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PubMed1996

Dosimetric results from a feasibility study of a novel radiosurgical source for irradiation of intracranial metastases.

PURPOSE: A feasibility study addressing the role of a new miniature x-ray device, the Photon Radiosurgery System (PRS), for interstitial radiosurgical treatment of intracranial metastatic neoplasms, was conducted at our institution. To gain insight into the role of PRS vis-à-vis other currently available radiosurgical treatment modalities, dosimetric comparisons of Linac Radiosurgery and proton beam therapy were performed in the treatment of a small approximately spherical metastasis. METHODS AND MATERIALS: The photon radiosurgery system is a miniature, battery operated, high-voltage x-ray generator that produces low-energy x-rays with an effective energy of 10-20 keV emanating from the tip of a probe stereotactically inserted into small tumors (< 3 cm in diameter) in humans. Patients, 18 years or older, with supratentorial mass lesions less than 3 cm in diameter were eligible if they were likely to survive their systemic cancer and be capable of self-care for more than 4 months. Patients were ineligible if presenting with infratentorial lesions, contraindications for biopsy, or receipt of chemotherapy or radiotherapy within 4 weeks were ineligible. RESULTS: Fourteen patients with metastatic supratentorial lesions were treated from December 1992 to December 1993 for metastatic tumors to the brain. Single doses of 10-20 Gy were delivered to spherical targets of 10 to 35 mm in diameter. Treatment, including biopsy, pathologic review and radiation treatment, generally took less than 3 h. One patient, later found to have an ischemic stroke, developed a small hemorrhage from the biopsy that preceded interstitial irradiation. There were no other complications. Median survival was 10 months. Three locally recurrent lesions failed at 3.5, 4, and 10 months after treatment. All patients had stable or improved Karnofsky status for 2 weeks to 21 months after treatment. The PRS dosimetry appears at least as good as that obtained using 6 MV Linac or 160 MeV protons. Analyses of dose-volume histograms comparing the volumes of normal CNS tissue irradiated employing each of the respective modalities suggest a small sparing of normal tissue with PRS, as opposed to linac or protons, in this patient population with small, approximately spherical tumors. CONCLUSIONS: The PRS device provides a unique cost and time efficient procedure for providing interstitial radiation therapy immediately following histologic confirmation of malignancy in patients undergoing biopsy of intracranial lesions. The PRS treatment appears safe, and preliminary data suggest no evidence of treatment-related morbidity within the life span of the selected patient population. When treating small, spherical lesions, PRS appears to offer a modest dosimetric advantage over Linac or proton beam therapy in sparing normal tissue. These encouraging results have prompted a Phase II trial that is currently underway. Further efforts are necessary in the design of a clinically relevant trial addressing the role of fractionated external beam radiation therapy with boost vs. PRS treatment with WBRT in the treatment of single metastases.

Adult↗

PubMed2004

Characterization of RS29, a blue-green proteorhodopsin variant from the Red Sea.

Using structural modeling comparisons and mutagenesis, amino acid residue 105 was found to function as a spectral tuning switch in marine proteorhodopsins (PR). Changes at this position account for most of the spectral difference between blue-absorbing PRs (B-PRs), and green-absorbing PRs (G-PRs). Here we analyzed a Red Sea variant (RS29) from a new family of PRs that is composed of G-PR type variants that possess glutamine instead of leucine at position 105 like in B-PRs. The absorption spectrum as well as photocycle of RS29 variant were measured and compared to point-mutated 'position 105' PRs. Unexpectedly, the absorption maximum of RS29 was 515 nm, a smaller blue shift compared to the 498 nm maximum of G-PR_L105Q. We found that two additional residues at positions 65 and 70 each contribute a small red shift to the absorption spectrum of G-PR and therefore appear to account for the intermediate absorption maximum of RS29 by their opposing influences on the spectrum. Our results show that in addition to the retinal pocket position 105 determinant, other residues predicted to be outside the retinal pocket fine-tune the absorption spectra of marine PRs. The RS29 photochemical reaction cycle was found to be 2 orders of magnitude slower than that of G-PR with a t(1/2) of >600 ms. This result raises the possibility of regulatory (i.e. sensory) rather than energy harvesting functions for some members of the PR family.

