Effects of pericardiectomy on training- and myocardial infarction-induced left ventricular hypertrophy, chamber dimensions and gene expression.

The primary purpose of the study was to evaluate whether a pericardiectomy (PERI) alters training- or myocardial infarction (MI)-induced left ventricular hypertrophy (LVH), chamber geometry, gene expression and/or running performance. Mice were randomized into 6 groups: naïve control (CONT)-sedentary (Sed), CONT-trained (Tr), PERI-Sed, PERI-Tr, MI-Sed and MI-Tr. MI mice also received a pericardiectomy as part of the MI surgical procedure. 10 weeks of treadmill running resulted in enhanced running performance-to-exhaustion in all 3 trained groups (CONT-Tr, PERI-Tr, MI-Tr) compared to sedentary cohorts (P<0.001). Training also resulted in similar increases in normalized LVH (LV/BW) in CONT-Tr and PERI-Tr mice. 2D-echocardiographic evaluation of LV internal chamber dimensions revealed that stroke diameter (SD) was larger in PERI compared to MI (P<0.01) but not CONT mice. Ventricular B-type natriuretic peptide mRNA (BNP) was elevated only in the 2 MI groups. Left ventricle ß1-adrenergic receptor (ß1-AR) and melusin transcripts both demonstrated an overall increase in trained compared to sedentary mice (both P<0.05). Additionally long-term pericardiectomy did not further enhance running performance or increase LV/BW in either sedentary or trained mice.

Number of portal tract macrophages correlates with the modified hepatic activity index in chronic hepatitis C infection.

The Ishak modified hepatic activity index (mHAI) is widely used to score disease activity in chronic hepatitis C infection. However, the scoring of the mHAI components is subjective and prone to interobserver variation. Liver injury results in increased numbers of portal tract macrophages, which are easily identified via periodic acid-Schiff with diastase digestion stain. Evaluation of 30 liver biopsies from patients with chronic hepatitis C revealed increasing numbers of portal tract macrophages as scores of liver inflammation increased. Specifically, the number of PASD-positive portal tract macrophages per centimeter of biopsy length correlated with the level of portal inflammation and total mHAI score, and these correlations were statistically significant (P = .039 and .029, respectively). Although the portal macrophage count appeared to correlate with the interface activity and lobular necroinflammatory score, this did not meet statistical significance (P = .073 and .079, respectively). Interobserver agreement by κ analysis was greater for the portal macrophage count than for any individual component of the mHAI score. In summary, the number of periportal ceroid-laden macrophages correlates with liver inflammation as measured using the mHAI, with better interobserver agreement. This technique may serve as a useful adjunct to the mHAI in the assessment of liver injury in hepatitis C.

DDT: sublethal effects on brook trout nervous system.

When brook trout are exposed for 24 hours to sublethal doses of DDT, the cold-blocking temperature for a simple reflex, which shows lability related to thermal history, is altered in a way suggesting that DDT is aflecting the thermal acclimation mechanism. Sublethal dosage of DDT also prevents the establishment of a visual conditioned avoidance response.

Vac1p coordinates Rab and phosphatidylinositol 3-kinase signaling in Vps45p-dependent vesicle docking/fusion at the endosome.

The vacuolar protein sorting (VPS) pathway of Saccharomyces cerevisiae mediates transport of vacuolar protein precursors from the late Golgi to the lysosome-like vacuole. Sorting of some vacuolar proteins occurs via a prevacuolar endosomal compartment and mutations in a subset of VPS genes (the class D VPS genes) interfere with the Golgi-to-endosome transport step. Several of the encoded proteins, including Pep12p/Vps6p (an endosomal target (t) SNARE) and Vps45p (a Sec1p homologue), bind each other directly [1]. Another of these proteins, Vac1p/Pep7p/Vps19p, associates with Pep12p and binds phosphatidylinositol 3-phosphate (PI(3)P), the product of the Vps34 phosphatidylinositol 3-kinase (PI 3-kinase) [1] [2]. Here, we demonstrate that Vac1p genetically and physically interacts with the activated, GTP-bound form of Vps21p, a Rab GTPase that functions in Golgi-to-endosome transport, and with Vps45p. These results implicate Vac1p as an effector of Vps21p and as a novel Sec1p-family-binding protein. We suggest that Vac1p functions as a multivalent adaptor protein that ensures the high fidelity of vesicle docking and fusion by integrating both phosphoinositide (Vps34p) and GTPase (Vps21p) signals, which are essential for Pep12p- and Vps45p-dependent targeting of Golgi-derived vesicles to the prevacuolar endosome.

