Mixed corticomedullary adrenal carcinoma.

Truly mixed corticomedullary tumors (MCMTs) are extremely rare and present as a single tumor mass composed of an intimately admixed population of both adrenal cortical cells and pheochromocytes. The current study describes the first case of a mixed corticomedullary adrenal carcinoma. In addition, we also review the published data on MCMTs to determine their clinical features, biochemical characteristics, pathological findings, and management. In order to compose this review, a search of the international literature for MCMTs was conducted. Fifteen related articles were found. The clinical and pathological information was obtained for all reported cases. MCMTs were found almost exclusively in females. In the vast majority of patients, the symptoms were related to the tumor's hormone hypersecretion. Hypertension and diabetes were present in 80 and 40 % of cases, respectively. Cushing's syndrome was reported in eight cases (53.33 %). A final diagnosis was made in all cases after surgery based on the pathological results. As of the writing of this article, all published cases of MCMTs had benign clinical behavior, with no instances of metastasis or death due to the tumor. MCMTs are currently considered to be benign tumors. Ours is the first case of malignant MCMT reported in the literature. The potential for malignancy should therefore be considered for these tumors.

Can chronic intra-abdominal hypertension cause oxidative stress to the abdominal wall muscles? An experimental study.

BACKGROUND: The aim of this study was to test the hypothesis that intra-abdominal hypertension alone could trigger such changes to the rectus abdominis muscle that would lead to an imbalance between oxidant production and antioxidant protection. MATERIALS AND METHODS: Forty-five New Zealand white rabbits were divided into three groups and a rubber bag was implanted into their peritoneal cavity. In group A (n = 15), the bag was empty. In group B (n = 15), it was filled with normal saline to achieve an intra-abdominal pressure of over 12 mm Hg. In group C (n = 15), it was filled with lead equiponderant to the mean weight of the normal saline injected in group B. After 8 weeks, we measured in rectus abdominis muscle biopsies the lipid peroxidation products, the protein carbonyl content, the total glutathione and superoxide dismutase (SOD) concentration, the activity of glutathione reductase and glutathione peroxidase, and the pro-oxidant-antioxidant balance. RESULTS: The lipid peroxidation products were significantly higher in group B compared with both group A (P = 0.026) and group C (P < 0.001). The total protein carbonyl content was significantly higher in group B compared with both group A (P = 0.006) and group C (P < 0.001). No difference was found between the three groups in total glutathione (P = 0.735) and SOD (P = 0.410) concentration. Glutathione peroxidase activity was higher in groups B and C compared with group A (P = 0.05 and P = 0.003, respectively). Glutathione reductase activity was higher in group B compared with group A (P = 0.005) and group C (P = 0.001). The pro-oxidant antioxidant balance was higher in group B compared with the group A (P = 0.012). CONCLUSIONS: Maintaining the IP over 12 mm Hg for 8 wk caused increased oxidative damage to both lipids and proteins with an increased pro-oxidant-antioxidant balance. In an attempt to compensate for this damage the muscle fibers increased their glutathione reductase and glutathione peroxidase activity.

Rupture of right hepatic duct into hydatid cyst.

Echinococcal disease can develop anywhere in the human body. The liver represents its most frequent location. Hepatic hydatid cysts may rupture into the biliary tract, thorax, peritoneum, viscera, digestive tract or skin. We report a rare case with rupture of the right hepatic duct into a hydatid cyst in a woman with known hydatid disease and choledocholithiasis. The increased intra-luminal pressure in the biliary tree caused the rupture into the adjacent hydatid cyst. The creation of the fistula between the right hepatic duct and the hydatid cyst decompressed the biliary tree, decreased the bilirubin levels and offered a temporary resolution of the obstructive jaundice. Rupture of a hydatid cyst into the biliary tree usually leads to biliary colic, cholangitis and jaundice. However, in case of obstructive jaundice due to choledocholithiasis, it is possible that the cyst may rupture by other way around while offering the patient a temporary relief from his symptoms.

The effect of chronically increased intra-abdominal pressure on rectus abdominis muscle histology an experimental study on rabbits.

