In vitro skin permeation and bioassay of chlorhexidine phosphanilate, a new antimicrobial agent

An in vitro technique was developed to study the permeation and antimicrobial activity of graded concentrations of a new antibacterial agent, chlorhexidine phosphanilate (CHP), in cream formulations using Franz diffusion cells. Formulations containing from 0.2 to 2% CHP were quantitatively applied to intact excised skin and to skin from which the stratum corneum and partial epidermis had been enzymatically removed. Receptor fluids from diffusion cells were sampled over time and assayed by HPLC methods for chlorhexidine and phosphanilic acid; 24- and 48-hr samples of the diffusate from studies with damaged skin were also bioassayed using clinical isolates of appropriate microbial species. Through intact skin almost no permeation of CHP was observed over 48 hr. The failure of CHP to penetrate intact human skin suggests that normal stratum corneum is the rate-limiting barrier to penetration by this antimicrobial agent. In damaged skin lacking stratum corneum barrier, the release of CHP from the formulation becomes the rate-determining step. Coincident with penetrating damaged skin, CHP dissociates, and the molar ratio of the chlorhexidine and phosphanilate moities in the diffusate changes to favor phosphanilic acid. The extent of changes in the permeation rates of both moieties of CHP was directly related to the CHP concentration in cream. Both CHP moieties were found to reach equilibrium in the dermis within 24 hr after application. It was also observed that CHP creams down to 0.2% concentration yielded diffusates with activity exceeding the minimum inhibitory concentration of all test microorganisms within 24 hr.

Detection of avian infectious bronchitis viral infection using in situ hybridization and recombinant DNA

A recombinant DNA probe with specificity for the 3' end of genomic RNA from the Ark 99 strain of infectious bronchitis virus (IBV) was found to hybridize with extracted RNA of three strains with the Ark serotype, as well as the Mass41, Holl52, Gray, JMK, Conn, Fla and SE17 strains of IBV. Viral infection was detected in the cytoplasm of chicken embryo kidney cells inoculated with Mass41, Ark99, SE17 or two recent field isolates of IBV using in situ cytohybridization and a biotinylated probe. In vivo infections were detected in individual cells of tracheas and lungs 2,4, and 6 days after inoculation of chicks with Mass41 and Ark99. In situ hybridization of Ark99 infected tissue sections using 32P-dATP labelled probe indicated that more viral replication was present in the trachea on day 4 than either days 2 or 6; whereas more viral RNA was found in the lungs on day 6 than days 2 or 4 after inoculation.

Phase retrieval from two intensity measurements in an optical system involving nonunitary transformation

Phase retrieval from measured intensities is achieved for a practical optical system involving nonunitary transformation. We use two specific light field distributions as an example to demonstrate the iterative algorithm for phase retrieval. We chose the initial phase value to have arbitrary random distribution. For a system with different diffraction losses, we find that the retrieval can be successfully achieved even though the measured intensities contain certain random fluctuations.

Human Kupffer cells are cytotoxic against human colon adenocarcinoma

Colorectal liver metastases are a common clinical problem and require more effective therapy. Kupffer cells (KC) perform many important homeostatic functions within the liver and may also possess the ability to mediate tumor cytotoxicity. We investigated the ability of human KC to mediate cytotoxicity against human colon adenocarcinoma targets (HT 29) in vitro. Unstimulated human KC were cytotoxic against the HT 29 targets at all effector/target ratios tested. This cytotoxicity was increased significantly (p less than 0.05) when the KC were stimulated with interferon-gamma and lipopolysaccharide. Human KC produced tumor necrosis factor (TNF), and KC stimulation significantly (p less than 0.05) increased secretion of this monokine. The addition of anti-TNF antibody to the KC-HT 29 cocultures completely neutralized all of the available TNF yet cytotoxicity was not affected, suggesting the participation of a membrane-bound form of TNF or other mechanisms.

