The normal color vision evaluated with FM 100-hue test

One hundred and twenty normal subjects (240 eyes) aged from 10 to 69 were tested with FM 100-hue test. They were divided into 6 groups according to their age. It was shown that there were no statistically significant difference in the total error score (TES) between the males and females or between the right and left eyes, but there existed some relationships between the TES and age. The total error score (TES) was the lowest in the 20-29 age group and increased gradually with aging. The analysis of the partial error score (PES) in each age group showed that the PES was the lowest in 20-29 age group and that the larger PES appeared around the axis of titan with age increasing.

Fukuyama type congenital muscular dystrophy with central-temporal EEG foci (rolandic spikes)

Central-temporal EEG foci (rolandic spikes) in three patients who satisfied all the diagnostic criteria for Fukuyama type congenital muscular dystrophy (FCMD) are reported. Clinically one case remained silent and two cases were accompanied by epileptic seizures, characterized as follows: 1) partial seizures with elementary motor symptomatology; 2) brief and rare seizures, but occasionally with frequent or prolonged convulsions; 3) seizures were easily induced by defined precipitating factors such as fever; 4) seizures could be quickly controlled by routine antiepileptic treatment. Electroencephalographically, the appearance of repetitive stereotyped diphasic spikes over central and mid-temporal areas were quite similar to those described in rolandic epilepsy. We believe that the EEG findings in our cases corroborate the postulation that the prognosis is as good in these severely brain-damaged children as in normal children in terms of recovery from the epilepsy.

[Fast identification of Salmonella by chemiluminescent photographic detection]

Salmonella anatis was identified by the chemiluminescent photographic detection technique established in this lab. The horseradish peroxidase labelled antibody was incubated with the bacteria immobilized on nitrocellulose film; after washing, the film was contacted with a filter paper with absorbed chemiluminescence substrate solution. Twenty minutes of exposure of the chemiluminescence produced to X-ray film gave the positive results. As few as one hundred bacteria could be detected in about 2h. The tests showed that the specificity of the method is good.

Mouse thymic dendritic cell subpopulations

Mouse thymic dendritic cells (DC) have been isolated after collagenase digestion, selection of the low-density cell fraction, then depletion of T-lineage cells and other non-DC by treatment with specific monoclonal antibodies (mAb) and removal with anti-Ig-coated magnetic beads. The resulting DC preparation represented 0.1-0.2% of total thymic cells and contained 70-80% DC. Flow cytometry analysis of MHC class II (MHC II) expression by DC showed that 40% of DC expressed intermediate levels of MHC II, and 60% expressed high levels of this marker. Moreover, immunofluorescent 2-colour staining allowed the characterization of two clearly distinguishable DC subpopulations: MHC IIinter DC were CD45hi, CD44hi, HSAhi, whereas MHC IIhi DC were CD45lo, CD44lo, HSAlo. These results are discussed with regard to the functional significance of MHC IIinter and MHC IIhi DC subpopulations in the mouse thymus.

[Quantitative perimetry for early diagnosis of open-angle glaucoma]

105 eyes were examined with the OCTUPUS 2000R automated perimeter. Of 19 glaucomatous eyes with abnormal visual fields by arc perimeter and campimeter, all showed field abnormalities by the quantitative perimetry, the defects being mostly of the mixed type (13/19), in the medium stage (10/19). Among 48 eyes of glaucoma or suspected glaucoma with normal visual fields by arc perimeter and campimeter, 33 showed field abnormalities by the quantitative perimetry, the defects being mostly of the mixed and diffuse type (29/33), in the early minor stage (23/33). The characteristic field defects were mostly sectorial and arcuate scotomata and some in the form of nasal steps. Among 38 normal eyes, minor local or diffuse field defects were found in 6 eyes.

The CD44 expressed on the earliest intrathymic precursor population functions as a thymus homing molecule but does not bind to hyaluronate

A minute population of cells representing the earliest lymphoid-restricted precursor cells in the adult mouse thymus has been isolated recently in our laboratory. This population expresses low levels of CD4, very high levels of CD44 and has a surface antigenic phenotype similar to that of bone marrow hemopoietic stem cells. To examine the role of CD44 on these cells, and to ascertain its ligand, we analysed the ability of the early thymic precursor cells to bind hyaluronate (HA) which functions as a cell adhesion molecule and a ligand for CD44. We also examined if anti-CD44 antibodies (clones IM7.8.1 and KM201) can block the thymic precursor activity. The majority of the thymic precursor cells did not show specific HA binding, indicating that HA is not the ligand for the CD44 molecules expressed on these precursor cells. HA and CD44 interactions are therefore unlikely to play a role in development of cells at this early intrathymic precursor stage. When the purified intrathymic precursor cells were incubated with anti-CD44 antibodies before intravenous transfer into recipients, very few progeny cells were detected in the thymus, although progeny were found in the spleen and lymph nodes. Coating the cells with other isotype-matched antibodies did not have this effect. However, when the same anti-CD44-coated cells were transferred directly into the recipient thymus, normal levels of progeny cells were detected in this organ. This suggests that the CD44 on the intrathymic precursor cells is a homing molecule, able to direct cells to the thymus but utilizing some ligand other than HA.

3'-end processing of the maize 27 kDa zein mRNA

Cis-regulatory elements involved in the mRNA 3'-end processing of the 27 kDa zein gene have been investigated by deletion and site-directed mutagenesis analyses. In the 3' flanking region of the 27 kDa zein gene, several AATAAA-like sequences and a sequence resembling the mammalian GT-rich sequence are present around the polyadenylation sites. Among the multiple AATAAA-like sequences, the duplicated AATGAA motifs, located 30-40 bp upstream from the polyadenylation sites, have been shown to play roles as polyadenylation signals. Although either of the two AATGAA motifs can function as a polyadenylation signal in chimeric gene constructs, the one proximal to the polyadenylation sites is likely to be the functional polyadenylation signal in the 27 kDa zein gene. Deletion of the downstream GT-rich sequence as well as alteration of the sequence surrounding the poly-adenylation sites has little effect on the mRNA 3'-end processing. However, the sequence elements located upstream from the polyadenylation signals are essential for the mRNA 3'-end processing. Mutations in the AATGAA motifs or the upstream sequences reduced the level of a reporter gene expression. A model depicting the mechanism involved in the 3'-end processing of the 27 kDa zein mRNA is presented.

