using NSAIDs in the previous 3 months; of these, 25.5% (n=50), 17.9% (n=35) and 47.4% (n=93) consumed NSAIDs the day before, immediately before and during the race, respectively. Among NSAID users, 48.5% (n=95) consumed them without medical prescription. The main reason given for NSAID consumption in the previous 3 months was the treatment of injuries, while the main reason given for consuming NSAIDs during the race was pain prevention. Despite anti-inflammatory and analgesic effects, most athletes were unaware of the effects of NSAIDs, and the only adverse effects known by most athletes were the gastrointestinal complications. CONCLUSIONS: this study found a high prevalence of NSAID consumption, limited awareness of the effects and side effects of them and a high rate of nonprescribed use. It is suggested that long-distance triathlon events include in their programmes educational devices such as talks or folders about NSAID use, effects and side effects.

Gelatin-based microcarriers as embryonic stem cell delivery system in bone tissue engineering: an in-vitro study.

Mouse embryonic stem cells were cultured on commercially available biodegradable macroporous microcarriers. A culture period of 1-2 weeks was needed to colonize the microcarriers. Embryonic stem cells retained their pluripotency for up to 14 days when cultured in medium supplemented with leukemia inhibitory factor. Replacing this medium by differentiation medium for 2 weeks initiated osteogenic differentiation. Encapsulation of the cell-loaded microcarriers in photopolymerizable polymers (methacrylate-endcapped poly-D,L-lactide-co-caprolactone), triacetin/hydroxyethylmethacrylate (HEMA) as solvent and with/without gelatin as porogen, resulted in a homogeneous distribution of the microcarriers in the polymer. As observed by transmission electron microscopy, viability of the cells was optimal when gelatin was omitted and when using triacetin instead of HEMA.

Heat-induced changes in intracellular Na+, pH and bioenergetic status in superfused RIF-1 tumour cells determined by 23Na and 31P magnetic resonance spectroscopy.

The acute effects of hyperthermia on intracellular Na+ (Nai+), bioenergetic status and intracellular pH (pHi) were investigated in superfused Radiation Induced Fibrosarcoma-1 (RIF-1) tumour cells using shift-reagent-aided 23Na and 31P nuclear magnetic resonance (NMR) spectroscopy. Hyperthermia at 45 degrees C for 30 min produced a 50% increase in Na, a 0.42 unit decrease in pHi and a 40-45% decrease in NTP/P(i). During post-hyperthermia superfusion at 37 degrees C, pHi and NTP/P(i) recovered to the baseline value, but Na initially decreased and then increased to the hyperthermic level 60 min after heating. Hyperthermia at 42 degrees C caused only a 15-20% increase in Nai+. In the presence of 3 microM 5-(N-ethyl-N-isopropyl)amiloride (EIPA), an inhibitor of the Na+/H+ exchanger, the increase in Nai+ during 45 degrees C hyperthermia was attenuated, suggesting that the heat-induced increase in Nai+ was mainly due to an increase in Na+/H+ anti-porter activity. EIPA did not prevent hyperthermia-induced acidification. This suggests that pHi is controlled by other ion exchange mechanisms in addition to the Na+/H+ exchanger. EIPA increased the thermo-sensitivity of the RIF-1 tumour cells only slightly as measured by cell viability and clonogenic assays. The hyperthermia-induced irreversible increase in Nai+ suggests that changes in transmembrane ion gradients play an important role in cell damage induced by hyperthermia.

The use of vinca alkaloids in adult patients with refractory chronic idiopathic thrombocytopenia.

