EBF1, MYO6 and CALR expression levels predict therapeutic response in diffuse large B-cell lymphomas

Background

Diffuse large B-cell lymphoma (DLBCL) is a hematological malignancy representing one-third of non-Hodgkin's lymphoma cases. Notwithstanding immunotherapy in combination with chemotherapy (R-CHOP) is an effective therapeutic approach for DLBCL, a subset of patients encounters treatment resistance, leading to low survival rates. Thus, there is an urgent need to identify predictive biomarkers for DLBCL including the elderly population, which represents the fastest-growing segment of the population in Western countries.

Methods

Gene expression profiles of n=414 DLBCL biopsies were retrieved from the public dataset GSE10846. Differentially expressed genes (DEGs) (fold change >1.4, p-value <0.05, n=387) have been clustered in responder and non-responder patient cohorts. An enrichment analysis has been performed on the top 30 up-regulated genes of responder and non-responder patients to identify the signatures involved in gene ontology (MSigDB). The more significantly up-regulated DEGs have been validated in our independent collection of formalin-fixed paraffin-embedded (FFPE) biopsy samples of elderly DLBCL patients, treated with R-CHOP as first-line therapy.

Results

From the analysis of two independent cohorts of DLBCL patients emerged a gene signature able to predict the response to R-CHOP therapy. In detail, expression levels of EBF1, MYO6, CALR are associated with a significant worse overall survival.

Conclusions

These results pave the way for a novel characterization of DLBCL biomarkers, aiding the stratification of responder versus non-responder patients.

Recapitulating thyroid cancer histotypes through engineering embryonic stem cells

Thyroid carcinoma (TC) is the most common malignancy of endocrine organs. The cell subpopulation in the lineage hierarchy that serves as cell of origin for the different TC histotypes is unknown. Human embryonic stem cells (hESCs) with appropriate in vitro stimulation undergo sequential differentiation into thyroid progenitor cells (TPCs-day 22), which maturate into thyrocytes (day 30). Here, we create follicular cell-derived TCs of all the different histotypes based on specific genomic alterations delivered by CRISPR-Cas9 in hESC-derived TPCs. Specifically, TPCs harboring BRAF^V600E or NRAS^Q61R mutations generate papillary or follicular TC, respectively, whereas addition of TP53^R248Q generate undifferentiated TCs. Of note, TCs arise by engineering TPCs, whereas mature thyrocytes have a very limited tumorigenic capacity. The same mutations result in teratocarcinomas when delivered in early differentiating hESCs. Tissue Inhibitor of Metalloproteinase 1 (TIMP1)/Matrix metallopeptidase 9 (MMP9)/Cluster of differentiation 44 (CD44) ternary complex, in cooperation with Kisspeptin receptor (KISS1R), is involved in TC initiation and progression. Increasing radioiodine uptake, KISS1R and TIMP1 targeting may represent a therapeutic adjuvant option for undifferentiated TCs.

P430 TUMORAL THROMBOTIC MICROANGIOPATHY: A RARE CAUSE OF ACUTE PULMONARY HYPERTENSION

Introduction

Among the causes of acute pulmonary hypertension, the occlusion of the little pulmonary vessels caused by tumoral microemboli, even from an unknown neoplasm, is an infrequent condition with a very poor prognosis.

Clinical Case

A 55–years old woman with no relevant past medical history presented to the Emergency Department with dyspnea at rest, desaturation, palpitations and a brief episode of chest pain, after several days of fatigue and exertional dyspnea. ECG showed sinus tachycardia and signs of right ventricle pressure overload with inverted T waves in V3–V4 and in the inferior leads (Fig. 1). On laboratory tests there were high D–dimer values and a slightly elevated TnI. Blood gas analysis showed hypoxemic hypocapnic respirstory alkalosis. An Echocardiogram revealed severe dilatation and dysfunction of the right ventricle and signs of high probability of pulmonary hypertension (Fig. 2). Pulmonary CT scan ruled out embolism and showed irregular thickening of the interstitium and mediastinal lymphoadenopathy. Then, a rapid clinical deterioration happened, refractory to inotropes infusion and larger volumes of oxygen. The programmed diagnostic pathway cannot be pursued. On day 4, there was respiratory distress and pulseless electrical activity cardiac arrest during endotracheal intubation. ECMO mechanical support was positioned but on day 7 the patient died. Autopsy, made to discover the cause of pulmonary hypertension, revealed the presence of a colonic invasive adenocarcinoma with micropapillary pattern and thoracic and pelvic lymph–nodal metastases. Microscopic evaluation of the lungs showed a widespread neoplastic vascular invasion with microthromboemboli (Fig. 3).

