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.

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.

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.

Mercury in eggs and feathers of great egrets (Ardea albus) from the Florida Everglades.

Great egret (Ardea albus) eggs and nestling feathers were collected for total mercury (THg) and methylmercury (MeHg) analysis from two colonies in the Florida Everglades in 1999 and 2000. THg was present in all eggs at a mean concentration of 0.39 +/- 0.19 microg/g fresh weight (n = 33, range = 0.08-0.86 microg/g). Egg-THg levels did not differ significantly between colonies or years. MeHg concentration in eggs was 0.35 +/- 0.18 microg/g fresh weight (n = 20, range = 0.05-0.82 microg/g,), and on average represented 85% of the THg found in the egg. Concentration of THg in feathers from egret nestlings, age 11-31 days, ranged from 1.4 to 8.6 microg/g dry weight. Feather-THg levels also did not differ significantly between colonies or years. THg concentrations in feathers, normalized based on bill length, were positively correlated to THg concentrations in eggs from the same clutch. Levels of THg in both eggs and feathers were lower in 1999 and 2000 than values reported for similar samples collected in 1993-95, indicating that MeHg exposure has decreased in the southern Everglades since the mid-1990s. THg levels in eggs and nestling feathers for the period of this study were below levels associated with toxic reproductive effects. Clutch size, fledging success, and brood size observed in this study were consistent for this species in the Everglades. Collectively, these results suggest that MeHg was not adversely affecting the reproductive performance of this population during the study.

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.

The benefits of hormone replacement therapy in pre-menopausal women with oestrogen deficiency on haemodialysis.

BACKGROUND: Impaired sexual function is an important cause of depression in uraemic females. Hyperprolactinaemia is frequent, and often associated with decreased serum oestradiol concentration, which can significantly contribute to accelerated bone loss. The aim of the study was to evaluate the effect of hormone replacement therapy (HRT) on sexual function, serum 17beta-oestradiol and prolactin, and bone mineral density (BMD) in pre-menopausal women undergoing haemodialysis. METHODS: Among 63 women on haemodialysis, aged 18-45 years, 23 with secondary amenorrhoea and serum oestradiol < 30 pg/ml were enrolled into the 1 year study. They were divided into: group I (n = 13) treated with transdermal oestradiol with cyclic addition of noretisterone acetate, and control group II (n = 10). BMD was measured with dual energy X-ray absorptiometry (DEXA). RESULTS: No important changes in sexual function and hormonal profile were observed in the control group, whereas in all women from group I the treatment induced regular menses and a marked improvement of libido and sexual activity. Serum 17beta-oestradiol increased after the first month from 20.5 +/- 11.7 to 46.8 +/- 13.6 pg/ml (P < 0.001) and remained at that level until the end of the study, accompanied by a decrease of serum prolactin (from 1457 +/- 1045 to 691 +/- 116 mIU/ml after 12 months; P < 0.001). In group I, the treatment induced an increase in BMD, although significant only in L2-L4 (P < 0.05), whereas in group II a mild insignificant decrease was observed. However, a comparison of BMD values after 12 months in both groups revealed marked (P < 0.01-P < 0.05) differences at all studied sites. CONCLUSIONS: Transdermal HRT allows sustained physiological serum oestradiol concentrations in pre-menopausal women with oestrogen deficiency on haemodialysis, with the restoration of regular menses and a marked improvement in their sexual function. The treatment inhibits bone demineralization and can play an important role in the prevention of early osteoporosis in this group of patients.

[The prevention of bone mineral loss with hormonal replacement therapy in premenopausal women on dialysis with estrogen deficiency]. / Hormonalna terapia zastepcza w zapobieganiu utracie mineralu kostnego u kobiet w wieku rozrodczym z niedoborem estradiolu leczonych powtarzanymi dializami pozaustrojowymi.

