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Biomedical subjects

B Kock

Publications and source records attributed to B Kock.

At least 19 recordsLinked to original sources
PubMed1992

In vivo measurements of lead in bone at four anatomical sites: long term occupational and consequent endogenous exposure.

Measurements of bone lead concentrations in the tibia, wrist, sternum, and calcaneus were performed in vivo by x ray fluorescence on active and retired lead workers from two acid battery factories, office personnel in the two factories under study, and control subjects. Altogether 171 persons were included. Lead concentrations in the tibia and ulna (representative of cortical bone) appeared to behave similarly with respect to time but the ulnar measurement was much less precise. In an analogous fashion, lead in the calcaneus and sternum (representative of trabecular bone) behaved in the same way, but sternal measurement was less precise. Groups occupationally exposed to lead were well separated from the office workers and the controls on the basis of calculated skeletal lead burdens, whereas the differences in blood lead concentrations were not as great, suggesting that the use of concentrations of lead in blood might seriously underestimate lead body burden. The exposures encountered in the study were modest, however. The mean blood lead value among active lead workers was 1.45 mumol l-1 and the mean tibial lead concentration 21.1 micrograms (g bone mineral)-1. The kinetics of lead in the tibia appeared to be noticeably different from that in the calcaneus. Tibial lead concentration increased consistently both as a function of intensity of exposure and of duration of exposure. Calcaneal lead concentration, by contrast, was strongly dependent on the intensity rather than duration of exposure. This indicated that the biological half life of lead in calcaneus was less than the seven to eight year periods into which the duration of exposure was split. Findings for retired workers clearly showed that endogenous exposure to lead arising from skeletal burdens accumulated over a working lifetime can easily produce the dominant contribution to systemic lead concentrations once occupational exposure has ceased.

Adult↗
PubMed1984

Glucocorticosteroids in renal transplantation. II. Impact of high- versus low-dose postoperative methylprednisolone administration on graft survival and on the frequency and type of complications.

In a previous clinical trial we demonstrated that, by increasing the postoperative administration of methylprednisolone from 1.0 to 3.5 mg/kg/day, the onset of the first inflammatory rejection episode was significantly delayed and the size of the inflammation was reduced. The 'high initial' steroid treatment specifically depleted blast cells and macrophages from the in situ inflammatory infiltrate. In this trial we demonstrate that the 'high initial' glucocorticosteroid administration significantly improves 1-year cadaver allograft survival from 44% to 68% (P = 0.003) without increasing the number of complications. Although the 'high initial' steroid administration only partially overcomes the impact of HLA-AB incompatibility, it seems to overcome entirely the impact of absence of blood transfusions. The 'high initial' steroid administration also makes the first episodes of inflammation easier to overcome: less steroids are needed to counteract the first rejection, and, as a consequence, only 30% more steroids were used in the 'high initial' versus the 'low initial' steroid programme.

Blood Transfusion↗
PubMed1983

Long-term 1,25-dihydroxycholecalciferol treatment in renal failure.

1,25-Dihydroxycholecalciferol (1,25-DHCC) was administered to four patients on maintenance hemodialysis and to four patients with renal failure not requiring hemodialysis. Secondary hyperparathyroidism was found in both groups of patients. Before initiation of 1,25-DHCC treatment both groups had serum 1,25-DHCC levels below the normal range (33.1 +/- 15.3 pg/ml). During the treatment period, serum 1,25-DHCC concentrations were normalized. Parathormone concentration in serum decreased in both groups during the observation period. Serum calcium concentration was normalized in patients with renal failure and within the upper normal range in patients on maintenance hemodialysis. Bone biopsy and densitometry, of the radius showed a trend towards normalization of bone during the treatment period, while X-ray studies showed no clear effect of 1,25-DHCC treatment. This study shows that changes in bone mineralization can be reversed by normalization of 1,25-DHCC.

Adolescent↗
PubMed1983

Ultrasonic scanning after percutaneous renal biopsy.

Renal ultrasonic scanning was performed before and after 57 consecutive kidney biopsies in order to assess the value of this method in the diagnosis of complications. One large and six small perirenal haematomas were found, corresponding to an incidence of 13%. This figure is considerably larger than the incidence found with conventional diagnostic methods, but smaller than with computed tomography. One hydronephrosis and a blood clot in the urinary bladder were also diagnosed. No clinically significant complications were missed. We recommend ultrasonography as the first diagnostic procedure when biopsy complications are suspected.

Adolescent↗
PubMed1983

Early neurotoxic effects of occupational lead exposure: a prospective study.

