Continuous positive airway pressure treatment may negatively affect auditory maturation in preterm infants

AIM

Nasal continuous positive airway pressure (CPAP) devices generate loud noise, which might harm auditory function and maturation. The function of auditory pathways can be examined by using brainstem auditory evoked potential (BAEP) and brainstem audiometry (BA) recordings. Our objective was to study whether CPAP treatment during the neonatal period is associated with abnormalities in BAEP and BA recordings.

METHODS

Included in this retrospective study were preterm infants (birth weight ≤1500 g and/or gestational age ≤32 weeks) born between 2002 and 2006 with a comprehensive clinical background and follow-up data, including the duration of CPAP treatment (n = 162). BAEP and BA were recorded near the mean corrected age of one month. The following variables from BAEP and BA examinations were analysed: latencies of BAEP components I, III, V, interpeak intervals (IPI) I-V, I-III, III-V (ms), amplitude I and V (µV), amplitude ratio I/V and BA thresholds.

RESULTS

In the adjusted analysis, a longer CPAP treatment leads to longer latencies of BAEP component III (p = 0.01) and V (p = 0.02) in the right ear.

CONCLUSION

CPAP treatment may impair the auditory maturation and processing mediated via the dominant right ear. The hearing and neurodevelopment of the children who are treated with CPAP should be followed.

Neonatal brainstem auditory function associates with early receptive language development in preterm children

AIM

To study whether auditory function measured with brainstem auditory evoked potential and brainstem audiometry recordings in the neonatal period associates with language development 1 year later in preterm infants.

METHODS

This retrospective study included 155 preterm infants (birthweight ≤1500 g and/or birth ≤32 gestational weeks) born between 2007 and 2012 at the Turku University Hospital. Auditory function was recorded in neonatal period. Information of language development was gathered at the mean corrected age of 1 year by using the Finnish version of the MacArthur Communicative Development Inventory.

RESULTS

Slower auditory processing (longer interpeak interval, IPI I-V) in the right ear in the neonatal brainstem auditory evoked potential recording associated with smaller receptive lexicon size at 1 year (P = .043). Infants with longer IPI I-V were more likely to have a deviant (≤17 words) receptive lexicon size (P = .033). The absence of a contralateral response with right ear stimulation increased the risk for deviant lexicon size (P = .049).

CONCLUSION

The results suggest that impaired auditory function in the neonatal period in preterm infants may lead to a poorer receptive language outcome 1 year later. Auditory pathway function assessment provides information for the identification of preterm children at risk for weak language development.

Dislocation of cochlear implant magnet as a complication following MRI

According to current best knowledge, an MRI scan can be performed for patients with cochlear implants. The warnings and recommendations of the implant manufacturers must be followed strictly to prevent complications, such as overheating, migration or demagnetization of the magnet in the implant. We report on a case of cochlear implant magnet dislocation as a complication for an MRI scan. The patient had a tight bandage around the head to hold the magnet in place as recommended by the manufacturer, but apparently the bandage was not in the correct place.

Antibacterial properties of nitric oxide-releasing porous silicon nanoparticles

In this study, the antibacterial efficacy of NO-releasing porous silicon nanoparticles (pSiNPs) is reported. NO-releasing pSiNPs were produced via the conjugation of S-nitrosothiol (SNO) and S-nitrosoglutathione (GSNO) donors to the nanoparticle surfaces. The release of the conjugated NO caused by the decomposition of the conjugated SNO and GSNO was boosted in the presence of ascorbic acid. The released NO was bactericidal to Gram-positive (Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli), and eliminated bacterial growth within 2 h of incubation without compromising the viability of mammalian cells. These results demonstrate the advantages of NO-releasing pSiNPs for antibacterial applications, for example, in chronic wound treatment.

