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Biomedical subjects

A Ali

Publications and source records attributed to A Ali.

At least 199 records · Page 11Linked to original sources
PubMed1997

Prevalence of adrenal carcinoma among incidentally discovered adrenal masses. A retrospective study from 1989 to 1994. Gruppo Piemontese Incidentalomi Surrenalici.

BACKGROUND: The incidental discovery of an adrenal mass poses the problem of distinguishing between the frequent benign masses and the infrequent malignant ones that require surgery. Univocal guidelines to approach this problem are unavailable. OBJECTIVE: To perform a survey of the clinical management of incidentally discovered adrenal masses (ie, adrenal incidentalomas). DESIGN: A multicentric retrospective analysis of hospital medical records of adrenal incidentalomas diagnosed during a 5-year period; the medical records were scrutinized for demographic data and clinical details by means of a specifically tailored questionnaire. SETTING: The major surgical and medical centers of Piedmont, a northern Italian region with approximately 4 million inhabitants. The recruitment pattern of these centers was unselected. PATIENTS: The definition of adrenal incidentaloma was limited to patients with a physical examination and a clinical history unindicative of adrenal disease. Exclusion criteria also included hypertension of suspected endocrine origin and a history of neoplasms known to metastasize frequently in the adrenal glands. Two hundred twenty-four medical records were collected, and 210 were analyzed (14 excluded a posteriori). RESULTS: Most patients were in their 50s and 60s, and women were predominantly affected. The frequency of adrenocortical cancer was 13% among patients operated on. The tumor diameter was highly correlated with the risk of cancer; a cutoff at 5 cm had a sensitivity of 93% with a specificity of 64% in discriminating between benign and malignant cortical lesions. CONCLUSIONS: The occurrence of adrenocortical carcinoma among adrenal incidentalomas is not rare. The evaluation of the mass size is a simple and effective method for selecting patients at risk for cancer. The indication for surgery of masses larger than 5 cm, or of masses of any diameter that have suspicious imaging characteristics, limits unnecessary operations and costs.

Adrenal Gland Diseases↗
PubMed1997

Cushing's syndrome due to ACTH-independent bilateral adrenocortical macronodular hyperplasia.

ACTH-independent macronodular adrenocortical hyperplasia (AIMAH) is a rare cause of Cushing's syndrome in which adrenal glands become very enlarged, occupied and distorted by multiple cortical nodules. We report on such two patients, a 44-year-old man and a 40-year-old woman. Physical examination revealed in both cases a classic cushingoid habit. Laboratory studies showed overt hypercortisolism with high urinary free cortisol excretion and elevated serum cortisol with loss of the circadian rhythm. Serum cortisol levels were not modified after high dose dexamethasone. ACTH levels were undetectable both in baseline conditions and following CRH or metyrapone. In both cases, abdominal CT demonstrated bilaterally enlarged adrenal glands which were distorted by multiple bumps. 131I-Norcholesterol scintiscan showed bilateral uptake of the radionuclide. Pituitary region was normal at neuroradiologic imaging. Bilateral adrenalectomy was performed in both cases. In patient I, adrenal glands weighted 77 and 90 g, respectively, while in patient II they were of 90 and 55 g, respectively. At histological examination, the adrenal cortex was occupied by multiple nodular lesions composed mostly of clear cells. In the internodular regions, no evidence of cortical architecture was observed. At the immunohistochemical evaluation, both cases displayed KI-67 staining comparable with that of ACTH-dependent diffuse hyperplasia. Postoperative course was uneventful and signs of Cushing's syndrome resolved in about three months. At the last follow up, the patients are going well on glucocorticoid and mineralocorticoid supplementation. Plasma ACTH levels are 65 and 107 pg/ml, respectively.

Adrenal Cortex↗
PubMed1997

Heat shock protein gene expression during Xenopus development.

Stress-induced heat shock protein gene expression is developmentally regulated during early embryogenesis of the frog, Xenopus laevis. For example, a number of heat shock protein genes, such as hsp70, hsp90, and ubiquitin are not heat-inducible until after the midblastula stage of embryogenesis. Furthermore, the family of small heat shock protein genes, hsp30, are differentially expressed after the midblastula stage as well as being regulated at the level of mRNA stability. Many of these stress proteins are also synthesized constitutively during oogenesis and embryogenesis during which they may act as molecular chaperones as well as being involved in sequestering proteins in an inactive state until required by the developing embryo. Furthermore the induction of these stress protein genes has been correlated with enhanced thermoresistance. During stressful conditions heat shock proteins probably prevent aggregation or misfolding of damaged proteins within the embryo.

Animals↗
PubMed1997

A biomechanical study of the flexor digitorum superficialis: effects of digital pulley excision and loss of the flexor digitorum profundus.

