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At least 73 records · Page 4Linked to original sources
PubMed2001

Pregnancy rates (prs) according to embryo cell number at time of embryo transfer (ET).

PURPOSE: To evaluate pregnancy and implantation rates following fresh and frozen embryo transfer (ET) according to blastomere number. METHODS: A retrospective study from 1/1/97 to 9/30/98 including all cycles with ETs irrespective of age. RESULTS: 65% of fresh transfers had at least one 8-cell embryo vs only 39.6% for frozen ET. The clinical pregnancy and implantation rates were higher when one 8-cell embryo was transferred (64% and 24%) vs a 5-7 cell embryo (41% and 14.5%) for fresh transfers. There was less of a difference with frozen ETs (46% and 19% for 8-cell vs 38% and 17% for 5-7 cell). CONCLUSIONS: Since mostly only 8-cell embryos at day 3 reach the blastocyst stage, these data raise questions as to whether the quest to attain the highest pregnancy rate per transfer through blastocyst transfer, may be at the expense of overall pregnancy rate (fresh and frozen) from a given oocyte harvest.

Adult↗
PubMed2002

Effects of pedunculopontine nucleus (PPN) stimulation on caudal pontine reticular formation (PnC) neurons in vitro.

Stimulation of the pedunculopontine nucleus (PPN) is known to induce changes in arousal and postural/locomotor states. Previously, PPN stimulation was reported to induce prolonged responses (PRs) in extracellularly recorded PnC neurons in the decerebrate cat. The present study used intracellular recordings in semihorizontal slices from rat brain stem (postnatal days 12-21) to determine responses in PnC neurons following PPN stimulation. Two-thirds (65%) of PnC neurons showed PRs after PPN stimulation. PnC neurons with PRs had higher amplitude afterhyperpolarizations (AHP) than non-PR (NPR) neurons. Both PR and NPR neurons were of mixed cell types characterized by "A" and/or "LTS," or neither of these types of currents. PnC cells showed decreased AHP duration with age, due mostly to decreased AHP duration in NPR cells. The longest mean duration PRs were induced by stimulation at 60 and 90 Hz compared with 10 or 30 Hz. Maximal firing rates in PnC cells during PRs were induced by PPN stimulation at 60 Hz compared with 10, 30, or 90 Hz. BaCl2 superfusion blocked PPN stimulation-induced PRs, suggesting that PRs may be mediated by blockade of potassium channels, in keeping with increased input resistance observed during PRs. Depolarizing pulses failed to elicit, and hyperpolarizing pulses failed to reset, PPN stimulation-induced PRs, suggesting that PRs may not be plateau potentials. Pharmacological testing revealed that nifedipine superfusion failed to block PPN stimulation-induced PRs; i.e., PRs may not be calcium channel-dependent. The muscarinic cholinergic agonist carbachol induced depolarization in most PR neurons tested, and the muscarinic cholinergic antagonist scopolamine reduced or blocked PPN stimulation-induced PRs in some PnC neurons, suggesting that some PRs may be due to muscarinic receptor activation. The nonspecific ionotropic glutamate receptor antagonist kynurenic acid failed to block PPN stimulation-induced PRs, as did the metabotropic glutamate receptor antagonist (R, S)-alphamethyl-4-carboxyphenylglycine, suggesting that PRs may not be mediated by glutamate receptors. These findings suggest that PPN stimulation-induced PRs may be due to increased excitability following closing of muscarinic receptor-sensitive potassium channels, allowing PnC neurons to respond to a transient, frequency-dependent depolarization with long-lasting stable states. PPN stimulation appears to induce PRs using parameters known best to induce locomotion. This mechanism may be related to switching from one state to another (e.g., locomotion vs. standing or sitting, waking vs. non-REM sleep or REM sleep).

Action Potentials↗
PubMed2005

Prognosis of airway obstruction and feeding difficulty in the Robin sequence.

