Feeding behavior in rats subjected to gastrectomy or gastric bypass surgery.

BACKGROUND/AIM: Gastric bypass (GB) is usually designed to restrict food intake and to induce malabsorption. Gastric hormones have been thought to play a role in the regulation of food intake and body weight. The aim of the present study was to analyze feeding behavior after total gastrectomy (Gx) or GB in rats. METHODS: Animals were subjected to Gx, GB, or sham operations. Eating and drinking behaviors after surgeries were assessed by a comprehensive laboratory animal monitoring system. Gastric hormones were measured by radioimmunoassay and energy density in feces by adiabatic bomb calorimeter. RESULTS: Compared with sham operation, both Gx and GB reduced the body weight as measured during 3-8 weeks postoperatively, which was associated with increased energy expenditure per 100 g body weight. Daily accumulated food intake and meal size (during nighttime) were reduced following Gx, but not GB. The water intake (during daytime) was increased after Gx and GB. The energy density in feces was unchanged. Serum concentrations of ghrelin, obestatin, leptin, gastrin, and pancreastatin were greatly reduced after Gx. CONCLUSIONS: Control of food intake and meal size was independent of the food reservoir function of the stomach. Surgical depletion of gastric hormones is associated with reduced meal size, but increased water intake.

Health status and life satisfaction after decompressive craniectomy for malignant middle cerebral artery infarction.

OBJECTIVES: To study the long-term outcome in patients with malignant middle cerebral artery (MCA) infarction treated with decompressive craniectomy. The outcome is described in terms of survival, impairment, disabilities and life satisfaction. MATERIALS AND METHODS: Patients were examined at a minimum of 1 year (mean 2.9, range 1-6) after the surgery and classified according to the Glasgow Outcome Scale (GOS), the National Institutes of Health Stroke scale (NIHSS), the Barthel Index (BI), the short-form health survey (SF-36) and the life satisfaction checklist (LiSat-11). RESULTS: Eighteen patients were included. The long-term survival was 78%. The mean NIHSS score was 13.8 (range 6-20). No patient was left in a vegetative state. The mean BI was 63.9 (5-100). The SF-36 scores showed that the patients' view of their health was significantly lower in most items compared with that of a reference group. According to the LiSat checklist, 83% found their life satisfying/rather satisfying and 17% found their life rather dissatisfying/dissatisfying. CONCLUSION: We conclude that the patients remained in an impaired neurological condition, but had fairly good insight into their limitations. Although their life satisfaction was lower compared with that of the controls, the majority felt that life in general could still be satisfying.

Long-term follow-up of a patient with traumatic brain injury using diffusion tensor imaging.

This case report describes a patient who sustained severe head trauma with diffuse axonal injury (DAI). Examination with magnetic resonance diffusion tensor imaging (MRDTI), 6 days post-injury, showed a severe reduction in fractional anisotropy (FA) in the rostral pons containing the corticospinal tract, which correlated to the patient's severe hemiparesis. By 18 months post-accident, the patient had recovered completely and conventional MRI showed no pathology. However, although her FA values in the rostral pons had increased, they were still not normalized. It seems that a complete normalization of the FA values is not required to achieve clinical recovery, and that MR-DTI seems to be more sensitive to DAI compared to conventional MRI.

Long-time outcome after transient transtentorial herniation in patients with traumatic brain injury.

BACKGROUND: This study investigates mortality and morbidity in patients with traumatic brain injury (TBI) who developed episode(s) of transtentorial herniation. The transtentorial herniation was defined as a deterioration of consciousness accompanied by uni- or bilateral pupil dilatation. METHODS: The medical records of all patients with traumatic brain injury admitted during 1999 to the Neuro- or General Intensive Care Units at Sahlgrenska University Hospital were analyzed, and patients with at least one episode of transtentoryal herniation were included. Information regarding patient age, gender, type of trauma, initial GCS, precipitating reason for herniation, uni-/bilateral pupil dilatation, treatment(s) and outcome after at least 6 months, assessed with the Glasgow Outcome Scale (GOS), was collected from medical records. RESULTS: The study included 27 patients, average age 44 years (range 6-81), with a male proportion of 81%. The majority of the patients were victims of traffic accidents and falls. The results demonstrated that 16/27(59%) of the patients had a favorable outcome (GOS 4/5), 4/27(15%) were severely disabled (GOS 3), none was vegetative (GOS 2) and 7/27(26%) died (GOS 1). When analyzing patient subgroups, best outcome was found in children where 3/4 (75%) had a GOS 4/5. CONCLUSION: Transtentorial herniation is a serious consequence of supratentorial edema/mass lesions in patients with TBI. However, with aggressive neurointensive care and neurosurgical treatments we found a 59% patient incidence of a favorable outcome.

