Using social media to support small group learning.

BACKGROUND: Medical curricula are increasingly using small group learning and less didactic lecture-based teaching. This creates new challenges and opportunities in how students are best supported with information technology. We explored how university-supported and external social media could support collaborative small group working on our new undergraduate medical curriculum. METHODS: We made available a curation platform (Scoop.it) and a wiki within our virtual learning environment as part of year 1 Case-Based Learning, and did not discourage the use of other tools such as Facebook. We undertook student surveys to capture perceptions of the tools and information on how they were used, and employed software user metrics to explore the extent to which they were used during the year. RESULTS: Student groups developed a preferred way of working early in the course. Most groups used Facebook to facilitate communication within the group, and to host documents and notes. There were more barriers to using the wiki and curation platform, although some groups did make extensive use of them. Staff engagement was variable, with some tutors reviewing the content posted on the wiki and curation platform in face-to-face sessions, but not outside these times. A small number of staff posted resources and reviewed student posts on the curation platform. CONCLUSIONS: Optimum use of these tools depends on sufficient training of both staff and students, and an opportunity to practice using them, with ongoing support. The platforms can all support collaborative learning, and may help develop digital literacy, critical appraisal skills, and awareness of wider health issues in society.

Gene expression profiling of pluripotency and differentiation-related markers in cat oocytes and preimplantation embryos.

During mammalian preimplantation development, two successive differentiation events lead to the establishment of three committed lineages with separate fates: the trophectoderm, the primitive endoderm and the pluripotent epiblast. In the mouse embryo, the molecular mechanisms underlying these two cell fate decisions have been studied extensively, leading to the identification of lineage-specific transcription factors. Species-specific differences in expression patterns of key regulatory genes have been reported, raising questions regarding their role in different species. The aim of the present study was to characterise the gene expression patterns of pluripotency (OCT4, SOX2, NANOG) and differentiation (CDX2, GATA6)-related markers during feline early development using reverse transcription-quantitative polymerase chain reaction. In addition, we assessed the impact of in vitro development on gene expression by comparing transcript levels of the genes investigated between in vitro and in vivo blastocysts. To normalise quantitative data within different preimplantation embryo stages, we first validated a set of stable reference genes. Transcript levels of all genes investigated were present and changed over the course of preimplantation development; a highly significant embryo-stage effect on gene expression was observed. Transcript levels of OCT4 were significantly reduced in in vitro blastocysts compared with their in vivo counterparts. None of the other genes investigated showed altered expression under in vitro conditions. The different gene expression patterns of OCT4, SOX2, CDX2 and GATA6 in cat embryos resembled those described in mouse embryos, indicative of a preserved role for these genes during early segregation. However, because of the absence of any upregulation of NANOG transcription levels after embryonic genome activation, it is unlikely that NANOG is a key regular of lineage segregation. Such results support the hypothesis that the behaviour of early lineage markers can be species specific. The present study also revealed a pool of maternal NANOG mRNA transcripts, the role of which remains to be elucidated. Comparing transcription levels of these genes between in vivo and in vitro blastocysts revealed low levels of OCT4 mRNA in the latter, which may contribute to the reduced developmental competence of embryos under suboptimal conditions.

Pharmacological treatment of obstructive sleep apnea with a combination of pseudoephedrine and domperidone.

OBJECTIVES: To determine the effect of the drug combination domperidone and pseudoephedrine on nocturnal oximetry measurements and daytime sleepiness in patients with obstructive sleep apnea. METHODS: We recruited patients with severe snoring and apneic episodes willing to undergo repeated nocturnal oximetry testing. Following baseline clinical history, Epworth Sleepiness Scale administration, and home overnight nocturnal oximetry, patients were started on weight-adjusted doses of domperidone and pseudoephedrine. Follow-up oximetry studies were performed at the patient's convenience. On the final visit, a repeat clinical history, Epworth score, and oximetry were obtained. RESULTS: Seventeen of 23 patients noted disappearance of snoring and apneic episodes. Another 2 patients reported improvement in snoring and no apneic episodes. All but one patient had a decrease in Epworth scores (mean decrease 9.4 (95% CI, 6.8-12.1, p < 0.0001). Mean oxygen saturation (2.5; 95% Cl, 0.66-4.41, p = 0.008), percent time with oxygen saturation < 90% (14.8; 95% CI, 24.4 to 5.2, p = 0.003), and the 4% oxygen desaturation index (18.2; 95% CI, 27.3 to 9.1, p < 0.0001) improved significantly. No adverse effects of treatment were noted. CONCLUSIONS: The combination of domperidone and pseudoephedrine improved self reported snoring and sleepiness, and may have improved apneic episodes and sleep-related nocturnal oxygen desaturation in patients with obstructive sleep apnea provided the proportion of time spent asleep did not diminish. This drug combination warrants further study as a treatment for obstructive sleep apnea. KEYWORDS: Obstructive sleep apnea; oximetry; sleepiness; domperidone; pseudoephedrine; pharmacotherapy; desaturation; treatment CITATION: Larrain A; Kapur VK; Gooley TA; Pope CE. Pharmacological treatment of obstructive sleep apnea with a combination of pseudoephedrine and domperidone.

