[Chest pain in a 37-year-old Sikh]

Chest pain can be the only sign of osteomalacia. The case of a 37 years old patient from India, member of the religious group of the sikh, with vitamin D deficiency is presented. The disease developed as a consequence of reduced sun exposure (covering a substantial part of the body for ethnic reasons). The pathogenesis, clinical picture and implications for daily practice are discussed.

Evidence of secondary structure by high-resolution magic angle spinning NMR spectroscopy of a bioactive peptide bound to different solid supports

The structure of the 19-amino acid peptide epitope, corresponding to the 141-159 sequence of capsid viral protein VP1 of foot-and-mouth disease virus (FMDV), bound to three different resins, namely, polystyrene-MBHA, PEGA, and POEPOP, has been determined by high-resolution magic angle spinning (HRMAS) NMR spectroscopy. A combination of homonuclear and heteronuclear bidimensional experiments was used for the complete peptide resonance assignment and the qualitative characterization of the peptide folding. The influence of the chemicophysical nature of the different polymers on the secondary structure of the covalently attached FMDV peptide was studied in detail. In the case of polystyrene-MBHA and polyacrylamide-PEGA resins, the analysis of the 2D spectra was hampered by missing signals and extensive overlaps, and only a propensity toward a peptide secondary structure could be derived from the assigned NOE correlations. When the FMDV peptide was linked to the polyoxyethylene-based POEPOP resin, it was found to adopt in dimethylformamide a helical conformation encompassing the C-terminal domain from residues 152 to 159. This conformation is very close to that of the free peptide previously analyzed in 2,2,2-trifluoroethanol. Our study clearly demonstrates that a regular helical structure can be adopted by a resin-bound bioactive peptide. Moreover, a change in the folding was observed when the same peptide-POEPOP conjugate was swollen in aqueous solution, displaying the same conformational features as the free peptide in water. The possibility of studying solid-supported ordered secondary structures by the HRMAS NMR technique in a wide range of solvents can be extended either to other biologically relevant peptides and proteins or to new synthetic oligomers.

Carcinoid syndrome, acromegaly, and hypoglycemia due to an insulin-secreting neuroendocrine tumor of the liver

We report a patient with a hepatic neuroendocrine tumor showing an extraordinary change of the tumor's humoral manifestations from a clinically documented extrapituitary acromegaly and a typical carcinoid syndrome toward a hyperinsulinemic hypoglycemia syndrome. At the primary manifestation of the tumor, an increased serum level of insulin-like growth factor I due to overproduction of GHRH and an increased urinary excretion of 5-hydroxyindoleacetic acid were found. The clinical manifestation of the GHRH excess was an arthralgia, which resolved completely after operative tumor debulking and normalization of insulin-like growth factor I and GHRH serum levels. The secretion of serotonin from the tumor resulted in a typical carcinoid syndrome including right-sided valvular heart disease. On the later course of the disease, the humoral manifestations of the tumor were supplemented by the secretion of insulin, leading to recurrent severe hyperinsulinemic hypoglycemia. The hepatic origin of hyperinsulinism was demonstrated by selective arterial calcium stimulation. Moreover, tumor cells revealed insulin and C-peptide immunoreactivity in the immunohistochemical analysis. The patient died 8 yr after the initial diagnosis of the tumor, and a carefully performed autopsy procedure confirmed the absence of any extrahepatic tumor manifestation.

Effects of flue gas composition on the catalytic destruction of chlorinated aromatic compounds with a V-oxide catalyst

When using catalytic flue gas cleaning, several flue gas compounds may influence oxidation reactions of hazardous volatile organic compounds, possibly leading to lower reaction rates and, thus, to an incomplete destruction. Experimental investigations were performed with regard to the influence of selected flue gas compounds, like hydrogen chloride, sulfur dioxide, oxygen, and water vapour, on the catalytic destruction behavior of chlorobenzenes under flue gas cleaning conditions of an incineration plant. For this purpose, a metal oxide catalyst was operated at different temperatures at a space velocity of 3600 h-1 in a laboratory-scale fixed bed reactor with model flue gases, and with real flue gases generated from the TAMARA waste incineration plant. The results obtained from the studies with model flue gas were analyzed with respect to reaction kinetics. These kinetics were applied for comparison with the experimental data gained in the real flue gas.

