The Protective Effect of a Human Umbilical Cord Mesenchymal Stem Cell Supernatant on UVB-Induced Skin Photodamage

The skin is constantly exposed to a range of environmental stressors, including ultraviolet (UV) radiation, which can cause damage to the skin. Repairing UV-damaged skin has been a major focus of research in recent years. The therapeutic potential of human umbilical cord mesenchymal stem cells (HUCMSCs) exhibits anti-photoaging properties. In this study, we developed a strategy for concentrating an HUCMSC supernatant, and examined the protective effects of CHS on UVB exposure in vitro and in vivo. Our results demonstrate that CHS repairs UVB exposure by promoting cell viability and migration and reducing senescent and apoptosis cells. We further found that the photoprotective effect of CHS is due to autophagy activation. Moreover, CHS reduces wrinkles and senescent cells, increases collagen expression, and improves immune function in UVB exposure-induced skin damage. In summary, our study provides a new approach for repairing cell damage, and suggests that CHS might be a potential candidate for preventing UVB-induced skin photodamage.

[Preliminary study on three-dimensional morphological reconstruction method for external nose defect based on three-dimensional face template]

Objective: To provide a new solution for the digital design of nasal prostheses, this study explores the three-dimensional (3D) facial morphology completion method for external nasal defects based on the non-rigid registration process of 3D face template. Methods: A total of 20 male patients with tooth defect and dentition defect who visited the Department of Prosthodontics, Peking University School and Hospital of Stomatology from June to December 2022 were selected, age 18-45 years old. The original 3D facial data of patients were collected, and the 3D facial data of the external nose defect was constructed in Geomagic Wrap 2021 software. Using the structured 3D face template data constructed in the previous research of the research group, the 3D face template was deformed and registered to the 3D facial data of external nose defect (based on the morphology of non-defective area) by non-rigid registration algorithm (MeshMonk program), and the personalized deformed data of the 3D face template was obtained, as the complemented facial 3D data. Based on the defect boundary of the 3D facial data of the external nose defect, the complemented external nose 3D data can be cut out from the complemented facial 3D data. Then the nasofacial angle and nasolabial angle of the complemented facial 3D data and the original 3D facial data was compared and analyzed, the ratio between the nose length and mid-face height, nose width and medial canthal distance of the complemented facial 3D data was measured, the edge fit between the edge curve of the complemented external nose 3D data and the defect edge curve of the 3D facial data of external nose defect was evaluated, and the morphological difference of the nose between the complemented external nose 3D data and the original 3D facial data was analyzed. Results: There was no significant statistically difference (t=-0.23, P=0.823; Z=-1.72, P=0.086) in the nasofacial angle (28.2°±2.9°, 28.4°±3.5° respectively) and nasolabial angle [95.4°(19.2°), 99.9°(9.5°) respectively] between the 20 original 3D facial data and the complemented facial 3D data. The value of the ratio of nose length to mid-face height in the complemented facial 3D data was 0.63±0.03, and the value of the ratio of nose width to medial canthal distance was 1.07±0.08. The curve deviation (root mean square value) between the edge curve of the complemented external nose 3D data and the defect edge curve of the 3D facial data of external nose defect was (0.37±0.09) mm, the maximum deviation was (1.14±0.32) mm, and the proportion of the curve deviation value within±1 mm was (97±3)%. The distance of corresponding nose landmarks between the complemented facial 3D data and the original 3D facial data were respectively, Nasion: [1.52(1.92)] mm; Pronasale: (3.27±1.21) mm; Subnasale: (1.99±1.09) mm; Right Alare: (2.64±1.34) mm; Left Alare: (2.42± 1.38) mm. Conclusions: The method of 3D facial morphology completion of external nose defect proposed in this study has good feasibility. The constructed complemented external nose 3D data has good facial coordination and edge fit, and the morphology is close to the nose morphology of the original 3D facial data.

Mid1ip1b modulates apical reorientation of non-centrosomal microtubule organizing center in epithelial cells

In most kinds of animal cells, the centrosome serves as the main microtubule organizing center (MTOC) that nucleates microtubule arrays throughout the cytoplasm to maintain cell structure, cell division and intracellular transport. Whereas in epithelial cells, non-centrosomal MTOCs are established in the apical domain for generating asymmetric microtubule fibers and cilia in epithelial cells for the organ morphogenesis during embryonic development. However, the mechanism by which MTOCs localize to the apical domain in epithelial cells remains largely unknown. Here, we show that Mid1ip1b has a close interaction with γ-tubulin protein, the central component of MTOC, and modulates lumen opening of the neural tube, gut, intestine, and kidney of zebrafish. Knockdown or dominant negative effect of Mid1ip1b resulted in failure of lumen formation of the organs as aforementioned. Moreover, the non-centrosomal MTOCs were unable to orientate to the apical domain in Mid1ip1b knockdown epithelial cells, and the centrosomal MTOCs were inaccurately placed in the apical domain, resulting in defective formation of asymmetric microtubules and misplacement of cilia in the apical domain. These data uncover a molecule that controls the proper localization of MTOCs in the apical domain in epithelial cells for organ morphogenesis during embryonic development.

Polymorphisms of TGFB1, TLE4 and MUC22 are associated with childhood asthma in Chinese population

OBJECTIVE

To investigate whether the genetic variants of TGFB1, TLE4, MUC22 and IKZF3 are associated with the development of asthma in Chinese children.

METHODS

572 adolescent asthma patients and 590 age-matched healthy controls were included in this study. A total of four SNPs were genotyped, including rs2241715 of TGFB1, rs2378383 of TLE4, rs2523924 of MUC22, and rs907092 of IKZF3. Allele frequencies of the patients and the control group were compared by the Chi-square test. The Student t test was used to analyse the relationship between genotypes and clinical feature of the patients.

RESULTS

Patients were found to have significantly different frequencies of allele A of rs2241715, allele G of rs2378383 and allele A of rs2523924 as compared with the controls (40.4% vs. 45.9%, p=0.01 for rs2241715; 17.2% vs. 13.4%, p=0.01 for rs2378383; 15.3% vs. 11.9%, p=0.02 for rs2523924). For patients with severe asthma, those with genotype AA/AG of rs2241715 had remarkably higher FEV1% as compared with those with genotype GG (59.1±4.3% vs. 55.4±3.7%, p<0.001). Moreover, those with genotype GG/GA of rs2378383 had remarkably lower FEV1% as compared with those with genotype AA (54.6±2.9% vs. 58.6±4.1%, p<0.001).

CONCLUSIONS

Genes TGFB1, TLE4 and MUC22 are associated with the risk of childhood asthma in Chinese population. Our results associating TGFB1 and TLE4 with clinical features of asthma suggest potential application of these parameters in the management of asthma children.

