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Extreme aspect ratio tubes and wires of polycrystalline silicon and germanium have been deposited within silica microstructured optical fibers using high-pressure precursors, demonstrating the potential of a platform technology for the development of in-fiber optoelectronics. Microstructural studies of the deposited material using Raman spectroscopy show effects due to strain between core and cladding and the presence of amorphous and polycrystalline phases for silicon. Germanium, in contrast, is more crystalline and less strained. This in-fiber device geometry is utilized for two- and three-terminal electrical characterization of the key parameters of resistivity and carrier type, mobility and concentration. [ABSTRACT FROM AUTHOR]

Introduction: Experiences of people of color with maternity care are understudied but understanding them is important to improving quality and reducing racial disparities in birth outcomes in the United States. This qualitative study explored experiences with maternity care among people of color to describe the meaning of quality maternity care to the cohort and, ultimately, to inform the design of a freestanding birth center in Boston., Methods: Using a grounded theory design and elements of community-based participatory research, community activists developing Boston's first freestanding birth center and academics collaborated on this study. Semistructured interviews and focus groups with purposefully sampled people of color were conducted and analyzed using a constant comparative method. Interviewees described their maternity care experiences, ideas about perfect maternity care, and how a freestanding birth center might meet their needs. Open coding, axial coding, and selective coding were used to develop a local theory of what quality care means., Results: A total of 23 people of color participated in semistructured interviews and focus groups. A core phenomenon arose from the narratives: being known (ie, being seen or heard, or being treated as individuals) during maternity care was an important element of quality care. Contextual factors, including interpersonal and structural racism, power differentials between perinatal care providers and patients, and the bureaucratic nature of hospital-based maternity care, facilitated negative experiences. People of color did extra work to prevent and mitigate negative experiences, which left them feeling traumatized, regretful, or sad about maternity care. This extra work came in many forms, including cognitive work such as worrying about racism and behavioral changes such as dressing differently to get health care needs met., Discussion: Being known characterizes quality maternity care among people of color in our sample. Maternity care settings can provide personalized care that helps clients feel known without requiring them to do extra work to achieve this experience., (© 2021 The Authors. Journal of Midwifery & Women's Health published by Wiley Periodicals LLC on behalf of American College of Nurse Midwives (ACNM).)

Background.: Professionalism has been given different definitions over time. These are, commonly theoretical and difficult to operationalize., Purpose.: This study aimed to provide an operational definition of the concept of professionalism in occupational therapy., Method.: Based on a concept analysis design, a meta-narrative review was conducted to extract information from 30 occupational therapy manuscripts., Findings.: Professionalism is a complex competence defined by the manifestation of distinct attitudes and behaviours that support excellence in the occupational therapy practice. In addition, professionalism is forged and evolves according to personal and environmental characteristics. The manifestation of professionalism can lead to positive consequences for occupational therapists, clients, and the discipline, notably contributing to a positive and strong professional identity. Moreover, professionalism is also subject to cultural influences, which leads to variations in its development, manifestations, and consequences., Implications.: This study offers a contemporary operational definition of professionalism and levers to promote its development and maintenance.

Chronic low-grade inflammation is known to be linked to obesity, and to occur in the early stages of the disease. This mechanism is complex and involves numerous organs, cells, and cytokines. In this context, inflammation of white adipose tissue seems to play a key role in the development of obesity. Because of its properties, prostaglandin E2 (PGE2), an emblematic inflammatory mediator, has been proposed as an actor linking inflammation and obesity. Indeed, PGE2 is involved in mechanisms that are dysregulated in obesity such as lipolysis and adipogenesis. Microsomal prostaglandin E synthase-1 (mPGES-1) is an enzyme, which specifically catalyzes the final step of PGE2 biosynthesis. Interestingly, mPGES-1 invalidation dramatically alters the production of PGE2 during inflammation. In the present work, we sought to determine whether mPGES-1 could contribute to inflammation associated with obesity. To this end, we analyzed the energy metabolism of mPGES-1 deficient mice (mPGES-1 -/- ) and littermate controls, fed with a high-fat diet. Our data showed that mPGES-1 -/- mice exhibited resistance to diet-induced obesity when compared to wild-type littermates. mPGES-1 -/- mice fed with a high-fat diet, showed a lower body weight gain and a reduced adiposity, which were accompanied by a decrease in adipose tissues inflammation. We also observed an increase in energy expenditures in mPGES-1 -/- mice fed with a high-fat diet without any changes in activity and browning process. Altogether, these data suggest that mPGES-1 inhibition may prevent diet-induced obesity.

