Fabrication of a fixed partial denture in the Class II partial edentulous mandible using the UCLA abutment: a clinical report

Several methods are currently available to restore the partially edentulous patient with osseointegrated implants. The UCLA abutment eliminates the unesthetic, traditional transmucosal abutment and can provide esthetic crowns, fixed prostheses, and subgingival porcelain margins without the need for excessive instrumentation and components. A clinical report for the fabrication of a direct, implant-borne fixed prosthesis using the UCLA abutment is presented.     

Involvement of dental occlusion and trigeminal neuralgia: a clinical report

Over a 12-month period 501 children (age range 11 months to 15 years) underwent surgery for a possible middle ear effusion. All had tympanometry performed within 2 h of surgery. The results of tympanometry were correlated with the surgical findings in 955 ears. A type-B tympanogram has a high sensitivity (0.91) in predicting middle ear effusion with good specificity (0.79). A type-A tympanogram has a very high specificity (0.99) in predicting a dry middle ear but low sensitivity (0.34). Both the positive (0.91) and negative (0.84) predictive values of a type-A tympanogram are high. The addition of a type-C tympanogram increases the sensitivity of predicting a dry middle ear to 0.79. The positive predictive value of a peaked (type-A or -C) tympanogram is 0.71 and should be considered strong evidence that the middle ear is dry. Tympanometry is the best clinical test for the presence or absence of a middle ear effusion, and on the basis of preoperative tympanometry alone the need for surgery should be carefully reassessed.     

A procedure for relining a complete or removable partial denture without the use of wax

Various procedures are used to reline removable dentures. Some of these involve the use of wax to seal the denture to the cast for flasking and processing. This necessitates the use of high temperatures for an extended period and involves the risk of warpage of the denture. It is also relatively time-consuming. This article describes a procedure that uses polyvinyl siloxane instead of wax. The procedure is more time efficient and decreases the risk of warpage of the denture.     

Minimum alveolar anesthetic concentrations for airway occlusion in cats: a new concept of minimum alveolar anesthetic concentration-airway occlusion response

The role of ergosterol in yeast stress tolerance, together with heat shock proteins (hsps) and trehalose, was examined in a sterol auxotrophic mutant of Saccharomyces cerevisiae. Ergosterol levels paralleled viability data, with cells containing higher levels of the sterol exhibiting greater tolerances to heat and ethanol. Although the mutant synthesised hsps and accumulated trehalose upon heat shock to the same levels as the wild-type cells, these parameters did not relate to stress tolerance. These results indicate that the role of ergosterol in stress tolerance is independent of hsps or trehalose.     

The LineFinder: a new method for finding the bone center line and femoral head center point

A plastic template-type device with a central slot is described. This device allows rapid identification of the center line of long bones and the center point of femoral heads.     

Aneuploidy: a report of an ECETOC task force

Aneuploidy plays a significant role in adverse human health conditions including birth defects, pregnancy wastage and cancer. Although there is clear evidence of chemically induced aneuploidy in experimental systems, to date there are insufficient data to determine with certainty if chemically induced aneuploidy contributes to human disease. However, since there is no reason to assume that chemically induced aneuploidy will not occur in human beings, it is prudent to address the aneugenic potential of chemicals in the safety assessment process. A wide range of methods has been described for the detection of chemically induced aneuploidy including subcellular systems, tests with fungi, plants and Drosophila as well as in vitro mammalian systems and in vivo mammalian somatic and germ cell assays. However, none of these methods is sufficiently validated or widely used in routine screening. Underlying the efforts to develop aneuploidy-specific assays is the presumption that current genetic toxicology tests do not detected chemicals that have aneuploidy-inducing potential. To address this, we have critically evaluated data from standard genetic toxicology assays for 16 known or suspected aneugens. The conclusions from the review are listed below. 1. At present there are only nine chemicals that can be classified as definitive aneugens, as determined by positive results in in vivo rodent assays. 2. As expected, the majority of definitive and suspected aneugens are negative in the bacterial mutation assay. 3. The majority of definitive aneugens evaluated induce polyploidy in vitro. With few exception, they also induced structural chromosome aberrations in vitro. 4. All of the definitive aneugens that have been sufficiently tested induce micronuclei in rodent bone marrow cells in vivo. A number of these chemicals also induced structural chromosome aberrations in vivo. 5. There is no evidence for a unique germ cell aneugen, that is a chemical that induces aneuploidy in germ cells and not in somatic cells. Furthermore, an analysis of several databases indicates the proportion of chemicals which induce polyploidy and not chromosome aberrations in vitro is low. Based on these conclusions, the following recommendations are made: for screening purposes, a standard genotoxicity test battery (including an in vitro cytogenetic assay with an assessment of polyploidy and clastogenicity at the same harvest time) should be performed; in the absence of polyploidy induction in vitro no further evaluation of aneuploidy-inducing potential is needed; if polyploidy is observed, in vitro follow-up testing to investigate further the aneuploidy-inducing potential should be conducted; such follow-up testing will generally start with the conduct of a standard in vivo somatic cell micronucleus assay; if the in vivo somatic cell micronucleus assay is negative, with adequate evidence of exposure of the bone marrow to the test compound, no further testing of aneuploidy-inducing potential is needed; if the in vivo somatic cell micronucleus assay is positive, further information on mechanisms of micronucleus induction can be obtained by using kinetochore/centromeric staining in vitro and/or in vivo; an assessment of potential germ cell aneuploidy activity may then be considered; aneuploidy induction which does not involve the direct interaction of a chemical or its metabolite(s) with DNA is expected to have a threshold. This must be considered in the risk assessment of such chemicals; this is not addressed by current risk assessment guidelines.     

