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Biomedical subjects

A Blumberg

Publications and source records attributed to A Blumberg.

At least 73 records · Page 4Linked to original sources
PubMed1982

Modulation of the vasoconstrictor response to adrenergic stimulation by nucleosides and nucleotides.

The ability of nucleosides and nucleotides to modulate adrenergic neuromuscular transmission was examined in the isolated, perfused rat mesentery. The nucleosides adenosine and cytidine and the stable nucleotide of ATP, beta, gamma-methylene ATP (APPCP), and GTP depressed in a concentration-dependent manner the vasoconstrictor response to nerve stimulation (NS). APPCP and cytidine required concentrations less than those of adenosine or GTP to cause inhibition of the constriction to NS. Guanosine had no apparent effect on the constriction to NS, whereas cytidine 5'-triphosphate enhanced this response. In contrast to the inhibitory effect of several nucleotides and nucleosides on the response to NS, only adenosine depressed the vasoconstriction to exogenous norepinephrine (NE). APPCP, GTP, cytidine 5'-triphosphate and guanosine were essentially equipotent in potentiating the vasoconstriction to NE; cytidine had no apparent effect. The ability of these agents to enhance vasoconstriction is not specific for alpha adrenergic receptor-mediated effects inasmuch as APPCP also potentiated the vasopressor response to KCl. Theophylline abolished the depressant effects of adenosine, cytidine, APPCP and GTP on the vasoconstriction to NS and the ability of adenosine to inhibit the constrictor response to NE. Theophylline did not inhibit the ability of APPCP to potentiate the vasoconstriction to NE. These results indicate that the nucleosides adenosine, guanosine and cytidine and the nucleotides APPCP and GTP act prejunctionally, possibly at a common receptor, to inhibit the neuronal release of NE. In addition, the data suggest the existence of two postjunctional sites, one that is inhibitory and selective for adenosine and another that enhances vasoconstrictor responses and is activated by nucleotides and guanosine.

Adenosine↗
PubMed1982

Treatment of pneumothorax, pneumopericardium and pneumomediastinum.

Fifty-four patients with pneumothoraces were treated by tube thoracostomy. Three of these also suffered from pneumomediastinum, two from pneumopericardium, and one from pneumoperitoneum. Except for 2 pneumomediastina, all of these were drained. A chest drain was inserted after chest radiography or transillumination and/or localization of the extrapulmonary air by fine needle aspiration. The drain was placed surgically at the highest point of air accumulation, after creation of a long subcutaneous tunnel and perforation of the intercostal space by blunt dissection. Pressure upon vital structures by pathological air accumulations was relieved in all cases. On a few occasions a tension pneumothorax redeveloped despite there being a chest tube in place, and new chest tubes had to be inserted. No complications due to the procedure were observed.

Adolescent↗
PubMed1981

[Diagnosis, significance and treatment of urinary tract infections].

Although for the diagnosis of urinary tract infection (UTI) quantitative urine bacteriology is generally recommended, certain drawbacks of the method must be taken into consideration. Indications for radiological examinations in UTI are mentioned. The long-term prognosis of UTI is excellent provided the urinary tract is functionally and morphologically intact, even though recurrences may be frequent. In the presence of a pathological urinary tract UTI may lead to destruction of renal parenchyma. Uncomplicated UTI may be treated with suitable antibacterial drugs either conventionally over a one-week course or by single-dose therapy. The prevention of recurrences, which usually are due to reinfection, may be a problem. The treatment of UTI in the presence of special circumstances such as pathological urinary tract, indwelling catheter, or renal insufficiency is briefly discussed.

Anti-Infective Agents, Urinary↗
PubMed1981

Thromboxane A2 is the major arachidonic acid metabolite of human cortical hydronephrotic tissue.

Human cortical hydronephrotic microsomes converted [14C] arachidonic acid to [14C] thromboxane B2 as the major metabolic product. Using [14C] PGH2 as substrate, similar enzymatic conversions were noted with HHT greater than TXB2 less than 6KPGF1 alpha greater than PGE2 greater than PGE2 alpha as the major products. Inhibition of thromboxane synthetase with imidazole 5 mM reduced thromboxane B2 production by 60% and the major product then was 6 keto PGF1 alpha. After addition of imidazole, the metabolic profile showed PKPGF1 alpha greater than PGE2 greater than HHT greater than PGF 2 alpha. Control experiments were carried out using normal cortical tissue obtained from kidneys removed surgically for carcinoma of kidney and rejected for transplantation secondary to fracture as a consequence of blunt trauma. These control kidneys, while they demonstrated an ability to generate thromboxane B2 in vitro, had much less activity than hydronephrotic kidneys and with PGH2 as substrate PGE2 greater than TxB2. In addition, inhibition with imidazole produced mainly PGE2. Thus, like the rabbit and rat, there is enhanced thromboxane and prostacyclin synthesis in human ureteral obstruction and are, therefore, potential vasoactive compounds which may in part be responsible for the hemodynamic alterations occurring in human obstructive uropathy.

