Essential pathogenic role for endogenous interferon-gamma (IFN-gamma) during disease onset phase of murine experimental autoimmune orchitis. I. In vivo studies

We previously found that immunization of CH3/He male mice with syngeneic testicular germ cells (TGC) without the aid of any adjuvants was sufficient to induce DTH to TGC and experimental autoimmune orchitis (EAO). To evaluate the role of endogenous IFN-gamma in this model, C3H/He mice immunized subcutaneously with TGC on days 0 and 14 received a single injection of anti-murine IFN-gamma MoAb on day 15, 20 or 25. On day 45, DTH to TGC was tested, testis specimens were collected for histological examination, and blood samples collected for IFN-gamma measurement. The results showed that whilst MoAb treatment on day 15 or 25 did not influence DTH responses, EAO development, and appearance of IFN-gamma in the circulation, treatment on day 20 significantly suppressed all of them. Thus, a single injection with anti-IFN-gamma MoAb may successfully down-regulate testicular autoimmunity, provided that the treatment is given at an optimal time point during disease development.

Estimation of the numerical densities of neurons and synapses in cerebral cortex

In this paper we discuss a stereological technique, 'the unfolding method', for a quantitative study of the nervous system [1,31]. Stereology implies a geometric analysis of structures and textures, and is a method to derive directly metric properties of structures from two-dimensional sections on the basis of geometrico-statistical reasoning [36,37]. Recent advances in the stereological method allow quantitative analysis [8,19,27,32]. Images on sections provide only two-dimensional information, but the stereological method can offer three-dimensional and quantitative information [19]. The need for quantitative analysis is more important and useful in the central nervous system (CNS) than in other organs. Two functional units, neurons and synapses, are of particular interest in evaluating CNS function. Numerical densities of neurons and synapses in rat visual cortex were estimated using the unfolding method at light and electron microscopic levels, respectively. Once the numerical densities of neurons and synapses were obtained, synapse-to-neuron ratios could be calculated. The ratios are interpreted as a means to obtain an index of interneuronal connectivity [9]. The unfolding method may become a powerful strategy in neuroscience research when numerical estimates are performed in restricted areas such as cortical layers II-IV, because this method is less time-consuming than other stereological methods [6,21,22].

A novel antioxidant gene from Mycobacterium tuberculosis

Among the major antimicrobial products of macrophages are reactive intermediates of the oxidation of nitrogen (RNI) and the reduction of oxygen (ROI). Selection of recombinants in acidified nitrite led to the cloning of a novel gene, noxR1, from a pathogenic clinical isolate of Mycobacterium tuberculosis. Expression of noxR1 conferred upon Escherichia coli and Mycobacterium smegmatis enhanced ability to resist RNI and ROI, whether the bacteria were exposed to exogenous compounds in medium or to endogenous products in macrophages. These studies provide the first identification of an RNI resistance mechanism in mycobacteria, point to a new mechanism for resistance to ROI, and raise the possibility that inhibition of the noxR1 pathway might enhance the ability of macrophages to control tuberculosis.

Different susceptibility of three clinically isolated strains of Cryptococcus neoformans to the fungicidal effects of reactive nitrogen and oxygen intermediates: possible relationships with virulence

We investigated the susceptibility of three clinically isolated strains of Cryptococcus neoformans with different virulences to reactive nitrogen and oxygen intermediates (RNI and ROI, respectively), representing two important mediators of macrophage microbicidal activity. All mice infected with the highly virulent strain of C. neoformans, YC-11, died within 3 to 6 weeks because of rapid multiplication of the organism in the lungs and dissemination to the brain. In contrast, a weakly virulent strain, YC-13, was almost completely eradicated from the lungs and did not disseminate to the brain, leading to survival of all infected animals during the period of observation (15 weeks). The virulence of the third strain, YC-5, was intermediate between the other two strains. To examine the susceptibility of C. neoformans to the fungicidal effect of nitric oxide (NO) and superoxide anions (O2-), the organisms were exposed to these oxidants, which were chemically generated in a cell-free system. Interestingly, the number of live YC-13 yeast cells was markedly reduced after exposure to NO and O2-. In contrast, YC-11 was almost completely resistant to the killing effect of these oxidants. YC-5 showed an intermediate susceptibility. Our results demonstrate that the resistance of C. neoformans to the fungicidal effects of RNI and ROI is related to virulence, and suggest that the resistance to nitrogen- and oxygen-derived oxidants may be one of the factors to determine the outcome of infection with C. neoformans.

Association of residual ridge resorption with systemic factors in home-living elderly subjects

Residual ridge resorption after loss of teeth is a multifactorial oral problem. To examine the association of residual ridge resorption with systemic factors, a cross-sectional study was made of 177 edentulous subjects (43 men and 134 women) aged 76, 81, and 86 years. Resorption in the mandibular and maxillary residual ridges was assessed from panoramic radiographs. The effects on residual ridge resorption of the age, gender, smoking, alcohol intake, body mass index, functioning in daily living, and certain systemic diseases of the subjects were investigated. After adjustment for age and duration of edentulousness, the elderly women had a greater amount of reduction in the mandibular residual ridge than the men (P < 0.001). When the resorption was classified into slight or moderate and severe resorptions, the elderly with asthma were at high risk of severe reduction in the edentulous mandible (odds ratio, 6.0; 95% confidence interval (CI), 1.3-28.2); the elderly women were at high risk of severe resorption in the edentulous mandible, with an odds ratio of 4.5 (95% CI, 1.2-17.1); an inverse association was found between alcohol intake and severe resorption in the edentulous maxilla (odds ratio, 0.4; 95% CI, 0.2-0.9). This study suggests that asthma due to corticosteroid treatment is to be considered a risk indicator for severe resorption of the edentulous mandible, alcohol intake in the elderly may be related to a lesser degree of resorption of the edentulous maxilla. Female gender is confirmed as a major factor resulting in mandibular atrophy.

