Otitis media: treatment with intranasal aerosolized surfactant

OBJECTIVES/HYPOTHESIS: The objective was to determine the effect of intranasal surfactant alone and with other medications administered by metered dose inhaler aerosol on the function of the eustachian tube and on the resolution of experimentally induced otitis media with effusion (OME) and acute otitis media (AOM). STUDY DESIGN: Randomized, experimental, controlled animal studies. METHODS: Previously unreported (experiment 4) as well as published (experiments 1-3) data were detailed so that the reader could understand the continuum of information leading to the conclusions. In experiment 1, after a live-animal technique of measuring eustachian tube passive opening pressure was developed and validated, eustachian tube passive opening pressure was determined in 61 adult gerbils and 34 mice at baseline and 5 and 10 minutes after delivery of aerosolized intranasal metered dose inhaler surfactant. In experiments 2 and 3 (Klebsiella pneumoniae), lipopolysaccharide-induced OME was developed in gerbils. Thirty-five animals were randomly assigned to control, placebo, surfactant, surfactant with betamethasone, and surfactant with phenylephrine groups. Seventy animals were randomly assigned to control, placebo once daily (QD) and twice daily (BID), surfactant QD and BID, surfactant with betamethasone QD and BID, and surfactant with phenylephrine QD and BID groups. Intranasal aerosolized MDI medications were administered from postinfection day 2 until the effusion resolved. Otomicroscopy and tympanometry were performed on alternate days for 30 days. In experiment 4, AOM was developed in 39 chinchillas via transbullar injection of nontypeable Haemophilus influenzae on day 1. Thirteen animals each received placebo BID or surfactant BID, beginning on day 1. Thirteen animals received surfactant BID beginning on day 3. All administrations were continued for 10 days. Examinations were performed on seven occasions until day 27. Appropriate statistical measurements were employed, including one- and two-way ANOVA, strength-of-association measure (omega) calculation, chi, and Newman-Keuls post hoc multiple comparison tests. Significance was set as P value of less than.05. RESULTS: In experiment 1, a significant reduction in passive opening pressure was seen in both 5- and 10-minute postsurfactant measurements. Propellant alone was not effective. In experiments 2 and 3, OME resolved after an average period of 16 to 16.5 days in control, placebo QD and BID, and surfactant with phenylephrine QD groups. A significant decrease in OME days was seen in the surfactant QD (10.57 d) and BID (8.57 d), and surfactant with betamethasone QD (8.57 d) and BID (6.3 d) groups. A significant increase was seen in the phenylephrine BID group (18.67 d). In experiment 4, tympanometry was normal or near-normal in 62% and 48% of treated ears and in only 24% of placebo ears on day 12. Sixty-seven percent of placebo ears were culture positive at day 27, compared with 10% and 16% in surfactant groups 1 and 2. Seventy-five percent of untreated animals developed severe labyrinthitis, compared with 15% in groups 1 and 2. On day 27, 58% of placebo group middle ears had fluid, whereas 61% and 62% of ears in groups 1 and 2, respectively, were dry. These findings were significant. CONCLUSION: Intranasal application of aerosolized metered dose inhaler surfactant alone or with steroid reduced eustachian tube passive opening pressure in normal animals and duration of effusion in animals with experimental OME. Intranasal surfactant reduced the severity and duration of middle ear infection in AOM in this animal model.     

Technetium-99m-L,L-ethylenedicysteine renal scan as a single-modality investigation for the evaluation of renal morphology and function: a comparative study with technetium-99m-dimercaptosuccinic acid

AIM: To evaluate whether cortical scars can be detected using the summed images of technetium-99m-L,L-ethylenedicysteine (99mTc-L,L-EC) renal dynamic scan, and to compare the results with technetium-99m-dimercaptosuccinic acid (99mTc-DMSA) scan. To evaluate the inter-observer variability for 99mTc-L,L-EC and 99mTc-DMSA scan reporting. METHODS: One hundred and three patients were initially included in the study; 21 were excluded, five due to a single functioning kidney and 16 due to impaired renal function (serum creatinine>2.5 mg.dl(-1)). Eighty-two patients (39 females, 43 males), including 31 children, with a mean age of 33.4+/-11.3 years (range, 4 months to 74 years), underwent both 99mTc-DMSA and 99mTc-L,L-EC scintigraphy within a period of 14 days. 99mTc-L,L-EC images were regrouped into 2 min image sets, and the initial 2 min summed image (cortical phase) was used for the evaluation of scars. Three independent observers analysed both images separately on different days without being aware of the identity and clinical details of the patients. Their 99mTc-L,L-EC findings were compared with the consensus 99mTc-DMSA scan findings taken as reference. RESULTS: The overall sensitivity of 99mTc-L,L-EC scans was 93% and the specificity was 96%. The inter-observer variability was 0.91 for 99mTc-L,L-EC and 0.94 for 99mTc-DMSA scan reporting, using the weighted kappa analysis at P<0.05. CONCLUSIONS: 99mTc-L,L-EC is an excellent single-modality comprehensive investigational agent for renal morphology, function and outflow tract evaluation with the added advantages of lower cost, convenience and low radiation exposure to the patient.     