Endovascular coil occlusion of a traumatic basilar-cavernous fistula: technical report

OBJECTIVE AND IMPORTANCE: We describe an unusual case of an 8-year-old male patient presenting with a traumatic basilar artery aneurysm associated with a basilar-cavernous fistula. CLINICAL PRESENTATION: The fistula occurred as the result of an accident involving a vehicle and a pedestrian. The patient originally presented in a coma and with a dense left hemiparesis. INTERVENTION: The traumatic basilar aneurysm and basilar-cavernous fistula were successfully occluded by endovascular coil embolization in two sessions. By 6 months after injury, the patient had made an excellent neurological recovery, requiring only a left leg brace for walking. CONCLUSION: Endovascular coil embolization provided an effective treatment option in the case of this complex and unusual arteriovenous fistula. We discuss the radiological and clinical features of related traumatic neurovascular lesions.     

Cytogenetic effects of cryopreservation on human sperm: assessment using an improved method for analyzing human sperm chromosomes

OBJECTIVE: To evaluate any cytogenetic effects of cryopreservation on human sperm by comparing the frequencies of sperm chromosome anomalies and sex ratios before and after freezing. METHODS: Using in vitro fertilization of zona-free hamster oocytes, analysis of sperm chromosomes was first performed on portions of fresh human semen samples. The residual semen was then analyzed for sperm chromosomes after cryopreservation for several weeks. Sperm donors were 5 healthy men aged 26-38 years. RESULTS: A total of 166 sperm karyotypes were analyzed, 94 before freezing and 72 after freezing. The results indicated no significant differences between fresh and frozen sperm in either frequencies of aneuploidy (fresh: 0%, frozen: 2.8%) or structural anomalies (fresh: 7.5%, frozen: 9.7%). The sex ratios did not differ from the expected 1:1 ratio under either condition. CONCLUSIONS: The results of these studies indicate that cryopreservation does not exert any cytogenetic mutagenicity on human spermatozoa or alter X/Y ratio of human sperm.     

Extending the concept of the autograft for complete repair of transposition of the great arteries with ventricular septal defect and left ventricular outflow tract obstruction: a report of ten cases of a modified procedure

