Retinal transplants restore visually evoked responses in rats with photoreceptor degeneration.

PURPOSE: To assess whether transplantation of intact sheets of fetal retina with retinal pigment epithelium (RPE) into a retina with photoreceptor degeneration restores visually evoked responses. METHODS: Sheets of fetal retina with RPE were transplanted into the subretinal space of Royal College of Surgeons (RCS) rats at 37 to 69 days of age. Sixty-three days to 10 months after transplantation, multiunit visual responses were recorded in the superior colliculus (SC) of transplanted rats, age-matched untransplanted rats, and rats with sham surgery. RESULTS: In 19 of 29 RCS rats with transplants, visually evoked responses were recorded from and restricted to a small area of the SC that corresponds topographically to the portion of the retina in which the transplant was placed. Outside of this area, no visual responses were evoked. Visually evoked responses were never recorded in age-matched, nontransplanted RCS rats. Visually evoked responses were recorded in 6 of 13 RCS rats with sham surgery, but these responses were significantly different from responses in rats with transplants. CONCLUSIONS: These results demonstrate that this transplantation technique restores visually evoked responses in the brain. Although the underlying mechanism is unknown, we propose that the central visual response results from increased synaptic efficacy within the host retina. If it can be established that functional connections between the transplant and the host retina produce the effect, then it would indicate that the technique could be explored as a therapeutic strategy in some diseases of retinal degeneration.

Behavior of hypoglossal inspiratory premotor neurons during the carbachol-induced, REM sleep-like suppression of upper airway motoneurons.

In individuals with compromised upper airway anatomy, genioglossus (GG), the main protruder muscle of the tongue, is an important upper airway dilator which helps prevent upper airway obstructions. During rapid eye movement (REM) sleep, both the tonic and inspiratory-modulated components of GG activity are suppressed in parallel with the characteristic postural atonia. We tested whether the REM sleep-related reduction in the respiratory activity of GG may, in part, result from a reduced inspiratory drive relayed to hypoglossal (XII) motoneurons from their premotor medullary inspiratory neurons. In 15 urethane-anesthetized, paralyzed, vagotomized and artificially ventilated rats, we recorded XII nerve activity and the extracellular activity of medullary inspiratory-modulated neurons antidromically activated with latencies of 0.8 ms +/- 0.3(SD) from within (n = 19) or adjacent to (n = 11) the XII nucleus. Carbachol (10-20 nl, 10 mM), a cholinergic agonist, was microinjected into the dorsomedial pons. Such injections trigger a REM sleep-like state in chronically instrumented, intact animals and, in anesthetized rats, produce respiratory and electrocortical changes similar to those of REM sleep. Following the injections, the respiratory component of XII nerve activity was depressed by 51 +/- 22%, while the mean inspiratory firing rate of the neurons decreased by only 7.4 +/- 13.8% (from 69 +/- 34 Hz to 65 +/- 37 Hz; P < 0.02; n = 30). The activity of ventral respiratory group (VRG) and reticular formation inspiratory neurons with axons within the XII nucleus was reduced by 10 +/- 14% (P < 0.005; n = 19), whereas the activity of neurons located near the VRG that had axons passing below the XII nucleus did not change (n = 5). Thus, the depressant effect of carbachol on medullary inspiratory neurons was slightly more pronounced in reticular formation and VRG cells premotor to XII motoneurons than in other medullary inspiratory cells. For all cells, the magnitude of the decrease of cell activity was not related to the magnitude of depression of XII nerve activity, the simultaneously occurring decrease in respiratory rate or the cell's control firing rate. Since the magnitude of this depressant effect on all cell types was disproportionately small when compared with the depression of XII nerve activity, the REM sleep-like decrease in GG activity must be mainly mediated by non-respiratory premotor pathways.

[Bacteriologic evaluation of middle ear fluid during the course of secretory otitis media in children]. / Bakteriologiczna ocena plynu z ucha srodkowego w przebiegu o.m.s. u dzieci.

