Temperature and time variations during osteotomies performed with different piezosurgical devices: an in vitro study

AIM

The aim of this experimental in vitro study was to evaluate the effects of the piezoelectric device in temperature and time variations in standardized osteotomies performed with similar tip inserts in bovine bone blocks.

METHODS

Two different piezosurgical devices were used the OE-F15(®) (Osada Inc., Los Angeles, California, USA) and the Surgybone(®) (Silfradent Inc., Sofia, Forli Cesena, Italy). Serrated inserts with similar geometry were coupled with each device (ST94 insert/test A and P0700 insert/test B). Osteotomies 10 mm long and 3 mm deep were performed in bone blocks resembling type II (dense) and type IV (soft) bone densities with and without irrigation. Thermal changes and time variations were recorded. The effects of bone density, irrigation, and device on temperature changes and time necessary to accomplish the osteotomies were analyzed.

RESULTS

Thermal analysis showed significant higher temperatures during piezosurgery osteotomies in hard bone without irrigation (P < 0.05). The type of piezosurgical device did not influence thermal variations (P > 0.05). Time analysis showed that the mean time values necessary to perform osteotomies were shorter in soft bone than in dense bone (P < 0.05).

CONCLUSIONS

Within the limitations of this in vitro study, it may be concluded that the temperature increases more in piezosurgery osteotomies in dense bone without irrigation; the time to perform the osteotomy with piezosurgery is shorter in soft bone compared to hard bone; and the piezosurgical device have a minimal influence in the temperature and time variations when a similar tip design is used during piezosurgery osteotomies.

Human visceral leishmaniasis is not associated with expansion or accumulation of Foxp3+ CD4 cells in blood or spleen

Natural regulatory T cells (CD4(+) CD25(+) Foxp3(+)), natural regulatory T cells (nTreg), play an important role in the regulation of inflammatory immune responses. However, the immunosuppressive properties of nTreg may unfavourably affect the host's ability to clear certain infections. In human visceral leishmaniasis (VL), reports on the frequency and function of nTreg are not conclusive. A limitation of our own previous studies that did not indicate a major role for Foxp3(+) nTreg in VL pathogenesis was that Foxp3 was measured by mRNA expression alone, as other tools were not available at the time. We have in this study assessed CD4(+)CD25(+)Foxp3(+) cells in splenic aspirates and peripheral blood mononuclear cells (PBMC) from an extensive series of patients with VL and endemic controls (EC) by flow cytometry (FACS). The results do not show increased frequencies of Foxp3(+) cells in patient with VL pre- and post-treatment, neither were they elevated when compared to PBMC of EC. We conclude that active VL is not associated with increased frequencies of peripheral Foxp3 Treg or accumulation at the site of infection.

Reporting standards for endovascular repair of saccular intracranial cerebral aneurysms

BACKGROUND AND PURPOSE

The goal of this article is to provide consensus recommendations for reporting standards, terminology, and written definitions when reporting on the radiological evaluation and endovascular treatment of intracranial, cerebral aneurysms. These criteria can be used to design clinical trials, to provide uniformity of definitions for appropriate selection and stratification of patients, and to allow analysis and meta-analysis of reported data.

METHODS

This article was written under the auspices of the Joint Writing Group of the Technology Assessment Committee, Society of NeuroInterventional Surgery, Society of Interventional Radiology; Joint Section on Cerebrovascular Neurosurgery of the American Association of Neurological Surgeons and Congress of Neurological Surgeons; and Section of Stroke and Interventional Neurology of the American Academy of Neurology. A computerized search of the National Library of Medicine database of literature (PubMed) from January 1991 to December 2007 was conducted with the goal to identify published endovascular cerebrovascular interventional data about the assessment and endovascular treatment of cerebral aneurysms useful as benchmarks for quality assessment. We sought to identify those risk adjustment variables that affect the likelihood of success and complications. This article offers the rationale for different clinical and technical considerations that may be important during the design of clinical trials for endovascular treatment of cerebral aneurysms. Included in this guidance article are suggestions for uniform reporting standards for such trials. These definitions and standards are primarily intended for research purposes; however, they should also be helpful in clinical practice and applicable to all publications.

