Interventions about physical activity and diet and their impact on adolescent and young adult cancer survivors: a Prisma systematic review.

PURPOSE: Over the past few decades, the incidence of cancer among adolescents and young adults (AYA) has been increasing. The impact of behaviors, such as physical activity (PA) and nutrition, on disease progression, prognosis, and overall health and quality of life for AYA cancer survivors is of significant importance. This systematic review aims to evaluate the effectiveness of PA and diet interventions for AYA cancer survivors and to critically evaluate existing literature, gaps, and limitations. METHODS: A search of literature was conducted in PubMed, Science Direct, Scopus, and Google Scholar following the PRISMA guidelines. Twenty-two studies were included from online databases from 2012 to 2022, 13 of which were randomized controlled trials. RESULTS: Most interventions were related to PA, with only four studies including nutrition or Diet interventions. The interventions were generally feasible and acceptable to AYA cancer survivors, and digitally based PA interventions were commonly used. PA interventions mainly comprised aerobic and resistance training and were individualized. Overall, this review found various PA and diet interventions for AYA cancer survivors that were feasible and well-accepted, but gaps in knowledge and design still exist. CONCLUSIONS: This systematic review underscores the importance of conducting more research on diet interventions for YCS. PROSPERO REGISTRATION: https://www.crd.york.ac.uk/prospero/#aboutregpage.

The genetic landscape of mitochondrial diseases in the next-generation sequencing era: a Portuguese cohort study.

Introduction: Rare disorders that are genetically and clinically heterogeneous, such as mitochondrial diseases (MDs), have a challenging diagnosis. Nuclear genes codify most proteins involved in mitochondrial biogenesis, despite all mitochondria having their own DNA. The development of next-generation sequencing (NGS) technologies has revolutionized the understanding of many genes involved in the pathogenesis of MDs. In this new genetic era, using the NGS approach, we aimed to identify the genetic etiology for a suspected MD in a cohort of 450 Portuguese patients. Methods: We examined 450 patients using a combined NGS strategy, starting with the analysis of a targeted mitochondrial panel of 213 nuclear genes, and then proceeding to analyze the whole mitochondrial DNA. Results and Discussion: In this study, we identified disease-related variants in 134 (30%) analyzed patients, 88 with nuclear DNA (nDNA) and 46 with mitochondrial DNA (mtDNA) variants, most of them being pediatric patients (66%), of which 77% were identified in nDNA and 23% in mtDNA. The molecular analysis of this cohort revealed 72 already described pathogenic and 20 novel, probably pathogenic, variants, as well as 62 variants of unknown significance. For this cohort of patients with suspected MDs, the use of a customized gene panel provided a molecular diagnosis in a timely and cost-effective manner. Patients who cannot be diagnosed after this initial approach will be further selected for whole-exome sequencing. Conclusion: As a national laboratory for the study and research of MDs, we demonstrated the power of NGS to achieve a molecular etiology, expanding the mutational spectrum and proposing accurate genetic counseling in this group of heterogeneous diseases without therapeutic options.

A high salt intake in early life affects stress-coping response in males but not in female rats.

Eating diets high in salt has been associated with alterations in the immune system and the potential development of neuropsychiatric disorders. This area of research shows promise, but there is currently a limited amount of research on this topic. The present study investigated whether a high salt diet (HSD) affects anhedonia and stress-coping response behaviors in young male and female Wistar rats. In this study, male and female Wistar rats were fed an HSD (8 % NaCl w/w) from weaning to post-natal day (PND) 64. From PND 60 to 64, the rats underwent a spontaneous locomotor activity test (SLA), sucrose splash test (SST), sucrose preference test (SPT), and forced swim test (FST), followed by euthanasia at PND 65. Male and female rats consuming the HSD exhibited an increase in water intake compared to the corresponding control diet (CD) groups. Male rats had lower body weight despite having similar food intakes compared to the CD group. Male rats displayed an active stress-coping behavior in the FST, characterized by increased mobility. Additionally, HSD-fed males exhibited a greater preference for sucrose solution in the SPT. However, no effect of diet and sex were detected in the SST and the SLA, and hypothalamic levels of leptin and ghrelin receptors. On the other hand, female rats were less susceptible to the experimental conditions applied in this protocol than males.

Antiviral and Antibacterial Cold Spray Coating Application on Rubber Substrate, Disruption in Disease Transmission Chain.

