PDGF-BB regulates splitting angiogenesis in skeletal muscle by limiting VEGF-induced endothelial proliferation

VEGF induces normal or aberrant angiogenesis depending on its dose in the microenvironment around each producing cell in vivo. This transition depends on the balance between VEGF-induced endothelial stimulation and PDGF-BB-mediated pericyte recruitment, and co-expression of PDGF-BB normalizes aberrant angiogenesis despite high VEGF doses. We recently found that VEGF over-expression induces angiogenesis in skeletal muscle through an initial circumferential vascular enlargement followed by longitudinal splitting, rather than sprouting. Here we investigated the cellular mechanism by which PDGF-BB co-expression normalizes VEGF-induced aberrant angiogenesis. Monoclonal populations of transduced myoblasts, expressing similarly high levels of VEGF alone or with PDGF-BB, were implanted in mouse skeletal muscles. PDGF-BB co-expression did not promote sprouting and angiogenesis that occurred through vascular enlargement and splitting. However, enlargements were significantly smaller in diameter, due to a significant reduction in endothelial proliferation, and retained pericytes, which were otherwise lost with high VEGF alone. A time-course of histological analyses and repetitive intravital imaging showed that PDGF-BB co-expression anticipated the initiation of vascular enlargement and markedly accelerated the splitting process. Interestingly, quantification during in vivo imaging suggested that a global reduction in shear stress favored the initiation of transluminal pillar formation during VEGF-induced splitting angiogenesis. Quantification of target gene expression showed that VEGF-R2 signaling output was significantly reduced by PDGF-BB co-expression compared to VEGF alone. In conclusion, PDGF-BB co-expression prevents VEGF-induced aberrant angiogenesis by modulating VEGF-R2 signaling and endothelial proliferation, thereby limiting the degree of circumferential enlargement and enabling efficient completion of vascular splitting into normal capillary networks despite high VEGF doses.

Interest of video-assisted minimally invasive surgery in primary hyperparathyroidism

INTRODUCTION

Surgery is the only radical and definitive treatment for primary hyperparathyroidism. Exploration of the four parathyroid sites is giving way to minimally invasive techniques. The present study sought to compare two minimally invasive parathyroidectomy techniques, by classical cervicotomy (MIP-C) and by video-assistance (MIP-VA), in terms of success rate, complications rate, operating time, and patient and community physician satisfaction.

MATERIALS AND METHOD

A non-randomized retrospective comparative study included 112 patients presenting with primary hyperparathyroidism with identified parathyroid adenoma, operated on between January 2005 and October 2010. The two groups were constituted according to the surgeons' habitual practice: 54 cases of MIP-VA and 58 of MIP-C.

RESULTS

Results for MIP-VA and MIP-C were respectively: success, 96.3% vs. 100% (P=0.09); mean scar size, 1.47 vs. 3.43cm (P<0.01); hypocalcemia, 2 vs. 3 cases (P=0.1); theater time, 94.25 vs. 76min (P=0.02); and postoperative stay, 1.08 vs. 1.37 days (P=0.07). Patient satisfaction was comparable between groups, while 93.3% of community physicians found MIP-VA preferable to MIP-C, although only 39.3% had known the MIP-VA technique.

CONCLUSION

With efficacy, morbidity and patient satisfaction comparable to classical surgery, MIP-VA significantly reduced cervicotomy size and hospital stay. Community physicians considered it to be preferable to MIP-C.

Traumatic intra-sphenoidal pseudoaneurysm lodged inside the fractured sphenoidal sinus

We describe a case of traumatic intra-sphenoidal right internal carotid artery pseudoaneurysm lodged inside the fractured sphenoidal sinus that developed in a patient with a previous history of frontal and skull base fractures involving the sphenoid sinus and walls of the carotid canal, but with normal intracranial findings at early CT angiography. The patient presented two episodes of massive life-threatening delayed epistaxis before successful endovascular treatment combining the use of coils and an uncovered stent was instituted. This case report highlights that patients with head trauma who present sphenoid sinus fractures with or without massive epistaxis should be evaluated for the development of traumatic internal carotid artery pseudoaneurysm as soon as possible. If the first angiographic evaluation reveals normal findings, repeated epistaxis should prompt a second angiographic evaluation because psudoaneurysm takes time to develop. Early treatment with uncovered stent of the aneurysm can be a life-saving therapeutic approach.

