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In patients with cancer, spontaneous renal bleeding can stem from a range of underlying factors, necessitating precise diagnostic tools for effective patient management. Benign and malignant renal tumors are among the primary culprits, with angiomyolipomas and renal cell carcinomas being the most common among them. Vascular anomalies, infections, ureteral obstructions, and coagulation disorders can also contribute to renal-related bleeding. Cross-sectional imaging techniques, particularly ultrasound and computed tomography (CT), play pivotal roles in the initial detection of renal bleeding. Magnetic resonance imaging and CT are preferred for follow-up evaluations and aid in detecting underlying enhancing masses. IV contrast-enhanced ultrasound can provide additional information for active bleeding detection and differentiation. This review article explores specific disorders associated with or resembling spontaneous acute renal bleeding in patients with renal tumors; it focuses on the significance of advanced imaging techniques in accurately identifying and characterizing renal bleeding in these individuals. It also provides insights into the clinical presentations, imaging findings, and treatment options for various causes of renal bleeding, aiming to enhance the understanding, diagnosis, and management of the issue.
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BACKGROUND: Adequate oxygen saturation (SpO2 ) is crucial for managing sickle cell disease (SCD). Children with SCD are at increased risk for occult hypoxemia; therefore, understanding SpO2 threshold practices would help identify barriers to oxygen optimization in a population sensitive to oxyhemoglobin imbalances. We investigated SpO2 cutoff levels used in clinical algorithms for management of acute SCD events at children's hospitals across the United States, and determined their consistency with recommended national guidelines (SpO2 > 95%). METHODS: Clinical pathways and algorithms used for the management of vaso-occlusive crisis (VOC) and acute chest syndrome (ACS) in SCD were obtained and reviewed from large children's hospitals in the United States. RESULTS: Responses were obtained from 94% (140/149) of eligible children's hospitals. Of these, 63 (45%) had available clinical algorithms to manage VOC and ACS. SpO2 cutoff was provided in 71.4% (45/63) of clinical algorithms. Substantial variation in SpO2 cutoff levels was noted, ranging from ≥90% to more than 95%. Only seven hospitals (5% of total hospitals and 15.6% of hospitals with clinical algorithms available) specified oxygen cutoffs that were consistent with national guidelines. Hospitals geographically located in the South (46.8%; n = 29/62) and Midwest (54.8%; n = 17/31) were more likely to have VOC and ACS clinical algorithms, compared to the Northeast (26.5%; n = 9/34) and West (36.4%; n = 8/22). CONCLUSION: There is inconsistency in the use of clinical algorithms and oxygen thresholds for VOC and ACS across US children's hospitals. Children with SCD could be at risk for insufficient oxygen therapy during adverse acute events.
Subject(s)
Acute Chest Syndrome , Anemia, Sickle Cell , Volatile Organic Compounds , Child , Humans , United States , Oxygen Saturation , Anemia, Sickle Cell/therapy , Anemia, Sickle Cell/complications , Acute Chest Syndrome/etiology , Acute Chest Syndrome/therapy , Oxygen , HospitalsABSTRACT
OBJECTIVE: This study evaluated embryological and clinical outcomes in couples with severe male factor infertility versus those with normozoospermia undergoing ICSI and in vitro fertilisation. METHODS: This multicentre, retrospective cohort study included all couples who had undergone autologous ICSI cycles at My Duc Hospital and My Duc Phu Nhuan Hospital in Vietnam between January 2018 and January 2021 (female age < 35 years and males with severe male factor or normozoospermia based on the World Health Organization 2010 criteria). The primary outcome was the cumulative live birth rate after the first ICSI cycle. RESULTS: A total of 1296 couples were included, including 648 with severe male factor infertility and 648 with normozoospermia. The number of two pronuclei zygotes, embryos, and frozen embryos was significantly lower in couples with severe male factor infertility compared with normozoospermia (p < 0.05). In contrast, there were no significant differences between the two groups with respect to cumulative pregnancy outcomes, including the live birth rate, and secondary outcomes including clinical pregnancy rate, ongoing pregnancy rate, and miscarriage rate. CONCLUSION: Severe male factor infertility appeared to have an impact on the fertilisation and early developmental potential of embryos, but sperm quality did not affect cumulative clinical fertility outcomes.
