Microbial sensing by goblet cells controls immune surveillance of luminal antigens in the colon.

The delivery of luminal substances across the intestinal epithelium to the immune system is a critical event in immune surveillance, resulting in tolerance to dietary antigens and immunity to pathogens. How this process is regulated is largely unknown. Recently goblet cell-associated antigen passages (GAPs) were identified as a pathway delivering luminal antigens to underlying lamina propria (LP) dendritic cells in the steady state. Here, we demonstrate that goblet cells (GCs) form GAPs in response to acetylcholine (ACh) acting on muscarinic ACh receptor 4. GAP formation in the small intestine was regulated at the level of ACh production, as GCs rapidly formed GAPs in response to ACh analogs. In contrast, colonic GAP formation was regulated at the level of GC responsiveness to ACh. Myd88-dependent microbial sensing by colonic GCs inhibited the ability of colonic GCs to respond to Ach to form GAPs and deliver luminal antigens to colonic LP-antigen-presenting cells (APCs). Disruption of GC microbial sensing in the setting of an intact gut microbiota opened colonic GAPs, and resulted in recruitment of neutrophils and APCs and production of inflammatory cytokines. Thus GC intrinsic sensing of the microbiota has a critical role regulating the exposure of the colonic immune system to luminal substances.

[Secondary forms of osteoporosis. Special features of diagnostics in childhood and adolescence]. / Sekundäre Formen der Osteoporose. Besonderheiten der Diagnostik im Kindes- und Jugendalter.

Rheumatic diseases in childhood and adolescence can lead to secondary osteoporosis based on various pathophysiologies. The underlying disease, medication and immobility resulting in a reduced osteoanabolic stimulus contribute to the development of a fragile skeletal system. For diagnostic purposes dual-energy X-ray absorptiometry (DXA) is the most frequently used technology. For interpretation of the areal bone mineral density, age and gender matched reference data have to be used. Particularly in the pediatric field, body height must additionally be taken into consideration. Further techniques which can provide detailed information are peripheral quantitative computed tomography and high resolution magnetic resonance imaging. Nowadays, skeletal assessments have to be interpreted in the context of the muscular system. The concept of the functional muscle-bone unit is widely accepted and uses the muscles as the dominating factor. In a second step the adaptation of the skeletal system to the applied muscle force is evaluated. This allows a differentiation between primary and secondary skeletal diseases depending on the ratio of muscles to bone. Therapeutic options for secondary osteoporosis include reduction of the causative medication, treatment of the underlying disease, antiresorptive treatment with bisphosphonates and different programs to activate the muscles. A multimodal interval rehabilitation program including alternating side vibration shows positive effects on mobility, muscle function and bone mass in children and adolescents.

Ophthalmologic procedures in the emergency department--Part III: Slit lamp use and foreign bodies.

The emergency physician (EP) must be familiar with carrying out ophthalmologic procedures for evaluation and treatment of a multitude of eye complaints. This article is the last of three articles addressing ophthalmologic procedures of use by the EP. This article reviews the indications and the techniques for slit lamp examination of the eye and techniques of foreign body removal. Criteria for consultation also are addressed.

Ophthalmologic procedures in the emergency department--Part II: Routine evaluation procedures.

The emergency physician (EP) must be familiar with performance of ophthalmologic procedures for evaluation and treatment of a multitude of eye complaints. This article is the second of three articles addressing ophthalmologic procedures potentially of use by the EP. This article reviews the indications and the techniques for the following routine procedures: visual acuity testing, pupil dilatation, topical anesthesia use, and tonometry. Criteria for consultation also are addressed.

A comparative study of the percutaneous versus intraoral technique for mental nerve block.

OBJECTIVE: Mental nerve block is frequently used to aid repair of facial lacerations; both percutaneous and intraoral approaches to blocking this nerve are used, but have never been compared. The authors compared the two techniques for pain of administration and effectiveness of anesthesia. METHODS: A prospective, randomized, single-blind, crossover study was conducted using ten healthy volunteers aged 22 to 33 years. Patients having prior experience with mental nerve blocks, lidocaine allergy, active oral/facial infection, or previous facial fractures were excluded. Bilateral mental nerve blocks were done using intraoral technique on one side and percutaneous technique on the other. Both techniques were used by the same investigator and were carried out with 27-gauge needles and 2.5 mL of 2% buffered lidocaine at room temperature injected over 20 seconds. The oral mucosa was topically anesthetized with viscous lidocaine for 1 minute prior to intraoral injection. The orders of the blocks and sides of the face anesthetized were randomized. Subjective and objective pain (visual-analog scale), efficacy (anesthesia of lower lip), time to onset, and duration of anesthesia were evaluated. RESULTS: The intraoral technique was subjectively less painful than the percutaneous approach in nine of ten subjects (p = 0.02). Scores on the visual-analog pain scale were significantly lower for the intraoral technique (p = 0.03). Intraoral injection produced lower-lip anesthesia in 10/10 subjects versus 7/10 for percutaneous (p = 0.25). Times to onset (approximately 1-2 minutes) and durations of anesthesia (approximately one hour) were similar for the two techniques. CONCLUSION: The intraoral approach to the mental nerve block with adjunctive topical anesthesia was subjectively and objectively less painful than the percutaneous approach without adjunctive anesthesia. While the intraoral approach had a greater efficacy of lower-lip anesthesia and a longer duration of action, these differences were not statistically significant.

Comparison of digital versus metacarpal blocks for repair of finger injuries.

STUDY OBJECTIVE: This study compared efficacy, degree of discomfort, and time to anesthesia of digital blocks and metacarpal blocks for digital anesthesia. DESIGN: Randomized, prospective, nonblinded, clinical study conducted from April 1992 to January 1993. Patients served as their own controls. SETTING: Inner-city and community hospital emergency departments. TYPE OF PARTICIPANTS: Convenience sample of 30 adult patients, with third or fourth finger injuries including and distal to the proximal interphalangeal joint that required digital anesthesia. INTERVENTIONS: Digital blocks and a metacarpal blocks were performed (one per side) on all 30 patients (total of 60 blocks). The order of the blocks was randomized. MEASUREMENTS: A digital block and a metacarpal block were performed on each patient. Patients immediately rated the pain associated with each technique on a nonsegmented visual analog scale. Efficacy was assessed by requirement for additional anesthesia and anesthesia to pinprick. Time to anesthesia was assessed after each block in 23 patients. RESULTS: Mean visual analog scale pain scores were 2.53 for digital block and 3.38 for metacarpal block (P = .1751, Student's t-test). Metacarpal block failed anesthesia to pinprick in 23% of patients compared to 3% for digital block (P = .0227, chi 2). Time to anesthesia was significantly shorter for digital block compared to metacarpal block, with a mean of 2.82 minutes versus 6.35 minutes (P < .0001, Student's t-test). CONCLUSION: Digital block and metacarpal block, as described in this study, are equally painful procedures. Digital block, however, is more efficacious and requires significantly less time to anesthesia for the injured finger.