Tracheal rhinoscleroma

INTRODUCTION

Tracheal rhinoscleroma is an infectious granulomatosis of the tracheobronchial tract caused by a Gram-negative bacillus. Exclusively tracheal involvement has been rarely reported in the literature. The purpose of this study was to report a case of subglottic stenosis secondary to rhinoscleroma.

SUMMARY

A 46-year-old North African woman with no medical or surgical history presented with inspiratory dyspnoea that had been present for several years. Endoscopic examination under general anaesthesia revealed tracheal stenosis. Histological examination of mucosal biopsies demonstrated Mikulicz cells and culture of bacteriological samples taken during a second biopsy confirmed the diagnosis of rhinoscleroma. CO2 laser subglottic obstruction relief was performed and treatment with ofloxacin was initiated. No recurrence of tracheal stenosis was observed with a follow-up of 6 months.

DISCUSSION

The diagnosis of rhinoscleroma is based on histological and bacteriological examination. Cultures are positive in 60% of cases, but negative cultures do not exclude the diagnosis of rhinoscleroma. Specific treatment consists of long-term antibiotic therapy, while surgery may be indicated for symptomatic treatment.

[Infections in hospitalized patients with cirrhosis]

We evaluated the prevalence and the clinical relevance of bacterial and nonbacterial infections in predominantly alcoholic cirrhotic patients, admitted to an intermediate complexity hospital, and we also compared the clinical characteristics, laboratory and evolution of these patients with and without bacterial infection in a prospective study of cohort. A total of 211 consecutive admissions in 132 cirrhotic patients, between April 2004 and July 2007, were included. The mean age was 51.8 (+/-8) years, being 84.8% male. The alcoholic etiology of cirrhosis was present in 95.4%. One hundred and twenty nine episodes of bacterial infections were diagnosed in 99/211 (46.9%) admissions, community-acquired in 79 (61.2%) and hospital-acquired in 50 (38.8%): spontaneous bacterial peritonitis (23.3%); urinary tract infection (21.7%); pneumonia (17.8%); infection of the skin and soft parts (17.1%), sepsis by spontaneous bacteremia (7.7%); other bacterial infections (12.4%). Gram-positive organisms were responsible for 52.2% of total bacterial infections documented cases. There were eight serious cases of tuberculosis, fungal and parasitic infections; the prevalence of tuberculosis was 6% with an annual mortality of 62.5%; 28.1% (9/32) of the coproparasitological examination had Strongyloides stercolaris. The in-hospital mortality was significantly higher in patients with bacterial infection than in non-infected patients (32.4% vs. 13.2%; p=0.02). The independent factors associated with mortality were bacterial infections, the score of Child-Pügh and creatininemia > 1.5 mg/dl. By the multivariate analysis, leukocytosis and hepatic encephalopathy degree III/IV were independent factors associated to bacterial infection. This study confirms that bacterial and nonbacterial infections are a frequent and severe complication in hospitalized cirrhotic patients, with an increase of in-hospital mortality.

[Hypertriglyceridemia during active intercurrent infections in HIV-infected patients]

BACKGROUND

Many reports have confirmed that hypertriglyceridemia (HTG) is more common in HIV-infected patients than in the general population, but the relationship between HTG and clinical conditions have not been well established. This work analyzes the relationships between CD4+ cell count, HTG and the presence of active intercurrent infections in patients hospitalized for HIV infection.

METHODS

Blood specimens from hospitalized HIV-infected patients and healthy controls without HIV infection were analyzed. Clinical conditions when the specimens were collected were recorded.

RESULTS

The average level of serum triglycerides from 89 HIV-infected patients was significantly higher than the 29 healthy controls (1.57 +/- 0.09 vs 0.78 +/- 0.08 mmol/l respectively) (p < 0.001). In the study group, HTG was detected in 25 patients (27%). Twenty-six patients had intercurrent infections and 50 were asymptomatic. Clinical conditions of the remaining 13 were not available. HTG was detected in 18 out of 26 patients having intercurrent infections (68%), and in 4 out of the 50 patients without active infections (8%) (p < 0.000000417).

CONCLUSIONS

HTG was more frequent in HIV-infected patients than in healthy controls, and it was significantly associated with the presence of intercurrent infections. This has important diagnostic implications, because the presence of HTG might be considered an unspecific marker for intercurrent infections in HIV patients.