Pathological case of the month. Incontinentia pigmenti.
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Adult↗
Biomedical subjects
J Garcia
Publications and source records attributed to J Garcia.
Design of molecules that specifically recognize and cleave apurinic sites in DNA.
We have prepared a series of tailor-made molecules that recognize and cleave DNA at apurinic sites in vitro. These molecules incorporate in their structure different units designed for specific function: an intercalator for DNA binding, a nucleic base for abasic site recognition and a linking chain of variable length and nature (including amino and/or amido functions). The cleavage efficiency of the molecules can be modulated by varying successively the nature of the intercalating agent, the nucleic base and the chain. All molecules bind to native calf thymus DNA with binding constants ranging from 10(4) to 10(6) M-1. Their cleavage activity was determined on plasmid DNA (pBR 322) containing 1.8 AP-sites per DNA-molecule. The minimum requirements for cleavage are the presence of the three units, the intercalator, the nucleic base and at least one amino function in the chain. The most efficient molecules cleave plasmid DNA at nanomolar concentrations. Enzymatic experiments on the termini generated after cleavage of AP-DNA suggest a strand break induced by a beta-elimination reaction. In order to get insight into the mode of action (efficiency, selectivity, interaction), we have used synthetic oligonucleotides containing either a true abasic site at a determined position to analyse the cleavage parameters of the synthetic molecules by HPLC or a chemically stable analog (tetrahydrofuran) of the abasic site for high field 1H NMR spectrometry and footprinting experiments. All results are consistent with a beta-elimination mechanism in which each constituent of the molecule exerts a specific function as indicated in the scheme: DNA targeting, abasic site recognition, phosphate binding and beta-elimination catalysis.(ABSTRACT TRUNCATED AT 250 WORDS)
Amino Acid Sequence↗
Effects of regional myocardial lidocaine infusion on high energy phosphates.
High energy phosphates [phosphocreatine (PCr) and adenosine triphosphate (ATP)] are maintained in the heart under conditions of altered myocardial contractility and under certain conditions of maintained in the heart under conditions of altered myocardial contractility and under certain conditions of myocardial ischemia (such as hibernating myocardium). However, the metabolic consequences of reduced regional contractility have not been investigated. This study was designed to test the hypotheses that (1) under conditions of normal blood flow, reduction in regional contractility does not result in changes in PCr or ATP and (2) under conditions of reduced blood flow, reduction in regional contractility prevents the expected decline in high energy phosphates usually seen in regional ischemia. An in situ open chest swine preparation was used in which regional contractility was reduced with the administration of intracoronary lidocaine. High energy phosphates were measured using phosphorus-31 magnetic resonance spectroscopy (NMR) under conditions of normal flow and reduced flow. Intracoronary lidocaine infusion in 9 animals did not change blood flow from basal levels, but significantly reduced regional segment shortening from 0.16 +/- 0.02 to 0.02 +/- 0.01. The ratio of PCr/ATP did not change with lidocaine infusion (control: 1.53 +/- 0.09; lidocaine: 1.59 +/- 0.11), but oxygen content in the anterior interventricular vein increased from 8.25 +/- 0.69 to 9.83 +/- 0.91 ml/O2/100 ml blood in parallel studies (P = 0.04). While the lidocaine infusion was maintained, subsequent coronary stenosis significantly reduced subendocardial blood flow from 0.91 +/- 0.06 to 0.41 +/- 0.06 ml/min/g without significantly altering high energy phosphates (PCr/ATP = 1.51 +/- 0.15). In contrast to the 29% decline in PCr previously seen with regional ischemia, PCr was unchanged with this degree of flow reduction in the presence of lidocaine. Thus, PCr and ATP are unchanged under conditions of reduced contractility, consistent with equilibrium of energy synthesis and utilization. In addition, factors which reduce myocardial contractility, either pharmacologically or endogenously, protect against the metabolic consequences of reduced flow by reducing MVO2.
Adenosine Triphosphate↗
Case report 860: Bacillary angiomatosis of the calcaneum.
Bacillary angiomatosis (BA) is newly reported infectious disease observed mainly in HIV-infected patients, caused by a small gram-negative bacillus of the Rochalimea genus. From a purely dermatological presentation similar to that of Kaposi's sarcoma, it may evolve into a systemic disease. Bone lesions seem fairly frequent. We report a case of an isolated osteolytic lesion due to the BA bacillus.
