Ecological half-life of radiocesium in white-tailed deer on the Department of Energy's Savannah River Site: What can a half century of field monitoring tell us?

This paper estimates the ¹³⁷Cs ecological half-life of white-tailed deer inhabiting the Department of Energy's Savannah River Site (SRS) based on sex and age using data collected over a 51-year time-period. With a physical half-life of 30.2 yr, the biological half-life for the deer herd is considerably shorter because of the isotope's biochemical mimicry of K+ inside the body. Leveraging this long-term dataset and robust sample size, we compared the long-term half-century estimates to shorter decadal increments. The simple exponential decay model for the entire 51-year sampling period predicted an ecological half-life of 23.15 years. When breaking the sample data into decadal increments ¹³⁷Cs body burden had complex temporal dynamics with predicted half-lives ranging from 9.25 to 32.33 years. Exponential decay for the entire 51-year sampling period for models evaluated by sex, age, sex*age to determine how these variables influence the predictability in the mean depuration rate, the ecological half-lives were between 21 and 23 years for all permutations, except for fawns that had a half-life no different than the physical half-life of the isotope itself. Differential habitat use and competition most likely explains why both yearling and adult females consistently had higher body burdens than males over the 51-year time period, showing how dynamic this radioisotope is in biological systems. This study is one of the most robust long-term datasets in the world (n = 42,412) that is specifically focused on monitoring the uptake and depuration of ¹³⁷Cs in a wild species.

Design and synthesis of novel conformationally restricted HIV protease inhibitors

A set of HIV protease inhibitors represented by compound 2 has previously been described. Structural and conformational analysis of this compound suggested that conformational restriction of the P1/P2 portion of the molecule could lead to a novel set of potent protease inhibitors. Thus, probe compounds 3-7 were designed, synthesized, and found to be potent inhibitors of HIV protease.

Design, synthesis, and conformational analysis of a novel series of HIV protease inhibitors

A combination of structure-based design and both solution, and solid-phase synthesis were utilized to derive a potent (nM) series of HIV-1 protease inhibitors bearing a structurally novel backbone. Detailed structural analysis of several inhibitors prepared in this series has suggested that rigidification of the P1/P2 region of this class of molecules may result in compounds with improved potency.

Separate clones in concomitant multiple myeloma and a second B-cell neoplasm demonstrated by molecular and immunophenotypic analysis

The occurrence of multiple myeloma (MM) and a second B-cell neoplasm in the same patient is a rare event. We present 2 such patients, and provide evidence to support the presence of separate clones in these coexisting neoplasms. In the first case, MM became evident 14 months after the diagnosis of chronic lymphocytic leukemia (CLL). In past reports, most occurrences of this association, when investigated, have been regarded to be biclonal disease processes; however, with few exceptions, most were documented by immunologic studies alone. To establish the clonality in our case of CLL with MM, we examined both immunophenotypic data obtained by standard two-color flow cytometric analysis, and patterns of immunoglobulin gene rearrangement, using standard Southern analysis and hybridization with 32P-labelled JH and JK probes. This provided evidence for the presence in this patient of two separate monoclonal populations of B cells, manifested as light chain restrictions and gene rearrangements which differed in blood (CLL) and bone marrow (MM) samples. In the second case, MM presented simultaneously with bone marrow lymphocytosis and abnormal peripheral lymphocytes. Clonality studies on blood were not done. Bone marrow B-cell gene rearrangement studies, however, revealed the presence of three bands in the JK blot of significantly different intensities, suggestive of two monoclonal populations. A monoclonal population of small cells with surface B markers and surface IgM was demonstrated by flow cytometry, while a second population of larger cells with intracytoplasmic IgG matching the patient's serum monoclonal protein was detected by immunofluorescence microscopy. The results in these 2 cases expand previous findings of the rare association of MM with a second B-cell neoplasm, and demonstrate the usefulness of molecular diagnostic investigation.

