Sustained nonoxidative glucose utilization and depletion of glycogen in reperfused canine myocardium

AbstractIschemically injured reperfused myocardium is characterized by increased 18F-fluorodeoxyglucose uptake as demonstrated by positron emission tomography. To elucidate the metabolic fate of exogenous glucose entering reperfused myocardium, D-[6-14C] glucose and L-[U-13C] lactate were used to determine glucose uptake, glucose oxidation and the contribution of exogenous glucose to lactate production. The pathologic model under investigation consisted of a 3 h balloon occlusion of the left anterior descending coronary artery followed by 24 h of reperfusion in canine myocardium. The extent and severity of myocardial injury after the ischemia and reperfusion were assessed by histochemical evaluation (triphenyltetrazolium chloride and periodic acid-Schiff stains). Thirteen intervention and four control dogs were studied.The glucose uptake in the occluded/reperfused area was significantly enhanced compared with that in control dogs (0.40 ± 0.14 versus 0.15 ± 0.10 μmol/ml, respectively). In addition, a significantly greater portion of the glucose extracted immediately entered glycolysis in the intervention group (75%) than in the control dogs (33%). The activity of the nonoxidative glycolytic pathway was markedly increased in the ischemically injured reperfused area, as evidenced by the four times greater lactate release in this area compared with the control value. The dual carbon-labeled isotopes showed that 57% of the exogenous glucose entering glycolysis was being converted to lactate. Exogenous glucose contributed to >90% of the observed lactate production. This finding was confirmed by the histochemical finding of sustained glycogen depletion in the occlusion/reperfusion area. The average area of glycogen depletion (37%) significantly exceeded the average area of necrosis (17%).These data demonstrate enhanced and sustained activity of the nonoxidative glycolytic pathway after a prolonged occlusion with reperfusion in canine myocardium. Because glycogen stores remain depleted, exogenous glucose becomes an important myocardial substrate under these pathologic conditions

The Story of Serratia Marcescens: Pathologic Risk Factors in Breast Implant Surgery

Serratia marcescens (S. marcescens) emerged as an opportunist in the setting of immunodeficiency in the 1970s, when serious infections occurred in San Francisco hospitals after USA. Navy experiments had aerosolized the bacteria to study biologic warfare. We investigate the risks of S. marcescens in San Franciscans who undergo mastectomy with implant reconstruction. From 2007 to 2011, the senior author took breast capsule cultures for all patients at the time of tissue expander exchange/explant. Of the 142 women who had reconstruction, 23 had positive cultures. Only the two patients who were positive for S. marcescens developed clinical infections that required explantation. Both had postoperative chemotherapy with transient neutropenia, and both had close ties to San Francisco. Clinical signs of infection emerged for both patients months after initial surgery, despite having previously well healed incisions. Other patients were culture positive for Pseudomonas, Proteus, Enterococcus and MRSA and did not develop require explant. While the link between San Francisco and S. marcescens is controversial, a patient's geography is a simple screening tool when considering postoperative risks, especially in the immunocompromised. Closer monitoring for neutropenia during chemotherapy, and a lower threshold to administer S. marcescens targeted antibiotics may be warranted in these patients

Myofibroma in the Palm Presenting with Median Nerve Compression Symptoms

Summary: A myofibroma is a benign proliferation of myofibroblasts in the connective tissue. Solitary myofibromas are a rare finding especially in an adult. We report a case of a 23-year-old man presenting with an enlarging mass over his right palm. The patient is an active weight lifter. He reported numbness and tingling in the median nerve distribution. Nerve conduction studies and magnetic resonance imaging scans suggested a tumor involving or compressing the median nerve. The final diagnosis of myofibroma was made only after the histopathological diagnosis

Use of Acellular Dermal Matrix to Prevent Recurrence of Radioulnar Heterotopic Ossification.

Radioulnar heterotopic ossification is a rare occurrence found in approximately 2% of all forearm injuries. Treatment is complicated by relatively high recurrence rates. Strategies to decrease recurrence have included the range of motion exercises and the interposition of inert or autogenous barriers. We report on the interposition of human acellular dermal matrix (ADM) for the treatment of distal radioulnar synostosis. We report a novel technique for the treatment of distal radioulnar heterotopic ossification. After resection, ADM in a cigar-shaped construct is interposed between the radius and ulna. Patients are followed clinically and radiographically. Two female patients were treated. Both patients had significant improvement in the range of motion in supination and pronation of the affected wrist postoperatively with an average follow-up of 36 months. There were no postoperative complications. Neither patient had recurrent disease. We describe the successful treatment of 2 patients with distal radioulnar heterotopic ossification with the use of human ADM. The ADM provides a barrier between the radius and ulna to prevent the recurrent formation of heterotopic ossification. ADM usage results in no donor site morbidity and is theoretically more resistant to infection when compared with nonbiologic barriers such as silicone and Integra. This technique is a simple, safe, and effective way to treat and prevent the recurrence of radioulnar heterotopic ossification

The use of acellular dermal matrix in release of burn contracture scars in the hand