A zebrafish mosaic assay to study mammalian stem cells in real time in vivo

The differentiation potentials of stem cells have been evaluated by various in vivo and in vitro assays. However, these assays have different limitations hindering efficient study of mammalian stem cells. Here we describe a rapid and powerful mosaic assay to study the differentiation potentials of stem cells in real time in vivo by using zebrafish embryo. We transplanted mouse neural stem cells into zebrafish embryos at different developmental stages and found that they mainly formed neural tissues while occasionally trans-differentiated into mesoderm- and endoderm-derived tissues. Because zebrafish embryo is transparent, the behaviors of transplanted mouse stem cells can be easily tracked in a real-time manner and at single-cell resolution. We expect that this assay may be widely applied to explore the in vivo behaviors of any stem cells available.

Pathophysiology, Clinical Importance, and Management of Neurogenic Lower Urinary Tract Dysfunction Caused by Suprasacral Spinal Cord Injury

Management of persistent lower urinary tract dysfunction resulting from severe thoracolumbar spinal cord injury can be challenging. Severe suprasacral spinal cord injury releases the spinal cord segmental micturition reflex from supraspinal modulation and increases nerve growth factor concentration in the bladder wall, lumbosacral spinal cord, and dorsal root ganglion, which subsequently activates hypermechanosensitive C-fiber bladder wall afferents. Hyperexcitability of bladder afferents and detrusor overactivity can cause urine leaking during the storage phase. During urine voiding, the loss of supraspinal control that normally coordinates detrusor contraction with sphincter relaxation can lead to spinal cord segmental reflex-mediated simultaneous detrusor and sphincter contractions or detrusor-sphincter dyssynergia, resulting in inefficient urine voiding and high residual volume. These disease-associated changes can impact on the quality of life and life expectancy of spinal-injured animals. Here, we discuss the pathophysiology and management considerations of lower urinary tract dysfunction as the result of severe, acute, suprasacral spinal cord injury. In addition, drawing from experimental, preclinical, and clinical medicine, we introduce some treatment options for neurogenic lower urinary tract dysfunction that are designed to: (1) prevent urine leakage arising because of detrusor overactivity during bladder filling, (2) preserve upper urinary tract integrity and function by reducing intravesical pressure and subsequent vesicoureteral reflux, and (3) prevent urinary tract and systemic complications by treating and preventing urinary tract infections.

Efficacy and safety of bone marrow cell transplantation for chronic ischemic heart disease: a meta-analysis

Background

Although bone marrow-derived cells (BMCs) have shown great therapeutic potential in patients with chronic ischemic heart disease (CIHD), the exact efficacy and safety of BMCs therapy is still not completely defined.

Material/Methods

We searched PubMed, OVID, EMBASE, the Cochrane Library, and ClinicalTrials.gov and finally identified 20 qualified trials in this meta-analysis. Assessment of efficacy was based on left ventricular ejection fraction (LVEF), left ventricular end-systolic volume (LVESV), and left ventricular end-diastolic volume (LVEDV) improvement, by weighted mean difference (WMD) with 95% confidence intervals (CIs). Results of all-cause death, ventricular arrhythmia, recurrent myocardial infarction, and cerebrovascular accident were pooled to assess safety. Subgroup analysis was performed by stratifying RCTs into 2 subgroups of those with revascularization and without revascularization.

Results

BMC transplantation significantly improved LVEF in patients with revascularization (3.35%, 95% CI 0.72% to 5.97%, p=0.01; I²=85%) and without revascularization (3.05%, 95% CI 0.65% to 5.45%, p=0.01; I²=86%). In patients without revascularization, BMC transplantation was associated with significantly decreased LVESV (−11.75 ml, 95% CI −17.81 ml to −5.69 ml, p=0.0001; I²=81%), and LVEDV (−7.80 ml, 95% CI −15.31 ml to −0.29 ml, p=0.04; I²=39%). Subgroup analysis showed that the route of transplantation, baseline LVEF, and type of cells delivered could influence the efficacy of BMC transplantation.

Conclusions

Autologous transplantation of BMCs was safe and effective for patients who were candidates for revascularization with CABG/PCI and those who were not. However, large clinical trials and long-term follow-up are required to confirm these benefits.

Proteomic analysis of interstitial fluid in bone marrow identified that peroxiredoxin 2 regulates H(2)O(2) level of bone marrow during aging

Hematopoiesis in bone marrow declines during aging owing to alteration of the hematopoietic niche. However, due to difficult accessibility and other complexities, senescence-related alteration of the hematopoietic niche is largely unknown. The interstitial fluid of bone marrow (IFBM), a pivotal component of the hematopoietic niche, includes soluble secretory factors that are present between bone marrow cells. To characterize the proteomic profile changes of IFBM during aging, we analyzed the IFBMs of young, adult, and senescent rats using 2-DE combined with ESI/MALDI-Q-TOF MS. Finally, 31 differentially expressed proteins involved in multiple biological functions were identified. Peroxiredoxin 2 (Prx2), down-regulated during aging, was further analyzed and demonstrated that it is produced by bone marrow stromal cells. Interestingly, higher levels of hydrogen peroxide (H(2)O(2)) were detected in the bone marrow with lower Prx2 expression. Moreover, exogenous Prx2 reduced the intracellular H(2)O(2) level in bone marrow stromal cells in vitro. Therefore, Prx2 is implied in the regulation of H(2)O(2) production in the bone marrow during aging. Our data characterized the dynamic protein profiles of the bone marrow microenvironment during aging and we provided clues to elucidate the mechanism of creating a low ROS level in the hematopoietic niche.

Variation of human papillomavirus 16 in cervical and lung cancers in Sichuan, China

Although the crucial role of human papillomaviruses (HPVs), especially HPV-16 in various cancers has been confirmed, the variation of HPV-16 among different cancers have not been investigated in a specific geographic location. In order to elucidate whether similar HPV-16 variants are involved in different kinds of cancers in the same geographic location, the analysis of sequence variants of E6 and E7 oncogenes and L1 gene of HPV-16 in cervical and lung cancers in Sichuan, China, was carried out. Tissue samples from 122 cervical cancers, 104 lung cancers, and 138 controls were subjected to RT-PCR or PCR, sequencing, and sequence analysis. The infection rates of HPV-16 in cervical, lung cancers, and non-malignant controls were 68.9%, 17.3%, and 37.0%, respectively. Asian prototype variants prevailed in cervical and lung cancers, while European prototype variants in non-malignant controls. In comparison to the lung cancer, cervical cancer showed a much higher diversity of HPV-16 oncogenes. These results indicate that in Sichuan, China, Asian prototype variants of HPV-16 are more pathogenic than their European counterparts.

Suppression of human MDA-MB-435S tumor by U6 promoter-driven short hairpin RNAs targeting focal adhesion kinase

PURPOSE

Focal adhesion kinase (FAK) is a non-receptor protein tyrosine kinase implicated in cancer cell survival, proliferation, and in various steps in the metastatic cascade. In the present study, we took advantage of a cationic liposome as gene carrier and targeted FAK function through both in vitro and in vivo approaches.