Oral status and prosthetic factors related to residual ridge resorption in elderly subjects

Our earlier studies on edentulous elderly subjects have shown associations of severe resorption in the mandibular residual ridge with female gender and systemic diseases. The aim of this study was to examine whether other factors also were related to residual ridge resorption (RRR). Among 177 edentulous elderly subjects effects on RRR were investigated with regard to history of edentulousness and denture-wearing, the condition of the dentures and soft tissues, dental status of the opposing jaw, and oral hygiene habits. No significant association was found between degree of resorption and duration of edentulousness in either the mandible or the maxilla. RRR was related to denture quality (P < 0.05); however, severe resorption was not. In the maxilla previous use of removable partial dentures was a factor contributing to the resorption (odds ratio (OR), 2.4); flabby ridge was related to the severity of the resorption (OR, 2.4). This study showed local factors related to RRR more often in the maxilla than in the mandible, thus suggesting that severe resorption in the mandible is influenced more by systemic factors than by those investigated in this study.

A novel lipopolysaccharide-response element contributes to induction of nitric oxide synthase

The gene encoding the high output isoform of nitric oxide synthase represents a large class of alarm and defense genes transcriptionally induced in response to bacterial lipopolysaccharide (LPS). The promoters of most of these genes contain at least two LPS-response elements, one of which commonly binds transcription factors of the NF-kappaB/Rel family. Here a novel LPS-response element is identified in the inducible nitric oxide synthase promoter, termed LREAA, which contains critical adenosine residues lying 19-20 base pairs downstream of the proximal NF-kappaB binding element (NFkappaBd). Both NFkappaBd and LREAA are required for LPS-induced promoter activity. A protein partially recognized by antibody against transcription factor Oct-1 binds to the LREAA element constitutively in untreated macrophages while contributing to a DNA-protein complex that includes NF-kappaB p50 in macrophages treated with LPS. NF-kappaB p50 and the LREAA-binding proteins may together recruit an LPS-triggered transactivator of transcription.

Resorption of mandibular canal wall in the edentulous aged population

STATEMENT OF PROBLEM

The mandibular canal wall may be affected by the progress of residual ridge resorption after tooth extraction. Little knowledge is available regarding the relationship of specific systemic factors and the resorption of the mandibular canal wall.

PURPOSE

The purpose of this study was to assess the status of the mandibular canal in the edentulous mandible and to determine whether there is any relationship between the resorption of the mandibular canal wall and selected health indices in the elderly.

MATERIAL AND METHODS

The status of the mandibular canal was assessed from panoramic radiographs of 128 edentulous elderly subjects (32 men and 96 women).

RESULTS

The superior border of the mandibular canal was more frequently resorbed in women (32.6%) than in men (9.8%). Resorption in the mandibular canal wall was significantly more prevalent in subjects with asthma (odds ratio: 6.0), with thyroid disease (odds ratio: 3.04), and with a cortical thickness at the mandibular angle less than 1 mm thick (odds ratio 2.74).

CONCLUSION

The findings suggest that gender, asthma, and thyroid disease play important roles in resorption of the mandibular canal wall.

[Antiallergic effects of tranilast in rats and guinea pigs]

Tranilast is an anti-allergic drug. In this study, we made a comparision between the Tranilast synthized by School of Pharmacy WCUMS using new technical and the Tranilast produced by Kissei pharmaceutical Co. LTD, Japan on their antiallergic effects. We found that the two tranilasts had the same antiallergic effects: (1) they inhibit the passive cutaneous anaphylaxis in sensitized rats with the dose of 100, 200 mg/kg(P < 0.01); (2) they inhibit degranulation of mast cells in sensitized rats (10(-5) and 10(-4) mol/L) (P < 0.05); (3) they inhibit schultz-Dale response in sensitized guinea pigs (10(-3) and 10(-4) (mol/L); (4) the inhibit SRS-A release from the lung of sensitized guinea pigs(10(-3), 10(-4) and 10(-5) mol/L) (P < 0.05); and (5) they inhibit the contraction of ileum of normal guinea pigs induced by SRS-A(10(-4) and 10(-3) mol/L).

Quantitative assessment of vertical heights of maxillary and mandibular bones in panoramic radiographs of elderly dentate and edentulous subjects

The clinical applicability of vertical measurements of the mandible and maxilla in panoramic radiographs was studied by assessing the variety of vertical heights among 91 elderly dentate subjects. Measurements in each jaw and calculations of a maxillary ratio were made at five sites. Variations in measurements of the dentate subjects were small: 9-11% for vertical measurements in the mandible, 6-11% for vertical measurements in the maxilla, and 8-10% for the maxillary ratios. These findings suggest that it is possible quantitatively to assess heights of the mandibular and maxillary bones in panoramic radiographs. Reductions in the edentulous jaws were assessed by comparing the heights of jaws of elderly dentate subjects with those measured in 177 elderly edentulous subjects. Significant differences in heights of the mandibular body and maxilla were found between the dentate and the edentulous (P < 0.001). Edentulous women had greater values for percentage reduction in the mandibles than did the men (P < 0.01; P < 0.001 in various locations).

