The prosubiculum in the human hippocampus: A rostrocaudal, feature-driven, and systematic approach.

The hippocampal subfield prosubiculum (ProS), is a conserved neuroanatomic region in mouse, monkey, and human. This area lies between CA1 and subiculum (Sub) and particularly lacks consensus on its boundaries; reports have varied on the description of its features and location. In this report, we review, refine, and evaluate four cytoarchitectural features that differentiate ProS from its neighboring subfields: (1) small neurons, (2) lightly stained neurons, (3) superficial clustered neurons, and (4) a cell sparse zone. ProS was delineated in all cases (n = 10). ProS was examined for its cytoarchitectonic features and location rostrocaudally, from the anterior head through the body in the hippocampus. The most common feature was small pyramidal neurons, which were intermingled with larger pyramidal neurons in ProS. We quantitatively measured ProS pyramidal neurons, which showed (average, width at pyramidal base = 14.31 µm, n = 400 per subfield). CA1 neurons averaged 15.57 µm and Sub neurons averaged 15.63 µm, both were significantly different than ProS (Kruskal-Wallis test, p < .0001). The other three features observed were lightly stained neurons, clustered neurons, and a cell sparse zone. Taken together, these findings suggest that ProS is an independent subfield, likely with distinct functional contributions to the broader interconnected hippocampal network. Our results suggest that ProS is a cytoarchitecturally varied subfield, both for features and among individuals. This diverse architecture in features and individuals for ProS could explain the long-standing complexity regarding the identification of this subfield.

Cardiovascular disease and maternal mortality: perceptions in a Midwest birthing population.

BACKGROUND: Missouri has one of the highest rates of maternal mortality in the United States. To date, there are currently no studies describing birthing peoples' knowledge or perceptions of contributing causes of maternal mortality. An improved understanding of population-specific knowledge can help to define how best to design targeted interventions to reduce disease-specific causes of maternal mortality. OBJECTIVE: This study aimed to examine the knowledge and understanding of maternal mortality in a Missouri birthing population. STUDY DESIGN: A 46-question, cross-sectional survey to assess the familiarity with local maternal mortality rates, groups affected, and causality was developed by the Missouri Perinatal Quality Collaborative and the Maternal-Child Learning and Action Network and emailed to a random sample of birthing people across Missouri. Those who identified as someone with birthing potential with a Missouri zip code and who were ≥18 years of age were eligible for inclusion. Unadjusted descriptive statistics were generated and stratified by age, race, and region. RESULTS: Among 2196 surveys sent, 1738 people completed the survey. Of those who responded, 78.2% were aware of the risk of pregnancy-related death with 14.7% reporting that they intimately knew someone who died. When asked if a certain group is affected disproportionately more, 66.4% responded affirmatively. Black (58.7%), uninsured (61.8%), poor (71.0%), those with substance abuse disorders (57.4%), and Native American (28.8%) birthing people were identified as groups that were perceived as suffering higher rates of maternal death. When polled on etiology, severe bleeding (56.9%) was believed to be the leading cause of death, and the second stage of labor was thought to be the period of highest risk (42.3%). Beliefs about the timing of death differed by age (P=.042) but not race (P=.81) or region (P=.191). CONCLUSION: Missouri birthing people are cognizant of the social factors associated with increased maternal mortality but are unaware of the leading causes of death, namely cardiovascular disease and mental health conditions. Future Perinatal Quality Collaborative work should focus on campaigns that raise public awareness about cardiovascular disease and mental health-related birthing risks and the importance of monitoring early warning signs after delivery.

Validation of a noninvasive cardiac output monitor in maternal cardiac disease: comparison of NICOM and transthoracic echocardiogram.

BACKGROUND: The physiological changes to the cardiovascular system during pregnancy are considerable and are more pronounced in those with cardiac disease. In the general population, noninvasive hemodynamic monitoring is a valid alternative to pulmonary artery catheterization, which poses risk in the pregnant population. There is limited data on noninvasive cardiac output monitoring in pregnancy as an alternative to pulmonary artery catheterization. OBJECTIVE: We sought to compare transthoracic echocardiography with a noninvasive cardiac output monitor (NICOM, Cheetah Medical) in pregnant patients with and without cardiac disease. STUDY DESIGN: This was a prospective, open-label validation study that compared 2-dimensional transthoracic echocardiography with NICOM estimations of cardiac output in each trimester of pregnancy and the postpartum period. Participants with and without cardiac disease with a singleton gestation were included. NICOM estimations of cardiac output were derived from thoracic bioreactance and compared with 2-dimensional transthoracic echocardiography for both precision and accuracy. A mean percentage difference of ±30% between the 2 devices was considered acceptable agreement between the 2 measurement techniques. RESULTS: A total of 58 subjects were enrolled; 36 did not have cardiac disease and 22 had cardiac disease. Heart rate measurements between the 2 devices were strongly correlated in both groups, whereas stroke volume and cardiac output measurements showed weak correlation. When comparing the techniques, the NICOM device overestimated cardiac output in the control group in all trimesters and the postpartum period (mean percentage differences were 50.3%, 52.7%, 48.1%, and 51.0% in the first, second, and third trimesters and the postpartum period, respectively). In the group with cardiac disease, the mean percentage differences were 31.9%, 29.7%, 19.6%, and 35.2% for the respective timepoints. CONCLUSION: The NICOM device consistently overestimated cardiac output when compared with 2-dimensional transthoracic echocardiography at all timepoints in the control group and in the first trimester and postpartum period for the cardiovascular disease group. The physiological changes of pregnancy, specifically the mean chest circumference and total body water, may alter the accuracy of the cardiac output measurement by the NICOM device as they are currently estimated. Although NICOM has been validated for use in the critical care setting, there is insufficient data to support its use in pregnancy.

