Growth-promoting activity of tissue inhibitor of metalloproteinases-1 (TIMP-1) for a wide range of cells. A possible new growth factor in serum

Human tissue inhibitor of metalloproteinases-1 (TIMP-1), but not TIMP-2, has potent growth-promoting activity for a wide range of human and bovine cells. TIMP-1 seems to be a new cell-growth factor in serum and to stimulate the cells independently of its inhibitory activity.

The Alzheimer's peptide a beta adopts a collapsed coil structure in water

The self-assembly of the soluble peptide Abeta into Alzheimer's disease amyloid is believed to involve a conformational change. Hence the solution conformation of Abeta is of significant interest. In contrast to studies in other solvents, in water Abeta is collapsed into a compact series of loops, strands, and turns and has no alpha-helical or beta-sheet structure. Conformational stabilization is primarily attributed to van der Waals and electrostatic forces. A large conspicuous uninterrupted hydrophobic patch covers approximately 25% of the surface. The compact coil structure appears meta-stable, and because fibrillization leads to formation of intermolecular beta-sheet secondary structure, a global conformational rearrangement is highly likely. A molecular hypothesis for amyloidosis includes at least two primary driving forces, changes in solvation thermodynamics during formation of amyloid deposits and relief of internal conformational stress within the soluble precursor during formation of lower-energy amyloid fibrils.

The precore/core promoter mutant (T1762A1764) of hepatitis B virus: clinical significance and an easy method for detection

Recently, a new hepatitis B virus (HBV) mutant with HBe antigen-negative phenotype has been characterized, in which one TATA box-like motif of the precore/core promoter had degenerated: most frequently by both A-->T and G-->A mutations at positions 1762 and 1764, respectively. The clinical significance of this mutant is as yet unknown. In our present study, the T1762 A1764 mutant was sought in sera from HBV-infected blood donors and chronic liver disease patients by directly sequencing a PCR-amplified region of HBVDNA. Also, because the A1764 mutation generates a Sau3AI cleavage site (GGTC-->GATC), we digested the PCR products with Sau3AI to see if cleavage would occur at this specific site. Our results mostly corroborated the earlier report but we found a higher-than-predicted frequency of HBe antigen-positive blood donors positive for the mutant (22%). The titres of HBe antigen in these mutant-positive sera were slightly decreased compared to the titres in wild-type HBV infection. In addition, these blood donors had relatively high (though within the normal range) serum alanine aminotransferase (ALT) levels, suggesting that the T1762 A1764 mutation could be used as a sensitive laboratory marker for insidious hepatitis in these otherwise 'asymptomatic' carriers. The Sau3AI assay, which is much more convenient than sequencing, was shown to be useful for the detection of the T1762 A1764 mutant in an extensive number of clinical samples.

Prevalence of serum and salivary antibodies to HTLV-1 in Sjögren's syndrome

There is accumulating evidence that human T-lymphotropic virus-1 (HTLV-1) infection contributes to the development of various inflammatory disorders. To elucidate the relation between the infection and Sjögren's syndrome, seroepidemiological and virological studies were conducted on patients with this syndrome in Nagasaki Prefecture, Japan, an area heavily endemic for HTLV-1. The HTLV-1 seroprevalence rate among the patients with Sjögren's syndrome (17/74, 23%) was significantly higher than that among blood donors (916/27,284, 3%), whereas the difference between patients with systemic lupus erythematosus and blood donors was insignificant. Moreover, among Sjögren's syndrome patients the seroprevalence was high irrespective of age, unlike that among blood donors, which rose with age. Titres of serum antibodies in the HTLV-1 seropositive patients with Sjögren's syndrome were similar to those among patients with HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) and significantly higher than those among healthy carriers. IgM class antibodies were commonly detected in the serum of patients with Sjögren's syndrome. However, unlike that in HAM/TSP patients, the viral load in peripheral-blood mononuclear cells was not necessarily high in the seropositive Sjögren syndrome group. Salivary IgA antibodies to HTLV-1 were common among seropositive patients with Sjögren's syndrome (5/7), which might be due to increased viral activity in the salivary glands. These antibodies were barely detectable in HAM/TSP patients (prevalence 1/10) or in healthy carriers (0/11). The findings strongly suggest that HTLV-1 is involved in the pathogenesis of the disease in a subset of patients with Sjögren's syndrome in endemic areas.

