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Biomedical subjects

R Lang

Publications and source records attributed to R Lang.

At least 235 records · Page 13Linked to original sources

The use of the balloon-tipped floating catheter in temporary transvenous cardiac pacing.

The effectiveness and safety of balloon-tipped, flow guided, electrodes for ventricular pacing as opposed to the fluoroscopy-guided semi-rigid bipolar electrodes have never been compared in a controlled study. A prospective study was therefore undertaken to compare both techniques in semi-elective and emergency procedures. Flow guided electrodes were inserted in 67 patients (group A) and semi-rigid electrodes in 44 patients (group B). The results of group A were judged to be superior to those of group B in four aspects: a) shorter time (6'45" vs. 13'30", p less than 0.0005); b) lower incidence of catheter displacement (13.4 vs. 32.0 percent, p less than 0.05); c) longer interval of time between implantation and catheter displacement (4.4 vs. 1.9 days, p less than 0.0005); d) lower incidence of serious ventricular arrhythmias during insertion (1.5 vs. 20.4 percent, p less than 0.005). Threshold at insertion was not significantly different (0.6 +/- 0.3 vs 0.7 +/- 0.2 milliampere). The superiority of flow-guided electrodes over fluoroscopy-guided electrodes persisted in the comparison of semielective insertions in groups A and B. We conclude that the flow-guided insertion technique is safer, more expeditious and more stable than the fluoroscopy-guided technique in semi-elective as well as in emergency insertions.

Adolescent↗

Mid-systolic click and echocardiographic evidence of mitral valve prolapse during electrical pacing.

A mid-systolic click was present in a patient during three years of follow-up after implantation of a permanent transvenous pacemaker. Echocardiography revealed posterior motion of the anterior leaflet which resembled mitral valve prolapse. Both the click and echocardiographic evidence of prolapse disappeared simultaneously with resumption of sinus rhythm and during supraventricular tachyarrhythmias. Wtih spontaneous change in the position of the electrode three years after initial implantation, both the click and the posterior motion of the mitral valve disappeared. The association of mitral valve prolapse with electrical pacing is most unusual and appears to have a distinct pathophysiological mechanism.

Aged↗

The influence of calcium intake and the status of intestinal calcium absorption on the diagnostic utility of measurements of 24-hour cyclic adenosine 3',5'-monophosphate excretion.

Twenty-five normal subjects, 45 patients with idiopathic hypercalciuria, and 50 patients with primary hyperparathyroidism were studied with an oral calcium tolerance test and with measurements of 24-h calcium and total cAMP excretion on defined 400-mg and 1000-mg calcium diets. There was a strong positive correlation (r = 0.62; P less than 0.001) between the calciuric response to the tolerance test and the increase in calcium excretion on the 100-mg relative to the 400-mg calcium diet. The increase in daily calcium intake was associated with a significant (P less than 0.001) suppression in total cAMP excretion in each patient group. The suppression in cAMP excretion was sufficient to completely segregate patients with absorptive hypercalciuria from those with renal hypercalciuria on the 1000-mg calcium diet (ranges, 1.24-3.50 and 3.97-4.87 nmol/100 ml glomerular filtrate, respectively). In patients with primary hyperparathyroidism, results for total cAMP excretion were elevated in 48 (96%) patients on the restricted calcium diet but were within the normal range in 14 (28%) patients on the high-normal calcium diet. Net intestinal calcium absorption has a prominent influence on results for 24-h total cAMP excretion, which may be used to diagnostic advantage or seriously impair diagnostic accuracy, depending upon the patient population and the conditions of study.

Adult↗

[Isolated tumor of the rectum as primary manifestation of Burkitt lymphoma (author's transl)].

Burkitt tumors are malignant lymphoblastic lymphomas occurring predominantly in Africa in children and young adults and involving in many cases the intestinal tract; these tumors occur rather seldom outside Africa. A case report is given of a white 21 old female suffering from this disease; that first manifestation was an isolated ulcerating tumor of the rectum without involvement of other organs of lymph nodes. Diagnosis was confirmed by rectum biopsy. X-ray therapy, cytostatic therapy and amputation of the rectum did not prevent a fast progression of the disease and final death, which is the usual course of the disease when it occurs outside Africa.

Adult↗

Recurrent post-partum gastroenteritis with eosinophilia.

A young woman experienced twice in eight years acute, self-limited episodes of gastroenteritis with marked eosinophilia, each one associated with or triggered by a normal delivery. This patient had a normal gastric mucosal biopsy, thus lacking one of the major criteria required by previous authors for the definition of eosinophilic gastroenteritis. Nevertheless, it is our belief that this case does represent a milder and more benign form of the very same syndrome, associated in a dubious way with labour.

Eosinophilia↗

[Triceps and subscapular skinfold thickness. A random sample, Geneva 1972].

