Lack of Evidence for Crossover Fatigue with Plantar Flexor Muscles

The occurrence and mechanisms underlying non-local or crossover muscle fatigue is an ongoing issue. This study aimed to investigate crossover fatigue of the plantar flexor muscles. Sixteen recreationally active males (n = 6) and females (n = 10) visited the laboratory for four sessions and performed a single 5-s pre-test maximal voluntary isometric contraction (MVIC) with each plantar flexors muscle. Thereafter, the fatigue intervention involved two 100-s MVICs (60-s recovery) with their dominant plantar flexors or rested for 260-s (control). Subsequently, in two separate sessions, Hoffman reflexes (H-reflex) were evoked in the non-dominant, non-exercised, leg before and following the dominant leg fatigue or control intervention (Fatigue-Reflex and Control-Reflex conditions). MVIC forces and volitional (V)-waves were monitored in the non-dominant leg in the other two sessions (Fatigue-MVIC and Control-MVIC) before and after the intervention (fatigue or control) as well as during 12 repeated MVICs and immediately thereafter. Despite the force reduction in the dominant leg (42.4%, p = 0.002), no crossover force deficit with single (F_(1,9) = 0.02, p = 0.88, pƞ² = 0.003) or repeated (F_(1,9) = 0.006, p = 0.93, pƞ² = 0.001) MVIC testing were observed. The H-reflex did not change after the fatigue (F_(1,7) = 0.51; p = 0.49; pƞ² = 0.06) or repeated MVICs (F_(1,8) = 0.27; p = 0.61; pƞ² = 0.03). There were also no crossover effects of fatigue on the V-wave with single (F_(1,8) = 3.71, p = 0.09, pƞ² = 0.31) or repeated MVICs (F_(1,6) = 1.45, p = 0.27, pƞ² = 0.19). Crossover fatigue was not evident with the plantar flexors nor any significant changes in H-reflex and V-waves in the soleus muscle. This finding suggests that crossover fatigue may not necessarily occur in slow-twitch predominant muscle groups. Key points

• There were no significant crossover impairments in muscle endurance suggesting that when unilaterally training the plantar flexors, crossover decrements may not be an issue.
• Unilaterally fatiguing the plantar flexors induces only a trivial chance of experiencing single or discrete contraction force or strength decrements in the contralateral limb.

Key words: Non-local muscle fatigue, soleus, fatigue, Hoffman reflex, V-wave     

Transscleral vs transpupillary diode laser photocoagulation for the treatment of zone II type 1 retinopathy of prematurity: Anatomical and refractive outcomes

Purpose:To compare the anatomical and refractive outcomes of transscleral diode versus transpupillary laser photocoagulation for the treatment of zone II type 1 retinopathy of prematurity (ROP).Methods:In this prospective comparative interventional case series, infants with type 1 ROP in zone II were assigned to either transpupillary or transscleral laser based on the surgeons’ expertise area. The rate of regression, need for retreatment, and structural and biometric outcomes at month 6 were evaluated and compared between the two treatment groups.Results:In total, 209 eyes were enrolled; 145 eyes of 77 infants and 64 eyes of 33 infants and were in transscleral and transpupillary groups, respectively. There was no significant difference in baseline characteristics between the groups. There was no significant difference in retreatment rates (1.6% vs. 3.4%; P = 0.669) and progression to stage 4 (1.6% vs. 2.8%; P = 0.999) between the transpupillary and transscleral groups, respectively. At month 6, the mean spherical equivalent was 0.31 ± 3.57 and 0.44 ± 2.85 diopters, and the axial length was 18.28 ± 6.22 and 18.36 ± 6.87 mm in the transpupillary and transscleral groups, respectively, without a significant difference between groups. There was no significant difference in the rate of myopia (43.8% vs. 33.8%; P = 0.169) and high myopia (4.7% vs. 4.8%; P = 0.965) in transpupillary and transscleral groups at month 6.Conclusion:The transpupillary and transscleral laser photocoagulation routes are both effective in the treatment of zone II type 1 ROP and show no significant differences in anatomical or refractive outcomes in relation to the route chosen.     

The role of the tumor microenvironment in colorectal cancer and the potential therapeutic approaches

BackgroundColorectal cancer (CRC) with a high prevalence is recognized as the fourth most common cause of cancer‐related death globally. Over the past decade, there has been growing interest in the network of tumor cells, stromal cells, immune cells, blood vessel cells, and fibroblasts that comprise the tumor microenvironment (TME) to identify new therapeutic interventions.MethodsDatabases, such as Google Scholar, PubMed, and Scopus, were searched to provide an overview of the recent research progress related to targeting the TME as a novel therapeutic approach.ResultsTumor microenvironment as a result of the cross talk between these cells may result in either advantages or disadvantages in tumor development and metastasis, affecting the signals and responses from the surrounding cells. Whilst chemotherapy has led to an improvement in CRC patients'' survival, the metastatic aspect of the disease remains difficult to avoid.ConclusionsThe present review emphasizes the structure and function of the TME, alterations in the TME, its role in the incidence and progression of CRC, the effects on tumor development and metastasis, and also the potential of its alterations as therapeutic targets. It should be noted that providing novel studies in this field of research might help us to achieve practical therapeutic strategies based on their interaction.     