Multistep synthesis of 2,5-diketopiperazines on different solid supports monitored by high resolution magic angle spinning NMR spectroscopy

The solid-phase synthesis of 2,5-diketopiperazines containing the trans-4-hydroxy-L-proline amino acid residue (Hyp) was performed on Ellman polystyrene, polyoxyethylene-polyoxypropylene (POEPOP), polystyrene-polyoxyethylene NovaSyn, and Wang resins, respectively. The reaction pathway allowed the introduction of different functional groups around the bicyclic scaffold in a combinatorial approach, and it generated mixtures of isomers. A detailed characterization of the single reaction steps by high resolution magic angle spinning (HRMAS) NMR spectroscopy was performed. The NMR spectral resolution of the resin-bound intermediates and final products was greatly influenced by the polymer matrix. The POEPOP resin permitted to obtain HRMAS NMR spectra with a resolution comparable with that of the spectra of the molecules in solution. Moreover, configurational and conformational isomers formed during the solid-phase reaction steps could be detected and easily assigned. Therefore, the combination of the HRMAS NMR technique with the use of nonaromatic resins may become an extremely powerful tool in solid-phase organic synthesis. This approach will allow the monitoring of multistep reactions and the conception of on-bead structural studies either on small molecules or on natural and/or synthetic oligomers.

[Mastocytosis: an important differential diagnosis in anaphylactoid reaction to Hymenoptera sting. A case report and overview of clinical aspects, diagnosis and current therapy of mastocytosis]

A 77-year old farmer presented with a history of three severe anaphylactoid reactions after hymenoptera stings for the last three years. No sensitisation to hymenoptera venoms could be shown on allergological work-up. The serum level of tryptase however was clearly elevated (37.1 micrograms/l; normal value: < 13.5 micrograms/l). The diagnosis of systemic mastocytosis could be confirmed by bone marrow biopsy. Patients with mastocytosis are at increased risk of anaphylactic/anaphylactoid reactions. They should be educated how to avoid trigger factors and they should always carry an emergency kit (H1 blocker, corticosteroid, adrenalin) and a "mastocytosis pass" with them. Venom immunotherapy is indicated in patients with proven hymenoptera allergy. Selected patients at very high risk of anaphylactic reactions may need a continuous prophylactic medication with H1 and H2 blocker and eventually a cyclooxygenase inhibitor.

Thiamin deficiency in HIV-positive patients: evaluation by erythrocyte transketolase activity and thiamin pyrophosphate effect

BACKGROUND AND AIMS

The aim of the study was to determine the thiamin status in HIV-positive patients.

METHODS

Measurement of erythrocyte transketolase activity (ETK) and thiaminpyrophosphate (TPP) effect in 55 consecutive HIV-positive patients of a specialized outpatient clinic were grouped into five groups according to their CD4 counts. Comparison of results of HIV-positive patients with age-matched control group of 22 healthy subjects.

RESULTS

Of the patients, 27% had a pathologically-increased TPP effect, 18% of the patients had pathologically-low ETK. The percentage of pathological values of TPP effect in the patients was significantly higher compared with the control group. There was no statistically significant correlation between pathological thiamin status and stage of the disease, zidovudine therapy or nutritional status of the patients.

CONCLUSIONS

Thiamin deficiency in HIV-positive patients was found in a higher percentage than previously reported. Thiamine deficiency is not only present in advanced stages of HIV-infection, but also in clinically asymptomatic patients.

Headache and bilateral visual loss in a young hypothyroid Indian man

We describe the exceptional association of Vogt-Koyanagi-Harada syndrome (VKHS) and hypothyroidism in a 29-year-old man of Indian heritage. VKHS is a rare uveomeningoencephalitic syndrome with probably autoimmune pathogenesis. Nontraumatic uveitis, aseptic meningoencephalitis, vitiligo, alopecia and poliosis are the leading clinical features of VKHS. The reported patient presented with bilateral visual loss and progressive frontal headache. VKHS was diagnosed due to characteristic ophthalmological findings and the diagnosis of aseptic meningitis. Due to the autoimmune pathogenesis, VKHS may be rarely associated with other autoimmune disorders. Association of VKHS with autoimmune thyroid disease has been described in the literature in three patients. In the reported case hypothyroidism due to chronic autommune thyroiditis was diagnosed in association with VKHS. Routinely determination of thyroid function in patients with VKHS is recommended.

Origin of the residual NMR linewidth of a peptide bound to a resin under magic angle spinning

The tetrapeptide Ala-lle-Gly-Met bound to a Wang resin via the methionine residue was studied by NMR under MAS conditions and compared to the same peptide in solution. The bound peptide exhibits average linewidths superior to those observed for the peptide in solution. The origin of the residual NMR linewidth observed for the bound form was investigated. The dynamics of the peptide is shown to be only marginally responsible for the increased linewidth; the major cause of the line broadening appears to be nonaveraged magnetic susceptibility differences.