Fluid collected from tympanic cavity during operation from 43 children with O.M.S. was subjected to bacteriological examination. After the collection, each sample was immediately applied to Bactec Peds Plus/F liquid medium from Becton Dickinson. The number of samples, where each genus and species of bacteria were found, was determined, as well as the number of samples where every two genus coexisted; also the pH genes, in which each genus was found were calculated. Obtained results showed that 22 species of bacteria, belonging to 6 genus lived in the samples. The most commonly occurring genus were Staphylococcus, Streptococcus and Haemophilus; the most rare genus were Moraxella and Bacillus. The most common species were: Haemophilus influenzae (18.6% of samples), Staphylococcus aureus (14.0%), Staphylococcus epidermidis (11.6%), Staphylococcus warneri (9.3%) and Streptococcus oralis (7.0%). Streptococcus coexisted most frequently with Staphylococcus and Haemophilus; Staphylococcus--with Haemophilus and Bacillus; Haemophilus--with Streptococcus and Staphylococcus. The pH ranges for the three most often found genus were: for Staphylococcus--7.7-9, for Streptococcus--7.7-9.3 and for Haemophilus--8.2-8.8.

[Bacterial flora in infections of the urinary system system in pregnant women with pre-gestational diabetes]. / Flora bakteryjna w zakazeniach ukladu moczowego u ciezarnych z cukrzyca przedciazowa.

Urinary tract infections are accounted to serious complications, particularly in pregnancy complicated by diabetes. In this paper, cases of pregnancy have been analysed, affected by diabetes of type 1 and type 2, according to status of metabolic control and the type of urinary tract infection. In a group of 217 diabetic pregnant women, the incidence of urinary tract infections was 26.7%, 19.0% of them being recurrent. In the group with bad metabolic control, infections were statistically more frequent (17.4% vs. 37.3%, p = 0.001); bacteriuria without clinical demonstrations 10.4% vs. 19.6% (p > 0.05), pyelonephritis (7.0% vs. 17.7%, p = 0.001). The following types of pathogenic bacteria were found: E. coli--44.4%, Staphylococcous--28.9%, Enterococcocus--18.7%. A high frequency of Gram (+) bacteria was observed. A good metabolic control without chronic diabetic complications correlated with less frequent infections of the urinary tract.

Prevalence of Helicobacter pylori in children dependently on age and living conditions.

The aim of the study was to examine the prevalence of Helicobacter pylori (H. pylori) in children in Lódz (Poland). The study was a serological survey of IgG antibodies to H. pylori in randomly chosen 240 children aged 6 months to 17 years. The serum was tested by ELISA technique (Porton-Cambridge, England) and by immunoenzymatic test (Quidel, USA). Some aspects of the family environment were studied. We found 15% infected children under 2 years, 16.6% infected children aged 3-5 years, 28.3% aged 6-10 years and 41.6% aged 11-17 years. We observed much higher prevalence of H. pylori infection in children from poor living conditions and in children from families with seropositive adults.

Behaviour of raphe cells projecting to the dorsomedial medulla during carbachol-induced atonia in the cat.

1. The activity of most brainstem serotonergic cells is suppressed during sleep, particularly the rapid eye movement (REM) phase. Thus, they may play a major role in state-dependent changes in CNS functioning. Our main goal was to search for medullary raphe cells having axonal branches in the region of the hypoglossal (XII) motor nucleus and assess their behaviour during the atonia produced by microinjections of a cholinergic agonist, carbachol, into the dorsal pontine tegmentum. In chronic animals, such microinjections evoke a desynchronized sleep-like state similar to natural REM sleep; in decerebrate animals, they produce eye movements and a motor suppression similar to the postural atonia of REM sleep. 2. In decerebrate, paralysed, vagotomized and artificially ventilated cats, we recorded extracellularly from medullary raphe cells antidromically activated from the XII nucleus region. Forty-five cells recorded in the raphe obscurus and pallidus nuclei were antidromically activated with latencies characteristic of non-myelinated fibres (4.4-42.0 ms). For thirty-three of the forty-five cells, we found one or more axonal branches within or just below the XII nucleus. The remaining twelve cells, in addition to the XII nucleus, had axonal ramifications in the medial nucleus of the solitary tract (NTS) and/or the dorsal motor nucleus of the vagus (DMV). 3. A subset of fourteen spontaneously active cells with identified axonal projections were held long enough to be recorded during the carbachol-induced atonia, and eight of these also during the subsequent recovery and a systemic administration of the serotonergic 1A receptor agonist (+/-)8-hydroxy-2-(di-N-propylamino)tetrealin hydrobromide (8-OH-DPAT). All but one were suppressed during the atonia in parallel to the suppression of XII, phrenic and postural nerve activities (firing rate, 1.3 +/- 0.7 Hz before and 0.1 +/- 0.2 Hz after carbachol (means +/- S.D.)). Following the recovery from the atonia, the firing rates of the eight cells increased to the pre-carbachol level (1.6 +/- 1.0 Hz). Subsequently, all were silenced by 8-OH-DPAT. 4. These cells fulfil most physiological criteria for serotonergic cells and have the potential to modulate, in a state-dependent manner, activities in the motor XII nucleus, visceral sensory NTS, and DMV. The decrements in serotonergic neuronal activity that occur during the carbachol-induced atonia suggest that a similar withdrawal of serotonergic input may occur during REM sleep and contribute to the characteristic reductions in upper airway motor tone.