Invasive Candida infections in surgical patients in intensive care units: a prospective, multicentre survey initiated by the European Confederation of Medical Mycology (ECMM) (2006-2008)

A prospective, observational, multicentre study of invasive candidosis (IC) in surgical patients in intensive care units (ICUs) was conducted from 2006 to 2008 in 72 ICUs in 14 European countries. A total of 779 patients (62.5% males, median age 63 years) with IC were included. The median rate of candidaemia was 9 per 1000 admissions. In 10.8% the infection was already present at the time of admission to ICU. Candida albicans accounted for 54% of the isolates, followed by Candida parapsilosis 18.5%, Candida glabrata 13.8%, Candida tropicalis 6%, Candida krusei 2.5%, and other species 5.3%. Infections due to C. krusei (57.9%) and C. glabrata (43.6%) had the highest crude mortality rate. The most common preceding surgery was abdominal (51.5%), followed by thoracic (20%) and neurosurgery (8.2%). Candida glabrata was more often isolated after abdominal surgery in patients ≥60 years, and C. parapsilosis was more often isolated in neurosurgery and multiple trauma patients as well as children ≤1 year of age. The most common first-line treatment was fluconazole (60%), followed by caspofungin (18.7%), liposomal amphotericin B (13%), voriconazole (4.8%) and other drugs (3.5%). Mortality in surgical patients with IC in ICU was 38.8%. Multivariate analysis showed that factors independently associated with mortality were: patient age ≥60 years (hazard ratio (HR) 1.9, p 0.001), central venous catheter (HR 1.8, p 0.05), corticosteroids (HR 1.5, p 0.03), not receiving systemic antifungal treatment for IC (HR 2.8, p <0.0001), and not removing intravascular lines (HR 1.6, p 0.02).

Hearing aid compliance in the elderly

OBJECTIVES

A decreasing but still substantial proportion of elderly persons with hearing aids use them only occasionally. Because the prevalence of age-related hearing loss is increasing, it is important for the hearing rehabilitation process to be effective. The aim of this study was to use a mailed questionnaire to evaluate the rate of hearing aid use and the reasons for minimal use or nonuse.

METHODS

Questions about hearing aid use and associated problems were included in a survey of hearing mailed to 4,067 people in age cohorts of 70, 75, 80 and 85 years in an industrialized urban community in Finland.

RESULTS

In this sample of 249 hearing aid users, 55.4% used their hearing aid daily, and 27.3% used it > 6 hours a day. The percentage of subjects who never used their hearing aid was 10.7%. Use of hearing aids tended to decline with advancing age. The most common reasons for minimal use were disturbing background noise, acoustic feedback problems, battery cost, and a lack of motivation to use the hearing aid.

CONCLUSIONS

Compliance with hearing aid use by the elderly is increasing, but a significant proportion of hearing aids are still used only occasionally or never. We discuss methods to improve compliance in this patient group. Our results may be used to reexamine existing procedures for fitting hearing aids for counseling, which may increase patient compliance with hearing aids, leading to greater benefits from their use.

Chemical stability studies of thermally-carbonized porous silicon

We have studied chemical stability of thermally-carbonized porous silicon (PS). The initial hydrogen termination of PS has been replaced by carbon using thermal dissociation of acetelyne molecules. This kind of carbonized surface has been found to be at least as stable in humid atmosphere as a thermally-oxidized PS surface. It is also found to be stable in an aqueous KOH and HF. In-vitro studies of tissue compatible in simulated human fluid indicate improved stability and that the carbonized surface could be bioactive.

Dispersive Fourier Transform Spectroscopy Of Free-Standing Porous Silicon Films

We have investigated optical constants of free-standing porous silicon films by dispersive Fourier transform spectroscopy (DFTS) in the NIR-VIS range. This allows the spectral variation of both the absorption coefficient and the refractive index of a material to be determined from the measurements of the attenuation and phase shift imposed on an electromagnetic wave by its interaction with a specimen. Using these optical constants, we have studied the complex dielectric function and the complex conductivity. To avoid the additive error in the absorption spectra arising from the pseudocoherence, we measured the transmission spectra by conventional Fourier transform spectroscopy (FTS). Using the refraction spectrum derived from the DFTS measurements, we have corrected for reflection losses in calculation of the absorption spectrum from the FTS transmission spectrum. The changes in the absorption coefficient and the refractive index due to oxidation, which is the most common aging phenomenon in porous silicon, have been studied using samples with different types of oxidization.

Investigations of Oxidation Dependence on Type of Porous Silicon Near Room Temperature by Isothermal Microcalorimeter

Oxidation of porous silicon has been studied using thermal activity monitoring, i.e. isothermal microcalorimeter. It was found that, at room temperature (25 °C) the micro-calorimetric signal from the oxidation of the p+-type porous silicon (PS) reduces exponentially, while in the case of n-type PS, the signal starts to increase slowly, reaching its highest value after some hours. This kind of behaviour is typical of autocatalytic reactions. To clarify the origin of the difference, we varied the preparation parameters of the porous silicon. We determined the activation energy from the measurements near the room temperature (25–70 °C). The results of this research have been compared with the previous observations and the possible origin of the difference has been discussed.

