Respiratory activity during seizures induced by pentylenetetrazole

This study investigated the respiratory activity in adult Wistar rats across different behavioral seizure severity induced by pentylenetetrazole (PTZ). Animals underwent surgery for electrodes implantation, allowing simultaneous EEG and diaphragm EMG (DIAEMG) recordings and the respiratory frequency and DIAEMG amplitude were measured. Seizures were acutely induced through PTZ injection and classified based on a pre-established score, with absence-like seizures (spike wave discharge (SWD) events on EEG) representing the lowest score. The respiratory activity was grouped into the different seizure severities. During absence-like and myoclonic jerk seizures, the breathing frequency decreased significantly (∼50% decrease) compared to pre- and post-ictal periods. Pronounced changes occurred with more severe seizures (clonic and tonic) with periods of apnea, especially during tonic seizures. Apnea duration was significantly higher in tonic compared to clonic seizures. Notably, during PTZ-induced tonic seizures the apnea events were marked by tonic DIAEMG contraction (tonic-phase apnea). In the majority of animals (5 out of 7) this was a fatal event in which the seizure-induced respiratory arrest preceded the asystole. In conclusion, we provide an assessment of the respiratory activity in the PTZ-induced acute seizures and showed that breathing dysfunction is more pronounced in seizures with higher severity.

Different types of Status Epilepticus may lead to similar hippocampal epileptogenesis processes

About 1-2% of people worldwide suffer from epilepsy, which is characterized by unpredictable and intermittent seizure occurrence. Despite the fact that the exact origin of temporal lobe epilepsy is frequently unknown, it is frequently linked to an early triggering insult like brain damage, tumors, or Status Epilepticus (SE). We used an experimental approach consisting of electrical stimulation of the amygdaloid complex to induce two behaviorally and structurally distinct SE states: Type I (fully convulsive), with more severe seizure behaviors and more extensive brain damage, and Type II (partial convulsive), with less severe seizure behaviors and brain damage. Our goal was to better understand how the various types of SE impact the hippocampus leading to the development of epilepsy. Despite clear variations between the two behaviors in terms of neurodegeneration, study of neurogenesis revealed a comparable rise in the number of Ki-67 + cells and an increase in Doublecortin (DCX) in both kinds of SE.

Divergent Effects of Systemic and Intracollicular CB Receptor Activation Against Forebrain and Hindbrain-Evoked Seizures in Rats

Cannabinoid (CB) receptor agonists are of growing interest as targets for anti-seizure therapies. Here we examined the effect of systemic administration of the CB receptor agonist WIN 55,212-2 (WIN) against audiogenic seizures (AGSs) in the Genetically Epilepsy Prone Rat (GEPR)-3 strain, and against seizures evoked focally from the Area Tempestas (AT). We compared these results to the effect of focal administration of the CB1/2 receptor agonist CP 55940 into the deep layers of the superior colliculus (DLSC), a brain site expressing CB1 receptors. While systemic administration of WIN dose-dependently decreased AGS in GEPR-3s, it was without effect in the AT model. By contrast, intra-DLSC infusion of CP 55940 decreased seizures in both models. To determine if the effects of systemic WIN were dependent upon activation of CB1 receptors in the DSLC, we next microinjected the CB1 receptor antagonist SR141716, before WIN systemic treatment, and tested animals for AGS susceptibility. The pretreatment of the DLSC with SR141716 was without effect on its own and did not alter the anti-convulsant action of WIN systemic administration. Thus, while CB receptors in the DLSC are a potential site of anticonvulsant action, they are not necessary for the effects of systemically administered CB agonists.

Behavioral and EEGraphic Characterization of the Anticonvulsant Effects of the Predator Odor (TMT) in the Amygdala Rapid Kindling, a Model of Temporal Lobe Epilepsy

Background: Clinical and experimental evidence indicates that olfactory stimulation modulates limbic seizures, either blocking or inducing ictal activity.

Objective: We aim to evaluate the behavioral and electroencephalographic (EEGraphic) effects of dihydro-2,4,5-trimethylthiazoline (TMT) olfactory exposure on limbic seizures induced by amygdala rapid kindling (ARK).

Materials and Methods: Wistar male rats (280–300 g) underwent stereotaxic surgery for electrode implantation in piriform cortex (PC), hippocampal formation (HIP), and amygdaloid complex (AMYG). Part of the animals was exposed to a saturated chamber with water or TMT, while others had ARK and olfactory exposure prior to the 21st stimulus. Behavioral responses were measured by traditional seizure severity scales (Racine and Pinel and Rovner) and/or by sequential analysis/neuroethology. The electrographic activity of epileptogenic limbic networks was quantified by the occurrence of the first and second EEG afterdischarges, comparing the 1st and 21st stimulus. The spectral analysis [Fast Fourier Transform (FFT)] of the first afterdischarge was performed at the 21st stimulus.

Results: TMT olfactory exposure reduced the seizure severity in kindled rats, altering the displayed behavioral sequence. Moreover, TMT decreased the occurrence of first and second afterdischarges, at the 21st stimulus, and altered the spectral features.

Conclusions: Both behavioral and EEGraphic evaluations indicated that TMT, a potent molecule with strong biological relevance, in fact, “predator odor,” suppressed the epileptiform activity in limbic networks.

