Altered resting-state functional connectivity between subregions in the thalamus and cortex in migraine without aura.

BACKGROUND AND PURPOSE: Migraine is a complex and disabling neurological disorder, the exact neurological mechanisms of which remain unclear. The thalamus is considered to be the hub of the central processing and integration of nociceptive information, as well as the modulation of these processes. METHODS: A total of 48 migraineurs without aura (MWoAs) during the interictal phase and 48 age- and sex-matched healthy controls underwent resting-state functional magnetic resonance imaging scans. We utilized masked independent component analysis and seed-based functional connectivity (FC) to investigate whether MWoAs exhibited abnormal FC between subregions in the thalamus and the cortex regions. RESULTS: The MWoAs showed significantly weaker FC between the anterior dorsal thalamic nucleus and left precuneus. Additionally, MWoAs exhibited significantly reduced FC between the ventral posterior nucleus (VPN) and left precuneus, right inferior parietal lobule (R-IPL) and right middle frontal gyrus. Furthermore, the FC Z-scores between the VPN and R-IPL were negatively correlated with pain intensity in MWoAs. The disease duration of patients was negatively correlated with the FC Z-scores between the VPN and R-IPL. CONCLUSION: These altered thalamocortical connectivity patterns may contribute to multisensory integration abnormalities, deficits in pain attention, cognitive evaluation and pain modulation. Pain sensitivity and disease duration are closely tied to abnormal FC between the VPN and R-IPL. Remarkably, recurrent headache attacks might contribute to this maladaptive functional plasticity closely related to pain intensity.

[Teleost Type 2 Interleukin-1 Receptor (IL-1R2) from the Spotted Halibut (Verasper variegatus): 3D Structure and a Role in Immune Response].

The type 2 interleukin-1 receptor (IL-1R2) is one of natural IL-1ß singling inhibitors in mammals. We cloned and sequenced the IL-1R2 gene in V. variegatus (VvIL-1R2). The phylogenetic analysis showed that the molecular structure VvIL-1R2 is similar to that of its orthologues in other vertebrates. The expression levels of VvIL-1R2 are relatively high in the peripheral blood leukocytes (PBLs), gill, and spleen. In addition, peculiar expression patterns for his molecule were detected at various developmental stages, implying that in flatfishes the IL-1R2 may have be important for embryonic development and metamorphosis. In PBLs, the treatment with pathogen-associated molecular patterns (PAMPs) induced a significant and rapid up-regulation of VvIL-1R2, pointing at its involvement in the immune responses against bacterial and viral pathogens.

[Clinical study of intensity modulated radiotherapy and three-dimensional conformal radiotherapy with three-dimensional brachytherapy and concurrent chemotherapy for patients with advanced cervical cancer].

Objective: To compare the dose, clinical efficacy and acute adverse reactions of intensity modulated radiotherapy (IMRT) and three-dimensional conformal radiotherapy (3D-CRT) combined with three-dimensional brachytherapy (3D-BT) in the treatment of concurrent radiotherapy and chemotherapy for advanced stage cervical cancer patients. Methods: Data collection was performed from January 2011 to November 2015 in Chinese PLA General Hospital and Inner Mongolia Cancer Hospital. All 89 patients with advanced stage (Ⅱ b-Ⅲ b) cervical cancer were treated by pelvic radiotherapy and concurrent chemotherapy, 46 cases of them received IMRT and 3D-BT (IMRT group) , 43 cases received 3D-CRT and 3D-BT (3D-CRT group) , along with cisplatin chemotherapy. The dose accumulation of external beam radiotherapy and 3D-BT was calculated by deformable image registration to analyze clinical efficacy, acute adverse reactions and prognosis of the two groups. Results: (1) Dose of radiotherapy: planning target volume (PTV) coverage of IMRT group and 3D-CRT group were respectively (95.4±4.7)% and (95.1±5.1)%, without significant differences (t=0.289, P=0.773). Compared with the patients treated with 3D-CRT, the volumn receiving at least 30 Gy (V(30)), V(50) of rectum, colon, bladder and small intestine and V(20) of bone marrow in the IMRT group were significantly decreased (P<0.05). Regarding the combined dose, the maximum dose (D(max)) and the minimum dose received by the most exposed 2 cm(3) volume of the analyzed organ (D(2CC)) of rectum, colon, bladder and small intestine of IMRT group were significantly lower than those of 3D-CRT group (P<0.05). (2) Short-term efficacy: the effective rate of IMRT and 3D-CRT group were respectively 93% (43/46) and 91% (39/43), with no significant differences (χ(2)=0.237, P=0.626). (3) Acute adverse reactions: compared with 3D-CRT, IMRT could significantly reduce grade 1-2 acute toxicity in gastrointestinal [63%(29/46) vs 84%(36/43)], genitourinary [17%(8/46) vs 37%(16/43)] and hematologic [57%(26/46) vs 79%(34/43)] system (all P<0.05). There were no significant differences of grade 3 acute adverse reactions of gastrointestinal, genitourinary and hematologic system between two groups (all P>0.05). No grade 4 acute adverse reactions were observed. (4) Prognosis: the overall survival rate at 1, 2-year of IMRT and 3D-CRT group were respectively 95.6%, 89.1% and 93.1%, 86.1%. The progression-free survival rateat 1, 2-year of IMRT and 3D-CRT group were 91.1%, 89.1% and 88.4%, 86.1%, respectively. There were no significant differences in overall survival rate and progression-free survival rate between two groups (P>0.05). Conclusions: Compared with 3D-CRT, IMRT combined with 3D-BT has dosimetry advantages based on dose accumulation algorithms by deformable image registration. IMRT could ensure clinical efficacy and significantly reduce the incidence rate of acute toxicities.