In 25-30% of premenopausal dialysis women low serum estrogen concentrations are observed. This "premature menopause" can significantly contribute to accelerated bone loss. The aim of the study was to evaluate the effect of estrogen-gestagen replacement therapy on bone mineral density (BMD) in hemodialysis women with secondary to uremia estrogen deficiency. Among 20 hemodialysis women, aged 18-45 years, with serum 17 beta-estradiol < 30 pg/ml, ten (group I) received transdermal estradiol with cyclic addition of noretisterone acetate (Estracomb TTS 50/0.25), and another ten formed the control group (group II). BMD was evaluated by dual photon x-ray absorptiometry (DEXA, Lunar) in: lumbar spine (L2-L4), 1/3 distal radius and femoral neck, before and after the study. Serum 17 beta-estradiol concentrations were measured before, and after 1, 3, 6 and 12 months of the study. After one year, in group I, in which serum 17 beta-estradiol normalized already during the first month (p < 0.001), an increase of in BMD was noted, although significant only in L2-L4 (p < 0.05). In group II, no change in serum 17 beta-estradiol and mild but insignificant decrease in BMD were observed. However, a comparison of BMD values after 12 months in both groups revealed the marked differences in all studied sites (p < 0.01, p < 0.02, p < 0.05 in L4-L2, distal radius and femoral neck, respectively). The mean serum calcium, phosphate, PTH and alkaline phosphatase activity were similar in both groups and did not change during the study. In premenopausal hemodialysis women with estrogen deficiency, hormonal replacement therapy inhibits bone demineralization and can be useful in prevention of early osteoporosis.

[Hormonal replacement therapy and lipid metabolism in women on hemodialysis with secondary to uremia estrogen deficiency]. / Hormonalna terapia zastepcza a gospodarka lipidowa u kobiet dializowanych z wtórnym do mocznicy niedoborem estrogenów.

UNLABELLED: It has been reported that postmenopausal women taking hormonal replacement therapy (HRT) are at reduced risk for cardiovascular disease mainly because of favorable changes in serum LDL- and HDL-cholesterol. However, the therapy is also known to increase hepatic triglyceride production. Cardiovascular events are the leading cause of death in patients on dialysis and lipid abnormalities are common. The aim of the study was to evaluate the influence of HRT on lipid metabolism in premenopausal women undergoing hemodialysis with premature oestrogen withdrawal. 25 hemodialyzed women, aged 37 +/- 9 years (19-44 years) with serum 17 beta-estradiol < 30 pg/ml were divided into: group I (n = 13) treated with transdermal HRT (estradiol with cyclic norethisterone acetate--Estracomb TTS 50/0.25; Novartis), and control group II (n = 12). Before the treatment serum LDL-cholesterol concentrations were increased in 24% and serum triglycerides in 40% of patients, whereas HDL-cholesterol was decreased in 72% of patients. During one year, in group I a noticeable, 15% increase in serum HDL-cholesterol was observed from 0.90 +/- 0.23 to 1.04 +/- 0.19 mmol/l (34.8 +/- 8.8 to 39.8 +/- 7.4 mg/100 ml; p < 0.01). It was parallel to the increase in serum 17 beta-estradiol concentrations (from 20.5 +/- 8.91 to 50.3 +/- 17.20 pg/ml; p < 0.01). Serum LDL-cholesterol and triglycerides did not change significantly. In the control group all those values remained unchanged. CONCLUSIONS: In hemodialysis women with premature estrogen deficiency the transdermal cyclic HRT leads to the clinically important increase in serum HDL-cholesterol without significant changes in serum triglyceride concentrations and could be beneficial in reducing cardiovascular risk in this population.

[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.

[Treatment of severe uremic hyperparathyroidism using a method for percutaneous injection of the parathyroid glands with ethanol]. / Leczenie ciezkiej mocznicowej nadczynnosci przytarczyc metoda przezskórnego ostrzykiwania gruczolaków alkoholem etylowym.

The results of recent studies suggest that uremic patients with large parathyroid hyperplasia are often resistant to active vitamin D3 therapy. Percutaneous ethanol injection has become an interesting option in such cases, although there are only a few publications on that subject. In this work we would like to present our experience with this method. 20 patients with serum iPTH > 400 pg/ml and 1-4 hyperplastic parathyroids (mean volume 1.07) underwent 56 percutaneous ethanol injection sessions under ultrasonographic guidance. In 9 patients a marked (> 75%), long-term (12-24 months) decrease in serum iPTH was achieved; lesser (> 50%) reduction in parathyroid activity persisted for 36-42 months in 5 out of 9 patients observed in this period. In almost every patient a significant reduction of alphacalcidol dose was possible. Our data confirm that percutaneous ethanol injection therapy is a useful and safe adjunct in severe uremic hyperparathyroidism treatment strategy which allows to restore the responsiveness to active vitamin D3 metabolites.

[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.

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.