Self-association of a DNA loop creates a quadruplex: crystal structure of d(GCATGCT) at 1.8 A resolution.

BACKGROUND: The flexibility of DNA enables it to adopt three interconvertible types of duplex termed the A-, B- and Z-forms. It can also produce hairpin loops, triplex structures and guanine-rich quadruplex structures. Conformational flexibility assists in the tight packaging of DNA, for example in chromosomes. This is important given the large quantity of genetic information that must be packaged efficiently. Moreover, the ability of DNA to specifically self-associate or interact with complementary sequences is fundamental to many biological processes. Structural studies provide information about DNA conformation and DNA-DNA interactions and suggest features that might be relevant to how the molecule performs its biological role. RESULTS: We have characterized the structure of a synthetic heptanucleotide that folds into a novel loop structure. The loop is stabilized by association with a cation, by intra-strand hydrogen bonds between guanine and cytosine that are distinct from the normal Watson-Crick hydrogen bonds, and by van der Waals interactions. Two loops associate through the formation of four G.C pairs that exhibit pronounced base-stacking interactions. The formation of a symmetric A.A base pair further stabilizes loop dimerization. Stacking of the A.A pair on a symmetry-related A.A pairing assists the formation of a four-stranded assembly. A T.T pairing is also observed between symmetry-related loops. CONCLUSIONS: This analysis provides a rare example of an experimentally determined non-duplex DNA structure. It provides conformational detail relevant to the tight packaging or folding of a DNA strand and illustrates how a cation might modulate phosphate-phosphate repulsion in a tightly packed structure. The observation of base quartets involving G.C base pairs suggests a further structure to be considered in DNA-DNA interactions. The structure also provides detailed geometries for A.A and T.T base pairs.

The three-dimensional structure of a Plasmodium falciparum cyclophilin in complex with the potent anti-malarial cyclosporin A.

Cyclosporin A (CsA) is a potent anti-malarial compound in vitro and in vivo in mice though better known for its immunosuppressive properties in humans. Crystal structures of wild-type and a double mutant Plasmodium falciparum cyclophilin (PfCyP19 and mPfCyP19) complexed with CsA have been determined using diffraction terms to a resolution of 2.1 A (1 A=0.1 nm). The wild-type has a single PfCyP19/CsA complex per asymmetric unit in space group P1 and refined to an R-work of 0.15 and R-free of 0.19. An altered cyclophilin, with two accidental mutations, Phe120 to Leu in the CsA binding pocket and Leu171 to Trp at the C terminus, presents two complexes per asymmetric unit in the orthorhombic space group P2(1)2(1)2. This refined to an R-work of 0.18 and R-free 0.21. The mutations were identified from the crystallographic analysis and the C-terminal alteration helps to explain the different crystal forms obtained. PfCyP19 shares approximately 61 % sequence identity with human cyclophilin A (hCyPA) and the structures are similar, consisting of an eight-stranded antiparallel beta-barrel core capped by two alpha-helices. The fold creates a hydrophobic active-site, the floor of which is formed by side-chains of residues from four antiparallel beta-strands and the walls from loops and turns. We identified C-H.O hydrogen bonds between the drug and protein that may be an important feature of cyclophilins and suggest a general mode of interaction between hydrophobic molecules. Comparisons with cyclophilin-dipeptide complexes suggests that a specific C-H.O hydrogen bonding interaction may contribute to ligand binding. Residues Ser106, His99 and Asp130, located close to the active site and conserved in most cyclophilins, are arranged in a manner reminiscent of a serine protease catalytic triad. A Ser106Ala mutant was engineered to test the hypothesis that this triad contributes to CyP function. Mutant and wild-type enzymes were found to have similar catalytic properties.

Seasonality of schizophrenic births in the United States.

The birth months of persons later diagnosed as schizophrenic were studied. Data were collected from 19 states on 53,584 schizophrenics born between 1920 and 1955. The controls were the general births in the same states for the same years. A highly significant peak in schizophrenic births was found from December to May, most marked in March and April. The seasonality was stronger in New England and the Midwest than in the South. Previous studies of schizophrenic births are also reviewed. The cumulative evidence would appear to establish more firmly a winter and spring seasonality of schizophrenic births in northern Europe and the eastern United States. Selection of patients, nutritional factors, environmental factors, genetic factors, and infectious agents are discussed as possible etiological explanations.

A mammalian homologue of SLY1, a yeast gene required for transport from endoplasmic reticulum to Golgi.

We characterized rat cDNAs that predict a protein, r-Sly1, which is similar to SLY1, a yeast protein that plays a critical role in endoplasmic reticulum to Golgi apparatus vesicle trafficking. The r-Sly1 gene is expressed in all tissues examined.