Contracture deformities of the upper extremity are encountered frequently in burn victims. Surgical repair of this problem is challenged by a paucity of soft tissue, poor functional outcome, and a high rate of recurrence. Acellular dermal matrix has become increasingly popular in reconstructive surgery--at times--as an alternative to local and free tissue transfer in different parts of the body. However, its applicability in contracture release, particularly in hand surgery, has not been widely explored. Nine patients with burn contracture scars involving different locations in the hand and the wrist underwent two-stage reconstruction consisting of contracture release and use of acellular dermal matrix followed by definitive coverage with skin graft at the second stage. Patients were followed up for a period of at least 10 months (range, 10 to 25 months), during which time the passive range of motion of the hand was used as a quantitative measure of surgical outcome. All nine patients retained at least 83 percent of the corrected range of motion involving the affected joints by 1 year and at least 89 percent of correction at each webspace. No patient required a revision procedure. Acellular dermal matrix can be an effective tool in surgical treatment of difficult burn contracture deformity in the hand, with lasting results

Preserving the Posttrapeziectomy Space with a Human Acellular Dermal Matrix Spacer: A Pilot Case Series of Patients with Thumb Carpometacarpal Joint Arthritis

Background: Advanced thumb carpometacarpal arthritis is widely treated with trapeziectomy and tendon interposition despite donor-site morbidities. Trapeziectomy alone leaves a postresection space, leading to proximal metacarpal migration and scaphoid/trapezoid impingement. Prosthetic implants have been unsuccessful due to particulate debris, silicone synovitis, osteolysis, and migration. Recent studies have shown successful use of allograft for interposition material in the posttrapeziectomy space both in animal and human models. To obviate the need for autologous tissue, maintain thumb length, and reduce the risk of scaphoid impingement, the senior author developed an interposition arthroplasty technique using a spacer constructed from human acellular dermal matrix (HADM). Methods: Sixteen patients with Eaton stage III–IV thumb carpometacarpal osteoarthritis received the above procedure from the 2 senior authors. HADM was imbricated to fill the posttrapeziectomy space and secured to the volar capsule and metacarpal base. Pre- and postoperative trapezial space on radiograph, pain scores, and grip strength were recorded. Results: Six months postoperatively, radiographs showed an average joint space loss of 11%. Heights postoperatively were not significantly different from immediate postoperative heights (P ≥ 0.01). At 6 months, patients had improved pain and grip strength (P ≤ 0.01). No infections, foreign body reactions, or other complications occurred. Conclusions: HADM has been used extensively in other forms of reconstruction and has been shown to incorporate into surrounding tissues through neovascularization. Our early results illustrate that HADM can safely fill the dead space left by trapeziectomy

The Use of Acellular Dermal Matrix in Release of Burn Contracture Scars in the Hand

Long-term management of burn wounds isplagued by unpredictable scar formation.When involving joint surfaces, this processcommonly leads to development of contracturebands. Such scars are especially common in theupper extremity and can result in extensive functionaldisability.1 In addition, with the high likelihoodof recurrent contractures, most burn patientsrequire multiple reconstructive operationsfollowing their initial acute care. Therefore, theoptimal surgical intervention for this populationwould have to result in resumption of functionwhile minimizing recurrence.Commonly used techniques to release contracturescars consist of local flaps, skin autografts,and distant tissue transfer to cover the wound sitefollowing surgical release. Reliable use of skingrafts when local flaps are not available or sufficientobviates free tissue transfer. However, skingrafts can variably contract and result in failure ofthe reconstructive effort. The risk of recurrentscarring and contracture formation is inverselyrelated to the amount of dermis at the woundsite.2,3 A thinner skin graft that carries less dermiswould thus be expected to be affected more byscarring and contracture than a thicker graft.However, using a thick split-thickness or full-thicknessskin graft is not always possible because ofdonor-site morbidity or availability. In contrast,the use of allograft is challenged by immunogenicrejection and thus the need for eventual woundcoverage. However, the use of a nonimmunogenicskin substitute to augment or replace the dermisat the wound site could be a solution in treatmentof contracture scars.Over the past decade, the use of various skinsubstitutes has gained popularity in reconstructiv

Current Challenges of Plastic Surgical Care in Sub-Saharan Africa (Maputo, Mozambique)

Background:. Limited data exist on plastic surgery practices in Sub-Saharan Africa. The aim of this study was to characterize the spectrum of disease and operative procedures at a teaching hospital in Maputo, Mozambique to help understand the challenges of providing care for the local providers and to provide contextual relevance for training through partnerships. Methods:. A mixed-methods approach was utilized to perform an ongoing needs assessment. A retrospective review was performed of plastic surgery operative records, ward admissions records, and death records in a tertiary-care hospital in Maputo, Mozambique for the period January 2015 to December 2015. Results:. Limited resources (equipment, block-time, personnel, and perioperative services) were observed. The most common diagnoses for the 455 patients evaluated were burns (44%) and neoplasms (17%). Congenital abnormalities accounted for only 1% of the patient diagnoses. Of the 408 procedures performed, the majority were skin grafts (43%) and skin excisions (31%). Sepsis from burns accounted for 70% of documented deaths (14/20). The mean number of days to skin grafting for inpatients was 53 days. Conclusion:. We observed a large burden of burns and skin graft procedures at a public referral teaching hospital in Mozambique. Our findings provide contextual relevance to help focus public health efforts and improve plastic surgery training and practices