Many reports have been devoted to characterizing the significance of the pulleys for the flexor digitorum profundus (FDP). However, no comparable work has been published on the flexor digitorum superficialis (FDS). This study characterized the FDS in a human cadaver model. Eleven fresh-frozen cadaver hands were used. By using a tensiometer, data were gathered for tendon excursion, tendon load, and work of flexion. Changes in efficiency were caused by excision of annular pulleys A1, A2, A3, and the palmar aponeurotic pulley. We also measured the effect of FDP excision on FDS efficiency. Sectioning of the A2 and A3 pulleys together caused statistically significant losses of efficiency in all three parameters (work, load, and excursion). When the FDP was removed from a finger with an intact pulley system, losses in both work and excursion efficiencies were significant. Removing the FDP while cutting different pulleys caused significant decrease in FDS excursion efficiency. We conclude that A2 and A3 are the most important pulleys for maintaining normal FDS function, and that the presence of the FDP in the digital sheath is essential for optimal FDS excursion efficiency.

Biomechanical Phenomena↗
PubMed1997

Heterogeneity of cardiac allograft vasculopathy: clinical insights from coronary angioscopy.

OBJECTIVES: With this study, we sought to examine the heterogeneity of cardiac allograft vasculopathy in vivo using coronary angioscopy as an adjunct to intravascular ultrasound, and we evaluated the clinical relations of immunologic and nonimmunologic risk factors with the different forms of cardiac allograft vasculopathy detected angioscopically. BACKGROUND: Intravascular ultrasound detects vascular intimal proliferation accurately but is limited in its ability to delineate morphologic characteristics. Coronary angioscopy can evaluate intimal surface morphology by direct visualization and can differentiate pathologically distinct forms of plaque topography on the basis of color and contour. METHODS: We studied 107 consecutive heart transplant recipients with intravascular ultrasound and angioscopy at the time of their annual angiogram, and we assessed the relation of nonimmunologic and immunologic risk factors to the development of cardiac allograft vasculopathy distinguished angioscopically into a pigmented (yellow) or nonpigmented (white) intimal thickening. We further evaluated the clinical differences in cardiac events among these two forms of angioscopically heterogeneous forms of cardiac allograft vasculopathy. RESULTS: Significant clinical predictors of nonpigmented intimal thickening were advanced donor age and lower mean cyclosporine levels, whereas hyperlipidemia, cumulative prednisone dose and time since transplantation correlated with pigmented intimal hyperplasia. In addition, comparisons between the two angioscopic groups revealed increased intimal thickening, serum cholesterol, low density lipoprotein cholesterol, acute allograft rejection and time since transplantation in the group with pigmented intimal thickening (p < 0.05). With regard to cardiac events, nonpigmented plaque was more frequently found in the sudden death group (53% vs. 20%, p = 0.05), whereas the nonsudden cardiac event group had a significantly higher prevalence of pigmented plaque (80% vs. 47%, p = 0.07). CONCLUSIONS: These findings indicate that cardiac allograft vasculopathy is a heterogeneous disease with varied morphologic expressions with different clinical implications. Furthermore, this investigation provides insight into the cohesive, yet diverse influences of various factors, particularly immunosuppression, in these forms of cardiac allograft vasculopathy.

Adult↗
PubMed1997

What in-vitro method should surgeons use to evaluate the clinical behavior of arterial bypass conduits.

UNLABELLED: Surgeons have traditionally relied on ring preparations to predict how arterial bypass conduits will behave in the postoperative circulation. OBJECTIVE: This study compared pharmacologic [norepinephrine (NE) challenge] and physiologic [arterial preload] responses of gastroepiploic (GEA) and internal thoracic (ITA) arteries in a standard static ring preparation and a dynamic perfusion system. METHODS: Six GEAs (1.0-1.5 mm dia.) and six ITAs (1.5-2.0 mm dia.) 11 cm long were harvested from adult pigs and mounted on a computer controlled perfusion system. Inflow pressure was set at 80 mmHg and outflow resistance was adjusted to simulate high (80-90 ml/min) and low (15-20 ml/min) flow demands. NE response (10(-9)-10(-5) M) was measured under low flow conditions and at high flow conditions when distal arterial pressure (load) was reduced. NE response (10(-9)-10(-5) M) was also evaluated in arterial rings (ITA N = 6, GEA N = 6) with tensions adjusted to simulate the loads occurring at low flow (80 mmHg) and high flow (60 mmHg) situations. RESULTS: In the static ring preparation, NE response [ED50] was similar for both GEA and ITA and was not affected by load. The dynamic preparation demonstrated that the GEAs were significantly more responsive to NE than the ITAs [ED50 high flow ITA 6.1 +/- 0.3**, GEA 7.2 +/- 0.3***; *P < 0.05 versus baseline, **P < 0.05 versus low flow values, ***P < 0.05 versus ITA]. Furthermore, in the dynamic preparation, NE response was profoundly affected by reduced load which occurs under high flow conditions [7.18 +/- 0.3 versus 6.1 +/- 0.3 under high flow and 5.8 +/- 0.1 versus no response under low flow conditions]. CONCLUSION: Static ring preparations do not discern differences between ITA and GEA susceptibility to spasm and fail to detect the effect of load. The dynamic preparation demonstrated significant differences between the GEA and ITA potential to spasm which is consistent with widespread clinical experience. Furthermore a dynamic preparation is highly sensitive to reduced load which occurs under high flow conditions. Although it is more demanding, the dynamic preparation provides superior information to the surgeon in predicting the behavior of arterial bypass grafts.

