Association of induction of a fully tumorigenic phenotype in murine radiation-induced T-lymphoma cells with loss of differentiation antigens, gain of CD44, and alterations in p53 protein levels

We investigated the mechanism of radiation induction of murine thymic lymphomas by studying the characteristics of primary x-ray-induced thymic lymphoma (PXTL) cell lines and of their oncogene-induced, progressed progeny. It is widely thought that proto-oncogene alterations are associated with the induction of murine lymphomas; however, few, if any primary murine radiation-induced lymphomas possess (proto-)oncogene alterations. Independently derived cell lines grown directly (i.e., without in vivo transplantation) from thymic lymphomas of irradiated C57BL/6 mice possess the properties of immortalized pre-T cells and lack many of the characteristics of "tumor cells". PXTL cells are poorly tumorigenic upon transplantation, do not clone in methylcellulose cultures, are growth factor dependent and autocrine, and lack consistent chromosome and oncogene abnormalities. However, the thymic lymphomas are malignant and cause the death of each afflicted mouse. PXTL cells expressed two immunologically distinct forms of the tumor suppressor protein p53 that have moderately increased stability (t1/2 = 1 h) when compared with p53 of normal splenic T lymphocytes. Early PXTL cells could progress in vitro to a fully tumorigenic phenotype after infection with retroviruses encoding the c-myc and v-ras oncogenes. Progressed T-lymphoma cells acquired growth factor independence, a highly transplantable and tumorigenic phenotype, and the ability to quantitatively clone in methylcellulose cultures. Progressed lymphoma cells coordinately downregulated the expression of five T-cell differentiation markers, upregulated the expression of CD44 (Pgp-1), and harbored vastly elevated levels of two immunologically distinct forms of p53. Our results suggest that the early thymic lymphomas consist of differentiation-inhibited, immortal pre-T cells that are precursors to progressed, fully tumorigenic T-lymphoma cells.

Suppression of acute lymphoblastic leukemia by the human wild-type p53 gene

Independent mutations in both alleles of the p53 tumor suppressor gene are a frequent finding in human T-cell acute lymphoblastic leukemia (T-ALL) cell lines and in the cells of some T-ALL patients in relapse. One major goal of studying the status of p53 (and other tumor suppressor genes) in human cancer is to facilitate the suppression of the tumorigenic phenotype through the restoration of the expression of the wild-type allele. While the efficient insertion of a suppressor into all cells of solid/metastatic human tumors may at present be impossible, insertion into leukemia cells may be feasible due to the accessibility of the leukemia cells in the body. To examine the feasibility of suppressing the tumorigenicity of human T-leukemia cells, the human T-ALL cell line Be-13, which lacks endogenous p53 protein, was infected with a recombinant retrovirus encoding the wild-type allele of human p53 (hwtp53). Expression of p53 reduced the growth rate of infected Be-13 cells in vitro, suppressed colony formation in methylcellulose cultures, and abrogated their tumorigenic phenotype in nude mice in vivo. These results suggest that suppression of the leukemic phenotype of relapse T-ALL-derived Be-13 cells is feasible. Acute leukemia cell suppression via high-efficiency infection with retroviruses encoding wtp53 may be feasible and beneficial in T-ALL cases as part of a bone marrow transplantation regimen in an effort to reduce the frequency of posttransplantation relapse.

[Clinical results and material behavior of composite, ceramic and gold inlays]

Laboratory-manufactured gold, ceramic and composite inlays were compared with the CAD/CAM produced CEREC inlay experimentally and clinically. The following systems were examined: Dicor, Optec, Hi-Ceram, Du-Ceram, Cerec, Kulzer, Coltene, SR-Isosit composite inlays, and gold inlays (Degulor C) with adhesive fixation (group I) and with zinc oxide phosphate cement (group II). In the clinical trial inlays in 270 teeth were re-evaluated in a total of 73 patients after 2.3 to 5 years. After 3 years the results obtained with Optec, Hi-Ceram and the Coltene composite inlay were less favorable than those of other systems--statistically however, this difference was of rather low significance (p less than 0.05). Fractures of ceramic inlays occurred in 6 cases within 8 months. 10 failures of ceramic and composite inlays were due to secondary caries.

