Slow degeneration of zebrafish Rohon-Beard neurons during programmed cell death.

Rohon-Beard cells are large, mechanosensory neurons located in the dorsal spinal cord of anamniote vertebrates. In most species studied to date, these cells die during development. We followed labeled Rohon-Beard cells in living zebrafish embryos and found that they degenerate slowly, over many days. During degeneration, the soma shrinks and finally disappears, and the processes become beady in appearance and finally break apart, but they do not retract. Zebrafish Rohon-Beard cells apparently fragment their DNA, as revealed by terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) labeling, before undergoing degenerative morphologic changes. We also followed the development of labeled dorsal root ganglion neurons, as they are developing at the same stages that Rohon-Beard cells are degenerating. We found that, although axons of both cell types extend into similar regions, Rohon-Beard cells degenerate normally in mutants lacking dorsal root ganglia, providing evidence that interactions between the two cell types are not responsible for Rohon-Beard cell degeneration. Developmental Dynamics 229:30-41,2004.     

Cephalosporin C acylase in the autolysis of filamentous fungi

Cephalosporin C acylase activity was studied using fluorescamine determination of free--NH2 groups produced in the deacylation of cephalosporin C by the enzyme. Fourteen fungi from different genera were studied and low extracellular cephalosporin C acylase activity was found in the genera Aspergillus, Fusarium and Penicillium. Forty one fungi of these genera were checked but not all presented acylase activity. The enzyme was generally found to be an extracellular enzyme and during the process of autolysis its activity increased with incubation time and with increasing pH of the medium. In no case was beta-lactamase activity detected. Penicillium rugulosum and Penicillium griseofulvum were identified as good cephalosporin C acylase producers. Deacetyl esterase activity was also detected in these fungi.     

Improvement in quality of life after initiation of lamotrigine therapy in patients with epilepsy in a naturalistic treatment setting.

Quality of life is impaired in patients with epilepsy and can be improved by effective therapy. Randomised clinical trials have shown that lamotrigine treatment is associated with improved quality of life. However, little information is available on quality of life or treatment effects in patients with epilepsy in the general population. The objective of this study was to estimate the impact of lamotrigine on quality of life in a naturalistic treatment setting. The study included adult patients with epilepsy in whom lamotrigine therapy was initiated. Each subject completed the Quality of Life in Epilepsy Inventory (QOLIE)-31 quality of life questionnaire at inclusion and at a follow-up visit in the next 4 months. Demographic information and medical history were provided by the investigator. These were evaluated as potential determinants of change in quality of life using logistic regression. Three hundred and forty-one patients were evaluated, 192 starting lamotrigine in combination with another drug, 90 as a first-line monotherapy, 45 as a switch from another drug and 14 as a reduction to monotherapy from a previous combination. Baseline scores on the QOLIE-31 ranged from 53.8 in the combination group to 69.5 in the first-line group. 34.6% of patients were considered to be responders, with no significant differences between treatment regimen. Most improvement was seen for the energy-fatigue and medication effects subscales and, for the first-line group, seizure worry. Seizure type was the only determinant of improvement of quality of life identified. In conclusion, lamotrigine treatment is associated with improved quality of life, regardless of treatment regimen.     

Distribution and spatial geometry of dopamine interplexiform cells in the retina. II. External arborizations in the adult rat and monkey

The morphology and distribution of dopaminergic interplexiform cells in adult rat and monkey retinas were analyzed to determine any correlation with the function of dopamine in the outer retinal layers. The retinas were processed as whole mounts for tyrosine hydroxylase immunohistochemistry. There was a network formed by the sclerally directed processes of interplexiform cells in the inner nuclear, outer plexiform, and outer nuclear layers running throughout the retina. Their density was higher in the superior retina than in the inferior retina of the rat and was especially high in the superior temporal quadrant. The external network in this quadrant was significantly less dense in the monkey than in the rat, as are the interplexiform cells. The somata of interplexiform and other dopaminergic cells were about the same size in both rats and monkeys. Computer-assisted reconstruction of external arborizations of individual cells showed that external processes lay very close to horizontal and photoreceptor cells and also to blood capillaries. Because they were long, thin, and highly varicose; branched at right angles; and often arose from an axon hillock, the external processes were identified as axons. Therefore, we define the dopaminergic interplexiform cells as multiaxonal neurons, with at least one outwardly directed axon that reaches the outer plexiform layer. The function of the network of external processes from the interplexiform dopaminergic cells is discussed in terms of modulating the release of dopamine to external layers.     

Human papillomavirus detection: verification with cervical cytology.

OBJECTIVE: Thirteen specific types of human papillomavirus (HPV), classified as high-risk for the development of cervical cancer, have been reported in 99.7% of all cervical cancers. For this reason, and because of the reported lack of sensitivity of the Papanicolaou (Pap) smear for detecting HPV, some experts believe that the use of papillomavirus DNA testing may replace cytology for routine gynecological screening. Our goal was to validate a commercial assay, the Digene Hybrid Capture-2 for the detection of human papillomavirus by comparing the results to cytological detection of cervical abnormalities. DESIGN: Cytology results of concurrent liquid-based Papanicolaou smears were compared to the Hybrid Capture-2 results. Correlation was assessed and discordant cytology results were reviewed. SETTING: Louisiana State University Health Sciences Center at Shreveport, Department of Pathology, HPV Diagnostic Laboratory. PATIENTS: All liquid cytology specimens submitted for HPV testing between November 1, 2000 and April 1, 2001. RESULTS: Of the 291 cases tested by Hybrid Capture-2, 12% and 28% were positive with the low-risk and high-risk probes, respectively, and 265 had concurrent cytology results. Fourteen specimens testing positive only with the low-risk probe were not included in this comparison. Thus, the results for 251 of the 291 (86%) specimens tested for human papillomavirus DNA were compared to the original cytology report. Overall concordance between Hybrid Capture-2 and the original smear cytology result was 78%. Slide review reduced the number of discordant specimens from 22% to 12%. CONCLUSION: Based upon these data, we find the HPV assay to be useful as a routine screen for Human papillomavirus.