BACKGROUND: The aim of this study was to specify the histologic response of the rectus abdominis muscle of the rabbit, to the chronically increased intra-abdominal pressure. MATERIALS AND METHODS: Forty-five New Zealand white rabbits were divided into three groups. In all groups, a rubber bag was implanted into the peritoneal cavity. In group A (n=15) the bags were kept empty. In group B (n=15) the bags were filled with normal saline in order to achieve an intra-abdominal pressure of over 12 mmHg. This pressure was kept at this level for 8 wk. In group C (n=15) the intra-abdominal rubber bags were filled with lead covered by silicone, equiponderant to the mean weight of the normal saline insufflated in group B. After 8 wk we took biopsies of the rectus abdominis muscle and counted the proportion of the different types of muscular fibers (type I, IIA, and IIB/X). RESULTS: Significant difference was found in the proportion of the three types of muscle fibers. Intra-abdominal hypertension led to an increase in type I fibers (P=0.008). No difference was noticed between groups A and C. CONCLUSIONS: The histologic response to the increased intra-abdominal pressure was an increase in type I muscle fibers. Charging with lead did not cause any significant change in the proportion of muscular fibers.

Management of an extrasphincteric fistula in an HIV-positive patient by using fibrin glue: a case report with tips and tricks.

BACKGROUND: Individuals with impaired immunity are at higher risk of perianal diseases. Concerning complex anal fistulas impaired healing and complication rates are also higher. Definitive treatment of a fistula aims controlling the purulent discharge and prevents its recurrence. It depends mainly on the trajectory of the fistula and the underlying disease. We present a case of a HIV-positive patient with a complex extrasphincteric anal fistula who was treated successfully with fibrin glue application. We further, discuss tips and tricks when applying fibrin glue as plugging material in complex anal fistulas. CASE PRESENTATION: A sixty-one-year-old HIV-positive male referred to us for warts and extrasphincteric fistula. Because of the patients' immunological status, we opted against surgery and recommended fibrin glue plugging. The patient was discharged the same day. A follow-up examination was performed 5 days after the initial fibrin glue application showing that the fistula canal was obstructed. Three months and a year post-intervention the fistula tract remains closed. CONCLUSION: The best treatment for a disease gives at least the same result with the other treatments with minimised risk for the life of the patient and minimal application effort. Conservative closure of fistula with fibrin plugging is simple, safe and with less morbidity than surgery. Our patient was successfully treated without endangering his life despite his precarious medical state. Not everybody believes in the effectiveness of fibrin glue application, however we consider this solution in cases of complex fistulas at least as primary procedure in special populations such as the immunosupressed.

Retroperitoneal ganglioneuroma in an adult patient: a case report and literature review of the last decade.

Ganglioneuromas arise from the neural crest and are highly differentiated and benign. The case of a 43-year-old female who presented with a 6.5 cm primary extra-adrenal retroperitoneal ganglioneuroma (RGN) is presented, and the relevant English literature from the last decade is reviewed. Histology showed mature ganglion cells and nerve fibers without any malignancy (S-100 and neuron- specific enolase [NSE] positive). Hospitalization lasted four days. The patient has shown no signs of recurrence. Radical excision of the tumor is unnecessary, especially when vascular structures are endangered. RGN-related hospitalization is short and the prognosis is good.

Endoscopic fibrin sealing of gastrocutaneous fistulas after sleeve gastrectomy and biliopancreatic diversion with duodenal switch.

BACKGROUND AND AIM: Gastrocutaneous fistulas (GCF) are uncommon complications accounting for 0.5-3.9% of gastric operations. When their management is not effective, the mortality rate is high. This study reports the conservative treatment of GCF in morbidly obese patients who underwent biliopancreatic diversion with duodenal switch. METHODS: Ninety-six morbidly obese patients were treated in our department with biliopancreatic diversion with duodenal switch (Marceau technique) and, in six of them, a high-output GCF developed. A general protocol was applied to all patients presenting a GCF. Everyone was treated by total parenteral nutrition (TPN) and somatostatin for at least 7 days after the appearance of the leak. If the leak continued, then fibrin glue was used as a tissue adhesive. Endoscopic application of the sealant was accomplished under direct vision via a double-lumen catheter passed through a forward-viewing gastroscope. RESULTS: All patients were treated successfully with conservative treatment (either solely with TPN and somatostatin, or with endoscopic fibrin sealing sessions). No evidence of fistula was observed at gastroscopy 3 and 24 months after therapy. CONCLUSION: The conservative treatment of GCF following biliopancreatic diversion with duodenal switch is highly effective. All patients should enter a protocol that includes TPN and somatostatin. When the GCF persist, endoscopic sealing glue should be considered before operation because it is simple, safe, effective and, in some cases, life-saving. Therefore, conservative treatment should be employed as a therapeutic option in GCF developing after bariatric surgery.

