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Biomedical subjects

Dan H Moore

Publications and source records attributed to Dan H Moore.

At least 19 recordsLinked to original sources

Ductal carcinoma in situ in BRCA mutation carriers.

PURPOSE: The current literature suggests that ductal carcinoma in situ (DCIS) of the breast is infrequently diagnosed in patients with BRCA germline mutations. We studied women at high risk of hereditary breast cancer syndromes who underwent testing for BRCA1 and BRCA2 to estimate DCIS prevalence and incidence in known BRCA-positive women compared with high-risk women who were mutation negative. METHODS: We analyzed breast event outcomes in a retrospective cohort of 129 BRCA-positive and 269 BRCA-negative women undergoing genetic testing for a BRCA mutation between September 1996 and December 2003 at University of California, San Francisco. We estimated the frequency of DCIS and invasive cancer and time to breast events from birth using a Cox proportional hazard model for competing risks. Histologic grade of DCIS was also compared between groups. RESULTS: Among BRCA carriers, 48 (37%) had DCIS (with or without invasive cancer) compared with 92 noncarriers (34%). Univariate analysis showed that both DCIS and invasive cancer had an earlier onset in mutation carriers than in noncarriers, although on a per-woman basis, this difference was not statistically significant. High-grade DCIS was more common in BRCA1 mutation carriers than in patients without a mutation (P = .02). CONCLUSION: DCIS is equally as prevalent in patients who carry deleterious BRCA mutations as in high familial-risk women who are noncarriers, but occurs at an earlier age. Our results argue for the consideration of DCIS as a criterion for BRCA risk assessments with appropriate weighting in prediction models such as BRCAPRO.

Adult↗

Type and duration of exogenous hormone use affects breast cancer histology.

BACKGROUND: It is unclear whether hormone replacement therapy (HRT), in addition to increasing risk for breast cancer, affects the type of breast cancer diagnosed. We conducted this investigation to assess whether the type of hormone used (none, estrogen, progesterone, or combined) and duration of use influences subsequent breast cancer histology. METHODS: We performed a retrospective cohort analysis among women listed as incident cases of breast malignancy in the Kaiser Permanente Northern California Cancer Registry during 2003 (n = 2830). Type and duration of hormone used (none, estrogen, progesterone, or combined) before breast cancer diagnosis was obtained from electronic pharmacy records. The association between type and duration of hormone use with characteristics of subsequent breast cancers was examined. RESULTS: Among women aged >50 years (n = 1701), any use of estrogen, progesterone, or combination therapy was not associated with an increased risk of estrogen receptor (ER)-positive disease. However, >6 months' use of combined HRT increased the odds of ER-positive tumors (odds ratio, 1.65; 95% confidence interval, 1.07-2.5; P = .02). Estrogen HRT patients were more likely than nonusers to present with low-grade (P = .05), and early-stage tumors (P = .03). This trend was not seen in combined HRT users. CONCLUSIONS: Short-duration HRT did not increase the likelihood of ER-positive breast cancer. However, prolonged duration of combined HRT, but not estrogen or progesterone alone, resulted in a marked increase in ER-positive disease. Our findings suggest that the effect of combined HRT on breast cancer incidence or progression is not immediate and that long-term use is more likely to affect breast cancer histology.

Adolescent↗

Magnetic resonance imaging captures the biology of ductal carcinoma in situ.

PURPOSE: Magnetic resonance imaging (MRI) is an important tool for characterizing invasive breast cancer but has proven to be more challenging in the setting of ductal carcinoma in situ (DCIS). We investigated whether MRI features of DCIS reflect differences in biology and pathology. PATIENTS AND METHODS: Forty five of 100 patients with biopsy-proven DCIS who underwent MRI and had sufficient tissue to be characterized by pathologic (nuclear grade, presence of comedo necrosis, size, and density of disease) and immunohistochemical (IHC) findings (proliferation, Ki67; angiogenesis, CD34; and inflammation, CD68). Pathology and MRI features (enhancement patterns, distribution, size, and density) were analyzed using pairwise and canonical correlations. RESULTS: Histopathologic and IHC variables correlated with MRI features (r = 0.73). The correlation was largely due to size, density (by either MRI or pathology), and inflammation (P < .05). Most small focal masses were estrogen receptor-positive. MRI enhancement patterns that were clumped were more likely than heterogeneous patterns to be high-grade lesions. Homogenous lesions were large, high grade, and rich in macrophages. Presence of comedo necrosis and size could be distinguished on MRI (P < .05). MRI was most likely to over-represent the size of less dense, diffuse DCIS lesions. CONCLUSION: The heterogeneous presentation of DCIS on MRI reflects underlying histopathologic differences.

