Dentin in severe fluorosis: a quantitative histochemical study

Dentin responds to different alterations in the enamel with hypermineralization, and is a biomarker of fluoride exposure. We hypothesized that severe fluorosis would lead to hypermineralization of the dentin when the enamel was severely affected. We used scanning electron microscopy and quantitative electron-probe microanalysis to compare dentin and enamel from healthy and fluorotic teeth. The dentin in fluorotic teeth was characterized by a highly mineralized sclerotic pattern, in comparison with control teeth (p < 0.001) and fluorotic enamel lesions (p < 0.001). Enamel near the lesions showed hypercalcification in comparison with dentin (p < 0.001). In response to the effects of severe fluorosis in the enamel, the dentin showed hypermineralization, as found in other enamel disorders. The hypermineralization response of the dentin in our samples suggests that the mechanism of the response should be taken into account in dental caries and other dental disorders associated with severe fluorosis.

[Adverse reactions induced by gadopentetate dimeglumine in magnetic resonance imaging]

BACKGROUND AND OBJECTIVES

It is considered that the Gadolinium salts used as a contrast medium in the Magnetic Resonance Imaging (MRI) studies present an index of adverse reactions below the iodine contrast mediums. The main objective of this study is to determine, in our medium, the frequency and intensity of the adverse reactions related to the administration of Gadopentotate Dimeglumine (Gd-DTPA) and compare it with the rate of adverse reactions induced by the iodine contrast mediums.

MATERIAL AND METHODS

During the period comprised between 1st of January 2005 and 30th of June 2006, the adverse affects were collected for all the studies by means of MRI in which the Gd-DTPA contrast was applied, programmed or urgent, performed in Eresa Diagnosis Centres by Image located ( 11 centre in total) in the provinces of Castellón and Valencia. The adverse effects induced by the iodine salts were also collected in this period.

RESULTS

A total of 54,909 studies with magnetic resonance were performed in the referred study centres, and 12,791 studies with MCI. The total of adverse reactions observed was 62 (0.11%) and 47 (0.36%) respectively. The profile of adverse reactions with both contrast mediums was similar, except in the moderate reactions where we objectively observed a greater percentage of palpebral edema and dyspnea with the usage of MCI than with Gd-DTPA. No cases of anaphylaxia or exitus were observed.

CONCLUSIONS

The data contributed by this series support a safety profile of Gadolinium superior to that of the MCI in line with the results shown by extensive published series.

Histological and histochemical evaluation of human oral mucosa constructs developed by tissue engineering

Reconstruction of large oral mucosa defects is often challenging, since the shortage of healthy oral mucosa to replace the excised tissues is very common. In this context, tissue engineering techniques may provide a source of autologous tissues available for transplant in these patients. In this work, we developed a new model of artificial oral mucosa generated by tissue engineering using a fibrin-agarose scaffold. For that purpose, we generated primary cultures of human oral mucosa fibroblasts and keratinocytes from small biopsies of normal oral mucosa using enzymatic treatments. Then we determined the viability of the cultured cells by electron probe quantitative X-ray microanalysis, and we demonstrated that most of the cells in the primary cultures were alive and had high K/Na ratios. Once cell viability was determined, we used the cultured fibroblasts and keratinocytes to develop an artificial oral mucosa construct by using a fibrin-agarose extracellular matrix and a sequential culture technique using porous culture inserts. Histological analysis of the artificial tissues showed high similarities with normal oral mucosa controls. The epithelium of the oral substitutes had several layers, with desmosomes and apical microvilli and microplicae. Both the controls and the oral mucosa substitutes showed high suprabasal expression of cytokeratin 13 and low expression of cytokeratin 10. All these results suggest that our model of oral mucosa using fibrin-agarose scaffolds show several similarities with native human oral mucosa.

Evaluation of the viability of cultured corneal endothelial cells by quantitative electron probe X-ray microanalysis

Construction of artificial organs and tissues by tissue engineering is strongly dependent on the availability of viable cells. For that reason, the viability and the physiological status of cells kept in culture must be evaluated before the cells can be used for clinical purposes. In this work, we determined the viability of isolated rabbit corneal endothelial cells by trypan blue staining and quantitative electron probe X-ray microanalysis. Our results showed that the ionic content of potassium in cultured corneal endothelial cells tended to rise initially, but significantly decreased in cells in the fifth (and final) subculture, especially in comparison to cells in the fourth subculture (P < 0.001). However, the concentration of sulfur was higher in the fifth subculture than in the fourth subculture (P < 0.001), with a nonsignificant increase in sodium in the fifth subculture (P = 0.031). These data imply a remarkable decrease in the K/Na ratio from the fourth to the fifth subculture. Our microanalytical results, along with the morphological differences between cells in the last two subcultures, are compatible with an early phase of the preapoptotic process in the fifth subculture, and suggest that cells of the first four subcultures would be better candidates for tissue engineering.

