[Prediction and evaluation of heterosis of beef cattle and their application]

The genetic structure and genetic variation of eight beef cattle cross parents populations were analyzed by six microsatellite loci, and heterosis of beef cattle was predicted. On the basis of microsatellite analysis, the effect of 18 cross combinations was estimated by the method of individual animal model BLUP. A new method of molecular quantitative genetics that select best of all cross combination was submitted. The results showed that the combinations with Hereford Limousine and Charolais as paternal parent are better than others in Fengning and Longhua regions; the combinations with Limousine Angus and Hereford as paternal parent are better than others in Zanhuang regions; the combinations with Hereford Limousine and Piemontese as paternal parent are better than others in Funing regions. Effect of three breeds cross is better than two breeds.

Collateral projections of nucleus raphe dorsalis neurones to the caudate-putamen and region around the nucleus raphe magnus and nucleus reticularis gigantocellularis pars alpha in the rat

It was examined whether or not the nucleus raphe dorsalis (RD) neurons projecting to the caudate-putamen (CPu) might also project to the motor-controlling region around the nucleus raphe magnus (NRM) and nucleus reticularis gigantocellularis pars alpha (Gia) in the rat. Single RD neurons projecting to the CPu and NRM/Gia by way of axon collaterals were identified by the retrograde double-labeling method with fluorescent dyes, Fast Blue and Diamidino Yellow, which were injected respectively into the CPu and NRM/Gia. Then, serotonin (5-HT)-like immunoreactivity of the double-labeled RD neurons was examined immunohistochemically; approximately 60% of the double-labeled RD neurons showed 5-HT-like immunoreactivity. The results indicated that some of serotonergic and non-serotonergic RD neurons might control motor functions simultaneously at the levels of the CPu and NRM/Gia by way of axon collaterals.

Origins of spontaneous and noxious stimuli-evoked miniature EPSCs in substantia gelatinosa

The origins of spontaneous and noxious stimuli-evoked glutamatergic miniature excitatory postsynaptic currents (mEPSCs) in substantia gelatinosa (SG) neurons were investigated by using whole-cell voltage-clamp technique on adult rat spinal cord slice. The properties of mEPSCs of SG neurons from rats either neonatally capsaicin-treated or sciatic nerve ligated showed no difference from those of intact SG neurons, indicating independence of spontaneous mEPSCs on primary afferent fibers. In the presence of tetrodotoxin (TTX), capsaicin, which noxiously stimulated fine primary afferent fibers, caused increase of the mEPSCs frequency, but did not affect the amplitude profiles or mean amplitudes. TTX affected neither the spontaneous mEPSCs nor capsaicin-induced mEPSCs frequency increase. The results suggest that spontaneous mEPSCs in SG are mediated by presynaptic spontaneous glutamate release predominantly originating from interneuron terminals rather than from primary afferent terminals; under noxious stimulation, however, mEPSCs frequency increase is mediated by primary afferent excitation.

Derivative matrix isopotential synchronous fluorescence spectroscopy for the direct determination of 1-hydroxypyrene as a urinary biomarker of exposure to polycyclic aromatic hydrocarbons

Urinary 1-hydroxypyrene is a biomarker in the measurement of human exposure to polycyclic aromatic hydrocarbons. A rapid and simple derivative isopotential synchronous fluorescence method was developed for the direct determination of 1-hydroxypyrene in urine. A length of iso-intensity route was scanned on the three-dimensional fluorescence spectrum of urine and this result was combined with that from derivative technique. Thus the strong background signals of urine were removed and the 1-hydroxypyrene can be determined directly in urine without tedious pre-separation. The derivative isopotential synchronous fluorescence spectrum was directly obtained from a single scan on a spectrofluorometer, which further simplified isopotential synchronous fluorescence technique. The recoveries of 93% to 115% were obtained for 1-hydroxypyrene added to urine.

Intracellular labeling study of neurons in the superficial part of the magnocellular layer of the medullary dorsal horn of the rat

Morphology and electrical membrane properties of neurons in the superficial part of the magnocellular layer of the rat medullary dorsal horn (MDH: caudal subnucleus of the spinal trigeminal nucleus) were examined by using horizontal slice preparations. Intracellular recording and biocytin-injection combined with histochemical and immunohistochemical staining were done. Twenty-four neurons were examined successfully and classified into projection neurons (PNs) and intrinsic neurons (INs). The PNs were further divided into type I PNs (I-PNs) and type II PNs (II-PNs). The I-PNs sent axons to the medullary reticular formation; the II-PNs sent axons to the interpolar subnucleus of the spinal trigeminal nucleus but had no axons extending to the medullary reticular formation. The INs that sent no axons to the brain regions outside the MDH were also divided into small INs with spiny dendrites (INSSs) and large INs with aspiny dendrites (INLAs). The dendritic fields of the PNs extended to laminae I and II of the MDH and occasionally further to the spinal tract of the trigeminal nerve, whereas those of the INs were confined within the magnocellular layer of the MDH. The axonal branches of each IN formed a dense axonal mesh around the cell body of the parent neuron. Although the main bodies of the axonal fields of the INs were located in the magnocellular layer, some axonal branches extended to laminae I and II of the MDH. Immunoreactivity for NK1 receptor (substance P receptor) was found in approximately half of the PNs but not in the INs. Although no strong correlation was found between morphology and electrical membrane properties, there were some differences in electrical properties among the morphologically classified neuron groups, e.g., hyperpolarizing sag was observed in some PNs but not in the Ins; inward rectification was observed in some of the INSSs and INLAs but not in the PNs; the slow ramp depolarization and the slow afterdepolarization were observed in all INSSs examined but not in the PNs or INLAs.

A nine-year prospective study on the incidence of childhood type 1 diabetes mellitus in China

To investigate the epidemiological characteristics of childhood type 1 diabetes mellitus in China, newly diagnosed cases of type 1 diabetes with an onset age under 15 years were retrospectively registered by 23 local centers in China following a standardized protocol on the basis of the nationwide registry established by the WHO DiaMond Project China Participating Center, Chinese Academy of Preventive Medicine (CAPM). A population of about 24 million children were covered in the defined areas. A two-sample capture-recapture method was used to estimate case ascertainment. Between 1988 and 1996, 903 diabetic cases were registered in 9 ethnic groups. The overall ascertainment corrected incidence rate (IR) was 0.59 per 100,000 person-year. The IR was 0.52/100,000 (95% CI: 0.50-0.54) for males and 0.66/100,000 (95% CI: 0.64-0.68) for females. The standardized ascertainment corrected IR by the national age-specific population in 1990 was 0.57 per 100,000 person-year. The incidence among various ethnic groups ranged from 0.25/100,000 to 3. 06/100,000. The IRs increased with northern latitude, and the IR of Han population was significantly higher in North China compared with South China (0.67 versus 0.53 per 100,000 respectively, P < 0.01). A correlation model of incidence and calendar time showed that the IR increased significantly between 1988 and 1996 (r = 0.86, P = 0.0027). The relative risk (RR) of type 1 diabetes mellitus for different age-groups estimated by a Poisson regression model showed that taking RR as 1.00 for age-group from 0 to 4 years, the RR for age-group from 5 to 9 year and from 10 to 14 year was 2.30 and 3.60 respectively. The standardized ascertainment corrected IR of childhood type 1 diabetes mellitus in China in much lower than in other countries. The geographic and ethnic variability of the incidence suggests that both genetic and environmental factors play a role in the development of childhood diabetes in China.

Rapid simultaneous determination of four anthracene derivatives using a single non-linear variable-angle synchronous fluorescence spectrum

A rapid, simple and inexpensive spectrofluorimetric method has been developed for the simultaneous identification and quantification of anthracene (ANT), 9,10-dimethylanthracene (DIM), 2-aminoanthracene (AMI) and dibenz[ah]anthracene (DIB). A well-resolved spectrum for the mixture of these four compounds is obtained based on a single non-linear variable-angle synchronous scanning. The linear concentration ranges are 10-1,000, 5-500, 50-1,000 and 10-200 ng mL(-1) for ANT, DIM, AMI and DIB, respectively, at lambdaex/lambdaem = 358/380, 399/408, 414/465 and 298/394 nm, respectively. The analyses are performed in cyclohexane. Recoveries of 90.0-111.0% in synthetic mixtures are obtained. The detection limits are 2.0 ng mL(-1) for DIM, 2.7 ng mL(-1) for ANT, 15.8 ng mL(-1) for AMI and 4.2 ng mL(-1) for DIB. The method has also been applied to several real water samples with satisfactory results.