Discussion

Tumoral thrombotic microangiopathy is a cause of pulmonary hypertension of multifactorial origin and should be suspected in cases of pulmonary hypertension without pulmonary embolism or interstitial lung disease. The rarity of this condition and the absence of an oncological medical history make difficult the diagnostic hypothesis. Besides, the lacking of an effective therapy makes the prognosis poor.

Dual Inhibition of Myc Transcription and PI3K Activity Effectively Targets Colorectal Cancer Stem Cells

Simple Summary

Compelling evidence has shown that cancer stem cells (CSCs) are responsible for high resistance to conventional anti-cancer therapies. Here, we demonstrate that the tumor microenvironment protects CR-CSCs from EGFR/HER2, BRAF and PI3K targeting, promoting CD44v6 and Myc expression. Alternatively, as a substitution for HER2 and BRAF, the Myc transcription inhibitor can overcome the protective effects of microenvironmental cytokines, impairing the survival of CR-CSCs. These data highlight the targeting of Myc and PI3K activity as a novel therapeutic strategy against advanced colorectal cancer.

Abstract

Despite advances in the curative approach, the survival rate of advanced colorectal cancer (CRC) patients is still poor, which is likely due to the emergence of cancer cell clones resistant to the available therapeutic options. We have already shown that CD44v6-positive CRC stem cells (CR-CSCs) are refractory toward standard anti-tumor therapeutic agents due to the activation of the PI3K pathway together with high HER2 expression levels. Tumor microenvironmental cytokines confer resistance to CR-CSCs against HER2/PI3K targeting by enhancing activation of the MAPK pathway. Here, we show that the CSC compartment, spared by BRAF inhibitor-based targeted therapy, is associated with increased expression levels of CD44v6 and Myc and retains boosted clonogenic activity along with residual tumorigenic potential. Inhibition of Myc transcription, downstream of the MAPK cascade components, and PI3K pathway activity was able to overcome the protective effects of microenvironmental cytokines, affecting the survival and the clonogenic activity of CR-CSCs, regardless of their mutational background. Likewise, the double targeting induced stabilization of mouse tumor avatars. Altogether, these data outline the rationale for dual kinase targeting of CR-CSCs to prevent their adaptive response, which would lead to disease progression.

Targeting Phosphatases and Kinases: How to Checkmate Cancer

Metastatic disease represents the major cause of death in oncologic patients worldwide. Accumulating evidence have highlighted the relevance of a small population of cancer cells, named cancer stem cells (CSCs), in the resistance to therapies, as well as cancer recurrence and metastasis. Standard anti-cancer treatments are not always conclusively curative, posing an urgent need to discover new targets for an effective therapy. Kinases and phosphatases are implicated in many cellular processes, such as proliferation, differentiation and oncogenic transformation. These proteins are crucial regulators of intracellular signaling pathways mediating multiple cellular activities. Therefore, alterations in kinases and phosphatases functionality is a hallmark of cancer. Notwithstanding the role of kinases and phosphatases in cancer has been widely investigated, their aberrant activation in the compartment of CSCs is nowadays being explored as new potential Achille's heel to strike. Here, we provide a comprehensive overview of the major protein kinases and phosphatases pathways by which CSCs can evade normal physiological constraints on survival, growth, and invasion. Moreover, we discuss the potential of inhibitors of these proteins in counteracting CSCs expansion during cancer development and progression.

Messing Up the Cancer Stem Cell Chemoresistance Mechanisms Supported by Tumor Microenvironment

Despite the recent advances in cancer patient management and in the development of targeted therapies, systemic chemotherapy is currently used as a first-line treatment for many cancer types. After an initial partial response, patients become refractory to standard therapy fostering rapid tumor progression. Compelling evidence highlights that the resistance to chemotherapeutic regimens is a peculiarity of a subpopulation of cancer cells within tumor mass, known as cancer stem cells (CSCs). This cellular compartment is endowed with tumor-initiating and metastasis formation capabilities. CSC chemoresistance is sustained by a plethora of grow factors and cytokines released by neighboring tumor microenvironment (TME), which is mainly composed by adipocytes, cancer-associated fibroblasts (CAFs), immune and endothelial cells. TME strengthens CSC refractoriness to standard and targeted therapies by enhancing survival signaling pathways, DNA repair machinery, expression of drug efflux transporters and anti-apoptotic proteins. In the last years many efforts have been made to understand CSC-TME crosstalk and develop therapeutic strategy halting this interplay. Here, we report the combinatorial approaches, which perturb the interaction network between CSCs and the different component of TME.

