Examination of failed retrieved temporomandibular joint (TMJ) implants.

In the management of end-stage temporomandibular joint disorders (TMD), surgeons must often resort to alloplastic temporomandibular joint (TMJ) total joint replacement (TJR) to increase mandibular function and form, as well as reduce pain. Understanding wear and failure mechanisms of TMJ TJR implants is important to their in vivo longevity. However, compared to orthopedic TJR devices, functional wear of failed TMJ TJR implants has not been examined. Not only do wear and corrosion influence TJR implant in vivo longevity, but so does reactivity of peri-implant tissue to these two events. The aim of this study was to examine and report on the wear of retrieved, failed metal-on-metal (MoM), metal-on-polymer (MoP), and titanium-nitride coated (TiN Coated) TMJ TJR implant components. A total cohort of 31 TMJ TJR devices were studied of which 28 were failed, retrieved TMJ TJRs, 3 were never implanted devices that served as controls. The mean time from implantation to removal was 7.24 years (range 3-15), SD 3.01. Optical microscopy, White Light Interferometry (WLI), Scanning Electron Microscopy (SEM), and Raman spectroscopy were utilized to characterize the surfaces of the devices. Data was acquired and evaluated by analyzing alloy microstructure. Substantial surface damage was observed between the articulating areas of the condylar head and the glenoid fossa components. Damage included pitting corrosion, evidence of deposited corrosion products, specific wear patterns, hard phases, surface depressions, and bi-directional scratches. Electrochemical analysis was performed on the MoM Control, retrieved, failed MoM, and TiN Coated devices. Electrochemical tests consisted of open circuit potential (OCP) and electrochemical impedance spectroscopy (EIS) tests conducted using the condylar head of the retrieved failed devices. EIS confirmed material properties as well as corrosion kinetics in vivo help to mitigate corrosion as reflected by the Raman spectroscopy results. In summary, this study demonstrated the role of wear and corrosion interactions on the early failure of TMJ TJR devices. Since the materials employed in most orthopedic TJR devices are similar to those used in TMJ TJR implants, studies such as this can provide data that will improve future embodiment paradigms for both. Further studies will include in vitro investigation of corrosion kinetics and the underlying tribocorrosion mechanism of TMJ TJR devices. STATEMENT OF SIGNIFICANCE: An attempt is made in this study, to examine the retrieved TMJ implants and conduct surface and electrochemical analysis; further a translation research approach is employed to compare the observations from the total hip replacement (THR) retrievals. A total cohort of 31 TMJ TJR devices were studied of which 28 were failed, retrieved TMJ TJRs, 3 were never implanted devices that served as controls. Data was acquired and evaluated by analyzing alloy microstructure. Substantial surface damage was observed between the articulating areas of the condylar head and the glenoid fossa components. Electrochemical analysis was performed on the MoM Control, retrieved, failed MoM, and TiN Coated devices. This study demonstrated the role of wear and corrosion interactions on the early failure of TMJ TJR devices. Since the materials employed in most orthopedic TJR devices are similar to those used in TMJ TJR implants, a comparison study was conducted.

Nuclear and mitochondrial DNA quantification of various forensic materials.

Due to the different types and quality of forensic evidence materials, their DNA content can vary substantially, and particularly low quantities can impact the results in an identification analysis. In this study, the quantity of mitochondrial and nuclear DNA was determined in a variety of materials using a previously described real-time PCR method. DNA quantification in the roots and distal sections of plucked and shed head hairs revealed large variations in DNA content particularly between the root and the shaft of plucked hairs. Also large intra- and inter-individual variations were found among hairs. In addition, DNA content was estimated in samples collected from fingerprints and accessories. The quantification of DNA on various items also displayed large variations, with some materials containing large amounts of nuclear DNA while no detectable nuclear DNA and only limited amounts of mitochondrial DNA were seen in others. Using this sensitive real-time PCR quantification assay, a better understanding was obtained regarding DNA content and variation in commonly analysed forensic evidence materials and this may guide the forensic scientist as to the best molecular biology approach for analysing various forensic evidence materials.