Protein gene product 9.5-immunoreactive nerve fibres and cells in human skin

Sections of human skin were processed according to the indirect immunofluorescence technique with a rabbit antiserum against human protein gene product 9.5 (PGP 9.5). Immunoreactivity was detected in intraepidermal and dermal nerve fibres and cells. The intraepidermal nerves were varicose or smooth with different diameters, running as single processes or branched, straight or bent, projecting in various directions and terminating in the stratum basale, spinosum or granulosum. The density of the intraepidermal nerves varied between the different skin areas investigated. PGP 9.5-containing axons of the lower dermis were found in large bundles. They separated into smaller axon bundles within the upper dermis, entering this portion of the skin perpendicular to the surface. Then they branched into fibres mainly arranged parallel to the epidermal-dermal junctional zone. However, the fibres en route to the epidermis traversed the upper dermis more or less perpendicularly. Furthermore, immunoreactive dermal nerve fibres were found in the Meissner corpuscles, the arrector pili muscles, hair follicles, around the eccrine and apocrine sweat glands and around certain blood vessels. Such fibres were also observed around most subcutaneous blood vessels, sometimes heavily innervating these structures. Numerous weakly-to-strongly PGP 9.5-immunoreactive cells were found both in the epidermis and in the dermis.

Existence of solitary waves in optical fibers owing to the mutual support between bright and dark pulses

We introduce a new type of solitary wave in a lossless single-mode fiber in which a bright solitonlike pulse in the anomalous-dispersion range propagates together with a stationary dark pulse in the normal-dispersion range. Such a solitary wave can be generated by launching a bright pulse in the anomalous-dispersion range together with a long pulse of the same speed in the normal-dispersion range into a fiber. The results of numerical simulations show that the dark pulse is not a dark soliton. The generation and maintenance of such a solitary wave are attributed to the mutual chirping through cross-phase modulation between those two waves in the anomalous- and normal-dispersion ranges.

Mapping the cardiogenic impedance signal on the thoracic surface

The cardiogenic impedance signal from band electrodes placed in the traditional position around the neck and lower thorax was studied by mapping the location of the signal on the sternum using 10 cm strip electrodes in eight male subjects. The band current electrodes on the neck and waist were replaced with 10 cm strip electrodes on the forehead and 10 cm below the xiphisternal joint, respectively, with only small changes in the dZ/dt peak amplitude and Z0. Similarly, using a strip voltage pickup electrode at the level of the xiphisternal joint resulted in very small changes in the waveform. The amplitude of dZ/dt measured between the xiphisternal joint and points along the sternum remains small until approximately 10 cm below the suprasternal notch, after which it increased linearly to the top of the neck. An average of 17 per cent and 24 per cent of the dZ/dt signal and 24 per cent and 22 per cent of the Z0 signal for supine and standing, respectively, occurs above the suprasternal notch. Replacing the current electrodes with strip electrodes on the forehead and waist caused only small changes in the signal. The position of the neck strip electrode is more critical.

Luteal function associated with single, multiple and ectopic embryo implantation in natural cycles or after ovarian hyperstimulation for in-vitro fertilization/gamete intra-fallopian transfer

Levels of reproductive steroids and gonadotrophins were analysed retrospectively during the peri-implantation period following non-conceptional and conceptional natural cycles and in cycles associated with ovarian hyperstimulation for in-vitro fertilization or gamete intra-Fallopian transfer. In cycles not associated with conception, the luteal phase of hyperstimulated cycles (n = 100) was characterized by higher serum progesterone and oestradiol levels (P less than 0.01) and with an earlier decline in steroids than in natural cycles (n = 21). On day 11 (day of oocyte recovery = day 0), the level of progesterone in twin (n = 59) and triplet (n = 13) pregnancies was higher than singleton pregnancies (n = 176) (P less than 0.006, P less than 0.006 respectively) while those destined to abort (n = 66) had lower progesterone levels (P less than 0.01). Ectopic implantation (n = 11) had the lowest progesterone concentrations on day 11 (P less than 0.01) and this may imply a delay in corpus luteum rescue or a later implantation time than intrauterine conception.

