Evaluation of pharmacodynamic biomarkers in a Phase 1a trial of dulanermin (rhApo2L/TRAIL) in patients with advanced tumours.

BACKGROUND: Dulanermin (rhApo2L/TRAIL) induces apoptosis by binding to death receptors DR4 and DR5, leading to caspase activation and subsequent cell death. A Phase1a trial evaluated the safety and tolerability of dulanermin in patients with advanced tumours. One aim was to develop and validate pharmacodynamic biomarkers to monitor dulanermin activity in patient serum. METHODS: We optimised assays to measure the cell-death markers caspase 3/7, cytokeratin 18 and genomic DNA in serum. Mice bearing Colo205 xenografts were treated with dulanermin and sera were collected and assayed for apoptotic markers. Upon validating these assays, we monitored apoptotic markers in patients who received dulanermin. RESULTS: We detected transient increases in apoptotic markers in mouse sera 8-24 h after dulanermin treatment. This increase was dose-dependent and correlated with active caspase 3 detected by IHC in Colo205 tumours. A statistically significant increase in serum caspase 3/7 was detected in cohorts of colorectal and sarcoma patients 24 h after receiving dulanermin dosed above 4 mg kg(-1). CONCLUSION: Owing to limited responses in the Phase 1a study, the changes in circulating cell-death markers were not evaluable. Future studies with dulanermin are needed to determine the utility of these assays with respect to providing evidence of activity or predicting overall response.

The use and validation of a laser scanner for computer aided design and manufacturing of wheelchair seating.

Professionals in wheelchair seating services over several decades have captured many thousands of patient shapes in various forms to manufacture customized seating systems for people with complex disabilities. With the exception of a few commercial companies, the predominant methodology employs a plaster casting technique to record the required shape. This can be labour-intensive and shape information is often retained in the cast and may not be recoverable over time due to storage issues. This paper describes the development of processes utilizing a laser scanner to advance the fabrication of customized seating systems. The study employed two 3D laser scanners and hence validated the use of the lower cost scanner (accuracy ± 0.1 mm) for both research purposes and clinical work. The paper concludes that these technologies have the potential to develop the knowledge of individuals' shapes with complex disabilities within specialist seating and other clinical fields.

Protein modification: docking sites for kinases.

The substrate specificities of protein kinases have been found, in many cases, to be determined at least in part by short regions within the substrate known as docking sites. Docking sites are specific and modular, and can dramatically increase the efficiency of phosphorylation.

Multiple signaling pathways for the activation of JNK in mast cells: involvement of Bruton's tyrosine kinase, protein kinase C, and JNK kinases, SEK1 and MKK7.

Stimulation of the high affinity IgE receptor (FC epsilonRI) as well as a variety of stresses induce activation of c-Jun N-terminal protein kinases (JNKs) stress-activated protein kinases in mast cells. At least three distinct signaling pathways leading to JNK activation have been delineated based on the involvements of Bruton's tyrosine kinase (Btk), protein kinase C (PKC), and the JNK-activating cascades composed of multiple protein kinases. The PKC-dependent pathway, which is inhibited by a PKC inhibitor Ro31-8425 and can be activated by PMA, functions as a major route in FC epsilon RI-stimulated mast cells derived from btk gene knockout mice. On the other hand, wild-type mouse-derived mast cells use both PKC-dependent and PKC-independent pathways for JNK activation. A PKC-independent pathway is regulated by Btk and SEK1 via the PAK-->MEKK1-->SEK1-->JNK cascade, and is sensitive to phosphatidylinositol 3-kinase inhibitors, wortmannin and LY-294002, while the PKC-dependent pathway is affected to a lesser extent by both wortmannin treatment and overexpression of wild-type and dominant negative mutant SEK1 proteins. Another PKC-independent pathway involves Btk and MKK7, a recently cloned direct activator of JNK. Among the stresses tested, UV irradiation seems to activate Btk and JNK via the PKC-independent pathways.

MKK7 is a stress-activated mitogen-activated protein kinase kinase functionally related to hemipterous.

Exposure of mammalian cells to stressful stimuli results in activation of the c-Jun NH2-terminal kinase (JNK)/stress-activated protein kinases (SAPKs), a family of protein kinases related to mitogen-activated protein (MAP) kinase. JNK/SAPKs are activated by specific MAP kinase kinases (MKKs), one of which, MKK4/SEK1, has been characterized extensively. In Drosophila, the JNK/SAPK Basket (Bsk) and the MKK Hemipterous (Hep), are important for embryonic development. Loss of function of either gene inhibits dorsal closure, a morphogenetic movement in which the edges of the embryonic ectoderm move together over the amnioserosa. There is evidence that the Rho GTPases Rac and Cdc42 are also required for dorsal closure, suggesting that Rac or Cdc42 may regulate Hep and Bsk. We have identified MKK7, a murine homolog of Hep. MKK7 functionally rescues hep mutant flies. In fibroblasts, MKK7 is activated by stress and by the GTPase Rac1. MKK7 directly phosphorylates and activates JNK/SAPK. Thus, MKK7 is a homolog of hep and functions in a conserved signaling pathway involving JNK/SAPK and the GTPase Rac1.

Detection of specific polymerase chain reaction product by utilizing the 5'----3' exonuclease activity of Thermus aquaticus DNA polymerase.

