Development of A Multi-Modality Navigational Based Training System for Fetoscopic Surgical Therapy

Fetal surgery is regarded as a technically difficult and new field of research, requiring the use of fetoscopic and ultrasound (US) navigation to perform minimally invasive procedures within the amniotic cavity. The Surgical Apprenticeship Training model (SAT) centres around the subjective assessment of a surgical resident's cognitive competency and technical skills under proctorship using opportunity-based environments. The restrictiveness and rarity of fetal procedures limit the effectiveness of the SAT model, resulting in a slow learning curve (LC) and higher procedural complication rates. This paper aimed to investigate the use of optical tracking technology to construct a novel simulated training system and accompanying scoring assessment under the Proficiency-Based Training model (PBT), providing real-time positional feedback of surgical tools and a quantitative feedback assessment of a surgical resident's technical skills. Clinical Relevance- Clinical feedback deemed the system as valid and confirmed that this novel approach to surgical training will significantly benefit smaller clinics that lack opportunity-based environments. Clinical feedback also suggested that the training system could be adapted to provide access to complex surgical training across the world.

Therapeutic relevance of the protein phosphatase 2A in cancer

Chromosomal Instability (CIN) is regarded as a unifying feature of heterogeneous tumor populations, driving intratumoral heterogeneity. Polo-Like Kinase 1 (PLK1), a serine-threonine kinase that is often overexpressed across multiple tumor types, is one of the key regulators of CIN and is considered as a potential therapeutic target. However, targeting PLK1 has remained a challenge due to the off-target effects caused by the inhibition of other members of the polo-like family. Here we use synthetic dosage lethality (SDL), where the overexpression of PLK1 is lethal only when another, normally non-lethal, mutation or deletion is present. Rather than directly inhibiting PLK1, we found that inhibition of PP2A causes selective lethality to PLK1-overexpressing breast, pancreatic, ovarian, glioblastoma, and prostate cancer cells. As PP2A is widely regarded as a tumor suppressor, we resorted to gene expression datasets from cancer patients to functionally dissect its therapeutic relevance. We identified two major classes of PP2A subunits that negatively correlated with each other. Interestingly, most mitotic regulators, including PLK1, exhibited SDL interactions with only one class of PP2A subunits (PPP2R1A, PPP2R2D, PPP2R3B, PPP2R5B and PPP2R5D). Validation studies and other functional cell-based assays showed that inhibition of PPP2R5D affects both levels of phospho-Rb as well as sister chromatid cohesion in PLK1-overexpressing cells. Finally, analysis of clinical data revealed that patients with high expression of mitotic regulators and low expression of Class I subunits of PP2A improved survival. Overall, these observations point to a context-dependent role of PP2A that warrants further exploration for therapeutic benefits.

Prevalence of breastfeeding at four months in general practices in south London

BACKGROUND

Successive quinquennial National Infant Feeding Surveys have provided a valuable picture of national and regional variations in infant feeding practices within the United Kingdom. Social variation in breastfeeding has been recognised to be an important source of health inequalities in childhood by the Independent Inquiry into Inequalities in Health Report.

AIM

To determine the prevalence of breastfeeding at birth and at four months in a sample of women from urban general practices, its variation between practices, and relation to practice population deprivation scores. To report the timing of introduction of solid feeds.

DESIGN OF STUDY

Cross-sectional questionnaire survey based on a random cluster sample.

SETTING

Women with infants aged four months in general practices in South London.

METHOD

Mode of infant feeding at birth and four months, and time of introduction of solids. Jarman score as a measure of practice population deprivation. Housing tenure, maternal ethnic group, and maternal age at leaving full-time education.

RESULTS

Twenty-five general practices were sampled. Median practice Jarman score was 15.0 (interquartile range [IQR] = 12.6-21.9). Responses were received from 1053 out of 1532 mothers approached (69%). Of these, 87% (897) had breastfed at birth, while 59% (609) were still breastfeeding their babies at four months. Mothers in rented accommodation were less likely to breastfeed than owner-occupiers (odds ratio [95% CI] = 0.52 [0.37-0.74]), as were women of white, compared with those of black, ethnic origin (odds ratio [95% CI] = 0.55 [0.36-0.82]). Those who completed up to two years and more than two years education after the age of 16 were 2.94 (95% CI = 1.85-4.66) and 9.25 (95% CI = 6.02-14.21) more likely to breastfeed at four months, respectively, than mothers whose formal education was completed at or before 16 years. Practice-specific rates of breastfeeding ranged from 71% to 100% at birth (median 87%; IQR = 79-93%) and 22% to 83% at four months (median 61%; interquartile range = 47-66%). The intra-practice correlation coefficient for breastfeeding at four months was 0.052 (within-cluster variance = 0.23, between-cluster variance = 0.013). There was no association between breastfeeding at four months and practice-specific Jarman score. Median age of starting solids was 16 weeks (IQR = 15-17 weeks).

