Localization of 5-hydroxytryptamine-like immunoreactive cells and nerve fibers in the rat female reproductive system

The presence of 5-hydroxytryptamine (5-HT)-like immunoreactivity (IR) was studied in the rat female reproductive system using polyclonal antibodies directed against 5-HT. Moreover, 5-HT levels in the ovary, Oviduct, uterus, and cervix were measured by high-pressure liquid chromatography with electrochemical detection. The highest 5-HT concentrations were found in the oviduct, followed in descending order by the cervix, the ovary, and the uterus. Most 5-HT-like IR was observed in the cytoplasm of mast cells. These cells were found in the connective tissue around the fimbria, in the oviduct, in the uterus, and in the ovary. Mast cells are clustered in the proximity of the parenchymal blood vessels. Moreover, a few 5-HT-like nerve fibers were found distributed mainly perivascularily in the uterine cervix and in the uterine horns as well as in the oviduct. IR nerve fibers were rarely seen within the ovary. The present data provide direct evidence that 5-HT in the female reproductive system not only is associated with mast cells but is located in nerve fibre-like structures as well. The functional significance of this probable 5-HT-ergic innervation of the female reproductive tract discovered in the present study should be clarified in future investigations. © 1992 Wiley-Liss, Inc.     

The peripheral dopaminergic system: morphological analysis,functional and clinical applications

In vivo administration or in vitro application of dopamine or of dopamine receptor agonists induce vasodilatation in the cerebral, coronary, renal and mesenteric vascular beds and cause hypotension. Moreover, dopamine stimulates cardiac contractility and induces diuresis and natriuresis. Peripheral (cardiovascular and renal) dopamine receptors belong to the D1-like and D2-like receptor superfamilies, thought to be located post-junctionally and pre-junctionally respectively. Stimulation of vascular D1-like receptors causes direct vasodilatation and reduction of vascular resistance. Stimulation of vascular D2-like receptors causes indirect vasodilatation, resulting from inhibition of sympathetic vasoconstrictor tone. Combined radioligand binding assay and light microscope autoradiography have investigated the anatomical localization of cardiovascular and renal dopamine D1-like and D2-like receptors in different animal species including humans. The application of molecular biology techniques to dopamine receptor research has shown that the picture of dopamine receptor subtypes is more complicated than it was suggested in the past, with at least 5 subtypes belonging to the dopamine D1-like (D1 and D5 receptors) and D2-like (D2, D3 and D4 receptors) superfamilies. The development of antibodies raised against selected sequences of dopamine receptor subtypes has allowed a more detailed characterization of the density and pattern of peripheral dopamine receptors. Dopamine receptor protein immunohistochemistry confirmed the localization of dopamine D1 and D5 receptors in the tunica media of systemic arteries and of prejunctional dopamine D2-D4 receptors closely associated with sympathetic neuroeffector junctions. The distribution and the density of prejunctional dopamine D2-like receptors was different in various vascular beds investigated. The kidney expresses the 5 different subtypes of dopamine receptors, displaying a not homogeneous vascular and tubular localization. Dopamine acting as autocrine or paracrine substance is probably involved in the regulation of immune activity. Human peripheral blood lymphocytes contain dopamine and express plasma membrane and vesicular dopamine transporters as well as dopamine D3, D4 and D5 receptors. Another recently characterized peripheral dopaminergic system is located in the lung. Dopamine D1-like receptor immunoreactive structures were found in a small percentage of nerve fibres contained in pulmonary nerve trunks. D1-immunoreactive nerve fibres were approximately 2-3% of total fibres, whereas D5-immunoreactive fibres accounted approximately for 5-6% of total fibres. Also dopamine D2-like receptor immunoreactive fibres were found in pulmonary trunks. D2-immunoreactive fibres accounted for approximately 3-5% of total nerve fibres, D3 receptor-immnunoreactive fibres accounted for about 8-10% of total nerve fibres, whereas only rare profiles of D4 receptor protein-immunoreactive fibres were observed. Dopamine recepetor protein immunostaining was also found in neurons of nodose ganglion, that display immunoreactivity for different neuropeptides. Based on the correspondence between the number of dopamine receptor immunoreactive pulmonary nerve fibres and of vagal ganglionic neurons immunoreactive for dopamine receptors it is possible to hypothesize that these receptors are located on pulmonary afferents. In spite of the heterogeneity of peripheral systems expressing dopamine receptors, analysis of their localization with appropriate microanatomical techniques may contribute to investigate their role in health and disease.     