Deposition and removal of cutaneous beta 2-microglobulin

These studies were designed to track the cutaneous deposition of beta 2-microglobulin (beta 2M) in patients on chronic hemodialysis, patients with chronic renal insufficiency and patients with successful renal transplants. Immunoperoxidase staining of skin biopsies from dialysis patients demonstrated significantly increased amounts of beta 2M compared to controls (p < 0.01). There was a strong positive correlation between the skin beta 2M content and the years of dialysis treatment. Renal transplant recipients had decreased skin content of beta 2M compared to hemodialysis patients. There was no difference in the skin beta 2M content in patients with chronic renal insufficiency not on hemodialysis and controls. No dialysis patient had amyloid in the skin by Congo red stain. We conclude that beta 2M accumulates in the skin of patients on chronic hemodialysis. This beta 2M is not in the form of amyloid. Successful renal transplantation allows for the removal of beta 2M from the skin indicating that beta 2M not in the form of amyloid can be mobilized from tissue sites.

[Caries status and periodontal health in 6- to 10-year old elementary school children in Graz compared to Swiss, Swedish and WHO principles]

In a complete survey, 7500 primary pupils in Graz aged between six and ten years were examined for caries and periodontal health. Comparison with the DMF-T values of primary school pupils in Switzerland and Sweden indicated that considerable efforts are required in Austria if preventive dental health education is to achieve the standard status it has enjoyed for years in the other countries mentioned.

[The effect of age and educational level on the risk profile of men and women in industrial occupations]

The authors investigated a population group of 660 men and 440 women aged 35-60 years selected in the Skoda works and examined as part of the integrated programme of prevention of chronic non-infectious diseases. The risk profile of subjects associated with the life-style of the population was evaluated with regard to sex, age and education. It was revealed that the blood pressure rises with age and body weight in men and women. With rising body weight rises also the triglyceride and uric acid level and in women also the total cholesterol level. The authors confirmed the relationship between smoking and the thiocyanate blood level. The magnesium level declines with age in both sexes and correlates with the reported alcohol intake. Men and women with higher education smoke less, have a lower body weight and lower triglyceride blood levels. Women have also a lower total cholesterol level. University educated men consume less alcohol, while the reverse is true in university educated women.

Determination of in vivo and in vitro drug effects of mycobacteria from the mass spectrometric analysis of single organisms

Laser microprobe mass analysis of single bacterial organisms allows the determination of their intrabacterial ratio of sodium-to-potassium ions and the registration of fragment ions originating from their organic bacterial cell matrices as mass fingerprint spectra. It has been established previously that the intrabacterial cation ratio provides information on the physiological state of an individual bacterial cell. In the present experiments it is also shown, with different cultivable mycobacterial species and strains (drug sensitive and resistant) exposed to various drugs, that data derived from the evaluation of the mass fingerprint spectra reflect changes in the degree of impairment. The analysis of Mycobacterium leprae derived from a limited number of skin biopsies of lepromatous/borderline lepromatous leprosy patients under World Health Organization-recommended multiple-drug therapy (WHO/MDT) showed impairment of the organisms with both of the methods of measurement in proportion to the duration of treatment except in one case. In one M. leprae population from a patient who had been treated for 19 months, the fingerprint evaluation gave the first evidence for an insufficient response to treatment. This was further confirmed by the unusual frequency distribution of the Na+,K+ ratios which revealed the existence of two subpopulations, one impaired and one unimpaired.

[3H]bumetanide binding to mouse kidney membranes: identification of corresponding membrane proteins

Crude plasma membranes from whole mouse kidneys have two classes of [3H]bumetanide binding sites. High-affinity sites (K1/2 approximately equal to 0.04 microM; Bmax = 1-2 pmol/mg protein) are similar to those identified on dog kidney membranes (B. Forbush and H.C. Palfrey. J. Biol. Chem. 258: 11787-11792, 1983) both with respect to affinity and in that Na, K, and Cl are required for [3H]bumetanide binding. Low-affinity sites (K1/2 approximately equal to 1 microM; Bmax = 7-14 pmol/mg) are unaffected by removal of these ions; such sites are not seen with dog kidney. When mouse kidney membranes are photolabeled with 4-[3H]benzoyl-5-sulfamoyl-3-(3-thenyloxy)benzoic acid [( 3H]BSTBA), a photoreactive bumetanide analogue, specific incorporation of the label is seen in two regions. As with dog kidney [M. Haas and B. Forbush. Am. J. Physiol. 253 (Cell Physiol. 22): C243-C252, 1987], an approximately 150-kDa protein is labeled with high affinity (K1/2 approximately equal to 0.05 microM). This labeling also requires Na, K, and Cl and appears to correspond to the high-affinity [3H]bumetanide binding sites and to the Na-K-Cl cotransport system. A second peak of [3H]BSTBA photolabeling, centered at approximately 75 kDa, incorporates the label with lower affinity (K1/2 = 2-3 microM). The photolabeling at approximately 75 kDa is unaffected by Na, K, and Cl concentrations and thus may correspond, at least in part, to the low-affinity [3H]bumetanide binding sites. Western blot analysis of [3H]BSTBA-labeled mouse kidney membranes was performed using an antiserum raised to proteins of approximately 82 and approximately 39 kDa isolated from mouse Ehrlich ascites tumor cells using a bumetanide affinity gel (P. B. Dunham, F. Jessen, and E. K. Hoffmann. Proc. Natl. Acad. Sci. USA 87: 6828-6832, 1990). This antiserum cross-reacts with a approximately 150-kDa mouse kidney protein, the staining profile of which on Western blot corresponds very closely to the peak of specific [3H]BSTBA incorporation in this region. The antiserum also reacts with proteins in the range of 65-85 kDa, overlapping the low-affinity peak of [3H]BSTBA incorporation.