Base Sequence↗

PubMed2002

Acute and chronic stress differently affect visceral sensitivity to rectal distension in female rats.

Stressful life events are frequently associated with outward signs of irritable bowel syndrome (IBS). Increasing evidence suggests that acute and chronic stress stimuli implicate different physiological mechanisms and neuroendocrine responses. Therefore, we investigated the influence of acute and chronic stress on visceral nociception in female rats and the involvement of colonic mast cells in this effect. The effect of acute and chronic partial restraint stress (PRS) on visceral sensitivity to rectal distension (RD) was assessed by abdominal muscle electromyography. Colonic mast cell activation was determined by measuring histamine release after in vitro stimulation with substance P (SP) in colonic samples from rats experiencing RD vs. controls. Acute PRS significantly enhanced abdominal response to RD compared with sham PRS for all volumes of distension. In contrast, chronic PRS induced a hyperalgesic response for the highest volumes of distension (0.8 and 1.2 mL), but did not affect the number of abdominal contractions for the lowest volume (0.4 mL) compared with controls. Both acute and chronic PRS increased in vitro SP-induced histamine release without affecting mast cell numbers. RD induced similar in vitro histamine release from colonic samples from both acute and chronic PRS rats; this release, however, was significantly higher than that measured in sham-PRS rats. Acute and chronic PRS differently influence visceral sensitivity in response to RD in female rats. This difference, however, cannot be attributed to a different effect of either stress paradigm on mast cell histamine release.

Abdomen↗

PubMed1997

Radiolucent pancreatic lithiasis: a precursor stage for calcified pancreatic lithiasis or a new entity?

OBJECTIVE: Radiolucent pancreatic lithiasis (RPL) has been identified as a different entity from calcified pancreatic lithiasis. The purpose of this study is to evaluate the frequency, characteristics and evolution of RPL. PATIENTS: Between 1983 and 1995, 278 consecutive patients who presented with pancreatic lithiasis were studied. Forty-four patients had RPL (15.8%): 27 had pure radiolucent stones (PRS) (group 1), 5 had pure radiolucent stones combined with evenly calcified stones (ECS) (group 2), 2 had target calculi (TC) (radiolucent core with calcified shell) (group 3), 10 had TC combined with ECS (group 4). RESULTS: Among the 27 patients with PRS, there were 19 males with a mean age of 41 years. PRS were mainly located in the head of the pancreas with a mean diameter of 5 mm (range 3-26 mm). Seven patients among 27 with PRS (26%) were less than 20 years old (juvenile form) or more than 60 years old (senile form). They were characterized by no or low alcohol consumption and a high rate of attacks of acute pancreatitis. In group 1, PRS turned to more advanced calcified stages in 6/16 of patients (37%) followed in 30 to 144 months with a prior stage of TC in 2 cases. An evolution toward more calcified stages (TC or ECS) occurred in half of the patients belonging to group 2 and 4 in 36 to 84 months. Genetic disposition and alcohol consumption could account for the evolution toward more calcified stages. A genetic factor is suggested by a rapid evolution to evenly calcified stones in two aged children 8 and 10 years and by a high frequency of familial cases in patients belonging to groups 2 and 4 (60% and 20%) as compared to group 1 with PRS (4%). Alcohol consumption could accelerate the calcifying process since patients belonging to groups 2 and 4 had a significantly higher alcohol consumption than those with PRS (group 1). CONCLUSION: RPL is a heterogeneous pancreatic disease including juvenile and senile presentation which may represent about 15% of pancreatic lithiasis. Evolution towards calcified stages (PRS then TC then ECS) occurred in 37-50% of cases and could be related to a genetic factor and increased alcohol consumption.

Adolescent↗

PubMed2004

Enhancing prototype reduction schemes with recursion: a method applicable for "large" data sets.

