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Biomedical subjects

A Strauss

Publications and source records attributed to A Strauss.

At least 73 records · Page 4Linked to original sources
PubMed1996

Acute stridor as a presentation of bilateral abductor vocal cord paralysis.

We report the case of a 48-year-old woman, referred to the Intensive Care Unit with community-acquired pneumonia, who was noted to have stridor of acute onset. Subsequent indirect laryngoscopy revealed bilateral abductor vocal cord paralysis, secondary to unsuspected carcinoma of the oesophagus, requiring immediate tracheostomy. We highlight the importance of visualisation of the vocal cords in cases of stridor of uncertain aetiology.

Carcinoma, Squamous Cell↗
PubMed1996

In vivo immobilization of enzymatically active polypeptides on the cell surface of Staphylococcus carnosus.

Many surface proteins of Gram-positive bacteria are covalently anchored to the cell wall by a ubiquitous mechanism, involving a specific, C-terminal sorting signal. To achieve cell-wall immobilization of a normally secreted enzyme in vivo, we constructed a hybrid protein consisting of Staphylococcus hyicus lipase and the C-terminal region of Staphylococcus aureus fibronectin binding protein B (FnBPB). This region comprised the authentic cell-wall-spanning region and cell-wall sorting signal of FnBPB. Expression of the hybrid protein in Staphylococcus carnosus resulted in efficient cell-wall anchoring of enzymatically active lipase. The cell-wall-immobilized lipase (approximately 10,000 molecules per cell) retained more than 80% of the specific activity, compared to the C-terminally unmodified S. hyicus lipase secreted by S.carnosus cells. After releasing the hybrid protein from the cell wall by lysostaphin treatment. Its specific activity was indistinguishable from that of the unmodified lipase. Thus, the C-terminal region of FnBPB per se was fully compatible with folding of the lipase to an active conformation. To study the Influence of the distance between the cell-wall sorting signal and the C-terminus of the lipase on the activity of the immobilized lipase, the length of this spacer region was varied. Reduction of the spacer length gradually reduced the activity of the surface-immobilized lipase. On the other hand, elongation of this spacer did not stimulate the activity of the immobilized lipase, indicating that the spacer must exceed a critical length of approx. 90 amino acids to allow efficient folding of the enzyme, which probably can only be achieved outside the peptidoglycan web of the cell wall. When the lipase was replaced by another enzyme, the Escherichia coli beta-lactamase, the resulting hybrid was also efficiently anchored in an active conformation to the cell wall of S. carnosus. These results demonstrate that it is possible to immobilize normality soluble enzymes on the cell wall of S. carnosus-without radically altering their catalytic activity-by fusing them to a cell-wall-immobilization unit, consisting of a suitable cell-wall-spanning region and a standard cell-wall sorting signal.

Adhesins, Bacterial↗
PubMed1995

C-terminal glycine-histidine tagging of the outer membrane protein Iga beta of Neisseria gonorrhoeae.

A glycine-histidine tag (Gly3His6) was added to the C-terminus of a fusion protein consisting of the cholera toxin B-subunit (CtxB) and the IgA protease beta-domain (Iga beta). The aim was to facilitate single-step purification and to create a suitable tool for kinetic and structural studies on Iga beta-driven protein translocation across the outer membrane of Gram-negative bacteria. We demonstrate that the glycine-histidine tag does not interfere with the assembly of Iga beta in the outer membrane and that the translocator function of the modified Iga beta is maintained. The applicability of the new construct for the dissection of the Iga beta mediated translocation process and general aspects of C-terminal histidine tagging of outer membrane proteins are discussed.

Amino Acid Sequence↗
PubMed1995

The CARE telematics network for the surveillance of influenza in Europe.

Since the 1950s, national networks for the surveillance of influenza have been progressively implemented in several countries. New epidemiological arguments have triggered changes in order to increase the sensitivity of existent early warning systems and to strengthen the communications between European networks. The WHO project CARE Telematics, which collects clinical and virological data of nine national networks and sends useful information to public health administrations, is presented. From the results of the 1993-94 season, the benefits of the system are discussed. Though other telematics networks in this field already exist, it is the first time that virological data, absolutely essential for characterizing the type of an outbreak, are timely available by other countries. This argument will be decisive in case of occurrence of a new strain of virus (shift), such as the Spanish flu in 1918. Priorities are now to include other existing European surveillance networks.

Computer Communication Networks↗
PubMed1994

Neoplastic transformation dose response of oncogene-transfected rat embryo cells by gamma rays or 6 MeV alpha particles.