The structure and fragmentation of B n (n≥3) ions in peptide spectra.

The unimolecular and low energy collision-induced fragmentation reactions of the MH(+) ions of N-acetyl-tri-alanine, N-acetyl-tri-alanine methyl ester, N-acetyl-tetra-alanine, tetra-alanine, penta-alanine, hexa-glycine, and Leu-enkephalin have been studied with a particular emphasis on the formation and fragmentation of B n (n=3,4,5) ions. In addition, the metastable ion fragmentation reactions of protonated tetra-glycine, penta-glycine, and Leu-enkephalin amide have been studied. B n ions are prominent stable species in all spectra. The B n ions fragment, in part, by elimination of CO to form A n ions; this reaction occurs on the metastable ion time scale with a substantial release of kinetic energy (T 1/2=0. 3-0. 5 eV) that indicates that a stable configuration of the B n ion fragments by way of a reacting configuration that is higher in energy than the fragmentation products, A n + CO. Ab initio calculations strongly suggest that the stable configuration of the B3 and B4 ions is a protonated oxazolone formed by interaction of the developing charge with the next-nearest carbonyl group as HX is lost from the protonated species H-(Yyy) n -X · H(+). The higher B n ions also fragment, in part, to form the next-lower B ion, presumably in its stable protonated oxazolone form. This reaction is rationalized in terms of the three-dimensional structure of the B n ions and it is proposed that the neutral eliminated is an α-lactam.

Why Are B ions stable species in peptide spectra?

Protonated amino acids and derivatives RCH(NH2)C(+O)X · H(+) (X = OH, NH2, OCH3) do not form stable acylium ions on loss of HX, but rather the acylium ion eliminates CO to form the immonium ion RCH = NH 2 (+) . By contrast, protonated dipeptide derivatives H2NCH(R)C(+O)NHCH(R')C(+O)X · H(+) [X = OH, OCH3, NH2, NHCH(R″)COOH] form stable B2 ions by elimination of HX. These B2 ions fragment on the metastable ion time scale by elimination of CO with substantial kinetic energy release (T 1/2 = 0.3-0.5 eV). Similarly, protonated N-acetyl amino acid derivatives CH3C(+O)NHCH(R')C(+O)X · H(+) [X = OH, OCH3, NH2, NHCH(R″)COOH] form stable B ions by loss of HX. These B ions also fragment unimolecularly by loss of CO with T 1/2 values of ∼ 0.5 eV. These large kinetic energy releases indicate that a stable configuration of the B ions fragments by way of activation to a reacting configuration that is higher in energy than the products, and some of the fragmentation exothermicity of the final step is partitioned into kinetic energy of the separating fragments. We conclude that the stable configuration is a protonated oxazolone, which is formed by interaction of the developing charge (as HX is lost) with the N-terminus carbonyl group and that the reacting configuration is the acyclic acylium ion. This conclusion is supported by the similar fragmentation behavior of protonated 2-phenyl-5-oxazolone and the B ion derived by loss of H-Gly-OH from protonated C6H5C(+O)-Gly-Gly-OH. In addition, ab initio calculations on the simplest B ion, nominally HC(+O)NHCH2CO(+), show that the lowest energy structure is the protonated oxazolone. The acyclic acylium isomer is 1.49 eV higher in energy than the protonated oxazolone and 0.88 eV higher in energy than the fragmentation products, HC(+O)N(+)H = CH2 + CO, which is consistent with the kinetic energy releases measured.

A comparison of cervical pathology between United States Air Force women who did and did not serve in the Persian Gulf War.

PURPOSE: The purpose of this study was to look objectively at cervical cytological differences between women Gulf War female veterans (GWFV) and Gulf War-era active duty females not deployed to the Gulf (NDF) during Operation Desert Shield/Desert Storm using Pap smear results. METHODS: A cohort of 6715 active duty Air Force women who also served on active duty between August 7, 1990-March 1, 1991 provided at least one Pap smear as part of routine medical care during 1994. Of these, 1446 were identified as GWFV and 5269 were identified as NDF. Diagnoses were compared using Chi-square tests with Yate's continuity correction. RESULTS: There were no differences between the two groups, overall, in the diagnosis of other than within normal limits (OTWNL), the diagnoses of significant disease or in Bethesda system diagnoses in each of the three years for which comparisons were made. GWFV diagnosed in the 26-30 age group were significantly more likely to have a diagnosis of OTWNL than were NDF in the same age group in 1994. There were no differences between the two groups in any other age category. CONCLUSIONS: The data provide little support for the hypothesis that a difference exists between GWFV and NDF with respect to abnormal cervical cytology.