Rapid one-step sandwich enzyme immunoassay for tissue inhibitor of metalloproteinases. An application for rheumatoid arthritis serum and plasma

A 1 h, one-step sandwich enzyme immunoassay was set up with a pair of monoclonal antibodies prepared against bovine tissue inhibitor of metalloproteinases (TIMP). TIMP in samples was allowed to react simultaneously with both solid-phase antibody and peroxidase-labeled Fab' of another antibody. Minimum sensitivity was 1 pg/well for bovine TIMP and 1.5 pg/well for human TIMP. The TIMP level in the sera of 38 rheumatoid arthritis (RA) patients (241 +/- 53 ng/ml, mean +/- SD) was significantly higher (P less than 0.001) than the level in the sera of 81 healthy subjects (175 +/- 39). A similar significant difference (P less than 0.001) was observed between the TIMP level in platelet-poor plasma of normal subjects (64 +/- 10) and that of RA patients (84 +/- 23), suggesting that the increase in TIMP seen in RA sera can not be ascribed merely to an increase in platelet-derived TIMP.

Tissue Doppler-derived index of left ventricular filling pressure, E/E', predicts survival of patients with non-valvular atrial fibrillation

OBJECTIVES

To investigate whether the ratio of early transmitral flow velocity (E) to early diastolic mitral annular velocity (E') predict prognosis in patients with non-valvular atrial fibrillation.

METHODS

230 patients with non-valvular atrial fibrillation were enrolled and studied. According to E/E' value, patients were divided into groups with lower (group A with E/E' <or= 15) and higher (group B with E/E' > 15) E/E'.

RESULTS

During follow up (average 245 days), 21 (9.1%) deaths were documented. All cause death (15/90 (16.7%) v 6/140 (4.3%)), cardiac death (10 (11.1%) v 2 (1.4%)) and congestive heart failure (16 (17.8%) v 8 (5.7%)) were more common in group B than in group A (all p < 0.01). A Kaplan-Meier survival curve showed that the cumulative survival rate was significantly lower in group B than in group A (log rank p = 0.0013). By multivariate logistic regression analysis, E/E' (chi(2) = 4.47, odds ratio (OR) 1.05, 95% confidence interval (CI) 1.01 to 1.11, p = 0.03) and age (chi(2) = 6.45, OR 1.06, 95% CI 1.01 to 1.11, p = 0.02) were independent predictors of mortality.

CONCLUSION

The Doppler-derived index of left ventricular filling pressure, E/E', is a powerful predictor of the clinical outcome of patients with non-valvular atrial fibrillation.

Molecular dynamics of MHC genesis unraveled by sequence analysis of the 1,796,938-bp HLA class I region

The intensely studied MHC has become the paradigm for understanding the architectural evolution of vertebrate multigene families. The 4-Mb human MHC (also known as the HLA complex) encodes genes critically involved in the immune response, graft rejection, and disease susceptibility. Here we report the continuous 1,796,938-bp genomic sequence of the HLA class I region, linking genes between MICB and HLA-F. A total of 127 genes or potentially coding sequences were recognized within the analyzed sequence, establishing a high gene density of one per every 14.1 kb. The identification of 758 microsatellite provides tools for high-resolution mapping of HLA class I-associated disease genes. Most importantly, we establish that the repeated duplication and subsequent diversification of a minimal building block, MIC-HCGIX-3.8-1-P5-HCGIV-HLA class I-HCGII, engendered the present-day MHC. That the currently nonessential HLA-F and MICE genes have acted as progenitors to today's immune-competent HLA-ABC and MICA/B genes provides experimental evidence for evolution by "birth and death," which has general relevance to our understanding of the evolutionary forces driving vertebrate multigene families.

Response properties and organization of nociceptive neurons in area 1 of monkey primary somatosensory cortex