[Hypertension refractory to therapy]

A 41-year-old musician developed severe refractory hypertension 13 years after radiotherapy of the retroperitoneum because of a teratocarcinoma of the right testis. An angiography revealed severe stenoses of both renal arteries. After percutaneous transluminal angioplasty of both renal arteries, blood pressure valves returned to the normal range. Radiation-induced injury of arteries may provoke premature atherosclerosis, which cannot be differentiated morphologically from common atherosclerosis. Patients who develop severe hypertension some years after radiotherapy of the retroperitoneum should therefore be screened for the presence of renovascular hypertension.

Skin capillary aneurysms detected by indocyanine green in type I diabetes with and without retinal microaneurysms

Functional diabetic microangiopathy of skin vessels is well known (decreased reactivity of arterioles to various stimuli, increased capillary pressure and permeability). In contrast to conventional capillaroscopy, recently introduced infrared fluorescence videomicroscopy with indocyanine green allows one to depict capillary aneurysms, even when filled with plasma alone. Seventeen healthy volunteers (mean age 37.7 years), 14 patients with type I diabetes without (31.3 years) and 17 with retinal microaneurysms (46.8 years) were studied. The mean duration of diabetes in patients without retinal microaneurysms was 14.2 years (4-36 years) and in those with retinal microaneurysms 21.5 years (8-49 years). Nailfold capillary aneurysms were present in 3 of 17 healthy controls, in 7 of 14 patients without and in 10 of 17 patients with retinopathy. Patients with type I diabetes with and without retinopathy exhibited significantly more skin microaneurysms (p < 0.05 and < 0.005, respectively) than the controls. The prevalence in the patients with retinal microaneurysms tended to be even higher. Skin capillary aneurysms, which may be depicted in vivo by sophisticated infrared fluorescence videomicroscopy, even when filled by plasma alone, are an important morphological feature of diabetic microangiopathy.

[Histiocytosis X. Clinical aspects and course in 5 patients]

Histiocytosis X developed in five patients (one woman and four men) when aged between 15 and 44 years. The initial sign in four of them was eosinophilic granuloma of the bone, in one it was pulmonary involvement. In three patients the disease remained confined to bone, while in two it involved the lungs and central nervous system, respectively. Osteolysis regressed spontaneously in one of the men, while in the woman there has been no recurrence 8 years after resection of the focus. In another man an osteolytic focus in a rib was noted after a 9-year recurrence-free interval. The man with pulmonary and bone involvement received chemotherapy with vinblastine and prednisone: dyspnoea and cough disappeared, vital capacity improved and the interstitial lung changes regressed. The osteolytic foci were repeatedly irradiated in the man with bone and CNS involvement. This brought about considerable reduction in pain but no significant radiological changes of the foci. Two courses of chemotherapy were given over 12 years, once with vincristine and prednisone, afterwards with cyclophosphamide. This arrested the progression of the osteolytic foci, but each time they recurred when the drugs were stopped.

[Diabetes insipidus in chronic myeloid leukemia. Remission of hypophyseal infiltration during busulfan treatment]

In a 53-year-old male who presented with diabetes insipidus as the first symptom of chronic myelocytic leukemia, computed tomography of the sella showed infiltration of the posterior pituitary gland. Busulfan treatment was given for one month and the infiltration had disappeared ten weeks after initiation of therapy. At the same time the severity of the diabetes insipidus diminished for a period of three months. Diabetes insipidus is a rare complication of chronic myelocytic leukemia: only 8 similar cases have been reported in the last 75 years.

Decreased thiosulfate sulfur transferase (rhodanese) in Leber's hereditary optic atrophy

In mammals the major portion of cyanide is converted to thiocyanate by the liver enzyme thiosulfate sulfur transferase (TST) (rhodanese). We have found a much reduced activity of this enzyme in liver biopsies from two affected males of a family with Leber's hereditary optic atrophy and in two isolated cases of the same disease, (compared to liver biopsies from controls or liver samples obtained at autopsy). In one of the patients we studied the effect of a 3-day thiosulfate infusion. The urinary excretion of thiocyanate which was low prior to the infusion was raised during the thiosulfate treatment; in a healthy control person the same thiosulfate infusion did not alter the thiocyanate excretion rate. This suggests that cyanide detoxification which is suboptimal in patients with Leber's disease may be increased by thiosulfate infusion.