CONCLUSIONS

The evaluation and treatment of brain aneurysms often involve multiple medical specialties. Recent reviews by the American Heart Association have surveyed the medical literature to develop guidelines for the clinical management of ruptured and unruptured cerebral aneurysms. Despite efforts to synthesize existing knowledge on cerebral aneurysm evaluation and treatment, significant inconsistencies remain in nomenclature and definition for research and reporting purposes. These operational definitions were selected by consensus of a multidisciplinary writing group to provide consistency for reporting on imaging in clinical trials and observational studies involving cerebral aneurysms. These definitions should help different groups to publish results that are directly comparable.

Alum-precipitated autoclaved Leishmania major plus bacille Calmette-Guérrin, a candidate vaccine for visceral leishmaniasis: safety, skin-delayed type hypersensitivity response and dose finding in healthy volunteers

In a previous efficacy study, autoclaved Leishmania major (ALM) + bacille Calmette-Guérrin (BCG) vaccine was shown to be safe, but not superior to BCG alone, in protecting against visceral leishmaniasis. From June 1999 to June 2000, we studied the safety and immunogenicity of different doses of alum-precipitated ALM + BCG vaccine mixture administered intradermally to evaluate whether the addition of alum improved the immunogenicity of ALM. Twenty-four healthy adult volunteers were recruited and sequentially allocated to receive either 10 microg, 100 microg, 200 microg, or 400 microg of leishmanial protein in the alum-precipitated ALM + BCG vaccine mixture. Side effects were minimal for all doses and confined to the site of injection. All volunteers in the 10 microg, 100 microg, and 400 microg groups had a leishmanin skin test (LST) reaction of > or = 5 mm by day 42 and this response was maintained when tested after 90 d. Only 1 volunteer out of 5 in the 200 microg group had a LST reaction of > or = 5 mm by day 42 and the reasons for the different LST responses in this group are unclear. This is the first time that an alum adjuvant with ALM has been in used in humans and the vaccine mixture was safe and induced a strong delayed type hypersensitivity (DTH) reaction in the study volunteers. On the basis of this study we suggest that 100 1 microg of leishmanial protein in the vaccine mixture is a suitable dose for future efficacy studies, as it induced the strongest DTH reaction following vaccination.

Molecular aspects of parasite-vector and vector-host interactions in leishmaniasis

Leishmania-sand fly interactions are reviewed in the context of the potential barriers to the complete development of the parasite that exist within the midgut environment of phlebotomine flies and the molecular adaptations that the parasite has evolved that permit the development of transmissible infections to proceed. Cell surface and secreted phosphoglycans protect the parasite from the proteolytic activities of the blood-fed midgut, mediate attachment to the gut wall in order to maintain infection during excretion of the bloodmeal, and contribute to the formation of a biological plug in the anterior gut that may promote transmission by bite. The importance of vector saliva in modulating the host response to transmitted parasites is also reviewed.

Care of the adolescent sexual assault victim

Sexual assault is a broad-based term that encompasses a wide range of sexual victimizations, including rape. Since the American Academy of Pediatrics published its last policy statement on this topic in 1994, additional information and data have emerged about sexual assault and rape in adolescents, the adolescent's perception of sexual assault, and the treatment and management of the adolescent who has been a victim of sexual assault. This new information mandates an updated knowledge base for pediatricians who care for adolescent patients. This statement provides that update, focusing on sexual assault and rape in the adolescent population.

Condom use by adolescents

The use of condoms as part of the prevention of unintended pregnancies and sexually transmitted diseases (STDs) in adolescents is evaluated in this policy statement. Sexual activity and pregnancies decreased slightly among adolescents in the 1990s, reversing trends that were present in the 1970s and 1980s, while condom use among adolescents increased significantly. These trends likely reflect initial success of primary and secondary prevention messages aimed at adolescents. Rates of acquisition of STDs and human immunodeficiency virus (HIV) among adolescents remain unacceptably high, highlighting the need for continued prevention efforts and reflecting the fact that improved condom use can decrease, but never eliminate, the risk of acquisition of STDs and HIV as well as unintended pregnancies. While many condom education and availability programs have been shown to have modest effects on condom use, there is no evidence that these programs contribute to increased sexual activity among adolescents. These trends highlight the progress that has been made and the large amount that still needs to be accomplished.