Lifetime measurements of metastable states in Fe+.

The lifetime of two metastable levels in Fe+ has been measured by laser probing of a stored ion beam. In the dense spectrum of Fe+, the metastable levels a (6)S(5/2) and b (4)D(7/2) were selected and their lifetimes were determined to be 230 +/- 30 and 530 +/- 30 ms, respectively. The lifetimes are compared with previous theoretical results. Metastable lifetime measurements of Fe+ are of great importance for interpretation of spectra from astronomical objects. The present experiment opens for the possibilities to investigate lifetimes of metastable states in complex atomic ions, which have, so far, been unexplored.

Captopril-induced changes in MAG3 clearance in patients with renal arterial stenosis and the effect of renal angioplasty.

UNLABELLED: Angiotensin-converting enzyme inhibition by captopril decreases renal (131)I-o-iodohippurate sodium or iothalamate extraction in patients with renal artery stenosis (RAS). This study investigated the effect of captopril on another renal radiopharmaceutical, (99m)Tc-mercaptoacetyltriglycine (MAG3), in particular its plasma clearance. METHODS: Three groups of patients were studied. Group I contained 22 patients with hypertension but a low likelihood of RAS according to negative captopril renography results, confirmed by angiography in 5. Group II contained 22 hypertensive patients with RAS documented by angiography and positive captopril and plasma renin response. Group III contained 10 patients after successful percutaneous transluminal renal angioplasty (PTRA) with negative captopril renography results. The 60-min, single-sample technique was used for measurement of the plasma clearance of MAG3 during baseline and captopril renography. RESULTS: In 18 of 22 group I patients, clearance increased (P < 0.01) during captopril renography compared with baseline conditions, whereas in 18 of 22 group II patients, clearance decreased (P< 0.01). In group III patients, clearance was not significantly altered. The clearance decrease in group II did not correlate with the blood pressure decrease or plasma renin activity increase during captopril renography. CONCLUSION: Renal function assessed by MAG3 plasma clearance decreases in hypertensive patients with RAS but increases in patients without RAS. MAG3 clearance measurements during baseline and captopril renography can thus serve as additional diagnostic information when investigating patients with hypertension for the possibility of an RAS.

Radionuclide hysterosalpingography is not predictive in the diagnosis of infertility.

OBJECTIVE: To investigate whether radionuclide hysterosalpingography (radionuclide HSG), which has been suggested as a more functional approach to the diagnosis of tubal infertility than conventional patency tests, is predictive in the diagnosis of infertility. DESIGN: A retrospective analysis of data from an inquiry form containing questions about pregnancy outcome after radionuclide HSG. SETTING: University hospital-based, tertiary care infertility clinic. PATIENT(S): Two hundred sixteen women had an infertility work-up including radionuclide HSG performed between April 1986 and April 1993. Forty-one (18.9%) women were excluded from the study; 9 had moved to unknown addresses, 16 did not answer the inquiry, and 16 gave answers that were not interpretable. There were 175 (81.1%) women in the final study group. INTERVENTION(S): An inquiry form containing questions regarding pregnancy was sent to 207 women who undergone radionuclide HSG as a routine procedure in their infertility workup. MAIN OUTCOME MEASURE(S): Occurrence of pregnancy related to outcome of radionuclide HSG and its test properties calculated. RESULT(S): Bilateral or unilateral tubal transport was demonstrated by radionuclide HSG in 129 women, of whom 66 (51%) later became pregnant. Of the pregnant women, 36 (55%) had successful infertility treatment, whereas 30 (45%) reported spontaneous pregnancy. Forty-six women showed no transport at radionuclide HSG. Twenty-five (54%) of these women became pregnant, 14 (56%) with infertility treatment and 11 (44%) without infertility treatment. The predictive values of transport and no transport radionuclide HSG were 0.51 and 0.46, respectively. The sensitivity of radionuclide HSG was 0.25, and the sensitivity was 0.73. Likelihood ratios for pregnancy when radionuclide HSG showed transport and no transport were 1.03 and 0.93, respectively. CONCLUSION(S): Our data strongly indicate that a single radionuclide HSG investigation is not able to predict fertility potential.