Excitotoxic lesions are frequently used to assess the role of cerebral structures in cognitive processes in rodents. However, the precise site and extent of these lesions remain unknown without histological verifications. Using a 7-Teslas MRI system and a T2-weighted turbo-RARE sequence, MR images were acquired at several time points following NMDA lesions (1h, 6h, 24h, 48h, 1 week and 2 weeks). NMDA infusions into the parenchyma induced a clear and delineable hyperintense signal from 1h up to 1-week post-surgery. Hyperintensity volumes were compared with NeuN and Cresyl violet histological quantifications of the lesion magnitude. NMDA-induced hypersignal is observed as soon as 1h post-injection and is a reliable estimate of the presence (or absence) of a lesion. Compared to NeuN, Cresyl violet staining underestimates the extent of the lesion in significant proportions. The MRI hyperintensity generated by NMDA instillation into the parenchyma can be used as a powerful tool to confirm the diffusion of the drug into the cerebral tissue, to ascertain the locus of injection and predict with a high success rate the fate of NMDA lesions as soon as 1h post-surgery. This approach could be very useful in a large variety of lesion studies in rodents., Competing Interests: The authors have declared that no competing interests exist.

We hypothesize that the trisomy 21 (Down syndrome) is the additive and interactive outcome of the triple copy of different regions of HSA21. Because of the small number of patients with partial trisomy 21, we addressed the question in the Mouse in which three chromosomal regions located on MMU10, MMU17 and MMU16 carries almost all the HSA21 homologs. Male mice from four segmental trisomic strains covering the D21S17-ETS2 (syntenic to MMU16) were examined with an exhaustive battery of cognitive tests, motor tasks and MRI and compared with TS65Dn that encompasses D21S17-ETS2. None of the four strains gather all the impairments (measured by the effect size) of TS65Dn strain. The 152F7 strain was close to TS65Dn for motor behavior and reference memory and the three other strains 230E8, 141G6 and 285E6 for working memory. Episodic memory was impaired only in strain 285E6. The hippocampus and cerebellum reduced sizes that were seen in all the strains indicate that trisomy 21 is not only a hippocampus syndrome but that it results from abnormal interactions between the two structures.

Global Cerebral Ischemia (GCI) occurs following cardiac arrest or neonatal asphyxia and leads to harmful neurological consequences. In most cases, patients who survive cardiac arrest develop severe cognitive and motor impairments. This study focused on learning and memory deficits associated with brain neuroanatomical reorganization that appears after GCI. The four-vessel occlusion (4VO) model was performed to produce a transient GCI. Hippocampal lesions in ischemic rats were visualized using anatomical Magnetic Resonance Imaging (aMRI). Then, the learning and memory abilities of control and ischemic (bilaterally or unilaterally) rats were assessed through the olfactory associated learning task. Finally, a "longitudinal" histological study was carried out to highlight the cellular reorganizations occurring after GCI. We demonstrated that the imaging, behavioral and histological results are closely related. In fact, aMRI revealed the appearance of hyper-intense signals in the dorsal hippocampus at day 3 post-GCI. Consequently, we showed a rise in cell proliferation (Ki 67 + cells) and endogenous neurogenesis especially in the dentate gyrus (DG) at day 3 post-GCI. Then, hyper-intense signals in the dorsal hippocampus were confirmed by strong neuronal losses in the CA1 layer at day 7 post-GCI. These results were linked with severe learning and memory impairments only in bilaterally ischemic rats at day 14 post-GCI. This amnesia was accompanied by huge astroglial and microglial hyperactivity at day 30 post-GCI. Finally, Nestin + cells and astrocytes gave rise to astroglial scars, which persisted 60days post-GCI. In the light of these results, the 4VO model appears a reliable method to produce amnesia in order to study and develop new therapeutic strategies., (Copyright © 2017 Elsevier Inc. All rights reserved.)