Central distribution of sensory fibers in the facial nerve: an anatomical and immunohistochemical study

Wheat germ agglutinin-conjugated horseradish peroxidase (WGA-HRP) injection into the facial nerve of the cat resulted in retrograde labeling in the geniculate and jugular ganglia ipsilaterally. Labeled fibers were found to enter into the brain stem through the intermediate and vagal nerves. These fibers ascended or descended into the dorsal portion of the spinal trigeminal tract and were distributed to the principal sensory nucleus of the trigeminal nerve, marginal layer of the interpolar part of the spinal trigeminal nucleus, nucleus of the solitary tract and ventrolateral portion of the cuneate nucleus. It was of particular interest in the present study that the intensive labeling was present in the medial portion of laminae I-IV of the upper cervical spinal cord. The immunohistochemical study revealed a lot of substance P-immunoreactive neurons in the geniculate and jugular ganglia, and heavy accumulation of immunoreactive fibers in laminae I-II of the upper cervical spinal cord.

Expression and phosphorylation of a MARCKS-like protein in gastric chief cells: further evidence for modulation of pepsinogen secretion by interaction of Ca2+/calmodulin with protein kinase C

In gastric chief cells, agents that activate protein kinase C (PKC) stimulate pepsinogen secretion and phosphorylation of an acidic 72-kDa protein. The isoelectric point and molecular mass of this protein are similar to those for a common PKC substrate; the MARCKS (for Myristoylated Alanine-Rich C Kinase Substrate) protein. We examined expression and phosphorylation of the MARCKS-like protein in a nearly homogeneous suspension of chief cells from guinea pig stomach. Western blotting of fractions from chief cell lysates with a specific MARCKS antibody resulted in staining of a myristoylated 72-kDA protein (pp72), associated predominantly with the membrane fraction. Using permeabilized chief cells, we examined the effect of PKC activation (with the phorbol ester PMA), in the presence of basal (100 nM) or elevated cellular calcium (1 microM), on pepsinogen secretion and phosphorylation of the 72-KDa MARCKS-like protein. Secretion was increased 2.3-, 2.6-, and 4.5-fold by incubation with 100 nM PMA, 1 microM calcium, and PMA plus calcium, respectively. A PKC inhibitor (1 microM CGP 41 251) abolished PMA-induced secretion, but did not alter calcium-induced secretion. This indicates that calcium-induced secretion is independent of PKC activation. Chief cell proteins were labeled with 32P-orthophosphate and phosphorylation of pp72 was detected by autoradiography of 2-dimensional polyacrylamide gels. In the presence of basal calcium, PMA (100 nM) caused a > two-fold increase in phosphorylation of pp72. Without PMA, calcium did not alter phosphorylation of pp72. However, 1 microM calcium caused an approx. 50% attenuation of PMA-induced phosphorylation of pp72. Experiments with a MARCKS "phosphorylation/calmodulin binding domain peptide" indicated that calcium/calmodulin inhibits phosphorylation of pp72 by binding to the phosphorylation/calmodulin binding domain and not by inhibiting PKC activity. These observations support the hypothesis that, in gastric chief cells, interplay between calcium/calmodulin binding and phosphorylation of a common domain on the 72-kDa MARCKS-like protein plays a role in modulating pepsinogen secretion.

Structure of chain d of the gigantic hemoglobin of the earthworm

The extracellular hemoglobin of the earthworm has four major O2-binding chains, a, b, c and d, together with additional non-heme structural chains that are required for assembly. Although the abc trimer self-associates extensively at least to (abc)10, addition of chain d results in the formation of a discrete 280 kDa complex corresponding to (abcd)4. Thus a primary function of chain d is to cap the abc association and convert an abc trimer that binds O2 with weak cooperativity to a highly cooperative (abcd)4 complex. Amino-acid sequences of the major globin chains a, b, c have been determined previously by peptide and cDNA analysis. However, the peptide sequence reported for the major chain d (Shishikura, F., Snow, J.W., Gotoh, T., Vinogradov, S.N. and Walz, D.A. (1987) J. Biol. Chem., 262. 3123-3131), has a calculated molecular mass 134-167 Da higher than masses for components of chain d determined by mass spectrometry (Owrby, D.W., Zhu, H., Schneider, K., Beavis, R.C., Chait, B.T. and Riggs, A.F. (1993) J. Biol. Chem. 268, 13539-13547). Reverse-phase HPLC confirms the presence of two distinct polypeptides, d1 and d2, together with d'1, a variant of d1, cDNA derived amino acid sequences have been determined for chains d'1 and d2 by application of the polymerase chain reaction with primers based on the NH2-terminal sequences and oligo-dT. Each of the two cDNA-derived sequences has 140 residues and they differ by 28 substitutions. The data show that the sequence originally reported had been derived from peptides generated from both polypeptides.

[Expression level of MDR1, and MRP in patients with malignant blood disease and its clinical significance]

RT-PCR method was used to detect the expression level of multi-drug resistance gene (MDR1) and multi-drug resistance associated protein (MRP) in patients with malignant blood disease, including 19 cases of acute leukemia and 6 cases of multiple myeloma. The results showed: expression level of MDR1 in patients with known clinical drug resistance elevated obviously and was significantly associated with clinical drug resistance (r = 0.612, P < 0.01), which indicated that expression of MDR1 was the main mechanism of clinical drug resistance. There is no obvious relationship between expression level of MDR1 and MRP (r = 0.035, P > 0.05).