Generation of domestic transgenic cloned kittens using lentivirus vectors.

The efficient use of somatic cell nuclear transfer (SCNT), in conjunction with genetic modification of donor cells provides a general means to add or inactivate genes in mammals. This strategy has substantially improved the efficacy of producing genetically identical animals carrying mutant genes corresponding to specific human disorders. Lentiviral (LV) vectors have been shown to be well suited for introducing transgenes into cells to be used as donor nuclei for SCNT. In the present study, we established an LV vector-based transgene delivery approach for producing live transgenic domestic cats by SCNT. We have demonstrated that cat fetal fibroblasts can be transduced with EGFP-encoding LV vectors bearing various promoters including the human cytomegalovirus immediate early (hCMV-IE) promoter, the human translation elongation factor 1alpha (hEF-1alpha) promoter and the human ubiquitin C (hUbC) promoter. Among the promoters tested, embryos reconstructed with donor cells transduced with a LV-vector bearing the hUbC promoter displayed sustained transgene expression at the blastocyst stage while embryos reconstructed with LV vector-transduced cells containing hCMV-IE-EGFP or hEF-1alpha-EGFP cassettes did not. After transfer of 291 transgenic cloned embryos into the oviducts of eight recipient domestic cats (mean =36.5 +/- 10.1), three (37.5%) were diagnosed to be pregnant, and a total of six embryos (2.1%) implanted. One live male offspring was delivered by Cesarean section on day 64 of gestation, and two kittens were born dead after premature delivery on day 55. In summary, we report the birth of transgenic cloned kittens produced by LV vector-mediated transduction of donor cells and confirm that cloned kittens express the EGFP reporter transgene in all body tissues.

Chromosomal aneuploidy in African Wildcat somatic cells and cloned embryos.

In the present study, we compared the incidence of aneuploidy in in vitro fertilized domestic cat embryos (DSH-IVF) with that of African Wildcat (AWC) cloned embryos reconstructed with AWC fibroblast donor cells from different passages (AWC-NT). Fibroblast cells were cultured to passages 1 (P1), 3 (P3), 4 (P4), and 9 (P9), after which cells at each passage were karyotyped and serum-starved before being frozen for nuclear transfer. AWC-NT embryos were produced by fusion of a single AWC somatic cell at P1, P3, P4, or P9 to enucleated domestic cat cytoplast derived from in vitro matured (IVU) oocytes. DSH-IVF embryos were produced after IVU oocytes were fertilized in vitro with domestic cat spermatozoa. To determine chromosome numbers, embryos (2-4-cell) or fibroblast cells were cultured in medium containing 0.28 microg/mL of Colcemid for 22-24 h or 15-24 h, respectively. Subsequently, embryos and cells were placed in hypotonic solution, fixed, and stained for analysis of chromosome spreads by bright field microscopy. Chromosomal abnormalities in AWC fibroblast cells increased progressively during culture in vitro: P1 (43%), P3 (46%), P4 (62%), and P9 (59%). In fibroblast cells, hypoploidy (94/202, 46%) was the major chromosomal abnormality, and it occurred more frequently than hyperploidy (14/202, 7%; p < 0.05). While the percentage of hyperploid cells remained stable during all passages, the proportion of hypoploidy in fibroblast cells increased significantly after P4. The overall incidence of chromosomal abnormalities in AWC-NT embryos at P1 (45%), P3 (60%), and P4 (50%) was similar to that of the fibroblast cells from which they were derived; however, the incidence was higher for embryos reconstructed with donor fibroblasts at P9 (89%). Hypoploidy was the most common chromosomal abnormality observed in either AWC-NT or DSH-IVF embryos. AWCNT embryos reconstructed with donor cells at early passages (P1, P3, and P4) had similar frequencies of chromosomal diploidy, as did DSH-IVF embryos. Accordingly, based on the present results, for NT we are currently using cat donor cells at early passages, when the percentage of cells with chromosomal abnormalities is low. It is recommended that the chromosomal stability of each cell line be analyzed before use as NT donor cells to reduce the incidence of chromosomal anomalies in reconstructed embryos and to possibly produce a subsequent increase in cloning efficiency.

