Hypoxic expression of NLRP3 and VEGF in cultured retinal pigment epithelial cells: contribution of P2Y2 receptor signaling

Retinal hypoxia is a major condition of the chronic inflammatory disease age-related macular degeneration. Extracellular ATP is a danger signal which is known to activate the NLRP3 inflammasome in various cell systems. We investigated in cultured human retinal pigment epithelial (RPE) cells whether hypoxia alters the expression of inflammasome-associated genes and whether purinergic receptor signaling contributes to the hypoxic expression of key inflammatory (NLRP3) and angiogenic factor (VEGF) genes. Hypoxia and chemical hypoxia were induced by a 0.2%-O₂ atmosphere and addition of CoCl₂, respectively. Gene expression was determined with real-time RT-PCR. Cytosolic NLRP3 and (pro-) IL-1β levels, and the extracellular VEGF level, were evaluated with Western blot and ELISA analyses. Cell culture in 0.2% O₂ induced expression of NLRP3 and pro-IL-1β genes but not of the pro-IL-18 gene. Hypoxia also increased the cytosolic levels of NLRP3 and (pro-) IL-1β proteins. Inflammasome activation by lysosomal destabilization decreased the cell viability under hypoxic, but not control conditions. In addition to activation of IL-1 receptors, purinergic receptor signaling mediated by a pannexin-dependent release of ATP and a release of adenosine, and activation of P2Y₂ and adenosine A₁ receptors, was required for the full hypoxic expression of the NLRP3 gene. P2Y₂ (but not A₁) receptor signaling also contributed to the hypoxic expression and secretion of VEGF. The data indicate that hypoxia induces priming and activation of the NLRP3 inflammasome in cultured RPE cells. The hypoxic NLRP3 and VEGF gene expression and the secretion of VEGF are in part mediated by P2Y₂ receptor signaling.

Osmotic expression of aldose reductase in retinal pigment epithelial cells: involvement of NFAT5

BACKGROUND

Diabetic retinopathy is associated with osmotic stress resulting from hyperglycemia and intracellular sorbitol accumulation. Systemic hypertension is a risk factor of diabetic retinopathy. High intake of dietary salt increases extracellular osmolarity resulting in systemic hypertension. We determined the effects of extracellular hyperosmolarity, chemical hypoxia, and oxidative stress on the gene expression of enzymes involved in sorbitol production and conversion in cultured human retinal pigment epithelial (RPE) cells.

METHODS

Alterations in the expression of aldose reductase (AR) and sorbitol dehydrogenase (SDH) genes were examined with real-time RT-PCR. Protein levels were determined with Western blot analysis. Nuclear factor of activated T cell 5 (NFAT5) was knocked down with siRNA.

RESULTS

AR gene expression in RPE cells was increased by high (25 mM) extracellular glucose, CoCl₂ (150 μM)-induced chemical hypoxia, H₂O₂ (20 μM)-induced oxidative stress, and extracellular hyperosmolarity induced by addition of NaCl or sucrose. Extracellular hyperosmolarity (but not hypoxia) also increased AR protein level. SDH gene expression was increased by hypoxia and oxidative stress, but not extracellular hyperosmolarity. Hyperosmolarity and hypoxia did not alter the SDH protein level. The hyperosmotic AR gene expression was dependent on activation of metalloproteinases, autocrine/paracrine TGF-β signaling, activation of p38 MAPK, ERK1/2, and PI3K signal transduction pathways, and the transcriptional activity of NFAT5. Knockdown of NAFT5 or inhibition of AR decreased the cell viability under hyperosmotic (but not hypoxic) conditions and aggravated the hyperosmotic inhibition of cell proliferation.

CONCLUSIONS

The data suggest that sorbitol accumulation in RPE cells occurs under hyperosmotic, but not hypoxic and oxidative stress conditions. NFAT5- and AR-mediated sorbitol accumulation may protect RPE cells under conditions of osmotic stress.