OBJECTIVE: To evaluate the course and prognosis of airway obstruction and feeding difficulty in the Pierre Robin sequence (PRS). METHODS: Retrospective review of 60 patients with PRS between 1993 and 2002 at the University of California, Davis Medical Center. Patients were placed into diagnostic subgroups: (1) Isolated PRS; (2) Syndromic PRS (known syndrome with PRS); (3) Unique PRS (unique anomalies with PRS). Data regarding severity, duration, and management of airway obstruction and feeding difficulty were collected. RESULTS: Airway obstruction requiring intervention beyond positional therapy was seen in 28% isolated, 42% syndromic, and 58% unique PRS. One-third of patients who failed positional therapy were temporarily stabilized with a nasopharyngeal airway or endotracheal intubation. The remaining two-thirds of patients, who failed positional therapy required a surgical airway procedure. Four patients underwent mandibular distraction osteogenesis, resulting in successful decannulation or avoidance of tracheostomy. Thirteen patients underwent tracheostomy; mean duration of tracheostomy-dependence was 17.0 months in Isolated PRS and 31.7 months in Unique PRS (p < 0.01). Successful decannulation by age of 3 years was confirmed in 85% of patients who underwent tracheostomy. Tube feeding was required in 53% Isolated, 67% Syndromic, and 83% Unique PRS. Forty-two percent of PRS patients with a successful positional airway still demonstrated feeding difficulty. Short-term (0-3 months) and intermediate (4-18 months) tube feeding was more commonly required in Isolated and Syndromic PRS, while long-term (beyond 18 months) gastrostomy tube feeding was more commonly required in Unique PRS (p < 0.01). By 3 years of age, a successful oral diet was seen in 91% Isolated, 92% Syndromic, and 78% Unique PRS. CONCLUSIONS: Diagnostic subgroups based on the presence of additional anomalies help families and physicians in understanding the severity and duration of feeding and airway difficulty in PRS. Two-thirds of PRS patients who fail positional therapy may ultimately require a surgical airway procedure. Feeding difficulty can be present in the absence of clinically significant airway obstruction. Families and physicians should be encouraged that by 3 years of age, most patients were successfully taking an oral diet without airway obstruction.

Airway Obstruction↗
PubMed2026

Polygenic risk score for early identification of coronary artery disease in a real-world clinical setting within the Latvian patient population.

STUDY OBJECTIVE: Polygenic risk scores (PRS) are increasingly recognized for their potential to improve coronary artery disease (CAD) prediction beyond traditional clinical models. This study evaluated the utility of genome-wide association study (GWAS) - derived PRS and pathway-specific PRS (PS-PRS) in the Latvian population, aiming to assess their association with CAD and compare their predictive performance with conventional risk factors. DESIGN PARTICIPANTS AND MAIN OUTCOME MEASURES: The study included 90 early-onset CAD patients and 43 controls with no evidence of atherosclerotic lesions on coronary angiography, with next-generation sequencing performed. PRS was calculated using 192 single nucleotide variants identified from the CARDIoGRAMplusC4D GWAS meta-analysis. The predictive accuracy of PRS, PS-PRS, clinical risk factors, and their combinations was analyzed via ROC curves. RESULTS: The average age was 48.7&#xa0;years in CAD patients and 49.8 in controls. CAD patients showed significantly higher PRS (mean 0.31) compared to controls (mean&#xa0;-&#xa0;0.65; p&#xa0;<&#xa0;0.0001). PRS alone had moderate discriminatory power (AUC&#xa0;=&#xa0;0.773), slightly lower than LDL cholesterol (AUC&#xa0;=&#xa0;0.775) and total cholesterol (AUC&#xa0;=&#xa0;0.821). Combining clinical risk factors improved prediction (AUC&#xa0;=&#xa0;0.872), with the highest accuracy when PRS was integrated with all clinical factors (AUC&#xa0;=&#xa0;0.933). The PRS distributions were significantly elevated in early-onset CAD patients across the angiogenesis/tissue repair pathway (p&#xa0;=&#xa0;0.00038), inflammation pathway (p&#xa0;=&#xa0;0.043), vascular remodelling pathway (p&#xa0;=&#xa0;0.0116), and pathway of genes with unknown function in atherosclerosis (p&#xa0;=&#xa0;0.0035), but overall PRS demonstrated superior discrimination compared to pathway-specific PRS. CONCLUSIONS: Incorporating PRS enhances early-onset CAD risk prediction. Pathway specific PRS had lower discriminative ability than the overall PRS.

