Loneliness and Alcohol use among College Students During the COVID-19 Pandemic in Rural Appalachia.

Objective: Binge drinking and heavy alcohol use are highly prevalent among college students. During the COVID-19 pandemic, due to lockdown restrictions and other challenges, many college students were burdened with loneliness, which can contribute to chronic stress, and substance use. The current study explores the association between loneliness and various levels of alcohol use among college students in the rural, underserved region of Central Appalachia, USA. Methods: Data were collected from a regional sample (n = 320) of college age adults, age 18-25 in the Central Appalachian region. The UCLA-3 item Loneliness Scale (UCLA-3) was used in the study to evaluate loneliness. Logistic regression analysis was conducted to assess the association between levels of loneliness and three separate outcomes, including past year binge drinking, past year heavy alcohol use, and past year weekly alcohol use. Results: Overall, 25.5% of the participants reported severe loneliness, 33.6% reported moderate, and 40.9% reported low levels of loneliness. Results of the adjusted models revealed that severe loneliness was associated with higher odds of heavy alcohol use (AOR = 1.89, 95% CI [1.02, 3.50]) and binge drinking (AOR = 2.96, 95% CI [1.16, 7.51]), and not associated with weekly alcohol use. Conclusion: The study found that higher levels of loneliness were linked to both binged drinking and heavy alcohol use. Further efforts for counseling and treatment among college students who are burdened with severe loneliness should be considered. The chronic stress associated with severe loneliness needs to be further addressed, particularly among emerging adults.

Virtual Ileostomy as an Option for Complicated Colorectal Resections.

When surgery requires a colorectal anastomosis, a diverting ostomy may be created to decrease the clinical impact of anastomotic failure. Unfortunately, diverting ileostomies are also associated with significant morbidity. Recent literature suggests that diverting ostomies are not necessary for the majority of patients undergoing colorectal anastomosis and that creation of a virtual ileostomy (VI) may spare patients the complications that accompany diverting ileostomy creation. We present 4 patients with complex medical histories who underwent colorectal resections with primary anastomoses and VI creation. None of these patients suffered anastomotic leak or required conversion of VI to defunctioning ileostomy and there were no major complications associated with VI creation. Our results, although limited by sample size, support the creation of a virtual ileostomy as a safe and effective alternative to diverting ileostomy creation at the time of colorectal anastomosis.

Dominant effects of the histone mutant H3-L61R on Spt16-gene interactions in budding yeast.

Recent studies have unveiled an association between an L61R substitution within the human histone H3.3 protein and the presentation of neurodevelopmental disorders in two patients. In both cases, the mutation responsible for this substitution is encoded by one allele of the H3F3A gene and, if this mutation is indeed responsible for the disease phenotypes, it must act in a dominant fashion since the genomes of these patients also harbour three other alleles encoding wild-type histone H3.3. In our previous work in yeast, we have shown that most amino acid substitutions at H3-L61 cause an accumulation of the Spt16 component of the yFACT histone chaperone complex at the 3' end of transcribed genes, a defect we have attributed to impaired yFACT dissociation from chromatin following transcription. In those studies, however, the H3-L61R mutant had not been tested since it does not sustain viability when expressed as the sole source of histone H3 in cells. In the present work, we show that H3-L61R impairs proper Spt16 dissociation from genes when co-expressed with wild-type histone H3 in haploid cells as well as in diploid cells that express the mutant protein from one of four histone H3-encoding alleles. These results, combined with other studies linking loss of function mutations in human Spt16 and neurodevelopmental disorders, provide a possible molecular mechanism underlying the neurodevelopmental disorders seen in patients expressing the histone H3.3 L61R mutant.

Effects of Music Volume Preference on Endurance Exercise Performance.

The purpose of this study was to examine the effects of preferred versus non-preferred music volume on relative power output, trial time to completion (TTC), heart rate (HR), rate of perceived exertion (RPE), and motivation during endurance rowing exercise. Physically active females (age 18−25) volunteered to participate. In a crossover counterbalanced design, participants completed two trials: non-preferred (NPV) and preferred (PV) music volume. Participants began with a rowing warm-up at 50% of HRmax for 5 min. Following this, participants completed a 2000 m rowing time trial as quickly as possible. Relative power output, HR, and RPE were documented each minute during the exercise bout. TTC and motivation levels were documented at the cessation of exercise. Results showed that there were no significant differences between NPV and PV for relative power output (p = 0.287; d = 0.17), TTC (p = 0.816; d = 0.01), and HR (p = 0.956; d = 0.08). However, RPE was significantly lower (p = 0.002; d = 0.86) and motivation was significantly higher (p < 0.001; d = 2.14) during the PV condition versus NPV. Findings suggest that while PV does not impart performance-enhancing effects during endurance exercise compared to NPV, it may improve psychological responses related to intensity and effort which could have important implications for enduring intense exercise and training.