Synaptosomes: new vesicles for neuronal mitochondrial transplantation

Background

Mitochondrial dysfunction is a critical factor in the onset and progression of neurodegenerative diseases. Recently, mitochondrial transplantation has been advised as an innovative and attractive strategy to transfer and replace damaged mitochondria. Here we propose, for the first time, to use rat brain extracted synaptosomes, a subcellular fraction of isolated synaptic terminal that contains mitochondria, as mitochondrial delivery systems.

Results

Synaptosome preparation was validated by the presence of Synaptophysin and PSD95. Synaptosomes were characterized in terms of dimension, zeta potential, polydispersity index and number of particles/ml. Nile Red or CTX-FITCH labeled synaptosomes were internalized in LAN5 recipient cells by a mechanism involving specific protein–protein interaction, as demonstrated by loss of fusion ability after trypsin treatment and using different cell lines. The loading and release ability of the synaptosomes was proved by the presence of curcumin both into synaptosomes and LAN5 cells. The vitality of mitochondria transferred by Synaptosomes was demonstrated by the presence of Opa1, Fis1 and TOM40 mitochondrial proteins and JC-1 measurements. Further, synaptosomes deliver vital mitochondria into the cytoplasm of neuronal cells as demonstrated by microscopic images, increase of TOM 40, cytochrome c, Hexokinase II mitochondrial proteins, and presence of rat mitochondrial DNA. Finally, by using synaptosomes as a vehicle, healthy mitochondria restored mitochondrial function in cells containing rotenone or CCCp damaged mitochondria.

Conclusions

Taken together these results suggest that synaptosomes can be a natural vehicle for the delivery of molecules and organelles to neuronal cells. Further, the replacement of affected mitochondria with healthy ones could be a potential therapy for treating neuronal mitochondrial dysfunction-related diseases.

Cancer Stem Cells in Thyroid Tumors: From the Origin to Metastasis

Thyroid tumors are extremely heterogeneous varying from almost benign tumors with good prognosis as papillary or follicular tumors, to the undifferentiated ones with severe prognosis. Recently, several models of thyroid carcinogenesis have been described, mostly hypothesizing a major role of the thyroid cancer stem cell (TCSC) population in both cancer initiation and metastasis formation. However, the cellular origin of TCSC is still incompletely understood. Here, we review the principal epigenetic mechanisms relevant to TCSC origin and maintenance in both well-differentiated and anaplastic thyroid tumors. Specifically, we describe the alterations in DNA methylation, histone modifiers, and microRNAs (miRNAs) involved in TCSC survival, focusing on the potential of targeting aberrant epigenetic modifications for developing novel therapeutic approaches. Moreover, we discuss the bidirectional relationship between TCSCs and immune cells. The cells of innate and adaptive response can promote the TCSC-driven tumorigenesis, and conversely, TCSCs may favor the expansion of immune cells with protumorigenic functions. Finally, we evaluate the role of the tumor microenvironment and the complex cross-talk of chemokines, hormones, and cytokines in regulating thyroid tumor initiation, progression, and therapy refractoriness. The re-education of the stromal cells can be an effective strategy to fight thyroid cancer. Dissecting the genetic and epigenetic landscape of TCSCs and their interactions with tumor microenvironment cells is urgently needed to select more appropriate treatment and improve the outcome of patients affected by advanced differentiated and undifferentiated thyroid cancers.