Treatment of severe snoring with a combination of pseudoephedrine sulfate and domperidone.

STUDY OBJECTIVES: Pharmacologic treatment of severe snoring has not been considered to be of great value. The objective of this study was to determine whether the combination of a nasal decongestant and a prokinetic drug would decrease or eliminate severe snoring. METHODS: Thirty healthy individuals whose sleeping partners reported that the patients had severe nightly snoring entered an open-label trial of 60 mg of pseudoephedrine and 10 mg of domperidone at bedtime for 30 days. Each night's snoring was scored on a diary by the sleeping partner. At the end of the open-label trial, a subset of subjects whose snoring had recurred were randomized to one or both placebo-controlled trials, either 60 mg of pseudoephedrine sulfate plus 10 mg of domperidone or to 30 mg of pseudoephedrine sulfate plus 10 mg of domperidone. In another placebo-controlled trial, the drug combination was compared with each component. RESULTS: In the open-label trial, 493 of 772 evaluable subject-nights were free of snoring; another 232 nights were scored as mild snoring. In the placebo-controlled trials, low-dose therapy caused a reduction in snoring, and high-dose therapy even a greater reduction in snoring. The drug combination was more effective than either agent alone. CONCLUSION: Treatment with a prokinetic agent plus a nasal decongestant reduced or eliminated severe snoring in the majority of subjects treated.

Typical GERD symptoms and esophageal pH monitoring are not enough to diagnose pharyngeal reflux.

BACKGROUND: Abnormal pharyngeal reflux of acid (PR) (as measured by pH monitoring) is associated with microaspiration, and is a good predictor of airway symptom response to medical and surgical anti-reflux therapy. However, in clinical practice the link between airway disease and Gastroesophageal reflux disease (GERD) is still based on the presence of typical symptoms (e.g., heartburn) and/or standard esophageal function testing (manometry and 24-pH monitoring). PR is rarely measured directly. We undertook this study to determine if typical symptoms and standard testing could reliably predict the presence of PR. METHODS: The study group consisted of 518 patients with suspected reflux induced airway disease evaluated from December 1998 through January 2002. Each patient completed a standardized symptom questionnaire, underwent esophageal manometry, and 24-h esophageal and pharyngeal pH monitoring. Patients were classified having abnormal pharyngeal reflux (PR+) if they had >1 episode of PR detected during pH monitoring. RESULTS: One hundred eighty-one patients were PR+ and 337 were PR-. The most common symptoms, namely cough (PR +73%, PR- 68%), hoarseness (PR +64%, PR- 66%), and dyspnea (PR +59%, PR- 59%) were present with similar incidence in PR+ and PR- patients. The incidence of heartburn was 54% in the PR+ and 52% in the PR- patients. Logistic regression analysis revealed that abnormal esophageal acid exposure was a predictor of PR+ (P < 0.001). Neither the presence of heartburn or specific respiratory symptoms, the pressure of the lower esophageal sphincter (LES) or upper esophageal sphincter (UES), or amplitude of esophageal contractions predicted PR+. There was substantial variability in esophageal length (UES to LES), thus the placement of the distal pH probe from the LES varied considerably (median = 13 cm, 2-20 cm). Using established normal values of acid exposure at multiple levels of the esophagus, 24% of PR+ patients had normal amounts of esophageal acid exposure. CONCLUSIONS: Typical GERD symptoms, such as heartburn, and typical symptoms of aspiration such as hoarseness, cough, or dyspnea are not enough to positively identify PR. While patients with abnormal esophageal acid exposure are three times more likely than those with normal values to have PR, abnormal esophageal acid exposure alone does not identify all patients with PR. Therefore, relying on symptoms and standard diagnostic testing may fail to identify patients with extraesophageal reflux. Pharyngeal pH monitoring should be considered for patients with suspected reflux-induced airway disease.

