Initiating transitional care for adolescents with cystic fibrosis at the age of 12 is both feasible and promising.

AIM: Adolescence is a vulnerable period in cystic fibrosis, associated with declining lung function. This study described, implemented and evaluated a transition programme for adolescents. METHODS: We conducted a single centre, nonrandomised and noncontrolled prospective programme at the cystic fibrosis centre at Copenhagen University Hospital Rigshospitalet from 2010 to 2011, assessing patients aged 12-18 at baseline and after 12 months. Changes implemented included staff training on communication, a more youth-friendly feel to the outpatient clinic, the introduction of youth consultations partly alone with the adolescent, and a parents' evening focusing on cystic fibrosis in adolescence. Lung function and body mass index (BMI) were measured monthly and adolescents were assessed for their readiness for transition and quality of life at baseline and 12 months. RESULTS: We found that 40 (98%) of the eligible patients participated and youth consultations were successfully implemented with no dropouts. The readiness checklist score increased significantly over the one-year study period, indicating increased readiness for transfer and self-care. Overall quality of life, lung function and BMI remained stable during the study period. CONCLUSION: A well-structured transition programme for cystic fibrosis patients as young as 12 years of age proved to be both feasible and sustainable.

The accessibility of topical treatment in the paranasal sinuses on operated cystic fibrosis patients assessed by scintigraphy.

BACKGROUND: Nasal irrigations with antibiotics are used to eradicate Pseudomonas aeruginosa from the upper airways in patients with cystic fibrosis (CF) and thereby avoid lung colonisations; nevertheless, the efficacy is uncertain. METHODOLOGY: The aim of this study was to investigate the accessibility and durability of solutions in the sinuses before and after sinus surgery. The participants irrigated their noses with radioactively marked saline and were evaluated using a dynamic SPECT/CT scan. The preoperative and postoperative (after 30 days) examinations were compared. RESULTS: Twelve CF patients were included. In 10 out of the 24 scanned maxillary sinuses an improvement was seen postoperatively compared with the preoperative fluid volume. Notably, in 7 out of the 24 sinuses the mucosa was so swollen postoperatively that no fluid was detected. Ten patients had developed their frontal sinuses. We observed no fluid in the frontal or sphenoid sinuses, neither before nor after surgery. At best, a mean of 23% of the maxillary sinuses were filled with fluid; thus, all sinuses had postoperatively areas of the mucosa that did not have contact with the fluid. A mean of 76% of the initial volume was present after 30 min in the maxillary sinuses. CONCLUSION: Fluid-depositing using nasal irrigation will not sufficiently or not at all get in contact with all the sinus mucosa despite of sinus surgery. Thus, the efficacy of topical deposition of antibiotics is presumably reduced.

Sinus surgery postpones chronic Gram-negative lung infection: cohort study of 106 patients with cystic fibrosis.

BACKGROUND: In patients with cystic fibrosis (CF) the sinuses are a bacterial reservoir for Gram-negative bacteria (GNB). From the sinuses the GNB can repeatedly migrate to the lungs. In a one-year follow-up study, endoscopic sinus surgery (ESS) with adjuvant therapy reduced the frequency of pulmonary samples positive for GNB. We investigated whether the effect is sustained. METHODOLOGY: We report the effect of ESS and adjuvant therapy three years postoperatively in a CF cohort participating in this prospective clinical follow-up study. The primary endpoint was the lung infection status defined by Leeds criteria. RESULTS: One hundred and six CF patients underwent ESS; 27 had improved lung infection status after three years. The prevalence of patients free of lung colonization with GNB significantly increased from 16/106 patients (15%) preoperatively to 35/106 patients (33%) after three years. The total cohort had decreasing lung function during follow-up; however, in 27 patients with improved lung infection status lung function was stable. Revision surgery was performed in 31 patients (28%). CONCLUSION: ESS with adjuvant therapy significantly improves the lung infection status for at least three years in our cohort of patients with CF and may postpone chronic lung infection with GNB and thus stabilize lung function.

Enzyme replacement therapy for alpha-mannosidosis: 12 months follow-up of a single centre, randomised, multiple dose study.

