Prevalence of hearing loss and use of hearing aids among children and adolescents in Germany: a systematic review.

BACKGROUND: Current data suggest that approximately 466 million people (5.0%) of the world's population have disabling hearing loss, therefrom, 34 million children, impacting their quality of life. To provide estimates on the prevalence of hearing loss on a national level, we reviewed the epidemiological literature addressing hearing loss in children and adolescents living in Germany as an example for a Western country. METHODS: We searched Medline, Web of Science, Cochrane Library, ScienceDirect and LIVIVO to identify published data. Furthermore, we manually searched websites of relevant institutions and journals not listed in electronically and searched for ongoing studies and/or not yet published data in clinicaltrials.gov . Study selection, data extraction, and methodological assessment were carried out by two reviewers. RESULTS: In total, 11 reports provided data with sample sizes ranging from 310 up to more than 14 million children and adolescents. Prevalence data were collected by interviews (self-assessments), using pure-tone audiometry or the international classification of diseases (ICD-10) coding and ranged from 0.1 to 128 per 1000 children. Although the estimate of the prevalence of hearing loss goes down, when the threshold was raised, generating a comprehensive and coherent set of estimates proved challenging owing to clinical heterogeneity including variation in age, the study setting, the definition of hearing loss and the assessment method. Moreover, representativeness (external validity) was often impaired owing to estimates lacking currentness (i.e., referring to former West Germany) or selected (patient) data and may not be typical for a more general population. CONCLUSIONS: In conclusions, this work raises public awareness of the high prevalence of hearing loss, highlights issues associated with epidemiological research and is of great importance for researcher and those who use epidemiological data to inform clinical and political decision making.

Resilience of the Asian atmospheric circulation shown by Paleogene dust provenance.

The onset of modern central Asian atmospheric circulation is traditionally linked to the interplay of surface uplift of the Mongolian and Tibetan-Himalayan orogens, retreat of the Paratethys sea from central Asia and Cenozoic global cooling. Although the role of these players has not yet been unravelled, the vast dust deposits of central China support the presence of arid conditions and modern atmospheric pathways for the last 25 million years (Myr). Here, we present provenance data from older (42-33 Myr) dust deposits, at a time when the Tibetan Plateau was less developed, the Paratethys sea still present in central Asia and atmospheric pCO2 much higher. Our results show that dust sources and near-surface atmospheric circulation have changed little since at least 42 Myr. Our findings indicate that the locus of central Asian high pressures and concurrent aridity is a resilient feature only modulated by mountain building, global cooling and sea retreat.

[The role of perisinusoidal (Ito) cells in the course of hepatocellular carcinoma: light and electron microscopic data to the pathogenesis of hepatocellular carcinoma]. / A perisinusoidalis (Ito-) sejtek szerepe a hepatocellularis carcinoma kórlefolyásában: fény- és elektronmikroszkópos adatok a hepatocellularis carcinoma patogeneziséhez.

The clinical history of a 49 year old female patient suggested a multifocal, rapidly progressive liver disease of one month duration, apparently due to metastatic tumour. An open needle biopsy of the liver revealed a primary hepatocellular carcinoma of low grade malignancy; the diagnosis was confirmed by histological, immunohistochemical and electron microscopic studies. Besides the ultrastructural examination of the liver biopsy disclosed an unusually marked proliferation of perisinusoidal (Ito)-cells. The authors assume that the myofibroblast proliferation and transformation of Ito-cells in the noncirrhotic liver led to the formation of multifocal areas. The perisinusoidal cell proliferation was presumably due to vitamin A intoxication caused by an extreme vegetarian diet (daily consumption of large amounts of carrot juice for years, as disclosed by a retrospectively obtained history). It is assumed that the vitamin A abuse, and perisinusoidal cell proliferation may have promoted the unusually rapid progression of the multifocal, but histologically low grade hepatocellular tumour. Spectacular clinical improvement could be observed after chemotherapy, combined with local hyperthermic treatment. Presumably, the change in diet (cessation of excessive retinol and carotene intake) also may have had a beneficial effect. After one year the clinical course suggests a slower progression of tumour growth which would be more in keeping with the prognosis based on the histologic appearance of the low grade hepatocellular carcinoma. This patient's case illustrates the importance of electron microscopy supplementing diagnostic histological and immunohistochemical examinations.