Subject(s)
Infertility, Male , Infertility , Pregnancy , Male , Humans , Female , Adult , Sperm Injections, Intracytoplasmic/methods , Retrospective Studies , Semen , Infertility, Male/therapy , Fertilization in Vitro/methods , Pregnancy Rate , Birth Rate , Live BirthABSTRACT
BACKGROUND: Asthma in preschool children is poorly defined, proving to be a challenge for early detection. The Breathmobile Case Identification Survey (BCIS) has been shown to be a feasible screening tool in older SCD children and could be effective in younger children. We attempted to validate the BCIS as an asthma screening tool in preschool children with SCD. METHODS: This is a prospective, single-center study of 50 children aged 2-5 years with SCD. BCIS was administered to all patients and a pulmonologist blinded to the results evaluated patients for asthma. Demographic, clinical, and laboratory data were obtained to assess risk factors for asthma and acute chest syndrome in this population. RESULTS: Asthma prevalence (n = 3/50; 6%) was lower than atopic dermatitis (20%) and allergic rhinitis (32%). Sensitivity (100%), specificity (85%), positive predictive value (30%), and negative predictive value (100%) of the BCIS were high. Clinical demographics, atopic dermatitis, allergic rhinitis, asthma, viral respiratory infection, hematology parameters, sickle hemoglobin subtype, tobacco smoke exposure, and hydroxyurea were not different between patients with or without history of ACS, although eosinophil was significantly lower in the ACS group (p = 0.0093). All those with asthma had ACS, known viral respiratory infection resulting in hospitalization (3 RSV and 1 influenza), and HbSS (homozygous Hemoglobin SS) subtype. CONCLUSION: The BCIS is an effective asthma screening tool in preschool children with SCD. Asthma prevalence in young children with SCD is low. Previously known ACS risk factors were not seen, possibly from the beneficial effects of early life initiation of hydroxyurea.
Subject(s)
Anemia, Sickle Cell , Asthma , Dermatitis, Atopic , Rhinitis, Allergic , Humans , Child, Preschool , Aged , Asthma/diagnosis , Asthma/epidemiology , Asthma/etiology , Hydroxyurea , Prospective Studies , Anemia, Sickle Cell/complications , Anemia, Sickle Cell/diagnosis , Anemia, Sickle Cell/epidemiology , Rhinitis, Allergic/complicationsABSTRACT
ABSTRACT: A 58-year-old man with metastatic prostate cancer was treated with prostatectomy, radiation therapy to bone metastasis, and androgen deprivation therapy plus abiraterone. He had posttreatment nadir PSA of 0.1 ng/mL. A follow-up 18 F-fluciclovine PET performed with PSA of 0.3 ng/mL showed a focal tracer-avid lesion in the left prostatectomy bed. This lesion was negative on 18 F-DCFPyL PET/CT, but with typical MRI features for disease recurrence. Minimal urinary activity of fluciclovine helped detection of local disease recurrence in the prostatectomy bed.
Subject(s)
Prostate-Specific Antigen , Prostatic Neoplasms , Male , Humans , Middle Aged , Positron Emission Tomography Computed Tomography , Prostatic Neoplasms/diagnostic imaging , Prostatic Neoplasms/surgery , Prostatic Neoplasms/pathology , Neoplasm Recurrence, Local/diagnostic imaging , Androgen Antagonists , ProstatectomyABSTRACT
BACKGROUND: Screening for pulmonary hypertension (PHT) is recommended in children with sickle cell disease (SCD). However, best approaches are poorly described. We examined the utility of PHT symptoms, echocardiogram (ECHO), N-terminal-pro hormone brain natriuretic peptide (NT-proBNP), and BNP to screen for PHT in the SCD pediatric population. METHODS: Children (8-18 years old) with SCD-HbSS and HbSthal° were prospectively included and underwent PHT screening. The screening consisted of a comprehensive PHT symptoms evaluation, ECHO measurement, and NT-proBNP and BNP levels. RESULTS: A total of 73 patients were included (mean age 12 ± 5.7 years; >80% on hydroxyurea), of which 37% had a symptom consistent with PHT, including exertional dyspnea (26.5%), fatigue (17.6%), palpitation (14.7%), and chest pain (10.3%). ECHO was obtained in 53 (72.6%) patients, with only ECHO of 48 patients included in the final analysis. Elevated ECHO peak tricuspid regurgitant jet velocity (TRV) >2.5 m/s or indirect findings to suggest PHT were seen in only two of 48 (4.2%). No significant differences were seen between those with and without PHT symptoms when compared for NT-proBNP, BNP, hemoglobin, pulmonary function testing, fractional exhaled nitric oxide, asthma, oxygen saturation, and sleep apnea. CONCLUSION: PHT symptoms are not consistent with ECHO, NT-proBNP nor BNP findings in children with SCD. PHT prevalence based on TRV was low in children on hydroxyurea, therefore screening may not be warranted for this group.