BACKGROUND: Alpha-mannosidosis (OMIM 248500) is a rare lysosomal storage disease (LSD) caused by alpha-mannosidase deficiency. Manifestations include intellectual disabilities, facial characteristics and hearing impairment. A recombinant human alpha-mannosidase (rhLAMAN) has been developed for weekly intravenous enzyme replacement therapy (ERT). We present the preliminary data after 12 months of treatment. METHODS: This is a phase I-II study to evaluate safety and efficacy of rhLAMAN. Ten patients (7-17 y) were treated. We investigated efficacy by testing motor function (6-minutes-Walk-Test (6-MWT), 3-min-Stair-Climb-Test (3-MSCT), The Bruininks-Oseretsky Test of Motor Proficiency (BOT2), cognitive function (Leiter-R), oligosaccharides in serum, urine and CSF and Tau- and GFA-protein in CSF. RESULTS: Oligosaccharides: S-, U- and CSF-oligosaccharides decreased 88.6% (CI -92.0 -85.2, p < 0.001), 54.1% (CI -69.5- -38.7, p < 0,001), and 25.7% (CI -44.3- -7.1, p < 0.05), respectively. Biomarkers: CSF-Tau- and GFA-protein decreased 15%, p < 0.009) and 32.5, p < 0.001 respectively. Motor function: Improvements in 3MSCT (31 steps (CI 6.8-40.5, p < 0.01) and in 6MWT (60.4 m (CI -8.9 -51.1, NS) were achieved. Cognitive function: Improvement in the total Equivalence Age of 4 months (0.34) was achieved in the Leiter R test (CI -0.2-0.8, NS). CONCLUSIONS: These data suggest that rhLAMAN may be an encouraging new treatment for patients with alpha-mannosidosis.The study is designed to continue for a total of 18 months. Longer-term follow-up of patients in this study and the future placebo-controlled phase 3 trial are needed to provide greater support for the findings in this study.

Clinical effects of sinus surgery and adjuvant therapy in cystic fibrosis patients - can chronic lung infections be postponed?

BACKGROUND: The paranasal sinuses can be a bacterial reservoir for pulmonary infections in patients with cystic fibrosis (CF) METHODOLOGY: In this prospective, non-randomised, uncontrolled, intervention cohort study, the clinical effect of sinus surgery followed by two weeks` intravenous antibiotics, 6 months` antibiotic nasal irrigations was assessed in 106 CF patients. RESULTS: One year after sinus surgery, the prevalence of intermittently colonised patients had decreased by 38%, while the prevalence of non-colonised patients had increased by 150%. The frequency of pulmonary samples with CF pathogens was reduced after surgery. Specific IgG against P. aeruginosa decreased after six months. Additionally, the self reported symptoms of chronic rhinosinusitis and quality of life improved. CONCLUSION: Combined sinus surgery and postoperative systemic and topical antibiotic treatment significantly reduced the frequency of pulmonary samples positive for CF pathogens in the first year after sinus surgery.

Choice of nasal nitric oxide technique as first-line test for primary ciliary dyskinesia.

Nasal nitric oxide (nNO) has a well-known potential as an indirect discriminative marker between patients with primary ciliary dyskinesia (PCD) and healthy subjects, but real-life experience and usefulness in young children is sparsely reported. Three nNO sampling methods were examined and compared as first-line tests for PCD. Healthy subjects, confirmed PCDs, consecutive referrals with PCD-like symptoms and patients with cystic fibrosis (CF) had nNO sampled during breath hold (BH-nNO), oral exhalation against resistance (OE-R-nNO) and tidal breathing (TB-nNO) aiming to expand age range into infancy. 282 subjects, 117 consecutive referrals, 59 PCDs, 49 CF patients and 57 healthy subjects, were included. All methods separated significantly between PCD and non-PCD, including CF with reliability, in ranking order BH-nNO>OE-R-nNO>TB-nNO. Acceptability in children ranked in reverse order. A problematic high fraction (39%) of false positive TB-nNO was found in young children. An unexpected large fraction (6.8%) of PCDs had nNO values above cut-off. nNO is a helpful first-line tool in real-life PCD work-up in all age groups if the sampling method is chosen according to age. nNO can be misleading in a few patients with true PCD. Further studies are strongly needed in young children.

Factors influencing age at diagnosis of primary ciliary dyskinesia in European children.