Impact of strain, sex, and estrous cycle on gamma butyrolactone-evoked absence seizures in rats

Childhood absence epilepsy (CAE) is the most common pediatric epilepsy syndrome and is characterized by typical absence seizures (AS). AS are non-convulsive epileptic seizures characterized by a sudden loss of awareness and bilaterally generalized synchronous 2.5-4 Hz spike and slow-wave discharges (SWD). Gamma butyrolactone (GBL) is an acute pharmacological model of AS and induces bilaterally synchronous SWDs and behavioral arrest. Despite the long use of this model, little is known about its strain and sex-dependent features. We compared the dose-response profile of GBL-evoked SWDs in three rat strains (Long Evans, Sprague-Dawley, and Wistar), and examined the modulatory effects of estrous cycle on SWDs in female Wistar rats. We evaluated the number of seizures, the cumulative time seizing, and the average seizure duration as a function of dose, strain, and sex/estrous phase. Long Evans rats displayed the greatest sensitivity to GBL, followed by Wistar rats, and then by Sprague-Dawley rats. GBL-evoked SWDs were modulated by estrous cycle in female rats, with the lowest sensitivity to GBL occurring during metestrus. Wistar rats showed the greatest variability as a function of dose, and the least variability within dose; these features make this strain desirable for interventional studies. Moreover, our finding that the SWD response to GBL differs as a function of estrous cycle underscores the importance of cycle monitoring in studies examining female animals using this model. Together, these strain and sex-dependent findings provide guidance for future studies.

Eficácia do Extrato de Própolis Verde no Controle de Staphylococcus aureus em Superfície de Prótese Ocular

O objetivo deste estudo foi avaliar a eficácia do extrato de própolis verde na desinfecção de resina acrílica específica para prótese ocular contaminada com cepa de estafilococos. Para isso a simulação “in vitro” das condições de implantação do biofilme de Staphylococcus aureus foi realizada. Discos de resina acrílica foram tratados com gel dental de própolis verde industrializado      na concentração de 5% (Néctar Farmacêutica Ltda., Belo Horizonte, Brasil), ou com solução desinfetante etanólica de extrato      de própolis verde, nas concentrações de 2,5%, 5% ou 10%. Todos os tratamentos foram realizados para os períodos de tempo de 5min, 10min, 15min, 30min e 60 min. Adicionalmente, gluconato de clorexidina a 4% e água destilada foram avaliadas, seguindo os mesmos períodos de tempo, respectivamente como controle positivo e negativo. Na sequência, os discos permaneceram imersos em meio de cultura com implantação da bactéria por 24 horas. Após esse período, o aumento visível de turgescência na cultura foi considerado como indicativo de adesão bacteriana aos discos. Os resultados foram analisados de maneira qualitativa, baseado na turbidez. O extrato de própolis verde indicou atividade antimicrobiana, sendo que, apenas a solução etanólica de própolis verde, na concentração de 10%, apresentou efetividade constante, assim como o gluconato de clorexidina a 4%. Pode-se concluir que o extrato de própolis verde apresentou efeito antimicrobiano promissor contra o biofilme de S. aureus em discos de resina acrílica especifica para prótese ocular.Palavras-chave: Resinas Acrílicas. Biofilmes. Própolis.

Kappa opioid receptors regulate hippocampal synaptic homeostasis and epileptogenesis

OBJECTIVE

Homeostatic synaptic plasticity (HSP) serves as a gain control mechanism at central nervous system (CNS) synapses, including those between the dentate gyrus (DG) and CA3. Improper circuit control of DG-CA3 synapses is hypothesized to underlie epileptogenesis. Here, we sought to (1) identify compounds that preferentially modulate DG-CA3 synapses in primary neuronal culture and (2) determine if these compounds would delay or prevent epileptogenesis in vivo.

METHODS

We previously developed and validated an in vitro assay to visualize the behavior of DG-CA3 synapses and predict functional changes. We used this "synapse-on-chip" assay (quantification of synapse size, number, and type using immunocytochemical markers) to dissect the mechanisms of HSP at DG-CA3 synapses. Using chemogenetic constructs and pharmacological agents we determined the signaling cascades necessary for gain control at DG-CA3 synapses. Finally, we tested the implicated cascades (using kappa opioid receptor (OR) agonists and antagonists) in two models of epileptogenesis: electrical amygdala kindling in the mouse and chemical (pentylenetetrazole) kindling in the rat.

RESULTS

In vitro, synapses between DG mossy fibers (MFs) and CA3 neurons are the primary homeostatic responders during sustained periods of activity change. Kappa OR signaling is both necessary and sufficient for the homeostatic elaboration of DG-CA3 synapses, induced by presynaptic DG activity levels. Blocking kappa OR signaling in vivo attenuates the development of seizures in both mouse and rat models of epilepsy.

SIGNIFICANCE

This study elucidates mechanisms by which synapses between DG granule cells and CA3 pyramidal neurons undergo activity-dependent homeostatic compensation, via OR signaling in vitro. Modulation of kappa OR signaling in vivo alters seizure progression, suggesting that breakdown of homeostatic closed-loop control at DG-CA3 synapses contributes to seizures, and that targeting endogenous homeostatic mechanisms at DG-CA3 synapses may prove useful in combating epileptogenesis.