MMP and TIMP gene expression in head and neck squamous cell carcinomas and adjacent tissues

OBJECTIVE

To compare the frequency of gene expression of matrix metalloproteinases (MMP) stromelysins -1, -2 and -3 (MMP-3, -10, and -11), matrilysin (MMP-7), MTI-MMP (MMP-14), and of TIMPs (Tissue Inhibitors of MMPs) -1, -2, -3 and -4 in head and neck squamous cell carcinomas with those of matched adjacent normal tissues.

MATERIALS AND METHODS

The present study included 20 surgically removed head and neck squamous cell carcinomas, seven of which were accompanied by matched adjacent oral mucosa excised from the border of the specimens outside the tumor area. RNA isolated from tumors and control samples was subjected to RT-PCR using primers specific for MMP-3, -7, -10, -11 and -14 and for TIMPs -1, -2, -3, and -4.

RESULTS

Our findings demonstrate that each of the five MMP genes studied were expressed in essentially all the tumors, while the adjacent marginal tissue samples showed a more varied picture: while stromelysin-3 was located to a majority of the marginal samples, matrilysin was expressed in four of seven adjacent samples, stromelysin-1 and MTI-MMP genes were each expressed in three of these samples, and stromelysin-2 transcript was only expressed in two marginal tissue samples. Whereas TIMP-1 and TIMP-2 transcripts were identified in all tumor and adjacent tissue samples studied, TIMP-3 was expressed, albeit often at low levels, in 17 of 20 tumor samples but only in three of seven adjacent tissues. The novel TIMP-4 gene was not expressed at all.

CONCLUSIONS

Specific MMP (MMP-3, -7, -10, -14) and TIMP-3 transcripts observed in head and neck squamous cell carcinomas compared to their frequency in specimens of matching tissues provide important information about expression of extracellular matrix degrading enzymes and their tissue inhibitors in head and neck carcinomas.

Distribution of substance P-like immunoreactive fibers in feline temporomandibular joint

OBJECTIVE

To study the distribution of substance P-like immunoreactive fibers in feline temporomandibular joint.

METHODS

The immunohistochemical PAP method was used for the investigation of the distribution of substance P-like immunoreactive fibers in feline temporomandibular joint.

RESULTS

The TMJ capsule and the anterior and posterior disc attachments all contained SP-immunoreactive nerve fibers, but the medium fibers in diameter were mainly observed. The density of the distribution of SP-positive nerve fibers was the highest in the subsynovium of the TMJ capsule. The density of distribution was similar in the anterior and posterior disc attachments, but lower than in the subsynovium and the lateral joint capsule. Such fibers in the synovial membrane were sparser, and a part of the fibers were seen around the thin blood vessels in all the foregoing tissues.

CONCLUSION

These results provide the morphological data for exploring the neurobiological mechanisms of temporomandibular joint disorder and its pain.

Fucosyl transferase (H) transgenic heart transplants to Gal-/- mice

BACKGROUND

We have previously described the rejection of Gal+ mouse hearts by mice lacking Gala(1,3)Gal (Gal-/-) and demonstrated this to be a model of xenogeneic hyperacute rejection (HAR) which would occur in pig-to-human/primate xenotransplantation, where Gal+ antibody (Ab) and complement (C') mediate HAR. To reduce the amount of Gal present we used fucosyl transferase (H) as a transgene, H transferase competes for the same substrate as Gal transferase and reduces Gal expression by >90%.

METHODS

Gal-/- mice received a heart graft from C57BL/6 Gal+ or H transgenic mice and additional Gal Ab and C' provided; HAR was monitored by direct observation for up to 90 min, or by palpation thereafter. When grafts were rejected they were examined macro- and microscopically.

RESULTS

H transgenic mice were used as donors to Gal-/- mice; it was found that: 1) C57BL/6 or H transgenic hearts were not rejected by Gal-/- recipients within 90 min in the absence of additional Gal Ab. 2) If additional Gal Ab and C' were provided as fresh normal human serum (NHS), Gal+ (C57BL/6) grafts were rejected by Gal-/- mice in approximately 34 min, whereas H transgenic hearts mostly lasted up to 17 hr, but were then rejected. The histological appearances showed features of both Arthus and Shwartzmann phenomena. 3) Mice hyperimmunized with Gal with anti-Gal titers of >1:20,000, rejected Gal+ grafts in 31 min; the survival was prolonged to 75 min with the H transgenic hearts.

CONCLUSION

The presence of the H transgene in donor hearts transplanted to naive Gal-/- mice delays the onset of HAR, but rejection ultimately occurs; if the mice are hyperimmune earlier rejection occurs. The expression of the H transgene alone is insufficient to avoid HAR in the Gal-/- mouse model; the presence of other transgenes and techniques will be required to give an appropriate increase in survival of pig-to-human/primate grafts.

Synaptic interaction between GABAergic terminals and substance P receptor-positive neurons in rat spinal superficial laminae

AIM

To identify synaptic relationship between gamma-aminobutyric acid (GABA)-containing terminals and substance P receptor-positive neurons in the superficial dorsal horn of rat spinal cord.

METHODS

A combination of preembedding immunoperoxidase staining for substance P receptor with postembedding immunogold staining for GABA was employed.

RESULTS

Intense substance P receptor-expressing neurons were concentrated in medial half of the lamina I and the outer lamina II of the spinal cord. Under electron microscopy, substance P receptor immunoreactivity was found mainly in perikarya and dendrites, and deposited along neuronal membranes, in Golgi complex, in rough endoplasmic reticulum and on the surface of mitochondria with patch- or granular-like staining. The double-labeling studies revealed that substance P receptor-expressing dendrites received symmetric synaptic contacts from axonal terminals labeled with immunogold particles indicating GABA. GABA also co-localized with substance P receptors in the dendrites.

CONCLUSION

The synaptic contact between GABA-containing terminal and substance P receptor-expressing neuron provided important morphological evidence for previous pharmacological studies concerning antinociceptive function of GABA in the spinal cord.

[The function of T7 promoter as cis-acting elements for polymerase II in eukaryotic cell]

Using the chlorampheniol acetyltransterase gene as reporter, the function of phage T7 promoter in mammalian cells was studied by inhibition of transcription with alpha-amanitin. The experiment proved that the reporter under T7 promoter was transcribed by RNA polymerase II. Competitive electropho retic mobility shift assay (CEMSA) with TATA box, CAAT box, GC box and octamer showed that the TATA box was competitive molecular for synthetic T7 promoter. It is possible that T7 promoter is bound with TF II D transcription factor. The TATA box and octamer were inserted into Pvu II site upstream from the T7 promoter of pT7CAT. Two recombinant plasmids, pT7TATACAT and pT7OCTCAT, were constructed and transfected into CHO cells. CAT-activity test showed that T7 promoter strength was increased by octamer factor, not by TATA box. These results suggested that T7 promoter functions as cis-acting elements of RNA polymerase II transcriptional system in eucaryotic cells.

Postsynaptic origin of N-methyl-D-aspartate-induced slow currents in substantia gelatinosa neurons: an in vitro voltage-clamp study in adult rat

We investigated whether N-methyl-D-aspartate (NMDA)-induced slow current in substantia gelatinosa (SG) neurons might be of presynaptic or postsynaptic origin. Whole-cell voltage-clamp recordings were made from adult rat spinal cord slices to examine the effect of NMDA receptor upon miniature excitatory postsynaptic currents (mEPSCs) in SG neurons. At a holding potential of -70 mV, bath application of NMDA (10 microM, 30s), an NMDA receptor agonist, affected neither the frequency nor the mean amplitude of mEPSCs, while NMDA induced a slow excitatory membrane current which persisted in the presence of tetrodotoxin. On the other hand, AP-5 (an NMDA receptor antagonist) had no noticeable effects on mEPSCs in the SG neurons tested, while it markedly depressed the NMDA-induced slow currents. The NMDA-induced slow currents varied with the changing of holding potentials (from -70 to 0 mV). The results suggested that the NMDA-induced slow currents in SG neurons were of postsynaptic origin.