The potency and durability of DNA- and protein-based vaccines against Leishmania major evaluated using low-dose, intradermal challenge

DNA- and protein- based vaccines against cutaneous leishmaniasis due to Leishmania major were evaluated using a challenge model that more closely reproduces the pathology and immunity associated with sand fly-transmitted infection. C57BL/6 mice were vaccinated s.c. with a mixture of plasmid DNAs encoding the Leishmania Ags LACK, LmSTI1, and TSA (AgDNA), or with autoclaved L. major promastigotes (ALM) plus rIL-12, and the mice were challenged by inoculation of 100 metacyclic promastigotes in the ear dermis. When challenged at 2 wk postvaccination, mice receiving AgDNA or ALM/rIL-12 were completely protected against the development of dermal lesions, and both groups had a 100-fold reduction in peak dermal parasite loads compared with controls. When challenged at 12 wk, mice vaccinated with ALM/rIL-12 maintained partial protection against dermal lesions and their parasite loads were no longer significantly reduced, whereas the mice vaccinated with AgDNA remained completely protected and had a 1000-fold reduction in dermal parasite loads. Mice vaccinated with AgDNA also harbored few, if any, parasites in the skin during the chronic phase, and their ability to transmit L. major to vector sand flies was completely abrogated. The durable protection in mice vaccinated with AgDNA was associated with the recruitment of both CD8(+) and CD4(+) T cells to the site of intradermal challenge and with IFN-gamma production by CD8(+) T cells in lymph nodes draining the challenge site. These data suggest that under conditions of natural challenge, DNA vaccination has the capacity to confer complete protection against cutaneous leishmaniasis and to prevent the establishment of infection reservoirs.

CPT coding by interventional radiologists: accuracy and implications

PURPOSE

To evaluate the accuracy of Current Procedural Terminology (CPT) coding for interventional radiology services when coding is performed by the operating physician.

MATERIALS AND METHODS

Coding data for 1,174 interventional radiology encounters in 736 patients were analyzed for appropriate use of CPT codes. Physician operators initially assigned provisional codes. Formal coding for billing purposes was performed at a later date by one of two experienced interventional radiology physician coders. Initial operator coding errors and associated relative value unit (RVU) impact were analyzed. The coding patterns of experienced physician coders were compared with those of the other interventionalists.

RESULTS

Only 82% of encounters were initially coded correctly, with a small net tendency toward undercoding. The overall net RVU impact of errors was only -1.2%, with the effects of undercoding outweighing those of overcoding. More complex cases (> or =4 CPT codes) were much more likely to be coded erroneously than less complex cases (24% vs 14%, P <.001). Experienced physician coders committed significantly fewer errors than other physicians (10% vs 25%, P <.001), but there was a similar minimal net RVU impact of errors (-1.1% vs -1.4%, P =.198).

CONCLUSION

Although initial physician coding errors for interventional radiology procedures are common, the net RVU impact is minimal. The accuracy of experienced physician coders is significantly higher than that for other interventionalists. Because of the regulatory consequences of coding inaccuracies, practices should establish quality improvement systems to minimize errors and use the skills of experienced individuals in their coding processes.

Protection against cutaneous leishmaniasis resulting from bites of uninfected sand flies

Despite the fact that Leishmania are transmitted exclusively by sand flies, none of the experimental models of leishmaniasis have established infection via sand fly bites. Here we describe a reproducible murine model of Leishmania major infection transmitted by Phlebotomus papatasi. Prior exposure of mice to bites of uninfected sand flies conferred powerful protection against Leishmania major that was associated with a strong delayed-type hypersensitivity response and with interferon-gamma production at the site of parasite delivery. These results have important implications for the epidemiology of cutaneous leishmaniasis and suggest a vaccination strategy against this and possibly other vector-borne diseases.

