RETRACTED ARTICLE: Unicompartmental knee arthroplasty: a review of literature

There has been a resurgence of interest in unicompartmental knee arthroplasty (UKA) for treatment of medial unicompartmental knee osteoarthritis (OA). Improved prosthetic design, minimally invasive surgical techniques, and strict patient selection criteria have resulted in improved survivorship and functional outcomes. A review of orthopedic literature was conducted regarding the advantages of UKA versus total knee arthroplasty (TKA), UKA indications, survivorship, conversion of UKA to TKA, rehabilitation, and outcomes. The UKA appears to be a viable option for patients with knee medial compartment OA, including younger and active patients. Survivorship rates of 94% to 97% at 10 years have been reported.     

RETRACTED ARTICLE: Gut microbiota and related diseases: clinical features

Intestinal microbiota is essential for gut homeostasis. Specifically, the microorganisms inhabiting the gut lumen interact with the intestinal immune system, supply key nutrients for the major components of the gut wall, and modulate energy metabolism. Host–microbiome interactions can be either beneficial or deleterious, driving gastrointestinal lymphoid tissue activities and shaping gut wall structures. This overview briefly focuses on the potential role played by abnormalities in gut microbiota and relative responses of the gastrointestinal tract in the determination of important pathological conditions such as the irritable bowel syndrome, inflammatory bowel diseases and colorectal cancer.     

RETRACTED ARTICLE: Angiotensin-II-induced oxidative stress elicits hypoadiponectinaemia in rats

Aims/hypothesis Hypertension, endothelial dysfunction and insulin resistance are associated conditions that share oxidative stress and vascular inflammation as common features. Adiponectin is an abundant plasma adipokine that plays a physiological role in modulating lipid metabolism and exerts a potent anti-inflammatory activity. We hypothesised that adiponectin levels decrease in response to oxidative stress and that this may promote the development of hypertension, endothelial dysfunction and insulin resistance.Methods Rats were infused with angiotensin II (AngII) or its vehicle, either alone or in combination with tempo1 (4-hydroxy-2,2,6,6-tetramethyl piperidinoxyl), a membrane-permeable metal-independent superoxide dismutase mimetic, or tetrahydrobiopterin (BH4), one of the most potent naturally occurring reducing agents and an essential cofactor for nitric oxide synthase activity. Heart rate, systolic blood pressure, body weight and serum levels of adiponectin were measured on day 7 of treatment, and then the animals were killed. Vessel tone and superoxide production were measured ex vivo in thoracic vascular rings. The expression of adiponectin mRNA in adipose tissue was assessed by Northern blotting, and in 3T3-L1 adipocytes exposed to H₂O₂ by real-time PCR. The expression of NAD(P)H oxidase subunit mRNAs in the rats was assessed by RT-PCR and real-time PCR.Results Hypertension and endothelial dysfunction were induced in rats by infusion of AngII and reversed by administration of tempol. Plasma concentrations of adiponectin and adipose tissue levels of adiponectin mRNA were decreased in AngII-infused rats, and this effect was prevented by cotreatment with tempol or BH4. The production of superoxide anions (O₂^–) was significantly increased in the aortae of AngII-treated rats, and this increase was prevented by the administration of tempol or BH4. Levels of mRNAs that encode NAD(P)H oxidase components, including p22phox, gp91phox, p47phox and Rac1, were similarly increased in adipose tissue, aortae and hearts of AngII-infused rats. Cotreatment of rats with tempol or BH4 reversed AngII-induced increases in NAD(P)H oxidase subunit mRNAs. Fully differentiated 3T3-L1 adipocytes, also exhibited diminished adiponectin mRNA levels when exposed to low concentrations of H₂O₂.Conclusions/interpretation Our results demonstrate that AngII-induced oxidative stress and endothelial dysfunction are accompanied by a decrease in adiponectin gene expression. Since antioxidants were observed to prevent the actions of AngII, and H₂O₂ on its own suppressed adiponectin expression, we conclude that adiponectin gene expression is negatively modulated by oxidative stress. Plasma adiponectin levels may provide a useful indicator of oxidative stress in vivo, and suppressed levels may contribute to the proinflammatory and metabolic derangements associated with type 2 diabetes, coronary artery disease and the metabolic syndrome.     

