Monoclonal antibodies recognizing normal and retrovirus-transformed chicken hematopoietic cells

The avian hematopoietic system has long been an invaluable model to study the mechanisms of cell growth and differentiation. We have developed six MAbs against either chicken embryonic hematopoietic precursor cells or retrovirus-transformed cells. MAbs Mo1, Mo2, and Mo3 recognized transformation-associated markers expressed in AMV-transformed nonproducer cell line-BM2. Not only were these markers expressed 7 to 10 folds higher on BM2 than on normal monocytic cells, but their expression was drastically reduced when BM2 cells were induced to differentiate into macrophages by PMA. The control of marker expression is associated with v-myb-transforming cascade, since another monocytic lineage-specific oncogene, v-myc, did not enhance the expression of these markers. MAb Em1 detected a marker that is normally present in 20% of the cells from the 30/50% interface of a discontinuous percoll gradient of normal 4-day-embryo yolk sac. Its expression is also found in AEV-transformed cells and MSB1 cells. The epitope for Em1 was exposed after neuraminidase treatment on erythroleukemia cell line 6C2, which suggested that sialylation and/or glycosylation is pivotal in regulating the expression of specific markers in differentiation pathways during embryogenesis and tumorigenesis. MAb Em2 recognized proliferating hematopoietic cells after the fourth day of embryogenesis. MAb Em3, on the other hand, is presumed to be specific for an oncofetal antigen expressed in various transformed cells but only in 10% of the cells from 30/50% interface of a discontinuous percoll gradient of normal 4-day-embryo yolk sac. These MAbs will be useful for dissecting the expression of differentiation markers within normal versus abnormal differentiation pathways in molecular terms.

Antimutagenic effect of eight natural foods on moldy foods in a high liver cancer incidence area

Ames test procedures were used to test 8 natural food extracts for their antimutagenic activity against the mutagenic activity induced in S. typhimurium strains TA98 and TA100 by aflatoxin B1 (AFB1) or metabolic extracts from A. versicolor or A. ochraceus. The tested substances were extracted repeatedly with acetone. The revertants induced by AFB1, metabolic extracts of A. versicolor or A. ochraceus were significantly decreased when extracts of the 8 natural foods were added to the media. The results showed that these extracts had marked inhibitory effects on the mutagenic activity induced by AFB1 or metabolic extracts of the two molds and also suggested that antimutagenic substances were present in these natural foods. These experiments provide a scientific basis for the study of food substances for the prevention of carcinogenesis. It is considered that these 8 natural food extracts produce marked antimutagenic effects and are practically valuable in the field of chemoprophylaxis of liver cancer in humans.

Marek disease virus encodes a basic-leucine zipper gene resembling the fos/jun oncogenes that is highly expressed in lymphoblastoid tumors

Marek disease virus (MDV) is a herpesvirus of chickens that induces T lymphomas within 3 weeks of infection. The short latency and polyclonal nature of MDV-induced tumors have suggested that the virus may encode one or more direct-acting oncogenes. To date, however, no MDV-specific tumor antigens or candidate transforming genes have been demonstrated. In this paper, we report the identification of a MDV gene encoding a protein with homology to the leucine-zipper class of nuclear oncogenes. It also contains a proline-rich domain characteristic of another class of transcription factors. This gene, designated meq, maps to the long repeat of MDV and is one of the few genes that are highly expressed in MDV-induced T-cell tumors. To our knowledge, a herpesvirus gene closely related to the fos/jun family of oncogenes has not been reported previously.

