Detection of glaucomatous damage using multifocal ERG

The first‐order kernel analysis in multifocal electroretinogram (mfERG) using low contrast stimulation is suggested as a way to detect the inner retinal responses in animal studies. In this case report, this protocol is applied to human patients with glaucoma to demonstrate the possibility of using mfERG as a tool to detect glaucomatous damage. Two patients with glaucoma were recruited and had mfERG measurements with the 103‐scaled hexagonal stimulus pattern at low (50 per cent) contrast. Their responses were analysed and compared with those from normal subjects with the mfERG measured under the same condition. In the normal subjects, there were obvious oscillatory components on the ascending and descending limbs of the first‐order kernel response to 50 per cent contrast. In the glaucomatous patients, the oscillatory component on the descending limb was obviously diminished. In addition, this component was significantly diminished in the quadrant with a glaucomatous visual field defect. This suggests that the low‐contrast stimulation condition in mERG measurement may provide a good way to detect glaucomatous damage and this may help in clinical diagnosis of glaucoma.     

Prospective randomized comparison of mezlocillin therapy alone with combined ampicillin and gentamicin therapy for patients with cholangitis

Forty-six patients with cholangitis were randomized to receive therapy with mezlocillin sodium (24 patients) or a combination of ampicillin sodium--gentamicin sulfate (22 patients). The biliary concentration of mezlocillin was 112 times higher than that of ampicillin and 778 times higher than that of gentamicin. The ratio of the concentration in serum or bile over the minimum inhibitory concentration against aerobic gram-negative bacilli (therapeutic index) was higher for mezlocillin than for either ampicillin or gentamicin. Twenty (83%) of 24 patients were cured following mezlocillin therapy compared with 9 (41%) of 22 patients after ampicillin-gentamicin therapy. The 3 patients with superinfection were in the ampicillin-gentamicin arm of the study. Fewer toxic or adverse effects occurred in association with mezlocillin treatment than with ampicillin-gentamicin treatment. Mezlocillin therapy was more effective, less toxic, and less expensive than treatment with ampicillin and gentamicin for patients with cholangitis.     

Policy Perspective on Housing and HIV/AIDS

For persons battling HIV/AIDS a stable place to live may decide the length and quality of life itself. It is nearly impossible for a person on the streets to engage in a needed continuous AIDS treatment regimen when the very basic question of where that person will rest his or her head when darkness comes in just a few hours is unresolved. When danger lurks on the streets, when cold numbs the limbs, when tiredness overwhelms the mind, when fear breaks the spirit, a place to call home would make all the difference.     

Co-operative mineralization and protein self-assembly in amelogenesis: silica mineralization and assembly of recombinant amelogenins in vitro

An amorphous silica mineralization technique was used to produce inorganic/protein composites to elucidate the structure and mechanism of formation of amelogenin assemblies, which may play an important role in regulating enamel structure during the initial stages of amelogenesis. Full-length recombinant amelogenins from mouse (rM179) and pig (rP172) were investigated along with key degradation products (rM166 and native P148) lacking the hydrophilic C terminus found in parent molecules. The resulting products were examined using transmission electron microscopy and/or small-angle X-ray scattering. Using protein concentrations of 0.1–3 mg ml⁻¹, large monodisperse spheres of remarkably similar mean diameters were observed using rM179 (124 ± 4 nm) and rP172 (126 ± 7 nm). These spheres also exhibited 'internal structure', comprising nearly spherical monodisperse particles of ≈ 20 nm in diameter. In the presence of rM166, P148, and bovine serum albumin (control), large unstructured and randomly shaped particles (250–1000 nm) were observed. Without added protein, large dense spherical particles of silica (mean ≈ 500 nm) lacking internal structure were produced. These findings demonstrate that full-length amelogenins have the ability to form higher-order structures, whereas amelogenins that lack the hydrophilic C terminus do not. The results also suggest that full-length amelogenin can guide the formation of organized mineralized structures through co-operative interactions between assembling protein and forming mineral.     

Reactive arthritis and internal derangement of the temporomandibular joint.

OBJECTIVE: The objective of this study was to determine if temporomandibular joint (TMJ) samples positive for Chlamydia trachomatis have a greater presence of tumor necrosis factor-alpha (TNFalpha) or interleukin-6 (IL-6) when compared with Chlamydia-negative samples. STUDY DESIGN: Posterior bilaminar tissue samples removed during TMJ surgery from 70 patients were evaluated. Cryosections were stained using monoclonal antibody that identifies C. trachomatis. The presence of IL-6 and TNFalpha were evaluated by immunostaining in 15 samples positive and in 25 samples negative for the presence of C. trachomatis. RESULTS: Of the 70 TMJ samples, 32 (46%) were positive for C. trachomatis. In 15 samples positive for C. trachomatis, 10 (67%) were positive for TNFalpha and 7 (47%) for IL-6. In 25 samples negative for C. trachomatis, only 4 (16%) were positive for TNFalpha and only 2 (8%) for IL-6. Differences in C. trachomatis-positive samples versus negative were significant for both TNFalpha (P < .002) and IL-6 (P < .008). CONCLUSION: The presence of C. trachomatis in the TMJ is associated with a significantly increased presence of TNFalpha and IL-6.     

Capillary gas chromatographic assay of camphor and m-cresol in dermatological creams

Camphor and m-cresol mixtures are used in antiseptic and anti-itching creams. No compendial method exists for these preparations. This paper reports a capillary gas chromatographic method using FID detection with 2,6-di-tert-butyl-4-methylphenol as internal standard on a 30 m×0.32 mm Supelcowax®-10 column (0.25 μm film) with helium as carrier gas. Ramped temperature programming was applied. The method allows simultaneous quantitation of camphor and m-cresol in the presence of o- and p-cresols, calamine and zinc oxide. Overall percent recoveries (±SD, n=9) of camphor, o-, p- and m-cresol from spiked placebo creams, at a labeled amount of 10 (w/w)% were 96.9±0.6, 98.2±0.6, 99.2±0.5 and 101.0±0.9%, respectively, and at a labeled amount of 1% were 96.7±0.6, 97.8±0.9, 97.8±0.6, and 100.3±1.0%, respectively. The recovery studies were carried out at ±30% of the labeled amounts. Linear peak area or height ratios were obtained (r>0.999) for camphor, o-, p- and m-cresol covering a concentration range of 10–200% of the labeled amount. Linearity (r>0.999) was also obtained for m-cresol when the relative concentration of o- and p-cresol was varied from 5 to 100% of the m-cresol concentration. The resolution between the ‘critical pair’ of p- and m-cresol was ≥1.1. The limit of quantitation was 23 pg for m-cresol and 9.3 pg for camphor using an injection split of 1:50. The repeatability (%RSD) for all compounds were <2% for peak area and <1.4% for peak height ratios. System suitability and robustness of the method were established. The method was successively applied to the assay of available commercial products and allows assay of camphor and the three cresol isomers.