Prostacyclin production by perturbed bovine aortic endothelial cells in culture

This study reports that endotoxin (Escherichia coli serotype 026:B6) and 12-O-tetradecanoyl-phorbol-13-acetate stimulate cultured bovine aortic endothelial cells to generate prostacyclin. The prostacyclin concentration of the culture medium was measured indirectly by radioimmunoassay for 6-keto-PGF1 alpha. The amount of prostacyclin generated depended on the concentration of endotoxin or phorbol diester. Prostacyclin generation was not immediate, but occurred slowly after a six-hour lag period. The perturbed cells contracted and showed marked shape changes that correlated temporally with the start of enhanced prostacyclin production. Cytochalasins B and D, vinblastine, and colchicine inhibited prostacyclin production, indicating involvement of the cytoskeleton in the cellular response to endotoxin and phorbol diester. The increase in prostacyclin production was prevented by trifluoperazine, an inhibitor of the Ca++-calmodulin system, which is known to be involved in cytoskeletal function. Generation of prostacyclin was inhibited by cycloheximide and actinomycin D, indicating dependence on protein and ribonucleic acid synthesis. It is postulated that exposure to endotoxin or phorbol diester leads, via a series of reactions that involve RNA and protein synthesis and require intact cytoskeletal function, to the generation of toxic active intermediate(s) that stimulate the enzymes necessary for prostacyclin production.     

An anionic material at the advancing front of blood cells entering the bone marrow circulation

The selective entry of mature blood cells into the peripheral circulation of the bone marrow is a transcellular process. The mature blood cells penetrate the cytoplasm of the endothelial cells lining the myeloid sinuses and form a migration pore in the cell body of the lining cell, which closes after the blood cell reaches the intravascular space. The changes at the surfaces of the cells involved in this selective transcellular process were studied by means of the cationic cell surface markers colloidal iron (CI) and polycationic (high isoelectric point) ferritin (PCF). The anionic cell surface charges resulting from the presence of sialated glycoproteins remain, as shown by the application of these markers at low pH (1.8), evenly distributed at the cell surfaces of both the blood cell and the sinus lining cell. However, there is at the advancing margin of the diapedesing blood cells a marked accumulation of a nonsialated anionic material binding PCF at high pH (7.2). This material first accumulates extravascularly beneath the endothelium at an area of the blood cell surface near the site of the migration pore formation, remains at the cell surface during the initial phases of transcellular passage and disappears, either through shedding in the vascular lumen or through redistribution on the cell surface, when the cell reaches the intravascular space. This anionic material, which is neuraminidase resistant and has a pKa higher than sialic acid, is a characteristic concommitant in the selective transcellular blood cell passage in bone marrow.     

Prospective randomized controlled trial comparing partially absorbable lightweight mesh and multifilament polyester anatomical mesh in laparoscopic inguinal hernia repair

Introduction

Tension‐free mesh repair is currently the gold standard treatment for inguinal hernia. Recent evidence has shown that both open and laparoscopic approaches to inguinal hernia repair can achieve good results. Lots of meshes with different properties are available on the market, but direct comparisons between them are scare. We conducted a prospective randomized controlled trial comparing a partially absorbable lightweight mesh (ULTRAPRO?) and a multifilament polyester anatomical mesh (Parietex?) in laparoscopic total extraperitoneal inguinal hernia repair.

Methods

This study was a single‐center, prospective randomized controlled trial to compare the surgical handling and clinical outcomes between two different types of meshes. All operations were performed using a standardized operative protocol. This study was approved by the Institutional Review Board of the Hong Kong East Cluster Health Service in 2009 (reference number: 2009‐087). The study was registered in the Australian New Zealand Clinical Trial Registry (ACTRN12610000031066).

Results

From October 2009 to August 2011, 85 laparoscopic total extraperitoneal inguinal hernia repairs were performed. The mean mesh handling time was 152 s for the ULTRAPRO group and 206 s for the Parietex group (P = 0.001). There were three cases of seroma formation in the ULTRAPRO group and nine in the Parietex group (P = 0.02). The overall recurrence rate was 2.5%.

Conclusion

It took less time to manipulate the flat mesh (ULTRAPRO) than the anatomical mesh (Parietex) in laparoscopic total extraperitoneal inguinal hernia repair, but the time difference was small. Lightweight mesh and heavyweight mesh offered similar clinical outcomes in terms of discomfort sensation and foreign body sensation during long‐term follow‐up.

     

A jogger with painful heels

A 54-year-old man had chronic pain of his left heel region, which was initially diagnosed as 'tendinopathy'. An X-ray of the ankle joint showed a Haglund deformity. After successful surgery, he developed pain on his right heel, where again a Haglund deformity was diagnosed.     

Human platelet cGI-PDE: expression in yeast and localization of the catalytic domain by deletion mutagenesis

Cyclic adenosine monophosphate (cAMP) is an important modulator of platelet responses to agonists. Cyclic nucleotide phosphodiesterase (PDE) controls intracellular cAMP concentrations by hydrolyzing it to AMP. The major PDE activity in platelets is PDE3A (cyclic guanosine monophosphate [cGMP]-inhibited PDE). To obtain structural information on platelet PDE3A, we cloned the enzyme cDNA from a human erythroleukemia cell (HEL) library since the cell line expresses many platelet proteins. This clone consists of 87% of the full-length human myocardial PDE3A cDNA, spanning from nucleotides 456 to 4606, and is identical in sequence. The nucleotide coding for the N terminal 179 amino acid sequence (nt 1-536) as well as four other cDNAs (nt 1459- 1632, nt 1765-1986, nt 2152-2538, and nt 2978-3375) obtained by RT-PCR of platelet RNA are also identical to the myocardial sequences, indicating that the HEL, myocardial, and platelet PDE3As are the same. Northern blot analysis of HEL cell RNA detected two mRNAs of 7.5 and 4.4 kb. Four new deletion mutants are reported. PDE 3A delta 1 and PDE 3A delta 2, encoding amino acids 665 to 1141 and amino acids 679 to 1141, respectively, were expressed in a PDE-deficient yeast. They displayed PDE activities of 172 and 79 pmol/mg/min, respectively. PDE 3A delta 3 and PDE 3A delta 4, encoding amino acids 686 to 1141 and 700 to 1141, had no detectable PDE activity. All mutant proteins were expressed as determined by Western blot analysis. These findings localize the PDE3A catalytic domain to within amino acid residues 679 to 1141.     

Microscopic measurement of cellular infiltration in the rheumatoid arthritis synovial membrane: a comparison of semiquantitative and quantitative analysis

Microscopic measurement of inflammation in synovial tissue may be important in studies of clinical status, prognosis and response to treatment. The aim of this study was to compare quantitative microscopic analysis of inflammation with a semiquantitative grading system in rheumatoid arthritis (RA) synovial membrane. Knee synovial membrane samples from 16 patients with RA, including paired samples taken before and after treatment in nine patients, were immunostained with anti-CD68 and anti-CD3 monoclonal antibodies using standard techniques. The intensity of macrophage and T-lymphocyte infiltration was measured both by quantitative and semiquantitative techniques, and the results were compared. In a cross-sectional comparison, both methods correlated significantly for lining layer macrophage infiltration, as well as sublining layer macrophage and T-cell infiltration. However, in some patients demonstrating a clinical response to treatment, semiquantitative analysis lacked sensitivity to biologically relevant changes in mononuclear cell infiltration. These observations have important implications for future studies of therapeutic modalities.