METHODS

We utilized a plasmid-encoded hairpin RNA targeting the human FAK mRNA (pGensil2-shRNA/FAK), as a means to inhibit FAK expression for evaluating its anti-tumor effect in vitro and in vivo. Human MDA-MB-435S breast cancer cells were transfected with pGensil2-shRNA/FAK and examined for apoptosis by propidium iodide staining, DNA ladder, and flow cytometric analysis. For in vivo study, subcutaneous breast carcinomatosis models in nude mice were established to evaluate the therapeutic potential of pGensil2-shRNA/FAK. Assessments of proliferation (Ki-67), apoptosis (TUNEL) and angiogenesis (CD31) were done using immunohistochemical analysis.

RESULTS

Transcripts expressed from plasmid both in vitro and in vivo were identified by northern blot analysis. pGensil2-shRNA/FAK effectively down-regulated the expression of FAK as demonstrated in vitro by real time RT-PCR and western blot analysis, whereas by real time RT-PCR and IHC staining of MDA-MB-435S tumors growing subcutaneously. Breast cancer cells lacking FAK expression undergo apoptosis in vitro. Systemic delivery of cationic liposome-complexed plasmids targeting FAK, resulted in the diminishment of subcutaneous tumor growth beyond the effects observed with liposomes carrying a non-specific shRNA. This diminishment in growth was associated with elevated levels of apoptosis (TUNEL staining), decreased cell proliferation (Ki-67 staining) and diminished endothelial cell density (CD31 staining).

CONCLUSION

These results indicate that the systemic delivery of plasmid DNA targeting FAK function using cationic liposome as a gene carrier, represents a promising avenue for breast cancer therapy.

[Cancer stem cell theory and cancer therapy]

OBJECTIVE

To analyze the advances of cancer stem cell (CSC) in recent years, and to propose a prospect for CSC research and cancer therapy.

METHODS

Articles about important advances of CSC theory and cancer therapy were reviewed, and then selected and summarized.

RESULTS

In 2001, CSC was first put forward as a concept, till now, which has been confirmed in many tissues. In recent years, efforts were dedicated to such topics including: identification of CSC in solid tumors, the origin of CSC, its niche and growth mechanism, cancer therapy, etc. According to the CSC theory, traditional therapeutic methods have deficiencies, and new treatment targeting CSC may thoroughly eliminate tumors.

CONCLUSION

At present, CSC theory is still controversial, while it proposed revolutionary methods and directions for the therapy of cancer.

[Experimental study on culture of human mesenchymal stem cells from cord blood using autologous serum]

In this study, we collected human umbilical cord blood and separated the autologous serum and clear cells. Then the human mesenchymal stem cells were cultured with the use of autologous serum and fetal serum, respectively. By identifing surface markers with flow cytometry and testing the osteogenic, adipogenic and cardiomyocytes differentiation capacity of the cells, we affirmed that the cultured cells are mesenchymal stem cells. Among 21 cases of umbilical cord blood, 11 cases using fetal bovine serum and 15 cases using autologous successfully cultured mesenchymal stem cells from umbilical cord blood. The UCB-MSCs did not express CD34 and CD45, but they expressed CD29, CD44 and CD105, and they were successfully induced into osteogenic cells, adipogenic cells and cardiomyocytic-like cells. All of these suggest that using autologous serum to culture UCB-MSCs is better than using fetal bovine serum, and the autologous serum cultured UCB-MSCs can also be induced into osteogenic cells, adipogenic cells cardiomycyote-like cells.

Unaltered graft survival and intragraft lymphocytes infiltration in the cardiac allograft of Cxcr3-/- mouse recipients

Previous studies showed that absence of chemokine receptor Cxcr3 or its blockade prolong mouse cardiac allograft survival. We evaluated the effect of the CXCR3 receptor antagonist MRL-957 on cardiac allograft survival, and also examined the impact of anti-CXCR3 mAb in human CXCR3 knock-in mice. We found only a moderate increase in graft survival (10.5 and 16.6 days, p < 0.05) using either the antagonist or the antibody, respectively, compared to control (8.7 days). We re-evaluated cardiac allograft survival with two different lines of Cxcr3(-/-) mice. Interestingly, in our hands, neither of the independently derived Cxcr3(-/-) lines showed remarkable prolongation, with mean graft survival of 9.5 and 10.8 days, respectively. There was no difference in the number of infiltrating mononuclear cells, expansion of splenic T cells or IFN-gamma production of alloreactive T cells. Mechanistically, an increased other chemokine receptor fraction in the graft infiltrating CD8 T cells in Cxcr3(-/-) recipients compared to wild-type recipients suggested compensatory T-cell trafficking in the absence of Cxcr3. We conclude Cxcr3 may contribute to, but does not govern, leukocyte trafficking in this transplant model.

[Cloning, expression, distribution and subcellular localization of AK078438 gene]

OBJECTIVE

To investigate the molecular cloning, tissue distribution, tumor distribution and the subcellular localization of AK078438 gene.

METHODS

Reverse transcriptase-polymerase chain reaction (RT-PCR) technique was applied to amplify the open reading frame of AK078438 gene. Prokaryotic expressing vector and affinity purification were used to get the fusion protein. At mRNA expressing levels semi-quantitative RT-PCR was employed for the investigation of its distribution in normal rat tissues, tumor cell and mesenchymal stem cell (MSC) lines. The eukaryotic expression green fluorescence protein (GFP) fusion protein vector was transfected into cells and identified subcellular localization.

RESULTS

The full open reading frame of AK078438 gene with 1065 bp, 355aa were identified. mRNA of the gene distributed in brain, uterus, colon, bone marrow, testis and kidney, but not in stomach, liver, the lung, spleen and heart. Murine colon adenocarcinoma C26, melanoma B16, Lewis lung carcinoma LL/2 and MSC had the gene and mouse myeloma cell line NS-1 and Hepa mouse hepatoma cell line had no the gene. The protein was localized in cytoplasm.

CONCLUSION

Protein expression, expressing profile and subcellular localization of AK078438 gene set the basis for further exploration of its functions.

[Construction of recombinant adenovirus vector carrying secondary lymphoid organ chemokine]

OBJECTIVE

To construct a recombinant adenovirus vector carring the SLC gene for further studies on gene therapy for carcinoma.

METHODS

The SLC gene was amplified from the pORF5 vector with polymerase chain reaction (PCR) technique. The amplified gene was cloned into the pENTR11 vector. With the pENTR11-SLC plasmid and the backbone plasmid pAd/CMV/V5-DEST, the homologous recombination reaction took place in vitro. The reaction mixture was transferred into TOP10 E. coli strains (without F' episome). The recombination adenovirus plasmid was then generated. The recombinant adenoviruses were packaged and amplified in 293A cells.

RESULTS

The SLC gene was successfully cloned into the pAd/CMV/V5-DEST plasmid and the recombinant adenoviruses carrying SLC gene were detected by PCR, with a viral titer of 2. 6 X 10(8) pfu/mL.