Adult↗

Genes and pathways downstream of telomerase in melanoma metastasis.

Recent studies have demonstrated a role for telomerase in driving tumor progression, but its mechanism of action remains unclear. Here we show that stable, ribozyme-mediated suppression of mouse telomerase RNA reduced telomerase RNA expression, telomerase activity, and telomere length, which significantly reduced tumor invasion and metastatic potential. Our studies reveal that previously unidentified effects of telomerase may mediate its tumor-promoting effects. First, reducing telomerase activity induced a more dendritic morphology, accompanied by increased melanin content and increased expression of tyrosinase, a key enzyme in melanin biosynthesis. Second, gene expression profiling revealed that telomerase targeting down-regulated expression of several glycolytic pathway genes, with a corresponding decrease in glucose consumption and lactate production. Thus, telomerase activity controls the glycolytic pathway, potentially altering the energy state of tumor cells and thereby modulating tyrosinase activity and melanin production. These studies have important implications for understanding the mechanisms by which telomerase promotes tumor invasion and metastasis.

Animals↗

AM1241, a cannabinoid CB2 receptor selective compound, delays disease progression in a mouse model of amyotrophic lateral sclerosis.

Effective treatment for amyotrophic lateral sclerosis (ALS) remains elusive. Motor neuron degeneration is the primary pathology in ALS; however non-neuronal cells contribute to the disease process. In particular, inflammatory processes have been shown to play an important role. AM1241 is a cannabinoid CB2 receptor selective agonist that has been shown to be effective in models of inflammation and hyperalgesia. Here we report that treatment with AM1241 was effective at slowing signs of disease progression when administered after onset of signs in an ALS mouse model (hSOD1(G93A) transgenic mice). Administration at the onset of tremors delayed motor impairment in treated mice when compared to vehicle controls. Three conditions of ALS, the loss of motor function, paralysis scoring and weight loss, were analyzed using a mathematical model. Loss of motor function (as assessed by performance on a rotarod) was delayed by 12.5 days in male mice by AM1241. In female mice, AM1241 extended rotarod performance by 3 days, although this was not statistically significant. In male mice, AM1241 also extended by 5 days the time to reach the 50% point on a visually-assessed performance scale. AM1241 did not affect weight loss or survival (129.8+/-1.7 days, vehicle; 129.1+/-7.0 days, AM1241, n=16). As AM1241 was well tolerated by the animals, cannabinoid CB2 receptor-selective compounds may be the basis for developing new drugs for the treatment of ALS and other chronic neurodegenerative diseases.

Amino Acid Substitution↗

Prognostic value of PAI1 in invasive breast cancer: evidence that tumor-specific factors are more important than genetic variation in regulating PAI1 expression.

Plasminogen activator inhibitor-1 (PAI1) can promote cancer progression, and its protein expression in tumors is an independent indicator of poor prognosis in many forms of cancer. Here, we show that high PAI1 mRNA levels also predict for shorter overall survival in two independent breast cancer data sets, highlighting the importance of its transcriptional regulation. The -675insG (4G/5G) single-nucleotide polymorphism in the PAI1 gene promoter has been shown to influence PAI1 transcription, with the 4G allele eliciting higher reporter gene expression in vitro and higher levels of circulating PAI1 in vivo. Nevertheless, its genotypic distribution in 2,539 British women with invasive breast cancer was virtually identical to that seen in 1,832 matched controls (P = 0.72), and annual mortality rates for 4G4G, 4G5G, and 5G5G cases were 2.6%, 2.8%, and 3.1% per year, respectively (P = 0.10). Thus, there was no association with breast cancer incidence or outcome, and in a separate set of breast cancers, the 4G/5G single-nucleotide polymorphism showed no association with PAI1 mRNA expression (P = 0.85). By contrast, connective tissue growth factor (CTGF), which can regulate PAI1 expression in culture, was associated with PAI1 expression in three independent cohorts (P << 0.0001). In addition, PAI1 gene copy number differences in the tumors were correlated with PAI1 mRNA expression (P = 0.0005) and seemed to affect expression independently of CTGF. Thus, local factors, such as CTGF and genomic amplification, seem to be more important than germ line genetic variation in influencing PAI1 expression and its untoward effects in breast cancer.

