Biomedical subjects
Publications and source records attributed to R Mora.
Primitive synovial chondromatosis of the hip is quite rare. Through the presentation of four new cases, the authors discuss the pathologic and clinical features of this disease and evaluate the performance of imaging studies, emphasizing the value of CT scan for confirmation of radiographic findings. The indication for surgical treatment is analyzed for each stage of the disease.
Voluntary intake and nutritive value of diets selected by goats grazing a shrubland at Marin county, N.L., Mexico were determined. Four esophageally cannulated Spanish female goats (average BW 35 kg), were used to collect extrusa samples monthly throughout 1 yr (June 1987 to May 1988). Organic matter intake (OMI) was estimated by total fecal collections from four castrated Spanish male goats (average BW 42 kg). Diets selected by goats were high in CP throughout the year (means = 18.9%). Available CP represented only about half the total CP. The ADF content of extrusa samples differed (P less than .05) among months, with high ADF values during winter months. Dietary lignin followed a similar pattern during the year. Goats consumed forage with sufficient amounts of Ca, Na, K, Mg, Cu, ZN, Mn, and Fe to meet requirements. The OMI of goats was different (P less than .05) among sampling periods. On the average, estimated OMI (means = 878.7 g/d) compared well with results of other studies in the area. Amounts of DE consumed by goats (1.1 Mcal DE/d) were not sufficient to meet requirements for maintenance plus low activity. High levels of browse in the diets presumably were responsible for low in vitro OM digestibility (means = 34.1%) throughout the year. Thus, productivity of range goats in these areas should be improved by supplementing with protein and energy.
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Extracellular liposomes (EL) that accumulated in the aortic intima of rabbits on 2 weeks (prelesional stage) and 16 weeks (lesional stage) of diet-induced hyperlipidemia were isolated and purified by gel filtration, ultracentrifugation, and affinity chromatography on anti-apoB and anti-albumin Sepharose. The material obtained after each step was examined by negative staining electron microscopy, by protein analysis (SDS-PAGE, immunoblotting, autoradiography, uronic acid), and by lipid analysis for unesterified cholesterol (UC), cholesteryl esters (CE), phospholipids (PL), triglycerides (TG), thiobarbituric acid reactants (TBAR). EL represented the major constituent of intimal lipid deposits; their predominance on particulate beta-lipoproteins (LP) increased with the duration of hyperlipoproteinemia. As compared with serum low density lipoproteins (LDL) and beta-very low density lipoproteins (beta-VLDL), the crude EL fraction obtained after gel filtration and ultracentrifugation had a decrease in CE and TG, with augmentation of UC, PL, and apoB. After removal of apoB and some albumin by immunoadsorption, the purified EL fraction consisted only of UC, PL, and albumin. The albumin was resistant to proteolytic digestion with pronase, and reacted with anti-albumin antibody only after delipidation of EL. This indicated that albumin was trapped in the aqueous core of vesicles, presumably acting as a scavenger of oxygen-free radicals. TBAR was highly associated with intact or degraded beta-LP. The EL that accumulate in the aortic intima of hyperlipidemic rabbits represent the predominant form of lipid deposits, resulting from the transcytosed excess beta-LP, which is degraded and reassembled upon interaction with the extracellular matrix components.
The Authors report their clinical experience about the use of atracurium besylate in preventing succinylcholine-induced fasciculations and postoperative myalgias in fifty athletes (ASA class 1), submitted to arthroscopic meniscectomy. The patients were pretreated with atracurium 5 mg i.v. or saline solution in a double-blind fashion. After 2.5 minutes, succinylcholine 1.3 mg/kg was administered, and fasciculations were recorded on a scale ranging from 0 to 3. Twenty-four hours after surgery all subjects were questioned about myalgias occurrence, scored by a 0-3 scale. Fasciculations occurred in all patients who received saline and in 44% of those treated with atracurium. Myalgias on the postoperative day were observed in 80% of patients treated with saline solution, but only in 36% of patients who received atracurium. The difference between atracurium and saline solution was statistically significant (p less than 0.001) either for fasciculations or myalgias incidence. These findings show that atracurium 5 mg i.v. is effective in preventing succinylcholine-induced fasciculations and postoperative myalgias, and suggest atracurium as the drug of choice for this purpose, particularly in muscular subjects.