Most of the prototype reduction schemes (PRS), which have been reported in the literature, process the data in its entirety to yield a subset of prototypes that are useful in nearest-neighbor-like classification. Foremost among these are the prototypes for nearest neighbor classifiers, the vector quantization technique, and the support vector machines. These methods suffer from a major disadvantage, namely, that of the excessive computational burden encountered by processing all the data. In this paper, we suggest a recursive and computationally superior mechanism referred to as adaptive recursive partitioning (ARP)_PRS. Rather than process all the data using a PRS, we propose that the data be recursively subdivided into smaller subsets. This recursive subdivision can be arbitrary, and need not utilize any underlying clustering philosophy. The advantage of ARP_PRS is that the PRS processes subsets of data points that effectively sample the entire space to yield smaller subsets of prototypes. These prototypes are then, in turn, gathered and processed by the PRS to yield more refined prototypes. In this manner, prototypes which are in the interior of the Voronoi spaces, and thus ineffective in the classification, are eliminated at the subsequent invocations of the PRS. We are unaware of any PRS that employs such a recursive philosophy. Although we marginally forfeit accuracy in return for computational efficiency, our experimental results demonstrate that the proposed recursive mechanism yields classification comparable to the best reported prototype condensation schemes reported to-date. Indeed, this is true for both artificial data sets and for samples involving real-life data sets. The results especially demonstrate that a fair computational advantage can be obtained by using such a recursive strategy for "large" data sets, such as those involved in data mining and text categorization applications.

Algorithms↗

PubMed2026

Harnessing Polygenic Risk Scores to Refine Venous Thromboembolism Risk Stratification.

BACKGROUND: Venous thromboembolism (VTE) is a major cause of morbidity in patients of all ages. Despite growing interest in polygenic risk scores (PRS) for VTE, their utility remains understudied. Our objective was to evaluate the independent impact of a PRS on VTE susceptibility in adults and children. METHODS: We completed a retrospective, case-control study of two separate cohorts with evaluation of three VTE PRS models, with the primary analysis focused on a 293 single nucleotide polymorphism (SNP) PRS. The adult cohort included 597 VTE cases and 31 998 controls, and the pediatric cohort included 109 cases and 448 controls, both obtained from a de-identified databank with linked genetic data. Separate adult and pediatric multivariable logistic regressions were performed to measure the association of risk factors with VTE. RESULTS: Higher PRS in adults was significantly associated with increased odds of VTE, with each 1-standard deviation increase in PRS conferring an adjusted odds ratio of 1.25 (OR = 1.25, 95% CI 1.15-1.36, p < 0.001). Leading risk factors for adults were cancer (OR = 2.43, 95% CI: 2.04-2.89, p < 0.001) and recent surgery (OR = 2.16, 95% CI: 1.83-2.54, p < 0.001). The standardized PRS also exhibited increased risk for VTE in children (OR = 1.38, 95% CI 1.10-1.74, p = 0.003). Central venous catheterization (OR = 5.65, 95% CI 3.40-9.50, p < 0.001) was the foremost risk factor for pediatric VTE. CONCLUSION: VTE in adults and children is multifactorial, with clinical and genome-wide risk factors contributing. PRS may serve as a valuable adjunct to clinical risk factors for VTE risk stratification.

Humans↗

PubMed2006

Lactobacillus farciminis treatment suppresses stress induced visceral hypersensitivity: a possible action through interaction with epithelial cell cytoskeleton contraction.

