In-plane motion correction for MR spectroscopic imaging

A motion-detection method is described that is specifically suited for MR spectroscopic imaging (MRSI) studies. Information on in-plane rotation and translation of the subject was obtained using external spatial reference markers that are uniquely identified via their chemical shift. The marker locations were obtained directly from the acquired data at each encoding step, and no additional data acquisition was required. This method was applied to brain ¹H MRSI studies that include subcutaneous lipid signals, which otherwise result in enhanced sensitivity to subject motion.     

Distal muscular dystrophy of Miyoshi type

Miyoshi myopathy (MM) is a rare distal myopathy that mainly occurs in Japan. And that is characterized by prominent involvement of the gastrocnemius muscles. Here we report two patients, brother and sister, from a German family. Onset of the disease was at the age of 20 and 22 years, respectively. In both siblings, there was an early and predominant involvement of the gastrocnemius muscles. Creatine kinase activity was elevated 37- to 95-fold above normal. Electromyography revealed fibrillations, positive sharp waves and a myopathic pattern, particularly in the distal muscles of the lower limbs. Histology of the gastrocnemius muscles showed myopathic changes consistent with muscular dystrophy. Occurrence in these two siblings but in no other family members was indicative of an autosomal-recessive inheritance. Our report indicates that MM may also be found in Germany, and that it should be considered in the differential diagnosis of distal myopathies. Received: 25 April 1996 Received in revised form: 26 July 1996 Accepted: 26 August 1996     

The Mechanism of Photoaffinity Labeling

Photoaffinity labeling is a recently introduced method for covalently binding chemical tags to the active sites of protein molecules, which is potentially capable of very great specificities of labeling. A labeling reagent is used that is converted by photolysis to an extremely reactive intermediate. According to the expected mechanism, the reagent molecules that are specifically and reversibly bound to the active site at the instant of photolysis react irreversibly in the site before they can dissociate from the site. In two such reagent-protein systems studied in this paper, however, it is shown that, while by the usual criteria photoaffinity labeling appears to have occurred, the expected mechanism in fact does not hold. This was discovered in experiments with scavengers present in the mixtures that were photolyzed. The general properties of, and criteria for, photoaffinity labeling reactions are discussed in the light of these findings.     

PAM cell assay as a tests for multiple-sclerosis associated agent.

Contrary to previous reports, no evidence for a multiple sclerosis-associated agent (MSAA) was obtained when coded brain samples from multiple sclerosis patients and controls were tested in PAM cells.     

Cochlear implantation with preservation of residual deep frequency hearing

BACKGROUND: The aim of the present paper is to evaluate the clinical parameters in patients implanted for combined, ipsilateral electric-acoustic stimulation of the auditory system. METHODS: A total of 18 patients with residual deep frequency hearing were implanted with a Combi 40+cochlear implant (MED-EL, Austria). Insertion depths ranged from 18 to 22 mm (360 degrees ). A modified surgical technique should contribute to hearing preservation in low frequency regions of the cochlea. Pure-tone audiometric thresholds were measured pre- and postoperatively. A speech audiometric evaluation was performed on two subjects. RESULTS: Utilizing adapted surgical procedures, the preservation of low frequency hearing was accomplished in 16 of 18 subjects (88.9%). Seven (38.9%) patients had complete and nine (50.0%) partial preservation of residual hearing. The speech discrimination scores of two patients documented an increase in sentence intelligibility when compared with only the cochlear implant. CONCLUSIONS: Hearing preservation in cochlear implant surgery is possible. Insertions of 360 degrees provide a full functioning cochlear implant to stimulate sufficient neural structures for above average discrimination scores with the implant alone. A synergistic effect of the electric and the acoustic stimulation modes leads to high discrimination scores in background noise.     

