Healing of an MRSA-colonized, hydroxyurea-induced leg ulcer with honey

BACKGROUND

With the everincreasing emergence of antibiotic-resistant pathogens, in particular methicillin-resistant Staphylococcus aureus (MRSA) in leg ulcers, a means of reducing the bacterial bioburden of such ulcers, other than by the use of either topical or systemic antibiotics, is urgently required.

METHODS

We report the case of an immunosuppressed patient who developed a hydroxyurea-induced leg ulcer with subclinical MRSA infection which was subsequently treated with topical application of manuka honey, without cessation of hydroxyurea or cyclosporin.

RESULTS

MRSA was eradicated from the ulcer and rapid healing was successfully achieved.

CONCLUSION

Honey is recognized to have antibacterial properties, and can also promote effective wound healing. A traditional therapy, therefore, appears to have enormous potential in solving new problems.

The protein tyrosine phosphatase Shp-2 regulates RhoA activity

Remodeling of filamentous actin into distinct arrangements is precisely controlled by members of the Rho family of small GTPases [1]. A well characterized member of this family is RhoA, whose activation results in reorganization of the cytoskeleton into thick actin stress fibers terminating in integrin-rich focal adhesions [2]. Regulation of RhoA is required to maintain adhesion in stationary cells, but is also critical for cell spreading and migration [3]. Despite its biological importance, the signaling events leading to RhoA activation are not fully understood. Several independent studies have implicated tyrosine phosphorylation as a critical event upstream of RhoA [4]. Consistent with this, our recent studies have demonstrated the existence of a protein tyrosine phosphatase (PTPase), sensitive to the dipeptide aldehyde calpeptin, acting upstream of RhoA [5]. Here we identify the SH2 (Src homology region 2)-containing PTPase Shp-2 as a calpeptin-sensitive PTPase, and show that calpeptin interferes with the catalytic activity of Shp-2 in vitro and with Shp-2 signaling in vivo. Finally, we show that perturbation of Shp-2 activity by a variety of genetic manipulations results in raised levels of active RhoA. Together, these studies identify Shp-2 as a PTPase acting upstream of RhoA to regulate its activity and contribute to the coordinated control of cell movement.

Preparing the wound bed--debridement, bacterial balance, and moisture balance

Successful diagnosis and treatment of patients with chronic wounds involve holistic care and a team approach. The integration of the work of an interdisciplinary care team that includes doctors, nurses, and allied health professionals with the patient, family, significant others, and caregivers offers an optimal formula for achieving wound resolution. Such an approach challenges practitioners and everyone participating in wound care to integrate data and information that arise from a number of sources and mitigating factors. In this article, the authors define the changing paradigm that links treatment of the cause and focuses on three components of local wound care: debridement, wound-friendly moist interactive dressings, and bacterial balance. The authors demonstrate that the treatment of chronic wounds can be accomplished through a series of recommendations and rationales based on the literature and their experience. These recommendations lay the groundwork for thorough assessment and evaluation of the wound.

Oral health knowledge, attitudes and preventive practices of third grade school children

PURPOSE

The aim of study was to investigate the oral health knowledge, attitudes and preventive practices of third grade school children in Harris County.

METHODS

In this cross-sectional study, oral health knowledge, attitudes, and preventive practices of the children were investigated by means of a self-administered, bilingual questionnaire. Three calibrated examiners collected data on dental caries, periodontitis, and fluorosis of 1,031 school children.

RESULTS

Most children reported "fairly adequate" oral hygiene habits (58%) and oral health knowledge (48%), and "adequate" dietary patterns (59%). Children with inadequate oral health knowledge were twice as likely to have caries than children with adequate knowledge (OR = 2.05, 95% CI = 1.29, 3.28). The mean combined DMFT/dft scores of children with inadequate knowledge were significantly higher than the mean for children with adequate knowledge (t = 2.6, P = 0.009).

CONCLUSIONS

Results indicate a need to improve oral health knowledge and preventive practices among the study population. Because of the cross-sectional nature of the study, it is not possible to illustrate a cause-effect relationship between oral health education and prevalence of caries.

