Apical root canal anatomy in the mesiobuccal root of maxillary first molars: influence of root apical shape and prevalence of apical foramina - a micro-CT study.

AIM: To determine whether a relationship exists between the apical shape of roots and root canal system complexity by performing a micro-computed tomography analysis. METHODOLOGY: One hundred extracted permanent maxillary first molars were scanned using a micro-computed tomography device at 19.6 µm voxel size. Two groups of mesiobuccal roots were formed according to the root aspect ratio value in the apical 3-mm cross-sectional level ('<2 and ≥ 2.00'). Data were recorded regarding the number and presence of accessory canals and their location, isthmus, presence of the mesiobuccal canal and dentine thickness. Depending on the analysed variable, Mann-Whitney U test and Z-test for proportions were used to compare groups. The significant level was set at 5%. RESULTS: Mesiobuccal roots with an aspect ratio ≥ 2.00 at the apical 3-mm cross-sectional level had higher percentages of accessory canals, apical foramina and MB2 root canals in the apical 3 mm. The vertical average distance from the accessory foramina and origin from the anatomic apex was 1.40 and 2.19 mm, respectively. Overall, 21.8% of the accessory canals had their origin coronal to a 3-mm root resection line. There was no difference between the groups regarding dentine thickness. CONCLUSION: The shape of the apical 3 mm of maxillary first molar mesiobuccal roots was a predictive factor for the presence of complex root canal systems. Roots with a lower aspect ratio had less complex apical anatomy.

Photorefractive keratectomy for hyperopic and mixed astigmatism.

BACKGROUND: The correction of astigmatism with photorefractive keratectomy has been recommended in simple and myopic astigmatism. Therefore in this study the excimer laser was used to correct compound hyperopic and mixed astigmatism. METHODS: We present a prospective clinical study of photorefractive keratectomy in 30 eyes of 24 patients with compound hyperopic astigmatism with a mean spherical equivalent of +4.30 D and mean astigmatism of 2.33 D (group I) and in 17 eyes of 15 patients with mixed astigmatism with a mean spherical equivalent refraction of +0.46 D and mean astigmatism of 4.75 D (group II). The excimer laser used in this study was an MEL 60 (Aesculap-Meditec). In both groups an 18-month follow-up study was performed. RESULTS: In the compound hyperopic astigmatism group after 18 months, 14 of 17 treated eyes (82.3%) were within +/-1.00 D, and 11 (64.7%) were within 60.50 D of the intended correction. In the mixed astigmatism group after 18 months, 10 of 11 eyes (90.9%) were within +/-1.00 D, 8 eyes (72.7%) were within +/-0.50 D of the intended correction. In regard to the stability the 1 year regression of spherical equivalent in the compound hyperopic astigmatism group is 0.78 D and in the mixed astigmatism group 0.37 D. At 18 months, spectacle corrected visual acuity in the compound hyperopic astigmatism group was unchanged or improved in 14 eyes (87.5%); 2 eyes (12.5%) had lost one line. In the mixed astigmatism group at 18 months, spectacle corrected visual acuity was unchanged or improved in 9 eyes (81.8 %); 2 eyes (18.1%) lost one line. Preoperatively, the mean uncorrected visual acuity was 20/100 in the compound hyperopic astigmatism group and the mixed astigmatism group. At 18 months, 14 eyes (93.3%) in the compound hyperopic astigmatism group had an uncorrected visual acuity of 20/40 or better; 4 (26.6%) eyes had an uncorrected visual acuity of 20/20 or better. In the mixed astigmatism group, 9 (81.8%) eyes had an uncorrected visual acuity of 20/40 or better; 4 (36.3%) eyes had an uncorrected visual acuity of 20/20 or better. CONCLUSION: Photorefractive keratectomy is an efficient and relatively safe procedure for reducing or eliminating compound hyperopic and mixed astigmatism up to 6.00 D.

Incidence and position of the canal isthmus. Part 1. Mesiobuccal root of the maxillary first molar.