Primary ciliary dyskinesia (PCD) is a hereditary disorder of mucociliary clearance causing chronic upper and lower airways disease. We determined the number of patients with diagnosed PCD across Europe, described age at diagnosis and determined risk factors for late diagnosis. Centres treating children with PCD in Europe answered questionnaires and provided anonymous patient lists. In total, 223 centres from 26 countries reported 1,009 patients aged < 20 yrs. Reported cases per million children (for 5-14 yr olds) were highest in Cyprus (111), Switzerland (47) and Denmark (46). Overall, 57% were males and 48% had situs inversus. Median age at diagnosis was 5.3 yrs, lower in children with situs inversus (3.5 versus 5.8 yrs; p < 0.001) and in children treated in large centres (4.1 versus 4.8 yrs; p = 0.002). Adjusted age at diagnosis was 5.0 yrs in Western Europe, 4.8 yrs in the British Isles, 5.5 yrs in Northern Europe, 6.8 yrs in Eastern Europe and 6.5 yrs in Southern Europe (p < 0.001). This strongly correlated with general government expenditures on health (p < 0.001). This European survey suggests that PCD in children is under-diagnosed and diagnosed late, particularly in countries with low health expenditures. Prospective studies should assess the impact this delay might have on patient prognosis and on health economic costs across Europe.

Primary ciliary dyskinesia: a consensus statement on diagnostic and treatment approaches in children.

Primary ciliary dyskinesia (PCD) is associated with abnormal ciliary structure and function, which results in retention of mucus and bacteria in the respiratory tract, leading to chronic oto-sino-pulmonary disease, situs abnormalities and abnormal sperm motility. The diagnosis of PCD requires the presence of the characteristic clinical phenotype and either specific ultrastructural ciliary defects identified by transmission electron microscopy or evidence of abnormal ciliary function. Although the management of children affected with PCD remains uncertain and evidence is limited, it remains important to follow-up these patients with an adequate and shared care system in order to prevent future lung damage. This European Respiratory Society consensus statement on the management of children with PCD formulates recommendations regarding diagnostic and therapeutic approaches in order to permit a more accurate approach in these patients. Large well-designed randomised controlled trials, with clear description of patients, are required in order to improve these recommendations on diagnostic and treatment approaches in this disease.

Radioiodine therapy for multinodular toxic goiter.

BACKGROUND: Radiolabeled iodine 131 therapy is used for treatment of multinodular toxic goiter, but long-term follow-up studies are lacking. METHODS: A prospective study of 130 consecutive patients (115 women) treated with 131I for multinodular toxic goiter and followed by evaluation of thyroid volume (determined using ultrasound) and thyroid function variables. RESULTS: The patients were observed for a median of 72 months (range, 12-180 months). Sixty-six patients received antithyroid drug pretreatment; 64 did not. Iodine 131 treatment (3.7 MBq/g thyroid tissue corrected to a 100% 24-hour 131I uptake) was given as a single dose in 81 patients, 2 doses in 38, and 3 to 5 doses in 11. One or 2 treatments cured 119 patients (92%), and 68 (52%) became euthyroid within 3 months after 131I treatment. The median 131I dose was 370 MBq (range, 93-1850 MBq). Forty-nine patients needing more than 131I dose had a reduction in median thyroid volume from 56 mL (range, 21-430 mL) to 44 mL (range, 15-108 mL), representing a 24% reduction related to the insufficient 131I dose. In all patients, the initial median thyroid volume of 44 mL (range, 16-430 mL) decreased to 25 mL (range, 8-120 mL) (P<.005), representing a median reduction of 43%, 24 months after the last 131I dose. Hypothyroidism evaluated using life-table analysis developed in 6% of patients who did not receive antithyroid pretreatment and 20% who did (P<.005) after a median of 42 months (range, 3-60 months), the total hypothyroidism frequency being 14% within 5 years of treatment. CONCLUSIONS: Ninety-two percent of patients with multinodular toxic goiter were cured with 1 or 2 treatments. The thyroid volume was reduced by 43%, with few side effects. Iodine 131 should be the choice of treatment in patients with multinodular toxic goiter.

A longitudinal study of lung bacterial pathogens in patients with primary ciliary dyskinesia.