PTEN deletion increases hippocampal granule cell excitability in male and female mice

Deletion of the mTOR pathway inhibitor PTEN from postnatally-generated hippocampal dentate granule cells causes epilepsy. Here, we conducted field potential, whole cell recording and single cell morphology studies to begin to elucidate the mechanisms by which granule cell-specific PTEN-loss produces disease. Cells from both male and female mice were recorded to identify sex-specific effects. PTEN knockout granule cells showed altered intrinsic excitability, evident as a tendency to fire in bursts. PTEN knockout granule cells also exhibited increased frequency of spontaneous excitatory synaptic currents (sEPSCs) and decreased frequency of inhibitory currents (sIPSCs), further indicative of a shift towards hyperexcitability. Morphological studies of PTEN knockout granule cells revealed larger dendritic trees, more dendritic branches and an impairment of dendrite self-avoidance. Finally, cells from both female control and female knockout mice received more sEPSCs and more sIPSCs than corresponding male cells. Despite the difference, the net effect produced statistically equivalent EPSC/IPSC ratios. Consistent with this latter observation, extracellularly evoked responses in hippocampal slices were similar between male and female knockouts. Both groups of knockouts were abnormal relative to controls. Together, these studies reveal a host of physiological and morphological changes among PTEN knockout cells likely to underlie epileptogenic activity.

SIGNIFICANCE STATEMENT

Hyperactivation of the mTOR pathway is associated with numerous neurological diseases, including autism and epilepsy. Here, we demonstrate that deletion of the mTOR negative regulator, PTEN, from a subset of hippocampal dentate granule impairs dendritic patterning, increases excitatory input and decreases inhibitory input. We further demonstrate that while granule cells from female mice receive more excitatory and inhibitory input than males, PTEN deletion produces mostly similar changes in both sexes. Together, these studies provide new insights into how the relatively small number (≈200,000) of PTEN knockout granule cells instigates the development of the profound epilepsy syndrome evident in both male and female animals in this model.

PTEN deletion from adult-generated dentate granule cells disrupts granule cell mossy fiber axon structure

Dysregulation of the mTOR-signaling pathway is implicated in the development of temporal lobe epilepsy. In mice, deletion of PTEN from hippocampal dentate granule cells leads to mTOR hyperactivation and promotes the rapid onset of spontaneous seizures. The mechanism by which these abnormal cells initiate epileptogenesis, however, is unclear. PTEN-knockout granule cells develop abnormally, exhibiting morphological features indicative of increased excitatory input. If these cells are directly responsible for seizure genesis, it follows that they should also possess increased output. To test this prediction, dentate granule cell axon morphology was quantified in control and PTEN-knockout mice. Unexpectedly, PTEN deletion increased giant mossy fiber bouton spacing along the axon length, suggesting reduced innervation of CA3. Increased width of the mossy fiber axon pathway in stratum lucidum, however, which likely reflects an unusual increase in mossy fiber axon collateralization in this region, offsets the reduction in boutons per axon length. These morphological changes predict a net increase in granule cell innervation of CA3. Increased diameter of axons from PTEN-knockout cells would further enhance granule cell communication with CA3. Altogether, these findings suggest that amplified information flow through the hippocampal circuit contributes to seizure occurrence in the PTEN-knockout mouse model of temporal lobe epilepsy.

Assessment of the hemodynamic profile in periodontal tissues of diabetic subjects with periodontitis by optical spectroscopy

BACKGROUND AND OBJECTIVE

The influence of diabetes mellitus (DM) on the hemodynamics of periodontal tissues has not been assessed previously. The primary objective of this study was to validate optical spectroscopy as a periodontal diagnostic tool for subjects with type 2 DM and chronic periodontitis.

MATERIAL AND METHODS

Using a portable optical near-infrared spectrometer, optical spectra were obtained from healthy (n = 127), gingivitis (n = 115), and periodontitis (n = 109) sites of 65 subjects with type 2 DM and chronic periodontitis. Healthy (n = 65) sites of 15 nondiabetic subjects without periodontitis were used as controls. A modified Beer-Lambert unmixing model that incorporates a nonparametric scattering-loss function was used to determine the relative contribution of deoxygenated hemoglobin and oxygenated hemoglobin (HbO2 ) to the overall spectrum. The balance between tissue oxygen delivery and oxygen utilization in periodontal tissues was assessed.

RESULTS

In diabetic subjects, tissue oxygen saturation and HbO2 concentration were significantly decreased in the periodontitis sites (p < 0.01) compared with the healthy and gingivitis sites. Furthermore, tissue oxygenation in healthy sites of control subjects was significantly higher than that in sites of diabetic subjects (p < 0.01).

CONCLUSION

In summary, the results of this study suggest that optical spectroscopy can monitor the hemodynamic profile in diabetic subjects with chronic periodontitis. Furthermore, healthy sites of diabetic subjects presented lower tissue oxygenation than did those of nondiabetic subjects.