Characterization of a major member of the rat pregnancy-specific glycoprotein family

The gene encoding the human pregnancy-specific glycoprotein (PSG) belongs to a gene subfamily, comprised of the carcinoembryonic antigen (CEA) and PSG subgroups, within the immunoglobulin superfamily. To study the functional roles of PSG during development in an animal model, we isolated and characterized a near full-length cDNA (rnCGM6) encoding a PSG-related protein from a rat placental cDNA library. rnCGM6 is 2,068 bp in length and contains an open reading frame that encodes a 475-amino-acid polypeptide with a predicted molecular mass of 53 kD. The 5' noncoding sequence is 173 nucleotides, and primer-extension experiments demonstrate that the transcriptional initiation site is located 22-24 nucleotides further upstream. The 3' noncoding sequence contains 470 nucleotides which is followed by a poly(A) tail. In contrast to human PSGs, which contain one immunoglobulin variable-like and two to three immunoglobulin constant-like protein domains, rnCGM6 contains three immunoglobulin variable-like domains and one immunoglobulin constant-like domain. rnCGM6 contains six potential N-linked glycosylation sites and, in its carboxyl-terminal domain, a tyrosine protein kinase phosphorylation site. The tyrosine phosphorylation site is conserved among all rat and human PSG members. rnCGM6 hybridized with a major 2.5-kb and two minor 3.0- and 3.5-kb mRNAs, all primarily expressed in the rat placenta. Ribonuclease protection analysis, using probes specific to the 5', middle, and 3' regions of rnCGM6, and the 5' region of a previously identified cDNA, rnCGM1, mainly yielded fully-protected fragments indicating relatively low sequence similarity among rat PSG-related proteins. Northern hybridization and ribonuclease protection assays also suggest that rnCGM6 may be the major PSG member in rat.

[Clinical analysis of radiation optic neuropathy]

As a result of enhanced cure rate and survival time of patients with nasopharyngeal carcinoma (NPC) treated by radiotherapy, sequelae of radiation injury to the optic nerve are becoming important, of which the authors report 5 cases (6 eyes) observed in the past 2 years. The diagnoses were based on rapid visual deterioration or blindness in one or both eyes, with visual field defects, signs of papillary ischemic optic atrophy under fluorescein angiography, normal ERG but reduced amplitude and prolonged latency or even extinction of VEP, onset of the malady within 7 years after the initial session of radiotherapy, and survival of the patient over 1 year with no signs of NPC recurrence or metastasis. Good vision was saved in 2 eyes treated with hyperbaric oxygen.

Structural analysis and transcriptional mapping of the Marek's disease virus gene encoding pp38, an antigen associated with transformed cells

The gene encoding a Marek's disease virus (MDV) pp38 phosphoprotein has been identified, sequenced, and localized to the BamHI H fragment to the left of the putative MDV origin of replication. The open reading frame was defined by sequencing of a lacZ-pp38 fusion protein gene from a lambda gt11 expression library. The entire open reading frame is 290 amino acids long and codes for a protein with a calculated molecular weight of 31,169, compared with the size of 38 kDa of the phosphorylated form estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. S1 nuclease protection analysis showed that the pp38 gene is transcribed leftward as an unspliced mRNA. On the basis of transcriptional mapping studies, the pp38 transcript is predicted to be about 1.8 kb in length without a poly(A) sequence. Its promoter-enhancer region overlaps that of the major rightward BamHI H 1.8-kb transcript implicated in tumor induction. This region contains Oct-1, Sp1, and CCAAT motifs as well as the putative origin of replication. The pp38 protein is the only presently known antigen that is consistently associated with the transformation state. It may play a significant role in MDV transformation.

[Effect of hypertonic NaCl solution on arterial pressure compensation after hemorrhage in rats]

Rats were bled within 5 min in lowering mean arterial pressure (MAP) to 25 mmHg and were subsequently infused intravenously with hypertonic (7.5% NaCl) or normal saline in a volume equal to 10% of the amount of the lost blood. Intravenous infusion of hypertonic saline significantly facilitated posthemorrhagic recovery of MAP, which was markedly attenuated by 6-hydroxydopamine or Captopril. When these two drugs were used together, the attenuation effect was complete. While hypertonic saline significantly increased plasma Na+ concentration, normal saline only gave rise to a decrease. Intracerebroventricular injection of hypertonic NaCl solution also facilitated the recovery of MAP significantly. These results suggest that after hemorrhage increased plasma Na+ concentration following i.v. of a small amount of hypertonic saline may act on the central nervous system and activate sympathetic nervous system and renin angiotensin system to facilitate a rapid recovery of MAP.

