H-Abstraction reactions by OH, HO2, O, O2 and benzyl radical addition to O2 and their implications for kinetic modelling of toluene oxidation

Alkylated aromatics constitute a significant fraction of the components commonly found in commercial fuels. Toluene is typically considered as a reference fuel. Together with n-heptane and iso-octane, it allows for realistic emulations of the behavior of real fuels by the means of surrogate mixture formulations. Moreover, it is a key precursor for the formation of poly-aromatic hydrocarbons, which are of relevance to understanding soot growth and oxidation mechanisms. In this study the POLIMI kinetic model is first updated based on the literature and on recent kinetic modelling studies of toluene pyrolysis and oxidation. Then, important reaction pathways are investigated by means of high-level theoretical methods, thereby advancing the present knowledge on toluene oxidation. H-Abstraction reactions by OH, HO2, O and O2, and the reactivity on the multi well benzyl-oxygen (C6H5CH2 + O2) potential energy surface (PES) were investigated using electronic structure calculations, transition state theory in its conventional, variational, and variable reaction coordinate forms (VRC-TST), and master equation calculations. Exploration of the effect on POLIMI model performance of literature rate constants and of the present calculations provides valuable guidelines for implementation of the new rate parameters in existing toluene kinetic models.

Efficacy of an emollient dermoprotective cream in the treatment of elderly skin affected by xerosis

AIM

Xerosis cutis is a frequent condition in the elderly and the topical treatments are aimed to maintain a balance between the physiological components of the epidermis and an optimal moisturization. The aim was to evaluate the efficacy of a dermoprotective cream, glycerol and paraffin-based, in the treatment of individuals affected by senile xerosis.

METHODS

The patients were recruited at the Professional Dermatology and Allergology Outpatient Clinic of the San Gallicano Dermatological Institute of Rome, between 1st January 2013 and 30th September 2014. To assess the efficacy of the cream, two different areas of treatment were identified in each patient upper the limbs. All patients were staged at baseline (T0) and evaluated after 14 days (T1) and 28 days (T2) of topical treatment, using five clinical parameters: scaling, sensation of skin tightness, presence of fissuring and excoriations from scratching and erythema. The itching degree was also evaluated using a 10-steps analogical scale.

RESULTS

Fifty patients with xerosis, 25 with a severe and 25 with a moderate form, over 60 were recruited and evaluated. Median age was 65 years (IQR=61-70). After 28 day of topical administration of the cream, the 54.0% of patients showed the absence of signs of xerosis, the 44.0% a mild form and the 2.0% (one patient) a moderate form. Consistently, a progressive and significative reduction of itching and transepidermal water loss (TEWL), and an improvement in skin hydration was also measured. A good profile of tolerability and no episodes of undesirable side effects, was also observed.

CONCLUSION

The topical daily use of a cream glycerol and paraffin-based, seem to able to control the xerosis in elderly patients, with a significant reduction of all associated signs and symptoms. Further additional data should be collected to better confirm the role of the topical treatment in the control of disease.

Immunologic biomarkers for clinical and therapeutic management of psoriasis

BACKGROUND

The therapeutic management of psoriasis includes conventional treatments as well as the new generation of highly effective TNF-α inhibitors. However, psoriasis has proven to be a complex therapeutic challenge and treatment failures are not uncommon. Thus, laboratory biomarkers of disease progression/therapeutic efficacy may greatly help in the clinical management of psoriasis.

AIMS

To identify laboratory biomarkers for clinical management and therapeutic monitoring of psoriasis.

METHODS

An observational study performed on 59 patients, presenting moderate to severe psoriasis, undergoing treatment with anti-TNF-α agents (etanercept, adalimumab, and infliximab). Soluble and cellular immune/inflammatory parameters were assessed at baseline and after 12 and 24 weeks of treatment.

RESULTS

Clinical efficacy was achieved in 88% of the subjects at 12 weeks, reaching 90% after 24 weeks. IL-6 and IL-22, which were elevated at baseline, were significantly reduced, in association with a significant decrease of CLA+ T cells and an increase of Treg lymphocytes. T, B, and NK cell subsets and T cell response to recall antigens did not show any evidence of immune suppression.

CONCLUSIONS

Immune/inflammatory parameters including IL-6 and IL-22, CLA+ T cells, and Treg lymphocytes may prove to be valuable laboratory tools for the clinical and therapeutic monitoring of psoriasis.

Analysis of nerve supply pattern in human lymphatic vessels of young and old men

BACKGROUND

The present work deals with innervation patterns along collector lymphatic vessels from cervical, mesenteric, and femoral regions, and lymph capillaries in young and elderly subjects.

METHODS AND RESULTS

Morphological and morphometric analysis of nerve fibers along lymph vessels was performed by immunohistochemistry for PGP 9.5, NPY, TH, ChAT, VIP, SP, and dopamine. Nerves containing NPY and TH were frequent, whereas immunoreactivity for ChAT and VIP were few. SP-positive fibers were widely distributed in the medial and endothelial layers. Dopamine neurotransmitters were observed in a few short nerve fibers. A more diffuse presence of nerve fibers in mesenteric and femoral lymph vessels, compared to cervical ones, was detected. In lymph capillary vessels, a few nerve fibers positive for neuropeptides and neurotransmitters were detected, whereas no dopamine and VIP immunoreactive fibers were detected. A wide reduction of all specific nerve fibers analyzed was detected in lymph vessels from elderly subjects.

CONCLUSIONS

The presence on lymph vessels of sympathetic and parasympathetic nerve systems can be declared. The differences observed in lymphatic vessel innervation patterns may note the involvement in lymph flow regulation, calling attention in aging, when nerve fibers reduction may cause functional default of lymph vessels.

