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H Jacob

Publications and source records attributed to H Jacob.

At least 37 records · Page 2Linked to original sources
PubMed1993

Feedback regulation of angiotensin converting enzyme activity and mRNA levels by angiotensin II.

Although renin and angiotensinogen are known to be subject to feedback regulation, the effects of angiotensin II (Ang II) on the regulation of angiotensin converting enzyme (ACE) gene expression and enzymatic activity have not yet been studied. Therefore, the effects of exogenous Ang II infusion and ACE inhibition on ACE mRNA expression were examined. Ang II was infused intravenously in male Sprague-Dawley rats for 3 days at 100 (low dose), 300 (medium dose), or 1,000 (high dose) ng/kg per minute (n = 8 for each group). Compared with control (vehicle infusion, n = 8), Ang II infusion increased plasma Ang II concentration (62, 101, 126 [p < 0.05], and 187 [p < 0.05] fmol/ml) and mean arterial blood pressure (106, 119 [p < 0.05], 134 [p < 0.05], and 125 mm Hg for control, low, medium, and high doses, respectively). Ang II infusion decreased ACE mRNA levels in the lung (57%, 52%, and 51%; p < 0.05 for each) and testis (49%, 63%, and 53% of control for low, medium, and high doses, respectively; p < 0.05 for each), two major sites of ACE synthesis. There was, albeit less pronounced, a parallel decrease in pulmonary ACE activity (4.38, 3.92, 3.07 [p < 0.05], and 3.48 [p < 0.05] nM/mg per minute for control, medium, and high doses, respectively). In contrast, serum (54, 50, 48, and 38 [p < 0.05] nM/ml per minute) and testicular (2.63, 2.08 [p < 0.05], 2.24, and 2.18 nM/mg per minute for control, low, medium, and high doses, respectively) ACE activities displayed only minimal change in animals infused with Ang II.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiotensin II↗
PubMed1992

High blood pressure in transgenic mice carrying the rat angiotensinogen gene.

Transgenic mice were generated by injecting the entire rat angiotensinogen gene into the germline of NMRI mice. The resulting transgenic animals were characterized with respect to hemodynamics, parameters of the renin angiotension system, and expression of the transgene. The transgenic line TGM(rAOGEN)123 developed hypertension with a mean arterial blood pressure of 158 mmHg in males and 132 mmHg in females. In contrast, the transgenic line TGM(rAOGEN)92 was not hypertensive. Rat angiotensinogen was detectable only in plasma of animals of line 123. Total plasma angiotensinogen and plasma angiotensin II concentrations were about three times as high as those of negative control mice. In TGM(rAOGEN)123 the transgene was highly expressed in liver and brain. Transcripts were also detected in heart, kidney and testis. In TGM(rAOGEN)92 the brain was the main expressing organ. In situ hybridization revealed an mRNA distribution in the brain of TGM(rAOGEN)123 similar to the one in rat. In TGM(rAOGEN)92 the expression pattern in the brain was aberrant. These data indicate that overexpression of the angiotensinogen gene in liver and brain leads to the development of hypertension in transgenic mice. The TGM(rAOGEN)123 constitutes a high angiotensin II type of hypertension and may provide a new experimental animal model to study the kinetics and function of the renin angiotensin system.

Angiotensinogen↗
PubMed1992

Reciprocal feedback regulation of kidney angiotensinogen and renin mRNA expressions by angiotensin II.

The present study asks whether angiotensin II (ANG II), a potent inhibitor of renal renin synthesis and release, regulates renal angiotensinogen synthesis. ANG II (or vehicle) was intravenously infused into male Sprague-Dawley rats for 3 days (vehicle or 100, 300, and 1,000 ng.kg-1 x min-1, n = 8/group), significantly increasing mean plasma ANG II concentrations and raising mean arterial blood pressure (MAP). ANG II dose dependently suppressed plasma renin concentration, kidney renin concentration, and renal renin mRNA levels. In contrast, ANG II infusion increased renal angiotensinogen mRNA levels stepwise to 122, 136 (P < 0.05), and 150% (P < 0.05) of control and also increased both liver mRNA levels (P < 0.05) and plasma angiotensinogen concentration (P < 0.05). Three days of angiotensin-converting enzyme inhibition (10 mg.kg-1 x day-1 quinapril in drinking water, n = 8) significantly decreased MAP (P < 0.05) and increased both mean plasma renin concentration (P < 0.05) and renal renin mRNA levels (P < 0.005). Plasma ANG II concentration tended to decrease (not significant), and neither renal nor hepatic angiotensinogen mRNA levels displayed significant difference. However, when data from ANG II-infused and quinapril-treated rats were analyzed together, correlation between plasma ANG II concentrations and renal angiotensinogen mRNA levels was highly significant (P < 0.005, r = 0.585). Thus plasma ANG II upregulates renal angiotensinogen gene expression and downregulates renal renin gene expression, a reciprocal feedback regulation that may have important physiological consequences.

