Donor-state-enabling Er-related luminescence in silicon: direct identification and resonant excitation.

We conclusively establish a direct link between formation of an Er-related donor gap state and the 1.5 microm emission of Er in Si. The experiment is performed on Si/Si:Er nanolayers where a single type of Er optical center dominates. We show that the Er emission can be resonantly induced by direct pumping into the bound exciton state of the identified donor. Using two-color spectroscopy with a free-electron laser we determine the ionization energy of the donor-state-enabling Er excitation as E(D) approximately 218 meV. We demonstrate quenching of the Er-related emission upon ionization of the donor.

Gene cloning and nucleotide sequencing and properties of a cocaine esterase from Rhodococcus sp. strain MB1.

A strain of Rhodococcus designated MB1, which was capable of utilizing cocaine as a sole source of carbon and nitrogen for growth, was isolated from rhizosphere soil of the tropane alkaloid-producing plant Erythroxylum coca. A cocaine esterase was found to initiate degradation of cocaine, which was hydrolyzed to ecgonine methyl ester and benzoate; both of these esterolytic products were further metabolized by Rhodococcus sp. strain MB1. The structural gene encoding a cocaine esterase, designated cocE, was cloned from Rhodococcus sp. strain MB1 genomic libraries by screening recombinant strains of Rhodococcus erythropolis CW25 for growth on cocaine. The nucleotide sequence of cocE corresponded to an open reading frame of 1,724 bp that codes for a protein of 574 amino acids. The amino acid sequence of cocaine esterase has a region of similarity with the active serine consensus of X-prolyl dipeptidyl aminopeptidases, suggesting that the cocaine esterase is a serine esterase. The cocE coding sequence was subcloned into the pCFX1 expression plasmid and expressed in Escherichia coli. The recombinant cocaine esterase was purified to apparent homogeneity and was found to be monomeric, with an M(r) of approximately 65,000. The apparent K(m) of the enzyme (mean +/- standard deviation) for cocaine was measured as 1.33 +/- 0.085 mM. These findings are of potential use in the development of a linked assay for the detection of illicit cocaine.

A novel splice variant of the cell adhesion molecule BIG-2 is expressed in the olfactory and vomeronasal neuroepithelia.

We have cloned a mouse cDNA encoding a novel truncated form of the gene BIG-2 from the vomeronasal organ. The related proteins BIG-2 and BIG-1 possess a C-terminal glycosylphosphatidylinositol anchor, six immunoglobulin domains and four fibronectin type III repeats. They are related to certain axonal-associated cell adhesion molecules (AxCAMs) exhibiting most similarity to the TAG-1/F3 subgroup of neural cell adhesion molecules. The cDNA we have identified, termed BIG-2A, appears to represent a novel splice variant of BIG-2 possessing six Ig-like domains, a single fibronectin repeat and lacking the glycosylphosphatidylinositol-anchoring domain (GPI). To determine the expression of this gene, in situ hybridization analysis was performed in adult and developing mice using a riboprobe specific for BIG-2A. Maximum expression was observed in mature sensory cells of the vomeronasal neuroepithelium and a less intense signal was also evident in the olfactory neuroepithelium. These results suggest that alternative splicing of the BIG-2 gene transcript may play an important role in the organization of the vomeronasal and olfactory neuroepithelia.

MR imaging of the rotator cuff mechanism: comparison of spin-echo and turbo spin-echo sequences.

OBJECTIVE: Although well documented in other MR imaging applications, the value of turbo spin-echo sequences in evaluating the shoulder has not been addressed. This study was designed to directly compare matched spin-echo and turbo spin-echo sequences in the MR imaging evaluation of the rotator cuff. MATERIALS AND METHODS: Using otherwise matched double-echo sequences of equal time duration, we performed 123 paired spin-echo (TR/TE, 200/25,75; one excitation) and turbo spin-echo (3500-5000/22,90; two excitations) sequences in the paracoronal and/or parasagittal plane of the shoulders of 76 patients referred to our institution for possible rotator cuff tear. The sequences were retrospectively analyzed for cuff signal and morphology, fluid conspicuity, coracoacromial arch morphology, and bone marrow signal abnormalities. Surgical and nonsurgical clinical results were correlated when available. RESULTS: We found 100% diagnostic correlation between spin-echo and turbo spin-echo sequences for rotator cuff integrity. Surgical data were available for 26 patients, and clinical follow-up for another 37. For complete rotator cuff tear in the surgical subpopulation, sensitivity was 89%, specificity was 94%, and diagnostic accuracy was 24 of 26 (92%). We found no diagnostically significant difference between the two imaging sequences for fluid conspicuity, coracoacromial morphology, or marrow signal. Signal-to-noise ratios were superior in the turbo spin-echo sequences. CONCLUSION: Turbo spin-echo sequences are an accurate and efficient tool in the MR imaging evaluation of the rotator cuff. Potential benefits include time saving, increased spatial resolution, and improved signal-to-noise ratio.

