Discovery and Characterization of a Novel Series of Chloropyrimidines as Covalent Inhibitors of the Kinase MSK1.

We describe the identification and characterization of a series of covalent inhibitors of the C-terminal kinase domain (CTKD) of MSK1. The initial hit was identified via a high-throughput screening and represents a rare example of a covalent inhibitor which acts via an SAr reaction of a 2,5-dichloropyrimidine with a cysteine residue (Cys440). The covalent mechanism of action was supported by biochemical experiments and was confirmed by mass spectrometry.

Psoriatic epidermis is associated with upregulation of CDK2 and inhibition of CDK4 activity.

Background: The cyclin-dependent kinases (CDKs) CDK2 and CDK4 are involved in regulation of cell-cycle progression, and psoriasis is characterized by hyperproliferation of basal epidermal cells. CDK inhibitory proteins (CKIs) such as p16 (p16) bind CDK4/6 kinases and prevent their interaction with D-type cyclins. CKIs such as p21 (p21) and p27 (p27) associate with CDK-cyclin complexes and prevent their activation.

Fluorescent peptide biosensor for monitoring CDK4/cyclin D kinase activity in melanoma cell extracts, mouse xenografts and skin biopsies.

Melanoma constitutes the most aggressive form of skin cancer, which further metastasizes into a deadly form of cancer. The p16(INK4a)-Cyclin D-CDK4/6-pRb pathway is dysregulated in 90% of melanomas. CDK4/Cyclin D kinase hyperactivation, associated with mutation of CDK4, amplification of Cyclin D or loss of p16(INK4a) leads to increased risk of developing melanoma.

TP-2Rho Is a Sensitive Solvatochromic Red-Shifted Probe for Monitoring the Interactions between CDK4 and Cyclin D.

Understanding the intricate steps of protein kinase regulation requires characterization of protein-protein interactions between the catalytic subunit, its regulatory partners and the substrate. Fluorescent probes are useful tools with which to study such interactions and to gain insight into their affinities and specificities. Solvatochromic probes, which display changes in their fluorescence emission in response to changes in the polarity of the medium, are particularly attractive.

Targeting cyclin-dependent kinases in human cancers: from small molecules to Peptide inhibitors.

Cyclin-dependent kinases (CDK/Cyclins) form a family of heterodimeric kinases that play central roles in regulation of cell cycle progression, transcription and other major biological processes including neuronal differentiation and metabolism. Constitutive or deregulated hyperactivity of these kinases due to amplification, overexpression or mutation of cyclins or CDK, contributes to proliferation of cancer cells, and aberrant activity of these kinases has been reported in a wide variety of human cancers. These kinases therefore constitute biomarkers of proliferation and attractive pharmacological targets for development of anticancer therapeutics.

Fluorescent biosensors for drug discovery new tools for old targets--screening for inhibitors of cyclin-dependent kinases.

Cyclin-dependent kinases play central roles in regulation of cell cycle progression, transcriptional regulation and other major biological processes such as neuronal differentiation and metabolism. These kinases are hyperactivated in most human cancers and constitute attractive pharmacological targets. A large number of ATP-competitive inhibitors of CDKs have been identified from natural substances, in high throughput screening assays, or through structure-guided approaches.

Fluorescent biosensors for high throughput screening of protein kinase inhibitors.

High throughput screening assays aim to identify small molecules that interfere with protein function, activity, or conformation, which can serve as effective tools for chemical biology studies of targets involved in physiological processes or pathways of interest or disease models, as well as templates for development of therapeutics in medicinal chemistry. Fluorescent biosensors constitute attractive and powerful tools for drug discovery programs, from high throughput screening assays, to postscreen characterization of hits, optimization of lead compounds, and preclinical evaluation of candidate drugs. They provide a means of screening for inhibitors that selectively target enzymatic activity, conformation, and/or function in vitro.

Poland's syndrome in one identical twin.

Female twins were evaluated at the Shriners Hospital in Lexington, Kentucky. One twin was normal, and the other twin had the classic findings of Poland's syndrome, manifested by absence of the pectoralis major and symbrachydactyly of the right upper extremity. Buccal smears from each child were submitted for DNA testing.