[Transcapillary diffusion of Na-fluorescein in skin areas of the dorsum of the foot in juvenile diabetics]

Fluorescence videomicroscopy after intravenous injection of Na-fluorescein serves to quantitate dye diffusion out of single capillaries or capillary groups in an almost atraumatic manner [2, 4, 6, 8, 9]. In 14 young patients with a mean disease duration of 10 years and in 16 healthy controls, fluorescent light intensity was measured continuously during one hour at the dorsum of the foot by a videodensitometer covering an average of 68 capillaries. 1 second and 5 minutes after first appearance of the dye in the foot skin, the amount of the tracer detected in the area of measurement was significantly increased in the diabetics (p less than 0.05-0.001). At 1 minute, for example, mean fluorescent light intensity reached 47.2 +/- 18.1% of the maximal individual intensity and in the normals only 29.3 +/- 10.8% (p less than 0.01). In the patients the capillaroscopic image was characterized by early blurring, whereas the pericapillary halo of the controls contained more dye than the more remote interstitial space and remained well delineated for a much longer time. The new technique offers the possibility of studying transcapillary diffusion as an expression of microangiopathy in different groups of diabetic patients, and of following the effect of therapeutic regimens.

Patterns of diffusion through skin capillaries in patients with long-term diabetes

We used intravital fluorescence videomicroscopy to study the pattern of transcapillary and interstitial diffusion in the nail folds of 13 patients with long-term diabetes and of 12 healthy controls. In both groups intravenously injected sodium fluorescein left the intravascular compartment. Its distribution in the pericapillary space and in the remote parts of the interstitial space was measured on single frames of the television tape by videodensitometers that are sensitive to intensities of fluorescent light. In the diabetics the dye passed both physiologic diffusion barriers--the capillary wall and the pericapillary space--in significantly increased amounts (P less than 0.01). The enhanced penetration of the tracer into the remote area caused an early homogeneous, milky blurring of the capillary image, whereas in the controls the pericapillary space remained clearly delineated for as long as 40 to 50 minutes after the appearance of the dye. The altered pattern of diffusion could be explained by increased permeability of the diffusion barriers, or, alternatively, by either changes of the mobility of the dye due to binding of the dye by intravascular or interstitial proteins or abnormal hemodynamics in the microvascular circulation. This technique provides a quantitative, noninvasive method of studying the natural history of diabetic microangiopathy.

[Factitious hypoglycemia: clinical aspects, diagnosis and course in a non-diabetic male]

The case of a 37-year-old man without diabetes is reported who began to experience repetitive episodes of loss of consciousness. For 11/2 years the patient suffered from attacks of fatigue associated with sweating, tachycardia, blurred vision and finally unconsciousness. In the presence of low blood sugar and high plasma insulin values, an insulin producing pancreatic adenoma was initially suspected. In view of the negative results of radiological investigations, the different blood sugar reactions during fasting tests with and without supervision, together with low concentrations of C-peptide and high insulin values during various hypoglycemic episodes, factitious hypoglycemia was diagnosed. Finally, an ampoule of insulin was found in a locked suitcase of the patient. Therefore, in patients with fasting hypoglycemia as well as insulin producing adenoma, surreptitious insulin injections as part of a Müncchausen syndrome should be considered.

Changes in tissue sensitivity to vasopressin in hereditary hypothalamic diabetes insipidus

Specific binding of (125I) arg8-vasopressin to mononuclear phagocytes of the circulating blood was studied in 3 patients (one male, two females) with hereditary hypothalamic diabetes insipidus before, during and after therapy with 1-desamino-8-D-arginine vasopressin and compared with values of 15 normal donors (7 males, 8 females). Before therapy specific radioligand binding activity was considerably increased (0.3 +/- 0.08 fmoles/2.2 X 10(5) cells/ml) versus controls (0.23 +/- 0.04 fmoles/2.2 X 10(5) cells/ml). Increased binding was due to increase in receptor concentration per cell. In contrast, during treatment and after withdrawal of therapy the receptor binding activity was 0.1 +/- 0.05 fmoles/2.2 X 10(5) cells/ml. The dissociation constant (KD) for hormone binding before therapy (25 +/- 0.2 pM) was roughly identical with that of normal donors (24 +/- 0.8 pM), indicating insignificant changes in receptor affinity. During treatment and 48 h after withdrawal of therapy, however, the KD value was 11 +/- 0.45 pM, which amy be accounted for by an elevation in the binding affinity. We conclude that untreated patients with hereditary hypothalamic diabetes insipidus have increased tissue sensitivity to vasopressin, but have decreased binding capacity during and even two days after discontinuation of therapy, possibly as the result of 1-desamino-8-D arginine vasopressin-induced desensitization phenomena.