The aim of the study was to evaluate the application of vincristin or vinblastin in patients with chronic idiopathic thrombocytopenic purpura (ITP), resistant to corticosteroids or with partial contraindication to their application. Twenty-two patients were treated with vincristin or vinblastin in doses of 2 and 10 mg, respectively. Eight of these patients were additionally administered prednisone in an oral dose of 0.5 mg/kg body mass (bm). Two-hour intravenous infusions of drugs were made once a week, at least three times. In every patient, the platelet count was evaluated before and after the three infusions. A rise of the platelet count of at least 100 x 10(9)/l was assumed to signify improvement. Statistically significant improvement (P <0.01) was obtained in nine (41%) patients (including five (35%) patients treated with vinca alkaloids only and in four (50%) patients treated with vincristin and corticosteroids). On the average, 8 weeks after the termination of the treatment there was a 40% drop in the platelet. Patients with a shorter duration of the disease and without detectable platelet antibodies responded well to the treatment more frequently. Minor complications were observed in five patients (23%), notably in the form of paresthesia. Leukopenia was not present. Vinca alkaloids could find their application in clinical situations requiring short-term increase of the platelet count in chronically ill patients with ITP, resistant to corticosteroids or with counterindication to their application.

Hemoglobin F in primary myelofibrosis and in myelodysplasia.

Our study investigated two groups of adult patients with established diagnoses of primary myelofibrosis (21 patients) and myelodysplastic syndromes (MDS) (21 patients). The objective was to assess fetal hemoglobin (HbF) concentration and to investigate correlations with organomegaly and extramedullary hematopoiesis and with the level of anemia and blood transfusion requirement. In all patients, the diagnosis was confirmed by histopathological examination. Patients with myelofibrosis were investigated by ferrokinetics using 59Fe. The percentage of marrow sideroblasts was assessed in patients with refractory anemia with ringed sideroblasts. Increased values of HbF were found to occur both in patients with myelofibrosis and with MDS, although a higher incidence and higher concentrations were evident in patients with myelofibrosis. Statistically significant increases in HbF concentration were found when there was accompanying organomegaly, as compared to patients without this feature. The average HbF concentration in both groups of patients under study was twice as high in cases with as in those without marrow fibrosis. The difference was statistically significant. Increased HbF levels appear to correlate with extramedullary hematopoiesis. HbF concentration did not correlate with the level of anemia or with requirement for blood transfusion.

Usefulness of a state-legislated, comparative database to evaluate quality in colorectal surgery.

PURPOSE: Colorectal surgery, a high-volume procedure, has been targeted for performance improvement to reduce length of stay. Specific postoperative quality indicators and readmission rates should be analyzed concomitantly to assure that adverse events are not associated with earlier discharge. METHODS: From July 1, 1990, to June 30, 1997, 1,218 consecutive patients who underwent transabdominal colorectal surgery were analyzed for length of stay, mortality, morbidity, and discharge disposition. Each patient was assigned an Admission Severity Group rating 0 to 4 using a hospital-based state-legislated software system (Atlas) to validate comparative performance internally and externally. Readmission data within 120 days of discharge were available for the last 678 consecutive patients from July 1, 1993, to June 30, 1997, using Lastword (computerized medical records). RESULTS: The annual frequencies of the 1,218 procedures were 173, 183, 175, 146, 167, 189, and 185, respectively, from July 1990 through June 1997. Severity distribution was 32 for Admission Severity Group 0, 517 for Admission Severity Group 1, 540 for Admission Severity Group 2, 128 for Admission Severity Group 3, and 1 for Admission Severity Group 4, with no annual difference (P = 0.012). There was a significant reduction in total length of stay of 3.1 (12.9-9.8) days during the seven years (P = 0.001). The overall operative mortality rate was 1.4 percent, and the morbidity was 2.6 percent, with no annual differences (P = 0.655 and P = 0.033, respectively). The disposition to home did not change (P = 0.21). Of the 678 patients followed up for readmission, 100 (14.7 percent) were readmitted within 120 days, with no annual difference (P = ().302). CONCLUSION: Mortality, morbidity, disposition, and readmission rates were not affected by a decreased length of stay after colorectal surgery.

Correlation of pseudohypoxemia and leukocytosis in chronic lymphocytic leukemia.