Stereology neuron counts correlate with deep learning estimates in the human hippocampal subregions.

Hippocampal subregions differ in specialization and vulnerability to cell death. Neuron death and hippocampal atrophy have been a marker for the progression of Alzheimer's disease. Relatively few studies have examined neuronal loss in the human brain using stereology. We characterize an automated high-throughput deep learning pipeline to segment hippocampal pyramidal neurons, generate pyramidal neuron estimates within the human hippocampal subfields, and relate our results to stereology neuron counts. Based on seven cases and 168 partitions, we vet deep learning parameters to segment hippocampal pyramidal neurons from the background using the open-source CellPose algorithm, and show the automated removal of false-positive segmentations. There was no difference in Dice scores between neurons segmented by the deep learning pipeline and manual segmentations (Independent Samples t-Test: t(28) = 0.33, p = 0.742). Deep-learning neuron estimates strongly correlate with manual stereological counts per subregion (Spearman's correlation (n = 9): r(7) = 0.97, p < 0.001), and for each partition individually (Spearman's correlation (n = 168): r(166) = 0.90, p <0 .001). The high-throughput deep-learning pipeline provides validation to existing standards. This deep learning approach may benefit future studies in tracking baseline and resilient healthy aging to the earliest disease progression.

Pentad: A reproducible cytoarchitectonic protocol and its application to parcellation of the human hippocampus.

Introduction: The hippocampus is integral for learning and memory and is targeted by multiple diseases. Neuroimaging approaches frequently use hippocampal subfield volumes as a standard measure of neurodegeneration, thus making them an essential biomarker to study. Collectively, histologic parcellation studies contain various disagreements, discrepancies, and omissions. The present study aimed to advance the hippocampal subfield segmentation field by establishing the first histology based parcellation protocol, applied to n = 22 human hippocampal samples. Methods: The protocol focuses on five cellular traits observed in the pyramidal layer of the human hippocampus. We coin this approach the pentad protocol. The traits were: chromophilia, neuron size, packing density, clustering, and collinearity. Subfields included were CA1, CA2, CA3, CA4, prosubiculum, subiculum, presubiculum, parasubiculum, as well as the medial (uncal) subfields Subu, CA1u, CA2u, CA3u, and CA4u. We also establish nine distinct anterior-posterior levels of the hippocampus in the coronal plane to document rostrocaudal differences. Results: Applying the pentad protocol, we parcellated 13 subfields at nine levels in 22 samples. We found that CA1 had the smallest neurons, CA2 showed high neuronal clustering, and CA3 displayed the most collinear neurons of the CA fields. The border between presubiculum and subiculum was staircase shaped, and parasubiculum had larger neurons than presubiculum. We also demonstrate cytoarchitectural evidence that CA4 and prosubiculum exist as individual subfields. Discussion: This protocol is comprehensive, regimented and supplies a high number of samples, hippocampal subfields, and anterior-posterior coronal levels. The pentad protocol utilizes the gold standard approach for the human hippocampus subfield parcellation.

Patient-Perceived Satisfaction and Knowledge Uptake in a Combined Cardio-Obstetrics Clinic.

Heart disease is the leading cause of pregnancy-related mortality in the United States and has led to the development of combined cardio-obstetrics (COB) clinics as a model for prenatal care. In other areas of medicine, these types of collaborative care models have shown improvement in morbidity, mortality, and patient satisfaction. There is some data to suggest that a combined COB clinic improves maternal outcomes but there is no data to suggest patients prefer this type of care model. This study aims to evaluate patient satisfaction in a combined COB clinic and whether this type of model enhances perceived communication and knowledge uptake. A quality questionnaire was developed to assess patient perceptions regarding communication, satisfaction, and perceived knowledge. Patients who attended the clinic (n = 960) from 2014-2020 were contacted by email, with a response received from 119 (12.5%). Participants completed a questionnaire assessing satisfaction and perceived knowledge uptake with answers based on a Likert scale (7 representing very satisfied and 1 representing very unsatisfied). Safe and effective contraceptive use was evaluated by multiple choice options. Knowledge was also assessed by comparing contraceptive use before and after the clinic. Participants reported high levels of satisfaction with the clinic (6.2 ± 1.5), provider-to-patient communication (6.1 ± 1.6), and with the multidisciplinary appointment approach (6.3 ± 1.5). As well, participants reported an increase in knowledge about heart disease a result of collaborative counseling. In summary, a multidisciplinary approach to cardio-obstetrics not only improves outcomes but is a patient satisfier.