In patients with primary ciliary dyskinesia (PCD), impaired mucociliary clearance leads to an accumulation of secretions in the airways and susceptibility to repeated bacterial infections. The primary aim of this study was to investigate the bacterial flora in non-chronic and chronic infections in the lower airways of patients with PCD. We retrospectively reviewed the presence of bacteria from patients with PCD during an 11-year period and genotyped 35 Pseudomonas aeruginosa isolates from 12 patients with chronic infection using pulsed-field gel electrophoresis. We identified 5450 evaluable cultures from 107 patients with PCD (median age 17 years, range 0-74 years) (median age at diagnosis 7.8 years, range 0-63 years). Haemophilus influenzae was the most frequent microorganism. Other common pathogens were P. aeruginosa, Streptococcus pneumoniae, Moraxella catarrhalis and Staphylococcus aureus. The number of patients colonized with P. aeruginosa at least once varied from 11 to 44 patients (15-47%) annually, and 42 patients (39%) met the criteria for chronic infection at least once. Pseudomonas aeruginosa was more frequently isolated in teenagers and adults than children (p 0.02) and the prevalence was significantly lower in patients with preschool (<6 years) PCD diagnosis (p 0.04). Ten out of 12 patients (83%) were chronically infected with a unique clone-type of P. aeruginosa. No sharing of clone-types or patient-to-patient transmission was observed. In conclusion, PCD patients were infected by a unique set of bacteria acquired in an age-dependent sequence. Pseudomonas aeruginosa frequently colonizes the lower respiratory tract and the incidence of chronic infection was higher than previously reported.

Immediate dermal changes in pig skin after exposure to moderate amounts of heat and electrical energy.

Pig skin was exposed to approximately 80 joules of heat and electrical energy [50 Hz alternating current (a.c.) and direct current (d.c.)], respectively, under controlled conditions in order to find methods to document electrical torture. Biopsies were obtained immediately after exposure, and the morphology of the electrical lesions was compared with that of heat lesions and unexposed skin by using normal and polarized light microscopy. In areas exposed to 50 Hz a.c. and in cathode areas after d.c., where calcified collagen fibers have been found 2 days after injury, the collagen fibers showed a regular, densely spaced, cross-striation. This type of cross-striation was not found in heat or anode lesions. It was possible to blindly group all biopsies correctly with regard to influence of heat, 50 a.c. and d.c.

Iohexol: effects on uptake of radioactive iodine in the thyroid and on thyroid function.

RATIONALE AND OBJECTIVES: The authors attempted to determine whether the use of nonionic contrast media causes uptake of iodine by the thyroid to be blocked and whether use of these agents could cause iodine-induced hyperthyroidism. MATERIALS AND METHODS: Twenty-eight persons, including 22 with thyroid disease, were included in the study. Subjects underwent computed tomography (CT) of the thyroid after injection of 100 mL of iohexol. Thyroid function variables were measured before CT scanning and 1 week and 1 month later. In 16 subjects, uptake of iodine-131 by the thyroid was measured before and 1 week after CT. RESULTS: I-131 uptake was reduced to 53.4% at 1 week after the injection of iohexol but became normal within a few weeks (followed up in one patient). An accelerated escape of I-131 from the thyroid was seen during the 1st days after the iohexol administration. Eight of 22 patients with an underlying thyroid disease had a temporary change in thyroid function. In four patients, the serum thyrotropin level was increased 1 week after the iohexol administration. In four other patients, temporary hyperthyroidism developed during the following months. CONCLUSION: Iohexol can be used in patients with an underlying thyroid disease, but close monitoring in the following months is necessary.

Device and methods for the measurement of energy transfer in experiments involving thermal and electrical injuries of skin.

This work is part of a larger investigation aiming at tracing differences between injuries caused by heat and electricity. Electrodes and heaters similar to the electrodes of an electric cattle baton are used to dissipate approximately 40 joules in 40 seconds in pig skin. Voltages in the range 40-60 volts (AC or DC) are applied via stainless steel electrodes and temperatures in the range 50-100 degrees C are applied via heaters made of copper wire. Heat transfer is controlled by electronically regulated heaters utilizing the temperature dependence of the heater wire itself as a thermometer. Transfer of electricity takes place from either commercial DC supply, from transformed voltage from the mains or from a sine voltage generator connected to a power amplifier. The energy transfer is in all cases measured by electronic integration of the dissipated power in time. The power supplied to th electrodes or the heaters is found by electronic multiplication of the applied voltage and current. Typical power vs. time curves are presented.

Early epidermal changes in heat- and electrically injured pig skin. I. A light microscopic study.

In order to find methods applicable for disclosing electrical torture, pig skin was exposed to heat and electricity under controlled circumstances. Biopsies were obtained immediately after exposure and the morphology of the heat lesions was compared to that of electrical lesions. The cytoplasm of epidermal cells in heat lesions appeared granular or fibrillar, while the nuclei were rather unaffected. In electrical lesions the cytoplasm appeared homogeneous often with a peculiar white colour in hematoxylin-eosin stained sections. The nuclei were either dark and shadowy or enlarged and vesicular. The keratin in electrical lesions often showed a bright yellow colour. Small defects in the epidermis were seen in some electrical lesions. Thus the morphology of electrical lesions differed markedly from that of heat lesions. Although some of these differences may be due to differences in distribution and intensity of energy, it is probable that pH shifts in the cells due to electrolysis is the main cause of the specific morphology of electrical lesions.

