Deposition of combustion aerosols in the human respiratory tract: comparison of theoretical predictions with experimental data considering nonspherical shape

Total deposition of petrol and diesel combustion aerosols and environmental tobacco smoke (ETS) particles in the human respiratory tract for nasal breathing conditions was computed for 14 nonsmoking volunteers, considering the specific pulmonary function parameters of each volunteer and the specific size distribution for each inhalation experiment. Theoretical predictions were 34.6% for petrol smoke, 24.0% for diesel smoke, and 18.5% for ETS particles. Compared to the experimental results, predicted deposition values were consistently smaller than the measured data (41.4% for petrol smoke, 29.6% for diesel smoke, and 36.2% for ETS particles). The apparent discrepancy between experimental data on total deposition and modeling results may be reconciled by considering the nonspherical shape of the test aerosols by diameter-dependent dynamic shape factors to account for differences between mobility-equivalent and volume-equivalent or thermodynamic diameters. While the application of dynamic shape factors is able to explain the observed differences for petrol and diesel combustion particles, additional mechanisms may be required for ETS particle deposition, such as the size reduction upon inspiration by evaporation of volatile compounds and/or condensation-induced restructuring, and, possibly, electrical charge effects.

Identification of some skeletal deformities in freshwater teleosts raised in Egyptian aquaculture

This study examines different forms of skeletal deformities detected in fish species collected from two Egyptian aquaculture facilities during two harvest seasons in 2008. Various patterns of skeletal deformities were observed in 19 of 959 fish collected. Deformities were diagnosed using a number of techniques including clinical, radiographic, sonographic and histopathological evaluations. Observed deformities included: lordosis and kyphosis in African catfish (Clarius gariepenius); lateral projection of the mandible, parrot-like head, scoliosis, kyphosis, lordosis and fusion of dorsal with anal fins in Nile tilapia (Oreochromis niloticus); and stump body, scoliosis and mandibular joint deformity in common carp (Cyprinus carpio). Relative incidences of deformities in fish from a facility located in the Sharkia province were 5.12%, 2.66% and 2.85% among catfish, Nile tilapia and common carp, respectively. At a second fish farm located in the Kafr Elsheikh province, the incidences of deformities were 1.02%, 1.55% and 0% among catfish, Nile tilapia and common carp, respectively. Some of the deformities were confirmed using both sonographic and histopathological evaluations. The reasons for the observed deformities could not be definitively determined, but possible aetiologies are discussed.

Evaluation of closure versus non-closure of vaginal vault after vaginal hysterectomy

This randomised prospective study in 53 women having vaginal hysterectomy for benign conditions compared a closed vault technique with an open technique. Twenty-seven had the vault closed (group A) whereas 26 patients had an open vault (group B). The primary outcomes include, vault haematoma (as detected by ultrasound on day 3) and fever. Secondary outcomes are haemorrhage, urinary tract infection, urinary retention and vault granulation tissue. The study did not show any statistical difference between either group. Prolapse of the fallopian tube was recorded in one case in the open vault group. A randomised controlled study on a larger scale is recommended.

[Primary malignant melanoma of the nasal cavity presenting as a large tumor of the cheek]

INTRODUCTION

Malignant melanoma of the nasal cavity is a rare tumor usually causing unilateral nasal obstruction and nasal bleeding. Diagnosis is achieved with immunohistochemistry analysis. Surgery is proposed for curative treatment.

CASE REPORT

We report the case of a 60-year-old man with a malignant melanoma of the nasal cavity revealed by an important tumor of the cheek. Epistaxis and nasal obstructive syndrome occurred later. Because of the tumor stage, palliative chemotherapy was performed but the patient died 4 months after the diagnosis.

DISCUSSION

This clinical presentation of malignant melanoma of the nasal cavity, related to local spreading, is exceptional. CT scan and MRI are essential for tumor staging and therapeutic decision-making. Prognosis remains poor.