Cardiovascular disease in athletes

Cardiovascular disease (CVD) is the leading cause of death in the United States, resulting in increased awareness of the preventive importance of regular physical activity. Because athletes are considered physically fit, occurrence of sudden athlete death from CVD is perplexing. Regular intense physical activity can cause changes to the cardiovascular system that mimic known CVD processes. Therefore, screening of athletes for conditions that may increase risk for sudden cardiac death (SCD) is challenging. This article focuses on this problem, discussing the athlete's heart, SCD and associated CV conditions, and preparticipation screening. We also review recommendations of the 26th Bethesda Conference on determining eligibility for competition in athletes with known CV abnormalities, and how the recommendations relate to individual disease processes.     

Interaction of BKCa channel modulators with adrenergic agonists in the rat aorta is influenced by receptor reserve

Our main objective was to study the interaction of BKCa channel modulators with adrenergic agonists UK 14304 and noradrenaline (NA), acting on alpha1-adrenoceptors, in the rat aorta and how this is affected by receptor reserve. NA and UK 14304 evoked concentration-dependent contractions of the rat aorta. UK 14304 was a partial agonist relative to NA in this preparation. The BK(Ca) channel blocker tetraethylammonium (TEA, 1 mM) and opener NS 1619 (3 x 10(-5) M) modulated NA- and UK 14304-induced contractions, and were more effective on UK 14304-induced contractions. TEA (1 mM) increased the maximum response to NA and UK 14304 by about 13% and 300%, respectively, while NS 1619 (3 x 10(-5) M) reduced the maximum response to UK 14304 by about 81% compared to 31% for noradrenaline. The effect of TEA on the noradrenaline concentration-response curve was increased after treatment of the aorta with phenoxybenzamine (PBZ), an irreversible alpha1-adrenoceptor antagonist, to reduce receptor reserve. We concluded that the interaction of BKCa channel modulators with alpha1-adrenergic agonists in the rat aorta was influenced by receptor reserve.     

Formulation of an HPMC gel drug reservoir system with ethanol-water as a solvent system and limonene as a penetration enhancer for enhancing in vitro transdermal delivery of nicorandil

The objective of the present study was to formulate a hydroxypropyl methylcellulose (HPMC) gel drug reservoir system with ethanol-water as a solvent system and limonene as a penetration enhancer for enhancing the transdermal delivery of nicorandil so as to develop and fabricate a membrane-moderated transdermal therapeutic system (TTS). The in vitro permeation of nicorandil was determined across rat abdominal skin from a solvent system consisting of ethanol or various proportions of ethanol and water. The ethanol-water (70:30 v/v) solvent system that provided an optimal transdermal permeation was used in formulating an HPMC gel drug reservoir system with selected concentrations (0% w/w, 4% w/w, 6% w/w, 8% w/w or 10% w/w) of limonene as a penetration enhancer for further enhancement of transdermal permeation of nicorandil. The amount of nicorandil permeated in 24 h was found increased with an increase in the concentration of limonene in the drug reservoir system up to a concentration of 6% w/w, but beyond this concentration there was no further increase in the amount of drug permeated. The flux of nicorandil was 370.9 +/- 4.2 microg/cm2 x h from the drug reservoir system with 6% w/w of limonene, which is about 2.6 times the required flux to be obtained across rat abdominal skin for producing the desired plasma concentration for the predetermined period in humans. The results of a Fourier Transform Infrared study indicated that limonene enhanced the percutaneous permeation of nicorandil by partially extracting the stratum corneum lipids. It is concluded that the HPMC gel drug reservoir system prepared with a 70:30 v/v ethanol-water solvent system containing 6% w/w of limonene is useful in designing and fabricating a membrane-moderated TTS of nicorandil.     

Enhanced transport of a novel anti-HIV agent--cosalane and its congeners across human intestinal epithelial (Caco-2) cell monolayers