Electrical and thermal injuries in pig skin--evaluated and compared by light microscopy.

The morphology of pig skin after electrical (el) and thermal exposure was studied in order to find methods applicable for disclosing electrical torture. Biopsies from pig skin exposed 24 hours earlier to either heat or electrical current under general anesthesia were studied by light microscopy. The amount of energy used of either type ranged from about 6 to about 100 joule deposited on two circular areas of the skin measuring 12 mm in diameter. In sections stained with hematoxylin and eosin alterations were found in heat-influenced specimens following the administration of moderate and large doses of energy. Changes were observed in el-influenced specimens also after the administration of low amounts of energy, which did not lead to macroscopical changes in the skin. The two types of energy induced different patterns of alterations inside the epidermis. The most characteristic change following heat exposure was the presence of a granular or fibrillar eosinophilic cytoplasm and subepidermal clefts, while el-expoure often produced white homogeneous cytoplasm and shadowy nuclei ("white necrosis") in the attached epidermis. The individual changes could be produced by both types of injury, but to a highly different degree. However, the alteration classified as "vesicular nuclei" was only observed observed in el-damaged skin. The dermis from the more severely injured skin of both groups showed a homogeneous appearance ("necrosis"). While the changes of epidermis and dermis in response to heat were diffusely distributed, the changes created by electrical injury were often present in segments. By electrical damage homogeneous areas with loss of stainability and shadowy nuclei were occasionally observed in sweat glands, hair sheaths and in vessel walls, structures which are suggested to serve as conductors for the electrical current. "Vesicular nuclei" were observed in similar structures. Some of the findings may be associated with differences in intensity of energy during exposure to heat and electricity. Furthermore, the existence of different biological patterns following the two types of exposure should be considered. The studies are being continued to elucidate these basic questions, and to study further the medical diagnostic potential of examining skin biopsies from tortured individuals.

Early epidermal changes in heat- and electrically injured pig skin. II. An electron microscopic study.

In order to find methods applicable for disclosing electrical torture, pig skin was exposed to heat and electricity under controlled circumstances. Biopsies for electron microscopy were obtained immediately after exposure. In heat lesions the nuclei were slightly distorted, sometimes with broken nuclear membranes. The tonofilaments were clumped, intracellular oedema was present and cell membranes were ruptured between desmosomes. In electrical lesions the nuclei were usually enlarged with strongly condensed chromatin. Some nuclei were composed of fine, evenly dispersed granular material. The cytoplasm appeared homogeneous, in large magnification finely granular. Cell borders could sometimes be identified located in situ. In the stratum corneum, which appeared normal in heat lesions, single or several cells or large areas had an electron-dense appearance. The difference in ultrastructure of heat and electrical lesions makes it probable that electricity has a specific action on epidermal cells.

Electrically-induced collagen calcification in pig skin. A histopathologic and histochemical study.

Deposition of calcium salts on collagen fibres in skin of fully anaesthetized pigs was induced by exposure to direct current (d.c.). In biopsies obtained from cathode areas successively from day 1 to day 7 after exposure the histopathologic and histochemical changes before and after the initial deposition of calcium salts have been examined. For comparison skin sites with intradermal injected calcium hydroxyapatite crystals were studied in addition. Small areas of calcified collagen and elastic fibres were noted in viable tissue 2 days after d.c. exposure. In succeeding days the calcified areas enlarged with new deposits always more superficial and closer to the epidermis than the original calcium deposits. Preconditions for calcification appear to be (1) a pH change in basic direction and/or the electrochemical processes specific to the cathode area and (2) a viable tissue. Elastic fibres appear to have a lower calcification threshold than collagen fibres. A positive staining for glycoproteins (PAS) and glycosaminoglycans (alcian blue pH 2.5) was noted in the calcified collagen fibres simultaneously with the calcification. In succeeding days the intensity of the staining reactions increased. Whether changes in the glycoproteins, collagen and its intimately bound glycosaminoglycans precede the calcification or the staining reactions develop secondarily to this deposition is not known. However, seven days after intradermal injections of Ca-apatite crystals in pig skin small and large crystals were observed ultrastructurally without any relation to collagen fibrils, but the calcified tissue presented a positive PAS and alcian blue reaction from day 2. Thus the PAS and alcian blue stainings in this model develop secondary to the deposition of calcium salts.