Normative findings of electrically evoked compound action potential measurements using the neural response telemetry of the Nucleus CI24M cochlear implant system

One hundred and forty-seven adult recipients of the Nucleus 24 cochlear implant system, from 13 different European countries, were tested using neural response telemetry to measure the electrically evoked compound action potential (ECAP), according to a standardised postoperative measurement procedure. Recordings were obtained in 96% of these subjects with this standardised procedure. The group results are presented in terms of peak amplitude and latency, slope of the amplitude growth function and ECAP threshold. The effects of aetiological factors and the duration of deafness on the ECAP were also studied. While large intersubject variability and intrasubject variability (across electrodes) were found, results fell within a consistent pattern and a normative range of peak amplitudes and latencies was established. The aetiological factors had little effect on the ECAP characteristics. However, age affected ECAP amplitude and slope of the amplitude growth function significantly; i.e., the amplitude is higher in the lowest age category (15-30 years). Principal component analysis of the ECAP thresholds shows that the thresholds across 5 electrodes can be described by two factors accounting for 92% of the total variance. The two factors represent the overall level of the threshold profiles ('shift') and their slopes across the electrode array ('tilt'). Correlation between these two factors and the same factors describing the T- and C-levels appeared to be moderate, in the range of 0.5-0.6.     

Cardiovascular screening with parallel imaging techniques and a whole-body MR imager

The purpose of this study was to integrate parallel acquisition techniques into a comprehensive whole-body cardiovascular screening protocol to image all relevant organ systems without compromising spatial or temporal resolution. The study was approved by the institutional review board, and oral and written informed consent was obtained from each subject. Fifty subjects underwent whole-body magnetic resonance imaging that included imaging of heart, blood vessels, brain, lungs, and abdominal organs with a standard eight-channel imager. Image quality and pathologic findings were evaluated by two readers. The same protocol was then implemented with a new 32-channel whole-body imager. Depiction of 1476 (73.2%) of 2016 vessel segments was rated as good to excellent, and that of 1744 (86.5%), as without venous overlay. Interobserver agreement was good in evaluation of image quality and excellent in evaluation of pathologic findings. Acquisition time was reduced significantly (P < .05) with use of the whole-body imager and parallel acquisition techniques, which provided high-quality fast cardiovascular imaging.     

Effect of antagonists vs agonists on in vitro fertilization outcome

PURPOSE: To compare outcome following in vitro fertilization-embryo transfer (IVF-ET) using controlled ovarian hyperstimulation (COH) regimens using either the gonadotropin-releasing hormone (GnRH) agonist leuprolide acetate vs the GnRH antagonist ganirelix. METHODS: Women needing IVF for conception were randomly assigned to 300 IU of gonadotropins with ganirelix used in the follicular phase when a follicle with a 14 mm average diameter was attained vs a regimen using leuprolide acetate from the mid-luteal phase of the previous cycle. RESULTS: There were no differences found in clinical, ongoing, delivered pregnancy rates or implantation rates between groups. CONCLUSIONS: The use of GnRH antagonists do not seem to reduce IVF outcome compared to using GnRH agonists in COH regimens.     

The effect of osteoprotegerin administration on the intra-tibial growth of the osteoblastic LuCaP 23.1 prostate cancer xenograft

Osteoprotegerin (OPG) plays a central role in controlling bone resorption. Exogenous administration of OPG has been shown to be effective in preventing osteolysis and limiting the growth of osteolytic metastasis. The objective of this study was to investigate the effects of OPG on osteoblastic prostate cancer (CaP) metastases in an animal model. LuCaP 23.1 cells were injected intra-tibially and Fc-OPG (6.0 mg/kg) was administered subcutaneously three times a week starting either 24 hours prior to cell injection (prevention regimen) or at 4 weeks post-injection (treatment regimen). Changes in bone mineral density at the tumor site were determined by dual x-ray absorptiometry. Tumor growth was monitored by evaluating serum prostate specific antigen (PSA). Fc-OPG did not inhibit establishment of osteoblastic bone lesions of LuCaP 23.1, but it decreased growth of the tumor cells, as determined by decreases in serum PSA levels of 73.0 ± 44.3% (P < 0.001) and 78.3 ± 25.3% (P < 0.001) under the treatment and prevention regimens, respectively, compared to the untreated tumor-bearing animals. Administration of Fc-OPG decreased the proliferative index by 35.0% (P = 0.1838) in the treatment group, and 75.2% (P = 0.0358) in the prevention group. The results of this study suggest a potential role for OPG in the treatment of established osteoblastic CaP bone metastases.