Osmotic induction of placental growth factor in retinal pigment epithelial cells in vitro: contribution of NFAT5 activity

One risk factor of neovascular age-related macular degeneration is systemic hypertension; hypertension is mainly caused by extracellular hyperosmolarity after consumption of dietary salt. In retinal pigment epithelial (RPE) cells, high extracellular osmolarity induces vascular endothelial growth factor (VEGF)-A (Hollborn et al. in Mol Vis 21:360-377, 2015). The aim of the present study was to determine whether extracellular hyperosmolarity and chemical hypoxia trigger the expression of further VEGF family members including placental growth factor (PlGF) in human RPE cells. Hyperosmotic media were made up by addition of 100 mM NaCl or sucrose. Chemical hypoxia was induced by CoCl2. Gene expression was quantified by real-time RT-PCR, and secretion of PlGF-2 was investigated with ELISA. Nuclear factor of activated T cell 5 (NFAT5) was depleted using siRNA. Extracellular hyperosmolarity triggered expression of VEGF-A, VEGF-D, and PlGF genes, and secretion of PlGF-2. Hypoosmolarity decreased PlGF gene expression. Hypoxia induced expression of VEGF-A, VEGF-B, VEGF-D, and PlGF genes. Extracellular hyperosmolarity and hypoxia produced additive PlGF gene expression. Both hyperosmolarity and hypoxia induced expression of KDR and FLT-4 receptor genes, while hyperosmolarity caused neuropilin-2 and hypoxia neuropilin-1 gene expression. The hyperosmotic, but not the hypoxic, PlGF gene expression was in part mediated by NFAT5. The expression of PlGF in RPE cells depends on the extracellular osmolarity. The data suggest that high consumption of dietary salt may exacerbate the angiogenic response of RPE cells in the hypoxic retina via transcriptional activation of various VEGF family member genes.

[Bipolar disorders: the disease of extreme emotions]

Bipolar disorder is characterized by alternating phases of manic and depressive states that are separated by variably long and sometimes symptom-free intervals. Rapid changes in symptoms and mixed states during acute episodes can make diagnosis difficult. The risk of suicide is high. For diagnostic confirmation, the patient should be referred to a specialist as early as possible. The therapy should also be carried out in close collaboration with a neurologist or psychiatrist. The role of the family physician is to monitor the pharmaceutical phase prophylaxis and to attend to the patient's comorbidities.

[Rare complication of a heparin-induced thrombocytopenia type II]

HISTORY AND CLINICAL FINDINGS

A 63-year-old man was admitted to a surgery department with fracture of the acetabulum and luxation of the hip joint. Eight days after intracondylar nail-extension during subcutaneous heparin prophylaxis he developed a dramatic deterioration of his condition with severe abdominal pain and fever and was admitted to our hospital.

INVESTIGATIONS

White cell count was 12,000/microliter, C-reactive protein 7.90 mg/dl. CT-scan, abdominal ultrasound, mesenteric angiography and exploratory laparotomy revealed no pathological findings. At day 13 abdominal ultrasound showed adrenal haemorrhages on the right. Together with a drop in platelet count below 50,000/microliter, adrenal haemorrhage caused by heparin-induced thrombocytopenia (type II; immunological [HIT II]) was suggested.

THERAPY

After discontinuation of heparin and starting therapy with recombinant hirudin and hydrocortisone, a dramatic clinical recovery followed within 24 hours. One year after the initial diagnosis the patient is in a good condition.

CONCLUSION

When abdominal pain, hypotension and fever occurs with a drop in platelet count during heparin therapy HIT II should be considered. An early diagnosis is essential for treatment of this life-threatening complication at an early stage.

Toxic shock syndrome associated with newly diagnosed type I diabetes

Studies of two post-mortem pancreata of children at the onset of type I diabetes have suggested activation and expansion of islet infiltrating T cells by a superantigen. We present the first reported case of a superantigen mediated disease, toxic shock syndrome (TSS), occurring at the diagnosis of type I diabetes. A 12-year-old girl presented with TSS and newly diagnosed diabetes with ketoacidosis. At presentation she was unconscious, febrile and hypotensive, with a desquamating erythematous rash and Kussmaul breathing. During resuscitation, her renal impairment, diarrhoea, thrombocytopaenia and ketoacidosis resolved. Vaginal discharge and blood cultures grew Staphylococcus aureus. T cell studies at 2 weeks after diagnosis detected a high level of spontaneous and islet antigen-specific proliferation with associated interleukin-10 production compared to human leucocyte antigen DR matched controls.

[Intra-arterial DSA of the pelvic/leg vasculature using a 57 cm image intensifier]

100 consecutive intraarterial DSA's of the lower extremities obtained with a 57 cm image intensifier were evaluated retrospectively by 2 radiologists and 3 surgeons. The studies were considered diagnostic in 95% of the cases. The results, advantages and possible disadvantages are presented and compared to those associated with conventional film angiography and with i.v. DSA.