[Screening for hearing loss in newborns at Turku University Central Hospital]

BACKGROUND

Since 2005 all newborns at Turku University Central Hospital, Finland have been screened for hearing loss with two-stage procedure (otoacoustic emission and automated auditory brainstem response).

METHODS

We reviewed medical records of all newborns screened for hearing loss in 2006-2008. Costs of the screening were estimated.

RESULTS

12011 newborns were screened. In 12 newborns moderate to severe bilateral hearing defect was detected. The incidence of hearing defect was 0.06% among healthy newborns and 0.8% among very preterm infants. Costs of the two-stage screening were 26% lower than those of the one-stage model.

CONCLUSIONS

Two-stage screening for hearing improved identification of newborns with hearing loss in a cost-effective manner.

[What's new in auditory rehabilitation?]

The availability of auditory rehabilitation has significantly improved with the current legislation. Rehabilitation options have developed with advanced hearing aid technology. With the aging population, the number of persons using a hearing aid is increasing. A physician will need basic abilities to communicate with an elderly for whom the use of a hearing aid may be problematic. Besides a hearing aid, a hearing-impaired person may need other appliances, such as a better audible doorbell or an amplified telephone. In severe cases, alarm systems comprising of a fire alarm and indicator of doorbell and telephone ringing may be necessary.

Ten years of the North Karelia project

Medical and epidemiological research into the aetiology of CHD has drawn attention to the likely causal role of certain risk factors, especially elevated serum (LDL) cholesterol and blood pressure levels, and smoking. Conventional trials to establish the causality have come up against problems of feasibility and study design. Community-based studies have considerable potential in introducing changes to the general lifestyle and risk factors in large numbers of people (since the risk factors are closely related to the way of life and other features of the community). Thus a well evaluated community-based study can augment our knowledge on the role of the risk factors. Furthermore, a community study examines how the existing service structure and community resources can be used and assesses the overall feasibility and consequences of such an intervention. The North Karelia project, started in eastern Finland in 1972, has been a major community-based study on the prevention of CHD. The results of the 10-year evaluation of the project illustrate the feasibility and consequences of the approach. During the 10-year period 1972-82 the following net changes (i.e. adjusted for changes in the reference area) occurred in the risk factor means of the population aged 30-59 in North-Karelia: -28% for smoking (p less than .001), -3% for serum cholesterol (p less than .001) and -3% for systolic BP (p less than .001). During the period 1974-79 the age-standardized CHD mortality of men aged 30-64 was reduced by 22% in North Karelia, 12% in the reference area and 11% in the rest of Finland (p less than .05 compared with NK).(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluation of mesoporous TCPSi, MCM-41, SBA-15, and TUD-1 materials as API carriers for oral drug delivery

The feasibility of four mesoporous materials composed of biocompatible Si (TCPSi) or SiO(2) (MCM-41, SBA-15, and TUD-1) were evaluated for oral drug delivery applications. The main focus was to study the effect of the materials different pore systems (unidirectional/2D/3D) and their pore diameters, pore size distributions, pore volumes on the maximal drug load capacity, and release profiles of a loaded active pharmaceutical ingredient. Ibuprofen was used as the model drug. The total pore volume of the mesoporous solid was the main factor limiting the maximum drug load capacity, with SBA-15 reaching a very high drug load of 1:1 in weight due to its high pore volume. Dissolution experiments were performed in HBSS buffers of pH 5.5, 6.8, and 7.4 to mimic the conditions in the small intestine. At pH 5.5 the dissolution rate of ibuprofen released from the mesoporous carriers was significantly faster compared with the standard bulk ibuprofen (86-63% versus 25% released at 45 min), with the fastest release observed from the 3D pore network of TUD-1 carrier. The utilization of mesoporous carriers diminished the pH dependency of ibuprofen dissolution (pK(a) = 4.42), providing an interesting prospect for the formulation of poorly soluble drug compounds.