CONCLUSION

The constructed recombinant adenovirus can introduce SLC gene into tumor tissues, which provides a foundation for the study of antitumor efficacy of SLC.

Delaying Acute Graft-Versus-Host Disease in Mouse Bone Marrow Transplantation by Treating Donor Cells with Antibodies Directed at l-Selectin and alpha4-Integrin Prior to Infusion

Acute graft-versus-host disease (GVHD) is still a major hurdle for successful bone marrow transplantation (BMT). Although many immunosuppressive drugs are available, none of them alone or in combination are able to completely abolish acute GVHD. The lifelong immunosuppression profoundly reduces the quality of life of BMT recipients. Therefore, new therapeutic approaches are needed. We previously reported that, in an acute GVHD model using SCID mice as recipient, incubating donor spleen cells with antibodies directed at CD49d and CD62L could significantly delay the occurrence of acute GVHD. To test the potential usefulness of this treatment in BMT, we examined this therapeutic protocol in a mouse BMT model. The present mouse BMT study confirmed our previous results that incubation of donor cells with antibodies directed at CD49d and CD62L prior to infusion into the recipient can effectively delay acute GVHD, allowing the recipients to recover from the side effects of total body irradiation. This one-time treatment is easy and simple and may be modified for clinical usage.

[Establishment of transgenic mice of hepatitis B virus X gene (adr subtype) mediated by spermatogonial cells]

OBJECTIVE

To test the possibility of using spermatogonial cells as vector in the establishment of HBV X gene transgenic mice.

METHODS

Eukaryoti expression vector pcDNA3-X of hepatitis B virus X gene was constructed. The recombinant pcDNA3-X packed by liposome was injected into testicle tissue of male C57BL/6N mice using microvolume injector. Six weeks after the first injection, the mice were crossed with female mice. Polymerase chain reaction and immunohistochemistry were applied to identify the viral DNA(HBx gene) harbored n liver tissue.

RESULTS

The sequence of the X gene is consistent with that reported in literature. The X gene can be expressed in Hela cells. The positive rate in daughter mice was 6.25%.

CONCLUSION

It is possible to use spermatogonial cells as vector to establish HBx transgenic mice.

[Isolation, cultivation and identification of neural stem cell from human embryonic CNS]

This is a study on the cultivation condition in vitro and differentiation of neural stem cells from human embryonic brain in order to find a way to get purified multipotential neural stem cells. The single cells was derived from the three-month embryonic brain digested with trypsin, some cells was frozen, the other cells were expanded with EGF and bFGF, the single-cell-clone was obtained by the way of limited dilution, and the serum was used to induce the cells differentiation. The cells were detected with the method of immunohistochemistry. The results showed that a lot of neurospheres could be seen in the presence of mitogens (both EGF and bFGF) and serum could induce neural stem cells to differentiate into neurons, astrocytes, and oligodendrocytes. These indicate that the survival and proliferation of neural stem cells rely on the cooperation of EGF and bFGF. The neural stem cells can also be harvested from the frozen cells.

T cell infiltration and chemokine expression: relevance to the disease localization in murine graft-versus-host disease

Acute graft-versus-host disease (GVHD) involves mainly skin, liver and intestines. Other organs such as heart, muscle and central nervous system are seldom affected, although their parenchymal cells also express alloantigens, such as MHC class I antigens. The mechanism of this selective involvement of distinct organs in acute GVHD is not well understood. We postulated that it might be related to the selective migration of activated alloreactive T cells. Indeed, T cell infiltration, revealed by examination of serial samples using flow cytometry and immunohistology, occurred early and continuously in the target organs such as the liver, but not in a non-target organ, the heart, in a murine acute GVHD model. Since T cell migration is largely controlled by the expression of chemokine and chemokine receptors, we investigated the chemokine spectrum in target/non-target organs of mice with acute GVHD. We found that in the spleen and liver MIP-1alpha, MIP-2 and Mig were the predominant chemokines expressed. In another target organ, the skin, MIP-1alpha, MIP-2, MCP-1 and MCP-3 were all highly expressed. In a non-target organ of acute GVHD, the heart, the predominant chemokines expressed were MCP-1 and MCP-3. This distinct pattern of chemokine expression in these organs may contribute to the preferential recruitment of inflammatory cells into the liver and skin, but not into the heart, in acute GVHD.

P2X(7) receptors in the enteric nervous system of guinea-pig small intestine

The P2X(7) purinergic receptor subtype has been cloned and emphasized as a prototypic P2Z receptor involved in neurotransmission in the central nervous system and ATP-mediated lysis of macrophages in the immune system. Less is known about the neurobiology of P2X(7) receptors in the enteric nervous system (ENS). We studied the distribution of the receptor with indirect immunofluorescence and used selective agonists and antagonists to analyze pharmacologic aspects of its electrophysiologic behavior as determined with intracellular "sharp" microelectrodes and patch-clamp recording methods in neurons identified morphologically by biocytin injection in the ENS. Application of ATP or 2'- (or-3'-) O-(4-benzoylbenzoyl) adenosine 5'-triphosphate (BzBzATP) activated an inward current in myenteric neurons. Brilliant blue G, a selective P2X(7) antagonist, suppressed the responses to both agonists. Potency of the antagonist was greatest (smaller IC(50)) for the current evoked by BzBzATP. The P2X(7) antagonists 1-[N,O-bis (1,5-isoquinolinesulfonyl)-N-methyl-l-tyrosyl]-4-piperazine (KN-62) and oxidized ATP also suppressed the BzBzATP-activated current. Micropressure application of BzBzATP evoked rapidly activating depolarizing responses in intracellular studies with "sharp" microelectrodes. Oxidized-ATP suppressed these responses in both myenteric and submucosal neurons. Rapidly activating depolarizing responses evoked by application of nicotinic, serotonergic 5-HT(3), or gamma-aminobutyric acid A (GABA(A)) receptor agonists were unaffected by brilliant blue G. Immunoreactivity for the P2X(7) receptor was widely distributed surrounding ganglion cell bodies and associated with nerve fibers in both myenteric and submucous plexuses. P2X(7) immunoreactivity was colocalized with synapsin and synaptophysin and surrounded ganglion cells that contained either calbindin, calretinin, neuropeptide Y, substance P, or nitric oxide synthase. The mucosa, submucosal blood vessels, and the circular muscle coat also showed P2X(7) receptor immunoreactivity.