Electroretinography in dogs using a fiber electrode prototype

We compared two electroretinography (ERG) electrodes in dogs using ERG standards of the International Society for Clinical Electrophysiology of Vision (ISCEV). Ten healthy Yorkshire terrier dogs (mean age, 2.80 ± 1.42 years; 6 females) weighing 5.20 ± 1.56 kg were evaluated using an ERG system for veterinary use. Dark- and light-adapted ERG responses were recorded using an ERG-Jet electrode and a fiber electrode prototype. The examinations were performed during 2 visits, 3 weeks apart. Both electrodes (ERG-Jet or fiber prototype) were used on each animal and the first eye to be recorded (OD × OS) was selected randomly. Three weeks later the examination was repeated on the same animal switching the type of electrode to be used that day and the first eye to be examined. The magnitude and waveform quality obtained with the two electrode types were similar for all ERG responses. ERG amplitudes and implicit times obtained from dogs using the fiber electrode prototype were comparable to those obtained with the ERG-Jet electrode for rod, maximal rod-cone summed, cone, and 30-Hz flicker responses. The fiber electrode prototype is a low-cost device, available as an alternative instrument for clinical veterinary ERG recording for retinal function assessment.

Impact of corticosterone treatment on spontaneous seizure frequency and epileptiform activity in mice with chronic epilepsy

Stress is the most commonly reported precipitating factor for seizures in patients with epilepsy. Despite compelling anecdotal evidence for stress-induced seizures, animal models of the phenomena are sparse and possible mechanisms are unclear. Here, we tested the hypothesis that increased levels of the stress-associated hormone corticosterone (CORT) would increase epileptiform activity and spontaneous seizure frequency in mice rendered epileptic following pilocarpine-induced status epilepticus. We monitored video-EEG activity in pilocarpine-treated mice 24/7 for a period of four or more weeks, during which animals were serially treated with CORT or vehicle. CORT increased the frequency and duration of epileptiform events within the first 24 hours of treatment, and this effect persisted for up to two weeks following termination of CORT injections. Interestingly, vehicle injection produced a transient spike in CORT levels – presumably due to the stress of injection – and a modest but significant increase in epileptiform activity. Neither CORT nor vehicle treatment significantly altered seizure frequency; although a small subset of animals did appear responsive. Taken together, our findings indicate that treatment of epileptic animals with exogenous CORT designed to mimic chronic stress can induce a persistent increase in interictal epileptiform activity.

Subgingival biodiversity in subjects with uncontrolled type-2 diabetes and chronic periodontitis

BACKGROUND AND OBJECTIVE

There is a bidirectional relationship between periodontal disease and type-2 diabetes mellitus (DM). Inflammatory mediators may negatively affect glycemic control, and increased glucose levels and resultant glycation end-products may alter the host response against bacterial infection. However, no agreement has been reached regarding the effect of DM on periodontal subgingival microbiota. Therefore, the purpose of the present study was to compare the subgingival biodiversity in deep periodontal pockets of subjects with chronic periodontitis and either uncontrolled type-2 diabetes or no diabetes using 16S rRNA gene cloning and sequencing.

MATERIAL AND METHODS

Twelve subjects with uncontrolled type-2 diabetes (glycated hemoglobin > 8%) and eleven nondiabetic subjects presenting severe and generalized chronic periodontitis were selected. Subgingival biofilm from periodontal pockets > 5 mm were assessed using the 16S rRNA gene cloning and sequencing technique.

RESULTS

Significant differences were observed in subgingival microbiota between diabetic and nondiabetic subjects. Diabetic subjects presented higher percentages of total clones of TM7, Aggregatibacter, Neisseria, Gemella, Eikenella, Selenomonas, Actinomyces, Capnocytophaga, Fusobacterium, Veillonella and Streptococcus genera, and lower percentages of Porphyromonas, Filifactor, Eubacterium, Synergistetes, Tannerella and Treponema genera than nondiabetic individuals (p < 0.05). Moreover, some phylotypes, such as Fusobacterium nucleatum, Veillonella parvula, V. dispar and Eikenella corrodens were detected significantly more often in diabetic subjects than in nondiabetic subjects (p < 0.05).

CONCLUSION

Subjects with uncontrolled type-2 diabetes and chronic periodontitis presented significant dissimilarities in subgingival biodiversity compared with nondiabetic subjects.

A preliminary study on the FAM5C expression in generalized chronic periodontitis

OBJECTIVE

The Family with sequence similarity 5 member C (FAM5C) has been suggested to contribute in aggressive periodontitis. However, there is no data regarding its role in chronic periodontitis. The aim of this study was to evaluate the FAM5C expression in chronic periodontitis and to study association of FAM5C with key immunoinflammatory markers.

MATERIAL AND METHODS

Gingival biopsies were harvested from periodontally healthy subjects (n = 10) and chronic periodontitis subjects (n = 15). The levels of mRNA of FAM5C, interleukin (IL)-17, IL-6, IL-23, IL-10, IL-4, interferon-c, toll-like receptor (TLR)-2, TLR-4, osteoprotegerin (OPG), receptor activator of NF-κB ligand (RANKL), tumor necrosis factor (TNF)-a, transforming growth factor-b, transcription factor forkhead box p3, and transcription factor orphan nuclear receptor C2 were evaluated by real-time polymerase chain reaction.