Effects of Acute Yohimbine Hydrochloride Supplementation on Repeated Supramaximal Sprint Performance.

The purpose of this study was to examine the effects of a single acute dose of yohimbine hydrochloride on repeated anaerobic sprint ability. Physically active females (n = 18) completed two separate repeated supramaximal sprint trials each with a different single-dose treatment: placebo (PL; gluten-free corn starch) or yohimbine hydrochloride (YHM; 2.5 mg). For each trial, participants consumed their respective treatment 20 min before exercise. Following a warm-up, participants completed 3 × 15 s Wingate anaerobic tests (WAnTs) separated by 2 min of active recovery. A capillary blood sample was obtained pre- and immediately post-exercise to measure blood concentrations of lactate (LA), epinephrine (EPI), and norepinephrine (NE). Heart rate (HR) and rate of perceived exertion (RPE) were measured following each WAnT. Findings showed that mean power (p < 0.001; η2 = 0.024), total work (p < 0.001; η2 = 0.061), and HR (p < 0.001; η2 = 0.046), were significantly higher with YHM supplementation versus PL. Fatigue index (p < 0.001; η2 = 0.054) and post-exercise LA (p < 0.001; d = 1.26) were significantly lower with YHM compared to PL. YHM resulted in significantly higher EPI concentrations versus PL (p < 0.001; η2 = 0.225) pre- and post-exercise while NE only increased as a function of time (p < 0.001; η2 = 0.227) and was unaffected by treatment. While RPE increased after each WAnT, no differences between treatments were observed (p = 0.539; η2 < 0.001). Together, these results suggest that acute YHM ingestion imparts ergogenic benefits which may be mediated by lower blood LA and fatigue concomitantly occurring with blood EPI increases. Thus, YHM may improve sprint performance although more mechanistic study is warranted to accentuate underlying processes mediating performance enhancement.

Patient, family and carer experiences of nutritional screening: a systematic review.

BACKGROUND: Despite recommendations for nutritional risk screening of all inpatients, outpatients and care home residents, as well as work to assess clinician's experiences and the validity of tools, little attention has been paid to the experiences of patients undergoing nutritional screening. This review aims to synthesise systematically the current evidence regarding nutritional risk screening with respect to the experiences and views of patients, their families and carers. METHODS: A systematic search was performed in MEDLINE, Embase, PsychINFO, CINAHL, Web of Science and British Nursing Database (inception - July 2019); with screening terms related to malnutrition, screening tools and experience. Titles, abstracts and full-text papers were independently reviewed by two reviewers and then quality-appraised. Qualitative papers and quantitative surveys were included. A narrative review of surveys and a thematic framework synthesis of interviews were used to identify themes. RESULTS: Nine studies, including five qualitative interview papers, were included. Qualitative and quantitative study results were combined using a matrix chart to allow comparison. Surveyed participants reported processes of nutritional screening as acceptable. Three key themes emerged from qualitative data: (i) experience of nutritional screening; (ii) misunderstanding of malnutrition: of causes, role of screening and poor self-perception of risk; and (iii) barriers to and opportunities for change. CONCLUSIONS: Although the screening process is acceptable, patients' misunderstanding and poor knowledge regarding causes and consequences of malnutrition result in reduced risk perception and disbelief or disregard of nutritional screening results. Findings should inform policy and clinical practice, as well as highlight the known paucity of data regarding the effectiveness of screening on clinical outcomes.

Does gadolinium improve magnetic resonance arthrography of the hip beyond fluid distension alone?