Surface chemistry and pore size affect carrier properties of mesoporous silicon microparticles

Six different types of mesoporous silicon microparticles were prepared to evaluate the effect of surface treatment and pore sizes on their properties as drug carriers. The studied porous silicon particles were as-anodized, thermally carbonized (TCPSi) and thermally oxidized (TOPSi) in addition to three novel ones: annealed TCPSi, annealed TOPSi and thermally hydrocarbonized porous silicon (THCPSi). Drug dissolution at pH 5.5 and physical and chemical stabilities after 3 months of storage were used as experimental models to investigate the loaded particles. Loading degrees of ibuprofen in the particles were determined by several methods before and after storage, and the results were in good agreement with each other. Loading improved the dissolution rate of ibuprofen in all the studied cases, while the hydrophilic TCPSi material resulted in the fastest dissolution and the most stable mesoporous microparticles. The release profiles of ibuprofen did not change markedly during storage. The effect of storage on the loading degrees of the other PSi microparticles than the unstable (easily oxidized) as-anodized porous silicon was not notable.

Alexithymia, depression and tinnitus in elderly people

OBJECTIVE

Tinnitus is known to have an association with depression and other psychiatric disorders. As part of a larger epidemiological survey, we evaluated the associations among tinnitus, depression and alexithymia in a group of elderly people.

METHODS

A survey of hearing loss, audiological rehabilitation and associated morbidity in a senior population was conducted in Turku, Finland. The study sample consisted of 583 participants aged between 70 and 85 years. The Toronto Alexithymia Scale (TAS-20) was used to measure alexithymia, whereas the 13-item version of the Beck Depression Inventory was used to measure depression; the subjective experience of tinnitus was queried with a questionnaire.

RESULTS

Depression had a clear association with subjectively annoying tinnitus. Contrary to expectations, the TAS-20 score did not correlate with the severity of tinnitus. In fact, the highest TAS-20 scores were found among the subjects who had tinnitus but did not find it to be subjectively annoying. No significant association between high TAS-20 scores and hearing loss was found.

CONCLUSION

Although we found an association between TAS-20 scores and the presence of tinnitus, alexithymia does not seem to be helpful in explaining tinnitus annoyance among elderly people.

A retrospective nationwide case study on the use of a new antifungal agent: patients treated with caspofungin during 2001–2004 in Finland

The aim of this study was to evaluate the efficacy and safety of caspofungin in patients treated in Finland during the period 2001-2004. The medical records of 78 adult patients treated with caspofungin in five major hospitals were reviewed retrospectively. Fifty-nine (76%) patients had proven invasive fungal infection, of whom 22 (28%) had aspergillosis and 37 (47%) had candidiasis. Nineteen (24%) patients were treated empirically; only 13 (17%) patients received caspofungin as primary therapy. A favourable response was achieved in 52 (67%) patients. The response rate was 78% in patients with candidiasis, and 50% in patients with aspergillosis. At the end of the study period, 40 (51%) patients remained alive; of the 38 deaths, nine (24%) were caused by fungal infection. The response rates were lower, although not significantly, for patients with high (>20) vs. low (< or =20) Acute Physiology and Chronic Health Evaluation (APACHE II) scores (response rate 50% vs. 68%, p 0.48, respectively), and were also lower in patients with long-term (>20 days) vs. shorter duration (< or =20 days) neutropenia (55% vs. 73%, p 0.32, respectively), and in those with an underlying haematological malignancy vs. patients with other diseases (59% vs. 73%, p 0.2, respectively). In five (6%) patients, caspofungin therapy was discontinued prematurely because of adverse drug reactions (ADRs) (elevated liver enzyme values in three patients, neuropathic pain in one, and skin rash in one). Serious ADRs occurred in two (3%) patients (severe hepatic insufficiency with consequent death, and eosinophilia with elevated alkaline phosphatase levels), and laboratory abnormalities, mostly mild and reversible, in 24 (31%) patients. In this unselected patient population, caspofungin was safe, well-tolerated, and had an efficacy comparable to that in previous reports from prospective trials.