AIDS-Related Opportunistic Infections↗
Postnatal home visiting by midwives.
Information about postnatal home visiting is presented from a postal survey of all directors of midwifery in English NHS districts, carried out in April and May 1991. The main finding was that almost all districts had changed from the traditional policy of daily home visits up to the tenth postnatal day to selective home visits by midwives. What was meant by 'selective' varied greatly, however, and the study highlighted the need to carry out audits of postnatal midwifery visiting.
Female↗
New aspects of allergic reactions to betalactams: crossreactions and unique specificities.
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Anti-Bacterial Agents↗
Comparative study of the action of flunixin meglumine and tolfenamic acid on prostaglandin E2 synthesis in bovine inflammatory exudate.
An acute non-immune inflammation model was used to compare the action of two non-steroidal anti-inflammatory drugs, flunixin meglumine and tolfenamic acid, on prostaglandin E2 (PGE2) synthesis in bovine inflammatory exudate. The tissue cage model used involves subcutaneous implantation of polypropylene cages and subsequent stimulation by carrageenan injection of the granulation tissue which develops within the cage. Twelve calves were randomly assigned to three groups receiving placebo, flunixin meglumine and tolfenamic acid, respectively. Inflammatory exudate was sampled 30 min after carrageenan injection and at seven subsequent time points. PGE2 levels were determined by radioimmunoassay. At each time point post-carrageenan injection, flunixin meglumine inhibited PGE2 synthesis to a greater extent than tolfenamic acid. At 4, 8, 12 and 24 h these differences were statistically significant.
Animals↗
Relation among regional O2 consumption, high-energy phosphates, and substrate uptake in porcine right ventricle.
Changes in phosphate metabolites may play a role in the regulation of myocardial oxidative phosphorylation in vivo. We tested the hypothesis that changes in phosphate metabolites with increased myocardial oxygen consumption (MVO2) depend on the mechanism by which MVO2 is increased. In 17 open-chest pigs, regional MVO2 of the right ventricular (RV) free wall was increased from control by isoproterenol infusion (Iso) and by pulmonary artery constriction (PAC). The phosphocreatine-to-ATP ratio (PCr/ATP), which is inversely related to free ADP concentration ([ADP]), was determined by 31P-nuclear magnetic resonance (NMR) spectroscopy. Regional MVO2 and lactate, glucose, and free fatty acid (FFA) uptake were determined in the myocardium directly beneath the NMR coil. Iso and PAC increased MVO2 nearly equally, to approximately twice control, but produced directionally opposite changes in PCr/ATP: a significant decrease with PAC (control 1.52 +/- 0.06, PAC 1.35 +/- 0.06, means +/- SE) but a significant increase with Iso (to 1.72 +/- 0.07). Thus increased [ADP] may have stimulated oxidative phosphorylation during PAC but could not have done so during Iso. With Iso, uptake of FFA was more than three times that with PAC, and the sum of the oxygen extraction ratios for lactate, glucose, and FFA was more than double that with PAC. Enhanced substrate uptake during Iso may have increased mitochondrial NADH, which in turn may have provided an alternative stimulus to the rate of oxidative phosphorylation. These results support multifactorial control of RV oxidative phosphorylation in vivo.
Adenosine Diphosphate↗
Inhibition of fatty acid metabolism alters myocardial high-energy phosphates in vivo.
We previously observed that isoproterenol (ISO) stimulation of the in situ porcine right ventricle (RV) increases the ratio of phosphocreatine (PCr) to ATP, accompanied by marked augmentation of myocardial free fatty acid (FFA) uptake. We hypothesized that increased FFA uptake and utilization cause the increase in PCr/ATP and that inhibition of FFA metabolism during ISO would prevent such an increase. In open-chest pigs, myocardial oxygen consumption (MVO2) of the RV free wall was increased with ISO (0.15 microgram.kg-1.min-1 iv) in the absence (n = 6) and presence (n = 6) of oxfenicine (65 mg/kg iv), an inhibitor of carnitine palmitoyltransferase I. ISO caused twofold increases in MVO2 and arterial FFA concentration. In the absence of oxfenicine, ISO increased RV FFA uptake from a control of 0.01 +/- 0.01 to 0.11 +/- 0.02 (SE) mumol.g-1.min-1. The PCr/ATP, measured by 31P-nuclear magnetic resonance spectroscopy, rose from 1.75 +/- 0.05 to 2.22 +/- 0.10 (P < 0.05). In the presence of oxfenicine, FFA uptake did not increase with ISO, despite elevated arterial FFA concentration. PCr/ATP fell from 1.65 +/- 0.05 to 1.53 +/- 0.07 (P < 0.01 vs. response without oxfenicine). In four additional pigs, arterial FFA concentration was increased in the absence of ISO by infusion of Intralipid and heparin sodium. PCr/ATP increased in each pig. When oxfenicine was administered with Intralipid, PCr/ATP decreased in each pig. We conclude that increased utilization of FFA raises the RV PCr/ATP ratio in vivo. Inhibition of FFA metabolism prevents the rise in PCr/ATP otherwise observed with ISO or with high arterial FFA.(ABSTRACT TRUNCATED AT 250 WORDS)
Adenosine Triphosphate↗
Comparison of Vespula germanica venoms obtained from different sources.
