Anatomy of head injury

The scalp has an extremely rich blood and nerve supply. It comprises five layers – skin, connective tissue, aponeurosis, loose areolar tissue and periosteum. The blood vessels lie within the tough fibrous septa of the connective tissue layer and cannot retract when divided – hence the copious bleeding from a scalp laceration. The loose areolar tissue beneath the aponeurosis is the plane in which the scalp is avulsed in trauma and in which the surgeon mobilizes a scalp flap. The periosteum adheres to the suture lines of the skull and a haematoma in this plane outlines the affected skull bone (cephalohaematoma).     

Distribution of interleukin-1-immunoreactive microglia in cerebral cortical layers: implications for neuritic plaque formation in Alzheimer's disease

Activated microglia overexpressing interleukin-1 (IL-1) are prominent neuropathological features of Alzheimer’s disease. We used computerized image analysis to determine the number of IL-1α-immunoreactive (IL-1α⁺ ) microglia in cytoarchitectonic layers of parahippocampal gyrus (Brodmann’s area 28) of Alzheimer and control patients. For cortical layers I and II, the numbers of IL-1α⁺ microglia were similar in Alzheimer and control patients. For layers III–VI, the numbers of IL-1α⁺ microglia were higher than that seen in layers I–II for both Alzheimer and control patients. Moreover, for layers III–VI, the number of IL-1α⁺ microglia in Alzheimer patients was significantly greater than that in control patients (relative Alzheimer values of threefold for layer III–V and twofold for layer VI; P<0.05 in each case). The cortical laminar distribution of IL-1α⁺ microglia in Alzheimer patients correlated with the cortical laminar distribution of β-amyloid precursor protein-immunoreactive (β-APP⁺ ) neuritic plaques found in Alzheimer patients (r=0.99, P<0.005). Moreover, the cortical laminar distribution of IL-1α⁺ microglia in control patients also correlated with the cortical laminar distribution of β-APP⁺ neuritic plaques found in Alzheimer patients (r=0.91, P<0.05). These correlations suggest that pre-existing laminar distribution patterns of IL-1α⁺ microglia (i.e. that seen in control patients) are important in determining the observed laminar distribution of β-APP⁺ neuritic plaques in Alzheimer patients. These findings provide further support for our hypothesis that IL-1 is a key driving force in neuritic plaque formation in Alzheimer’s disease.     

Synaptic and photoreceptor components in retinal pigment epithelial cell transplanted retinas of Royal College of Surgeons dystrophic rats

Plexiform layer synaptic and photoreceptor cell components were investigated in retinas of Royal College of Surgeons (RCS) dystrophic rats transplanted with normal retinal pigment epithelial (RPE) cells by immunocytochemistry using previously characterized monoclonal antibodies. In retinas of normal adult rats and RPE-cell transplanted retinas of 4 month-old RCS rats, HNK-1, a marker for a carbohydrate of the neural cell adhesion molecule (N-CAM), was detected immunocytochemically in the inner and outer plexiform layers and ganglion cell bodies and their axons. HNK-1 was also detected in the inner plexiform layer of nontreated retinas of 4 month-old RCS rats, but was reduced to scattered patches in the outer plexiform layer. In addition, immunoreactivity for the SVP-38 antibody recognizing synaptophysin was found in both plexiform layers of normal adult rat retinas and RPE-transplanted retinas of 4 month-old RCS rats. Furthermore, photoreceptor cell bodies and their inner and outer segments were immunostained for the opsin monoclonal antibody RET-P1 in retinas of normal adult rats and RPE-cell transplanted retinas of 4 month-old RCS rats. However, in nontreated retinas of 4 month-old RCS rats, only immunostained debris material was detected. These results strongly suggest that normal RPE transplants not only rescue photoreceptor cells in RCS rats, but also maintain an essential functional capacity, in this case, synaptic components in the plexiform layers. © 1993 Wiley-Liss, Inc.     

Evidence for a laminar organization of basal forebrain afferents to the visual cortex

The present study shows that restriction of HRP injections to layer I within the visual cortex results in negligible retrograde labeling within the nuclei of the basal forebrain. In contrast, when the injections of either HRP or WGA-HRP are restricted to the granular and infragranular layers of visual cortex, extensive retrograde labeling occurs within the basal forebrain. Based upon these findings, we argue that the projection from the basal nucleus terminates preferentially within the deep layers of the visual cortex, and thus contributes minimally to the supragranular layers, including layer I.     

Stimulus dependent colour specificity of monkey lateral geniculate neurones

Summary From six flaxedilized rhesus monkeys neuronal activity of 75 cells in the dorsal, and 45 cells in the ventral layers of the lateral geniculate body was recorded. Responses to large fields switched on and off, to moving slits, and to moving spots were obtained for several wavelengths.In the dorsal layers, colour selectivity was strong for large field stimuli, but weak for moving spots. Residual colour selectivity for spots was more evident for smaller eccentricities. In comparison, ventral layer cells were less colour selective for all stimuli used. Large field responses wer weak, they often consisted of a sequence of excitation and inhibition.The subdivision of the dorsal cells into different colour opponency types based on large field responses is compared to the subdivision based on centre and surround functions.Results are compared to colour responses in retina and visual cortex, and the tonic and phasic cell type subdivision is discussed.     

Electrokinetic properties of polymer and glass surfaces in aqueous solutions: Experimental evidence for swollen surface layers

Streaming potential and streaming current measuring techniques have been applied to polymer and glass surfaces to study solid/liquid interface electrical properties. The streaming current technique provides a reliable electrokinetic potential value, preexcluding surface conduction. A combination of both techniques results in experimental evidences for swollen, gel-like layers at (even apolar) polymer surfaces. Protons and hydroxide ions are the potential-determining ions indicated by the dependence of streaming potential on pH. Human serum albumin adsorption at a glass surface is discussed in terms of spatial distribution of the fixed macromolecular electric charges.     