RETRACTED ARTICLE: Gastric Changes Following Colchicine Therapy in Patients with FMF

BACKGROUND: Familial Mediterranean fever (FMF) is also called recurrent polyserositis. The salient features of this disease include brief recurrent episodes of peritonitis, pleuritis, and arthritis, which are usually associated with fever. Colchicine is highly effective in the treatment of FMF and in preventing the development of recurrent attacks and amyloidosis, and it is essential to make the correct diagnosis and institute daily therapy with colchicine (0.5-0.6 mg bid). Colchicine is used to treat a variety of conditions but it is known to have gastrointestinal (GI) side effects. In this study, effects of colchicines on the gastrointestinal tract were evaluated in patients with FMF treated with colchicine. METHODS: Biopsies were reviewed from 43 patients attending Ain Shams University Hospital (Egypt) who were diagnosed with FMF and treated with colchicine. One-hundred and twelve GI biopsies, obtained over a 14-year period, were reviewed. This included biopsies from stomach body (38), stomach antrum (50), and colon (24). In addition, gastric biopsies were reviewed from 17 control patients who did not have FMF and were not on colchicine. RESULTS: Three patients known to have FMF and on colchicine therapy showed typical histological features of colchicine (metaphase mitoses, epithelial pseudoproliferation, mucin depletion, and frequent apoptosis). These features were seen only in gastric antral biopsies and not in colonic biopsies. None of the control group showed the characteristic morphological features of colchicine toxicity. CONCLUSION: This is the first report of histological changes seen in the stomach following colchicine therapy. In contrast with previous reports, we did not find any definitive change in the large intestine. Our data show that gastric changes can be encountered in symptomatic patients who have recently had colchicine. If these finding are seen histologically, they merit correlation with the clinical impression and should not be interpreted as toxicity in isolation.     

The porphyrias

The porphyrias are a group of metabolic disorders arising from defects in the haem biosynthetic pathway. Most forms are inherited as Mendelian autosomal dominant characters, but some are recessive and others acquired. There is a linked group of diseases, which are not porphyrias, but have in common alterations of haem biosynthesis. The haem biosynthetic pathway is now well understood and the molecular biology of its function and dysfunction in the porphyrias is currently an area of major investigation. The acute porphyrias are of most importance since attacks of these may be life-threatening. A variety of factors may precipitate these attacks including various drugs, alcohol, strict dieting or fasting and hormonal fluctuations. The non-acute porphyrias are largely dermatological conditions, which present clinically as cutaneous photosensitivity. The dermatological changes are brought about by the photosensitizing properties of circulating porphyrins. On the basis of this photoactivity, porphyrins are now being used, therapeutically, in the treatment of cancer.     

The porphyrias

Opinion statement  

RETRACTED ARTICLE: Total elbow arthroplasty: history, current concepts, and future

Total elbow arthroplasty (TEA) has proven to be a reliable joint replacement procedure that has a high degree of patient satisfaction. The long-term functional and implant survival scores rival those of total knee arthroplasty. Despite these favorable outcomes, few patients with disabling elbow degenerative conditions have TEA recommended to them as an alternative procedure by rheumatologists, physiatrists, or orthopedists. This article reviews the history, current concepts, and future of TEA.     

The porphyrias.

