The mast cell and mast cell disease

Mast cell disease or mastocytosis is a heterogeneous group of clinical disorders characterized by the proliferation and accumulation of mast cells in a variety of tissues, most often the skin. The signs and symptoms of mast cell disease are varied, dependent on the localization of mast cells in different organs and the local and systemic effects of mediators released from these cells. Although mast cell disease is most commonly identified in the skin, involvement of the skeletal, hematopoietic, gastrointestinal, cardiopulmonary, and central nervous systems may be seen. Clinical management of mastocytosis depends most heavily on knowledge of the diverse effects of mast cell mediators on various tissues and organs, the stimuli that can cause their release, and the different methods available for blocking the effects of these mediators.

An encyclopedia of mouse genes

The laboratory mouse is the premier model system for studies of mammalian development due to the powerful classical genetic analysis possible (see also the Jackson Laboratory web site, http://www.jax.org/) and the ever-expanding collection of molecular tools. To enhance the utility of the mouse system, we initiated a program to generate a large database of expressed sequence tags (ESTs) that can provide rapid access to genes. Of particular significance was the possibility that cDNA libraries could be prepared from very early stages of development, a situation unrealized in human EST projects. We report here the development of a comprehensive database of ESTs for the mouse. The project, initiated in March 1996, has focused on 5' end sequences from directionally cloned, oligo-dT primed cDNA libraries. As of 23 October 1998, 352,040 sequences had been generated, annotated and deposited in dbEST, where they comprised 93% of the total ESTs available for mouse. EST data are versatile and have been applied to gene identification, comparative sequence analysis, comparative gene mapping and candidate disease gene identification, genome sequence annotation, microarray development and the development of gene-based map resources.

Cisplatin ototoxicity in guinea pigs with special reference to toxic effects in the stria vascularis

The toxic effects of cisplatin (cis-diamminedichloroplatinum [II]) on the organ of Corti are well established. Few and conflicting data on this drug's effects on the stria vascularis exist. The present study presents animal experiments on the toxic effects of cisplatin in the stria vascularis and in the organ of Corti. Cisplatin-induced toxicity in albino and pigmented guinea pigs was evaluated morphologically and functionally, using light and transmission electron microscopy as well as auditory brainstem-evoked potentials on the organ of Corti and the stria vascularis. The results showed variability in hearing thresholds, ranging from no change to hearing loss of 30 dB, and prominent damage in the organ of Corti and in the stria vascularis. The toxic effects to both the organ of Corti and the stria vascularis should be considered when cisplatin is used in chemotherapy.

Study on the antimicrobial effect of silver-containing inner liners in refrigerators

AIMS

To investigate the effect of silver-based antimicrobial material incorporated in the inner liners of refrigerators on food safety and quality.

METHODS AND RESULTS

In the first stage, the bactericidal effect was tested in the laboratory. Silver-containing samples and control plates were inoculated with different bacterial suspensions and stored at various temperatures. After defined storage periods the bacterial reduction was calculated by comparing viable cell count on reference plates and on silver-containing plates. The reduction caused by the silver-containing material varied between 1.0 and 5.9 log(10) units, depending on bacterial strain, incubation time and temperature. In the second stage, food storage experiments have been carried out. Thus, perishable foods were stored in coated and untreated refrigerators. After certain time periods the products were analysed for their sensorial and microbiological characteristics. A clear drop in viable counts both on the refrigerator wall and on the food was demonstrated using the silver-based antimicrobial material.

CONCLUSIONS

Silver prevents refrigerators from being a hot spot for contaminants that could be transferred upon contact with food.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study provides original results regarding the antimicrobial activity of silver-containing refrigerator surfaces.

Randomized, controlled trial comparing once daily and three times daily gentamicin in children with urinary tract infections

OBJECTIVE

To undertake population pharmacokinetic modeling and to determine the safety and efficacy of once daily (OD) gentamicin dosing in children with severe urinary tract infections (UTI).

METHODS

An open, randomized, controlled trial comparing OD with three times daily (TD) gentamicin dosing in hospitalized children ages 1 month to 12 years with UTI. Daily doses (milligrams per kg per day) of gentamicin in both groups were 7.5 (<5 years old), 6.0 (5 to 10 years old) and 4.5 (>10 years old).

