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Results for “functionality”

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At least 145 records · Page 8Linked to original sources

PubMed1990

Analysis of E1A-mediated growth regulation functions: binding of the 300-kilodalton cellular product correlates with E1A enhancer repression function and DNA synthesis-inducing activity.

Adenovirus E1A transforming function requires two distinct regions of the protein. Transforming activity is closely linked with the presence of a region designated conserved domain 2 and the ability of this region to bind the product of the cellular retinoblastoma tumor suppressor gene. We have investigated the biological properties of the second transforming region of E1A, which is located near the N terminus. Transformation-defective mutants containing deletions in the N terminus (deletion of residues between amino acids 2 and 36) were deficient in the ability to induce DNA synthesis and repress insulin enhancer-stimulated activity. The function of the N-terminal region correlated closely with binding of the 300-kilodalton E1A-associated protein and not with binding of the retinoblastoma protein. These results indicate that transformation by E1A is mediated by two functionally independent regions of the protein which interact with different specific cellular proteins and suggest that the 300-kilodalton E1A-associated protein plays a major role in E1A-mediated cell growth control mechanisms.

Adenovirus Early Proteins↗

PubMed1989

Assessment of testicular function after acute and chronic irradiation: further evidence for an influence of late spermatids on Sertoli cell function in the adult rat.

To study cell to cell communications within the testis of adult Sprague-Dawley rats, we used acute whole body neutron plus gamma-irradiation (0.99 Gray of neutron and 0.24 Gray of gamma-rays, 3 min; Exp A) over 7-121 days postirradiation and chronic whole body gamma-irradiation (7 cGy/day 60Co gamma-rays; Exp B) over 14-84 days of irradiation and 7-86 days postirradiation. Neither irradiation protocol had an effect on the body weight of the animals. Neutron plus gamma-rays induced dramatic damages to spermatogonia, preleptotene spermatocytes, spermatozoa, and, to a lesser extent, pachytene spermatocytes. In contrast, gamma-rays induced a selective destruction of spermatogonia. Subsequently, in both experiments a maturation-depletion process led to a marked decrease in all germ cell types. A complete or near complete recovery of the different germ cell types and spermatozoa took place during the two postirradiation periods. Under both irradiation protocols Sertoli cells number was unchanged. Androgen-binding protein and FSH levels were normal in spite of the disappearance of most germ cells from spermatogonia to early spermatids. However, the decline of androgen-binding protein as well as the rise of FSH and their subsequent recovery were highly correlated to the number of late spermatids and spermatozoa. Moreover, it appeared that spermatocytes may also interfere with the production of inhibin (Exp B). With neither irradiation was Leydig cell function altered, except in Exp B in which elevated LH levels were temporarily observed. Correlation analysis suggested a relationship between preleptotene spermatocytes and Leydig cell function. In conclusion, this study establishes that chronic gamma-irradiation is particularly useful in the study of intratesticular paracrine regulation in vivo and provides further support to the concept that late spermatids play a major role in controlling some aspects of Sertoli cell function in the adult rat.

Animals↗

PubMed1978

Clinical application of the functional matrix: mandibular reconstruction and monobloc functional therapy.

A 13-year-old black girl with an extensive ameloblastoma of the mandible required subtotal mandibular resection and immediate reconstruction with use of an autogenous, ipsilateral, corticocancellous graft from the iliac crest and monobic functional therapy. Twenty-seven months later, clinical evaluation showed normal mandibular function and no facial asymmetry. Bony architectural changes after 27 months included reformation of the coronoid process, angular process, and external oblique ridge; preservation of mandibular length and thickness; and maintenance of the alveolar ridge height. The reformation of the coronoid process suggests the importance of the functional matrix (temporalis muscle) in skeletal tissue growth. The monobloc appliance in conjunction with bone grafting is an effective means for transmission of biophysical stimuli and for maintenance of appropriate stress for remodeling of bone in the mandible.