[Digital image intensifier radiography: imaging qualities and initial use in the gastrointestinal area]

We determined the quality of digital radiographs delivered by a large image intensifier (diameter 54 cm) and by a conventional fluoroscopic unit with a 33 cm image intensifier, and compared them to that of 100 mm spot films obtained from the same units. A special image processor was available allowing 25 images/s using a 512/512 matrix or 7.5 images/s with a 1024 X 1024 matrix. The spatial resolution of digital radiographs was well below that of the spot films, while no difference was found in contrast resolution. Images of colon specimens and gastrointestinal studies demonstrate that digital radiography does not imply a loss in diagnostic information inspite of the lower spatial resolution. Gastrointestinal studies using digital radiographs will reduce the amount of irradiation exposure of the patient and could represent an additional use for an existing equipment for DSA.

Computer processed fluoroscopic images for digital intravenous renal angiography

We investigated intravenous digital angiography using computer processed fluoroscopic images. Computer processed fluoroscopy (CPF) was compared to conventional digital subtraction angiography (DSA) in 39 patients referred for renal vessel evaluation. For assessment of CPF the anterior-posterior images were compared with the corresponding digital subtraction angiograms. 79% percent of DSA and 71% of CPF studies were diagnostic. Peripheral injection of contrast medium caused deterioration of CPF images. Skin dose measurements were obtained in 24 patients. The median dose for DSA was 8.2 rad, compared to 1.1 rad for CPF. It is concluded that sophisticated algorithms should be investigated for digital angiography, so that high image quality can be achieved with a reduced radiation exposure.

[Possibility of erroneous diagnosis with digital subtraction angiography and its causes]

In digital subtraction angiography (DSA) motion artifacts, artifacts due to overshoot, high contrast enhancement, and long exposure time may result in erroneous evaluation of the vessels. Examples are given to demonstrate and analyse the causes of possible misdiagnoses.

[Contribution of digital subtraction angiography to the diagnosis of rejection reactions after kidney transplantation]

The ability to diagnose rejection changes in renal transplants using DSA was evaluated retrospectively taking intrarenal vascular changes into consideration. The findings obtained with DSA were compared to those of scintigraphy in 26 graft recipients, on whom both methods had been performed within a narrow time period for evaluation of hypertensive disease. The scintigraphic diagnosis was based on function and perfusion studies. The intrarenal vascular tree was demonstrated on DSA better by intraarterial than by intravenous contrast media injection, however both techniques delivered useful diagnostic information. The status of the graft was evaluated with comparable results by DSA and scintigraphy in 73% of the cases. In our experience, functional effects produced by morphological changes demonstrated by DSA, can be defined better with the help of scintigraphy. On the other hand, by performing DSA it is possible to clarify morphologically functional findings, which may be detected by scintigraphy but often are diagnostically nonspecific. The availability of both morphological and functional data increases the diagnostic accuracy which can be obtained with these two low invasive procedures in the assessment of vascular changes in renal transplants.

[Results of transvenous digital subtraction angiography with a 57 cm image intensifier in circulatory disorders of the lower extremities]

The size of conventional image intensifiers is a limiting factor in performing transvenous digital subtraction angiography of the lower extremities. The results of transvenous digital subtraction angiography using a 57 cm image intensifier on 205 patients with vasoocclusive disease of the legs are presented. Two exposed fields sufficed in most cases for demonstration of all arteries, from the aortic bifurcation to the trifurcation at the lower leg. The principal advantages were the reduction of the contrast medium volume and the decrease in examination time. The reduced resolving power was a limiting factor in evaluating discrete wall lesions and of small vessels, but this did not induce diagnostic difficulties. The studies were evaluated retrospectively by an experienced vascular surgeon and in 85% of the cases were considered to be of diagnostic value.

[Experimental and clinical determination of renal size after intravenous and intra-arterial administration of ionic and non-ionic contrast media]

A quantitative comparison of changes in renal size after the intravenous injection of contrast media showed no difference between ionic and non-ionic contrast medium. Contrast media of similar osmolarity (Metrizamide and Ioxaglate with 470 and 490 mosn/kg H2O) did show significant variations. Evidently properties of the contrast medium, other that their osmotic behaviour, are of significance (chemical structure, viscosity, iodine content, specific toxicity, and the effect on the permeability of biological membranes, calcium-binding activity, effect on coagulation). Changes in renal size could be reproduced by repeating the contrast injection at 24 to 48 hours.