The organization and response properties of nociceptive neurons in area 1 of the primary somatosensory cortex (SI) of anesthetized monkeys were examined. The receptive fields of nociceptive neurons were classified as either wide-dynamic-range (WDR) neurons that were preferentially responsive to noxious mechanical stimulation, or nociceptive specific (NS) that were responsive to only noxious stimuli. The cortical locations and the responses of the two classes of neurons were compared. An examination of the neuronal stimulus-response functions obtained during noxious thermal stimulation of the glabrous skin of the foot or the hand indicated that WDR neurons exhibited significantly greater sensitivity to noxious thermal stimuli than did NS neurons. The receptive fields of WDR neurons were significantly larger than the receptive fields of NS neurons. Nociceptive SI neurons were somatotopically organized. Nociceptive neurons with receptive fields on the foot were located more medial in area 1 of SI than those with receptive fields on the hand. In the foot representation, the recording sites of nociceptive neurons were near the boundary between areas 3b and 1, whereas in the hand area, there was a tendency for them to be located more caudal in area 1. The majority of nociceptive neurons were located in the middle layers (III and IV) of area 1. The fact that nociceptive neurons were not evenly distributed across the layers of area 1 suggested that columns of nociceptive neurons probably do not exist in the somatosensory cortex. In electrode tracks where nociceptive neurons were found, approximately half of all subsequently isolated neurons were also classified as nociceptive. Low-threshold mechanoreceptive (LTM) neurons were intermingled with nociceptive neurons. Both WDR and NS neurons were found in close proximity to one another. In instances where the receptive field shifted, subsequently isolated cells were also classified as nociceptive. These data suggest that nociceptive neurons in area 1 of SI are organized in vertically orientated aggregations or clusters in layers III and IV.

Increased matrix metalloproteinase activity and reduced tissue inhibitor of metalloproteinases-1 levels in amniotic fluids from pregnancies complicated by premature rupture of membranes

OBJECTIVES

It has been suggested that increased matrix metalloproteinases activity promotes the weakening of the amniochorion during normal and premature rupture of membranes. This study was designed to determine whether levels of matrix metalloproteinases and the tissue inhibitor of metalloproteinases-1 in amniotic fluid change in a pattern consistent with this hypothesis.

STUDY DESIGN

Gelatinolytic activity, measured by a soluble substrate assay and zymography, and the concentrations of tissue inhibitor of metalloproteinases-1 were estimated in amniotic fluid obtained from (1) normal early gestations, (2) normal term pregnancies with labor, (3) normal term pregnancies without labor, and (4) pregnancies complicated by premature rupture of membranes. The 92 kd type IV collagenase (matrix metalloproteinase-9) was also detected in amniotic fluid by Western blotting.

RESULTS

Matrix metalloproteinase activities were higher in amniotic fluid from normal term pregnancies with labor and pregnancies complicated by premature rupture of membranes than from early pregnancies and term gestations without labor. The amniotic fluid from term pregnancies with labor or pregnancies with premature rupture of membranes contained several gelatinases, as revealed by zymography. The major amniotic fluid gelatinolytic activity in premature rupture of membranes and term pregnancies with labor corresponded to matrix metalloproteinase-9. Tissue inhibitor of metalloproteinases-1 concentrations were highest in early-pregnancy amniotic fluid, followed by term gestation with labor, term gestation without labor, and premature rupture of membranes.

CONCLUSIONS

Normal labor and premature rupture of membranes are associated with increased levels of matrix metalloproteinases, particularly matrix metalloproteinase-9 in amniotic fluid. Premature rupture of membranes is associated with reduced levels of tissue inhibitor of metalloproteinases-1. The imbalance between matrix metalloproteinases and tissue inhibitor of metalloproteinases-1 in amniotic fluid may reflect a disorder that promotes premature rupture of membranes.

A one-step sandwich enzyme immunoassay for human matrix metalloproteinase 2 (72-kDa gelatinase/type IV collagenase) using monoclonal antibodies

A one-step sandwich enzyme immunoassay (EIA) for human matrix metalloproteinase 2 (MMP-2, 72-kDa gelatinase/type IV collagenase, EC 3.4.24.24) was established with a pair of monoclonal antibodies prepared against the precursor form of MMP-2 (proMMP-2) purified from the conditioned medium of human skin fibroblasts or against a synthetic peptide corresponding to the N-terminal domain of proMMP-2. ProMMP-2 in samples was allowed to simultaneously react with both solid-phase and peroxidase-labeled antibodies. Sensitivity of this EIA system was 2.4 pg/assay (0.24 microgram/l) and linearity was obtained between 10 and 5,000 pg/assay (1.0-500 micrograms/l). The EIA system recognized both the free form of proMMP-2 and its complex form with TIMP-2 with the same degree of immunoreactivity. ProMMP-2 levels in human sera from patients in various disease states were analyzed. In sera from patients with hyperthyroidism (12), primary biliary cirrhosis (8) and hepatocellular carcinoma (11), 749 +/- 166, 716 +/- 135 and 686 +/- 236 micrograms/l of proMMP-2 were detected, respectively and these were significantly higher than that observed in 213 normal human sera (570 +/- 118 micrograms/l). In contrast, the levels in sera from 33 patients with osteoarthritis (449 +/- 72 micrograms/l), 45 with rheumatoid arthritis (408 +/- 139 micrograms/l), 13 with stomach cancer (427 +/- 103 micrograms/l) and 10 with pancreatic cancer (422 +/- 130 micrograms/l) were significantly lower than that found in normal sera. Immunoblot and gel filtration analyses showed that human sera contain several MMP-2 species in addition to proMMP-2 which exist in a complex form with TIMP-2.