AIM: To determine if there is a difference in the detection of labral tears and cartilage lesions using the T2-weighted sequences of magnetic resonance arthrography (MRA) only, which simulate MRA with saline alone, compared with the full examination including T1-weighted sequences. MATERIALS AND METHODS: One hundred hip MRA examinations performed at 3 T were identified retrospectively. Each study was reviewed by a musculoskeletal radiologist using either the T2-weighted sequences only (without gadolinium-based contrast agent [GBCA] effect) or the entire examination, including T1-weighted sequences (with GBCA effect). Receiver operating characteristic (ROC) curves were calculated for both groups and compared within a non-inferiority framework, using - 0.10 as the limit of non-inferiority. RESULTS: For labral tears, the difference area under the curve (AUC) was -0.004 (95% confidence interval [CI]: -0.064-0.056, p=0.90). For acetabular cartilage lesions, the difference AUC was 0.011 (95% CI: -0.073-0.096, p=0.79). For femoral cartilage lesions, the difference AUC was -0.059 (95% CI: -0.206-0.087, p=0.43). CONCLUSION: T2-weighted sequences alone were not inferior in diagnostic accuracy compared with the full examination (including T1-weighted sequences with intra-articular GBCA) in detecting acetabular cartilage lesions and labral tears. Further study with prospective comparison of saline injectate to GBCA-containing injectate may help clarify the necessity of continued GBCA use in MRA of the hip.

Segmentation of Glomeruli Within Trichrome Images Using Deep Learning.

INTRODUCTION: The number of glomeruli and glomerulosclerosis evaluated on kidney biopsy slides constitute standard components of a renal pathology report. Prevailing methods for glomerular assessment remain manual, labor intensive, and nonstandardized. We developed a deep learning framework to accurately identify and segment glomeruli from digitized images of human kidney biopsies. METHODS: Trichrome-stained images (n = 275) from renal biopsies of 171 patients with chronic kidney disease treated at the Boston Medical Center from 2009 to 2012 were analyzed. A sliding window operation was defined to crop each original image to smaller images. Each cropped image was then evaluated by at least 3 experts into 3 categories: (i) no glomerulus, (ii) normal or partially sclerosed (NPS) glomerulus, and (iii) globally sclerosed (GS) glomerulus. This led to identification of 751 unique images representing nonglomerular regions, 611 images with NPS glomeruli, and 134 images with GS glomeruli. A convolutional neural network (CNN) was trained with cropped images as inputs and corresponding labels as output. Using this model, an image processing routine was developed to scan the test images to segment the GS glomeruli. RESULTS: The CNN model was able to accurately discriminate nonglomerular images from NPS and GS images (performance on test data: Accuracy: 92.67% ± 2.02% and Kappa: 0.8681 ± 0.0392). The segmentation model that was based on the CNN multilabel classifier accurately marked the GS glomeruli on the test data (Matthews correlation coefficient = 0.628). CONCLUSION: This work demonstrates the power of deep learning for assessing complex histologic structures from digitized human kidney biopsies.

A qualitative analysis to optimize a telemonitoring intervention for heart failure patients from disparity communities.

BACKGROUND: The use of telemonitoring is a promising approach to optimizing outcomes in the treatment of heart failure (HF) for patients living in the community. HF telemonitoring interventions, however, have not been tested for use with individuals residing in disparity communities. METHODS: The current study describes the results of a community based participatory research approach to adapting a telemonitoring HF intervention so that it is acceptable and feasible for use with a lower-income, Black and Hispanic patient population. The study uses the ADAPT-ITT framework to engage key community stakeholders in the process of adapting the intervention in the context of two consecutive focus groups. In addition, data from a third focus group involving HF telemonitoring patient participants was also conducted. All three focus group discussions were audio recorded and professionally transcribed and lasted approximately two hours each. Structural coding was used to mark responses to topical questions in the interview guide. RESULTS: This is the first study to describe the formative process of a community-based participatory research study aimed at optimizing telehealth utilization among African-American and Latino patients from disparity communities. Two major themes emerged from qualitative analyses of the focus group data. The first theme that arose involved suggested changes to the equipment that would maximize usability. Subthemes identified included issues that reflect the patient populations targeted, such as Spanish translation, font size and medical jargon. The second theme that arose involved suggested changes to the RCT study structure in order to maximize participant engagement. Subthemes also identified issues that reflect concerns of the targeted patient populations, such as the provision of reassurances regarding identity protection to undocumented patients in implementing an intervention that utilizes a camera, and that their involvement in telehealth monitoring would not replace their clinic care, which for many disparity patients is their only connection to medical care. CONCLUSIONS: The adaptation, based on the analysis of the data from the three focus groups, resulted in an intervention that is acceptable and feasible for HF patients residing in disparity communities. TRIAL REGISTRATION: NCT02196922 ; ClinicalTrials.gov (US National Institutes of Health).