The heterogeneous group of diseases called the porphyrias may all be characterised by derangement of specific stages in the haem biosynthetic pathway. In the acute porphyrias; acute intermittent porphyria, urophorphyrinogen 1 synthase, hereditary coproporphyria, coproporphyrinogen oxidase and variegate porphyria, ferrochelatase or protoporphyrinogen oxidase, are the enzymes affected, whilst in the non acute porphyrias, cutaneous hepatic porphyria, uroporphyrinogen decarboxylase, congenital porphyria, uroporphyrinogen cosynthase; and erythropoietic protoporphyria; ferrochelatase are the enzymes affected. In each of the porphyrias, the activity of the initial and rate controlling enzyme of the pathway, delta-aminolaevulinic acid synthase is raised which constitutes the principal control point of the pathway. Secondary control in each of these diseases lies at the leve of uroporphyrinogen 1 synthase. As a consequence of this secondary control, there is excessive excretion of the porphyrin precursors delta-aminolaevulinic acid and porphobilinogen in the acute porphyrias and excessive excretion of porphyrins leading to solar photosensitivity in the non-acute porphyrias and in variegate and hereditary coproporphyria. There are a number of secondary metabolic aspects in the porphyrias, such as the role of steroid metabolism; the influence of drugs in the potentiation of attacks; and the potential for the pathway to branch at stages prior to porphyrin formation which result in the synthesis of various monopyrroles. The therapy of the two groups of porphyrias are quite different. Prophylaxis is important in both types but is particularly important in the avoidance of various drugs in the acute porphyrias. The acute attack may be specifically treated with carbohydrates, beta-blockers and haematin. Cutaneous hepatic porphyria may be treated by venesection, erythropoietic protoporphyria with beta caratene whilst congenital porphyria may be improved by splenectomy and chloroquine therapy.     

RETRACTED ARTICLE: Preoperative endoscopic pancreatic stenting: a novel prophylactic measure against pancreatic fistula after distal pancreatectomy

Background/Purpose

The prevention of pancreatic fistula is still a major problem in distal pancreatectomy (DP). We have recently adopted preoperative endoscopic pancreatic stenting with the aim of preventing the leakage of pancreatic juice from the resection plane of the remnant pancreas after DP. We reviewed ten patients who underwent this intervention.

Methods

One to 6 days before surgery, the patients underwent an endoscopic transpapillary pancreatic stent (7 Fr., 3 cm) placement. The perioperative short-term outcomes were assessed.

Results

Preoperative endoscopic pancreatic stenting was successfully performed in all ten patients. Two (20%) patients, both with intraductal papillary mucinous tumor, developed mild acute pancreatitis after the stent placement. None of the ten patients developed pancreatic fistula. The pancreatic stent was removed 8–28 days (mean, 11 days) postoperatively.

Conclusions

Preoperative endoscopic pancreatic stenting may be an effective prophylactic measure against pancreatic fistula development following DP.

     

RETRACTED ARTICLE: Minimally Invasive Peroral Endoscopic Removal of a Regurgitated Giant Polysegmented Fibrovascular Polyp of the Esophagus

Giant fibrovascular polyps (FVP) are relatively rare benign neoplasms of the upper part of the esophagus. Without a previous history, their diagnosis might be difficult because the endoscopic findings are sometimes misinterpreted. The present report describes a case in which the patient regurgitated a giant polypoid mass into his mouth and captured it between his teeth and buccal surface until emergency endoscopic removal. Although the adequate therapy for these lesions is open surgical resection, most often via cervical esophagotomy, in our case the polyp was removed successfully by peroral endoscopy with minimally invasive surgery. After 5 years of follow-up the patient is doing well, without recurrence.

Hepatic porphyrias

The porphyrias are metabolic disorders characterized by abnormal heme biosynthesis with excessive accumulation and excretion of porphyrias or porphyrin precursors. Defects in the enzymes of the heme biosynthetic pathway result in porphyria. Several of the disorders have been classified as hepatic because the major site of the biochemical defect has been localized to the liver. This article describes the enzymes of the heme biosynthetic pathway, the clinical features of the hepatic porphyrias and management of the disorders.