Evolution of lesion formation, parasitic load, immune response, and reservoir potential in C57BL/6 mice following high- and low-dose challenge with Leishmania major

A model of cutaneous leishmaniasis using 10(2) Leishmania major metacyclic promastigotes inoculated into the footpads of genetically resistant C57BL/6 mice was studied in order to more accurately reproduce the evolution of lesion formation and the kinetics of parasite growth and immune response as they might occur in naturally exposed reservoirs and in human hosts. In contrast to the more conventional experimental model employing 10(6) metacyclic promastigotes, in which the rapid development of footpad lesions was associated with an increasing number of amastigotes in the site, the low-dose model revealed a remarkably "silent" phase of parasite growth, lasting approximately 6 weeks, during which peak parasitic loads were established in the absence of any overt pathology. Footpad swelling was observed after 6 weeks, coincident with the onset of parasite clearance and with production of high levels of interleukin-12 (IL-12) and gamma interferon (IFN-gamma) in draining lymph nodes. Low-dose challenge of IL-12- and IFN-gamma-depleted or -deficient mice provided strong evidence that the induction or expression of cellular immunity is essentially absent during the first 6 to 8 weeks of intracellular growth, since the concentration of amastigotes in the site was not enhanced compared to that for wild-type animals during this time. By monitoring the ability of infected mice to transmit parasites to vector sand flies, it was observed that following low-dose challenge, footpads without apparent lesions provided an efficient source of parasites for exposed flies and that the low-dose challenge actually extended the duration of parasite transmissibility during the course of infection.

A natural model of Leishmania major infection reveals a prolonged "silent" phase of parasite amplification in the skin before the onset of lesion formation and immunity

A model of Leishmania major infection in C57BL/6 mice has been established that combines two main features of natural transmission: low dose (100 metacyclic promastigotes) and inoculation into a dermal site (the ear dermis). The evolution of the dermal lesion could be dissociated into two distinct phases. The initial "silent" phase, lasting 4-5 wk, favored establishment of the peak load of parasites in the dermis in the absence of lesion formation or any overt histopathologic changes in the site. The second phase corresponds to the development of a lesion associated with an acute infiltration of neutrophils, macrophages, and eosinophils into the dermis and was coincident with the killing of parasites in the site. The onset of immunity/pathology was correlated with the appearance of cells staining for IL-12p40 and IFN-gamma in the epidermal compartment, and an expansion of T cells capable of producing IFN-gamma in the draining lymph node. Parasite growth was not enhanced over the first 4.5 wk in anti-CD4-treated mice, SCID mice, or C57BL/6 mice deficient in IL-12p40, IFN-gamma, CD40 ligand, or inducible NO synthase. These mice all failed to ultimately control infection in the site, but in some cases (anti-CD4 treated, IL-12p40-/-, CD40 ligand-/-, and SCID) high dermal parasite loads were associated with little or no pathology. These results extend to a natural infection model a role for Th1 cells in both acquired resistance and lesion formation, and document the remarkable avoidance of this response during a prolonged phase of parasite amplification in the skin.

Evidence that the high incidence of treatment failures in Indian kala-azar is due to the emergence of antimony-resistant strains of Leishmania donovani

The possibility that the high frequency of treatment failures in Indian kala-azar might be due to infection with antimony-resistant strains of Leishmania donovani has not been experimentally addressed. L. donovani isolates were obtained from splenic aspiration smears of 24 patients in Bihar, India, who either did not respond (15) or did respond (9) to 1 or more full courses of treatment with sodium antimony gluconate (SAG). A strong correlation (P<.001) between clinical response and SAG sensitivity in vitro was observed only when strains were assayed as intracellular amastigotes: responsive isolates ED50=2.4+/-2.6, ED90=6.4+/-7.8 microgram SAG/mL; unresponsive isolates ED50=7.4+/-3.7 microgram SAG/mL, ED90=29.1+/-11.1 SAG/mL. No correlation with clinical response was found by use of extracellular promastigotes (ED50=48+/-22 vs. 52+/-29 microgram/mL). The emergence of antimony-resistant L. donovani strains appears to be a cause of treatment failures in India.

Dialysis graft declotting with very low dose urokinase: is it feasible to use "less and wait?"

PURPOSE

"Lyse and wait" dialysis graft declotting is simple and effective, but the minimum necessary dose of urokinase is unknown. The efficacy of the technique with very low dose urokinase is evaluated.