Activator Appliances↗

PubMed1985

Deterioration of renal function during angiotensin converting enzyme inhibition in hypertensive patients with a poorly functioning solitary kidney.

During treatment with the angiotensin converting enzyme inhibitor, Captopril, glomerular filtration rate (GFR) decreased in three unilaterally nephrectomized hypertensive patients with a poorly functioning remaining kidney. The fall in GFR was not related to changes in the blood pressure, and was reversed when Captopril was stopped. In a fourth nephrectomized patient the initially normal GFR was not affected by captopril. These observations point to a functional reduction in GFR due to a withdrawal of an intrarenal action of angiotensin II. Maintenance of GFR may become critically dependent on a functioning renin-angiotensin system when renal perfusion pressure is reduced to a certain degree. Inhibition of angiotensin II formation may lead to a decrease in GFR in patients with renal hypertension and pre-existing renal insufficiency.

Aged↗

PubMed1976

Renal pelvic function following total alloplastic replacement of ureter in pigs. Electrophysiology, renal function and morphology.

Total replacement of one ureter was under-taken in pigs. After an observation period of 2-3 months further studies were made. Pelvic peristaltic activity as reflected by pelvic pressure waves and electrical activity was indistinguishable from that in normal pigs. In particular, retrograde activity was not observed. It appears that ureteric peristalsis is not a prerequisite of normal pelvic function. Providing only that the calibre is sufficient, function of a ureteric prosthesis is satisfactory, and no changes in kidney or pelvis function and morphology are apparent.

Action Potentials↗

PubMed1975

Long-term functional results of surgery for coronary artery disease in patients with poor ventricular function.

Thirty-two patients with coronary artery disease and an ejection fraction (EF) below 0.40 had coronary bypass and/or left ventricular aneurysm (LVA) resection. Twenty-four patients had a previous infarction, 12 had congestive heart failure (CHF), and left ventricular end-diastolic pressure averaged 15 mm. Hg. Nineteen patients had three-vessel involvement and there was an average of 2.4 vessels involved per patient. Bypass was accomplished on 87 per cent of vessels; 11 patients had resection of LVA; 11 had coronary endarterectomy. There were no hospital deaths, 63 per cent of the patients were improved, and 56 per cent were able to return to work or full activity. There were five late deaths (16 per cent). There was good functional improvement in 83 per cent of the survivors, followed 1 to 4 years. We believe that patients with poor ventricular function due to severe coronary artery disease should not categorically be denied surgery, and that operation can be done with a low hospital mortality rate and good functional results.

Adult↗

PubMed1975

[Breath rate as a function of parameters of pulmonary function in body plethysmography (author's transl)].

Parameters of pulmonary function were measured at resting breathing rates (mean 15-17/min) and at breathing rates of 20-40/min in 238 subjects (79 normals, 44 patients with normal pulmonary function in spite of lung disease, and 115 patients, most of whom had obstructive-emphysematous lesions) in a constantvolume body plethysmograph with a respiratory bag. In the subjects with normal pulmonary function the resistance increased significantly by 25 and 45 percent, resp., with more rapid respiration (p smaller than 0,01). Nevertheless it is assumed that this rarely accounts for false interpretations in everyday routine practice. No relationship of breathing rate to respiratory passage resistance was observed in patients with increased total resistance. By way of contrast, ventilation work of breathing (pV diagram) and the index of ventilation work of breathing (defined Vp ratio) showed a close correlation to breathing rate in all 3 groups. This leads us to conclude that these parameters provide more exact information on the breathing mechanism than does total resistance. Studies on ventilation work of breathing must be conducted under clearly defined breathing rates and consideration of the respiratory volume. intrathoracic gas volume was not correlated to the breath rate.

Adult↗

PubMedDate not supplied

[Search for functional domain boundaries and localization of functional sites based on oligopeptide vocabularies].