Aspects of the organization of neurons and dendritic bundles in primary somatosensory cortex of the rat.

In order to analyze some aspects of the spatial organization in the primary somatosensory cortex of the rat, we have reconstructed the positions of bundles of apical dendrites and neurons in a cortical prisms measuring 0.5 mm x 0.4 mm x cortical thickness, with special reference to a hypothetical columnar organization. Complete series of semithin (0.65 microm) sections were cut, tangentially from the pial surface down to the white matter, stained and digitizalized into a computer and represented as a stack of 2D images. The mean neuron density (N(V)-value) was (60 x 10(3) +/- 15 x 10(3)) neurons/mm3. The mean number of neurons beneath 1 mm2 of cortical surface (NC-value) was (113 x 10(3) +/- 8 x 10(3)) neurons/mm2. Well-defined bundles of apical dendrites emanating from layer V pyramidal cells were observed. The bundles consisted of 3-12 (mean 5 +/- 2) dendrites. The dendrites within a bundle converged while ascending towards the pial surface and reached a maximal close packing in layer IV. Superficially, the packing density decreased again. The mutual positions of the dendrites within the bundles shifted only slightly along their course towards the pial surface. The occurrence of bundles in tangential sections through layer IV was about 190 bundles/mm2 and the average number of neurons per bundle was estimated at approximately 600. However, when calculating Voronoi-diagrams, the number of neurons, which with this mathematical technique, is ascribed to each of the reconstructed dendritic bundles, varied between 200 and 1000. The possibility that the dendritic bundles are centers in cortical cell modules is discussed.

Myocardial manganese elevation and proton relaxivity enhancement with manganese dipyridoxyl diphosphate. Ex vivo assessments in normally perfused and ischemic guinea pig hearts.

Manganese (Mn) dipyridoxyl diphosphate (MnDPDP) is the active component of a contrast medium for liver MRI. By being metabolized, MnDPDP releases Mn(2+), which is taken up and retained in hepatocytes. The study examined whether MnDPDP elevates Mn content and enhances proton relaxivity in normal myocardium, but not in ischemic myocardium with reduced coronary flow and impaired metabolism. Isolated guinea pig hearts were perfused at normal flow or low flow, inducing global subtotal ischemia. Ventricular ATP and Mn contents, T(1) and T(2) were measured. At normal flow tissue Mn content increased from the control level of 4.1 to 70.4 micromol/100g dry wt with MnDPDP (3000 microM), while low-flow perfusion with MnDPDP (3000 microM) resulted in a Mn content of 16.6 micromol/100 g dry wt. Prolonged ischemia (35 and 90 min) reduced tissue Mn down to the control level. T(1) shortening closely paralleled myocardial Mn elevations during both normal and low-flow perfusion. The use of a Mn(2+)-releasing contrast agent like MnDPDP may be a promising principle in MRI assessments of myocardial function and viability in coronary heart disease by revealing a differential pattern of changes in T(1) relative to coronary flow, cell Mn uptake and retention, ion channel function and metabolism.

The existence of a layer IV in the rat motor cortex.

We have reconstructed the laminar pattern of rat primary motor cortex (Fr1) using a computerized analysis system based on the so-called 'optical dissector'. Data were visualized on a graphics terminal. In contrast to current views, which state that there is no prominent layer IV in the motor cortex of the rat, our method of analysis revealed a genuine layer IV consisting of densely packed small neurons.

Aspects of the quantitative analysis of neurons in the cerebral cortex.

We address three problems concerning the quantitative analysis of nerve cell distribution in the cerebral cortex: (i) preparatory tissue deformation (shrinkage); (ii) difficulties in differentiating between small neurons and astroglia; and (iii) the bias introduced by the counting method. We found that staining with Richardson's solution led to no shrinkage in Vibratome-cut sections of aldehyde-fixed rat brains, but did result in staining of the neurons and left the glial cells unstained. This was in striking contrast to Nissl staining which introduced a linear shrinkage of 20-30% and stained all kinds of cortical cells indiscriminately. A computer-based unbiased counting method was implemented by taking advantage of the stereological procedure referred to as the 'optical disector' (Gundersen, H.J.G. (1986) Stereology of arbitrary particles, J. Microsc., 143: 3-45).

Heterogeneity in the columnar number of neurons in different neocortical areas in the rat.

