Harald Klein

Publications of Harald Klein

• Beta-cell development and turnover during prenatal life in humans.

  Authors: Juris Meier, Christina Kohler, Bacel Alkhatib, Consolato Sergi, Theresa Junker, Harald Klein, Wolfgang Schmidt, Helga Fritsch

  European journal of endocrinology / European Federation of Endocrine Societies. 12/2009;

  Beta-cell regeneration is an area under active investigation, but little is known about the dynamics of prenatal beta-cell development. We addressed the questions: In prenatal humans, (1) what is theBeta-cell regeneration is an area under active investigation, but little is known about the dynamics of prenatal beta-cell development. We addressed the questions: In prenatal humans, (1) what is the timing of islet growth, and (2) what are the dynamics of beta-cell replication and apoptosis? Pancreatic tissue was obtained from 65 human embryos and fetuses aged between 8 weeks post conceptionem and birth. Sections were stained for insulin, glucagon, Ki67, TUNEL, and CD31, and morphometric analyses were performed. Beta-cells were detected from gestational week 9 onward, whereas glucagon expression was detected already at week 8. The fractional beta-cell area of the pancreas increased in a linear fashion until birth (r = 0.60, p < 0.001). The first endocrine cells were found within or adjacent to the primitive ductal epithelium. Beta-cell replication was readily detected in the newly forming islets already starting at week 9 p.c. (average frequency 2.8 +/- 0.4 %). A small percentage of cells co-expressed insulin and glucagon during the early fetal period. There was a close relationship between the development of endocrine islets and blood vessels during all stages of prenatal pancreas development suggesting a possible interaction between both cell types. The frequency of beta-cell apoptosis was relatively high throughout all ages (1.5 +/- 0.3 %). Beta-cell differentiation in humans occurs from week 9 p.c. onward. The first endocrine cells are closely associated with the ductal epithelium. High rates of beta-cell replication suggest that this mechanism plays an important role in the prenatal expansion of beta-cell mass.

• Salivary cortisol and psychological mechanisms in patients with acute versus chronic low back pain.

  Authors: Sigrid Sudhaus, Britta Fricke, Axel Stachon, Stefan Schneider, Harald Klein, Monika von Düring, Monika Hasenbring

  Psychoneuroendocrinology. 12/2008;

  This study was designed to explore whether the basal adrenocortical activity is related with pain-related coping, nonverbal pain behavior, depressive mood, and fatigue in patients with acute andThis study was designed to explore whether the basal adrenocortical activity is related with pain-related coping, nonverbal pain behavior, depressive mood, and fatigue in patients with acute and chronic nonspecific low back pain. 19 patients with acute low back pain (ALBP) and 24 with chronic low back pain (CLBP) participated in the study. The adrenocortical activity was assessed through the cortisol awakening response. All participants provided five saliva samples (0, 15, 30, 45, and 60min after waking) on two consecutive days off work. Pain-related coping [fear-avoidance coping (FAC) and endurance coping (EC)], nonverbal pain behavior (NPB), depressive mood, and fatigue were assessed through questionnaires. Among ALPB patients, EC was negatively associated with the cortisol release, whereas fatigue was positively associated with it. Among CLBP patients, FAC, NPB, depressive mood, and fatigue were negatively associated with the cortisol awakening response, whereas EC tended to be positively associated with it. The results indicate that pain-related coping strategies which are expected to be successful appear to lower the adrenocortical activity among ALBP patients, whereas affective distress may enhance the level of cortisol in this group. Among CLBP patients, long-term maladaptive coping strategies might contribute to hypocortisolism.

• Salivary cortisol and psychological mechanisms in patients with acute versus chronic low back pain

  Authors: Sigrid Sudhaus, Britta Fricke, Axel Stachon, Stefan Schneider, Harald Klein, Monika von Düring, Monika Hasenbring

  Psychoneuroendocrinology.

  This study was designed to explore whether the basal adrenocortical activity is related with pain-related coping, nonverbal pain behavior, depressive mood, and fatigue in patients with acute andThis study was designed to explore whether the basal adrenocortical activity is related with pain-related coping, nonverbal pain behavior, depressive mood, and fatigue in patients with acute and chronic nonspecific low back pain.19 patients with acute low back pain (ALBP) and 24 with chronic low back pain (CLBP) participated in the study. The adrenocortical activity was assessed through the cortisol awakening response. All participants provided five saliva samples (0, 15, 30, 45, and 60 min after waking) on two consecutive days off work. Pain-related coping [fear-avoidance coping (FAC) and endurance coping (EC)], nonverbal pain behavior (NPB), depressive mood, and fatigue were assessed through questionnaires.Among ALPB patients, EC was negatively associated with the cortisol release, whereas fatigue was positively associated with it. Among CLBP patients, FAC, NPB, depressive mood, and fatigue were negatively associated with the cortisol awakening response, whereas EC tended to be positively associated with it.The results indicate that pain-related coping strategies which are expected to be successful appear to lower the adrenocortical activity among ALBP patients, whereas affective distress may enhance the level of cortisol in this group. Among CLBP patients, long-term maladaptive coping strategies might contribute to hypocortisolism.