A new method based on the analysis of oligopeptide composition of the amino acid sequences from different protein families is presented. We assume, that any protein family can be characterized by the set of oligopeptides (oligopeptides vocabulary). We demonstrate, that oligopeptides vocabulary comparison can distinguish different families from each other and from random sequences. It should be noted, that this comparison can be successfully performed on the set of only 25 dipeptides and without preliminary alignment. We demonstrate, that characteristic peptides are localized in the regions of functional significance, as shown on the example of GTP-binding domain of translation elongation factors. We suggest how to use this method to localize the boundaries of functional domains in amino sequences. On the example of few functional domains we demonstrate, that the average error of prediction does not exceed 3-4 amino acid residue.

Amino Acid Sequence↗

PubMed1991

A site-directed approach for constructing temperature-sensitive ubiquitin-conjugating enzymes reveals a cell cycle function and growth function for RAD6.

We have determined the gene sequence of a temperature-sensitive allele of the cell cycle-related ubiquitin-conjugating enzyme CDC34 (UBC 3) from Saccharomyces cerevisiae. The basis of temperature sensitivity is a missense mutation resulting in a proline to serine substitution at a residue that is conserved in all ubiquitin-conjugating enzymes identified thus far. This observation raised the possibility that other temperature-sensitive ubiquitin-conjugating enzymes could be generated in the same way. We therefore created the corresponding substitution in the DNA repair-related ubiquitin-conjugating enzyme, RAD6 (UBC2), and examined the effect of temperature on the cell proliferation and DNA repair-related functions of this altered polypeptide. Yeast strains carrying this mutation proved to be temperature-sensitive with respect to cell proliferation but not with respect to the DNA damage-processing phenotypes exhibited by other rad6 mutants. Upon further investigation of the proliferation defect exhibited by this mutant, we discovered that other rad6 gene mutants deleted for the gene undergo cell cycle arrest at the nonpermissive temperature, whereas the engineered temperature-sensitive allele showed no evidence of a cell cycle defect. From these findings, we conclude that the proliferation function of RAD6 can be subdivided into a growth component and a cell division cycle component and that the growth component is unrelated to the DNA repair functions of RAD6. A reasonable interpretation of these results is that different proteins are targeted for ubiquitination in each case. The conserved proline residue of RAD6 and CDC34 is part of a turn motif common to all ubiquitin-conjugating enzymes. It is therefore likely that site-directed substitution of prolines located in turns can be generally applied for the creation of other temperature-sensitive ubiquitin-conjugating enzymes and possibly other proteins as well.

Alleles↗

PubMedDate not supplied

Evaluation of CSF shunt function: value of functional examination with contrast material.

Functional positive-contrast shuntography includes a patency check of both limbs of the shunt and the shunt valve by fluoroscopy following the injection of an iodinated contrast agent (anatomic shuntogram) and an assessment of the adequacy of ventricular fluid drainage under physiologic conditions by using serial CT scans to assess the rate of iodine dissipation from the ventricular system (physiologic shuntogram). To demonstrate its efficacy and utility, 82 functional shuntograms were obtained in 55 patients. Fifty-one of the 82 studies were abnormal. Of these, 22 demonstrated patency of both the proximal and distal limbs with an accompanying slow dissipation of contrast material after injection (21 of 22 patients were adults). Eighteen of these 22 patients improved following the reduction of shunt drainage pressure. In the case of frank shunt obstruction, the site of obstruction was delineated clearly in all 29 cases. Correlation of clinical outcome with test results confirmed the utility of this technique, especially when applied to the shunted adult hydrocephalic patient whose response to the shunt had been inadequate. The technique described here allows the clinician to differentiate between physiologic and anatomic shunt failure and between shunt failure and normal shunt function. It also allows for precise localization of the shunt obstruction in anatomic shunt failure and for demonstration of physiologic shunt failure when shunt patency is demonstrated in the presence of the slow dissipation of intraventricular contrast medium.

Adult↗

PubMed1991

[Improvement of hearing function through ear reoperation. The role of tympanic revision for functional indications].