Full-genome nucleotide sequence of a hepatitis E virus strain that may be indigenous to Japan

We identified hepatitis E virus (HEV) RNA in serum from a Japanese patient with acute hepatitis, who had never been abroad. The full-genome nucleotide sequence of the HEV isolate (JRA1) from this patient was composed of 7227 nucleotides excepting the poly(A) tail and had ORF1 coding for 1703 amino acids (aa), ORF2 coding for 660 aa, and ORF3 coding for 122 aa. This Japanese strain showed approximately 87% nucleotide similarity to human and swine strains reported from the United States, while it had only 73-76% similarity to Asian and Mexican strains. Here we report the characteristics of the HEV-JRA1 isolate, which might be the first example of an indigenous strain(s) of HEV in Japan.

Inhibition of metastin (kisspeptin-54)-GPR54 signaling in the arcuate nucleus-median eminence region during lactation in rats

Follicular development and ovulation are suppressed during lactation in various mammalian species, mainly due to the suppression of pulsatile GnRH/LH secretion. Metastin (kisspeptin-54), a KiSS-1 gene product, is an endogenous ligand for GPR54, a G-protein-coupled receptor, and suggested to play a critical role in regulating the gonadal axis. The present study therefore aims to determine whether metastin (kisspeptin-54)-GPR54 signaling in discrete brain areas is inhibited by the suckling stimulus that causes suppression of LH secretion in lactating rats. Quantitative RT-PCR revealed that the KiSS-1 mRNA level was significantly lower in the arcuate nucleus (ARC)-median eminence region in lactating ovariectomized (OVX) and estrogen-treated OVX rats than in nonlactating controls. KiSS-1 mRNA in the anteroventral periventricular nucleus was kept at a low level in both lactating and nonlactating rats despite estrogen treatment. GPR54 mRNA levels were significantly lower in lactating than nonlactating rats in the anteroventral periventricular nucleus, but the levels in lactating mothers of the preoptic area and ARC-median eminence were comparable with nonlactating controls. Although KiSS-1 mRNA-expressing cells or metastin (kisspeptin-54) immunoreactivities were densely located in the ARC of nonlactating controls, few were found in the ARC of lactating OVX animals. Various doses of metastin (kisspeptin-54) (0.02, 0.2, and 2 nmol) injected into the third ventricle caused a significant increase in LH secretion in both lactating and nonlactating OVX rats, suggesting that lactating rats are responsive to metastin (kisspeptin-54) stimulus. Thus, the present study demonstrated that KiSS-1 mRNA/metastin (kisspeptin-54) expression is inhibited in the ARC by the suckling stimulus, suggesting that the inhibition is most probably involved in suppressing LH secretion in lactating rats.

A review of tissue inhibitor of metalloproteinases-3 (TIMP-3) and experimental analysis of its effect on primary tumor growth

The family of tissue inhibitors of metalloproteinases (TIMPs) presently numbers four distinct gene products that are specific inhibitors of the matrix metalloproteinases (MMPs). The local balance between MMPs and TIMPs is believed to play a major role in extracellular matrix (ECM) remodeling during development and in diseases such as cancer and arthritis. Unlike the other TIMPs, which are soluble. TIMP-3 is unique in being a component of ECM. Mutations in the human TIMP-3 gene cause a dominantly inherited, adult-onset blindness (Sorsby's fundus dystrophy or SFD). In this article, we summarize what is currently known about TIMP-3, discuss possible mechanisms leading up to SFD, and investigate the effect of TIMP-3 on tumor growth. Breast carcinoma and malignant melanoma cell lines were transfected with TIMP-3 expression plasmids and injected subcutaneously into nude mice. Growth curves of the resulting tumors over a period of 6 to 8 weeks demonstrated that increased expression of TIMP-3 resulted in a statistically significant suppression of tumor growth. Deposition of TIMP-3 in the surrounding ECM by tumor cells may inhibit tumor growth by preventing local expansion of tumor, retarding the release of growth factors sequestered in ECM, or inhibiting angiogenesis. TIMP-3 over-expression had no effect on the growth of the two tumor cell lines in vitro. Because recombinant TIMP-3 inhibits endothelial cell migration and tube formation in response to angiogenic factors, we believe that the effect of TIMP-3 on tumor growth seen in this study may be a consequence of its angiostatic action.