Histologic features of reflux-attributed laryngeal lesions.

The purpose of this study was to compare the histologic appearance of the normal larynx and the larynx presumably affected by reflux. A secondary objective was to determine the safety of performing laryngeal biopsies. Biopsy specimens from the interarytenoid area of 15 patients with reflux laryngitis were compared with specimens from 9 control subjects. Control subjects were asymptomatic, had normal 24-hour pH studies, and had a normal videostroboscopic laryngeal examination. Patients with reflux laryngitis had abnormal pH studies and videostroboscopic examinations. There were no consistent changes in mucosal detail or cellular infiltration that distinguished the biopsies from normal patients and those with reflux laryngitis. In this small sample of subjects it was not possible to define any characteristic histologic features of reflux laryngitis.

Nuclear transfer of synchronized african wild cat somatic cells into enucleated domestic cat oocytes.

The African wild cat is one of the smallest wild cats and its future is threatened by hybridization with domestic cats. Nuclear transfer, a valuable tool for retaining genetic variability, offers the possibility of species continuation rather than extinction. The aim of this study was to investigate the ability of somatic cell nuclei of the African wild cat (AWC) to dedifferentiate within domestic cat (DSH) cytoplasts and to support early development after nuclear transplantation. In experiment 1, distributions of AWC and DSH fibroblasts in each cell-cycle phase were assessed by flow cytometry using cells cultured to confluency and disaggregated with pronase, trypsin, or mechanical separation. Trypsin (89.0%) and pronase (93.0%) yielded higher proportions of AWC nuclei in the G0/G1 phase than mechanical separation (82.0%). In contrast, mechanical separation yielded higher percentages of DSH nuclei in the G0/G1 phase (86.6%) than pronase (79.7%) or trypsin (74.2%) treatments. In both species, pronase induced less DNA damage than trypsin. In experiment 2, the effects of serum starvation, culture to confluency, and exposure to roscovitine on the distribution of AWC and DSH fibroblasts in various phases of the cell cycle were determined. Flow cytometry analyses revealed that the dynamics of the cell cycle varied as culture conditions were modified. Specifically, a higher percentage of AWC and DSH nuclei were in the G0/G1 phase after cells were serum starved (83% vs. 96%) than were present in cycling cells (50% vs. 64%), after contact inhibition (61% vs. 88%), or after roscovitine (56% vs. 84%) treatment, respectively. In experiment 3, we evaluated the effects of cell synchronization and oocyte maturation (in vivo vs. in vitro) on the reconstruction and development of AWC-DSH- and DSH-DSH-cloned embryos. The method of cell synchronization did not affect the fusion and cleavage rate because only a slightly higher percentage of fused couplets cleaved when donor nuclei were synchronized by serum starvation (83.0%) than after roscovitine (80.0%) or contact-inhibition (80.0%). The fusion efficiency of in vivo and in vitro matured oocytes used as recipient cytoplasts of AWC donor nuclei (86.6% vs. 85.2%) was similar to the rates obtained with DSH donor nuclei, 83.7% vs. 73.0%, respectively. The only significant effect of source of donor nucleus (AWC vs. DSH) was on the rate of blastocyst formation in vitro. A higher percentage of the embryos derived from AWC nuclei developed to the blastocyst stage than did embryos produced from DSH nuclei, 24.2% vs. 3.3%, respectively (P < 0.05). In experiment 4, the effect of calcium in the fusion medium on induction of oocyte activation and development of AWC-DSH-cloned embryos was determined. The presence of calcium in the fusion medium induced a high incidence of cleavage of DSH oocytes (54.3%), while oocyte cleavage frequency was much lower in the absence of calcium (16.6%). The presence or absence of calcium in the fusion medium did not affect the fusion, cleavage, and blastocyst development of AWC-DSH-cloned embryos. In experiment 5, AWC-DSH-cloned embryos were transferred to the uteri of 11 synchronized domestic cat recipients on Day 6 or 7 after oocyte aspiration. Recipients were assessed by ultrasonography on Day 21 postovulation, but no pregnancies were observed. In the present study, after NT, AWC donor nuclei were able to dedifferentiate in DSH cytoplasts and support high rates of blastocyst development in vitro. Incomplete reprogramming of the differentiated nucleus may be a major constraint to the in vivo developmental potential of the embryos.