Subject(s)
Anemia, Sickle Cell , Hypertension, Pulmonary , Child , Humans , Adolescent , Hypertension, Pulmonary/diagnosis , Hypertension, Pulmonary/etiology , Hypertension, Pulmonary/epidemiology , Hydroxyurea/therapeutic use , Anemia, Sickle Cell/epidemiology , Peptide Fragments , Respiratory Function Tests , PrevalenceABSTRACT
There is increasing evidence that sex hormones may impact the development of obstructive lung disease (OLD). Therefore, we studied the effect of bilateral oophorectomy (oophorectomy) on the development of OLD. Women were identified from the Mayo Clinic Cohort Study of Oophorectomy and Aging-2. Data were collected using the Rochester Epidemiology Project records-linkage system. A total of 1653 women who underwent oophorectomy and 1653 referent women of similar age were assessed for OLD using diagnostic codes and medical record abstraction. Women who underwent oophorectomy had an overall higher risk of all OLD, all chronic obstructive pulmonary disease (COPD), emphysema, and chronic bronchitis but not of all asthma, confirmed asthma, or confirmed COPD. The association with all OLD was stronger in women who were age ≤45 years at oophorectomy, never smokers, non-obese, and in women with benign indications; however, the interactions were not statistically significant. There was an increased risk of all asthma in women age ≤45 years at oophorectomy who took estrogen therapy. Never smokers of all ages had a stronger association of oophorectomy with all asthma and all COPD, whereas smokers had a stronger association of oophorectomy with emphysema and chronic bronchitis. Non-obese women of all ages had a stronger association of oophorectomy with all COPD, emphysema, and chronic bronchitis. The results of this study combined with the increased risk of several chronic diseases reported in previous studies suggest that oophorectomy in premenopausal women should be avoided unless there is clear evidence of a high genetic risk of ovarian cancer.
Subject(s)
Asthma , Bronchitis, Chronic , Emphysema , Pulmonary Disease, Chronic Obstructive , Female , Humans , Middle Aged , Cohort Studies , Bronchitis, Chronic/etiology , Ovariectomy/adverse effects , Pulmonary Disease, Chronic Obstructive/diagnosis , Risk Factors , Asthma/epidemiology , Asthma/etiology , Emphysema/etiologyABSTRACT
BACKGROUND Columnar metaplasia of the lower esophagus includes both gastric and intestinal metaplasia. Children with severe neurologic impairment and congenital esophageal atresia often have gastroesophageal reflux disease, which can lead to Barrett's esophagus, a form of lower esophageal columnar metaplasia and precursor to esophageal adenocarcinoma, with some, but not all, guidelines specifically requiring the presence of intestinal metaplasia for diagnosis. This case series illustrates how iron deficiency anemia may be the primary symptom of esophageal columnar metaplasia in such children and how upper endoscopy is essential in their initial and ongoing evaluation. CASE REPORT We review 5 cases of columnar metaplasia of the lower esophagus in children, 3 with severe neurologic impairment and 2 with esophageal atresia. Each child presented with marked iron deficiency anemia and minimal-to-no gastrointestinal symptoms. CONCLUSIONS We conclude that columnar metaplasia of the esophagus may present with iron deficiency anemia in children with neurologic impairment or congenital esophageal atresia, even if without overt gastrointestinal symptoms. Accordingly, we propose that early endoscopic evaluation should be considered in this specific patient population. Based on our literature review, we also emphasize the need for guidelines on the endoscopic surveillance of such children with any type of columnar metaplasia of the lower esophagus, given the associated risk of malignant transformation.