RESULTS

There were 179 children enrolled (90 OD, 89 TD). Baseline clinical characteristics and pathogens were similar, except that circulatory compromise and renal cortical scintigraphic defects were more common in the OD group. Median gentamicin treatment durations were 3.0 (OD) and 2.7 (TD) days. Mean peak gentamicin concentrations were 17.3 (OD) vs. 6.4 (TD) mg/l; 99% of peak concentrations were >7 mg/l in the OD group whereas 16% of peak concentrations were <5 mg/l in the TD group. Mean trough concentrations were 0.35 (OD) vs. 0.55 (TD) mg/l. In the OD group 4% of trough concentrations were > or = 2 mg/l, whereas in the TD group only 0.7% were > or = 2 mg/l. Age or prior elevated peak concentrations did not predict high trough concentrations. Population pharmacokinetic modeling of the data fitted a one-compartment model with first order elimination. There were no clinical or bacteriologic failures. The two disease-related complications were confined to the OD group. No nephro- or ototoxicity was identified.

CONCLUSIONS

With age-appropriate dosing and measurement of serum trough concentrations before the second dose, OD gentamicin is safe and effective for the treatment of UTI requiring parenteral treatment in children aged 1 month to 12 years.

Endothelial injury of capillaries in the stria vascularis of guinea pigs treated with cisplatin and gentamicin

The drugs cisplatin and gentamicin are used for treatment of various cancer patients suffering from infection. The authors report a detailed electron microscopic study of blood vessels in stria vascularis of guinea pigs after treatment with cisplatin alone and in combination with gentamicin. The most distinctive features expressing endothelial cellular injury were mitochondrial, including occasional paracrystalline inclusions; electron-lucent foci with depleted organelles; intracytoplasmic vacuole formations; lipid bodies; cytoplasmic extrusions located on the luminal surface; and severe luminal constriction of part of the vessels from animals treated with the combined drugs. The study suggests that the damage to strial capillaries due to treatment with cisplatin alone and in combination with gentamicin may contribute to the injurious effects of these drugs on the strial tissue. Furthermore, the results of this study may enlarge the awareness of the potential vascular damage and vascular complications in additional body systems after medical use of cisplatin alone or in combination with gentamicin.

Toxic effects of cisplatin alone and in combination with gentamicin in stria vascularis of guinea pigs

The toxic effects on the stria vascularis of treatment with cisplatin alone and combined with the aminoglycoside antibiotic, gentamicin, were studied in guinea pigs. The toxicity induced in albino and pigmented guinea pigs was investigated morphologically with light and transmission electron microscopy, and functionally by brainstem-evoked response audiometry. The results of hearing thresholds were variable, ranging from no change in one ear in some of the animals to a hearing loss of 20 dB in one or both ears when treated with low-dose cisplatin alone or in combination with gentamicin. Bilateral deafness resulted from high-dose cisplatin combined with gentamicin. The combined treatment produced prominent structural damage in the stria vascularis. The results should be considered when aminoglycoside therapy is required in conjunction with cisplatin.

Effect of centrifuge speed, refrigeration medium, and sperm washing medium on cryopreserved sperm quality after thawing

Cryopreservation and subsequent thawing of semen for assisted reproductive procedures decreases sperm motility; motility further reduces when the cryoprotectant medium is removed because of the osmotic shock and centrifugation done to prepare the sperm. To compare motility and thus pregnancy rates, this study examined the effects of adding an additional refrigeration medium and three different centrifugation speeds for sperm preparation. Semen samples from 16 healthy normal volunteers were obtained by masturbation after 48 h of abstinence. Sperm motility and other motion characteristics were analyzed with a computer-assisted semen analyzer before freezing, after thawing, and after centrifugation. Each sample was divided into 6 aliquots and frozen using the liquid nitrogen vapor method. After thawing, human tubal fluid (HTF) with 5% human serum albumin was added to 3 aliquots, and refrigeration medium (identical to freezing medium without glycerol) was added to the remaining 3 tubes for each specimen. The tubes containing the two media were then washed by centrifugation at 100 g, 300 g, and 500 g for 10 min. Aliquots with refrigeration medium did not significantly differ from those with HTF for percent motility, curvilinear velocity, straight-line velocity, and amplitude of lateral head displacement at any centrifugation speed. Motile sperm count was significantly greater only at 100 g and 300 g for refrigeration medium (p = .02 and .01) and HTF (p = 0.001); at 300 g, average path velocity in refrigeration medium aliquots (p = .01) and linearity in HTF (p = .01) were greater. The results indicated that the reduction in motility and other motion characteristics probably cannot be overcome by changing factors such as the sperm preparation medium or centrifugation speed. More effective cryopreservation techniques or preparation methods that eliminate centrifugation need to be developed.