Advances in wound care and healing technology

Wounds are unique in so far as no disease process other than wounds would have existed from the beginning of mankind. Over the years, the management of wounds, especially that of chronic wounds, has had enormous social and economic implications worldwide. With an aging population, this impact is likely to increase. In recent years, this has been reflected by the birth and rapid growth of the new speciality of 'wound healing'. Continuous advances made in the study of the wound microenvironment, an ever-broadening understanding of the pathophysiology of wounds, and improved techniques in monitoring the response of healing have led to continuing developments in the treatment of chronic wounds. Current research focuses on growth factors and human skin substitutes that provide promising results. This article reviews advances made in wound care management over the years. Despite all these advances, it must be borne in mind that basic principles of wound care in a multidisciplinary team setting still remain the backbone of wound management.

Effect of resistance training on single muscle fiber contractile function in older men

The purpose of this study was to examine single cell contractile mechanics of skeletal muscle before and after 12 wk of progressive resistance training (PRT) in older men (n = 7; age = 74 +/- 2 yr and weight = 75 +/- 5 kg). Knee extensor PRT was performed 3 days/wk at 80% of one-repetition maximum. Muscle biopsy samples were obtained from the vastus lateralis before and after PRT (pre- and post-PRT, respectively). For analysis, chemically skinned single muscle fibers were studied at 15 degrees C for peak tension [the maximal isometric force (P(o))], unloaded shortening velocity (V(o)), and force-velocity parameters. In this study, a total of 199 (89 pre- and 110 post-PRT) myosin heavy chain (MHC) I and 99 (55 pre- and 44 post-PRT) MHC IIa fibers were reported. Because of the minimal number of hybrid fibers identified post-PRT, direct comparisons were limited to MHC I and IIa fibers. Muscle fiber diameter increased 20% (83 +/- 1 to 100 +/- 1 microm) and 13% (86 +/- 1 to 97 +/- 2 microm) in MHC I and IIa fibers, respectively (P < 0.05). P(o) was higher (P < 0.05) in MHC I (0.58 +/- 0.02 to 0.90 +/- 0.02 mN) and IIa (0.68 +/- 0.02 to 0.85 +/- 0.03 mN) fibers. Muscle fiber V(o) was elevated 75% (MHC I) and 45% (MHC IIa) after PRT (P < 0.05). MHC I and IIa fiber power increased (P < 0.05) from 7.7 +/- 0.5 to 17.6 +/- 0.9 microN. fiber lengths. s(-1) and from 25.5 to 41.1 microN. fiber lengths. s(-1), respectively. These data indicate that PRT in elderly men increases muscle cell size, strength, contractile velocity, and power in both slow- and fast-twitch muscle fibers. However, it appears that these changes are more pronounced in the MHC I muscle fibers.

Celiac disease : a brief overview

Historically, the term celiac disease evolved within pediatric practice during the nineteenth century, defining children with severe wasting and putrid stools (1). In the earlier twentieth century, similar complaints in adults were categorized as "intestinal insufficiency" or "idiopathic steatorrhea." It was also realized at that time that, for many of these adult patients, celiac-like features had been present since early childhood.

Ultrasound imaging of forearm fractures in children: a viable alternative?

OBJECTIVE

A pilot study to investigate whether ultrasonography can be reliably used to demonstrate uncomplicated greenstick and torus fractures in children.

METHOD

Children between the ages of 2 and 14 years with a high clinical suspicion of a non-articular, undisplaced forearm fracture were included. Ultrasound imaging of the injury was performed by a consultant radiologist who gave an immediate report. Standard radiographs of the forearm were then obtained and the patient treated in the normal way. The radiograph was formally reported on at a later date.

RESULTS

26 patients were included. There was an absolute correlation between the ultrasound and radiographic findings. The procedure was well tolerated.

CONCLUSION

Ultrasound seems effective for detecting uncomplicated forearm fractures in children. The procedure is easy to perform and the images easy to interpret. A larger study will now be undertaken to confirm these initial findings.

The von Willebrand factor-glycoprotein Ib/V/IX interaction induces actin polymerization and cytoskeletal reorganization in rolling platelets and glycoprotein Ib/V/IX-transfected cells