BACKGROUND: Stress induced increase in colonic paracellular permeability results from epithelial cell cytoskeleton contraction and is responsible for stress induced hypersensitivity to colorectal distension (CRD). The probiotic Lactobacillus farciminis releases spontaneously nitric oxide (NO) in the colonic lumen in vivo and exerts anti-inflammatory effects. This study aimed: (i) to evaluate the effects of L farciminis on stress induced hypersensitivity to CRD and increase in colonic paracellular permeability; and (ii) to ascertain whether these effects are NO mediated and related to changes in colonocyte myosin light chain phosphorylation (p-MLC). METHODS: Female Wistar rats received either 10(11) CFU/day of L farciminis or saline orally over 15 days before partial restraint stress (PRS) or sham-PRS application. Visceral sensitivity to CRD and colonic paracellular permeability was assessed after PRS or sham-PRS. Haemoglobin was used as an NO scavenger. Western blotting for MLC kinase, MLC, and p-MLC were performed in colonic mucosa from L farciminis treated and control rats after PRS or sham-PRS. RESULTS: PRS significantly increased the number of spike bursts for CRD pressures of 30-60 mm Hg as well as colonic paracellular permeability. L farciminis treatment prevented both effects, while haemoglobin reversed the protective effects of L farciminis. p-MLC expression increased significantly from 15 to 45 minutes after PRS, and L farciminis treatment prevented this increase. CONCLUSION: L farciminis treatment prevents stress induced hypersensitivity, increase in colonic paracellular permeability, and colonocyte MLC phosphorylation. This antinociceptive effect occurs via inhibition of contraction of colonic epithelial cell cytoskeleton and the subsequent tight junction opening, and may also involve direct or indirect effects of NO produced by this probiotic.

Animals↗

PubMed2005

Induction of long-lasting depolarization in medioventral medulla neurons by cholinergic input from the pedunculopontine nucleus.

Stimulation of the pedunculopontine nucleus (PPN) is known to induce changes in arousal and postural/locomotor states by activation of such descending targets as the caudal pons and the medioventral medulla (MED). Previously, PPN stimulation was reported to induce prolonged responses (PRs) in intracellularly recorded caudal pontine neurons in vitro. The present study used intracellular recordings in semihorizontal slices from rat brain stem (postnatal days 12-21) to determine responses in MED neurons following PPN stimulation. One-half (40/81) of MED neurons showed PRs after PPN stimulation. MED neurons with PRs had shorter duration action potential, longer duration afterhyperpolarization, and higher amplitude afterhyperpolarization than non-PR MED neurons. PR MED neurons were significantly larger (568 +/- 44 microm2) than non-PR MED neurons (387 +/- 32 microm2). The longest mean duration PRs and maximal firing rates during PRs were induced by PPN stimulation at 60 Hz compared with 10, 30, or 90 Hz. The muscarinic cholinergic agonist carbachol induced depolarization in all PR neurons tested, and the muscarinic cholinergic antagonist scopolamine reduced or blocked carbachol- and PPN stimulation-induced PRs in all MED neurons tested. These findings suggest that PPN stimulation-induced PRs may be due to activation of muscarinic receptor-sensitive channels, allowing MED neurons to respond to a transient, frequency-dependent depolarization with long-lasting stable states. PPN stimulation appears to induce PRs in large MED neurons using parameters known best to induce locomotion.

Animals↗

PubMed2026

Methods for modeling gene-environment interplay using polygenic risk scores.

Polygenic risk scores (PRS) are increasingly recognized as pivotal tools for quantifying disease risk through the aggregation of multiple genetic variants. As sample sizes in genome-wide association studies (GWAS) continue to expand and PRS become more powerful, they are set to play a key role in translational research and personalized medicine. Understanding the interplay of PRS with environmental factors is critical for interpreting and applying PRS in diverse contexts. This interplay manifests in two forms: PRS-by-environment interaction (PRS × E) and gene-environment correlation (rGE). However, despite the growing application and importance of PRS, there are limited guidelines for performing PRS × E interaction analyses while controlling for rGE, which can lead to inconsistencies across studies and misinterpretation of results. Here we provide a review of different methods for performing PRSxE interaction in various epidemiological study designs, propose recommendations for best-practice, and discuss future challenges.

Gene-Environment Interaction↗

PubMed2006

The genetic basis of the Pierre Robin Sequence.