[1 year's experience with a 57-cm image intensifier in a universal roentgen work station]

3342 patients were examined by means of a 57 cm image intensifier during one year. The installation permits examination with the patient standing or lying. The resolution was measured with a lead grid under conditions resembling actual practice and were found to be similar to those obtained with angiographic equipment. Using a medium format technique for examining the gut and vascular system resulted in radiographic quality which was not significantly different from the use of a large format technique. For examination of the skeleton, radiographic quality, using the intensifier, was markedly poorer than that resulting from Bucky examinations. There was no diagnostic difference when carrying out lymphograms. The large intensifier window of 53 cm was particularly advantageous for DSA of the pelvic and lower limb vessels when compared with smaller intensifiers. Possible savings of film and contrast medium costs are discussed.

[Causes of hypertension following kidney transplantation with special reference to arterial stenoses]

Hypertension is regarded as a significant complication in renal transplant recipients. Its frequency was 48,1% after cadaver donor and 40,6% after living donor transplantation. The etiology is multifactorial. A correlation could be demonstrated between blood pressure and graft function or presence or absence of the diseased kidneys while no influence was found with regard to steroid dosage in patients with long term graft function. After 575 renal transplantations with 147 angiographies arterial stenoses were observed in nine patients (1,6%) and corrected surgically.

[Supine thoracic images with a mobile roentgen unit: comparison between the soft-ray and hard-ray technics]

To compare the influence of kilovoltage on the quality of supine chest roentgenograms obtained with a mobile x-ray unit, we examined the films of 50 patients on whom supine chest radiographs had been taken incidentally within a period of 24 hours both with high and with low-kVp technique. For evaluation of the image quality, a total of 11 criteria were compared and quantitated by 5 observers using a simple score method. The same advantages that have been attributed to the high-kVp technique on upright films were found on the corresponding supine examinations. These films showed a more balanced penetration and greater sharpness than those taken with low-kVp. The wider latitude of the high-kVp technique simplifies the exposure, and fewer repeat takes will therefore be necessary. The diagnostic gain outweights the few disadvantages, which are mostly coupled to the increase in scattered radiation. This, as well as the availability of more powerful and efficient mobile generators, should promote routine application of high-kVp technique for supine chest examinations.

Digital subtraction angiography in the preoperative evaluation of patients with a renal tumor

Inguinal intravenous digital subtraction angiography (DSA) was performed in 14 patients referred for preoperative evaluation of a renal tumor previously diagnosed by CT and ultrasound. Conventional cavography and aortography were used as reference methods for comparison. Both DSA and conventional angiography were carried out following selective arterial injection to the abnormal kidney. The diagnostic value of DSA in examination of the inferior vena cava was generally comparable to that of conventional cavography. Intravenous aortography was unsuccessful in 2 patients due to motion artifacts. In all other patients, the information provided by DSA regarding the aorta, renal arteries and renal veins was similar to that of conventional aortography. Intrarenal vascular detail, however, was far superior on conventional films and was only useful with DSA when intra-arterial injection was implemented. In one of the 12 diagnostic examinations, localization of the renal mass could not be established by intravenous DSA, but was possible in all others. The inguinal approach advocated permits simultaneous inferior vena cavography and intravenous aortography with one single injection of contrast medium; the method is less traumatic than aortography , and does not require hospitalization of the patient. DSA may also be of value in those cases still requiring selective catheterization of the renal arteries, i.e. for angiotherapy . Intra-arterial DSA then allows reduction of the amount of contrast medium and a rapid processing of the images without detriment to the quality of the examination.

Detection of neoplastic lymph node involvement in the retroperitoneal space. Diagnostic value of CT, echography and lymphography

The diagnostic value of echography, computerized tomography and lymphography in the detection of infiltrating retroperitoneal lymph nodes was assessed in a prospective study. Ninety-six patients suffering from Hodgkin's disease, non-Hodgkin lymphoma, seminomatous and and non-seminomatous tumours of the testis were examined with all three methods. Sixty-two (30 non-seminomas, 32 Hodgkin's diseases) had an exploratory laparotomy at least one week after the diagnostic examinations. Sensitivity and specificity were assessed on the basis of the pathohistological findings. The sensitivity was 92% for CT, 79% for echography and 83% for lymphography. The specificity was 89% for CT, 95% for echography and 84% for lymphography. The presented findings suggest that a re-evaluation of the diagnostic strategy in assessment of lesions involving retroperitoneal lymph node is required.

Spontaneous pneumatocele during radiation of a giant meningosarcoma

A man, aged 66 years, sustained a pneumatocele after radiotherapy for a frontabasal meningeal sarcoma. There was improvement initially, but a fall was experienced without injury to the head and the condition worsened. X-rays of the skull revealed a pneumatocele which was treated conservatively and disappeared within 4 weeks. The literature on spontaneous pneumatocele is reviewed briefly and the etiology discussed.