Cross-linking of surface Ig receptors on murine B lymphocytes stimulates the expression of nuclear tetradecanoyl phorbol acetate-response element-binding proteins

Cross-linking of sIg on primary B lymphocytes leads to increased nuclear DNA-binding activity specific for the tetradecanoyl phorbol acetate-response element (TRE), as judged by gel mobility shift assays. Stimulation of B cells to enter S phase of the cell cycle by treatment with the combination of phorbol ester plus calcium ionophore also stimulated nuclear TRE-binding activity within 2 h, with maximal expression at 4 h; however, phorbol ester and calcium ionophore were not as effective in stimulating binding activity when examined separately. Stimulated nuclear expression of TRE-binding activity appears to require protein synthesis. Fos- and Jun/AP-1-related proteins participate directly in the identified nucleoprotein complex, as shown by the ability of c-fos- and c-jun-specific antisera to either alter or completely abolish electrophoretic migration of the complex in native gels. Further, UV photo-cross-linking studies identified two major TRE-binding protein species, whose sizes correspond to TRE-binding proteins derived from HeLa cell nuclear extracts. The results suggest that in primary B cells nuclear TRE-binding activity represents a "downstream" signaling event that occurs subsequent to changes in protein kinase C activity and intracellular Ca2+ but that can be triggered "physiologically" through sIg.

Cross-linking of surface Ig receptors on murine B lymphocytes stimulates the expression of nuclear tetradecanoyl phorbol acetate-response element-binding proteins

Cross-linking of sIg on primary B lymphocytes leads to increased nuclear DNA-binding activity specific for the tetradecanoyl phorbol acetate-response element (TRE), as judged by gel mobility shift assays. Stimulation of B cells to enter S phase of the cell cycle by treatment with the combination of phorbol ester plus calcium ionophore also stimulated nuclear TRE-binding activity within 2 h, with maximal expression at 4 h; however, phorbol ester and calcium ionophore were not as effective in stimulating binding activity when examined separately. Stimulated nuclear expression of TRE-binding activity appears to require protein synthesis. Fos- and Jun/AP-1-related proteins participate directly in the identified nucleoprotein complex, as shown by the ability of c-fos- and c-jun-specific antisera to either alter or completely abolish electrophoretic migration of the complex in native gels. Further, UV photo-cross-linking studies identified two major TRE-binding protein species, whose sizes correspond to TRE-binding proteins derived from HeLa cell nuclear extracts. The results suggest that in primary B cells nuclear TRE-binding activity represents a "downstream" signaling event that occurs subsequent to changes in protein kinase C activity and intracellular Ca2+ but that can be triggered "physiologically" through sIg.

Inducible nuclear expression of NF-kappa B in primary B cells stimulated through the surface Ig receptor

Constitutive expression of NF-kappa B has been associated with developmental maturity in B cells on the basis of studies using continuously growing cell lines and plasmacytomas; however, little is known about the behavior of NF-kappa B in primary, mature B cells. In the present work, the regulation of NF-kappa B expression was studied by analyzing subcellular fractions of adult murine splenic B cells with the electrophoretic mobility shift assay using a kappa B-containing oligonucleotide. Although nuclear extracts from resting B cells contained kappa B-binding activity, additional kappa B-binding activity was present in cytosolic fractions in a form that became apparent after treatment with detergent. Competition analysis indicated that the DNA binding activity detected by electrophoretic gel mobility shift assay was specific for the kappa B motif, and UV photo-cross-linking showed the molecular size of kappa B-binding protein to be similar to that of the DNA binding subunit of NF-kappa B. Nuclear expression of kappa B-binding activity was markedly induced by treatment of B cells with phorbol ester or with LPS. Most notably, kappa B-binding activity was induced after surface IgR cross-linking, and the mechanism of this induction involved PKC. Further, anti-Ig-induced activity was superinduced in the presence of cycloheximide. These results indicate that nuclear NF-kappa B is rapidly induced as a result of B cell stimulation, and further suggest that NF-kappa B may play a specific role in mature B cells after ligand binding to surface Ig distinct from its postulated developmental role as a stage-specific factor involved in kappa-enhancer function.

