The effect of maximum bite force on marginal bone loss of mini-implants supporting a mandibular overdenture: a randomized controlled trial.

OBJECTIVES: To evaluate the effect of maximum bite force (mBF) on marginal bone loss (MBL) around mini-implants in edentulous patients wearing mandibular overdentures with two retention systems: ball and bar. MATERIAL AND METHODS: Forty-five totally edentulous patients were selected from a public health center. All of them received two mini-implants (1.8 x 15 mm; Sendax) in the anterior mandible using a minimally invasive technique. A single randomization was performed to allocate the patients in two groups. Group I (n=22) received two single ball-type mini-implants and Group II (n=23) received two mini-implants splinted with a prefabricated bar. The mBF was recorded using a press-sensitive sheet Dental Prescale (Fuji) and MBL using standardized radiographs of each mini-implant at the baseline and 5, 7, 10, and 15 months after surgery; the values were compared between groups. RESULTS: Two members of Group I failed to complete the study, decreasing the number of participants to 20. There was no relationship between the mBF and the MBL of the mini-implants (Spearman's rhor(s)=0.147; P=0.378). At the 15-month follow-up, the average mBF for Group I (ball) was 247.53 +/- 132.91 N and that of Group II (bar) only 203.23 +/- 76.85 N (Mann-Whitney test; P=0.586). The MBL values were also higher for Group I (1.40 +/- 1.02 mm) than Group II (0.84 +/- 0.66 mm) during the entire 15-month follow-up period (Mann-Whitney test; P=0.077). CONCLUSIONS: No relationship was found between mBF and MBL for patients wearing overdentures retained on mini-implants using bar or ball attachment systems.

Acute renal failure in renal allograft recipients and patients with native kidneys.

In order to evaluate the role of underlying disease in the high mortality observed in acute renal failure (ARF) and risk factors related to the development of oliguric ARF in renal allograft recipients, two groups were selected: 34 patients with native kidneys, aged 16 and 57 years, and presenting ischemic ARF caused by cardiovascular collapse, with no signs of infection at the time of diagnosis; and 34 renal allograft recipients who developed ARF immediately after transplantation, without rejection. ARF was defined either as 30% increase of basal plasmatic creatinine in patients with native kidneys or nonnormalization of plasmatic creatinine at day 5 after transplantation in renal allograft recipients; oliguria as diuresis < or = 400 mL/24 h. There were no differences in age, male frequency, oliguria presence and duration, need for dialysis, and infection episodes for renal allograft recipients and patients with native kidneys. The development of sepsis (3% and 41%) and death rate (3% and 44%) were higher in patients with native kidneys (p < 0.01). The renal allograft recipients with both oliguric (n = 18) and nonoliguric (n = 16) ARF were evaluated and no difference was observed in the recipient's age, donor's age, cold ischemia time, time elapsed until plasmatic creatinine normalization, donor's plasmatic creatinine or urea, and mean arterial pressure. No differences were observed between the groups regarding frequency of infection episodes during ARF and frequency of death. In conclusion, renal allograft recipients presented a lower death rate and were less susceptible to sepsis. Cold ischemia time, age, and hemodynamic characteristics of the donor did not affect the development of oliguria.

[Protective effect of ranitidine and bismuth salts on gastritis induced by ethanol]. / Efecto protector de la ranitidina y de las sales de bismuto sobre la gastritis producida por etanol.

In normal males volunteers a double-blind parallel trial was performed to study protection induced by ranitidine and bismuth subcitrate on the damage induced by ethanol on the gastric mucosa. Subjects were randomized assigned in three groups: I (R) n = 9 Ranitidine 150 mg, II (B) n = 6 Bismuth 240 mg, and III (R + B) n = 9 both compounds. Drugs were administered one hour before endoscopy. If the subject initially showed absence of any lesion, he received through and endoscopic cannula an infusion of 100 ml of ethanol at 40%. Endoscopic evaluation was performed at 15 and 30 minutes, without retrieving the endoscope. Quantification of gastric lesions was performed using the scale of Tarnawski et al (Am J Med 83:31-37, 1987). In the group I there was no lesion in 67%, in the group II 0% and in the group III 78%. Petechial lesions were observed in 33%, 67% and 11% respectively. In summary, combination R + B and the R gave the best cytoprotection that observed only bismuth. Possible mechanism of action are discussed.

Effects of the immunosuppressant FK506 on a penetrating keratoplasty rejection model in the rat.