We measured a dose-response relationship for induction of neoplastic transformation by 6 MeV alpha particles and 137Cs gamma rays in REC:myc and REC:ras cells, that is, rat embryo cells (REC) transfected with the c-myc or the Ha-ras oncogenes. The 6 MeV alpha particles simulated 222Rn emissions for risk assessment relative to low-LET radiations. The dose of gamma rays was approximately twice that of alpha particles for a neoplastic transformation frequency of 10(-3). The survival of the REC cells containing oncogenes was comparable to that of the commonly used C3H 10T1/2 cells for the same dose, but the former were more refractory to radiation-induced neoplastic transformation. Neoplastic transformation frequency measured in REC cells was 3 times lower than those typically measured in C3H 10T1/2 cells at a gamma-ray dose of 6 Gy, and 5-10 times lower at an alpha-particle dose of 3 Gy.

Alpha Particles↗
PubMed1993

Evaluation of a program for rehabilitation of osteoporotic patients (PRO): 4-year follow-up. The Bone and Mineral Group of the University of Toronto.

The value of a program for the rehabilitation of osteoporotic patients (PRO) was assessed from a 4-year follow up of 139 patients referred to the program over its initial 2 years of operation. The program consisted of educational seminars, social activities and regular exercise supervision. Patients had annual clinical assessments, and bone mass measurements by neutron activation analysis (reported as CaBI). Fitness was assessed by performance on a treadmill (reported in terms of VO2max, ml/kg/min). Seventy-eight of the 139 patients remained in the program over the 4-year follow-up. This unusually high level of commitment to the program is indicative of the psychological value that patients have derived from it. The effect of the program on the osteoporosis process was inconclusive. Group 2, the 37 patients who obtained the greatest improvement in fitness (VO2max > 6 ml/kg/min), had a significantly greater reduction in back pain than did group 1, the 36 with less significant improvement (VO2max < or = 6 ml/kg/min). The bone mass and incidence of vertebral fractures on entry into the program were not significantly different between the two groups. Group 2 had on average a greater increase in bone mass over the 4 years; mean increases in CaBI, (+/- SD) were 0.09 +/- 0.09 and 0.05 +/- 0.10 for groups 2 and 1 respectively. Group 2 had on average fewer new vertebral fractures (0.08 +/- 0.36 and 0.28 +/- 0.75 for groups 2 and 1 respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1993

Central line perforation associated with Staphylococcus epidermidis infection.

We present detailed case reviews of four very low birth weight (VLBW) infants in whom central venous silastic catheter perforation was associated with Staphylococcus epidermidis sepsis. The diagnostic and therapeutic dilemma presented by the intracavitary fluid collections occurring in all four of these cases proved to be of clinical interest. Additionally, we propose a model that may account for the etiology of catheter displacement--localized phlebitis as a result of S epidermidis infection with resultant extralumenal migration of the central venous catheter.

Algorithms↗
PubMed1992

[Value of duplex sonography in diagnosis of renal artery stenosis and its value in follow-up after angioplasty (PTA)].

The assessment of the renal arteries is particularly important in the detection of a renovascular cause of the arterial hypertension. The purpose of the present study was twofold: to evaluate the accuracy of duplex scanning in non-invasively diagnosing renal artery stenoses in hypertensive patients, and to determine the results of transluminal angioplasty of renal artery stenoses as assessed by duplex scanning. In 76 patients with arterial hyertension, 170 renal arteries (18 kidneys supplied by two renal arteries) were examined by both duplex scanning and angiography (DSA in intraarterial and intravenous technique, and conventional arteriography). Peak systolic and end-diastolic flow velocity parameters as well as the Pourcelot-index were determined in the proximal renal artery and compared with the indendently performed angiography. In 102 angiographically proven normal renal arteries, mean +/- SD peak systolic and end-diastolic velocity values were 84.7 +/- 13.9 cm/s and 31.2 +/- 7.8 cm/s, respectively, with a Pourcelot-index of 0.66 +/- 0.07. For detecting renal artery stenoses greater than 50%, duplex scanning had a sensitivity of 86%, and a specificity of 83% for a systolic peak velocity of 140 cm/s and more in the renal artery. In 13 patients with 14 stenosed renal arteries, duplex scanning and intraarterial DSA densitometry were performed before and after transluminal angioplasty of the renal artery stenoses. There was fairly good agreement between transstenotic peak systolic velocities and densitometrically determined degrees of stenosis in the renal artery (r = 0.84). These results show that duplex scanning is an accurate noninvasive diagnostic tool in detecting proximal renal artery stenoses.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Adrenal responsiveness in very-low-birth-weight infants treated with dexamethasone.