Intestinal Transplantation in a Country Without Home Parenteral Nutrition: The Largest Report from the Middle East

Background:Many regions of the world, especially middle- and low-income countries, lack facilities for home parenteral nutrition and thus cannot follow existing guidelines for intestinal transplantation. Herein, we report our experiences with treatment protocols, intraoperative management, and early postoperative outcomes among patients undergoing either isolated intestinal transplantation or multivisceral transplantation in our center.Methods:During a 1-year period from March 2019 to March 2020, a total of 9 intestinal transplantations including 6 isolated intestinal transplantations and 3 multivisceral transplantations were performed in our center. We reported on donor selection strategies, surgical treatment, anesthesiology care and protocols for total parenteral nutrition, immunosuppression regimen, and pathology evaluation.Results:Mean (standard deviation) age of patients was 37.5 ± 12.5 years. The majority of patients were females (7/9). The median (interquartile range) waiting time for patients from diagnosis to transplantation was 79 (34, 164) days. Our 7-day survey of the amount of fluid therapy after transplantation revealed that the greatest need for fluid therapy was seen on the second postoperative day. After transplantation, 2 patients showed a total of 3 episodes of severe rejection, 1 of which was antibody-mediated. The 1-year survival was 66.6% and the 2-year survival was 44.5% in our study population. The median (interquartile range) time to death was 157 (26.5, 382) days. The most common cause of death was sepsis in our series (3/5).Conclusion:Acceptable outcomes can be obtained with intestinal transplantation in countries without home parenteral nutrition by application of specific treatment protocols.     

Associations of MTHFR rs1801133 (677C>T) and rs180113 (1298A>C) Polymorphisms with Susceptibility to Bladder Cancer: A Systematic Review and Meta-Analysis

The effects of the MTHFR rs1801133 (677C>T) and rs180113 (1298A>C) polymorphisms on bladder cancer risk have been evaluated in some studies. However, the results were conflicting and ambiguous. Therefore, we aimed to perform a comprehensive meta-analysis to investigate the association of these polymorphisms with risk of bladder cancer from all eligible case-control studies. PubMed, Web of science, Scopus, SID, CNKI and SciELO databases were searched to identify all relevant studies published up to 1 January, 2021. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to estimate the strength of associations. A total of 20 case-control studies including 11 studies with 3463 cases and 3927 controls on MTHFR rs1801133 (677C>T) and 9 studies with 3177 cases and 3502 controls on rs180113 (1298A>C) polymorphism were selected. Pooled data revealed that the MTHFR rs1801133 (677C>T) and rs180113 (1298A>C) polymorphisms were not associated with risk bladder cancer in overall. Stratified analysis by ethnicity revealed that the MTHFR rs1801133 (677C>T) and rs180113 (1298A>C) polymorphisms were associated with bladder cancer risk in Asians, but not in Caucasians. There was no publication bias. The current meta-analysis revealed that the MTHFR rs1801133 (677C>T) and rs180113 (1298A>C) polymorphisms were not risk factor for development of bladder cancer globally. However, large sample size, well-designed, and population-based studies should be performed to verify the association of the MTHFR polymorphisms with bladder cancer risk.Key Words: Bladder cancer, urinary neoplasms, folate, MTHFR, polymorphism, meta-analysis     

Three cases of brain hydatidosis in North Khorasan,Iran

Cystic hydatidosis is a serious public health problem in Iran. Although cysts can develop in almost all organs and the brain cysts are very rare. Here, we present 3 confirmed cases of brain hydatidosis and the patients who underwent successful surgery. Pathological examinations demonstrated the presence of cystic hydatidosis.     

The relationship between cardiological parameters and PCR in patients with coronavirus infection: A cross-sectional study

Cardiovascular injuries induced by SARS CoV-2 have been reported repeatedly in various studies. Therefore, it is necessary to understand cardiac complications at a low cost, quickly. This study aimed to determine the relationship between cardiological parameters and polymerase chain reaction (PCR) in patients with coronavirus infection. : Patients who were admitted to the emergency department due to the ongoing pandemic, all patients with similar symptoms to coronavirus disease 2019 infection were initially admitted to the respiratory emergency room and underwent subsequent evaluations to confirm or rule out SARS-COV2 infection symptoms were assessed for eligibility. Patient were categorized into 2 groups 1. Positive PCR and negative PCR groups. Binary logistic regression was performed to assess the effect of several factors on the likelihood of developing positive troponin, reduced ejection fraction (EF), and Positive brain natriuretic peptide (BNP). Among 195 patients included, 115 (58.9%) had positive PCR. Patient in the positive PCR and negative PCR were 58.04 ± 18.03 and 59.19 ± 15.38 years of age, respectively. Patients in the “positive PCR” were significantly less likely to have chronic kidney disease (6.69% vs 17.5%, P value: .022), consume calcium channel blockers (6.69% vs 18.75%, P value:0.012). At the univariable level, positive PCR was significantly associated with fewer odds for positive BNP (OR:0.46, P = .019); nevertheless, the association was no longer significant after adjusting for confounders (adjusted OR:0.56, P = .158). Unadjusted positive PCR results were not found to have a significant association with positive troponin or reduced EF. Likewise, multivariable regression revealed no association between positive PCR and positive troponin (aOR:1.28, P = .529) and reduced EF (aOR:0.65, P = .369). PCR positivity did not result in positive troponin and BNP and did not appear to decrease EF. In other words, serial troponin and BNP checks and initial echocardiography in coronavirus disease 2019 respiratory emergencies do not make significant differences in diagnostic and therapeutic management and inpatient outcomes of patients with positive or negative PCR and are not specific findings. Evidence suggests some coronavirus-induced cardiac complications will be manifested in the long term.