Assessment of the effect of an oscillating/rotating electric toothbrush on oral health. A 12-month longitudinal study

The aim of this 12-month parallel design controlled clinical trial was to assess the effect of the Braun Oral-B Plak Control electric toothbrush on supragingival plaque and gingival health, and to compare it with a conventional soft manual toothbrush (Jordan). A total of 111 patients aged between 20 and 63 years, from a general population, with bleeding on probing at 30% or more of all sites examined were entered into the study. At baseline, immediately after periodontal examination, all volunteers received a thorough scaling of their teeth. Volunteers in both groups were told to brush their teeth for 2 min 2 x a day. Oral hygiene instruction was given at the start of the study and was not repeated. At 3, 6 and 12 months, assessments were carried out by a single clinician who was not aware which group the volunteers belonged to. Analysis of results demonstrated that over the 12 months of the study, the Braun Oral-B Plak Control was significantly more effective in improving gingival health than the manual toothbrush. There was, however, no difference between the 2 groups in terms of plaque removal, with the number of sites with visible plaque decreasing by a similar amount in both groups. In conclusion, results indicate that the Braun Oral-B Plak Control toothbrush is safe and more effective than a manual toothbrush in improving gingival health.

Canine parvovirus capsid structure, analyzed at 2.9 A resolution

The DNA-containing capsid of canine parvovirus (CPV) is analyzed following atomic refinement at 2.9 A resolution. The capsid contains 60 copies of the capsid protein related by icosahedral symmetry. The atomic model has been extended from the first residue (Gly37) of the unrefined 3.25 A structure towards the N terminus. The electron density shows that approximately 87% of the capsid proteins have N termini on the inside of the capsid, but for approximately 13%, the polypeptide starts on the outside and runs through one of the pores surrounding each 5-fold axis, explaining apparently conflicting antigenic data. Analysis of potential hydrogen bonds reveals approximately 50% more secondary structure than previously apparent. Most of the additional secondary structure are in the 71 and 221 residue-long loop insertions between beta-strands E and F and G and H, forming subunit-bridging sheets that likely add specificity to assembly interactions. Structural analysis of the extensive subunit interactions around the 3-fold axes shows that assembly is a multistep process with loops intertwining following initial contact. Estimated free energies of association suggest that the formation of 3 and 5-fold contacts likely takes precedence over 2-fold interactions. Energies for initial association into trimers or pentamers would be similar, but the intertwining of loops about the 3-fold axis adds an additional large activation barrier to dissociation. Analysis of the surfaces of the assembled capsid shows a surprising lack of basic amino acids that might have been expected to interact with the negatively charged phosphoribose backbone of the DNA. Instead, uncharged polar and van der Waal's interactions predominate in the packaging of single-stranded DNA into the capsid.

Height of mandibular basal bone in dentate and edentulous subjects

Age-related differences in the height of the mandibular basal bone were compared between young and old dentate subjects and between dentate and old edentulous subjects by means of panoramic radiographs. The distances of the mental foramen and mandibular canal from the lower border of the mandible, when measured, showed the mandibular basal bones in old dentate and in old edentulous men to be higher than those of young dentate men in the molar region (P < 0.05). The height of the basal bone below the mental foramen was smaller in old edentulous women than in young and old dentate women (P < 0.05). A slight bone deposition along the lower border of the mandible in the molar region seems to take place with increasing age. The mental foramina of edentulous women move toward the lower border of the mandible as a result of alveolar bone resorption.

Stoichiometry of subunits and heme content of hemoglobin from the earthworm Lumbricus terrestris

The extracellular hemoglobin (Hb) of the earthworm, Lumbricus terrestris, has four major O2-binding chains, a, b, c (forming a disulfide-linked trimer), and d ("monomer"). Additional structural chains, "linkers," are required for the assembly of the approximately 200-polypeptide molecule. The proportion of linker chains had been reported to be one-third of the total mass on the basis of densitometry of Coomassie Blue-stained SDS-gels. Reverse-phase high performance liquid chromatography (HPLC), however, gave 16.3% linkers on the basis of both 220-nm absorbance and amino acid analysis (Ownby, D. W., Zhu, H., Schneider, K., Beavis, R. C., Chait, B. C., and Riggs, A. F. (1993) J. Biol. Chem. 268, 13539-13547). The subunit proportions have now been redetermined by SDS capillary electrophoresis as a test of the HPLC results. The electrophoresis, monitored at 214 nm, avoided the use of Coomassie Blue and provided results identical with those obtained by HPLC. Capillary electrophoresis monitored at both 214 and 415 nm was used to show that linker chains do not bind heme. Heme content has been found to be 2.9% by determination of hemin, amino acid analysis and dry weight. Measurement of the rate of hemin loss from oxidized L. terrestris Hb shows that high rates of loss can account for values of heme content significantly below 2.9% (or 0.26% iron).

