Biomedical subjects
Publications and source records attributed to J Torhorst.
A series of shape descriptors were developed for the morphometrical analysis of cell nuclei. These included five descriptors measuring ellipticity, two measuring concavity, and one measuring the bending energy of a contour. These different shape descriptors were compared using a test sample of 1800 contours of cell nuclei.
A tumor-centered family history obtained in 50 patients with colorectal carcinoma without polyposis coli revealed that first-degree relatives of such patients have a 3.6 times greater risk of developing colorectal carcinoma themselves. The simple and harmless family history method can be employed by any physician for the identification of healthy persons at high risk for colorectal carcinoma.
Explore the source record for details and available documents.
Incidence and type of de novo tumours were studied retrospectively in 187 consecutive patients who had received kidney transplants between 1967 and 1981 and undergone immunosuppressive therapy for 2 months or longer. Up to the end of June 1983, 18 patients (9.6%) had developed 22 malignancies and 7 of them had died from the tumour. The risk of developing a malignancy appeared to increase with prolonged immunosuppression. No significant difference was noted between patients with and without tumours regarding primary renal disease, duration of pretransplant dialysis, and type or total dose of immunosuppressive drugs. The risk of developing any malignancy appeared to be some 20 times that in the general population. The practical management of patients with de novo tumours is described in the light of our own patient material and the recent literature. Finally, two further oncological problems are discussed: first, the incidental grafting of malignant cells with the transplant, and second, how to proceed in a transplant candidate with a previous malignancy.
Experiments were performed on rats to investigate the significance of the medullary hyperemia known to follow renal ischemia. To this end, its frequency was determined, its severity was quantified, and its relation to renal function was examined early (1 to 3 hr) and later (18 hr) after 45 min of warm ischemia. All kidneys were found to have a hyperemic outer medulla early after ischemia, which was shown to develop during the period of ischemia itself, but which was found to be highly variable in its severity. The degree of hyperemia was assessed both subjectively by grading and by histometric determinations of inner stripe capillary volume. One to hours after ischemia, the severity of medullary hyperemia was reflected in all indices of renal function, the least congested kidneys showing the best function. Eighteen hours after ischemia, the degree of medullary hyperemia was reflected in all indices of renal function, except urine flow rate; the non-congested kidneys showed functional recovery and the still-congested kidneys showed worsening function. Glomerular blood flow, known to be preferentially reduced in deep nephrons 1 to 3 hr after ischemia, had normalized 18 hr after ischemia in the non-congested kidneys but was still severely and unevenly depressed in the congested kidneys. It is concluded that congestion of the outer medulla is a key event in ischemic renal failure, its occurrence is coincidental with the reduction in deep nephron perfusion and urinary concentrating power in the early and maintenance phase and its disappearance heralds the restoration of deep nephron perfusion and urinary concentrating ability in the recovery phase.
The following morphological findings can lead to false negative results in steroid hormone receptor concentration tests: Tumour-free mammary tissue besides carcinoma tissue in the biochemically analysed specimen. Focal necroses of the tumour tissue. After exclusion of these findings, more than 80% of the tumours are positive for oestrogen receptors and more than 50% are positive for progesterone receptors in the cytosol. The histological type of tumour has no significant influence on the receptor status, with the exception of the medullary carcinoma of the breast. The semi-quantitatively determined tumour cell content of the invasive ductal carcinoma of the breast does not exercise any influence on the qualitative and quantitative receptor status. This means that tumours which are rich in cells largely consist of cells without receptors which do not respond to endocrine therapy.
Explore the source record for details and available documents.
Report is given on a 68-year-old man who suffered primarily from progressive weight loss and repeated episodes of fever and arthralgia. Later, liver dysfunction and renal insufficiency developed. Liver and kidney biopsies disclosed granulomatous hepatitis and nephritis. Because of the morphologic and clinical findings, the diagnosis of Boeck's disease was made. Shortly before death, diarrhea developed. Autopsy revealed a massive systemic involvement in Whipple's disease proven by light and electron microscopy and immunofluorescence. Tuberculoid and epitheloid cell granulomas and isolated giant cells were found in addition to the biopsy findings in skeleton muscles, the small intestine, lymphnodes and bronchi. At autopsy, the kidney showed chronic interstitial nephritis. The literature of kidney involvement in Whipple's disease is reviewed. This is the first case with granulomatous interstitial nephritis and chronic renal insufficiency in an inadequately treated Whipple's disease.