Ultrastructural age-related changes in the sensory corpuscles of the human genital skin

In human genital skin the majority of superficial sensory corpuscles is represented by glomerular corpuscles. These corpuscles show an own morphology. Our aim is to compare the ultra-structure of superficial sensory corpuscles in the penis skin of younger and older subjects. In this report the ultra-structure of the sensitive corpuscle in the penis skin of the younger and older subjects was compared, showing that the genital skin of the older humans contains more simple complexes than the younger ones. Our findings support the view that the age-related changes that can be observed in human glomerular genital corpuscles are consistent with an increase of the simple complexes and a strong decrease of the poly-lamellar one in the older people. These findings demonstrate that human genital corpuscles underwent age-related changes. Moreover our morphological findings can be correlated in relation to the clinical evolution of the sensitivity in the genital skin.

Inflammation and Neurotransmission of the Vescico-Uterine Space in Cesarean Sections

Collagen IV and laminin play a key role in regulating stiffness, elasticity and flexibility of the vescico-uterine space (VUS) tissue. The neurotensin (NT), the neuropeptide tyrosine (NPY) and the protein gene product 9.5 (PGP 9.5) possessing vasorelaxation and tissue vascularization activities, play key roles in cervical ripening, scar innervations and pain control. We propose that the integrity of these substances in VUS tissue is compromised after Cesarean section (CS), since wound healing disturbances and pelvic pain, as well as pregnancy and delivery complications, are related with lower uterine segment dysfunctions after CS. Therefore, the contents of collagen IV, laminin, NT, NPY and PGP 9.5 nerve fibres from the VUS tissue samples obtained during the first CS and the repeated CS were comparatively studied. VUS specimens were collected from 104 patients during CS and evaluated by immunohistochemistry. Collagen IV and laminin were mostly found in the vascular membrane bounds and their images were quantitatively evaluated by Quantimet Leica analyzer software. Differences of collagen IV, laminin, NT, NPY and PGP 9.5 values in VUS tissue between the first CS and the repeat CS samples were calculated by Student's Mest. Reduced laminin and increased collagen IV values were observed in the VUS scar tissue after the repeated CS in comparison with those of VUS intact tissue obtained during the first CS. Significantly higher values of nerve fibres, containing NT, NPY and PGP 9.5 were registered in intact VUS tissue samples, respectively 5±0.7, 7±0.6 and 5±0.9 CU, than those of VUS scar tissue samples obtained during the repeated CS, respectively 3±0.6,2±0.4 and 3±0.7 CU (p<0.05). The authors observed increased collagen IV and reduced laminin values after the repeated CS which might be the key signs of inflammatory damage of VUS scar tissue by CS. These findings were strengthened by the registration of decreased NT, NPY and PGP 9.5 values in the same samples, which are important neurotransmitters and are responsible for optimal wound healing, pain control and lower uterine segment functions.

Dopaminergic receptors in the human skin

Dopamine is a neurotransmitter which plays an important role in many human organs including the skin. In this study we will examine the presence and the distribution of D1 and D2 dopamine receptors in a particular zone of the human skin. Samples of the human plantar skin were harvested during autopsies after the consent of relatives of the dead donors. In this study the following experimental procedures were performed: 1) drawing of the human plantar skin; 2) cutting of tissues; 3) staining of tissues; 4) staining of the nerve fibres; 5) radio-binding methods for labelling D1 and D2 dopamine receptors; 6) light microscope autoradiography; 7) quantitative analysis of images and 8) statistical analysis of data. The dopamine receptors D1 are distributed particularly in the dermis layer of the human plantar skin. They are numerous in lower epidermal layers (with exclusion of the corneal layer) and few in subcutaneous tissue. On the contrary D2 dopamine receptors are prominent in the subcutaneous tissue near the vessels. Quantitative analysis of images and statistical analysis of the data confirm all our results. The specific distribution of D1 and D2 dopamine receptors in the human plantar skin is in close relation with the functions of a particular zone of the human skin that supports the weight of all the body. Moreover the character of dopamine receptors distribution is very important for further understanding the role of these receptors in the human skin.

Role of dopaminergic receptors in the human dura mater in the pathogenesis of headache

AIMS

We hypothesize that dopaminergic receptors of dura mater may play a possible role in headache.

MATERIALS AND METHODS

The dopaminergic receptors of cranial dura mater in man were studied by examining several dural zones (vascular, peri-vascular, inter-vascular) in different brain regions (basal, calvarial, tentorial, occipital, frontal, parietal, temporal).

RESULTS

Our results demonstrate that dopaminergic receptors are present in human cranial dura mater and that these receptors show a specific morphological location. There are more dural dopaminergic receptors in the basal region than in the calvarial one. Moreover, these receptors are more abundant in the vascular and perivascular dural zone than in the intervascular one.

CONCLUSIONS

The location of dopaminergic receptors in the dura mater may represent an important factor in the pathogenesis of headache. Further studies will be necessary in order to determine the role of dopaminergic system in this disease.

Surgical technique to avoid bladder flap formation during cesarean section

Cesarean section (CS) is now the most common major surgical procedure performed on women worldwide. A CS can be performed by either suturing or not suturing of the visceral peritoneum. Creation of the bladder flap is an integral step of the standard cesarean section. The bladder flap is made by superficially incising and dissecting the peritoneal lining to separate the urinary bladder from the lower uterine segment. It's still debated whether the formation of bladder flap is advantageous or not. If the uterine incision is made slightly above the vesicouterine peritoneal fold, the loose connective tissue between the uterus and the urinary bladder allows spontaneous descent of the bladder. Evidence on the role of the bladder flap in cesarean section is very limited. At present, it remains to be established whether there is any advantage in dissecting the bladder from the lower uterine segment during cesarean section.