Atherosclerosis↗
PubMed1994

Identification of amino-acid residues linked to different properties of phosphoribosylpyrophosphate synthetase isoforms I and II.

The catalytic subunit of rat liver phosphoribosylpyrophosphate synthetase is composed of two isoforms, PRS I and PRS II. The amino-acid sequences differ only by 13 residues, out of which two Lys residues of PRS I at positions 4 and 152 give net additional positive charges to PRS I. Previous work has shown that PRS I is more sensitive to inhibition by ADP and GDP and more stable to heat treatment than is PRS II. To identify amino-acid residues responsible for the different properties, five chimeric enzymes between rat PRS I and PRS II and two mutated enzymes with a single point mutation at position 152 were constructed; these enzymes were produced in Escherichia coli. Changing Lys-4 of PRS I to Val, together with Ile-5 to Leu, completely abolished sensitivity to GDP inhibition of PRS I, indicating that Lys-4 in PRS I is critical for GDP inhibition. The substitutions at position 152 had little effect on GDP inhibition. Characterization of the chimeric enzymes revealed that residues between residues 54-110 and 229-317, namely, Val-55 and/or Ala-81, and Arg-242 and/or Cys-264 of PRS I also contribute to the strong GDP inhibition. Lys-4 was also important for the strong ADP inhibition of PRS I. Regarding the physical properties, chimeric enzymes bearing residues 12-53 of PRS I were stable at 49 degrees C and with digestion with papain and proteinase K. Our observations suggest that Lys-17, Ile-18, and/or Cys-40 of PRS I contribute to stability of the enzyme.

Amino Acids↗
PubMed2026

Cross-Ancestry and Phenome-Wide Associations of Cancer-Specific Polygenic Risk Scores.

PURPOSE: Genome-wide association studies have identified many common variants associated at low effect sizes with various cancers. Summing the effects of these variants into polygenic risk scores (PRS) can improve cancer risk prediction. However, cross-cancer and cross-phenotype pleiotropic associations of cancer-specific PRS are limited. METHODS: Using logistic regression models, we tested the association of 13 cancer-specific PRS with curated phenotypes representing the same 13 cancers and 340 cancer and cardiometabolic phecodes in 560,287 individuals (114,255 African ancestry [AFR] and 446,032 European ancestry [EUR]) from the Million Veteran Program. Models were stratified by ancestry and used age, principal components, and cancer-specific PRS per standard deviation as independent variables, and correction was applied for multiple comparisons. RESULTS: All 13 cancer-specific PRS were significantly associated with their respective cancers among EUR individuals with odds ratios per standard deviation of PRS (odds ratio [OR]) 1.05-1.70. Among AFR individuals, the effect sizes of the cancer PRS were lower, with OR 1.01-1.48, and cancer-specific PRS were significantly associated with their respective cancers for five of 13 cancers (bladder, breast in female patients, colorectal, prostate, and thyroid). In cancer-cancer pleiotropy studies, only the renal cancer-specific PRS was significantly associated with skin cancer (OR = 1.04, P = 4.5 &#xd7; 10-06) among EUR individuals. PheWAS demonstrated five positive pleotropic associations with cardiometabolic conditions (thyroid cancer PRS with thyroid goiter, oral cancer PRS with diabetes phenotypes, and hypothyroidism) and two negative associations (oral and lung cancer PRS separately with coronary artery disease). CONCLUSION: Cancer PRS have stronger associations per cancer among EUR versus AFR individuals. In contrast to PRS of other chronic diseases, the majority of cancer-related PRS are highly specific and pleiotropic associations with other cancers and cardiometabolic traits are uncommon.

Female↗
PubMed2025

Associations Between Polygenic Risk Score for Blood Pressure and Risk of Hypertension in Northeast Asian Individuals.