Collateral projection of substance P receptor expressing neurons in the medullary dorsal horn to bilateral parabrachial nuclei of the rat

Employing a combination of fluorescent retrograde double labeling and immunofluorescence histochemistry for substance P receptor (SPR), we examined the collateral projection from single SPR-like immunoreactive neurons in the medullary dorsal horn (caudal subnucleus of the spinal trigeminal nucleus) to bilateral parabrachial nuclei in the rat. After injection of fast blue (FB) or diamidino yellow (DY) into the right or left parabrachial nucleus, respectively, single-labeled FB or DY neurons and double-labeled FB/DY neurons were observed mainly bilaterally in laminae I and II of the medullary dorsal horn. Some of the single-labeled FB or DY and double-labeled FB/DY neurons showed SPR-like immunoreactivity, especially in lamina I. In lamina I of left medullary dorsal horn which is ipsilateral to the DY injection into the PBN, the percentages of double-labeled FB/DY neurons to the total number of FB- or DY-labeled neurons were 34.0% or 20.2%, triple-labeled FB/DY/SPR neurons to the total number of FB/DY double-labeled or SPR-like immunoreactive neurons were 22.0% or 2.4%, respectively. In lamina I of the right medullary dorsal horn which is ipsilateral to the FB injection into the PBN, the percentages of double-labeled FB/DY neurons to the total number of FB- or DY-labeled neurons were 12.9% or 59.3%, triple-labeled FB/DY/SPR neurons to the total number of double-labeled FB/DY or SPR-like immunoreactive neurons were 24. 6% or 3.9%, respectively. The results suggest that some of the single SPR expressing neurons in the medullary dorsal horn might be innervated by substance P containing primary afferent fibers and transmit sensory information diffusely to bilateral parabrachial nuclei by way of their axonal collaterals.

KAI1/CD82 gene expression in benign prostatic hyperplasia and late-stage prostate cancer in Chinese

AIM

To evaluate KAI1/CD82 expression in Chinese patients with benign prostatic hyperplasia (BPH) and late-stage carcinoma of prostate (CaP).

METHODS

Thirty Chinese patients with benign prostatic hyperplasia and 34 with CaP (adenocarcinoma clinical stage C and D) were analyzed by means of immunohistochemical methods.

RESULTS

The KAI1/CD82 expression in BPH tissue was all positive, which was uniformly located on the glandular cell membrane at the cell-to-cell borders, but KAI1/CD82 expression in metastasis CaP tissues was either significantly lower than that of BPH or negative, and the immunostaining pattern was not continuous. In late-stage CaP KAI1/CD82 expression was correlated inversely to the pathological grade ( P < 0.05), but not to clinical stage ( P > 0.05).

CONCLUSION

The authors believe that decreased and negative KAI1/CD82 expression in late-stage CaP may be related to tumor progression and metastasis, and appears to be a prognostic marker.

Synaptic relationship of the neurons containing a metabotropic glutamate receptor, MGluR5, with nociceptive primary afferent and GABAergic terminals in rat spinal superficial laminae

Recent pharmacological evidence showed that metabotropic glutamate receptors (mGluRs), particularly mGluRs1/5, had a potential role in spinal nociceptive processing. However, previous morphological studies on mGluRs have been limited mainly to their distribution in the spinal cord. In the present study, electron microscopic immunocytochemistry was employed to identify the synaptic relationship of the neurons containing mGluR5, with nociceptive primary afferent and gamma-aminobutyric acid-ergic (GABAergic) terminals in the superficial dorsal horn of the spinal cord. Nociceptive C- and A(delta)-primary afferent terminals selectively labeled with horseradish peroxidase conjugated to wheat-germ agglutinin were in asymmetric synaptic contacts with or in direct apposition to mGluR5 positive dendritic profiles. The double-labeling studies revealed that mGluR5 immunoreactive dendrites also received symmetric synaptic contacts from axon terminals labeled with immunogold particles indicating GABA. The present demonstration of mGluR5 neurons receiving inputs from both nociceptive primary afferents and GABAergic terminals of presumed interneurons further supports the involvement of mGluR5 in the transmission and modulation of nociceptive information in the spinal cord.

Radiation-induced apoptosis in the neonatal and adult rat spinal cord

This study was designed to characterize radiation-induced apoptosis in the spinal cord of the neonatal and young adult rat. Spinal cords (C2-T2) of 1-, 2- and 10-week-old rats were irradiated with a single dose of 8, 18 or 22 Gy. Apoptosis was assessed histologically according to its specific morphological features or by using the TUNEL assay. Cell proliferation was assessed immunohistochemically using BrdU. Identities of cell types undergoing apoptosis were assessed using immunohistochemistry or in situ hybridization using markers for neurons, glial progenitor cells, microglia, oligodendrocytes and astrocytes. The time course of radiation-induced apoptosis in 1- or 2-week-old rat spinal cord was similar to that in the young adult rat spinal cord. A peak response was observed at about 8 h after irradiation, and the apoptosis index returned to the levels in nonirradiated spinal cords at 24 h. The neonatal rat spinal cord demonstrated increased apoptosis compared to the adult. Values for total yield of apoptosis over 24 h induced by 8 Gy in the neonatal rat spinal cord were significantly greater than that in the adult. Immunohistochemistry studies using Leu7, galactocerebroside, Rip and adenomatous polyposis coli tumor suppressor protein indicated that most apoptotic cells were cells of the oligodendroglial lineage regardless of the age of the animal. No evidence of Gfap or factor VIII-related antigen-positive apoptotic cells was observed, and there was a small number of apoptotic microglial cells (lectin-Rca1 positive) in the neonatal and adult rat spinal cord. In the neonatal but not adult rat spinal cord, about 10% of the apoptotic cells appeared to be neurons and were immunoreactive for synaptophysin. Labeling indices (LI) for BrdU in nonirradiated 1- and 2-week-old rat spinal cord were 20.0 and 16.3%, respectively, significantly greater than the LI of 1.0% in the 10-week-old rat spinal cord. At 8 h after a single dose of 8 Gy, 13.4% of the apoptotic cells were BrdU-positive in 10-week-old rat spinal cord, whereas 62.4 and 44.1% of the apoptotic cells showed BrdU incorporation in 1- and 2-week-old rat spinal cord, respectively. Regardless of the age of the animal, the apoptosis indices in BrdU-positive cells were greater than those in BrdU-negative cells. We conclude that the neonatal spinal cord demonstrates a greater level of apoptosis after exposure to ionizing radiation than the young adult spinal cord. This increase in apoptosis may be associated in part with the greater percentage of proliferating cells in the neonatal spinal cord, which demonstrate a greater level of radiation-induced apoptosis than nonproliferating cells.

Capsaicin induces a slow inward current which is not mediated by substance P in substantia gelatinosa neurons of the rat spinal cord

Whole-cell voltage-clamp techniques were employed to investigate a capsaicin-induced current in substantia gelatinosa (SG) neurons in the dorsal horn of adult rat spinal cord slices. Bath-applied capsaicin (2 microM) for 30 s activated a slow excitatory current having an amplitude of 21.3+/-6.3 pA and a duration of 93+/-13 s (n=10; V(H)=-70 mV). This capsaicin current was compared in amplitude under various conditions among different SG neurons. After either neonatal capsaicin treatment or sciatic-nerve transection, by which C-afferent fibers are known to degenerate, this capsaicin current was reduced in amplitude to 5.0+/-3.5 pA (n=8) or 4.5+/-2.3 pA (n=6), respectively. A non-N-methyl-D-aspartate (NMDA)-receptor antagonist, CNQX (10 microM), depressed greatly the capsaicin current to 4.0+/-1.3 pA (n=9). On the other hand, this current had an amplitude of 14.4+/-2.7 pA (n=10) in the presence of an NMDA-receptor antagonist, AP-5 (50 microM); this value was not significantly different from that in the control (P>0.05). Substance P (SP; 1-2 microM) superfused for 2 min had no detectable effect on all SG neurons examined (n=7). After SP washout, however, these cells exhibited a capsaicin current (22.8+/-12.1 pA); this current persisted in the presence of a neurokinin-1 receptor antagonist, L-732,138 (1 microM; 19.8+/-3.5pA, n=9). The capsaicin current was not abolished by an intracellular dialysis with GDP-beta-S (1 mM; 20. 2+/-2.4 pA, n=9) which inhibited a baclofen (10 microM) response mediated by the G-protein-coupled GABA(B) receptor. These results indicate that the capsaicin-induced current is mediated through the activation of C-fibers by non-NMDA receptors. This mechanism in SG neurons is different from that known in neurons in other laminae of the dorsal horn that is thought to be a direct action of SP released from C-fibers. This current in SG neurons would contribute to the pain sensation caused by capsaicin.