An immunologic study on age-related macular degeneration

Forty-one patients with age-related macular degeneration (AMD) were detected for serum autoantibodies against normal human retinal protein by means of Western immunoblot analysis. Twenty-seven out of the 41 patients showed positive response, with a rate of 66 per cent. The positive rate of anti-retinal antibody in the AMD patients was significantly higher than that in normal controls (18%) and in patients with other retinal diseases (24%) (p < 0.0005). These antiretinal antibodies from the AMD patients partly reacted with the retinal protein of molecular weight between 28 and 32 Kd, partly with Mr of 38 to 42 Kd, 48 to 52 Kd, 62 to 65 Kd or 110 to 130 Kd. Of them, the antiretinal antibody against the protein with Mr of 28 to 32 Kd in the AMD patients was higher than in normal controls (p < 0.05). Two or more antibodies were found in the serum from AMD patients, showing a significant difference between the patients and the controls (p < 0.005). The results indicated that in the occurrence of AMD and/or during its developing process there were inflammation and immunological response, involving antibodies against retinal proteins of various molecular weight.

Neural effects of parathyroid hormone: modulation of the calcium channel current and metabolism of monoamines in identified Helisoma snail neurons

Neuronal effects of parathyroid hormone (PTH) have been reported in vertebrates. The effect of PTH on invertebrate central neurons within the buccal ganglion of Helisoma trivolvis snails was examined in the present study. By using a vibrating probe, PTH was found to induce a transient calcium-dependent inward current in intact buccal ganglia. Intracellular microelectrode recording revealed that PTH broadened the spontaneous action potential in buccal B5 neurons in situ. By using the whole-cell configuration of the patch-clamp technique, PTH was demonstrated to increase the N-like calcium channel currents in isolated B5 neurons in a concentration-dependent manner. This effect of PTH on the N-like calcium channel currents depended on the activation of a G protein insensitive to pertussis toxin, but was unlikely to be mediated by the cyclic AMP dependent protein kinase. Furthermore, the release of gamma-glutamyl conjugate of dopamine from buccal ganglia was selectively increased in the presence of PTH. These results represent the first demonstration that a vertebrate peptide hormone, PTH, selectively modulates the N-like voltage-dependent calcium channel currents in identified invertebrate neurons. Therefore, a novel role of PTH in the regulation of invertebrate central neural functions is indicated.

Cyclin A expression in normal and transformed alveolar epithelial cells

The mature adult alveolar epithelial cell (AEC) is a highly differentiated phenotype that does not readily divide and exhibits numerous specialized functions. Yet, transformed AEC proliferate aggressively in certain forms of lung cancer. Normal AEC also proliferate but in a coordinated manner during embryonic growth and fetal development as well as during lung repair. Therefore, biochemical mechanisms regulating the cell cycle in AEC are clearly of fundamental significance for understanding lung development, lung injury, and cancer. Cyclin A is a protein that varies in abundance during the cell cycle and regulates critical transition points through its association with cyclin-dependent protein kinase subunits. We postulated that high expression of cyclin A might be associated with rapid proliferation in transformed AEC. We compared the expression of cyclin A mRNA and protein in primary cultures of fetal and adult rat AEC, in the E1A-T2 neonatal rat AEC, and in the malignant A549 human AEC. We used pharmacologic blockades with mimosine, aphidicolin, and nocodazole for cell cycle synchronization, which was verified by fluorescence-activated cell sorter (FACS) analysis of cellular DNA content. Transformed cells (A549 and E1A-T2) exhibited a much higher level of expression for both cyclin A mRNA and protein than did normal rat AEC. Induction of cyclin A mRNA expression in A549 human AEC and E1A-T2 rat AEC occurred in late G1, prior to the onset of S phase. Fetal and adult rat AEC and rat E1A-T2 AEC expressed two cyclin A mRNA transcripts, whereas human A549 cells in S phase and M phase expressed three cyclin A mRNA transcripts. We conclude that transformed AEC overexpress cyclin A in comparison with primary AEC cultures, while retaining cell cycle-dependent differences in cyclin A expression. We speculate that cyclin A expression is regulated both at the transcriptional and post-transcriptional levels, and that cyclin A may play a key role in the increased proliferation of transformed AEC that is associated with the pathogenesis of lung cancer.

Protection against murine cytomegalovirus infection in aged mice and mice with severe combined immunodeficiency disease with the biological response modifiers polyribosinic-polycytidylic acid stabilized with L-lysine and carboxymethylcellulose, maleic anhydride divinyl ether and colony stimulating factor 1

A variety of biological response modifiers (BRMs) have provided antiviral protection to immunocompetent mice, and this prompted us to determine their efficacy against murine cytomegalovirus (MCMV) infection in immunocompromised mice-including the profoundly immunocompromised SCID mice and C57Bl/6 and B6D2F1 aged mice. SCID mice showed a marked decrease (> 20-fold) in resistance to MCMV, while there was a slight decrease (3-fold) in aged mice. In BRM antiviral protection studies, SCID mice were almost completely protected against MCMV infection by the pleiotropic immunomodulators, MVE-2 and pICLC, but much less by the more selective CSF-1. pICLC-induced IFN and NK cell cytotoxicity were maintained in SCID mice, suggesting that pleiotropic immunomodulatory effects may be required for antiviral protection in such a profoundly immunocompromised model. pICLC also effectively protected aged mice against lethal MCMV infection and effectively induced IFN. These results emphasize the potential for BRM treatment in immunocompromised hosts.