Effective remediation of grossly polluted acidic, and metal-rich, spoil heap drainage using a novel, low-cost, permeable reactive barrier in Northumberland, UK

A permeable reactive barrier (PRB) for remediation of coal spoil heap drainage in Northumberland, UK, is described. The drainage has typical chemical characteristics of pH<4, [acidity]>1400 mg/L as CaCO3, [Fe]>300 mg/L, [Mn]>165 mg/L, [Al]>100mg/L and [SO4]>6500 mg/L. During 2 years of operation the PRB has typically removed 50% of the iron and 40% of the sulphate from this subsurface spoil drainage. Bacterial sulphate reduction appears to be a key process of this remediation. Treatment of the effluent from the PRB results in further attenuation; overall reductions in iron and sulphate concentrations are 95% and 67% respectively, and acidity concentration is reduced by an order of magnitude. The mechanisms of attenuation of these, and other, contaminants in the drainage are discussed. Future research and operational objectives for this novel, low-cost, treatment system are also outlined.

A new autologous keratinocyte dressing treatment for non-healing diabetic neuropathic foot ulcers

AIMS

To evaluate the use of a new cell-tailored carrier surface (TranCell) for delivery of autologous keratinocytes to promote wound healing in patients with chronic neuropathic foot ulcers.

METHODS

TranCell is a sterile medical grade polymer coated with a plasma-polymerized functional surface containing 20% carboxylic acid which enables keratinocytes to attach and proliferate. Six diabetic patients with neuropathic ulcers resistant to conventional therapy were treated with weekly applications of autologous keratinocytes delivered on TranCell. A split-thickness skin biopsy was taken from each patient followed by isolation, expansion and freezing down of keratinocytes. Keratinocytes were thawed and seeded on TranCell 48 h prior to application. This procedure was repeated weekly in addition to conventional therapy until wound healing was achieved.

RESULTS

Complete healing was achieved in six out of nine ulcers in six patients, a reduction in ulcer size was achieved in one ulcer and no response was seen in one ulcer. Treatment was discontinued in one patient due to development of Methicillin-Resistant Staphylococcus aureus (MRSA) after only three applications of TranCell. Wound healing took 6-17 applications over 6-20 weeks. There were no recurrences in the healed ulcers after a follow-up of 6 months.

CONCLUSIONS

TranCell delivery of autologous cells is a promising treatment for chronic diabetic foot ulcers with no side-effects and no recurrence in the healed ulcers.

Latanoprost-induced pigmentation in human iridial melanocytes is fibroblast dependent

The prostaglandin F2alpha derivative, latanoprost (LT), used in glaucoma treatment, can induce pigmentation in irises of patients with hazel or heterochromatic eye colour. The mechanism by which LT induces pigmentation in the iris is not yet established, although it does not appear to induce proliferation of iridial melanocytes. The purpose of this study was to develop an in vitro model in which to investigate this mechanism. The pigmentary responses to LT and prostaglandin F(2alpha) (PGF(2alpha)) were examined in human iridial melanocytes alone or in co-culture with epithelial cells (non-ocular human epidermal keratinocytes and iris pigment epithelial cells) or mesenchymal cells (non-ocular dermal fibroblasts or iridial fibroblasts). Melanogenesis was assessed after 4 days culture with prostanoids, using dopa oxidase activity. Prostaglandin FP expression on human iridial fibroblasts and melanocytes was investigated using an immunofluorescent technique employing antibody to PGF(2alpha) receptor and RT-PCR. Iridial melanocytes did not show a convincing increase in dopa oxidase when cultured alone but in the presence of fibroblasts (ocular or non-ocular) there was a significant increase (25-30%) in dopa oxidase activity in response to 10(-7)-10(-5)m LT and PGF(2alpha). Co-culture of melanocytes with epithelial cells, while leading to increased dopa oxidase activity, did not lead to any melanogenic response to LT or PGF(2alpha). FP receptor expression was detected on fibroblasts but not iridial melanocytes by immunocytochemistry and RT-PCR. The melanocyte/fibroblast co-culture model developed in this study also showed that LT and PGF(2alpha) increased dopa oxidase activity in melanocytes from donors with brown but not blue eyes. These results suggest that LT may be inducing pigmentation in the human iris indirectly through the FP receptor on adjacent fibroblasts.

The effect of cholecystokinin antagonism on postprandial lower oesophageal sphincter function in asymptomatic volunteers and patients with reflux disease

BACKGROUND

Postprandial acid reflux is thought to be mediated by the increase in transient lower oesophageal sphincter relaxations (TLOSR) frequency and fall in lower oesophageal sphincter (LOS) pressure seen after ingestion of a meal. Studies in animals and healthy volunteers suggest that cholecystokinin (CCK) may play a role.