Medical audit on asthma in an emergency department

BACKGROUND

To determine the management of acute bronchial asthma in an adult emergency department.

METHODS

A retrospective medical audit of 46 consecutive adult patients with acute asthma exacerbations was performed. We collected information from 48 episodes of acute asthma over a 5-month period. Using classical audit methodology, four indicators were examined: severity evaluation, diagnostic tests, specific treatment, and discharge treatment plans.

RESULTS

The least recorded severity indicators were respiratory rate (27 %), heart rate (50 %) and peak expiratory flow (20 %). Heart and respiratory auscultation were recorded in all patients and oxygen saturation was recorded in 93 %. Laboratory blood test and chest radiograph were performed in all patients. Arterial blood gas was tested in 57 %, electrocardiography in 17 %, and coagulation in 39 %. No treatment was provided in 12 % of patients. Bronchodilator medications were administered in all treated patients and oxygen was prescribed in 60 %. Systemic corticosteroids (methylprednisolone or hydrocortisone) were administered in 80 % of treated patients. Seventeen percent of patients were discharged from hospital with no change to their usual treatment.

CONCLUSIONS

The following weak points were identified: 1) Severity assessment is inadequate, 2) use of diagnostic tests is excessive, 3) patients discharged to home with no treatment plan. Opportunities for improvement consisted of: 1) greater availability of peak expiratory flow meters, 2) individualized use of diagnostic tests, and 3) management protocols.

Therapeutic compliance among asthma patients in an allergy clinic: third evaluation (SEGARIA Project)

OBJECTIVES

To perform a third evaluation of therapeutic compliance in asthma patients managed in our department by using identical methodology to that employed in two prior evaluations (1995 and 1993). To study the possible association between correct inhalation technique and the patient's degree of knowledge about asthma.

MATERIAL AND METHODS

A random sample with a fixed rate was obtained, comprising 54 adult patients with asthma (aged more than 18 years old) managed in our department in an outpatient regime. Patients who reported that they habitually failed to comply with the treatment duration, the number of dosage times per day, or the dose at each specific dosage time were classified as noncompliers with the medication in question. The study was performed during October and November, 2003. First visits were excluded. The same categories of medications and procedures as those employed in the 1993 and 1995 studies were used.

RESULTS

Of the 54 patients studied, 19% revealed some type of pharmacological noncompliance. The overall percentage of incorrectly used medication was 8%. Among noncompliers, clinical course was poor in 44% and additional visits to specialists or the emergency room were required in 45%. Incorrect use was most frequent with the turbuhaler (32.1%), and faulty technique was also most common with this device (67.9%).

CONCLUSIONS

In this evaluation, overall therapeutic compliance was clearly better than that in 1995 (81% compared with 54%), indicating a positive tendency over time. These results were more positive than those reported in the scientific literature on therapeutic compliance. Nevertheless, correct inhalation technique was markedly less frequent than in our previous studies. The most incorrectly used pharmacological groups continue to be the controller medications. A nonsignificant tendency among noncompliers to require more additional visits and to have worse clinical course and less knowledge about their disease than compliers was maintained. This type of evaluation continues to be useful in the clinical monitoring of therapeutic complicance in daily clinical practice.

Total serum IgE: adult reference values in Valencia (1981-2004). Usefulness in the diagnosis of allergic asthma and rhinitis

BACKGROUND

The reference values for total serum IgE are accepted to vary according to the geographical area involved. In 1981 we published the reference values for a donor population in the city of Valencia (Spain) and its metropolitan area. Since then, we have noted an increase in the prevalence of asthma and rhinitis in countries with a Western lifestyle, including Spain.

AIM

To update the adult reference values for total serum IgE in the city of Valencia and its metropolitan area, and to determine their diagnostic usefulness in asthma and allergic rhinitis.