The effect of biliopancreatic diversion with pylorus-preserving sleeve gastrectomy and duodenal switch on fasting serum ghrelin, leptin and adiponectin levels: is there a hormonal contribution to the weight-reducing effect of this procedure?

BACKGROUND: Ghrelin is a peptide hormone with orexigenic properties, primarily produced by the stomach. Different changes in fasting ghrelin levels have been reported following bariatric surgery. In this study, we investigate the hypothesis that because ghrelin is mainly produced by the fundus of the stomach, biliopancreatic diversion with sleeve gastrectomy with total resection of the gastric fundus and duodenal switch (BPD-DS) will cause substantial decrease in circulating ghrelin levels. METHODS: Serum fasting ghrelin, leptin and adiponectin concentrations were measured by ELISA in 13 patients with morbid obesity who achieved weight loss by BPD-DS, before the operation and 18 months after. RESULTS: After BPD-DS, BMI decreased significantly, from 59.15+/-15.82 kg/m(2) to 32.91+/-6.46 kg/m(2) (P=0.001). Serum fasting ghrelin level decreased from 1.44+/-0.77 ng/ml to 0.99+/-0.35 ng/ml (P=0.019). Serum leptin level decreased from 1.81+/-0.38 ng/ml to 1.65+/-0.32 ng/ml, (P=0.196), and adiponectin level increased from 37.85+/-11.24 microg/ml to 39.84+/-16.27 microg/ml (P=0.422). CONCLUSIONS: BPD-DS is associated with markedly suppressed ghrelin levels, possibly contributing to the longlasting weight-reducing effect of the procedure. Leptin levels decreased and adiponectin increased, as expected, after weight loss. Sleeve gastrectomy with resection of the gastric fundus seems to be the main cause of the postoperative reduction in ghrelin levels.

Serum ghrelin, leptin and adiponectin levels before and after weight loss: comparison of three methods of treatment--a prospective study.

BACKGROUND: Ghrelin is a peptide hormone with orexigenic properties, primarily produced by the stomach. Leptin and adiponectin are the two adiposity products that participate in body weight control. Leptin always decreases and adiponectin increases after weight loss. Different changes in fasting ghrelin levels have been reported following bariatric surgery. In this study, we compare the changes in fasting ghrelin, leptin and adiponectin levels in 3 groups of patients who achieved weight loss by either diet, MacLean vertical banded gastroplasty (VBG) or biliopancreatic diversion with duodenal switch (BPD-DS). METHODS: Serum fasting ghrelin, leptin and adiponectin concentration was measured in 40 obese patients who achieved weight loss by either diet (n=14), VBG (n=13) or BPD-DS (n=13), before and after weight loss. The follow-up period was 18 months for BPD-DS and VBG and 6 months for diet. Serum ghrelin level was measured by ELISA. RESULTS: BMI was significantly decreased in all 3 groups: 9.2+/-2.4% (P<0.01) following diet, 38.47+/-7.26% (P<0.01) after VBG, and 42.88+/-9.09% after BPD-DS (P<0.01). Serum fasting ghrelin level increased after diet (110.45+/-117.84%, P=0.002) and VBG (65.48+/-92.93%, P=0.001),but decreased after BPD-DS (-21.63+/-28.63%, P=0.019). Leptin concentration decreased and adiponectin increased in all groups. CONCLUSIONS: Unlike after diet or gastric restrictive surgery, BPD-DS is associated with markedly suppressed ghrelin levels, possibly contributing to the weight-reducing effect of this operation. Sleeve gastrectomy seems to be the main cause of this reduction.

Pre- and postoperative esophageal and gastric pH levels in morbidly obese patients undergoing vertical gastroplasty.