Nim1 kinase promotes mitosis by inactivating Wee1 tyrosine kinase

In most species, including the fission yeast Schizosaccharomyces pombe, the Cdc2/cyclin B mitosis-inducing kinase is maintained in an inhibited state during interphase as a result of phosphorylation of a tyrosine residue in the ATP-binding region of Cdc2 (refs 1-3). This site is phosphorylated by Wee1 kinase and dephosphorylated by Cdc25 phosphatase. In fission yeast an additional element of the G2/M control Nim1/Cdr1 kinase, has been identified which functions as a potent mitotic inducer. These studies suggested that Nim1 acts by inhibiting Wee1, perhaps by direct phosphorylation. Consistent with this model, we report here that Wee1 is hyperphosphorylated in cells that overproduce Nim1. Likewise, Wee1 phosphorylation is reduced in nim1- cells. Highly purified Nim1 kinase phosphorylates Wee1 in vitro, resulting in strong inhibition of Wee1 kinase. These observations show that Nim1 promotes the onset of mitosis by inhibiting Wee1.

Expression cloning and characterization of human 17 beta-hydroxysteroid dehydrogenase type 2, a microsomal enzyme possessing 20 alpha-hydroxysteroid dehydrogenase activity

17 beta-Hydroxysteroid dehydrogenase (17 beta-HSD) is an enzyme crucial to the regulation of intracellular levels of biologically active steroid hormones in a variety of tissues. Here, we report the isolation, structure, and characterization of a cDNA encoding the human 17 beta-HSD type 2. A 1.4-kilobase cDNA was identified, and DNA sequence analysis indicated that 17 beta-HSD type 2 was a protein of 387 amino acids with a predicted molecular weight of 42,782. The protein contained an amino-terminal type II signal-anchor motif and a carboxyl-terminal endoplasmic reticulum retention motif, which suggested that 17 beta-HSD type 2 was associated with the membranes of the endoplasmic reticulum. 17 beta-HSD type 2 was capable of catalyzing the interconversion of testosterone and androstenedione as well as estradiol and estrone. The enzyme also demonstrated 20 alpha-HSD activity toward 20 alpha-dihydroprogesterone. The amount of 17 beta-HSD type 2 mRNA in placenta was found to be high. The data suggest that the 17 beta-HSD type 2 cDNA encodes the microsomal 17 beta-HSD of human placenta, described by several laboratories.

Role of NK cells in immunomodulator-mediated resistance to herpesvirus infection

Seven chemically diverse biological response modifiers (BRM) were compared for antiviral activity in intact and NK cell-depleted CD-1 mice. Both spontaneous and BRM-induced splenic NK cell cytotoxicity were depleted for at least 5 days following treatment with the monoclonal antibody NK1.1. Antiviral protection of standard doses of MVE-2, pIC, pICLC, rmIFN-tau and CL246,738 against lethal MCMV or HSV-2 infections was not abrogated by NK cell depletion, demonstrating that NK cells are not required for BRM-induced antiviral activity against these herpesviruses. When mice were treated with 100,000 U of rHuIFN-alpha B/D, NK cells were not required for activity against MCMV, while at a dose of 25,000 U, NK cells appeared to be partially required against MCMV. At lower doses, the activity of rHuIFN-alpha B/D against MCMV appeared dependent upon the presence of NK cells. A similar dose-related requirement for NK cells was observed for activity of OK-432. Thus, at higher doses of rHuIFN-alpha B/D and OK-432, elements of the natural immune system in addition to or other than NK cells are apparently involved, while at lower doses NK cells appear to play a more important role in antiviral protection against MCMV infection.

Brief communication: variation in the frequency and form of the lower permanent molar middle trigonid crest

The frequency and form of the middle trigonid crest (MTC) in lower permanent molars is reported for 1,131 dental casts of Bushman (San), Bantu, Solomons, Hawaiians, Pima, Eskimo, Navajo, Chinese, and American whites. The MTC occurs most often on the first molar. We found very little intra-trait variation, so observations were scored on a present-absent basis. The MTC is most frequent in the African samples and rare in those of the other populations. Two reference plaques can be obtained to add to the existing series in the ASU dental anthropology system.

[The clinical use of steady-state flash visual evoked potentials]

The authors applied 30Hz flash stimuli to record steady-state flash visual evoked potentials (FVEP) and extracted the amplitudes and phases of the first and second harmonics as the characteristic value by discrete Fourier transform (DFT). 46 normal controls (89 eyes) and 78 patients (109 eyes) were detected and analysed by this method. The result showed that the characteristic values of the normal controls are significantly different in three age groups and showed the positive in 35 eyes with the optic never diseases (82.9%), 25 eyes with age-related macular degeneration (92%), and 9 eyes with retinal detachment involved macular (100%). It indicates the method is a sensitive index to evaluate the macular visual function. After preliminary observation, the visual acuities of postoperation were found above 0.4 in cataracts (28 eyes) or opacities (12 eyes) if preoperative FVEP were normal and non-complicated, or less than 0.4 if preoperative FVEP were abnormal. This suggests the method is one of the effective index to detect the postoperative vision of the media opacities. The advantages, disadvantages and the clinical applications were discussed.