Effect of zinc supplementation on epidermal Langerhans' cells of elderly patients with decubital ulcers

In the present study, Langerhans' cells (LCs) in the sacral epidermis, 8-10 cm from lesions of patients (mean age 71 years) with decubital ulcers, were compared ultrastructurally and morphometrically with those in the patients' own normal epidermis from the upper leg, before and after supplementation with 50 mg/day elementary zinc (in the form of a 220-mg tablet of Avazinc, administered once daily) for four months. Zinc intake resulted in from 80% to full healing of the decubital ulcers in the patients studied. The percentages of LCs were low in both perilesional sacral epidermis (2.07 +/- 0.71%) and in control leg epidermis (2.71 +/- 1.38%) before zinc supplementation and also afterward (2.12 +/- 0.16% and 2.59 +/- 0.88%, respectively). LCs demonstrated a more dendritic morphology after zinc supplementation: 68.15 +/- 9.28% and 77.0 +/- 3.45% of sacral and of control leg epidermal LCs, respectively, had dendrites before, and 91.52 +/- 3.43% and 84.15 +/- 3.64% of sacral and of control leg epidermal LCs, respectively, had dendrites after zinc supplementation. The LC section area in the sacral epidermis near the lesion as well as in the control leg epidermis and the number of LC granules in LC sections were not affected by zinc supplementation. The higher percentage of LCs having dendrites in the epidermis of patients with decubital ulcers after zinc supplementation may indicate that these LCs are in a more motile state, which might affect the healing process of the lesions.

Measurement of the Electron Antineutrino Oscillation with 1958 Days of Operation at Daya Bay

We report a measurement of electron antineutrino oscillation from the Daya Bay Reactor Neutrino Experiment with nearly 4 million reactor ν[over ¯]_{e} inverse β decay candidates observed over 1958 days of data collection. The installation of a flash analog-to-digital converter readout system and a special calibration campaign using different source enclosures reduce uncertainties in the absolute energy calibration to less than 0.5% for visible energies larger than 2 MeV. The uncertainty in the cosmogenic ^{9}Li and ^{8}He background is reduced from 45% to 30% in the near detectors. A detailed investigation of the spent nuclear fuel history improves its uncertainty from 100% to 30%. Analysis of the relative ν[over ¯]_{e} rates and energy spectra among detectors yields sin^{2}2θ_{13}=0.0856±0.0029 and Δm_{32}^{2}=(2.471_{-0.070}^{+0.068})×10^{-3}  eV^{2} assuming the normal hierarchy, and Δm_{32}^{2}=-(2.575_{-0.070}^{+0.068})×10^{-3}  eV^{2} assuming the inverted hierarchy.

Evolution of the Reactor Antineutrino Flux and Spectrum at Daya Bay

The Daya Bay experiment has observed correlations between reactor core fuel evolution and changes in the reactor antineutrino flux and energy spectrum. Four antineutrino detectors in two experimental halls were used to identify 2.2 million inverse beta decays (IBDs) over 1230 days spanning multiple fuel cycles for each of six 2.9 GW_{th} reactor cores at the Daya Bay and Ling Ao nuclear power plants. Using detector data spanning effective ^{239}Pu fission fractions F_{239} from 0.25 to 0.35, Daya Bay measures an average IBD yield σ[over ¯]_{f} of (5.90±0.13)×10^{-43}  cm^{2}/fission and a fuel-dependent variation in the IBD yield, dσ_{f}/dF_{239}, of (-1.86±0.18)×10^{-43}  cm^{2}/fission. This observation rejects the hypothesis of a constant antineutrino flux as a function of the ^{239}Pu fission fraction at 10 standard deviations. The variation in IBD yield is found to be energy dependent, rejecting the hypothesis of a constant antineutrino energy spectrum at 5.1 standard deviations. While measurements of the evolution in the IBD spectrum show general agreement with predictions from recent reactor models, the measured evolution in total IBD yield disagrees with recent predictions at 3.1σ. This discrepancy indicates that an overall deficit in the measured flux with respect to predictions does not result from equal fractional deficits from the primary fission isotopes ^{235}U, ^{239}Pu, ^{238}U, and ^{241}Pu. Based on measured IBD yield variations, yields of (6.17±0.17) and (4.27±0.26)×10^{-43}  cm^{2}/fission have been determined for the two dominant fission parent isotopes ^{235}U and ^{239}Pu. A 7.8% discrepancy between the observed and predicted ^{235}U yields suggests that this isotope may be the primary contributor to the reactor antineutrino anomaly.