Testis development in the opossum Monodelphis domestica

Testis development in the grey short-tailed opossum, Monodelphis domestica, was investigated by light and electron microscopy in 180 animals. On the day of birth, half the karyotyped males were found to have histologically differentiated testes. By day (d) 1 testicular cords were clearly distinguished in all XY gonads and the tunica albuginea was fully developed. At this stage the large and pale primordial germ cells could be differentiated from dark pre-Sertoli cells. From d 3 the testis became progressively rounded and testicular cords were surrounded by peritubular cells. Leydig cells were then distinguishable by the expected ultrastructural features of steroidogenically active cells, showing abundant vesicles of SER, extensive mitochondria with tubular cristae and numerous lipid inclusions. Subsequently these cells formed clusters and were surrounded by envelope cells until wk 12. Testes were located in the abdomen, attached to the large mesonephroi, until d 24 after birth when they began their descent to the scrotal sac. From 7 wk the interstitial tissue became less cellular. At the prepubertal stage (12 wk), the seminiferous tubules lacked lumina. Leydig cell cytoplasm was electron-dense with increased amounts of SER forming parallel profiles. By 4 mo (pubertal stage), seminiferous tubules were patent and various spermatogenic stages, including spermatozoa, were seen for the first time. Leydig cells then greatly outnumbered other interstitial tissue cells and were closely-packed around blood vessels but no longer clustered by envelope cells; their SER was very highly organised into masses of parallel arrays and lipid inclusions were reduced. In the adult (1 y) Leydig cells reached their greatest size; their morphological features resembled those seen at 4 mo except that lipid inclusions were sparse. In ageing Leydig cells (2-3 y), large amounts of SER were present but disorganised.

Plant cells contain a novel member of the retinoblastoma family of growth regulatory proteins

The product of the retinoblastoma susceptibility gene (Rb) controls the passage of mammalian cells through G1 phase. Animal virus oncoproteins interact with the Rb protein via an LXCXE motif and disrupt Rb-E2F complexes, driving cells into S-phase. Recently, we found that the RepA protein of a plant geminivirus contains an LXCXE motif that is essential for its function, a finding that predicts the existence of Rb-related proteins in plant cells. Here we report the isolation of a maize cDNA clone encoding a protein (ZmRb1) which, based on structural and functional studies, is closely related to the mammalian Rb family of growth regulatory proteins. ZmRb1 shows a high degree of amino acid conservation when compared with animal Rb members, particularly in the A/B 'pocket' domain, but ZmRb1 has a shorter N-terminal domain. ZmRb1 forms stable complexes with plant LXCXE-containing proteins, e.g. geminivirus RepA protein. Geminivirus DNA replication is reduced in plant cells transfected with plasmids encoding either ZmRb1 or human p130, a member of the Rb family. This suggests that ZmRb1 controls the G1/S transit in plant cells and is consistent with the fact that geminiviruses need an S-phase environment for DNA replication, as animal DNA tumor viruses do. Our results allow the extension of the Rb family of tumor suppressor proteins to plants and have implications on animal and plant strategies for cell growth control.

HIV infection and AIDS in China, 1985 through 1994

OBJECTIVES

This paper analyzes data on the distribution of and risk factors for the acquired immunodeficiency syndrome (AIDS) and human immunodeficiency virus (HIV) infection in China.

METHODS

Ten years of data on persons tested for HIV infection and AIDS and the proportion who tested positive were analyzed against the background of China's population count. The Chinese- and English-language literature on HIV and AIDS from 1985 through 1995 was also reviewed.

RESULTS

Overall, more males than females had HIV infection. Intravenous drug use was the primary source of transmission, followed by heterosexual contacts. Only a small number of the persons tested were homosexual, but their proportion of HIV seropositivity ranked third to that of drug users; that of general hospital patients ranked fourth.

CONCLUSIONS

HIV infection and AIDS in China began as a highly regionalized and largely rural problem in Yunnan Province. However, HIV infection and AIDS have become an emerging urban problem. HIV seropositivity is low among several groups thought to have an elevated risk.

Height of the residual ridge and radiographic appearance of bony structure in the jaws of clinically edentulous elderly people

Alveolar atrophy and its relation to osteopenia of the mandible were studied in 124 edentulous 76-, and 81- and 86-year-old subjects (32 males and 92 females). Both variables were assessed visually from panoramic radiographs. Mandibular alveolar atrophy was found to be more severe in women (P < 0.001). No statistically significant differences were found between the three age-groups in mandibular alveolar atrophy, nor between the sexes or age-groups in maxillary alveolar atrophy. The structure of the mandibular bone was osteopenic in 38 patients (30.7%), a situation that was more frequent in women (P < 0.001). The relationship between the observed osteopenia and the severity of the mandibular alveolar atrophy in women was statistically significant (P < 0.05).

IL-12 protects mice against pulmonary and disseminated infection caused by Cryptococcus neoformans

We examined the role of IL-12 in host resistance to Cryptococcus neoformans using a murine model of pulmonary and disseminated infection. In this model, mice were infected intratracheally with viable yeast cells. Mice untreated with IL-12 allowed an uncontrolled multiplication of yeast cells in the lung with infiltrations of few inflammatory cells, and a cryptococcal dissemination to the brain and meningitis by 3 weeks, resulting in death of all animals within 4-6 weeks. IL-12, when administered from the day of tracheal infection for 7 days, induced a marked infiltration of inflammatory cells, consisting mostly of mononuclear cells, and significantly reduced the number of viable yeast cells in the lung. The treatment suppressed brain dissemination, as shown by a marked reduction of yeast cells in the brain and prevention of meningitis. These effects resulted in a significant increase in the survival rate of infected mice. In contrast, late administration of IL-12 commencing on day 7 after instillation of yeast cells failed to protect the mice against infection with C. neoformans. In further experiments, early administration of IL-12 markedly induced interferon-gamma (IFN-gamma) mRNA in the lungs of infected mice, while no IFN-gamma mRNA was detected without this treatment. Our results indicate that IL-12 is effective when administered in the early period of pulmonary cryptococcal infection.