We have investigated cytochemically the correlative distribution of lipoprotein (LP) components in successive lesional stages of plaque formation in hyperlipoproteinemic atherogenesis in the rabbit. Apoprotein B (apo B) was detected by an immunoperoxidase procedure, unesterified cholesterol (UC) by filipin and tomatine and phospholipid lamellae of the extracellular liposomes (EL) as they appear in standard EM. The changes were evaluated in relation to the state of endothelial cells and their transport pathways, and the reaction of the cellular and extracellular components of the intima. Each lesional stage has a relatively characteristic pattern distribution of the LP components. In fatty streaks with no endothelial denudation, apo B reaction product occurs mostly in non-particulate form associated with UC-rich EL; this suggests that transcytosed LP upon partial degradation and interaction with the extracellular components, reassemble as polymorphic EL-UC-apo B complexes. Serofibrinous insudates, although commonly devoid of EL and apo B, may contain UC presumably transported by a carrier other than LP. In advanced fibrolipidic lesions with open endothelial junctions and deendothelialized areas, a bulky intramural insudation of plasma results in the presence of large amounts of apparently little modified LP. This may represent what several investigators have isolated as 'aortic LP', which may be insudated rather than transported plasma LP.
The E6 protein of human papillomavirus type 18 (HPV-18) is a putative zinc-finger protein that is expressed in HPV-18-induced genital neoplasias. We have studied the biochemical properties of E6 protein synthesized in large amounts with a baculovirus expression vector. When E6 protein was synthesized in insect cells infected with an E6-expressing baculovirus, the protein was localized to both nuclear and membrane fractions, with half-lives of 4 and 2 h, respectively. Changing the first five amino acids of E6 did not alter the pattern of cellular localization of the protein but dramatically increased the half-life of the nuclear component to longer than 30 h and increased the half-life of the membrane component to 8 h. Although the baculovirus-expressed E6 protein bound to double-stranded DNA with high affinity, no sequence specificity for HPV-18 DNA was detected.
The authors underline the importance of the precocious surgical treatment of the complex lesions of the carpal bones, especially in case of concomitant neurological lesions. The quality of the late results depends on the careful anatomical reconstruction and on the fixation during a suitable period with the aim to obtain a satisfactory repair of the carpal ligaments.
Infected tibial nonunions, with bone loss and extensive soft tissue damage, often require long multistage treatment. Epidermo-fascial osteoplasty according to Umiarov allows the removal of important bone loss without previous sterilization of purulent foci or coverage of the soft tissues. The results obtained in 5 cases treated by Umiarov technique are very satisfactory and allow to consider this method as a valid alternative to the traditional treatments.
In the quantitation of amino acids by precolumn derivatization with phenylisothiocyanate, the yields of N'-phenylthiocarbamyl (PTC)-aspartate and PTC-glutamate from protein hydrolysates are often suboptimal, particularly in analyses following rapid hydrolysis at 160 degrees C. In this paper we show that these losses are due to the presence of materials extracted from the glass container during hydrolysis. In the presence of these extracts, the repeated drying and neutralization steps which precede phenylthiocarbamylation result in samples not fully solubilized by the presently used derivatizing mixtures. Thus the coupling yields for the acidic residues are highly variable. A coupling buffer with the composition 35% H2O, 30% acetonitrile, 25% pyridine, and 10% triethylamine (v/v/v/v) is an efficient solvent for all amino acids in hydrolysates and permits consistent, quantitative derivatization of all amino acids, including aspartate and glutamate.
