Discrepancy between training,competition and laboratory measures of maximum heart rate in NCAA division 2 distance runners

A percentage of either measured or predicted maximum heart rate is commonly used to prescribe and measure exercise intensity. However, maximum heart rate in athletes may be greater during competition or training than during laboratory exercise testing. Thus, the aim of the present investigation was to determine if endurance-trained runners train and compete at or above laboratory measures of ''maximum'' heart rate. Maximum heart rates were measured utilising a treadmill graded exercise test (GXT) in a laboratory setting using 10 female and 10 male National Collegiate Athletic Association (NCAA) division 2 cross-country and distance event track athletes. Maximum training and competition heart rates were measured during a high-intensity interval training day (TR HR) and during competition (COMP HR) at an NCAA meet. TR HR (207 ± 5.0 b·min^-1; means ± SEM) and COMP HR (206 ± 4 b·min^-1) were significantly (p < 0.05) higher than maximum heart rates obtained during the GXT (194 ± 2 b·min^-1). The heart rate at the ventilatory threshold measured in the laboratory occurred at 83.3 ± 2.5% of the heart rate at VO₂ max with no differences between the men and women. However, the heart rate at the ventilatory threshold measured in the laboratory was only 77% of the maximal COMP HR or TR HR. In order to optimize training-induced adaptation, training intensity for NCAA division 2 distance event runners should not be based on laboratory assessment of maximum heart rate, but instead on maximum heart rate obtained either during training or during competition.

Key points

• A percentage of maximum heart rate is commonly used to prescribe and measure exercise intensity. However, maximum heart rate may be greater during competition or training than during laboratory exercise testing.
• Heart rates during training and competition were significantly higher than maximum heart rates obtained during laboratory exercise testing.
• To optimize training-induced adaptation, training intensity for NCAA division 2 distance event runners should not be based on laboratory assessment of maximum heart rate, but instead on maximum heart rate measure obtained either during training or during competition.

Key words: Competition, heart rate, laboratory, performance, running, training     

Volume of Physical Activity and Injury Occurrence in Young Basketball Players

Participation in organised, competitive physical activity by young athletes is increasing rapidly. This is concurrent with an increase in sporting injuries in the young population. This pilot study aimed to compare the weekly volume and types of physical activity in young basketball players injured and not injured during the season. Detailed physical activity and injury data were prospectively collected in 46 school-level basketball players aged 14 to 18 years. Participants completed physical activity logs which documented the type of physical activity undertaken, what the activity consisted of (i.e. training, competition) and the level at which it was played on a daily basis. Allied health staff completed a weekly injury form. Results showed that injured and uninjured athletes participated in a similar volume of total weekly physical activity over the season. However, injured athletes (p = 0.04) and athletes who specifically sustained overuse injuries (p = 0.01) participated in a greater amount of basketball refereeing than uninjured athletes. Based on these findings it was concluded that greater participation in running-type physical activity such as refereeing, as an addition to training and competition, may predispose the young basketball player to increased injury risk. Future research using larger sample sizes are required to further investigate the role of participation volume and type on injury occurrence in adolescent athletes.

Key points

• Basketball players participating in larger amounts of running-type physical activity, in addition to regular training and competition, may be predisposed to overuse injury
• Future studies using larger sample sizes are required to investigate the precise volumes of physical activity that increase injury risk
• This would assist in the development of participation guidelines to decrease the current injury rates observed in the young athletic population.

Key words: Adolescent, sport injury, overuse, workload     

A comparative analysis of the accuracy, diagnostic uncertainty and cost of imaging modalities in suspected scaphoid fractures

INTRODUCTION: Clinical examination of suspected scaphoid fractures is sensitive, but not specific, and initial plain radiographs lack sensitivity. A variety of second-line imaging techniques have been proposed to improve immediate diagnosis and reduce overtreatment. Different sample populations and methods of reporting test performance have made side-by-side comparison difficult. The aim of this study is to describe the epidemiology of clinically suspected scaphoid fracture and determine the prevalence of true fracture. These data are used to compare second-line imaging techniques in our population. PATIENTS AND METHODS: 200 consecutive patients attending a trauma service with clinically suspected scaphoid fracture were followed through diagnosis to discharge. RESULTS: The prevalence of true fracture was 16% and was associated with male sex and injury playing sport. Magnetic resonance imaging has the best diagnostic performance, with the added benefit of soft tissue evaluation, but was the most expensive option. Ultrasound examination was least effective in detecting true fractures. CONCLUSIONS: Future studies should further evaluate the clinical and economic sequelae of overtreatment of suspected fractures. Clinicians should examine alternatives to "empirical" treatment without definite diagnosis based on their local facilities and patient demographics.     