CONCLUSIONS

Housing tenure, maternal education, and ethnic group are significantly associated with breastfeeding prevalence at four months. Between-practice variation in breastfeeding prevalence is not associated with measures of practice population deprivation, as assessed by Jarman scores. Consideration should be given to including information on maternal ethnic group and housing tenure in future National Infant Feeding Surveys. Current weaning practices fall short of the recommendation of the World Health Assembly.

Psychiatric status, prevention, and outcome in patients with burns: a prospective study

One hundred consecutive patients admitted to the Tampa Bay Regional Burn Center were assessed to determine cause of injury, preburn psychiatric status, and outcome (survival, length of stay in the hospital, and emergence of new psychiatric or physiologic disorders). Patients with psychiatric disorders were more likely to have injuries that were preventable, and there was a trend for this group to have more emergent psychiatric disorders and longer lengths of hospital stay. We suggest that the Burn Severity Index might be revised to include the presence of preburn psychiatric disorders and then be evaluated in a larger group with use of the Burn Registry.

Mucosal immunity in extrinsic allergic alveolitis: salivary immunoglobulins and antibody against inhaled avian antigens among pigeon breeders

BACKGROUND

Inhaled antigens from pigeons can cause extrinsic allergic alveolitis (EAA); a model disease of pulmonary inflammation. Among pigeon breeders, serum antibody and sensitized lymphocytes specific for these antigens have been described primarily, but not always, with disease. Antibody activity within the lung may have a closer association with disease, however, sampling by alveolar lavage at bronchoscopy is impractical for screening, therefore we used saliva to quantify the mucosal antibody response.

OBJECTIVE

To establish: (a) if antibody activity against inhaled avian antigens was detectable in the saliva of pigeon breeders, (b) if the distribution of saliva antibody and total immunoglobulin levels were quantitatively or qualitatively different from serum, and (c) whether the hypersensitivity symptoms of EAA were associated more with the mucosal or the systemic humoral immune response.

MEASURES

Saliva and serum total and avian antigen-specific IgG, IgA (IgA1 and IgA2) antibody activity in 87 pigeon breeders and 24 control subjects with no avian exposure. Albumin levels were used as a protein reference and cotinine levels confirmed smoking status. Specific hypersensitivity symptoms and various exposure indices to pigeons were established by interview.

RESULTS

Absolute levels and relative proportions (vs albumin) of IgG, IgA and IgA1 in saliva, and IgG in serum, were significantly higher in pigeon breeders compared with controls, suggesting mucosal inflammation. Avian antigen-specific antibody of all isotypes was readily demonstrable in saliva (predominantly IgA) and serum (predominantly IgG) from pigeon breeders, and there were no significant titres in controls. The levels of IgG antibody in saliva and in serum correlated significantly (r = 0.52, P < 0.001), and both correlated with the raised immunoglobulin levels. In both saliva and serum the IgG rather than the IgA antibody activity was associated with symptoms of EAA.

CONCLUSIONS

Antibody activity in saliva and serum, representing the mucosal and systemic responses, respectively, were both strongly stimulated by inhaled antigens. The IgG antibody titres of saliva and serum correlated significantly and were a useful index of inflammation, as measured by the raised total immunoglobulin levels, and symptoms. This suggests that IgG antibody in serum may reflect clinical and immunological sensitization of the lung mucosa. Collecting saliva is noninvasive, and saliva antibody measurement is a convenient method for monitoring EAA, especially in children, and will facilitate sampling for example in epidemiological studies of antibody prevalence.

Eating pathology before and after bariatric surgery: a prospective study

OBJECTIVE

The objectives of the study were (1) to determine the prevalence of eating pathology in patients before bariatric surgery and at follow-up; (2) to assess the relationship of presurgical eating pathology to various measures of psychopathology; and (3) to assess the relationship between presurgical eating pathology and outcome.

METHOD

One hundred sixteen patients were evaluated prior to surgery and at follow-up an average of 5.5 years after surgery.

RESULTS

Preoperative binge eating occurred in 52% of patients, 16% met criteria for binge eating disorder, and 10% had the night eating syndrome. All three forms of presurgical eating pathology were statistically associated with cognitive distortions. At follow-up, 33% of patients were vomiting at least weekly. There was no relationship between presurgical eating pathology and weight outcome or presence of vomiting at follow-up.