Non-reciprocal control of rhythmic activity in respiratory-modulated XII motoneurons.

To elucidate the nature of phasic respiratory inputs to hypoglossal (XII) motoneurons, we assessed the phasic changes in membrane resistance (RN) in inspiratory- and expiratory-modulated motoneurons. In expiratory motoneurons, RN was consistently lower in inspiration than in expiration and intracellular injection of negative current reversed the phasic hyperpolarizing membrane potential wave in inspiration. In inspiratory motoneurons, RN changed less but also was minimal in inspiration. In these neurons, injection of a negative current sufficient to reverse a lingual nerve-evoked IPSP did not reverse the phasic expiratory hyperpolarization. Thus, respiratory-related inhibitory inputs are non-reciprocal in inspiratory and expiratory XII motoneurons, with inspiratory motoneurons probably lacking a somatic, amino acid-mediated inhibitory input in expiration.

Role of GABAB receptors in the control of hypoglossal motoneurons in vivo.

There is little information on GABAB receptor-mediated effects on orofacial motoneurons. We recorded the inspiratory activity from both hypoglossal (XII) nerves in urethane-anesthetized, paralyzed, vagotomized and artificially ventilated rats. A GABAB receptor agonist, baclofen, or antagonist, CGP-35348, was microinjected into one XII nucleus. Baclofen rapidly reduced the XII nerve activity in a dose-dependent manner by over 50%. The antagonist caused a delayed suppression of activity by 40%. We conclude that: (1) GABAB receptors within the XII nucleus may suppress the activity of inspiratory XII motoneurons, but they are not tonically active under the conditions of our experiment; (2) there is a net endogenous excitatory effect in XII motoneurons that is mediated by GABAB receptors located in the reticular formation surrounding the XII nucleus.

[Asymptomatic bacteriuria in pregnant women with insulin-dependent diabetes]. / Bezobjawowy bakteriomocz u ciezarnych z cukrzyca insulinozalezna.

Results of studies of the urinary tract of 43 pregnant women with insulin-dependent diabetes have been presented. No clinical symptoms of infection of this system were observed in particular trimesters of pregnancy. It was found that, despite the lack of symptoms of the urinary tract infection, the infection as such did occur-most frequently in the 2nd trimester. The most common bacteria in pregnant women with insulin-dependent diabetes (lasting over 10 years) were Staphylococcus epidermidis and Staphylococcus saprophiticus.

[Biochemical differentiation of proteus strains from various clinical materials]. / Biochemiczne róznicowanie szczepów proteus z róznego materialu klinicznego.

The material consisted of 729 strain of Proteus isolated from clinical samples in three microbiological laboratories of city of Lódz region. Our of these strains, 466 were Proteus mirabilis, and remaining represented: P. penneri-13 strains, P. vulgaris (II biogroup)-56 and 54 strains which were not classifiable on the basis of biochemical properties and scheme elaborated by Hickman et al. for biogroups of P. vulgaris. The authors indicate feasibility of differentiation of P. vulgaris basing on biochemical tests as a supplementary method to other tests of intracellular differentiation of Proteus.