OsCM regulates rice defence system in response to UV light supplemented with drought stress.

Studies on plant responses to combined abiotic stresses are very limited, especially in major crop plants. The current study evaluated the response of chorismate mutase overexpressor (OxCM) rice line to combined UV light and drought stress. The experiments were conducted in pots in a growth chamber, and data were assessed for gene expression, antioxidant and hormone regulation, flavonoid accumulation, phenotypic variation, and amino acid accumulation. Wild-type (WT) rice had reduced the growth and vigour, while transgenic rice maintained growth and vigour under combined UV light and drought stress. ROS and lipid peroxidation analysis revealed that chorismate mutase (OsCM) reduced oxidative stress mediated by ROS scavenging and reduced lipid peroxidation. The combined stresses reduced biosynthesis of total flavonoids, kaempferol and quercetin in WT plants, but increased significantly in plants with OxCM. Phytohormone analysis showed that SA was reduced by 50% in WT and 73% in transgenic plants, while ABA was reduced by 22% in WT plants but increased to 129% in transgenic plants. Expression of chorismate mutase regulates phenylalanine biosynthesis, UV light and drought stress-responsive genes, e.g., phenylalanine ammonia lyase (OsPAL), dehydrin (OsDHN), dehydration-responsive element-binding (OsDREB), ras-related protein 7 (OsRab7), ultraviolet-B resistance 8 (OsUVR8), WRKY transcription factor 89 (OsWRKY89) and tryptophan synthase alpha chain (OsTSA). Moreover, OsCM also increases accumulation of free amino acids (aspartic acid, glutamic acid, leucine, tyrosine, phenylalanine and proline) and sodium (Na), potassium (K), and calcium (Ca) ions in response to the combined stresses. Together, these results suggest that chorismate mutase expression induces physiological, biochemical and molecular changes that enhance rice tolerance to combined UV light and drought stresses.

E2F1-induced upregulation of lncRNA HCG18 stimulates proliferation and migration in gastric cancer by binding to miR-197-3p.

OBJECTIVE: LncRNA HCG18 is considered to be an oncogene in many types of tumors. The aim of this study was to explore the role of lncRNA HCG18 in gastric cancer (GC). PATIENTS AND METHODS: HCG18 levels in GC tissues were detected. Potential biological influences of HCG18 on GC cell phenotypes were examined by Cell Counting Kit-8 (CCK-8), wound healing and transwell assay. Subsequently, bioinformatics analysis, Chromatin immunoprecipitation (ChIP), Luciferase assay and rescue experiments were conducted to identify the regulatory network of HCG18 in GC. RESULTS: It was found that HCG18 was upregulated in GC samples, and the knockdown of HCG18 inhibited proliferative and migratory abilities in GC. The transcription factor E2F1 could directly bind to the promoter region of HCG18 and thus activate its transcription. In addition, HCG18 sponged miR-197-3p to stimulate the malignant development of GC. CONCLUSIONS: HCG18 is upregulated in GC samples by E2F1 induction, which stimulates proliferative and migratory abilities in GC by binding to miR-197-3p.