The morphogenesis of electrically and heat-induced dermal changes in pig skin.

In order to establish pathological evidence in dermis for distinguishing between sequelae of electrical torture and those of other superficial injuries, the skin of eleven fully anaesthetized Danish Landrace pigs have been exposed to heat and electrical energy from either 50 Hz alternating current (a.c.) or direct current (d.c.) via 12 mm large contact knobs or via a pointed 0.5 mm large electrode (only 50 Hz a.c.). The lesions have been examined from 1 to 126 days after the injury. While heat lesions exposed to energy lower than 60 joule only gave minor changes, heat lesions exposed to more than 60 joule showed changes in both collagen fibres (basophilic or eosinophilic fibres without any birefringence or coarse cross-striation in polarized light, respectively) and dermal cells (granular cytoplasm). Areas exposed to 50 Hz a.c. via 0.5 mm. electrode showed basophilic collagen fibres and in a few biopsies on day 7 calcium salts on collagen fibres. Using 12 mm large electrodes the changes were minor, but basophilic and eosinophilic collagen fibres with no birefringence or with fine/coarse cross-striation respectively were seen. Even cells with 'vesicular nuclei' were seen on day 1 and 2 after the injury. The changes in the anode area showed resemblance to that of heat lesions (basophilic collagen fibres). Eosinophilic collagen fibres with fine densely spaced cross-striation in polarized light and 'vesicular nuclei' as well as collagen fibres with calcium salts were seen in the cathode lesions. It is concluded that the dermal changes in the cathode area are specific for electrical injury from day 1 to 14. However, earlier studies have demonstrated dermal changes specific for electrical injury at day 0 and the presence of calcified collagen fibres up to 2 months after injury. The dermal changes in anode lesions were non specific and could not be differentiated from those found in heat lesions. Alternating current lesions (50 Hz) were specific from day 1 to day 7, when the pointed electrode was used, but only in a few days when the energy was transferred via the 12-mm electrodes.

The effect of sodium hydroxide and hydrochloric acid on pig dermis. A light microscopic study.

In order to compare the dermal changes after exposure to direct current (d.c.) with changes after influence of acid and base influence, the skin of fully anaesthetized Danish Landrace pigs were exposed to acid and basic solutions. Biopsies were obtained immediately after and up to day 7 after the injury. Collagen fibres with increased affinity for eosin and irregular cross-striation in polarized light together with shrunken cells with dark stained nuclei were found just beneath the epidermis immediately after application of 1 N HCl. Immediately after exposure to 1 N NaOH dispersed collagen fibres showed increased eosinophilia and a fine densely spaced cross-striation in polarized light and vesicular nuclei were present within dermal cells. During the following days a narrow demarcation zone of neutrophilic granulocytes separated the zone containing abnormal collagen fibres from normal tissue below. Calcified collagen fibres were not observed and no other abnormal histochemical reactions were present. It is concluded that the morphology of acid induced lesions and base induced lesions shows resemblance to the morphology of anode and cathode lesions, respectively, but not to heat lesions. The reason for not finding depositions of calcium salts on collagen fibres in skin exposed to basic solutions could be a non-optimal pH in the tissue or that other electrochemical processes than shift in pH are necessary for the calcification process.

The occurrence of calcium salt deposition on dermal collagen fibres following electrical injury to porcine skin.

Deposition of calcium salts on collagen fibres has been shown to occur in cathode areas from 2 days to 2 months after exposure to direct current (d.c.) via contact knobs measuring 12 mm in diameter using energy level from 0.5 to 96 J and on day 7 after exposure to alternating current (a.c.) via pointed electrodes using energy level from 30 to 50 J. In order to determine the statistical relation of this histological observation to the type of energy applied 1095 biopsies from 49 pigs including biopsies from skin areas exposed to heat, 50 Hz a.c., 100 kHz a.c. and d.c. as well as from unexposed skin were examined. The specificity was 1.0 using calcium deposition as the test criterium. The sensitivity for cathode areas was found to vary from 0.52 to 1.0 depending on the biopsy technique and the number of days after exposure. Calcium salts on collagen fibres seem uniformly to be present in the cathode area from day 4 to 7, the positive test answer being depending on the biopsy technique. For 50 Hz a.c. the sensitivity using a pointed electrode was found to vary from 0.08 to 0.27 dependent on the number of days after exposure. For all other types of energy the sensitivity was 0.