Diversity of sites for measles virus binding and for inactivation of complement C3b and C4b on membrane cofactor protein CD46

The complement system membrane cofactor protein (MCP) CD46 serves as a C3b/C4b inactivating factor for the protection of host cells from autologous complement attack and as a receptor for measles virus (MV). MCP consists of four short consensus repeats (SCR) which are the predominant extracellular structural motif. In the present study, we determined which of the four SCR of MCP contribute to its function using Chinese hamster ovary cell clones expressing each SCR deletion mutants. The results were as follows: 1) SCR1 and SCR2 are mainly involved in MV binding and infection; 2) SCR2, SCR3, and SCR4 contribute to protect Chinese hamster ovary cells from human alternative complement pathway-mediated cytolysis; and 3) SCR2 and SCR3 are essential for protection of host cells from the classical complement pathway. These results on cell protective activity of the mutants against the human classical and the alternative complement pathways were compatible with factor I-mediated inactivation profiles of C4b and C3b, respectively, in the fluid-phase assay using solubilized mutants and factor I; the results were mostly consistent with those reported by Adams et al. (Adams, E. M., Brown, M. C., Nunge, M., Krych, M., and Atkinson, J. P. (1991) J. Immunol. 147, 3005-3011). SCR2 and SCR3 were required for C3b and C4b inactivation, and SCR4-deleted MCP showed weak cofactor activity for C4b cleavage but virtually no cofactor activity for C3b cleavage. The functional domains of MCP for the three natural ligands C3b, C4b, and MV, therefore, map to different, although partly overlapping, SCR domains.

Medullary dorsal horn neuronal activity in rats with persistent temporomandibular joint and perioral inflammation

Studies at spinal levels indicate that peripheral tissue or nerve injury induces a state of hyperexcitability of spinal dorsal horn neurons that participates in the development of persistent pain and hyperalgesia. It has not been demonstrated that persistent injury in the orofacial region leads to a similar state of central hyperexcitability in the trigeminal system. The purpose of the present study was to conduct a parametric analysis of the response properties of nociceptive and nonnociceptive neurons in trigeminal nucleus caudalis (medullary dorsal horn, MDH) in a rat model of persistent orofacial inflammation. Neurons were recorded extracellularly and classified as low-threshold mechanoreceptive (LTM, n = 49), wide dynamic range (WDR, n = 82), and nociceptive-specific (NS, n = 11) neurons according to their response properties to mechanical stimuli applied to their cutaneous receptive fields (RFs). The inflammation was induced 24 h before the recordings by injecting complete Freund's adjuvant (CFA) into the temporomandibular joint (TMJ) capsule or the perioral (PO) skin. The mean areas of the high-threshold RFs of WDR neurons in TMJ (8.66 +/- 0.61 cm(2), n = 25) and PO (5.61 +/- 2.07 cm(2), n = 25) inflamed rats were significantly larger than those in naive rats (1.10 +/- 0. 16 cm(2), n = 32). The mean RF size in TMJ-inflamed rats also was significantly larger than that in PO-inflamed rats (P < 0.01). Furthermore the mean area of the RFs of NS neurons (3.74 +/- 1.44 cm(2), n = 5) was significantly larger in TMJ inflamed rats as compared with naive rats (0.4 +/- 0.09 cm(2), n = 3) (P < 0.05). The background activity in the TMJ- and PO-inflamed rats was generally greater in WDR and NS neurons, but less in LTM neurons, when compared with naive rats. The responses of WDR neurons to noxious mechanical stimuli were increased significantly in TMJ-inflamed rats (P < 0.05) as compared with naive rats. WDR neuronal responses to mechanical stimulation also were increased in PO-inflamed rats but to a lesser extent than in TMJ-inflamed rats. The injection of CFA into the TMJ or PO skin resulted in reduced responses of LTM neurons to mechanical stimuli. The responses of MDH nociceptive neurons to 48-55 degrees C heating were greater in inflamed rats as compared with naive rats. A subpopulation of WDR neurons recorded from TMJ (n = 4 of 10)- or PO (n = 3 of 13)-injected rats responded to cooling in addition to heating of the RFs but did not grade their responses with changes in stimulus intensity. These results indicate that persistent orofacial inflammation produced hyperexcitability of MDH nociceptive neurons. TMJ inflammation resulted in more robust changes in MDH nociceptive neurons as compared with PO inflammation, consistent with previous studies of increased inflammation, increased MDH Fos-protein expression, and increased MDH preprodynorphin mRNA expression in this deep tissue orofacial model of pain and hyperalgesia. The inflammation-induced MDH hyperexcitability may contribute to mechanisms of persistent pain associated with orofacial deep tissue painful conditions.