MATERIAL AND METHODS

We studied two groups of 69 and 100 individuals each. One group comprised apparently healthy blood donors, as assessed by a routine blood bank study protocol and the application of a questionnaire to exclude perceived allergic or parasitic diseases, while the other group consisted of individuals with atopic respiratory disease (bronchial asthma and allergic rhinitis) studied in our service in the same time period (spring 2004). Total serum IgE was determined by the UniCAP method developed by Pharmacia.

RESULTS

The geometric mean of total serum IgE among blood donors was 46.65 kU/l (95% CI: 15.5-77.8) versus 204.29 kU/l (95% CI: 93.3-515) among allergic subjects. The difference between the two groups was statistically significant. No significant difference was found between our donor sample in 1981 and the sample in the present study. Establishing an arbitrary cut-off point of 1.65 standard deviations (SD)(equivalent to 95 % of the donor population), we obtained a figure of > 183 kU/l whereby 44% of all allergic individuals presented a value below this cut-off point. To practical effects, these allergic patients behaved as low responders (LRs) in relation to total IgE, whereas the remaining individuals were high responders (HRs) in relation to total IgE.

CONCLUSIONS

Our data confirm the current validity of the reference values obtained in 1981, which continue to be significantly different from those of the UniCAP method for Swedish donors. The population of allergic subjects can be divided into two subgroups: subjects with total IgE levels similar to those of the donors, which we refer to as LRs, and which represent 44% of all allergic subjects, and a second subgroup with total IgE values above those of the donors (HRs), who would therefore be the only subjects that would be identified by individual serum IgE study.

Post-operative unwashed shed blood transfusion does not modify the cellular immune response to surgery for total knee replacement

BACKGROUND

In patients undergoing total knee replacement (TKR), most blood loss occurs post-operatively, and the return of unwashed filtered shed blood (USB) from post-operative drainage may represent an alternative to allogeneic blood transfusion (ABT). We evaluated the impact of USB return on the cellular immune response (CIR) after TKR.

PATIENTS AND METHODS

Forty TKR patients, intended to receive post-operative USB, entered the study. Blood samples were obtained before and 6 h, 24 h, 72 h and 7 days after surgery, and from USB, after it had been passed through a 40-microm filter. Full blood cell counts, lymphocyte subsets and immunoglobulins (IgA, IgG, IgM) were measured in all samples. A set of clinical data was collected from each patient.

RESULTS

Twenty-four of the 25 patients received a mean of 1.2 USB units and did not need additional ABT (USB group). Twelve of the 15 remaining patients who received neither USB nor ABT served as a control group for the post-operative CIR study. All patients showed a post-operative decrease in T-cell and natural killer (NK) cell counts, but not B-cell counts, and there were no significant differences between the groups with regard to CIR parameters, post-operative infection or hospital stay.

CONCLUSIONS

Post-operative salvage and return of USB after TKR does not seem to increase the post-operative infection rate or hospital stay, and does not modify CIR induced by surgery. These findings add to the clinical experience that post-operative USB return, as a source of autologous blood, is safe, and questions the beneficial effect of blood washing.

Changes in intracellular electrolyte concentrations during apoptosis induced by UV irradiation of human myeloblastic cells

Decreases in the intracellular concentrations of both K+and Cl−have been implicated in playing a major role in the progression of apoptosis, but little is known about the temporal relationship between decreases in electrolyte concentration and the key events in apoptosis, and there is no information about how such decreases affect different intracellular compartments. Electron probe X-ray microanalysis was used to determine changes in element concentrations (Na, P, Cl, and K) in nucleus, cytoplasm, and mitochondria in U937 cells undergoing UV-induced apoptosis. In all compartments, the initial stages of apoptosis were characterized by decreases in [K] and [Cl]. The largest decreases in these elements were in the mitochondria and occurred before the release of cytochrome c. Initial decreases in [K] and [Cl] also preceded apoptotic changes in the nucleus. In the later stages of apoptosis, the [K] continued to decrease, whereas that of Cl began to increase toward control levels and was accompanied by an increase in [Na]. In the nucleus, these increases coincided with poly(ADP-ribose) polymerase cleavage, chromatin condensation, and DNA laddering. The cytoplasm was the compartment least affected and the pattern of change of Cl was similar to those in other compartments, but the decrease in [K] was not significant until after active caspase-3 was detected. Our results support the concept that normotonic cell shrinkage occurs early in apoptosis, and demonstrate that changes in the intracellular concentrations of K and Cl precede apoptotic changes in the cell compartments studied.