We present the first comparative investigation of the Nuclear Magnetic Resonance (NMR) relaxivity of a series of nanosized cyano-bridged coordination networks stabilized in aqueous solution. These Ln(3+)/[Fe(CN)6](3-) (Ln = Gd, Tb, Y) and M(2+)/[Fe(CN)6](3-) (M = Ni, Cu, Fe) nanoparticles with sizes ranging from 1.4 to 5.5 nm are stabilized by polyethylene glycols (MW = 400 or 1000), polyethylene glycol functionalized with amine groups (MW = 1500), or by N-acetyl-D-glucosamine. The evaluation of NMR relaxivity allowed estimation of the Magnetic Resonance Imaging (MRI) contrast efficiency of our systems. The results demonstrate that Gd(3+)/[Fe(CN)6](3-) nanoparticles have r1p and r2p relaxivities about four times higher than the values observed in the same conditions for the commercial Contrast Agents (CAs) ProHance or Omniscan, regardless of the stabilizing agent used, while nanoparticles of Prussian blue and its analogues M(2+)/[Fe(CN)6](3-) (M = Ni, Cu, Fe) present relatively modest values. The influence of the chemical composition of the nanoparticles, their crystal structure, spin values of lanthanide and transition metal ions, and stabilizing agent on the relaxivity values are investigated and discussed.

Community mobilization and collaboration among diverse partners are vital components of the effort to reduce and eliminate cancer disparities in the United States. We studied the development and impact of intersectoral connections among the members of the Massachusetts Community Network for Cancer Education, Research, and Training (MassCONECT). As one of the Community Network Program sites funded by the National Cancer Institute, this infrastructure-building initiative utilized principles of Community-based Participatory Research (CBPR) to unite community coalitions, researchers, policymakers, and other important stakeholders to address cancer disparities in three Massachusetts communities: Boston, Lawrence, and Worcester. We conducted a cross-sectional, sociometric network analysis four years after the network was formed. A total of 38 of 55 members participated in the study (69% response rate). Over four years of collaboration, the number of intersectoral connections reported by members (intersectoral out-degree) increased, as did the extent to which such connections were reported reciprocally (intersectoral reciprocity). We assessed relationships between these markers of intersectoral collaboration and three intermediate outcomes in the effort to reduce and eliminate cancer disparities: delivery of community activities, policy engagement, and grants/publications. We found a positive and statistically significant relationship between intersectoral out-degree and community activities and policy engagement (the relationship was borderline significant for grants/publications). We found a positive and statistically significant relationship between intersectoral reciprocity and community activities and grants/publications (the relationship was borderline significant for policy engagement). The study suggests that intersectoral connections may be important drivers of diverse intermediate outcomes in the effort to reduce and eliminate cancer disparities. The findings support investment in infrastructure-building and intersectoral mobilization in addressing disparities and highlight the benefits of using CBPR approaches for such work.

Background: The Boston REACH Coalition developed a case management intervention for Black women in primary care settings to identify and reduce medical and social obstacles to cervical cancer screening and following up abnormal results., Methods: The 5-year intervention was evaluated among 732 Black women aged 18 to 75 who were at high risk for inadequate Pap smear screening and follow-up. Case managers provided social services referrals to address patient-identified social concerns (e.g., transportation, housing), as well as navigation to prompt screening and follow-up of abnormal tests. The three study aims were to (1) identify the social factors associated with Pap smear screening at baseline before intervention, (2) evaluate the correlation between exposure to case management intervention and achieving recommended Pap screening intervals, and (3) evaluate the correlation between exposure to case management intervention and having timely follow-up of abnormal Pap smear tests., Results: We found that a lack of a regular clinical provider, concerns communicating with providers, poor self-rated health, and having less than a high school education were important correlates of recent Pap smear screening before the case management intervention. During the case management intervention, we found a significant increase in achieving recommended Pap smear screening intervals among women with a recent Pap smear at study entry (increasing from 52% in the first year to 80% after 4 or more years; p < .01), but not among women who entered the study without a recent Pap smear (increasing from 31% in the first year to 44% after 4 or more years; p = .39). During case management intervention, having social support for childcare was associated with regular screening among women without a recent Pap smear (odds ratio [OR], 3.52; 95% confidence interval [CI], 1.28-9.69). Insurance status was the key factor in timely clinically indicated follow-up of abnormal results (uninsured OR, 0.27; 95% CI, 0.08-0.86), rather than case management intervention., Conclusions: Exposure to case management was associated with regular Pap smear screening among women who recently engaged in screening. Future research should focus on systems changes to address social determinants of health, including strategies to facilitate screening for Black women without social support for childcare. To improve follow-up of abnormal results, financial access to care should be addressed.

