Use of a cell-based, lawn format assay to rapidly screen a 442,368 bead-based peptide library

A cell-based, lawn format assay utilizing an in situ photocleavage method has been developed that allows the rapid examination of large bead-based compound libraries as discrete molecules. The format uses frog melanophore cells in a contiguous, adherent, confluent layer in small petri dishes covered with a 0.5-1-mm layer of agarose containing 130 micron diameter TentaGel beads at a density of 2-20 beads/mm2. Employing this technique a 9-mer, 442,368-member peptide library (designed around the 13 amino acid alpha-MSH peptide sequence) made up of 12 separate pools of 36,864 peptides/pool was assayed. Initially, a fraction (approximately 10%) of each pool was scanned (approximately 3700 beads from each pool) in 60-mm petri dishes to identify the most active pools. Upon direct photocleavage of the beads with UV light (365 nm), each petri dish was photographed over a 60-min period with a CCD camera to record changes in light intensity as an index of melanosome dispersion. Active beads were those that were surrounded by a localized decrease in light transmittance indicating melanosome dispersed cells. Upon examination with a dissecting microscope, single beads centrally located to a circular array of dispersed cells were identified and removed from the agarose and sequenced by Edman degradation to determine the peptide sequence. Re-synthesized peptides were re-examined against alpha-MSH receptor to confirm and quantify the activity. Several 9-mer peptides were identified with potencies similar to the natural 13-mer peptide. This method allows for the rapid screening of large bead-based photo-cleavable peptide libraries with the advantage that each compound is screened as a discrete molecule in a well-less format.     

Double sodium and potassium sulphates revealed by microprobe analysis in dried cervical mucus: a mid-cycle crystallographic index

The use of physical techniques such as scanning electron microscopyand microprobe analysis permits the analysis of valuable detailsof the structure of dried samples of mid-cycle cervical mucusduring the period of maximum ferning. From a crystallographicpoint of view, particular attention was paid to the location,morphology and chemical composition of anisotropic organic sulphatemicrostructures. As distinct from the isotropic sodium chloridepattern described by Papanicolaou, these appear in a narrowperiod of time corresponding to the middle of the period ofmaximum ferning. Anisotropic microstructures were revealed tobe tiny isolated crystals or polycrystalline aggregates composedof double salts of potassium and sodium. The potassium/sodiumcation ratio, equal to 3/1, was constant in the best specimens.Using a simple polarizing microscope, the detection of anisotropicmicrostructures may be useful to determine the period of maximumfertility more accurately. In addition, experiments have beencarried out in order to determine the relative importance ofsulphate anisotropic structures as compared with the whole crystallizedsurface and to investigate precisely their transience afterthey appear.     

The flaws of laser Doppler in negative‐pressure wound therapy research

Recent studies, using modalities other than laser Doppler, have indicated that perfusion during negative‐pressure wound therapy (NPWT) is reduced, contrary to world literature. The aim of the present study was to evaluate whether the measuring technique of the laser Doppler could be influenced by the compressive nature of NPWT dressings and whether this could explain the conflicting findings. A hypothesis that it may be possible for laser Doppler to record similar readings to those obtained during NPWT by merely compressing tissues manually was tested on 12 NPWT dressings, with each undergoing an alternating series of manual compressive forces and NPWT (?125 mmHg). During the periods of NPWT (n = 12), the mean perfusion recording increased in five experiments, reduced in six, and remained unchanged in one. During the period when manual pressure was applied (n = 12), there was a mean increase in perfusion in six experiments and a reduction in six. The type of change in perfusion (increase or decrease) was the same for both NPWT and manual pressure in 10 of the 12 experiments. In conclusion, laser Doppler can incorrectly record increased perfusion when tissues are compressed, implying that it is flawed in the field of NPWT research as tissues are always compressed to some degree by the NPWT dressing.     

Acute appendicitis: sonographic criteria based on 250 cases

Two hundred and fifty consecutive patients with suspected appendicitis were examined with graded compression sonography. The initial diagnostic criterion for appendicitis was visualization of a noncompressible appendix; this was later modified to include the dimensions of the visualized appendix. The appendix was visualized in 91 of 250 patients (36%). Five adult patients with sonographically visible appendixes that were 6 mm or less in maximal diameter had either benign clinical follow-up (three patients) or a histologically normal appendix removed at surgery (two patients). However, two patients with appendixes measuring 6 mm in diameter and multiple appendicoliths had surgically confirmed acute appendicitis. Of 84 patients with visible appendixes measuring greater than 6 mm in maximal diameter, 78 had surgically confirmed acute appendicitis. In the remaining six, symptoms resolved spontaneously, and no surgery was required. In the absence of compelling clinical findings or an appendicolith, adult patients with maximal appendiceal diameters of 6 mm or less should undergo a period of close observation rather than immediate surgery. A diagnosis of appendicitis can be made in adult patients with persistent right lower quadrant pain and a visualized appendix greater than 6 mm in diameter.     

Acute coronary syndrome associated with coronary aneurysm: a case report

An elderly female patient presented to our Emergency Department with an acute coronary syndrome. After stabilization, cardiac catheterization disclosed a solitary aneurysm of her diagonal coronary artery. Such aneurysms are rare and are an unusual etiology for acute coronary syndrome.