The mesiobuccal roots of 50 randomly selected maxillary first molars were examined to assess the incidence and position of the canal isthmus. Transverse serial sections of the apical 6 mm of each root were prepared in 1-mm increments. The apical side of each section was stained with methylene blue dye, viewed with a surgical operating microscope, and videotaped. Forty percent of the roots had one canal, whereas 60% had two canals. None of the sections had more than two main canals. The incidence of an isthmus was highest in the apical 3- to 5-mm levels. In teeth that had two canals, the 4-mm sections contained a complete or partial isthmus 100% of the time. The concept of a partial isthmus was presented. Failure to deal with the isthmus may explain why some posterior teeth do not heal completely following endodontic surgery.

Levels of mercury in alligators (Alligator mississippiensis) collected along a transect through the Florida Everglades.

As part of a multi-agency study of alligator health, 28 American alligators (Alligator mississippiensis) were captured along a transect through the Florida Everglades in 1999. Liver and tail muscle tissues were sampled and analyzed on a wet weight basis for total mercury (THg) using cold-vapor atomic absorption spectrophotometry. All tissues had detectable concentrations of THg that ranged from 0.6 to 17 mg/kg in liver and from 0.1 to 1.8 mg/kg in tail muscle. THg was more concentrated in liver tissue than tail muscle, but levels were highly correlated between tissues. THg concentrations in tissue differed significantly among locations, with animals from Everglades National Park (ENP) having mean concentrations of THg in liver (10.4 mg/kg) and tail muscle (1.2 mg/kg) that were two-fold higher than basin-wide averages (4.9 and 0.64 mg/kg, respectively). The reasons for higher contamination of ENP alligators were unclear and could not be explained by differences in sex, length, weight or animal age. While delta15N values were positively correlated with THg concentrations in tail muscle, spatial patterns in isotopic composition did not explain the elevated THg levels in ENP alligators. Therefore, it appears that ENP alligators were more highly exposed to mercury in their environment than individuals in other areas. Comparisons to a previous survey by Yanochko et al. [Arch Environ Contam Toxicol 32 (1997) 323] suggest that mercury levels have declined in some Everglades alligators since 1994.

Re-inventing intentional replantation: a modification of the technique.

Intentional Replantation (IR) has traditionally been considered a treatment of last resort due to complications during extraction, handling, and replantation. Root resorption and failure often resulted from drying of the root surface during extraoral manipulations. Replantation techniques have been recently modified to prevent desiccation. This article presents a modified IR technique with continuous immersion of the tooth in a tissue culture solution. This allows extension of the extraoral time period to permit inspection of the root surfaces, precise root-end resections and preparations, and placement of root-end fillings.

[Acute kidney failure associated with pregnancy and delivery]. / Ostra niewydolnosc nerek zwiazana z ciaza i porodem.

The cases of acute renal failure are presented. Severity of the disease, employed treatment and diagnostic problems were discussed. The early dialysis treatment at those patients is postulated (discussed).

[Ethylene glycol poisoning as a cause of chronic renal failure]. / Zatrucie glikolem etylenowym jako przyczyna przewleklej nefropatii.

We showed some observations two Dialysis Centres concerning acute ethylene glycol poisoning and four cases of chronic renal failure progress. Renal biopsy at one patient and our clinical observations indicate for possibility of chronic renal failure development in some pts. We discussed hypotension of CRF development at those pts.

[Hypernatremia in a patient with extrarenal kidney failure during the course of prostatic adenoma]. / Hipernatremia u chorego z pozanerkowa niewydolnoscia nerek w przebiegu gruczolaka stercza.

A case is described of a rare cause of hypernatraemia in a 68-year-old patient in whom renal failure developed due to an obstacle in urine flow in the course of prostatic adenoma. Of interest are high, life-threatening values of sodium concentration in the plasma, severe course of the disease, and high grade urinary sodium loss.

[Glycol ethylene poisoning as a cause of chronic renal failure]. / Zatrucie glikolem etylenowym jako przyczyna przewleklej nefropatii.