Neuropeptides of human thymus in normal and pathological conditions

Human thymus of healthy subjects and patients affected by thymoma-associated Myastenia Gravis were studied in order to visualize and compare the morphological distributive pattern of four neuropeptides: vasoactive intestinal peptide, substance P, neuropeptide Y, and neurotensin. Based on our observations, we formulated hypotheses on their relations in neuro-immunomodulation under physiological and pathophysiological conditions. Immuno-histochemical staining for neuropeptides was performed and morphological and morphometrical analyses were conducted on healthy and diseased thymus. In normal thymus, a specific distributive pattern was observed for the several neuropeptide-positive nerves in different thymus lobular zones. In particular substance P-positive fibers were observed in subcapsular zone, specifically located into parenchyma, where they represent the almost total amount of fibers; neurotensin-positive fibers were observed primarily located in parenchyma than perivascular site of several thymus lobular zones, and more abundant the cortico-medullary and medullary zones. Instead VIP- and NPY-positive fibers were widely distributed in perivascular and parenchymal sites of several thymus lobular zones. In thymoma, the distribution of neuropeptide-positive fibers was quantitatively reduced, while cells immunopositive to VIP and substance P were quantitatively increased and dispersed. Observation of the perivascular and parenchymal distribution of the analyzed neuropeptides suggests evidence that a regulatory function is performed by nerves and cells that secrete neuropeptide into the thymus. The alteration of neuropeptide patterns in thymoma suggests that these neurotransmitters play a role in autoimmune diseases such as Myastenia Gravis.

Stickler syndrome in Pierre-Robin sequence prenatal ultrasonographic diagnosis and postnatal therapy: two cases report

The Pierre-Robin Syndrome (PRS) is a rare congenital abnormality, with an approximately 1/30,000 estimated rate, characterized by the presence of the combination of mandibular hypoplasia (micrognathia or small jaw), glossoptosis (retrusion of the tongue into the pharyngeal airway) and, often, a posterior cleft of the secondary palate. It may be an isolated occurrence or part of a more complex syndrome and it is associated with long-term respiratory, nutritional, and developmental difficulties. Stickler syndrome (SS) is a rare autosomal dominant connective tissue disorder estimated to affect approximately 1/7500 newborns. It is diagnosed clinically and, at present, there is no consensus on a minimal clinical diagnostic criterion. The most frequent diagnosis in patients with syndromic Pierre Robin sequence is Stickler syndrome, which may be complicated by congenital high myopia and substantial risk of retinal detachment. However, cases of Stickler syndrome with probable visual complications are rarely identified among this group of patients by members of the cleft team. The patient had an acute unilateral hydrops, with a monolateral keratoconus. The ocular abnormalities included: severe myopia, abnormalities of the vitreous, and high risk of retinal detachment (with subsequent blindness). We report two extremely rare cases of prenatal diagnosis of PRS and SS, prematurely identified by prenatal ultrasonography and successively managed by oculists ophthalmogists.

The combination latanoprost-timolol versus twice daily 0.50% timolol administration either associated or not with latanoprost: efficacy and tolerability in the primary open-angle glaucoma

AIMS

To evaluate the ocular hypotensive effects and tolerability of the once daily fixed combination latanoprost-timolol versus twice daily 0.50% timolol associated or not with once daily latanoprost in patients suffering from Primary Open-Angle Glaucoma (POAG).

METHODS

We compared the effects of such a combination with those of 0.50% timolol alone twice daily in a group of 24 patients and with the effects of timolol 0.50% twice daily associated with once daily latanoprost in a second group of 20 patients with a follow-up of 24 months.

RESULTS

In the first group of patients after one month the Intraocular Pressure (IOP) was reduced from a mean of 19.93 to a 17.04 mmHg. This reduction remained stable with a mean value of 17.00 mmHg at the third month, of 16.49 mmHg at the sixth month, of 17.04 at the twelfth month, 16.00 at the eighteenth month, and of 15.86 mmHg in the twenty-fourth month. In the second group there was a statistically significant reduction from 19.4 to 16.84 mmHg after one month. This reduction remained constant with mean values of 16.47 at the sixth month, of 16.20 at the twelfth month and of 16.00 mmHg at the twentyfourth month of treatment.

CONCLUSIONS

The once daily latanoprost-timolol combination was shown to furtherly reduce the Intraocular Pressure (IOP) (p=0.001) and to maintain under control the intraocular pressure for the observation period (24 months). Both topical and systemic side-effects were scarse and tolerability was good.

Intrinsic innervation and dopaminergic markers after experimental denervation in rat thymus

The aim of this study was to examine rat thymus innervation using denervation techniques and to explore the related microanatomical localization of dopamine, D1, D2 receptors and dopamine membrane transporter (DAT).

In the thymus subcapsular region, the parenchymal cholinergic fibers belong exclusively to phrenic nerve branching. No somatic phrenic nerve branching was detected in any other analysed thymus lobule regions.

In rats subjected to sympathetic or parasympathetic ablation, it was observed that catecholaminergic and cholinergic nerve fibers respectively contributed to forming plexuses along vessel walls.

In the subcapsular and septal region, no parenchymal nerve branching, belonging to sympathetic or parasympathetic nervous system was noted. Instead, in the deep cortical region, cortico-medullary junction (CM-j) and medulla, catecholaminergic and cholinergic nerve fibers were detected along the vessels and parenchyma.

Dopamine and dopamine receptors were widely diffused in the lobular cortico-medullary junction region and in the medulla, where the final steps of thymocyte maturation and their trafficking take place.

No variation in dopamine and DAT immune reaction was observed following total or partial parasympathectomy or phrenic nerve cutting. After chemical or surgical sympathectomy however, neither dopamine nor DAT immune reaction was noted again. Instead, D1 and D2 dopamine receptor expression was not affected by thymus denervation.

In rats subjected to specific denervation, it was observed the direct intraparenchymal branching of the phrenic nerve and sympathetic and parasympathetic fibers into thymus parenchyma along vessels. These findings on the dopaminergic system highlight the importance of neurotransmitter receptor expression in the homeostasis of neuroimmune modulation.

[Pancreaticoduodenectomy for adenocarcinoma of the pancreatic head and papilla of Vater]

AIM

The authors report their consecutive experience in the surgical management of adenocarcinoma (ADC) of head of pancreas and papilla of Vater, in order to review the available literature.

METHODS

One hundred and seventy cases (131 in the head of pancreas and 39 in the papilla of Vater) were operated upon for ADC by radical pancreaticoduodenectomy in the period 1972-2005. The stomach was resected in 81 patients (47.7%) and the pylorus was preserved in 89 (52.3%). Follow-up was completed in all patients.