We have investigated the number of neurons in three neocortical areas of the rat brain. Our results challenge the uniformity concept proposed by Rockel et al. [Brain, 103 (1980) 221-244]. Area Fr1, HL and Oc2 (primary motor, primary somatosensory and secondary visual cortex) from Sprague-Dawley rats were examined. The brains were glutaraldehyde fixed, sectioned in 50 mu m thick sagittal slices and stained in Richardson's solution. The counting was carried out using a computerized system based on the optical disector. The cortical thickness was measured to be 1.9 mm, 1.9 mm, and 1.4 mm in area Fr1, HL, and Oc2, respectively. The number of neurons under 1 mm2 cortical surface was calculated to be 91 100 in Fr1, 133 500 in HL and 106 100 in Oc2. The number of neurons in a volume of tissue 30 x 25 mu m through the depth of the cortex was calculated to be 68 in Fr1, 100 in HL and 80 in Oc2. The density of neurons was calculated to be 48 500 neurons/mm3 in Fr1, 69 400 neurons/mm3 in HL and 76,900 neurons/mm3 in Oc2. There were significant (P < 0.01) differences between all areas regarding both the number of neurons under a certain area of surface as well as the neuron density. The results indicate that there is no basic uniformity in the number of neurons under a certain area of cortical surface.

A method for 3D reconstruction of neuronal processes using semithin serial sections displayed as a cinematographic sequence.

In order to study the organization and distribution of dendrites and axons in the cerebral cortex, we have developed a computer-assisted method for 3D reconstruction of neuronal processes based on serial light microscopic images displayed as a continuous sequence. A series of tangential sections (0.65 micron thick) through rat parietal cortex was aligned, digitized into the computer and then used to build a sequence (stack) of images which was stored to a digital real-time video disk. Apical dendrites located in dendritic bundles in laminae III and IV were traced through the sequence. Two tracing modes were tested: (1) cinematographic mode, in which the image stack was displayed continuously and automatically by the computer at various preset speeds (max. speed: 25 images/s) and (2) stepping mode, in which the interval between each image was varied manually according to the choice of the operator. Coordinates were stored in a database and used to build a 3D reconstruction where apical dendrites were displayed as wires or tubes. Tracing in cinematographic mode was about 3 times faster than tracing in stepping mode. We believe that the former mode exploits the built in 'filtering' capacity of the visual system to perform temporal averaging.

Automated correction of linear deformation due to sectioning in serial micrographs.

This paper describes an objective and automatic method for detection and correction of sectioning deformations in digitized micrographs, as well as an evaluation of the method applied to light and electron microscopic images of semi-thin and ultra-thin serial sections from brain cortex. The detection is based on matching of image subregions and the deformation model is bi-linear, i.e. two first-order polynomials are used for modelling compression/expansion in perpendicular directions. The procedure is applicable to prealigned serial two-dimensional sections and is primarily aimed at three-dimensional reconstruction of tissue samples consisting of a large number of cells with random distribution and morphology.

A method for 2D reconstruction of intracellularly labeled neurons from sequential sections.

A technique for 2D reconstruction of intracellularly labeled neurons from sequential sections is described. The system consists of a Charged Coupled Device-camera mounted on a microscope, a videomixer and a IBM-compatible PC with a framegrabber. The neurons (interneurons from the spinal cord of the cat) were labeled iontophoretically by horshradish peroxidase and subsequently cut in 60 microns sections. The sections were aligned using the video mixer by fitting the cut dendrites and axon from one section with their counterparts in the following section. The images were then digitized in the PC where they were fused to create a superimposed picture of the aligned parts of the neuron; a 2D reconstruction was created.

Computer-assisted 3D analysis of cell distributions in the normal and epileptic cerebral cortex: description of a methodology in progress.

This paper describes software routines that (a) visualizes a stack of several thousands of aligned sequential photographic two-dimensional (2D) images stored in an image processing system; (b) creates a data base containing information about objects identified sequentially from the 2D images; (c) transfers the data base to a graphical terminal; (d) reconstructs a three-dimensional (3D) object space; and (e) supports on-line interaction between the image processing system and the graphical terminal. As an application example, the cell content of a prism of motor cerebral cortex of the cat is reconstructed. Preliminary results from reconstructing human epileptic temporal cortex (cortical microdysgenesia) are also reported.

3D reconstruction of biological objects from sequential image planes--applied on cerebral cortex from cat.

A prism of cat cerebral cortex was reconstructed with a method for three-dimensional (3D) representation of biological objects. A series of 918 semithin sections were digitized into an image analysis system. The images were aligned and analyzed, and a data base with the coordinates and a classification of the cells was created. The data base (i.e., the cortical prism) was visualized in a 3D graphic terminal, and parameters such as columnar and lamellar organization, clustering, and cell density were analyzed. A neuronal perikaryon and its neurites was reconstructed and shown together with the cortical prism.