[Notes on the differential diagnosis of nodules in the lung: Rendu-Osler-Weber disease (author's transl)]

The hereditary hemorrhagic teleangiectasia, commonly known as "Rendu-Osler-Weber" disease, is a relatively seldom found affection manifesting itself by the formations of localized arteriovenous capillary connections which are tiny arteriovenous fistulas. They are found in the skin, the mucous membranes and in nearly all organs of the body. The diseases is transmitted by a dominant character. Affections of the lung can be seen in 89% of the cases (1). In the following paper five exemplary cases are to show that the simple radiological method of the roentgenogram of the thorax taken in the frontal projection and in the lateral view, assisted by the conventional tomography in most cases will bring the last diagnosis. In the differential diagnosis nodules in the lung can be delimited by the connecting arteries and veins.

[The frequency of adult anticonvulsant osteomalacia in relation to duration of therapy and dosage of anticonvulsants (author's transl)]

Of 837 epileptics over 16 years of age treated with mono- or combined hydantoin therapy 20.3% showed radiographic signs of anticonvulsant osteomalacia. With the exception of the patients with severe disturbances of the skeletal system no positive correlation was found with duration of therapy. The percentage of moderate bone changes was the highest in the patients treated for 1 to 2 years; the percentage of severe bone changes in the group treated over 10 years. The rate of osteomalacia correlated with the total dose of hydantoin, phenobarbital, or primidone; the correlation with the dose per year was even more evident. The risk of osteomalacia rose distinctly with doses over 3000 equivalent units/year. The patients with combined hydantoin-barbiturate treatment showed a higher risk than those treated with phenytoin alone. The rate of osteomalacia was the highest in the patients aged under 20 years and over 50 years. Males showed a relatively higher rate of osteomalacia than females, they were treated however with a higher dose per year. The chemical parameters blood alkaline phosphatase and 25-hydroxycholecalciferol corresponded to the radiographic signs, whereas calcium and anorganic phosphate showed no correlation. Early routine radiologic and chemical control especially of the epileptic patients with high risk of osteomalacia should be routinely performed in future.

Skeletal X-ray findings and bone histology in patients on hemodialysis

X-ray films of the hand skeleton (mammography technique), serum chemistry, and quantitative bone histology (micromorphometry of undecalcified sections, iliac crest spongiosa) were compared in 25 patients on maintenance hemodialysis. The X-ray findings correlated better with serum PTH levels than with bone histology. Of all radiological signs of renal osteodystrophy, pronounced subperiosteal resorption (radial aspect, second finger, middle phalanx) and periosteal new bone formation (middle phalanx) correlated best with histological indicators of osteitis fibrosa. These signs were never seen in control patients. Acroosteolysis (endphalanx) and intracortical or endosteal resorption (middle phalanx) were less specific (i.e., seen even in the absence of metabolic bone disease) and correlated less with bone histology. Osteosclerosis in iliac cancellous bone was paralleled by abnormal texture of spongy bone in the proximal metaphysis of the middle phalanx (second finger).

[Diagnosis of anticonvulsant osteomalacia in adults (author's transl)]

In 100 epileptic patients under treatment with long-term anti-convulsants, radiographs of the hands and feet, and estimations of serum 25-hydroxycholecalciferol, parathormone, alkaline phosphatase, calcium, and inorganic phosphate were done to detect a medication-induced osteomalacia. The correlation between the individual parameters was investigated. It was shown that the serum 25-hydroxycholecalciferol level and the skeletal radiograph were the most valuable in the early detection of osteomalacia. One of these investigations in addition to routine serum chemistry is recommended for the future at the yearly follow-up examinations of adult epileptics so that early and adequate treatment with vitamin D can be started.

Intraosseous ganglion (author's transl)

The intraosseous ganglion must be always included in the differential diagnosis of cystic epiphysial bone lesions, which are localised in the vicinity of a joint, especially since this bone disease can be succesfully operated on. The preoperative diagnosis can be established with the help of conventional and tomographic x-rays examination. A communicating chanel, which is recognizable in tomographic cuts as a lucent line between the ganglion and a joint, is a pathognomic finding. The interpretation of the radiological symptoms can be difficult in those cases in which the lesions are not yet well developed or in which concomitant degenerative joint changes are present.