[Furosemide and metolazone: a highly effective diuretic combination]

The natriuretic and diuretic effects of combined treatment with furosemide and metolazone have been studied quantitatively. 15 hospitalized patients with severe fluid retention who showed no reduction of body weight despite treatment with furosemide received metolazone in addition for 3 days. 11 patients had biventricular heart failure with edema, and 4 had cirrhosis of the liver with ascites. Following the addition of metolazone at a starting dose of 2.5 mg/d, a highly significant increase in diuresis and natriuresis, with a corresponding reduction in body weight, was seen in all patients pretreated with a daily dose of 40-370 mg furosemide (mean 122 mg/d). On the first day of this combined treatment the mean sodium excretion increased from 131 to 303 mval/d (2 p less than 0.01) and the mean urine volume increased from 1677 to 2940 ml/d (2 p less than 0.01). The mean reduction in body weight was 6.1 kg (2 p less than 0.001) within 7 days of continuous treatment. Even at low doses metolazone significantly potentiates the diuretic effects of furosemide and therefore simplifies the treatment of fluid retention. High doses of furosemide can be avoided in many cases, a factor of particular advantage in ambulatory long term therapy and in patients with decreased kidney function. It may also lower the cost of the therapy. In 3 patients the furosemide dose had to be lowered after metolazone was started, to avoid an excessive negative fluid balance. These cases clearly demonstrate the importance of daily checks on the patient's body weight after starting combined therapy with furosemide and metolazone.

Treatment of abdominal angina with percutaneous dilatation of an arteria mesenterica superior stenosis. Preliminary communication

Percutaneous transluminal dilatation of an atherosclerotic stenosis of the superior mesenteric artery was done in a 65-year-old woman with abdominal angina. The patient was relieved of abdominal pain immediately after the dilatation.

Renovascular hypertension: treatment by percutaneous transluminal dilatation

Eight patients with unilateral renovascular hypertension underwent percutaneous transluminal dilatation. In seven, renal-artery stenoses were caused by atherosclerotic lesions and in one, by fibromuscular hyperplasia. After a 6-month follow-up period, three patients were cured of hypertension anf four showed improvement. Only one patient failed to respond: Failure was caused by an occluded left renal artery 3 months after the procedure. Renal angiographic studies were repeated in six patients after 6 months of follow-up and showed patent vessels in five and reoccurrence of a slight renal-artery stenosis in one. In one patient angiographic control studies done after 3 months showed an occluded renal artery. In five patients mean pressure gradient across the renal-artery stenoses was 89 +/- 22.8 mm Hg before percutaneous transluminal dilatation and 16.4 +/- 18.5 mm Hg after being controlled for 6 months. Our results indicate that percutaneous transluminal dilatation may be valuable in the treatment of renovascular hypertension.

[Minoxidil in treatment resistant hypertension]

22 patients (4 female, 18 male, mean age 47 +/- 10.7 years) with severe essential hypertension (n = 21) and renovascular hypertension (n = 1) were treated with a mean daily dosage of 16.3 +/- 5.1 mg minoxidil for up to 42 weeks. In addition, all patients received a diuretic (hydrochlorothiazide or furosemide) and a beta-blocker (pindolol or propranolol). 8 patients were treated simultaneously with alpha-methyl-dopa. Within one week minoxidil led to a significant reduction in both systolic and diastolic supine blood pressure (p less than or equal to 0.005) from 201.3 +/- 29.0/125.4 +/- 19.2 mm Hg to 172.8 +/- 28.3/106.0 +/- 19.9 mm Hg. The maximum initial blood pressure response was observed after 3 weeks with a mean daily dosage of 12.2 +/- 9.4 mg of minoxidil (160.5 +/- 20.7/99.4 +/- 13.8 MM Hg, p less than or equal to 0.001). Throughout the remaining period a constant and significant reduction in supine systolic and diastolic and upright diastolic blood pressure was achieved (p less than 0.005-less than 0.001) whereas at times systolic blood pressure values could not be lowered significantly. Body weight and pulse rate showed no significant changes throughout the study. In some cases furosemide had to be added by up to 500 mg/day to counteract minoxidil induced water and salt retention. Only moderate doses of beta-blockers were required to prevent a drug induced rise in pulse rate. In these patients a significant change in renal function was not observed. The results show that minoxidil is a potent drug in the treatment of severe essential hypertension.