Morphologic features and electrical membrane properties of projection neurons in the marginal layer of the medullary dorsal horn of the rat

Possible correspondence between morphologic features and electrical membrane properties of projection neurons in lamina I [the marginal zone (MZ)] of the caudal subnucleus of the spinal trigeminal nucleus [the medullary dorsal horn (MDH)] was examined by using intracellular recordings and biocytin-injections combined with histochemical and immunohistochemical staining techniques. The experiments were done in horizontal slice preparations of the rat brain. Thirteen MZ neurons were recorded stably and stained successfully. These neurons were confirmed to send their axons to the brain regions outside the MDH by camera lucida reconstruction. They were divided into two types on the basis of branching patterns of their axons within the MDH: Type I projection (P-I) neurons (n = 7 neurons) had main axons that rarely emitted axon collaterals within the MDH, whereas type II projection (P-II) neurons (n = 6 neurons) had main axons that emitted many axon collaterals within laminae I, II (substantia gelatinosa), and III (magnocellular part) of the MDH and also to the spinal tract of the trigeminal nerve; these axon collaterals usually constituted a dense mesh of axonal processes within laminae I and II of the MDH, especially in lamina II. About half of the neurons of each type showed immunoreactivity for the neurokinin-1 receptor. Resting membrane potentials were significantly more positive in P-I neurons than in P-II neurons. The P-II neurons had higher input resistance, a longer membrane time constant, and a higher threshold for spike than P-I neurons. In response to weak, long depolarizing current pulses, P-II neurons often showed slow ramp depolarization; the same neurons exhibited delayed repolarization to the resting potential (slow after depolarization) after the offset of the long depolarizing current pulses. Neither the slow-ramp depolarization nor the slow after depolarization was observed in P-I neurons. Slow return to resting membrane potential after offset of hyperpolarizing current pulses also was observed frequently in P-II neurons but not in P-I neurons. The results indicate that P-II neurons differ in their membrane properties compared with P-I neurons, and P-II neurons may be involved in the local circuit mechanism within the MDH more deeply than P-I neurons.

Serotonin potentiates the response of neurons of the superficial laminae of the rat spinal dorsal horn to gamma-aminobutyric acid

Employing the Nystatin-perforated whole-cell patch-clamp recording technique, the modulatory effects of serotonin (5-HT) on gamma-aminobutyric acid (GABA)-activated whole-cell currents were investigated in neurons acutely dissociated from the superficial laminae (laminae I and II) of the rat spinal dorsal horn. The results showed: (1) GABA acted on GABA(A) receptors and elicited inward Cl(-) currents (I(GABA)) at a holding potential (V(H)) of -40 mV; (2) 5-HT potentiated GABA-induced Cl(-) current without affecting the reversal potential of I(GABA) and the apparent affinity of GABA to its receptor; (3) alpha-methyl-5-HT, a selective agonist of 5-HT(2) receptor, mimicked the potentiation effect of 5-HT on I(GABA), whereas ketanserine, an antagonist of 5-HT(2) receptor, blocked the potentiation effect of 5-HT; (4) Chelerythrine, an inhibitor of protein kinase C, reduced the potentiation effect of 5-HT on I(GABA). The present results indicate: (1) The potentiation of 5-HT on I(GABA) is mediated by 5-HT(2) receptor and through a protein kinase-dependent transduction pathway; (2) The interactions between 5-HT and GABA might play an important role in the modulation of nociceptive information transmission at spinal cord level.

Radiation-induced apoptosis in the adult central nervous system is p53-dependent

Oligodendrocytes and subependymal cells in the adult CNS have been shown to undergo radiation-induced apoptosis. Here, we examined the role of p53 in radiation-induced apoptosis in the adult mouse CNS. In the spinal cord of p53+/+ mice, apoptotic glial cells were observed within 24 h after irradiation, and the apoptotic response peaked at 8 h. These apoptotic cells demonstrated the immunohistochemical phenotype of oligodendrocytes, and decreased oligodendrocyte density was observed at 24 h after 22 Gy. A similar time course of radiation-induced apoptosis was seen in subependymal cells in the adult mouse brain. Radiation-induced apoptosis was preceded by an increase in nuclear p53 expression in glial cells of the spinal cord and subependymal cells of the brain. There was no evidence of radiation-induced apoptosis in the spinal cord and subependymal region of p53-/- animals. We conclude that the p53 pathway may be a mechanism through which DNA damage induces apoptosis in the adult CNS.

Bilirubin and bile acids may modulate their own metabolism via regulating uridine diphosphate-glucuronosyltransferase expression in the rat

BACKGROUND AND AIMS

Uridine diphosphate (UDP)-glucuronosyltransferase (UGT) is a critical enzyme in the elimination of bilirubin and it also plays a role in the metabolism of bile acids. The aim of this study was to determine whether bilirubin and bile acids could modulate their own metabolism by regulating UGT levels in cultured rat hepatocytes.

METHODS AND RESULTS

Incubation of hepatocytes with bilirubin (48 micromol/L) for 24 h significantly increased the mRNA expression of UGT1A1 and UGT1A5, two UGT isoforms responsible for the conjugation of bilirubin. The induction of UGT1A1 and UGT1A5 by bilirubin was concentration and time dependent. Treatment with chenodeoxycholic acid, cholic acid, deoxycholic acid, hyodeoxycholic acid and lithocholic acid at a concentration of 100 micromol/L for 48 h significantly enhanced the mRNA expression of UGT2B1, a UGT isoform responsible for the glucuronidation of bile acids. The UGT2B3 mRNA level was also increased by hyodeoxycholic acid. The regulation of UGT2B1 mRNA by chenodeoxycholic acid and hyodeoxycholic acid was dose and time dependent.

CONCLUSION

Our results suggest that bilirubin and bile acids can induce UGT expression and as a result, these compounds may modulate their own metabolism. Such regulation could play a compensatory role in the pathological increased concentrations of these compounds in some hepatobiliary diseases.

gamma-aminobutyric acid- and glycine-immunoreactive neurons postsynaptic to substance P-immunoreactive axon terminals in the superficial layers of the rat medullary dorsal horn

gamma-Aminobutyric acid (GABA)ergic and glycinergic neurons were examined light- and electron-microscopically in laminae I and II of the medullary dorsal horn (MDH, i.e. spinal trigeminal nucleus caudalis in the rat). The majority of GABA- and glycine (Gly)-immunoreactive (-ir) neurons showed both GABA- and Gly-immunoreactivities (-IRs). Noxious stimulation (subcutaneous injection of formalin into perioral regions) induced Fos-IR in some of GABA- and Gly-ir neurons. GABA- and Gly-ir neuronal profiles were postsynaptic to substance P-ir axon terminals. These results suggest that nociceptive information being carried by primary afferent SP-fibers may be relayed directly to GABAergic and glycinergic neurons in laminae I and II of the MDH.

[Transplantation of free scapular flap to repairing injury of faciocervical region]

OBJECTIVE

To sum up transplantation of free scapular flap to repairing injury of faciocervical region, 103 cases in past 16 years were reviewed.

METHODS

The scapular flap contained the ascending, descending, and transverse branches of the circumflex scapular artery. The range of the flap was as following: across the scapular spine to the acromion in upper edge, to the level of anterior iliac spine in lower edge, to the bilateral middle axillary line in both sides.

RESULTS

The clinical result was good. Fifty eight cases were followed up for 3 months to 10 years, the function of the faciocervical region was recovered with satisfied contour. In part of the patients, a second-stage operation was performed to make the flap thinner.

CONCLUSION

The maximal range of the flap can be 45 cm x 16 cm. For its sufficient blood supply, it should be of no influence on survival of the flap if the window is open in suitable site. Because of its large range of donating region and sufficient blood supply, it is fit for children.

Co-existence of calcium-binding proteins in neurons of the medullary dorsal horn of the rat

Double immunofluorescence histochemistry for calcium-binding proteins was performed in the caudal subnucleus of the rat spinal trigeminal nucleus; for calbindin D28k (CB) and calretinin (CR), for CB and parvalbumin (PV), and for CB and CR. CB-immunoreactive (-ir) neurons were seen 1.7 times more frequently than CR-ir neurons and 5.5 times more frequently than PV-ir neurons. About 70-90% of these neurons were distributed in substantia gelatinosa. Co-existence of CB and CR was indicated in 2.3% of CB-ir and 3.9% of CR-ir neurons. Co-existence of CB and PV was indicated in 1.0% of CB-ir and 5.5% of PV-ir neurons. Co-existence of CR and PV was indicated in 1.4% of CR-ir and 5.1% of PV-ir neurons. In these doubly immunostained neurons, 59.5-69.5% were observed in substantia gelatinosa, 5.9-17.8% in the marginal zone, and 12.7-31.0% in the magnocellular part.