Mesoporous silica material TUD-1 as a drug delivery system

For the first time the feasibility of siliceous mesoporous material TUD-1 (Technische Universiteit Delft) for drug delivery was studied. Model drug, ibuprofen, was adsorbed into TUD-1 mesopores via a soaking procedure. Characterizations with nitrogen adsorption, XRD, TG, HPLC and DSC demonstrated the successful inclusion of ibuprofen into TUD-1 host. The amount of ibuprofen adsorbed into the nanoreservoir of TUD-1 material was higher than reported for other mesoporous silica drug carriers (drug/carrier 49.5 wt.%). Drug release studies in vitro (HBSS buffer pH 5.5) demonstrated a fast and unrestricted liberation of ibuprofen, with 96% released at 210 min of the dissolution assay. The drug dissolution profile of TUD-1 material with the random, foam-like three-dimensional mesopore network and high accessibility to the dissolution medium was found to be much faster (kinetic constant k = 10.7) and more diffusion based (release constant n = 0.64) compared to a mesoporous MCM-41 material with smaller, unidirectional mesopore channels (k = 4.7, n = 0.71). Also, the mesoporous carriers were found to significantly increase the dissolution rate of ibuprofen, when compared to the pure crystalline form of the drug (k = 0.6, n = 0.96). TUD-1 was constituted as a potential drug delivery device with fast release property, with prospective applications in the formulation of poorly soluble drug compounds.

Role of candidate genes in the lipid responses to intensified treatment in Type 2 diabetes

OBJECTIVE

To identify genetic factors related to individual differences in lipid responses to intensified treatment in Type 2 diabetes.

DESIGN AND METHODS

After evaluation and intensification of their treatment, 107 Type 2 diabetes patients with poor metabolic control were re-evaluated after mean follow-up time of 15.6 (0, 4) (SE) months. The genes coding major lipid regulatory proteins and their relations to plasma lipid and lipoprotein changes were studied.

RESULTS

During the follow-up, levels of glycohemoglobin A1 (GHBA1) decreased (-1.7%), plasma HDL cholesterol (+0.05 mmol/l) and lipoprotein (a) [Lp(a)] (+4.2 mg/dl) increased, while triglyceride (TG) levels decreased (-1.2mmol/l) despite mean weight gain of 2.1 kg (p from <0.01 to <0.001). Of the gene markers studied, the lipoprotein lipase (LPL) Pvull (p=0.005) independently affected changes in HDL-cholesterol and was associated with the frequency of coronary heart disease (CHD). Lp(a) changes were associated with apolipoprotein B (ApoB) Glu4154Lys polymorphism (p=0.004).

CONCLUSIONS

These results suggest that genetic variations at LPL and ApoB loci are among the factors contributing to the variability in response to lipid parameters to therapy in Type 2 diabetes. LPL Pvull rare allele homozygote status seems to be beneficial with more favorable lipid changes and protection against CHD.

Mesoporous silicon microparticles for oral drug delivery: Loading and release of five model drugs

Mesoporous silicon (PSi) microparticles were produced using thermal carbonization (TCPSi) or thermal oxidation (TOPSi) to obtain surfaces suitable for oral drug administration applications. The loading of five model drugs (antipyrine, ibuprofen, griseofulvin, ranitidine and furosemide) into the microparticles and their subsequent release behaviour were studied. Loading of drugs into TCPSi and TOPSi microparticles showed, that in addition to effects regarding the stability of the particles in the presence of aqueous or organic solvents, surface properties will affect compound affinity towards the particle. In addition to the surface properties, the chemical nature of the drug and the loading solution seems to be critical to the loading process. This was reflected in the obtained loading efficiencies, which varied between 9% and 45% with TCPSi particles. The release rate of a loaded drug from TCPSi microparticles was found to depend on the characteristic dissolution behaviour of the drug substance. When the dissolution rate of the free/unloaded drug was high, the microparticles caused a delayed release. However, with poorly dissolving drugs, the loading into the mesoporous microparticles clearly improved dissolution. In addition, pH dependency of the dissolution was reduced when the drug substance was loaded into the microparticles.

Bronchoalveolar lavage in immunocompromised patients with haematological malignancy--value of new microbiological methods

PURPOSE

To assess the usefulness of new culture-independent microbiological methods to analyse bronchoalveolar lavage (BAL) fluid from haematological patients with clinical pneumonia.

PATIENTS AND METHODS

Results of 135 BALs from 122 disease episodes in 99 patients treated between 1996 and 2002 were retrospectively analysed. Forty-three patients had undergone haematopoietic stem cell transplantation and 56 patients had been treated with conventional chemotherapy for haematological malignancy. In addition to conventional microbiological methods, polymerase chain reaction (PCR) tests for Pneumocystis carinii, cytomegalovirus (CMV), Legionella sp., mycobacterium, Mycoplasma pneumoniae, and Chlamydia pneumoniae and the Aspergillus antigen test were performed.