The aim of this study was to compare cytosol estrogen (ER) and progesterone (PgR) receptor levels measured in normal and pathological tissue specimens (n = 395) of endometrium (ED), endocervical mucosa (EM) and cervical vaginal portion (VP) from 108 patients (age 27-79). The highest ER levels were found in ED which decreased to 25% in VP. The PgR decline was more pronounced in VP since the majority of samples were PgR-negative. In addition pathological tissue from ED exhibited marked differences in steroid receptor levels: The highest ER and PgR concentrations were detected in the proliferative phase, whereas the secretory phase exhibited significantly reduced ER and PgR levels. The lowest ER and PgR amounts were measured in atrophic and quiescent tissues; in proliferative tissue ER and PgR levels were comparable to hyperplastic tissue. Cervical ER and PgR concentrations were significantly lower as compared with ED (25-30%), and no cyclic variations were detectable. Also ER and PgR levels were different between EM and VP. 96% of ER were positive in the cervix, whereas 73% were PgR-negative in VP. Furthermore an inverse correlation between ER and progesterone was found in ED and a positive correlation between estradiol and PgR. These results suggest that the cytosol ER and PgR levels vary markedly in the uterine corpus and may explain in part the different response to endocrine therapy.
The minimum sample size for semiquantitative and quantitative evaluation of interstitial tubular and glomerular parameters is calculated. For the majority of parameters a renal cortex area of 2 mm2 or 7 glomeruli (adults) or 13 glomeruli (children) is sufficient. Larger biopsies or more glomeruli are necessary for the evaluation of the area density of interstitium patent and obsolescent glomeruli as well as the numerical density of obsolescent glomeruli. The most sensitive parameters are those concerning crescents which require biopsies of 11-19 glomeruli in adults and 40 glomeruli in children. In summary, biopsies of usual size (10 mm2) containing about 20 glomeruli are sufficient for qualitative and quantitative evaluation.
Morphology, frequency and significance of capillary sclerosis (CS) in the ureter and electron microscopic findings in early papillary necrosis are described. CS of the urinary tract is characterized by a thickening of the basement membrane of capillaries lying just underneath the urothelium. The basement membrane changes can be demonstrated by PAS, Sudan stain and autofluorescence with equal reliability. By electron microscopy the thickened basement membranes exhibit a tree ring like pattern permeated by lipid vacuoles. CS is most often present in the renal pelvis and the ureter and only in particularly severe cases also in the urinary bladder. The most severe CS is found in the proximal and middle third of the ureter. In a prospective autopsy study CS was found in 3.5% of autopsies of adults and in 83% of clinically recognized phenacetin abusers. Since there is no association with other renal or metabolic diseases, CS can be considered as specific for phenacetin abuse. This finding is further substantiated by a significant correlation between the degree of severity of capillary sclerosis and the daily dose of phenacetin in grams. In about half of the patients with known analgesic abuse but without CS, possible causes for the lack of CS can be identified, of which the most important is regression of CS after stopping the abuse. Electron microscopic studies of early papillary necrosis show the same BM changes as in the ureter in peritubular capillaries, loops of Henle and similar BM alterations in the collecting ducts. The morphologic findings in the ureter and in the renal papilla suggest that CS in papillary necrosis are the consequence of a toxic damage of endothelial and in the kidney of endothelial and epithelial cells.
Aim of the study was to investigate the reproducibility and the reliability of the morphological diagnosis, of different morphological parameters and representativity of needle biopsy material compared with transurethral resection material. 416 needle biopsies of carcinomas of the prostate were studied by 5 pathologists. 130 biopsies were evaluated twice by the same investigators and 325 at least by one other investigator. In 65 cases, tissue obtained by transurethral resection was evaluated by the same investigator who had seen the biopsy. The diagnosis of carcinoma of the prostate was highly reproducible, only in 2% of the cases the original diagnosis was not confirmed; 5 out of 27 systematically evaluated parameters proved to be very reliable and reproducible, i.e. histological tumor classification, cribriform glands, invasion of perineural spaces, nucleoles, nuclear polymorphism, 8 parameters were sufficiently reproducible and 14 were unreliable among which cytologic differentiation was one. The diagnostic reproducibility between biopsy material and transurethral resection material was only 48.8%. This very low figure can be explained by the marked histologic heterogeneity of the tumors of which only 13% were classified as uniform carcinomas. The conclusions of the investigation are: 1. The diagnosis carcinoma is highly reliable and reproducible in needle biopsies. 2. Needle biopsy tissue is not representative for the entire tumor. 3. Grading of prostate carcinoma is highly subjective and therefore no sound basis for therapy and prognosis in the individual patient.
