Application of intermaxillary fixation screws in maxillofacial trauma.

PURPOSE: The use of intermaxillary fixation (IMF) in the treatment of maxillofacial trauma represents the cornerstone of fracture reduction and immobilization. Many modalities of IMF have been described; recently IMF screws have been introduced into clinical practice, however, hardware failure can occur. We performed a retrospective study evaluating hardware-associated complications for self-drilling/tapping IMF screws. MATERIALS AND METHODS: A retrospective study on 49 patients requiring IMF was performed. The diagnosis, duration of IMF, screw site, use of elastic or wire fixation, and associated complications were recorded. IMF screws were used to adjunct open reduction techniques, for definitive closed reduction, or fracture prevention following dentoalveolar surgery. Follow-up examinations were performed until fracture healing was complete (6 to 8 weeks). RESULTS: A single adverse event occurred in 19 patients (39%) while 4 patients (8%) had more than 1 complication. The most common event was screw loosening; 29% of patients had at least 1 screw dislodged in the treatment period. Of the total number of screws placed (229), 15 (6.5%) became loose, and were equally distributed among the mandible and maxilla. The remaining complications noted were root fracture, 4% (2 of 49); loosened wires, 6% (3 of 49); screw shear, 2% (1 of 49); malocclusion, 2% (1 of 49); and ingested hardware, 2% (1 of 49). CONCLUSIONS: Overall the IMF self-drilling/tapping screws have been shown to be a useful modality to establish maxillomandibular fixation. It is a safe, and time-sparing technique; however, it is not without limitations or potential consequences which the surgeon must be aware of in order to provide safe and effective treatment.     

Effects of the PPAR-gamma agonist rosiglitazone on renal haemodynamics and the renin-angiotensin system in diabetes.

BACKGROUND: Thiazolidinediones (TZD) have been reported to improve early stages of diabetic nephropathy independent of glycaemic control. Since blockade of the renin-angiotensin system (RAS) is known to reduce the risk of nephropathy, we hypothesised that the renal effect of TZDs might be related to a favourable effect on the intrarenal RAS. We aimed to determine if the TZD rosiglitazone could reduce RAS activation. METHODS: We studied adult type 2 diabetic patients and placed them on rosiglitazone for three months. We have previously used the renal haemodynamic response to angiotensin-converting enzyme (ACE) inhibition to demonstrate the state of RAS activation, and thus measured renal plasma flow (RPF) and glomerular filtration rate (GFR) before and after administration of captopril at 0 month and at three months. Plasma renin activity (PRA), active renin, aldosterone and natriuretic peptides were analysed. RESULTS: The RPF response to ACE inhibition was not altered. There was no change in GFR, PRA, active renin and aldosterone levels. Two patients developed oedema one had an elevated baseline active renin and another had an elevated baseline aldosterone level. CONCLUSION: The favourable effects of TZDs on diabetic nephropathy is likely not related to an influence on the RAS.     

Quality assurance, efficiency indicators and cost-utility of the evaluation workup for liver transplantation.

We report the results of a retrospective review of the outpatient pretransplantation workup for United Network for Organ Sharing (UNOS) 3 patients adopted at a liver transplantation (LT) center and illustrate the efficiency indicators used for quality evaluation and cost-analysis. A single-center, pre-LT evaluation workup was performed on an outpatient basis at a cost per patient evaluation of 2,770 Euros (). Objective measures were: the number of patients admitted to and excluded from each phase of the algorithm; the rate of patients admitted to pre-LT evaluation out of the total of referred patients (the referral efficiency rate); the rate of waitlisted patients out of those admitted to pre-LT evaluation (the evaluation efficiency rate); the rate of waitlisted patients out of those referred for LT (the process efficiency rate); and the cost per waitlisted patient, as the ratio of the cost per patient evaluation to the evaluation efficiency rate. From January 1, 1996, to October 1, 2004, 1,837 patients were referred for LT on an outpatient basis. Based on preemptive evaluation of the available clinical data, 412 patients (22.4%) were excluded from pre-LT evaluation and 1,425 (77.6%) were admitted to preliminary consultation. Among these, 603 (42.3%) were excluded from and 822 (57.7%) were admitted to pre-LT evaluation with a referral efficiency rate of 44.7% (822 of 1,837). Out of the patients evaluated for LT, 484 were waitlisted with a cost-utility and evaluation efficiency rate of 58.8% each (484 of 822). Of the 1,837 patients originally addressed for LT 484 were waitlisted, yielding a process efficiency rate of 26.3% (484 of 1,837) and a cost per waitlisted patient of 4,710.8. In conclusion, the 3 indicators allowed monitoring of the efficiency of the pre-LT evaluation algorithm. The current process efficiency rate at our center is low (26.3%), but avoiding early referrals we might increase it to 31.6%, with a 12% net saving on costs per waitlisted patient (from 4,710.8 to 4,165.4).     