Increased number of parvovirus B19 infections in southeast Scotland in 2012-2013.

Parvovirus B19 (B19V) infections are a common but under-investigated and under-reported cause of intrauterine infections. An increased number of acute B19V infections was identified in the Edinburgh area in 2012-2013, with 123 infections diagnosed in 33 pregnant women, 76 non-pregnant women and 14 men. All except one pregnant woman were asymptomatic. An overall infection rate of 18% was measured in pregnant women who were tested following B19V exposure (26/141). Furthermore, a 7% seroconversion rate was recorded in non-immune pregnant women who were re-tested after exposure (7/104). A high fetal loss rate (25%; 3/12) was observed in those who had acute B19V infection in early pregnancy (<11 weeks) whereas all pregnancies progressed to term in those where acute infection occurred after a gestational age of 12 weeks. These results suggest that more efforts should be targeted to investigate suspected B19V infections in early pregnancy during epidemic seasons.

Tympanic plate fractures in temporal bone trauma: prevalence and associated injuries.

BACKGROUND AND PURPOSE: The prevalence of tympanic plate fractures, which are associated with an increased risk of external auditory canal stenosis following temporal bone trauma, is unknown. A review of posttraumatic high-resolution CT temporal bone examinations was performed to determine the prevalence of tympanic plate fractures and to identify any associated temporal bone injuries. MATERIALS AND METHODS: A retrospective review was performed to evaluate patients with head trauma who underwent emergent high-resolution CT examinations of the temporal bone from July 2006 to March 2012. Fractures were identified and assessed for orientation; involvement of the tympanic plate, scutum, bony labyrinth, facial nerve canal, and temporomandibular joint; and ossicular chain disruption. RESULTS: Thirty-nine patients (41.3 ± 17.2 years of age) had a total of 46 temporal bone fractures (7 bilateral). Tympanic plate fractures were identified in 27 (58.7%) of these 46 fractures. Ossicular disruption occurred in 17 (37.0%). Fractures involving the scutum occurred in 25 (54.4%). None of the 46 fractured temporal bones had a mandibular condyle dislocation or fracture. Of the 27 cases of tympanic plate fractures, 14 (51.8%) had ossicular disruption (P = .016) and 18 (66.6%) had a fracture of the scutum (P = .044). Temporomandibular joint gas was seen in 15 (33%) but was not statistically associated with tympanic plate fracture (P = .21). CONCLUSIONS: Tympanic plate fractures are commonly seen on high-resolution CT performed for evaluation of temporal bone trauma. It is important to recognize these fractures to avoid the preventable complication of external auditory canal stenosis and the potential for conductive hearing loss due to a fracture involving the scutum or ossicular chain.

Prognostic monitoring of aircraft wiring using electrical capacitive tomography.

Electrical capacitive tomography (ECT) has been used to monitor sections of aircraft wiring, as a tool for prognostic analysis. To apply the principles of ECT across a cross section of only 4 mm, modification of the basic circuit was required. Additionally, a more novel method of placing the necessary electrodes was needed, this being accomplished by etching them from flexible copper sheeting and wrapping them inside the perimeter of an enclosure. Results showed that at this small scale, it was possible to determine the position of a wire-under-test inside the 4 mm diameter enclosure to about 0.1 mm, and that by measuring capacitance between pairs, it was also possible to determine whether or not the insulation of wire passed between the electrodes was damaged. With more than one wire-under-test present, it was possible to determine whether or not damage was present, and if so, which wire was damaged. By detecting insulation damage in this way, ECT has proven to be a useful tool in prognostic monitoring, helping faults to be found before they become safety-critical onboard an aircraft.

Polymorphism of the ovine beta3-adrenergic receptor gene (ADRB3) and its association with wool mean staple strength and yield.

We investigated the possibility that variation in ovine ADRB3 is associated with various wool traits, in particular mean staple strength (MSS). Polymerase chain reaction-single strand conformational polymorphism analysis of part of the ADRB3 intron was used to genotype 695 Merino lambs born on three farms in the South Island of New Zealand and which were shorn as 2-tooths. For each fleece, MSS, mean fibre diameter, mean staple length and yield were measured. The results from mixed-effects models and half-sib analyses suggest that ADRB3 alleles A and D have a negative impact on some wool traits, whereas ADRB3 alleles C and E appear to have a positive impact, with allele C potentially having a greater impact than allele E on MSS. This variation in the ADRB3 may assist in the genetic selection for increased MSS and yield in Merino sheep.