RESULTS

FAM5C mRNA levels were not different between periodontally healthy and diseased tissues (P > 0.05). Gene expressions of IL-17, TNF-a, OPG, RANKL, TLR-2, and TLR-4 were higher in periodontitis, when compared to periodontally healthy sites (P < 0.05), while no differences between groups were observed for the other genes evaluated (P > 0.05). There were no correlations between the gene expression of FAM5C and the other immunoinflammatory markers (P > 0.05).

CONCLUSION

Within the limits of this study, it seems that FAM5C expression does not contribute to chronic periodontitis.

Possible involvement of IL-21 and IL-10 on salivary IgA levels in chronic periodontitis subjects

Specific cytokines and the costimulatory protein CD40 play role in inducing immunoglobulin (Ig)A production by B cells in the humoral immune response. However, to date, the role of these mediators was not investigated in chronic periodontitis. Therefore, the aim of this study was to assess the local levels of interleukin (IL)-21, IL-21 receptor (IL-21R), IL-4, IL-10 and CD40 ligand (CD40L) on chronic periodontitis subjects and their relationship with the salivary levels of IgA. Gingival biopsies and un-stimulated saliva were collected from chronic periodontitis (n = 15) and periodontally healthy (n = 15) subjects. The mRNA levels of IL-4, IL-10, IL-21, IL-21R, CD40L in the gingival biopsies were evaluated by quantitative real-time polymerase chain reaction. The salivary levels of IgA and the levels of IL-4 and IL-10 in the gingival biopsies were analyzed by ELISA. The mean levels of IgA were significantly higher in the chronic periodontitis compared to periodontally healthy group (P < 0.05). The mRNA levels for IL-21 was higher (P < 0.05) in the chronic periodontitis when compared to the healthy group. However, the expression of IL-21R and CD40L did not differ between groups. The IL-10 was significantly elevated at mRNA and protein levels in chronic periodontitis when compared to periodontally healthy group (P < 0.05). Conversely, the mRNA levels as well as the protein amount of IL-4 were significantly lower (P < 0.05) in chronic periodontitis than healthy ones. In conclusion, the upregulation of IL-21 and IL-10 and downregulation of IL-4 in periodontitis tissues may be collectively involved in the increased levels of salivary IgA in chronic periodontitis subjects.

Contributions of mature granule cells to structural plasticity in temporal lobe epilepsy

During the development of epilepsy in adult animals, newly generated granule cells integrate abnormally into the hippocampus. These new cells migrate to ectopic locations in the hilus, develop aberrant basal dendrites, contribute to mossy fiber sprouting, and exhibit changes in apical dendrite structure and dendritic spine number. Mature granule cells do not appear to exhibit migration defects, basal dendrites, and mossy fiber sprouting, but whether they exhibit apical dendrite abnormalities or spine changes is not known. To address these questions, we examined the apical dendritic structure of bromodeoxyuridine (Brdu)-birthdated, green fluorescent protein (GFP)-expressing granule cells born 2 months before pilocarpine-induced status epilepticus. In contrast to immature granule cells, exposing mature granule cells to status epilepticus did not significantly disrupt the branching structure of their apical dendrites. Mature granule cells did, however, exhibit significant reductions in spine density and spine number relative to age-matched cells from control animals. These data demonstrate that while mature granule cells are resistant to developing the gross structural abnormalities exhibited by younger granule cells, they show similar plastic rearrangement of their dendritic spines.

Oral candidiasis treatment with Brazilian ethanol propolis extract

The Brazilian commercial ethanol propolis extract, also formulated to ensure physical and chemical stability, was found to inhibit oral candidiasis in 12 denture-bearing patients with prosthesis stomatitis candidiasis association.

Surface effects and desorption of tetracycline supramolecular complex on bovine dentine

The aim of this in vitro study was to evaluate the antimicrobial activity, the substantivity, and surface effects of the inclusion compound tetracycline: beta-cyclodextrin on bovine roots. The antimicrobial activity was assessed by dentine slabs which had been immersed in the inclusion complex in concentrations 8.0%, 4.0%, 2.0%, 1.0%, 0.5% and 0.25% for 5min compared to a control of tetracycline hydrochloride. Each slab was tested in a broth of overnight culture of Actinobacillus actinomycetemcomitans (Y4-FDC). The inclusion complex significantly inhibited the A. actinomycetemcomitans (p<0.01) verified at concentrations from 1.0% to 8.0%. The substantivity of tetracycline was evaluated by the measure of desorption from the slabs previously immersed in solution samples and removed at 24h intervals. The tetracycline encapsulated in beta-cyclodextrin showed a flow rate near to zero order in comparison to free tetracycline. The surface morphology determined by SEM showed a more homogeneous and integrated layer with the complex compared to the effect of free tetracycline. We concluded that the root surfaces treated with tetracycline: beta-cyclodextrin release lower concentrations of active drug over 5 days at inhibitory concentrations against A. actinomycetemcomitans with enhanced disponibility in comparison to tetracycline.

Oral paracoccidioidomycosis: a retrospective study of 62 Brazilian patients

OBJECTIVE

The purpose of this study was to evaluate retrospectively the profile of patients with oral paracoccidioidomycosis referred to two Dental Schools in Belo Horizonte (MG, Brazil) between 1955 and 1998. Despite the importance of the oral manifestations of this disease, few papers in the English literature have provided epidemiological data.