G1 expression and multistage dynamics of cyclin A in human osteosarcoma cells

Cyclin A was initially characterized as a 'mitotic cyclin', believed to function exclusively at the G2-to-M phase transition; however, recent studies have provided compelling evidence that cyclin A additionally functions earlier in the mammalian somatic cell cycle as a putative 'S-phase-promoting factor'. Moreover, numerous inconsistencies have arisen concerning the temporal induction, subcellular localization, subunit configuration, covalent modification and proteolytic destruction of cyclin A, as well as the physiological function of the cyclin A-associated protein kinase complexes. Utilizing precisely synchronized human MG-63 osteosarcoma cells, the present study demonstrates that cyclin A mRNA and protein are clearly expressed in late G1 prior to S-phase entry, as is cyclin A-associated kinase activity and concomitant phosphorylation of the Rb protein. A series of monospecific cyclin A antibodies were generated and utilized to confirm that multiple covalent modifications of cyclin A occur during the course of the cell cycle, and to characterize the subcellular dynamics in additional detail. Pharmacological blockade with mimosine was utilized to further delineate cyclin A expression and to distinguish the temporal induction from the mechanisms of enzyme activation. Subcellular fractionation and immunocytochemical staining localized nascent cyclin A to the cytoplasm, and revealed a distinct translocation to the nucleus during the G1-to-S phase transition. The results of these studies support a multistage model of cyclin A metabolism and enzyme activation.

[The effect of acupuncture on plasticity of spinal Clarke's nucleus synaptic terminals]

Ten unilateral spared root cats with sectioned L1-S2 dorsal root ganglia, except L6, were used to explore the effect of acupuncture on plasticity of spinal Clarke's nucleus synaptic terminals. Five of the cats were needled on the operated hind limb for two courses (ten days as a course), and the other five were kept for control. Two pairs of acupoints located in the innervated area of L6 spinal nerve were used. The number of synaptic terminals per photo in neuropil of L3 Clarke's nucleus was compared directly, because there was no significant change in the area of Clarke's nucleus and its neuropil on the operated side of both groups. No significant difference was found in the number of three types of synaptic terminals between the unoperated sides of two groups, suggesting that acupuncture may not influence the contralateral side. In the control group, the number of giant axonal terminals from dorsal root of the operated side decreased to 75% of the unoperated side; however, in the experimental group, it recovered to contralateral or normal level of the operated side and was significantly higher than that of the control group's operated side, denoting that acupuncture may promote the plasticity such as collateral sprouting and synaptic reinnervation of coarse myelinated fibers from intact dorsal root, L6 mainly. The number of other two types of terminals from spinal interneurons showed no significant difference between the operated sides of two groups, indicating that acupuncture may not enhance the plasticity of nondorsal root nerve fibers.

A G-protein beta-subunit is essential for Dictyostelium development

Recent studies have demonstrated that G-protein-linked signal transduction pathways play a significant role in the developmental program of the simple eukaryotic organism Dictyostelium. We have reported previously the isolation of a G-protein beta-subunit and present here a more complete analysis of this gene. Low-stringency Southern blots and RFLP mapping studies suggest that the beta-subunit is a unique gene found on linkage group II. Its deduced amino acid sequence of 347 residues is approximately 60% identical to those of the human, Drosophila, and Caenorhabditis elegans beta-subunits. The carboxy-terminal 300 residues are about 70% identical; the amino-terminal 50 residues are quite divergent, containing only 10 identities. At all stages of growth and development, a single 1.9-kb beta-subunit mRNA is present at a high level, and a specific antibody detects a single 37-kD protein. We propose that G-protein heterotrimers are formed when this beta-subunit couples with each of the eight distinct G-protein alpha-subunits that are transiently expressed during development. Targeted disruption of the beta-subunit gene had no effect on the viability of haploid cells, but resulted in the inability of cells to aggregate.

Two potentially oncogenic cyclins, cyclin A and cyclin D1, share common properties of subunit configuration, tyrosine phosphorylation and physical association with the Rb protein

Originally identified as a 'mitotic cyclin', cyclin A exhibits properties of growth factor sensitivity, susceptibility to viral subversion and association with a tumor-suppressor protein, properties which are indicative of an S-phase-promoting factor (SPF) as well as a candidate proto-oncogene. Other recent studies have identified human cyclin D1 (PRAD1) as a putative G1 cyclin and candidate proto-oncogene. However, the specific enzymatic activities and, hence, the precise biochemical mechanisms through which cyclins function to govern cell cycle progression remain unresolved. In the present study we have investigated the coordinate interactions between these two potentially oncogenic cyclins, cyclin-dependent protein kinase subunits (cdks) and the Rb tumor-suppressor protein. The distribution of cyclin D isoforms was modulated by serum factors in primary fetal rat lung epithelial cells. Moreover, cyclin D1 was found to be phosphorylated on tyrosine residues in vivo and, like cyclin A, was readily phosphorylated by pp60c-src in vitro. In synchronized human osteosarcoma cells, cyclin D1 is induced in early G1 and becomes associated with p9Ckshs1, a Cdk-binding subunit. Immunoprecipitation experiments with human osteosarcoma cells and Ewing's sarcoma cells demonstrated that cyclin D1 is associated with both p34cdc2 and p33cdk2, and that cyclin D1 immune complexes exhibit appreciable histone H1 kinase activity. Immobilized, recombinant cyclins A and D1 were found to associate with cellular proteins in complexes that contain the p105Rb protein. This study identifies several common aspects of cyclin biochemistry, including tyrosine phosphorylation and the potential to interact directly or indirectly with the Rb protein, that may ultimately relate membrane-mediated signaling events to the regulation of gene expression.