Extended transthoracic resection compared with limited transhiatal resection for adenocarcinoma of the mid/distal esophagus: five-year survival of a randomized clinical trial

OBJECTIVE: To determine whether extended transthoracic esophagectomy for adenocarcinoma of the mid/distal esophagus improves long-term survival. BACKGROUND: A randomized trial was performed to compare surgical techniques. Complete 5-year survival data are now available. METHODS: A total of 220 patients with adenocarcinoma of the distal esophagus (type I) or gastric cardia involving the distal esophagus (type II) were randomly assigned to limited transhiatal esophagectomy or to extended transthoracic esophagectomy with en bloc lymphadenectomy. Patients with peroperatively irresectable/incurable cancer were excluded from this analysis (n = 15). A total of 95 patients underwent transhiatal esophagectomy and 110 patients underwent transthoracic esophagectomy. RESULTS: After transhiatal and transthoracic resection, 5-year survival was 34% and 36%, respectively (P = 0.71, per protocol analysis). In a subgroup analysis, based on the location of the primary tumor according to the resection specimen, no overall survival benefit for either surgical approach was seen in 115 patients with a type II tumor (P = 0.81). In 90 patients with a type I tumor, a survival benefit of 14% was seen with the transthoracic approach (51% vs. 37%, P = 0.33). There was evidence that the treatment effect differed depending on the number of positive lymph nodes in the resection specimen (test for interaction P = 0.06). In patients (n = 55) without positive nodes locoregional disease-free survival after transhiatal esophagectomy was comparable to that after transthoracic esophagectomy (86% and 89%, respectively). The same was true for patients (n = 46) with more than 8 positive nodes (0% in both groups). Patients (n = 104) with 1 to 8 positive lymph nodes in the resection specimen showed a 5-year locoregional disease-free survival advantage if operated via the transthoracic route (23% vs. 64%, P = 0.02). CONCLUSION: There is no significant overall survival benefit for either approach. However, compared with limited transhiatal resection extended transthoracic esophagectomy for type I esophageal adenocarcinoma shows an ongoing trend towards better 5-year survival. Moreover, patients with a limited number of positive lymph nodes in the resection specimen seem to benefit from an extended transthoracic esophagectomy.     

The combination of antagonists of LHRH with antagonists of GHRH improves inhibition of androgen sensitive MDA-PCa-2b and LuCaP-35 prostate cancers

BACKGROUND: Antagonists of growth hormone-releasing hormone (GHRH) could extend the duration of response of androgen sensitive prostate cancers to androgen deprivation. METHODS: We investigated the effect of new GHRH antagonists MZ-J-7-118 and MZ-J-7-138 and luteinizing hormone-releasing hormone (LHRH) antagonist Cetrorelix or castration on androgen sensitive MDA-PCa-2b and LuCaP-35 prostate cancer models xenografted into nude mice. Animals bearing androgen-independent LuCaP-35V prostatic cancer model were also treated with MZ-J-7-118. RESULTS: Receptors for LHRH and GHRH were present in MDA-PCA-2b, LuCaP-35, and LuCaP-35V tumors. GHRH antagonists increased the inhibitory effect of surgical castration and LHRH antagonists on androgen sensitive MDA-PCa-2b and LuCaP-35 tumors. The time to relapse of androgen-dependent LuCaP-35 tumors was extended by GHRH antagonists. Growth of androgen-independent LuCaP-35V xenografts was also significantly inhibited by MZ-J-7-118. In MDA-PCa-2b tumors treatment with MZ-J-7-118 caused a significant decrease of VEGF and Cetrorelix or its combination with MZ-J-7-118 reduced EGF. The B(max) of EGF receptors was significantly reduced by Cetrorelix, MZ-J-7-118 and their combination. CONCLUSIONS: Our findings suggest that the use of a combination of antagonists of GHRH and LHRH could improve the therapy for androgen sensitive prostate cancer. Antagonists of GHRH could be also considered for treatment of androgen-independent prostate cancers.     

Evaluation of 28 years of surgical treatment of children and young adults with familial adenomatous polyposis

Background

In this retrospective study, 28 years of surgical treatment of children and young adults with familial adenomatous polyposis (FAP) was analyzed.

Methods

Forty-three patients were operated on before the age of 26 years. Endoscopic aspects, operative data, and complications were analyzed, and the resection specimens were reevaluated. Functional outcome was assessed by telephone questionnaire.

Results

Primary ileorectal anastomosis (IRA) was performed in 34 patients with a mean age of 16 years (range, 7-25 years). Primary ileal-pouch anal anastomosis (IPAA) was performed in 9 patients at a mean age of 19 years (range, 15-24 years). Secondary excision of the rectum was performed in 7 patients. Overall, rectal carcinoma was present in 4 patients, at the age of 35, 36, 37, and 38 years. Two patients, aged 39 and 40 years, died because of invasive carcinoma with distant metastasis. The functional outcome and postoperative complications after both procedures were similar to those described in literature for children with FAP. Most patients did not experience alterations in lifestyle, and there was no urinary incontinence.

Conclusions

In this retrospective study, both IRA and IPAA showed to be feasible techniques in young patients with FAP. A prospective study with a sufficient follow-up is needed to compare both techniques in this specific group of patients.     