Molecular cloning of a novel allele of SMR1 which determines sulfometuron methyl resistance in Saccharomyces cerevisiae

A different mutation (SMR1B) to SMR1-410 (ilv2), which determines resistance to sulfometuron methyl in Saccharomyces cerevisiae, was cloned by PCR. Sequence analysis indicated a C to T change at position 575 of the ILV2 coding sequence, which results in a proline transition to leucine at position 192. Similarly to SMR1-410, the SMR1B gene was confirmed as a convenient dominant selective marker for yeast transformation including industrial strains.

Effect of head positioning in panoramic radiography on vertical measurements: an in vitro study

OBJECTIVE

To assess whether it is possible to make accurate vertical measurements of the jaws from panoramic radiographs.

METHODS

Five dry skulls were shifted 5 mm forwards and backwards and tilted 5 degrees up and down in the sagittal plane. Panoramic radiographs of each skull were obtained in nine different positions. In the maxilla, three reference lines were used and vertical measurements were made at the distal surfaces of the first premolar and first molar and in the midline. In the mandible, measurements were made at the distal surfaces of the first premolar and first molar, and at the mental foramen on both sides, and in the midline. The points and lines were marked manually and the radiographs were digitized, magnified and measured.

RESULTS

Sagittal shifting and tilting had only a slight effect on measurements in the mandible. Sagittal tilting of the head had the greatest effect on all the measurements made from the line between the articular eminences to the alveolar crest, as well as measurements in the maxillary midline.

CONCLUSIONS

The line between the articular eminences is unsuitable as a reference line for measurements of the tooth-bearing areas. A slight misalignment of the head does not significantly affect the vertical measurements in the mandible or of the posterior maxilla if the reference lines are in the same vertical plane as the teeth.

Marek's disease virus (MDV) ICP4, pp38, and meq genes are involved in the maintenance of transformation of MDCC-MSB1 MDV-transformed lymphoblastoid cells

An antisense strategy has been used to identify genes important for the maintenance of transformation of MDCC-MSB1 (MSB1) Marek's disease virus-transformed lymphoblastoid cells. Oligodeoxynucleotides antisense to the predicted translation initiation regions of ICP4 and pp38 mRNAs inhibited proliferation of MSB1 cells but not MDCC-CU91 (CU91) reticuloendotheliosis virus-transformed cells. Control oligodeoxynucleotides having the same base composition but a different sequence did not inhibit MSB1 cell proliferation. In addition, ICP4 and pp38 antisense oligodeoxynucleotides resulted in 77- and 100-fold reductions in colony formation by MSB1 cells in soft agar, respectively. To extend and corroborate these results, a novel system based on efficiently regulated expression of eukaryotic genes by a chimeric mammalian transactivator, LAP267 (S. B. Baim, M. A. Labow, A. J. Levine, and T. Shenk, Proc. Natl. Acad. Sci. USA 88:5072-5076, 1991), was used. MSB1-derived stably transfected cell lines in which RNA antisense to Marek's disease virus ICP4, pp38, or meq could be induced by treatment of the cells with isopropyl-beta-D-thiogalactopyranoside (IPTG) were constructed. Control cell lines in which expression of ICP4 sense or pUC19 sequences could be induced by IPTG were also constructed. Induction of the cell lines indicated that ICP4 antisense RNA, but not ICP4 sense RNA or pUC19 RNA, inhibited proliferation of MSB1 cells. Induction of ICP4, meq, or pp38 antisense RNAs, but not ICP4 sense or pUC19 RNAs, had a dramatic effect on relative colony formation by MSB1 cells in soft agar. These results indicate that ICP4, pp38, and Meq are all involved in the maintenance of transformation of MSB1 cells.

Contribution of interferon-gamma in protecting mice during pulmonary and disseminated infection with Cryptococcus neoformans

In the present study, the role of interferon-gamma (IFN-gamma) in the host resistance against Cryptococcus neoformans was examined using a murine model of pulmonary and disseminated infection. In this model, mice were infected intratracheally with live yeast cells, and the histological changes in the lungs and the number of microorganisms in the lung and brain were compared in mice treated and untreated with anti-IFN-gamma monoclonal antibody (mAb) to define the contribution of endogenously synthesized IFN-gamma in the natural course of infection. Administration of this mAb reduced the accumulation of inflammatory cells in the alveolar septa, peribronchial and perivascular areas, and promoted the expansive growth of microorganisms in the alveoli and destruction of alveolar structure. The neutralization of endogenous IFN-gamma by mAb increased the number of microorganisms in the lung and brain, and significantly shortened the survival time of infected mice. On the other hand, administration of IFN-gamma decreased the number of microorganisms in these organs, and significantly extended their survival time. Considered together, our results suggest that endogenous IFN-gamma protects mice from infection with C. neoformans by inducing a cellular inflammatory response, potentiating the clearance of microorganism from the lungs and preventing its dissemination into the central nervous system.

[Missed diagnosis in prostate incidental carcinoma]

522 cases of benign prostate hyperplasia from 1980 to 1994 were reviewed. Prostate incidental carcinoma (PIC) was identified in 26 cases (4.98%). In order to study the pathomorphological features and to study the causes for missed diagnosis of this entity, the authors observed and analysed the numbers of carcinomatous foci their distribution, classification, staging and differentiation, morphological features and prostate specific antigen (PSA) markers. It was found that 23 cases exhibited a pathological structure of uniform pattern and 3 cases with pluriform pattern. Adenocarcinoma was most common. 17 cases were A1 stage and 9 cases were A2 stage. Isolated multiple foci of invasion and alterations of architecture are important pathological features of these cases. Missed diagnosis of prostate cancer is related to the small amount of biopsy tissue, contrast between benign and malignant prostate epithelial tissue not distinct, scarce nuclear anaplasia, careless microscopic observation, or observer lacks the ability to differentiate between pathologic types and pluriform patterns. Different PSA reactions may be related to tumor differentiation and classification.