Platelet adhesion to sites of vascular injury is initiated by the binding of the platelet glycoprotein (GP) Ib-V-IX complex to matrix-bound von Willebrand factor (vWf). This receptor-ligand interaction is characterized by a rapid on-off rate that enables efficient platelet tethering and rolling under conditions of rapid blood flow. We demonstrate here that platelets adhering to immobilized vWf under flow conditions undergo rapid morphological conversion from flat discs to spiny spheres during surface translocation. Studies of Glanzmann thrombasthenic platelets (lacking integrin alpha(IIb)beta(3)) and Chinese hamster ovary (CHO) cells transfected with GPIb/IX (CHO-Ib/IX) confirmed that vWf binding to GPIb/IX was sufficient to induce actin polymerization and cytoskeletal reorganization independent of integrin alpha(IIb)beta(3). vWf-induced cytoskeletal reorganization occurred independently of several well characterized signaling processes linked to platelet activation, including calcium influx, prostaglandin metabolism, protein tyrosine phosphorylation, activation of protein kinase C or phosphatidylinositol 3-kinase but was critically dependent on the mobilization of intracellular calcium. Studies of Oregon Green 488 1, 2-bis(o-amino-5-fluorophenoxy)ethane-N,N,N',N-tetraacetic acid tetraacetoxymethyl ester-loaded platelets and CHO-Ib/IX cells demonstrated that these cells mobilize intracellular calcium in a shear-dependent manner during surface translocation on vWf. Taken together, these studies suggest that the vWf-GPIb interaction stimulates actin polymerization and cytoskeletal reorganization in rolling platelets via a shear-sensitive signaling pathway linked to intracellular calcium mobilization.

Possible antimigraine mechanisms of action of the 5HT1F receptor agonist LY334370

This study investigated whether the selective 5HT1F receptor agonist LY334370 has other possible antimigraine mechanisms in addition to the proposed inhibition of dural plasma extravasation. LY334370 (up to 10(-5) M) had no vasoconstrictor effects on human cerebral arteries in vitro. It had no effect (up to 10 mg kg-1, i.v.) on neurogenic vasodilation of dural blood vessels produced by electrical stimulation of the dura mater in anesthetized rats. Nor had it any effect (at 3 mg kg-1, i.v.) on the hyperalgesia produced by injection of carrageenan into the paw of conscious rats or on nociceptive reflex responses in the spinalized, decerebrate rabbit (up to 3 mg kg-1, i.v.), indicating that it has no general analgesic properties. However, it significantly inhibited activation of second-order neurons in the trigeminal nucleus caudalis produced by electrical stimulation of the dura mater in anesthetised rats at 3 mg kg-1, i.v. These results provide evidence to suggest that LY334370 has a central mechanism of action in blocking the transmission of nociceptive impulses within the trigeminal nucleus caudalis and that this may represent a mechanism through which it has its antimigraine effect.

Platelet adhesion receptors: novel targets for anti-thrombotic therapy

The critical role of platelets in the development of the acute coronary syndromes is now well recognised, and a great deal of effort has therefore focused on elucidating the key adhesion receptors mediating platelet-vessel wall and platelet-platelet interactions. The vascular adhesion protein von Willebrand factor (vWf) plays a key role in supporting platelet adhesion to the damaged vessel wall and binds to two adhesion receptors on the platelet surface, the glycoprotein (GP) Ib-V-IX complex and glycoprotein IIb-IIIa. The GP Ib-V-IX complex is a unique adhesion receptor which enables platelets to roll on a vWf matrix under conditions of rapid blood flow as well as transducing signals leading to the activation of GP IIb-IIIa. This latter receptor binds to a distinct site on vWf and is essential for stabilising platelet adhesion to the site of vessel wall injury. In addition to supporting platelet adhesion, GP IIb-IIIa plays a key role in a number of other platelet responses including platelet spreading, aggregation, the release of procoagulant-rich microvesicles, and clot retraction. Given its central role in platelet function GP IIb-IIIa has become an attractive target for the development of novel anti-thrombotic agents. In this paper, we consider the advantages of inhibitors of GP IIb-IIIa compared with other established anti-platelet drugs including aspirin and ticlopidine, and also discuss some potential problems associated with the inhibition of GP IIb/IIIa and other platelet adhesion receptors.

Acute airway obstruction--an unusual cause

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Management of double-layered patellae by compression screw fixation

Tripartite patella is a form of double-layered patella in which the anterior layer is bipartite. It was first described by Büttner in 1925 (1). More recently, an association with multiple epiphyseal dysplasia has been described (2,3). In this article, we describe a case of symptomatic tripartite patella in a 13-year-old child who was subsequently found to have features of multiple epiphyseal dysplasia. Her patellae had an abnormal excursion with a click and a visible jump in the longitudinal line of movement, but no lateral instability. We present a surgical solution not previously described by fusion of the two main components and report an excellent result.

