Metronidazole may inhibit intestinal colonization with Clostridium difficile

OBJECTIVE: To evaluate the clinical and microbiological efficacy of minocycline in a subgingival local delivery system as an adjunct to tooth scaling and root planing in dogs with periodontal disease. ANIMALS: Nine 4- to 7-year-old Beagles with periodontitis. PROCEDURE: After scaling of teeth and root planing, 2 treatment and 1 or 2 control sites were selected for each dog: treated sites (n = 18) received minocycline hydrochloride periodontal formulation and control sites (n = 12) received ointment base (no minocycline). Gingival crevicular fluid was collected at a baseline (prior to treatment) and at week 4. Clinical and microbiological effects were evaluated and compared among sites. RESULTS: In minocycline-treated sites, clinical indices were significantly decreased at week 4, compared with those at baseline. Minocycline-treated sites were associated with a significant decrease in gingival crevicular fluid, probing depth, and bleeding on probing values, compared with those for control sites at week 4. Compared with that for control sites, total bacteria count in periodontal pockets of minocycline-treated sites had an obvious tendency to decrease by week 4. Proportions of Porphyromonas and Fusobacterium spp were significantly decreased at week 4, compared with proportions at control sites and with pretreatment (baseline) values. CONCLUSIONS: When used as an adjunct to tooth scaling and root planing, minocycline periodontal formulation stimulated favorable clinical and antimicrobial responses.     

Quantification of intravascular and extravascular contributions to BOLD effects induced by alteration in oxygenation or intravascular contrast agents

A simple model is presented that allows quantitative separation of the contributions of signals from water in blood and extravascular parenchyma due to changes in blood oxygenation, induced either by brain activation or by alteration of inspired oxygen. The separation is based on the progressive attenuation of the signals in the vasculature of different levels when bipolar field gradient pulses are applied. Diffusion-weighted spin-echo echo-planar imaging sequences were used to measure signal changes under various conditions in both animals and human volunteers. Normoxic-hyperoxic episodes were induced in rats before and after injection of a superparamagnetic iron oxide contrast agent. Signal changes produced by visual stimulation were measured in human volunteers, and in volunteers subject to alternating normoxic-hyperoxic episodes, and with administration of Gd-DTPA. Analysis of the results with our simple model suggests that the apparent diffusion coefficient increases and R2 (= 1/T2) decreases upon brain activation, with a large component from extravascular water related to the decrease in the blood deoxyhemoglobin concentration. Furthermore, this study suggests that apparent diffusion coefficient of the extravascular component alone may provide localization of neuronal activation.     

Further evidence that rats rely on local rather than global spatial information to locate a hidden goal: Reply to Cheng and Gallistel (2005).

Naive male Hooded Lister rats (Rattus norvegicus) were required to find a submerged platform in a right-angled corner between a long and a short wall of a pool in the shape of an irregular pentagon. Tests in a rectangular pool revealed a preference for the corners that corresponded with the correct corner in the pentagon. These findings indicate that rats identified the correct corner in the pentagon by local cues. They contradict the suggestion that rats navigate by moving in a particular direction relative to the principal axis of the shape of their environment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

National security/emergency preparedness and the next-generation network

National security/emergency preparedness (NS/EP) requires-effective communications supporting leadership and key staff in their access to information and their coordination of decisions. Results of testing voice over Internet protocol (VoIP) as a next-generation network (NGN) application are presented and illustrate that effective NS/EP support is at risk during congestion possible in events requiring NS/EP services. The results also demonstrate substantial benefit of mitigating the risks with the types of differentiated service capabilities currently being advanced within the Internet engineering task force (IETF). The test results are shown to align with predictions from event simulation. Extending the event simulation to a more complex topology and application arrangement than those tested in the laboratory suggests the feasibility and means of ensuring effective NS/EP support.     

Effect of in vitro incubation on spontaneous acrosome reaction in fresh and cryopreserved human spermatozoa

OBJECTIVES: Capacitation and acrosome reaction are prerequisites for fertilization. However, in vitro capacitation is not necessary for an agonist-induced acrosome reaction. We studied whether in vitro capacitation is important in spontaneous acrosome reaction and analyzed how capacitation before cryopreservation influences the acrosomal status of thawed spermatozoa. METHODS: Semen specimens from normal donors (n = 15) were processed by the swim-up technique and divided into two aliquots. One aliquot was capacitated (capacitation induced) for three hours by incubation in a modified-BWW medium with 3% HSA at 37 degrees C under 5% carbon dioxide. The other aliquot did not receive any treatment. Both aliquots were analyzed by CASA to assess the capacitation status of the spermatozoa and then cryopreserved. Spontaneous acrosome reaction was assessed by FITC-PNA lectin before and after cryopreservation. Sperm viability was measured using Hoechst-33258 stain. RESULTS: Before freezing, the frequency of spontaneous acrosome reaction was higher in the capacitation-induced sperm preparation (median, 20.5% [interquartile range, 17.2-37.8]) than in swim-up-induced specimens (median, 10.6% [range, 4.8-23.2]; P <.001). The percentage of viable cells showing acrosome reaction increased after cryopreservation in both swim-up-induced specimens (median, 241.4% [interquartile range, 37.1-678.6]; P <.001) and capacitation-induced specimens (median, 48.2% [range, 6.1-63.3]; P = 0.002). Although this increase was higher in the swim-up-induced specimens (P = 0.002), frequency of postthaw spontaneous acrosome reaction was similar in both groups (P = 0.18). CONCLUSIONS: We conclude that sperm capacitation significantly optimizes the acrosome reaction. However, a small proportion of normal spermatozoa do not require capacitation to undergo spontaneous acrosome reaction in vitro. After cryopreservation, the percentage of spermatozoa that had intact acrosomes was similar in both groups, despite the fact that one aliquot underwent prefreeze capacitation. These findings suggest that the acrosome reaction may involve complex mechanism(s) rather than a physiological change induced by capacitation.     