Explore the source record for details and available documents.
In the initial phase of ischemic acute renal failure in the rat the outer medulla is characterized by widening of peritubular capillaries in the inner stripe and by accumulation of cytoplasmic blebs in dilated proximal straight tubules in the outer stripe. Both findings contribute to tubular obstruction. In the maintenance phase, outer and inner stripes show tubular necrosis mainly of proximal straight tubules and thick ascending loops of Henle. In both phases the papilla is apparently spared from damage. Protective measures act at least partly by prevention of peritubular capillary widening in the inner stripe of outer medulla.
90 min of renal artery occlusion in previously unilaterally nephrectomized rats produce acute renal failure (ARF) (plasma creatinine at 48 h after ischemia: 636 +/- 44 vs. 133 +/- 9 mumol/l in controls). Between 1 and 48 h after releasing the occlusion, two populations of superficial nephrons could be observed, one with dilated tubules and elevated proximal tubular pressures (PTP: 39 +/- 1 vs. 12 +/- 1 mm Hg in controls) and the other with collapsed tubules and decreased PTP (9 +/- 1 mm Hg). Proximal tubular passage time (PPT) could not be determined with the Lissamine green technique. Seven methods of pretreatment were tested, 5 of which provided partial functional protection (DOCA/NaCl/NaCl, furosemide infusion, inosine bolus, mannitol bolus and the combination of the last two). Neither renal renin levels nor urinary NaCl excretion were consistently correlated with protection. Functionally protected rats consistently showed no PTP increase and normal PPT in the tubules at the kidney surface. However, plasma creatinine at 48 h differed markedly within the 5 protected groups, ranging from 168 +/- 18 to 398 +/- 35 mumol/l. Extensive medullary congestion was seen at 1-6 h after ischemia only in those rats with obstructed, high pressure nephrons at the kidney surface. To conclude: (1) Functional protection from ischemic ARF, both with and without an accompanying increase in solute excretion, was achieved by the abolition of tubular obstruction. (2) Despite similar degrees of restoration of superficial nephron function, the persisting impairment of whole kidney function differed markedly between the protected groups. (3) Impairment of deeper nephron function must therefore play a major role, perhaps through persisting obstruction in the long loops of Henle. (4) High pressure nephrons may compromise medullary venous outflow in the outer zone of the outer medulla.
Explore the source record for details and available documents.
A 48-year-old female patient developed sensory and motor palsy of the V-Xth cranial nerves immediately after kidney transplantation due to terminal uremia. A second exacerbation followed about 4 weeks later. After 46 days post transplantation she died from bronchopneumonia. Autopsy showed multiple acute and subacute necrotic foci in proximal portions of the cranial nerves as well as a discontinuous necrotizing encephalopathy localized mainly in the subpial zone of the brain stem. The mechanism by which lesions of the nervous system were produced remains speculative. A possible neurotoxic role was attributed to the drugs administered after transplantation. Herpes virus hominis antigen could be demonstrated in the cells of the pons and of the trigeminal ganglion, but its presence was thought to be coincidental and probably not causally related to the described lesions.
A variety of pretreatment-treatment protocols were applied to rats with ARF induced by the subcutaneous injection of 6 mg of HgCl2 per kilogram body weight. Renin depletion induced by DOCA-saline pretreatment was associated with protection against HgCl2-induced ARF only when the saline diuresis was maintained by drinking 1% NaCl after injury. Twenty-four dehydration followed by free access to tap water annihilated the protective effect of DOCA-saline pretreatment despite maintained depletion of renal renin. Continuous intravenous loading with saline and furosemide, although increasing renal renin levels, afforded as much protection as saline loading alone. Ethacrynic acid, which did not increase salt excretion in our rats, as well as water diuresis, failed to be protective. A loose correlation was found between he amount of histological damage to the convoluted parts of the proximal tubules and the degree of renal functional impairment. Thus protection against HgCl2-induced ARF was independent of the renal renin level but closely related to urinary NaCl excretion after the injury. Saline diuresis could act by relieving or preventing tubular obstruction.