RESULTS

Three (2.2%) quantitative and four (3.0%) special bacterial cultures gave an aetiological diagnosis. A respiratory virus was isolated in 10 episodes (8.2%). The diagnostic yield increased to 35.6% (48 of 135) by other methods. The P. carinii PCR test was positive in 21 of 24 patients with P. carinii pneumonia, being the only microbiological indication of P. carinii in four cases. The CMV PCR test was positive in 18 patients, but in 14 patients the clinical significance of the finding remained unproven. The Aspergillus antigen test was positive in seven of nine patients with aspergillosis, being the only microbiological indication of Aspergillus in three cases. The result of BAL indicated commencement of specific antimicrobial treatment in 27 episodes (22.1%).

CONCLUSION

The contribution of new culture-independent methods to the total diagnostic yield was of note. Among these methods, the P. carinii PCR and Aspergillus antigen tests proved the most valuable, while the CMV PCR test was not clinically useful.

Invasive fungal infections in autologous stem cell transplant recipients: a nation-wide study of 1188 transplanted patients

Based on small single-centre series, the risk of invasive fungal infections (IFI) has been considered small in autologous stem cell transplant (ASCT) recipients.

PURPOSE

To analyse epidemiological and clinical features of (IFI) among ASCT recipients in Finland 1990-2001.

PATIENTS

During the study period, 1188 adult patients received high-dose therapy supported by ASCT in six centres. Altogether, 1112 patients (94%) received blood progenitor cells. The graft was CD34+ selected in 261 patients (22%). The major diagnostic groups were non-Hodgkin's lymphoma (n = 417), multiple myeloma (n = 395), breast cancer (n = 132) and Hodgkin's lymphoma (n = 53).

RESULTS

Eighteen patients (1.5%) with IFI were identified. The incidence of proven or probable invasive aspergillosis was 0.8%, followed by candidaemia with an incidence of 0.3%. The median time to the diagnosis of IFI was 35 d (6-162) from the progenitor cell infusion. In fourteen patients (78%) IFI was diagnosed during lifetime and they were treated with antifungal therapy for a median of 50 d. Nine patients (64%) were cured.

CONCLUSIONS

IFI appears to be a rare event after ASCT and Aspergillus infections seem to be predominant. These epidemiological features have an impact in planning prophylactic and empirical antifungal strategies in ASCT recipients.

The stimulated acoustic relaxation emission of maize starch tablets

Stimulated acoustic relaxation emissions from maize starch tablets after compression were detected and recorded in the audible region. Stimulation was found to enhance the detected acoustic emission and to maintain recordable acoustic emission level longer. Based on the fact, that the stimulation by a halogen lamp and a preheated chamber produced similar results, the effect of stimulation on acoustic relaxation emission is proposed to be connected to the temperature rather than the visible emission. A mathematical model of acoustic activity and its dependence on stimulation temperature is also introduced.

Aspergillus antigen in serum, urine and bronchoalveolar lavage specimens of neutropenic patients in relation to clinical outcome

We have used a new, commercial enzyme-linked immunosorbent assay (ELISA, Platelia Aspergillus) to detect Aspergillus antigen in serum, urine and bronchoalveolar lavage (BAL) samples of 105 haematological patients who received empirical amphotericin B treatment for suspected fungal infection. 14% (60/419) of serum and 5% (18/373) of urine samples were positive. Ten-fold concentration of urine increased the number of positive samples to 31 (8%). The antigen was detected in 5 of 20 BAL samples, but fungal culture was negative in all of them. 22 patients had positive antigen test. Serum was positive in 17, urine in 7 and concentrated urine in 12 patients. Six patients had confirmed invasive aspergillosis. In all these patients, antigen was detected in serum, but urine was positive in only 2 patients. Patients whose antigen test turned negative during the amphotericin B treatment had significantly lower mortality than patients with persistently positive antigen test (2/10 vs. 8/8, p = 0.002). We conclude that Aspergillus galactomannan can be detected by ELISA in serum, urine and BAL samples of haematological patients, but the higher sensitivity of serum testing makes it preferable for screening. Disappearance of the antigen during antifungal therapy seems to correlate with good, and persistence with poor, clinical outcome.