RESULTS

Postoperative morbidity was reported in 66 patients (38.8%) and pancreatic fistulae were observed in 39 patients (22.9%). Postoperative mortality was 9.4% (16 patients), but in the last 10 years it was reduced to 4.1% (4/97 patients). Five-year survival for pancreatic ADC was 75% in stage IA, 43.9% in stage IB and IIA, 3.2% in stage IIB. In ADC of the papilla of Vater, for the same stages, the 5-year survival rates were 54.4%, 51.4%, 0% and 37.5%, respectively. None of the III-staged patients survived at a 5-year follow-up in both groups.

CONCLUSIONS

Preoperative studies should include laparoscopy with cytological examination of peritoneal lavage, while preoperative biliary drainage is rarely indicated in case of obstructive jaundice. The Wirsung duct has to be anastomosed directly to the jejunum and the pancreatic section needs to be checked. Extended lymphadenectomy, in addition to the standard peripancreatic excision, is seldom indicated, there is no controindication to pylorus preservation and Wirsung drainage is not necessary. This operation should be performed in Centres with substantial experience.

Changes of dopamine-sensitive cyclic AMP-generating system in the rat hippocampus as a function of age

The dopamine (DA) D(1) and D(2) receptors coupled to the 3',5'-cyclic adenosine monophosphate (cAMP)-generating system were studied in membrane particles of the dorsal hippocampus in 3 (considered to be young), 12 (considered to be adult) and 24 (considered to be old) month male Sprague-Dawley rats. Activation of D(1) receptors with DA, apomorphine or SKF 82526 enhanced accumulation of cAMP in the hippocampus of rats of the three age groups examined. This stimulatory effect was significantly reduced in adult rats. No further changes were noticeable in old animals. D(2) receptors negatively coupled to cAMP generation were demonstrated by incubating hippocampus membrane particles with SCH 23390 plus DA or with D(2) receptor agonists quinpirole or bromocriptine. The D(2) inhibitory effect on cAMP generation was unchanged in the three age groups. No difference was detectable between young, adult and old rats in the activation of cAMP production by forskolin.

Dopamine nerve fibres and related receptors in bronchus-associated lymphoid tissue (BALT)

Age-related changes of the dopamine nerve fibres of bronchus associated lymphoid tissue (BALT) were investigated in male Wistar rats of 3 months (young), and 24 months (old/aged). Dopamine histofluorescence techniques have been used, associated with image analysis for the detection of dopamine nerve fibres. In young rats, white, fluorescent nerve fibres supply BALT. This tissue is innervated by a delicate network of nerve fibres rich in varicosities. In old rats these fluorescent nerve fibres are strongly reduced. Moreover, dopamine D1a and D1b receptors were stained using fluorescent monoclonal antibodies. The BALT of young rats possesses a higher number of D1a and D1b receptors, while, in the old rats, these receptors are strongly reduced. The possible significance of reduced dopamine neurotransmission in BALT of aged rats is discussed.

Dopaminergic receptors in rat dura mater: pharmacological characteristics

1. The location and distribution of dopaminergic receptors in rat dura mater was studied by examining several dural zones (vascular, perivascular, intervascular) in different cranial and spinal regions. 2. The pharmacological characteristics and anatomical distribution of dopamine D1- and D2-like receptors sites were investigated using combined pharmacological techniques and immunofluorescent microscopy. 3. Samples of rat dura mater were obtained from 10 adult Wistar rats. On frozen slices, dopaminergic D1 and D2 receptors were stained immunohistochemically using monoclonal antibodies. 4. Inhibition studies were performed using fluorescent and non-fluorescent agonists or antagonists to define the pharmacological specificity of the immunostaining. 5. The greater sensitivity to displacement by amisulpride, bromocryptine, domperidone, haloperidol, raclopride and l-sulpiride than to displacement by N-propyl-nor-apomorphine, quinpirole and clozapine suggests that the immunofluorescent sites observed in these experiments are likely to belong to the dopamine D2 receptor subtype. 6. Our observations provide evidence of the presence of D1 and D2 receptors in the wall of meningeal vessels. The dopaminergic receptors are located in the adventitia, media and intima of dural arteries. Furthermore, the density of receptors is higher in close proximity to arteries and decreases passing from the vascular to the perivascular and intervascular zones. 7. In the rat dura mater, dopamine regulates the meningeal blood vessels and, through this action, dopamine and its receptors can play an important role in the pathogenesis of cephalalgia.

Catecholaminergic nerve fibers in bronchus-associated lymphoid tissue: age-related changes

Age-related changes of the catecholaminergic nerve fibers of the trachea, bronchial smooth muscle, lung capillaries and bronchus-associated lymphoid tissue (BALT) were studied in male Wistar rats aged 3 months (young), 12 months (adult) and 24 months (old/aged). Catecholamine histo- and immuno-fluorescence techniques were used, associated with image analysis and high pressure liquid chromatography with electrochemical detection of nor-epinephrine (nor-adrenaline). In young rats, blue-green fluorescent nerve fibers supply the trachea-bronchial smooth muscle and tracheal and bronchial glands. These structures are innervated by a delicate network of nerve fibers, being rich in varicosities. Pulmonary capillaries are sparsely innervated. The highest nor-epinephrine concentration was found in the trachea and bronchi, followed by BALT. The density and the pattern of noradrenergic nerve fibers of the trachea-bronchial tree or of the pulmonary vessels were similar in young and adult rats. In aged rats, a loss of noradrenergic nerve fibers, involving primarily the supply to the smooth muscle of the trachea-bronchial tree, was observed. Fluorescence microscopic techniques demonstrated a higher sensitivity than nor-epinephrine assay in detecting changes of the sympathetic nerve supply of the trachea-bronchial tree, pulmonary vessels and BALT. The possible significance of reduced noradrenergic nerve supply of the trachea-bronchial-pulmonary tree in aged rats is discussed.