Accumulation of High Levels of Monocytic Myeloid-Derived Suppressor Cells Enhances Graft Survival in Almost-Tolerant Kidney Transplant Recipients.

BACKGROUND: Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population of immature cells that suppress immune responses during organ transplantation and participate in mediating long-term graft survival and immune tolerance in animal transplant models. However, their role in regulating transplant tolerance in human subjects is not well understood. In the present study, we investigated the role of MDSCs in mediating long-term graft survival in almost-tolerant kidney transplant recipients (ATKTRs) and the mechanism(s) responsible for increasing MDSC numbers in these recipients. METHODS: Peripheral blood mononuclear cells (PBMCs) from whole blood samples were collected from 30 ATKTRs (graft survival, > 10 years after kidney transplant [KTx]) treated with low doses of immunosuppressive drugs and with stable kidney function, 10 short-term graft survival kidney transplant recipients (STKTRs; graft survival, ∼1-3 years post-KTx) with stable kidney function, and 10 healthy donors (HDs). MDSC and regulatory T cell (Tregs) levels were analyzed using multicolor flow cytometry in PBMCs. RESULTS: ATKTRs had significantly higher levels of monocytic MDSCs (P < .001) and CD4+CD25+FoxP3+ Tregs than STKTRs and HDs. Furthermore, the M-MDSC levels correlated positively with the survival rates, estimated glomerular filtration rates (eGFRs) of grafts, and the levels of CD4+CD25+FoxP3+ Tregs in ATKTRs. CONCLUSIONS: Accumulation of high levels of MDSCs was observed in ATKTRs. Changes in MDSC levels may play important roles in mediating transplant tolerance and regulating Tregs. Therefore, we propose that MDSCs may be potentially used for recognizing tolerant transplant recipients and guiding dosage reduction for immunosuppressive drugs for KTx.

The first clinical results of "wide-focus and low-pressure" ESWL.

A clinical study of the concept "wide-focus and low-pressure" extracorporal shock-wave lithotripsy (ESWL) was performed in a scientific cooperation between the Physical Institute of the University of Stuttgart and the Xixin Medical Instruments Co. Ltd. in Wuxian-Suzhou, China. In this cooperation, self-focusing electromagnetic shock-wave generator systems from the University of Stuttgart were integrated into Xixin lithotripters and installed in seven hospitals in China. A total of 297 detailed patient protocols revealed an average of 1532 shock pulses for successful treatment with no necessity for pain medication and auxiliary measures, and a stone-free rate of 86% after a follow-up of 3 months. These results are discussed in terms of the wide-focus low-pressure conditions and the mechanism of binary fragmentation by squeezing.

Trophic effects of interleukin-11 in rats with experimental short bowel syndrome.

Interleukin-11 (IL-11) is a multifunctional cytokine, derived from bone marrow stromal cells, that stimulates proliferation of stem/progenitor precursor cells in the small intestinal crypts and accelerates recovery of intestinal mucosa after cytoablative therapy. This study evaluates whether IL-11 can improve the function and structure of the small intestine and enhance adaptation in an experimental model of short bowel syndrome. After 90% small bowel resection, 32 Sprague-Dawley rats were divided randomly into eight experimental groups of four animals each. Four groups were treated with IL-11 (125 micrograms/kg twice daily, subcutaneously), and the four control groups were treated with a similar volume (0.1%) of bovine serum albumin (BSA). The animals were weighed daily and were killed on day 2, 4, 6, or 8; remnant small bowel was evaluated for villus height and crypt cell mitosis. The body weight of the animals that received IL-11 was significantly greater at the beginning of postoperative day 4 in comparison to that of the BSA groups (P < .01 during days 5 to 7). The rats that had IL-11 also had significantly greater villus height and crypt cell mitotic rates (P < .05). These observations suggest that IL-11 has a trophic effect on the small bowel during the adaptive phase that follows massive bowel resection and may be useful in the treatment of short bowel syndrome.

Intestinal metaplasia and gastric carcinoma. A histochemical and immunohistochemical study.