Pictorial review: Non-neoplastic soft-tissue masses.

As a tertiary centre for soft-tissue sarcomas, numerous non-neoplastic masses are referred to our institution. In many cases, review of the imaging allows a confident diagnosis to be made without the need for biopsy. Lesions include anomalous muscles and variants, muscle injury, haematoma, myositis ossificans, aneurysm, abscess, tumoral calcinosis, amyloidosis and elastofibroma. The purpose of this article is to review the imaging characteristics of these non-neoplastic lesions and highlight the features that help differentiate these lesions from a soft-tissue sarcoma.

Polymorphism of the KAP1.1, KAP1.3 and K33 genes in Merino sheep.

The wool fibre is a complex structure composed primarily of proteins from the keratin family. These proteins are responsible for the major structural and mechanical properties of the wool fibre. This study examines variation in the genes encoding key keratin (K) and keratin-associated proteins (KAP) in Merino sheep. Variation at these loci has the potential to be developed as genetic-markers associated with wool traits. This study used 1541 Merino lambs born to 40 sires sourced from three farms in the South Island of New Zealand. Polymerase chain reaction-single strand conformational polymorphism (PCR-SSCP) analysis was used to identify sequence variation in the KAP1.3 (formerly known as B2C) and K33 (formerly known as KRT1.2) genes, whereas PCR-agarose gel electrophoresis was used to identify length polymorphism in the KAP1.1 (formerly known as B2A) gene. All allelic variation was confirmed by DNA sequencing. We report three alleles at the KAP1.1 locus, nine alleles at the KAP1.3 locus and five alleles at the K33 locus of Merino sheep.

The collagenase-1 (MMP-1) gene promoter polymorphism - 1607/2G is associated with favourable prognosis in patients with colorectal cancer.

Matrix metalloproteinase (MMP) overexpression has been implicated in the pathogenesis of colorectal carcinoma (CRC). Accumulating evidence suggests that MMP promoter single nucleotide polymorphisms (SNPs) effecting gene transcription are associated with enhanced susceptibility for the development of malignant disease, increased tumour invasiveness and poor patient survival. The aim of the current investigation was to determine whether such associations exist in a large CRC patient/control study population. Using an allelic discrimination real-time polymerase chain reaction, polymorphisms in the MMP-1, MMP-2 and MMP-3 gene promoters (-1607, -1306, and -1612 bp, respectively) were assessed in normal blood mononuclear cells from patients with CRC (n=503) and control subjects (n=471). Genotypes corresponding to each MMP SNP were correlated with tumour characteristics and clinical outcome. The frequency of each genotype was not statistically different between patients and control subjects and no significant differences were noted between the genotypes and tumour characteristics for the three MMP SNPs. CRC patients with the 2G/2G genotype for the MMP-1 SNP had significantly better 5-year survival compared to patients with a 1G allele (P<0.05). Our results demonstrate that CRC patients with a 2G/2G genotype in the MMP-1 gene promoter SNP have a favourable prognosis. Although our results were unexpected, given that this genotype is associated with enhanced MMP-1 transcriptional activity, they are consistent with recent data highlighting the anti-tumorigenic properties of MMPs.

In vitro and in vivo tissue repair with laser-activated chitosan adhesive.

BACKGROUND AND OBJECTIVES: Sutures are currently the gold standard for wound closure but they are still unable to seal tissue and may induce scarring or inflammation. Biocompatible glues, based on polysaccharides such as chitosan, are a possible alternative to conventional wound closure. In this study, the adhesion of laser-activated chitosan films is investigated in vitro and in vivo. In particular we examine the effect of varying the laser power, as well as adding a natural cross-linker (genipin) to the adhesive composition. STUDY DESIGN/MATERIALS AND METHODS: Flexible and insoluble strips of chitosan films (surface area approximately 34 mm(2), thickness approximately 20 microm) were bonded to sheep intestine using several laser powers (0, 80, 120, and 160 mW) at 808-nm wavelength. The strength of repaired tissue was tested by a calibrated tensiometer to select the best power. A natural cross-linker (genipin) was also added to the film and the tissue repair strength compared with the strength of plain films. The adhesive was also bonded in vivo to the sciatic nerve of rats and the thermal damage induced by the laser assessed 4 days post-operatively. RESULTS: Chitosan adhesives successfully repaired intestine tissue, attaining a maximum repair strength of 14.7+/-4.3 kPa (n = 30) at the laser power of 120 mW. The chitosan-genipin films achieved lower repair strength (9.1+/-2.9 kPa). The laser caused partial demyelination of axons at the site of operation, but the myelinated axons retained a normal morphology proximally and distally. CONCLUSIONS: The chitosan adhesive effectively bonded to tissue causing only localized thermal damage in vivo, when the appropriate laser parameters were selected.