BACKGROUND: The aim of this study was to determine whether the anatomicofunctional changes induced by vertical gastroplasty lead to pH alterations in the esophagus and body and antrum of the stomach. MATERIALS AND METHODS: 23 non-smoking volunteers (3 men, 20 women) mean age 35.29 +/- SD 6.85 years, mean weight 163.17 +/- 52.11 kg and mean BMI 56.06 +/- 14.01 kg/m2 were studied. The pH of the esophagus, body and antrum of the stomach were measured preoperatively and 18 months postoperatively (after excess weight loss). Data was analyzed statistically using paired student t-test. RESULTS: The pH values before (pH(1)) and after (pH(2)) the operation were: for the esophagus pH(1e) +/- SD = 6.12 +/- 0.31 and pH(2e) +/- SD = 5.92 +/- 0.37 (P =0.38), for the body of the stomach pH(1b) +/- SD = 2.2 +/- 0.30 and pH(2b) +/- SD = 2.56 +/- 0.34 (P =0.30), and for the antrum pH(1a) +/- SD = 1.78 +/- 0.28, and pH(2a) +/- SD = 1.65 +/- 0.36 (P =0.011). CONCLUSIONS: Vertical gastroplasty does not affect the pH levels in the esophagus and in the body of the stomach. However, there is acidification in the antrum, which could lead to pH-related diseases.

The effect of vacuum-assisted closure in bacterial clearance of the infected abdomen.

BACKGROUND: Laparostomy with vacuum-assisted closure (VAC) plays an important role in improving survival in the presence of abdominal infection. We conducted a study of the qualitative changes in the bacterial flora of the peritoneal cavity in patients with severe abdominal infection treated with laparostomy and a VAC device. METHODS: Thirty-nine patients with severe abdominal infection treated with abdominal opening and VAC were registered in a clinical study. When an incidence of 53.8% of hospital-acquired peritoneal infection (HAPI) was found in the study patient population, it was decided to divide the patients in two groups according to whether or not they developed a HAPI. The patients' outcomes were then analyzed. RESULTS: The durations of abdominal opening (p=0.04), length of stay in the intensive care unit (ICU) (p=0.01), and of hospitalization (p=0.04) were significantly greater in patients with HAPI than in those without it, whereas mortality did not differ on the basis of these three variables. CONCLUSIONS: Superinfection is common in laparostomy done with a VAC device for managing severe abdominal infection. The data in the present study show that VAC does not alter the quality of the bacterial burden in primary abdominal contamination, nor does it seem to prevent a high incidence of HAPI. However, VAC is as effective in reducing mortality among patients with HAPI as among those without it.

Laparoscopic spleen-preserving distal pancreatectomy in a solitary true pancreatic cyst.

BACKGROUND: Solitary true pancreatic cysts (STPCs), or epithelial cysts, are benign lesions that are extremely rare in adult patients. Advances in radiographic techniques have improved the ability to identify pancreatic cystic lesions. We report a case of a large and symptomatic STPC in a 47-year-old female patient who was treated successfully with spleen-preserving laparoscopic distal pancreatectomy. We also review the clinical and pathologic features of all reported STPCs within the past 25 years. DATABASE: To compose the review, we did a search of the international literature for STPCs that had occurred in adults. Fourteen related articles were found describing cases of STPCs. Clinical and pathologic information was collected for all of the reported pancreatic cysts, and a database was formed. STPCs are detected more frequently in women than in men. The mean age of occurrence is 43.2 years, and the mean cyst size is 5.6 cm. Fifty percent of true cysts are located in the head of the pancreas. Size and site are responsible for the symptoms caused, although 22.8% were asymptomatic. Diagnosis was made postoperatively in all cases by histopathologic studies. No case of malignancy was reported in any STPC. CONCLUSIONS: STPCs are rare and benign lesions commonly discovered incidentally during abdominal imaging. Surgical treatment is considered the appropriate therapy for large and symptomatic STPCs. The definitive diagnosis is established by histopathologic and immunohistochemical studies.

Neuroendocrine tumors of extrahepatic biliary tract.

Neuroendocrine tumors of the extrahepatic bile ducts (EBNETs) are very rare. The aim of the present review is to elucidate the characteristics of EBNETs, their treatment and prognosis. An exhaustive systematic review of the literature was performed from 1959 up-to-date. One hundred articles, describing 150 cases were collected. Each article was carefully analyzed and a database was created. The most common symptoms were jaundice (60.3 %) and pruritus (19.2 %). Cholelithiasis co-existed in 15 cases (19.2 %). Hormone- and vasoactive peptide- related symptoms were present in only 7 cases (9 %). The most frequent sites were found to be the common hepatic duct and the proximal common bile duct (19.2 %). Surgical management was considered the main treatment for EBNETs, while excision of extrahepatic biliary tree (62.82 %) with portal vein lymphadenectomy (43.6 %) was the most popular procedure. EBNETs are extremely rare. Their rarity makes their characterization particularly difficult. Up to date the final diagnosis is made after surgery by pathology and immunohistochemistry findings. The present analysis of the existing published cases elucidates many aspects of these tumours, giving complete clinicopathological documentation.