There were shown some observations from two Dialysis Centres concerning acute Ethylene Glycol poisoning and four cases of chronic renal failure progress. The renal biopsy made at one patient and our clinical observations indicate for possibility of chronic renal failure development in some pts. There were discussed hypothesis of CRF development at these pts.

Intracranial aneurysms in autosomal dominant polycystic kidney disease.

BACKGROUND AND PURPOSE: ADPKD correlates with an increased frequency of ICANs, but universal screening for ICANs in patients with ADPKD is not currently recommended. The aim of our study was to determine which groups might benefit from screening by determining the prevalence of ICANs in the Polish ADPKD population and identifying any subgroups with an increased risk for ICANs. MATERIALS AND METHODS: Eighty-three adult, predialysis-phase patients with ADPKD underwent screening for ICANs with MRA of the brain. RESULTS: The prevalence of ICANs in the studied population was 16.9%, with 6% of the screened group requiring neurosurgical intervention. We also found that the frequency of ICANs increases with age, reaching 22.4% in patients older than 45 years. All diagnosed ICANs were small (< 9 mm) and were localized in the anterior circulation. In addition, MR imaging revealed arachnoid cysts in 4.8% of patients with ADPKD. CONCLUSIONS: We suggest that patients older than 45 years with ADPKD be considered as candidates for screening for ICANs, and we propose a clinical algorithm for this subgroup. However, we could not find risk factors for ICANs in younger patients with ADPKD.

Continuous Erythropoietin Receptor Activator (C.E.R.A.) administered at extended administration intervals corrects anaemia in patients with chronic kidney disease on dialysis: a randomised, multicentre, multiple-dose, phase II study.

This dose-finding, open-label study examined the potential of subcutaneous Continuous Erythropoietin Receptor Activator (C.E.R.A.) to correct anaemia at extended administration intervals in 61 erythropoiesis-stimulating agent-naïve patients with chronic kidney disease (CKD) on dialysis. After a 4-week run-in, patients were randomised to C.E.R.A. 0.15, 0.30 and 0.45 microg/kg/week. Within these dose groups, patients were further randomised to once weekly, once every 2 weeks or once every 3 weeks treatment. Mean changes in haemoglobin (Hb) increased with increasing C.E.R.A. dose during a period of 6 weeks where no dose adjustments were permitted. The effect was independent of administration schedule. Erythropoietic responses were sustained until the end of the study (12 weeks) in all groups. In total, 90% of patients in the 0.30 microg/kg/week group and 79% in the 0.45 microg/kg/week group responded to treatment (Hb increase > or =1.0 g/dl), compared with 72% in the 0.15 microg/kg/week group. Faster median response time was associated with increasing dose (51, 38 and 31 days, respectively) and response was unrelated to administration frequency. C.E.R.A. was generally well tolerated. Our results suggest that 0.60 microg/kg twice monthly would be a suitable starting dose of C.E.R.A. for the initiation of anaemia correction in patients with CKD on dialysis. Phase III studies will confirm the feasibility of using C.E.R.A. at extended administration intervals in patients with CKD and anaemia.

Hyperosmotic saline dextran for resuscitation from traumatic-hemorrhagic hypotension: effect on regional blood flow.

The macro- and microcirculatory effect of small-volume resuscitation with hyperosmotic-hyperoncotic solutions was analyzed in 21 anesthetized beagles subjected to standardized traumatic-hemorrhagic hypotension (laparotomy and exteriorization of the intestine; MAP 40 mmHg for 75 min). Primary resuscitation consisted of bolus infusion of 10% of the blood loss (approx. 4 ml/kg) of either hyperosmotic (7.2%) saline -HSS-, hyperoncotic (10%) dextran 60 -HDS-, or hyperosomotic-hyperoncotic saline dextran (10% dextran 60 in 7.2% saline; HHS). Within 5 min CO was restored and systemic pressure significantly increased. In the HHS-group nutritional blood flow (RBF, measured by radiolabeled microspheres phi 15 microns) in kidneys, gastric mucosa, small intestine, colon, and pancreas was completely restored, while RBF to the myocardium, brain, and skeletal muscles exceeded baseline values. Despite the identical response in central hemodynamics, RBF to gastric mucosa, intestine, pancreas, and kidneys was significantly lower in HSS-animals (P less than 0.05 vs. HHS). In contrast, in the HDS-group CO, splanchnic, myocardial, and renal blood flow remained significantly reduced (P less than 0.05 vs. HHS). Despite the normalization of cardiac output by small volumes of hypertonic solutions, 7.2% saline alone failed to fully restore RBF after protracted traumatic hemorrhage. For the concept of small-volume resuscitation, the hyperosomotic-hyperoncotic solution of 10% dextran 60 in 7.2% saline appears to be most effective to improve organ perfusion during the prehospital period of trauma patients.

