PubMed Health⌕ Search

Biomedical subjects

B Brehm

Publications and source records attributed to B Brehm.

7 recordsLinked to original sources
PubMed2002

Renin producing neuroendocrine pancreatic carcinoma--a case report and review of the literature.

A 44 year old male patient presented with severe hypertension. The diagnostic work-up revealed elevated levels of plasma renin activity (about 10 times the upper limit of normal) in the presence of normal plasma aldosterone levels and serum potassium concentrations. Renovascular disease was excluded by angiography. Selective renal vein sampling did not show any renin gradient. CT-scans of the abdomen demonstrated normal morphology of the kidneys and adrenals but revealed a big mass in the pancreatic corpus and tail with infiltration of the splenic vein and the presence of enlarged local lymph nodes. The endocrine nature of the pancreatic mass was further supported by a positive octreotide scintigraphy scan. Surgical removal of the tumor by left sided pancreatectomy combined with splenectomy resulted in rapid normalization of elevated renin concentrations as well as blood pressure. Histological examination of the tumor tissue revealed the presence of a neuroendocrine pancreatic carcinoma. Highly (x 70) elevated renin levels were detected by radioimmunoassay in the tumor tissue. To our knowledge this is the first renin-producing neuroendocrine pancreatic carcinoma described in the literature. The present paper describes the case in detail and reviews the available literature on clinical symptomatology, diagnosis and treatment of renin-producing tumors.

Adult↗
PubMed2001

[Multidetector CT Angiography - is it a valuable screening tool to detect significant renal artery stenosis?].

PURPOSE: To evaluate the diagnostic value of multidetector CT angiography (MDCTA) of the renal arteries. METHODS: 27 patients underwent MDCTA of the renal arteries. Scan parameters were: collimation 4 x 1 mm, pitch 1.5, effective slice thickness 1.25 mm, reconstruction increment 0.8 mm, circulation time measurement, power injection of 80 ml iomeprol 400, flow 4 ml/sec. Independent reading on laser film was done by two radiologists using edited maximum intensity projections, multiplanar reconstructions and source images. Standard of reference was a 3D-FLASH MR angiography (1.5 T, 3.9/1.2, 10 degrees 0.2 mmol GdDTPA/kg bw) in 10 and intraarterial angiography in 17 patients. RESULTS: Analysing 63 arteries, sensitivity, specificity, positive predictive value and negative predictive value in terms of detection of moderate and high grade renal artery stenosis (n = 10) were 90, 98, 90 and 98 % for reader A, and 90 % each for reader B, respectively (kappa = 0.91 interobserver agreement). 1/11 accessory renal arteries was missed by both angiography and MDCTA. Image quality was graded as excellent or good in 26/27 of cases by both readers. CONCLUSION: MDCTA proved to be a highly accurate tool in the detection of therapeutically relevant renal artery stenosis.

Aged↗
PubMed1997

Three-dimensional computer-assisted stereotactic-guided microneurosurgery combined with cortical mapping of the motor area by direct electrostimulation.

TIM (Zeppelin Chirurgische Instrumente GmbH, 82 049 Pullach, Germany) is a tomographic imaging system which enables surgeons to visualize the pathologic lesions three dimensionally in relationship to the surrounding structures. The distance and the angle between the pathologic lesion and the anatomical and/or bony landmarks as well as the volume of the mass lesion can be measured. Therefore an accurate localization of the lesion is possible with this technique. It is very applicable for planning of surgery on skull base tumors. The surgical procedure for small and well-defined, intrinsic pathologic deep-seated brain lesions, however, becomes much easier by using the stereotactic techniques of this system. The target point and the direction brain-surface-to-lesion can be determined within seconds. Before the aiming probe is inserted to the target, the cortical motor area is mapped by direct electrical stimulation. The approach can be varied depending on the results of these neurophysiologic investigations of the brain surface. The dissection is made along the aiming probe up to the target point. Because of the fixation of the brain with the needle, a brain shifting due to the dissection as well as to CSF release is diminished. Forty patients with deep-seated intracerebral lesions were operated on during a 13 months period by these combined techniques in our service. Using this technique, we never made a negative exploration. In all but three patients, total removal of the mass lesion was achieved. Permanent neurological deficits were observed in two patients only. In our opinion, this combined imaging and neurophysiological technique is easy to perform, and of major benefit for the patients due to its accuracy and is preferable in comparison with other single computer localizer techniques without neurophysiological monitoring.