Stem cell-based therapy has been proposed as a potential means of treatment for a variety of brain disorders. Because ethical and technical issues have so far limited the clinical translation of research using embryonic/fetal cells and neural tissue, respectively, the search for alternative sources of therapeutic stem cells remains ongoing. Here, we report that upon transplantation into mice with chemically induced hippocampal lesions, human olfactory ecto-mesenchymal stem cells (OE-MSCs) - adult stem cells from human nasal olfactory lamina propria - migrated toward the sites of neural damage, where they differentiated into neurons. Additionally, transplanted OE-MSCs stimulated endogenous neurogenesis, restored synaptic transmission, and enhanced long-term potentiation. Mice that received transplanted OE-MSCs exhibited restoration of learning and memory on behavioral tests compared with lesioned, nontransplanted control mice. Similar results were obtained when OE-MSCs were injected into the cerebrospinal fluid. These data show that OE-MSCs can induce neurogenesis and contribute to restoration of hippocampal neuronal networks via trophic actions. They provide evidence that human olfactory tissue is a conceivable source of nervous system replacement cells. This stem cell subtype may be useful for a broad range of stem cell-related studies.

The Boston Public Health Commission's Center for Health Equity and Social Justice provides grant funding, training, and technical assistance to 15 organizations and coalitions across New England to develop, implement, and evaluate community-based policy and systems change strategies that address social determinants of health and reduce racial and ethnic health inequities. This article describes Boston Public Health Commission's health equity framework, theory of change regarding the elimination of racial and ethnic health inequities, and current grantmaking model. To conclude, the authors evaluate the grant model and offer lessons learned from providing multiyear regional grants to promote health equity.

Epidemiological studies have highlighted a season of birth effect in multiple sclerosis and schizophrenia. As a result, low prenatal vitamin D has been proposed as a candidate risk factor for these brain diseases, with cognitive impairments. In order to further investigate the long-term consequences of a transient gestational hypovitaminosis D, we used a mouse developmental vitamin D (DVD) deficiency model. Female C57Bl/6J mice were fed a vitamin D-free diet for 6 weeks prior to conception and during gestation. At birth, dams and their offspring were fed a normal vitamin D-containing diet. The adult offspring underwent a learning test based on olfactory cues, at 30 weeks and 60 weeks of age. In addition, using magnetic resonance imaging (MRI), volumes of cerebrum, hippocampus and lateral ventricles were measured at 30 weeks and 70 weeks of age. We found that DVD-deficient mice, when compared to control animals at Week 30, displayed impaired learning and smaller lateral ventricles. At Weeks 60-70, both groups deteriorated when compared to young mice and no significant difference was observed between groups. This study confirms that transient prenatal vitamin D deficiency alters brain development and functioning and induces cognitive impairments in the young adult offspring., (Copyright 2010 Elsevier B.V. All rights reserved.)