Biomarkers, Tumor↗

Fractional genomic alteration detected by array-based comparative genomic hybridization independently predicts survival after hepatic resection for metastatic colorectal cancer.

PURPOSE: Although liver resection is the primary curative therapy for patients with colorectal hepatic metastases, most patients have a recurrence. Identification of molecular markers that predict patients at highest risk for recurrence may help to target further therapy. EXPERIMENTAL DESIGN: Array-based comparative genomic hybridization was used to investigate the association of DNA copy number alterations with outcome in patients with colorectal liver metastasis resected with curative intent. DNA from 50 liver metastases was labeled and hybridized onto an array consisting of 2,463 bacterial artificial chromosome clones covering the entire genome. The total fraction of genome altered (FGA) in the metastases and the patient's clinical risk score (CRS) were calculated to identify independent prognostic factors for survival. RESULTS: An average of 30 +/- 14% of the genome was altered in the liver metastases (14% gained and 16% lost). As expected, a lower CRS was an independent predictor of overall survival (P = 0.03). In addition, a high FGA also was an independent predictor of survival (P = 0.01). The median survival time in patients with a low CRS (score 0-2) and a high (> or =20%) FGA was 38 months compared with 18 months in patients with a low CRS and a low FGA. Supervised analyses, using Prediction Analysis of Microarrays and Significance Analysis of Microarrays, identified a set of clones, predominantly located on chromosomes 7 and 20, which best predicted survival. CONCLUSIONS: Both FGA and CRS are independent predictors of survival in patients with resected hepatic colorectal cancer metastases. The greater the FGA, the more likely the patient is to survive.

Aged↗

Alteration of gene expression in macroscopically normal colonic mucosa from individuals with a family history of sporadic colon cancer.

PURPOSE: We have shown that the expression of several genes associated with human colon cancer is altered in the morphologically normal colonic mucosa (MNCM) of APC(min) mice and humans with colon cancers. To determine whether these alterations also occur in the MNCM of individuals who have not developed colon cancer but are at high risk of doing so, we measured gene expression in the MNCM of individuals with a family history of colon cancer. METHODS: Expression of 16 genes in the MNCM of 12 individuals with a first-degree relative with sporadic colon cancer and 16 normal controls were measured by quantitative reverse transcription-PCR. All subjects tested had normal colonoscopic examinations. Biopsy samples of MNCM were obtained from the ascending, transverse, descending, and rectosigmoid regions of the colon (2-8 biopsy samples were obtained from each region). RESULTS: Relative to normal controls, the expression of several genes, including PPAR-gamma, SAA1, and IL-8 were significantly altered in the macroscopically normal rectosigmoid mucosa from individuals with a family history of colon cancer. CONCLUSIONS: Molecular abnormalities that precede the appearance of adenomatous polyp are present in the MNCM of individuals who have a family history of colon cancer. This observation raises the possibility of screening for individuals who are at an increased risk of developing colon cancer by analysis of gene expression in rectosigmoid biopsy samples. To assess this possibility, prospective studies will be needed to determine whether or not altered gene expression is associated with the subsequent development of adenomatous polyps and/ or colonic carcinomas.

Adolescent↗

Altered gene expression in normal colonic mucosa of individuals with polyps of the colon.

PURPOSE: Expression levels of many genes are altered in colon cancer, relative to normal colonic mucosa. We recently reported that such differences also exist between grossly normal colonic mucosa of individuals with and without colon cancer, and between individuals with and without a family history of colon cancer. Here we report a study of individuals with no cancer but with polyps in the transverse, ascending/descending, or rectosigmoid colon. METHODS: Biopsies of grossly normal-appearing colonic mucosa from the rectosigmoid colon were taken from individuals with polyps, with or without personal/family history of colon cancer, and gene expression profiles compared with those from biopsies of control patients, with no polyps or known personal/family history. A global expression analysis was conducted of the same 15 genes used in our previous studies. RESULTS: We found significant differences in gene expression in normal-appearing rectosigmoid colonic mucosa between individuals with polyps and controls, regardless of whether personal or family history of cancer was present. CONCLUSIONS: Alterations in gene expression patterns in morphologically normal-appearing colonic mucosa are associated with the presence of adenomatous polyps. Prospective studies will be required to determine whether these alterations in gene expression can be used to predict risk of developing colon cancer.