Subscapular and triceps skinfold thickness were measured by using a Lange skinfold caliper, on a random sample of 2861 boys and 2692 girls aged 4 to 191/2 years. The technique of measurement is specified, and the data are submitted to statistical analysis with a view to standardization. For both skinfolds, the sample size, the arithmetic mean and the standard deviation in each age group and either sex are given in tabular form. Correspondingly, fitted percentiles are shown on separate graphs for both of these skinfolds, related to age as well at to standing height of boys or girls.

Adolescent↗

Biochemical evaluation of patients with cancer-associated hypercalcemia: evidence for humoral and nonhumoral groups.

In 50 consecutive patients with cancer-associated hypercalcemia, we measured nephrogenous cyclic AMP, tubular phosphorus threshold, fasting calcium excretion, plasma 1,25-dihydroxyvitamin D, and immunoreactive parathyroid hormone as determined by four region-specific antiserums. Nephrogenous cyclic AMP excretion was elevated in 41 patients and suppressed in nine (means, 5.85 vs. 0.51 nmol per 100 ml of glomerular filtrate). There was no overlap between these groups. When compared with 15 patients with primary hyperparathyroidism, the group with increased cyclic AMP excretion had similar reductions in tubular phosphorus threshold; higher fasting calcium excretion (means, 0.66 vs. 0.25 mg per 100 ml of glomerular filtrate, P < 0.01); marked reductions in 1,25-dihydroxyvitamin D (means, 20 vs. 83 pg per milliliter, P < 0.001); and lower levels of immunoreactive parathyroid hormone in all four assays. The data suggest that elevated excretion of nephrogenous cyclic AMP may be a useful marker of humorally mediated cancer-associated hypercalcemia, that this type of hypercalcemia is common, that the humoral factor responsible for this syndrome is not native 1-84 parathyroid hormone, and that the various subtypes of cancer-associated hypercalcemia are biochemically distinguishable from primary hyperparathyroidism.

Animals↗

Hypophosphatemia and glucose intolerance: evidence for tissue insensitivity to insulin.

Although hypophosphatemia is commonly present in diabetics, little is known about its isolated effects on glucose and insulin metabolism. We therefore investigated glucose metabolism in six nondiabetic subjects with chronic hypophosphatemia. When glucose was infused to maintain a constant hyperglycemic level (125 mg per deciliter [6.9 mmol per liter] above basal levels), the glucose infusion rate was 36 per cent less in the hypophosphatemic group than in controls (4.90 +/- 0.34 mg per kilogram of body weight per minute vs. 7.64 +/- 0.37, P < 0.001), although responses to endogenous insulin were similar. When exogenous insulin was infused at a constant rate to maintain an insulin level about 100 microU per milliliter (718 pmol per liter) above basal levels and glucose was infused as necessary to maintain fasting glucose levels, the infusion rate of glucose was 43 per cent lower in the hypophosphatemic group than in controls (3.80 +/- 0.58 mg per kilogram per minute vs. 6.70 +/- 0.33, P < 0.001), although the clearance rate of insulin was similar in both groups. These results indicate that hypophosphatemia is associated with impaired glucose metabolism in both the hyperglycemic and euglycemic states, and that this associated primarily reflects decreased tissue sensitivity to insulin. (N Engl J Med. 1980; 303; 1259-63.).

Adult↗

Effects of a beta 1-selective adrenergic agonist in normal human volunteers.

In healthy volunteers, the effects of prenalterol, a new beta 1-adrenoceptor agonist, on renal hemodynamics, excretory function, plasma-renin-activity, plasma cAMP concentration, and plasma and urinary norepinephrine were studied. Besides an increase in blood pressure, which was adjusted to about 20 mmHg above the resting values, and an increase of heart rate, prenalterol induced only transient decreases of urinary volume and free water clearance and in increase of sodium excretion. The other parameters measured did not change. Thus prenalterol mainly exerts positive inotropic and chronotropic effects and does not affect renal circulation.

Adrenergic beta-Agonists↗

[Computer tomography in the diagnosis of adrenal disease (author's transl)].

Computer tomography of the adrenals was performed on 35 patients. Abnormal findings were noted in 19, histologically confirmed in 14. In the course of localization of endocrine processes, as well as in elucidating suspected tumours, a normal adrenal gland can be visualised by computer tomography in over 90% of instances, and lesions detected if greater than 0.5--1.0 cm in diameter. It should be used after all clinical and biochemical tests and conventional radiological measures have been employed, invasive angiography being reserved only for special problem cases.

Adrenal Gland Diseases↗

[Sézary syndrome (author's transl)].

Morphological demonstration of the typical Sézary cell in peripheral blood confirmed the diagnosis of Sézary syndrome in a 64-year-old patient with generalized erythrodermia and typical histopathological skin changes. Enzymes and immunocytological membrane characteristics of Sézary cells changed in the course of the disease after cytostatic therapy. Polychemotherapy clinically led to transitory complete regression of skin changes. Reviewing the few published investigations it is found that the morphologically sufficiently defined Sézary cells are apparently not uniform cytochemically and immunocytologically in different patients.

Autopsy↗