Infraorbital nerve injury associated with zygoma fractures: documentation with neurosensory testing

Persistent sensibility abnormalities after correction of zygoma fractures indicate injury to the infraorbital nerve and may produce pain. To investigate this, a retrospective study of 25 patients who had undergone surgical correction of a zygoma fracture was performed. Bilateral neurosensory measurements were obtained with the Pressure-Specified Sensory Device (Sensory Management Services, Baltimore, Md.). Seven of the 25 patients had required orbital floor reconstruction. Each patient had undergone fracture correction at least 6 months earlier and was interviewed, at the time of sensibility testing, regarding symptoms related to the fracture. The data were evaluated by a blinded examiner, from a separate clinical facility, who attempted to predict the side of the fracture and the degree of zygoma displacement on the basis of measurements of sensibility of the paranasal, upper lip, and zygomaticotemporal areas. Seventy-six percent of patients demonstrated abnormal sensibility on the side of the zygoma fracture, compared with the contralateral side. Sensibility was abnormal for 100 percent of the patients who required orbital floor reconstruction. Seventy-four percent of patients with abnormal sensibility reported symptoms related to the fracture. Eighty percent of the zygoma fractures were correctly identified, with respect to the side of the fracture, by the blinded examiner on the basis of the neurosensory measurements alone (p < 0.005). Predictions proved correct for 91 percent of the patients with widely displaced fractures and none of the patients with nondisplaced fractures. The results of this study suggest that neurosensory testing is an important clinical adjunct for the evaluation of patients with facial pain or dysesthesia after facial fracture reconstruction. The results suggest the need to develop algorithms for the diagnosis and treatment of trigeminal nerve injuries after craniofacial trauma. This approach could also be applicable to dysesthesia or pain after aesthetic facial surgical procedures.     

Disabilities caused by unstable mutations in Costa Rica

Motonic dystrophy and fragile X syndrome are two genetically determined relatively common disabilities. Both are examples of a new type of mutation mechanism called unstable or dynamic mutations, triple repeats expansions or DNA amplification. Fragile X syndrome is recognized as the main cause of hereditary mental retardation and myotonic dystrophy is considered the most common muscular dystrophy of adults. This is a prospective non randomized study of clinically affected people, in order to confirm the diagnosis with molecular techniques (Southern blot and PCR) and to perform cascade screening of the rest of the family to offer them adequate genetic counseling. We were able to corroborate the initial diagnosis in most clinical cases of myotonic dystrophy, but in the cases of mental retardation more than half studies were negative for fragile X syndrome, stressing the difficulties encountered by medical practitioners to diagnose this syndrome. The reasons for this are several; probable the main culprit is the subtle and unspecific clinical picture affected individuals exhibit, particularly children before puberty. Cascade screening, genetic counseling and selective abortion are the only tools available to prevent these disabling diseases for the moment.     

Past, present and future of cytogenetics in Costa Rica

This is an overview of the past, present and future of human Cytogenetics in Costa Rica. It started in 1965 at the University of Costa Rica where it has been developed slowly but steadily. There is only one overloaded clinical cytogenetic laboratory in the social security system. The tests currently performed are peripheral blood and blood marrow karyotypes, prenatal cytogenetic diagnosis (amniotic fluid and fetal blood) and less frequently skin biopsies. The task now is to standardize molecular cytogenetic techniques, we are actually working with PRINS in order to study submicroscopic subtelomeric rearrangements associated with mental retardation and other microdeletion syndromes as well.     

Dengue virus detection by using reverse transcription-polymerase chain reaction in saliva and progeny of experimentally infected Aedes albopictus from Brazil

Oral susceptibility and vertical transmission of dengue virus type 2 (DENV-2) in an Aedes albopictus sample from Rio de Janeiro was estimated. The infection (36.7%) and transmission (83.3%) rates for Ae. albopictus were higher than those of an Ae. aegypti colony used as control, 32.8 and 60%, respectively. Fourth instar larvae and females descendants of 48.5 and 39.1% of experimentally infected Ae. albopictus showed to harbor the virus. The oral susceptibility and the high capacity to assure vertical transmission exhibited by Ae. albopictus from Brazil reinforce that this species may play a role in the maintenance of the virus in nature and be a threat for dengue control in the country.     