Cholinergic innervation of BALT (bronchus associated lymphoid tissue) in rat

The presence and distribution of acetylcholinesterase (AChE) and cholineacetyl transferase activities (Chat) were examined in the bronchus-associated lymphoid tissue (BALT) of juvenile, adult and old rats. Histoenzymatic and immunochemical methods were used in association with quantitative analysis of images and statistical analysis of the data. Our results showed that both AChE and Chat activities were primarily confined to the BALT lymphoid cells. Only a low level of activity was observed in the sub-pleural parenchyma of the lung and in the wall of the bronchus. Moreover, both AChE and Chat activities in the BALT are specifically located in the lymphoid cells. Histoenzymatic staining and corresponding values of quantitative analysis of images confirmed morphological and immunochemical results. Finally, the intensity of histoenzymatic staining for AChE and of immunochemical staining for Chat in BALT of rats strongly decreases with age. On the basis of our results we hypothesize that both AChE and Chat activities may play an important role in BALT and both these enzymes undergo specific age-related changes.

Direct demonstration of iron in a term placenta in two cases of beta-thalassemia

The aim of this study was to quantify iron in the placentas at the end of pregnancy in two patients suffering from beta-thalassemia and compare the data to that recorded from the placentas of healthy women. Iron was quantified in placental specimens taken after the delivery. The specimens were subjected to chemical treatments in order to remove extracellular iron and leave the intracellular iron intact. After coloration, each specimen was subjected to quantitative analysis of images in order to identify and quantify iron. Our results demonstrated that in beta-thalassemia there is an accumulation of iron in the outer basal cytoplasm of the epithelial cells of placental cotyledons.

Diabetic rats treated by low molecular weight heparin OP 2123/parnaparin: morphological changes in the kidney and heart

AIM

Early morphological alterations in the rat kidney and heart due to experimentally induced diabetes are described in order to evaluate the possible therapeutic role of low molecular weight heparin (LMWH; OP 2123/parnaparin).

METHODS

Our findings concern the alterations observed in the rat kidney and heart because these are the organs (together with the retina) mainly involved in the early morphological angiopathic modifications associated with diabetic damage of organs and tissues. In diabetic animals treated with LMWH, the Periodic Acid-Schiff (PAS) reaction showed a slight decrease when compared with the diabetic control group. Photographs were submitted to the quantitative analysis of images using a Quantimet 500 Image Analyzer (Leica) equipped with specific software. The following parameters were measured: (1) total area occupied by alkaline phosphatase (AP)-positive capillaries; (2) number and diameter of AP-positive capillaries; (3) distribution and total area occupied by PAS-positive structures (related to the intensity of the reaction resulting from the different amount of mucopolysaccharides).

RESULTS

LMWH treatment is efficient in preventing these modifications, above all in the kidney. The histological study of the heart and kidney shows no significant, relevant alterations. However, the histological study of the mucopolysaccharides in diabetic animals highlighted a tendency for the heart to accumulate these substances. LMWH treatment only modestly reduced this accumulation.

CONCLUSIONS

Previous evidence demonstrating a beneficial effect of therapy based on heparan sulphate proteoglycans and/or other heparin-like substances in insulin-dependent diabetes mellitus seems to be confirmed by our experimental results in different organs of adult rats. In fact, parnaparin treatment is effective (in our experience) for ameliorating the morphological pattern observed early in some diabetic tissues of rats and, above all, in the kidney.

Age-related changes of monoaminooxidases in rat cerebellar cortex

Age-related changes of the monoaminoxidases, evaluated by enzymatic staining, quantitative analysis of images, biochemical assay and statistical analysis of data were studied in cerebellar cortex of young (3-month-old) and aged (26-month-old) male Sprague-Dawley rats. The enzymatic staining shows the presence of monoamino-oxidases within the molecular and granular layers as well as within the Purkinje neurons of the cerebellum of young and aged animals. In molecular layer, and in Purkinje neurons the levels of monoaminooxidases were strongly increased in old rats. The granular layer showed, on the contrary, an age-dependent loss of enzymatic staining. These morphological findings were confirmed by biochemical results. The possibility that age-related changes in monoaminooxidase levels may be due to impaired energy production mechanisms and/or represent the consequence of reduced energetic needs is discussed.

Age-related changes in catecholaminergic nerve fibers of rat heart and coronary vessels

BACKGROUND

Age-related changes of catecholaminergic nerve fibers supplying the myocardium and the coronary vessels were studied in adult and in old rats.

OBJECTIVE

The purpose of this study was to investigate whether there are quantitative changes in myocardial and/or coronary catecholaminergic nerve fibers and related neurotransmitters.

METHODS

Samples of myocardium and/or coronary vessels were studied by means of glyoxylic acid induced fluorescence, aldehyde-induced fluorescence, and neuropeptide Y immunoreactivity. All morphological results were submitted to quantitative analysis of images. Biochemical dosage of proteins and of norepinephrine was also performed, and morphological data were compared with biochemical ones. Finally, all data were subjected to statistical analysis.

RESULTS

Our findings are indicative of an age-related decrease of all types of fluorescent sympathetic nerve fibers in rat heart and coronary arteries. Moreover, our data show that aging induces a strong decrease of norepinephrine levels in tissue homogenates of rat heart and coronary vessels. The majority of the catecholaminergic nerve fibers that show strong age-related changes are not contiguous with contractile cells of myocardium and/or of vascular wall. In fact, these fibers are located in adventitial (or epicardial) and in endothelial (or endocardial) layers.

CONCLUSION

The decrease of the catecholaminergic innervation of heart and coronary vessels of old rats can be in close relationships to the poor cardiac and/or coronary functions observed in old animals.

