Different catecholamines induce different patterns of takotsubo-like cardiac dysfunction in an apparently afterload dependent manner

Background

Takotsubo cardiomyopathy (TCM) is characterized by regional left ventricular dysfunction that cannot be explained by an occlusive lesion in a coronary artery. Catecholamines are implicated in the pathogenesis of TCM but the mechanisms involved are unknown. Because the endogenous and the most commonly used exogenous catecholamines have well defined adrenoceptor subtype affinities, inferences can be made about the importance of each adrenoceptor subtype based on the ability of different catecholamines to induce TCM. We therefore studied which of five well-known catecholamines, that differ in receptor subtype affinity, are able to induce TCM-like cardiac dysfunction in the rat.

Methods

255 rats received intraperitoneally isoprenaline (β₁/β₂-adrenoceptor agonist), epinephrine (β₁/β₂/α-adrenoceptor agonist), norepinephrine (β₁/α-adrenoceptor agonist), dopamine (α/β₁/β₂-adrenoceptor agonist) or phenylephrine (α-adrenoceptor agonist). Each catecholamine was given in five different doses. We measured blood pressure through a catheter inserted in the right carotid artery and studied cardiac morphology and function by echocardiography.

Results

All catecholamines induced takotsubo-like cardiac dysfunction. Isoprenaline induced low blood pressure and predominantly apical dysfunction whereas the other catecholamines induced high blood pressure and basal dysfunction. In another set of experiments, we continuously infused hydralazine or nitroprusside to rats that received epinephrine or norepinephrine to maintain systolic blood pressure < 120 mm Hg. These rats developed akinesia of the apex instead of the base. Infusion of phenylephrine to maintain blood pressure > 120 mm Hg after isoprenaline administration prevented apical TCM-like dysfunction.

Conclusions

Catecholamine-induced takotsubo-like cardiac dysfunction appears to be afterload dependent rather than depend on stimulation of a specific adrenergic receptor subtype.     

Qualitative and quantitative analysis of glycine- and GABA-immunoreactive nerve terminals on motoneuron cell bodies in the cat spinal cord: A postembedding electron microscopic study

The distribution of glycine- and gamma-aminobutyric acid (GABA)-like immunoreactivity (LI) in nerve terminals on the cell soma of motoneurons in the aldehyde-fixed cat L7 spinal cord was examined using postembedding immunogold histochemistry in serial ultrathin sections. Quantitative examination of 405 terminals on eight neurons of α-motoneuron size in the L7 motor nuclei from one animal was performed. A majority of the terminals (69%) were immunoreactive to glycine and/or GABA. These terminals contained flat or oval synaptic vesicles, thus classifying them as F type or as C type in one case. In no case was a type-F terminal unlabeled for both glycine and GABA. Most of the immunolabeled terminals were immunoreactive to glycine only (62.5%), whereas 35.4% contained both glycine- and GABA-LI. A very small number of immunolabeled terminals (2%) were immunoreactive to GABA only. In those terminals, where glycine- and GABA-LI coexisted, the gold particle density for each amino acid was only half of that seen in boutons containing only one of the two amino acids. The involvement of glycine and GABA in postsynaptic inhibition of spinal α-motoneurons is discussed, with particular reference to the possibility that these two inhibitory amino acids may be coreleased from a significant proportion of the nerve terminals impinging on the cell bodies. © 1996 Wiley-Liss, Inc.     

Ego functioning in eating disorders: Description and relation to diagnostic classification

A working assumption for many clinicians is that differences in personality functioning among eating-disordered patients are crucial for treatment planning and prognosis. However, the empirical documentation is scarce. The present study used analyses of 13 objectively rated ego functions in a sample of 48 eating-disordered patients to try to establish a firmer empirical basis in the area. The variation in ego functioning was great, and a cluster analysis identified four clusters. These were tentatively named “higher neurotic,” “lower neurotic,” “borderline,” and “borderline-psychotic.” The clusters were unrelated to DSM-III-R eating disorder diagnoses and to the restricter/bulimic distinction and related markedly differently from those classifications to other clinical variables. The most interesting associations occurred between ego functioning and variables of possible prognostic value. Ego functioning thus constitutes a complementary diagnostic dimension of potential importance for prognosis.     

Oncogenic H-Ras V12 promotes anchorage-independent cytokinesis in human fibroblasts

Cell anchorage is required for cell proliferation of untransformed cells, whereas anchorage-independent growth can be induced by oncogenes and is a hallmark of transformation. Whereas anchorage-dependent control of the progression of the G(1) phase of the cell cycle has been extensively studied, it is less clear whether and how anchorage may control other cell cycle phases and whether oncogenes may affect such controls. Here, we found that lack of cell anchorage did not influence progression through the cell cycle S phase, G(2) phase, or most of mitosis of primary human fibroblasts. However, unanchored fibroblasts could not complete cytokinesis. The cleavage furrow and central spindle were still formed in the absence of anchorage, but cells were unable to complete ingression, causing binucleation. Importantly, V12 H-Ras-transformed fibroblasts and two cancer cell lines progressed through the entire cell cycle without anchorage, including through cytokinesis. This indicates that oncogenic signaling may contribute to anchorage-independent growth and tumorigenesis by promoting the final cleavage furrow ingression during cytokinesis.     