OBJECTIVE: The Pierre Robin Sequence (PRS) is subgroup of the cleft palate population. As with the etiology of cleft lip or palate, the etiology of PRS is generally unknown. Some factors are suggestive of a genetic basis for PRS. The purpose of this study was to compare genetic information on PRS available in the literature and in a cytogenetic database to facilitate focused genetic studies of PRS. DESIGN: After searching Medline for "pierre robin and genetics," the Mendelian Cytogenetics Network database for "robin" and "pierre robin," and two reviews from the Human Cytogenetics Database for "cleft palate" and "micrognathia," a comparison of the data and a search in Online Mendelian Inheritance in Man (OMIM) Gene Map was performed to identify relevant candidate genes. RESULTS: The findings revealed consistency to a certain degree to loci 2q24.1-33.3, 4q32-qter, 11q21-23.1, and 17q21-24.3. A search in the OMIM Gene Map provided many candidate genes for PRS in these regions. The GAD67 on 2q31, the PVRL1 on 11q23-q24, and the SOX9 gene on 17q24.3-q25.1 are suggested to be of particular importance. CONCLUSION: Candidate loci and a few potential candidate genes for PRS are proposed from the present study. This may enable researchers to focus their effort in the studies of PRS.

Cleft Lip↗

PubMed1995

Hearing levels in Pierre Robin syndrome.

Hearing was tested in 18 patients with Pierre Robin syndrome (PRS). These results were compared with those obtained for 243 patients with either cleft lip or cleft palate, or both. None of the PRS group patients had middle ear or inner ear malformations, or sensorineural hearing loss in speech frequencies. Hearing loss in PRS is usually conductive, bilateral, and more frequent in PRS patients (30 ears or 83.33%) than in patients who do not have PRS (290 ears or 59.67%). A significantly higher (p < .01) mean of hearing loss for air conduction in speech frequencies (MHLSF = 24.5 dB) was found in PRS patients than in patients without PRS (MHLSF = 17.8 dB). The ears of the PRS patients with hearing loss were examined, revealing middle ear effusion. In all cases, hearing was restored to a normal level through suction and the use of ventilation tubes.

Adolescent↗

PubMed2026

Genetic Risk Factors for Kidney Function in Individuals with Type 1 Diabetes.

KEY POINTS: Previous research has identified polygenic risk scores that are associated with low eGFR and albuminuria in the general population. We observed that these eGFR and albuminuria polygenic risk scores were associated with eGFR and albuminuria, respectively, in type 1 diabetes. Associations were independent of glycemic control and suggest shared genetic kidney risk factors between type 1 diabetes and the general population. BACKGROUND: Genetic risk factors underlying kidney disease in type 1 diabetes (T1D) remain poorly understood. We examined whether previously established polygenic risk scores (PRS) for eGFR and albuminuria are associated with these measures in adults with T1D in the Diabetes Control and Complications Trial (DCCT)/Epidemiology of Diabetes Interventions and Complications study. METHODS: We applied eGFR and albuminuria PRS derived in general population cohorts to 1304 DCCT/Epidemiology of Diabetes Interventions and Complications participants with genome-wide genotyping. We tested PRS associations with eGFR and urine albumin excretion rate (AER) as well as incident eGFR <60 ml/min per 1.73 m 2 , AER ≥30 mg/24 h, and AER ≥300 mg/24 h. For consistency, PRS values were linearly transformed so higher scores corresponded to higher eGFR and AER. We also examined associations of kidney outcomes with rs55703767 in COL4A3 , which has previously been associated with CKD in T1D. RESULTS: At DCCT baseline, participants had a mean age of 27 years; 53% were male. 49% of participants were randomized to intensive versus conventional glucose-lowering therapy. Participants were followed for median of (first-third quartiles) 35 (33-37) years. The eGFR PRS was significantly associated with continuous eGFR (per one SD higher PRS 2.72 ml/min per 1.73 m 2 higher [95% confidence interval (CI), 2.05 to 3.40]) and incident eGFR <60 ml/min per 1.73 m 2 (hazard ratio [HR]=0.82 [95% CI, 0.73 to 0.92]), but not consistently with albuminuria. There was no association with quantitative AER (2.42 mg/24 h [95% CI, -1.86 to 6.89]) or sustained AER ≥30 mg/24 h (HR=1.03; [95% CI, 0.94 to 1.14]). The albuminuria PRS was significantly associated with incident AER ≥30 mg/24 h (HR=1.12 [95% CI, 1.02 to 1.22]) but not continuous eGFR (0.49 ml/min per 1.73 m 2 higher [95% CI, -0.23 to 1.21]) or incident eGFR <60 ml/min per 1.73 m 2 (HR=0.96 [95% CI, 0.85 to 1.08]). Associations were similar in analyses stratified by DCCT treatment group assignment. rs55703767 was associated with lower incident macroalbuminuria in the overall cohort (HR=0.77 per minor allele [95% CI, 0.59 to 0.99]), and upon stratification by DCCT treatment group assignment, only within the conventional and not intensive glucose-lowering therapy group. CONCLUSIONS: PRS associated with eGFR and albuminuria in the general population were associated with corresponding measures in adults with T1D. The results suggest shared genetic risk factors for kidney disease between T1D and the general population but different genetic risk factors for albuminuria and eGFR in T1D. CLINICAL TRIALS REGISTRATION NUMBERS: NCT00360893 , NCT00360815 .