A prospective follow-up study focusing on workers who entered a battery factory was started in 1975. Out of an initial number of 89 workers, 23 were available for the 1-yr, 15 for the 2-yr and 10 for the 4-yr re-examination. From an initially larger non-exposed reference group (N = 34), 23 were matched with respect to age, sex, and initial nerve conduction velocities and similarly followed. In the exposed group especially the sensory conduction velocities of the median nerve decreased during the 2-yr follow-up. Some increase in the motor distal latency of the median nerve was also noted. When the lead workers were divided into two groups according to the median Pb-B value (30 micrograms/100 ml), several motor and sensory conduction velocities were significantly slower in the lead group with the higher Pb-B levels in the 1- and 2-yr follow-up examinations as compared with those with the lower levels. Those workers whose Pb-B level hd quickly risen to over 30 micrograms/100 ml quit after one or two years. Those who continued in the battery plant for up to four years had a slower initial rise in their Pb-B levels, which rarely exceeded 30 micrograms/100 ml; this group showed no significant differences in their conduction velocities in the 4-yr re-examination in comparison with the reference group.

Adult↗
PubMed1981

Striated muscle capillaries in uremic patients and in renal transplant recipients.

With the use of light and electron microscopic and morphometric methods, we studied the gastrocnemius muscle capillaries in nine uremic patients and eight renal transplant recipients. Observations of intramuscular microangiopathy, eg, thickening and remnants of the capillary basement membrane (BM) and vacuolation of endothelial cells, were prominent in both patient groups. In morphometric analysis, the mean BM fraction of the total capillary area was larger, and the capillary lumen was smaller, in the uremic patients and in the renal transplant recipients than in the normal control subjects. The capillary-to-fiber ratio was higher in the patients with transplants than in the uremic patients or in the normal control subjects.

Adult↗
PubMed1980

Hyperreninemia, lysozymuria, and erythrocytosis in Fanconi syndrome with medullary cystic kidney.

Adult onset Fanconi syndrome with medullary cystic kidney was diagnosed in a 30-year-old male with muscular weakness, hypokalemia, normal BP, hyperreninemia, and secondary aldosteronism. He also had non-specific aminoaciduria, lysozymuria, and beta 2-microglobulinuria. Urinary concentrating and acidifying capacity was impaired, and both sodium and potassium were lost into the urine. I.v. pyelography revealed medullary cystic kidney. Renal biopsy showed juxtaglomerular hyperplasia, heavy subintimal deposits and C3 and IgG in preglomerular arteriolar walls, and degenerative changes in the tubules, including loss of brush border and "macula densa-like" lesions. Polycythemia with elevated serum erythropoietin levels, and raised blood ACTH values with features of cortisolism were also present. Indomethacin therapy decreased plasma renin activity (PRA), plasma aldosterone, and urinary loss of potassium and sodium, while serum potassium approached normal levels. Metoprolol, a beta-adrenergic blocking agent, caused similar effects. Insensitivity to the pressor effect of angiotensin II was reversed by indomethacin treatment. Somatostatin infusion lowered PRA and aldosterone without affecting BP. Several biochemical aberrations of this patient resemble Bartter's syndrome, including the effect of indomethacin.

Adult↗
PubMed1980

Kidney transplantation and tumours.

During the period 1964--1978 700 renal transplants were given to 602 patients. Eight patients had a history of tumour before transplantation. After transplantation six cases with a de novo tumour were found. The treatment of the pretransplant tumours was completed on average 3 years before transplantation. The average interval from transplantation to discovery of de novo tumour was 2 years. The pretransplant tumours appeared 5 to 9 years before last control (Jan. 79) (mean 8 years). Two of the transplanted patients with previous tumours died later of their tumours. The others are still alive. Two of the patients with de novo tumour died of vascular accidents and one of tumour. The other three are alive. It seems that transplantation can be successful in patients with previous tumours. This study does not support previous reports of increased risk of de novo tumours in transplanted patients.

Adolescent↗
PubMed1980

Kidney transplantation in patients over 60 years of age.

Between 1972 and the end of 1978 kidney transplantation was performed on 39 patients over 60 years of age. In one case a kidney from a live donor was used. The other patients received cadaver kidneys. Patient and graft survival in this group of patients did not differ from the results obtained with younger age groups. 14 patients have died. The chief reasons for death were cardiac infarction and infection. The mortality rate was no higher among patients over 60 years than among younger groups. The results show that kidney transplantation can be performed successfully on patients of relatively advanced age.

Aged↗
PubMed1979

Fatal renal vasculitis and minimal change glomerulonephritis complicating treatment with penicillamine. Report on two cases.

Two cases with different and not previously described fatal renal complications during treatment with penicillamine are reported. A man with seronegative rheumatoid arthritis with features of systemic lupus erythematosus was treated with penicillamine for six months and developed a mild membranous glomerulonephritis and a severe renal vasculitis leading to uremia and death. A woman with primary biliary cirrhosis was treated with penicillamine for nine months and developed a nephrotic syndrome, the renal biopsy showing minimal change glomerulonephritis. The nephrotic syndrome responded to prednisone but the patient died, probably from septicemia. Penicillamine may thus cause glomerular damage without deposition of immune complexes. A restricted use of the drug is recommended.