The delayed reaction paradigm, consisting to discover two different rules consecutively (delayed alternation and non-alternation task) followed by a delayed reversal task, is a specific marker for the functioning of primate prefrontal cortex. Although several works in rodents report the use of operant delayed alternation tasks, in none of the studies mice with lesion of the prefrontal cortex were used in this paradigm. In the current study, mouse experiments were conducted using a new, totally automated device, the olfactory H-maze. Here, we show that unilateral lesion of the dorsomedial prefrontal cortex in mice induced similar deficits to those observed after frontal lesions in monkeys and humans. These pronounced learning deficits seem to come from difficulty elaborating a new rule and the inability to inhibit the previous rule, characterized by perseveration after prefrontal cortex lesion. The present results demonstrate that this very simple experimental paradigm using the olfactory H-maze presents the advantage to be fast (one training session) and well suited to assess the frontal functions in mice. It should be useful for testing pharmacological or stem cell approaches in order to reduce organic damages or gain insight into the cognitive functions of the frontal cortex using transgenic or gene-targeting mice.

Sensorimotor activity has been shown to play a key role in functional recovery after partial spinal cord injury (SCI). Most studies in rodents have focused on the rehabilitation of hindlimb locomotor functions after thoracic or lumbar SCI, whereas forelimb motor and somatosensory abilities after cervical SCI remain largely uninvestigated, despite the high incidence of such injuries in humans. Moreover, little is known about the neurophysiological substrates of training-induced recovery in supraspinal structures. This study was aimed at evaluating the effects of a training procedure combining both motor and sensory stimulation on behavioral performance and somatosensory cortical map remodeling after cervical (C4-C5) spinal hemisection in rats. This SCI severely impaired both sensory and motor capacities in the ipsilateral limbs. Without training, post-lesion motor capacities gradually improved, whereas forepaw tactile abilities remained impaired. Consistently, no stimulus-evoked responses were recorded within the forepaw representational zone in the primary somatosensory (S1) cortex at 2 months after the SCI. However, our data reveal that with training started from the 7th day post-lesion, a nearly complete recovery (characterized by an early and rapid improvement of motor functions) was associated with a gradual compensation of tactile deficits. Furthermore, the recovery of tactile abilities was correlated with the areal extent of reactivation of S1 cortex forepaw representations. Rehabilitative training promoted post-lesion adaptive plasticity, probably by enhancing endogenous activity within spared spinal and supraspinal circuits and pathways sustaining sensory and motor functions. This study highlights the beneficial effect of sensorimotor training in motor improvement and its critical influence on tactile recovery after SCI.

Background and Aims: Accurately documenting mammography use is essential to assess quality of care for early breast cancer detection in underserved populations. Self-reports and medical record reports frequently result in different accounts of whether a mammogram was performed. We hypothesize that electronic medical records (EMRs) provide more accurate documentation of mammography use than paper records, as evidenced by the level of agreement between women's self-reported mammography use and mammography use documented in medical records., Methods: Black women aged 40-75 were surveyed in six primary care sites in Boston, Massachusetts (n = 411). Survey data assessed self-reported mammography prevalence within 2 years of study entry. Corresponding medical record data were collected at each site. Positive predictive value (PPV) of self-report and kappa statistics compared data agreement among sites with and without EMRs. Logistic regression estimated effects of site and patient characteristics on agreement between data sources., Results: Medical records estimated a lower prevalence of mammography use (58%) than self-report (76%). However, self-report and medical record estimates were more similar in sites with EMRs. PPV of self-report was 88% in sites with continuous access to EMRs and 61% at sites without EMRs. Kappa statistics indicated greater data agreement at sites with EMRs (0.72, 95% CI 0.56-0.88) than without EMRs (0.46, 95% CI 0.29-0.64). Adjusted for covariates, odds of data agreement were greatest in sites where EMRs were available during the entire study period (OR 4.31, 95% CI 1.67-11.13)., Conclusions: Primary care sites with EMRs better document mammography use than those with paper records. Patient self-report of mammography screening is more accurate at sites with EMRs. Broader access to EMRs should be implemented to improve quality of documenting mammography use. At a minimum, quality improvement efforts should confirm the accuracy of paper records with supplemental data.