Dyspnea resulting from fibromyalgia

Two patients with chronic, severe, episodic dyspnea underwent prolonged, extensive, and invasive evaluations without a diagnosis being made. Both were subsequently diagnosed with fibromyalgia, and therapy directed at this condition resulted in resolution of their symptoms. Fibromyalgia is rarely included in the differential diagnosis of dyspnea, and timely diagnosis and treatment may be delayed. However, this condition must be considered because it can only be established by seeking the appropriate history and physical findings.     

Comparison of single- and two-layer Percoll separation for selection of motile spermatozoa

OBJECTIVE: Sperm recovery using a single-layer Percoll procedure is significantly better than using the swim-up technique for infertile men and patients with normal sperm characteristics; however, in normal men results have been contradictory. Some studies have shown further improvement in semen quality with multiple layers. Therefore, this study compared the effect of single-layer and two-layer Percoll procedures on sperm characteristics of normozoospermic men. METHODS: Semen specimens from 10 normal donors were processed by layering 1 mL of the liquefied ejaculate on a single layer of 80% Percoll or on a two-layer (47% and 90%) Percoll gradient. Computer-assisted semen analysis was done to examine total motile sperm, percentage of recovery of motile cells, percent motility, curvilinear velocity, linearity, and amplitude of lateral head displacement. Each specimen was evaluated by the hypo-osmotic swelling (HOS) test, bovine cervical mucus penetration test, viability (eosin-nigrosin stain), and sperm morphology (World Health Organization and Kruger's strict criteria). RESULTS: Specimens processed with the two-layer Percoll procedure had significantly better recovery of spermatozoa, and significantly better percentage motility, linearity, amplitude of lateral head displacement, percentage tail swelling, and percentage viability than those separated on single-layer Percoll. Results for sperm morphology using WHO and Kruger's criteria were similar between the two methods (P = 0.92 for both sets of criteria). CONCLUSIONS: In normozoospermic men, the two-layer Percoll separation procedure significantly improves semen characteristics compared with separation on a single layer.     

Synthetic lipid A-induced uveitis and endotoxin-induced uveitis--a comparative study

Endotoxin-induced uveitis (EIU) is an animal model of ocular inflammation induced by lipopolysaccharide (LPS). The lipid A (LA) region of the LPS chemical structure is believed to be responsible for virtually all the biological activities induced by LPS. The aim of this study was to perform a more detailed investigation of the potency of LA in reproducing EIU. Various doses of either LPS or LA were injected into the footpad of an inbred strain of Lewis rat and the inflammation patterns were compared by assessing the protein concentration, by cytological study, and by determining the inflammatory cell content in samples of aqueous humor obtained during 96-hour follow-up. Evaluation of the cell number and protein concentration ratio of both groups showed the LA-stimulated group presented a higher ratio than the LPS group (Welch's t-test, (P < 0.00001). It was noteworthy that even the injection of high doses of LPS could not reproduce the level of cellular infiltration induced by LA. Histological study confirmed the enhanced cellularity in the LA group, neutrophils being predominant in both the LPS- and the LA-stimulated groups. The divergent findings in these two models of uveitis may be valuable to further investigations of the process of inflammatory cell migration into the anterior chamber of the eye.     

Potent cyano and carboxamido side-chain analogues of 1', 1'-dimethyl-delta8-tetrahydrocannabinol

The synthesis and pharmacological profile of several cyano (1a-e) and carboxamido (2a-h) side-chain-substituted analogues of 1', 1'-dimethyl-Delta8-THC are described. Commercially available cyano compound 3 was transformed to the resorcinol 6 in a three-step sequence. Condensation of 6 with p-menth-2-ene-1,8-diol formed the THC 7a which, with sodium cyanide/DMSO, gave 1b. Protection of the phenol in 7a as the MOM derivative provided the common intermediate 8 for the synthesis of 1a,c,e. Compound 1d was also synthesized from 7a via the aldehyde 9a. Base hydrolysis of 1b gave the acid 10 which, via its acid chloride and subsequent treatment with the appropriate amine, formed the target compounds 2a-h. The pharmacological profile indicated that the cyano analogues 1a-e had very high CB1 binding affinity (0.36-13 nM) and high in vivo potency as agonists. Two analogues (1a,b) had extremely high potency in the mouse tetrad tests. The dimethylcarboxamido analogue 2a showed a similar profile to 1a,b. The high potency was also retained in analogue 2c. In contrast the sulfonamide analogue 2d was unique as it had greater affinity than Delta9-THC, yet it was practically devoid of agonist effects. This study suggests that the incorporation of a cyano or an amide substituent in the side chain of Delta8-THC-DMH can enhance potency and can also lead to compounds with a unique profile which have high binding affinity and are practically devoid of agonist effects.