MATERIALS AND METHODS

Twenty-one grafts in 17 patients were declotted with use of the lyse and wait technique, but with 5,000-15,000 U of urokinase initially. Graft angiography was performed when an interventional suite was available. Declotting was completed in the manner chosen by the individual operator. Angiograms, interventional radiology records, and dialysis records were reviewed.

RESULTS

Technical and clinical success were achieved in 95% of cases. Mean initial urokinase dose was 6,667 U. Initial angiography was performed at a mean 86 minutes. Two cases required second 5,000-U boluses to achieve complete graft thrombolysis. In all other cases, complete or near complete graft thrombolysis was observed with the initial very low dose. No bleeding, arterial embolic, or pulmonary embolic complications were observed.

CONCLUSIONS

Doses of urokinase as low as 5,000 U are effective for lyse and wait declotting. A substantial reduction in drug costs can be expected with the "less and wait" modification. Bleeding risk may also be reduced.

Leishmania tropica: the identification and purification of metacyclic promastigotes and use in establishing mouse and hamster models of cutaneous and visceral disease

Few experimental studies on Leishmania tropica have been undertaken despite the importance of this parasite as the cause of cutaneous leishmaniasis, and now visceral disease, in the Old World. In part, this is due to the absence of convenient animals models, especially mice, for L. tropica infections. An anti-lipophosphoglycan (LPG) monoclonal antibody XCIV 1H2-A8 (T11), specific for L. tropica, was found to distinguish between culture-derived procyclic and metacyclic promastigotes. The antibody was used to negatively select for nonagglutinated metacyclic forms in stationary cultures, and the exceptional virulence of the purified metacyclics was verified by their infectivity for mouse macrophages in vitro and by their ability to produce cutaneous lesions in footpads of BALB/c mice. The lesions produced by three cutaneous isolates of L. tropica were nonulcerative and nonprogressive. Nonetheless, the lesions failed to heal, and high numbers of parasites could be recovered from footpads and draining lymph nodes up to 9 months after infection. Infections using L. tropica metacyclics purified from cutaneous, visceral and viscerotropic (Desert Storm) isolates of L. tropica were compared in both mouse and hamster models. Differences in disease progression were found that may reflect the parasite tissue tropism and virulence displayed by these strains in their human hosts. These findings suggest a role for parasite-related determinants in the clinical spectrum of disease.

Common menstrual concerns of adolescents

Symptoms associated with menstruation are among the most common concerns of adolescent women. However, the factual information that adolescent women need is not always available to them. Physicians can do much to correct the myths and misinformation that the teenager may have concerning her menstrual cycle. This paper addresses clinical office concerns about normal menstruation, dysmenorrhea, amenorrhea and dysfunctional uterine bleeding.

Reciprocal regulation of endothelial nitric-oxide synthase by Ca2+-calmodulin and caveolin

The endothelial nitric-oxide synthase (eNOS) is a key determinant of vascular homeostasis. Like all known nitric-oxide synthases, eNOS enzyme activity is dependent on Ca2+-calmodulin. eNOS is dynamically targeted to specialized cell surface signal-transducing domains termed plasmalemmal caveolae and interacts with caveolin, an integral membrane protein that comprises a key structural component of caveolae. We have previously reported that the association between eNOS and caveolin is quantitative and tissue-specific (Feron, O., Belhassen, L., Kobzick, L., Smith, T. W., Kelly, R. A., and Michel, T. (1996) J. Biol. Chem. 271, 22810-22814). We now report that in endothelial cells the interaction between eNOS and caveolin is importantly regulated by Ca2+-calmodulin. Addition of calmodulin disrupts the heteromeric complex formed between eNOS and caveolin in a Ca2+-dependent fashion. In addition, overexpression of caveolin markedly attenuates eNOS enzyme activity, but this inhibition is reversed by purified calmodulin. Caveolin overexpression does not affect the activity of the other NOS isoforms, suggesting eNOS-specific inhibition of NO synthase by caveolin. We propose a model of reciprocal regulation of eNOS in endothelial cells wherein the inhibitory eNOS-caveolin complex is disrupted by binding of Ca2+-calmodulin to eNOS, leading to enzyme activation. These findings may have broad implications for the regulation of Ca2+-dependent signal transduction in plasmalemmal caveolae.