Patterns in the parathyroid response to sodium bicarbonate infusion test in healthy volunteers.

BACKGROUND: The sodium bicarbonate infusion test evaluates the function of the parathyroid glands. The present study aims to evaluate the range of parathyroid response in healthy individuals and the potential influence of various factors. METHODS: Fifty healthy volunteers were subjected to the test. Levels of vitamin D, calcium, albumin, and PTH were measured before infusion. PTH was measured at 3, 5, 10, 30, and 60 minutes after infusion. RESULTS: A curve describing the response of parathyroids to the test was drawn. Twenty percent of the subjects had blunted PTH response. No significant difference was observed between normal and blunted responders concerning age, BMI, baseline PTH, or calcium levels. Nonetheless, there was a significant difference in vitamin D levels (P = 0.024). INTERPRETATION: The test is easy to perform and may be used for everyday screening. It has to be clarified whether our observations are, at least partly, produced due to the presence of individuals with a constitutively blunted response or if low levels of vitamin D decrease the ability of the parathyroids to respond. Whichever the case, PTH response of normal individuals to sodium bicarbonate infusion test is more varied than previously thought and vitamin D levels influence it.

Necrotizing cellulitis of the abdominal wall, caused by Pediococcus sp., due to rupture of a retroperitoneal stromal cell tumor.

INTRODUCTION: Soft tissue necrotizing infections are a significant cause of morbidity and mortality. The aim of this study is to present a patient with necrotizing infection of abdominal wall resulting from the rupture of a retroperitoneal stromal tumor. PRESENTATION OF CASE: We present a 60-year-old Caucasian male patient with necrotizing infection of abdominal wall secondary to the rupture of a retroperitoneal stromal tumor. The patient was initially treated with debridement and fasciotomy of the anterior abdominal wall. Laparotomy revealed purulent peritonitis caused by infiltration and rupture of the splenic flexure by the tumor. Despite prompt intervention the patient died 19 days later. The isolated microorganism causing the infection was the rarely identified as cause of infections in humans Pediococcus sp., a gram-positive, catalase-negative coccus. DISCUSSION: Necrotizing infections of abdominal wall are usually secondary either to perineal or to intra-abdominal infections. Gastrointestinal stromal cell tumors could be rarely complicated with perforation and abscess formation. In our case, the infiltrated by the extra-gastrointestinal stromal cell tumor ruptured colon was the source of the infection. The pediococci are rarely isolated as the cause of severe septicemia. CONCLUSION: Ruptured retroperitoneal stromal cell tumors are extremely rare cause of necrotizing fasciitis, and before this case, Pediococcus sp. has never been isolated as the responsible agent.

The role of allopurinol's timing in the ischemia reperfusion injury of small intestine.

INTRODUCTION: Allopurinol acts protectively in the ischemia reperfusion injury of the small intestine. The aim of this experimental study is to define the ideal time of administration of allopurinol, in experimental models of ischemia/reperfusion. MATERIALS AND METHODS: We used 46 rabbits that were divided into four groups. Group A was the control. In Group B allopurinol was administered 10 min before ischemia and in Group C 2 min before reperfusion. In Group D, allopurinol was administered before ischemia and before reperfusion in half doses. Blood samples were collected at three different moments: (t1) prior to ischemia, (t2) prior to reperfusion, and (t3) after the end of the reperfusion, in order to determine superoxide dismutase (SOD) and neopterin values. Specimens of the intestine were obtained for histological analysis and determination of malondialdehyde (MDA). RESULTS: In Group A, mucosal lesions were more extensive compared to those of the other three groups. Similarly, MDA, SOD and neopterin values were significantly higher. On the contrary, Group D showed the mildest mucosal lesions, as well as the lowest MDA, SOD and neopterin values. Finally, the lesions and the above mentioned values were bigger in Group C than in Group D. CONCLUSIONS: The administration of allopurinol attenuates the production and damage effect of free oxygen radicals during ischemia reperfusion of the small intestine, thus protecting the intestinal mucosa. Its maximum beneficial action is achieved when administered both before ischemia and before reperfusion of the small intestine.