Age-related changes in rat optic nerve: morphological studies

Age-related changes of the optic nerve were studied in 3-month-old (young), 12-month-old (adult) and 24-month-old (aged) male Sprague-Dawley rats. Cross sections of the intracranial portion of the optic nerves of animals of different age groups were stained with haematoxylin-eosin and examined under a light microscope at low and high magnification. Other sections were stained with crystal violet for demonstration of glial cells. A third group of sections were stained immunohistochemically to detect glial fibrillary acidic protein (GFAP) which is a marker for localizing and characterizing astrocytes. All morphological results were subjected to the quantitative analysis of images and to statistical analysis to identify significant morphometrical data. Tissue protein concentrations were determined on homogenized fragments of optic nerve. Our results demonstrate the following age-related changes: (1) increase of the optic nerve sheaths (meningeal membranes); (2) increased number of astrocytes; (3) increase of areal density of GFAP immunoreactivity; (4) increased diameter and area of the optic nerve; (5) decreased number of nerve fibres; (6) decreased-size of nerve fibres and (7) decrease of the nerve fibres/meningeal membrane ratio from 3:1 to 1:1. Moreover, the protein amount does not change with age. The rat optic nerve, therefore, appears sensitive to ageing processes and can be considered as a useful model for the studies on neuronal ageing.

Occurrence of catecholaminergic nerve fibers in the human uveoscleral tissue in conditions of normal and raised intraocular pressure

The distribution of catecholaminergic nerve fibers (CNF) in human uveoscleral tissue was studied in six human eyes with normal intraocular pressure and in five eyes with increased pressure. The eyes with increased pressure had no visual field alterations and the patients did not have any glaucoma-related optic neuropathies. The amount of norepinephrine in these structures was also analysed. Catecholaminergic nerve fibers were detected by means of fluorescence microscopy and were counted using the quantitative analysis of images. Our results demonstrate that the occurrence of catecholaminergic nerve fibers (expressed in Conventional Units = C.U.) in human uveoscleral tissue is 15.4 +/- 1.6 C.U. in eyes with normal intraocular pressure. In eyes with increased intraocular pressure, these values were 12.2 +/- 1.2 C.U. Moreover, the amount of norepinephrine in tissue homogenates of the same eyes was evaluated and found to be 21.7 +/- 1.3 microg/gr tissue fresh weight of the human uveoscleral tissue in eyes with normal intraocular pressure. This value decreased to 18.8 +/- 1.1 microg/gr tissue fresh weight in the same tissue in conditions of raised intraocular pressure. In these experiments, the small number of eyes examined made it difficult to draw general conclusions. However, the role of human uveoscleral tissue was emphasized by the rich catecholaminergic innervation. A decrease of catecholaminergic nerve fibers and norepinephrine occurs when intraocular pressure is elevated. The modifications of these parameters, involved in the sympathetic control of aqueous humor outflow, may support the hypothesis of a possible relevant role for the human uveoscleral tissue in different pathological conditions.

Effect of interferon on human thymus microenvironment

Interferon, a thymic immunostimulator, was used with the aim of assessing the importance of adrenergic nerve fibers (ANF) and/or AChE-positive nerve fibers (AChENF) in the regulation of some immunological functions in humans. Thymic normal control fragments and/or thymic fragments of immunostimulated patients were removed during surgical biopsies. Thymic slices were stained with eosin-orange (for the recognition of microanatomical details of the microenvironment) and with Bodian's method for staining of nerve fibers. Histofluorescence microscopy was employed for staining ANF. AChENFs were detected by means of the direct-coloring thiocholine method. All images were submitted to quantitative morphometrical analysis and statistical comparisons of data. Moreover, the amount of proteins and noradrenaline was measured on thymic homogenates of the same patients. Treatment with interferon induces substantial changes in the thymic microenvironment, on ANF, on AChENFs and on the total amount of proteins and noradrenaline in thymic tissue homogenates. In conclusion immunostimulation with interferon induces substantial changes in the whole thymus and in its microenvironment, involving both sympathetic and parasympathetic nerve fibers.

Morphological changes in the sciatic nerve of diabetic rats treated with low molecular weight heparin OP 2123/parnaparin

This study points out the early alterations that affect the sciatic nerve of rats with experimentally induced diabetes. It emphasizes the advantages deriving from treatment with low molecular weight heparin (LMWH) OP 2123/parnaparin and correlates these findings with observations emerging from a review of the relevant literature. In fact, the number and diameter of the capillaries within the sciatic nerve of diabetic rats appear to be increased consistent with a microangiopathy (the main characteristic of which is the fragility of new vessels), that is related to the evolution of diabetes in humans and animals. Our results suggest a possible therapeutic role for OP 2123/parnaparin in both diabetic neuropathy and microangiopathy, frequent complications of diabetes.

Effect of interleukin 1beta on rat thymus microenvironment

The effect of interleukin 1beta on the thymus of control and chemically sympathectomized adult and aged rats was studied with the aim of assessing the importance of adrenergic nerve fibres (ANF) in the regulation of some immunological functions. The whole thymus was removed from normal, sympathectomized (with the neurotoxin 6-OH-dopamine) and treated (interleukin 1beta) rats. Thymic slices were stained with eosin orange (for the recognition of microanatomical details of the thymic microenvironment) and with Bodian's method for staining of nerve fibres. Histofluorescence microscopy was employed for staining ANF and immunofluorescence was used for detecting NPY-like immunoreactivity. All images were submitted to quantitative morphometrical analysis and statistical analysis of data. Moreover, the amount of proteins and noradrenaline was measured on thymic homogenates. The results indicate that in normal conditions the formation of the thymic nerve plexi in the rat is complex: the majority of ANF are destroyed after chemical sympathectomy with 6-OH-dopamine and do not change after treatment with interleukin 1beta; on the contrary, treatment with interleukin 1beta induces substantial changes in the fresh weight of the thymus, the thymic microenvironment, thymic nerve fibers, ANF, NPY-like positive nerve fibres, and on the total amount of proteins and noradrenaline in rat thymic tissue homogenates. Immunostimulation with interleukin 1beta induces substantial changes in the whole thymus, in its microenvironment and in ANF and NPY-like nerve fibres. After chemical sympathectomy, no significant immune response was evoked by interleukin 1beta, since the majority of ANF was destroyed by chemical sympathectomy.

