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H Weiss

Publications and source records attributed to H Weiss.

528 records · Page 30Linked to original sources
PubMedDate not supplied

[Guidelines for planning studies to determine the resistance of infectious agents of veterinary relevance].

This paper describes the most important criteria for the planning of statistically sound and representative studies on the prevalence of antimicrobial resistance among pathogenic bacteria from animals. The statistical design of the study is of particular importance and therefore described in some detail. The existing published data about antimicrobial resistance are mostly retrospective summaries of results and do not give a true picture of the resistance situation. The authors propose to conduct a pilot study initially because many basic elements for a sound study design are still not known. The systematic recording and assessment of the target variables including the necessary quality assurance are an important prerequisite. Moreover, potential cause variables can be further narrowed down and conclusively identified. To ensure the representativity of the cross-sectional study and avoid potential bias, it is important to achieve the highest possible response rate. This will form the basis of a scientifically sound resistance monitoring programme which should be the joint responsibility of regulatory authorities, industry and academia.

Animals↗
PubMedDate not supplied

[Sampling plans in microbiological criteria for food and their "performance criteria"].

Statistically based acceptance sampling plans have been integrated into microbiological criteria for food in international trade for some time. Especially two- and three-class sampling plans for attributes are used, variables plans are applied less. A lot of examples can be found in the so-called ICMSF (International Commission on Microbiological Specifications for Foods) "sampling book" or in EU guidelines. However, quite often the required confidence and the assumptions on tolerable lot qualities on which the choice and design of sampling plans are based can't be deduced from such recommendations and prescriptions. These problems have led to critical discussion of the performance of two- and three-class sampling plans used in microbiological criteria, showing complex dependencies on microbiological limits and on the expected variability of sampling results. As a result means should be considered to use knowledge gained from process analyses in food production in the design of sampling plans. In this context the performance of acceptance sampling plans as prescribed in microbiological criteria for foods will be discussed as well as their role in recently developed food safety concepts.

Animals↗
PubMedDate not supplied

Four-year follow-up of retinal status and glycosylated haemoglobin in patients with insulin-dependent diabetes mellitus.

Retinal status and glycosylated hemoglobin (GHb) was followed in 32 patients with insulin-dependent diabetes mellitus (18 females; age upon entering the study 26 +/- 8 years; duration of diabetes 10 +/- 6 years; means +/- SD) during a total of 136 patient-years, i.e. during 4.3 +/- 0.6 years per patient. Annual mean GHb (given in percent of the mean normal GHb) was calculated from 7 +/- 3 determinations of GHb per patient-year. Fluorescein angiographs were performed at least once per patient-year, and retinal status was assessed by counting microaneurysms. Upon entering the study, early diabetic (background) retinopathy was present in 14 patients; at the end of the follow-up period, it was present in 20 patients. Retinal status deteriorated in 4/42 patient-years with excellent metabolic control (annual mean GHb less than or equal to 125%), in 13/70 patient-years with good control (annual mean GHb 126-150%) and in 8/24 patient-years with poor control (annual mean GHb greater than 150%). The incidence rate of retinal deterioration differed significantly between years with excellent control and years with poor control (X2 5.7, df = 1, p less than 0.05). It is concluded that excellent metabolic control within 14 +/- 6 years after onset of insulin-dependent diabetes mellitus appears to be a protective factor against the development or progression of early diabetic retinopathy.

Adult↗