Recurrent middle ear disease may carry a high probability of complications, and there is no doubt of the necessity of revision surgery for either cholesteatoma or tumor. However, failures in function should be individually analyzed before a second procedure is decided upon. A pre-requisite for surgical improvement of hearing is adequate tubal and inner ear function. Chronic suppurative otitis media has a higher tendency for reperforation than cholesteatoma. Adhesive otitis indicates poor tubal function. Tympanosclerosis may cause refixation requiring stapedectomy at a second stage. Middle ear fibrosis recurs in about 50% of cases. Post-operative failures such as extrusion of ossicles, lateralization of the tympanic membrane, and blunting of the anterior tympanomeatal angle as well as failures after stapes surgery are discussed.

Aged↗

PubMed1990

[Development of functional jaw orthopedics and function regulator].

Functional jaw orthopedics is an orthodontic treatment which uses muscle stimuli developed from the functions and tonus changes of masticatory, tongue, lip and cheek muscles. The functional regulator which is one of the appliances used in this treatment, takes support not from the teeth, but directly from the soft tissues in order to make changes in alveolar bone and teeth.

Activator Appliances↗

PubMed1990

Structure-function analysis of the human interferon gamma. The COOH terminus is not essential for functional activity.

The structure-function relationships for the human interferon gamma (HuIFN-gamma) were studied using recombinant variants that had various deletions at the carboxyl terminus. Four COOH-terminal deletion variants were constructed that contained the amino-terminal 122, 117, 111, and 106 amino acid residues. These variants were constructed by specific DNA modifications and were expressed in Escherichia coli. The deletion of 21 amino acid residues resulted in only 2- and 3-fold reduction in the antiviral and antiproliferative specific activities, respectively. Thus, the carboxyl-terminal 21 residues are not directly involved in the function of the HuIFN-gamma. The level of intracellular accumulation was also decreased by 3-5-fold. Further deletions of 26, 32, and 37 residues from the COOH terminus resulted in the lack of detectable activity as well as in 50-100-fold reduction in the level of accumulation in the bacterial cell. However, each of the modified plasmids was found to have comparable efficiency in directing the production of the respective variant molecules relative to the full-length HuIFN-gamma molecule in an in vitro transcription-translation assay. Thus, the failure of some of the deletion variant molecules to accumulate in the E. coli cell is likely due to their instability in vitro. The loss of the COOH-terminal 21 amino acid residues of HuIFN-gamma also resulted in a substantial reduction in the ability of the molecule to be renatured in vitro from the treatment with chaotrophic agents, a method frequently used to extract and purify recombinant polypeptides from E. coli host. The latter result may account for some earlier reports which inferred the involvement of the COOH terminus in the functions of the HuIFN-gamma molecule due to their failure to detect activity upon deletions of only 11-18 residues.

Amino Acid Sequence↗

PubMedDate not supplied

[Study of the somatotropic function of the pituitary gland and the glucocorticoid function of the adrenal glands in rats with alloxan diabetes].

The somatotropichormone (STH) content was studied in the hypophysis and the peripheral blood of rats with alloxan diabetes; the corticosterone content was determined in their peripheral blood. The STH content in the peripheral blood and the hypophysis of these rats failed to differ from that in the control group, but the blood STH content rose considerably in the sick animals. Exclusion of the insular apparatus function was accompanied by the adrenal gland hypertrophy, which correlated with the rise of the blood corticosterone level. The data obtained indicated that the insular apparatus insufficiency induced by alloxan was accompanied by changes in the somatotropic function of the hypophysis and of glucocorticoid function of the adrenal glands.

Adrenal Cortex↗

PubMed1990

[CT morphology and function of the temporomandibular joint following conservative functional treatment of temporomandibular joint fractures].