The objective of this study was to prepare a copper-coated rubber surface using cold spray technology with improved virucidal and antimicrobial properties to fight against highly transmissible viruses and bacteria. A successful cold spray coating was produced using irregular-shaped pure Cu powder on an escalator handrail rubber. The powder particles and the deposited coatings (single and double pass) were characterized in terms of particle morphology and size distribution, coating surface and coat/substrate cross-section properties. The bonding between powder and rubber surfaces was purely mechanical interlocking. The Cu powder penetration depth within the rubber surface increases with a number of depositions pass. The virucidal properties of the coated surface were tested utilizing surrogates for SARS-CoV-2: HCoV-229E, a seasonal human coronavirus, and baculovirus, a high-titer enveloped insect cell virus. A double-pass coated surface showed significant baculovirus inactivation relative to a bare rubber control surface after 2-h (approximately 1.7-log) and 4-h (approximately 6.2-log), while a 4-h exposure reduced HCoV-229E titer to below the limit of detection. A similar microbial test was performed using E. coli, showing a 4-log microbial reduction after 2-h exposure relative to the bare rubber. These promising results open a new application for cold spray in the health sector. Supplementary Information: The online version contains supplementary material available at 10.1007/s11666-023-01553-x.

Robotic Intracorporeal Rectus Aponeuroplasty: Early Experience of a New Surgical Technique for Ventral Hernia Repair.

Introduction: The laparoscopic intracorporeal rectus aponeuroplasty (LIRA) was developed as an alternative for minimally invasive ventral hernia repair. This technique allows the closure of the defect and restoration of the midline without tension by plication of both aponeurosis of the abdominal rectus muscles combined with a minimally invasive intraperitoneal underlay mesh repair. The objective of this study is to report our early experience with the Robotic-LIRA (R-LIRA) technique and its safety and short-term efficacy. Methods: We performed a retrospective analysis of patients undergoing R-LIRA repair for ventral hernias from March 2019 to April 2022. Results: Eight patients underwent R-LIRA from March 2019 to April 2022. Median age was 47 years (interquartile range [IQR] 34.5-62.8). Median body mass index was 34.2 kg/m2 (IQR 29.9-35.2). Four patients (50%) had a primary ventral hernia being one M2, two M3, and one M2/M3. There were three incisional hernias, being one recurrent, 6 patients (75%) had associated diastasis of the rectus muscle and 1 patient presented pure diastasis. The median hernia width was 4 cm (IQR 2-6), and the median defect area was 16 cm2 (IQR 4-42). The median mesh area was 290 cm2 (IQR 211.2-300). In all cases, a barbed suture was also used for mesh fixation, and tackers were added in 4 cases. The median operative time was 172 minutes (IQR 139.8-293.3). The median length of stay was 0.5 days (IQR 0-1.8), and the median follow-up was 20 days (IQR 16-46). Conclusion: The R-LIRA has been shown to be safe and feasible for ventral and incisional hernia repairs with or without Diastasis of the Rectus Abdominis Muscle in the short term.

Social media as a tool for surgical education: a qualitative systematic review.

BACKGROUND: Social media use has exploded, attaining a significant influence within medicine. Previous studies have denoted the use of social media in various surgical specialties as a means to exchange professional ideas and improve the conference experience and at the same time, some have assessed its feasibility as a method of education. This systematic review aims to characterize the use of social media as a tool for general surgery education. METHODS: A systematic review of several databases from each database inception was conducted following the PRISMA guidelines. The JBI's critical appraisal tools were used to assess quality of the studies. RESULTS: A total of 861 articles were identified of which 222 were duplicates removed. The titles and abstracts from the remaining 639 abstracts were screened and 589 were excluded. The remaining 51 full articles were analyzed for eligibility, of which 24 met inclusion criteria and were included in the systematic review. These studies covered the general surgery specialty, of which 11 (n = 46%) focused on the laparoscopic surgical approach, 1 (n = 4%) on robotic-assisted surgical procedures, 1 (n = 4%) on both surgical approaches previously mentioned and 11 (n = 46%) on the general surgery specialty regardless of the surgical approach or technique. CONCLUSIONS: Advantages that SM offers should be considered, and content creators and institutions should help collectively to make sure that the content being published is evidence and guideline-based so its use it is taken to the maximum benefit.

Phase changes of tris(glycinato)chromium(III) monohydrate crystal systematically studied by thermal analyses, XRPD, FTIR, and Raman combined with ab initio calculations.

