A closed-loop negative feedback model for the pancreas: A new paradigm and pathway to a cure.

BACKGROUND AND AIMS: To develop a model that describes how the pancreas functions, how the rate of synthesis of digestive enzymes is regulated, and finally what puts the pancreas to rest between meals. METHODS: We applied the principals of control theory to previously published canine data to develop a model for how the canine pancreas functions. Using this model, we then describe the steps needed to apply this model to the human pancreas. RESULTS: This new closed-loop negative feedback model describes what regulates digestive enzyme synthesis. This model is based on basolateral exocytosis of butyrylcholinesterase (BCHE) into the interstitial space. It is this level of BCHE * BCHE activity that controls the rate of canine pancreas digestive enzyme synthesis, and in the absence of stimulation from the vagus nerve, puts the pancreas to rest between meals. CONCLUSIONS: Finding secretagogue-specific inhibitory enzymes in the human pancreas that are analogous to BCHE in the canine, and blocking its associated receptors, may lead to a cure for human pancreatitis.

Recurrent Surgical Site Infections in the Spine After Treatment With the Vacuum-assisted Closure (VAC) System.

STUDY DESIGN: This study retrospectively reviewed recurrences of surgical site infections (SSI) in spinal patients treated with vacuum-assisted closure (VAC) technology. OBJECTIVE: Identify patient and treatment factors associated with recurrence of SSI after VAC treatment. SUMMARY OF BACKGROUND DATA: Patients treated with VAC can achieve healing of deep spine wound infections; however, some patients develop a recurrent infection. Risk factors associated with a recurrence have not been identified. MATERIALS AND METHODS: One hundred and eleven patients with SSI after spine surgery from 2002 to 2010 were studied. They had been treated with irrigation and debridement, placement of VAC, and IV antibiotics. They subsequently were taken to surgery for primary closure of their wound. Patients with SSI who healed after the initial infection treatment were compared with patients who experienced recurrence. Patient and treatment factors that were studied included smoking status, body mass index, obesity status, diagnosis of diabetes, fusion surgery, methicillin-resistant Staphylococcus aureus, or polybacteria infection, number of irrigation and debridement treatments before closure, duration of IV antibiotic treatment, and duration of treatment time with VAC. Patients with SSI who healed after the initial treatment were compared with patients who experienced recurrence. RESULTS: Fourteen patients had at least one recurrence of wound infection. None of the patient or treatment factors was associated with the recurrence of a SSI. CONCLUSIONS: Among spine surgery patients with a SSI treated with the VAC system, those factors which predispose a patient to develop a recurrent SSI remain unknown. LEVEL OF STUDY: Level IV.

Discussion of laser-assisted liposuction.

UNLABELLED: There has been a significant advancement in the use of lasers for body contouring over the past several years. This article will review the recent past and discuss the future of this trend. INTRODUCTION: There is much confusion over the definition of procedures using lasers for lipolysis and liposuction. This review article discusses the definitions of suction-assisted liposuction, laser lipolysis, and laser-assisted liposuction in detail. The development of these procedures is then discussed and pertinent articles are reviewed. MATERIALS AND METHODS: Pubmed and FDA.gov web sites were searched for published articles and FDA approved devices employing lasers for targeting fat for body contouring. This information along with the authors' personal experience was used to review and discuss this topic. DISCUSSION: There is a specific difference between suction-assisted liposuction, laser-assisted liposuction, and laser lipolysis. This review article clarifies these definitions and highlights the recent articles employing lasers for minimally invasive fat reduction.

Therapy of spinal wound infections using vacuum-assisted wound closure: risk factors leading to resistance to treatment.

STUDY DESIGN: This study retrospectively reviewed spine surgical procedures complicated by wound infection and managed by a protocol including the use of vacuum-assisted wound closure (VAC). OBJECTIVE: To define factors influencing the number of debridements needed before the final wound closure by applying VAC for patients with postoperative spinal wound infections. SUMMARY OF BACKGROUND DATA: VAC has been suggested as a safe and probably effective method for the treatment of spinal wound infections. The risk factors for infection resistance and need for debridement revisions after VAC placement are unknown. METHODS: Seventy-three consecutive patients with 79 wound infections after undergoing spine surgery were studied (6 of them had recurrence of infection). All patients were taken to the operating room for irrigation and debridement under general anesthesia followed by placement of the VAC with subsequent delayed closure of the wound. Linear regression and t test were used to identify if the following variables were risk factors for the resistance of infection to VAC treatment: timing of clinical appearance of infection, depth of infection (deep or superficial), presence of instrumentation, positive culture for methicillin-resistant Staphylococcus aureus (MRSA) or more than 1 microorganism, age of the patient, and presence of other comorbidities. RESULTS: There were 34 males and 39 females with an average age of 58.4 years (21 to 82). Once the VAC was initiated, there was an average of 1.4 procedures until and including closure of the wound. The wound was closed an average of 7 days (range 5 to 14) after the placement of the initial VAC on the wound. The average follow-up was 14 months (range 12 to 28). All of the patients but 2 achieved a clean, closed wound without removal of instrumentation at a minimum follow-up of 1 year. Sixty patients had implants (instrumentation or allograft) within the site of wound infection. Thirteen patients had a decompression with exposed dura. Sixty-four infections (81%) presented with a draining wound within the first 6 weeks postoperatively. Sixty-nine infections (87.3%) were deep below the fascia. There was no statistical significance (P>0.05) of all tested risk factors for the resistance of infection to treatment with the VAC system. The parameter more related to repeat VAC procedures was the culture of MRSA or multiple bacteria. CONCLUSIONS: VAC therapy may be an effective adjunct in closing spinal wounds even after the repeat procedures. The MRSA or multibacterial infections seem to be most likely to need repeat debridements and VAC treatment before final wound closure.