Serotonergic innervation of mesencephalic trigeminal nucleus neurons: a light and electron microscopic study in the rat

Neurons of the mesencephalic trigeminal nucleus (MTN) are considered to be homologous to mechanosensitive neurons in the sensory ganglia. The sites of origin of serotonin (5HT)-immunoreactive axons on neuronal cell bodies in the MTN were studied in the rat by combining immunofluorescence histochemical techniques with retrograde tracing of Fluoro-Gold (FG) and anterograde tracing of biotin-conjugated dextran amine (BDA). The tracing studies, which were combined with multiple-labeling immunohistochemistry and confocal microscopy, indicated that 5HT-immunoreactive axon terminals on the cell bodies of MTN neurons originated from the medullary raphe nuclei, such as the nucleus raphes magmus (RMg), alpha part of the nucleus reticularis gigantocellularis (GiA) and nucleus raphes obscurus (ROb), as well as from the mesopontine raphe nuclei, such as the nucleus raphes dorsalis (DR), nucleus raphes pontis (PnR) and nucleus raphes medianus (MnR); mainly from the RMg, GiA and DR, and additionally from the ROb, PnR and MnR. The cell bodies in close apposition to 5HT-immunoreactive axon terminals were found through the whole rostrocaudal extent of the MTN. Electron microscopically a number of axon terminals that were labeled with BDA injected into the raphe nuclei were confirmed to be in asymmetric synaptic contact with the cell bodies of MTN neurons. It was also indicated that substance P existed in some of the 5HT-containing axosomatic terminals arising from the ROb, RMg and GiA. The present results indicated that proprioceptive sensory signals from the muscle spindles or periodontal ligament might be modulated at the level of the primary afferent cell bodies in the MTN by 5HT-containing axons from the mesopontine and medullary raphe nuclei including the GiA.

Alcohol up-regulates UDP-glucuronosyltransferase mRNA expression in rat liver and in primary rat hepatocyte culture

The interactions between alcohol and cytochrome P-450 enzymes have been well investigated. However, the data regarding the effect of alcohol on the regulation of UDP-glucuronosyltranferase (UGT) activity are less clear. The aim of the present study was to determine the role of alcohol in the regulation of UGT mRNA expression by using whole animal and primary cultured hepatocytes. Chronic ethanol feeding of rats significantly increased the expression of liver UGT1A1 mRNA to 177% of control. The mRNA levels for UGT1A5, UGT2B1 and UGT2B3 were also enhanced, but did not reach statistical significance. In cultured hepatocytes, treatment with either ethanol or isopentanol significantly increased the expression of UGT1A1, UGT1A5, UGT2B1, and UGT2B3 mRNAs, but to different degrees. The induction of UGT1A1 and UGT2B1 mRNAs by ethanol or isopentanol was time-dependent and maximal changes occurred at 48 h. The expression of UGT1A6 mRNA was not significantly modified by either ethanol or isopentanol. In conclusion, ethanol and isopentanol have direct roles in the regulation of UGT.

Inhibition of hyperacute transplant rejection by soluble proteins with the functional domains of CD46 and FcgammaRII

BACKGROUND

Recombinant soluble forms of complement regulatory molecules, including the human complement regulatory protein CD46 (rsCD46), have been shown to inhibit hyperacute transplant rejection (HAR) and protect against complement-mediated inflammatory tissue damage. Similarly, recombinant soluble forms of the immunoglobulin receptor FcgammaRII (rsFcgammaRII) can attenuate antibody-mediated inflammatory responses. We have produced and tested the function of novel recombinant chimeric proteins that incorporate the functional domains of both CD46 (membrane cofactor protein, MCP) and the low affinity human IgG receptor FcgammaRII (CD32).

METHODS

Two recombinant soluble chimeric proteins (CD46:FcR and FcR:CD46) were designed and produced using a human cell expression system. Their ability to protect cells against complement-mediated lysis (through the CD46 domain) and bind human IgG (through the Fc receptor domain) was assessed in vitro. They were also tested in vivo in the rat reverse passive Arthus reaction and a murine model of hyperacute cardiac transplant rejection.

RESULTS

In vitro, the functional domains of the chimeric proteins each retained their activity. In vivo, the serum half-life of the recombinant chimeric proteins in mice was more than either rsCD46 or rsFcgammaRII. In the rat reverse passive Arthus reaction, intradermal injection of each recombinant protein substantially reduced inflammatory skin edema (>50%) and polymorphonuclear neutrophil infiltration (>90%). In the hyperacute rejection model, i.v. treatment with FcR:CD46 prevented complement-mediated rejection, macroscopic bruising, edema, and thrombosis more effectively than rsCD46.

CONCLUSIONS

CD46/FcgammaRII bifunctional proteins have an improved ability to control complement-mediated hyperacute graft rejection and have therapeutic potential in other conditions involving antibody-mediated inflammation.

Calcium-binding protein-immunoreactive projection neurons in the caudal subnucleus of the spinal trigeminal nucleus of the rat

It has been reported that calcium-binding proteins are good markers for different sets of neurons in various brain regions. We examined expression of the main calcium-binding proteins in projection neurons in the rat medullary dorsal horn (MDH) by combining immunofluorescence histochemistry for calbindin D28k (CB), calretinin (CR) and parvalbumin (PV) with the retrograde tract-tracing method. A fluorescence tracer, tetramethylrhodamine-dextran amine (TMR-DA), was injected into the parabrachial, thalamic or hypothalamic region. After such injections, a number of PV-, CR-, and/or CB-immunoreactive MDH neurons were labeled retrogradely with TMR-DA. Triple-immunofluorescence histochemistry further revealed that a number of CB-, CR-, or PV-immunoreactive TMR-DA-labeled MDH neurons showed immunoreactivity for substance P receptor (NK1), and that they expressed immunoreactivity for c-fos protein in the rats which were injected with formalin into the lips. Thus, it was indicated that some of CB-, CR-, or PV-containing projection neurons in the MDH might be involved in the transmission of nociceptive stimuli.

Substance P receptor-like immunoreactive neurons in the caudal spinal trigeminal nucleus send axons to the gelatinosus thalamic nucleus in the rat

By means of substance P receptor (SPR) immunofluorescence histochemistry combined with Fluoro-Gold (FG) fluorescent retrograde labeling, SPR-like immunoreactive neurons in the caudal spinal trigeminal nucleus of the rat were observed to send their axons to the gelatinosus thalamic nucleus with a clear ipsilateral dominance. FG/SPR double-labeled neurons were distributed mainly in the ventral part of lamina I at the rostral level of the caudal spinal trigeminal nucleus. The percentages of FG/SPR-LI neurons in the total number of SPR-LI neurons and FG-labeled neurons are 10.5% and 31.1%, respectively. The present results suggest that trigemino-gelatinosus thalamic projection neurons with SPR-LI in the caudal spinal trigeminal nucleus might receive SP-containing, nociceptive primary afferent fibers from the orofacial region and transmit nociception to the gelatinosus thalamic nucleus.

Upregulation of vascular endothelial growth factor is associated with radiation-induced blood-spinal cord barrier breakdown

The pathogenesis of radiation-induced injury to the central nervous system (CNS) remains unclear. Dysfunction of the blood-brain barrier (BBB) is associated with radiation-induced white matter lesions. The aim of this study was to determine if vascular endothelial growth factor (VEGF) is implicated in radiation-induced BBB disruption. Adult rats were irradiated with a single dose of 8 or 22 Gy to the spinal cord from C2 to T2. At various times up to 20 weeks following irradiation, blood-spinal cord barrier (BSCB) permeability was assessed using immunohistochemistry with anti-albumin antibody. Cell proliferation was assessed using bromodeoxyuridine (BrdU), and endothelial cell identity was assessed morphologically and using immunostaining for factor VIII-related antigen. Expression of VEGF protein and message was assessed using immunohistochemistry and in situ hybridization respectively. In the unirradiated rat spinal cord, there was no evidence of albumin immunoreactivity and little evidence of VEGF expression. After a dose of 22 Gy, focal albumin staining in white matter was observed at 16 weeks. Diffuse staining was seen at 20 weeks and was associated with necrosis and demyelination in white matter. This was associated with a significant increase in white matter glial cells that showed immunoreactivity and in situ hybridization signal for VEGE VEGF expressing cells showed dual immunoreactivity for glial fibrillary acidic protein. No increase in VEGF positive cells was observed in gray matter after 22 Gy. After a dose of 8 Gy, there was no increase in VEGF expression or albumin immunostaining in either white or gray matter. Microvessel endothelial cell density showed a trend towards a decrease with time after 22 Gy as compared with 8 Gy or unirradiated controls. BrdU immunostaining provided no evidence for endothelial cell proliferation in control or in the irradiated spinal cord. It is concluded that radiation-induced BSCB dysfunction is associated with upregulation of VEGF in astrocytes without associated endothelial proliferation. The temporal and spatial association of VEGF upregulation with the white matter lesions suggests a role of VEGF in radiation-induced late CNS injury.