Tris(glycinato)chromium(III) monohydrate [Cr(C2H4NO2)3·H2O] crystals were grown through the slow solvent evaporation method. The crystals were studied by Fourier transform infrared (FTIR) and Raman spectroscopy at room temperature. The assignments of vibration modes were performed using the Density Functional Theory (DFT). Thermal analyses (TGA, DTA, and DSC), X-ray diffraction (XRD), and Raman were used to study the phase changes on the crystals under high- and low-temperature conditions. Temperature-dependent XRPD measurements were carried out in the interval of 473-12 K. Several changes were observed in the patterns, like the appearance of new peaks and the disappearance of peaks occurring within 373-393 K due to water loss. In addition, the Raman measurements were performed in the 423-10 K interval. Several changes on the inter and intramolecular vibration bands during the cooling, such as decreasing bands' intensities, the appearance of vibration modes, and discontinuities on the modes' behavior, were observed. These spectral modifications occurred at about 370 K and within 120-220 K, thus, confirming that the crystals undergo two phase changes, one being structural and the other one conformational, respectively, at high- temperature and low-temperature conditions. Finally, thermal investigations corroborated the structural and vibrational results under high temperatures.

Portuguese adaptation of the S3-non-invasive ventilation (S3-NIV) questionnaire for home mechanically ventilated patients.

Short, valid and easy to use tools are needed to monitor non-invasive ventilation in clinical practice and for organization of home mechanical ventilation services. The aim of this study was to develop a professional translation and cultural adaptation of the Portuguese S3 non-invasive ventilation questionnaire. 234 stable patients (128 male patients, 53.8%) with a mean age of 69.3 years under long-term home non-invasive ventilation were recruited from a single-center outpatient clinic. The most frequent diagnostic groups were obesity hypoventilation syndrome, chronic obstructive pulmonary disease and restrictive chest wall disorders. The Portuguese version of the questionnaire was obtained using translation back-translation process with two professional translators. Internal consistency for the total score was good (Cronbach's α coefficient of 0.76) as well as for the "respiratory symptoms" and the "sleep and side effects" domains (Cronbach's α coefficient=0.68 and Cronbach's α coefficient=0.72, respectively). An exploratory factor analysis was performed leading to an explained variance of 54.6%, and resulted in 3 components. The Portuguese version of the S3-NIV questionnaire is a simple and valid tool for the routine clinical assessment of patients receiving home NIV.

Is Minimally Invasive Repair the New Gold Standard for Primary Unilateral Inguinal Hernias? Results of an International Survey of Surgeons.

Background: The Lichtenstein repair has long been heralded as the gold standard for unilateral primary inguinal hernias. However, minimally invasive surgery (MIS) repairs have gained popularity over the past decades given its advantages in recurrent, bilateral, and now even in primary inguinal hernias. We aim to further explore the perception of different techniques among surgeons internationally. Methods: A questionnaire was posted in three closed groups for surgeons and residents on Facebook® and surgical groups on WhatsApp®. It was also e-mailed to members of the following surgical societies: Mexican Society of Surgery, Brazilian Hernia Society, Asia Pacific Hernia Society, and European Hernia Society. Descriptive and basic comparative statistical analyses were performed. Results: In total, 874 surgeons answered the survey: 759 (86.9%) were male and 418 (47.8%) were from North America, 735 (84.1%) had completed training and 605 (69.2%) considered themselves hernia specialists. If safety profiles of inguinal herniorrhaphy were equal, 533 (61%) would choose MIS. Laparoscopic transabdominal preperitoneal ranked first among preferred techniques if the cost of all techniques was the same. Safety of the procedure followed by experience of the surgeon is the most influential factors. Lastly, hernia specialists were more likely to choose an MIS technique (P < .0001). Conclusion: When an international sample of 874 attending and trainee surgeons were surveyed about what technique they would prefer to repair their own uncomplicated unilateral inguinal hernia, most chose MIS. Safety of the procedure and the surgeon's experience were the most important factors in choosing a surgical technique.

A role of Na+, K+ -ATPase in spatial memory deficits and inflammatory/oxidative stress after recurrent concussion in adolescent rats.