Animals↗
PubMed1997

Group A beta-haemolytic streptococcal infection and Henoch-Schonlein purpura with cardiac, renal and neurological complications.

A 6-year-old girl had a group A beta-haemolytic streptococcal (GABS) throat infection and Henoch-Schonlein purpura (HSP). The clinical course was complicated by nephrotic syndrome due to crescentic glomerulonephritis, transient neurological symptoms due to focal ischaemia of the brain, and congestive cardiac failure due to myocarditis. The clinical presentation highlights the diversity of systemic involvement in HSP, the transient nature of apparently serious central nervous system involvement, and a possible role of GABS in its aetiology.

Child↗
PubMed1997

Binding characteristics of SLE anti-DNA autoantibodies to modified DNA analogues.

Native calf thymus DNA was modified with furocoumarins and reactive oxygen species (ROS). The modifications were probed by UV & Fluorescence spectroscopy, thermal denaturation and hydroxyapatite chromatography. In CD spectroscopy changes in the ellipticity of the DNA molecule were observed as a result of modification. The binding specificity of naturally occurring anti-DNA antibodies with modified DNA molecules was assessed by ELISA and quantitative precipitin titration. The affinity of anti-DNA antibodies for modified conformers was found to be quite high.

Antibodies, Antinuclear↗
PubMed1997

Antigenic and genetic variations among Japanese encephalitis virus strains belonging to genotype 1.

Hyperimmune antisera against four Japanese encephalitis (JE) virus strains, ThCMAr4492 and ThCMAr6793 from Thailand and Nakayama and JaGAr01 from Japan, were used to analyze the antigenic relationships among 12 Thai strains belonging to genotype 1, and two Japanese strains and one Chinese strain belonging to genotype 3. The antiserum for ThCMAr6793 significantly neutralized nine of the 12 Thai strains, none of which was significantly neutralized by antisera for the Nakayama and JaGAr01 strains. The antiserum for ThCMAr4492 neutralized only its homologous strain; therefore, ThCMAr4492 was antigenically different from all other strains. Two Thai strains (Subin and KE-093/83) were significantly less neutralized by all four of the antisera tested. In the deduced amino-acid sequence of the E protein, the 12 Thai strains revealed 100 to 98.2% identity among them and 90.0 to 98.8% identity with the published strains, respectively. Among significant amino-acid substitutions, three residues at positions E-222, E-327 and E-366 were shared by all of the Thai strains, whereas residues at E-89, E-123, E-131, E-178, E-293, E-351 and E-373 seemed to be strain-specific. The amino acids at positions E-178, E-327, E-351, E-373 and E-366 are found either in the peptides with functional T-helper cell epitopes or in the ectodomain of the E protein of other flaviviruses. These amino acids may therefore be responsible for determining the antigenic heterogeneity of these strains.

Amino Acid Sequence↗
PubMed1997

Usefulness of serology in preendoscopic screening. The Italian Helicobacter pylori Study Group.

BACKGROUND: Over the last 20 years, upper gastrointestinal endoscopy has become the investigation of choice for patients with symptoms referrable to the upper gastrointestinal tract. As the increasing number of patients referred for endoscopy has led to enlarged waiting lists and medical expenses, it has been recommended that preendoscopic screening strategies might identify patients at low risk of having major pathology. These patients could avoid prompt endoscopy and might safely undergo different management. Since the recognition of the major role played by Helicobacter pylori in gastroduodenal pathology, H. pylori serological and demographical features have been proposed as part of preendoscopic screening strategies in dyspeptic patients referred to endoscopy, in an attempt to reduce endoscopic workload and medical expenses. METHODS: We evaluate data presented in the literature and aim to give interpretations possibly helpful in the clinical practice. RESULTS: The analysis of the endoscopic findings showed that applying a preendoscopic strategy based on age and H. pylori status in local hospitals without a specific interest in H. pylori research would have meant missing a proportion of relevant pathology: 35 of 557 (6.3%) peptic ulcers (24 duodenal and 11 gastric ulcers) and two gastric cancers (0.3%). CONCLUSIONS: Although we do understand the need to increase the cost-effectiveness of endoscopy and realize that considering age and H. pylori status could help to get to this target, we conclude that similar preendoscopic screening strategies must be refined further before being adopted on a large scale.