Adult↗

Cannabinoids selectively inhibit proliferation and induce death of cultured human glioblastoma multiforme cells.

Normal tissue toxicity limits the efficacy of current treatment modalities for glioblastoma multiforme (GBM). We evaluated the influence of cannabinoids on cell proliferation, death, and morphology of human GBM cell lines and in primary human glial cultures, the normal cells from which GBM tumors arise. The influence of a plant derived cannabinoid agonist, Delta(9)-tetrahydrocannabinol Delta(9)-THC), and a potent synthetic cannabinoid agonist, WIN 55,212-2, were compared using time lapse microscopy. We discovered that Delta(9)-THC decreases cell proliferation and increases cell death of human GBM cells more rapidly than WIN 55,212-2. Delta(9)-THC was also more potent at inhibiting the proliferation of GBM cells compared to WIN 55,212-2. The effects of Delta(9)-THC and WIN 55,212-2 on the GBM cells were partially the result of cannabinoid receptor activation. The same concentration of Delta(9)-THC that significantly inhibits proliferation and increases death of human GBM cells has no significant impact on human primary glial cultures. Evidence of selective efficacy with WIN 55,212-2 was also observed but the selectivity was less profound, and the synthetic agonist produced a greater disruption of normal cell morphology compared to Delta(9)-THC.

Benzoxazines↗

N-acetylcysteine for the prevention of contrast-induced nephropathy. A systematic review and meta-analysis.

OBJECTIVE: Contrast-induced nephropathy is a common cause of acute renal failure in hospitalized patients. Although patients are often given N-acetylcysteine to prevent renal injury from contrast agents, there are no clear guidelines supporting its use. We conducted a systematic review to determine whether administering N-acetylcysteine around the time of contrast administration reduces the risk of contrast-induced nephropathy. DESIGN: We searched MEDLINE, EMBASE, the Cochrane Collaboration Database, bibliographies of retrieved articles, and abstracts of conference proceedings, and consulted with experts to identify relevant studies. Randomized controlled trials of N-acetylcysteine in hospitalized patients receiving contrast were included. Studies were excluded if they did not report change in creatinine or incidence of contrast-induced nephropathy at 48 hours. MEASUREMENTS AND MAIN RESULTS: Nine randomized controlled trials satisfied all inclusion criteria and were included in the analysis. The difference in mean change in creatinine between the N-acetylcysteine-treated group and controls was -0.27 mg/dl (95% confidence interval [CI], -0.43 to -0.11). The relative risk of developing contrast-induced nephropathy was 0.43 (95% CI, 0.24 to 0.75) in subjects randomized to N-acetylcysteine. Significant heterogeneity existed among studies, suggesting differences in patient populations or study methodology not identified by sensitivity analyses. The incidence of dialysis was rare (0.2%). CONCLUSIONS: Our findings suggest that N-acetylcysteine helps prevent declining renal function and contrast-induced nephropathy. While N-acetylcysteine is inexpensive and nontoxic, undeviating insistence for dosing at least 12 hours in advance of contrast exposure may delay diagnostic and therapeutic procedures. Future studies are needed to address the longer-term clinical outcomes and cost-effectiveness of this agent.

Acetylcysteine↗

Effect of neuroprotective drugs on gene expression in G93A/SOD1 mice.

