Publisher Summary The classification of cell death can be based on morphological or biochemical criteria or on the circumstances of its occurrence. Currently, irreversible structural alteration provides the only unequivocal evidence of death; biochemical indicators of cell death that are universally applicable have to be precisely defined and studies of cell function or of reproductive capacity do not necessarily differentiate between death and dormant states from which recovery may be possible. It has also proved feasible to categorize most if not all dying cells into one or the other of two discrete and distinctive patterns of morphological change, which have, generally, been found to occur under disparate but individually characteristic circumstances. One of these patterns is the swelling proceeding to rupture of plasma and organelle membranes and dissolution of organized structure—termed “coagulative necrosis.” It results from injury by agents, such as toxins and ischemia, affects cells in groups rather than singly, and evokes exudative inflammation when it develops in vivo. The other morphological pattern is characterized by condensation of the cell with maintenance of organelle integrity and the formation of surface protuberances that separate as membrane-bounded globules; in tissues, these are phagocytosed and digested by resident cells, there being no associated inflammation.

Cell death : the significance of apoptosis

Publisher Summary This chapter explores that the changes that take place in the protein molecules during denaturation constitute one of the most interesting and complex classes of reactions that can be found either in nature or in the laboratory These reactions are important because of the information they can provide about the more intimate details of protein structure and function They are also significant because they challenge the chemist with a difficult area for the application of chemical principles The chapter reviews that the denaturation is a process in which the spatial arrangement of the polypeptide chains within the molecule is changed from that typical of the native protein to a more disordered arrangement The chapter also discusses the classification of protein structures: primary, secondary, and tertiary structures The primary structure is that expressed by the structural chemical formula and depends entirely on the chemical valence bonds that the classical organic chemist would write down for the protein molecule The secondary structure is the configuration of the polypeptide chain that results from the satisfaction of the hydrogen bonding potential between the peptide N-H and C=O groups The tertiary structure is the pattern according to which the secondary structures are packed together within the native protein molecule The term “denaturation” as used in this chapter is indented to include changes in both the secondary and tertiary structures

Some factors in the interpretation of protein denaturation.

The rat estrogen receptor (ER) exists as two subtypes, ER alpha and ER beta, which differ in the C-terminal ligand binding domain and in the N-terminal transactivation domain. In this study we investigated the messenger RNA expression of both ER subtypes in rat tissues by RT-PCR and compared the ligand binding specificity of the ER subtypes. Saturation ligand binding analysis of in vitro synthesized human ER alpha and rat ER beta protein revealed a single binding component for 16 alpha-iodo-17 beta-estradiol with high affinity [dissociation constant (Kd) = 0.1 nM for ER alpha protein and 0.4 nM for ER beta protein]. Most estrogenic substances or estrogenic antagonists compete with 16 alpha-[125I]iodo-17 beta-estradiol for binding to both ER subtypes in a very similar preference and degree; that is, diethylstilbestrol > hexestrol > dienestrol > 4-OH-tamoxifen > 17 beta-estradiol > coumestrol, ICI-164384 > estrone, 17 alpha-estradiol > nafoxidine, moxestrol > clomifene > estriol, 4-OH-estradiol > tamoxifen, 2-OH-estradiol, 5-androstene-3 beta, 17 beta-diol, genistein for the ER alpha protein and dienestrol > 4-OH-tamoxifen > diethylstilbestrol > hexestrol > coumestrol, ICI-164384 > 17 beta-estradiol > estrone, genistein > estriol > nafoxidine, 5-androstene-3 beta, 17 beta-diol > 17 alpha-estradiol, clomifene, 2-OH-estradiol > 4-OH-estradiol, tamoxifen, moxestrol for the ER beta protein. The rat tissue distribution and/or the relative level of ER alpha and ER beta expression seems to be quite different, i.e. moderate to high expression in uterus, testis, pituitary, ovary, kidney, epididymis, and adrenal for ER alpha and prostate, ovary, lung, bladder, brain, uterus, and testis for ER beta. The described differences between the ER subtypes in relative ligand binding affinity and tissue distribution could contribute to the selective action of ER agonists and antagonists in different tissues.

Comparison of the ligand binding specificity and transcript tissue distribution of estrogen receptors alpha and beta

Protein extracts derived from bone can initiate the process that begins with cartilage formation and ends in de novo bone formation. The critical components of this extract, termed bone morphogenetic protein (BMP), that direct cartilage and bone formation as well as the constitutive elements supplied by the animal during this process have long remained unclear. Amino acid sequence has been derived from a highly purified preparation of BMP from bovine bone. Now, human complementary DNA clones corresponding to three polypeptides present in this BMP preparation have been isolated, and expression of the recombinant human proteins have been obtained. Each of the three (BMP-1, BMP-2A, and BMP-3) appears to be independently capable of inducing the formation of cartilage in vivo. Two of the encoded proteins (BMP-2A and BMP-3) are new members of the TGF-beta supergene family, while the third, BMP-1, appears to be a novel regulatory molecule.

https://science.sciencemag.org/content/sci/242/4885/1528.full.pdf

Novel regulators of bone formation: molecular clones and activities.