SUBJECTS AND METHODS

The medical records of 62 patients presenting oral paracoccidioidomycosis were reviewed in detail. Patient age, gender, race, occupation, site of lesion and type of clinical manifestation of the disease were tabulated.

RESULTS

There was a predominance of male patients (97%), with a male:female ratio of 30:1. The mean age was 40 years. Most of the patients were farm workers (53%). Some patients presented multiple oral lesions (19 cases, 30%). The fungal lesions were found principally in the alveolar process and gingiva, but were also seen on the palate, lip and buccal mucosa. All patients had chronic proliferative mulberry-like ulcerated oral lesions and the diagnosis was confirmed histologically. The clinical records did not contain notes about pulmonary involvement by the lesions.

CONCLUSION

The purpose of this study was to describe the epidemiological profile of a specific population with the diagnosis of oral paracoccidioidomycosis. The major goal is to establish a scientific basis for initiating educational programs for prevention and early diagnosis of oral paracoccidioidomycosis.

Unintentional ileostomy: a complication of the videolaparoscopic method? Report of the first case

Jejunostomy is widely acknowledged in the literature as a means for enteral nutrition. Complication rates range from 16% to 46% for the classical open technique and from 11% to 70% for the several mini-invasive techniques currently in use, including the laparoscopic techniques. The most probable complications are abscess, intestinal obstruction, abdominal wall infection, intraperitoneal leakage, enterocutaneous fistula, and loss, elbowing, or even rupture of the enteral probe. The authors report the case of a patient with severe malnutrition concomitant with advanced gastric cancer who underwent jejunostomy because of an incapacity for normal oral feeding. Previous attempts to pass a nasal enteral probe were not successful, even with the aid of endoscopy. Videolaparoscopy was indicated for adequate staging of the neoplasm and for performance of video-assisted jejunostomy. During the procedure, an extensive carcinomatous process was observed that rendered comprehension of the abdominal anatomy extremely difficult. Consequently, while attempting jejunal catheterization, unintentional catheterization of the terminal ileum took place. The authors discuss this first reported case of unintentional ileostomy and review the literature.

Mobilization of peripheral-blood stem cells by concurrent administration of daniplestim and granulocyte colony-stimulating factor in patients with breast cancer or lymphoma

PURPOSE

To evaluate the safety and hematopoietic activity of daniplestim administered concurrently with granulocyte colony-stimulating factor (G-CSF) for peripheral-blood stem-cell (PBSC) mobilization.

PATIENTS AND METHODS

In the initial dose-escalation phase, 25 patients with adenocarcinoma of the breast (AB; 13 patients) or lymphoma (12 patients) were given daniplestim at doses ranging from 0.1 to 3.75 microgram/kg/d plus G-CSF 10 microgram/kg/d. In the randomized phase, 52 patients with AB (27 patients) or lymphoma (25 patients) were randomized within disease categories to the daniplestim dose chosen in the dose-escalation phase plus G-CSF 10 microgram/kg/d (D+G) or placebo plus G-CSF 10 microgram/kg/d (P+G) for up to 7 days.

RESULTS

A daniplestim dose of 2. 5 microg/kg/d was chosen for further study because it was hematopoietically active and had an acceptable side-effect profile. In the randomized phase, in patients with AB, D+G was associated with a higher probability (P =.0696) of collecting >/= 2.5 x 10(6) CD34(+) cells/kg and significantly higher circulating CD34(+) cell counts (P =.0498) on days 6 through 9 after the initiation of dosing. The target level was more likely to be reached with additional leukaphereses in the patients given D+G. Patients given P+G did not benefit from additional leukaphereses beyond the first procedure. The type of mobilization did show a trend toward a shorter duration of neutropenia in the D+G group. The adverse events with D+G consisted largely of mild to moderate flu-like symptoms, including headache and fever, and occurred more frequently than with P+G.

CONCLUSION

Daniplestim administered at 2.5 microgram/kg/d is tolerable and active when combined with G-CSF, and the combination may prove more effective than G-CSF alone in promoting the collection of adequate numbers of CD34(+) cells for PBSC infusion in patients with AB.

Chromobacterium violaceum infection in Brazil. A case report

We report the second case of infection with Chromobacterium violaceum that occurred in Brazil. A farm worker living in the State of São Paulo presented fever and severe abdominal pain for four days. At hospitalization the patient was in a toxemic state and had a distended and painful abdomen. Chest X-ray and abdominal ultrasound revealed bilateral pneumonia and hypoechoic areas in the liver. The patient developed failure of multiple organs and died a few hours later. Blood culture led to isolation of C. violaceum resistant to ampicillin and cephalosporins and sensitive to chloramphenicol, tetracyclin, aminoglicosydes, and ciprofloxacin. Autopsy revealed pulmonary microabscesses and multiple abscesses in the liver. The major features of this case are generally observed in infections by C. violaceum: rapid clinical course, multiple visceral abscesses, and high mortality. Because of the antimicrobial resistance profile of this Gram-negative bacillus, for appropriate empirical antibiotic therapy it is important to consider chromobacteriosis in the differential diagnosis of severe community infections in Brazil.