Pre- and postsynaptic inhibition by nociceptin in guinea pig small intestinal myenteric plexus in vitro

Actions of nociceptin on electrical and synaptic behavior of morphologically and neurochemically identified neurons in the guinea pig duodenal myenteric plexus were studied with conventional techniques. Nociceptin hyperpolarized the membrane potential in 104 of 121 AH-type and 28 of 51 S-type neurons with an EC(50) of 11.9 +/- 1.2 nM. Increased K(+) conductance accounted for the hyperpolarizing responses that were blocked by pertussis toxin and unaffected by naloxone. The selective opioid receptor-like (ORL)(1) receptor antagonist [Phe(1)-psi(CH(2)-NH)-Gly(2)]nociceptin(1--13)-NH(2) suppressed the nociceptin-evoked responses while behaving like a partial agonist. The nonselective ORL(1) antagonist naloxone benzoylhydrazone competitively suppressed nociceptin actions with a pA(2) value of 5.8. Nociceptin acted at presynaptic inhibitory receptors to suppress fast excitatory nicotinic postsynaptic potentials in 25 of 30 neurons (EC(50) = 22.5 +/- 4.4 nM) and slow synaptic excitation in 38 of 45 neurons (EC(50) = 15.1 +/- 1.6 nM). Presynaptic inhibitory action of nociceptin was unaffected by naloxone and was antagonized by [Phe(1)-psi(CH(2)-NH)-Gly(2)]nociceptin(1--13)-NH(2) or naloxone benzoylhydrazone. The results suggest that nociceptin acts both pre- and postsynaptically by activating an ORL(1) receptor that is distinct from typical naloxone-sensitive opioid receptors.

Galanin suppresses calcium conductance and activates inwardly rectifying potassium channels in myenteric neurones from guinea-pig small intestine

Whole-cell patch-clamp recording methods were used to investigate the ionic mechanisms underlying the hyperpolarizing action of galanin in enteric neurones. Galanin suppressed calcium current (ICa) and activated inwardly rectifying potassium current (IK,ir) in AH-type myenteric neurones of guinea-pig small intestine. Both suppression of ICa and activation of IK,ir were concentration-dependent, with an EC50 of 1.4 nmol L-1 and 55 nmol L-1, respectively. Pretreatment with pertussis toxin eliminated both actions of galanin, suggesting that both galanin-induced inhibition of ICa and galanin-induced activation of IK,ir involved activation of Gi/Go proteins. Both suppression of ICa and activation of IK,ir by galanin were mimicked by the N-terminal fragment of galanin, galanin-(1-16) suggesting that the first 16 amino acids of the peptide were sufficient for both actions. The galanin receptor antagonist galantide suppressed the galanin-induced activation of IK,ir with an EC50 of 16 nmol L-1. However, galantide alone suppressed ICa. The results suggest two mechanisms of action for galanin: one is opening of inwardly rectifying potassium channels and the second is blockade of voltage-activated calcium channels.

Glutamate receptors in the enteric nervous system: ionotropic or metabotropic?

Intracellular recording methods were used to investigate actions of glutamate on morphologically identified neurones in the myenteric and submucous plexuses of guinea-pig small intestine. Glutamate evoked a tetrodotoxin-resistant, slowly activating depolarizing response in most of the submucous neurones (86 of 125, 69%) and a smaller number of myenteric neurones (6 of 60, 10%). The depolarizing responses were restricted to S-type neurones with uniaxonal morphology. The group I metabotropic glutamate receptor (mGluRs) agonists quisqualate, 1S, 3R-ACPD and DHPG mimicked the depolarizing action of glutamate. A group I mGluRs antagonist, S-4-carboxyphenylglycine (S-4CPG), suppressed the glutamate responses with an IC50 of 357 microM at 30 microM glutamate. Group II or III mGluRs agonists did not produce depolarizing responses and group II or III mGluRs antagonists did not alter glutamate-evoked depolarization. The ionotropic glutamate receptor (iGluRs) agonists NMDA, AMPA, or kainate did not evoke depolarizing responses and glutamate-evoked depolarization was unaffected by the iGluRs antagonists D-APV, MK-801, or DNQX. No rapidly activating fast depolarizing responses reminiscent of fast excitatory postsynaptic potentials (EPSPs) were ever observed during application of glutamate or AMPA and stimulus-evoked fast EPSPs were unaffected by DNQX. The results suggest that the excitatory action of glutamate on enteric neurones is mediated by group I metabotropic glutamate receptors and that ionotropic glutamate receptors are not involved. The results also suggest that glutamate-mediated fast EPSPs may not be present in myenteric and submucous neurones in guinea-pig small bowel.

Expression of angiotensin II AT2 receptor in the acute phase of stroke in rats

A male Wistar rat model of stroke (middle cerebral artery occlusion; MCAO) was used to study the angiotensin II (Ang II) receptor subtype 2 (AT2) gene expression by reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemical staining. After permanent occlusion of the middle cerebral artery (MCA), AT2 receptor gene expression was found to increase in the infarct cortex by 2.7-fold (1 day) and 1.7-fold (3 days), respectively. Positive AT2 immunostaining was also observed in the infarct area of the cerebral cortex. Apoptotic markers were detected in the necrotic area of the stroke cerebral cortex 1 day after MCAO. This demonstrated up-regulation of AT2 receptor may be involved in the apoptosis of tissue repair after stroke.

Clostridium difficile toxin A excites enteric neurones and suppresses sympathetic neurotransmission in the guinea pig

BACKGROUND AND AIMS

Evidence suggests that the intestinal actions of Clostridium difficile toxin A-stimulation of secretion and motility, and an acute inflammatory response-have a neurally mediated component.

METHODS

Direct intracellular electrophysiological recording of electrical and synaptic behaviour in enteric neurones was performed in the submucous plexus of guinea pig small intestine during exposure to the toxin.

RESULTS

Application of toxin A affected both the electrical behaviour of the neuronal cell bodies and inhibitory noradrenergic neurotransmission to the cell bodies. Altered electrical behaviour included depolarisation and increased excitability. Tetrodotoxin or a histamine H(2) receptor antagonist did not affect the depolarisation evoked by toxin A. Failure of the histamine antagonist to suppress the actions of toxin A is evidence that its actions were not mediated by degranulation of intramural mast cells. The action of toxin A on neurotransmission was suppression of inhibitory postsynaptic potentials evoked in the neuronal cell bodies by stimulation of sympathetic nerve fibres that synapsed with the cell bodies. The inhibitory postsynaptic potentials were mediated by norepinephrine (noradrenaline) acting at postsynaptic alpha adrenoceptors on the cell bodies. Hyperpolarising responses evoked in the cell bodies by micropressure application of norepinephrine were unaffected by toxin A. This fulfils criteria for a presynaptic inhibitory action of toxin A to suppress release of norepinephrine from sympathetic postganglionic axons.

CONCLUSIONS

Results suggest that the neural component of the action of toxin A involves both direct excitation of enteric neurones and suppression of norepinephrine release from postganglionic sympathetic nerve fibres in the enteric nervous system.