[The effect of carbamide feeding over a long period of time on thyroid gland activity in bulls]. / Auswirkungen von Karbamidverfütterung über längere Zeit auf die Schilddrüsentätigkeit bei Mastbullen.

In this experiment, 10 fattening bulls were given 0.27-0.42 g/kg body-weight of urea daily for 4 months. The bulls slaughtered after the experiments showed enlarged thyroid glands. These thyroid glands were much larger than the control glands (P = 0.1%). At the end of the experiment the bulls fed with urea weighed, on average, 44 kg more than the control bulls (P = 5%). The histology and electron-microscopy tests revealed that the bulls had hyperplasia of the thyrocytes, grave hydropic and vacuolar degeneration of the thyroid glands, and a considerable decrease in the colloids of the folliculus. The morphological test on the thyroid glands of bulls fed with the aforementioned level of urea daily for a longer period corresponded with the considerable alterations observed when treating bulls with thiouracil by-products. The consequences of urea-rationing for a longer period were tested and the dangers of thyroid-gland alterations were made apparent. Blood samples (120 cases) were taken in the experiment to determine the concentrations of NH3-N, urea and of thyroxine and triiodothyronine (480 pcs), referring to pre-test conditions. The same parameters were determined five times (every 2 months) during the experiment. The parameters received in the tests were, on average and in terms of extreme values as follows: [table: see text] Except for the histological outcome, the blood tests did not show the hypothyreosis of the whole organism.

Further data to the aetiology, pathogenesis and therapy of infectious bovine keratoconjunctivitis.

Out of a total of 224 bovine eye secretions, 126 Moraxella bovis and 64 Neisseria ovis strains were isolated. The pathogenesis and histological lesions caused by Neisseria ovis have been studied on the eyes of three calves naturally affected with IBK, using electron microscopy. Neisseria ovis caused in 1-12 weeks old calves acute, transient and mostly benign serous conjunctivitis with only slight affection of the cornea. More rarely erosions and even ulceration of the cornea have been observed. Moraxella bovis and Neisseria ovis strains proved nearly unanimously sensitive in vitro to chloramphenicol, neomycin, oxytetracyclin, nitrofurantoin, erythromycin and cefoperazone. Other antibiotics and chemotherapeutics inhibited the growth of these agents only partly or were ineffective. Experimental therapy has been carried out using a single i.m. injection of Terramycin/LA inj. (Pfizer) in a dose of 20 mg/kg body mass, repeated if necessary after 72-96 h. This formulation proved more effective and practical than treatments used earlier.

Evaluation of bupivacaine nerve blocks in the modification of pain and pulmonary function changes after thoracotomy.

Thirty-one patients undergoing thoracotomy were prospectively randomized to receive (1) no nerve blocks (n = 12), (2) placement of percutaneous catheters for intermittent nerve blocks with bupivacaine (Marcaine) (n = 10), or (3) bupivacaine nerve blocks intraoperatively (n = 8). One patient refused postoperative evaluation and was not included in this study. All patients received similar preoperative, intraoperative, and postoperative medications. Comparison of preoperative and postoperative arterial blood gases, assessments of pain and alertness, and chest roentgenograms showed no statistical advantage for any group. Analgesic requirements and pulmonary functions (functional residual capacity, tidal volume, minute ventilation peak flow, or forced expiratory volume) did not differ among the groups. Statistically significant differences were seen in mean respiratory rate and forced vital capacity. These differences, however, indicate that bupivacaine either by intraoperative use or by intermittent percutaneous administration did not improve postoperative increases in respiratory rate or decreases in forced vital capacity.

Effect of CH-123 on vascular cholesterol deposition in experimental atherosclerosis of rabbits.

The effect of CH-123, a new antiarteriosclerotic pyrido-1,2a-pyramide derivate was checked in experimental atherosclerosis of rabbits. Cholesterol deposition was found to continue after 4-week cholesterol feeding even after the cholesterol level had returned to normal. This allowed to study the action of drugs in a phase dominated by lipid apposition to the vascular wall. In the experiments, clofibrate was used for reference. As judged by the lipid values in serum and aortic wall, CH-123 reduced substantially the deposition of lipids, mainly of cholesterol, into the aortic wall.