Acrocephalosyndactyly syndromes: a review.

Over the last quarter century, a revision has taken place in the classification of the acrocephalosyndactyly syndromes. This reflects the advances in molecular biology that have led to improved genetic mapping of these syndromes. In this review we provide an overview of these major acrocephalosyndactyly syndromes, including the current classification system.

Endoscopic retrieval of severed flexor tendons: a study of technique using cadaveric hands.

Retrieval of retracted zone 1, 2, and 3 flexor tendons without a proximal incision can occasionally lead to excessive tendon trauma or injury to neurovascular structures. To determine if endoscopic flexor tendon retrieval is a reliable, reproducible technique, 34 zone 2 flexor tendon lacerations were created in four cadaveric hands (2 male; 2 female). The tendons were retracted proximally an average of 4.

Nonmetallic fixation in traumatic midfacial fractures.

The possibility of resorbable plate and screw fixation devices that provide adequate strength to allow facial fracture healing and are completely degraded thereafter has long had significant appeal. Favorable clinical experiences, however, have been very limited, and their use in the traumatized facial skeleton has yet to be proven a useful technology in the actual patient. In this regard, we review our experience in the management of orbital, zygomatic, and maxillary skeletal injuries with resorbable fixation.

A biomechanical analysis of the stability of titanium bone fixation systems in proximal phalangeal fractures.

Apex bending and torsional loading were utilized to study the effects of different plate design and thickness, and screw size and design on the rigidity and strength of seven different titanium mini- and microplates placed onto osteotomized proximal phalanges. One hundred forty-four fresh frozen human cadaveric proximal phalangeal bones underwent a mid shaft osteotomy followed by application of one of the following plates: (1) Synthes linear 1.5-mm five-hole plates, (2) Leibinger linear 1.

A comparative biomechanical analysis of resorbable rigid fixation versus titanium rigid fixation of metacarpal fractures.

Linear (two-dimensional) and three-dimensional (3D) plating systems (Poly-Medics) composed of the resorbable copolymer of polyglycolic acid (PGA) and poly-l-lactic acid (PLLA) (Lactosorb) were studied in vitro. The plates were applied to osteotomized fresh frozen human cadaveric metacarpal bones that were then tested for torsional rigidity and three-point bending strength and rigidity. The results were compared to those from another study of two low-profile titanium plating systems (Leibinger and Synthes).

Biomechanical testing of titanium self-tapping versus pretapped lag screw fixation of spiral metacarpal fractures.

Biomechanical tests of torsional loading and cantilevered bending were used to study the effects of varying screw size design of five different titanium miniscrews and microscrews in a metacarpal spiral oblique fracture model. Sixty-six fresh frozen human cadaveric metacarpal bones were subjected to torsional loading until failure, producing a spiral oblique fracture. The randomized fractured metacarpal bones were then repaired utilizing two 1.

Resorbable bone fixation: its potential role in cranio-maxillofacial trauma.

The concept of biodegradable bone fixation devices, which provide sufficient rigidity to allow fracture healing and resorption thereafter, has significant appeal in cranio-maxillofacial trauma treatment; however, biodegradable bone fixation devices have not yet become available for clinical use in the craniofacial skeleton. This article reviews the obstacles in developing a resorbable polymer bone fixation system and describes the initial use of such a system in the treatment of cranio-maxillofacial trauma patients. It also discusses the potential role of a resorbable polymer bone fixation system in conjunction with the use of metal fixation in the management of facial fracture.

Histoplasma capsulatum necrotizing myofascitis of the upper extremity.

Necrotizing myofascial fungal infections of the upper extremity is a rare event even in immunocompromised hosts. We report the course of a renal transplant patient who developed extensive necrotizing myofascial infection of an upper extremity secondary to Histoplasma capsulatum. Initial, functional, upper limb salvage was achieved after aggressive surgical debridement and high doses of amphotericin B.

Fibro-osseous pseudotumor of the distal phalanx.