Thereisgrowinginterestinthepossiblehealththreatposedbyendocrine-disruptingchemicals (EDCs), which are substances in our environment, food, and consumer products that interfere with hormone biosynthesis, metabolism, or action resulting in a deviation from normal homeostatic control or reproduction. In this first Scientific Statement of The Endocrine Society, we present the evidence that endocrine disruptors have effects on male and female reproduction, breast development and cancer, prostate cancer, neuroendocrinology, thyroid, metabolism and obesity, and cardiovascular endocrinology. Results from animal models, human clinical observations, and epidemiological studies converge to implicate EDCs as a significant concern to public health. The mechanisms of EDCs involve divergent pathways including (but not limited to) estrogenic, antiandrogenic, thyroid, peroxisome proliferator-activated receptor , retinoid, and actions through other nuclear receptors; steroidogenic enzymes; neurotransmitter receptors and systems; and many other pathways that are highly conserved in wildlife and humans, and which can be modeled in laboratory in vitro and in vivo models. Furthermore, EDCs represent a broad class of molecules such as organochlorinated pesticides and industrial chemicals, plastics and plasticizers, fuels, and many other chemicals that are present in the environment or are in widespread use. We make a number of recommendations to increase understanding of effects of EDCs, including enhancing increased basic and clinical research, invoking the precautionary principle, and advocating involvement of individual and scientific society stakeholders in communicating and implementing changes in public policy and awareness. (Endocrine Reviews 30: 293–342, 2009)

/pdf/endocrine-disrupting-chemicals-an-endocrine-society-3fgbtp8gql.pdf

Endocrine-Disrupting Chemicals: An Endocrine Society Scientific Statement

Summary 3-Methylcholanthrene was administered intramuscularly for 22–102 days to six women with metastatic mammary cancer; five of these patients had been treated earlier with adrenalectomy-oophorectomy. The compound had no beneficial effect in one case. In five cases, there was subjective and objective evidence of inhibition of the malignant process, and in one woman the recession was of major magnitude and had clinical therapeutic significance. The regression of metastatic human mammary cancer induced by 3-methylcholanthrene was remarkable, since the responding neoplasms were not dependent on hormones but were of undifferentiated types which have been hitherto refractory to inhibitory influences. In all the patients there were temporary decreases in the levels of circulating hemoglobin and serum proteins during the administration of 3-methylcholanthrene. These proteins increased in amount after the injections of the polycyclic hydrocarbon were discontinued. It must be emphasized that the administration of 3-methylcholanthrene to man is potentially dangerous, since the compound may give rise to new neoplasms; but a carcinogenic effect was not observed in the patients in the brief period of 9 months.

https://cancerres.aacrjournals.org/content/canres/17/10/1028.full.pdf

Regression of Human Metastatic Mammary Cancer Induced by 3-Methylcholanthrene

A problem in science can be solved in only one way: a question is proposed in such a simple way that Nature must provide a categorical answer. But man cannot devour a big meal with a single gulp. For difficult problems a series of connected interrogations are necessary; as a result of the answers the most difficult problem progressively becomes simpler as solutions emerge. The cure of cancer has proved to be unusually difficult to obtain. But progress has been made as I shall show. New areas of investigation can be introduced only through a conceptual scheme, but the investigator discovers the truth by activity. Science is ruled by the duumvirate of idea and technique. In medicine the idea frequently comes from observation of the vivid but essentially simple displays of Nature at the bedside and in the laboratory; both theaters are of high importance in the quest for cures

https://jamanetwork.com/HttpHandlers/ArticlePdfHandler.ashx?journal=jama&articleId=655916&pdfFileName=jama_192_13_008.pdf

Propositions in Hormonal Treatment of Advanced Cancers

Cutaneous Ureterostomy with Contra-lateral Ureteral Ligation1

Spermatocele, Including its X-Ray Treatment1

An early sign of erythroblastic leukemia in rat was nodule formation in the spleen. Hyperplastic foci of stem cells, indistinguishable histologically from leukemic stem cells, were found in the red pulp whereas the malpighian corpuscles were uninvolved. Anemia is a normal phenomenon in immature rats and the spleen of the prepubertal rat possesses considerable hemopoietic potential. Pulse-doses of 7, 8, 12-trimethylbenz(a)anthracene prevented the physiologic hematological development of maturing rats and was associated with subsequent development of leukemic stem cells in the red pulp of the spleen. Significant enzyme changes were observed in leukemic spleens. Compared with the spleens of normal littermates, the concentration of lactate dehydrogenase rose while that of malate dehydrogenase fell; the content of alkaline phosphatase rose whereas acid phosphatase fell. Increased alkaline phosphatase activity in leukemic spleen was attributed to nonleukemic foci of myelopoiesis.

/pdf/leukemia-evoked-with-7-8-12-trimethylbenz-a-anthracene-in-uyh9kc5s03.pdf

Charles Huggins

Papers

Regression of Human Metastatic Mammary Cancer Induced by 3-Methylcholanthrene

Propositions in Hormonal Treatment of Advanced Cancers

Cutaneous Ureterostomy with Contra-lateral Ureteral Ligation1

Spermatocele, Including its X-Ray Treatment1

Leukemia evoked with 7, 8, 12-trimethylbenz(a)anthracene in rat : i. changes in spleen and thymus