Multi-Lorentzian representation of deuterium spectrum to study water spin magnetization exchange in MCM-41

Water behavior on the pore surface of nano-silica MCM-41, at a hydration level corresponding to one water molecule per OH group, is studied using (2)H NMR spectra in the temperature range 213 to 313 K. In an earlier study [J. Hassan, E. Reardon, H. Peemoeller, Microporous Mesoporous Materials, 122 (2009) 121-127] it was shown that at this hydration level, deuterons of water at single OH sites exhibit a Lorentzian line shape and deuterons of water at hydrogen-bonded OH sites exhibit a powder pattern. Here it is shown that magnetization exchange occurs between these two deuteron spin groups. This exchange cannot be described using the common, two-site exchange model, involving two Lorentzians. We successfully apply a multi-Lorentzian exchange model, prompted by Woessner's work [D. E. Woessner, Mol. Phys. 34, 4, (1977) 899-920] on the effects of motion on the shape of water spin resonance lines exhibiting doublet splitting. For this low hydration sample the rate of magnetization exchange out of the hydration site, where the water deuterons exhibit a Lorentzian line in the (2)H spectra, is 1.3 ms(-1) and the activation energy for the exchange is found to be 3.4±0.1 kcal/mole.

Rapamycin causes down-regulation of CCR5 and accumulation of anti-HIV beta-chemokines: an approach to suppress R5 strains of HIV-1

Propagation of R5 strains of HIV-1 on CD4 lymphocytes and macrophages requires expression of the CCR5 coreceptor on the cell surface. Individuals lacking CCR5 (CCR5 Delta 32 homozygous genotype) are phenotypically normal and resistant to infection with HIV-1. CCR5 expression on lymphocytes depends on signaling through the IL-2 receptor. By FACS analysis we demonstrate that rapamycin (RAPA), a drug that disrupts IL-2 receptor signaling, reduces CCR5 surface expression on T cells at concentrations as low as 1 nM. In addition, lower concentrations of RAPA (0.01 nM) were sufficient to reduce CCR5 surface expression on maturing monocytes. PCR analysis on peripheral blood mononuclear cells (PBMCs) showed that RAPA interfered with CCR5 expression at the transcriptional level. Reduced expression of CCR5 on PBMCs cultured in the presence of RAPA was associated with increased extracellular levels of macrophage inflammatory protein (MIP)-1 alpha and MIP-1 beta. In infectivity assays, RAPA suppressed the replication of R5 strains of HIV-1 both in PBMC and macrophage cultures. In total PBMC cultures, RAPA-mediated inhibition of CCR5-using strains of HIV-1 occurred at 0.01 nM, a concentration of drug that is approximately 103 times lower than therapeutic through levels of drug in renal transplant recipients. In addition, RAPA enhanced the antiviral activity of the CCR5 antagonist TAK-779. These results suggest that low concentrations of RAPA may have a role in both the treatment and prevention of HIV-1 infection.

Substance abuse service utilization under managed care: HMOs versus carve-out plans

Managed behavioral health care organizations are increasingly managing Americans' substance abuse by using carve-outs, but little information is available about how this has affected service utilization and costs when compared to HMOs. One employer's claims for substance abuse services delivered under a carve-out arrangement are compared to prior HMO claims information. Under the carve-out arrangement, inpatient and outpatient service utilization are found to decrease, but intermediate service utilization dramatically increases. Costs per unit service decrease for all services. The pattern of changes is different from that seen for mental health services, suggesting that different factors may be applicable to substance abuse services.

Image-guided endoscopic surgery: results of accuracy and performance in a multicenter clinical study using an electromagnetic tracking system

Image-guided surgery has recently been described in the literature as a useful technology for improved functional endoscopic sinus surgery localization. Image-guided surgery yields accurate knowledge of the surgical field boundaries, allowing safer and more thorough sinus surgery. We have previously reviewed our initial experience with The InstaTrak System. This article presents a multicenter clinical study (n=55) that assesses the system's capability for localizing structures in critical surgical sites. The purpose of this paper is to present quantitative data on accuracy and performance. We describe several new advances including an automated registration technique that eliminates the redundant computed tomography scan, compensation for head movement, and the ability to use interchangeable instruments.

Anxiety and the colposcopy experience

The purpose of this study was to explore the anxiety of an abnormal Papanicolaou (Pap) result, the need for colposcopy, and the colposcopic examination experienced by first-time colposcopy clients. Spielberger's State-Trait Anxiety Inventory (STAI) and a Woman's Profile were administered to 149 women who had abnormal Pap smears necessitating colposcopy. The results confirm that this experience evokes anxiety. Younger women who knew less and had concurrent stressors in their lives were most anxious. Women identified ways that health professionals could be more helpful in alleviating their anxiety. Their suggestions included the provision of more information and an opportunity for personal contact with a health professional.

Purification and characterization of acyl carrier protein from two cyanobacteria species

The acyl carrier protein (ACP), an essential protein cofactor for fatty acid synthesis, has been isolated from two cyanobacteria: the filamentous, heterocystous, Anabaena variabilis (ATCC 29211) and the unicellular Synechocystis 6803 (ATCC 27184). Both ACPs have been purified to homogeneity utilizing a three-column procedure. Synechocystis 6803 ACP was purified 1800-fold with 67% yield, while A. variabilis ACP was purified 1040-fold with 50% yield. Yields of 13.0 micrograms ACP/g Synechocystis 6803 and 9.0 micrograms ACP/g A. variabilis were achieved. Amino acid analysis indicated that these ACPs were highly charged acidic proteins similar to other known ACPs. Sequence analysis revealed that both cyanobacterial ACPs were highly conserved with both spinach and Escherichia coli ACP at the phosphopantetheine prosthetic group region. Examining the probability of alpha-helix and beta-turn regions in various ACPs, showed that cyanobacterial ACPs were more closely related to E. coli ACP than spinach ACP I. Immunoblot analysis and a competitive binding assay for ACP illustrated that both ACPs bound poorly to spinach ACP I antibody. SDS/PAGE and native PAGE of Synechocystis 6803 ACP and A. variabilis ACP showed that cyanobacteria ACPs co-migrated with E. coli ACP and had relative molecular masses of 18,100 and 17,900 respectively. Both native and urea gel analysis of acyl-ACP products from fatty acid synthase reactions demonstrated that bacterial ACPs and plant ACP gave essentially the same metabolic products when assayed using either bacterial or plant fatty acid synthase. A. variabilis and Synechocystis 6803 ACP could be acylated using E. coli acyl ACP synthetase.