Epidermal Langerhans' cells in Behçet's disease

Langerhans' cells were studied in the epidermis of two patients with active Behçet's disease and compared with those in two normal controls. Ultrastructural morphology and the percentage of Langerhans' cells found were similar in patients' (1.88%) and the control epidermis (1.79%). The density of Langerhans' cells in adjacent sites of the same epidermis was not homogeneous, being in the range of 0.8-2.8% in Behçet's disease and 0.6-4% in the controls. In the controls, Langerhans' cells were distributed unevenly. Some were located near the basal layer of the epidermis while the rest were in the mid and upper layers. In Behçet's disease most Langerhans' cells were in the mid-epidermis, but some were immediately beneath the stratum granulosum. In the Behçet's disease epidermis the area occupied by Langerhans' cells was increased by about 25% and the number of granules found increased by about 44%. It is suggested that in Behçet's disease the Langerhans' cells are in a more active state.

Measurement of the Reactor Antineutrino Flux and Spectrum at Daya Bay

This Letter reports a measurement of the flux and energy spectrum of electron antineutrinos from six 2.9 GWth nuclear reactors with six detectors deployed in two near (effective baselines 512 and 561 m) and one far (1579 m) underground experimental halls in the Daya Bay experiment. Using 217 days of data, 296 721 and 41 589 inverse β decay (IBD) candidates were detected in the near and far halls, respectively. The measured IBD yield is (1.55±0.04) ×10(-18)  cm(2) GW(-1) day(-1) or (5.92±0.14) ×10(-43)  cm(2) fission(-1). This flux measurement is consistent with previous short-baseline reactor antineutrino experiments and is 0.946±0.022 (0.991±0.023) relative to the flux predicted with the Huber-Mueller (ILL-Vogel) fissile antineutrino model. The measured IBD positron energy spectrum deviates from both spectral predictions by more than 2σ over the full energy range with a local significance of up to ∼4σ between 4-6 MeV. A reactor antineutrino spectrum of IBD reactions is extracted from the measured positron energy spectrum for model-independent predictions.

[Postoperative analgesia: epidural injection of dexamethasone sodium phosphate]

Epidural administration of steroids has been suggested for the prevention of postoperative epidural fibrosis after lumbar lamino-arthrectomy. In order to assess the efficacy of this technique on pain occurring after such surgery, the demand of pentazocine during the first 24 postoperative hours was studied in 39 patients randomly assigned to two groups. Pain intensity was assessed by a five-point verbal scale (0: none; 1: poor; 2: moderate; 3: severe; 4: very severe) at five intervals (0-4, 5-8, 9-12, 13-16 and 17-24 h). The patients in group T (n = 20) did not receive any steroid, whereas those in group C (n = 19) were given, just after the end of surgery, a single dose of dexamethasone (4 mg) via an epidural lumbar catheter previously inserted by the surgeon. In group T, 18 patients required one or several intramuscular injections of pentazocine, whereas only three patients of group C (p less than 0.001) did so. Patients in group T expressed more severe pain (4 moderate, 12 severe, 3 unbearable) than those patients who had received steroids (1 moderate, 1 severe, 1 unbearable). As a consequence, they requested more pain killer (30 injections vs 8 injections, respectively; p less than 0.001) and sooner than patients of the steroid group (8 h vs 12 h; p less than 0.05). It was concluded that epidural administration of dexamethasone was helpful in preventing postoperative pain after lumbar lamino-arthrectomy.