Variable genetic alterations and survival in head and neck cancer

OBJECTIVE

To evaluate multiple genetic loci in patients with head and neck cancer to determine if, as in colorectal carcinoma, there is an orderly occurrence of genetic alterations, and if an accumulation of alterations affects patient survival.

DESIGN

Cohort study of patients with head and neck cancer in which fresh tissue was retrieved.

SETTING

Academic medical center.

PATIENTS

Forty-three patients treated surgically for squamous cell carcinoma of the head and neck from 1991 to 1994.

MAIN OUTCOME MEASURES

The DNA from tumor and healthy tissue was evaluated for loss of heterozygosity at p53, retinoblastoma, and chromosome 16q and for amplification of cyclin D1. The respective RNA was probed for levels of p53, p 16, p21, and p27 messenger RNA. These findings were compared with tumor stage and patient survival.

RESULTS

DNA analysis showed that loss of heterozygosity occurred at p53 in 21% of tumors, at retinoblastoma in 35%, and at 16q in 21%, and that cyclin D1 was amplified in 42%. Messenger RNA levels of the assessed proteins were variably increased and decreased compared with healthy tissues obtained from the same patients with no discernable pattern. There was no correlation between any one of these genetic alterations and overall survival. When patients were analyzed for loss of heterozygosity at p53, retinoblastoma, 16q, or altered cyclin D1 in combination, 19 patients had no detectable alterations, 13 had 1, 6 had 2, and 5 had 3. Single genetic alterations did not affect survival; however, there was a trend toward decreased survival with multiple alterations. The 2-year Kaplan-Meier survival in patients with less than 1 genetic loss was 78% vs 58% in patients with 2 or more losses.

CONCLUSIONS

The lack of a pattern of genetic alterations in head and neck cancer demonstrates that its progression can be mediated by a multitude of pathways, complicating its genetic evaluation. Single genetic alterations do not appear to affect survival; however, when multiple alterations are detected-regardless of combination-survival is affected. This observation lends credence to the theory that multiple genetic alterations contribute to cancer progression; however, the lack of a pattern of this genetic change is a significant obstacle to applying genetic findings to routine cancer therapy.

Substantia gelatinosa neurons in the medullary dorsal horn: An intracellular labeling study in the rat

Morphologic features and electrical membrane properties of neurons in the substantia gelatinosa (SG) of the caudal spinal trigeminal nucleus (the medullary dorsal horn; MDH) were examined in the rat. Intracellular recording and biocytin-injection combined with histochemical staining were performed in horizontal slices. Twenty-four SG (lamina II) neurons were recorded stably and stained successfully. Both projection neurons (PNs; n = 9) that sent axons to regions outside the MDH and intrinsic neurons (INs; n = 15) that sent axons only to the MDH were observed. The INs were divided into those with dense axonal arborization (INDAs; n = 7) and those with sparse axonal arborization (INSAs; n = 8). In the PNs, the dendrites with spines spread to all MDH layers (laminae I-III). The main axons sent collaterals within the SG and rostrally, caudally, or medially to laminae I and III of the MDH, interpolar spinal trigeminal nucleus, spinal tract of the trigeminal nerve, or upper cervical cord segments. In the INDAs, the dendrites arising from the rostral and caudal pole of the cell bodies mainly extended rostrally and caudally parallel to the rostrocaudal axis of the SG: the dendritic trees were elongated and oval in shape and were confined within the SG. The axonal field of each INDA, a dense mesh of axonal processes, was elongated and oval in shape and almost was confined within the SG. In the INSAs, a small, round cell body was located in the center of each dendritic field, which usually was limited within the SG. Axonal processes ran radially to spread to all layers of the MDH, constituting round or oval axonal fields. The three groups of SG neurons showed more or less different intracellular responses to current injections. In particular, adaptation of spike frequency, hyperpolarizing sag, and rebound excitation were observed in the PNs and INSAs but not in the INDAs. Slow ramp depolarization and slow afterdepolarization were recorded only in INDAs.

Quantum-noise measurements in high-efficiency single-pass second-harmonic generation with femtosecond pulses

The quantum-noise properties of single-pass second-harmonic blue-light generation with femtosecond pulses have been measured. A conversion efficiency of as much as 63.5% of second-harmonic generation at 428.8 nm was observed in a KNbO(3) crystal with femtosecond (130-fs) pulses with wavelengths centered at 857.6 nm. The quantum noise on the generated blue light was measured to be 1.0 dB (1.4 dB of squeezing inferred) below the shot-noise limit. The noise reduction was found to be sensitive to the average power and the center wavelength of the input fundamental pulses under the condition of strong pump depletion.

A cytotoxic triterpene saponin from the root bark of Aralia dasyphylla

A novel triterpene saponin (1) was isolated from an ethanol extract of the root bark of Aralia dasyphylla. Its structure was elucidated as 3-O-[beta-D-glucopyranosyl (1-->3)-beta-D-galactopyranosyl(1-->2)]-beta-D-glucuronopyranosyl- ole anolic acid-28-O-beta-D-glucopyranoside, according to spectral and chemical evidence. Compound 1 showed significant cytotoxic activity against KB and Hela-S(3) cells.

[The sequence analysis of the 3' end of intron 15 from human LDL receptor gene and its application in the study of gene diagnosis for familial hypercholesterolaemia]

To understand intron 15 of human LDL receptor gene, the DNA fragments from exon 15 to exon 16 and the 3' end of intron 15 were amplified with long chain PCR and anchored PCR. The 3' end of intron 15 was sequenced with Dynalbeads-Streptavidin Solid Phase technique. The sequence analysis showed that the 3' end of intron 15 contained the 3' splicing site and the branch site at 31 nucleotides upstream of the 3' end. Besides the authentic branch site, it is possible that the 3' end of intron 15 contains a cryptic site (GCCTCAC) at 20 nucleotides upstream of the 3' end. The sequences suggest that the PvuII polymorphism at Intron 15 is caused by the T-C substitution. According to the sequences of the 3' end, the new PCR-RFLP protocol for detection of PvuII polymorphism at intron 15 was developed. Using this protocol a representative familial hypercholesterolaemia family was identified with linkage analysis of PvuII polymorphism at intron 15.

Action of capsaicin on dorsal root-evoked synaptic transmission to substantia gelatinosa neurons in adult rat spinal cord slices

An action of capsaicin was investigated on dorsal root-evoked synaptic transmission to substantia gelatinosa (SG) neurons in adult rat spinal cord slices by use of the whole-cell voltage-clamp technique. In 79% of neurons examined, superfusing capsaicin (1 microM) for 30 s depressed a C-fiber-evoked excitatory synaptic current in a manner sensitive to a capsaicin-receptor antagonist, capsazepine (10 microM). On the contrary, Adelta-fiber-evoked excitatory and inhibitory synaptic currents were unaffected by capsaicin in all of cells tested. It is concluded that capsaicin specifically acts on C-afferents, resulting in an inhibition of evoked excitatory transmission to the SG; this may contribute to, at least in part, an acute analgesic action of capsaicin.

Preprodynorphin-like immunoreactivity in medullary dorsal horn neurons projecting to the thalamic regions in the rat

Preprodynorphin (PPD)-like immunoreactive (-LI) neuronal cell bodies in the trigeminal sensory nuclear complex of the rat were found in laminae I and II of the medullary dorsal horn (MDH; caudal spinal trigeminal nucleus) and the paratrigeminal nucleus. A PPD immunofluorescence histochemistry combined with a fluorescence retrograde tract-tracing method revealed that some of the PPD-LI neurons in the MDH and paratrigeminal nucleus projected to the thalamic regions. Nociceptive nature of the PPD-LI MDH neurons projecting to the thalamic regions was also demonstrated by a triple labeling method, using the technique of the noxious stimulus-evoked expression of the immediate-early gene, c-fos. In the rats which were subcutaneously injected with formalin into the upper and lower lips, c-fos protein (Fos) was found in PPD-LI neurons which were labeled with a retrograde tracer injected into the thalamic regions.