Subject(s)
Anemia , Barrett Esophagus , Esophageal Atresia , Esophageal Neoplasms , Iron Deficiencies , Nervous System Diseases , Barrett Esophagus/diagnosis , Barrett Esophagus/epidemiology , Barrett Esophagus/pathology , Child , Esophageal Atresia/complications , Esophageal Atresia/diagnosis , Esophageal Neoplasms/complications , Esophageal Neoplasms/diagnosis , Humans , Metaplasia/complications , Nervous System Diseases/complicationsABSTRACT
PURPOSE: To directly compare the performance of pelvic mpMRI versus recently approved and increasingly used PSMA-based 18F-DCFPyL PET/CT in intermediate-high risk and biochemical recurrent prostate cancer patient cohort while exploring their potential differing applications in specific clinical scenarios. METHODS: A retrospective analysis was performed on patients who had 18F-DCFPyL PET/CT and pelvic mpMRI done from September 2021 to January 2022 at a single institution. The inclusion criteria were paired exams within a 3-month interval. Exclusion criteria were intervening treatment between exams, a change in PSA by more than 50% and absolute difference more than 1 ng/mL, or concurrent history of other malignancy. Abnormal lesions on these 2 imaging exams were reviewed with the identification of concordant and discordant imaging findings. The findings were verified by pathology or other imaging techniques within minimal 5-month clinical follow-up. RESULTS: A total of 57 patients with 57 paired exams were included. The rate of concordant exams was 43/57 or 75.4%. Lesion-based analyses of sensitivity, specificity, PPV and NPV for mpMRI and 18F-DCFPyL PET/CT in the prostate bed were 96%, 94%, 98%, 89% and 96%, 100%, 100%, 90% respectively. For pelvic lymph node metastases, the sensitivity, specificity, PPV and NPV for mpMRI and 18F-DCFPyL PET/CT were 52%, 100%, 100%, 55% and 100%, 100%, 100%, 100% respectively. For bone metastases, the sensitivity, specificity, PPV and NPV for mpMRI and 18F-DCFPyL PET/CT were 86%, 73%, 50%, 94% and 100%, 98%, 95%, 100% respectively. Exact McNemar's test for paired data suggested that in diagnostic performance between 18F-DCFPyL PET/CT and mpMRI was not statistically significant in prostate bed (p-value = 1.00), but significantly in pelvic lymph nodes (p-value < 0.0001) and bone lesions (p-value = 0.0026). CONCLUSION: Our study demonstrated that PSMA-based 18F-DCFPyL PET/CT and pelvic mpMRI have a good concordance rate in the detection of primary or recurrence prostate disease and can have complementary roles in the clinical assessment of the prostate bed lesions. However, there are key differences in their performance, with the notably superior performance of PSMA-based 18F-DCFPyL PET/CT in the detection of small metastatic nodal disease and bone metastases.
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BACKGROUND: Intrathoracic involvement with lymphomas is common and manifests lymphadenopathy as well as a wide spectrum of imaging abnormalities in the lungs. Intravascular large B-cell lymphoma (IVLBCL) is a rare extranodal subtype of large B-cell lymphoma that typically involves small blood vessels and is difficult to detect. METHODS: Using a computer-assisted search, we identified patients with histopathologically proven IVLBCL in the lungs at Mayo Clinic from 2001 through 2018. Medical records, imaging studies, and pathologic specimens were reviewed. RESULTS: A total of 5 patients were diagnosed with a median age at diagnosis of 68 years (range, 44-73); 4 patients were male. The diagnosis of IVLBCL was achieved by surgical lung biopsy in 3 and at autopsy in 2. At presentation, all 5 patients had dyspnea and systemic symptoms including fever, fatigue, night sweats, and/or weight loss. Chest radiography and computed tomography (CT) failed to demonstrate the diffuse infiltrative process; positron emission tomography (PET) scan performed in 2 patients did not show fluorodeoxyglucose (FDG) uptake in the lungs. Pulmonary function tests obtained in 3 patients showed reduced diffusing capacity in all; transthoracic echocardiography yielded evidence of pulmonary hypertension in 2 of 4 patients. All 3 patients diagnosed antemortem underwent chemotherapy with 1 patient remaining alive at 4 years after diagnosis. CONCLUSIONS: IVLBCL is difficult to diagnose given variable and nonspecific clinical presentations. Microvascular disease processes such as IVLBCL should be kept in mind in cases of undiagnosed progressive dyspnea accompanied by systemic symptoms even when imaging studies are unrevealing.
