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Purpose: This report addresses the incidence of vascular endothelial cell apoptosis in the mouse small intestine in relation to the radiation-induced gastrointestinal (GI) syndrome. Methods and Materials: Nonanesthetized mice received whole-body irradiation at doses above and below the threshold for death from the GI syndrome with 250 kVp X-rays, 137 Cs gamma rays, epithermal neutrons alone, or a unique approach for selective vascular irradiation using epithermal neutrons in combination with boronated liposomes that are restricted to the blood. Both terminal deoxynucleotidyl transferase biotin-dUTP nick end labeling (TUNEL) staining for apoptosis and dual-fluorescence staining for apoptosis and endothelial cells were carried out in jejunal cross-sections at 4 h postirradiation. Results: Most apoptotic cells were in the crypt epithelium. The number of TUNEL-positive nuclei per villus was low (1.62 ± 0.03, mean ± SEM) for all irradiation modalities and showed no dose–response as a function of blood vessel dose, even as the dose crossed the threshold for death from the GI syndrome. Dual-fluorescence staining for apoptosis and endothelial cells verified the TUNEL results and identified the apoptotic nuclei in the villi as CD45-positive leukocytes. Conclusion: These data do not support the hypothesis that vascular endothelial cell apoptosis is the cause of the GI syndrome.

Carboranes represent a potentially rich but underutilized class of inorganic and catabolism-inert pharmacophores. The regioselectivity and ease of derivatization of carboranes allows for facile syntheses of a wide variety of novel structures. The steric bulk, rigidity, and ease of B- and C-derivatization and lack of π-interactions associated with hydrophobic carboranes may be exploited to enhance the selectivity of previously identified bioactive molecules. Transthyretin (TTR) is a thyroxine-transport protein found in the blood that has been implicated in a variety of amyloid related diseases. Previous investigations have identified a variety of nonsteroidal antiinflammatory drugs (NSAIDs) and structurally related derivatives that imbue kinetic stabilization to TTR, thus inhibiting its dissociative fragmentation and subsequent aggregation to form putative toxic amyloid fibrils. However, the cyclooxygenase (COX) activity associated with these pharmaceuticals may limit their potential as long-term therapeutic agents for TTR amyloid diseases. Here, we report the synthesis and evaluation of carborane-containing analogs of the promising NSAID pharmaceuticals previously identified. The replacement of a phenyl ring in the NSAIDs with a carborane moiety greatly decreases their COX activity with the retention of similar efficacy as an inhibitor of TTR dissociation. The most promising of these compounds, 1-carboxylic acid-7-[3-fluorophenyl]-1,7-dicarba- closo -dodecaborane, showed effectively no COX-1 or COX-2 inhibition at a concentration more than an order of magnitude larger than the concentration at which TTR dissociation is nearly completely inhibited. This specificity is indicative of the potential for the exploitation of the unique properties of carboranes as potent and selective pharmacophores.

A novel homotrifunctional conjugation reagent, 1,3,5-tris-( N -maleimidomethyl)benzene has been synthesized in high yield with minimum purification. The reactivity of this compound was examined by using l -cysteine as a nucleophile.

The scope and limitations of the alkylation of [closo-B12(OH)12]2- using a series of fourteen alkyl and aralkyl halides and two p-toluenesulfonic acid esters in the presence of N,N-diisopropylethylamine have been investigated. The dodecaalkoxy-closo-dodecaborate products, [closo-B12(OR)12]2-, and their hypercloso two-electron oxidation products have been explored. The species [closo-B12(OR)12]2- containing 26 cage-bonding electrons may undergo two reversible, sequential, one-electron oxidation processes, producing a 25-electron radical anion and a 24-electron neutral species. Several oxidizing reagents were investigated for the chemical oxidation of [closo-B12(OR)12]2- and [hypercloso-B12(OR)12]- to [hypercloso-B12(OR)12]. Both FeCl3.6H2O and K3Fe(CN)6 in 90/5/5 ethanol/acetonitrile/H2O were found to be the reagents of choice. The reverse reaction leading from the neutral species to the radical anion and subsequently to the dianion was achieved using sodium borohydride in ethanol. A variety of alkoxyl derivatives have been synthesized by heating the reactants for extended periods of time in acetonitrile at the reflux temperature. The use of elevated reaction temperatures attained by employing moderate argon pressure (autoclave) over the reaction mixture led to drastic reductions in reaction times and increased efficiency. X-ray diffraction studies of substituted dodecabenzyl ether derivatives proved that 2(2-) has approximate Ih symmetry while hypercloso-2, -3, -9, -11, -12, and -13 have approximate D3d point group symmetry due to Jahn-Teller distortion from Ih.