Previous studies have shown that severe sepsis after major trauma results in the reprioritization of release of hepatic acute-phase proteins (APP). They suggest competition for leucine for nutritional utilization may be responsible. To test this hypothesis, a branched-chain enriched (46.6%) amino acid mixture (BCAA) was administered on a prospective randomized basis with standard TPN therapy to 16 septic post-trauma patients. After sepsis was diagnosed, a randomized therapy (control-TPN or BCAA-TPN) was given for 12 days, or until death occurred. Total calories and amino acid nitrogen (N) administered were not different in the two groups (t-test) and q 8 h (347 study periods) amino acid clearances, urinary urea nitrogen excretion, muscle proteolysis from 3-methyl-histidine (3-MH) excretion, and standard indices of sepsis severity and hepatic function were measured, as well as platelets (PLAT), leucocytes (WBC), albumin (ALB), and six acute-phase proteins: C-reactive protein (CRP), alpha-1-antitrypsin (A1TRIP), fibrinogen (FIBRIN), alpha-2-macroglobulin (AMACRO), ceruloplasmin (CERUL), and transferrin (TRANS). Using Scheffé analysis of all contrasts the data showed: BCAA resulted in a fall in 24-hour urea N excretion (24.0 to 20.0 gm/24 hr) and in proteolysis (138 to 126 gm/24 hr) (p less than 0.0001). Prestudy CRP levels were all elevated, but compared to control where APP reprioritization occurred, over the initial 10 days of therapy BCAA patients had a more rapid fall in CRP with a more rapid rise in FIBRIN, TRANS, CERUL, ALBUMIN, AMACRO, and A1TRIP (all p less than 0.0001) relative to CRP. Also, the sepsis-reduced clearances of glutamine and glutamate, alanine, and proline were increased (p less than 0.0001) during BCAA even though urea nitrogen production was reduced (p less than 0.0001). The increase in leucine clearance with BCAA-enriched TPN was positively correlated (r2 = 0.601; p less than 0.0001) with the increase in the sum of all APP and ALB and was also associated with an increase both in FIBRIN and in platelets (p less than 0.0001). The BCAA-related increase in FIBRIN (9.1 to 11.9 mg/ml) occurred at the same time as a fall in prothrombin time (p less than 0.0001). BCAA-enriched TPN reduced proteolysis and amino acid catabolism and appeared to increase the levels of the more rapidly appearing anti-inflammatory and nutritional hepatic APP and formed coagulation elements in post-traumatic sepsis.
One of our 2 cases of periosteal chondroma of the tibia recurred three times before definitive cure, and required extensive radiographic and histologic evaluation to avoid overinterpreting the malignancy. Our experience confirms that marginal excision should be employed.
When mammalian cells are grown in medium containing [3H]spermidine, a single major tritiated protein identical to eukaryotic initiation factor 4D becomes labeled. This protein contains 1 residue/molecule of tritiated hypusine (N epsilon-(4-amino-2-hydroxybutyl)lysine), a rare amino acid which has been found in no other protein. In order to investigate the conservation of this protein, we examined two nonmammalian eukaryotes, the yeast Saccharomyces cerevisiae and the insect Drosophila melanogaster, and the eubacterial prokaryote Escherichia coli for the presence of the hypusine-containing protein. When the eukaryotic cells were grown in the presence of [3H]spermidine, electrophoretic analysis revealed a single labeled protein. In each case, the apparent molecular weight was near 18,000 and the relative pI was approximately 5.2, similar to the hypusine-containing protein of mammals. Amino acid analysis confirmed the presence of tritiated hypusine in each case, and silver staining of two-dimensional polyacrylamide gels demonstrated that, in yeast and fruit flies as in mammals, the protein is relatively abundant. In the eubacterium E. coli, one tritiated protein was predominant, but its molecular weight was 24,000 and we found no evidence that it contained tritiated hypusine. We found no evidence for the existence of the hypusine-containing protein in the archaebacterium Methanococcus voltae. These data suggest that the hypusine-containing protein is conserved among eukaryotes.