[Renovascular hypertension. Prognostic value of renal venous renin determinations (author's transl)]

In the present study the effect of surgery on blood pressure was investigated in 35 patients with renovascular hypertension: 17 patients with fibromuscular hyperplasia (FMD) and 18 with atherosclerosis (ASS) of the renal artery. Patients with FMD were younger (31,8 years), showed a shorter duration of hypertension (1.8 years) and were prevalently female (82%), whereas patients with ASS were markedly older (48.2 years), showed a longer duration of hypertension (2.6 years) and were most often male (78%). In both groups of patients the intravenous urogram was positive in a comparable high percentage (FMD=64%, ASS=61%). Following surgical intervention 47%(n=8) of the 17 patients with FMD were cured, 47% (n=8) were improved and only 6% (n=1) showed insufficient reduction of blood pressure values. In ASS the respective values were 28, 55 and 17%. Consequently a good effect of surgery (cured and improved) was observed in 88.5% of all patients. Patients with ASS who failed to respond to surgery (n=3) showed a remarkable long duration of hypertension (7.0 plus or minus 1.4 years). Plasma renin activity (PRA) was determined preoperatively in both renal veins in all 35 patients. From these values the PRA-ratio (PRA affected/unaffected side) was calculated. In 27 patients PRA determinations were repeated following (15 and 30 min) intravenous injection of 40 mg furosemide. PRA-ratios of larger than or equal to 1.5 were considered to be significant. In 31 patients with unilateral renovascular hypertension PRA-ratios were correlated to the postoperative blood pressure reduction. No significant differences in mean PRA-ratios were observed between cured and improved patients. Furthermore, for the total group of 31 patients no significant correlations were obtained between PRA-ratios and postoperative blood pressure reduction. Our results do not support the widespread opinion that PRA determinations in both renal veins are useful to predict the effect of surgery in patients with unilateral renovascular disease. Therefore, from our experience this method should not be recommended as obligatory in the diagnostic work-up of renovascular hypertension.

Primary aldosteronism: inability to differentiate unilateral from bilateral adrenal lesions by various routine clinical and laboratory data and by peripheral plasma aldosterone

In 31 patients with primary aldosteronism routine clinical and laboratory data, the effect of orthostasis on plasma aldosterone (PA), plasma renin activity (PRA) and cortisol (PC), effect of fludrocortisone or high sodium intake on basal PA and night-day fluctuations of basal PA and PC with and without suppression of pituitary ACTH by dexamethasone were determined to differentiate patients with a unilateral aldosterone producing tumour (adenoma, APA, n=20; carcinoma, CA, n=1) from those with idiopathic bilateral adrenal hyperplasia (IAH, n=10). Mean systolic and diastolic blood pressure, age, serum potassium and urinary excretion of sodium and potassium were not significantly different in both groups of patients. Normokalaemic primary aldosteronism occurred both in patients with APA (n=2) and in patients with IAH (n=1). Mean basal PA and mean urinary excretion rate of aldosterone-18-glucuronide were higher though not significantly different in patients with APA or CA than in those with IAH. A substantial number of the patients with APA (n=5) and with IAH (n=3) showed urinary excretion rates of aldosterone-18-glucuronide less than 13 microgram/24 h. Mean PA and PRA significantly increased (P less than 0.025) in patients with IAH in response to posture. However, these changes also occurred at times in some patients with APA. Both fludrocortisone and high sodium intake produced a variable and no group-specific effect on basal PA. Night-day variations in PA were positively correlated with those in PC in all patients with APA (n=12) and in 5 of 8 patients with IAH. A dissociation of PA and PC, however, was only observed in patients with IAH. Finally, the effect of dexamethasone on plasma aldosterone curves was variable in both groups of patients. Our results indicate that under the described conditions analysis of routine clinical and laboratory data and of peripheral PA, PRA and PC are of limited value in differentiating patients with APA or CA from those with IAH.

[Renovascular hypertension: therapy by means of percutaneous transluminal dilatation of renal artery stenoses]

Percutaneous transluminal dilatation was performed in 5 patients with unilateral atherosclerotic renovascular disease and one patient with occlusion of a renal artery. Hemodynamic activity of the stenosis was documented by determination of pre- and poststenotic blood pressure values and by measurement of renal plasma flow. Flowing transluminal dilatation all patients showed a significant drop in blood pressure and antihypertensive treatment could be reduced or even discontinued. Only one patient became hypertensive again 3 months after the dilatation procedure. In this patient both the reduction of renal plasma flow and the delayed nephrographic effect on the stenotic side in the intravenous urogram were interpreted as symptoms of a recurrence of significant renal artery stenosis. In 2 of the six patients with impaired kidney function glomerula filtration are increased, as documented by a decrease in serum creatinine values. The results show that percutaneous transluminal dilatation may be a valuable method in the management of renovascular hypertension.