Adult↗

PubMed1982

Reiter's syndrome in the population. An Interview Study.

To obtain data on the incidence of Reiter's syndrome (RS) as well as on possible simultaneously appearing signs and symptoms of RS in sexual couples we have made interview reports of randomly selected 530 persons: 219 males and 311 females, aged 15 to 54. None had RS. Six males (2.7%) and seven females (2.3%) had a history of probable RS (PRS). Almost all (5/6) female sexual partners of the men with PRS and more than half (4/7) male sexual partners of the women with PRS had a history of urogenital involvement. Twenty-seven men and 54 women said they did not have any sexual partners at that time. Forty (21.5%) of the female sexual partners of the remaining 186 men and likewise 11 male sexual partners (4,4%) of the 250 women had a history of urogenital involvements. Thus the relative risk of urogenital involvement is increased 3.9-fold in females and 13-fold in males who are sexual partners of persons with a history of PRS. Likewise in couples where one of the consorts has a history of PRS the simultaneous occurrence of urogenital involvement in both partners as well as the simultaneous occurrence of joint involvement in one and urogenital involvement in the other consort were registered significantly more frequently than in couples where neither of the consorts has a history of PRS. Sexual partners of persons with PRS even show a tendency to have joint and back pains more frequently than sexual partners of persons lacking a history of PRS. These results emphasize the role of infections in the genito-urinary tracts of sexual couples as a possible channel and reservoir of microbes which may cause, or contribute to, the initiation of and/or repeated attacks of RS. Sexually acquired and maintained rheumatic diseases may be one of the major problems in rheumatology.

Adult↗

PubMed2006

[Image analysis of puborectalis syndrome and its clinical significance].

OBJECTIVE: To discuss the clinical value and application range of defecography, CT and MRI in diagnosis of puborectalis syndrome (PRS). METHODS: The clinical data of 83 PRS patients, including defecography, CT and MRI scanning in pelvic floor resting and defecation at maximum exertion, measurement of anorectal angle (ARA), length and depth of ARA impression and the thickness of the puborectalis muscle, were collected, and compared with those of 56 normal persons. RESULTS: For normal persons, ARA at maximum exertion was more significantly increased than that at resting. In 62 cases with PRS, ARA at maximum exertion was more obviously reduced than that at resting and associated with puborectalis muscle (PRM) impression. In the other 21 cases, ARA showed no changes at either maximum exertion or resting, a little or no excretion of barium appeared and "shelving syndrome" was showed. The cross-sectional images of CT and MRI showed that the puborectalis of PRS patients were thicker than that of normal persons (P<0.01). PRS patients also showed clear pelvic floor muscle, fasciae and peripheral crevice. CONCLUSIONS: Defecography, manifested the abnormal function of the puborectalis muscles, is a reliable method for diagnosis of PRS. In the meantime, CT and MRI are able to clearly display the position, growth status and size of the puborectalis muscles as well as its relation with adjacent structures, which provide further understandings on anatomical changes, abnormal adjacent structure and other functional diseases of pelvic floor in PRS patients. Therefore, an appropriate combination of the 3 methods play an important role in the early diagnosis of PRS and guidance for surgical treatment.