Quantitative and histologically validated measures of the entorhinal subfields in ex vivo MRI.

Neuroimaging studies have routinely used hippocampal volume as a measure of Alzheimer's disease severity, but hippocampal changes occur too late in the disease process for potential therapies to be effective. The entorhinal cortex is one of the first cortical areas affected by Alzheimer's disease; its neurons are especially vulnerable to neurofibrillary tangles. Entorhinal atrophy also relates to the conversion from non-clinical to clinical Alzheimer's disease. In neuroimaging, the human entorhinal cortex has so far mostly been considered in its entirety or divided into a medial and a lateral region. Cytoarchitectonic differences provide the opportunity for subfield parcellation. We investigated the entorhinal cortex on a subfield-specific level-at a critical time point of Alzheimer's disease progression. While MRI allows multidimensional quantitative measurements, only histology provides enough accuracy to determine subfield boundaries-the pre-requisite for quantitative measurements within the entorhinal cortex. This study used histological data to validate ultra-high-resolution 7 Tesla ex vivo MRI and create entorhinal subfield parcellations in a total of 10 pre-clinical Alzheimer's disease and normal control cases. Using ex vivo MRI, eight entorhinal subfields (olfactory, rostral, medial intermediate, intermediate, lateral rostral, lateral caudal, caudal, and caudal limiting) were characterized for cortical thickness, volume, and pial surface area. Our data indicated no influence of sex, or Braak and Braak staging on volume, cortical thickness, or pial surface area. The volume and pial surface area for mean whole entorhinal cortex were 1131 ± 55.72 mm3 and 429 ± 22.6 mm2 (mean ± SEM), respectively. The subfield volume percentages relative to the entire entorhinal cortex were olfactory: 18.73 ± 1.82%, rostral: 14.06 ± 0.63%, lateral rostral: 14.81 ± 1.22%, medial intermediate: 6.72 ± 0.72%, intermediate: 23.36 ± 1.85%, lateral caudal: 5.42 ± 0.33%, caudal: 10.99 ± 1.02%, and caudal limiting: 5.91 ± 0.40% (all mean ± SEM). Olfactory and intermediate subfield revealed the most extensive intra-individual variability (cross-subject variance) in volume and pial surface area. This study provides validated measures. It maps individuality and demonstrates human variability in the entorhinal cortex, providing a baseline for approaches in individualized medicine. Taken together, this study serves as a ground-truth validation study for future in vivo comparisons and treatments.

Estimation of the Genome-Wide Mutation Rate and Spectrum in the Archaeal Species Haloferax volcanii.

Organisms adapted to life in extreme habitats (extremophiles) can further our understanding of the mechanisms of genetic stability, particularly replication and repair. Despite the harsh environmental conditions they endure, these extremophiles represent a great deal of the Earth's biodiversity. Here, for the first time in a member of the archaeal domain, we report a genome-wide assay of spontaneous mutations in the halophilic species Haloferax volcanii using a direct and unbiased method: mutation accumulation experiments combined with deep whole-genome sequencing. H. volcanii is a key model organism not only for the study of halophilicity, but also for archaeal biology in general. Our methods measure the genome-wide rate, spectrum, and spatial distribution of spontaneous mutations. The estimated base substitution rate of 3.15 × 10-10 per site per generation, or 0.0012 per genome per generation, is similar to the value found in mesophilic prokaryotes (optimal growth at ∼20-45°). This study contributes to a comprehensive phylogenetic view of how evolutionary forces and molecular mechanisms shape the rate and molecular spectrum of mutations across the tree of life.

Nasal outcomes of presurgical nasal molding in complete unilateral cleft lip and palate.

Objective. Short-term nasal forms following primary lip repair were compared between presurgical nasal molding and control groups. Aim. To compare nasal symmetry between patients that had nasal molding and lip repair with those that had only lip repair. Design. Retrospective case-control study Patients. Complete unilateral CL+P patients had basilar and frontal photographs at two time points: (1) initial (2) postsurgical. 28 nasal molding patients and 14 control patients were included. Intervention. Presurgical nasal molding was performed prior to primary lip repair in intervention group. No nasal molding was performed in control group. Hypothesis. Nasal molding combined with lip surgery repair according to the Millard procedure provides superior nasal symmetry than surgery alone for nostril height-width ratios and alar groove ratios. Statistics. Shapiro-Wilk test of normality and Student's t-tests. Results. A statistically significant difference was found for postsurgical nostril height-width ratio (P < .05). No other statistically significant differences were found. Conclusions. Nasal molding and surgery resulted in more symmetrical nostril height-width ratios than surgery alone. Alar groove ratios were not statistically significantly different between groups perhaps because application of nasal molding was not early enough; postsurgical nasal splints were not utilized; overcorrection was not performed for nasal molding.