Radiofrequency hyperthermia: the design of coil transducers for local heating

Simple and complex coils have been designed and built for use as radiofrequency transducers for local and regional hyperthermia. The heating from such coils is produced by currents generated in the dielectric by the electromagnetic field radiated from the coil elements. The heating rate profile, as a function of phantom depth, is dependent upon the size and geometry of the coil, its proximity to the dielectric, and the transducer current. Since the fields of simple pancake coils are inhomogeneous, either complex geometries or some method of smoothing is required. A simple solution is to move the coil over the region to be heated or to use multiple applicators. However, many satisfactory heating patterns have been derived for stationary coils designed to heat well-defined subcutaneous volumes to a depth of 3-5 cm. Thermometry studies in static saline-gelatin phantoms demonstrate extensive heating ranges and flexibility since the coils couple with the dielectric through air.

Light-induced structural changes during incubation of isolated maize etioplasts

Etioplasts were isolated from leaves of 9-day-old etiolated maize (Zea mays L.) seedlings and incubated in a relatively simple medium in light and in the dark. During the first 5 h no changes occurred in the fine structure of the isolated etioplasts in the dark. In light the size of the prolamellar bodies decreased and significantly more plastid sections without prolamellar bodies were counted. The total length of the thylakoids per plastid section increased, but there was no evidence for bi- and polythylakoid formation. It is concluded that light induces the structural transformation of the prolamellar body membranes into primary thylakoids also in isolated etioplasts.

Quantitative analysis of tight junctions and the uptake of 99mTc in human gliomas

The structural dimensions of capillary tight junctions and the uptake of 99mTc pertechnetate in human gliomas were studied. Quantitative analysis revealed a correlation between the uptake of radionuclides and the length of endothelial tight junctions. It is suggested that brain scintigraphy might be used for the selection of malignant brain tumors with altered tight junctions which might be accessible to chemotherapy with water-soluble agents.

Limits on Active to Sterile Neutrino Oscillations from Disappearance Searches in the MINOS, Daya Bay, and Bugey-3 Experiments

Searches for a light sterile neutrino have been performed independently by the MINOS and the Daya Bay experiments using the muon (anti)neutrino and electron antineutrino disappearance channels, respectively. In this Letter, results from both experiments are combined with those from the Bugey-3 reactor neutrino experiment to constrain oscillations into light sterile neutrinos. The three experiments are sensitive to complementary regions of parameter space, enabling the combined analysis to probe regions allowed by the Liquid Scintillator Neutrino Detector (LSND) and MiniBooNE experiments in a minimally extended four-neutrino flavor framework. Stringent limits on sin^{2}2θ_{μe} are set over 6 orders of magnitude in the sterile mass-squared splitting Δm_{41}^{2}. The sterile-neutrino mixing phase space allowed by the LSND and MiniBooNE experiments is excluded for Δm_{41}^{2}<0.8  eV^{2} at 95%  CL_{s}.

Rapid dose calculations for stereotactic radiosurgery

A three-dimensional dose calculation algorithm is described for stereotactic radiosurgery using multiple noncoplanar beam arcs. Precalculated dose libraries of 20-deg arc segments, or mini arcs, are stored in computer memory which permits rapid calculation of complete, high resolution, three-dimensional isodose distributions and dose volume histograms. Three-dimensional patient contours and target volumes are obtained from CT scans and angiographic x rays. Rapid dose calculations are made possible by the use of arc libraries and an improved algorithm for mapping beam doses to the dose calculation grid. This permits more flexibility in designing optimum treatment plans, as five-six complete plans can be generated in less than 1 h. Thus many possible treatment options can be tested in the 3-4-h time period typically available in stereotactic procedures between CT scanning and treatment.

Improved Search for a Light Sterile Neutrino with the Full Configuration of the Daya Bay Experiment

This Letter reports an improved search for light sterile neutrino mixing in the electron antineutrino disappearance channel with the full configuration of the Daya Bay Reactor Neutrino Experiment. With an additional 404 days of data collected in eight antineutrino detectors, this search benefits from 3.6 times the statistics available to the previous publication, as well as from improvements in energy calibration and background reduction. A relative comparison of the rate and energy spectrum of reactor antineutrinos in the three experimental halls yields no evidence of sterile neutrino mixing in the 2×10^{-4}≲|Δm_{41}^{2}|≲0.3  eV^{2} mass range. The resulting limits on sin^{2}2θ_{14} are improved by approx imately a factor of 2 over previous results and constitute the most stringent constraints to date in the |Δm_{41}^{2}|≲0.2  eV^{2} region.