Subject(s)
Leukemia, B-Cell/physiopathology , Lung Neoplasms/diagnosis , Adult , Aged , Biopsy/methods , Female , Humans , Leukemia, B-Cell/diagnosis , Lung/diagnostic imaging , Lung/pathology , Lung Neoplasms/physiopathology , Male , Middle Aged , Tomography, X-Ray Computed/methodsABSTRACT
Background: Asthma is a chronic airway disorder with variable/recurring symptoms, airflow obstruction, bronchial hyperresponsiveness, and an inflammation. The expert panel report of the National Heart Lung and Blood Institute recommends asthma screening in sickle cell disease (SCD); however, specific approach is not mentioned. We hypothesize that the breathmobile case identification survey (BCIS) is a valid asthma screening tool in children with SCD.Methods: This prospective, single-center study enrolled 129 SCD patients aged 5 to 18 years from March 2016 to March 2018. All patients completed BCIS, spirometry, and fractional exhaled nitric oxide (FeNO). A single pulmonologist blinded to the BCIS results evaluated patients for asthma.Results: Asthma prevalence was 41%. Male gender (60.4%; p = 0.041), allergic rhinitis (86.8%; p < 0.01), hydroxyurea usage (73.6%; p < 0.01), and family history of asthma (34%; p < 0.01) were higher but not self-reported parental asthma history, eczema, and tobacco smoke exposure in the asthma group compared to the nonasthma group. FEV1 (p = 0.003), FVC (p = 0.02), FEV1/FVC (p = 0.053), and FEF25-75% (p = 0.02) were lower in asthma. FeNO levels were comparable in both groups. The sensitivity, specificity, positive predictive value, and negative predictive value of the abbreviated BCIS were 67.3%, 90.8%, 83.3%, and 80.2% for asthma; and 82.1%, 90.8%, 76.7%, and 93.2% for persistent asthma, respectively. Persistent asthma patients had a trend of higher hydroxyurea use (82.8% vs. 58.3%; p = 0.049) and tobacco smoke exposure (55.2% vs. 29.2%; p = 0.057) compared to intermittent asthma.Conclusion: We have validated the BCIS to screen for asthma in SCD. Spirometry but not FeNO may support an asthma diagnosis.
Subject(s)
Anemia, Sickle Cell/epidemiology , Asthma/diagnosis , Asthma/epidemiology , Mass Screening/methods , Adolescent , Age Factors , Child , Child, Preschool , Female , Humans , Hydroxyurea/administration & dosage , Male , Mass Screening/standards , Medical History Taking , Prevalence , Prospective Studies , Respiratory Function Tests , Rhinitis, Allergic/epidemiology , Severity of Illness Index , Sex Factors , Surveys and Questionnaires/standards , Tobacco Smoke Pollution/statistics & numerical dataABSTRACT
Spinal osseous neoplasms are frequently encountered and can be challenging when present as solitary lesions. Familiarity with the range of benign and malignant spinal pathology can help the radiologist formulate a comprehensive differential diagnosis. This article focuses on the spectrum of extradural spinal tumors, accounting for the majority of primary spinal tumors, by comparing the epidemiology, pathophysiology, clinical presentation, and characteristic imaging appearance of these lesions. The discussion includes the commonly encountered benign lesions, such as vertebral venous vascular malformation and enostosis, as well as malignant lesions including metastases and lymphoma. The article also includes other less-encountered primary spinal tumors such as plasmacytoma, osteoid osteoma, osteoblastoma, giant cell tumor, eosinophilic granuloma, chordoma, chondrosarcoma, osteosarcoma, Ewing's sarcoma, and angiosarcoma. Familiarity with the characteristic imaging features can help the radiologist reach an accurate diagnosis and obviate the need for unnecessary invasive procedures such as biopsy and surgery.
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The thoracic inlet is located at the crossroads between imaging of the neck and the chest. Its location is an important anatomic landmark, serving as the central conducting pathway for many vital structures extending from the neck into the chest and vice versa. Many critical body systems, including the respiratory, lymphatic, neurologic, enteric, musculoskeletal, endocrine, and vascular systems, are located within this region. Neoplasms, both benign and malignant, can arise in any of the body systems located in this area. Due to the small size of this anatomic location, pathology is easily overlooked and imagers should be aware of the imaging appearance of these neoplasms, as well as which imaging modality is the most appropriate for neoplasm evaluation. This article will present an image rich, system-based discussion of the neoplastic pathology that can occur in this region. The anatomy of the thoracic inlet and the non-neoplastic pathology of the thoracic inlet have been covered in our companion article.