DISCUSSION

Although postoperative vomiting usually does not represent purge behavior, it may represent failed attempts to binge.

Outcome of gastric restriction procedures: weight, psychiatric diagnoses, and satisfaction

BACKGROUND

Weight losses following bariatric surgery have varied widely, depending on length of follow-up and various pre-surgical characteristics of patients undergoing surgery.

METHODS

One hundred thirty one patients had a detailed presurgical psychiatric evaluation. Patients were assessed clinically for 2 years after surgery and at follow-up a mean of 5.7 years after surgery.

RESULTS

Mean presurgical body mass index (BMI) was 52.9 kg/m2; therefore, many patients had 'super obesity'. Two-thirds of the patients were located a mean of 5.7 years after surgery. The mean change in BMI at follow-up was 25% and the mean weight loss was 27%. One-third had excellent or good weight outcomes using the Griffen criteria. Five patients had died by follow-up. There was no relationship between age, gender, or fat content presurgically and weight loss at follow-up, although presurgical weight was associated with greater weight loss at follow-up. Weight regain began 2 years after surgery. There was no relationship between the presence or absence of a presurgical psychiatric diagnosis and weight loss at follow-up. There was also no relationship between the presence of a presurgical psychiatric diagnosis and various mental health parameters at follow-up. Satisfaction with the surgery was marginally associated with weight loss but significantly associated with improved mental and physical health.

CONCLUSIONS

Mean weight losses were less than have been previously reported with gastric restriction procedures but the follow-up was longer than usually reported and many patients had 'super obesity' prior to surgery. The implications of 'super obesity' for weight loss are discussed.

Psychiatric Issues in Bariatric Surgery

In this study, 100 patients were evaluated prior to surgery to assess psychiatric status. The demographic anthropometric and psychological characteristics are described. Seventeen patients developed severe psychiatric complications and required hospitalization; the diagnoses which precipitated hospital admission were most commonly affective disorders (especially major depression with suicidal ideation). The only deaths in the sample of 100 occurred among the patients who required post-surgical psychiatric hospitalization. The hospitalized group was compared to a matched group drawn from the original 100 patients. Factors associated with post-surgical psychiatric hospitalization were: presurgical psychiatric hospitalization, presence of multiple pre-surgical Axis I psychiatric diagnoses, and untreated Axis I diagnosis at the time of pre-surgical assessment. Psychiatric screening criteria were revised and 31 subsequent patients were evaluated; less than half of this group were found suitable for surgery at the time of preliminary assessment.

The effects of dietary calcium deprivation on serum calcitriol levels in premenopausal and postmenopausal women

The effect of the postmenopausal state on serum calcitriol levels was studied in 13 normal premenopausal women and 10 normal postmenopausal women under basal conditions and during seven days of dietary calcium deprivation. Calcitriol levels and the free calcitriol index were lower in the postmenopausal women, and this difference persisted during calcium deprivation. One of the major actions of calcitriol is to increase gut calcium absorption. Relative calcitriol deficiency, despite retained renal synthetic reserve, would in part explain the increased dietary calcium requirement to maintain calcium balance in postmenopausal women.

The colonization and establishment of invading bacteria in periodontium of ligature-treated immunosuppressed rats

The morphologic features and pattern of bacterial invasion of the periodontal tissue in ligature-induced periodontal defects of immunosuppressed rats were studied. Silk ligatures were placed circumferentially on the maxillary left second molar of 24 Sprague-Dawley rats. The treatment group (14 rats) received Cytoxan (75 mg/kg) the day after ligature placement and at Day 4. The control group (10 rats) received no medication. All animals were sacrificed on Day 8 and the maxillae processed for light and electron microscopy. Only ligated sites in immunosuppressed animals exhibited bacterial invasion. Invading bacteria consisted of microcolonies of Gram-negative and Gram-positive coccoid cells and rods located near the tissue surface. Each microcolony consisted of morphologically homogeneous microorganisms. The deeper sites revealed a diffuse invasion of Gram-negative rods which appeared morphologically similar. Other features associated with invasion were complete destruction of epithelial tissue next to the ligature and the lack of inflammatory cells in the gingival region. These findings, when compared to those of other reports of tissue penetration by bacteria, point to the necessity of differentiating between bacterial invasion of gingival tissues, associated with penetration of tissues by proliferating bacteria, and bacterial translocation, a situation in which bacteria are passively carried into the tissues, for example by mechanical manipulation immediately before or during biopsy taking, or possibly during processing for histology.