Sports-related concussions are particularly common during adolescence, and there is insufficient knowledge about how recurrent concussions in this phase of life alter the metabolism of essential structures for memory in adulthood. In this sense, our experimental data revealed that seven recurrent concussions (RC) in 35-day-old rats decreased short-term and long-term memory in the object recognition test (ORT) 30 days after injury. The RC protocol did not alter motor and anxious behavior and the immunoreactivity of brain-derived neurotrophic factor (BDNF) in the cerebral cortex. Recurrent concussions induced the inflammatory/oxidative stress characterized here by increased glial fibrillary acidic protein (GFAP), interleukin 1ß (IL 1ß), 4-hydroxynonenal (4 HNE), protein carbonyl immunoreactivity, and 2',7'-dichlorofluorescein diacetate oxidation (DCFH) levels and lower total antioxidant capacity (TAC). Inhibited Na+,K+-ATPase activity (specifically isoform α2/3) followed by Km (Michaelis-Menten constant) for increased ATP levels and decreased immunodetection of alpha subunit of this enzyme, suggesting that cognitive impairment after RC is caused by the inability of surviving neurons to maintain ionic gradients in selected targets to inflammatory/oxidative damage, such as Na,K-ATPase activity.

Sticholysin II shows similar immunostimulatory properties to LLO stimulating dendritic cells and MHC-I restricted T cell responses of heterologous antigen.

Induction of CD8+ T cell responses against tumor cells and intracellular pathogens is an important goal of modern vaccinology. One approach of translational interest is the use of liposomes encapsulating pore-forming proteins (PFPs), such as Listeriolysin O (LLO), which has shown efficacy at priming strong and sustained CD8+ T cell responses. Recently, we have demonstrated that Sticholysin II (StII), a PFP from the sea anemone Stichodactyla helianthus, co-encapsulated into liposomes with ovalbumin (OVA) was able to stimulate, antigen presenting cells, antigen-specific CD8+ T cells and anti-tumor activity in mice. In the present study, we aimed to compare StII and LLO in terms of their abilities to stimulate dendritic cells and to induce major histocompatibility complex (MHC) class I restricted T cell responses against OVA. Interestingly, StII exhibited similar abilities to LLO in vitro of inducing dendritic cells maturation, as measured by increased expression of CD40, CD80, CD86 and MHC-class II molecules, and of stimulating OVA cross-presentation to a CD8+ T cell line. Remarkably, using an ex vivo Enzyme-Linked ImmunoSpot Assay (ELISPOT) to monitor gamma interferon (INF-γ) producing effector memory CD8+ T cells, liposomal formulations containing either StII or LLO induced comparable frequencies of OVA-specific INF-γ producing CD8+ T cells in mice that were sustained in time. However, StII-containing liposomes stimulated antigen-specific memory CD8+ T cells with a higher potential to secrete IFN-γ than liposomes encapsulating LLO. This StII immunostimulatory property further supports its use for the rational design of T cell vaccines against cancers and intracellular pathogens. In summary, this study indicates that StII has immunostimulatory properties similar to LLO, despite being evolutionarily distant PFPs.

Endoscopic onlay repair for ventral hernia and rectus abdominis diastasis repair: Why so many different names for the same procedure? A qualitative systematic review.

BACKGROUND: A subcutaneous endoscopic onlay repair for ventral hernia with an anterior plication of diastasis recti (DR) has been published under different names in different countries. The aim of this systematic review is to assess the safety and feasibility of different named techniques with the same surgical concept. METHODS: The PRISMA guidelines were followed during all stages of this systematic review. The MINORS score system was used to perform qualitative assessment of all studies included in this review. Recommendations were then summarized for the following pre-defined key items: protocol, research question, search strategy, study eligibility, data extraction, study designs, risk of bias, publication bias, heterogeneity, and statistical analysis. RESULTS: The systematic literature search found 2548 articles, 317 of which were duplicates and excluded from analysis. The titles and abstracts from the remaining 2231 articles were assessed. After careful evaluation, 2125 articles were determined to be unrelated to our study and subsequently excluded. The full text of the remaining 106 articles was thoroughly assessed. Case reports, editorials, letters to the editor, and general reviews were then excluded. A total of 13 articles were ultimately included for this review, describing a similar subcutaneous endoscopic approach for repair of concomitant ventral hernias and rectus diastasis defined under nine different named techniques on 716 patients. The number of patients in those studies varied from 10 to 201. The mean operative time varied from 68.5 to 195 min. The most common complication was seroma, followed by pain requiring intervention, hematoma, and surgical site infection. CONCLUSIONS: There are a few technique variations described in different studies, but with no significant differences in outcomes. We, therefore, propose to unify these procedures under one term, ENDoscopic Onlay Repair (ENDOR). This technique has shown to be effective and safe, with seroma being the most common complication.