Colorectal cancer screening

Colorectal cancer (CRC) is the third most common cancer in the world, and mortality has remained the same for the past 50 years, despite advances in diagnosis and treatment. Because significant numbers of patients present with advanced or incurable stages, patients with pre-malignant lesions (adenomatous polyps) that occur as result of genetic inheritance or age should be screened, and patients with long-standing inflammatory bowel disease should undergo surveillance. There are different risk groups for CRC, as well as different screening strategies. It remains to be determined which screening protocol is the most cost-effective for each risk catagory. The objective of screening is to reduce morbidity and mortality in a target population. The purpose of this review is to analyze the results of the published CRC screening studies, with regard to the measured reduction of morbidity and mortality, due to CRC in the studied populations, following various screening procedures. The main screening techniques, used in combination or alone, include fecal occult blood tests, flexible sigmoidoscopy, and colonoscopy. Evidence from the published literature on screening methods for specific risk groups is scanty and frequently does not arise from controlled studies. Nevertheless, data from these studies, combined with recent advances in molecular genetics, certainly lead the way to greater efficacy and lower cost of CRC screening.

Video-laparoscopic treatment of a sizeable cyst of the cystic duct: a case report

A case of cystic dilation isolated from the cystic duct is described. The patient showed symptoms of chronic calculous cholecystitis; the ultrasonographic examination confirmed the clinical hypothesis and showed a 1.3-cm calculus impacted in the infundibulum of the gallbladder. The hepatic and biliary functions were normal. During surgery, the routine cholangiographic study showed a sizable cyst in the cystic canal, as well as an anomalous duct uniting the cyst to the right hepatic duct. As for the rest of the extrahepatic biliary canal, as well as the intrahepatic canal, nothing abnormal was noticed. The videolaparoscopic treatment consisted of a ligature with a clip of the cystic duct and the anomalous duct plus en bloc resection of the cyst and the gallbladder. Histopathologic study showed it to be a benign cyst and chronic calculous cholecystitis. It is important to establish the site of the cyst precisely before surgery, as the procedure should include its resection, since it could be the source of infection or development of lithiasis and even malignant degeneration. There are two hypotheses for the appearance of cysts in the biliary tract: congenital, due to a flaw in the multiplication of the cells that will form the biliary tract during the fetal life, and by aggression by pancreatic juice flowing back to the main biliary canal. The congenital origin seems to be the hypothesis that better explains the appearance of the cyst in the case described here, considering that the backflow of the pancreatic juice could hardly have occurred because of the anatomy as observed: the nonexistence of the common biliary-pancreatic canal and the valvular mechanism, present in the cystic canal, between the cyst itself and the confluence of the cystic canal into the main biliary canal, in addition to the anomalous biliary canal communicating the cyst to the right intrahepatic canal.

Effect of diphtheria-tetanus-pertussis immunization on prolonged apnea or bradycardia in siblings of sudden infant death syndrome victims

To determine whether the incidence of apnea or bradycardia increased after the first diphtheria-tetanus-pertussis (DTP) immunization in 100 subsequent siblings of victims of sudden infant death syndrome, we examined data obtained from floppy disk recordings attached to apnea-bradycardia monitors for episodes of apnea lasting 15 seconds or longer and episodes of bradycardia lasting 10 seconds or longer. The data were divided into three periods: (1) 10 days before the first DTP immunization was received (pre-DTP period), (2) 10 days immediately after the DTP (DTP period), and (3) 10 days after the DTP period (post-DTP period). Seventeen infants had at least one episode of prolonged apnea or prolonged bradycardia either before or after the 30-day study period (eight before only, eight after only, and one before and after). None of the infants had episodes of apnea lasting 15 seconds or more or bradycardia lasting 10 seconds or more during the pre-DTP or DTP period. One episode of apnea, 16 seconds long, and one episode of bradycardia lasting 11 seconds occurred in the post-DTP period. These results failed to confirm the clinical impression that DTP immunizations are associated with an increased frequency and severity of prolonged apnea. They also place in question the utility of assessing an infant's response to a DTP immunization to determine continued risk of apnea and bradycardia before home monitoring is discontinued.

Morning-to-evening change in refraction, corneal curvature, and visual acuity 2 to 4 years after radial keratotomy in the PERK Study

The authors previously reported morning-to-evening changes in ophthalmic measurements at 3 months and at 1-year after radial keratotomy in a self-selected group of patients in the Prospective Evaluation of Radial Keratotomy (PERK) study. Fifty-two patients included in the earlier study were examined again between 2 1/2 and 4 years after surgery before 10:00 AM and after 5:30 PM on the same day to determine if the changes persisted beyond 1 year after surgery. Between the morning and evening examinations, 31% of the eyes had an increase in minus spherical equivalent power of the manifest refraction of 0.50 to 1.50 diopters; 12% had a change in cylinder power of 0.50 to 1.00 D; 19% had a decrease in uncorrected visual acuity of two to five Snellen lines; and 29% showed central corneal steepening by 0.50 to 1.00 D. Thus, in some patients, morning-to-evening fluctuation persisted until 2 1/2 to 4 years after radial keratotomy.