Identification of lipoxin A4 and its relationship to the sulfidopeptide leukotrienes C4, D4, and E4 in the bronchoalveolar lavage fluids obtained from patients with selected pulmonary diseases

Lipoxins are biologically active trihydroxytetraene containing products derived from arachidonic acid that are formed by interactions between lipoxygenases. Although the lipoxins have been generated from mixed cell suspensions in vitro, it has not been established whether these products are synthesized in vivo. We have performed bronchoalveolar lavage (BAL) in 12 patients with lung disease (sarcoid, six; pneumonia, two; asthma, two; carcinoma, one; alveolitis of unknown cause, one) and in six normal control subjects. The BAL fluid was analyzed for lipoxin A4 (LXA4) using gas chromatography mass spectrometry with selective ion monitoring, and the levels of the sulfidopeptide leukotrienes were determined using reverse-phase high-performance liquid chromatography and radioimmunoassay. LXA4 was detected in BAL fluid from nine of the 12 patients studied. The levels of LXA4 ranged from 0.4 to 2.8 ng/ml. LXA4 was not detected in any of the six normal subjects. Sulfidopeptide leukotrienes were detected in all the BAL samples, ranging from 0.04 to 0.7 ng/ml, and there was no significant difference between the patients and the normal subjects. In patients with detectable LXA4 in BAL fluid, the ratio of the concentrations of LXA4 to those of the sulfidopeptide leukotrienes ranged from 1.9 to 62 (mean, 19.0). This is the first demonstration of the presence of LXA4 in disease.

15-Hydroxyeicosatetraenoic acid inhibits superoxide anion generation by human neutrophils: relationship to lipoxin production

Human neutrophils can aggregate, degranulate, and release mediators of inflammation including oxygen radicals and lipoxygenase (LO)-derived products of arachidonic acid. The regulation of 5- and 15-lipoxygenases appears to be important since their products (e.g. leukotrienes and lipoxins) display unique spectra of bioactions. Addition of 15-HETE, a product of the 15-LO, to neutrophils in suspension dramatically shifted the LO products generated and led to a dose-dependent increase in lipoxins, while the production of leukotriene B4 and its omega-oxidation products (i.e. 20-COOH-LTB4 and 20-OH-LTB4) was inhibited. Exogenous 15-HETE also dose-dependently inhibited the generation of superoxide anions induced by either the chemotactic peptide f-met-leu-phe or the divalent cation ionophore A23187. Neither lipoxin A4 nor lipoxin B4 (10(-8)-10(-6) M) inhibited O2-. generation induced by either f-met-leu-phe or A23187. These results indicate that in addition to serving as a substrate for lipoxin generation, 15-HETE also inhibits superoxide anion generation by human neutrophils. Together they provide further evidence to suggest that products of the 15-lipoxygenase may serve a regulatory role at inflammatory loci.

Lung pathology after high frequency jet ventilation combined with low rate intermittent mandatory ventilation in a canine model of meconium aspiration

The microscopic appearance of lungs subjected to six hours of conventional ventilation (CV), standard high frequency jet ventilation (HFJV), and HFJV combined with low rate intermittent mandatory ventilation (CHFJV) was studied in 22 mongrel puppies. A lung injury model was created by insufflating 4 ml/kg of a 20% mixture of meconium into the trachea. The animals were initially ventilated at the same mean airway pressure (Paw). Subsequently, if PCO2 fell below 20 torr, peak and mean airway pressures were reduced. A scoring system was devised which assigned 0-3 points for each of eight lung injury parameters, and a total lung injury score (TLIS) was calculated. CHFJV resulted in significantly less bronchopneumonia and edema, when compared to CV. A consistent, though not significant, trend toward lesser injury scores in CHFJV animals was noted for several other parameters. Six of eight lungs exposed to CV had TLIS greater than 5 compared to only 1 of 9 ventilated by CHFJV. (P = 0.02). It is concluded that CHFJV may have a protective effect on the lung, perhaps because effective gas exchange is achieved with a lower pressure amplitude and at lower Paw.

Heterotopic cervical salivary gland tissue in a family with probable branchio-otorenal syndrome

Heterotopic cervical salivary gland tissue was found in a 4-yr-old girl with branchial and otologic abnormalities. Her mother and sister also had heterotopic cervical salivary tissue in association with anomalies that suggest the branchio-otorenal (BOR) syndrome. Heterotopic cervical salivary gland tissue may result from abnormal branchial development.

Lingual tonsillectomy: a treatment for inflammatory lesions of the lingual tonsil

Lingual tonsillectomy is a surgical treatment that is seldom performed because lingual tonsillitis is infrequently diagnosed. We have reviewed a group of patients with lingual tonsillitis or lingual tonsil hyperplasia who were treated with lingual tonsillectomy. Lingual tonsil lesions, the anatomy and histology of the lingual tonsil, and surgical approaches to lingual tonsillectomy are discussed.