Apraxia in deep cerebral lesions.

In a series of 50 patients with cerebrovascular lesions (demonstrated with CT scan), seven patients had lesions located in the basal ganglia and/or thalamus. All these seven patients were apractic. Ideomotor apraxia was present in all patients; five also had constructional apraxia, and one had bucco-facial apraxia. None of the patients had utilisation apraxia. These observations indicated that apraxia is not only a "high cerebral (cortical) function", but may depend also on the integrity of subcortical circuits and structures.     

Dietary Carbohydrate as Glycemic Load,Not Fat,Coupled with Genetic Permissiveness Favoring Rapid Growth and Extra Calories,Dictate Metabolic Syndrome and Diabetes Induction in Nile Rats (Arvicanthis niloticus)

Objective: Whether dietary carbohydrate (CHO) or fat is more involved in type 2 diabetes (T2DM) induction uncomplicated by dietary fiber was addressed in a spontaneous diabetic model, the diurnal Nile rat that mimics the human condition. Methods: A total of 138 male Nile rats were fed plant-based and animal-based saturated fat where 10% energy as CHO and fat were exchanged across 5 diets keeping protein constant, from 70:10:20 to 20:60:20 as CHO:fat:protein %energy. Diabetes induction was analyzed by: 1. diet composition, i.e., CHO:fat ratio, to study the impact of diet; 2. quintiles of average caloric intake per day to study the impact of calories; 3. quintiles of diabetes severity to study the epigenetic impact on diabetes resistance. Results: High glycemic load (GLoad) was most problematic if coupled with high caloric consumption. Diabetes severity highlighted rapid growth and caloric intake as likely epigenetic factors distorting glucose metabolism. The largest weanling rats ate more, grew faster, and developed more diabetes when the dietary GLoad exceeded their gene-based metabolic capacity for glucose disposal. Diabetes risk increased for susceptible rats when energy intake exceeded 26 kcal/day and the GLoad was >175/2000 kcal of diet and when the diet provided >57% energy as CHO. Most resistant rats ate <25 kcal/day independent of the CHO:fat diet ratio or the GLoad adjusted to body size. Conclusion: Beyond the CHO:fat ratio and GLoad, neither the type of fat nor the dietary polyunsaturated/saturated fatty acid (P/S) ratio had a significant impact, suggesting genetic permissiveness affecting caloric and glucose intake and glucose disposition were key to modulating Nile rat diabetes. Fat became protective by limiting GLoad when it contributed >40% energy and displaced CHO to <50% energy, thereby decreasing the number of diabetic rats and diabetes severity.     

Static magnetic fields modulate X-ray-induced DNA damage in human glioblastoma primary cells

Although static magnetic fields (SMFs) are used extensively in the occupational and medical fields, few comprehensive studies have investigated their possible genotoxic effect and the findings are controversial. With the advent of magnetic resonance imaging-guided radiation therapy, the potential effects of SMFs on ionizing radiation (IR) have become increasingly important. In this study we focused on the genotoxic effect of 80 mT SMFs, both alone and in combination with (i.e. preceding or following) X-ray (XR) irradiation, on primary glioblastoma cells in culture. The cells were exposed to: (i) SMFs alone; (ii) XRs alone; (iii) XR, with SMFs applied during recovery; (iv) SMFs both before and after XR irradiation. XR-induced DNA damage was analyzed by Single Cell Gel Electrophoresis assay (comet assay) using statistical tools designed to assess the tail DNA (TD) and tail length (TL) as indicators of DNA fragmentation. Mitochondrial membrane potential, known to be affected by IR, was assessed using the JC-1 mitochondrial probe. Our results showed that exposure of cells to 5 Gy of XR irradiation alone led to extensive DNA damage, which was significantly reduced by post-irradiation exposure to SMFs. The XR-induced loss of mitochondrial membrane potential was to a large extent averted by exposure to SMFs. These data suggest that SMFs modulate DNA damage and/or damage repair, possibly through a mechanism that affects mitochondria.     