BACKGROUND: In most cases of transposition of the great arteries with ventricular septal defect and left ventricular outflow tract obstruction, a Lecompte procedure (réparation à l'étage ventriculaire) is possible without interposition of a conduit between the right ventricle and pulmonary artery. However, the anterior location of the pulmonary arteries after the Lecompte maneuver may be a potential cause for right ventricular outflow obstruction, which continues to be reported in 5% to 25% of cases. We have used a tubular segment of aortic autograft to connect the pulmonary artery, left in the orthotopic posterior position (without the Lecompte maneuver), to the right ventricle in 10 consecutive patients with transposition, ventricular septal defect, and left ventricular outflow tract obstruction. METHODS: Ten consecutive patients aged 2 months to 11 years (mean 32 months) have undergone a modified Lecompte operation. Eight had severe pulmonary stenosis, two had pulmonary atresia, and four had a restrictive ventricular septal defect at the time of the operation. Two had multiple ventricular septal defects. Seven had undergone one (n = 5) or two (n = 2) previous modified Blalock-Taussig shunts. All patients underwent a total correction with left ventricular-aortic intraventricular connection (four needed a ventricular septal defect enlargement), connection between the right ventricle and pulmonary arteries with a tubular segment of autograft aorta, without the Lecompte maneuver (anterior location of the bifurcation of the pulmonary arteries) on the right (n = 6) or the left (n = 4) of the aorta. No valvular device was used for the right ventricular outflow repair. RESULTS: No early or late deaths occurred. One patient with multiple ventricular septal defects needed an early (2 weeks) reoperation for a residual muscular ventricular septal defect. All patients are currently in New York Heart. Association class I, without medications, in sinus rhythm, at a mean follow-up of 30 months. Late results up to 3.6 years show no calcification on the chest roentgenogram, and at the most recent echocardiogram, right ventricular pressures were low (25 to 40 mm Hg, mean 33 mm Hg) and no significant gradient (over 10 mm Hg) was found between the right ventricle and pulmonary arteries. Left and right ventricular function was satisfactory. CONCLUSION: This modification of the Lecompte operation using a segment of autograft allows an excellent early and late result, with no danger of compression of anteriorly placed pulmonary arteries, no significant right ventricular outflow obstruction, and normal appearance of the tubular autograft. In view of laboratory and clinical evidence, normal growth of the autograft can be anticipated. It allows an elective correction of transposition, ventricular septal defect, and left ventricular outflow tract obstruction without a previous Blalock-Taussig shunt (three patients) and correction at a young age (three patients younger than 1 year).     

Scar traction appliance for a patient with microstomia: a clinical report

This clinical report illustrates how an active traction appliance was made for a patient with severe microstomia by attaching custom-made lip retractors to an orthodontic headgear. A steady, light tensile force was imparted to the lips with the elastic bands between the retractors and the headgear.     

New treatments for multiple sclerosis: a clinical perspective

A comprehensive screening program was initiated in Saudi Arabia in 1982 to determine the frequency of the sickle cell (Hb S) gene in the different regions of Saudi Arabia. Over a period of 10 years 30,055 samples were collected from 36 areas in the five provinces of Saudi Arabia; these were screened using electrophoretic techniques in alkaline and acid pH for the presence of Hb S in heterozygous and homozygous states. The overall prevalence of Hb AS was 7.36% and Hb SS was 1.06%, giving an Hb S gene frequency of 0.047. The results from the different regions were separated and the prevalence of Hb AS and Hb SS and Hb S gene frequencies were calculated in each province and each region. The prevalence of Hb AS and Hb SS cases ranged from O to 25.88% and O to 5.27%, respectively. No case of Hb AS or Hb SS were identified in certain areas of the central province (Al-Russ, Al-Unaiza, Al-Mesnab and Bkaria) and northern province (Qurayat and Al-Jouf). In the southern province both Hb S homozygotes and heterozygotes were encountered in all regions except Farasan Island. In all other regions the Hb S gene was encountered, but at a variable frequency. Applying Hardy-Weinberg equilibrium it was observed that in the majority of the regions the observed Hb S homozygotes were significantly higher compared to the number expected (p < 0.0001). This was believed to be due to bias as the samples were collected in the hospital. The Hb S gene frequency in the different regions ranged from 0 to 0.17 when the frequency was calculated on the basis of both Hb AS and Hb. SS cases, and 0 to 0.13 if the gene frequency was calculated after eliminating the Hb SS cases. A close correlation was observed between the Hb S gene frequency and malaria endemicity. This study shows that the Hb S gene occurs frequently in several regions of Saudi Arabia and there is an urgent need to implement control and prevention programs to reduce the number of Hb S homozygous cases.     