This article sums up the histochemical and immunohistochemical study of 55 cases of gastric carcinoma and 21 controls with benign gastric lesions. The results showed most of the adjacent mucosa of gastric carcinoma developed incomplete type intestinal metaplasia (IM). The percentage of Type IIb (ie, secreting sulphomucin) reached 72.5%. In most cases, high iron diamine (HID) rose in cancerous tissue and concomitantly in the IM epithelium of the adjacent gastric carcinoma. The phenomena of separation condition of HID+ in cancerous tissue, HID- in IM epithelium surrounding carcinoma, or HID- in cancerous cell but HID+ in IM of the surrounding epithelium of carcinoma, were much fewer. The two kinds of mucin antigen distribution were observed simultaneously. In the control and gastric carcinoma groups, neither large intestinal mucin antigen (LIMA) nor small intestinal mucin antigen (SIMA) could be detected in the normal epithelium of gastric mucosa. SIMA was mainly found in the goblet cells of IM and the mucous cells of columnar epithelium, while LIMA was mainly present in the columnar cells, in luminal border and/or in goblet cells. LIMA in the carcinoma group is apparently higher than that in the controls. The percentage of LIMA+ in the IM epithelium of adjacent gastric carcinoma and that in carcinoma cells were also raised in most cases. All these demonstrated a close relationship between IM and gastric carcinoma. Our results also showed that not only HID+, but also LIMA+ may represent a precancerous lesion in gastric carcinoma.

[Effects of histamine H2-receptor antagonists on hemopoietic reconstruction in bone marrow].

The effects of histamine H2-receptor antagonists (cimetidine and ranitidine) on bone marrow hematopoiesis of normal and sublethally irradiated mice were investigated. It was found that non-toxic dosage of cimetidine had no significant effect on CFU-s of the normal mouse, but it inhibited CFU-GM growth with a dosage-dependent relationship and the recovery of CFU-s formation from sublethal gamma-ray irradiation. These results suggest that histamine may play a role in bone marrow regeneration after sublethal irradiation. Histamine H2-receptor antagonists can inhibit hemopoietic reconstruction in regenerating bone marrow.

Interleukin-11: a multifunctional growth factor derived from the hematopoietic microenvironment.

IL-11 is a unique growth factor derived from cells making up the HM. Although cloned based on IL-6-like bioactivity, IL-11 and IL-6 have distinct biologic profiles (Table 1). IL-11, like many recently cloned growth factors, has pleiotropic effects on hematopoietic cells presumably depending on the cytokine and cellular environment into which it is introduced. However, some general findings are consistent (Table 2). In addition, IL-11 has significant effects, either primary or secondary, on nonhematopoietic cells, including neurons, small intestine crypt progenitor/stem cells, and preadipocytes. The institution of human trials with IL-11 will provide important information on the pharmacologic effects of IL-11 on human hematopoietic cells in the context of frequently used chemotherapy protocols. The physiologic role(s) of IL-11 are unknown but will become clear (at least in the mouse) with gene targeting experiments underway in several laboratories.

[Study on growth and differentiation of ES cells transfected with LIF gene].

We constructed plasmids pSVLD(+) and pSVLD(-) containing human D-form Leukemia Inhibitory Factor (LIF) cDNA sequence in sense or antisense orientation, transfected them into cells of an embryonic stem cell line ES-5, and isolated 248 pSVLD(+)-transfected and 93 pSVLD(-)-transfected G 418-resistant clones. By stepwise reducing LIF concentration in the medium, we obtained 3 pSVLD(+)-transfected clones (A 1-3) that could grow in 15% BRL-CM, including ESL(+)A 2 that could grow without LIF: we also obtained 13 pSVLD(-)-transfected clones (B 1-13) which would differentiate in 60% BRL-CM, including ESL(-)B 3 and B 5 that could not be passaged without LIF. ESL(+)A 2 and ESL(-)B 5 cells had the relatively stronger LIF mRNA or antisense LIF RNA expression, and LIF overexpression in ESL(+)A 2 cells was shown by biological assay for ES cell differentiation inhibition. ESL(+)A 2 cells could be continuously passaged for at least 13 passages without addition of exogenous LIF, retained undifferentiated morphology as well as a high growth rate, and resembled ES-5 cells in terms of stem cell characteristics and pluripotent properties, as analyzed for alkaline phosphatase activity and with staining the paraffin sections of tumor formed by inoculating ESL(+) A 2 cells into mouse. On the contrary, ESL(-) cells should be cultured in higher concentration of LIF than ES-5 cells, otherwise, would undertake extensive differentiation. By hanging drop culture for 3 days in the presence of 10(-6) mol/L RA then observing the differentiation of the formed embryonic bodies (EBs), we found that ESL(+) A 2 and ES-5 cells underwent similar morphologically differentiation, with round and epitheliallike cells occurring around the EBs; while ESL(-) B 5 cells, despite initial differentiation to round cells, differentiate into fibroblast-like and spindle shaped cells. The above results indicate that LIF overexpression in ESL(+) A 2 cells is able to completely free ES cells from the dependence on LIF-conditioned medium, and endogenous LIF gene expression, although is very low, may be indispensable for inhibiting the differentiation in vitro of ES cells; LIF overexpression might not obviously change the differentiation way of ES-5 cells, however, blocking endogenous LIF expression gives rise to the increased sensitivity of ES-5 cells to differentiate, with an altered differentiation pattern. The establishment of ESL(+) and ESL (-) cell lines provides models for further study of the growth and differentiation of ES-5 cells.