Pseudohypoxemia has been reported in leukemic patients with extreme leukocytosis, and it is characterized by a low oxygen saturation on arterial blood gas analysis despite normal saturation on pulse oximetry. We report the case of a 51-year-old man with chronic lymphocytic leukemia and an elevated white blood cell (WBC) count after splenectomy, his progressive postoperative pseudohypoxemia gradually improved as the leukocytosis was lowered by chemotherapy. We believe this is the first report to show a statistically significant correlation between the WBC count and the degree of pseudohypoxemia in a patient with leukemia.

Colorectal cancer after surveillance colonoscopy: false-negative examination or fast growth?

PURPOSE: Colonoscopy is the preferred method for colorectal cancer surveillance of high-risk patients. Despite its high sensitivity, polyps or cancers may be undetected by colonoscopy and later attributed to an accelerated adenoma-carcinoma sequence. This study assesses how the characteristics of colorectal cancers found at intervals between surveillance relate to the adenoma-carcinoma sequence and its prevention. METHODS: The records of 557 patients with colorectal cancer that were diagnosed from January 1, 1990, to December 31, 1996, were reviewed to identify those patients who had prior colonoscopic surveillance within 60 months of their diagnosis. RESULTS: There were 29 (5.2 percent) patients who had one or more colonoscopies before diagnosis of their colorectal cancer. Mean interval between diagnosis and prior colonoscopy was 23 (range, 4-59) months. The distribution of cancers included nine cecum, two ascending, three hepatic flexure, five transverse, one splenic flexure, three descending, two sigmoid, three rectum, and one anal canal. The mean tumor size was 4.4 cm for the cecum and 2.4 cm for all other locations. There were 7 Tis, 6 T1, 4 T2, and 12 T3 lesions. Six patients with T3 lesions had prior colonoscopies within 24 months of the diagnosis. Three of four patients with lymphatic metastases had tumors in the cecum. Twenty tumors (69 percent) were well or moderately differentiated. Mean follow-up was 41 (range, 7-95) months with two local recurrences and two unrelated deaths. CONCLUSIONS: Size, differentiation, and stage of colorectal cancer in addition to the interval to diagnosis suggest that the majority of cancers found during surveillance colonoscopy followed prior false-negative examinations. Because cecal landmarks are most constant, prior photographic documentation may help to prove or disprove fast growth of cancers found in the cecum during surveillance colonoscopy.

A new technique for intraoperative enteroscopy using a 12-mm trocar.

Intraoperative enteroscopy is a valuable method for localizing gastrointestinal bleeding of obscure origin. The insertion and manipulation of an endoscope through an enterotomy, however, may result in significant trauma to the intestinal wall, as well as contamination of the abdominal cavity. We have devised a new technique for the introduction of the endoscope that lessens trauma to the bowel wall and allows a complete enteroscopy with minimal contamination.

Retrorectal carcinoid tumor.

Retrorectal masses comprise a varied group of rarely encountered tumors. We present the case of a 42-year-old white woman with a retrorectal carcinoid tumor treated by abdominosacral resection. Diagnostic and therapeutic strategies are discussed.

Lower-extremity saphenous vein transposition arteriovenous fistula: an alternative for hemodialysis access in AIDS patients.

Arteriovenous access for long-term hemodialysis in patients with the acquired immunodeficiency syndrome (AIDS) represents a special challenge. Many of these patients are chronic intravenous drug abusers and do not have patent superficial upper-extremity veins available for conventional arteriovenous fistulas. This group of patients is also particularly prone to infections, which contraindicates the use of prosthetic grafts. Over a period of 13 months, five lower-extremity saphenous vein transposition arteriovenous fistulas (SVTAFs) were performed. Four patients had a diagnosis of AIDS at the time of operation; all of these were intravenous drug abusers. Three patients were male, two were female, and their age ranged from 34 to 66 years (mean, 48). Three patients had a SVTAF as their first hemodialysis access, and in two it was performed after multiple failed upper-extremity accesses. Four fistulas remain patent to date, after a mean follow-up of 11 months (range, 4 weeks to 16 months). One fistula thrombosed 4 weeks postoperatively, due to a hematoma that occurred after premature venipuncture for dialysis. There were no other major complications. We conclude that SVTAF is a suitable alternative to the limited hemodialysis venous access sites, especially in the AIDS population.