Serum cardiac troponin T levels during treatment of early-stage breast cancer

PURPOSE

To measure serum troponin T concentrations in patients with early-stage left breast cancer during breast-conserving radiation therapy. Troponin T has been introduced recently as a sensitive and specific marker for acute myocardial injury.

PATIENTS AND METHODS

We compared pretreatment and posttreatment serum troponin T values in 50 patients undergoing radiation therapy to the entire left breast following conservative surgery for stage I and II breast cancer.

RESULTS

No changes in troponin T concentrations were found after 45 to 46 Gy whole-breast irradiation. All women had undetectable or normal troponin T on the first and last day of treatment. There was no evidence of an upward trend during treatment.

CONCLUSION

Radiation therapy to the left breast does not affect serum cardiac troponin T levels, despite the fact that a portion of the myocardium lies within the high-dose region. This suggests that the acute effects of radiation on the myocardium are minor. Long-term evaluation of these patients is necessary to rule out the possibility of late cardiac morbidity due to accelerated atherosclerosis. This study also suggests that an elevated troponin T level during or shortly after left breast irradiation should not be attributed to treatment.

Effect of obesity on insulin resistance in normal subjects and patients with NIDDM

Insulin resistance (IR) is a characteristic feature of non-insulin-dependent diabetes mellitus (NIDDM) as well as obesity, and a majority of NIDDM patients are obese. To assess the effect of obesity independent of NIDDM on IR, we studied the relationship between IR and obesity in 65 normal and 58 NIDDM subjects; we used body mass index (BMI) as a measure of obesity and glucose infusion rate (GINF) during a euglycemic hyperinsulinemic (120 mU.m-2.min-1) glucose clamp as a measure of IR. In lean normal subjects, GINF was 57.7 +/- 2.2 mumol.kg-1.min-1 (10.4 +/- 0.4 mg.kg-1.min-1) and the lean NIDDM subjects were markedly insulin-resistant, with a GINF of 34.4 +/- 2.8 mumol.kg-1.min-1 (6.2 +/- 0.5 mg.kg-1.min-1). Obese normal subjects were also insulin-resistant compared with lean normal subjects, with a GINF of 36.1 +/- 2.2 mumol.kg-1.min-1 (6.5 +/- 0.4 mg.kg-1.min-1), and obesity caused an increase in IR in NIDDM, with a GINF of 21.1 +/- 1.4 mumol.kg-1.min-1 (3.8 +/- 0.25 mg.kg-1.min-1) in the obese NIDDM subjects. Therefore, approximately 61% of the IR in obese NIDDM subjects is due to NIDDM, with 39% due to obesity, demonstrating a greater impact of NIDDM than of obesity in causing IR. The correlation between GINF and BMI was much better in normal subjects (r = -0.75) than in NIDDM subjects (r = -0.50) as was the relationship between fasting insulin level and BMI (r = -0.59 in normal subjects, r = -0.48 in NIDDM subjects). As expected, the fasting insulin level was also strongly correlated to GINF in normal subjects (r = -0.61); however, this relationship was weaker in NIDDM subjects ( r = -0.46). In conclusion, 1) obesity has a major impact to cause insulin resistance in nondiabetic subjects, but the effect of obesity on IR in NIDDM is less; 2) NIDDM per se is the major contributor to IR in NIDDM; and 3) the fasting insulin level is a better surrogate marker of IR in nondiabetic subjects than in NIDDM patients.

Worsening right flank pain over a 24-hr period

AML is a benign renal tumor composed of variable quantities of mature vascular, smooth muscle and fatty elements. They occur as an isolated finding, classically in middle-aged females, or in association with tuberous sclerosis. When symptomatic, they typically present with flank pain secondary to hemorrhage. CT is the diagnostic imaging modality of choice. The diagnosis can usually be made based on the recognition of fat within the lesion. When discovered, asymptomatic lesions are generally monitored by follow-up imaging studies, and if they remain stable, no intervention is required. Arterial embolization has become the recommended treatment of choice in some instances, particularly in cases with associated hemorrhage.