Gene expression analysis is a powerful tool that has been used to define the pathological processes underlying many diseases. Several laboratories, including our own, have used this approach to identify molecular abnormalities in the G93A/SOD1 mouse, an animal model of amyotrophic lateral sclerosis (ALS). Here, we report the results of analysis of an expanded panel of genes throughout the entire lifetime in the spinal cord of these animals. In addition to upregulation of microglia/neuroinflammatory genes identified previously, we observed upregulation of metallothionein-I and -II (MT-I, MT-II). MT-I and MT-II play an important role in disposition of zinc ion, and other studies have also indicated their levels are altered in development of motor neuron disease in these animals. We also analyzed the effect on these expression profiles of several candidate drugs that have been shown to have neuroprotective effects in vivo or in vitro. That is, we asked whether administration to the G93A/SOD1 mice of any of these drugs could reverse the alterations in gene expression patterns that occur as the animals develop. The mice were given daily doses of these drugs when they were 9-11 weeks old, at a stage early in development of motor neuron disease, continuing for 5 weeks, at which time they were sacrificed. Treatment of the mice with l-carnosine, a dipeptide that scavenges free radicals and chelates zinc, did not affect expression of any of the genes altered in these animals. However, it did upregulate 3 genes unaffected by the presence of the G93A/SOD1 mutation: glial fibrillary acidic protein (GFAP), stroma-derived factor-1 (SDF-1), and excitatory amino acid transporter-2 (EAAT2). In contrast, metallothionein-III (MT-III) was downregulated. Treatment of the animals with baicalein, an herbal extract with anti-inflammatory and numerous other effects, downregulated the microglia markers CD68, CD80, and CD86, all of which were upregulated in untreated mutant animals. Baicalein treatment also downregulated tumor necrosis factor receptor (TNFRp55) and upregulated noninducible nitric oxide synthase (nNOS) and glutamine synthase (GS). These 3 genes were unaffected by the presence of the G93A mutation. We discuss the implication of these results for testing the effects of these and other candidate drugs in mutant SOD1 mice.

Amyotrophic Lateral Sclerosis↗

Patient and physician attitudes toward breast cancer clinical trials: developing interventions based on understanding barriers.

PURPOSE: Clinical trials are essential to develop and test novel therapies, yet only 2%-3% of women with breast cancer enroll. We sought to describe patient and physician barriers to trial participation and then implemented targeted interventions to increase awareness and interest in trial participation. Also, with increasing patient interest in complementary and alternative medicine (CAM) for cancer, we explored attitudes regarding CAM clinical trials. PATIENTS AND METHODS: Between 1997 and 2000, questionnaires were offered to patients with newly diagnosed or recurrent breast cancer and to physicians specializing in breast cancer. Programs aimed at patients and physicians from our geographic region to increase their support for breast cancer clinical trials were initiated in 1997. Correlation between perceived barriers and patient and physician demographics were explored. Reluctance to be randomized, extra time, and concerns about worse side effects with the experimental arm were the most significant patient barriers. Physician barriers included randomization, extra staff time, and increased costs of enrollment. Patients and physicians approved of studying CAM in clinical trials, with different scores based on age and type of practice. Physicians and patients developed more favorable views of clinical trials between 1997 and 2000. RESULTS: Although many barriers still exist, this study suggests that attitudes toward clinical trials are evolving and significantly affected by patient age and stage of disease. Because different patients and some different physicians were surveyed, it is difficult to conclude that the changes occurred as a result of the interventions. CONCLUSION: Future efforts to improve enrollment should focus on patients' individual concerns and the uneasiness with the randomization.

Adult↗

Patterns of chromosomal alterations in breast ductal carcinoma in situ.

PURPOSE: Ductal carcinoma in situ (DCIS) is thought to be a nonobligate precursor of invasive cancer. Genomic changes specific to pure DCIS versus invasive cancer, as well as alterations unique to individual DCIS subtypes, have not been fully defined. EXPERIMENTAL DESIGN: Chromosomal copy number alterations were examined by comparative genomic hybridization in 34 cases of pure DCIS and compared with 12 cases of paired synchronous DCIS and invasive ductal cancer, as well as to 146 additional cases of invasive breast cancer of ductal or lobular histology. Genomic differences between high-grade and low/intermediate-grade DCIS, as well as between pure DCIS and invasive cancer, were identified. RESULTS: Pure DCIS showed almost the same degree of chromosomal instability as invasive ductal cancers. A higher proportion of low/intermediate-grade versus high-grade DCIS had loss of 16q (65 versus 12%, respectively; P = 0.002). When compared with lower grade DCIS, high-grade DCIS exhibited more frequent gain of 17q (65 versus 41%; P = 0.15) and higher frequency loss of 8p (77 versus 41%; P = 0.04). Chromosomal alterations in those cases with synchronous DCIS and invasive ductal cancer showed a high degree of shared changes within the two components. CONCLUSIONS: DCIS is genetically advanced, showing a similar degree of chromosomal alterations as invasive ductal cancer. The pattern of alterations differed between high- and low/intermediate-grade DCIS, supporting a model in which different histological grades of DCIS are associated with distinct genomic changes. These regions of chromosomal alterations may be potential targets for treatment and/or markers of prognosis.