Kinetics of interferon-gamma secretion and its regulatory factors in the early phase of acute graft-versus-host disease

Increased serum levels of interferon-gamma (IFN-gamma) have been observed in acute graft-versus-host disease (GVHD). Recent in vitro studies have demonstrated that interleukin-12 (IL-12) and interleukin-18 (IL-18) synergistically up-regulate IFN-gamma secretion. In this communication, we investigated the factors relevant to IFN-gamma secretion in acute GVHD. A murine model of acute GVHD was established by injecting donor spleen cells into severe combined immunodeficiency (SCID) mice. A series of specimens, including sera, livers and spleens derived from the GVHD mice, were investigated with histological examination, enzyme-linked immunosorbent assay (ELISA), flow cytometry, and semiquantitative reverse transcription-polymerase chain reaction (RT-PCR). IFN-gamma secretion increased in serum 3 days after spleen cell transfer, peaked on day 7, and then gradually decreased close to the baseline level by day 35. A synchronized increase of activated T cells and mRNA expression of IL-12, IL-18 and their respective receptors was observed after spleen cell transfer. However, only the kinetic expression pattern of IL-12 receptor (IL-12R) beta2 chains was closely correlated with that of IFN-gamma, while IL-12 dropped to the baseline level earlier than IFN-gamma. Therefore, IFN-gamma expression in the early phase of acute GVHD is a mono-peak and self-restricted pattern. Its secretion is closely related with T-cell activation, the presence of IL-12, IL-18 and their respective receptors. However, the limiting factors for IFN-gamma secretion seem to be IL-12 and IL-12R beta2 chains.

Glutamate modulates neurotransmission in the submucosal plexus of guinea-pig small intestine

Effects of glutamate on synaptic transmission in the submucosal plexus of guinea-pig small intestine were studied with intracellular electrophysiological recording methods. Glutamate suppressed stimulus-evoked slow excitatory postsynaptic potentials (EPSPs) and increased the amplitude of slow inhibitory postsynaptic potentials (IPSPs) in submucosal neurons. The actions of glutamate were mimicked by the group I metabotropic glutamate receptor (mGluRs) agonist DHPG, but not by the group II agonist S-4C3HPG, the group III agonist L-AP4, or selective agonists for ionotropic glutamate receptors (iGluRs). Glutamate actions were suppressed by the selective group I mGluRs antagonist S-4CPG, but not by group II and III mGluRs antagonist CPPG or iGluRs antagonists. Glutamate suppressed substance P- and 5-HT-evoked slow EPSP-like responses and potentiated norepinephrine-induced slow IPSP-like responses. The results suggest that group I mGluRs mediate glutamate-induced suppression of slow EPSPs and potentiation of slow IPSPs in S-type uniaxonal submucosal neurons.

IL-1beta and IL-6 excite neurons and suppress nicotinic and noradrenergic neurotransmission in guinea pig enteric nervous system

Conventional intracellular microelectrodes and injection of biocytin were used to study the actions of IL-1beta and IL-6 on electrical and synaptic behavior in morphologically identified guinea pig small intestinal submucous neurons. Exposure to nanomolar concentrations of either IL-1beta or IL-6 stimulated neuronal excitability. The excitatory action consisted of depolarization of the membrane potential, decreased membrane conductance, and increased discharge of action potentials. Excitatory action of IL-1beta was suppressed by the natural IL-1beta human receptor antagonist. Electrical stimulation of sympathetic postganglionic axons evoked inhibitory postsynaptic potentials (IPSPs), and stimulation of cholinergic axons evoked nicotinic fast excitatory postsynaptic potentials (EPSPs). Both kinds of synaptic potentials occurred in neurons with uniaxonal morphology believed to be secretomotor neurons. Either IL-1beta or IL-6 suppressed the noradrenergic IPSPs and the fast EPSPs, and the two acted synergistically when applied in combination. Suppression of the IPSP resulted from presynaptic inhibition of the release of norepinephrine from sympathetic nerves. The results suggest that the presence of either or both inflammatory cytokines will release the sympathetic brake from secretomotor neurons to the intestinal crypts and from nicotinic synapses in the integrative microcircuits, where norepinephrine is known to have a presynaptic inhibitory action. This, in concert with excitation of secretomotor neurons, may lead to neurogenic secretory diarrhea.

Enhancement of GABA-activated current by muscarine in rat dorsal root ganglion neurons

The modulation of GABA-gated ion channel responses to GABA, pentobarbital and diazepam by muscarine was studied in freshly isolated rat dorsal root ganglion neurons using a whole-cell patch-clamp technique. Muscarine enhanced current activated by 5 microM GABA dose-dependently with an EC50 of 40 +/- 2 microM. This potentiation was not blocked by pirenzepine, gallamine and atropine, the specific and non-specific muscarinic receptor antagonists. Muscarine shifted the GABA dose-response curve to the left, with the GABA EC50 decreased from 45 +/- 2 to 13 +/- 2 microM. The maximal response to GABA was suppressed to 89.3 +/- 4.6% as compared with the control (100%) by 80 microM muscarine. Muscarine potentiated GABA (1-100 microM)-activated current in a voltage-independent manner. Muscarine shifted the dose-response curve for pentobarbital enhancement of GABA-activated current to the left, and the enhancement of GABA-activated current by muscarine was additive to that of pentobarbital over all pentobarbital concentrations. Muscarine shifted the dose-response curve for diazepam (1-100 nM) enhancement of GABA-activated current to the left. However, muscarine attenuated the facilitatory effect of saturating concentrations of diazepam (> 100 nM). The potentiating effect of muscarine was blocked by 1 nM ethyl-beta-carboline-3-carboxylate, the inverse agonist of benzodiazepine receptors. These results suggest that GABA-gated ion channel responses to GABA and pentobarbital were potentiated by muscarine and the binding site(s) for muscarine might be related to those for diazepam.

Long-lived Th2 clones specific for seasonal and perennial allergens can be detected in blood and skin by their TCR-hypervariable regions

We investigated the longevity of allergen-specific Th cells derived from patients suffering from either allergic rhinitis or atopic dermatitis. T cell clones (TCC) specific for seasonal and perennial allergens were raised. To determine whether these TCC were long-lived in vivo, PBMC and allergen-specific polyclonal T cell lines, collected and established inside a period of up to 4 years, were screened for the TCC of interest. For this purpose, a T cell tracing protocol was established in which oligonucleotides specific for the TCR beta-chain hypervariable junctional region were used as tools to identify each particular TCC. Seven pollen-specific TCC and two house dust mite-specific TCC, with a Th2-like cytokine production pattern in vitro, were demonstrated to be long-lived memory T cells in vivo. Specificity of the tracing protocol was ascertained by TCR sequence analysis. We conclude that allergen-specific TCC can persist for years, evidence for which can be monitored in blood, but also in the target organ of the allergic disorder. The data indicate that in vitro-characterized, allergen-specific, long-lived TCC may well reflect a repertoire of T lymphocytes of pathogenetic importance in vivo.