The reliability of reliability

Forty-five original articles addressing the subject of examiner reliability were reviewed to determine if the findings were adequately substantiated by the statistical analyses and experimental designs employed by the authors. Only 10 studies were determined to have properly supported conclusions, while an additional three studies contained correct conclusions by coincidence. Eight investigations had invalid designs and three contained claims that were contradicted by the author's findings. Half the studies were found to have conclusions that were based on inappropriate or inconclusive statistical analysis. To date, the research presented in the chiropractic literature cannot substantiate claims concerning the reliability of any diagnostic instrumentation or palpatory procedures commonly employed by chiropractic physicians.

Statistical methodology for reliability studies

Although a considerable number of reliability studies have appeared in the chiropractic literature in the last 10 yr, there is still no consensus on the definition of reliability, appropriate statistics for reliability testing or interpretation of results. This paper offers suggestions for the standardization of experimental design, analysis and evaluation for reliability studies. The primary focus is on appropriate concordance statistics, i.e., Kappa and intraclass correlation. These are presented in detail, together with a discussion of their limitations. Less suitable, but often used indices such as Pearson's r are also discussed. A measure of precision, the interexaminer measurement error, is introduced and a methodology for evaluating precision is presented. Clinical issues which must be considered in reliability studies are discussed; specifically, those issues relevant to studies of diagnostic indicators for spinal manipulation.

Interexaminer reliability for multiple diagnostic test regimens

A methodology is presented for conducting interexaminer reliability studies when indication for adjustment is based on the outcomes of multiple diagnostic procedures. The adjustment decision-making process is simulated by defining multitest scores to be computed from test battery results and defining threshold values of these scores to demarcate the selection/rejection decision made by the clinician. A probability analysis of random chance agreement suggests that intermediate values of the threshold multitest scores must be used to ensure moderate agreement between observers and the viability of concordance statistics.

The regulation of Na/K/2Cl cotransport and bumetanide binding in avian erythrocytes by protein phosphorylation and dephosphorylation. Effects of kinase inhibitors and okadaic acid

The Na/K/2Cl cotransport system in the avian erythrocyte can be activated by agents that raise intracellular cAMP suggesting the involvement of cAMP-dependent protein kinase (cAMP-PK) in its regulation. Another group of stimuli including fluoride and hypertonicity stimulate cotransport via cAMP-independent means. To further investigate the role of phosphorylation in these processes, we examined the effects of protein kinase inhibitors of 8 (p-Cl-phenylthio)-cAMP (cpt-cAMP), fluoride and hypertonic activation of cotransport in duck red cells, and [3H]bumetanide binding to isolated membranes. Preincubation of cells with the kinase inhibitors K-252a (Ki approximately 1.6 microM) and H-9 (Ki approximately 100 microM) blocked cpt-cAMP activation of bumetanide-sensitive 86Rb influx and bumetanide binding. These inhibitors also led to a rapid deactivation of cotransport and decrease in bumetanide binding when added to cells maximally stimulated by cpt-cAMP. K-252a and H-9 inhibited cotransport activation by cAMP-independent stimuli, but 10-fold higher concentrations were required, implying the involvement of a cAMP-independent phosphorylation process in the mechanism of action of these agents. Removal of stimuli that elevate cAMP leads to a rapid reversal of cotransport indicating the presence of active protein phosphatases in these cells. The protein phosphatase inhibitor okadaic acid (OA, EC50: 630 nM) stimulated both Na/K/2Cl cotransport and bumetanide binding to membranes. As with fluoride and hypertonic stimulation, the OA effect was inhibited only at relatively high concentrations of K-252a. Phosphorylation of the membrane skeletal protein goblin (Mr 230,000) at specific cAMP-dependent sites was used as an in situ marker for the state of activation of cAMP-PK. Goblin phosphorylation at these sites was increased by norepinephrine and cpt-cAMP and rapidly reversed by K-252a and H-9, confirming that both inhibitors do block cAMP-PK activity. While OA markedly increased overall phosphorylation of many erythrocyte membrane proteins, including goblin, it did not affect goblin phosphorylation at specific cAMP-dependent sites. These results implicate a cAMP-independent protein kinase in the mediation of the OA effect on cotransport and bumetanide binding. The bumetanide-binding component of the avian erythrocyte cotransporter, an Mr approximately 150,000 protein that can be photolabeled with the bumetanide analog [3H]4-benzoyl-5-sulfamoyl-3-(3-thenyloxy)-benzoic acid was found to be a phosphoprotein. These results strongly support the hypothesis that phosphorylation and dephosphorylation, possibly of the Na/K/2Cl cotransporter itself, regulates the activity of