Interleukin 1beta as stimulator of the rat thymus

The effects of interleukin 1beta administration on the thymus of adult and old rats were studied in order to study the interactions between the nervous and immune systems and to confirm the important role played by catecholaminergic nerve fibres (CNF) in the regulation of thymic functions. Moreover, chemical sympathectomy was performed in a group of rats to study the effects on thymus of the destruction of the majority of CNF. Our results indicate that thymic stimulation (performed by means of interleukin 1beta) induces substantial changes in the fresh weight of the whole thymus, as well as in the thymic microenvironment, thymic nerve fibres, CNF, neuropeptide Y (NPY)-like positive nerve fibres and total amount of both proteins and norepinephrine in rat thymic tissue homogenates. The majority of CNF are destroyed after chemical sympathectomy with 6-OH-Dopamine (DA) and remain unchanged after treatment with interleukin 1beta.

A morphometric study of age changes in the rat optic nerve

Age-related changes of the optic nerve fibres were studied in 3-month-old (young), 12-month-old (adult) and 24-month-old (aged) male Sprague-Dawley rats. The optic nerve was harvested with particular care from the intracranial portion. Cross sections from the optic nerve of animals of different age groups were stained with toluidine blue and examined under a light microscope at low and high magnification. Other sections were stained for the demonstration of glial cells using the method described by Holzer. A third group of sections were stained by the immunohistochemical method to detect glial fibrillary acidic protein, which is a marker for localising and characterising astrocytes. All these morphological results were subjected to the quantitative analysis of images and to statistical analysis of the values to identify significant morphometric data. Biochemical dosages of proteins were also performed on homogenised fragments of the optic nerve. Our results demonstrate that the following age-related changes can be observed: (1) an increase in meningeal membranes, (2) an increased number of astrocytes, (3) an increase in areal density of glial fibrillary acidic protein immunoreactivities, (4) an increased thickness of the entire optic nerve and an increased area of the nerve, (5) a decreased number of nerve fibres and (6) a decrease in the nerve fibre/meningeal membrane ratio from 3:1 to 1:1. Moreover, the amount of protein does not change with age. The rat optic nerve, therefore, appears sensitive to aging processes.

Determination of dopamine D1 receptors in the human uveo scleral tissue by light microscope autoradiography

The aim of this paper is to clarify the distribution of Dopamine D1 (DA D1) receptors in the uveo-scleral tissue of human eyes with or without elevated intraocular pressure (IOP) and to study the relationships between DA D1 receptors and uveo-scleral tissue. Samples of human uveo-scleral tissue were taken from seven men undergoing eye surgery for a traumatic lesion of the anterior segment of the eye, without involvement of the iris-corneal angle and /or from eye donors. The subjects (in whom one eye bulb had been surgically enucleated) had been previously enrolled in our medical protocols because they suffered for increased IOP, while the eye donors (of both eye bulbs) had a normal IOP. Frozen sections from the uveo-scleral tissue were submitted to biochemical characterization and to morphological autoradiographic techniques for detection of DA-D1 receptors. [3H]-SCH-23390 was used as a ligand of Dopamine D1 receptors. [3H]-SCH 23390 was bound by sections of the human uveo-scleral tissue. The pharmacological profile of the binding was consistent with the labeling of D1 receptors. Light microscope analysis was used for localization of D1 receptors and revealed an accumulation of the radioligand in the human uveo-scleral tissue. In eyes with normal IOP there is a high reaction. The Bmax of radioligand decreases in the eyes with increased IOP. The possibility that dopaminergic receptors play a role in the controlling uveo-scleral tissue functions is suggested.

Ultrastructure of lamellar complexes in glomerular Krause spherical corpuscles

The authors compared the ultrastructure of lamellar complexes in the penis skin of the green monkey and in the woman's clitoris skin. In the green monkey the lamellar complexes consist of a maximum of 5 lamellae of Schwann cells, their greatest width is about 4.5 microm. The interlamellar spaces are filled with fine filamentous material. In the woman the lamellar complexes consist of a maximum of 7 lamellae, the interlamellar spaces are narrower than in the first case and filled with collagenous fibrils. Their maximum width is about 6.5 microm. The findings thus support the view that the lamellar complexes of glomerular corpuscles are morphologically and functionally similar to other simple lamellar corpuscles. The glomerular corpuscles contain also some non myelinated thin nerve fibers. Therefore for these corpuscles an additional (unclear) function can be considered.

Catecholaminergic and acetylcholine esterase containing nerves of cranial and spinal dura mater in humans and rodents

The innervation of cranial and spinal dura mater in humans and rodents was studied by examining several dural zones (vascular, perivascular, intervascular) in different regions. Characterization and distribution of dural acetylcholinesterase-positive nerve fibers, catecholaminergic nerve fibers, and mast cells are analyzed and discussed. The results of chemical and surgical sympathectomy as well as the relationships between catecholaminergic nerve fibers and mast cells are studied. Our results are discussed in the light of possible implications in the physiopathology of dural algic syndromes including cephalalgia and spinal pain.

Metabolic changes in rabbit lens induced by treatment with dexamethasone

Metabolic changes in the rabbit lens have been studied by means of nuclear magnetic resonance spectroscopy. These changes have been induced by prolonged topical treatment with dexamethasone. Our results demonstrate an increase in sorbitol, sorbitol-3-phosphate, fructose-3-phosphate, glycerol-3-phosphate and glucose-6-phosphate levels and a decrease in glutathione sulphate (GSH) and myo-inositol levels, in agreement with what was observed in lenses from streptozocin-diabetic rats before lens opacity. The hyperglycaemia can only partially explain all these observed biochemical variations. The lack of increase in the intermediates of pentose cycle, such as sedoheptulose-7-phosphate, seems to support the hypothesis of an inhibition of glucose-6-phosphate dehydrogenase by dexamethasone treatment. Finally dexamethasone treatment induces a decrease in GSH. The decreasing or the loss of GSH has been suggested as a possible pathogenic mechanism in the cataract formation.

Age-related changes in rat retina

PURPOSE

To describe the changes in rat retina occurring with ageing by means of histological methods, scanning electron microscopic observations and morphometrical data; and to study by means of biochemical methods the amount of protein content in retinal tissues.