Two azurins with unusual redox and spectroscopic properties isolated from the Pseudomonas chlororaphis strains DSM 50083T and DSM 50135

Two azurins (Az624 and Az626) were isolated from the soluble extract of two strains of Pseudomonas chlororaphis, DSM 50083(T) and DSM 50135, respectively, grown under microaerobic conditions with nitrate as final electron acceptor. The azurins, purified to electrophoretic homogeneity in three chromatographic steps, exhibit several peculiar properties. They have high reduction potentials and lower pI than most azurins described in the literature. As previously observed for Pseudomonas aeruginosa azurin, their reduction potentials are pH-dependent, but the pK values of their oxidized forms are lower, which suggests that deeper structural changes are associated with the oxidation process of these novel azurins. A hitherto undescribed pH-dependence of the diffusion coefficient was observed in Az624, that could be caused either by conformational changes, or by the formation of supramolecular aggregates associated with a protonation process. Both azurins exhibit axial X-band electron paramagnetic resonance spectra in frozen solution showing a typical hyperfine with the copper nucleus (I=3/2) and a well-resolved superhyperfine structure with two equivalent 14N nucleus (I=1), which is not usually observed for azurins from other species.     

Alternative diphtheria, tetanus and whooping cough immunization schedule to evoke a Th2 tetanus and a Th1 pertussis immune response

In a previous study, using BALB/c mice, we found that while diphtheria (D), tetanus (T) and whooping cough (Pw, whole-cell Bordetella pertussis) immunization induces a Th1/Th2 tetanus response and memory T cells able to proliferate in response to in vitro stimulation with B. pertussis, DTPa immunization induces a Th2 tetanus immune response and no memory T cells that recognize B. pertussis as stimulus. Considering that a pro-inflammatory cytokine production is not necessary for protection against tetanus and therefore should be avoided, an alternative DTP immunization schedule with minimal Pw exposure was assessed in order to obtain a Th2 tetanus response and a Th1 pertussis response. BALB/c mice were primed with DT vaccine at day 0, with Pw vaccine at day 14 and boosted with DTPa vaccine at days 21 and 28. A control group was inoculated with saline. Antibodies against B. pertussis surface antigens, tetanus and diphtheria toxoids were produced by mice. Spleen cells stimulated in vitro with B. pertussis produced IL-6 and IFNgamma. Only IL-5 was produced by cells in response to tetanus toxoid stimulation. These results are in line with the low IgG1/IgG2a ratio for pertussis antibodies compared with those corresponding to tetanus and diphtheria. The immunization protocol presented herein succeeded in producing tetanus and pertussis immune responses of Th2 and Th1 type, respectively. In contrast to previous results obtained with DTPw immunization, no IL-12 production was observed. Our findings provide direct evidence that an immunization protocol with an interval of 14 days between DT and Pw primings, followed by DTPa boosters, can induce appropriate immune responses against DTP vaccine antigens.     

Microscopy images as interactive tools in cell modeling and cell biology education

The advent of genomics, proteomics, and microarray technology has brought much excitement to science, both in teaching and in learning. The public is eager to know about the processes of life. In the present context of the explosive growth of scientific information, a major challenge of modern cell biology is to popularize basic concepts of structures and functions of living cells, to introduce people to the scientific method, to stimulate inquiry, and to analyze and synthesize concepts and paradigms. In this essay we present our experience in mixing science and education in Brazil. For two decades we have developed activities for the science education of teachers and undergraduate students, using microscopy images generated by our work as cell biologists. We describe open-air outreach education activities, games, cell modeling, and other practical and innovative activities presented in public squares and favelas. Especially in developing countries, science education is important, since it may lead to an improvement in quality of life while advancing understanding of traditional scientific ideas. We show that teaching and research can be mutually beneficial rather than competing pursuits in advancing these goals.     