In 8 adult and 13 adolescent individuals who had undergone conservative treatment for condylar fractures 4.2 and 4.5 years earlier, respectively computed tomography was performed. In addition, joint mobility was examined clinically in 18 of these patients. The results of the radiological examination allow discrimination between high-grade and low-grade remodeling and excessive bone formation. With one exception, high-grade remodeling was invariably observed after childhood fractures. In the adult patients new bone formation was rarely observed. Correlation between the morphologic appearance and joint mobility was detectable only in cases of severely limited function. In the presence of less severe functional lesions, the size of the insertion area of the lateral pterygoid muscle might indicate the degree of functional rehabilitation. The radiological procedure is discussed.

Adolescent↗

PubMed1989

[Endocrine function of the heart: structuro-functional aspects].

Modern notions, accumulated during the period of investigation of before poorly studied endocrine++ function of the heart are presented. History of the problem, structural and functional aspects on argumentation of the cardiac endocrine function, place and role of physiologically active cardiac peptides in regulation of liquor and electrolytic homeostasis are followed, as well as interactions of the cardiac endocrine apparatus with the hormonal system of the organism. The authors' experience on the investigation connected with the problem is also demonstrated.

Atrial Natriuretic Factor↗

PubMed1989

[Prediction of operative mortality by a discriminant analysis for organ functions in patients with esophageal cancer--organ function index].

An "organ function index" (OFI) predicting the risk of operative mortality was presented. OFI was estimated on the basis of dysfunction of the systemic organs in patients with esophageal cancer. The pulmonary, cardiac, hepatic and renal functions were assessed by 23 parameters in 108 patients when they were admitted. Operative death was defined as death due to operative complications occurring within 120 days after esophagectomy or by-pass operation. For a discriminant analysis, patients were limited to those in the early period (from October 1981 until December 1985) when the incidence of operative mortality was relatively higher and the parameters were also limited to statistically evaluable ones. Then, a discriminant analysis was performed using data on 18 parameters of four organs in 35 patients each of whom had no deficit in these data. Operative death occurred in 8 out of these 35 patients. Based on the data, an equation to calculate OFI was generated. It consisted of 7 parameters regarding pulmonary, hepatic and renal functions. The values of OFI less than zero predicted no operative death while those more than zero did predict operative death. The prediction rate on presence or absence of operative mortality by this equation was 91.4% in 35 patients. For clinical application, the predictable risk of operative mortality based on OFI was classified as high (OFI less than 1.4), intermediate (0 less than OFI less than 1.4), or low (OFI less than 0).(ABSTRACT TRUNCATED AT 250 WORDS)

Discriminant Analysis↗

PubMed1989

[Serial assessment of cardiac function during and after exercise by an ambulatory ventricular function monitor (VEST)].

Cardiac function was serially assessed during and after exercise by an ambulatory ventricular function monitor (VEST) in 31 patients who received coronary angiography. Based on the study of fluctuation during the baseline recording, greater than or equal to 6% change in ejection fraction (EF) was considered significant. The serial changes in EF during exercise was divided into 5 types, including continuous increase (type A), initial increase but return to the baseline (type B), no change (type C), initial increase but later decrease below the baseline (type D), and continuous decrease (type E). Among 8 normal subjects, their EF changes during exercise showed type A in 3, type B in 2, type C in 2, and type D in 1. Among 21 patients with coronary artery disease, the EF changes showed type A in 5, type B in 4, type C in 4, type D in 5 and type E in 3. Thus, there was a significant overlap in EF response between normal and coronary patients. However, every patient showing type A and B had single-vessel disease, and 63% of them had persistent thallium defect without redistribution. After the exercise, 29 patients showed rapid increase in EF. The time to the peak EF was significantly longer in coronary patients (1.88 +/- 1.24 min) than that in normal cases (0.88 +/- 0.55 min) (p less than 0.05) particularly in patients with multi-vessel disease (2.22 +/- 1.29 min). In addition, those showing type C, D or E tended to have a longer time to peak EF and more increase in EF after exercise than those showing type A or B. These data suggest that VEST is suitable for continuous measurement of cardiac function during and after exercise which provided valuable indices for assessment of severity of ischemia in coronary artery disease.

Adult↗