Endoscopy, Gastrointestinal↗
PubMed1997

Preferential activation of HSF-binding activity and hsp70 gene expression in Xenopus heart after mild hyperthermia.

We have examined the effect of mild hyperthermia on the pattern of heat shock transcription factor (HSF) binding activity, heat shock protein 70 (hsp70) and hsp30 gene expression and protein denaturation in selected tissues of adult Xenopus namely, heart, hind limb muscle, eye, liver and spleen. In these studies it was found that heart tissue was the most thermally sensitive of all of the tissues examined since maintenance of adult frogs at 26 degrees C resulted in a preferential activation of HSF binding. Thus, heart has a lowered set point temperature for HSF activation compared to the other tissues examined. At 30 degrees C HSF activation was observed in all of the tissues examined. Heart HSF activation at 26 degrees C was correlated with an increase in hsp70 mRNA and Hsp70 protein accumulation. At 28 degrees C the largest amount of hsp70 and hsp30 mRNA accumulation was detected in heart and skeletal muscle compared to other tissues while hsp70 mRNA accumulation was relatively low in spleen and hsp30 mRNA accumulation was not detectable in eyes, liver and spleen. Incubation of adult frogs at 30 degrees C resulted in enhanced hsp70 and hsp30 mRNA accumulation in all of the tissues. Finally, we have used differential scanning calorimetry (DSC) to compare the temperatures at which protein denaturation occurs in heart and liver tissue. The onset of protein denaturation (T0) occurred approximately 8.5 degrees C lower in heart compared to liver. Also the midpoint of the DSC profile (T1/2) was approximately 10.4 degrees C lower in heart than in liver. Thus, heart proteins are generally more thermolabile than proteins in liver tissue. Taken together these data suggest that heart is more sensitive than the other tissues examined with respect to moderate increases in environmental temperature.

Animals↗
PubMed1997

Leishmaniases survey in the Awash Valley: leishmanin skin test profile in the Upper Awash and surrounding areas.

The occurrence of leishmanial infection in the Upper Awash and the surrounding areas was assessed in a survey conducted between December 1994 to March 1995, employing a cross-sectional leishmanin skin test. Out of the 803 study subjects skin tested, 775 (97%) returned for the reading of the reaction. The rate of leishmanin positivity in 10 representative study sites ranged from 16% to 65% with the over all prevalence of 33% in the study area. Prevalence of leishmanin positive skin test increased with age in male sex (40%) and in the indigenous Afars (60%), a profile suggesting a particular form of outdoor exposure to transmission. The difference in leishmanin positivity by study sites, sex and ethnic background were all statistically significant (X2 = 72.9; P < 0.001, X2 = 16.2; P < 0.001 and X2 = 62.8; P < 0.001 respectively). The current status of overt leishmanial disease in the area and the implication of the skin test findings are discussed.

Adolescent↗
PubMed1997

Use of Leishmania major derived leishmanin for skin test surveys of visceral leishmaniasis in Ethiopia.

The potential use of Leishmania major derived leishmanin in surveys of visceral leishmaniasis (VL) was examined. The study was conducted in Konso sub-district, southwest Ethiopia involving 51 VL patients, 18 VL contacts, four localised cutaneous leishmaniasis (LCL) cases and 15 healthy controls. Sixty three percent of treated VL patients, 44.4% of VL contacts, all of LCL cases and none of untreated VL patients were positive to the test. Leishmanin skin test (LST) induration sizes of 41 treated VL patients were in the ranges of 0 to 10 mm, with a mean of 4.9 mm. The mean induration size and the positive LST rates in female patients were found to be significantly lower than in males. The major drawback of the antigen in the survey was the relatively smaller and flatter indurations. The relationship of LST to gender and leishmanial disease variant is discussed.

Adolescent↗
PubMed1997

Immunization with bacterial antigens: infections with motile aeromonads.

Motile aeromonads are a heterogeneous group of organisms which are involved in a number of disease syndromes of warm water fish. They are commonly associated with bacterial haemorrhagic septicaemia, infectious dropsy, red mouth disease, ulcerative conditions etc. A variety of factors has been considered to be associated with virulence including haemolysins, proteases, surface array protein, acetylcholinesterase etc. We have studied the immune response of Indian major carps to antigens of motile aeromonads. The Indian major carp, Labeo rohita, showed immunological memory and secondary response on booster administration. The extent of protection showed good correlation with titres of agglutinating antibody. When polyvalent vaccine was used, the fish showed antibody titres against all the component strains. However, the level of antibody was less compared to immunization by monovalent vaccines. Cross-reacting antibodies induced by monovalent vaccines showed varying degrees of protection.

Aeromonas↗