Angiotensin II↗
PubMed1990

[Topics in clinical thanatology. Autopathothanatobiographies, -diaries, -epistulographies in comparison with Angloamerican clinical thanatologic experiences].

Extensive results of thanatologic sciences since the first decades of 20. century and multivarious practical knowledge in clinical thanatology are discussed--relating to the central problem of understanding different forms of "realisation of death". Possibilities of thanatologic information, forms of dialogue, communicative engagement and self-attitude in care-situations are critically conferred--this even in regard to mourning, grief and sorrow of the bereaved. The confrontation of thanatologic data in short-time illness until death to autopathothanatobiographic insights in long-time illness until death seems comparable in respect to relations between present clinical findings and anamnestic data. Awareness of approaching death seems not seldom due to "presentiment", averbal-communicative "preinformation" or impressions in face to progressive illness without successful therapy. Not only this is to think over in treatment and care, but also some new thanatologic experiences of the last years--for instance in respect to the question of timing, various circumstances and possible forms of informations and clearing up. Apart from individual forms of "living until death" there are certain pithy types in awareness, feeling, thinking, exposition or attitude. Some autobiographic, diaristic or epi-stulographic dates to long-time illness until death are characterized by striking limited possibilities of self-description and verbalization in situations of vital-existential distress. Silent suffering can be caused by loss of possibility in verbalization. Autothanatobiographic insights and experiences in thanatologic praxis in long-time illness until death lead to more differentiated insights than short-time illness until death--especially in respect of changing and contrary courses. Insight "evidences" of life continuities in the face of danger of death, changes in awareness of time, intensifications in intensities of perception, of feelings of the own life and changes in perception of the own ill organism, just as intensivation of partnership-relations ("synchronisation") can pass in the foreground. The last seems especially evident in special forms of "partnerautobiography" with alternating informations of the two. This illustrates the "two-sided aspect of death" death as a "dyadic event" (A. Toynbee), which is an important view relating to care of bereaved with changes in personal identity and awareness of time. Processes of dying and reactions of bereaved are integrated in complex anthropologic, psychologic, psychosociologic and psychosomatic factors. Certainly it is not possible such catastrophic incidents merely to interpret in psychoanalytic categories.

Attitude to Death↗
PubMed1990

[Intraoperative diagnosis of the heart and great vessels--echocardiography].

Two-dimensional echocardiography including color Doppler techniques can be used for analysis of the morphology and function and of the blood flow of the heart and the great vessels. Epicardial echocardiography has the advantage of high resolution and multiple scan planes. The restriction to the intraoperative period is a clear disadvantage. In addition, the scan planes are difficult to standardize. Transesophageal echocardiography can be used for monitoring during the whole operative period but is restricted to horizontal and/or longitudinal scan planes. It is a non-contact procedure and thus, sterile conditions are not affected. For evaluation of surgical success, intraoperative echocardiography can be used for analysis in patients with congenital heart disease, mitral valve regurgitation, hypertrophic obstructive cardiomyopathy, and aortic dissection. Acute intraoperative revisions with a second extracorporal circulation period will avoid reoperation. In patients with coronary artery disease the flow within the bypass and also the status of the anastomosis can be scanned and may contribute to reduce the perioperative infarct rate. Intraoperative echocardiography needs additional costs and man power. Only after randomized comparative prospective studies have demonstrated that patients controlled by intraoperative echocardiography have a better outcome and prognosis than patients without intraoperative control this method will become routine in open-heart surgery.

Echocardiography↗
PubMed1988

[Results of geriatric surgery in primary care].