[Hypoglycemia during the course of chronic renal failure]. / Hipoglikemia w przebiegu przewleklej niewydolnosci nerek.

In two patients with end stage renal failure and not treated diabetes spontaneous hypoglycaemiaes were observed. The lowest levels of glucose in blood serum were: 1.9 mmol/L and 1.16 mmol/L. These levels were accompanied by symptoms of severe neuroglycopenia. Despite of intensive pharmacological treatment recurrent hypoglycaemia episodes appeared for 34 hours in one case and 32 hours in the other. Authors discussed pathophysiological processes leading to hypoglycaemia in end stage renal failure patients. It seems that disturbances in renal gluconeogenesis together with lower degradation of insulin played the key role in creating hypoglycaemia in those two patients.

Effect of delays in processing on the survival of Mycobacterium avium-M. intracellulare in the isolator blood culture system.

Concentrations of Mycobacterium avium-M. intracellulare ranging from 10(-1) to 10(3) CFU/ml were added to blood, placed in Isolator tubes, and held at room temperature for intervals ranging from 4 h to 56 days before being processed (centrifugation and culture on Middlebrook 7H10 agar). At all concentrations tested, M. avium-M. intracellulare was recovered after hold times ranging from 4 h to 7 days; the number of final CFU actually increased progressively for hold times of 8 h or more. Hold times of up to 7 days did not increase the time from processing to the first appearance of visible colonies. At an inoculum of 10(2) CFU/ml, M. avium-M. intracellulare was recovered from Isolator tubes processed 56 days after inoculation. Two Isolator blood cultures were drawn from a patient with AIDS; M. avium-M. intracellulare was recovered from the sample processed immediately and from the sample processed after a hold time of 7 days. Since M. avium-M. intracellulare survives for prolonged periods in Isolator tubes, blood cultures may be collected in outpatient settings or in hospitals without mycobacterial culture facilities and shipped to reference laboratories for processing without loss of viability.

[Nephrotoxicity of aminoglycosides. I: Preventive intraperitoneal calcium administration]. / Nefrotoksycznosc aminoglikozydów. Czesc I. Próby zapobiegania dootrzewnowym podawaniem wapnia szczurom.

UNLABELLED: The effect was studied of intraperitoneal intake of calcium on gentamicin nephrotoxicity in the rats. Two groups of Wistar were studied: G--in the first group gentamicin was injected in single daily dose 100 mg/kg b.w. subcutaneously, GCa--in the second group gentamicin was given s.c. and calcium intraperitoneal in single daily dose 45 mg Ca++/kg b.w. Results were evaluated after 3, 7, and 10 days of gentamicin injections and after ten days of gentamicin removal, Mean creatinine level after ten days of gentamicin administration was in G group 4.52 +/- 0.77 mg%, GCa--1.87 +/- 0.21 mg%, p less than 0.02, mean urea 192. 62 +/- 21.88 mg%, 77.09 +/- 8.68 mg%, p less than 0.01, serum calcium 8.39 +/- 0.15 mg%, 9.96 +/- 0.21 mg%, p less than 0.001, gentamicin in the renal cortex 384.68 +/- 67.62 micrograms/g tissue, 327.38 +/- 81.89 micrograms/g tissue p less than 0.05. Urinary calcium excretion was higher in the GCa group than in the group of control rats. Statistical differences were significant after 3 and 7 days of gentamicin intake. Differences were found also in the light and electron microscopic examination. CONCLUSION: Intraperitoneal calcium loading significantly reduced the gentamicin nephrotoxicity in the rats and lowered gentamicin level in the renal cortex of the rats.