Plasma membrane-bound tissue inhibitor of metalloproteinases (TIMP)-2 specifically inhibits matrix metalloproteinase 2 (gelatinase A) activated on the cell surface

The cell-surface activation of pro-matrix metalloproteinase 2 (pro-MMP-2) is considered to be critical for cell migration and invasion. Treatment of human uterine cervical fibroblasts with concanavalin A activates pro-MMP-2 on the cell surface by converting it to the 65-kDa form with a minor form of 45 kDa. However, the 65-kDa MMP-2 was inactivated by tissue inhibitor of metalloproteinases (TIMP)-2 that was bound to the plasma membrane upon concanavalin A treatment. TIMP-2 binds to the plasma membrane through its N-terminal domain by two different modes of interaction as follows: one is sensitive to a hydroxamate (HXM) inhibitor of MMPs and the other is HXM-insensitive. TIMP-2 bound to the membrane in a HXM-insensitive manner, comprising about 40-50% of TIMP-2 on the membrane, is the inhibitor of the cell surface-activated MMP-2. It, however, does not inhibit MMP-3, MMP-9, and the 45-kDa MMP-2 lacking the C-terminal domain. The inhibition of the 65-kDa MMP-2 by TIMP-2 is initiated by the interaction of their C-terminal domains. Subsequently, the MMP-2.TIMP-2 complex is released from the membrane, and the activity of MMP-2 is blocked by TIMP-2. In the presence of collagen types I, II, III, V, or gelatin, the rate of inhibition of the 65-kDa MMP-2 by the membrane-bound TIMP-2 decreased considerably. These results suggest that the pericellular activity of MMP-2 is tightly regulated by membrane-bound TIMP-2 and surrounding extracellular matrix components.

Orofacial deep and cutaneous tissue inflammation and trigeminal neuronal activation. Implications for persistent temporomandibular pain

A rat model has been developed to characterize the responses of brainstem trigeminal neurons to orofacial deep and cutaneous tissue inflammation and hyperalgesia. Complete Freund's adjuvant (CFA) was injected unilaterally into the rat temporomandibular joint (TMJ) or perioral (PO) skin to produce inflammation in deep or cutaneous tissues, respectively. The TMJ and PO inflammation resulted in orofacial behavioral hyperalgesia and allodynia that peaked within 4-24 h and persisted for at least 2 weeks. Compared to cutaneous CFA injection, the injection of CFA into the TMJ produced a significantly stronger inflammation associated with a selective upregulation of preprodynorphin mRNA in the trigeminal spinal complex, an enhanced medullary dorsal horn hyperexcitability, and a greater trigeminal Fos protein expression, a marker of neuronal activation. The Fos-LI induced by TMJ inflammation persisted longer, was more intense, particularly in the superficial laminae, and more widespread rostrocaudally. Thus, the inflammatory irritant produces a stronger effect in deep than in cutaneous orofacial tissue. As there is heavy innervation of the TMJ by unmyelinated nerve endings, a strong nociceptive primary afferent barrage is expected following inflammation. An increase in TMJ C-fiber input after inflammation and strong central neuronal activation may initiate central hyperexcitability and contribute to persistent pain associated with temporomandibular disorders. Since deep inputs may be more effective in inducing central neuronal excitation than cutaneous inputs, greater sensory disturbances may occur in pain conditions involving deep tissues than in those involving cutaneous tissues.