This study was designed to investigate the effect of steroid administration in ill premature neonates. Twenty high-risk very-low-birth-weight (VLBW) infants [birth weight (BW) < or = 1,300 g] with a mean BW 948 +/- 220 g, gestational age (GA) 27 +/- 1.7 weeks underwent 1-hour ACTH (Cortrosyn) stimulation tests and determination of 17-hydroxyprogesterone (17OHP)/dehydroepiandrosterone sulfate (DHEAS) at 23.6 +/- 15.9 days poststeroid treatment for bronchopulmonary dysplasia (BPD)/airway obstruction. Metyrapone tests were also obtained in 18 infants. Baseline (nonsteroid-exposed) values for pre-/post-ACTH cortisol, 17OHP, DHEAS, and pre-/post-metyrapone compound S values were obtained in 5 infants. Eight of 18 (44%) infants had evidence of secondary (hypothalamic-pituitary) adrenal suppression based on abnormal metyrapone tests. No difference was found in BW, GA, time on O2 or AV, steroid dose/kg, or neonatal/postneonatal mortality between the suppressed and nonsuppressed groups. Two of 4 infants with borderline ACTH tests had subnormal compound S levels postmetyrapone. No relationship was found between steroid dose/kg and cortisol response post-ACTH. Additionally, corrected GA was not related to change in cortisol, 17OHP, and DHEAS pre-/post-ACTH. Two infants exhibited recovery of adrenal suppression documented by repeated metyrapone testing at 63 and 186 days poststeroid treatment. In conclusion, this study documents the apparent high incidence of secondary adrenal suppression in VLBW infants treated with dexamethasone. Clinical significance of these findings deserves further investigation.

17-alpha-Hydroxyprogesterone↗
PubMed1991

A nursing model for chronic illness management based upon the Trajectory Framework.

The trajectory framework developed by Strauss and associates provides a conceptual basis for developing a nursing model that gives direction for practice, teaching, and research in the area of chronic illness. This paper presents an overview of the trajectory framework and shows how it can be used to generate such a nursing model.

Adaptation, Psychological↗
PubMed1990

Fluoride-induced fractures: relation to osteogenic effect.

The possible effects of fluoride in inducing fractures were studied in 61 patients treated with sodium fluoride (NaF), 40-60 mg daily in combination with calcium and vitamin D. Nine patients developed the fluoride-(F) related lower extremity pain syndrome. Four other patients had stress fractures associated with trauma. Seven of the 61 patients had 10 upper femur fractures of which 5 were stress fractures. The bone mineral mass of the central skeleton including the hips was measured by neutron activation and the results expressed as a calcium bone index (CaBI) which normalizes the results to that of young adults of the same body size (normal range 0.75-1.2). At the time of hip fracture, 4 patients with a minimal increase in bone mass (mean delta CaBI 0.01) had 4 femur fractures and 3 patients with a marked increase (mean delta CaBI 0.24) had 6. The 7 patients with upper femur fractures at 4 years had a significantly higher bone fluoride retention, 30 mg/g Ca compared with 23.9 mg/g Ca for the other 54 (p less than 0.02) and were older, 73.1 versus 64.2 years (p less than 0.01). Using all 61 fluoride-treated patients, femur fractures/patient were significantly correlated to bone fluoride (p less than 0.05) and to age (p less than 0.05). By partial correlation, only the correlation between hip fractures/patient and bone fluoride remained significant after controlling for the effect of age (p less than 0.05). These results suggest that fluoride therapy may be implicated in the pathogenesis of hip fractures which may occur in treated patients despite a rapid, marked increase in bone mass. The lower extremity pain syndrome is not frequently associated with stress fractures in this study.

Aged↗
PubMed1990

Bone mineral mass associated with postmenopausal vertebral deformities.

Vertebral morphometry on thoracic and lumbar spine radiographs and bone mass measurements were carried out on 215 patients investigated for postmenopausal osteoporosis. Bone mineral mass was measured on the central third of the skeleton by neutron activation analysis and the result, normalized for body size, expressed as a calcium bone index (CaBI). The normal CaBI value for females (20-40 years) is 0.97 (0.11) with a lower limit for these young, normal women, of 0.75. Vertebral compression deformity was defined as a mean height more than 15% lower than adjacent normal vertebrae. Thoracic and lumbar anterior wedge deformities and central compression were defined as anterior/posterior (A/P) or mid/posterior (M/P) height ratios of less than 0.75. For the 129 patients without vertebral deformities, the mean CaBI was 0.80 (0.12) (1 SD) and 32% of these patients had CaBI values below the normal young adult range (CaBI less than 0.75). In 20 patients, vertebral deformities were limited to 1 or 2 mid-thoracic vertebrae, and the mean CaBI values for these 20 patients was 0.81 (0.15), equal to that for patients without any vertebral deformity. For the remaining 67 patients, (i.e., patients with one or more vertebral deformities involving at least one distal thoracic or one lumbar vertebra) the mean CaBI value was 0.66 (0.10), 17% below the value for patients without vertebral deformities. Low CaBI values (CaBI less than 0.75) were observed in 87% of these patients, consistent with the diagnosis of osteoporotic fractures. Based on our CaBI results, however, mid-thoracic deformity was not associated with significant osteopenia and is not, therefore, diagnostic of osteoporotic fracture.

Adult↗