Female↗
PubMed1979

Urography and isotope renography following renal transplantation.

The clinical yield from routine urography following renal transplantation was compared with that from isotope renography. In 50 recipients of renal transplants, 59 urograms and 55 renograms were studied. The most common pathologic finding at urography was renal papillary necrosis (in 6 patients). This condition had no obvious correlation with the further fate of the transplant. There were no other significant pathologic changes. It is concluded that isotope renography can be regarded as sufficient for routine follow-up. One baseline urogram is useful, but additional urographies should be carried out only when clinically indicated.

Creatinine↗
PubMed1979

Parathyroidectomy in chronic renal failure.

During the period 1971-1976, subtotal parathyroidectomy was performed on 34 patients with chronic renal failure, representing 8% of all uraemic patients treated on the Renal Ward. Preoperative treatment of renal failure was conservative therapy in 6, haemodialysis in 20 and renal transplantation in 8 patients. The operation was indicated by grave clinical symptoms (pruritus, bone pains and mental disturbances), gastric ulcer and radiological abnormalities (osteoporosis, fractures, subperiosteal resorption and metastatic calcifications). The serum immunoreactive parathyroid hormone was determined in 13 cases, and the value was elevated in all. The serum calcium level was elevated in 8 out of 34 cases. Less than 500 mg of parathyroid tissue was removed in 12 cases, between 500 and 6000 mg in 19 and over 6000 mg in 3. Nodular hyperplasia was present in 11 patients, diffuse hyperplasia in 23. Postoperatively marked falls in serum parathyroid hormone and serum calcium values were observed. The bone pains, pruritus and mental disturbances were alleviated, and the general condition was favourably influenced. The operation had a lesser and more retarded effect on the radiological changes. Complete recovery was only achieved with successful renal transplant. Parathyroidectomy often had a favourable effect on the grave symptoms and may, therefore, be considered in some cases of severe hyperparathyroidism secondary to chronic renal failure.

Adolescent↗
PubMed1979

Vascular access for haemodialysis with autogenous vein graft arteriovenous fistulas.

Nine autogenous vein grafts (AVG) have been used in nine patients to create arteriovenous fistulae for haemodialysis. All the patients lacked vessels for construction of a regular arteriovenous fistula. Three of the AVG failed during dialysis treatment 3, 10 and 14 months respectively following construction. Another AVG thrombosed but function was restored by thromboectomy. The same graft was later complicated by a false aneurysm and rupture but was then reconstructed with a vein patch. One AVG with a false aneurysm in the proximal anastomosis was repaired within six weeks.

Adult↗
PubMed1978

Angiography and isotope renography in acute rejection of renal transplant.

Isotope renography and transplant angiography were performed during 37 acute episodes of renal transplant rejection. Renography demonstrated rejection in 70% of the irreversible and 55% of the reversible processes. Angiography, though reliable in irrerversible rejection, was diagnostic in only 30% of the reversible cases. Renography is the method of choice for diagnosing rejection and its accuracy is improved by repitition. Angiography should be reserved for patients whose renal function is not restored by treatment for rejection.

Evaluation Studies as Topic↗
PubMed1977

Renal artery stenosis in hypertensive renal transplant recipients.

Reconstruction of a stenotic renal artery was done on 5 hypertensive renal transplant recipients, all of whom had deterioration of renal function when the stenosis was detected. After reconstruction renal function improved in 4 of the patients. The blood pressure was easier to control in all 5 patients, with 3 becoming normotensive. A high preoperative plasma renin activity returned to normal postoperatively in 4 patients. No recurrences were observed after a followup of more than a year.

Adult↗
PubMed1977

Early venous filling in transplanted kidneys.

Early venous filling in patients with renal transplants was found in the presence of ischaemic injury, acute rejection, and chronic rejection; thus it cannot be used in differential diagnosis. Early venous filling was present only when the cortical circulation was scored as adequate although when observed in acute or chronic rejection the prognosis for the graft was poor.

Acute Disease↗
PubMed1977

Surgical complications in 500 kidney transplantations.

The surgical complications in a series of 500 transplantations done by a single transplantation unit with over ten years' experience in the field are reported. The complications are divided into vascular, urological and gastrointestinal. In addition, renal rupture, primary wound infections and operative deaths are reported. Most of the losses of transplants caused by surgical complications are due to renal rupture and vascular complications, accounting for 3.6 and 2 percent of losses respectively out of the 500 kidney transplants. The urological complications caused a loss of the remaining 1.2% of a total of 6.8%. tthe overall mortality was highest in gastrointestinal complications with 6% of the total of 10% deaths following surgical complications. The mortality rate in the group of patients with gastrointestinal bleeding and perforations and with acute pancreatitis was extremely high. More accurate screening for potential candidates for gastroduodenal ulceration and better prophylactic treatment is needed. More active treatment of acute pancreatitis is suggested.

Adolescent↗