Changes in tissue-type plasminogen activator-like and plasminogen activator inhibitor activities in granulosa and theca layers during ovarian follicle development in the domestic hen

Changes in plasminogen activator (PA) and PA inhibitor (PAI) activities were measured during follicular development in granulosa cells (GC) and theca tissue (TT) isolated from the six largest yolk-filled preovulatory follicles (F1, F2, F3, F4, F5, F6) and large white follicles (LWF) of the domestic hen. PA activity increased and PAI activity decreased during follicular development, with the peak PA value and minimum activity for PAI observed in the largest preovulatory follicle (F1) 12-14 h before expected time of ovulation. The PA activity in GC and TT appears to be principally of the tissue (t)-PA type judging from its substrate specificity and biochemical characteristics. The enzyme cleaved the chromogenic substrate specific for t-PA (Spectrozyme TM t-PA; CH3SO2-D-CHT-Gly-Arg-p-nitroanilide) more efficiently (4-6 x) than that for u-PA (Spectrozyme TM UK; Cbo-L-Glu-(alpha-t-BuO)-Gly-Arg-p-nitroanilide), suggesting that t-PA may be the predominant PA in the chicken preovulatory follicle. Determination of PA activity following sodium dodecyl sulphate-polyacrylamide gel electrophoresis and isoelectric focussing suggested the presence of two forms of the enzyme in GC and TT. The predominant form of PA had a molecular weight of 75,000 and an isoelectric point (pI) of 7.7, characteristics similar to those reported for t-PA in humans, pigs, and rodents. The other form of PA had a molecular weight of 35,000 and pI of 8.4. PAI present in GC and TT had a molecular weight of 50,000 and pI of 4.7. In GC, an acid-labile PAI was detected with biochemical characteristics similar to those of the protease, nexin I.(ABSTRACT TRUNCATED AT 250 WORDS)

[Correlation between protein kinase C and differentiation of HL-60 cells induced by DMSO]

Treatment of HL-60 cells with DMSO caused cells to differentiate along the myeloid way and 84% of the cells showed a reduction in NBT after 120h. Protein kinase C activity increased of during differentiation. It would reach 2.7 times that of the control after 72h in the presence of DMSO. The increase of protein kinase C activity was traced to the cytosolic rather than the membrane fraction. Chelator EGTA was necessary to extract protein kinase C. DMSO itself could not enhance protein kinase C activity, indicating that the effect of DMSO was indirect. All of these results showed that the activation of protein kinase C is important in the differentiation of HL-60 cells.

[Electron microscopic observation of the effects of Rhodiola kirilowii (Regel.) Maxim. in preventing damage of the rat viscera by a hypoxic high altitude environment]

This paper has shown that the pathologic damages done to rat's viscera due to hypoxic environment of altitude can be reduced significantly by oral administrations of Shengmaiyin, Danshen-Chuanxiong mixture and Rhodiola kirilowii. Shengmaiyin that maintains interior substances in the plate layer bodies proves more effective than Danshen-Chuanxiong mixture, while the latter excels in preventing capillary contraction, thus improving blood circulation. Rhodiola kirilowii has the effects of both Shengmaiyin and Danshen-Chuanxiong mixtures.

[Study on the discrimination of bacteria by gas chromatographic profiles of cellular monosaccharides]

A procedure for obtaining gas chromatographic (GC) profiles of bacterial cellular monosaccharides was described. Some of the unknown component peaks in these profiles were identified. And, based on the complete linkage cluster analysis with the Euclidean distance coefficient, the interpretation of the resulting cellular monosaccharides of bacteria were performed by mini-computer. By means of this method, the discrimination of 5 species (24 strains) of aerobic endospore-forming bacteria. The results showed that there were defined differences between the profiles of cellular monosaccharides of B. anthracis and B. cereus. This procedure has provided a useful method for the classification and identification of microorganisms, for their physiological and biochemical studies, and for studies on their subcellular components.