[Artificial feeding practice in nursery: a new policy and maternal response]

While a single-bottle method is what mothers actually do in preparation of infant formula in their own home, in the hospital, each nursery makes its own rules about preparing formula. Early in 1988 a "self-service", artificial feeding practice was initiated in this 600-bed general hospital. Mothers who intended to bottle-feed were asked to purchase the powdered formula at their own expense. At feeding time, mothers prepare one bottle of formula at a time, and feed the infant immediately. Each mother's technique of formula preparation was observed by the nurses, and practical instructions were given if needed. Particular errors and hazards in the reconstitution of formula were emphasized with posters hung on the nursery wall and by the pamphlets distributed to the mothers. These practices avoid distribution of formula samples at the hospital, and provide repeated practice for mothers during their hospitalization. To explore the attitudes of mothers toward this new feeding practice, a questionnaire survey of 483 consecutive mothers who gave birth to healthy newborns was carried out. While 61.3% of the mothers thought that it was acceptable to purchase infant formula themselves, 85.1% thought preparing the formula themselves in hospital was acceptable. Furthermore, only 1.2% of the mothers said that this new practice was a great deal of trouble. Most mothers said that on-the-spot teaching by nurses was very helpful. Regarding overall attitudes, 5.4% and 2.1%, respectively, will not or may not return for the next delivery. After controlling for several socio-educational variables, only previous experience with bottle-feeding was associated with pro-and-con responses.(ABSTRACT TRUNCATED AT 250 WORDS)

Inducible nuclear expression of NF-kappa B in primary B cells stimulated through the surface Ig receptor

Constitutive expression of NF-kappa B has been associated with developmental maturity in B cells on the basis of studies using continuously growing cell lines and plasmacytomas; however, little is known about the behavior of NF-kappa B in primary, mature B cells. In the present work, the regulation of NF-kappa B expression was studied by analyzing subcellular fractions of adult murine splenic B cells with the electrophoretic mobility shift assay using a kappa B-containing oligonucleotide. Although nuclear extracts from resting B cells contained kappa B-binding activity, additional kappa B-binding activity was present in cytosolic fractions in a form that became apparent after treatment with detergent. Competition analysis indicated that the DNA binding activity detected by electrophoretic gel mobility shift assay was specific for the kappa B motif, and UV photo-cross-linking showed the molecular size of kappa B-binding protein to be similar to that of the DNA binding subunit of NF-kappa B. Nuclear expression of kappa B-binding activity was markedly induced by treatment of B cells with phorbol ester or with LPS. Most notably, kappa B-binding activity was induced after surface IgR cross-linking, and the mechanism of this induction involved PKC. Further, anti-Ig-induced activity was superinduced in the presence of cycloheximide. These results indicate that nuclear NF-kappa B is rapidly induced as a result of B cell stimulation, and further suggest that NF-kappa B may play a specific role in mature B cells after ligand binding to surface Ig distinct from its postulated developmental role as a stage-specific factor involved in kappa-enhancer function.

[A genetic and clinical study of retinoblastoma in twins]

A pair of monozygotic twins, confirmed by blood grouping (ABO, MN, Rh, P), serum typing (Hp, Gc), EsD phenotyping and HLA(A, B, Cw), both developed the "cat eye" 45 days after birth; the diagnosis of retinoblastoma (Rb) was established pathologically after enucleation. From data of 33 pairs of twins with Rb in literature of this century, the concordance rate of Rb twins and genetic index of Rb (76.56%) were calculated. In addition, the reliability of zygosity determination, the "mirror image" phenomenon, and the use of the second-mutation hypothesis of Knudson for cancer initiation were briefly discussed.