Adolescent↗

PubMed2025

Polygenic Contributions to Lithium Augmentation Outcomes in Unipolar Depression.

IMPORTANCE: Lithium augmentation is an effective treatment for patients with major depression after inadequate antidepressant response, but therapeutic outcomes vary considerably between individuals. Molecular studies may provide novel insights into treatment prediction and guide personalized therapy. OBJECTIVE: To investigate the association of polygenic risk scores (PRS) for schizophrenia (SCZ), major depressive disorder (MDD), and bipolar disorder (BIP) with clinical outcomes after lithium augmentation. DESIGN, SETTING, AND PARTICIPANTS: This cohort study analyzed prospectively assessed treatment outcomes in patients who underwent lithium augmentation. Disorder-specific PRS were calculated using well-powered genome-wide association study summary statistics. Participants were recruited from 13 psychiatric hospitals, primarily in the greater Berlin area, between 2008 and 2020. They were patients with MDD who showed inadequate response to at least 1 antidepressant, a baseline score of 12 or more on the 17-item Hamilton Depression Rating Scale (HAMD-17), adequate treatment duration (≥4 weeks), and no diagnostic or co-medication changes. Data analysis was conducted between June 2022 and November 2023. EXPOSURE: Polygenic risk scores for MDD, SCZ, or BIP. MAIN OUTCOMES AND MEASURES: Response was defined as a 50% or greater reduction in HAMD-17 score, remission as a HAMD-17 score of 7 or less. Cox proportional hazards models, adjusted for ancestry, demographic, and clinical covariates, were used to estimate hazard ratios (HRs) for favorable outcomes. RESULTS: Among 193 patients (mean [SD] age, 49.5 [13.4] years; 118 [61.1%] female and 75 [38.9%] male), higher BIP-PRS were associated with both response (HR, 1.29; 95% CI, 1.02-1.63; P = .03) and remission (HR, 1.52; 95% CI, 1.14-2.04; P = .004), explaining 2.51% and 4.53% of the variability in treatment outcomes, respectively. Individuals in the highest tertile of the BIP-PRS distribution had a 2.02-fold (95% CI, 1.15-3.53) higher likelihood of response and a 2.26-fold (95% CI, 1.17-4.36) higher chance of remission compared with those in the lowest tertile. Additionally, lower MDD-PRS was associated with better response to lithium augmentation (HR, 0.81; 95% CI, 0.66-1.00; P = .048; Nagelkerke R2 = 1.99%). No significant associations were observed between SCZ-PRS and response (HR, 1.00; 95% CI, 0.80-1.24; P = .97) or remission (HR, 1.12; 95% CI, 0.85-1.48; P = .42). CONCLUSIONS AND RELEVANCE: Individuals carrying a higher polygenic burden for BIP and lower polygenic risk for MDD are more likely to benefit from lithium augmentation. Our findings suggest that disease-related PRS may aid in developing treatment prediction models for lithium augmentation response in depression, potentially informing clinical decision-making.

Humans↗

PubMed2026

Polygenic Risk Scores for Incident Dementia in the Multi-Ethnic Study of Atherosclerosis.

