Ligation of alpha4ss1 integrin on human intestinal mucosal mesenchymal cells selectively Up-regulates membrane type-1 matrix metalloproteinase and confers a migratory phenotype.

Human intestinal lamina propria mesenchymal cells show high surface expression of the alpha4ss1 integrin. Ligation of alpha4ss1 on mesenchymal cell lines with an activating monoclonal anti-alpha4 antibody or vascular cell adhesion molecule-immunoglobulin (VCAM-IgG) leads to the appearance of activated forms of gelatinase A in culture supernatants, and the de novo expression of activated membrane type-1-matrix metalloproteinase (MT1-MMP). In functional assays, signaling through alpha4ss1 results in an increased capacity of mesenchymal cells to migrate through an artificial extracellular matrix, an effect inhibitable by excess tissue inhibitor of metalloproteinase-2. In organ cultures of human intestine, VCAM-IgG also up-regulates MT1-MMP, and in mucosal ulcers of inflammatory bowel disease patients, MT1-MMP transcripts are abundant, coincident with expression of VCAM-1 on cells at the ulcer margin. Collectively these results suggest that alpha4ss1-induced up-regulation of MT1-MMP may be a crucial factor in the migration of mesenchymal cells into ulcer beds during restitution of diseased gut mucosa.

Antibacterial peptides in bronchoalveolar lavage fluid.

Defensins and other antimicrobial peptides act in the innate host defense of epithelial surfaces. Human beta defensin 1 (hBD-1) has recently been shown to be expressed in airway epithelial cells and so has been implicated as a primary component of antibacterial activity in human lung. We attempted to purify these molecules from bronchoalveolar lavage fluid (BALF). Extraction of BALF on SepPak C-18 cartridges, followed by continuous acid-urea polyacrylamide gel electrophoresis and reverse-phase high-performance liquid chromatography yielded one fraction with antibacterial activity associated with factors of < 6.5 kD. N-terminal amino acid sequencing identified these peptides as human neutrophil defensins (HD) 1 through 3. No hBD-1 was detected. Together with lysozyme, it appears that HD-1 through -3 are the most prominent antimicrobial factors in BALF. The contribution of epithelial defensins such as hBD-1 to antibacterial defense of human airway in vivo remains to be elucidated.

Localization of expression of human beta defensin-1 in the pancreas and kidney.

Defensins are antimicrobial peptides which play a key role in innate immunity. High levels of human beta defensin-1 (hBD-1) have previously been detected in the kidney and pancreas, but the cell-specific location of hBD-1 mRNA has not been determined. The expression of hBD-1 mRNA has been examined in fetal and adult pancreas and kidney by mRNA in situ hybridization. In fetal pancreas, hBD-1 expression was detected in the developing acini and in adult pancreas in the acini, but not in the pancreatic ducts. In both fetal and adult kidney, hBD-1 expression was detected in the collecting ducts and in the loops of Henle in adult kidney. Expression of hBD-1 mRNA in the pancreas and kidney from early development and in the acini of the adult pancreas, rather than in the pancreatic ducts, may indicate that in these tissues, hBD-1 fulfils physiological functions in addition to host defence.

Purification and characterization of a proline-rich antibacterial peptide, with sequence similarity to bactenecin-7, from the haemocytes of the shore crab, Carcinus maenas.

Antibacterial peptides are important for non-specific host defence in many animals. They have been extensively characterized from mammals, amphibians, insects and chelicerates but have not so far been found in crustaceans. Here we report the presence of several constitutive antibacterial proteins, active against both gram-positive and gram-negative bacteria, in the haemocytes of the shore crab, Carcinus maenas. These proteins have molecular masses of > 70 kDa, approximately 45 kDa, approximately 14 kDa and 6.5 kDa. The 6.5 kDa peptide has been purified to homogeneity by Sep Pak C18 extraction, gel filtration and reverse-phase HPLC. Partial N-terminal sequence analysis further shows that it is proline rich and shares more than 60% identity in a 28-amino-acid overlap with the mature form of bactenecin 7, an antimicrobial peptide from bovine neutrophils which belongs to the cathelicidin family of mammalian peptide antibiotics.

Fever following intracavitary bacillus Calmette-Guerin therapy for upper tract transitional cell carcinoma.

PURPOSE: We attempted to identify the source of fever during intracavitary upper tract instillation of bacillus Calmette-Guerin (BCG). MATERIALS AND METHODS: Of 34 patients who had previously undergone percutaneous resection of upper tract transitional cell carcinoma 18 received weekly intracavitary BCG through the nephrostomy tubes for 6 consecutive weeks. After treatment 6 all patients underwent nephroscopy and biopsy, and all cases were retrospectively reviewed. Parameters analyzed were BCG related symptoms, maximum temperature during treatment, maximum renal pelvic pressure during treatment, culture results, chest x-ray findings, pretreatment serum creatinine concentration, serum liver enzyme values, untoward events and treatments performed for BCG related complications. RESULTS: No obvious pattern in appearance of fever occurred. During 88 treatment episodes evaluated there were 14 temperature elevations to more than 100F in 7 patients (39%). Positive urine cultures were associated with fever in only 4 cases and none was positive for Mycobacterium. There was no correlation between greater renal pelvic pressures and fever. All chest radiographs and serum creatinine levels were unchanged, and liver enzymes were normal in all but 1 patient. Two patients had prolonged fever with elevations to greater than 104F following treatment: 1 died in a motor vehicle accident and 1 died after the third BCG infusion led to overwhelming sepsis. No source of fever was identified in either patient. CONCLUSIONS: Patients with low grade fever coincident with upper tract BCG may be treated conservatively simply by withholding the infusion. Fever greater than 103F should be considered an emergency condition with high potential for mortality. Immediate and aggressive attempts at identifying a source along with institution of antituberculous therapy are priorities.

Facial skeletal growth after timed soft-tissue undermining.

This study was designed to answer the following questions: (1) Does aggressive bilateral soft-tissue undermining of the nasomaxillary complex in an immature animal without an iatrogenically produced cleft lip significantly inhibit growth? (2) If so, is the early timing of this undermining crucial? Fifty New Zealand White rabbits were used in this study, and bilateral buccal sulcus incisions with extensive nasomaxillary supraperiosteal undermining were performed in the experimental groups. There were five groups: (1) control, (2) undermining at 3 to 4 days, (3) undermining at 7 to 10 days, (4) undermining at 18 to 21 days, and (5) undermining at 50 to 56 days. The animals were sacrificed at 6 months of age, and direct osteometric measurements were made. Results demonstrated that a significantly retruded, constricted, and vertically shortened maxilla was produced as a direct result of bilateral nasomaxillary soft-tissue undermining alone regardless of the timing.