Long term effects of a first pregnancy on the hormonal environment: estrogens and androgens

An early (but not a late) first pregnancy is known to be protective for breast cancer. This effect might be mediated through a long term change in the hormonal environment caused by the early first pregnancy. To investigate the possibility of such a change we carried out a prospective longitudinal study of serum and urinary estrogens and serum androgens in four groups of women, namely early (age, 18-23 yr) first pregnancy (n = 15), early control (n = 20), late (age, 29-40 yr) first pregnancy (n = 9), and late control (n = 20). The pregnancy groups were studied before (initial visit) and 7-19 months after a first pregnancy (return visit). The control groups were similarly studied, but without an intervening pregnancy. The following were measured: serum estrone (E1), 17 beta-estradiol (E2), estriol (E3), and E1 sulfate; urinary total E1, E2, E3, and glucosiduronates of these three estrogens; and serum testosterone, dehydroepiandrosterone sulfate (DHAS), and dehydroepiandrosterone (DHA). There was no significant change between the initial and return visits in serum E1, E2, E1 sulfate, or any of the urinary estrogens in either pregnancy group or in the corresponding control groups. There was, however, a significant increase in serum E3 between initial and return visits for both pregnancy groups compared with the control values. There was no significant change in serum testosterone. There was a marked significant decrease in both serum DHAS and DHA between initial and return visits in both pregnancy groups compared with the corresponding control group values. There was also a significant increase in the serum E3 to DHA ratio in both pregnancy groups. A cross-sectional study (measuring serum DHAS and DHA only) was then carried out in a series of parous and nulliparous women. The serum DHAS and DHA levels were markedly and significantly lower in parous than in nulliparous women, as expected. There was no significant relationship between serum DHAS or DHA levels and months elapsed (up to 150) since last delivery, indicating that the changes last at least for this period of time. There was no significant relationship between serum DHAS or DHA levels and parity (one to three previous pregnancies), indicating that the changes occur only after a first pregnancy.(ABSTRACT TRUNCATED AT 400 WORDS)

Relationship between refractive error and visual acuity in the Prospective Evaluation of Radial Keratotomy (PERK) Study

As part of the Prospective Evaluation of Radial Keratotomy (PERK) study, we examined the relationship between post-operative refractive error and visual acuity without correction. We included 394 eyes (one eye per patient) with refractive errors ranging from -3.00 to +3.00 diopters one year after radial keratotomy. Within each 1-D range of the spherical equivalent of the refractive error, the visual acuity spanned five to ten Snellen lines. For visual acuities of 20/16 to 20/50, the refractive error spanned 3 to 5 D. Additionally, operated eyes had a better average uncorrected visual acuity than unoperated eyes with a similar refractive error. Within the narrow range of refraction between -2.00 and -2.50 D, the mean uncorrected visual acuity was 20/125 for 56 unoperated eyes and 20/63 for 29 operated eyes, a difference of three Snellen lines.

Comparison of ultrasonic corneal thickness measurements before and during surgery in the prospective evaluation of Radial Keratotomy (PERK) Study

Central corneal thickness, determined by an ultrasonic pachymeter, was studied in one eye each of 395 patients enrolled in the Prospective Evaluation of Radial Keratotomy (PERK) Study, to determine the changes in central corneal thickness between preoperative and intraoperative measurements. There was no statistical difference between the preoperative and the intraoperative measurement. However, 9.4% of the corneas were 0.03 to 0.08 mm thinner intraoperatively and 3.3% were 0.03 to 0.06 mm thicker intraoperatively, indicating that clinically meaningful changes in corneal thickness occurred between the preoperative and intraoperative measurements in some eyes. We conclude that the most reliable way to use ultrasonic pachymetry readings to set the length of the knife blade for radial keratotomy surgery is to measure the corneal thickness intraoperatively.

Diurnal change in refraction, corneal curvature, visual acuity, and intraocular pressure after radial keratotomy in the PERK Study

Selected patients who complained of fluctuating visual acuity in the Prospective Evaluation of Radial Keratotomy (PERK) Study were examined before 8:00 a.m. and after 7:00 p.m. on the same day to determine diurnal change in uncorrected visual acuity, best corrected visual acuity, manifest refractive error, average central keratometric power, and intraocular pressure. Sixty-three operated eyes were examined at three months, while 46 operated and 40 unoperated contralateral eyes were examined at one year after radial keratotomy. One year after surgery, 42% of the operated eyes had an increase in minus power of the manifest refraction of 0.50 to 1.25 diopters, 26% of the eyes changed their uncorrected visual acuity by 2 to 4 Snellen lines, and 35% of the operated eyes showed central steepening of the cornea by 0.50 to 1.25 diopters. These changes in the operated eyes at one year were similar to the changes at three months. Minimal diurnal changes occurred in the unoperated eyes at one year. Only 11% of the unoperated eyes changed their manifest refraction by 0.50 to 1.00 diopters, none changed their uncorrected visual acuity by 2 to 4 Snellen lines, and only one of the unoperated eyes changed its central keratometric power by 0.50 diopters. This study documents that many patients who experience diurnal fluctuation of vision have steepening of the cornea and an increase in the minus power of their refraction during the day.