The role of frontal neurons in pain and acupuncture analgesia

To study the role of frontal neurons in pain and acupuncture analgesia, experiments were carried out on 4 monkeys (Macaca mulatta) during performing two tasks, the Heat Discrimination Response GO/NO-GO Task (Task I) and the Heat Delayed Discrimination GO/NO-GO Task (Task II). After a criterion of 90% of correct performances over three successive days had been reached, activity of single neurons was recorded from the frontal cortex. Of 276 Task I-related neurons, 211 responded to noxious and/or innocuous heat stimuli. Of 73 Task II-related neurons, 59 responded to noxious and/or innocuous heat stimuli. During acupuncture, the nociceptive reaction time for lever release to avoid painful stimuli was increased, the percentage of correct performances was lowered, and the neuronal responses to noxious and/or innocuous stimuli were suppressed. These neurons were mainly located in a circumscribed area medial to the superior ramus of the arcuate sulcus in frontal cortex, including the prefrontal and premotor areas. It is suggested that neurons in this area may be related to the discrimination of noxious and innocuous stimuli. The suppression of the activity of these neurons during acupuncture may be involved in the whole mechanism of acupuncture to facilitate the production of analgesia.

[Observations on neuronal activity in frontal cortex and EMGs in monkeys during performing noxious and innocuous heat discrimination GO/NO-GO task]

To study the functional implication of neuronal responses in frontal cortex to noxious and innocuous heat stimuli, experiments were carried out on two monkeys (Macaca mulatta) during performing a delayed discrimination GO/NO-GO task. The animals were trained to hold a lever for at least 3 s in the response period when an innocuous heat stimulus had been applied to the forearm in the cue period, or release it within 1 s with a noxious one. After a criterion of 90% of correct responses in 3 successive days was reached, single neuronal activity was recorded from the frontal cortex along with EMGs from six muscles in both arms. Of 142 task-related neurons recorded, 87 (66.4%) were related to heat, 34 to visual, and 21 to both visual and heat stimuli. Among the heat-related neurons, 22 were responsive to noxious heat, 18 to innocuous heat, and 47 to both. Of the neurons responding to both noxious and innocuous heat stimuli, 4 neurons showed changes in discharge rates, depending on the type of stimuli. In most cases, muscular activities just appeared at the moment of lever pressing and/or releasing in m. extensor digitorium communis, m. flexor carpi ulnaris and m. flexor carpi radialis of the performing arm. No regular muscular activities appeared in other muscles and in other periods of the task. The result showed that the neuronal responses in frontal cortex elicited by heat stimuli in the cue period were not related directly to the initiation and modulation of behaviours.(ABSTRACT TRUNCATED AT 250 WORDS)

Improvement in the locally optimum run-length compression of CT images

In the locally optimum run-length compression of X-ray CT images, differential entropy is selected as the criterion for compression. The reported compressed results for 12 bit CT images are 8-9 bits per pixel, which are far from the differential entropies of the boundaries of the compression, from 5.5 to 6 bits per pixel. Our analysis shows that the compression strategy is defective and this is one reason why the compression cannot reach the boundary. Significant improvement has been achieved and the results challenge the selection of differential entropy as a 'theoretical bench mark' for compression.

[The role of sulfhydryls in indomethacin-induced gastric mucosal injury in rats]

The possible role of sulfhydryls in indomethacin-induced gastric mucosal injury was studied. No significant decrease of the contents of both non-protein and protein-binding sulfhydryls was observed in the gastric mucosa during injury. Indomethacin-induced gastric ulcer was inhibited by cysteamine of 132 and 264 mumol, i.g. or of 132 mumol, s.c. by 82%, 92% and 75% respectively. Such protective effect was not observed with cysteine in equal molar dose. Subcutaneously injected cysteamine (132 mumol) inhibited gastric acid secretion by 46% in indomethacin-treated rats, while no effect was observed on acid secretion when cysteamine was given intragastrically. Cysteamine, given through both routes, did not affect gastric barrier mucus secretion. It is suggested that sulfhydryls in gastric mucosa are not involved in the mechanism of indomethacin-induced injury and that the potent cytoprotective effect of cysteamine against indomethacin-induced ulcer maybe not caused by its sulfhydryl group.