An analysis was made of surgical interventions from 1967 to 1987, with patients above 65 years of age accounting for something between 19 and 24 per cent. Detailed investigations were conducted into 1,346 operations, with most of these having been performed on patients aged 70 to 74 (27.9 per cent). The overall lethality amounted to 25.2 per cent. The lethality risk increased with leapwise significance beyond the 75th year of age for both elective and emergency operations. Urgency of intervention, concomitant diseases, and age were found to be the major factors to determine prognosis and lethality. Reference is made to improved medical action in the perioperative phase as well as to consideration of ethical aspects.

Aged↗
PubMed1986

[Quantitative pathomorphological findings in chronic glomerulonephritis at autopsy: characterization of the grade of renal insufficiency for correlation studies].

The investigation is based on 49 autopsies at which chronic glomerulonephritis (GN) was found. The glomerular findings were classified by the WHO classification of renal diseases. The ratio of kidney weight (g) to body height (cm) gave a constitutional kidney index which correlated with the degree of global and segmental (more than 50%) sclerosis of glomeruli in chronic GN (diffuse intracapillary type). The negative correlative coefficient from simple linear regression was rho = -0.606. Chronic GN was then further subdivided into four groups which mutually correlate: diffuse sclerosing GN (so-called end-stage kidney). Index: 0.27 g/cm; diffuse sclerosing GN (over 80% glomerular sclerosis). Index: 0.49 g/cm; diffuse proliferative and extensive sclerosing GN (more than 50% and less than 80% sclerosis) Index: 0.59 g/cm; diffuse proliferative and mild to moderate sclerosing GN (less than 50% sclerosing). Index: 0.93 g/cm. The indices of the diffuse extracapillary GN were high in comparison with diffuse intracapillary GN. The kidney index of diffuse extracapillary proliferative and extensive sclerosing GN with over 80% fibrous crescents was 0.78 g/cm. Index of diffuse extracapillary proliferative and mild to moderate sclerosing GN, mostly epithelial and fibro-epithelial, few fibrous crescents was 1.30 g/cm. The mean values of the indices for normal kidneys were (males) 0.78-0.81 g/cm and (females) 0.73-0.75 g/cm (age: 20-60 years). These results may be used for correlative investigations with morphometric parameters of renal osteopathy.

Adolescent↗
PubMed1985

Villous adenoma depletion syndrome. Evidence for a cyclic nucleotide-mediated diarrhea.

Massive secretory diarrhea is associated with some villous adenomas. The mechanism of this secretion is unknown but the character of the diarrhea resembles that of cyclic nucleotide-mediated diarrheas. We have compared the cyclic nucleotide metabolism of a large secretory villous adenoma with a nonsecretory villous adenoma, a solid carcinoma and their normal mucosae. The adenylate cyclase, cyclic AMP content, and a cyclic AMP-dependent protein kinase ratios in the secretory tumor were increased as compared to these values in the nonsecretory tumors and normal mucosae, a situation similar to that seen with cholera toxin-induced diarrhea. Our data suggest that the massive diarrhea in our patient with a secretory villous adenoma may be related to increased adenylate cyclase activity.

Adenocarcinoma↗
PubMed1983

Beta-adrenergic blockade and the gastrointestinal system.

As beta-adrenergic blockers grow increasingly popular for the therapy of a wide variety of disorders, it becomes increasingly important to appreciate the spectrum of physiologic effects on the gastrointestinal system and the potential hazards associated with use of these agents. This review details the effects of the beta-adrenergic blocking agents on the gastrointestinal tract.

Adrenergic beta-Antagonists↗
PubMed1983

The esophageal motility disorder of polymyositis. A prospective study.

A prospective study of 12 patients with the diagnosis of polymyositis or dermatomyosiois was initiated to determine the characteristics of the esophageal manometric patterns in this group. All of the patients were women between the ages of 30 to 80 years and met three of four of Bohan's diagnostic criteria for these diseases. The patients' conditions were classified according to Rose and Walton's muscle weakness index. Almost two thirds of our patients exhibited distal esophageal dysfunction by manometry. Based on our roentgenographic and manometric data, we conclude that in addition to the well-described abnormalities in the striated portion of the esophagus, smooth-muscle dysfunction occurs with a high frequency in this patient population.

Adult↗