Tritiated Uridine Uptake in the Retinal Ganglion Cell Layer of the Cat during Normal Development and after Visual Cortex Ablation

The short-term metabolic response of immature retinal ganglion cells to destruction of their target cells in the dorsal lateral geniculate nucleus (dLGN) was assessed in newborn cats. Retrograde degeneration of virtually all dLGN cells was induced by ablation of the 13 contiguous areas of visual cortex on the day of birth. The metabolic response of retinal ganglion cells to this loss of target cells in dLGN was determined by exposing the ganglion cell layer to tritiated uridine, a precursor of RNA. Control measurements were made from unoperated littermates. Following sectioning and processing of the retinae from both groups of kittens for autoradiography, silver grain densities overlying the cellular profiles in the ganglion cell layer were calculated. These calculations revealed levels of uridine incorporation at Postnatal Day 4 in both groups of kittens significantly higher than at either Postnatal Day 2 or 7, but no significant differences between the two groups on any day examined. These results show that the level of RNA synthesis in retinal ganglion cells increases temporarily during the first postnatal week and that this synthesis is unaffected by the death of target cells in the dLGN. The temporary increase may be related to the establishment of synaptic connections on retinal ganglion cells by their afferent bipolar and amacrine neurons in the inner nuclear layer.     

Thalamic and cortical projections to middle suprasylvian cortex of cats: constancy and variation

 We investigated the constancy and variability in the numbers of thalamic and cortical neurons projecting to cat middle suprasylvian (MS) visual cortex. Retrograde pathway tracers were injected at a single anatomically and physiologically defined locus in MS cortex. Counts of labeled neurons showed that the visual thalamic projections to MS cortex consistently arose from a fixed set of nuclei in relatively constant proportions. In contrast, counts of cortical neurons revealed that transcortical inputs to MS cortex were much more variable. This differential variability may be linked to the developmental program, which affords greater influence of experiential factors on cortical pathway development than on thalamocortical pathway development. These results have implications for the development of models of cerebral connectivity that include measures of pathway variability. Received: 29 March 1996 / Accepted: 3 September 1996     

Escherichia coli Nissle 1917 distinctively modulates T-cell cycling and expansion via toll-like receptor 2 signaling

Although the probiotic Escherichia coli strain Nissle 1917 has been proven to be efficacious for the treatment of inflammatory bowel diseases, the underlying mechanisms of action still remain elusive. The aim of the present study was to analyze the effects of E. coli Nissle 1917 on cell cycling and apoptosis of peripheral blood and lamina propria T cells (PBT and LPT, respectively). Anti-CD3-stimulated PBT and LPT were treated with E. coli Nissle 1917-conditioned medium (E. coli Nissle 1917-CM) or heat-inactivated E. coli Nissle 1917. Cyclin B1, DNA content, and caspase 3 expression were measured by flow cytometry to assess cell cycle kinetics and apoptosis. Protein levels of several cell cycle and apoptosis modulators were determined by immunoblotting, and cytokine profiles were determined by cytometric bead array. E. coli Nissle 1917-CM inhibits cell cycling and expansion of peripheral blood but not mucosal T cells. Bacterial lipoproteins mimicked the effect of E. coli Nissle 1917-CM; in contrast, heat-inactivated E. coli Nissle 1917, lipopolysaccharide, or CpG DNA did not alter PBT cell cycling. E. coli Nissle 1917-CM decreased cyclin D2, B1, and retinoblastoma protein expression, contributing to the reduction of T-cell proliferation. E. coli Nissle 1917 significantly inhibited the expression of interleukin-2 (IL-2), tumor necrosis factor alpha, and gamma interferon but increased IL-10 production in PBT. Using Toll-like receptor 2 (TLR-2) knockout mice, we further demonstrate that the inhibition of PBT proliferation by E. coli Nissle 1917-CM is TLR-2 dependent. The differential reaction of circulating and tissue-bound T cells towards E. coli Nissle 1917 may explain the beneficial effect of E. coli Nissle 1917 in intestinal inflammation. E. coli Nissle 1917 may downregulate the expansion of newly recruited T cells into the mucosa and limit intestinal inflammation, while already activated tissue-bound T cells may eliminate deleterious antigens in order to maintain immunological homeostasis.     

