Energy production, substrate oxidation, serum protein levels, and weight change were studied in 16 non-steroid treated patients with severe head injury. Patients were evaluated during an average of 31.3 days from hospital admission to discharge. The mean measured energy expenditure (MEE) was 1.40 ± 0.5 times predicted energy expenditure. Caloric balance [calories received = calories expended[ was achieved by the 2nd week. Despite caloric balance and the administration of at least 1.5 g of protein per kg of body weight per day, the mean nitrogen balance was negative. There was a positive nitrogen balance in only 2 patients. These patients received a mean of 1.43 times the MEE in total kilocalories and 2.3 g of protein per kg of body weight. Fat and protein oxidation exceeded protein and fat administration for 3 weeks postinjury. Albumin levels dropped from a mean of 3.09 ± 0.2 on admission to 1.98 ± 0.4 within 2 weeks. The initial retinol binding protein levels were within the normal range, and the levels increased over time. There was marked weight loss (mean, 15.6 ± 5.9 lb). Head injury induces a profound traumatic response identified by increased energy expenditure, a negative nitrogen balance, weight loss, hypoalbuminemia, and altered substrate oxidation. This response seems to be caused by the head injury alone and is not due to the administration of corticosteroids. (Neurosurgery 17:784-791, 1985)
We report the results of partial melting experiments between 8 and 32 kbar, on four natural amphibolites representative of metamorphosed Archean tholeiite (greenstone), high-alumina basalt, low-potassium tholeiite and alkali-rich basalt. For each rock, we monitor changes in the relative proportions and composition of partial melt and coexisting residual (crystalline) phases from 1000 to 1150°C, within and beyond the amphibole dehydration reaction interval. Low percentage melts coexisting with an amphibolite or garnet amphibolite residue at 1000–1025°C and 8–16 kbar are highly silicic (high-K2O granitic at ∼5%; melting, low-Al2O3 trondhjemitic at ∼5–10%). Greater than 20% melting is only achieved beyond the amphibole-out phase boundary. Silicic to intermediate composition liquids (high-Al2O3 trondhjemitic-tonalitic, granodioritic, quartz dioritic, dioritic) result from ∼20–40% melting between 1050 and 1100°C, leaving a granulite (plagioclase + clinopyroxene ± orthopyroxene ± olivine) residue at 8 kbar and garnet granulite to eclogite (garnet + clinopyroxene) residues at 12–32 kbar. Still higher degrees of melting ( ∼40–60%) result in mafic liquids corresponding to low-MgO, high-Al2O3 basaltic and basaltic andesite compositions, which coexist with granulitic residues at 8 kbar and edogitic or garnet granulitic (garnet + clinopyroxene + plagioclase ± orthopyroxene) residues at higher pressures (12–28 kbar). As much as 40% by volume high-Al2O3 trondhjemitic-tonalitic liquid coexists with an eclogitic residue at 1100–1150°C and 32 kbar. The experimental data suggest that the Archean tonalite-trondhjemite-granodiorite (TTG) suite of rocks, and their Phanerozoic equivalents, the tonalite-trondhjemite-dacite suite (including 'adakites' and other Na-rich granitoids), can be generated by 10–40% melting of partially hydrated metabasalt at pressures above the garnet-in phase boundary (≥12 kbar) and temperatures between 1000 and 1100°C. Anomalously hot and/or thick metabasaltic crust is implied. Although a rare occurrence along modern convergent plate margins, subductionrelated melting of young, hot oceanic crust (e.g. ocean ridges) may have been an important (essential) element in the growth of the continental crust in the Archean, if plate tectonic processes were operative. Coupled silicic melt generation-segregation and mafic restite disposal may also occur at the base of continental or primitive (sub-arc?) crust, where crustal overthickening is a consequence of underplating and overaccretion of mafic magmas. In either setting, net growth of continental crust and crustmantle recycling may be facilitated by relatively high degrees of melting and extreme density contrasts between trondhjemitictonalitic liquids and garnet-rich residues. Continuous chemical trends are apparent between the experimental crystalline residues, and mafic migmatites and garnet granulite xenoliths from the lower crust, although lower-crustal xenoliths in general record lower temperatures (600–900°C) and pressures (5–13 kbar) than corresponding residual assemblages from the experiments. However, geo-thermobarometry on eclogite xenoliths in kimberlites from the subcontinental mantle indicates conditions appropriate for melting through and beyond the amphibole reaction interval and the granulite-eclogite transition. If these samples represent ancient (eclogitized) remnants of subducted or otherwise foundered basaltic crust, then the intervening history of their protoliths may in some cases include partial melting.