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BACKGROUND: Medication shortages prevent patients from receiving optimal care. Despite the frequency with which medical trainees care for inpatients, no assessment of their experiences in medication shortage management has been performed. OBJECTIVE: We evaluated trainees' experiences managing medication shortages. METHODS: We performed a cross-sectional survey of trainees postgraduate year 2 (PGY-2) and above in medicine, anesthesiology, and emergency medicine departments at 2 academic centers in 2018-2019. Categorical and ordinal assessments evaluated shortage awareness, substitution availability, pharmacy and therapeutics committee-based restrictions, communication, and education. Regressions were performed to determine effect of PGY, department, and institution on responses. RESULTS: A total of 168 of 273 subjects completed the survey (62% response rate). Most (95%, 159 of 168) reported managing medication shortages during training; 51% (86 of 168) described managing clinically relevant shortages daily or weekly. Seventy-seven percent (129 of 168) noted equivalent alternatives were unavailable at least one-quarter of the time, and 43% (72 of 168) reported clinically necessary medications were restricted at least weekly. Fifty-four percent (89 of 168) and 64% (106 of 167) of respondents discussed clinically relevant shortages with supervising physicians or patients "some of the time" or less, respectively. Most respondents (90%, 151 of 168) reported they would benefit from shortage management training, but few (13%, 21 of 168) reported prior training. CONCLUSIONS: Although trainees reported frequent involvement in clinically impactful shortage management, medication shortage communication between trainees and supervising physicians or patients appears sporadic. Medication shortage management training is uncommon but perceived as beneficial.
Subject(s)
Health Knowledge, Attitudes, Practice , Pharmaceutical Preparations , Physicians/psychology , Cross-Sectional Studies , Health Care Surveys , Humans , Illinois , Internship and ResidencyABSTRACT
The thoracic inlet is located at the crossroads between imaging of the neck and chest. It represents an important anatomic landmark, serving as the central conducting pathway for many vital structures extending from the neck into the chest and vice versa. Many important body systems are located within this region, including the enteric, respiratory, vascular, lymphatic, neurologic, and endocrine systems. A detailed examination of this region is essential when reviewing neck and thoracic imaging. This article will discuss the normal anatomic boundaries of the thoracic inlet and present an image-rich systematic discussion of the non-neoplastic pathology that can occur in this region. The neoplastic pathology of the thoracic inlet will be covered in a companion article.
ABSTRACT
Female mate choice can result in direct benefits to the female or indirect benefits through her offspring. Females can increase their fitness by mating with males whose genes encode increased survivorship and reproductive output. Alternatively, male investment in enhanced mating success may come at the cost of reduced investment in offspring fitness. Here, we measure male mating success in a mating arena that allows for male-male, male-female and female-female interactions in Drosophila melanogaster. We then use isofemale line population measurements to correlate male mating success with sperm competitive ability, the number of offspring produced and the indirect benefits of the number of offspring produced by daughters and sons. We find that males from populations that gain more copulations do not increase female fitness through increased offspring production, nor do these males fare better in sperm competition. Instead, we find that these populations have a reduced reproductive output of sons, indicating a potential reproductive trade-off between male mating success and offspring quality.
Subject(s)
Competitive Behavior , Drosophila melanogaster/genetics , Genetic Fitness , Sexual Behavior, Animal , Animals , Female , MaleABSTRACT
Polyandrous females allow for sexual selection to persist after mating. In the event that females successfully mate with more than one male, sperm competition can occur. Seminal fluid proteins can indirectly affect a male's success in sperm competition through reducing the remating behaviour of females and can directly influence sperm competition through directly displacing competitor sperm or inducing females to eject it. These direct effects on competitor sperm are thought to contribute to the 'second male advantage', whereby the second male to mate sires the majority of offspring. Here, we show an additional mechanism where seminal proteins already present within a mated female appear to enhance offspring production of later competitor males, and contribute to second male advantage. Counter to expectation, increased offspring production was not due to a priming effect of greater early female productivity, nor was it through a general and consistent increase in offspring production. Instead, enhanced productivity was solely through lengthening the time that offspring are sired by the second male, indicating that seminal proteins from the first male to mate may enhance second male advantage through a presumably unintended protective effect on subsequent competitor sperm.