METHODS

Samples of fresh retinal tissue obtained from young, adult, and aged rats were studied by means of traditional histological methods and by scanning electron microscopy. Particular attention was paid to morphometrical data and to the changes which occur with ageing. With the aid of a quantitative analysis of images, a large amount of morphometrical data was collected. Moreover, the amount of protein content in retinal tissues has been determined.

RESULTS

Retinal thickness significantly decreases with age. The ganglion cells seem to be more vulnerable to age-related loss than other retinal cells. The number of retinal capillaries is diminished with age. The intercellular connections between photoreceptors, the number of cellular processes, and the number of synaptic bodies of the bipolar cells also decrease significantly with age. These results were all confirmed by scanning electron microscopy observations and morphometrical findings. Biochemical dosage of proteins demonstrates that retinal tissues decrease with age.

CONCLUSIONS

All morphological, morphometrical, ultrastructural and biochemical data are concordant in demonstrating that the retinal tissues of rats undergo specific changes with age. Our findings are in agreement with those described by previous authors and underline that the rat retina can be considered an optimal model for studies on neuronal maturation and/or neuronal ageing. Since our data have confirmed that many changes occur in rat retina with ageing, we can hypothesize that rat retina is particularly sensitive to developmental changes and to senile decay.

Distribution of peptidergic nerve fibres in the guinea pig trabecular meshwork

A quantitative analysis of peptidergic nerve fibres located in the trabecular meshwork of the guinea pig has been performed. Our results confirm that this structure contains VIP-, NPY- and substance P-like immunoreactivity as major neurotransmitters. These findings were obtained using immunohistochemical techniques. For this purpose serial sections of the eye were stained by immunohistochemistry for each of three neurotransmitters and stained sections were analysed by quantitative image analysis. Our findings demonstrate that SP-positive, NPY-positive and VIP-positive nerve fibres occupy 11.2, 4.9 and 2.4%, respectively, of the observed area (expressed as conventional units, C.U.) in the trabecular meshwork of the guinea pig eye. It is relevant to emphasize that the area containing these three types of peptidergic nerve fibres appears to be large (18.5 +/- 6.6 C.U.) in proportion to the total observed area. The innervation of the drainage angle of the guinea pig eye has been well described by many authors. This is the first study to report quantitative measurements of three types of peptidergic nerve fibres identified and measured in this area. The presence of these three neurotransmitters in the trabecular meshwork of guinea pig eye suggests their possible participation in aqueous humor regulation.

Occurrence of cholinergic nerve fibers in the human uveoscleral tissue

We have studied the cholinergic nerve fibers (CNF) of human uveoscleral tissue in normal and pathological conditions (intraocular pressure: (IOP) of various degrees ) and have performed a quantitative image analysis of CNF with the aim of studying an hypothetical association between IOP and the uveoscleral level of cholinergic neurotransmitter in nerve fiber of the enucleated human eyes. Eleven patients, previously enrolled in our medical protocols are affected by an increase of IOP of various degrees, were subjected to surgical enucleation of one eyeball for traumatic or neoplastic reasons and were the donors of samples of the uveoscleral tissue for CNF demonstration. The samples were also submitted to quantitative image analysis. An enzymatic activity, Acetylcholinesterase (AChe), is present in nerve fibers that innervate the human uveoscleral tissue. The AChe-positive nerve fibers represent about 7.2% of the observed area in normal conditions, while in patients with elevated IOP AChe activity is about 20.3% of the total observed area. The increase of AChe activity in our experiments, all performed under the same conditions, and therefore, with comparable results, may be related with the increase of IOP.

Interleukin 1beta and GABA-transaminase activity in rat thymus

The occurrence and distribution of 4-aminobutyrate:2 oxoglutarate transaminase (GABA-t) activity were examined in the rat thymus of normal and immunostimulated rats using biochemical and histoenzymatical methods. Specific GABA-t reactivity was confined primarily to the arteries and, to a lesser extent, to the veins. Only a few activities could be observed in association with the subcapsular and medullar part of the parenchyma and nerve fibers. GABA-t was considered a linking enzyme between the immune and the nervous system and it was studied with the aim of analyzing the relationships between these two systems. Our findings indicate that the GABA-t activity in the thymus is specifically located in the wall of the blood vessels. Moreover, our results demonstrate the presence of a GABA-t activity in the peripheral blood vessels. Treatment with interleukin 1beta induces an increase of protein content of the amounts of GABA-t biochemically assayed and of the levels of histoenzymatically stained GABA-t. Furthermore, staining of the different structures of the thymus in treated or untreated rats shows that the significant modifications concern the parenchyma, the structures resembling nerve fibers and finally, the whole thymus. On the contrary, the highest activity of the GABA-t is located in the walls of arteries, veins and lymphatic vessels.

Anatomical variations of the ulnar and median nerves in the upper limb

The aim of our study was the evaluation of the anatomy of ulnar and median nerves in the upper limb in order to ameliorate knowledge on the clinical anatomy of these nerves. In fact, further information on this topic may be useful owing to its possible clinical relevance when planning surgical anatomy and reconstructive surgery in tumor affected and injured patients. The relationships between ulnar and median nerve and neighbouring anatomical structures have been examined, together with the course and ramification of the ulnar and median nerves in six fresh cadavers. Moreover, we have performed a review of the literature. Four specific aspects were evaluated during dissection: 1) division modality of the ulnar nerve at the wrist; 2) anatomical details of the medial humeral epicondyle; 3) anatomical relationships between median nerve and retinaculum flexorum; 4) median-ulnar nerves anastomosis. Our results show that: the medial humeral epicondyle shows specific anatomical details in relation to the ulnar nerve; the relationships between the median nerve and the transverse carpal ligament may be characterized by one or two nerve trunks (two cases of bifid median nerve in our experience); median-ulnar nerve anastomosis may be also found at various levels. Comparing our results with those of the available literature we can conclude that anatomical variations of ulnar and median nerve in the upper limb are not an infrequent finding and their clinical, diagnostic and surgical relevance should be considered.