Small bowel perforation due to CMV enteritis infection in an HIV-positive patient.

BACKGROUND: Cytomegalovirus infection of the gastrointestinal tract is common and is more often seen in patients with acquired immunodeficiency syndrome (AIDS). Although small bowel infection is less common than infection of other parts of the gastrointestinal system, it may lead to perforation, an acute complication, with dreadful results. CASE PRESENTATION: This article reports a case of Cytomegalovirus ileitis with multiple small bowel perforations in a young man with human immunodeficiency virus (HIV) infection. The patient developed abdominal pain with diarrhea and fever, and eventually acute abdomen with pneumoperitoneum. The patient had poor prognosis and deceased despite the prompt surgical intervention and the antiviral therapy he received. At pathology a remarkable finding was the presence of viral inclusions in smooth muscle fibers. The destruction of muscle cells was the main cause of perforation. CONCLUSION: Morbidity and mortality associated with perforation from CMV enteritis in AIDS patients are high and the life expectancy is short. Cytomegalovirus disease is multifocal; therefore, excision of one portion of the gastrointestinal tract may be followed by a complication elsewhere. Our case elucidate that muscle cell destruction by the virus is a significant cause leading to perforation.

Typical image of splenic hydatidosis.

This is a typical case of a splenic hydatid cysts. We present the clinical features, the diagnostic work-up and the management of the disease.

Intraoperative stimulation neuromonitoring versus intraoperative continuous electromyographic neuromonitoring in total thyroidectomy: identifying laryngeal complications.

BACKGROUND: Laryngeal complications occur in thyroidectomies as a result of several factors, but especially because of nerve damage. We compared intraoperative stimulation neuromonitoring (IONM) with intraoperative continuous electromyographic neuromonitoring (IEM) to evaluate their ability to identify postoperative laryngeal complications. METHODS: This prospective clinical trial included 174 patients (348 nerves) who had both IONM and IEM. We recorded age, sex, pathology, vocal fold motility, and complications. RESULTS: IONM identified 334 nerves, whereas IEM identified 348. Five patients had transient laryngeal complications, 2 bilateral, and 3 unilateral recurrent laryngeal nerve paresis. In addition, in 2 patients IEM showed placement of the tracheal tube balloon on the vocal folds, which led to correction. Sensitivity and specificity were 96.48% and 100% for IONM and 100% and 100% for IEM, respectively. IONM had a positive predictive value of 100% and a negative predictive value of 36.84%. The positive and negative predictive values of IEM were 100%. CONCLUSIONS: Both techniques identify recurrent laryngeal nerve injuries; however, IEM seems to have an advantage concerning the nonsurgical laryngeal complications and may play a role in preventing morbidity.

The effects of chronically increased intra-abdominal pressure on the rabbit diaphragm.

BACKGROUND: Diaphragmatic muscular remodeling is caused by various conditions and was mainly studied in pulmonary pathologies and chronic alterations of intra-thoracic pressure. We investigate the effect of the chronically increased intra-abdominal pressure (IAP) on the diaphragm by morphological and biochemical analysis. METHODS: Thirty rabbits were divided into control and study groups. IAP was increased in group B to 12 mmHg for 2 months. The left hemidiaphragm underwent morphological, while the right underwent biochemical analysis. RESULTS: In H&E, all fibers were normal. ATPase analysis demonstrated that type I fibers show no differences between groups. Type ΙΙ(Α) were decreased (p = 0.016) while type ΙΙ(Β/X) fibers were increased (p = 0.025) in group B. Fibers with resistance to fatigue were decreased in group B (p = 0.024). In group B, biochemical activity for glutathione reductase (p = 0.004), glutathione peroxidase (p = 0.021), protein carbonylation (0.029), lipid peroxidation (p = 0.005), and balance of preoxidative-antioxidative factors (p = 0.006) was increased. CONCLUSIONS: Chronically increased IAP induces alterations to the rabbit diaphragm. Adaptation, equivalent to strenuous contraction, transforms the diaphragm to be functionally more efficient toward workload but makes it vulnerable against oxidative stress.