The determination of amino Acid sequence abnormalities in proteins by HPLC Peptide analysis

Current techniques for DNA amplification and sequencing have greatly simplified the identification of genetic mutations underlying disorders of abnormal protein production. The need, however, for the direct characterization of an amino acid abnormality in a defective protein still arises in particular situations. The normal approach to this problem relies on the specific fragmentation of the protein and subsequent analysis of the resultant mixture of peptides. The techniques currently available for peptide analysis offer very high sensitivity and so require relatively small amounts of protein. Automated peptide sequencing or mass spectrometry can be achieved with subnanomole quantities of peptide. Consequently, sufficient material can be isolated from tryptic digests beginning with as little as a milligram or so of a pure protein.

Angiotensinogen cleavage by renin: importance of a structurally constrained N-terminus

Angiotensinogen, a plasma serpin, functions as a donor of the decapeptide angiotensin I, which is cleaved from the N-terminus by renin. To assess the contribution of the serpin framework to peptide cleavage we produced a chimaeric molecule of alpha1-antitrypsin carrying the angiotensinogen N-terminus and determined the kinetic parameters for angiotensin I release. The Km for plasma angiotensinogen was 18-fold lower than for the chimaeric protein while the catalytic efficiency was four-fold higher. We also show that Cys-18 participates in a disulphide bond and propose that constraints on the N-terminus profoundly affect the interaction with renin.

Bayesian decision procedures based on logistic regression models for dose-finding studies

Early-phase clinical trials, conducted to determine the appropriate dose of an experimental drug to take forward to later trials, are considered. The objective is to find the dose associated with some low probability of an adverse event. A Bayesian model is presented, and a decision-theoretic procedure for finding the optimal doses for each of a series of cohorts of subjects is derived. The procedure is flexible and can easily be conducted using standard statistical software. The results of simulations investigating the properties of the procedure are presented.

The correspondence between coronary heart disease mortality and risk factor prevalence among states in the United States, 1991-1992

OBJECTIVE

This study aimed to examine the correspondence between seven established risk factors for coronary heart disease (CHD) and CHD mortality among the states in the United States. An ecologic analysis relating CHD risk factor prevalences to CHD mortality rates among 49 states was undertaken in 1991-1992.

METHODS

Approximately 68,000 men and women ages 45-74 were randomly sampled and interviewed by telephone in surveys conducted in 49 states in 1991 and 1992. From these interviews, we estimated state-specific prevalences of smoking, overweight, physical inactivity, hypertension, elevated cholesterol, diabetes, and alcohol abstinence. These seven CHD risk factors were also combined to create a CHD risk index for each state. The main outcome measures were mortality rates from CHD (ICD9 codes 410.0-414.9) in each of 49 states in 1991-1992 for men and women ages 45-74. The analysis was based on multiple linear regression and Spearman's rank-order correlations between the CHD risk factor prevalences, the combined CHD risk index, and the CHD mortality rates among the 49 states.

RESULTS

The prevalences of most of the CHD risk factors correlated with CHD mortality rates in the expected directions, and correlations were similar for men and women. The CHD risk index correlated strongly with CHD mortality for both men (r = 0.75) and women (r = 0.80).

CONCLUSION

About 60% of the variance in CHD mortality between the states in the United States (56% for men and 64% for women) is attributable to differences between the states in the prevalences of seven established risk factors for CHD. As state health agencies prioritize resources for chronic disease prevention programs, they should consider the potential benefits of increased efforts to reduce the prevalences of modifiable CHD risk factors in their populations to reduce CHD mortality.

Factor V Cambridge: a new mutation (Arg306-->Thr) associated with resistance to activated protein C

A new factor V mutation associated with resistance to activated protein C and thrombosis (factor V Cambridge, Arg306-->Thr) was found in one patient from a carefully selected group of 17 patients with venous thrombosis and confirmed APC resistance in the absence of the common Gln506 mutation. The Arg306 mutation was also present in a first degree relative who also had APC resistance. Other potential causes of APC resistance, such as a mutation at the Arg679 site and the factor V HR2 haplotype, were excluded. Subsequent screening of 585 patients with venous thromboembolism and 226 blood donors did not show any other individual with this mutation. Factor VThr306 is the first description of a mutation affecting the Arg306 APC cleavage site and is the only mutation, other than factor V Leiden (Arg506-->Gln), that has been found in association with APC resistance. This finding confirms the physiologic importance of the Arg306 APC-cleavage site in the regulation of the prothrombinase complex. It also supports the concept that APC resistance and venous thrombosis can result from a variety of genetic mutations affecting critical sites in the factor V cofactor.