The 5'----3' exonuclease activity of the thermostable enzyme Thermus aquaticus DNA polymerase may be employed in a polymerase chain reaction product detection system to generate a specific detectable signal concomitantly with amplification. An oligonucleotide probe, nonextendable at the 3' end, labeled at the 5' end, and designed to hybridize within the target sequence, is introduced into the polymerase chain reaction assay. Annealing of probe to one of the polymerase chain reaction product strands during the course of amplification generates a substrate suitable for exonuclease activity. During amplification, the 5'----3' exonuclease activity of T. aquaticus DNA polymerase degrades the probe into smaller fragments that can be differentiated from undegraded probe. The assay is sensitive and specific and is a significant improvement over more cumbersome detection methods.

'Very late onset' cystoid macular edema.

Cystoid macular edema typically manifests 4 to 16 weeks after ocular surgery. It has only rarely been documented with an onset more than 2 years postoperatively. We report four patients who developed clinically significant cystoid macular edema between 7 and 16 years after initially successful surgery. Two patients had undergone intracapsular cataract extraction, one extracapsular cataract extraction, and one a scleral buckling procedure. Although such cases of "very late onset" cystoid macular edema are uncommon, it should be considered in patients who suffer visual loss many years after ocular surgery.

Postoperative subretinal neovascular membrane at the drain site of a scleral buckle.

A 57-year-old patient underwent a scleral buckle operation for a rhegmatogenous bullous retinal detachment. An episcleral buckle and cryotherapy were used. Drainage of subretinal fluid was performed beneath the buckle as well as posterior to the buckle, close to the posterior pole. The postoperative course was unremarkable. Eight months later, the patient developed a subretinal neovascular membrane at the drain site posterior to the buckle. This was documented by fluorescein angiography. Such membranes have not been previously documented at retinal drain sites in an ophthalmic journal.

Evolution of a retinal arterial macroaneurysm.

A 58-year-old hypertensive male developed a superior temporal branch vein occlusion in the left eye in 1979. Fluorescein angiography documented the venous occlusion, as well as normal arterial flow. Subsequent laser photocoagulation was performed for cystoid macular edema. In 1981 the patient developed a pre- and sub-retinal hemorrhage in the left eye due to a retinal arterial macroaneurysm in the superior temporal quadrant. Fluorescein angiography documented normal retinal arterial blood flow in the affected vessel at the time of development of the macroaneurysm, but the vessel subsequently occluded. This case adds to the scant literature documenting the evolution of a retinal arterial macroaneurysm.

Broad scleral buckle in the management of retinal detachments with giant tears.

One of us (T.R.S.) operated on 24 patients with 26 retinal detachments caused by giant tears between 1969 and 1975 with the use of a broad silicone implant and diathermy. Minimum follow-up was six months. The technique included a scleral dissection extending at least three circumferential rows of diathermy posterior to the folded edge of the retinal flap, up onto the ora serrata, and two hours of the clock beyond each end of the tear. The retina was intentionally incarcerated on the buckle when subretinal fluid was drained. Sixty-nine percent of the cases were successfully reattached. If those patients with radial tears extending from the circumferential tears to the disk were excluded, the success rate rose to 75%. Seventeen percent of the successful reattachments required a second scleral buckle operation. Giant tears with radial tears extending to the disk, tears greater than 180 degrees, and immobile posteriorly everted flaps were poor prognostic signs. Thirty-five percent of the eyes with giant tears and a detachment had other holes or tears in the retina of that eye.

A Method for the Numerical Evaluation of the Second Virial Coefficient for Polyatomic Molecules.

A numerical integration procedure to calculate the second virial coefficient of simple polyatomic molecules is proposed. The intermolecular pair potential is assumed to be a sum of a spherically symmetric contribution and an unsymmetric, angular dependent, contribution. The method is based on evaluating the possible different numerical values for this latter term. Quadrupolar and dipolar molecules are considered. Calculations for the virial coefficient for quadrupolar molecules are judged to be correct to within one part in 2500 or better, and to within one part in 300 or better for polar molecules. Results from the method are compared to corresponding results from the well-known Pople expansion procedure. It is shown that care must be taken to ensure this latter technique yields a convergent answer.

Levodopa-stimulated growth hormone secretion and diabetic retinopathy.

Since growth hormone has been implicated as a possible etiologic factor in the development of diabetic retinopathy, we examined growth hormone levels in two groups of growth-onset diabetics matched for age and duration of disease. The experimental group had definite proliferative diabetic retinopathy; the control group of growth-onset diabetics had no significant retinopathy. Basal and levodopa-stimulated levels of growth hormone were determined for each group. Growth hormone response could not be correlated with the presence or absence of diabetic retinopathy (P less than .05).

Myelinated nerve fibers and severe myopia.

Two 4-year-old boys, one white and one black, had unilateral extensive myelinization of retinal nerve fibers associated with severe myopia, esotropia, and amblyopia. The finding of unilateral extensive myelinization of the nerve head and retinal fibers in a child may indicate a potentially remediable anisometropic amblyopia.

Automated multiphasic health testing. Diagnostic and testing results obtained at the Health Evaluation Center. Public Health Service Hospital, Baltimore.

The results of automated multiphasic health testing (AMHT) were evaluated with special attention to diagnoses made by physicians and to false positive results, as well as to laboratory test results. The study population consisted of 1,157 patients at the Health Evaluation Center of the Public Health Service Hospital in Baltimore. Although 95 percent of the patients had at least one newly diagnosed disease or condition., the percentage dropped to 78 percent when dental abnormalities were excluded and to 70 percent when dental, vision, and hearing abnormalities were excluded. Abnormal laboratory test results were observed for 98 percent of the patients, and 36 percent had at least one false positive test result. The study results indicated that AMHT is a highly productive method for comprehensive medical testing with a variety of uses other than mass screening. The productive diagnostic yield combined witha high percentage of false positive results dictate the need for careful planning for followup care, strict attention to quality control, and excellent communication between the AMHT center and the practicing physician.