Recurrent soft-tissue digital masses with osseous components frequently result in diagnostic and treatment dilemmas. We discuss a case of a recurrent fibro-osseous pseudotumor of the digit, review specific diagnostic and histological features, and recommend treatment.

Small intestinal submucosa: utilization as a wound dressing in full-thickness rodent wounds.

Wound dressings are used as a temporary wound covering to promote wound healing, control wound exudate, and decrease wound contamination as well as evaporative water loss. A new material, porcine small intestinal submucosa, has been used successfully as an arterial and venous graft in both canine and primate animal models with graft patency and infection rates equal to autologous vein. Based on these studies, small intestinal submucosa was used as a biological wound dressing in 20 x 20 mm full-thickness wounds made on Sprague-Dawley rats.

Small intestinal submucosa: utilization for repair of rodent abdominal wall defects.

Prosthetic graft material is often used for the repair of abdominal wall defects that result from trauma, infection, neoplastic, or congenital deformities. A new material, porcine small intestinal submucosa, has been successfully used as an arterial and venous graft material in both canine and primate animal models with graft patency and infection rates equal to autologous vein. On the basis of these studies, small intestinal submucosa was used as a graft material for the repair of a 2 x 2-cm full-thickness defect of the muscle and fascia in the rodent abdominal wall (N = 11).

Experimental assessment of small intestinal submucosa as a bladder wall substitute.

Objectives: This study determined the feasibility of promoting urinary bladder regeneration with porcine-derived small intestinal submucosa (SIS).

Methods: Twenty-two Sprague-Dawley rats underwent partial cystectomy with immediate bladder augmentation with SIS. Bladders were harvested for histologic evaluation at 2, 4, 8, 12, 24, and 48 weeks.

Comparative biomechanical stability of titanium bone fixation systems in metacarpal fractures.

The biomechanical properties of apex bending and torsional rigidity of 11 different titanium mini- and microplates (Leibinger and Synthes) were examined to evaluate the effects of plate design and thickness and screw size and design. Two hundred sixteen fresh-frozen human cadaveric metacarpal bones underwent a midshaft transverse osteotomy followed by application of one of the following plates: Synthes 1.5-mm and 2.

Sympathetic blockade of isolated rat hindlimbs by intra-arterial guanethidine: the effect on blood flow and arterial-venous shunting.

In order to improve the understanding of the role of sympathetic nerve degeneration in reimplantation failure, the hindlimbs of eight rats (Group I) underwent near-complete amputation. The soft tissues of the hindlimb were transected at the proximal thigh with the femoral artery, vein and femur left intact. The femoral vessels were clamped and guanethidine was infused into a branch of the femoral artery of the right leg of each animal, while saline was injected into the left leg.

Mini and micro plating of phalangeal and metacarpal fractures: a biomechanical study.

Biomechanical testing was performed in a cadaver model to evaluate the effects of plate size and position on fracture stability using Leibinger mini and microplates applied on the proximal phalanx and metacarpal. Fresh frozen cadaveric metacarpal and proximal phalanges were subjected to a midshaft transverse osteotomy followed by application of titanium mini (1.7 mm screw diameter) and micro (1.

Mechanical anastomosis of nerves: a histological and functional comparison to conventional suturing.

The use of a mechanical coupling device in microsurgery offers speed of application in addition to a secure vascular union. Despite its success in a vascular setting, mechanical coupling device nerve repair remains to be studied. Forty-five male rats were tested over 7- and 14-week study periods.

Experimental evaluation of small intestinal submucosa as a microvascular graft material.

The evaluation of porcine small intestine submucosa (SIS) in a microsurgical model was conducted using an interpositional graft in the rat femoral artery. The SIS grafts were fabricated from processed porcine material that was wrapped around a glass tube and oversewn longitudinally to produce a tubular structure. Of the 42 animals studied, 7 received grafts of untreated SIS (group I), 7 of the grafts were presoaked (PSH) in heparin (Group II), 7 animals were treated with systemic heparin prior to implantation of PSH-SIS (group III), 7 animals received SIS grafts crosslinked to heparin (group IV), 7 animals received SIS grafts crosslinked to urokinase (group V), and 7 animals received untreated autologous epigastric vein grafts (group VI).