Identification of a novel cyclin-like protein in human tumor cells

Cyclins are key regulatory proteins that, in concert with cyclin-dependent protein kinase subunits (cdks), function to govern critical transitions and/or restriction points during the course of cell cycle progression. Recently, a number of putative mammalian G1 cyclins have been characterized at the molecular level; however, the specific activities of the cyclin/cdk complexes and the precise biochemical pathways regulated by the G1 cyclins remain to be elucidated. In the present study we identify a novel cyclin-like protein in pediatric bone and extremity tumors that appears to be related to, but is clearly distinct from, previously identified members of the cyclin D family, as determined by its profile of antibody cross-reactivity, apparent molecular size, chromatographic behavior, physicochemical properties, and pattern of peptide mapping. This 46-kDa cyclin-like protein, tentatively designated p46cyclin X, is first expressed in synchronized MG-63 osteosarcoma cells in mid-G1, well after the induction of p36cyclin D1, yet prior to the induction of cyclins E and A. Northern analysis, utilizing an oligonucleotide probe complementary to an epitope shared by cyclins D1, D2, and X, detected a novel mRNA species, the appearance of which correlates with p46cyclin X expression. The p46cyclin X protein in Ewing's sarcomas and Wilms' tumors is electrophoretically and chromatographically distinct from both p36cyclin D1 and p34cyclin D2. Moreover, the p46cyclin X protein is 1) precipitated by p9Ckshs1-agarose beads, 2) physically associated with p33cdk2, and 3) autophosphorylated in in vitro kinase reactions. Taken together with the biochemical data, the temporal expression of the p46cyclin X/p33cdk2 kinase system is suggestive of a potential role in regulating latter G1 events (i.e. START) in the commitment to S phase.

Thymic dendritic cells and T cells develop simultaneously in the thymus from a common precursor population

Dendritic cells, a minor cell population in lymphoid tissues, are specialized for presentation of antigenic peptides to T lymphocytes. Thymic dendritic cells are involved in the deletion of self-reactive T lymphocytes. Although all dendritic cells are ultimately of bone-marrow origin, it has not been clear whether thymic dendritic cells are produced in the adult thymus from a precursor cell or whether they migrate there preformed from the periphery. Recently we isolated from adult mouse thymus a population of early T precursors that could still form B lymphocytes, but not erythroid or myeloid cells, when transferred intravenously. Here we show that these thymic lymphoid precursor cells, as well as bone-marrow haematopoietic stem cells, are able to form both dendritic cells and T-cell progeny when transferred into an irradiated thymus. Such linked development may ensure that developing T cells are negatively selected predominantly by self antigens presented on newly formed thymic dendritic cells.

The incidence of perioperative myocardial infarction in men undergoing noncardiac surgery

OBJECTIVES

To determine the incidence of and risk factors for perioperative myocardial infarction with noncardiac surgery and to test the accuracy of a risk stratification system.

DESIGN

Prospective cohort study.

SETTING

A large urban Veterans Affairs hospital.

PARTICIPANTS

A total of 1487 men older than 40 years undergoing major, nonemergent, noncardiac operations.

MEASUREMENTS

Infarction was established by at least two of the following: development of new Q waves, typical change in creatine kinase MB, and positive technetium pyrophosphate scintigraphy. Patients were stratified preoperatively into high-, intermediate-, low-, and negligible-risk strata based on clinical markers corresponding to different levels of coronary artery disease prevalence.

MAIN RESULTS

Patients with coronary disease (high-risk stratum) had a 4.1% incidence of infarction (13 of 319; 95% CI, 1.8% to 6.4%); patients with peripheral vascular disease but no evidence of coronary disease (intermediate-risk stratum) had a 0.8% incidence (2 of 260, upper bound of CI, 2.0%); patients with high atherogenic risk factor profiles but no clinical atherosclerosis (low-risk stratum) had a 0% incidence (0 of 256, upper bound of CI, 1.2%). No cardiac deaths occurred in 652 men who had no atherosclerosis and low atherogenic risk factor profiles (the negligible-risk stratum). Factors independently associated with infarction included age more than 75 years (adjusted odds ratio, 4.77; CI, 1.17 to 19.41), signs of heart failure on the preoperative examination (adjusted odds ratio, 3.31; CI, 0.96 to 11.38), coronary disease (adjusted odds ratio, 10.39; CI, 2.27 to 47.46), and a planned vascular operation (adjusted odds ratio, 3.72; CI, 1.12 to 12.37).

CONCLUSIONS

Coronary artery disease is the major risk factor for perioperative infarction. The stratification scheme identifies subsets of patients with different risks, and finer within-stratum distinctions can be made using additional variables.

[A preliminary report on the preparation of antisera against Haemophilus influenzae]

The antigenicity of 5 strains of serotype b Haemophilus influenzae was compared. Strain 58534 showed a higher titer than the rest four. Three lots of antisera were made by immunizing rabbits with 6 strains of Haemophilus influenzae. The results indicated that the antibody titer against strain 58534 also showed a higher level, and the titer only dropped by one dilution after stored in cool place for half a year. We considered that Haemophilus influenzae serotype b strain 58534 is a good strain for the preparation of antiserum against Haemophilus influenzae.

Natural establishment and selenium accumulation of herbaceous plant species in soils with elevated concentrations of selenium and salinity under irrigation and tillage practices

The effects of irrigation and tillage practices were studied on species richness, biomass, and selenium accumulation of naturally established herbaceous plants in soils with elevated levels of selenium (Se) and salinity at Kesterson Reservoir, Merced County, California. The four different irrigation-tillage practice combinations were (1) no irrigation, no tillage; (2) irrigation, no tillage; (3) no irrigation, tillage; and (4) irrigation, tillage. The fields were allowed to become colonized naturally by herbaceous plant species. For the Mediterranean climate in the study site, irrigation was conducted biweekly through the summer months, and tillage was done in 3-month intervals. Biomass and Se accumulation of Atriplex patula L, Bassia hyssopifolia Kuntze, Rev. Gen. Pl., Melilotus indica (L.) All., and Salsola kali L. were substantially affected by irrigation. The degree and direction of the effects were found to be species dependent. The field plots which were tilled at 3-month intervals remained bare throughout the experiment. The total soil Se concentrations in the top 15 cm soil horizon were found to be in the range of 40 to 70 mg kg-1 dry wt. Soil Se concentrations below 25 cm soil depth were much lower and within a range of 2 to 4 mg kg-1. Less than 1/10th of the total soil Se inventory in the top soil horizon was water extractable, and the distribution of the Se inventory did not change significantly over the period of 1990 and 1991 despite the irrigation and tillage practices suggesting that a large portion of the Se inventory was not remobilized. The water-extractable soil Se concentration was found to be significantly lower in soils with the greatest biomass production suggesting an effective bioextraction of soil selenium by the native herbaceous plants.