[Nephrotoxicity of aminoglycosides. II. Preventive studies with oral administration of verapamil]. / Nefrotoksycznosc aminoglikozydów. Czesc II. Próby zapobiegania doustnym podawaniem werapamilu szczurom.

The effect was studied of oral verapamil administration in two different doses on gentamicin nephrotoxicity. Three groups of Wistar male rats were studied: 1) treated with gentamicin 100 mg/kg b.w. subcutaneously, 2) treated with gentamicin s.c. and verapamil 5 mg/100 ml given in drinking water, 3) treated with gentamicin s.c. and verapamil 20 mg/100 ml. The examinations were performed after 3, 7 and 10 days of gentamicin administration and after 10 days of gentamicin removal. Oral verapamil administration in these doses did not prevent the renal functional and histological damage after gentamicin administration. Renal cortex content of gentamicin was lower only after 3 days of gentamicin administration (statistically significantly) in the verapamil groups.

[Nephrotoxicity of aminoglycosides. III. Preventive studies with subcutaneous administration of converting enzyme inhibitor, captopril]. / Nefrotoksycznosc aminoglikozydów. Czesc III. Próby zapobiegania podskórnym podawaniem blokera enzymu konwertujacego, kaptoprylu szczurom.

The effect was studied of the converting enzyme inhibitor (captopril) on the gentamicin nephrotoxicity in rats. Captopril 25 mg/kg b.w. and gentamicin 100 mg/kg b.w. were injected subcutaneously in a single daily dose. Three groups of Wistar male rats were studied: 1) treated with gentamicin 3 and 7 days, 2) treated with gentamicin and captopril, 3) treated with captopril. The mean serum creatinine and urea levels and proteinuria in the second group were significantly higher than in the first one. Light and electron microscopy examinations demonstrated increased renal cortex damage in the second group. There were not differences between mean urea and creatinine levels in the third examined group and normal rats. Mechanism of gentamicin nephrotoxicity enhancement in the second group is unknown.

[Test with calcitonin as an index of parathyroid function in chronic renal failure]. / Test z kalcytonina jako wskaznik czynnosci przytarczyc w przewleklej niewydolnosci nerek.

The aim of this study was to evaluate the clinical usefulness of the calcitonin test in predicting the hyperparathyroid bone disease severity in uremia. 200 IU of synthetic salmon calcitonin was given intranasally to 77 hemodialysed patients with end-stage renal failure. Before the test, serum calcium, PTH and serum alkaline phosphatase had been sampled; serum calcium was determined also in 2 to 4 hours after. The subjects were divided into 3 groups according to their serum PTH levels. Group I consisted of 24 patients with at least 10-fold serum PTH elevation, group II of 34 patients with intermediate values, and group III of 19 patients with serum PTH within normal range. In the group I the mean serum calcium fall was 0.32 +/- 0.16 mmol/l (1.28 +/- 0.64 mg/dl) (p < 0.001) and 0.27 +/- 0.15 mmol/l (1.08 +/- 0.60 mg/dl) (p < 0.001), after 2 to 4 hours respectively. In the group II serum calcium decreased by 0.16 +/- 0.12 mmol/l (0.64 +/- 0.48 mg/dl) after 2 hours and by 0.14 +/- 0.09 mmol/l (0.56 +/- 0.36 mg/dl) after 4 hours; the differences were statistically insignificant. In the group III no reduction in serum calcium was observed. In the whole 77 patients population significant linear correlations between the hypocalcemic response and iPTH as well as serum alkaline phosphatase were found. Our results confirm that the calcitonin-induced hypocalcemia a test can be, in addition to serum alkaline phosphatase and PTH evaluation, a simple and useful index of advanced hyperparathyroid bone disease in hemodialysed patients with chronic renal failure.