Effective treatment of rumination with Nissen fundoplication.

Rumination is a syndrome characterized by the effortless regurgitation of recently ingested food. It has been linked to severe medical and psychosocial conditions including malnutrition, aspiration pneumonia, and complete social withdrawal. Psychotherapy, the current treatment modality for rumination, may improve symptoms but requires significant motivation and is rarely curative. We hypothesized that a complete fundoplication would eliminate, or at least impair, the ability to regurgitate gastric contents through the esophagogastric junction. We performed a Nissen fundoplication in five patients with a classic history of rumination. In all cases, symptoms had been resistant to medical and psychiatric intervention prior to fundoplication. Formal preoperative testing included esophageal manometry, 24-hour pH monitoring, endoscopy, and upper gastrointestinal barium swallow studies. All patients reported their primary symptom to be effortless recurrent postprandial regurgitation for 1 to 2 hours after meals consistent with rumination. Four (80%) of the five patients had low resting lower esophageal sphincter pressures with evidence of gastroesophageal reflux disease on 24-hour pH monitoring. All patients reported complete cessation of ruminating behavior after Nissen fundoplication. We report, for the first time, complete elimination of rumination symptoms after a Nissen fundoplication. Although further trials are needed to confirm our results, we recommend considering a Nissen fundoplication for treatment of rumination refractory to behavioral and medical interventions.

Laryngoscopy and pharyngeal pH are complementary in the diagnosis of gastroesophageal-laryngeal reflux.

Pharyngeal pH monitoring and laryngoscopy are routinely used to diagnose gastroesophageal-laryngeal reflux as a cause of respiratory symptoms. Although their use seems intuitive, their ultimate diagnostic value is yet to be defined. We studied 10 asymptomatic (control) subjects and 76 patients with respiratory symptoms. Both patients and control subjects were given a symptom questionnaire. Each underwent direct laryngoscopy using the reflux finding score (RFS) to grade laryngeal injury, esophageal manometry, and 24-hour esophagopharyngeal pH monitoring. The patients were then classified as RFS+, if the score was greater than 7, and pharyngeal reflux (PR)+, if they had more than one episode of PR detected during pH monitoring. The most common symptoms reported by patients were hoarseness (87%), cough (53%), and heartburn (50%). Control subjects had a significantly lower RFS (2.1 vs. 9.6, P < 0.01) and fewer episodes of PR (0.2 vs. 3.4, P < 0.01), than patients. None of the control subjects had more than one episode of PR during a 24-hour period. Fifty patients (66%) were RFS+ and 26 (34%) were RFS-. Thirty-two patients (42%) were PR+ and 44 (58%) were PR-. Fifteen patients had a normal RFS and no PR (group I = RFS-/PR-). Forty patients had discordance between the laryngoscopic findings and the pH monitoring (group II = RFS-/PR+ or RFS+/PR-). Twenty-one patients had both an abnormal RFS and PR (group III = RFS+/PR+). Patients in group III had significantly higher heartburn scores and distal esophageal acid exposure. Eighty-three percent of patients in group III but only 44% in group I improved their respiratory symptoms as a result of antireflux therapy. An abnormal PR or RFS differentiates patients with laryngeal symptoms from control subjects. Agreement between PR and RFS helps establish or refute the diagnosis of gastroesophageal reflux as a cause of laryngeal symptoms. Patients who are RFS+ and PR- may have laryngeal injury from another source, whereas patients who are RFS- and PR+ may not have acid entering the larynx, despite the presence of PR. Patients who are RFS+ and PR+ have more severe gastroesophageal reflux disease and their reflux causes laryngeal damage. Laryngoscopy and pharyngeal pH monitoring should be considered complementary studies in establishing the diagnosis of laryngeal injury induced by gastroesophageal reflux. ( J GASTROINTEST SURG 2002;6:189-194.)