Tumour oxygenation is increased by hyperthermia at mild temperatures

The effects of hyperthermia on the oxygenation status in R3230 AC tumours of Fischer rats were measured using a polarographic oxygen electrode system. The median pO2 in about 10 mm diameter tumours grown s.c. in the leg of rats was 3.7 +/- 0.3 mm Hg and it significantly increased upon heating at modest temperatures. For example, the tumour pO(2) measured within 10-15 min after heating for 30 min at 42.5 degrees C was about three-fold greater than that in the control tumours. About 62% of PO(2) values measured in control tumours were < 5 mm Hg. After heating at 42.5 degrees C for 30 min, 37% of PO(2) values were < 5 mm Hg. Such an increase in tumour oxygenation or reoxygenation of hypoxic cells appeared to result from an increase in tumour blood flow caused by the mild temperature hyperthermia. The presence of hypoxic cells in tumours is believed to be a major factor in limiting the effectiveness of radiotherapy, certain chemotherapy drugs and phototherapy. Hyperthermia at mild temperatures easily achievable with the use of presently available clinical hyperthermia devices may be an effective means to overcome the hypoxic protection in the treatment of human tumours.

Morphological and electrophysiological properties of ACCx nociceptive neurons in rats

A total of 33 neurons with cutaneous receptive fields were recorded from the anterior cingulate cortex (ACCx) and successfully injected with neurobiotin. All neurons were in area 24 of the ACCx. Neurons from the ACCx had large receptive fields (RFs), usually bilateral, and some had RFs covering the whole body surface. Most of the neurons were in the deep laminae and had a pyramidal soma with thick apical dendrites and many spines. Thirteen of 33 neurons were classified as pyramidal nociceptive specific (NS) neurons and 12 as noxious-tap neurons, 3 neurons received inhibitory input and were in lamina V. Two non-pyramidal noxious-tap neurons were located in lamina V and 1 pyramidal noxious-tap neuron was located in lamina VI, and 2 pyramidal NS neurons were in lamina III. Axon collaterals of NS neurons were mainly distributed around the soma, whereas those of noxious-tap neurons were also distributed far from the soma. A large number of varicosities were observed on the axon collaterals of both NS and noxious-tap neurons. Our results suggest that NS neurons in the ACCx send information locally to the vicinity of the soma, while noxious-tap neurons send information to a wider area of the ACCx.

A one-step sandwich enzyme immunoassay for tissue inhibitor of metalloproteinases-2 using monoclonal antibodies

A one-step sandwich enzyme immunoassay system was developed with a pair of monoclonal antibodies against two individual oligopeptides prepared from the amino acid sequence of the human tissue inhibitor of metalloproteinases-2 (TIMP-2). The assay system consisting of two simultaneous immunoreactions used a solid phase monoclonal antibody and a horse-radish peroxidase-labeled monoclonal antibody. The system detected a free form of TIMP-2 and that complexed with active forms of matrix metalloproteinases (MMPs) giving a different sensitivity for each MMP but not TIMP-2 complexed with the precursor of 72 kDa gelatinase/type IV collagenase (MMP-2). The sensitivity of the system was 1.6 microgram/l (16 pg/assay) and linearity was obtained between 6.3 and 50 micrograms/l (63-500 pg/assay). TIMP-2 levels in the sera of 20 patients with rheumatoid arthritis (68 +/- 25 micrograms/l, mean +/- S.D.) and 13 patients with hepatocellular carcinoma (76 +/- 46 micrograms/l) were significantly higher (P < 0.05) than those of 18 normal subjects (5.6 +/- 7.4 micrograms/l). In contrast, the levels in the sera of 10 patients with gastric cancer (45 +/- 18 micrograms/l) and 7 patients with cancer of the uterus (36 +/- 13 micrograms/l) were significantly lower (P < 0.05 or P < 0.01) than those of normal subjects. Immunoreactivity analyses suggested that the precursor of MMP-2 in normal sera exists in a complexed form with TIMP-2 by interacting with the C-terminal domain of TIMP-2.