Electrochemoterapy (ECT) for the treatment of superficial tumor localizations

e13526

Background: ECT is an effective local treatment for palliation on inoperable superficial neoplastic lesions from any type of tumour. It combines chemotherapy and electric pulses that permeabilize the cell membrane in a transient and reversible manner, allowing low-perrneant drugs to enter the cell, thus magnifying their cytotoxicity. Recent1y, a new device (Clinoporetor, IGEA-Srl, Italy) has been developed to supply electric pulses with appropriate parameters permitting the clinical use of ECT. Methods: We treated 26 pts, M/F 12/14; median age 61 yrs, range 38–87: 7 breast cancer with nodular or infiltrating lesions in thoracic or abdominal wall; 12 melanoma (2 wide infiltration of thoracic wall, 10 in transit metastases or loco-regional recurrences); 2 head-neck cancer with a wide neck-scalp infiltration; 3 lymphomas with cutaneous lesions, 1 soft tissue sarcoma with a subcutaneous recurrence, 1 gastric cancer with 2 cutaneous localizations. The areas treated ranged from 1 to 30 cm on diameter. 12 pts requested a prior surgery debulking and 3 pts received ECT in pre-irradiated area. Intravenous bleomycin (15 mg/m2) were used in all patient; electric pulses were than applied to the tumor areas by needle electrodes in a time window of 20 minutes. In total 32 procedures were performed, 6 as out-patient in local anaesthesia and 26 in general anaesthesia; 6 pts requested a second application. Results: Treatment was safe and well tolerated, particularly when general anaesthesia was used. At the second/third week, all pts showed a regression of almost all lesions with a necrotic, fibro-sclerotic evolution. After 1–2 months from ECT, we obtained a 70% CR and a 10%PR of the lesions. Some pts showed a response after the second procedure. About 50% of lesions remained in remission for a long period (median 8 months, range 1–23+); 11 of 12 pts previously undergone surgical debulking never relapsed in the treated area. Concomitant systemic treatment, no rapid spreading of the disease and surgical debulking were related to a better local control and survival. Conclusions: ECT is a promising and safe treatment for superficial lesions from different malignancies. General anaesthesia and surgical debulking permit to treat very large and deeper lesion with a very good local control.

No significant financial relationships to disclose.

Placement of long-term central venous catheters in outpatients: study of 134 patients over 24,596 catheter days

OBJECTIVE

Our goal was to investigate the feasibility of inserting long-term central venous access devices in outpatients using a simple technique that minimizes the risks of complications linked to venipuncture and errors in management.

MATERIALS AND METHODS

We placed 147 central venous catheters (CVCs) in 134 patients under local anesthesia. No sedation was used, and all procedures were done in our radiology department. Of the 134 patients, 101 patients were included in the follow-up. Overall follow-up of patients was 24,596 catheter days (mean, 243.52 days). Percutaneous access, mostly by the subclavian vein, was done by micropuncture technique under fluoroscopic guidance. Six CVCs were untunneled, 36 were connected to totally subcutaneous ports, and 105 were tunneled.

RESULTS

The only immediate complication was pneumothorax (3%). Late complications, expressed per 1000 catheter days, included CVC breakage (0.12), vascular thrombosis (0.08), catheter occlusion (0.04), dislodgment (0.24), and local or systemic infections (0.40).

CONCLUSION

Outpatient CVC placement is feasible because the procedure is not adversely affected when the patient is not hospitalized. The drawbacks are identical to those faced by inpatients. Improved materials and more extensive information on the management of patients with long-term CVCs would help reduce complications further.

Renal toxicity and arterial hypertension in rats chronically exposed to vanadate

The effects of 1, 10, or 40 micrograms/ml of vanadium, given for six or seven months as sodium metavanadate in drinking water on cardiovascular and biochemical variables and the electrolyte metabolism of male Sprague-Dawley rats were investigated. At the end of the exposure period, all animals exposed to vanadate had increased systolic and diastolic blood pressure. This effect was not dose dependent and heart rate and cardiac inotropism were not affected. The role of defective renal function and electrolyte metabolism in such effects was supported, in the rats exposed to 10 and 40 ppm of vanadium, by the following changes: (a) decreased Na, + K(+)-ATPase activity in the distal tubules of nephrons; (b) increased urinary excretion of potassium; (c) increase in plasma renin activity and urinary kallikrein, kininase I, and kininase II activities; (d) increased plasma aldosterone (only in the rats treated with 10 ppm of vanadium). The alterations in the rats exposed to 1 ppm of vanadium were: (a) reduced urinary calcium excretion; (b) reduced urinary kallikrein activity; (c) reduced plasma aldosterone. These results suggest that blood hypertension in rats exposed to vanadate depends on specific mechanisms of renal toxicity related to the levels of exposure.