Subject(s)
Drosophila melanogaster/physiology , Semen/physiology , Sexual Behavior, Animal/physiology , Spermatozoa/physiology , Animals , Drosophila Proteins/genetics , Female , Male , Mutation , Repressor Proteins/genetics , Semen/chemistryABSTRACT
BACKGROUND: Males and females often have opposing strategies for increasing fitness. Males that out-compete others will acquire more mating opportunities and thus have higher lifetime reproductive success. Females that mate with a high quality male receive either direct benefits through productivity or acquisition of additional resources or indirect benefits through the increased fitness of offspring. These components may be in conflict: factors that increase offspring fitness may decrease a female's productivity, and alleles that are beneficial in one sex may be detrimental in the opposite sex. Here, we use a multigenerational study with recently caught strains of Drosophila melanogaster to examine the relationship between parental, male offspring, and female offspring fitness when fitness is measured in a basal non-competitive environment. RESULTS: We find synergy between parental and offspring lifetime reproductive success, indicating a lack of parent-offspring conflict, and a synergy between son and daughter reproductive success, indicating a lack of intersexual conflict. Interestingly, inbreeding significantly reduced the lifetime reproductive success of daughters, but did not have a significant effect on short-term productivity measures of daughters, sons or parents. CONCLUSIONS: In wild-caught flies, there appears to be no parent-offspring conflict or intersexual conflict for loci influencing offspring production in a anon-competitive environment. Further, there may not be a biologically relevant selection pressure for avoidance of inbreeding depression in wild-type individuals of this short-lived species.
Subject(s)
Drosophila melanogaster/physiology , Sexual Behavior, Animal , Animals , Female , Genotype , Inbreeding , Male , Reproduction , Selection, Genetic , Sex FactorsABSTRACT
Vanillin is a potent fermentation inhibitor derived from the lignocellulosic biomass in biofuel production, and high concentrations of vanillin result in the pronounced repression of bulk translation in Saccharomyces cerevisiae. Studies on genes that are efficiently translated even in the presence of high concentrations of vanillin will be useful for improving yeast vanillin tolerance and fermentation efficiency. The BDH1 and BDH2 genes encode putative medium-chain alcohol dehydrogenase/reductases and their amino acid sequences are very similar to each other. Although BDH2 was previously suggested to be involved in vanillin tolerance, it has yet to be clarified whether Bdh1/Bdh2 actually contribute to vanillin tolerance and reductions in vanillin. Therefore, we herein investigated the effects of Bdh1 and Bdh2 on vanillin tolerance. bdh2Δ cells exhibited hypersensitivity to vanillin and slower reductions in vanillin than wild-type cells and bdh1Δ cells. Additionally, the overexpression of the BDH2 gene improved yeast tolerance to vanillin more efficiently than that of BDH1. Only BDH2 mRNA was efficiently translated under severe vanillin stress, however, both BDH genes were transcriptionally up-regulated. These results reveal the importance of Bdh2 in vanillin detoxification and confirm the preferential translation of the BDH2 gene in the presence of high concentrations of vanillin. The BDH2 promoter also enabled the expression of non-native genes under severe vanillin stress and furfural stress, suggesting its availability to improve of the efficiency of bioethanol production through modifications in gene expression in the presence of fermentation inhibitors.
ABSTRACT
Vanillin is one of the major phenolic aldehyde compounds derived from lignocellulosic biomass and acts as a potent fermentation inhibitor to repress the growth and fermentative ability of yeast. Vanillin can be reduced to its less toxic form, vanillyl alcohol, by the yeast NADPH-dependent medium chain alcohol dehydrogenases, Adh6 and Adh7. However, there is little information available regarding the regulation of their gene expression upon severe vanillin stress, which has been shown to repress the bulk translation activity in yeast cells. Therefore, in this study, we investigated expression patterns of the ADH6 and ADH7 genes in the presence of high concentrations of vanillin. We found that although both genes were transcriptionally upregulated by vanillin stress, they showed different protein expression patterns in response to vanillin. Expression of Adh6 was constitutive and gradually decreased under vanillin stress, whereas expression of Adh7 was inducible, and, importantly, occurred under severe vanillin stress. The null mutants of ADH6 or ADH7 genes were hypersensitive to vanillin and reduced vanillin less efficiently than the wild type, confirming the importance of Adh6 and Adh7 in vanillin detoxification. Additionally, we demonstrate that the ADH7 promoter is vanillin-inducible and enables effective protein synthesis even under severe vanillin stress, and it may be useful for the improvement of vanillin-tolerance and biofuel production efficiency via modification of yeast gene expression in the presence of high concentrations of vanillin.