Improving care through standardized treatment of spontaneous pneumothorax

PurposeThe objective of this quality improvement (QI) initiative was to implement a standardized clinical treatment protocol for patients presenting with primary spontaneous pneumothorax (PSP) in order to decrease hospital length of stay (LOS), diagnostic radiation exposure, and related cost.MethodsBaseline data from patients admitted with PSP from January 1, 2016 to July 31, 2018 were compared to data from patients managed using a newly developed evidence-based treatment pathway from August 1, 2018 to December 31, 2019. Standard QI methodology was used to track results.ResultsFifty-six episodes of PSP were observed during the baseline period and 40 episodes of PSP following initiation of the PSP protocol. The average LOS decreased from 4.5 days to 2.9 days. Patients underwent an average of 8.8 X-rays per admission preintervention versus 5.9 postintervention. The rate of CT scans decreased from 45% to 15% (p = 0.002). There was no significant difference in the rates of 30-day recurrence between the preintervention (13%) and postintervention (10%) groups (p = 0.7). Average admission costs per patient decreased by $1322 after adoption of the pathway.ConclusionsAdoption of a standardized treatment protocol for PSP led to a reduction in LOS, diagnostic imaging utilization, and cost without increasing clinical recurrence.Type of studyQuality improvement.Level of evidenceLevel III.     

Hemispheric specialization for processing auditory nonspeech stimuli

The left hemisphere specialization for speech perception might arise from asymmetries at more basic levels of auditory processing. In particular, it has been suggested that differences in "temporal" and "spectral" processing exist between the hemispheres. Here we used functional magnetic resonance imaging to test this hypothesis further. Fourteen healthy volunteers listened to sequences of alternating pure tones that varied in the temporal and spectral domains. Increased temporal variation was associated with activation in Heschl's gyrus (HG) bilaterally, whereas increased spectral variation activated the superior temporal gyrus (STG) bilaterally and right posterior superior temporal sulcus (STS). Responses to increased temporal variation were lateralized to the left hemisphere; this left lateralization was greater in posteromedial HG, which is presumed to correspond to the primary auditory cortex. Responses to increased spectral variation were lateralized to the right hemisphere specifically in the anterior STG and posterior STS. These findings are consistent with the notion that the hemispheres are differentially specialized for processing auditory stimuli even in the absence of linguistic information.     

Bovine sertoli cells colonize and form tubules in murine hosts following transplantation and grafting procedures

The contribution of somatic cells to nonrodent male germ cell transplantation success has not been well established due to lack of cell type-specific markers to distinguish donor cells from host cells. In the present study, we first screened antibodies and a lectin to identify markers suitable for unequivocal distinction between germ cells and Sertoli cells in bovine testes compared with mouse testes. Anti-vimentin and the Dolichos biflorus agglutinin (DBA) lectin detected only bovine Sertoli cells and spermatogonia, respectively; anti-NONO and anti-GCNA1 detected only mouse Sertoli and germ cells, respectively. The outcome of transplanting bovine testis cells into nude mouse testes was then studied using these markers. Our results clearly showed that immature bovine Sertoli cells survive and colonize mouse testes at 2.5 months after transplantation and that tubular structures composed of donor Sertoli cells formed adjacent to murine tubules within the host mouse testis. Bovine germ cell colonization and survival in mouse testes after transplantation were confirmed, but this was restricted to areas of bovine Sertoli cell colonization. In addition, ectopic grafts of intact bovine testis tissue and cell aggregates from hanging drop cultures were placed under the back skin and testis capsule of nude mice. Bovine Sertoli cells in ectopic grafts and aggregates were able to form tubular structures, and some bovine germ cells were observed around 2 months after implantation. This study therefore identifies a practical strategy to assess the outcome of testicular cell transplantation using different antibodies and a lectin to distinguish bovine cells from mouse cells. It identifies an approach that can readily be adapted to study other nonrodent species.     

Influence of Lifestyle Factors on Quantitative Heel Ultrasound Measurements in Middle-Aged and Elderly Men

We examined the distribution of quantitative heel ultrasound (QUS) parameters in population samples of European men and looked at the influence of lifestyle factors on the occurrence of these parameters. Men aged between 40 and 79 years were recruited from eight European centers and invited to attend for an interviewer-assisted questionnaire, assessment of physical performance, and quantitative ultrasound (QUS) of the calcaneus (Hologic; Sahara). The relationships between QUS parameters and lifestyle variables were assessed using linear regression with adjustments for age, center, and weight. Three thousand two hundred fifty-eight men, mean age 60.0 years, were included in the analysis. A higher PASE score (upper vs. lower tertile) was associated with a higher BUA (β coefficient = 2.44 dB/Mhz), SOS (β = 6.83 m/s), and QUI (β = 3.87). Compared to those who were inactive, those who walked or cycled more than an hour per day had a higher BUA (β = 3.71 dB/Mhz), SOS (β = 6.97 m/s), and QUI (β = 4.50). A longer time to walk 50 ft was linked with a lower BUA (β = ?0.62 dB/Mhz), SOS (β = ?1.06 m/s), and QUI (β = ?0.69). Smoking was associated with a reduction in BUA, SOS, and QUI. There was a U-shaped association with frequency of alcohol consumption. Modification of lifestyle, including increasing physical activity and stopping smoking, may help optimize bone strength and reduce the risk of fracture in middle-aged and elderly European men.