AIM

To study the role of CCK in postprandial LOS function using the CCK antagonist loxiglumide.

SUBJECTS

10 asymptomatic volunteers (7 male, 20-29 years) and 9 patients with symptomatic gastro-oesophageal reflux (4 male, 33-66 years).

METHODS

Oesophageal, LOS and gastric pressure and oesophageal pH readings were recorded for 1 h before and 2 h after intragastric infusion of a 200 kCal, 300 mL long chain triglyceride meal. Each subject underwent two studies and received intravenous loxiglumide or placebo infusion in randomized order.

RESULTS

During placebo infusion, postprandial LOS pressure fell [volunteers: 17 (9-31) to 7 (1-19) mmHg (P < 0.01), patients: 15 (6-26) to 9 (2-21) mmHg (P=0.02)] and TLOSR frequency increased [volunteers: 0 (0-1) to 2 (0-7) per hour (P=0.01), patients: 0 (0-3) to 2 (0-10) per hour (P=0.03)]. Loxiglumide infusion attenuated the postprandial fall in LOS pressure and the postprandial increase in TLOSR frequency [volunteers: 0 (0-3) per hour (P=0.04 vs. placebo), patients: 0 (0-2) per hour (P=0.03 vs. placebo)], but it had only modest effects on postprandial acid exposure [volunteers: placebo 45 (0-1725) vs. loxiglumide 0 (0-443) seconds (N.S.), patients: placebo 60 (0-3442) seconds vs. loxiglumide 31 (0-1472) seconds (N.S.)].

CONCLUSIONS

Loxiglumide inhibits TLOSR and attenuates the fall in LOS pressure following a meal, but has only modest effects on postprandial gastro-oesophageal acid reflux.

Cellular and hormonal regulation of pigmentation in human ocular melanocytes

The purpose of this study was to examine some of the factors that may be relevant to regulating pigmentation in the human eye, specifically whether choroidal and iridial melanocytes are sensitive to regulation by epithelial and stromal cells and alpha-melanocyte stimulating hormone (alpha-MSH). Human choroidal and iridial melanocytes were established in culture and co-cultured with epithelial cells and stromal cells derived both from skin and from eye in order to determine their influence on choroidal and iridial melanocyte dopa oxidase activity. In all cases, co-culture of melanocytes with either epithelial cells or fibroblasts led to an increase in dopa oxidase activity during 5 days of co-culture. The extent of the increase ranged from 60% (non-significant) to as much as 185% when both fibroblasts and keratinocytes were present. The optimal ratio of fibroblasts to melanocytes was 1:10 (for dermal fibroblasts) or 1:2 (for iridial fibroblasts) and 1:1 for all epithelial cells to melanocytes. Both choroidal (three out of three cultures) and iridial (two out of three cultures) melanocytes showed increases in dopa oxidase activity to alpha-MSH when cultured in Green's media but the same cells cultured in MCDB153 were unresponsive to alpha-MSH. These in vitro studies suggest that ocular melanocytes have the capacity to be influenced by adjacent epithelial and stromal cells with respect to pigmentation.

Once versus divided daily dosing with delayed-release mesalazine: a study of tissue drug concentrations and standard pharmacokinetic parameters

BACKGROUND

Delayed-release mesalazine is traditionally taken as three divided doses. However, it is well-recognized that dosing frequency has a significant impact on compliance and that once daily dosing is preferable.

METHODS

We measured serum, urinary, faecal and rectal tissue concentrations of 5-aminosalicylic acid and N-acetyl 5-aminosalicylic acid in 24 healthy volunteers following dosing with delayed-release mesalazine, 1.2 g or 2.4 g daily, given as either a single daily dose at 08:00 hours or in three divided doses at 08:00, 13:00 and 18:00 hours.

RESULTS

Urinary and faecal excretion and rectal tissue concentrations of 5-aminosalicylic acid and N-acetyl 5-aminosalicylic acid were similar following single or divided daily dosing, at both doses studied. Peak serum concentrations were found at 06:00-09:00 following divided dosing and at 17:00-20:00 following once daily dosing. However, peak and trough serum levels and serum area under curve values (AUC) were similar with both regimens and at both doses.

CONCLUSIONS

Urinary, faecal and rectal tissue concentrations are similar following single or divided daily dosing. Minor differences in serum levels were apparent but maximum, minimum and AUC values were similar. Clinical trials should examine the efficacy and toxicity of once daily dosing in patients with ulcerative colitis.