Direct evidence that ERK regulates the production/secretion of interleukin-2 in PHA/PMA-stimulated T lymphocytes

Although p21ras, raf-1 and MEK have been shown to regulate directly the transcriptional activity of NFAT (nuclear factor of activated T cells) and/or the interleukin-2 (IL-2) promoter, direct evidence that the extracellular signal-regulated protein kinase (ERK) is involved in regulating IL-2 production is still lacking. Here, we demonstrate that transfection of Jurkat cells with a dominant negative mutant of ERK1 (Erk1-K71R) resulted in the suppression of mitogen-stimulated production/secretion of IL-2. This was accompanied by a parallel inhibition of mitogen-stimulated ERK activity. These data provide direct evidence, for the first time, that ERK plays a vital role in regulating the production/secretion of IL-2.

Centrosome hyperamplification in human cancer: chromosome instability induced by p53 mutation and/or Mdm2 overexpression

We have previously reported that loss of p53 tumor suppressor protein results in centrosome hyperamplification, which leads to aberrant mitosis and chromosome instability. Since p53 is either deleted or mutated in human cancers at a high frequency, we investigated whether human cancers showed centrosome hyperamplification. Screening of advanced stage breast ductal carcinomas and squamous cell carcinomas of the head and neck (SCCHN) revealed that centrosome hyperamplification is frequent in both tumor types. Moreover, through the analyses of p53 in SCCHN samples by direct sequencing and by loss-of-heterozygosity test, we found that p53 mutations correlated with occurrence of centrosome hyperamplification. However, in some cases, we observed centrosome hyperamplification in tumors that retained wild-type p53. These tumors contained high levels of Mdm2. Since Mdm2 can inactivate p53 through physical association, we investigated whether Mdm2 overexpression induced centrosome hyperamplification. We found that Mdm2 overexpression, like loss of p53, induced centrosome hyperamplification and chromosome instability in cultured cells.

Regulation of lymphotoxin production by the p21ras-raf-MEK-ERK cascade in PHA/PMA-stimulated Jurkat cells

Although the production of lymphotoxin (LT) from activated Th1 lymphocytes has been reported extensively, the intracellular signaling mechanisms that regulate this T cell function remain totally undefined. We have examined whether the p21ras-raf-1-mitogen-activated protein kinase/extracellular signal-regulated protein kinase (ERK) kinase (MEK)-ERK cascade plays a role in regulating the production of LT, because the activity of these signaling molecules is up-regulated in activated T lymphocytes. Transfection of Jurkat leukemic T cells with a dominant negative mutant of p21ras (ras17N or ras15A), raf-1 (raf 1-130), or ERK1 (Erk1-K71R) resulted in the suppression of the mitogen/phorbol ester-stimulated production/secretion of LT. This suppression was accompanied by a parallel inhibition of mitogen-stimulated ERK activation. The selective antagonist of MEK1 activation, PD98059, also attenuated the mitogen-stimulated or anti-CD3 Ab and phorbol ester-stimulated production of LT from Jurkat cells or peripheral blood T lymphocytes. This study provides, for the first time, direct evidence that the p21ras-raf-MEK-ERK cascade plays a vital role in regulating the production of LT.

Cervical metastases of head and neck squamous cell carcinoma correlate with loss of heterozygosity on chromosome 16q

To assess the potential involvement of putative tumor suppressors or metastasis suppressors on chromosome 16q in head and neck squamous cell carcinoma (HNSCC), we have examined 42 primary HNSCCs for loss of heterozygosity (LOH) at 16q and correlated these findings with the occurrence of cervical nodal metastases and other clinical parameters. Seven of the 42 (17%) HNSCCs examined displayed LOH at chromosome 16q24. Three of the seven HNSCCs showed LOH at all of the informative loci analyzed along the chromosome arm, whereas the other four showed only loss of a subset of markers. When LOH at 16q was correlated with clinical parameters, there was no significant correlation with age, sex, clinical stage, T stage, N stage or survival. However, there was a correlation between LOH at chromosome 16q24 and involvement of cervical lymph nodes. Of the seven HNSCCs that had lost heterozygosity at 16q24, six had local metastases to lymph nodes indicating that LOH at 16q24 may have predictive value for the metastatic potential of HNSCCs.

Serotoninergic neurons in the brainstem expressing FOS protein after orofacial noxious stimulation: an immunocytochemical double-labeling study

Employing an immunocytochemical double-labeling technique, we investigated the co-localization of FOS protein, the expression product of c-fos proto-oncogene induced by orofacial noxious stimulation, and serotonin in the rat brainstem. About 3.2%-25.6% of serotonin-like immunoreactive neurons and 6.2%-46.7% of FOS-like immunoreactive neurons in the raphe nuclei, reticular formation and ventrolateral subdivision of the midbrain periaqueductal gray exhibit FOS-like immunoreactivity and serotonin-like immunoreactivity, respectively. The present results provide further morphological evidence for the involvement of serotoninergic neurons in modulating the transmission of noxious information.

Temporal changes of preproenkephalin mRNA and leu-enkephalin-like immunoreactivity in the neurons of the caudal spinal trigeminal nucleus and upper cervical cord after noxious stimuli

The changing levels of preproenkephalin (PPE) mRNA expression and leu-enkephalin-like immunoreactivity (L-ENK-LI) in the caudal spinal trigeminal nucleus (Vc) and the upper cervical cord subsequent to subcutaneous injection of formalin into orofacial region were examined using in situ hybridization histochemistry and immunohistochemistry. Formalin injection resulted in a significant increase in the number of neurons expressing PPE mRNA in the superficial (laminae I-II) and deep (lamina V) layers of the ipsilateral Vc and the first cervical cord (C1). The expression of PPE mRNA increased 2 h and 4 h after formalin injection in the neurons of deep layer and superficial layers of the Vc, respectively. An increased expression of PPE gene could still be observed 48 h after formalin injection. The PPE mRNA expression in the neurons of the C1 had similar temporal changes as in the Vc. In parallel, the L-ENK-LI did not show any significant changes in the Vc and C1. These results indicate that peripheral noxious stimulation trans-synapticaly activates the expression of PPE gene in the neurons of the Vc and C1 and suggest that enkephallin (ENK) plays an important role in the processing and modulation of the oroficial noxious stimulation.

The effect of hormones on the expression of five isoforms of UDP-glucuronosyltransferase in primary cultures of rat hepatocytes

PURPOSE

To investigate the direct effects of sex hormones, growth hormone, thyroid hormones and dexamethasone on the regulation of UDP-glucuronosyltransferase (UGT).

METHODS

Rat hepatocytes were cultured on matrigel and treated with various hormones. Northern blot analysis was carried out using cDNA probes to family 1 and family 2 isoforms.

RESULTS

Treatment with 10(-5) M testosterone increased the mRNA levels of UGT 2B1 by 29% and UGT2B3 by 32%. Incubation of growth hormone (10 mU) with hepatocytes suppressed the expression of UGT2B1 and UGT2B3 by 17% and 38%, respectively. T3 administration resulted in a time and dose-dependent effect on the expression of UGT 1 isoforms, with increased UGT1A6 by 70%, and decreased UGT1A1 by 38% and UGT1A5 by 35%. All UGT isoforms except UGT 1A6 studied in this assay were up-regulated by dexamethasone, but to different degrees. The regulation of UGT1A1 and UGT2B1 by dexamethasone was dose and time dependent, and the induction of dexamethasone in the expression of UGT1A1 and UGT2B1 was blocked by cycloheximide but not dichloro-1-D-ribofuranosylbenzimidazole.

CONCLUSIONS

This study demonstrates that multiple hormones take part in the regulation of UGT mRNA expression in the rat and individual genes can be differentially modulated.

Tumour proliferation and apoptosis in human uterine cervix carcinoma II: correlations with clinical outcome

PURPOSE

The prognostic value of tumour proliferation and apoptosis measurements were studied prospectively in patients with carcinoma of the uterine cervix, relative to other established clinical factors.

MATERIALS AND METHODS

The labelling index (LI) for bromodeoxyuridine was determined by flow cytometry (fc) and also by immunohistochemistry. Apoptosis was assessed histologically using morphological criteria. Patients were treated with radical radiation therapy (RT).