Adolescent↗
PubMed1992

Chronic beta-blockade transregulates inhibitory A1 adenosine and muscarinic M2 receptors of the adenylyl cyclase system.

Chronic beta-blockade has evolved to an important therapeutic strategy in medicine. Not all its therapeutic effects may be explained by its direct action on the beta-adrenergic system. We therefore investigated if chronic beta-blockade in vivo or in isolated cell systems may modulate also inhibitory receptors of the adenylyl cyclase system. Chronic treatment with metoprolol for 6 days (10 mg/day) induced an increase of beta-adrenergic receptors in rat cardiac plasma membranes (53 +/- 8 vs 80 +/- 12 fmol/mg protein). Simultaneously the density of cardiac muscarinic M2 receptors decreased significantly from 150 +/- 17 to 110 +/- 12 fmol/mg protein without any change of the affinity of the receptors for their agonists or antagonists. By this mechanism chronic beta-blockade leads to an unexpected impairment of the muscarinic-mediated inhibition of the adenylyl cyclase. This transregulation of inhibitory receptors by chronic beta-blockade was not restricted to the heart but also reduced the muscarinic receptors of rat lung (35 +/- 4 vs 24 +/- 3 fmol/mg protein). Additionally, other inhibitory receptors of the adenylyl cyclase system such as the A1 adenosine receptors of rat brain were reduced by chronic beta-blockade (532 +/- 32 vs 444 +/- 26 fmol/mg protein). This transregulation of A1 adenosine receptors occurred only after chronic beta-blockade with the active stereoisomer (-)-metoprolol whereas the (+)-isomer was ineffective. The ability of the remaining A1 adenosine receptors to form the agonist-promoted high affinity state was unaltered. Their reduction, however, was sufficient to abolish the phenylisopropyl-mediated inhibition of the adenylyl cyclase. To evaluate if this regulation of various inhibitory receptors in different organs may represent a general cellular regulation mechanism, we investigated whether this transregulation also occurred in isolated cells. Isolated smooth muscle cells derived from the vas deferens (DDT1 MF-2) were cultivated in the presence of the beta-blocker atenolol (10(-5) M) for 3 days. Chronic beta-blockade in these isolated cells induced an increase of beta-adrenergic receptors and concomitantly a significant decrease of A1 adenosine receptors (460 +/- 42 vs 368 +/- 18 fmol/mg protein). The affinity of the A1 adenosine receptors for their agonists and antagonists and the ability of the remaining receptors to form the agonist-promoted high affinity state remained unaltered. In contrast, the reduction of receptor density greatly impaired the adenosine-mediated inhibition of the adenylyl cyclase. These data demonstrate that chronic beta-blockade leads to a functionally significant reduction of inhibitory receptors of the adenylyl cyclase system.(ABSTRACT TRUNCATED AT 400 WORDS)

Adenylyl Cyclases↗
PubMed1992

Spontaneous splenic rupture complicating acute Q fever.

Q fever is usually a self-limited febrile illness that involves the lungs and the liver. Acute complications are rare. We present the case of a 30-yr-old patient with spontaneous splenic rupture during the course of acute Q fever infection. He was admitted to the hospital with high temperature and the radiological signs of an atypical pneumonia. Forty-eight hours after admission, he developed shock. Because of free intraabdominal liquid, a laparatomy was performed that revealed a tear in the enlarged spleen. A splenectomy was performed. The diagnosis of Q fever was established by a significant titer increase in complement fixation test and IgM-ELISA. Serological investigations into the patient's surroundings revealed evidence of Q fever infection in 10 additional persons. Q fever should be taken into account as a possible differential diagnosis in patients with unexplained febrile illness and symptoms of pneumonia. The acute course of Q fever infection can be complicated by splenic rupture. The diagnosis of an acute infection with Coxiella burnetii often requires serologic testing of a second serum sample obtained at least 10 days after the onset of symptoms. Q fever should be ruled out in cases of unexplained splenic rupture particularly in Q fever endemic areas.

Adult↗