6-Ketoprostaglandin F1 alpha↗
PubMed1980

[Arrhythmias in patients on long-term hemodialysis].

17 patients on maintenance hemodialysis were monitored for cardiac arrhythmias by ambulatory electrocardiographic recording. Only 3 patients had ventricular premature beats of potentially dangerous grades. Two of these cases were overdigitalized and two had severe cardiac disease (amyloid, old myocardial infarction).

Adult↗
PubMed1980

Influence of 1,25 dihydroxycholecalciferol on sexual dysfunction and related endocrine parameters in patiens on maintenance hemodialysis.

It has been postulated that hyperparahyroidism is in part responsible for sexual dysfunction in dialyzed patients and that this could improved by 1,25(Oh)2D3. In a single blind study patients on maintenance hemodialysis were treated after a control period with 1,25 (OH)2D3 and with placebo in random order. Sexual performance was assessed with a detailed semistructured psychiatric interview protocol in 14 and several endocrine parameters were analyzed in 15 patients. Under control conditions sexual function was disturbed in 11/14 patients. Plasma testosterone was moderately decreased in men, PRL and PTH levels were distinctly elevated in both sexes. 1,25(OH)2D3 raised serum calcium levels significantly from 9.6 to10.6 mg/100 ml ( P < 0.01) and lowered PTh from 1.39 to 0.82 ng/ml ( P < 0.01). However, no improvement in sexual function (such as libido, frequency of intercourse or masturbation) was found, and apart from a slight rise of testosterone in men and moderate fall of PRl in men and women endocrine parameters remained unchanged. It is concluded that in spite of an improvement of secondary hyperparathyroidism, treatment with 1,25(OH)2D3 for 2 to 4 months was of no value in improving sexual dysfunction in these hemodialysis patients.

Adult↗
PubMed1979

[Hemolytic crisis and acute kidney failure from rifampicin].

Two cases are reported of hemolytic crisis and acute anuria after intermittent rifampicin medication. Immunologic tests demonstrate that the hemolysis was of the drug-induced heteroimmune type whereas the pathogenesis of the anuria was uncertain. For both complications the prognosis is good.

Acute Kidney Injury↗
PubMed1979

[Urinary cytology in tumors of the urinary tract].

Views on the usefulness of urinary cytology and the best methodological technic differ widely. We perform the examination with spontaneously voided urine; after centrifugation, a smear of the sediment is Papanicolaou-stained. With this method 15 patients were found over a two-year period to have a tumor of the urinary tract or a positive urinary cytology. In 13 patients a tumor was diagnosed; of these 10 had a positive, 1 a questionable and 2 a false negative cytology. In 2 patients the cytology was false positive. Retrospective reexamination of the two false negative results revealed unequivocally malignant cells. One of the two false positive results was confirmed retrospectively and the second could not be checked. The sensitivity of the method was 84.6% and the specificity for unequivocally positive cytologies was 83.3%. Provided the examination is performed by an experienced cytologist, urinary cytology is a useful method which is suitable as a screening test in hematuria and for regular checks in high risk patients (e.g. with analgesic nephropathy).

False Negative Reactions↗
PubMed1979

Oxygen consumption during maintenance hemodialysis.

The influence of hemodialysis on oxygen consumption was studied in 15 patients on maintenance dialysis. Red cell 2,3-DPG, P50, an inverse measure of oxygen affinity of hemoglobin, arterial and central venous blood gases and cardiac index were measured. 2,3-DPG remained unchanged, whereas in vivo P50 fell significantly during dialysis due to a rise of pH (Bohr effect). Arterial PO2 was lower after than before dialysis, but arterial and central venous oxygen saturations did not change significantly. Cardiac index increased from 3.66 to 4.0k liter/min/m2. Oxygen consumption rose from 120.5 to 131.7 ml/min/m2 (p less than 0.05), the rise being accounted for by an increase in cardiac index and by a slight post-dialysis hemoconcentration. However, even correcting for these parameters did not reveal a decrease in oxygen consumption. It is concluded that, contrary to previous assumptions, the hemodialysis-induced rise in pH with its consequent increase of oxygen hemoglobin affinity did not impair oxygen delivery in this group of patients on maintenance dialysis.

Adult↗
PubMed1979

Idiopathic hypercalciuria with bilateral macular colobomata: a new variant of oculo-renal syndrome.