Synthesis and pharmacological evaluation of 4a-phenanthrenamine derivatives acting at the phencyclidine binding site of the N-methyl-D-aspartate receptor complex

A novel series of octahydrophenanthrenamines and their heterocyclic analogues have been synthesized as potential noncompetitive antagonists of the N-methyl-D-aspartate (NMDA) receptor complex. The compounds were evaluated for their affinity at the phencyclidine (PCP) binding site by determining their ability to displace [3H]TCP from crude rat brain synaptic membranes. A wide range of affinities were observed, with the most potent analogs possessing IC50's equivalent to that of the reference agent MK-801 (3, dizocilpine). NMDA antagonist activity was demonstrated by prevention of glutamate-induced accumulation of [45Ca2+] in cultured rat cortical neurons. Selected compounds were also studied in vivo to determine their ability to prevent the lethal effects of systemically injected NMDA in the mouse. In general, the SAR of the phenanthrenamine series may be summarized as follows: (a) for the amino group at C4a, NHMe > NH2 > NHEt >> NC5H10; (b) for the B-ring substitution, X = CH2 > S > O; (c) unsaturation of the C ring decreases receptor affinity; (d) cis-ring fusion between the B and C rings is desirable; (e) 6-hydroxy or 6-methoxy substitution of the phenanthrenamine system identified an additional hydrogen bonding interaction that substantially increased receptor affinity; (f) spiro analogues (such as 55, IC50 = 3400 nM), which altered the point of attachment of the C ring, caused a substantial reduction in PCP-site affinity. Molecules from this series were useful for refining a pharmacophore model consistent with previous models of the PCP site. In this model, the (R)-(+)-phenanthrenamine 13 superimposes closely onto MK-801 (3), and the angular 4a-amino group is believed to hydrogen bond with a putative receptor site atom. In the phenanthrenamine and thiaphenanthrenamine series, the (R)-(+)-enantiomers (9, 13, and 44) are more potent by approximately 5-10-fold than their corresponding (S)-(-)-enantiomers with respect to their affinity for the PCP site, their ability to prevent accumulation of [45Ca2+] in cultured neuronal cells, and their protection against the lethal effects of NMDA in mice. In general, there was no separation between the dose that prevented NMDA lethality and the dose that produced ataxia in mice, except in the case of the thiaphenanthrenamines 41 and 43. We have not yet obtained evidence that this small separation in activity offers a therapeutic advantage in the treatment of cerebral ischemia or other neurodegenerative disorders.

Synthesis and pharmacological evaluation of hexahydrofluorenamines as noncompetitive antagonists at the N-methyl-D-aspartate receptor

The noncompetitive (PCP) site of the N-methyl-D-aspartate (NMDA) receptor complex has been implicated in a number of pathologies, including the etiology of ischemic stroke. Recent testing has shown that cis-1,2,3,4,9,9a-hexahydro-N-methyl-4aH-fluoren-4a-amine (1), a rigid analog of PCP, is a potent antagonist at this site (IC50 = 30 nM for displacement of [3H]TCP). On the basis of this finding, a number of derivatives encompassing variations in stereochemistry, amine substitution and position, aromatic and aliphatic ring substitution, and heteroatom ring substitution have been prepared to explore the structure-activity relationships around this ring system. All compounds were evaluated for their PCP receptor affinity; potent compounds were also tested in vitro (cultured neurons) and in vivo (prevention of NMDA-induced lethality in mice). The present hexahydrofluorenamines demonstrated a wide range of potencies, with optimal affinity concentrated in analogs containing a heteroatom (sulfur) in the B ring (IC50 of 11 nM versus [3H]TCP for 16b), methyl substitution on the amine, and R stereochemistry at the 4a position. No significant improvement in affinity was seen with aromatic ring substitution. Aliphatic ring substitution, large amine substituents, and alterations in the position of amine substitution on the ring system resulted in a loss of potency. To explore the effect of simultaneous hydrogen bonding with a putative receptor atom from two directions, the 2-hydroxymethyl derivatives were prepared. This substitution resulted in a loss in receptor binding affinity. Molecular modeling, X-ray, and NMR studies have been used to determine an optimal conformation of the hexahydrofluoreneamines at the receptor site.

Necrobiotic xanthogranuloma with myocardial lesions and nodular transformation of the liver

A 73-year-old woman with a history of necrobiotic xanthogranuloma (NXG) with paraproteinemia died suddenly while hospitalized for bronchitis and congestive heart failure. At postmortem examination, myocardial lesions histologically typical of NXG were found. This is the fifth reported autopsy of a patient with NXG. In all five autopsied cases, and in two additional surgical cases, necrobiotic granulomas of internal viscera were present, and in three cases the myocardium was involved. In addition, our patient had nodular transformation of the liver, a rare lesion that was also reported in one of the previous autopsy cases with NXG.