Sevoflurane versus propofol for induction of anaesthesia for electroconvulsive therapy: a randomized crossover trial.

Propofol is often used to induce anaesthesia for electroconvulsive therapy. Some patients who receive propofol have fits of poor quality or inadequate duration despite increasing electroconvulsive therapy doses. Sevoflurane has been reported to exhibit pro-convulsant properties in some "at-risk" patients during anaesthesia for other procedures. The purpose of this study was to perform a randomized crossover trial in patients undergoing electroconvulsive therapy, comparing the effects on seizure parameters of propofol versus sevoflurane induction. Patients were randomly allocated to receive either sevoflurane or propofol for their first treatment. In the subsequent treatment the alternative agent was used. Patients in both treatment groups exhibited equally good fits, with those in the sevoflurane group having slightly better morphology, which is the most subjective of the parameters measured. The sevoflurane administrations were associated with slightly higher pulse rates and blood pressures. Sevoflurane provides a suitable alternative to propofol for anaesthesia in patients undergoing electroconvulsive therapy, although the slightly greater pulse rate rise and blood pressure rise should be considered in patients with ischaemic heart disease.

Chronic high dose L-DOPA alone or in combination with the COMT inhibitor entacapone does not increase oxidative damage or impair the function of the nigro-striatal pathway in normal cynomologus monkeys.

Parkinson's disease (PD) is characterised by a loss of pigmented dopaminergic neurones in the zona compacta of substantia nigra. The mechanisms underlying nigral cell death remain unknown but may involve oxidative damage. There has been concern that L-DOPA treatment may accelerate nigral pathology in PD through chemical and enzymatic oxidation to reactive oxygen species. In the present study, we examined tissues from normal macaque monkeys treated for 13 weeks with high doses of L-DOPA (in combination with the peripheral decarboxylase inhibitor, carbidopa) and/or the COMT inhibitor, entacapone. Plasma was analysed for changes in protein carbonyls as a marker of oxidative damage to protein. Cortical tissue was examined for changes in levels of protein carbonyls, lipid peroxidation and oxidative damage to DNA. The integrity of the nigro-striatal pathway was assessed by nigral tyrosine hydroxylase mRNA levels and specific [(3)H]mazindol binding to dopaminergic terminals in caudate-putamen. No alterations in plasma protein carbonyls were observed in any treatment group. An increase was found in the levels of protein carbonyls, lipid peroxidation and 5-OH uracil, but not other products of oxidative DNA damage, in cerebral cortex of monkeys treated with L-DOPA plus carbidopa or with L-DOPA plus carbidopa and entacapone but this was only statistically significant in the latter group. There was no change in nigral tyrosine hydroxylase mRNA levels or specific striatal [(3)H]mazindol binding in brain tissue from monkeys treated with either L-DOPA plus carbidopa or L-DOPA plus carbidopa and entacapone. The results show that in the normal monkeys L-DOPA does not provoke marked oxidative damage even at high doses, and that there is little or no potentiation of its effects by entacapone. Neither L-DOPA plus carbidopa nor L-DOPA plus carbidopa and entacapone led to obvious damage to the nigro-striatal pathway.

Adaptive mutations, mutator DNA polymerases and genetic change strategies of pathogens.

"Adaptive" or "stationary-phase" mutation is a collection of stress responses promoting mutations, some of which are advantageous. In 2000 and 2001, in Escherichia coli, adaptive gene amplification was documented, and a parallel adaptive point-mutation mechanism was linked to the error-prone DNA polymerase, DinB (pol IV). We suggest that DinB homologues may contribute to adaptive strategies of pathogens, including antigenic variation.