Two siblings from a consanguineous family, suffering from nephrocalcinosis and nephrolithiasis caused by idiopathic hypercalciuria are described. The condition is associated with bilateral macular colobomata and tapeto-retinal degeneration. It is known that the latter can occur together with different nephropathies; however, until now it has never been described in combination with idiopathic hypercalciuria. Blood calcium levels were found to be normal, calcium excretion rates were, with one exception, more than 6 mg/kg/24 h corrected for 100 ml GFR. Hypomagnesemia of 1.5 and 1.2 mg/dl and hyermagnesuria of 1.9 and 2.5 mg/kg/24 h corrected for 100 ml GFR were found in both patients. Tubular phosphate reabsorption reached 87% and 84% at serum parathormone levels of 0.34 microgram/l and 0.31 microgram/l in the two patients, respectively. Under calcium and magnesium loading the clearance rates of calcium and magnesium were raised whilst there was only a small insignificant increase in the blood levels of these cations. Acid-base titrations showed normal excretion rates of acid and base in one patient and a mild proximal tubular acidosis in the other. Quantitative investigation of the renal concentrating and diluting capacity established a decrease in the formation of the medullary concentrating gradient in both patients.

Adolescent↗
PubMed1978

[Uremic pericarditis: clinical aspects, echocardiography, therapy].

Over a 2-year period uremic pericarditis was observed in 11 of 62 patients treated by chronic dialysis. The uremic state appeared to be the most important contributing factor in these patients. Chest pain, fever and a pericardial friction rub were observed in the majority of patients; the illness may however be silent. Echocardiography proved to be the single most helpful diagnostic procedure. Intensive hemodialysis, indomethacin or steroid therapy given systemically or intrapericardially are generally accepted in the management of pericarditis. Although indomethacin produced regression of the clinical symptoms in these patients, the volume of fluid within the pericardial sac diminished in 3 of 9 patients only. 6 patients were given systemic steroid treatment and this was followed by prompt resolution of the effusion. Surgery was not necessary. All patients had an uneventful recovery.

Adult↗
PubMed1978

[Strongyloidiasis following kidney transplantation].

A 50-year-old Swiss male died from strongyloidiasis 8 weeks after renal allotransplantation. Past history revealed malaria at age 20 years, when the patient had stayed in tropical and subtropical areas, as well as pulmonary tuberculosis. Hypertension, erythrocyturia, proteinuria and unexplained episodes of blood eosinophilia were first noticed age 45, and 4 years later dialysis was started. A mild acute rejection crisis was successfully treated 4 weeks after transplantation. 2 weeks later, however, bilateral pneumonia developed. Despite vigorous antibiotic and tuberculostatic therapy the patient died in septic shock. Autopsy revealed strongyloidiasis with adult females, eggs and rhabditiform larvae of Strongloides stercoralis in the small intestine. Numerous filariform larvae were detected in the lungs, in the walls of bronchi and trachea, in the brain, in the walls of arteries, and in lymphnodes. Massive granulomatous inflammatory reaction and extensive pulmonary hemorrhage were the main pathological findings.

Chronic Disease↗
PubMed1978

[Diets for patients with kidney diseases].

Dietary treatment is indicated in the conservative management of chronic renal failure and in patients on maintenance dialysis. Water, sodium and potassium warrant chief consideration. The principles and different forms of protein-restricted diets are discussed.

Acute Kidney Injury↗
PubMed1978

Myoinositol--a uremic neurotoxin?

In 28 patients predialysis plasma myoinositol was significantly elevated to 10.8 +/- 2.5 versus 0.75 +/- 0.15 mg/100 ml in normals (mean +/- 1 SD), and was weakly correlated with plasma creatinine concentrations (r = 0.42, p less than 0.05). Dialysis decreased plasma myoinositol concentrations to 3.5 +/- 1.1 mg/100 ml. In 16 patients studied more extensively plasma myoinositol was similarly elevated to 10.6 +/- 3.4 mg/100 ml, and spinal fluid myoinositol was increased to 9.4 +/- 2.3 mg/100 ml (versus 2.7 +/- 0.7 in normals, p less than 0.001). Nerve conduction velocities were reduced in 15 and EEG tracings were abnormal in 12 of the 16 patients. However, neither spinal fluid nor plasma myoinositol showed any correlation with nerve conduction velocities or EEG changes (r = 0.05-0.20, NS) Myoinositol is one of the substances retained in renal insufficiency but no indication was found that it is a toxin causing uremic neurological disturbances.

Adult↗
PubMed1978

[Spontaneous colon perforation in patients with chronic kidney failure].

Although spontaneous colonic perforation is a rare event, if has recently been observed with increasing frequency in patients with renal failure. Several of the drugs given to such patients may induce dehydration of faeces; the combination of very hard faecal masses and an abnormal fragility of the uraemic intestinal mucosa will then lead to the formation of a decubital ulcer. Prophylaxis or at least early diagnosis are imperative because after completed perforation the prognosis is very poor. The operative method of choice is the incontinuous resection of the entire segment of the colon affected by faecal impaction.

Adult↗