Inhibitory effect of baclofen on GABA-induced depolarization and GABA-activated current in primary sensory neurons

It has been established that GABAA and GABAB receptors can exist separately and/or co-exist in the membrane of dorsal root ganglion neurons. In our previous investigation it has been shown that co-existence of these two kinds of receptors is about 80% of the neurons examined (20/25). The present study was aimed to explore whether the activation of these two kinds of receptors could interact with each other using intracellular and whole-cell patch-clamp recordings. Baclofen, a specific GABAB receptor agonist, was found to exert negative modulatory effects on the responses mediated by GABAA receptor. In experiments with intracellular recording, GABA (0.3-1000 microM)- and muscimol (100-1000 microM)-induced depolarization was attenuated markedly and reversibly by preapplication of baclofen (100 microM) (15/21 and 17/21, respectively). In whole-cell patch-clamp recordings GABA (100 microM) and two specific GABAA receptor agonists, muscimol (10 microM) and isoguvacine (50 microM), activated currents were inhibited markedly by preapplication of baclofen 30 s or more and the inhibition was concentration dependent (1-100 microM baclofen) and reversible. The possible mechanisms underlying the inhibition by baclofen of the responses mediated by GABAA receptor and the physiological significance implicated are discussed.

Modulation of nicotinic ACh-, GABAA- and 5-HT3-receptor functions by external H-7, a protein kinase inhibitor, in rat sensory neurones

1. The effects of external H-7, a potent protein kinase inhibitor, on the responses mediated by gamma-aminobutyric acid A type (GABAA)-, nicotinic acetylcholine (nicotinic ACh)-, ionotropic 5-hydroxytryptamine (5-HT3)-, adenosine 5'-triphosphate (ATP)-, N-methyl-D-aspartate (NMDA)- and kainate (KA)-receptors were studied in freshly dissociated rat dorsal root ganglion neurone by use of whole cell patch-clamp technique. 2. External H-7 (1-1000 microM) produced a reversible, dose-dependent inhibition of whole cell currents activated by GABA, ACh and 5-HT. 3. Whole-cell currents evoked by ATP, 2-methylthio-ATP, NMDA and KA were insensitive to external H-7. 4. External H-7 shifted the dose-response curve of GABA-activated currents downward without changing the EC50 significantly (from 15.0 +/- 4.0 microM to 18.0 +/- 5.0 microM). The maximum response to GABA was depressed by 34.0 +/- 5.3%. This inhibitory action of H-7 was voltage-independent. 5. Intracellular application of H-7 (20 microM), cyclic AMP (1 mM) and BAPTA (10 mM) could not reverse the H-7 inhibition of GABA-activated currents. 6. The results suggest that external H-7 selectively and allosterically modulates the functions of GABAA-, nicotine ACh- and 5-HT3 receptors via a common conserved site in the external domain of these receptors.

Modulation by adenosine of GABA-activated current in rat dorsal root ganglion neurons

1. The modulation by adenosine of GABA-activated current (IGADA) was studied in freshly isolated rat dorsal root ganglion (DRG) neurons using the whole-cell patch-clamp technique. 2. In most of the DRG neurons examined (68/90, 75.5%) adenosine (1-10 microM) suppressed IGABA, while in some neurons examined, it potentiated (16/90, 17.8%) IGABA. It exerted no effects on IGABA in a few cells (6/90, 6.7%). 3. Adenosine shifted the GABA concentration-response curve downward with no significant change of the EC50. The maximal response to GABA was suppressed by 29.6 +/- 2.6%. The adenosine-induced inhibition of IGABA showed no voltage dependence. 4. 8-Cyclopentyl-1,3-dimethylxanthine (DPCPX; 1 microM), a selective A1 adenosine receptor antagonist, partially reversed adenosine inhibition of IGABA and completely blocked N6-cyclo-hexyladenosine (CHA; an A1 adenosine receptor agonist) inhibition of IGABA. DPCPX (1 microM) also blocked the suppression of IGABA by 2-chloroadenosine (CADO). CGS21680, a selective A2A adenosine receptor agonist, did not inhibit IGABA and DMPX, a selective A2A adenosine receptor antagonist, did not prevent adenosine inhibition of IGABA. 5. Intracellular application of H-7 (20 microM; a protein kinase C inhibitor) reversed adenosine inhibition of IGABA while inclusion of cAMP (1 mM), H-9 (20 microM; a protein kinase A inhibitor) and BAPTA (10 mM; a chelator of calcium ions) in the recording pipette did not affect the depression of IGABA by adenosine. IGABA was also suppressed by internal perfusion of PMA, a protein kinase C activator. 6. The results suggest that adenosine, as a neuromodulator, exerts a modulatory effect on the GABA-induced presynaptic inhibition in primary sensory transmission.

Evidence for the existence of substance P autoreceptor in the membrane of rat dorsal root ganglion neurons

Substance P, a putative peptide neurotransmitter contained in primary sensory neurons, is suggested to play a major role in nociceptive transmission. In the present study, the existence of substance P autoreceptor in dorsal root ganglion neurons was identified with a method we developed recently and substance P-activated inward current in the dorsal root ganglion neurons and its ionic mechanism were also explored preliminarily. The majority of the cells examined (68/76, 89.5%) were sensitive to external application of substance P (0.01-10 microM) with a concentration-dependent inward current. This current was found to result from the opening of nonselective ion channel, preferring the Na+ channel. The substance P-activated current can be suppressed by Cd2+ (0.05 microM), which suggested Ca2+ may also be involved. Soon after the neurons had been identified to be endowed with substance P receptor with whole-cell patch-clamp technique, 17 cells were chosen for immunocytochemical staining to detect substance P-immunoreactivity. Seven neurons which were classified into small and intermediate size were found to reveal substance P-immunoreactivity. Using this method we have identified the existence of substance P autoreceptor in rat DRG neurons.

Substance P potentiates ATP-activated currents in rat primary sensory neurons

The aim of this study was to explore whether substance P could modulate the response mediated by ATP receptor. Experiments were carried out on rat dorsal root ganglion (DRG) neurons isolated acutely with enzymatic and mechanical treatment. The ATP-activated inward currents were recorded using the whole-cell patch-clamp technique. The majority of the neurons examined (82/85, 96.5%) were sensitive to ATP (1-1000 microM). Application of substance P (0.01-100 microM) also caused an inward current. Several differences between these two kinds of currents were observed. 0.01, 0.1 and 1 microM substance P increased the ATP (10 microM)-activated current to 113.7 +/- 3.1%, (n = 8); 127.2 +/- 6.7%, (n = 12) and 154.7 +/- 14.4% (n = 6) (means +/- S.E.M.), respectively. This potentiating effect can be blocked by spantide, an NK1 receptor antagonist, and intracellular application of H7 (which is a potent inhibitor of PKC) could also block this kind of potentiation of SP on ATP-activated current. Since the substance P receptor and ATP receptor can coexist in rat DRG neurons and activation of substance P receptor can modulate the response mediated by ATP receptor, it suggests that they may cooperate with each other in activating peripheral nociceptive endings of sensory neurons, especially during tissue damage and/or inflammation.