The natural history of dry type of age-related macular degeneration

To study the natural history of dry type of age-related macular degeneration (AMD) and search for a sensitive method for detecting the development of the disease, the fundus fluorescein angiography, visual acuity, electroretinogram and FM 100-hue test were used to examine 75 eyes, 147 eyes, 73 eyes, and 94 eyes respectively. These examinations were taken at least twice during the follow-up periods. The average age was 63.2 years (50-80 years). The average follow-up was 29.8 months with a range of 3-74 months. It was shown tht there were not any statistically significant difference in the macular lesions and electroretinogram between the initial examinations and after follow-up (P > 0.05). 91.14% of the eyes maintained good visual acuity during the follow-up. Subretinal neovascularization developed only in one of the eyes. The total error score of FM 100-hue test had a statistically significant difference between the initial test and the test taken two years afterwards (P < 0.01). It was suggested that most of the dry type of AMD had a favorable prognosis and that color visual test was a sensitive method for monitoring the development of dry type of AMD.

Conformational changes in chicken thyroid hormone receptor alpha 1 induced by binding to ligand or to DNA

A classic model of steroid/thyroid hormone receptor activation postulates that a conformational change or "transformation" occurs upon ligand binding as a first step toward regulation of gene transcription. In order to test this model, physical studies have been carried out using purified full-length chicken thyroid hormone receptor alpha 1 (cT3R-alpha 1) expressed in Escherichia coli. Circular dichroism spectroscopic studies reveal that cT3R-alpha 1 adopts a different conformation upon specific binding to a cognate ligand triiodothyroacetic acid as well as to a thyroid hormone response element, an idealized inverted repeat AGGTCA TGACCT. These results suggest that cT3R-alpha 1 may adopt distinct conformations whether free or bound to ligand or to DNA. These states may reflect the changes in the conformation of steroid/thyroid hormone receptors in the signal transduction pathway.

Mechanism of dioxin action: receptor-enhancer interactions in intact cells

We have used a ligation-mediated polymerase chain reaction technique to analyze protein-DNA interactions at a dioxin-responsive enhancer upstream of the CYP1A1 gene in intact mouse hepatoma cells. In its inactive state, the enhancer binds few, if any, proteins within the major DNA groove in vivo. Thus, the inactive enhancer is relatively inaccessible to DNA-binding proteins. Exposure of cells to 2,3,7,8-tetrachlorodibenzo-p-dioxin leads to the binding of the liganded Ah receptor at six sites within the major DNA groove of the enhancer. The receptor-enhancer interactions occur rapidly and do not require ongoing transcription, consistent with their role in regulating CYP1A1 gene expression. The liganded receptor, which is a heteromer composed of at least two basic helix-loop-helix proteins, is probably the only DNA-binding transcription factor necessary to activate the enhancer in vivo. The small size and irregular distribution of receptor binding sites suggest that chromatin structure imposes substantial steric constraints upon the function of the receptor-enhancer system in intact cells.

Segmentation in local hospital markets

This study examines evidence of market segmentation on the basis of patients' insurance status, demographic characteristics, and medical condition in selected local markets in California in the years 1983 and 1989. Substantial differences exist in the probability patients may be admitted to particular hospitals based on insurance coverage, particularly Medicaid, and race. Segmentation based on insurance and race is related to hospital characteristics, but not the characteristics of the hospital's community. Medicaid patients are more likely to go to hospitals with lower costs and fewer service offerings. Privately insured patients go to hospitals offering more services, although cost concerns are increasing. Hispanic patients also go to low-cost hospitals, ceteris paribus. Results indicate little evidence of segmentation based on medical condition in either 1983 or 1989, suggesting that "centers of excellence" have yet to play an important role in patient choice of hospital. The authors found that distance matters, and that patients prefer nearby hospitals, moreso for some medical conditions than others, in ways consistent with economic theories of consumer choice.

The changes in contractile status of single vascular smooth muscle cells and ventricular cells induced by bPTH-(1-34)

Single smooth muscle cells from rat tail artery and ventricular myocytes from neonatal rat were isolated by repeated enzyme digestion. The change in cell area as determined photographically was used as an index of cell contraction. The photographic areas of single smooth muscle cells bathed in normal Tyrode solution were 403 +/- 22 (n = 13) square micra. Exposure of smooth muscle cells to a modified Tyrode solution containing 60 mM KCl induced cell contraction. This contraction was inhibited by bPTH-(1-34) at a concentration of 1 microM. The inhibitory effect of bPTH-(1-34) was time-dependent with maximum inhibition at 5 min after administration. The photographic areas of ventricular myocytes bathed in the culture medium without fetal calf serum were 516 +/- 47 (n = 29) square micra. At a concentration of 1 microM, bPTH-(1-34) produced a time-dependent contraction in ventricular myocytes as shown by the decrease in the photographic cell area (88 +/- 2% of the control value at 15 min, n = 9, p < 0.01). Furthermore, 1 microM nifedipine inhibited the effect of bPTH-(1-34) on the contraction of ventricular myocytes, indicating that bPTH-(1-34) might exert its action via a calcium channel related mechanism. In addition, bPTH-(1-34) increased the contraction frequency of single ventricular cells, which could also be inhibited by nifedipine. The present study suggests that bPTH-(1-34) directly relaxes precontracted single vascular smooth muscle cells and contracts single ventricular myocytes.