Over 75 Alzheimer's disease (AD) and dementia-associated variants have been identified through genome-wide association studies, but the utility of polygenic risk scores (PRS) for predicting AD and dementia in diverse and admixed populations remains unclear. We compared how PRS approaches differing in p-value thresholds, variant weights, and source ancestry perform in predicting dementia in 6338 African American, Chinese, Hispanic, and White individuals from the Multi-Ethnic Study of Atherosclerosis. We tested clumping and thresholding (C+T) methods with varying parameters against Bayesian approaches (PRS-CS, PRS-CSx). We compared the ability of each method to predict incident dementia in all participants and in groups stratified by self-reported race/ethnicity. We additionally analyzed performance across groups stratified by estimated proportion of non-Finnish European (NFE)-like ancestry. Including more variants does not improve performance. We found comparable associations between dementia and PRS when comparing a C+T method with only 15 SNPs and PRS derived from Bayesian models that include > 800,000 SNPs (HR5e-08 = 1.18, 95% CI: 1.08-1.28; HRCSx = 1.17, 95% CI: 1.07-1.27). The p < 5e-08 C+T method was more strongly associated with incident dementia in populations genetically dissimilar from the source data (HRlowNFE_5e-08 = 1.27, 95% CI: 1.08-1.50; HRlowNFE_CSx = 1.12, 95% CI: 0.94-1.33). More selective PRS models using genome-wide significant SNPs may be preferable for dementia prediction in diverse populations.

Aged↗

PubMed1977

A specialized transducing lambda phage carrying the Escherichia coli genes for phenylalanyl-tRNA synthetase.

A lambda phage has been isolated which specifically transduces the Escherichia coli pheS and pheT genes coding for the alpha and beta subunits of the phenylalanyl-tRNA synthetase (PRS). This phage transduces with high frequency (i) several temperature-sensitive PRS mutants to thermoresistance and (ii) a p-fluorophenylalanine resistant PRS mutant to sensitivity against this amino-acid analog. The in vitro PRS activities of such lysogens suggest that the alpha and beta subunits coded by the transducing phage complement the mutant host PRS-subunits in vivo by means of formation of hybrid enzymes. The transducing lambda phages were also used to infect UV light irradiated cells. The SDS-gel electrophoretic analysis of the proteins synthesized in such cells revealed that the phage codes at least for four different E. coli proteins. Two proteins with molecular weights of 94,000 and 38,000 daltons cross-reacted with an anti PRS serum and were thus identified as the beta and alpha subunits of PRS, respectively. A third protein with a molecular weight of 22,000 daltons is identical with the ribosomal initiation factor IF3 (Springer et al., 1977b). The other protein (Mr 78,000) is still unidentified.

Amino Acyl-tRNA Synthetases↗

PubMed2025

Leveraging local ancestry and cross-ancestry genetic architecture to improve genetic prediction of complex traits in admixed populations.

The broader application of polygenic risk score (PRS) is hindered by the limited transferability of PRS developed in Europeans to non-European populations. While many statistical methods have been developed to improve the performance of PRS in non-European populations, most of them focused on discrete genetic ancestry clusters and did not consider admixed individuals. Admixed individuals pose a unique challenge for PRS calculation due to the complexity of local ancestry and cross-ancestry effect sizes. Here, we present a statistical method called SDPR_admix for calculating PRS in admixed individuals. SDPR_admix characterizes the joint distribution of the effect sizes of a genetic variant with two ancestries to be both zero, ancestry enriched, or shared with correlation. SDPR_admix outperformed other methods in simulations and improved the prediction of real traits in European-African admixed individuals in UK Biobank when trained on the Population Architecture using Genomics and Epidemiology (PAGE) dataset (N = 13,000). Deployment of SDPR_admix on All of Us (N = 52,000) further increased the prediction accuracy by approximately 5-fold on average compared with training on PAGE. This enhancement was achieved with manageable computational time and cost, demonstrating the feasibility of training PRS models on large-scale All of Us data. We provided several examples demonstrating that both ancestral-enriched and shared effects, as included in the SDPR_admix prediction model, are helpful for improving polygenic prediction in admixed populations. We also applied SDPR_admix to construct PRS for admixed Americans with mixture of European and Amerindigenous ancestries and showed that SDPR_admix overall outperformed other methods.

Humans↗