A mild protocol for the palladium-catalyzed Buchwald-Hartwig amidation of icosahedral carboranes is described. Employing 2-dicyclohexylphosphino-2'-(N,N-dimethylamino)biphenyl (1) as a ligand and K(3)PO(4) as a base, benzamide, trifluoroacetamide, acetamide, and formamide were coupled to a series of mono- and di-iodo carboranes furnishing the respective carborane derivatives in good to excellent yields. Subsequent base-mediated saponification of the trifluoroacetamide derivatives was shown to provide the free aminocarboranes. The structures of N-(1,7-dicarba-closo-dodecaboran-9-yl)benzamide (8a), N-(1,7-dicarba-closo-dodecaboran-9-yl)trifluoroacetamide (8b), N-(1,12-dicarba-closo-dodecaboran-2-yl)benzamide (10a), N-(1,2-dicarba-closo-dodecaboran-9-yl)benzamide (12a), N-(1,2-dicarba-closo-dodecaboran-9-yl)acetamide (12c), N-(1,2-dicarba-closo-dodecaboran-9-yl)formamide (12d), N-(1,2-dicarba-closo-dodecaboran-3-yl)benzamide (13a), N,N'-(1,7-dicarba-closo-dodecaboran-9,10-diyl)dibenzamide (15a), and N,N'-(1,7-dicarba-closo-dodecaboran-9,10-diyl)bis(trifluoroacetamide) (15b) have been established through X-ray single-crystal diffraction studies.

Aromatic polyhedral boranes and carboranes lend themselves to the construction of nanoesque structures suited for unique applications. These include cyclic, water-soluble hosts having a lipophilic core; self-assembling nanorods and bilayer membranes using amphiphilic carborane derivatives; and the huge family of functional structures obtainable from the [closo-B 1 2 (OH) 1 2 ] 2 - by derivatization of the hydroxyl groups. The latter species are potentially useful for molecular delivery devices important to biomedicine and material science. New developments in each of these areas of interest will be presented.

A 14-month-old girl with a virtual arrest in development at a 3-month stage was found to have methylmalonic acidemia. She was unresponsive to large doses of B12 or of dimethylbenzimadazole cobamide. Dietary therapy was devised to restrict protein containing isoleucine, threonine, valine, and methionine to the amounts required for growth. She had a dramatic response both clinically and chemically. Catch-up somatic growth was matched by growth in head size and intellectual development. These observations indicate that marked improvement in brain function may occur during the treatment of metabolic disease, even well after a year of age.

Cystic fibrosis (CF) of the pancreas was initially thought to be an inborn error of metabolism affecting only exocrine tissue. In 1969, the demonstration by Danes and Bearn1 of metachromasia in cultivated fibroblasts obtained from patients with CF gave experimental support to the hypothesis that all CF cells reflect the basic biochemical defect. After this initial report several investigators observed that tissue cultured cells from some patients with CF and heterozygotes accumulated increased quantities of acid mucopolysaccharides and glycogen. No basic defect in these cell culture systems has been identified. No definitive test for the detection of the heterozygote state is available. See table in the PDF file

A newborn infant presented with bloody stools at birth associated with swallowing maternal blood following partial abruption of the placenta. Hyperbilirubinemia appeared in the first 12 hours of life, and the usual causes were excluded. The postulate is made that the hyperbilirubinemia was the result of the absorption of heme from the ingested maternal blood.

A method is here described for the study of RNA methyla tion in short-term lymphocyte cultures. Results from CF heterozygotes and homozygotes as well as normals suggest that undermyethylation of RNA occurs in both heterozygotes and homozygotes for the cystic fibrosis gene, and that this occurrence reflects the basic defect in this disorder.

• Dyskeratosis congenita (DCG) is a rare genodermatosis characterized primarily by reticular hyperpigmentation of the skin, dystrophy of the nails, and leukoplakia. It is frequently associated with Fanconi-type pancytopenia. Although DCG has a male predisposition, it has been reported in several female patients. We encountered a case of DCG occurring in a girl whose clinical features simulated chronic graft-vs-host disease (GVHD). Because DCG and chronic GVHD share several clinical and histologic features, physicians should always examine a patient for possible DCG whenever a diagnosis of chronic GVHD is considered. In addition, the similar manifestations of the two disorders suggest a similar pathogenesis on a cellular level in the immunologic system. (Arch Dermatol1985;121:1424-1428)