Dimethyl sulfoxide-mediated primer Tm reduction: a method for analyzing the role of renaturation temperature in the polymerase chain reaction

We report a method for optimizing the specificity of product formation in the polymerase chain reaction (PCR). This technique is based on the use of dimethyl sulfoxide (DMSO) and takes into account primer Tm. The reduction in Tm by DMSO is directly correlated with renaturation temperature such that a DMSO gradient reflects a temperature gradient. We use this relationship to show that optimum product formation usually occurs at or within several degrees of the midpoint Tm of a given primer pair. We illustrate these correlations using three examples deriving PCR products from a human cDNA library, representing the casein kinase II alpha and beta subunits as well as the 5' untranslated region for the beta subunit. By following product formation as a function of renaturation temperature, we postulate rules for cycle design based on primer Tm. Implications for the use of degenerate primers are discussed.     

Psychological rehabilitation: A concept in need of a method.

Research indicates that the field of mental health is not doing an adequate job of rehabilitating psychiatric patients back into the community. The inefficacy of psychological rehabilitation appears to be a function of several variables: (a) the failure of mental health professionals to understand the pressing necessity for a psychological-rehabilitation approach within the mental health system; (b) the mistaken assumption that psychological rehabilitation and psychological prevention are separate and distinct functions (as opposed to the realization that rehabilitation, at the present state of our knowledge, is possibly the best use of our preventive energies); and (c) the inability to develop a psychological-rehabilitation model. As an alternative to the present practice of psychological rehabilitation, a skills-training approach is suggested. (16 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Spontaneous occlusion of supraclinoid aneurysms after the creation of extra-intracranial bypasses using long grafts: report of two cases

OBJECTIVE: We describe two cases of giant supraclinoid aneurysms, treated by means of saphenous vein grafting between the external carotid artery and the middle cerebral artery, which unexpectedly spontaneously occluded. CLINICAL PRESENTATION: Two patients presented with subarachnoid hemorrhage and headache, respectively. In the first case, angiography showed an aneurysm of the right internal carotid artery (ICA), which had been treated by clipping. Repeat angiography showed a giant aneurysm of the right ICA, the formation of which was probably caused by sliding of the clip that had been applied during the previous operation. The patient was operated on again, but it was impossible to exclude the aneurysm because no clear neck could be identified. In the second case, magnetic resonance imaging and cerebral angiography showed a large, partially thrombosed aneurysm of the supraclinoid segment of the left ICA. TECHNIQUE: In view of the patients' ages and the statuses of compensatory circulation, each patient underwent cerebral revascularization with a long saphenous vein graft placed between one branch of the middle cerebral artery and the external carotid artery, in anticipation of subsequent endovascular treatment of the aneurysm and/or closure of the ICA in the neck. Postoperative angiography demonstrated spontaneous occlusion of the aneurysms. CONCLUSION: Thrombosis of an aneurysm may occur spontaneously or after explorative surgery. However, it should be remembered that spontaneous occlusion of an aneurysm may be induced or favored by hemodynamic vascular alterations that take place inside the aneurysm after a high-flow extra-intracranial bypass has been created.     

Financial effect of clinical decisions: case study of a dialysis center

This paper explores, in the isolated guinea-pig ileum, the effects of temperature on the acute development of opioid dependence and on the precipitation of the abstinence response, using as reference the effect of temperature on the response to a standard nicotine concentration. Additionally, the influence of temperature on acute morphine neurodepression was examined. Three experimental groups were included. In the first, the bath temperature was adjusted and maintained along the experimental session (2.5 h) at one of the following values: 28, 32, 36 or 40 degrees C. In the second, the different values of bath temperature were applied only during the period of morphine exposure before testing the abstinence response at 36 degrees C. In the third, all segments were initially incubated at 36 degrees C for 1 h, and afterwards, abstinence and the nicotine response were elicited at the different temperatures mentioned. In all the series, a single challenge naloxone dose (3.1, 10, 31, 100, 316, 1000 or 3160 nM) was administered after 1h of morphine and complete naloxone concentration-response curves were obtained. The abstinence response was expressed as a percentage of the nicotine reference response. All segments showed robust nicotine responses at all the experimental protocols tested indicating that, at the temperature range studied, the contractile mechanisms were impaired. This study showed that changes in bath temperature modify the magnitude of acute morphine neurodepression, and of the abstinence response but did no affect the development of acute opioid dependence. These data, along with several lines of evidence, strongly suggest that acute neurodepression, the development of opiate dependence and antagonist-precipitated abstinence are separable. Results are discussed on the basis of drug-receptor interactions.