Restoration of visual orienting into a cortically blind hemifield by reversible deactivation of posterior parietal cortex or the superior colliculus

A contralateral hemineglect of the visual field can be induced by unilateral cooling deactivation of posterior middle suprasylvian (pMS) sulcal cortex of the posterior parietal region, and this neglect can be reversed by additional cooling deactivation of pMS cortex in the opposite hemisphere. The purpose of the present study was to test whether an enduring hemianopia induced by removal of all contiguous visual cortical areas of one hemisphere could be reversed by local cooling of pMS cortex in the opposite hemisphere. Two cats sustained large unilateral ablations of the contiguous visual areas, and cooling loops were placed in the pMS sulcus, and in contact with adjacent area 7 or posterior ectosylvian (PE) cortex of the opposite hemisphere. In both instances cooling of pMS cortex, but neither area 7 nor PE, restored a virtually normal level of orienting performance to stimuli presented anywhere in the previously hemianopic field. The reversal was highly sensitive to the extent of cooling deactivation. In a third cat, cooling deactivation of the superficial layers of the contralateral superior colliculus also restored orienting performance to a cortical ablation-induced hemianopia. This reversal was graded from center-to-periphery in a temperature-dependent manner. Neither the cortical ablation nor any of the cooling deactivations had any impact on an auditory detection and orienting task. The deactivations were localized and confirmed by reduced uptake of radiolabeled 2-deoxyglucose to be limited to the immediate vicinity of each cooling loop. The results are discussed in terms of excitation and disinhibition of visual circuits.     

Clinical evaluation of three rapid methods for the detection of significant bacteriuria.

Random urine specimens (848) were screened for significant bacteriuria by using the 30-min Lumac (3M, St. Paul, Minn.), the 2-min Bac-T-Screen (Marion Laboratories, Inc., Kansas City, Mo.), and the 13-h AutoMicrobic system (AMS) urine identification card (Vitek Systems, Inc., Hazelwood, Mo.). MacConkey and 5% sheep blood agar plates were inoculated with a 10(-4) dilution of urine and used for the reference method. Bac-T-Screen results were uninterpretable for 9.1% of the specimens owing to either urine sample pigmentation (5.3%) or clogging of the filter (3.8%). Screen-negative urine specimens made up 49.6, 57.2, and 48.5% of the total number of specimens evaluated with AMS, Lumac, and Bac-T-Screen, respectively. False-positive results with Lumac and Bac-T-Screen were 20.6 and 22.3%, respectively. False-negative results for cultures with greater than or equal to 10(4) CFU/ml were 22.0% with AMS, 29.4% with Lumac, and 25.5% with Bac-T-Screen, and false-negative results for cultures with greater than or equal to 10(5) CFU/ml were 29.6% with AMS, 9.9% with Lumac, and 7.0% with Bac-T-Screen. For each system, greater than 70% of false-negatives at greater than or equal to 10(5) CFU/ml consisted of mixed or pure cultures of common contaminants. With any of these screening methods, a clinically significant isolate at greater than or equal to 10(5) CFU/ml would rarely be missed (less than or equal to 1.7% for all systems). A cost-effective and rapid approach to urine microbiology could consist of screening out negative specimens by either Lumac or Bac-T-Screen and processing only screen-positive specimens by the AMS.     