PURPOSE: Cosalane is a potent inhibitor of HIV replication with activity against a broad range of viral targets. However, oral bioavailability of this highly lipophilic compound is extremely poor (<1%). The purpose of this study is to screen a variety of permeation enhancers (cyclodextrin derivatives, cremophor EL, bile salts and mixed micelles) for their ability to enhance the transport of cosalane and its analogs/prodrugs across Caco-2 cell monolayers. METHODS: Cosalane and its different analogs/prodrugs were synthesized and their physicochemical properties were determined. Caco-2 cells were cultured at a density of 66,000 cells/cm(2) either on collagen coated clear polyester membranes or Transwell inserts. Side-bi-side diffusion cells and Transwell inserts were employed to study for the transport of cosalane and its analogs/prodrugs with various permeation enhancers across Caco-2 cell monolayers. RESULTS: Permeabilities of EH-3-39, EH-3-55 and EH-3-57 significantly improved compared to that of cosalane in the presence of bile salt, sodium desoxycholate. Among the various cyclodextrins studied, hydroxypropyl beta cyclodextrin (HP-beta-CD) and dimethyl beta cyclodextrin (DM-beta-CD) exhibited 22.3-fold and 19-fold permeability enhancement of cosalane respectively across Caco-2 cell monolayers. Sodium desoxycholate (10 mM) also showed a remarkable (105-fold) enhancement on the permeability of cosalane (P(app) 11.72+/-3.31 x 10(-6) cm/s) without causing any measurable cellular damage. Cremophor EL resulted in higher transport of 14C mannitol. The mechanism of enhancement effect can be mainly attributed to the alteration of membrane fluidity by cyclodextrin and opening of tight junctions by cremophor EL. CONCLUSIONS: Among the enhancers tested, 10 mM sodium desoxycholate and HP-beta-CD appear to be viable candidates for further development of an oral formulation of cosalane and its congeners.     

Clinicopathological significance of tissue homeostasis in Indian breast cancer

BACKGROUND: Tissue homeostasis and the maintenance of cell populations depend on a delicate balance between the rates of cell proliferation and cell death. Disruption of this balance is an important factor in development and progression of tumors. In the present study we evaluated the growth index in a large group of breast cancer patients and correlated it with various clinical and histopathological features of the tumor. METHODS: Estimation of apoptosis was determined by TUNEL assay while immunocytochemistry for proliferating nuclear cell antigen (PCNA) was used as a measure of proliferation. Necrosis was identified morphologically by haematoxylin and eosin staining. RESULTS: A positive correlation was observed between the percentage of PCNA positive cells and the frequency of mitosis (r=0.6117, p<0.0001). A highly statistical significant correlation was observed between type of tissue analyzed and growth index (r=0.46869, p<0.0001). No significant association was observed between hormone receptor status and growth index. CONCLUSIONS: The growth index was found to be higher in carcinoma cells that metastasised into lymph nodes compared with primary lesions with no nodal metastasis. Growth index was particularly prominent in high-grade tumors in which increased proliferative activity was evident. Apoptotic cells were detected more frequently in tumor cells with higher rather than lower proliferative activity. This suggests that not only proliferative activity but also capacity for apoptosis is altered in breast tumors.     

In vivo demonstration that human parathyroid hormone 1-38 inhibits the expression of osteoprotegerin in bone with the kinetics of an immediate early gene.

Osteoprotegerin (OPG) is a potent inhibitor of osteoclast formation and function. To elucidate how OPG is regulated in bone, we examined (1) the expression and localization of OPG protein in bone tissue, (2) the effect of human parathyroid hormone 1-38 (hPTH 1-38) on OPG messenger RNA (mRNA) levels in rat femur metaphyseal and diaphyseal bone, and (3) the effect of hPTH(1-38) on expression of OPG mRNA in cultured osteoblast-like cells derived from the metaphysis and diaphysis, and in ROS 17/2.8 osteosarcoma cells. Because PTH has been shown to stimulate osteoblast activity via the cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA) signal transduction pathway we also investigated whether PTH action on OPG in vivo is dependent on activation of cAMP/PKA pathway. Immunohistochemistry was used to evaluate OPG protein expression and Northern blot hybridization was used to analyze OPG mRNA expression both in vivo and in vitro. Immunohistochemistry of OPG protein expression in the rat distal femur metaphysis revealed that it was localized predominantly in preosteoblasts, osteoblasts, lining cells, and the osteoid layer, with occasional immunoreactivity in osteocytes and cells of the bone marrow. Subcutaneous (sc) administration of a single injection of hPTH(1-38) at 80 microg/kg induced a rapid and transient decrease in OPG mRNA expression in both metaphyseal and diaphyseal bone. The decrease in OPG message was evident by 1 h and mRNA levels returned to baseline after 3 h. PTH analog PTH(1-31), which stimulates intracellular cAMP accumulation, inhibited OPG expression, whereas PTH analogs (3-34 and 7-34) that do not stimulate cAMP production had no effect on expression. In contrast to PTH, prostaglandin E2 (PGE2) had no effect on OPG mRNA expression in vivo in the metaphyseal bone cells, under conditions in which PGE2 does promote expression of the c-fos gene. The in vivo effects of hPTH(1-38) on OPG mRNA were confirmed in isolated primary osteoblast cultures derived from either metaphyseal or diaphyseal bone as well as in ROS 17/2.8 osteosarcoma cells. We propose that the rapid and transient decrease in OPG expression may initiate a cascade of events resulting in the differentiation of osteoclast progenitor. Such a spatially and temporally programmed effect of PTH might contribute to bone turnover.