Phase 1 treatment for the chronic and previously treated anorexia. Bulimia nervosa patient

Treatment of anorexia nervosa/bulimia patients with a chronic course who previously were treated is given little attention in the literature. At the Uppsala University Hospital, a special program was developed for this category. It is assumed that successful therapy requires (1) a combination of therapeutic modalities, (2) a stepwise treatment, (3) a combination of anorexia nervosa and bulimia treatment principles, and (4) a treatment goal that is subjectively valid for the patient. In the present article, “Phase 1” is described. This involves teaching eating control through detailed diet and activity regimens supported by daily talk sessions, body-awareness therapy, and occupational therapy. “Phase 2” psychotherapy is thereby made possible. Results are promising in that a substantial proportion of patients were able to reach eating and weight goals not attained in previous treatments. Possible ways of improving results, the role of medical management, and implications for treatment of young patients are discussed.     

24-h Systolic blood pressure and heart rate recordings in lean and obese adolescents

OBJECTIVE: We assessed the hypothesis that differences in day and night-time systolic blood pressure (SBP) and heart rate (HR) recordings were smaller in obese versus lean children and adolescents, and whether measurements obtained during a school week or during weekends or holidays influenced these nocturnal falls. We also wanted to determine whether the results were influenced by gender. METHODS: Ambulatory 24-h BP and HR measurements were performed in 80 subjects, 51 girls and 29 boys. Lean (n = 25) and obese (n = 55) subjects were classified according to body mass index (BMI)-standard deviation (SD) criteria. Forty-eight subjects had their 24-h recordings performed during a school week and 32 during leisure time. RESULTS: The SBP nocturnal dipping response was less pronounced in obese subjects (16.2 +/- 6.3 mmHg) compared with lean controls (21.1 +/- 5.7 mmHg) (P < 0.01) of which the girls constituted most of the difference. HR change between day and night was similar in both groups being approximately 15 b/min. A small but statistical negative correlation was observed between BMI-SD and nocturnal fall in SBP (r = -0.3, P = 0.0065). In all subjects, regardless of BMI-SD, daytime SBP was higher when readings were obtained during a school week (123 +/- 7 mmHg) than during weekends or holidays (119 +/- 7 mmHg) (P = 0.029). CONCLUSION: Obese children and adolescents showed smaller nocturnal falls in SBP compared with lean subjects. This pattern may cause increased cardiovascular loading; thus, it may reflect an early sign of high blood pressure development and adds to cardiovascular risk in young obese individuals.     

Food hypersensitivity and quality of life

PURPOSE OF REVIEW: The present article presents an accessible review of research results on food hypersensitivity and quality of life (QoL), including 15 original articles on the subject. RECENT FINDINGS: Research on food hypersensitivity and QoL covers children and their parents, adolescents and adults. Several domains of QoL are affected, such as family and social activities, emotional issues and family economy. Food-hypersensitive children are to a large extent limited in their autonomous social activities. Food-allergic adolescents have a higher number of weeks absent from school compared with a control group, and a relatively high percentage of food-allergic young adults do not participate in the labour market. Comorbidity has to be taken into consideration when assessing QoL in food-hypersensitive individuals. Research on gender differences in food hypersensitivity and QoL are scarce. SUMMARY: Although development in this research field has only just begun, it is obvious that food hypersensitivity has a significant impact on individuals' and families' QoL. An important advance is the disease-specific QoL measure instruments that have been created. There is still, however, a need for a more in-depth knowledge as a basis for further development of QoL instruments, and as a basis for societal interventions and family/individual support.     

Tissue oxygenation measured with near-infrared spectroscopy during normobaric and hyperbaric oxygen breathing in healthy subjects

To evaluate the possibility of using near-infrared spectroscopy (NIRS) to measure tissue oxygenation (StO₂) during hyperbaric oxygen (HBO) therapy. Nine healthy volunteers (1 female) age 25−37 years, breathed air or oxygen. Tissue oxygenation was measured using NIRS on the thumb. Subjects were blinded to breathing gas. A range of partial pressures of oxygen were administered in 10-min intervals: 21, 101, 21 kPa (compression to 280 kPa), 59, 280, 59 (decompression), 21 kPa. Data were averaged over last 5 min at each pressure. When switching from air to normobaric oxygen (NBO 101 kPa) StO₂ increased from 83% (82−85%, median and interquartile range) to 85% (84−87%) (P < 0.01), while when switching from air at pressure (59 kPa O₂) to HBO (280 kPa), StO₂ increased from 85% (85−86%) to 88% (87−89%) (P < 0.001). There was no difference between baseline StO₂ while air breathing before NBO or after decompression. Values did not reach the maximal value of 100% at any point. The changes in hemoglobin oxygen saturation in tissue registered by the NIRS monitor when switching from air to oxygen followed inspired PO₂ under normobaric and hyperbaric conditions.     

Detection of human papillomavirus in urine and cervical swabs from patients with invasive cervical cancer

Despite the high prevalence of both human papillomavirus (HPV) infections and cervical cancer among Zimbabwean women, the ability to test for HPV infection of the uterine cervix is limited by a lack of an easy sample collection method that does not require gynecological examination. The presence of HPVs in urine and cervical swab samples collected from 43 women who presented with invasive cervical cancer was investigated. HPV detection was done by means of degenerate primers in a nested polymerase chain reaction (PCR). Typing of HPVs was done using restriction fragment length polymorphism (RFLP) analysis. HPV was identified and typed in 98% (42/43) of cervical swabs and 72% (31/43) of paired urine samples. HPV type 16 was the most common (25/42, 59%), followed by types: 33 (13/42, 31%), 18 (6/42, 14%), and 31 (1/42, 2%). Type-specific concordance between cervical and urine samples was high (22/28, 79%). Therefore, the HPV types identified in urine samples in most cases represent the same HPV type infecting the cervical epithelium. The results suggest that urine may be a practical sample for testing of HPV urogenital infection. Further research is required before the detection of HPV in urine can be applied in the routine cervical screening programs.