Regulation of herpes simplex virus type 1 gene expression in nonpermissive murine resident peritoneal macrophages

The restriction of herpes simplex virus type 1 (HSV-1) gene expression in nonpermissive murine resident peritoneal macrophages (ResPMO) was analyzed at the level of transcription. Using nuclear run-on assays, we established that transcription of a representative gene from each HSV-1 kinetic class was initiated in both ResPMO and permissive Vero cells. Using transient expression assays, we observed that the promoters of two early genes were activated by the immediate-early protein ICP4 in ResPMO. However, the level of transactivation of these promoters by another immediate-early protein, ICP0, was markedly reduced in ResPMO. Furthermore, the synergistic trans-activation normally observed between ICPs 4 and 0 in Vero cells was noticeably absent in ResPMO. The data indicate that the block in viral gene expression in ResPMO occurs after initiation of viral gene transcription and involves dysfunction of a viral immediate-early regulatory protein, ICP0.

Osseous changes following placement of the transmandibular implant system in edentulous mandibles

The transmandibular implant system is designed for the reconstruction and rehabilitation of the endentulous mandible utilizing an extraoral approach. Transmandibular implants were placed in 19 patients and mandibular bony changes were followed using standardized panoramic radiography. Eleven sites were identified on each postoperative radiograph and the percentage of radiographic enlargement was calculated for each site. The true bony changes were then computed for both short-term (9.4 months) and long-term (53.4 months) follow-up. Patients with an average mandibular height in the saddle areas of 3.5 to 8.9 mm showed bilateral bony regeneration in the saddle areas and over the most distal cortical screws of the implants. Most of these bony changes were seen in the first year, but continued beyond that time. Patients with residual bone height of 9.0 to 12.9 mm had little bone change, while patients with bone height of 13.0 to 20.5 mm demonstrated slight resorption. Theories for the observed changes are presented. The transmandibular implant is especially indicated for the severely atrophic mandible because its position within the mandible and the rigid box frame design of the implant promote bilateral bone regeneration distal to the framework of the implant.

Alternative exon usage and processing of the major histocompatibility complex-encoded proteasome subunits

The finding that two subunits of the proteasome, LMP2 and LMP7, are encoded in the major histocompatibility complex (MHC) has linked the proteasome which represents a major extralysosomal proteolytic system to the processing of intracellular antigens. Here we describe a second form of the human LMP7 cDNA, LMP7-E2, which has been identified during the characterization of novel genes in the MHC. The analysis of the genome organization of LMP7 revealed that LMP7-E1 and LMP7-E2 arise by alternative exon usage. Using specific antibodies against LMP2 and LMP7, we show that they are co-expressed with class I MHC molecules as well as a putative peptide transporter. The polypeptides encoded by LMP7 and LMP2 undergo proteolytic processing when incorporated into proteasomes, and the LMP7 precursor is derived mainly from LMP7-E2. Furthermore, our data suggest that LMP7 and LMP2 are mutually dependent for their incorporation into the proteasomal complex.

Visual functions and trace element metabolism in tobacco-toxic optic neuropathy

Visual functions and nutrition metabolic characteristics were studied in 8 subjects (16 eyes) with tobacco-toxic optic neuropathy (TTON). Their visual functions tested by psychophysical and electrophysiologic methods showed that 1: 1. central vision diminished in 16 eyes, 2. dyschromatopsias were found in 14 tested eyes, 3. bilateral symmetrical central or cecocentral scotomas were the visual field characteristics in all cases, 4. PVEP were severe abnormal in 3 spatial frequencies in all cases and 56.3% of 15' checkboard PVEP showed flat responses, which indicated the impairment of optic nerve dominated by the central field. However, the preserved visual responses could be obtained by FVEP test in 14 tested eyes even though their visual acuity were between the range of 0.02-0.2 and flat PVEP responses. The II and III wave latencies of primary stage were more prolonged than those of control group (P < 0.01), which further indicated the preferential demyelination corresponding to the papillomacular bundles, 5. ERG showed slightly attenuated amplitudes in 5 of 8 tested eyes, which indicated the secondary and mild retinal lesion. On the other hand, TTON occurred on a background of long-term, heavy smoking, drinking, emaciation and malnutrition bodies with low serum zinc level.

The spectral VEP in normal subjects and dichromats

The spectral VEP in 13 normal subjects (25 eyes), four cases (8 eyes) of protanopes and 8 cases (15 eyes) of deuteranopes were tested. In normal subjects, the shortest latencies of N1, P1, N2 were in 560 nm and the greatest amplitudes of N1-P1 and P1-N2 were 560-570 nm, around which the latencies were delayed and the amplitudes were decreased as the wavelengths of stimulative light increased or decreased gradually. The spectral VEP pattern of deuteranopes was similar to the normal subjects. In the protanopes, the shorter latencies of N1,P1,N2 and greater amplitudes of N1-P1, P1-N2 appeared in 520-530 nm and 570 nm, forming the two-thoughs and two-peaks shapes, with the shortest latencies and the greatest amplitudes in 520-530 nm. There were statistically significant differences of amplitudes and/or latencies in some wavelengths between the protanopes and normals and between the deuteranopes and normals.

Quantitative evaluation of flicker ERG waveforms in low vision patients

Flicker electroretinograms (FERGs) of 30Hz were recorded for 46 eyes (23 cases) of low vision, including 38 eyes with retinal diseases and 8 eyes with optic neuropathy, and for 39 normal eyes (33 cases). The recorded wave forms were analysed by two methods: (1) to measure the peak to peak amplitude and pseudophase directly, and (2) to measure the amplitude and phase of fundamental response component (30Hz) by discrete Fourier transform (DFT). The abnormality ratios between these two methods were compared in low vision patients. All the eyes with optic neuropathy showed normal flicker ERG, the abnormality ratios of directly measured amplitude and the amplitude by DFT were 60.9% in 28 eyes and 71.7% in 33 eyes with retinal diseases respectively, the difference being no statistically significant (P > 0.05), while the abnormality ratios of directly measured pseudo-phase and the phase by DFT were 60.9% in 28 eyes and 82.6% in 38 eyes with retinal diseases respectively, the difference being statistically significant (P < 0.05). These results suggest that FERGs are an objective way to test the retinal function, and DFT for flicker ERGs are more useful in quantitative evaluation of the retinal function.

