Human liver contains two forms of lithocholic acid. One form is readily extractable by 95% ethanol/0.1% ammonia (soluble lithocholate, SL), while the other remains firmly bound to the residue (tissue-bound lithocholate, TBL). TBL could be hydrolytically released using clostridial cholanoylamino acid hydrolase, suggesting a peptide link between lithocholate and protein. With bovine serum albumin (BSA), lithocholic acid showed spontaneous amino group-modifying activity. When small molecular weight lysine (α-t-BOC-1-lysyl-β-naphthylamide) and arginine peptides (α-CBZ-di-arginyl-β-naphthylamide) were used in place of BSA, lithocholate bound specifically to the lysine peptide. The unusual affinity for lysine suggested that this amino acid might be involved as a residue in TBL. Synthesis of lithocholyl lysines and comparison with products of acid hydrolysis of TBL established ε-lithocholyl lysine as the predominant form in which lithocholic acid is found in tissue bound form.

A dehydrogenase which is relatively stable in formalin fixative and which reduces various leuco nitroxyl analogs is demonstrated cytochemically in rat myocardial, hepatic, and prostatic tubuloalveolar glandular cells.The various tissues were extricated and fixed in phosphate-buffered formaldehyde for up to 1 hr. The substrates used were products produced by catalytic hydrogenation of four different compounds with stable nitroxyl free radicals (Fig. 1). These compounds were 4-hydroxy-2,2,6,6, tetramethyl piperidine-l-oxyl (I), the urethane derivative (II) formed by reacting compound I with phenylisocyanate, 4-amino-2,2,6,6, tetramethyl piperidine-l-oxyl (III), and 2,2,6,6, tetramethyl piperidine-l-oxyl (IV). The nonosmiophilic tetrazolium salt, 2-(2'-benzothiazolyl)-5-styryl-3-(4'-phthalhydrazidyl) tetrazolium chloride (BSPT), which produces an insoluble, osmiophilic formazan upon reduction, was used as the electron acceptor at pH 7.4. Following incubation in the reaction medium, the tissues were osmicated in 2% osmium tetroxide at 50°C for 2 hr.

Three bis(phenylenediamines) are compared in formaldehyde-fixed rat liver and rat heart. Diaminobenzidine (DAB) demonstrated cytochrome oxidase on mitochondrial cristae, BAXD demonstrated both mitochondrial cytochrome oxidase and a terminal oxidase in endoplasmic reticulum and sarcoplasmic reticulum and BED demonstrated a terminal oxidase only on endoplasmic reticulum and sarcoplasmic reticulum.

A series of 17 bis(phenylenediamine) derivatives have been prepared and compared with 3,3′-diaminobenzidine (DAB) with regard to their ability to demonstrate cytochrome oxidase activity, peroxisome activity, horseradish peroxidase activity, erthrocytic peroxidase activity in cytochemical preparations, and bovine catalase activity in in vitro experiments. The results are tabulated, some illustrative photomicrographs are included and interesting correlations are discussed.

The syntheses of a series of p-substituted aromatic diamines and some representative thioureido- and mercapto-naphthols are described. Their cytochemical behavior in the Nadi reaction using fresh frozen sections of rat heart was studied in an attempt to learn more about the structural requirements of the Nadi reaction for cytochrome oxidase.

Homogenates of canine and human pancreas enriched with trypsin of endogenous origin only were obtained when such homogenates were incubated at 0°C. with aliquots of bovine trypsin (Tryptar) rendered insoluble by mechanical entrapment inside the lattices of polyacrylamide gel. Insoluble bovine trypsin was able to activate pancreatic trypsinogen and overcome pancreatic trypsin inhibitor prior to its removal by centrifugation. In addition, it was observed that some human pancreases readily developed tryptic activity in the usually long interval between death and autopsy, and that others generated substantial activity after homogenization and incubation at 0°C. In contrast, homogenates of canine pancreas required the addition of exogenous trypsin for conversion of trypsinogen to trypsin. When the generated tryptic activity of pancreatic homogenates was compared with that of purified bovine trypsin, human trypsin differed from bovine and canine trypsin in its substantially lower inhibition by ovomucoid and soybean trypsin inhibitor. The ease of conversion of human trypsinogen to trypsin, the stability of the latter, its lower sensitivity to trypsin inhibitor, and variation in content of the inhibitor are undoubtedly factors in the etiology of pancreatitis, and they may explain the significant rate of occurrence of this disease in man.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAcceleration of the Hydrolysis of Organic Fluorophosphates and Fluorophosphonates with Hydroxamic AcidsB. E. Hackley Jr., R. Plapinger, M. Stolberg, and T. Wagner-JaureggCite this: J. Am. Chem. Soc. 1955, 77, 13, 3651–3653Publication Date (Print):July 1, 1955Publication History Published online1 May 2002Published inissue 1 July 1955https://pubs.acs.org/doi/10.1021/ja01618a072https://doi.org/10.1021/ja01618a072research-articleACS PublicationsRequest reuse permissionsArticle Views419Altmetric-Citations97LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSynthesis of m-DialkylbenzenesG. Forrest Woods and Robert E. PlapingerCite this: J. Am. Chem. Soc. 1951, 73, 12, 5603–5605Publication Date (Print):December 1, 1951Publication History Published online1 May 2002Published inissue 1 December 1951https://pubs.acs.org/doi/10.1021/ja01156a031https://doi.org/10.1021/ja01156a031research-articleACS PublicationsRequest reuse permissionsArticle Views73Altmetric-Citations7LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSyntheses with Dihydroresorcinol Mono Ethyl Ether: 3-Alkyl-Δ2-cyclohexenonesG. Forrest. Woods, Paul H. Griswold, Bernard H. Armbrecht, David I. Blumenthal, and Robert. PlapingerCite this: J. Am. Chem. Soc. 1949, 71, 6, 2028–2031Publication Date (Print):June 1, 1949Publication History Published online1 May 2002Published inissue 1 June 1949https://doi.org/10.1021/ja01174a036RIGHTS & PERMISSIONSArticle Views399Altmetric-Citations19LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (424 KB) Get e-Alertsclose Get e-Alerts

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSyntheses with Dihydroresorcinol Mono Ethyl Ether: 3-Alkyl-Δ2-cyclohexenonesG. Forrest. Woods, Paul H. Griswold, Bernard H. Armbrecht, David I. Blumenthal, and Robert. PlapingerCite this: J. Am. Chem. Soc. 1949, 71, 6, 2028–2031Publication Date (Print):June 1, 1949Publication History Published online1 May 2002Published inissue 1 June 1949https://doi.org/10.1021/ja01174a036RIGHTS & PERMISSIONSArticle Views399Altmetric-Citations19LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (424 KB) Get e-Alertsclose Get e-Alerts