Congenital pseudohypoaldosteronism: case report and review. Effect of indomethacin during sodium chloride depletion

A newborn boy (birth weight 2550 g) presented from the first days of life with poor drinking, moderate vomiting and persistent weight loss. On hospital admission at age 4 weeks, there were severe dehydration, dystrophy and electrolyte disturbances (Na 107, Cl 80, K 5,4 mval/l). The usual causes of salt wasting were excluded, but plasma renin activity, plasma aldosterone and urinary aldosterone-18-glucuronide were markedly increased. DOCA had no salt-retaining effect, but a sodium chloride supplement of 3 g per day improved the clinical condition dramatically and normalized the electrolyte values. With this treatment, plasma renin activity and aldosterone were normal or almost normal beyond the age of 6.5 months, but urinary aldosterone-18-glucuronide remained slightly increased. Considerable augmentation of the plasma renin activity and of urinary aldosterone-18-glucuronide, but no clear salt loss were induced by spironolactone. With salt restriction, there was evidence for marked salt loss. Its progress could be inhibited by administration of indomethacin. Since indomethacin inhibits the synthesis of prostaglandins with saluretic activity, it is probable that the prostaglandins participate in the pathogenesis of the salt wasting in pseudohypoaldosteronism.

[Aldosterone and renin in liver cirrhosis with ascites]

Supine plasma aldosterone and plasma renin activity were determined in patients with cirrhosis of the liver and ascites (n = 10). Most of the patients initially showed an increase in plasma aldosterone and plasma renin activity. However, values within the normal range were observed (plasma aldosterone, n = 3; plasma renin activity, n = 4). In the ascitic fluid renin activity could not be detected, whereas aldosterone concentrations correlated significantly with the respective plasma levels (r = 0.8, p less than 0.01). During therapy with spironolactone alone (n =2) or in combination with furosemide (n = 4), diuresis and natriuresis showed no correlation with changes in plasma aldosterone and/or plasma renin activity. Our results suggest that other factors than renin and aldosterone secretion may be important in the formation of ascites in patients with cirrhosis of the liver. In addition, the inverse correlation between mean arterial blood pressure and plasma renin activity (r = -0.65, p less than 0.05) found in our patients supports the assumption that the increase in renin secretion is probably induced by changes in (renal) hemodynamics.

[Studies on the differential determination of renin activity in renal venous blood in renal artery stenosis]

Plasma renin activity (PRA) was determined in both renal veins of 37 patients with angiographically proven renal artery stenosis. Renal venous PRA was determined in 17 patients without furosemide stimulation and in 20 patients before and 15 and 30 min after intravenous injection of 40 mg furosemide. 21 of 37 patients showed abnormally high peripheral PRA. In the 17 patients in whom renal venous PRA was measured without stimulation, 11 showed a PRA ratio (PRA stenotic side/PRA unaffected side) greater than or equal to 1.5. The 20 patients in whom stimulation with furosemide was performed were divided into 2 groups each containing 10 patients: The first group was characterized by an increase in PRA ratio after furosemide stimulation, while in the second group this PRA ratio decreased. In the first group mean duration of hypertension was 4.5 years compared to 7.5 years in the second group. In 17 of 37 patients renal artery stenosis was corrected by surgery. After operation 12 patients became normotensive and in 2 patients hypertension improved. There was no effect of renovascular surgery on blood pressure in only 3 patients. None of these patients showed an increasing ratio in response to furosemide. Our results suggest that the validity of renal venous PRA measurements is enhanced when the procedure is performed before and after administration of furosemide.

Control of plasma aldosterone during hemodialysis in patients with terminal renal failure

The control of plasma aldosterone during hemodialysis was investigated in 31 patients with terminal renal failure. While before hemodialysis renin predominantly influenced aldosterone, this effect dissipated during hemodialysis. In addition, no relationship was observed between changes in aldosterone and those in sodium, potassium and plasma cortisol. In a group of 10 patients isokalemic and isonatremic hemodialysis failed to document an effect sodium or potassium on hemodialysis induced changes in aldosterone. Our data suggest that none of the four factors - renin, ACTH, sodium and potassium - had constantly caused the observed changes in aldosterone during hemodialysis.