Background: The Boston Racial and Ethnic Approaches to Community Health (REACH) 2010 Breast and Cervical Cancer Coalition developed a case management intervention for women of African descent to identify and reduce medical and social obstacles to breast cancer screening and following up abnormal results., Methods: We targeted black women at high risk for inadequate cancer screening and follow-up as evidenced by a prior pattern of missed clinic appointments and frequent urgent care use. Case managers provided referrals to address patient-identified social concerns (e.g., transportation, housing, language barriers), as well as navigation to prompt screening and follow-up of abnormal tests. We recruited 437 black women aged 40-75, who received care at participating primary care sites. The study was conducted as a prospective cohort study rather than as a controlled trial and evaluated intervention effects on mammography uptake and longitudinal screening rates via logistic regression and timely follow-up of abnormal tests via Cox proportional hazards models., Results: A significant increase in screening uptake was found (OR 1.53, 95% CI 1.13-2.08). Housing concerns (p < 0.05) and lacking a regular provider (p < 0.01) predicted poor mammography uptake. Years of participation in the intervention increased odds of obtaining recommended screening by 20% (OR 1.20, 95% CI 1.02-1.40), but this effect was attenuated by covariates (p = 0.53). Timely follow-up for abnormal results was achieved by most women (85%) but could not be attributed to the intervention (HR 0.95, 95% CI 0.50-1.80)., Conclusions: Case management was successful at promoting mammography screening uptake, although no change in longitudinal patterns was found. Housing concerns and lacking a regular provider should be addressed to promote mammography uptake. Future research should provide social assessment and address social obstacles in a randomized controlled setting to confirm the efficacy of social determinant approaches to improve mammography use.

A B(1) field gradient-based method previously described for the detection of mechanical vibrations has been applied to detect oscillatory motions in condensed matter originated from acoustic waves. A ladder-shaped coil generating a quasi-constant RF-field gradient was associated with a motion-encoding NMR sequence consisting in a repetitive binomial 13;31; RF pulse train (stroboscopic acquisition). The NMR response of a gel phantom subject to acoustic wave excitation in the 20-200 Hz range was investigated. Results showed a linear relationship between the NMR signal and the wave amplitude and a spectroscopic selectivity of the NMR sequence with respect to the input acoustic frequency. Spin displacements as short as a few tens of nanometers were able to be detected with this method.

A new method for NMR characterization of mechanical waves, based upon radiofrequency field gradient for motion encoding, is proposed. A binomial B1 gradient excitation scheme was used to visualize the mobile spins undergoing a periodic transverse mechanical excitation. A simple model was designed to simulate the NMR signal as a function of the wave frequency excitation and the periodicity of the NMR pulse sequence. The preliminary results were obtained on a gel phantom at low vibration frequencies (0-200 Hz) by using a ladder-shaped coil generating a nearly constant RF field gradient along a specific known direction. For very small displacements and/or B1 gradients, the NMR signal measured on a gel phantom was proportional to the vibration amplitude and the pulse sequence was shown to be selective with respect to the vibration frequency. A good estimation of the direction of vibrations was obtained by varying the angle between the motion direction and the B1 gradient. The method and its use in parallel to more conventional MR elastography techniques are discussed. The presented approach might be of interest for noninvasive investigation of elastic properties of soft tissues and other materials.

A method for in-plane imaging of large objects as compared to the RF coil is proposed based on the use of a single specially designed surface coil, without using B(0) gradients. A constant B(1) gradient was generated along the main axis of a ladder-shaped coil, and RF-encoding along the direction of the gradient made it possible to obtain spin-density profiles. Successive acquisitions of profiles obtained by translation of the NMR coil resulted in distorted images-due to the presence of non-zero gradients perpendicular to the constant gradient-that were successfully processed using a mathematical treatment based on linear combinations of calculated altered images from single-pixel objects. Copyright 2000 Academic Press.