High proliferative potential colony-forming cell heterogeneity identified using counterflow centrifugal elutriation.

Murine high proliferative potential colony-forming cells (HPP-CFC) are known to be heterogenous with respect to proliferative capacity and in vitro responsiveness to hematopoietic growth factors. We have separated HPP-CFC into several subpopulations using counterflow centrifugal elutriation. Although HPP-CFC were identified in all of the elutriated fractions of both C3H/HeJ and C57BI/6J bone marrow cells, the distribution of HPP-CFC as well as of colony-forming units-granulocyte-macrophage (CFU-GM) in each fraction differed between these two strains of inbred mice. Six subsets of HPP-CFC were resolved that differed in growth factor responsiveness. A low-density HPP-CFC subpopulation was isolated that was distinct from day-12 spleen colony-forming units (CFU-S12), CFU-GM, and bone marrow stromal cells. This unique subpopulation of HPP-CFC is rate (3% to 9% of total HPP-CFC), appears to be lymphocyte-like in morphology, and behaves the most primitive of the HPP-CFC subsets by requiring multiple hematopoietic growth factors for optimal in vitro cloning. Further characterization of this subpopulation of HPP-CFC will determine the position of these cells in the HPP-CFC heirarchy.

Molecular recognition and self-assembled polymer films for vapor phase detection of explosives.

Selective and sensitive polymer films for detecting explosives were studied and fabricated onto surface acoustic wave (SAW) devices. Polymers and molecular host species were self-assembled on functionalized silicon oxide surfaces through a catalytic hydrosilylation reaction. The covalently attached thin polymer films are stable, continuous and uniform with film thickness ranging from 15 to 30 nm. The microsensors coated with the polymer films show high sensitivity towards 2,4-dinitrotoluene (DNT) and o-nitrotoluene, an explosive simulant. Sensor responses to possible common interferents in land mine detection were studied and the sensor sensitivities to them were found to be much lower than that to DNT and explosives simulants. Response patterns for interferants and o-nitrotoluene were constructed and the sensors coated with functionalized cyclodextrins were able to detect 2,4-DNT and 2,4,6-trinitrotoluene (TNT) under ambient laboratory conditions.

Comparative effects of in vivo treatment using interleukin-11 and stem cell factor on reconstitution in mice after bone marrow transplantation.

Molecular analysis of the hematopoietic microenvironment (HM) has led to the characterization and molecular cloning of two unique growth factors produced by stromal cells. Interleukin (IL)-11 and stem-cell factor (SCF; steel factor [SF]) have been shown in a variety of in vitro culture systems to stimulate distinct populations of stem, progenitor, and more differentiated cell types. We have analyzed and compared the effects of each growth factor administered to mice undergoing bone marrow transplantation (BMT) after total body irradiation (TBI). We report that IL-11 stimulates platelet and neutrophil recovery, while the main effect of SCF is on erythroid cell recovery in this model. Mice treated with the combination of IL-11 and SCF show increases in all three lineages compared with control mice, without obvious toxicity. In addition, both the type of progenitor- and stem-cell populations stimulated and the anatomic localization of effects seen with each growth factor are distinct. These data in mice suggest that the combination of IL-11 and SCF might be useful in humans undergoing myeloablative therapies.