Glomerular Hypertrophy in Offspring of Subtotally Nephrectomized Ewes

We have shown that fetuses whose mothers underwent subtotal nephrectomy (STNx) before pregnancy had high urine flow rates and sodium excretions, but lower hematocrits, plasma chloride, and plasma renin levels compared with controls. To see if these functional differences in utero persist after birth and are the result of altered renal development, we studied 8 lambs born to STNx mothers (STNxL) and 10 controls (ConL) in the second week of life. These lambs were of similar body weights, nose–rump lengths and abdominal girths. Their kidney weights were not different (ConL 36.1 ± 1.9 vs. STNxL 39.8 ± 3.3 g), nor were kidney dimensions or glomerular number (ConL 423,520 ± 22,194 vs. STNxL 429,530 ± 27,471 glomeruli). However, STNxL had 30% larger glomerular volumes (both mean and total, P < 0.01) and there was a positive relationship between total glomerular volume and urinary protein excretion (P < 0.05) in STNxL. Despite this change in glomerular morphology, glomerular filtration rate, tubular function, urine flow, and sodium excretion rates were not different between STNxL and ConL, nor were plasma electrolytes, osmolality, and plasma renin levels. Thus while many of the functional differences seen in late gestation were not present at 1–2 weeks after birth, the alteration in glomerular size and its relationship to protein excretion suggests that exposure to this altered intrauterine environment may predispose offspring of mothers with renal dysfunction to renal disease in adult life. Anat Rec, 291:318–324, 2008. © 2008 Wiley‐Liss, Inc.     

Inhibition of Respiratory syncytial, parainfluenza 3 and measles viruses by 2-deoxy-D-glucose.

2-Deoxy-d-glucose was found to inhibit the replication and cytopathic effects of respiratory syncytial, parainfluenza 3 and measles viruses. The effects of the drug were completely reversible and appeared directed against viral functions occurring in the second half of the viral growth cycle. At least some viral functions appeared to be unaffected by the agent. Electron microscopic studies with a temperature-sensitive mutant of respiratory syncytial virus indicated that 2-deoxy-d-glucose produced a morphological change. Surface projections were greatly reduced in virions grown in the presence of the drug.     

Beeinflußt das geschlecht die zuweisung zur stationären psychiatrischen behandlung?

Zusammenfassung In Mannheim wurde im Jahre 1968 mit dem schrittweisen Aufbau eines gemeindenahen psychiatrischen Versorgungssystems begonnen. Bestandteil dieses Versorgungskonzepts sind Absprachen zwischen den beteiligten stationären Einrichtungen, die die Zuweisung der Patienten zur stationären Behandlung regeln. Eine modellgestützte, multivariate Analyse von Inanspruchnahmedaten einer Kohorte von 126 schizophrenen Patienten weist nach, daß die Ungleichverteilung der Geschlechter auf die Institutionen das Ergebnis dieser Absprache ist; dabei sind Krankheitsdauer und die Art der Zuweisung von entscheidender Bedeutung.Die vorliegende Arbeit entstand im Rahmen eines von der Deutschen Forschungsgemeinschaft geförderten Projekts im Sonderforschungsbereich 116 Psychiatrische Epidemiologie der Universität Heidelberg (Sprecher: Prof. Dr. Dr. M. Schmidt)     

The hippocampus in experimental chronic epilepsy: a morphometric analysis

The effect of intermittent seizures on the pyramidal neurons of the hippocampus is largely unknown. To determine whether recurrent seizures centered in the hippocampus can produce neuronal loss in this region, a morphometric analysis was performed from standardized sections of hippocampus using 5 groups of animals: (1) surgical control subjects, (2) rats kindled by the rapidly recurring hippocampal seizure (RRHS) paradigm, (3) kindled rats with a few additional limbic seizures (528 +/- 66 seizures), (4) kindled rats with many limbic seizures (1,523 +/- 130 seizures), and (5) rats experiencing limbic status epilepticus (SE) induced by "continuous" hippocampal stimulation. The RRHS and SE protocols induced significant neuronal loss in the CA1 region, but no evidence was found for additional cell loss with increasing numbers of intermittent seizures. These intermittent seizures were, however, associated with a significant thickening of the basal and apical dendritic fields of the CA1 region. These findings indicate that intermittent seizures produce no significant hippocampal neuronal loss and may result in a hypertrophy of CA1 dendritic fields.