Objective: To assess the treatment of peripancreatic fluid collections or abscess with percutaneous catheter drainage (PCD)., Summary Background Data: Surgical intervention has been the mainstay of treatment for infected peripancreatic fluid collections and abscesses. Increasingly, PCD has been used, with mixed results reported in the literature., Methods: A retrospective chart review of 1993 to 1997 was performed on 82 patients at a tertiary care public teaching hospital who had computed tomography-guided aspiration for suspected infected pancreatic fluid collection or abscess. Culture results, need for subsequent surgical intervention, length of stay, and death rate were assessed., Results: One hundred thirty-five aspirations were performed in 82 patients (57 male patients, 25 female patients) with a mean age of 40 years (range 17-68). The etiologies were alcohol (41), gallstones (32), and other (9). The mean number of Ranson's criteria was four (range 0-9). All patients received antibiotics. Forty-eight patients had evidence of pancreatic necrosis on computed tomography scan. Cultures were negative in 40 patients and positive in 42. Twenty-five of the 42 culture-positive patients had PCD as primary therapy, and 6 required subsequent surgery. Eleven patients had primary surgical therapy, and five required subsequent surgery. Six patients were treated with only antibiotics. The death rates were 12% for culture-positive patients and 8% for the entire 82 patients., Conclusions: Historically, patients with positive peripancreatic aspirate culture have required operation. This series reports an evolving strategy of reliance on catheter drainage. PCD should be considered as the initial therapy for culture-positive patients, with surgical intervention reserved for patients in whom treatment fails.

Introduction: APC and TP53 are tumor suppressor genes known to be altered frequently in human esophageal adenocarcinoma (EAC), which arises as a complication of reflux disease. To determine the functional role of these genes in the development of EAC, we have created reflux in mice gene-targeted for either Trp53 or Apc., Methods: Wild-type (WT), p53-knockout (Trp53-/-), or Apc-mutated (ApcMin/+) mice were generated in our breeding colony. Total gastrectomy with esophagojejunostomy was performed at 6 weeks of age, creating jejunoesophageal reflux. Unoperated control mice were maintained under identical conditions. Mice were sacrificed at 30 weeks of age. Histology of the esophagus and jejunal anastamosis or gastroesophageal junction was reviewed by a single pathologist blinded to the genotype of the animal., Results: The esophagus was normal in all of the unoperated mice (6 ApcMin/+, 6 WT, and 6 Trp53-/-). All operated mice (6 ApcMin/+, 12 WT, and 4 Trp53-/-) had esophagitis, with squamous hyperplasia and early focal ulceration. Barrett's metaplasia was identified in 33% of the operated ApcMin/+ (2/6) and 25% of the Trp53-/- (1/4) mice, but not in the WT mice. Of 4 operated Trp53-/- mice, all developed severe dysplasia of the squamous epithelium and 2 (50%) had EAC on histology, although no gross tumors were seen. No severe dysplasia or carcinoma was identified in any of the ApcMin/+ or WT mice., Conclusions: Loss of either Trp53 or Apc leads to the development of columnar metaplasia, whereas loss of Trp53, but not Apc, leads to development of cancer in mice with jejunoesophageal reflux., (Copyright 1999 Academic Press.)

Purpose: It was hypothesized that laparoscopic colon surgery may be associated with increased absorption of CO2 resulting from mobilization of lateral peritoneal reflections., Methods: Six pigs underwent laparotomy with removal of a measured quadrant of peritoneum before insufflation to 15 mmHg with CO2. Six paired control animals also underwent insufflation with CO2 to 15 mmHg. Measurements of the end-tidal CO2 (PetCO2), arterial blood gas analysis for CO2 (PaCO2), and pH were performed before insufflation, at 5 and 10 minutes following insufflation, then at successive 15-minute intervals for a total of two hours, and 15 minutes following desufflation. No attempt was made to correct the hypercarbia by increasing minute ventilation., Results: PaCO2 reached its maximum level at two hours with values of 70.77 +/- 5.54 mmHg and 64.62 +/- 5.18 mmHg in the peritonectomized and control groups, respectively. PetCO2 also peaked at two hours to 60 +/- 13 mmHg for the study group and 54 +/- 11 mmHg for controls. pH reached its nadir at two hours, falling from a baseline of 7.45 +/- 0.08 to 7.23 +/- 0.09 in the study group, and from 7.42 +/- 0.04 to 7.24 +/- 0.04 in the control group. There were no statistically significant differences between the two groups for any of the parameters measured at each time interval., Conclusions: The hypothesis that peritonectomy produces greater CO2 absorption during CO2 pneumoperitoneum was disproved under these experimental conditions.