Laboratory diagnosis of Clostridium difficile-associated gastrointestinal disease: comparison of a monoclonal antibody enzyme immunoassay for toxins A and B with a monoclonal antibody enzyme immunoassay for toxin A only and two cytotoxicity assays

A total of 320 stool specimens obtained from 262 patients suspected of having Clostridium difficile-associated gastrointestinal disease were examined with two cytotoxicity assays (CTAs) and two commercially available enzyme immunoassays (EIAs). The CTAs were an in-house-developed procedure (University of Massachusetts Medical Center [UMMC], Worcester, Mass.) and a commercial test (Bartels CTA; Baxter Healthcare Corp., West Sacramento, Calif.). One EIA was a monoclonal antibody-based assay for C. difficile toxins A and B (Cambridge Biotech Corp. [CBC], Worcester, Mass.). The other EIA employed monoclonal antibodies directed against only toxin A (Meridian Diagnostics, Cincinnati, Ohio). True-positive and true-negative results were defined on the basis of the results of the four assays, clinical assessments of patients, and the results of other laboratory tests. The sensitivities of the four assays were as follows: Bartels CTA, 100%; UMMC CTA, 97.2%; CBC EIA, 84.5%; and Meridian EIA, 69.0%. The Bartels CTA demonstrated a specificity of 99.2%. The other three assays had a specificity of 100%.

Superinduction of CYP1A1 transcription by cycloheximide. Role of the DNA binding site for the liganded Ah receptor

Nuclear run-off experiments reveal that four distinct DNA domains, each of which contains a binding site for the liganded Ah receptor, can mediate the superinduction of transcription by 2,3,7,8-tetrachlorodibenzo-p-dioxin plus cycloheximide. Superinduction requires substantial inhibition of protein synthesis by cycloheximide. Gel retardation analyses of nuclear extracts and methylation protection studies in intact cells reveal no evidence for cycloheximide-sensitive protein-DNA interactions that might mediate the superinduction response. These observations suggest the existence of a labile protein(s) that acts to inhibit the function of the dioxin-responsive receptor/enhancer regulatory system via protein-protein interactions.

The surface phenotype of dendritic cells purified from mouse thymus and spleen: investigation of the CD8 expression by a subpopulation of dendritic cells

A new procedure for rapid isolation of dendritic cells (DC) was devised, involving collagenase digestion of tissues, dissociation of lymphoid-DC complexes, selection of light-density cells, then depletion of lymphocytes and other non-DC by treatment with a mixture of lineage-specific monoclonal antibodies (mAbs) and removal with anti-immunoglobulin-coupled magnetic beads. This enriched population (approximately 80% DC) was further purified when required by fluorescence-activated cell sorting for cells expressing high levels of class II major histocompatibility complex (MHC). The isolated DC were characterized by immunofluorescent staining using a panel of 30 mAbs. Thymic DC were surface positive for a number of markers characteristic of T cells, but they were distinct from T-lineage cells in expressing high levels of class II MHC, in lacking expression of the T cell receptor (TCR)-CD3 complex, and having TCR beta and gamma genes in germline state. Splenic DC shared many markers with thymic DC, but were negative for most T cell markers, with the exception of CD8. A substantial proportion of DC from both thymus and spleen expressed CD8 at high levels, comparable with that on T cells. This appeared to be authentic CD8, and was produced by the DC themselves, since they contained CD8 alpha mRNA. Thymic DC presented both the CD8 alpha and beta chains on the cell surface (Ly-2+3+), although the alpha chain was in excess; the splenic DC expressed only the CD8 alpha chain (Ly-2+3-). It is suggested that the expression of CD8 could endow certain antigen-presenting DC with a veto function.

Use of nuclear morphometry, gleason histologic scoring, clinical stage, and age to predict disease-free survival among patients with prostate cancer

BACKGROUND

Currently, there are no accurate methods for predicting metastases or time to disease progression for patients with clinically localized prostate cancer after surgery.

METHODS

In this report, histologic sections were studied from prostate cancer specimens from 100 men with clinically localized prostate cancer (clinical Stages A1 [9 cases], A2 [24 cases], B1 [27 cases], and B2 [40 cases]; pathologic Stages A1 [9 cases], A2 [22 cases], B [23 cases], C1 [8 cases], and D1 [38 cases]) to determine whether nuclear morphometry--when analyzed with clinical stage, pathologic parameters, and age in a multivariate fashion--would predict time to disease progression.

RESULTS

These patients were treated with surgery alone for their clinically localized disease and were observed after surgery until disease progression or death. For each of the 100 specimens, 16 different mathematical descriptors described the shape of 150 nuclei. A series of 17 different statistical measurements were calculated to accurately describe the distribution, extremes, and variability within each descriptor. As univariate predictors, the variance of nuclear roundness, the mean of ellipticity, the Gleason score, age, and clinical stage were statistically significant predictors of disease progression when analyzed with Kaplan-Meier survival curves. A prognostic factor score calculated with multivariate analysis of clinical stage, Gleason score, age, and variance of nuclear roundness separated the patients into three statistically distinct groups and predicted time to progression by the Kaplan-Meier life table and Cox proportional hazards analysis.

CONCLUSIONS

This prognostic factor score may aid in stratifying patients into high-risk and low-risk groups for testing adjuvant therapies for prostate cancer.