A new reagent for the induction of T-cell depletion, anti-CD3-CRM9

We have developed a new reagent for inducing in vivo T-cell depletion and have tested this reagent in rhesus monkeys. The reagent is an anti-CD3 epsilon immunotoxin based on a diphtheria toxin binding-site mutant, CRM9. After administration to monkeys, T cells are depleted from both the blood and lymph node compartments to < 1% of their initial values. T-cell depletion is associated with transient immunosuppression, as judged by delayed rejection of RhLA-mismatched skin allografts. T cells are repopulated in both compartments; however, the rate of repopulation is age dependent. The rate is rapid in juvenile animals (12 days) and requires > 30 days in old animals. The correlation between repopulation rate and age suggests that the repopulation is thymus dependent and that the repopulated T cells are probably naive T cells. This reagent should be a valuable tool in studying the role of memory T cells in rhesus models of autoimmune diseases and protocols of tolerance induction after organ transplantation.

Thoughts on the thymus and the T-lymphocyte repertoire. Relevance to the tolerance of the immune response

The thymus is a central lymphoid organ, and has one important function in the immune system. It generates immunocompetent T (= thymus-dependent) cells. 'Immunocompetence' is the single most important characteristic acquired during the differentiation process of T-cells, from progenitor cell in the bone marrow to mature cell in peripheral lymphoid organs and blood. The basis of competence is recognition, mediated by the T-cell receptor on the cell surface. Using this receptor, T-cells recognize antigens only in the form of antigenic fragments complexed with molecules of the major histocompatibility complex. Within the thymus, progenitor cells rearrange gene segments encoding the various parts of the receptor molecule. After expression of all possible receptors (the potentially available repertoire) selection processes occur, yielding only those T-cells that have a receptor by which antigens can be recognized together with molecules of the major histocompatibility complex, and that do not recognize autoantigens (the actual repertoire). This process of selection is considered as a unique function of the thymus. In this review, first some histophysiological aspects of the thymus are described. Next, the events that occur during the sojourn of the lymphocytes in the thymus are presented. Finally, these data are considered with regard to thymic abnormalities. These include acute and age-associated involution, and the generation of autoimmune reactivity due to disturbed intrathymic selection.

T-cell receptor V beta-family usage in primary cutaneous and primary nodal T-cell non-Hodgkin's lymphomas

To evaluate whether the expression of T-cell receptor (TCR) V beta families in eight cases of malignant T-cell lymphomas took place in a preferential manner, we analyzed four cases of mycosis fungoides (MF), the most common form of primary cutaneous T-cell non-Hodgkin's lymphomas (NHL), and four cases of primary nodal T-cell NHL. The usage of V beta families in T-cell populations was investigated on mRNA that was transcribed to cDNA using a C beta primer and reverse transcriptase. Subsequently, the specific usage of the families was analyzed by polymerase chain reaction (PCR) using combinations of the selected C beta-oligonucleotide primer and one of the family-specific V beta primers. Peripheral blood lymphocytes from four healthy volunteers and 1 "reactive" lymph node served as a control and expressed all 20 V beta families tested for. In T-cell lines, with restricted V beta expression, and in three patients with advanced MF, only one or two V beta families were expressed at the mRNA level. In an early MF lesion this monoclonal expression was absent: several V beta families were expressed with a weak intensity. This may indicate either a polyclonal origin of MF, or that too few monoclonal neoplastic cells were present in the tissue specimen. In the four nodal T-cell NHL, only one family could be clearly distinguished, whereas some of the other V beta families showed only a weak expression. These latter families represent the reactive T-cell component in the nodal T-cell NHL. Both in nodal T-cell NHL and in MF there was no preferential expression of a particular V beta family. There was a good correlation between PCR data and the expression of V beta-family protein products observed by immunohistochemistry on tissue sections of the T-cell lymphomas. All T-cell lines, three cases of MF, and three cases of nodal T-cell NHL showed a rearrangement of the TCR beta chain on DNA level.

T cell receptor V beta variable gene family expression in human peripheral blood lymphocytes at the mRNA and membrane protein level

A polymerase chain reaction (PCR) was developed, using combinations of an oligonucleotide primer for a T cell receptor V beta gene family and one for the constant C beta gene segments, to assess the expression of each of 20 V beta gene families in RNA after reverse transcription into cDNA. The detection was done after agarose gel electrophoresis of PCR products and ethidium bromide staining. The positive identification of the PCR products was done by hybridization with a J beta oligonucleotide probe. For T cell lines, a signal was observed in the V beta 8 combination for Jurkat cells, V beta 5a in HSB cells, V beta 2 and V beta 12a in Molt-3 cells and V beta 2, V beta 5a and V beta 12a in Molt-4 cells. Using mixtures of RNA from different cell lines, the sensitivity of the method was in the range of 0.1-0.5%. In peripheral blood mononuclear cells from four donors, taken at three different occasions, all V beta families were detectable. The intensity of the PCR product varied between various V beta gene families. Flow cytometric analysis of blood mononuclear cells from the same donors with a restricted series of V beta gene family-specific antibodies also revealed the presence of all families. The approach to assess V beta gene family expression in heterogeneous populations opens the possibility to study T cell receptor variable gene expression in relation to physiology and pathologic processes.

[Study of Ag-NOR, SCE and micronucleus in peripheral blood lymphocyte of chromate producers]

Ag-NOR, SCE and micronucleus test of peripheral blood lymphocyte obtained from 31 chromate producers had been studied. We found that (1) in the workers who had been exposed over eight years, the frequency of Ag-NOR, Ag-AA and SCE were 6.905 +/- 1.100, 0.380 +/- 0.652 and 8.190 +/- 3.727, but in the control group, 6.512 +/- 1.595, 0.215 +/- 0.529 and 7.171 +/- 2.683, respectively. So there was considerably significant difference between the exposed and the unexposed (P less than 0.01); (2) the frequency of micronuclei was 3.71 +/- 1.419% in the exposed group; however, in the control group it was 0.333 +/- 0.479%. So there was also remarkably significant difference between them (P less than 0.001). The observations lead the authors to conclude that the genetic material of the workers who have been working over eight years may be damaged because of being exposed to chromate.

[Low-dose cytosine arabinoside in treatment of 17 patients with acute nonlymphocytic leukemia]

Low dose Ara-C (LDAra-C, Ara-C 10-15 mg/12 h, i.m. x 14-21 days) was used in the treatment of 17 patients with ANLL, and from 14 patients blast cells were isolated before chemotherapy and cultured in the presence of Ara-C (10(-8) and 10(-7) mol/L), no definite induction of differentiation of leukemic cells was found. Of the 17 cases, 5 obtained CR, only one of them with M4 entered CR without pancytopenia or bone marrow aplasia during the LDAra-C treatment. For the rest, 4 with M2 obtained PR, and 8 did not respond. Toxic effects, including pancytopenia and bone marrow aplasia, were observed in most of the patients. Laboratory results showed that differentiation was not induced by Ara-C in low concentration in in vitro culture. LDAra-C is thought to be effective in the treatment of ANLL, and the mechanism may involve both the cytotoxicity and the induction of differentiation of leukemic cells, but the former is far more important.