Urinary kallikrein excretion in type 1 (insulin-dependent) diabetes mellitus

Kidney haemodynamics appear to change after the early phases of diabetic nephropathy: increases in glomerular filtration rate and in renal plasma flow have been widely reported, while kidney size is increased. As the renal kallikrein-kinin system has been demonstrated to regulate kidney blood circulation, we have evaluated the excretion of urinary kallikrein in 87 Type 1 (insulin-dependent) diabetic patients with and without hyperfiltration. Urinary kallikrein excretion was measured in 24-h urine collections. The esterolytic activity was determined by fluorimetric assay. The excretion of urinary kallikreins was significantly higher in hyperfiltering patients (472 +/- 125 esterase units/24 h) than in normofiltering (168 +/- 77 esterase units/24 h) and control subjects (151 +/- 39 esterase units/24 h), p < 0.001. Furthermore, we observed a positive correlation between urinary kallikrein excretion and glomerular filtration rate (r = 0.785). These data suggest that variations of kallikrein and kinin concentrations may play a role in the alteration of renal haemodynamics in Type 1 diabetes. It is possible that the kinin-kallikrein system, the renin-angiotensin system and the prostaglandins may interact to determine the haemodynamic alterations which are present in the diabetic disease.

[Combined use of real-time digital subtraction radioscopy and computerized tomography: potential advantages in diagnostic and interventional radiology]

The idea of combining fluoroscopy and CT arose from the daily practice in diagnostic and interventional radiology. A Diasonics OEC high-performance image intensifier complete with a digital subtraction system was connected to a Siemens Somatom-DRH CT scanner to work in tandem. CT is used for a localization in-depth and fluoroscopy for the subsequent maneuvers within an organ or body compartment. With this combination, complex procedures such as transarterial portography, percutaneous embolizations, pain treatment and manipulation for catheterization of the bile ducts and urinary tract could be performed in one place and in one session. CTF is especially useful when patients should not be moved about from room to room or undergo an examination in several sessions, as it happens with children or critically ill or contagious patients.

Renal mechanisms in the cardiovascular effects of chronic exposure to inorganic mercury in rats

Male weanling Wistar rats received 200 micrograms/ml of mercury (Hg), as HgCl2, in drinking water for 180 days. At the end of the treatment, systemic arterial blood pressure was augmented, cardiac inotropism was reduced, and heart rate was unchanged. Light and electron microscopical studies of the kidney showed a mesangial proliferative glomerulonephritis in about 80% of the glomeruli. Tubular cells showed reduction of the acid phosphatase activity, which was related to functional abnormalities of the lysosomes. In the 24 hour urine samples of the Hg exposed rats, there was slight reduction of kallikrein activity, but evident proteinuria was not present in all samples. Plasma renin activity was reduced, that of angiotensin I-converting enzyme was augmented, and plasma aldosterone concentrations were unchanged. Mercury was accumulated mostly in the kidney of the Hg treated animals; and the content of Hg in the heart was higher than in the brain. These data show that chronic exposure to Hg acts on the kidney with complex mechanisms of toxicity; these contribute to modify systemic haemodynamics.

Localization and characterization of human salivary kininases

The human saliva of normal subjects containing large amounts of basic carboxypeptidase produces decarboxylated non inflammatory peptides, for instance, kinins and anaphilotoxins C3a, C4a and C5a. A reduction of epithelial cell-bonded enzyme (carboxypeptidase M-type or kininase I), produces inflammations by the active intact kinins and the initiation of the alternative activating pathway of complement by active anaphilotoxins, which generate complement cleavage products, containing potential destructive mechanism.

CT-fluoroscopy link-up (CTF): potential for special procedures

Some interventional radiological procedures call for unrestricted axial vision and monoplanar fluoroscopy at different angles. We have mounted a fluoroscopic image intensifier in front of the gantry of a CT scanner to assess whether the combination would be useful. This link-up has been tested in a variety of situations and, even with the shortcomings of makeshift equipment, the combination filled some gaps in our vision of what is going on inside the patient, especially before an invasive procedure. It also proved useful in the planning of multiple procedures in a single session, especially when they had to be performed under general anesthesia in children or in the management of critical cases. We feel that the possibilities afforded by CTF (computed tomography plus fluoroscopy) need further exploration prior to the construction of purpose-built equipment. The interim information supplied suggests that it will be worth developing.