Estrogen increases hyperemic microvascular blood flow velocity in postmenopausal women.

BACKGROUND: Epidemiologic studies suggest that estrogen replacement therapy (ERT) is protective against vascular disease. ERT confers this benefit by lowering lipid levels and improving arterial function. However, its effect on the microvasculature in vivo is unknown. Thus the purposes of this study were to evaluate effect of estrogen status on the hyperemic response of the microvasculature in vivo in postmenopausal women and to compare the hyperemic response of the microvasculature in postmenopausal women taking ERT with that of premenopausal women. METHODS: We measured forearm microvasculature flow velocity by using a laser Doppler in a cross section of 64 healthy premenopausal and postmenopausal women 23 to 72 years old. Microvasculature blood flow velocity was measured at baseline. throughout 2 minutes of ischemia, and immediately after the ischemic period was terminated (i.e., during the peak hyperemic response). RESULTS: The peak of the hyperemic flow velocity (PHFV) in the postmenopausal women who were taking long-term ERT at usual doses was greater than that of postmenopausal women who were not currently taking ERT (p < .0001). Moreover, the PHFV of postmenopausal women taking ERT was similar to that of premenopausal women. Multivariate regression analysis showed estrogen status and baseline flow velocity to be independent predictors of PHFV. CONCLUSIONS: Current, long-term ERT at usual replacement doses is associated with improved microvascular responses in postmenopausal women, which may explain some of its beneficial vascular effects.

Pyogenic granulomas of the cornea.

Pyogenic granulomas are vasoproliferative, inflammatory lesions composed of granulation tissue, which occur on cutaneous or mucosal tissues, often arising secondary to other processes such as trauma or infection. Conjunctival pyogenic granulomas are not rare, but corneal involvement is very unusual and can occasionally lead to problems in the differential diagnosis of corneal masses. We report three cases of pyogenic granuloma involving the cornea. The clinicopathologic features of these cases and a review of the literature on the ocular manifestations of this condition are presented.

D1-dopamine receptor agonists selectively activate striatal c-fos independent of rotational behaviour.

L-Dopa and dopaminergic agonists selective for the D1- or D2-dopamine receptor subtype induce contraversive rotation in rats which have been unilaterally lesioned with injections of 6-hydroxydopamine (6-OHDA) into the substantia nigra. D-Amphetamine, which releases dopamine from neurones on the unlesioned side of the animal, causes ipsiversive rotation. These increases in rotational behaviour are mediated, at least in part, by dopamine receptors in the striatum. In unilaterally lesioned animals, L-dopa and the D1-selective agonists SKF 38393 and CY 208-243 produce contralateral rotation and induction of the nuclear proto-oncogene c-fos in the lesioned striatum. D-Amphetamine induces both ipsilateral rotation and c-fos activation in the intact striatum. Three lines of evidence, however, dissociate fos induction and rotation. First, LY 171555, a selective D2-dopamine receptor agonist, also induces contraversive rotation but this rotation is not accompanied by c-fos activation in striatum. Second, D1-dopamine agonists produce activation of striatal c-fos even if rotation is prevented by an anaesthetic. Third, rotation induced by injection of SKF 38393 into substantia nigra is not accompanied by c-fos induction. These results suggest a mechanism by which D1-dopamine receptor mechanisms may regulate long-term changes in dopaminergic systems.

Synergistic and persistent interaction between the D2 agonist, bromocriptine, and the D1 selective agonist, CY 208-243.

In mice pretreated with reserpine and alpha-methyl-DL-p-tyrosine (alpha MPT) to deplete central catecholamines, the D2 dopamine receptor-selective agonist, bromocriptine, at a dose of 10 mg/kg produced no locomotor activity. The D1-selective agonist, CY 208-243, generated a dose-dependent locomotor response in this animal model for Parkinson's disease; low doses elicited little or no effect while higher doses resulted in a short burst of locomotor activity (2 h). The combination of CY 208-243 and bromocriptine had a dramatic synergistic effect on locomotion. Most importantly, this combination of D1 and D2 agonists converted a brief (2 h) effect on locomotion to one which persisted for up to 6 h. These results suggest that the combination of D1 and D2 dopamine receptor agonists can affect both the intensity and the persistence of a locomotor response.

A partial agonist at the anticonvulsant benzodiazepine receptor: reversal of the anticonvulsant effects of Ro 15-1788 with CGS-8216.