A prospective, multicentre, cohort study to assess the incidence of dengue illness in households from selected communities in Brazil (2014-2018).

OBJECTIVES: To estimate the incidence of dengue infection across geographically distinct areas of Brazil. METHODS: This prospective, household-based, cohort study enrolled participants in five areas and followed them up for up to 4 years (2014-2018). Dengue seroprevalence was assessed at each scheduled visit. Suspected dengue cases were identified through enhanced passive and active surveillance. Acute symptomatic dengue infection was confirmed through reverse-transcriptase quantitative polymerase chain reaction in combination with an antigenic assay (non-structural protein 1) and serology. RESULTS: Among 3300 participants enrolled, baseline seroprevalence was 76.2%, although only 23.3% of participants reported a history of dengue. Of 1284 suspected symptomatic dengue cases detected, 50 (3.9%) were laboratory-confirmed. Based on 8166.5 person-years (PY) of follow-up, the incidence of laboratory-confirmed symptomatic infection (primary endpoint) was 6.1 per 1000 PY (95% confidence interval [CI]: 4.5, 8.1). Incidence varied substantially in different years (1.8-7.4 per 1000 PY). The incidence of inapparent primary dengue infection was substantially higher: 41.7 per 1000 PY (95% CI: 31.1, 54.6). CONCLUSIONS: Our findings, highlighting that the incidence of dengue infection is underestimated in Brazil, will inform the design and implementation of future dengue vaccine trials. CLINICAL TRIAL REGISTRATION: NCT01751139.

Investigative strategies for fish bone foreign bodies during the coronavirus disease 2019 pandemic: an analysis of ENT UK guidelines.

BACKGROUND: By nature of their specialty, otolaryngologists are disproportionately exposed to coronavirus disease 2019 through aerosol-generating procedures and close proximity to the oropharynx during examination. METHODS: Our single-centre, retrospective study analysed the pertinence of guidelines produced by ENT UK to improve the investigation and management of suspected upper aerodigestive fish bone foreign bodies during the coronavirus disease 2019 pandemic. RESULTS: Our results demonstrated 43.3 per cent (n = 13) low-risk cases and 56.7 per cent (n = 17) moderate-risk cases. Nine fish bones (two low risk, seven moderate risk) were found; none of these were confirmed with X-ray and three (moderate risk) required nasoendoscopy for diagnosis. One patient required rigid pharyngoscopy. CONCLUSION: This study confirms that soft tissue neck X-ray and flexible nasoendoscopy are unnecessary in low-risk cases; however, early nasoendoscopy in higher suspicion cases is appropriate. Recommendations are made about the long-term sustainability of these guidelines, and additional measures are encouraged that relate to repeat attendances and varying prevalence of coronavirus disease 2019 in the hospital catchment area.

Diphenyl diselenide and cidofovir present anti-viral activity against Bovine Alphaherpesvirus 2 in vitro and in a sheep model.

Bovine alphaherpesvirus 2 (BoHV-2) - the agent of bovine herpetic mamillitis (BHM) - is related to Human alphaherpesviruses 1 and 2 (HHV-1, HHV-2) and, as such, has been proposed as a model for vaccine and drug testing. We herein investigated the anti-viral activity in vitro against BoHV-2 of three anti-herpetic drugs: Cidofovir (CDV), Fanciclovir (FAM), Foscarnet (PFA), and diphenyl disselenide (Ph2Se2), a compound that has showed activity against HHV-2. Plaque reduction assays (PRA) revealed a significant reduction in viral plaques (p < 0.05) in cells treated with Ph2Se2 (79.7% reduction) or CDV (62.8%). FAM treatment resulted in a slight decrease in plaque number (22.9%, p < 0.05); PFA showed no activity. The effects of Ph2Se2 and CDV, alone or in combination, were investigated in ewes inoculated with BoHV-2 transdermally and submitted to daily topic treatment. Virus inoculated ewes developed lesions progressing through the stages of hyperemia, large papules or depressed dark areas, followed by scab formation. Treatment with Ph2Se2 resulted in reduction in clinical score from day 10 pi onwards (P < 0.05), shortening of clinical course and reduction in duration of virus shedding (P < 0.05) compared to untreated controls. Combined treatment (Ph2Se2 + CDV) and CDV alone, also led to clinical improvement (P < 0.05), yet less pronounced and delayed. These results are promising towards the use of Ph2Se2, alone or in combination with anti-herpetic drugs, in the treatment of udder and teat lesions produced by BoHV-2 in dairy cows.