In mammalian cells, a single major cellular protein (eukaryotic initiation factor 4D) is post-translationally modified by the conversion of a lysine residue into the unusual amino acid hypusine. This modification was reported to occur during mitogen-stimulated growth of lymphocytes but not during quiescence, suggesting that alternative forms of eukaryotic initiation factor 4D might play a role in the regulation of cell growth perhaps through the control of protein synthesis itself (Cooper, H. L., Park, M. H., and Folk, J. E. (1982) Cell 29, 791-797). We took advantage of the drastic changes in translational specificity which occur in heat-shocked cells of Drosophila melanogaster, and of the wide variations in translation rates which occur in response to alterations of growth media in the fungus Saccharomyces cerevisiae, to investigate the relationship between the intracellular level and state of modification of the hypusine-containing protein and the rate and specificity of translation. We also studied whether the hypusine residue in this protein might be subject to further modification or reversion to lysine. Under all conditions examined, the protein was remarkably long-lived. Furthermore, the hypusine persists in this protein as hypusine, without further modification or reversion to lysine. Thus, we observe no correlation between the state of cellular translation and the persistence or reversal of this protein's modification. In addition, the data imply that neither are the state of such key cellular processes as DNA replication, RNA transcription, or carbohydrate metabolism so correlated.
A case of massive osteolysis of the arm is described where the typical bony lesions were associated with soft tissue lymphangiomatosis.
The appearance and accumulation of apolipoprotein B and unesterified cholesterol in the lesion-prone areas of the aorta in rabbits with diet-induced hyperlipidemia were investigated by histo-, and cytochemical techniques. Apolipoprotein B was detected by an indirect immunoperoxidase procedure both in the light and electron microscopy. Unesterified cholesterol was revealed using filipin and tomatine as specific probes. In the prelesional stages of atherogenesis, before the appearance of any structurally detectable lesions, as demonstrated by bright-field and fluorescence microscopy, apolipoprotein B and free cholesterol accumulated progressively in the extracellular matrix of the subendothelial space. At ultrastructural level, extracellular phospholipid liposomes, unesterified cholesterol and apolipoprotein B concomitantly appeared and accumulated focally in the same areas. Apolipoprotein B was preferentially located on the outer surface of the free cholesterol-containing phospholipid lamellae of the extracellular liposomes. In the lesional stages leading to fatty streak formation, the extracellular liposomes, apolipoprotein B and unesterified cholesterol had also topographically a superimposed localization pattern. Intracellular apolipoprotein B and unesterified cholesterol were also colocalized in some intimal lipid-laden cells. In the prelesional stages of hyperlipidemia the prevalent localization of apolipoprotein B around individual unesterified cholesterol-rich extracellular phospholipid liposomes, progressively accumulating in the subendothelial space, suggests their possible origin from serum-derived lipoproteins.
The effect of trauma serum on superoxide production by normal neutrophils was studied in 47 serum samples from 18 patients with multiple trauma. Ten patients became septic and eight patients remained nonseptic. Incubation in trauma serum significantly suppressed superoxide production by normal neutrophils compared with incubation in normal serum: 3.6 +/- 1.44 vs 4.04 +/- 1.64 nmole of superoxide produced by 10(6) neutrophils (mean +/- SD). There was no difference in the suppressive effect between septic and nonseptic trauma serum samples. The chemiluminescence response of normal neutrophils was likewise suppressed following incubation in trauma serum compared with incubation in normal serum. The chemiluminescence response correlated with superoxide reduction of cytochrome C. In addition, the chemiluminescence response was significantly less in septic-trauma serum than in nonseptic-trauma serum. Suppressive serum was found to inhibit the neutrophil-membrane depolarization response to latex particles, as measured by flow cytometry. We conclude that trauma serum suppresses superoxide production by normal neutrophils, and that such suppression can be detected reliably using the clinically applicable technique of chemiluminescence. A normal chemiluminescence response excludes serum-mediated suppression of neutrophil superoxide production. In addition, chemiluminescence may be of value in detecting altered resistance to sepsis following injury, while superoxide determinations do not seem to be helpful in this regard. The mechanism of action of the suppressor may involve reversible inhibition of membrane depolarization necessary for the production of bactericidal oxygen species.