Physiologic role of the peripheral enkephalinergic system in regulating cardiovascular homeostasis: evidence of interactions with the renin-angiotensin and kallikrein-kinin systems

On isolated heart preparation, it was found that Leu5-Enkephalin (Leu5-ENK) did not influence the cardiac function. On the other hand, Leu5-ENK induced a specific dose-related inhibition, in the cardiac perfusate, of the activities of kininase II (KII) and angiotensin converting enzyme (ACE) (but not of kininase I-KI). Instead no detectable alterations of the above enzymatic activities with the used concentrations of Leu5-ENK were observed in vitro. This opioid also increased specifically the effects induced by some of the autacoids, related to both renin-angiotensin and kallikrein-kinin systems, on the KII and ACE activities. A specific correlation between these Leu5-ENK-induced modifications and the functional responses of the heart to the same autacoids was observed. Naloxone (NAL) and more significantly ICI 174864 (ICI) opposed or reversed the inhibitory effect of the used opioid whereas they had neither inhibitory nor synergic effect on both KII and ACE activity by themselves. The possible physiologic role of the enkephalins in regulating cardiovascular function by acting peripherally on some humoral systems through modulatory mechanism was discussed.

Kallikrein and kininase excretion in football players after psychophysical stress

In eleven football players and in four football-reserve players urinary kallikrein and kininase activities were determined before and after an official match. The results showed a significant reduction of kallikrein after the match in football players when the football-reserve players were used for comparison (p less than 0.01). Kininase activity appears increased in football players after the match, but not significantly. The Kininase/Kallikrein ratio after the match resulted significantly increased in football players (p less than 0.05) and very significantly compared to the football-reserve players (p less than 0.01).

Urinary kallikrein and kininase activity in normal and complicated by hypertension pregnancy

Kallikrein and kininase activities were determined in urine of 58 hospitalized pregnant patients: 15 with E.P.H. gestosis, 10 with chronic hypertension, 18 with non proteinuric pregnancy induced hypertension, 15 with no hemodynamic disease as controls. All our cases with hypertension were treated with alpha-methyl-dopa. A significant increase in urinary kininase activity was shown by only E.P.H. gestosis group vs. controls. In the same group we found a significant decrease in urinary kallikrein activity vs. controls, in contrast with the results obtained previously, perhaps because of the different measuring method. The kininase/kallikrein ratio, theoretically indicative of kinins activity, increased significantly only in the E.P.H. gestosis group.

Kallikrein and kininase activities excretion in newborns affected by jaundice

In a homogeneous group of 30 newborns, aging between 10 hours--10 days, and affected by jaundice, urinary kallikrein and kininase activities were determined. The variable considered were: sex, time of life, weight and gestational age. Urinary samples were taken at the beginning and at the end of phototherapy.

A young girl with ring(18) mosaicism: cytogenetic studies and PEP A mapping

A young girl with 46,XX,r(18)/46,XX/45,XX,-18 chromosome constitution is reported. She displays a slight degree of mental retardation. The line with the ring chromosome predominates in blood lymphocytes. In skin fibroblast culture the ring(18) line showed a constant decreasing trend, from 45% at the first passage, down to its disappearance at the 19th passage, where only 46,XX cells were observed. The child/mid parents' ratio of Peptidase A activity in red cells was 0.36. The Peptidase A activity in a fibroblast clone 46,XX,r(18) was 0.55 compared to the 46,XX line. These data suggest that the PEP A locus was lost in ring formation.

Urinary kallikrein and hypertension in cadmium-exposed rats

Chronic exposure of rats to cadmium (Cd) in drinking water induced elevated systolic and diastolic blood pressure. Heart rate, however, was lowered, suggesting that the hypertension in these rates may be due to an increase of the total peripheral resistance, possibly involving a central nervous system (CNS) component in Cd-induced hypertension. Urinary kallikrein activity was reduced in the exposed animals and may explain the previously reported antinatriuretic effect of Cd, since renal kallikrein is an enzyme responsible for the synthesis of kallidin, a potent vasodilator and natriuretic polypeptide.

Chemical relations between renal and urinary kallikrein of rat

The ratio in micron-Moles between each aminoacid residue of both hydrolized renal and urinary kallikrein of rat, is about 1.00 +/- 0.3. Except for Glu, His and Glucosamine a good proportion between all residues of both enzymes was obtained. It is probable that the different molecular weight, respectively 40,000 for the renal kallikrein and 32,000 for the urinary enzyme, is an artefact of the different procedures used for the purification of rat kallikrein.