Report of fourteen cases of nonimmune hydrops fetalis in association with hemorrhagic endovasculitis of the placenta

Hemorrhagic endovasculitis of the placenta is a distinct vasodestructive process of unknown cause that has been associated with perinatal morbidity and mortality. A relationship between nonimmune hydrops fetalis and hemorrhagic endovasculitis has not been previously described. At a large teaching hospital, six cases of nonimmune hydrops fetalis were identified out of 72 cases of hemorrhagic endovasculitis over 6 years, for an incidence of 8%. Conversely, these same six cases represented 24% of the 25 cases of nonimmune hydrops fetalis from this time period. Eight additional cases of nonimmune hydrops fetalis were found among 2064 cases of hemorrhagic endovasculitis at the Michigan Placental Tissue Registry. In eight of the total 14 cases, after congenital malformations and cytomegalovirus infections were excluded, hemorrhagic endovasculitis was the only significant associated pathologic finding evident. The significance of the relationship between nonimmune hydrops fetalis and the vascular abnormalities of hemorrhagic endovasculitis remains to be determined.

New and versatile approaches to the synthesis of CPP-related competitive NMDA antagonists. Preliminary structure-activity relationships and pharmacological evaluation

Fourteen new CPP analogues have been prepared with methyl 1-(phenylmethyl) (+/-)-1,2-piperazinedicarboxylate 3 as a versatile synthetic intermediate. Derivatives were evaluated as NMDA ligands by their ability to displace [3H]CPP from rat cortical membranes. The binding affinity of various chain lengths at the N4-position of the CPP analogues, 5a, 5b, and 9a mimics the binding affinity observed for the acyclic derivatives AP6, AP8, and AP5. Analogue 9a, with a single methylene group in its phosphonate side chain, exhibited diminished affinity for the NMDA receptor when compared to the structurally similar piperidine compound CGS 19755. Replacement of the phosphonic acid moiety with monoionizable acidic groups such as a carboxylate or a phosphinate resulted in a reduction of binding affinity. An aryl spacer between the N4-nitrogen and the distal acidic group was detrimental to binding as was alkylation at the N1-position. Steric bulk, however, was better tolerated when a phenyl group was positioned alpha to the phosphonate, as seen with analogues 21 and 22.

Charcot-Leyden crystals in pleural fluids

Charcot-Leyden crystals have rarely been reported in serous fluids. We present eight examples of Charcot-Leyden crystals, all found in eosinophilic pleural effusions. The crystals were found in toluidine blue-stained wet films of pleural fluid after either the fluid or the wet film had stood for at least 24 hours at 4 C.

Curschmann's spirals in cervicovaginal smears. Prevalence, morphology, significance and origin

A retrospective examination of 172,119 cervical and vaginal smears was undertaken to study the prevalence, morphology, significance and origin of Curschmann's spirals in such specimens. Spirals morphologically identical to those seen in sputum were found in 101 specimens from 100 patients, for a prevalence of 1 in 1,704 smears. Spirals were found only in patients who had not had their cervices removed. The presence of the spirals could not be correlated with any particular gynecologic or nongynecologic abnormality. Most of the patients had no gynecologic abnormality. The literature contains suggestions that Curschmann's spirals in cervicovaginal smears are a manifestation of orogenital sexual contact or are formed in endocervical mucus, particularly in cigarette smokers. To investigate whether such spirals have an extraneous origin, we examined the smears for dust-containing histiocytes, vegetable cells, skeletal muscle fibers and other extraneous material, none of which was found. We found no correlation between the presence of spirals and cigarette smoking. Moreover, histologic sections of the uterine cervices from some of the patients who had spirals in their smears showed evidence of spiral formation in endocervical mucus. We conclude that Curschmann's spirals in cervicovaginal smears are an uncommon finding with no clinical significance, that they are formed from endocervical mucus and that their presence has nothing to do with orogenital sexual contact or cigarette smoking.

Cytopathology, including transmission and scanning electron microscopy, of pleomorphic liposarcomas in pleural fluids

Liposarcoma cells in pleural fluid from two patients with metastatic pleomorphic liposarcoma are described. The major diagnostic feature of such specimens, perceivable by light microscopy, is the presence of solitary, pleomorphic giant cells with cytoplasmic vacuoles. In some cells, transmission electron microscopy revealed numerous cytoplasmic lipidic droplets. With scanning electron microscopy, the cellular surfaces were markedly pleomorphic, with ruffles, blebs and long, thin processes.