A benzodiazepine antagonist (Ro 15-1788) prevents the development of kindled seizures. CGS-8216, another benzodiazepine antagonist, prevents DMCM-induced seizures (indicating that CGS-8216 acts at a benzodiazepine receptor) but has no effect on kindling or kindled seizures. CGS-8216 prevents the anticonvulsant actions of Ro 15-1788 suggesting that Ro 15-1788 is a partial agonist at an anticonvulsant benzodiazepine receptor. These results support that idea of of distinct, separate receptors for anticonvulsant and sedative effects of benzodiazepines.

Effect of dopaminergic agents on levels of dynorphin1-8 in rat striatum.

In this study, the possibility that striatal dynorphin1-8 levels would be altered by either acute or chronic treatment with dopaminergic agonists or antagonists is examined. Animals were treated chronically (3 weeks) with daily injections of d-amphetamine, phencyclidine or haloperidol. For the acute studies, animals were given a single dose of either d-amphetamine or haloperidol. Dynorphin1-8 levels were estimated using a radioimmunoassay. Only chronic treatment with d-amphetamine has any effect on dynorphin1-8 levels. Following 3 weeks of chronic d-amphetamine, the level of dynorphin1-8 increased in 2 separate experiments. Acute d-amphetamine or haloperidol treatment or chronic haloperidol or phencyclidine treatment had no effect on striatal dynorphin1-8 levels. However, chronic (but not acute) d-amphetamine administration does produce a small increase in striatal dynorphin1-8 levels.

Serologic and animal inoculation studies of a communal outbreak of viral hepatitis, type A.

Sera from individuals in an outbreak of viral hepatitis in a multifamily household, probably spread by contaminated food, were studied for antibodies to hepatitis A virus (anti-HAV), and selected acute phase sera were inoculated into marmosets. Significant rises in anti-HAV titers between acute and convalescent sera occurred in all of 15 individuals in the outbreak who experienced serum enzyme elevations and in one of 14 individuals whose serum enzyme levels remained normal. The remaining 13 individuals in the latter group had antibody levels in both early and late sera compatible with residual immunity from prior HAV infections and correlating with resistance to reinfection. Groups of marmosets were infected with acute phase sera from two of the cases; in both instances the inoculated sera contained substantial levels of anti-HAV. The marmosets developed specific anti-HAV seroconversions as well as enzyme elevations.

The surgical pathology and cytopathology of US Persian Gulf War military veterans.

BACKGROUND: Tens of thousands of Persian Gulf War veterans (GWVs) have presented with medical symptoms since Operation Desert Shield and Operation Desert Storm. The Kuwait Registry at the Armed Forces Institute of Pathology was established to act as a repository for surgical pathology, cytopathology, and autopsy material from GWVs. OBJECTIVE: To identify conditions known to be endemic to the theater of operations in our cohort of GWVs. METHODS: The Kuwait Registry database was searched by computer for listed conditions endemic to the Persian Gulf region included in the registry through December 31, 1997. RESULTS: Of the 2582 patients in this cohort, 1 patient with hepatitis B and 15 patients with hepatitis C were identified. Other known endemic conditions of the Persian Gulf region were not found. CONCLUSIONS: Viral hepatitis (B and C), which is prevalent in the US population, was the only listed endemic condition identified in surgical pathology or cytopathology specimens in our cohort of GWVs.

A study of the lifetime occurrence of neoplasia and breed differences in a cohort of German Shepherd Dogs and Belgian Malinois military working dogs that died in 1992.

The population of U.S. Department of Defense military working dogs provides an opportunity to study the lifetime occurrence of neoplasia in 2 breeds of dogs--the German Shepherd Dog and the Belgian Malinois. Medical records were reviewed for all dogs that died or were euthanized in 1992 (135 German Shepherd Dogs and 106 Belgian Malinois). Histologically confirmed neoplasms were recorded. More than 30% of both breeds (41 German Shepherd Dogs and 33 Belgian Malinois) developed at least 1 primary neoplasm during their lives, with 10% developing more than 1 neoplasm. Nearly 57% of the neoplasms were benign, and approximately 43% were malignant. German Shepherd Dogs lived 9.7 years, on average, and Belgian Malinois lived 7.9 years, on average. Of the dogs that developed any neoplasm, Belgian Malinois had a mean age at 1st diagnosis that was 1.1 years younger and a mean age at 1st diagnosis of malignancy that was 1.7 years younger than those in German Shepherd Dogs. The risk of a malignancy being the cause of death or euthanasia of a Belgian Malinois was 4.21 times the risk in German Shepherd Dogs (95% CI: 1.32, 13.47). Seminoma was the malignancy that occurred most frequently. Hemangioma was the benign neoplasm that occurred most frequently. Veterinarians identified masses clinically at equal rates in both groups.