MR imaging of the posterior cruciate ligament: normal, abnormal, and associated injury patterns.

The posterior cruciate ligament (PCL) of the knee has received little attention in the radiology literature, but its importance in knee stability has come under close scrutiny in recent years. Unrepaired injury of the PCL can lead to chronic instability and early joint degeneration. Three major mechanisms of trauma that involves the PCL are posterior displacement of the tibia in a flexed knee, hyperextension, and rotation combined with an adduction or abduction force. The spectrum of PCL injuries includes partial tear or intrasubstance injury, complete ligamentous rupture, and avulsion of the PCL insertion site on the posterior tibia. Associated injuries include injury of other ligaments, meniscal tear, bone injury, and joint effusion. PCL rupture is easily identified with magnetic resonance (MR) imaging by using simple signal intensity and structural characteristics. Because clinical and arthroscopic assessment of the PCL can be difficult, MR imaging can be valuable for evaluating the acutely injured knee when operative repair of the PCL is being considered.

MR imaging appearance of the extensor mechanism of the knee: functional anatomy and injury patterns.

Trauma to the extensor mechanism of the knee, a common clinical problem, can be accurately evaluated with magnetic resonance (MR) imaging. The extensor mechanism consists of the quadriceps muscle and tendon, patella, patellar tendon, and patellar retinacula. Injuries of these structures can be classified into partial and complete tears. Acute injuries are associated with edema, hemorrhage, and fluid collections; chronic injuries often demonstrate redundancy, atrophy, and retraction of the affected structures. MR imaging is useful in differentiating partial and complete tears and in evaluating tissue edema and hemorrhage. It also allows detection of unsuspected nondisplaced patellar fractures and chronic conditions due to repetitive trauma. Transient dislocation of the patella is an often clinically unsuspected entity for which MR imaging can serve an important diagnostic role. A detailed understanding of the functional and anatomic relationships of the extensor mechanism can greatly assist in interpretation of MR images of the traumatized knee.

The persistent computed tomography nephrogram: its significance in the diagnosis of contrast-associated nephrotoxicity.

A study was undertaken to find out if there is a quantitative relationship between the development of contrast-associated nephrotoxicity (CAN) and the mean renal cortical attenuation (RCA) as seen on computed tomography (CT) examination of the kidneys 24 hours after injection of contrast medium. 96 patients undergoing aortography were selected, who were considered "high risk" either because of the presence of a baseline serum creatinine (Cr) of 123.76 mumol l-1 (1.4 mg dl-1) or higher, or who were 73 or older with or without elevated creatinine levels. A CT study of the kidneys at approximately 24 h was correlated with baseline serum creatinine as well as 24 h Cr (48-72 h Cr when available). Medical history and medications were recorded. Eight of 96 patients had RCA of 108-236 HU at 24 h CT and all developed significant CAN of varying degree; 3/96 had RCA ranging from 48 to 67 HU and had transient CAN; two other patients with RCA of 67-90 HU developed CAN; and there was increased incidence of CAN in patients: (a) with pre-existing renal insufficiency; (b) with diabetes with renal insufficiency; (c) on diuretics; (d) who were older; and (e) had a unilateral atrophic kidney. It was concluded that a 24 h CT study evaluating the RCA had better predictive value for the development of CAN than a 24 h creatinine level.

Manipulations of germ-cell populations in the gonad of the fowl.

1. Embryos of the domestic fowl have been partially sterilised by injecting the drug busulphan into 24-h incubated eggs. 2. Some of these embryos were injected with primordial germ cells (PGCs) after 55 h of incubation to attempt to repopulate the gonads. 3. Primordial germ cells transfected with a defective retrovirus containing the reporter gene lac Z were shown to settle in these sterilised gonads. 4. Quantitative histology of 6-d embryos showed that busulphan produced 75% sterilisation but that PGCs could repopulate these gonads. 5. The technique of producing such germ line chimaeras is of value in studying cell kinetics, gonad differentiation and the production of transgenics.

[Method of treatment and platelet aggregation in patients with diabetes mellitus type II]. / Sposób leczenia a agregacja krwinek plytkowych u chorych na cukrzyce typu II.

Platelet aggregation after ADP administration in 84 diabetic patients and in 14 healthy subjects were examined. ADP concentration indispensable to start aggregation, velocity and intensivity of this process using Born method were measured. In diabetic patients (independently of kind of therapy) the increase platelet aggregation activity were found (significant difference between kind of insulin therapy).

[Certain complications of diabetes mellitus in old age]. / Niektóre powiklania w cukrzycy wieku podeszlego.