BACKGROUND: Data on associations between genetic predisposition to high blood pressure (BP) and hypertension and its complications in non-European populations are limited. The current study investigated associations between polygenic risk scores (PRSs) for BP and risks of hypertension, cardiovascular disease, and chronic kidney disease in Northeast Asian populations. METHODS: A genome-wide association study of systolic BP (SBP) and diastolic BP (DBP) was conducted using data from the KoGES (Korean Genome and Epidemiology Study). Results were meta-analyzed using summary statistics from Biobank Japan to construct PRSs. RESULTS: Compared with a PRS in the lowest 5 percentiles, a PRS in the highest 5 percentiles was associated with an increased risk of hypertension (hazard ratio [HR], 2.44 [95% CI, 1.67-3.56] for PRS for SBP; and HR, 1.77 [95% CI, 1.20-2.62] for PRS for DBP) and earlier onset of hypertension (by a median of 8.5&#x2009;years for PRS for SBP and 8.0&#x2009;years for PRS for DBP). These associations remained significant when continuous PRS was analyzed. The genetic risk of hypertension incidence was attenuated by moderate to vigorous physical activity. Adding the PRS for BP to the clinical risk factors improved the predictive value for hypertension (both area under the curve values, 0.787&#xa0;[95% CI, 0.771-0.803]; P=0.063 for PRS for SBP and [95% CI, 0.771-0.804]; P=0.031 for PRS for DBP). However, neither PRS for SBP nor PRS for DBP was associated with the incidence of cardiovascular or chronic kidney disease. CONCLUSIONS: The PRS for BP was associated with a higher risk of incident hypertension and earlier-onset hypertension in a Northeast Asian population. PRS may facilitate early identification and targeted management of individuals at high risk of developing hypertension.

Adult↗
PubMed2022

Patient and provider perspectives on polygenic risk scores: implications for clinical reporting and utilization.

BACKGROUND: Polygenic risk scores (PRS), which offer information about genomic risk for common diseases, have been proposed for clinical implementation. The ways in which PRS information may influence a patient's health trajectory depend on how both the patient and their primary care provider (PCP) interpret and act on PRS information. We aimed to probe patient and PCP responses to PRS clinical reporting choices METHODS: Qualitative semi-structured interviews of both patients (N=25) and PCPs (N=21) exploring responses to mock PRS clinical reports of two different designs: binary and continuous representations of PRS. RESULTS: Many patients did not understand the numbers representing risk, with high numeracy patients being the exception. However, all the patients still understood a key takeaway that they should ask their PCP about actions to lower their disease risk. PCPs described a diverse range of heuristics they would use to interpret and act on PRS information. Three separate use cases for PRS emerged: to aid in gray-area clinical decision-making, to encourage patients to do what PCPs think patients should be doing anyway (such as exercising regularly), and to identify previously unrecognized high-risk patients. PCPs indicated that receiving "below average risk" information could be both beneficial and potentially harmful, depending on the use case. For "increased risk" patients, PCPs were favorable towards integrating PRS information into their practice, though some would only act in the presence of evidence-based guidelines. PCPs describe the report as more than a way to convey information, viewing it as something to structure the whole interaction with the patient. Both patients and PCPs preferred the continuous over the binary representation of PRS (23/25 and 17/21, respectively). We offer recommendations for the developers of PRS to consider for PRS clinical report design in the light of these patient and PCP viewpoints. CONCLUSIONS: PCPs saw PRS information as a natural extension of their current practice. The most pressing gap for PRS implementation is evidence for clinical utility. Careful clinical report design can help ensure that benefits are realized and harms are minimized.

Clinical Decision-Making↗
PubMed2026

Role of Polygenic Risk Scores in Predicting Cognitive Functioning after Mild Traumatic Brain Injury: A TRACK-TBI Study.