Circulating microRNAs associated with liver fibrosis in chronic hepatitis C patients.

A major challenge in hepatitis C research is the detection of early potential for progressive liver disease. MicroRNAs (miRNAs) are small RNAs that regulate gene expression and can be biomarkers of pathological processes. In this study, we compared circulating miRNAs identified in hepatitis C virus (HCV)-infected patients presenting two extremes of liver disease: mild/moderate fibrosis and cirrhosis. The patients in the cirrhosis group subsequently developed hepatocellular carcinoma (HCC). We identified 163 mature miRNAs in the mild/moderate fibrosis group and 171 in the cirrhosis group, with 144 in common to both groups. Differential expression analysis revealed 5 upregulated miRNAs and 2 downregulated miRNAs in the cirrhosis group relative to the mild/moderate fibrosis group. Functional analyses of regulatory networks (target gene and miRNA) identified gene categories involved in cell cycle biological processes and metabolic pathways related to cell cycle, cancer, and apoptosis. These results suggest that the differentially expressed circulating miRNAs observed in this work (miR-215-5p, miR-483-5p, miR-193b-3p, miR-34a-5p, miR-885-5p, miR-26b-5p and miR -197-3p) may be candidates for biomarkers in the prognosis of liver disease.

Which Cholecystectomy Technique Would Surgeons Prefer on Themselves?

BACKGROUND: As the minimally invasive surgery revolution approaches 30 years, many techniques are now available for cholecystectomy: open, conventional laparoscopy, ini-laparoscopy, single incision, robotic, and natural orifice. Although much has been published about patient preferences regarding these techniques, less is known about surgeon perceptions and preferences. The aim of this study was to survey attending and trainee surgeons about which cholecystectomy technique they would prefer for themselves and what factors determine their decision. METHODS: Attending fellow and resident surgeons globally completed a Google Forms online questionnaire that was posted in 3 closed groups for surgeons on Facebook and WhatsApp. RESULTS: The online questionnaire was completed by 600 surgeons (453 attending surgeons and 147 residents/fellows). Most respondents were male individuals (87.6% of attending surgeons, 78.2% of trainee surgeons). The most common age range of respondents was 31 to 40 years. Surgeon response was global, with especially good representation from North American, Asian, and European physicians. When conventional laparoscopy, mini-laparoscopy, and robotic surgery were the options offered for cholecystectomy, 58.5% of trainees and 45.7% of surgeons chose conventional laparoscopy. When asked if they would consider a single-incision or natural orifice transluminal endoscopic surgery approach, 91.5% answered no. When asked which technique they would prefer if hypothetically all techniques were equally safe, about three-fourths chose either conventional laparoscopy (46%) or mini-laparoscopy (27%). When asked to rank which factors they considered most important in choosing a surgical technique, surgeon experience (52%) and safety of the procedure (45%) were the 2 most important factors. CONCLUSIONS: When an international sample of 600 attending and trainee surgeons were asked about undergoing a cholecystectomy on themselves, most chose either conventional laparoscopy or mini-laparoscopy as their preferred access technique. Single-incision and natural orifice transluminal endoscopic surgery approaches were unpopular. Surgeons ranked the experience of the operating surgeon and safety of the procedure as the most important factors guiding their decision.

Short communication: Heat stress does not affect induced luteolysis in Holstein cows.

Heat stress (HS) has deleterious effects on bovine reproduction, including prolongation of the luteal phase in Holstein cows, perhaps due to compromised luteolysis. The objective was to characterize effects of HS on luteolytic responses of nonlactating Holstein cows given 25 or 12.5 mg of PGF2α on d 7 of the estrous cycle. Cows were randomly distributed into 2 environments: thermoneutral (n = 12; 25°C) or HS (n = 12; 36°C). In each environment, cows were treated with 2 mL of saline, 25 or 12.5 mg of PGF2α (n = 4 cows per group). The HS environment induced a significant increase in rectal temperature and respiratory rate compared with the thermoneutral environment. Heat stress did not have significant effects on luteolytic responses or circulating progesterone concentrations. Rapid and complete luteolysis occurred in all cows given 25 mg of PGF2α and in 4 of 8 cows given 12.5 mg; the other 4 cows given 12.5 mg had partial luteolysis, with circulating progesterone concentrations initially suppressed, but subsequently rebounding. Therefore, we conclude that HS does not change corpus luteum sensitivity to PGF2α.