Rabeprazole containing triple therapy to eradicate Helicobacter pylori infection on the Texas-Mexican border

BACKGROUND

Antibiotic resistance and duration of therapy influence the success of proton-pump inhibitor-containing Helicobacter pylori eradication therapy. Clarithromycin resistance is associated with treatment failure.

AIM

To examine the success of a 7-day rabeprazole-clarithromycin-amoxicillin therapy in the study population.

METHODS

Adults from Ciudad Juarez with H. pylori infections identified by culture or histology received rabeprazole 20 mg, clarithromycin 0.5 g and amoxicillin 1 g, each b.d. for 7 days. Outcome was assessed by 13C-urea breath test carried out 4+ weeks after treatment.

RESULTS

A total of 111 patients were enrolled and evaluated by urea breath test; 102 completed the full 7 days therapy. Two deviated from protocol, and five stopped because of adverse events. The cure rate (intention-to-treat) was 85% (95% CI: 78-91%); the per-protocol cure rate was 85% (95% CI: 78-91%). Side-effects were not serious and only 6.6% of those with adverse events stopped medication. Only three isolates were clarithromycin-resistant and none was cured. Compliance explained most of the successes.

CONCLUSIONS

In the study population a 7-day rabeprazole triple eradication therapy was both effective and well-tolerated. Clarithromycin resistance was uncommon. We observed a slightly better outcome but consistent with results from recent large studies in US populations.

Use of oral sildenafil in patients with irreversible pulmonary hypertension not eligible for heart transplantation

Heart transplantation is contraindicated in patients with acute irreversible pulmonary hypertension (PH), but new drugs are opening up therapeutic possibilities. Sildenafil citrate is a nonselective pulmonary vasodilator that is being used in our hospital to treat several patients with PH and which has allowed the inclusion of 1 patient on the waiting list for heart transplantation. A 20-year-old man with Becker muscular dystrophy was diagnosed at the age of 19 years with dilated cardiomyopathy with severe pulmonary artery systolic pressure (PH = 60 mm Hg). A pretransplantation study, including a right hemodynamic analysis with an acute vasodilator test using intravenous epoprostenol, revealed the irreversible character of the PH. Inasmuch as the administration of dobutamine did not achieve an adequate reduction of PH, oral sildenafil was started (25 mg every 12 hours) as salvage therapy. An echocardiogram obtained 2 months after starting sildenafil therapy showed normal right cavities, previously dilated, as well as minimal protosystolic tricuspid regurgitation without PH. A new right hemodynamic study performed after 4 months showed a reduction in pulmonary vascular resistance, from 8 U to 3.5 U Woods. As a result, the patient has now been included on the waiting list for heart transplantation. The promising example of this patient confirms the necessity to carry out controlled trials to establish definitively the indications for the use of sildenafil in patients with irreversible PH.

Impact of postoperative shed blood transfusion, with or without leucocyte reduction, on acute-phase response to surgery for total knee replacement

BACKGROUND

In patients undergoing total knee replacement (TKR) most blood loss occurs postoperatively and return of unwashed filtered shed blood (USB) from postoperative drainage may represent an alternative to allogeneic blood transfusion (ABT). We evaluated the impact of USB return, with or without leucocytes, on the acute-phase response (APR) after TKR.

PATIENTS AND METHODS

Forty-eight TKR patients, intended to receive postoperative USB, entered the study. Blood samples were obtained before and 6, 24, 72 h and 7 days after surgery, and from the USB before and after it passed through a 40-microm filter (Group F40) or a leucocyte-reduction filter (Group LRF). Haematimetric parameters, APR proteins (albumin, prealbumin, ceruloplasmin, haptoglobin, C-reactive protein), complement C3 and C4, and cytokines (IL-1beta, IL-6, IL-8, IL-10, and TNF-alpha) were measured in all samples.

RESULTS

Twenty-eight patients (Group F40=14, Group LRF=14) received a mean of 1.2 USB units, without any clinically relevant incident, and did not need additional ABT. Sixteen out of the 20 remaining patients who received neither USB nor ABT served as a control group for the postoperative APR study. All patients showed the typical postoperative APR profile and there were no significant differences between groups for APR parameters, postoperative complications, or hospital stay.

CONCLUSIONS

Postoperative blood salvage and return, with or without a LRF, after TKR does not present any clinically relevant side-effects and does not modify APR induced by surgery. These findings seem to confirm the clinical experience that postoperative USB return is safe and questions the beneficial effect of using LRF.