Radionuclide hysterosalpingography does not distinguish between fertile women, before tubal sterilization, and infertile women.

The female genital tract is capable of active transport that can be demonstrated by serial scintigraphic imaging over time (radionuclide hysterosalpingography; RN-HSG). RN-HSG has been suggested to offer a more functional approach to tubal infertility diagnosis than conventional patency tests. However, before RN-HSG can be recommended as a routine method, its reliability in showing active transport in fertile women must be demonstrated. Therefore we compared RN-HSG in two groups: 38 fertile women before tubal sterilization and 38 women undergoing infertility work-up. Tubal transport demonstrated by RN-HSG was comparably distributed in both groups and classified as bilateral (17 versus 19), unilateral (12 versus 7) or no transport (6 versus 9). In each group three RN-HSG images were not interpretable. There was no association between patency test results and RN-HSG in the two groups. Our data suggest that RN-HSG in its present form does not seem to be a reliable method for infertility work-up. Because RN-HSG and patency tests most probably measure different properties of the genital tract, the phenomenon of active particle transportation should be studied further to enable the development of a reliable tool for the investigation of tubal function.

Developmental steps for radionuclide hysterosalpingography.

The active oviductal transportation capacity was studied in 73 infertile women by the use of a new deposition technique of radioactive particles into the internal cervical os. The main reason for this study was that a previous observation had shown that such a transportation capacity was lacking in 41% of the infertile patients with a normal hysterosalpingogram. The examination was performed in the immediate preovulatory phase, i.e. on days -3 to 0 before the ovulation, as measured by the basal body temperature during two preceding cycles. The deposition of 99mTc-labelled albumin particles of 0.2-1.0 micron at the internal cervical os and the interpretation of the radionuclide images are described in detail. The results show that the bilateral active tubal transportation capacity was present in 42 patients. An impaired transportation capacity was diagnosed in 22 patients. In 9 patients, the particles never reached the uterine cavity, or all activity leaked back to the vagina.

Radionuclide hysterosalpingography for measurement of human oviductal function.

A clinical method is described and claimed to evaluate the active transportation capacity of the luminal epithelium lining the human uterus and fallopian tube. After intracervical application of technetium-labelled human albumin spheres at 1-2 days before ovulation this radioactivity could be followed by gamma-camera when moved in ad ovarian direction. This method is called radionuclide hysterosalpingography (RN-HSG). The results were compared to the findings at normal hysterosalpingography (HSG). By use of this method it was possible to verify active passage in cases of tubal spasm at HSG, lack of transport in cases of normal patent oviducts at HSG as well as presence or absence of active transport through sactosalpinges with or without fimbrial passages to the abdominal cavity as seen at normal HSG. Congruent findings between HSG and RN-HSG was observed in 49%. The studied oviducts were found to be patent with normal HSG but lacked transportation capacity when studied by RN-HSG in 41%. The clinical use of this method is discussed in view of the selection of patients for different forms of in vitro fertilization and egg transfer (IVF-ET).

Late ischaemic sequelae after umbilical artery catheterization.

The acute complications of umbilical artery catheterization are well recognized but very little is known about long-term consequences. Two cases are presented which indicate that umbilical artery catheterization during the neonatal period may give rise to late ischaemic complications.

Stimulated emission in the ultraviolet by optical pumping from photoionization-produced inner-shell states in Cd(+).

Stimulated emission on three UV transitions in Cd(+) has been observed by transferring population from inner-shell d-electron states, populated by photoionization, to outer-shell p-electron states using the output from a narrow-frequency dye laser. The use of similar techniques in other elements could eventually result in a number of new lasers in the UV and VUV.

Spatially resolved temperature measurements in a flame using laser-excited two-line atomic fluorescence and diode-array detection.

Spatially resolved temperature measurements in a CH(4)-air flame have been achieved using two-line laser-induced fluorescence from indium atoms seeded to the flame.