A unique sigma/anti-sigma system in the actinomycete Actinoplanes missouriensis

Bacteria of the genus Actinoplanes form sporangia that contain dormant sporangiospores which, upon contact with water, release motile spores (zoospores) through a process called sporangium dehiscence. Here, we set out to study the molecular mechanisms behind sporangium dehiscence in Actinoplanes missouriensis and discover a sigma/anti-sigma system with unique features. Protein σSsdA contains a functional sigma factor domain and an anti-sigma factor antagonist domain, while protein SipA contains an anti-sigma factor domain and an anti-sigma factor antagonist domain. Remarkably, the two proteins interact with each other via the anti-sigma factor antagonist domain of σSsdA and the anti-sigma factor domain of SipA. Although it remains unclear whether the SipA/σSsdA system plays direct roles in sporangium dehiscence, the system seems to modulate oxidative stress responses in zoospores. In addition, we identify a two-component regulatory system (RsdK-RsdR) that represses initiation of sporangium dehiscence.

Population-based cohort study of variation in the use of emergency cholecystectomy for benign gallbladder diseases

Background

The aims of this prospective population-based cohort study were to identify the patient and hospital characteristics associated with emergency cholecystectomy, and the influences of these in determining variations between hospitals.

Methods

Data were collected for consecutive patients undergoing cholecystectomy in acute UK and Irish hospitals between 1 March and 1 May 2014. Potential explanatory variables influencing the performance of emergency cholecystectomy were analysed by means of multilevel, multivariable logistic regression modelling using a two-level hierarchical structure with patients (level 1) nested within hospitals (level 2).

Results

Data were collected on 4744 cholecystectomies from 165 hospitals. Increasing age, lower ASA fitness grade, biliary colic, the need for further imaging (magnetic retrograde cholangiopancreatography), endoscopic interventions (endoscopic retrograde cholangiopancreatography) and admission to a non-biliary centre significantly reduced the likelihood of an emergency cholecystectomy being performed. The multilevel model was used to calculate the probability of receiving an emergency cholecystectomy for a woman aged 40 years or over with an ASA grade of I or II and a BMI of at least 25·0 kg/m2, who presented with acute cholecystitis with an ultrasound scan showing a thick-walled gallbladder and a normal common bile duct. The mean predicted probability of receiving an emergency cholecystectomy was 0·52 (95 per cent c.i. 0·45 to 0·57). The predicted probabilities ranged from 0·02 to 0·95 across the 165 hospitals, demonstrating significant variation between hospitals.

Conclusion

Patients with similar characteristics presenting to different hospitals with acute gallbladder pathology do not receive comparable care.

Advantages of intra-capsular micro-enucleation of schwannoma arising from extremities

BACKGROUND

Schwannoma is the most common tumor of the peripheral nerves, with surgical enucleation being the established treatment modality. However, some schwannomas cannot be easily enucleated and this sometimes results in iatrogenic nerve injury even with atraumatic procedures. Here we present a retrospective review of the management of schwannoma in the extremities and compare clinical outcomes from the two techniques of extra-capsular and intra-capsular enucleation.

METHODS

We reviewed 36 schwannomas from 35 patients who underwent surgical excision of schwannomas arising from the extremities. Twenty had undergone extra-capsular resection and 16 had undergone enucleation using the intra-capsular technique. The post-operative neurological deficits were graded as minor, major, and transient. The duration of symptoms, maximum tumor diameter and site of occurrence were compared between patients with the three grades of deficit.

RESULTS

In total, 22 patients developed no sensory changes following enucleation of schwannoma or only temporary and minor changes that had fully resolved within 6 months. Ten patients developed new neurological deficits following surgery that took longer than 6 months to resolve. Four patients experienced new motor deficits or paresthesia following operation that had still not recovered at the final follow-up, all of whom underwent enucleation using the extra-capsular technique. Neurological deficit after enucleation was significantly lower using the intra-capsular compared with the extra-capsular technique. Patient age, duration of symptoms, maximum diameter of the tumor and site of occurrence did not influence the neurological deficit following enucleation of schwannoma.