Synchronous neural networks of nonlinear threshold elements with hysteresis

We use Hoffmann's suggestion [Hoffmann, G. W. (1986) J. Theor. Biol. 122, 33-67] of hysteresis in a single neuron level and determine its consequences in a synchronous network made of such neurons. We show that the overall retrieval ability in the presence of noise and the memory capacity of the network in the present model are better than in conventional models without such hysteresis. Second-order interaction further improves the retrieval ability of the network and causes hysteresis in the retrieval-noise curve for any arbitrary width of the bistable region. The convergence rate is increased by the hysteresis at high noise levels but is reduced by the hysteresis at low noise levels. Explicit formulae are given for calculations of average final convergence and noise threshold as functions of the width of the bistable region. There is neurophysiological evidence for hysteresis in single neurons, and we propose optical implementations of the present model by using ZnSe interference filters to test the predictions of the theory.

Effect of spectral flash on readaptation time

The effects of an adapting flash of different colors on human vision were investigated with various flashes and target luminances. The readaptation time (RAT) was measured using optokinetic nystagmus elicited by a projected moving striped pattern in a hemisphere. The RATs were recorded from 26 subjects with a multichannel pen recorder. Two target luminances (1.1 X 10(-5) cd/m2 and 2.6 X 10(-5) cd/m2) and 12 flash wavelengths (449 nm, 456 nm, 468 nm, 477 nm, 498 nm, 502 nm, 520 nm, 565 nm, 580 nm, 591 nm, 622 nm, and 703 nm) were used. A spectral RAT curve was obtained, which showed that the chromatic response of RAT follows this order: green greater than blue greater than yellow greater than red. A larger influence of the variation of the target luminance on the RAT was demonstrated at shorter wavelengths. The results also showed that the energy density of the flash has a larger variation with the RAT in blue and green than in red.

Trends in guardianship reform: implications for the medical and legal professions

In recent years, there has been a slow but dramatic change in society's attitudes toward persons with disabilities—an evolution away from traditional paternalistic approaches which foster dependency, toward policies focused on maximizing the potential for autonomy and independence among individuals of limited capacity. This change is clearly reflected in efforts across the country to revise state guardianship statutes. This article analyzes significant trends in these reform efforts, and highlights important practice implications for physicians and attorneys whose practices include serving persons who are limited in their capacity to make informed decisions.

A 3-D anthropomorphic brain phantom for ECT applications

A three-dimensional (3-D) anthropomorphic brain phantom was developed for ECT (emission computed tomography) applications. This phantom is made up of a stack of interlaced plates as an insert in a water tank containing radioactive solution. The thickness of the plates in the stack is chosen to create the desired spatial frequency content and object contrast between simulated grey and white matter regions for tracers commonly used to study regional blood flow or metabolism. The transverse, sagittal, and coronal SPECT images acquired with a rotating camera system show a realistic simulation of the grey matter distribution in a human brain.

Effect of clonazepam on brain development of mice

Twenty-seven Kun-Ming white mice were divided randomly into three groups of 9 animals. One of these groups served as a control group. Clonazepam (CZP), 0.1 or 0.5 mg/kg/day, was administered by oral gavage for 22 days. The water-maze test was performed before giving CZP and 10 and 22 days later. The step-down test was performed on the 1st and the 2nd day after discontinuing CZP treatment to determine toxic effects on brain development and learning-memory function. Body weights and brain weight were also recorded. Brain development and learning-memory function, evaluated by water-maze and step-down tests, were not impaired by CZP. Although there was a trend toward lower weights in the higher-dose group, CZP treatment did not significantly affect either body weight or total or regional brain weight. The results of this study indicate that 4 weeks of treatment with CZP does not impair brain development and learning-memory function in baby mice.