Retention of urethrovesical foreign bodies: case report and literature review

Insertion of foreign bodies into the urethram to obtain sexual pleasure may be complicated by their passage into the urinary bladder along with an inability for the patient to recover the foreign body. We present such a case, review the relevant literature, and discuss Emergency Department (ED) diagnosis and management.

Simple method for the determination of 5-aminosalicylic and N-acetyl-5-aminosalicylic acid in rectal tissue biopsies

We describe a sensitive high-performance liquid chromatographic method for the determination of 5-aminosalicylic acid and N-acetyl-5-aminosalicylic acid in rectal tissue biopsies. Samples were derivatised using propionic anhydride and proteins were precipitated with methanol. A Supelcosil ABZ column (150x4.6 mm I.D., 5 microm silica particles) was used with a mobile phase comprising 0.1 M acetic acid, acetonitrile and triethylamine (1600:114:6, v/v/v). Fluorescence detection was employed and detection limits were 0.2 ng/mg tissue at a signal-to-noise ratio of three (measured concentration: 5-aminosalicylic acid, 0.254 (0.228-0.286) ng/mg, C.V. 10.7%; N-acetyl-5-aminosalicylic acid, 0.18 (0.154-0.198) ng/mg, C.V 9.8%). This assay was validated for use with serum, urine and faecal samples for which it proved to be both precise and accurate (C.V.<10%, measured concentration within 10%).

Mesalazine release from a pH dependent formulation: effects of omeprazole and lactulose co-administration

AIMS

Delayed-release formulations of mesalazine often rely on the gastrointestinal luminal pH profile to deliver 5-aminosalicylic acid (5ASA) to the colon. The aim of this study was to examine the influence of luminal pH on mesalazine release.

METHODS

We studied the effect of co-administration of omeprazole and lactulose on the steady-state pharmacokinetics of Eudragit S-coated mesalazine in healthy volunteers.

RESULTS

No significant changes in urinary or faecal levels of 5ASA or its main metabolite, N-acetyl 5ASA, were apparent.

CONCLUSIONS

This study suggests that co-administration of omeprazole and lactulose does not impair the release of delayed-release mesalazine.

The effect of antigamete antibodies on the success of assisted reproduction

The aim of the study was to investigate the presence of antigamente antibodies in unexplained infertility patients and to prove the efficiency of IUI and IVF-ET treatments for these patients. The study includes 46 unexplained infertility patients and as controls, a group of 21 tubal infertility patients. Serum, follicular fluid and cervical mucus samples were collected from each patient and antibodies were measured with commercial ELISA kits. Twenty-two of the 46 unexplained infertility patients produced at least one of the antibodies against sperm or ovary. Fertilization rates were lower in immunological and unexplained infertility patients than in tubal infertility patients, being statistically significant. Pregnancy rates were lower in immunological and unexplained infertility patients than in tubal infertility patients after IVF-ET, but this was not statistically significant. Pregnancy rates after IUI treatment were equal in both immunological and unexplained infertility groups. AGA (antigamete antibodies) were found in 45% of unexplained infertility patients and therefore may be a possible cause of infertility. IUI and IVF-ET are successful choices for treatment of these patients.

Interferon gamma and interleukin 10 levels in preimplantation embryo culture media

PURPOSE

The aim of our study is to elucidate whether human oocytes/embryos secrete IFN gamma and/or IL-10 and whether the fertilization process depends on the balance between these cytokines.

METHODS

A total of 142 embryo culture media from 24 patients were collected and the cytokine levels were tested with ELISA.

RESULTS

IFN gamma and IL-10 were detectable in 40.1% and 29.6% of culture media respectively. The difference of IFN gamma and IL-10 levels in media from fertilized oocytes between day 1 and day 2 are significant (0.46 vs. 1.47 and 34.2 vs. 12.7, respectively). However there was no significant difference between the IFN gamma levels of the media from fertilized and nonfertilized oocytes 0.46 vs. 0.85 at day 1 and 1.47 vs 1.49 at day 2, as well as IL-10 levels 34.2 vs. 30.9 at day 1 and 12.7 vs. 9.58 at day 2 respectively.

CONCLUSIONS

Human preimplantation embryos secrete the cytokines IFN gamma and IL-10. No effect of these cytokines on fertilization process could be shown.