CONCLUSION

These results support intra-capsular micro-enucleation as a safe and reliable treatment for every type of schwannoma. To minimize the risk of nerve injury, en bloc resection should not be used because the main purpose of schwannoma surgery is the relief of symptoms, not tumor resection. Thorough pre-operative counseling of patients to inform them of the potential occurrence of neurological deficit is important.

The influence of a hexametaphosphate-containing chewing gum on the wetting ability of salivary conditioning films in vitro and in vivo

OBJECTIVE

Adsorbed conditioning films of salivary components on dental enamel surfaces or pellicles form the interface between teeth and the oral environment. The wetting ability of salivary conditioning films dictates biological adhesion phenomena such as plaque formation, calcification and staining, and also influences mouth perception through effects on lubricity. This study assessed the effects of hexametaphosphate release from a chewing gum matrix on the wetting ability of salivary conditioning films in vitro and in vivo.

METHODOLOGY

Results obtained for hexametaphosphate chewing gum were compared with those produced by hexametaphosphate-containing dentifrice, which has been clinically proven to have efficacy for stain removal and prevention and dental calculus prevention.

RESULTS

Contact angle assessments revealed that hexametaphosphate dentifrice produced markedly hydrophilic conditioning films in vitro. Hexametaphosphate chewing gums had only minor effects on surface contact angles in vitro. However, in vivo intra-oral contact angle measurements on tooth surfaces in volunteers showed that both hexametaphosphate dentifrice and chewing gum produced more hydrophilic tooth surfaces.

CONCLUSION

These results support the activity of hexametaphosphate on tooth surfaces delivered both from dentifrice and chewing gum forms.

Seat-belt syndrome revisited

This report describes a complex syndrome of injuries occurring in a young female who was a back seat passenger wearing a lap-belt restraint in a high-speed road traffic accident. As a consequence of the forced flexion distraction injury of her lumbar spine, she sustained a fracture-subluxation of the first lumbar vertebra in association with a jejunal perforation and extensive small intestinal mesenteric laceration. She also had a large traumatic hernia of the anterior abdominal wall, which was overlooked at primary laparotomy. This report highlights collectively the classical combination of injuries associated with the lap-belt syndrome and demonstrates the importance of carefully inspecting the anterior abdominal wall for deficiencies, because traumatic herniation may be easily overlooked.

Maximal expiratory flow-volume patterns in allergic rhinitis. Characteristic flow-volume patterns of the lower airways

On 37 patients with nasal allergy and 37 non-smoking healthy volunteers, maximal expiratory flow-volume curve and volume-time curve were obtained. To find the characteristic flow changes, the flow curves were classified into five patterns from type A to type E. The results showed that the incidence of type A was significantly lower in patients with nasal allergy than in the control group, while the rate of type E was significantly higher at 46% and the rate of type B was particularly high (32.4%) in the patient group. It was demonstrated that 77% of the subjects provided B or C flow-volume curves, while those with pale nasal mucous membranes developed D and E formats. In patients with nasal allergy, these patterns are useful in diagnosing remarkable differences in the lower airways.

Treatment of juvenile laryngeal papilloma with a combination of laser surgery and interferon

The therapeutic results obtained from the treatment of juvenile laryngeal papillomas with combined laser surgery and alpha-type IFN treatment are reported. Three cases of papilloma occurring under four years of age were found to be of the fulminant type with a strong tendency for recurrence. The results were complete remission of papilloma in two cases and a residual trace in one case. Thus, at present, control of the disease has been successful. A combination of several modes of treatment may be necessary for a more lasting therapeutic effect. Currently, no single method has been used to treat the disease. Laser surgery and IFN are both powerful therapies for this tenacious disease.