Improving the efficiency of PBPC collection by pre-apheresis peripheral blood and mid-apheresis product measurements of CD34 cells

BACKGROUND: The adequacy of HPC collection for BMT is typically assessed by the number of CD34 cells. However, during a series of leukapheresis procedures (LP) the CD34 value on the final HPC product may not be available for testing until late evening, sometimes resulting in additional, retrospectively unnecessary, LP in order to ensure an adequate HPC collection (>5x10(6) CD34/kg). We hypothesized that an estimate of the CD34 content of HPC products prior to 16:00 h on the day of LP would permit improved HPC collection planning. We therefore assessed the effectiveness of predicting the total amount of CD34 cells that would be collected in a given LP by either (a) the concentration of CD34 cells/microL in peripheral blood prior to LP (pre-CD34) or (b) the predicted total amount of CD34 cells to be collected based on sampling the LP product at the mid-point of each LP. We also compared the number of LP per patient and total HPC collected for the study group with data from the previous calendar year. METHODS: Allogeneic and autologous BMT donors who completed a 20-L HPC collection between September 2002 and February 2003 were eligible. CD34 cells were measured on blood drawn prior to LP and from the HPC product at the mid-point (10 L) of LP. The CD34 content of the final LP was predicted by doubling the value of total CD34 cells at the mid-run (MRp-CD34). The MRp-CD34/kg and the cumulative CD34/kg collected were made available before 16:00 h and used to determine the need for additional LP. The true CD34 content of each HPC collection was also measured from the final product the next day (CD34-FP). RESULTS: A 20-L LP was completed and data were available from 31 patients and nine allogeneic donors who underwent a total of 85 LP for diagnoses, including 11 myeloma, 10 lymphoma, seven HD, three acute leukemia and five others. The mean (range) and correlation (R2) vs. the CD34-FP were, for pre-CD34, 54 CD34/microL (0.3-232), R2=0.66 (P<0.01), and for MRp-CD34, 3.2x10(6) CD34/kg (0.04-22.48), R2=0.90 (P<0.01). The mean number of CD34/kg collected per LP in the patients/donors was 3.4x10(6) CD34/kg (0.05-18.94). The median number of CD34 cells employed for transplant in the study group vs. controls (5.7 vs. 5.6x10(6)/kg) and the time to engraftment of neutrophils (12 vs. 11 days) and platelets (12 vs. 12 days) was similar to historical controls. However, the study group had a significantly lower median number of LP (three vs. two; P<0.02) to obtain the required collection of 5x10(6) CD34 cells/kg. DISCUSSION: Both the pre-CD34 and the MRp-CD34 were significantly correlated with CD34-FP. However, the CD34-FP was more reliably predicted by MRp-CD34. Early availability of mid-run CD34 values was associated with a significant reduction in the number of LP required to collect 5x10(6) CD34 cells/kg, without reduction in the number of CD34 cells for transplant or prolongation of days to neutrophil or platelet engraftment.     

S-allylmercaptocysteine scavenges hydroxyl radical and singlet oxygen <Emphasis Type="Italic">in vitro</Emphasis> and attenuates gentamicin-induced oxidative and nitrosative stress and renal damage <Emphasis Type="Italic">in vivo</Emphasis>

Background  

Oxidative and nitrosative stress have been involved in gentamicin-induced nephrotoxicity. The purpose of this work was to study the effect of S-allylmercaptocysteine, a garlic derived compound, on gentamicin-induced oxidative and nitrosative stress and nephrotoxicity. In addition, the in vitro reactive oxygen species scavenging properties of S-allylmercaptocysteine were studied.     

Kinetochore Localization of Spindle Checkpoint Proteins: Who Controls Whom?

The spindle checkpoint prevents anaphase onset until all the chromosomes have successfully attached to the spindle microtubules. The mechanisms by which unattached kinetochores trigger and transmit a primary signal are poorly understood, although it seems to be dependent at least in part, on the kinetochore localization of the different checkpoint components. By using protein immunodepletion and mRNA translation in Xenopus egg extracts, we have studied the hierarchic sequence and the interdependent network that governs protein recruitment at the kinetochore in the spindle checkpoint pathway. Our results show that the first regulatory step of this cascade is defined by Aurora B/INCENP complex. Aurora B/INCENP controls the activation of a second regulatory level by inducing at the kinetochore the localization of Mps1, Bub1, Bub3, and CENP-E. This localization, in turn, promotes the recruitment to the kinetochore of Mad1/Mad2, Cdc20, and the anaphase promoting complex (APC). Unlike Aurora B/INCENP, Mps1, Bub1, and CENP-E, the downstream checkpoint protein Mad1 does not regulate the kinetochore localization of either Cdc20 or APC. Similarly, Cdc20 and APC do not require each other to be localized at these chromosome structures. Thus, at the last step of the spindle checkpoint cascade, Mad1/Mad2, Cdc20, and APC are recruited at the kinetochores independently from each other.