The mast cell - neurofibromatosis connection.

Neurofibromatosis type 1 (NF1) is an autosomal dominant disorder affecting 1/3000 individuals worldwide. It results from germline mutations of the neurofibromin gene and it is fully penetrant by the age of 5. Neurofibromin is a 2818 amino acid protein that is produced in many cell types, but its levels are especially high in the nervous system.

Genetic deletion of the bacterial sensor NOD2 improves murine Crohn's disease-like ileitis independent of functional dysbiosis.

Although genetic polymorphisms in NOD2 (nucleotide-binding oligomerization domain-containing 2) have been associated with the pathogenesis of Crohn's disease (CD), little is known regarding the role of wild-type (WT) NOD2 in the gut. To date, most murine studies addressing the role of WT Nod2 have been conducted using healthy (ileitis/colitis-free) mouse strains. Here, we evaluated the effects of Nod2 deletion in a murine model of spontaneous ileitis, i.e., the SAMP1Yit/Fc (SAMP) strain, which closely resembles CD. Remarkably, Nod2 deletion improved both chronic cobblestone ileitis (by 50% assessed, as the % of abnormal mucosa at 24 wks of age), as well as acute dextran sodium sulfate (DSS) colitis. Mechanistically, Th2 cytokine production and Th2-transcription factor activation (i.e., STAT6 phosphorylation) were reduced. Microbiologically, the effects of Nod2 deletion appeared independent of fecal microbiota composition and function, assessed by 16S rRNA and metatranscriptomics. Our findings indicate that pharmacological blockade of NOD2 signaling in humans could improve health in Th2-driven chronic intestinal inflammation.

The effect of nifedipine on the patency of microvascular anastomosis in rats.

Despite advances in microsurgical technique and experience in clinical microvascular surgery, there remains the possibility of vessel thrombosis. Factors that may contribute to vascular pedicle thrombosis include operative trauma, pedicle malposition, kinking, hypercoagulability and arterial vasoconstriction. The purpose of this study was to evaluate the effect of intravenous administration of nifedipine on the patency of the microvascular anastomosis of the femoral artery in rats. A total of 60 rats were used and divided into three groups. The first group (A) was used as a control group with no medical agent, the second group (B) was medicated with heparin, and the third group (C) was medicated with nifedipine. Patency was assessed with the distal empty refill test, one hour (1) and forty-eight hours (48) after completion of the anastomosis. The nifedipine and heparin treated groups (B & C) did not show higher patency rate compared to the control group (A). There was no statistically significant difference of patency percent after 1 hour and 48 hours among the three groups (p = 0.231/p = 0.480). Intravenous administration of nifedipine does not improve the patency of microvascular anastomosis. Surgical technique remains the most important factor for successful microvascular anastomosis.

Total nasal reconstruction using a prelaminated free radial forearm flap and porous polyethylene implants.

Reconstruction of total nasal defects remains one of the most difficult problems in plastic surgery as the nose combines aesthetics and function. Standard techniques using either forehead or nasolabial flaps do not have a place in the case of extensive scarring on the face or areas with high risk of cancer recurrence on the face. In these cases, microsurgical free tissue transfer for the soft tissue reconstruction in combination with bone grafts or implants for the nasal skeleton are ideal. We report the use of prelaminated radial forearm flap with porous polyethylene implants for total nasal reconstruction.

First Report of Fusarium Wilt of Alfalfa in Greece.

In August 2000, samples of alfalfa (Medicago sativa L.) plants cv. Iliki showing wilt symptoms consistent with those reported for Fusarium wilt (1) were collected from an alfalfa field of the Agricultural University of Athens. Symptoms of the disease were chlorosis, yellowing, premature defoliation, wilting, vascular discoloration (dark brown), stunting, and death of plants. Fusarium oxysporum was isolated from the stems of diseased plants. Fresh cultures of the isolated fungus on potato dextrose agar (PDA) media developed whitish purple mycelium, short phialides, microconidia, and later, macroconidia and chlamydospores matching the description of F. oxysporum Schlechtend.:Fr. f. sp. medicaginis (Weimer) W.C. Snyder & H.N. Hans. (2). The fungus was maintained on PDA cultures at 4°C. Pathogenicity tests were conducted in a greenhouse (12-h photoperiod at 25 to 32°C) on alfalfa Greek cv. Iliki. An aqueous suspension of 107 microconidia per ml was prepared, and roots of 7-week-old seedlings were dipped for 20 min and then returned to pots. Within 15 days, all inoculated plants exhibited typical Fusarium wilt symptoms similar to those observed in the field. Four weeks after inoculation, almost all plants were dead. Control seedlings (root-dipped for 20 min in sterile distilled water) remained healthy. The fungus was reisolated from the symptomatic seedlings, fulfilling Koch's postulates. Weimer (3) first described Fusarium wilt of alfalfa and identified the causal organism as Fusarium oxysporum f. sp. medicaginis. Cross-artificial inoculation to cotton plants cv. Myrto, Christina, and Acala CJ2 was also performed, but none of the cultivars developed any macroscopic symptoms of the disease. To our knowledge, this is the first report of alfalfa Fusarium wilt in Greece. Although the pathogen was located in a rather isolated spot of alfalfa cultivation in Attica County, the occurrence of the pathogen and its importance in other alfalfa growing regions of Greece will be investigated. References: (1) D. C. Erwin. Fusarium wilt. Pages 33-34 in: Compendium of Alfalfa Diseases. 2nd ed. D. L. Stuteville and D. C. Erwin eds. The American Phytopathological Society, St. Paul, MN, 1990. (2) W. C. Snyder and H. N. Hansen. Am. J. Bot. 27:64, 1940. (3) J. L. Weimer. J. Agric. Res. 37:419, 1928.