[Long-term treatment with large doses of alphacalicidol in secondary hyperparathyroidism of patients dialyzed for end stage renal failure]. / Dlugotrwale stosowanie duzych dawek alfakalcidolu w nadczynnosci przytarczyc u chorych dializowanych z powodu schylkowej niewydolnosci nerek.

The purpose of the study was to evaluate the effectiveness of the long-term oral pulse therapy with high doses of alphacalcidol (1 alpha (OH)D3) in severe uremic hyperparathyroidism. 43 hemodialysis patients with at least 5-fold 1-84 PTH serum elevation were given thrice a week oral (1 alpha (OH) D3) in doses up to 5 micrograms, according to serum calcium levels (monitored weekly). The drug was given in the evenings (Group A; 18 pts) or during hemodialysis sessions (Group B; 25 pts). The dialysate calcium was reduce to 1.40-1.45 mmol/l and CaCO3 was used as a main phosphate binder in doses up to 6 g/day; 13 pts received additionally small doses of Al (OH)3 (up to 3 g/day). After one month the PTH levels decreased by 67 +/- 7.7% (p < 0.001), while serum total calcium increased by 0.27 < or = 0.05 mmol/l. The parathyroid activity suppression progressed to 81 +/- 6.9% serum PTH reduction after 4 months and 74 +/- 6.1% fall after 8 months. Only 3 pts occurred to be non-responders; in 19 pts PTH levels normalized. A decrease of serum hydroxyproline and alkaline phosphatase with its bone isoenzyme activity was also observed with a direct correlation between those changes and parathyroid suppression. (1 alpha (OH) D3) dose at first month of therapy was 3.4 +/- 0.15 micrograms, but it was successively reduced because of hypercalcemia to a final dose of 2.2 +/- 0.22 micrograms. The frequency of hyperkalcemia was 7.6%; no difference between Group A and group B was noted. We conclude that oral (1 alpha (OH)D3) pulse therapy is very effective in the long-term parathyroid activity suppression in hemodialysis patients with severe hyperparathyroidism. To avoid dangerous hypercalcemia and relative hypoparathyroidism serum PTH and calcium levels should be carefully monitored.

[Combined therapy with calcitonin and high doses of active vitamin D3 metabolites in uremic hyperparathyroidism]. / Skojarzone leczenie kalcytonina i duzymi dawkami aktywnych metabolitów witaminy D3 we wtórnej do mocznicy nadczynnosci przytarczyc.

Active vitamin D3 pulse therapy effectively suppresses parathormone (PTH) synthesis in uremic hyperparathyroidism but high serum levels of calcitriol achieved can induce direct osteoclastic resorption and block bone formation. Therefore we found it interesting to examine whether an addition of the osteoclast inhibitor, calcitonin (CT), could reduce those unwanted effects. 75 hemodialysis patients with at least 5-fold 1-84 PTH serum level elevation were divided into 4 treatment groups: I (n = 19)-CT and 1 alpha-OH-D3; II (n = 20)-CT; III (n = 19)-1 alpha-OH-D3 (n = 10) or 1.25 (OH)2D3 (n = 9) alone; IV (n = 17)-none of these drugs. CT (200 IU) and 1 alpha-OH-D3/1.25(OH)2D3 (up to 5 micrograms) were given 3 times a week. Dialysate Ca was 1.40-1.45 (Group I, III) or 1.95-2.00 mmol/l (Group II, IV). Within 8 months serum 1-84 PTH fell by 75% (p < 0.001) in Group I and by 77% (p < 0.001) in Group II, serum Ca increased by 0.22 +/- 0.05 mmol/l in Group I (p < 0.005) and by 0.25 +/- 0.05 mmol/l in Group III (p < 0.005), alkaline phosphatase activity decreased by 35% in Group I (p < 0.01) and 31% in Group III (p < 0.005) whereas in Groups II and IV no significant changes were noted. In Group III no differences between patients taking 1 alpha-OH-D3 or 1.25 (OH)2D3 were observed. The significant reduction of serum hydroxyproline (37%; p < 0.001) was seen only in Group 1. The increase in bone mineral density (BMD) measured by dual-energy X-ray absorptiometry was greater in Group I than in Group III (p < 0.05). In Group II the effect was mostly insignificant, whereas in Group IV a substantial decrease (p < 0.001) in BMD was observed. These data suggest that combined therapy with CT and oral 1 alpha-OH-D3 pulses is more effective than pulses alone in inhibiting bone resorption and in increasing BMD in hemodialysis patients with uremic hyperparathyroid bone disease.

[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.

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.

[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).