Diencephalic projections from the superficial and deep laminae of the medullary dorsal horn in the rat

An important function of the medullary dorsal horn (MDH) is the relay of nociceptive information from the face and mouth to higher centers of the central nervous system. We studied the central projection pattern of axons arising from the MDH by examining the axonal transport of Phaseolus vulgaris-leucoagglutinin (PHA-L). Labeled axon and axon terminal distributions arising from the MDH were analyzed at the light microscopic level. After large injections of PHA-L into both superficial and deep laminae of the MDH in the rat, labeled axons were observed in the nucleus submedius of the thalamus (SUB), ventroposterior thalamic nucleus medialis (VPM), ventroposterior thalamic nucleus parvicellularis (VPPC), posterior thalamic nuclei (PO), zona incerta (ZI), lateral hypothalamic nucleus (LH), and posterior hypothalamic nucleus (PH). Restriction of PHA-L into only the superficial laminae resulted in heavy axon and varicosity labeling in the SUB, VPM, PO, and VPPC and light labeling in LH. In contrast, after injections into deep laminae, labeled axons were mainly distributed in ZI and PH; some were also in VPM and LH, and fewer still in PO and SUB. Varicosities in VPM, SUB, and PO were significantly larger than those in VPPC, ZI, LH, and PH. Varicosity density was highest in SUB and lowest in the VPPC. We concluded that there are two distinct nociceptive pathways, one originating from the superficial MDH and terminating primarily in the dorsal diencephalon and the second originating from deep laminae of the MDH and terminating primarily in the ventral diencephalon. We propose that in the rat, input from the deeper laminae is primarily involved in the motivational-affective component of pain, whereas input from the superficial MDH is related to both the sensory-discriminative and motivational-affective component of pain.

Three-dimensional dental cast analyzing system using laser scanning

The purpose of this article is to introduce the outline of our newly developed three-dimensional dental cast analyzing system with laser scanning, and its preliminary clinical applications. The system is composed of a measuring device with a slit-ray laser projector and two sets of coupled charged devised video cameras, an image processing unit, a 16-bit personal computer as a controller, and an engineering workstation as a post processor. The dental cast is projected and scanned with a slit-ray laser beam. The raster coordinates of the target are determined with an image processor. Triangulation is applied to determine the location of each point. Generation of three-dimensional graphics of the dental cast takes approximately 40 minutes. About 90,000 sets of X, Y, Z coordinates are stored in the main memory of the microcomputer. The measurement error is less than 0.05 mm. Besides the conventional linear and angular measurements of the dental cast, we are also able to demonstrate the size of the palatal surface area and the volume of the oral cavity. The advantage of this system is that it facilitates the otherwise complicated and time-consuming mock surgery necessary for treatment planning in orthognathic surgery.

Dynamin and rab5 regulate GRK2-dependent internalization of dopamine D2 receptors

Dopamine D2 receptors (D2Rs; short form, which is one of the alternative splicing variants) expressed in COS-7 cells are internalized in an agonist-dependent manner only when G protein-coupled receptor kinase 2 (GRK2) is coexpressed [Ito, K., Haga, T., Lameh, J. & Sadée, W., (1999) Eur. J. Biochem. 260, 112-119]. We have examined the effects of coexpression of dynamin, a small molecular mass GTP-binding protein, rab5A, and their mutants on the internalization of D2Rs in the presence of both dopamine (10 or 100 microM) and GRK2. The rate and extent of D2R internalization was increased or decreased by coexpression of dynamin I or a dominant-negative form of dynamin I (dynamin I K44E), respectively. The effects of coexpressing these two dynamins were more prominent at 10 microM dopamine than at 100 microM. In the presence of 10 microM dopamine, internalization of D2R was completely suppressed when dynamin I K44E was coexpressed, and the half-life (t 1/2) of D2R internalization decreased relative to cells not expressing dynamin from 82 to 29 min when dynamin I was coexpressed. Internalization of D2Rs was facilitated or suppressed by coexpression of a constitutively active form of rab5A (rab5A Q79L) or a dominant-negative form of rab5A (rab5A S34N), respectively. The t 1/2 of D2R internalization at 10 microM dopamine decreased from 82 to 16 min in cells coexpressing rab5A Q79L. The effect of coexpression of rab5A S34N was more apparent at 100 microM dopamine than at 10 microM; the t 1/2 of D2R internalization at 100 microM dopamine increased from 20 to 56 min and the proportion of internalized D2Rs after 120 min decreased from 53 to 28%. These results indicate that the internalization of D2Rs is dependent on the action of dynamin as well as GRK2, and is regulated by the action of rab5A.