A case of streptococcal myositis (misdiagnosed as hamstring injury).

Streptococcal myositis is a very rare bacterial infection of muscle with a high mortality. Diagnosis is difficult because of the paucity of clinical signs and symptoms at the onset. However, presentation of the disease appears to have changed over the last 50 years. A case of streptococcal myositis is presented (misdiagnosed as hamstring injury), which more closely reflects the current presentation of the disease. Some of the features that may help emergency clinicians to recognise the onset of the condition are highlighted.

Design and evaluation of a Lactobacillus group-specific ribosomal RNA-targeted hybridization probe and its application to the study of intestinal microecology in pigs.

The potential importance of anaerobic bacteria belonging to the Lactobacillus group has been well documented. Appropriate methods to rapidly evaluate species diversity and fluctuations in their population levels within the Lactobacillus group are being developed. Molecular tools such as hybridization probes based on rRNA sequences are well suited to these studies. The work reported here was undertaken to test the specificity of an hybridization probe to specifically recognize microorganisms of the Lactobacillus group and assess its usefulness as a quantitative tool to study fluctuations of the Lactobacillus population relative to the total bacterial population in gastrointestinal contents of pigs. We have designed a 25-mer oligonucleotide that targets a region common to and specific for the Lactobacillus group 16S rRNA sequences within the available database. The optimal wash temperature of the probe was experimentally determined to be 54 degrees C. The results obtained using the Lactobacillus group-specific probe (LGP) shows that Lactobacillus populations vary along the different segments of the gastrointestinal tract (GIT). In weaning piglets, the relative Lactobacillus signal intensity obtained constituted 100% of the relative RNA index in the stomach contents as determined by a bacterial domain probe (BDP), and between 90 to 100% in the duodenum. The signal of the Lactobacillus population decreased and reached its minimum in the distal part of the GIT. The same trend was observed in adult pigs, but in the stomach they constituted no more than 30% as determined by the BDP, and were present at lower levels in the other parts of the GIT. These studies document the quantitative importance of the lactobacilli in the stomach and small intestine of pigs. Further studies to investigate the role of lactobacilli in promoting the ecological balance of gut bacteria for probiotic therapy are being undertaken.

Our experience with the use of the dorsal ulnar artery flap in hand and wrist tissue cover.

We describe a series of six cases exploring the limits of reliability of the dorsal ulnar artery fasciocutaneous flap as described by Becker and Gilbert (1988a; b). Although the territory supplied by the dorsal ulnar artery is 10 cm to 20 cm long by 5 cm to 9 cm wide, Becker and Gilbert suggested that flaps should be confined to smaller dimensions. We have found that larger flaps (15 to 20 cm long and 5 to 8 cm wide) are feasible, extending the use of the flap to the radial side of the wrist and hand. However, problems were encountered with venous drainage and these larger flaps should be used with caution.

"Cycloperistaltic" intestinal segment: a new method to prevent excessive fluid loss in permanent ileostomies.

A 10-15 cm. long isolated intestinal segment, in which peristalsis has been altered to run in a circular fashion, was interposed in a series of permanent ileostomy-bearing dogs and in two clinical cases with severe diarrhea after total colectomy. Excellent results in both patients confirmed the experimental findings. Technically the method is easily accomplished by cutting the antimesenteric site of the intestinal segment lengthwise and resuturing it transversely. Two major advantages of this technic are postulated. First, the retarding action of the isolated loop does not depend on the great variations observed in peristaltic activity of the small intestine which in some patients results in obstruction. Second, the blood supply to the loop is unlikely to be impaired. Possibly both these advantages derive from the fact that the loop is twisted only 90% instead of 180 degrees required in the ordinary reversed loop interposition.