Home collection for frequent HIV testing: acceptability of oral fluids, dried blood spots and telephone results. HIV Early Detection Study Group

OBJECTIVE: To assess the feasibility and acceptability of bimonthly home oral fluid (OF) and dried blood spot (DBS) collection for HIV testing among high-risk individuals. DESIGN: A total of 241 participants [including men who have sex with men (MSM), injecting drug users (IDU), and women at heterosexual risk] were recruited from a randomly selected subset of study participants enrolled at four sites in the HIV Network for Prevention Trials (HIVNET) cohort, and assigned at random to bimonthly home collection of OF or DBS specimens over a 6 month interval. Participants could select telephone calls or clinic visits to receive HIV test results. METHODS: Bimonthly specimens were tracked for adherence to the schedule, were evaluated for adequacy for testing, and tested using antibody assays and polymerase chain reaction (PCR) for DBS. The acceptability of bimonthly home OF and DBS collection and telephone counseling was assessed in an end-of-study questionnaire. RESULTS: The laboratory received 96 and 90% of expected OF and DBS specimens, respectively; 99% of each specimen type was adequate for testing. Almost all (95%) participants chose results disclosure by telephone. The majority of participants (85%) reported that bimonthly testing did not make them worry more about HIV, and almost all (98%) judged that with bimonthly testing their risk behavior remained the same (77%) or became less risky (21%). CONCLUSION: Bimonthly home specimen collection of both OF and DBS with telephone counseling is acceptable and feasible among study participants at high risk. These methods will be useful for the early detection of HIV infection and remote follow-up of research cohort participants in HIV vaccine and prevention trials.     

Selective release of glutamate from cerebellar granule cells differentiating in culture

The aim of the present study was to assess whether endogenous and newly synthesized glutamate can be released from differentiating cultured cerebellar granule cells in a way compatible with a neurotransmitter role. Granule cells from 8-day-old rat cerebella were grown in basal Eagle's medium with 10% fetal calf serum for 2-12 days in vitro (DIV), then washed with Krebs-Ringer medium, and labeled for 45 min with tracer amounts of radioactive glutamine. Subsequently, the release of endogenous glutamate and of newly formed radioactive glutamate was measured in basal conditions and upon depolarization with elevated K⁺ concentration or veratridine. At 2 DIV, the release of endogenous and newly synthesized glutamate evoked by high K⁺ concentration was small and Ca²⁺ independent, but it progressively and steadily increased (up to 8- to 10-fold) and became Ca²⁺ dependent (up to 80-85%) at later stages (4, 8, and 12 DIV). Veratridine was almost ineffective with cells at 2 DIV but greatly increased glutamate release (endogenous and neosynthesized) at 8 DIV, and its action was totally antagonized by tetrodotoxin. The level and synthesis of glutamate remained fairly constant in cells from 2 to 12 DIV. γ-Aminobutyric acid synthesis from radioactive glutamine was about 3% of that of glutamate, and γ-aminobutyric acid release (endogenous and neosynthesized) was not measurable. Aspartate synthesis was about 10% of that of glutamate, and the high K⁺ concentration-evoked release of this amino acid was modest and scarcely affected by Ca²⁺. Neither high K⁺ concentration nor veratridine was able to induce glutamate release from confluent cerebellar astrocyte cultures at 14 DIV, although the level and synthesis of the amino acid were comparable to those in granule cells. In conclusion, the data show that a stimulus-coupled release of endogenous and neosynthesized glutamate is progressively expressed by cerebellar granule cells differentiating in culture, and this strongly supports the concept that glutamate is the neurotransmitter of these cells.