Skeletal changes and growth in experimental uremia

Longitudinal growth; bone and growth zone histology; growth cartilage and bone mineralization (tetracycline technique); bone Ca content (neutron activation analysis); bone radiology; serum and urine chemistry; urinary cAMP and serum 25-OH-vitamin D3 were studied in a long-term model of experimental uremia in the rat. Uremia was induced by two-stage subtotal nephrectomy with irradiation of the remaining parenchyma. Ccr in the experimental group was 113 +/- 5.8 micron1/min X 100 g (19.8% of controls) and serum creatinine 1.67 +/- 0.04 mg% (5.1 X control value). Uremic animals were pair-fed with sham-operated controls. In the proximal tibia delayed transformation of cartilage into primary spongiosa with appearance of chondro-osteoid and delayed transformation of primary spongiosa into secondary spongiosa was observed (rickets). Increased amounts of osteoid were present although 25-OH-vitamin D3-levels were high. There were only modest signs of secondary hyperparathyroidism (osteoclast counts; urinary cAMP). In spite of the presence of bone disease, longitudinal growth was not reduced in uremic animals as compared with pair-fed sham-operated animals, but was significantly reduced as compared with ad lib fed control animals. In contrast, weight gain was significantly diminished in uremic animals as compared with pair-fed sham-operated control animals. It is concluded that diminished intake of food is the major determinant of growth retardation in preterminal experimental renal failure.

["Numeric increase of microcalcifications, an important radiologic sign of occult breast cancer" (author's transl)]

An increase in the number or the sudden appearance of multiple microcalcifications in the course of a mammographic controls series represent a further important sign of malignancy. In 14 of our cases witha non palpable breast cancer we were able to observe an increase in the number or a sudden appearance of typical calcium precipitates during an observation period, which, according to the case, lasted from 6 to 21 months. Biopsy revealed in all cases an early cancer. Our observations demonstrate the absolute indication for biopsy in all patients, which during a mammographic control series suddenly present microcalcifications, or an increase in the number of the ones that were previously observed. All patients showing clustered microcalcifications, which because of their small number are not demanding a biopsy, should be regarded as risk-cases and observed regularly in order to rule out or demonstrate an increase in the number of calcifications. Follow-up series within six months are recommended.

[Growth velocity of breast carcinoma and radiographic "early diagnoses"]

Between 1960 and 1975, 53 mammary carcinomas have been observed in a collective of 15000 women a part of whom, comprising finally 80 per cent, was free from troubles (annual prophylactic examination for breast cancer). Of these 53 cases were available two up to eleven preceding mammographic series made within an observation period of 0.2 to eleven years. A "mean growth curve" was obtained empirically, based on 163 mammographic tumor measurements with tumor sizes between 2 mm and 60 mm. In the course of a development period between two and eleven years, 33 per cent of the carcinomas were seen to accelerate their further growth in comparison with the initial value; 66 per cent revealed an increasing slow-down of growth, and all tumors showed considerable changes in their growth rates. Mammary carcinomas altogether continually decelerated their growth as measured by the duplication time of the tumor volume from Tv = 309 days on the average up to an average of Tv = 381 days after two through eleven years. The mean growth curve exhibited an exponential shape which was completed by biomathematical methods and can be described by means of a Power function. It corresponds well to the rate of incidence of the mammary carcinoma which shows an identical rise in relation to increased old age. The medium growth time from a primary cancerous cell with ten micron in size up to the tumor 2 mm in diameter may be estimated biomathematically only and amounts to ten or twenty years with 23 duplication periods. The further average growth rate between the tumor sizes of two and ten millimeter, stages which can be diagnosed roentgenologically, was empirically six years; the most quickly growing tumor needed almost two years. For the purpose of early cancer detection (tumor size below 10 mm, lymph nodes histologically free from metastases), the serial mammography to be performed every 18 months or two years is the only technique which provides utilizable early recognition marks and besides does allow a simple judgement. Solely the symptoms "suspect desification, partly spiculated" in sixty per cent and "typical cancerous microcalcification" in forty per cent have been observed as the earliest signs. The reliability ("certainty") of mammography is frequently overestimated (false negative rate: 7 to 18%) and should be quoted only for collectives where control mammographies have been made over a period of five or ten years. Roentgenological controls of alterations below three millimeter in size and without an indication for biopsy ought to be performed within six months, and still sooner in case of larger alterations. It is not possible earlier than after five or ten years to judge of the radicality of a therapy, as spread cancerous cells, on he average, reveal similar growth rates as does the primary tumor.