Immobilization of a biologically active coating on a hydrophobic L-lactide-epsilon-caprolactone copolymer

The electron beam radiation induced grafting method was used to attach a reactive polyacrylamide (PAA) layer (20 wt %) on the surface of a biodegradable poly-L-lactide-co-epsilon-caprolactone (PLLA-co-CL). The biocompatibility of graft-polymer obtained was studied by cytotoxicity test and no signs of toxicity were observed. Heparin and sol-gel-produced silica-gel coatings were successfully attached on the top of the polymeric material produced. The amount of heparin immobilized directly on the surface can be controlled by reaction conditions: reaction time, temperature and pH of the incubation solution. By using acidic conditions, up to 98 microg cm(-2) of heparin was immobilized on the surface. The sol-gel-produced silica-gel layer formed by dipping technique was 30 microm thick and the cracking of the layer was minimal after bending several times to 90 degrees.

Real time detection of photoreactivity in pharmaceutical solids and solutions with isothermal microcalorimetry

PURPOSE

In this study an irradiation cell made as an accessory for an isothermal microcalorimeter is introduced, and its suitability for detection photoreactivity in pharmaceutical solutions and solids is demonstrated. The pharmaceuticals employed are chosen as sample materials to evaluate the usefulness and stability of the irradiation cell.

METHODS

An irradiation cell has been constructed and tested in an isothermal microcalorimeter with pharmaceutical solutions and solids known to be sensitive to daylight or UV light. Light is produced with an Xe-arc lamp, split into two parts and introduced into calorimetric vessels with optical light cables. One of the vessels containing the reference sample gives the response to the heat absorbed by the material (radiant power), and the other vessel containing the sample material gives the response also to the photoreaction. The two irradiation cells are positioned in the sample sides of two separate twin microcalorimetric units.

RESULTS

Nifedipine and L-ascorbic acid were found to be photosensitive in solutions and solid states, the extent of the degradation depending on the irradiation intensity and wavelength. The threshold values of the wavelength for the photoreactions, as well as the wavelengths for the maximum reaction rates, were estimated via the scanning irradiation measurements. The ability of photons with different energies to produce heat in the photosensitive reaction of nifedipine was calculated using constant lambda measurements.

CONCLUSIONS

The technique introduced offers a rapid and versatile method to study the photosensitivity of materials in any state. In the measurements, various conditions can be simulated and thus provide information on the real behavior of materials.

Collagenase-3 (matrix metalloproteinase-13) expression is induced in oral mucosal epithelium during chronic inflammation

Increased proliferation of mucosal epithelium during inflammation is associated with degradation of subepithelial connective tissue matrix and local invasion of the epithelial cells. Here we have studied, whether collagenase-3 (MMP-13), a collagenolytic matrix metalloproteinase with an exceptionally wide substrate specificity, is expressed in the epithelium of chronically inflamed mucosa. Examination of human gingival tissue sections from subjects with chronic adult periodontitis with in situ hybridization revealed marked expression of MMP-13 in basal cells of some epithelial rete ridges expanding into connective tissue. Immunohistochemical staining demonstrated that these cells also expressed strongly laminin-5, suggesting that they are actively migrating cells. A strong signal for MMP-13 mRNA was occasionally also noted in the suprabasal epithelial cells facing the gingival pocket, whereas no collagenase-1 (MMP-1) mRNA was detected in any areas of the epithelium. MMP-13 expression was also detected in fibroblast-like cells associated with collagen fibers of the inflamed subepithelial connective tissue. In organ culture of human oral mucosa, MMP-13 mRNA expression was observed in epithelial cells growing into connective tissue of the specimens. Regulation of MMP-13 expression was examined in cultured normal nonkeratinizing epithelial cells isolated from porcine periodontal ligament. In these cells, MMP-13 expression at the mRNA and protein level was potently enhanced (up to sixfold) by tumor necrosis factor-alpha, transforming growth factor-beta(1), and transforming growth factor-alpha and by keratinocyte growth factor in the presence of heparin. In addition, plating periodontal ligament epithelial cells on type I collagen stimulated MMP-13 expression (sevenfold) as compared with cells grown on tissue culture plastic. The results of this study show, that expression of MMP-13 is specifically induced in undifferentiated epithelial cells during chronic inflammation due to exposure to cytokines and collagen. Thus, it is likely that MMP-13 expression is instrumental in the subepithelial collagenolysis and local invasion of the activated mucosal epithelium into the connective tissue.