The incidence rate of the diabetes mellitus in the aged patients has been analyzed. The clinical picture, complications, and the treatment varieties were evaluated in 2260 patients observed in the diabetes dispensary. Among them this disease has been diagnosed in 500 patients after 60 year of life. The results of the observations were compared with that found in 160 patients with diabetes diagnosed before the 35 year of life. This analysis revealed that the insulin treatment decreases in the aged patients the retinopathy rate, that in them the hypersensitivity and the resistance against this hormone are rather exceptional.

[Does hypoglycemic treatment with gliclazide and gliquidone affect platelet function in type II diabetic patients?]. / Czy leczenie hypoglikemizujace gliklazydem i glikwidonem wplywa na czynnosc plytek u chorych na cukrzyce typu II?

The estimation of the influence of gliclazide and gliquidone treatment on platelet function in type II diabetic patients was undertaken in the study. Aggregation parameters were assessed before and after the change of hypoglycemic therapy. Gliclazide was applied in the group I (11 patients, mean age 63.1 +/- 7.22 years, duration of diabetes 5.63 +/- 2.98 years), group II (19 patients, mean age 58.3 +/- 12.4 years, duration of diabetes 7.1 +/- 2.4) received gliquidone. The reference group consisted of 10 healthy volunteers (mean age 51.7 +/- 6.9). Aggregation parameters (threshold ADP concentration, intensity and velocity of the aggregation) were measured in examined groups of subjects. Metabolic control was estimated basing upon spectrophotometric measurement of fructosamine level. Significant increase in threshold ADP concentration (1.89 +/- 0.47 mumol/l before and 2.36 +/- 0.58 mumol/l after the treatment change p < 0.05) in group II was found. Threshold ADP concentration did not change significantly in group I (2.5 +/- 0.8 mumol/l before v 2.14 +/- 0.68 mumol/l after treatment). Significant decrease in the aggregation intensity was found in both groups (in group I 8.48 +/- 1.7 before v 6.39 +/- 2.17 after; in group II 7.35 +/- 1.73 before v 6.05 +/- 1.6 after 1 month treatment--both p < 0.05). The aggregation velocity did not change significantly (group I 61. +/- 11 before v 51.3 +/- 18.7 after, group II 63.2 +/- 14.8 and 62.8 +/- 13.7 respectively). Reference group values were ADP 2.7 +/- 0.16, intensity 6.22 +/- 0.53, velocity 63.2 +/- 2.2.(ABSTRACT TRUNCATED AT 250 WORDS)

[Restoration of physiologic integrity of the gastrointestinal tract because of fever following partial jejuno-ileal anastomosis in extreme obesity]. / Przywrócenie fizjologicznej ciaglosci przewodu pokarmowego z powodu goraczki po czesciowym wylaczajacym zespoleniu czczo-kretniczym u skrajnie otylych.

The authors present three patients with fever of hectic profile following partial excluding jejuno-ileal anastomosis for extreme obesity. Cause of such a high fever was not detected in any patient. Despite the treatment with broad-spectrum antibiotics and intensive treatment no decrease in body temperature was achieved. Failure of these conservative methods forced surgeons to restore physiological integrity of the small intestine. Rapid normalization of body temperature and improvement in patients health status were noted after surgery.

Future role of thrombolytic therapy in emergency medicine.

Thrombolytic therapy offers the promise of major therapeutic intervention in many areas as well as in the treatment of patients with acute myocardial infarction who present to the emergency department. Infusion of tissue-type plasminogen activator (tPA) during field transport has been proven safe, but optimal methods for reliably diagnosing acute myocardial infarction in the prehospital setting have yet to be delineated. A major advance would be achieved if thrombolysis were proven effective in preventing the progression of unstable angina to actual infarction. However, early studies have yielded contradictory results. The use of tPA in dissolving peripheral arterial clots appears very promising, but long-term limb survival has yet to be demonstrated. Unlike heparin, thrombolytic agents can also lyse clot in peripheral deep veins and possibly lessen the tendency toward postphlebitic syndrome. The proper dosage regimen to minimize hemorrhage has not been determined. Pulmonary emboli can be lysed by tPA. IV infusion is as effective as intrapulmonary. Significant complications can be minimized, particularly if major vessel catheterization can be avoided for diagnosis. Even after catheterization for pulmonary angiography, however, thrombolytic therapy appears quite promising. The use of thrombolytic agents for embolic-thrombotic stroke is less promising: therefore, the risk of hemorrhagic complication may not outweigh the potential benefit. Thrombolytic therapy thus offers the potential for significant impact on the practice of emergency medicine.

The adult respiratory distress syndrome.

ARDS is a pulmonary injury syndrome associated with a variety of clinical disorders. The pathophysiology of ARDS has been clarified substantially in the past several years. Neutrophils are probably the chief mediators of pulmonary injury, serving as the focus for release of several toxic substances that cause capillary endothelial and alveolar epithelial damage. The mortality rate in ARDS remains high despite advances in elucidating of pathogenesis. Newer approaches to management stress earlier identification of patients and specific therapy aimed at interfering with the damage produced by toxic mediators of pulmonary injury.