Patients with traumatic brain injury (TBI) and Glasgow Coma Scale scores of 13-15 (historically called mild TBI [mTBI]) commonly experience changes in cognitive functioning, including processing speed, memory, and executive functioning. In a prospective sample (N = 523) of individuals of European descent who had been treated in a U.S. level 1 trauma center for mTBI, we examined the prognostic value of four polygenic risk scores (PRS) for cognitive outcomes at 6-months postinjury. To estimate the impact of mTBI on cognition, primary cognitive outcomes were scaled as z-scores reflecting changes in performance relative to predicted preinjury performance. The PRS examined were previously developed and validated to predict cognition-related outcomes of educational attainment (Education-PRS), intelligence (Intelligence-PRS), and Alzheimer's disease (AD-mild traumatic brain injury (APOE)-PRS and AD + APOE-PRS). Both the Education-PRS and Intelligence-PRS displayed bivariate associations with all four cognitive outcomes (&#x3b2; = 0.19-0.32), whereas neither Alzheimer's disease PRS was significantly associated with any outcome. After controlling for other factors known to predict cognitive outcomes of TBI (e.g., sex, education, mTBI severity defined by a combination of Glasgow Coma Scale scores and the presence/absence of acute intracranial findings on clinical neuroimaging), the Education-PRS and Intelligence-PRS remained independently predictive of verbal episodic memory (&#x3b2; = 0.10-0.16), whereas their associations with processing speed and executive functioning were mostly nonsignificant and were mediated through educational attainment. Looking across primary z-score and secondary raw score outcomes, cognitive outcomes 6 months post-mTBI were good on average, and PRS made small independent contributions to outcome prediction. The mediation model findings may support theories of cognitive reserve, which propose that individuals with stronger preinjury cognitive processing abilities (often estimated by educational history) can better compensate for TBI. Moreover, findings indicate that PRS may contribute modestly to multivariable models predicting cognitive function after TBI.

Humans↗
PubMed1990

Inbred testing of tomato (Lycopersicon esculentum L.) F1 varieties by ultrathin-layer isoelectric focusing of seed protein.

To test seed lots of tomato F1 hybrid varieties for the presence of undesirable inbred seeds by electrophoresis, a method has been developed on the basis of ultrathin-layer isoelectric focusing. The method is based on the genetic variation of the seed protein PRS-1 which could be visualized by isoelectric focusing of a 5 mM NaCl-soluble seed protein extract in a pH 6-9 gel followed by protein staining. Two genetic variants of the PRS-1 protein, PRS-1+ and PRS-1(1), were found among open-pollinated varieties, as well as among F1 hybrid varieties. The isoelectric points (pI) of the PRS-1 proteins are 7.1 and 6.1 for PRS-1+ and PRS-1(1), respectively. The PRS-1 protein is unique to seed tissue and is located primarily in the embryo. A genetic 1:2:1 segregation of the gene Prs-1 among several F2 populations shows monogenic inheritance. Analysis of commercial F1 hybrid varieties from several seed companies indicated that the Prs-1(1) allele, in contrast to the Prs-1+ allele, is primarily present in gene pools of "Money-maker type" tomatoes. The described method is generally applicable to all tomato F1 varieties that are heterozygous for the gene Prs-1. With the described method one person can routinely analyze more than 768 seeds per day.

Alleles↗
PubMed1984

Positive rolandic sharp waves in the electroencephalograms of premature neonates with intraventricular hemorrhage.

Seventy-eight electroencephalograms (EEGs) recorded from 44 premature infants with documented intraventricular hemorrhage (IVH) were retrospectively reviewed. Positive rolandic sharp waves (PRS) were observed in 13 of 44 (29.5%) patients. Among infants with grades 3 and 4 IVH, the incidence of PRS was 60% (9 of 15). During the period of study, typical PRS appeared in two EEGs of one premature infant who did not suffer an IVH. PRS were usually associated with moderately abnormal EEG backgrounds and with grades 3 and 4 IVH. Beta activity was superimposed on an average of 21.5% of PRS (beta-PRS). Infants with grades 3 and 4 IVH had a higher incidence of beta-PRS than those with smaller hemorrhages. PRS first appeared in early postnatal life, increased in abundance and then eventually disappeared from the records by 3-4 weeks of age. The field of distribution of PRS was centered at the central parasagittal region (Cz) with generous anteroposterior spread into the frontal and parietal vertices (Fz and Pz) and symmetric lateral spread into the rolandic areas (C3 and C4). Asymmetric involvement of PRS at C3 and C4 may signify differential hemispheric injury. The majority of infants whose EEGs contained PRS died or suffered serious neurologic sequelae. However, their outcomes were not significantly inferior to those without PRS.

Brain↗