This study was carried out to compare the allergenic potency of Vespula germanica (VG) venoms extracted by different methods and commercially available venoms from Vespula species currently used for in vivo and in vitro studies including immunotherapy. Pure VG venom was used as the reference material. Protein content and enzymatic and allergenic properties of all venoms studied were determined by dye stain reagent, hyaluronidase and phospholipase A1B enzyme activities, and radioallergosorbent test inhibition studies, respectively. Radioallergosorbent test discs sensitized with commercial and pure VG venom were compared using specific IgE antibodies from subjects allergic to VG venom. The data obtained indicate that there were important differences in the allergenic potency between the Vespula species venoms employed for in vivo and/or in vitro assays, VG venom obtained by sac dissection, and pure VG venom. These results indicate that venoms from Vespula species used for in vitro and in vivo tests have a lower concentration of allergens and contain nonvenom proteins. These data should be taken into account when these vespid venoms are used for diagnostic purposes and also when evaluating immunotherapy studies.
Allergens↗
Myocardial metabolism during increased work states in the porcine left ventricle in vivo.
It is not known whether myocardial energy requirements can be increased to the degree that they exceed myocardial O2 availability in the absence of abnormalities of coronary blood flow or coronary reserve. To determine whether this form of "demand ischemia" occurs, 10 swine were subjected to pressure overload induced by aortic constriction, inotropic and chronotropic stimulation by dobutamine, and the combination of these interventions. In an additional 9 animals, intravenous adenosine was administered during the combination of constriction and dobutamine to determine whether further increases in coronary flow could be achieved and if they would attenuate the metabolic changes. Left ventricular anterior wall transmural blood flow was measured by radioactive microspheres. Energy phosphates were assessed by 31P magnetic resonance spectroscopy using the Fourier series window technique to increase the proportion of signal derived from the subendocardium. Myocardial lactate release was quantified independent of net lactate uptake using an isotopic tracer technique. The three interventions produced 39% to 195% increases in myocardial O2 uptake from control measurements. The phosphocreatine to ATP ratio (PCr/ATP), uncorrected for partial saturation, fell significantly, from 1.39 +/- 0.10 at control conditions to 1.25 +/- 0.10 with dobutamine alone and 1.15 +/- 0.08 with dobutamine plus constriction (P < .05 for both). Myocardial lactate release rose from 0.21 +/- 0.03 mumol.g-1.min-1 at control conditions to 0.45 +/- 0.05 and 0.59 +/- 0.10 mumol.g-1.min-1, respectively (P < .05 for both), with these two interventions. Although transmurally averaged left ventricular blood flow rose from 0.97 +/- 0.09 mL.g-1.min-1 at control conditions to 3.25 +/- 0.47 mL.g-1.min-1 (P < .001) and subendocardial blood flow increased from 1.02 +/- 0.09 to 2.92 +/- 0.45 mL.g-1.min-1 (P < .001) at the highest of the three increased work states, the subendocardial to subepicardial flow ratio declined progressively from 1.13 +/- 0.08 to 0.87 +/- 0.04 (P < .05). With a further increase in aortic constriction, myocardial O2 uptake and subepicardial blood flow rose, whereas subendocardial blood flow did not change, and there was a further decline in PCr/ATP and a rise in lactate release. Although adenosine increased the average myocardial blood flow during high work state from 3.79 +/- 0.91 to 6.29 +/- 1.08 mL.g-1.min-1 (P < .001), the further rise in subendocardial flow from 3.08 +/- 0.62 to 3.78 +/- 0.68 mL.g-1.min-1 was not significant, nor were the accompanying changes in PCr/ATP or lactate metabolism.(ABSTRACT TRUNCATED AT 400 WORDS)
Adenosine↗
Radicular compression by gas in a spinal extra dural cyst. Report on two cases.