Changes in the position of the mental foramen as a result of alveolar atrophy

The location of the mental foramen has often been claimed to be unaffected by alveolar atrophy. In the present study, the distances of the mental foramen and the mandibular canal from the lower cortex of the mandible were compared in a radiographed series of 40 edentulous elderly women with advanced alveolar atrophy and 40 elderly women who had 10 or more lower teeth left. The mental foramen was situated on average 3.8 mm lower in dentulous jaws than in dentulous jaws (P < 0.0001). The mandibular canal was also situated lower in edentulous jaws, but the difference was not statistically significant. The results confirm the finding that the mental foramen seems to descend as a result of alveolar atrophy.

Identification and analysis of a retinoblastoma binding motif in the replication protein of a plant DNA virus: requirement for efficient viral DNA replication

Geminiviruses are plant DNA viruses with small genomes whose replication, except for the viral replication protein (Rep), depends on host proteins and, in this respect, are analogous to animal DNA tumor viruses, e.g. SV40. The mechanism by which these animal viruses create a cellular environment permissive for viral DNA replication involves the binding of a virally encoded oncoprotein, through its LXCXE motif, to the retinoblastoma protein (Rb). We have identified such a LXCXE motif in the Rep protein of wheat dwarf geminivirus (WDV) and we show its functional importance during viral DNA replication. Using a yeast two-hybrid system we have demonstrated that WDV Rep forms stable complexes with p130Rbr2, a member of the Rb family of proteins, and single amino acid changes within the LXCXE motif abolish the ability of WDV Rep to bind to p130Rbr2. The LXCXE motif is conserved in other members of the same geminivirus subgroup. The presence of an intact Rb binding motif is required for efficient WDV DNA replication in cultured wheat cells, strongly suggesting that one of the functions of WDV Rep may be the linking between viral and cellular DNA replication cycles. Our results point to the existence of a Rb-like protein(s) in plant cells playing regulatory roles during the cell cycle.

Cloning and molecular analysis of two different ILV5 genes from a brewing strain of Saccharomyces cerevisiae

Two different ILV5 genes encoding acetohydroxy-acid isomeroreductases, and named ILV5G and ILV5X, were cloned and sequenced from a Saccharomyces cerevisiae brewing strain. The coding sequence of ILV5X shows a single nucleotide change with respect to that from the ILV5 gene of a S. cerevisiae laboratory strain. In addition, all promoter motifs which are, or are presumed to be, implicated in transcription regulatory functions are identical in ILV5 and ILV5X. In contrast, the coding sequence of ILV5G differs in 5.6% of its nucleotides from that of ILV5 and most of its promoter regulatory motifs show a single nucleotide change with respect to those from ILV5.

The high-output nitric oxide pathway: role and regulation

Nitric oxide synthase (NOS) catalyzes the production of nitric oxide (NO), a short-lived radical gas with physiological or pathophysiological roles in nearly every organ system. The inducible NO synthase (iNOS) is a high-output isoform compared to the two constitutive NOSs. The iNOS from murine macrophages tightly binds calmodulin as a subunit, and its activity is not dependent on exogenous calmodulin or elevated calcium. This iNOS is induced at the transcriptional level by bacterial lipopolysaccharide (LPS) and interferon-gamma. The promoter region of the murine iNOS gene contains at least 24 oligonucleotide motifs corresponding to elements involved in the binding of transcription factors in the promoters of other cytokine-inducible genes. Nuclear factor NF-kappa B/c-rel, interacting with cycloheximide-sensitive protein(s) and binding to the NF-kappa Bd site in the iNOS promoter, controls the induction of iNOS by LPS. However, iNOS is also regulated posttranscriptionally. Complex regulation of iNOS at multiple levels may reflect the dual role of iNOS in host defense and autotoxicity.

Radiographic findings in the jaws of clinically edentulous old people living at home in Helsinki, Finland

In the present survey the radiographic findings in the jaws of 124 clinically edentulous old people living at home in Helsinki, Finland, were studied, using panoramic radiography supplemented by intraoral radiographs. Only 9% of the subjects had root remains. Impacted teeth were found in 4%, radiolucent lesions in 3%, and radiopaque findings in 13%. Deviations from normal condylar structure were found in 17% and mucosal thickenings in the maxillary sinuses in 7%. The mental foramen was situated at the top of the residual ridge in 42% of the subjects. Topically situated mental foramen and condylar changes were commoner in women. The radiographic oral health status of the population studied was good.

Sensibility threshold in patients with masticatory muscle pain

Sensibility and pain thresholds were measured in 27 patients with myofascial pain and craniomandibular disorders and in 19 controls. A monopolar electric stimulator with increasing direct current values was used to record pain and sensibility thresholds in the lower incisors. Patients with myofascial pain had a tendency towards lower sensibility and lower pain thresholds than the controls, although the differences were not statistically significant.