RESULTS

The median/mean LI-fc were 6.7%/7.9% (range 1.52-3.9%). The median/mean apoptosis index (AI) were 1.0%/1.6% (range 0-6.8%). To date, 27 patients have died of disease, and the median follow-up for alive patients is 3.2 years (range 0.4-6.0 years). Among 64 patients who completely responded to treatment, 25 patients have relapsed (six pelvic, 17 distant and two pelvic and distant). In univariate analysis, the most significant factors for disease-free survival (DFS) were large tumour size (P=0.0001), low haemoglobin (P=0.01 ), LI-fc (DFS 67% for LI < 7%, 33% for LI > or = 7%, P=0.03), and T(pot) (DFS 66% for T(pot) > 5 days, 35% for T(pot) < or = 5 days, P=0.04) Stage, overall treatment time (OTT), S-phase fraction, ploidy, T(s), LI by histology, mitotic index, and AI were not significant. Multivariate analysis (Cox's model) showed that the only significant prognostic factors for DFS were tumour size and OTT. However, for small tumours (diameter < 6 cm), either a high LI-fc ( > or = 7%) or a high AI ( > 1%) was associated with poorer DFS, whereas patients with larger tumours (diameter > or = 6 cm) fared poorly regardless of LI-fc and AI.

CONCLUSIONS

Tumour size was the most important prognostic factor in cervix carcinoma. Although none of the biologic parameters have independent prognostic significance when the effect of initial tumour size was taken into account, our data suggests that LI and AI may be useful in discriminating outcome for patients with smaller tumours when managed by radical RT. These findings support the hypothesis that rapidly proliferating tumours are less likely to be controlled with a conventional course of RT.

Effect of IL-4 deletion on cardiac allograft survival in the BALB/c to 129Sv x C57BL/6 strain combination

To investigate the effect of IL-4 deletion on cardiac allograft survival, vascularized BALB/c cardiac allografts were placed in C57BL/6, 129Sv x C57BL/6 (IL-4 +/+) or 129Sv x C57BL/6 IL-4 knockout mice (IL-4-/-). Untreated recipients rejected allografts in < 15 days while isografts survived indefinitely (> 100 days). Treatment with anti-CD4 (GK1.5) for 4 days at the time of allografting increased mean survival to > 100 days in C57BL/6, 90+/-16 days in 129Sv x C57BL/6 (IL-4 +/+) and 68 +/- 36 days in 129Sv x C57BL/6 (IL-4-/-) recipients. Although there was a trend towards shorter survival times in the IL-4-/- mAb-treated mice, survival in the three recipient groups was not significantly different (P = 0.07). A 30-day course of anti-CD4 did not further prolong BALB/c heart survival. All long-surviving hearts had histological evidence of parenchymal damage and transplant vascular disease. None of these recipients developed antigen-specific tolerance, since both donor and third party skin graft challenges were rejected when challenged at > 60 days post-graft and all primary grafts failed by 120 days. Thus the effects of IL-4 deletion were subtle and were seen only with low doses of immunosuppression in this high responder strain combination.

[Studies on the triterpenoid saponins of the root bark of Aralia taibaiensis]

Four triterpenoid saponins were isolated from the root bark of Aralia taibaiensis Z. Z. Wang et H. C. Zheng. On the basis of their chemical properties and spectral data, they were identified as oleanolic acid-3-O-[beta-D-xylopyranosyl(1-->2)] [beta-D-glucopyranosyl(1-->3)]-beta-D-glucuronopyranoside (1), tarasaponin V (2), 3-O-¿beta-D-xylopyranosyl(1-->2)[beta-D-glucopyranosyl (1-->3)]-6'-O-ethyl-beta-D-glucuronopyranosyl¿-oleanolic acid-28-O-beta-D-glucopyranoside (3) and 3-O-¿beta-D-xylopyranosyl(1-->2) [beta-D-glucopyranosyl(1-->3)] -6'-O-butyl-beta-D-glucuronopyranosyl¿-oleanolic acid-28-O-beta-D-glucopyranoside (4). Compound 1 is a new natural product named taibaienoside VI. 2 was isolated from the title plant for the first time. 3 and 4 are new compounds and named taibaienoside VII and taibaienoside VIII, respectively.

IL-10 and GM-CSF expression and the presence of antigen-presenting cells in chronic venous ulcers

BACKGROUND

White cell trapping and activation occurs in the legs of patients having chronic venous insufficiency (CVI), and it is thought that this process may be important in the development of CVI ulcers. This study has compared the tissue distribution of proinflammatory (GM-CSF) and anti-inflammatory cytokines (IL-10) and inflammatory cell markers (CD68, HLA-DR) between CVI ulcers, other chronic and acute wounds, and autologous nonwounded skin to determine whether cell-mediated immunity (CMI) is impaired in CVI ulcers.

METHODS

Wound and donor site tissue was obtained from 10 patients with CVI ulcers and 10 patients with other chronic and acute wounds. Serial Formalin-fixed sections were processed by standard hematoxylin and eosin staining or by indirect immunoperoxidase histochemical staining.

RESULTS

HLA-DR-positive antigen-presenting cells (APC), including CD68-positive macrophages and dermal dendritic cells, were found with greater frequency in CVI ulcers than in other chronic or acute wounds (P = 0.0015) or in the autologous CVI donor site tissue (P = 0.006). CVI ulcers also demonstrated increased IL-10 staining of the entire epidermis compared to non-CVI wounds (P = 0.0019) or autologous donor site tissue (P = 0.004), whereas there was no significant change in the presence of the counteracting cytokine, GM-CSF.

CONCLUSIONS

These findings suggest that although the cellular components of CMI are present in CVI ulcers, their function may be impaired by the increased level of IL-10. Future studies will examine whether IL-10-mediated suppression of CMI and/or inhibition of GM-CSF-stimulated keratinocyte proliferation may contribute to the chronic nature of CVI ulcers.

Apoptosis and its relationship with cell proliferation in the irradiated rat spinal cord

PURPOSE

To assess the relationship of oligodendroglial apoptosis with cell proliferation after irradiation.

MATERIALS AND METHODS

The adult rat spinal cord (C2-T2) was irradiated with a single dose of 2, 8 or 22 Gy alone, or a dose of 2, 8 or 22 Gy followed by a second 8 Gy dose given at 1-63 days after the initial dose. Apoptosis was assessed histologically according to its specific morphological features. Cell proliferation and glial cell identity were assessed immunohistochemically using BrdU, Leu-7 and GFAP as markers for oligodendrocytes and astrocytes respectively.

RESULTS

The total apoptotic yield (TAY) per spinal cord section over a 24h period after a single dose of 2, 8 or 22 Gy was 2.4, 9.0 and 10.9% respectively. Cycloheximide delayed the onset of apoptosis by about 8 h. Unirradiated spinal cord showed a very low BrdU labelling index (LI) of 0.13% in the glial cells. After a single dose of 8 Gy, the BrdU LI increased by 2 days, peaked at 14 days (1.05%), and returned to control level by 42 days. A smaller increase in the BrdU LI was seen after doses of 2 or 22 Gy compared with 8 Gy. Labelled cells at 2 weeks appeared to be Leu-7 positive and GFAP negative. After an initial dose of 2 Gy, a second 8 Gy dose given at 1-63 days gave reduced TAY values of 3.7-6.7% respectively. After an initial 22 Gy dose, little apoptotic response was induced by the second 8 Gy dose regardless of the time interval between the two doses (TAY = 1.2-2.6%). For an intermediate initial dose of 8 Gy, TAY from the second 8 Gy dose given at 1 day was reduced to 3.7%, but there was recovery of the apoptotic response with the second dose given at 14 days (TAY = 9.8%). A much higher percentage of apoptotic cells were observed in BrdU positive (4.8-21.7%) compared with the negative (0.25-0.54%) glial cells after split-dose irradiation, and 20.0% of apoptotic cells showed immunostaining for BrdU. Apoptotic cells after the second 8Gy dose remained Leu-7 positive, and no GFAP positive apoptotic cells were observed.

CONCLUSIONS

(1) There is cell proliferation following radiation-induced apoptosis in the adult rat spinal cord. (2) Dose- and time-dependent apoptotic recovery is seen after split-dose irradiation. It is postulated that this recovery is due to the cell proliferation that replenishes the apoptosis-sensitive oligodendrocytes.