Sensory and response contributions to visual awareness in extinction

Brain-damaged patients may extinguish contralesional stimuli when ipsilesional stimuli are presented simultaneously. Most theories of extinction postulate that stimuli compete for pathologically limited attentional resources with a bias to process ipsilesional over contralesional stimuli. Implicit in this view is the idea that responses follow the outcome of an earlier competition between inputs. In the current study of two patients, we used signal detection analyses to test the hypothesis that response criteria and response modalities also contribute to visual awareness. We found that identification was more sensitive than detection in uncovering deficits of contralesional awareness. Extinction was worse with bilateral stimuli when the ipsilesional stimulus was identical or similar to the target than when it was dissimilar. This diminished awareness was more likely to reflect a shift towards more conservative responses rather than diminished discrimination of contralesional stimuli. By contrast, one patient was better able to discriminate contralesional stimuli when using his contralesional limb to indicate awareness of targets than when using his ipsilesional limb. These data indicate that the nature of stimuli can modulate response criteria and the motor response can affect the sensory discriminability. Sensory discrimination and response output are not organized in a simple serial manner. Rather, input and output parameters interact in complicated ways to produce visual awareness. Visual awareness itself appears to be the outcome of two bottlenecks in processing, one having to do with sensory processing that may be covert and the other having to do with decision making, which by definition is overt. Finally, we advocate the use of signal detection analyses in studies of extinction, a method that has been surprisingly neglected in this line of research.     

Nutritional status as a central determinant of child mortality in sub‐Saharan Africa: A quantitative conceptual framework

Child mortality is a major public health problem in sub‐Saharan Africa and is influenced by nutritional status. A conceptual framework was proposed to explain factors related to undernutrition. Previously proposed conceptual frameworks for undernutrition do not consider child mortality and describe factors related to undernutrition from a qualitative viewpoint only. A structural equation modelling approach was applied to the data from World Bank and FAO databases collected from over 37 sub‐Saharan countries from 2000 to the most recent update. Ten food groups, exclusive breastfeeding, poverty and illiteracy rates, and environmental hygiene were investigated in relation to underweight, stunting, low birthweight, and child mortality. Standardized beta coefficient was reported, and graphical models were used to depict the relations among factors related to under‐five mortality in sub‐Saharan Africa. Child mortality in sub‐Saharan Africa ranged between 76 and 127 × 1,000. In the same period, low birthweight rate was about 14%. Poverty and illiteracy are confirmed to affect health resources, which in turn influenced nutritional status and child mortality. Among nutritional factors, exclusive breastfeeding had a greater influence than food availability. Low birthweight, more than underweight and stunting, influenced child mortality. Structural equation modelling is a suitable way to disentangle the complex quantitative framework among factors determining child mortality in sub‐Saharan Africa. Acting on poverty at the base appear to be the more effective strategy along with improvement of breastfeeding practice and improvement of hygiene conditions.     

Management of pneumothorax in hemodynamically stable preterm infants using high frequency oscillatory ventilation: report of five cases

Background

Despite an increased use of non-invasive ventilatory strategies and gentle ventilation, pneumothorax remains a common complication in preterm infants. The ventilator management of infants with air leaks remains challenging in terms of both prevention and treatment. Recently the safety and efficacy of expectant management avoiding chest tube drainage to treat large air leak in preterm infants hemodynamically stable has been reported.

Case presentation

In the present study, we report five cases of preterm infants with birth weight?≤?1250 g affected by respiratory distress syndrome and treated with nasal continuous positive airway pressure as first intention. They were intubated for worsening of respiratory distress with increasing oxygen requirement and concomitant increase of respiratory rate and P_CO2 values due to occurrence of pneumothorax, and they were successfully treated using high-frequency oscillatory ventilation without chest tube insertion.

Conclusion

In our experience high-frequency oscillatory ventilation provided a conservative management of a significant pneumothorax in preterm newborns hemodynamically stable and requiring mechanical ventilation. This approach allowed us to avoid the increasing of air leak and the insertion of chest tube drainage and all the subsequent associated risks.

     

5-Year control and treatment of edema and increased capillary filtration in venous hypertension and diabetic microangiopathy using O-(beta-hydroxyethyl)-rutosides: a prospective comparative clinical registry

This independent prospective controlled trial evaluates the efficacy of O-(beta-hydroxyethyl)-rutosides (HR) during 5 years of administration against signs and symptoms and further degeneration of microcirculatory disturbances. The protective effect of HR in preventing end-point complications such as venous ulceration is evaluated. This study is based on evaluation of edema and the capillary filtration rate (CFR) in association with a clinical score scale. Patients having a severe degree of chronic venous insufficiency (CVI) and venous microangiopathy and completing at least 5 years of treatment are included. The following 4 groups are considered: group A (patients with CVI but without diabetes mellitus, receiving 1500 mg/d of HR), group B (patients with CVI and diabetes mellitus, receiving 2 g/d of HR), group C (control subjects receiving no pharmacologic or compression treatment), and group D (patients using elastic compression stockings only). All patients received the "best" available treatment. No adverse effects or intolerance is noted, with good compliance (>85%). In group A, there is a statistically significant decrease in the CFR during 5 years of follow-up. In group B, the decrease in the CFR is greater than that in group A. Reductions in edema, swelling, and the CFR during 5 years are notable, and values approach normal levels. During 5 years, HR is effective in treating venous edema and hypertension and in preventing deterioration of the distal venous system. The prevention of ulcerations with HR is another important observation. The effects of HR seem to be partially dose related, and tolerability and compliance are good.