Serum and tissue levels of estradiol during estrogen-induced renal tumorigenesis in the Syrian hamster

The estrogen-induced renal tumor in the hamster has emerged as a major animal model in hormonal carcinogenesis. However, a fundamental aspect of this experimental model has as yet not been investigated. In the present study, comparisons between the serum and tissue 17 beta-estradiol (E2) levels in cyclic female hamsters and corresponding hormone levels in E2-treated castrated male hamsters have been made. Data is provided concerning the concentration of estrogenic hormones in the serum and target tissue typically required to elicit renal tumorigenesis in this species. Serum E2 levels in the cyclic female hamster average 79 pg/ml on days 1-2 and 311 pg/ml on days 3-4, attaining a maximum of 358 pg/ml on day 4 of the cycle. Elevation in uterine, renal and hepatic E2 tissue levels during days 3-4 of the cycle reflect increases in serum E2 levels which were 3.0-, 2.0-, and 2.6-fold higher when compared to day 1 of the cycle in these tissues. As expected, serum E2 levels of untreated castrated male hamsters did not appreciably vary over a 6 month period of aging and averaged about 32 pg/ml. Under conditions which produced essentially 100% renal tumor incidence, a rapid rise in serum E2 levels, averaging 71.0-fold higher than untreated castrated levels, was seen. A steady state serum E2 level of 2400 to 2700 pg/ml was maintained from 45-180 days of continuous estrogen treatment. Compared to kidneys of untreated hamsters, renal E2 levels in E2-treated hamsters rose only on average 5.4-fold between 15-180 days of hormone exposure. Serum levels of E2-treated hamsters were 5.7- to 8.0-fold higher than those observed in cyclic female hamsters on days 3 and 4. However, at these higher E2-treated serum levels there was no apparent effect either on weight loss or mortality of the animals.

[CT morphology of hepatocellular carcinoma lesions]

The preoperative CT appearances of hepatocellular carcinoma (HCC) lesions in 232 cases were analyzed. According to the CT features in shape, outline and boundary of the tumors, the HCC was divided into 3 Types: Type I--roundish expansive growth type (REG TYPE), Type II--irregular expansive growth type (IREG TYPE), and type III--irregular infiltration growth type (IIG TYPE). Comparing different CT types with findings at laparotomy or pathological specimens, it showed that the intrahepatic tumor dissemination rates of type I, II and III were 18.6%, 37.7%, and 47.8%, respectively. The lymph node metastasis rates were 0, 7.7% and 23.1%, respectively. The portal vein tumor thrombus formation rates were 2.3%, 20.8% and 46.4%, respectively. The proportion of encapsulation (67.4%, 27.3% and 5.28%, respectively) apparently decreased from type I to type III in turn. The differences were statistically significant. From type I to III the resection rate of large sized tumor decreased, and the prognosis was from bad to worse. Survival analysis (Cox's mode) showed significant differences from type I to type III. Therefore, CT classification may be used to evaluate the gross biological behavior of HCC lesions and may be of pathological and clinical relevance.

Experimental study on the corneal endothelium of traumatic cataract

The cell morphology of corneal endothelium in 84 mice with experimental traumatic cataract was investigated with stained corneal buttons. In the experimental group, the boundaries between adjacent corneal endothelial cells were significantly distorted, some cell boundaries manifested degenerative changes that led to coalescence of the cells. The mean density and mean area of endothelial cells of the controls showed significant difference from those of the experimental group during the 12 weeks of observation. The density of endothelial cells decreased from 3,312 +/- 337/mm2 of the control group to 2,944 +/- 418/mm2 in the group of partially opaque lenses and 2,713 +/- 472/mm2 in the group of totally opaque lenses. Meanwhile, the area of endothelial cells and the coefficient of variation also significantly changed correspondingly, and the degree of damage in the corneal endothelium correlated with the degree of the lens opacity.

[Clinical value of the Chengdu classification of non-Hodgkin's lymphomas]

Two hundred forty-nine cases of non-Hodgkin's lymphomas (NHL) were reviewed by using the working classification of NHL (Chengdu, 1985). The results showed that the patients of 249 cases of NHL ranging in age from 5 to 76 years, with the mean age of 42 of the types were separated into three major prognostic groupings as follows: 1. low (41 of 249 cases, small lymphocytic 27 cases, lymphoplasmacytoid 2 cases, follicular cleaved 7 cases, follicular cleaved and noncleaved 5 cases); 2. intermediate (58 of 249 cases, diffuse cleaved 28 cases, diffuse cleaved and noncleaved 27 cases, follicular noncleaved 3 cases); and 3. high grade malignancy (150 of 249 cases, diffuse noncleaved 49 cases, lymphoblastic 41 cases, immunoblastic 13 cases, polymorphic 39 cases, clear cell 2 cases, histiocytic 6 cases). Each group was significantly different from the others (P less than 0.05). The prognosis of patients with angioimmunoblastic lymphadenopathy like T-cell lymphoma (9 of 249 cases) was not more significant (P greater than 0.05) than that of patients with other polymorphic lymphoma (30 of 249 cases). The results showed this Chengdu classification of NHL is good for practice and usage in clinical evaluation and routine surgical pathology.

[Transitional mucosa in carcinoma of large bowel. Mucin histochemical and scanning electron microscopical study]

We studied the mucosa close to the carcinoma of large bowel (CLB) in 200 cases, the carcinoma tissue of CLB in 130 and the mucosa of fetus large bowel in 24 by mucin histochemistry, in addition to the mucosa near CLB studied by scanning electron microscope (SEM) in 25. The results suggested that mucin composition of transitional mucosa (TM) was similar to CLB and large bowel mucosa of the fetus. SEM showed significant changes in TM. The HID/AB Stain suggesting abnormal range of TM was within 2 cm in 68.0% (136/200) of cases of CLB, within 3 cm in 88.5% (177/200) and In SEM abnormal range within 2 cm in 88.0% (22/25). The measurement of TM can provide reference for resectable range of CLB.