[Effect of the angiotensin antagonist saralasin (1-sar-8-ala-angiotensin II) on the blood pressure in secondary hypertension]

The angiotensin antagonist saralasin (1-sar-8-ala-angiotensin II) was given to 27 patients with different forms of secondary hypertension. The blood pressure fell in 6 of 7 patients with renal artery stenosis and in 4 of 10 patients with terminal renal failure on regular hemodialysis. No change or a rise in blood pressure was observed in 3 patients with Cushing's syndrome, 4 patients with primary aldosteronism, 3 patients with hypertension and a unilateral small kidney of other than renovascular origin, and 6 patients with terminal renal failure. It can be concluded from the results that angiotensin II is involved in the pathogenesis of renovascular hypertension and in some cases of hypertension accompanying chronic renal failure.

Control of plasma aldosterone in terminal renal failure before and after nephrectomy and after renal transplantation

In two patients with terminal renal failure the night-day rhythm of plasma aldosterone (PA) renin activity (PRA) and plasma cortisol (PC) were examined before and after bilateral nephrectomy and after renal transplantation. Before nephrectomy changes in abnormally high PA coincided with PC whereas no significant correlation was observed between PA and PRA. In the anephric state secretory episodes of PA occurred independent from those of PC while PRA was undetectable. After renal transplantation a lack of night-day variation in renin secretion was observed in both patients; only one of the two patients showed episodic secretion of PA while PC was suppressed in both patients probably due to the chronic administration of prednisone. Our results indicate, that before nephrectomy under the conditions described in this study plasma aldosterone was predominantly controlled by ACTH. In the anephric state and after renal transplantation other (yet unidentified) factors might have caused episodic secretion of aldosterone. Finally, the lack of night-day variation and secretory episodes in renin secretion after transplantation points to an important role of the sympathetic nervous system in the control of circadian and episodic renal renin release.

[Primary aldosteronism]

The syndrome of primary aldosteronism is caused either by an aldosterone-producing adenoma or by idiopathic bilateral adrenal hyperplasia. Hypokalemic hypertension is the leading symptome of the disease. Diagnosis is by the combination of abnormally high and non-suppressible aldosterone values with undetectable or low renin values unresponsive to postural changes or salt restriction. Patients with aldosterone-producing adenoma normally show a fall in plasma aldosterone in response to posture and ACTH-dependent circadian rhythm of aldosterone, whereas bilateral hyperplasia is characterized by postural increases in plasma aldosterone and an ACTH-independent diurnal aldosterone rhythm. These creteria serve to differentiate between adenoma and hyperplasia. An aldosterone-producing adenoma can be localized by veinography, determination of aldosterone concentration in both adrenal veins and by 131I-cholesterol scintigraphy. In our hands the determination of aldosterone in blood from both adrenal veins is the most efficient procedure. In interpreting the results, however, rhythmic and sudden changes in adrenal hormone secretion should be considered. In cases where no adrenal venous blood is obtained, 131I-cholesterol scintigraphy may be used to localize adenoma. In patients with aldosterone-producing adenomas unilateral adrenalectomy should be performed, whereas patients with idiopathic bilateral hyperplasia should receive antihypertensive therapy. As rare instances of primary aldosteronism, a case of aldosterone-producing carcinoma of the adrenal cortex and a case of presumably unilateral adrenal hyperplasia are reported.

[Effect of saralasin on normal blood pressure and on reno-vascular hypertension (author's transl)]

The angiotensin antagonist saralasin was given intravenously to six normotensive students before and after dietary sodium restriction and to two patients with renovascular hypertension. Both patients responded to the angiotensin antagonist with a decrease of the systolic (32 and 38 mm Hg) and of the diastolic (29 and 16 mm Hg) blood pressure. The small changes in blood pressure observed in the normotensive subjects during the infusion of the angiotensin antagonist indicate that angiotensin II plays no important role in the control of normal blood pressure in recumbent men. The fall in blood pressure induced by saralasin in both patients, however, demonstrates that their hypertension was at least partly angiotensin-dependent. Renal vein renin determination led to the same conclusions. The saralasin infusion test seems to be a simple procedure to diagnose angiotensin-dependent hypertension and will probably help to identify patients with suspected renovascular hypertension.

In vivo effects of angiotensin antagonists on plasma aldosterone in the dog

The effects of infusions of equimolar doses of Sar1-Ile8-angiotensin II and of Sar1-Ala8-angiotensin II on plasma aldosterone, plasma renin activity and arterial blood pressure were compared in normal dogs. Plasma aldosterone increased significantly after Sar1-Ile8-angiotensin II whereas it was unaffected by Sar1-Ala8-angiotensin II. Changes in blood pressure and renin activity were small without marked differences between both groups of animals. The experiments demonstrate a clear steroidogenic potency of Sar1-Ile8-angiotensin II. Therefore, Sar1-Ala8-angiotensin II should be preferred as antagonist of the action of angiotensin II in the adrenal gland.