Noradrenergic innervation of serotonergic neurons in the dorsal raphe: demonstration by electron microscopic autoradiography

In this study, noradrenergic (NE) terminals in the dorsal raphe were identified by [3H]NE electron microscopic (EM) autoradiography. Lesioning of NE terminals by treatment with the selective catecholamine neurotoxin, 6-hydroxydopamine produced a marked decrease in NE-labelled terminals. [3H]5-HT EM autoradiography of the dorsal raphe produced labelling of cell bodies, dendrites and axons but labelled terminals with synaptic junctions were not observed. Serotonergic (5-HT) neurons were identified at an early stage of degeneration following treatment with the selective 5-HT neurotoxin, 5,7-dihydroxytryptamine (5,7-DHT). When both [3H]NE autoradiography and 5,7-DHT lesioning were combined, a majority of NE-labelled terminals, which formed synaptic specializations, innervated degenerating dendrites. These findings suggest that NE terminals directly innervate 5-HT cells in the dorsal raphe.     

Electrophysiological Assessment of Glaucomatous Visual Dysfunction During Treatment with Cytidine-5′-diphosphocholine (citicoline): A Study of 8 years of Follow-up

In this study we assessed, by simultaneous recordings of visual evoked potentials (VEPs) and pattern-electroretinograms (PERGs), the effects cytidine-5′-diphosphocholine (citicoline) on retinal function and/or visual cortical responses in glaucoma patients. Thirty glaucoma patients were randomly divided into two age-matched groups: patients in group GC (15 patients) were treated with citicoline (1000 mg/die intramuscularly) for 2 months; patients in group GP (15 patients) were treated with placebo for 2 months. After 4 months of wash-out (month 6), GC patients underwent a further 2-month period of citicoline treatment (months 7–8) followed by another 4-month period of wash-out (months 9–12). In GP patients the wash-out was extended for a further 6 months (months 7–12). During the following 13–96 months, GC patients received additional 2-month periods of treatment with citicoline (each period followed by 4 months of wash-out) for a total of 16 periods in 8 years. GP patients were also examined at months 24, 26, 48, 60, 72, 84 and 96. In GC patients the first two treatments with citicoline induced a significant (p<0.01) improvement of VEP and PERG parameters with respect to pre-treatment conditions. VEPs and PERGs recorded in GC patients after the first wash-out revealed that, although there was a worsening trend, the electrophysiological improvement was still maintained with respect to baseline conditions. The additional periods of citicoline treatment in GC patients during the subsequent 13–96 months induced a greater (p<0.01) improvement of VEP and PERG parameters with respect to pre-treatment conditions and when compared to GP patients. Thus, we observed that citicoline significantly improves retinal and cortical bioelectrical responses in glaucoma patients, suggesting a potential use of this substance in the medical treatment of glaucoma, as a complement to hypotensive therapy. The author states that he has no proprietary interest in the development or marketing of this or a competing drug.     

Pancreaticojejunal anastomosis, using a stent tube, in pancreaticoduodenectomy

We report our technique for pancreaticojejunostomy, using a stent tube, and examine the literature with regard to the use of a stent tube in pancreaticojejunostomy. The total number of stitches in the anastomosis of the pancreatic parenchyma and seromuscle layer of the jejunum should be more than 20, and there should be more than 8 stitches in the anastomosis of the pancreatic duct and parenchyma and all layers of the jejunal wall, even in a normal-sized main pancreatic duct. There is no dead space between the cut end of the pancreatic parenchyma and the jejunal wall. None of the 114 consecutive patients who underwent pancreaticoduodenectomy in our series died. We use a stent because this makes it easier to perform anterior wall anastomosis of the pancreaticojejunostomy. It is easy to find the pancreaticojejunal anastomosis at the anterior wall anastomosis. We never stitch the posterior wall of the anastomosis with a stent tube in place at the anterior wall anastomosis. If the anastomosis leaks, the massive flow of pancreatic juice around the anastomosis is prevented because of the pancreatic juice flowing out of the pancreatic tube.     

Multilayered Assembly of Cellulose Derivatives as Primer for Surface Modification by Polymerization

Summary: Rod‐like cellulose polymers, with flexible isopentyl side chains, form supramolecular constructs by the Langmuir‐Blodgett (LB) technique. These have been employed to model an ultrathin multilayered primer for surface modification by polymerization. Multilayers of this polymer were doped with a solution of a photosensitizer and then exposed to methyl methacrylate, (MMA) in either the vapor or liquid phase. Polymerization of the monomer swollen construct was induced photochemically. FT‐IR spectra reveal that photoinitiation in presence of the photosensitizer or irradiation in the far UV region induces photografting by hydrogen abstraction from the constituents of the layered assembly. Employing a combination of photoinitiators (benzophenone and 4,4′‐bis(diethylamino)‐benzophenone) and irradiation of the construct that was saturated by monomer from the gas phase in the near UV region caused the formation of a semi‐interpenetrating polymer network. Linear polymer chains of PMMA grow and entangle inside the layered assembly of the cellulose derivative. The resulting composite consists of two polymers, isopentylcellulose and poly(methyl methacrylate) demonstrating a possibility to produce a homogeneous layered composite film at nanoscopic scale as revealed by the X‐ray reflectometry. Surface photopolymerization was also achieved in the liquid phase where the monomer and photoinitiator solution was in direct contact with the layered assembly.

Schematic picture of the composite films consisting of multilayered CIPC and PMMA incorporated via vapor phase photopolymerization. The scale of the CIPC hairy‐rods and periodic spacing is only schematically represented.