Interleukin-11 inhibits adipogenesis and stimulates myelopoiesis in human long-term marrow cultures.

Interleukin-11 (IL-11) is a bone marrow (BM) stromal-derived growth factor that has been shown to stimulate murine myeloid and lymphoid cells both in vitro and in vivo and to inhibit adipogenesis in a murine fibroblast cell line. We have studied the effects of IL-11 on highly purified human BM stem and progenitor cells and on human long-term marrow cultures (LTMC). Adipocyte differentiation is an integral component of murine and human LTMC. IL-11 stimulates myeloid growth as a single cytokine when added to highly enriched CD34+, HLA-DR+ bone marrow cells. IL-11 stimulated no growth in the more primitive CD34+, HLA-DR- population even in the presence of additional cytokines. IL-11 addition to human LTMC resulted in the expansion of myeloid and mixed, but not erythroid, progenitor populations. IL-11 dramatically increased the adherent cell populations, including both stromal cells and macrophages. Treated cultures also showed marked inhibition of fat accumulation in the adherent cells due in part to a block in the differentiation of preadipocytes to adipocytes, as shown by RNA analysis using adipocyte-specific markers. These data show that IL-11 stimulates a more differentiated, although multipotential, progenitor cell in human BM and that LTMC provide a useful model for studying the effects of this cytokine in the context of the hematopoietic microenvironment.

Effects of recombinant human interleukin-11 on hematopoietic reconstitution in transplant mice: acceleration of recovery of peripheral blood neutrophils and platelets.

We have examined the effects of recombinant human interleukin-11 (rhIL-11) on the recovery of peripheral blood cell counts and proliferation of progenitors and hematopoietic stem cells (day 12 colony-forming units-spleen-CFU-S12) in vivo using a mouse bone marrow (BM) and spleen cell transplantation model. Recovery of leukocytes was accelerated in animals receiving daily administration of rhIL-11 (100 micrograms/kg/d) and reached normal levels by day 14 posttransplantation. This increased total leukocyte count reflected mainly an increase in neutrophils. Neutropenia (absolute neutrophil count [ANC] < 1,500) was present in control transplant mice for 14 to 15 days, while in the rhIL-11-treated group, neutrophils recovered to normal by days 8 to 10 and continued to increase until day 19. Animals treated with rhIL-11 had only 1 day with ANC demonstrated < 500. Correspondingly, rhIL-11 treatment increased granulocyte-macrophage progenitors (CFU-GM) derived from both spleen and BM cells. Higher doses of IL-11 increased CFU-GM nearly threefold and CFU-Mix fourfold to fivefold, while increasing burst-forming units-erythroid to a lesser degree. BM and spleen cellularity were both increased in IL-11-treated mice, but no increase in CFU-S12 was noted. In addition, in vivo daily administration of IL-11 increased peripheral platelet counts by threefold over control transplant mice at day 10 posttransplantation during the post-irradiation platelet nadir. Further treatment led to platelet counts higher than normal 18 days posttransplantation when control animals had just attained normal platelet counts. IL-11 can accelerate the recovery of the peripheral blood leukocytes, mainly neutrophils, and platelets in transplant mice, effects that may be clinically useful in future applications for BM transplantation and chemotherapy-related cytopenias.

A bone marrow stromal-derived growth factor, interleukin-11, stimulates recovery of small intestinal mucosal cells after cytoablative therapy.

The proliferation of epithelial cells lining the small intestinal mucosa may be regulated by microenvironmental signals leading to differentiation of precursor cells in the small intestinal crypts. Proliferation of hematopoietic cells within the hematopoietic microenvironment is known to be regulated by a growing number of glycoprotein growth factors in a hierarchial fashion. We studied the effects of administration of the microenvironment-derived hematopoietic growth factor interleukin-11 (IL-11) on mice given combination radiation/chemotherapy. Treatment of such mice with IL-11 led to significantly increased survival and evidence of rapid recovery of the small intestinal mucosa, which is severely damaged by these cytoxic agents. This recovery was associated with an increase in the mitotic index of crypt cells and an increased frequency of staining of these cells with a monoclonal antibody to proliferating cell nuclear antigen, a member of the cyclin family of nuclear antigens.