In two patients with retrocrural tumors, dissection of the tumors selectively into the posterior pararenal space was observed by computed tomography. Cadaver studies confirmed the presence of potential communications between the retrocrural space and the extrapleural space of the thorax or the posterior pararneal space of the abdomen.
An in vitro study was conducted to determine the adaptation of composite resin restorative material to rounded and acute-angled retention grooves of Class I cavity preparations on 24 extracted premolars. Two chemically cured (P-IO ® and Miradapt ®) and 2 lightcured (Prisma-Fil® and Ful-Fil®) composite resin materials, after being coded to create a blind study, were injected into cavity preparations containing rounded and acute-angled retention grooves. The restored premolars were cut in half and examined via SEM at 50 x magnification. A standardized method was used to determine the adaptation of each composite resin to the grooves. Interjudge evaluation showed all composite resin materials adapted well to both rounded and acute-angled retention grooves. Mean and standard deviation values revealed no significant difference in the average dentinresin gap between treatment groups and between the 2 types of retention grooves. There was only 0.6M difference between the lowest and highest mean values.
Amphotericin B colloidal solutions were prepared according to the manufacturer's directions and filtered with membrane filters of different porosity to test for particulate matter; and the concentration and in vitro microbiological activity of filtered and nonfiltered solutions were determined. The amphotericin B solutions contained numerous particles. Filtration through 0.85- and 0.45-μm filters did not reduce the in vitro antimicrobial activity, and filtration through 5-, 0.45-μm, and 0.22-μm filters did not alter the concentration of the drug when assayed spectrophotometrically.
Phenytoin serum levels were compared in a crossover study of a new 300 mg capsule form and three 100 mg capsules administered once daily. The new 300 mg capsule was equivalent to three 100 mg capsules in efficacy of seizure control and maintenance of phenytoin serum levels. This standard 300 mg dose produced a grand mean drug serum level of 7.63 mcg/ml and was below 10 mcg/ml in 15 to 20 patients. The authors recommend monitoring of phenytoin serum levels and clinical response, to detect needed dosage adjustments for optimum therapeutic benefit from phenytoin and to avoid toxic side effects.
Experimentally‐determined phase relations for a number of amphibolitized MORB compositions indicate that large volumes of high‐Al2O3 trondhjemitic‐tonalitic liquids (sodic‐granitoids) result from melting near and just beyond the high‐temperature limb of the amphibole‐out phase boundary at 0.8‐3.2 GPa, leaving dry and dense eclogitic residues. These liquids are strikingly similar in their major, minor and trace element chemical characteristics to the tonalite‐trondhjemite‐granodiorite (TTG) suite of rocks that dominate early Archean high‐grade gneiss and granite‐greenstone terrains. The temperatures required for complete dehydration of metabasalt by partial melting (∼1000 °C) imply subduction of anomalously hot (young) oceanic lithosphere; as a consequence, ‘‘slab melting’’ is rare in modern island arcs. Colder (older) oceanic lithosphere in ‘‘normal’’ subduction zones dehydrates before intersecting the wet basalt solidus, and water‐rich fluids produced in these subsolidus reactions infiltrate the overlying wedge of mantle lithosphere. Partial melting of this metasomatized mantle produces high‐Mg andesites and basalt. Intracrustal fractionation of these primary magmas, accompanied by varying extents of assimilation of crustal material, produces granitoids that are geochemically distinct from slab‐derived, sodic‐granitoids (TTG). In the Archean, shallow subduction and intraoceanic obduction may have led to imbricate thrust stacking of hot, buoyant oceanic lithosphere in compressional zones, partial melting of metabasalt and TTG magmatism. In the post‐Archean, deeper subduction of older, colder oceanic lithosphere results in (incomplete?) predominantly subsolidus slab dehydration, and metasomatism and partial melting of the mantle wedge to produce high‐Mg andesites and basalts. Andesite‐dominated arc magmatism is the final result of protracted fractionation of these magmas. Deep infusion of oceanic lithosphere, and water, into the mantle may be restricted to the subduction of cold slabs, and the post‐Archean.
