An examination of the reactive sputtering of silicon nitride on to gallium arsenide

The deposition of silicon nitride thin films by the reactive sputtering of elemental silicon in a nitrogen/argon plasma has been investigated. The composition of the thin films has been examined using infra-red reflectance, X-ray photoelectron and Auger electron spectroscopies and spark source mass spectrometry. Oxygen has been found to be a major contaminant in these sputter deposited films, the oxygen concentration depending on the ambient gas pressure. The use of the silicon oxy-nitride films as annealing encapsulants for the activation of silicon ion implanted semi-insulating gallium arsenide has also been investigated.     

The use of imaging studies in the diagnosis and management of thyroid cancer and hyperparathyroidism

With the variety of radiopharmaceutical agents and refined imaging techniques, thyroid and parathyroid imaging provides much valuable clinical information. The use of imaging is most important in the follow-up of differentiated (DTC) and medullary thyroid cancer (MTC). Patients with DTC are followed with serum thyroidglobulin and 131I whole body scintigraphy when the serum thyroglobulin level is elevated. When the 131I scintigram is negative, 201Tl scintigraphy may best identify the site of recurrent DTC. Alternative radioisotopes, ultrasound, CT, and FDG PET are also useful in localizing the site of DTC metastases. MTC recurrences and metastases are more difficult to image. Selective venous catheterization is the most sensitive and specific method for detecting areas of recurrent MTC. High-resolution ultrasound, CT, MR imaging, and scintigraphy are all capable of, and useful in, detecting macroscopic foci of metastatic tumor. Somatostatin receptor scintigraphy and 99mTc DMSA have been the most frequently used nuclear imaging agents in patients with recurrent MTC. Imaging for hyperparathyroidism remains controversial. Sestambi has become the preferred isotope for parathyroid scintigraphy; whereas high-resolution ultrasound is also frequently used. Preoperative imaging is being used as a method to allow a unilateral neck exploration, more recently, in conjunction with intraoperative 1-84 PTH assay and with intraoperative use of the gamma probe. Most often, parathyroid imaging is performed before reoperation for persistent hyperparathyroidism.     

Delayed onset of hand tremor related to cerebellar hemorrhage

Spontaneous hematomas are rare and can present with acute or chronic symptoms. Our patient presented with deep vein thrombosis of the lower extremity associated with a spontaneous pelvic hematoma. This lesion was radiologically and clinically indistinguishable from a soft-tissue neoplasm. The case of a spontaneous pelvic neoplasm in an otherwise healthy young man is presented and the literature reviewed regarding issues of differential diagnosis and clinical management.     

Medication adherence in rheumatoid arthritis patients: older is wiser

OBJECTIVES: To create a profile of individuals nonadherent to their medications in an age-stratified sample (ages 34-84) of community-dwelling rheumatoid arthritis patients. The relative contributions of age, cognitive function, disability, emotional state, lifestyle, and beliefs about illness to nonadherence were assessed. DESIGN: A direct observation approach was used in conjunction with structural equation modeling. All participants were administered a preliminary assessment battery. Medications were then transferred to vials with microelectronic caps that recorded medication events for all medications for the next 4 weeks. PARTICIPANTS AND SETTING: A volunteer sample of 121 community-dwelling rheumatoid arthritis (RA) patients were recruited from newspaper ads, posters, and via informal physician contact from private rheumatology practices in Atlanta and Athens, Georgia. Written verification of the RA diagnosis and a disease severity rating were obtained from personal physicians before patients were enrolled in the study. Patients were tested in a private physician's office, and their medication adherence was monitored electronically for a month in their every-day work and home settings. MEASUREMENTS AND RESULTS: Structural equation modeling techniques were used to develop a model of adherence behavior. Cognitive and psychosocial measures were used to construct latent variables to predict adherence errors. The model of medication adherence explained 39% of the variance in adherence errors. The model demonstrated that older adults made the fewest adherence errors, and middle-aged adults made the most. A busy lifestyle, age, and cognitive deficits predicted nonadherence, whereas coping with arthritis-related moods predicted adherence. Illness severity, medication load, and physical function did not predict adherence errors. Omission of medication accounted for nearly all errors. CONCLUSION: Despite strong evidence for normal, age-related cognitive decline in this sample, older adults had sufficient cognitive function to manage medications. A busy lifestyle and middle age were more determinant of who was at risk of nonadherence than beliefs about medication or illness. Thus, practicing physicians should not assume that older adults have insufficient cognitive resources to manage medications and that they will be the most likely to make adherence errors. Very busy middle-aged adults seem to be at the greatest risk of managing medications improperly.     

Ovine arylalkylamine N-acetyltransferase in the pineal and pituitary glands: differences in function and regulation

The enzyme arylalkylamine N-acetyltransferase (AANAT; EC 2.3.1.87) has been conventionally linked with the biosynthesis of melatonin within the pineal gland and retina. This study establishes that AANAT messenger RNA (mRNA) and functional enzyme occurs within the pars tuberalis (PT) and to a lesser degree within the pars distalis (PD) of the sheep pituitary gland; expression in these tissues is approximately 1/15th (PT) and 1/300th (PD) of that in the ovine pineal gland. AANAT mRNA in the PT appears to be expressed in the same cells as the Mel1a receptor. No evidence was obtained to indicate that either PT or PD cells have the ability to synthesize melatonin, suggesting that this enzyme plays a different functional role in the pituitary. We also found that cAMP regulation of the abundance of AANAT mRNA differs between the PT and pineal gland. Forskolin (10 microM) has no effect on pineal AANAT mRNA levels, yet represses expression in the PT. This suppressive influence could be mediated by ICER (inducible cAMP response early repressor), which is induced by forskolin in both tissues. Although it appears that the specific function and regulation of AANAT in the pituitary gland differ from that in the pineal gland, it seems likely that AANAT may play a role in the broader area of signal transduction through the biotransformation of amines.     

Genitourinary anomalies in the CHARGE association

PURPOSE: We identified the incidence and types of genital and urinary anomalies, and established a plan for evaluating the urinary system in the CHARGE association. MATERIALS AND METHODS: We retrospectively reviewed the charts of 32 patients in whom the CHARGE association was diagnosed. RESULTS: Of the 32 patients identified 22 (69%) had genitourinary abnormalities. Genital anomalies, including micropenis, penile agenesis, hypospadias, chordee, cryptorchidism, a bifid scrotum, atresia of the uterus, cervix and vagina, and hypoplastic labia majora, labia minora and clitoris, were present in 18 patients (56%). Of the 24 patients who underwent renal ultrasound 10 (42%) were diagnosed with urinary tract anomalies including a solitary kidney, hydronephrosis, renal hypoplasia and duplex kidneys. Further evaluation revealed vesicoureteral reflux, neurogenic bladder secondary to spinal dysraphism, nephrolithiasis, ureteropelvic junction obstruction and a nonfunctioning upper pole in both duplex kidneys. CONCLUSIONS: There is a high incidence of genitourinary anomalies in the CHARGE association. Because of this high incidence of anomalies, patients with this condition should undergo a careful genitourinary evaluation, including renal and bladder ultrasound, and voiding cystourethrography screening.