The authors describe two cases of secondary sciatica due to radicular compression by a gas containing cyst in the extra dural space. The diagnosis was realized with CT-Scan and magnetic resonance imaging. In both cases removal of the cyst provided relief. The pathogenesis of the presence of epidural gas is discussed and the literature reviewed.
Cysts↗
Randomized study of algorithms for discontinuing tube thoracostomy drainage.
BACKGROUND: The optimal method for removal of chest tubes has not been determined and opinion remains divided. The purpose of this study was to determine the difference between two algorithms for the removal of chest tubes: one with continuous negative intrathoracic pressure (suction group) and the other with a trial of water seal (water-seal group). STUDY DESIGN: This study was a prospective randomized trial of 80 trauma patients requiring tube thoracostomies. RESULTS: Both methods of chest tube removal had similar incidences of recurrent pneumothorax (2.5 percent). The suction group had a shorter total chest tube time (72.2 hours versus 92.5 hours, p = 0.013) and shorter time required to remove the chest tube following air leak resolution (25.2 hours versus 35.6 hours, p = 0.034). Additionally, there were more patients requiring prolonged (greater than 36 hours) removal times in the water-seal group (p = 0.009). CONCLUSIONS: Both suction and water-seal methods for chest tube removal are effective and have similar incidences of recurrent pneumothorax. The use of the suction algorithm significantly decreased both chest tube duration and the time taken for chest tube removal. In patients hospitalized for isolated pneumo- or hemothorax, the use of the suction algorithm potentially could lead to shorter length of stay.
Algorithms↗
[Magnetic resonance imaging in the diagnosis of myositis ossificans circumscripta].
A retrospective study of 5 cases, 4 of myositis ossificans circumscripta (MOC) and 1 of non-ossificans myositis, is presented. The clinical presentation was a painful soft-tissue swelling, and the final diagnosis was established by biopsy in 3 cases and clinical evolution in 2 cases. Different types of imaging techniques were performed: 4 MRI, 2 arteriographies, 3 Tc 99m scintigraphies, 3 US, 3 CT and plain film radiographs for all patients. MOC is a benign process (as opposed to myositis ossificans progressiva, which is an inherited pathology with a fatal prognosis) with 3 phases of evolution: an acute or pseudo-inflammatory phase, a sub-acute or pseudo-tumoral phase and a chronic phase with a spontaneous healing. The radiologic diagnostic findings are dependent of the phase of the disease. The calcifications are seen earlier with scintigraphy than plain films, with US being less helpful. A heterogenous mass and calcifications are seen with CT. MRI allows the characterization of oedema during the acute phase and sometimes can exclude a malignant process. MRI is the best method for an early diagnosis, the differential diagnosis and to follow the evolution.
Acute Disease↗
[CT-guided percutaneous puncture-biopsy of the spine. Review of 104 cases].
Percutaneous biopsies (PB) of the spine under CT guidance have become an important diagnostic tool in managing tumoral or infectious disease of the spine. This retrospective review reports the results of 104 biopsies of the spine, except the cervical spine, performed in 98 patients (66 females and 55 males), aged from 3 to 92 years, without complications. The overall accuracy is 71% but it must be emphasized that the diagnostic accuracy in tumoral lesions is 100% whereas in the case of suspected infectious lesions the accuracy falls to 61.5%. Our view is that the negative results are independent of the technique and we propose a second biopsy before considering a surgical approach. We conclude that this technique is safe, accurate and easy to perform, not only due to the advantages of CT but also to the improvement in biopsy needles and histocytological techniques.
Adolescent↗
Expected duration of hospital stay of low birth weight infants: graphic depiction in relation to birth weight and gestational age.
Neonatal duration of hospital stay correlated with both birth weight and gestational age in positively skewed, nonlinear relationships. Within increments of birth weight, gestational age had a semi-independent influence on length of stay. Log length of stay correlated with both birth weight and gestational age in linear, normally distributed relationships. A nomogram is provided for predicting individual lengths of stay.
Analysis of Variance↗
Chronic intrahepatic cholestasis and Sicca syndrome of sarcoidosis.
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Aged↗