A review of principles and techniques for making interocclusal records for mounting working casts

Obtaining an accurate interocclusal record for mounting working casts on an articulator is one of the most important procedures in determining the occlusal precision of restorations. This paper reviews the literature, describes some of the principles involved in making an interocclusal record, and illustrates practical techniques that may be used in a variety of clinical situations.     

LeVeen vs Denver peritoneovenous shunts for intractable ascites of cirrhosis. A randomized, prospective trial

Peritoneovenous shunts (PVSs) have provided salutary effects on medically recalcitrant ascites, functional renal impairment, nutritional derangements, ventilatory embarrassment, and locomotion potential in patients with cirrhosis. While the LeVeen (LPVS) and Denver (DPVS) PVSs are most frequently implanted in such patients, postoperative complications of bleeding gastroesophageal varices, sepsis, and shunt occlusion occur with notable frequency. Addressing primarily the complication of PVS occlusion, a randomized prospective trial of LPVSs and DPVSs was conducted in cirrhotic patients with refractory ascites. From July 1, 1982 to July 1, 1984, 26 initial PVSs were implanted for hepatic-related intractable ascites. Twenty-two patients were eligible for randomization (cirrhosis, sterile ascites, initial PVS, total bilirubin level less than or equal to 6.0 mg/dL, prothrombin time less than or equal to 5-s prolongation, serum creatinine level less than or equal to 2.0 mg/dL [creatinine clearance rate greater than or equal to 20 mL/min], absence of recent [less than 30 days] bleeding gastroesophageal varices, or absent spontaneous encephalopathy). Twelve LPVSs and ten DPVSs were implanted; however, one patient with a DPVS was found to have hepatic polycystic disease and was excluded from analysis. All patients were followed up until death or Jan 1, 1985. The PVS patency determinations included contrast shuntography, technetium Tc 99m albumin scintigraphy, sequential manual compression (DPVS), and operative or autopsy observation. Using the Kaplan-Meier actuarial analysis, the LPVS patency proved to be highly superior to that of the DPVS, while survival was not significantly different. As LPVS and DPVS complications other than patency are comparable, the LPVS is preferred for its superior patency in cirrhotic patients with intractable ascites.     

T-cell hybridomas specific for self and foreign thyroglobulins.

We have used somatic cell fusion techniques to produce and characterize murine T-cell hybridomas with specificity for self and foreign thyroglobulin (Tg). Two interleukin-2 (IL-2)-releasing I-Ak-restricted hybrid clones with specificity for self determinants on syngeneic Tg were derived from Tg-specific T-cell lines. These two autoreactive hybridomas were independently derived and were clonotypically distinct as determined by restriction fragment length polymorphism of the Ti beta-chain gene, but showed a similar pattern of cross-reactivity against rat and human (but not porcine) Tg. A third T-cell hybridoma showed a previously unknown specificity for the immunizing (non-inbred) Tg, but not for syngeneic Tg, indicating responsiveness to an allelic determinant. Although T-cell hybridization techniques have previously had only minimal application in experimental autoimmunity, this represents an approach to the study of Tg-specific T-cell responses at the molecular level.     

Independent component analysis of subdurally recorded occipital seizures

OBJECTIVE: To study the components of occipital seizures using independent component analysis (ICA) of subdurally recorded electroencephalogram (EEG) data. METHODS: Twenty-seven subdurally recorded occipital seizures from eight patients were studied. ICA was performed, and the resulting independent components (ICs) were compared with respect to their power, frequency, degree of spread within the epileptogenic zone, and propagation patterns. The ictal ICs were further subdivided into propagating and non-propagating types. RESULTS: ICA provided information over and above that supplied by standard visual EEG analysis, confirming that all the seizures originated in the occipital lobe, and affording additional knowledge regarding the nature of the seizure onset zone. Each seizure was composed of multiple ICs, some of which propagated while others remained within the epileptogenic zone. There was no statistical difference between the propagating and non-propagating ICs with respect to power or frequency. However, propagating ICs involved a significantly greater number of recording electrodes at their onset when compared to the non-propagating ICs. CONCLUSIONS: The propagation likelihood of ICs in occipital seizures is independent of their power or frequency, but it is dependent on the volume of brain giving rise to that signal; ICs that are generated by a greater volume of brain within the epileptogenic zone are more likely to propagate. SIGNIFICANCE: This study shows that ICA has the potential to be used to redefine the epileptogenic zone and guide the extent of cortisectomy for the treatment of patients with medically intractable occipital epilepsy.     

Search performance of healthy adults on cancellation tests

Cancellation tests are used extensively to identify visual search deficiencies in people with neurologic conditions, but little is known about how healthy adults perform on these tests. This study described the performance and types of search strategies used by healthy adults to complete cancellation tests from the Brain Injury Visual Assessment Battery for Adults. Study participants predominantly used structured left-to-right and top-to-bottom linear search patterns regardless of the configuration of the visual array. Other search qualities included (1) use of the same pattern throughout the search of an array, (2) symmetrical search of the array, and (3) rechecking performance on complex arrays. Older adult participants took more time to complete the tests than younger adults did. Knowing the strategies healthy adults use on cancellation tests enables therapists to identify visual search deficiencies in clients and design interventions to reestablish normal search strategies in daily occupations.     

Current state of the art in perforator flap imaging with computed tomographic angiography

Computed tomographic angiography (CTA) has become increasingly adopted for preoperative imaging in perforator flap surgery, as it has been shown to improve operative outcomes and decrease operating times prior to deep inferior epigastric artery perforator (DIEP) flap and anterolateral thigh perforator flap surgery. Current technologies are readily available for the preoperative imaging of all perforator flaps, however only sporadic reports of the use of CTA for the imaging of other perforators have been described. We describe our experience with 325 CTAs performed for the preoperative imaging of perforators prior to 370 perforator flaps throughout several body regions. The scanning techniques, software reconstructions and technical issues are explored. In all cases, CTA was scored by the radiologist as at least “sufficient”, and described as “optimal” in the majority of cases. Similarly, the surgeon described the correlation of imaging to operative findings as at least “good”, and described the correlation as “optimal” in the majority of cases. As such, a standardized protocol for the use of CTA prior to perforator flap surgery is provided, which has been shown to be successful prior to a range of perforator flap operations.     

Detection and characterization of neurotoxicity in cancer patients using proton MR spectroscopy

OBJECTIVE: The study objective was to detect abnormalities and identify relationships between brain metabolic ratios determined by proton magnetic resonance spectroscopic imaging ((1)H-MRSI) and neuropsychological (NP) function in cancer patients at risk for neurotoxicity. METHODS: Thirty-two patients received (1)H-MRSI using a multi-slice, multi-voxel technique on a 1.5T magnet. Cho/NAA, NAA/Cr, and Cho/Cr ratios were identified in seven pre-determined sites without tumor involvement. A battery of age-appropriate NP tests was administered within 7 days of imaging. Relationships were examined between test scores and metabolite ratios. CONCLUSIONS: This study identifies relationships between brain metabolite ratios and cognitive functioning in cancer patients. (1)H-MRSI may be useful in early detection of neurotoxic effects, but prospective longitudinal studies in a homogeneous population are recommended to determine the prognostic value.