PURPOSE: The immunosuppressive effects of FK506 on allogeneic corneal transplantation were tested in a rat model. METHODS: Inbred-strain Lewis rats were used as recipients, and Fisher rats were used as donors. Intraperitoneal injection of FK506 (0.3, 1.0, and 3.0 mg/kg per day) was administered for 2 weeks, and the grafts were inspected by clinical evaluation. Mixed lymphocyte culture assay, using lymphocytes from recipients of penetrating keratoplasty as responder cells and irradiated splenocytes from naive Fisher or Brown Norway as stimulator cells, was used to identify allogeneic stimulation. The rejection process was studied by histology and immunohistochemistry. RESULTS: The rat strain combination developed 100% graft rejection in about 2 weeks after the penetrating keratoplasty. FK506 prolonged the graft survival in a dose-dependent manner, as observed by clinical evaluation. In mixed lymphocyte culture assay, Lewis rats that had been primed to allogeneic stimulation at the time of cornea transplantation presented significant proliferation to Fisher stimulator splenocytes. FK506 suppressed this primed lymphocyte proliferation. Immunohistochemical and histologic studies confirmed the clinical evaluations. Untreated rat corneas, at the second postoperative week, presented a large number of helper/inducer T cells, macrophages, IL-2 receptor-expressing cells, and Ia-antigen-expressing cells. In the same period, FK506-treated rats appeared normal and had no cellular infiltration. Corneas rejected after FK506 cessation had less intense cell infiltration than the control corneas. CONCLUSIONS: These data indicate that FK506 prolonged the corneal graft survival and can be a potentially useful drug in the immunotherapeutic arsenal to suppress corneal graft rejection.

[Needle sphincterotomy: a safe method]. / Esfinterotomía de aguja: un método seguro.

We performed needle papillotomy in 26 patients. When the biliary tract was not approach by conventional methods. We used an home made sphincterotomy and begin the incision at the papillar orifice and cut in cephalic direction to the 11-12 o'clock, and stop the cutting when we observe bile flow or choledochus mucosa. The only complication was bleeding in two patients and it stopped with epinephrine injection. There were not perforations or mortality. We conclude that needle papillotomy is a safe and useful method in selected cases.

Lesiones esofágicas causadas por el virus del papiloma humano (VPH) / Esophageal injuries due to human papillomaviruses (HP)

Describimos 22 enfermos con lesiones histopatológicas en las biopsias esofágicas compatibles con infección por VPH. Los síntomas por los cuales consultaron los pacientes, no tuvieron nada de característico: pirosis con o sin odinofagia, otras veces era epigastralgia de carácter irregular e intermitente, disfalgia en dos casos con carcinoma y un caso asintomático. No hubo ninguna predilección para ningún sexo y la edad promedio del gupo fue de cuarenta años. La endoscopia digestiva superior mostró los siguientes hallazgos: a) Ulceras en el tercio medio, la mayoría menores de 10 mm, redondeadas u ovaladas, de profundidad moderada, separadas por mucosa sana aparentemente, con bordes bien delimitados e hiperémicos, fondo blanquecino y liso; b) En cinco enfermos hubo lesiones blanquecinas elevadas, también situadas en el tercio medio del órgano, múltiples, separadas por mucosa sin lesiones, no cubiertas con membranas fáciles de separar. Un paciente presentó dos papilomas; c) En dos casos hubo carcinoma epidermoide a 25 y 28 cm de la arcada dental, vegetante y estenosante. Las biopsias tomadas en la periferia del tumor, demostraron lesiones compatibles con VPH. La posible relación de las lesiones descritas aparentemente ceden sin tratamiento o con medicamento no específico, aunque algunos casos de nuestra serie han respondido en forma empírica a drogas antivirales

[Esophageal lesions caused by human papillomaviruses (HPV)]. / Lesiones esofágicas causadas por el virus del papiloma humano (VPH).

Twenty two patients are presented with histologic lesions on esophageal biopsy compatible with infection by human papillomavirus. Symptoms were uncharacteristic, there was no sex difference and the mean age was 40 years. Upper GI endoscopy showed the following: a) multiple ulcers in the middle esophagus, most of less than 10 mm in diameter, rounded or oval in shape, separated by normal appearing mucosa, well delimited erythematous margins, with a smooth white base; b) In five patients, multiple white elevated lesions were found in the middle esophagus, separated by normal appearing mucosa. One patient had 2 papillomas; c) In two cases there was an epidermoid carcinoma at 25 and 28 cm from the dental arcade. Biopsy taken at the border of the lesions were compatible with papilloma virus infection. The possible relation of the lesions with papillomavirus infection was established only on histologic criteria. The described lesions regress without treatment or with nonspecific treatment, some cases of our series have responded to empiric antiviral medication.