Purification of horse renal kallikrein and chemical relations with horse urinary kallikrein

Kallikrein was purified from horse kidney by several steps of chromatographic procedure and by affinity chromatography on Sepharose-Concanavaline. Horse urinary kallikrein was previously purified by DE-32 hydroxylapatite and by Sephadex G-100 gel filtration. On the purified final sample of renal and urinary kallikrein the aminoacid composition and the gel electrophoretic molecular weight were determined. The ratio in micronMoles between each aminoacid residue of both hydrolyzed renal and urinary kallikrein of horse is about 1,00 +/- 0,30. Except for Pro, 1/2 Cys and basic aminoacid residues a good proportion was obtained. It is confirmed that the different molecular weight, respectively 47,500 for renal kallikrein and 28,000 for the urinary enzyme is an artefact of the different procedures used for the purification of horse kallikrein.

Method for measurement of human urinary kininase activity

A method was developed to measure kininase activity in human urine. The method consists of dialysis of human centrifuged urine sample against phosphate buffer and partial fractionation of A-50 Sephadex column. The enzymatic property of urinary kininase, which destroys bradykinin when incubated, is estimated from its effect on a definite amount of bradykinin, using rat uterus.

Altered urinary excretion of human kininase activity in acute myocardial infarction

This study concerns the determination of levels of human urinary kininase excretion in acute myocardial infarction (AMI). The results obtained by a biological method show that there is a significant reduction of the enzymatic activity in patients affected by AMI in comparison with normals (6.4 +/- 0.4 ng of destroyed bradykinin/min. versus 164.4 +/- 31.4 ng; P less than 0.001), while urinary kallikrein excretion was close to normal values.

Urinary kallikrein excretion and plasma DBH activity in hypertension

Many factors are to be considered in maintaining normal blood pressure. Authors study the behavior of urinary kallikrein (U.K.) and plasma dopamine-beta-hydroxylase (DBH) activity in various forms of hypertension. The values of U.K. excretion in normals were 20.5 +/- 1.8 E.U./24 h. In essential hypertensive patients (9.4 +/- 2.0 E.U./24 h) U.K. decreased, while in secondary hypertension it was significantly higher (33.8 +/- 3.0 E.U./24 h). Plasma DBH activity in essential hypertensive patients (17.72 +/- 2.33 I.U./ml) was similar to controls (20.22 +/- 1.39 I.U./ml); in secondary hypertension the mean values of plasma DBH were decreased (12.31 +/- 2.55 I.U./ml). No correlation between U.K. and plasma DBH activity was observed in normals and in various forms of hypertensive patients. U.K. seems a more reliable factor than plasma DBH in defining the different types of hypertension.

Urinary kallikrein activity of workers exposed to lead

Two groups of men of different age ranges and with the same period of lead exposure were selected for study in a recently opened car-battery factory. Two other groups of age-matched men, not exposed to heavy metals in their work, were used as controls. Morning urines were collected from control and exposed groups for determination of urinary kallikrein activity, urinary delta-amino-levulinic acid (ALA) and lead levels. The environmental lead levels and the urinary ALA and lead values indicated that exposure in the factory was not heavy. The older group of lead-exposed workers showed greatly reduced urinary kallikrein activity compared with that of the age-matched controls. In contrast, the younger group did not show any significant alteration in urinary kallikrein excretion.

Purification of renal rat kallikrein and chemical relations with urinary rat kallikrein

A highly purified kallikrein from rat kidney was obtained by a multi-step purification procedure including gel filtration on Sephadex G-100, chromatography on Whatman CM-32 and DE-32 celluloses and Sephadex G-100 superfine. Molecular weight of 40,000 was estimated by sodium dodecyl sulfate polyacrylamide disc gel electrophoresis. On the purified enzyme the aminoacid analysis was determined. Some chemical differences between renal kallikrein and the most abundant rat urinary kallikrein were illustrated.

Isolation and partial characterization of a kallikrein from mouse submaxillary glands

A simple procedure to obtain relatively large amounts of purified kallikrein from male mouse submaxillary gland is described. Some chemical and biological properties of this kallikrein have been investigated. The enzyme has a m.w. of 32,000 and shows strong BAEE-esterase activity, as well as kininogenase activity. It is partially inhibited by Aprotinin.