[Functional plasticity of frontal neurons in rhesus monkeys during performing visual discrimination go/no-go task]

We previously reported that frontal neurons in monkeys may be essentially responsive to the biological meanings of the stimuli in a task, rather than to their physical attributes. To examine this hypothesis, activity of single neurons was recorded from the frontal cortex of monkeys (Macaca mulatta) while performing a visual delayed discrimination GO/NO-GO task (task I, n = 2) and a visual discrimination response GO/NO-GO task (task II, n = 2), respectively. A green or red light presented in the period 2 of task I and in the period 4 of task II was used as a cue to guide the monkeys' behaviour. The same green/red light was presented in the period 2 of task II as well, but this was not a cue and had no definite meanings in the task. The monkeys were trained to watch attentively the panel in period 3 of both tasks. A total of 163 task-related neurons were recorded: 98 in task I and 65 in task II. Although neuronal responses appeared in all periods of both tasks, the majority of the responses (70% of the total) were in the periods 2 and 3 of task I, and in the periods 3 and 4 of task II. Furthermore, in the period 2 of task I and period 4 of task II, but not in the period 2 of task II, most of neurons were responsive exclusively to either green or red light. The results support the hypothesis stated above, and suggest that the responses of the frontal neurons to signal stimulation are gradually established in the course of learning, and possess highly developed functional plasticity.

Na,K-ATPase: comparison of the cellular localization of alpha-subunit mRNA and polypeptide in mouse cerebellum, retina, and kidney

A clone encoding mouse brain Na,K-ATPase alpha-subunit was isolated from a mouse brain lambda gt11 cDNA library by using antisera to mouse and bovine brain alpha-subunit. A comparison of the nucleotide sequence of this clone with published sequences of rat brain alpha-subunit isoform clones showed it to be most similar to rat brain alpha 1. An RNA antisense probe prepared from the cDNA insert of the mouse clone detected a single mRNA of approximately 4.5 kb in Northern blots of mouse brain and kidney RNAs. This probe hybridized only to an alpha 1-cDNA insert from rat brain under high stringency conditions on Northern blots. The RNA antisense probe was used for in situ hybridization to sections of mouse kidney, cerebellum, and retina, and the cellular distribution of alpha-subunit mRNA (alpha-mRNA) was compared with that of alpha-subunit polypeptide (alpha-subunit) detected by immunofluorescence in similar sections. In kidney, alpha-mRNA distribution closely paralleled that of the polypeptide with abundant expression in ascending thick limbs and cortical distal tubules and weaker labeling in cortical proximal tubules. The co-distribution of alpha-mRNA and polypeptide in kidney where Na,K-ATPase localization is well established is consistent with the specificity of these probes. In the retina, prominent labeling with both probes was seen in photoreceptor inner segments, inner nuclear layer, and ganglion cell bodies. Plexiform layers and optic fibers expressed abundant alpha-subunit but little mRNA. Light labeling for both was seen in the outer nuclear layer. In cerebellum, alpha-mRNA and alpha-subunit were associated with soma of granule cells, basket cells, and stellate cells. Glomeruli and basket terminals contained abundant alpha-subunit but exhibited little reactivity with the riboprobe. In Purkinje cell bodies, in contrast, the antibody used to identify the cDNA clone did not resolve significant polypeptide in the somal plasmalemma despite abundant somal mRNA expression. Comparison of distribution of the two probes in cerebellum and retina indicates that message accumulation is primarily in cell bodies, while alpha-subunit epitopes may be co-expressed in cell bodies and/or transported to distant sites in cell-specific patterns.

Acute femoral neck fracture in children--preliminary report

Nineteen children, aged 3-15 years, with acute femoral neck fracture were treated. The follow-up period ranged from 2 years to 6 years, 9 months (avg. 54.8 +/- 14.5 months). The clinical and radiological assessments were carried out according to the assessment system of Ratliff. Undisplaced fractures and all intertrochanteric fractures were treated conservatively and displaced ones by reduction and multiple pinning. The outcomes reveal 14 (79%) with good results, 2 (10.5%), fair and 3 (15.8%), poor. Four hips (21%) developed avascular necrosis with 2 requiring secondary surgical procedures. Both of them also had leg length discrepancy. Another 3 hips (15.8%) developed coxa vara, one of them had mild leg length discrepancy.