Marked difference between angiotensin-converting enzyme and neutral endopeptidase inhibition in vivo by a dual inhibitor of both enzymes.

Dual inhibition of neutral endopeptidase 24.11 (NEP) and angiotensin-converting enzyme (ACE) offers the potential for improved therapy of hypertension and cardiac failure. S 21402-1 [(2S)-2-[(2S,3R)-2-thiomethyl-3-phenylbutanamido] propionic acid] is a sulfhydryl-containing potent inhibitor of both NEP (Ki = 1.7 nM) and ACE (Ki = 4.5 nM). S 21402-1 and the sulfhydryl-containing ACE inhibitor captopril were administered to rats by intraperitoneal injection (0, 0.3, 3, 30, 300 mg/kg). Urine was collected for 4 h; then plasma and kidneys were collected. The difference in NEP and ACE inhibition by S 21402-1 in vivo was greater than 1000-fold. All doses of S 21402-1 inhibited NEP, as indicated by plasma NEP activity, radioinhibitor binding to kidney sections, urinary sodium excretion and bradykinin-(1-7)/bradykinin-(1-9) ratio. However, only 300 mg/kg S 21402-1 inhibited ACE, as indicated by plasma angiotensin II/angiotensin I ratio, renin and angiotensinogen levels. Although S 21402-1 (30 and 300 mg/kg) inhibited renal NEP, as indicated by the bradykinin-(1-7)/bradykinin-(1-9) ratio in kidney, S 21402-1 had no effect on renal ACE, as indicated by the angiotensin II/angiotensin I ratio in kidney. Moreover, captopril was greater than 10-fold more potent than S 21402-1 as an ACE inhibitor in vivo. In separate experiments, the pressor response of anesthetized rats to angiotensin I showed more rapid decay in ACE inhibition by S 21402-1 than by captopril. These studies indicated that in vivo modification of S 21402-1 caused a much greater decrease in potency of ACE inhibition than NEP inhibition. Consequently, effective ACE inhibition by S 21402-1 required doses much higher than those required for NEP inhibition.

[Vibration syndrome and occupational exposure in Poland]. / Zespól wibracyjny w Polsce na tle narazenia zawodowego na wibracje.

The objective of the study was to analyse the data on the exposure to vibration, and the incidence of vibration syndrome in individual branches of the national economy and voivodships. The data were obtained from the records of The Nofer Institute of Occupational Medicine in Lódz, containing reports submitted to the Institute every three years, and the literature on fragmentary analyses of this kind of exposure. Although, the number of persons exposed to vibration, and the incidence of occupational diseases induced by vibration have decreased, the material collected provide evidence that vibration syndrome still plays an essential role in occupational pathology. The decrease in the vibration syndrome incidence observed during the years 1982-97 was lower than the decline in the number of persons exposed to vibration, but the ratio of the number of cases to the number of those exposed remained unchanged (2.1). In 1994-97, forestry workers constituted the largest working population exposed to vibration, and the number of persons with diagnosed vibration syndrome significantly increased, however, exposure to vibration in this branch of economy considerably declined. In the mining industry, a significant decrease in the number of persons exposed to vibration, as well as in the incidence of vibration syndrome was observed at that time. The worse situation in forestry might result from the past negligence of hygiene norms or less effective diagnosis in early stages of the disease development. The lack of measuring and monitoring of vibration intensity in the working environment is an alarming observation in view of the fact that both the number of persons exposed, and the incidence of occupational diseases caused by this kind of exposure are still high.