Adult↗

A molecular 'signature' of primary breast cancer cultures; patterns resembling tumor tissue.

BACKGROUND: To identify the spectrum of malignant attributes maintained outside the host environment, we have compared global gene expression in primary breast tumors and matched short-term epithelial cultures. RESULTS: In contrast to immortal cell lines, a characteristic 'limited proliferation' phenotype was observed, which included over expressed genes associated with the TGFbeta signal transduction pathway, such as SPARC, LOXL1, RUNX1, and DAPK1. Underlying this profile was the conspicuous absence of hTERT expression and telomerase activity, a significant increase in TbetaRII, its cognate ligand, and the CDK inhibitor, p21CIP1/WAF1. Concurrently, tumor tissue and primary cultures displayed low transcript levels of proliferation-related genes, such as, TOP2A, ANKT, RAD51, UBE2C, CENPA, RRM2, and PLK. CONCLUSIONS: Our data demonstrate that commonly used immortal cell lines do not reflect some aspects of tumor biology as closely as primary tumor cell cultures. The gene expression profile of malignant tissue, which is uniquely retained by cells cultured on solid substrates, could facilitate the development and testing of novel molecular targets for breast cancer.

Breast↗

Genetic aberrations in prostate carcinoma detected by comparative genomic hybridization and microsatellite analysis: association with progression and angiogenesis.

BACKGROUND: In spite of increasing knowledge about the tumor biology of prostate cancer (PC), molecular events involved in tumor progression are not well characterized. There is evidence that a number of genetic alterations play a role in tumor progression and in addition, angiogenesis also contributes. In this study, comparative genomic hybridization (CGH), a sensitive method for detecting regional DNA copy number abnormalities, and microsatellite analysis was used to identify frequent genome changes in PC. Correlation of these data with microvessel density (MVD) and clinical follow-up data was performed to determine genetic alterations that are associated with angiogenesis and subsequent tumor progression. METHODS: Fifty-seven paraffin embedded radical prostatectomy (RP) specimens were microdissected. DNA from the microdissected PC tissue was amplified by degenerate oligonucleoitide primed (DOP)-polymerase chain reaction (PCR), and CGH was performed on the PCR product. Quantitative analyses of the CGH profiles were performed using a t-statistic. Additionally, a microsatellite analysis of chromosome 13q was performed on a subgroup of 31 of the tumors. Using a polyclonal antibody against factor VIII, MVD was determined for all RP specimens. The results of CGH and microsatellite analysis were correlated with the clinical data of the patients and with MVD. RESULTS: Forty-two of the tumors (75%) showed one or more gains while 39 (70%) showed one or more losses per tumor. The most frequent DNA copy number gains were on chromosome 3, 4, 7, 8, 10, 11, 12, 13, and X. The most frequent losses were on chromosomes 2, 5, 6, 8, 10, 13, 15, and 16. Cancer recurrence occurred in 15 patients. The total number of DNA copy number losses was significantly higher in patients with this progression (86%) than without (52%) (P < 0.001). There was no significant difference in the number of gains in patients with or without progression. Contingency table analysis showed a significant correlation between progression and losses in regions of chromosomes 6q and 13q and a gain of chromosome 7q. In multivariate analysis, only loss of chromosome 6 was independently prognostic. The gains that correlated most closely with MVD > 35 were on chromosomes 2q, 7q, and Xq, while the losses most closely associated with MVD > 35 were on chromosomes 8q, 10q, and 13q. However, only the association between loss of chromosome 13q and MVD > 35 was statistically significant. Microsatellite analysis revealed a statistically significant correlation between MVD and instability of locus 171. CONCLUSIONS: This study indicates that the frequency of genetic alterations in PC as detected by CGH correlates with clinical outcome, and that losses of DNA from chromosomes 6q and 13q are important events that correlate with tumor progression, with loss of 13q, especially instability of locus 171, also associated with angiogenesis.

Chromosome Aberrations↗