Insulin-like growth factor-I supports proliferation of autocrine thymic lymphoma cells with a pre-T cell phenotype

We have studied the phenotypic characteristics and growth properties of murine T lymphoma cell lines derived from primary x-ray-induced thymic lymphomas at the earliest stage at which they can be detected, and well before spreading to other organs has occurred. These cell lines serve as model systems for the earliest events in T cell lymphoma induction, before tumor cell progression and spreading to other organs. We find that primary x-ray-induced T cell lymphoma lines have phenotypic characteristics of thymic pre-T cells and show no proliferative response to any of the IL tested nor to other hematopoietic growth factors. However, they do proliferate in response to insulin-like growth factor I (IGF-I) and to a small autocrine peptide distinct from IGF-I, which we term lymphoma growth factor. One of the earliest lesions in T cell lymphoma induction may therefore be an inhibition of differentiation at one of several specific points. In its early stages, T lymphoma cell growth may be restricted to an environment where local concentrations of specific growth factors such as IGF-I or lymphoma growth factor are sufficiently high.

Insulin-like growth factor-I supports proliferation of autocrine thymic lymphoma cells with a pre-T cell phenotype

We have studied the phenotypic characteristics and growth properties of murine T lymphoma cell lines derived from primary x-ray-induced thymic lymphomas at the earliest stage at which they can be detected, and well before spreading to other organs has occurred. These cell lines serve as model systems for the earliest events in T cell lymphoma induction, before tumor cell progression and spreading to other organs. We find that primary x-ray-induced T cell lymphoma lines have phenotypic characteristics of thymic pre-T cells and show no proliferative response to any of the IL tested nor to other hematopoietic growth factors. However, they do proliferate in response to insulin-like growth factor I (IGF-I) and to a small autocrine peptide distinct from IGF-I, which we term lymphoma growth factor. One of the earliest lesions in T cell lymphoma induction may therefore be an inhibition of differentiation at one of several specific points. In its early stages, T lymphoma cell growth may be restricted to an environment where local concentrations of specific growth factors such as IGF-I or lymphoma growth factor are sufficiently high.

A radiographic study of sacral base, sacrovertebral, and lumbosacral disc angles in persons with and without defects in the pars interarticularis

There remains a lack of definitive evidence regarding the etiology of pars defects, though evidence is mounting in favor of micro-trauma. Approximation of the articular facets, as occurs in subjects with increased sacral base angles, may result in greater stress to this area, leading to the development of pars defects. Alternatively, pars defects may facilitate approximation of the articular facets, resulting in a higher sacral base angle. The purpose of this study was to determine whether persons with spondylolysis have greater sacral base angles compared to persons without spondylolysis. The sacral base, sacrovertebral, and lumbosacral disc angles were measured on 30 subjects with radiographic evidence of spondylolysis at L5, and on 95 radiographically normal subjects. A 26% difference in the sacral base angle between spondylolytic and normal males was discovered. The results for females were inconclusive due to the sample size. Baseline data for the sacral base, sacrovertebral and lumbosacral disc angles were established for both normal and spondylolytic males and females. No relationship was found between spondylolysis and these two angles.

Regulation of Na-K-Cl cotransport in cultured canine airway epithelia: a [3H]bumetanide binding study

We examined [3H]bumetanide binding to membranes isolated from canine tracheal and bronchial epithelia and to confluent primary cultures of these cells. Crude plasma membranes from trachea and bronchus bind [3H]bumetanide in a saturable manner; tracheal membranes have a higher affinity but lower maximal binding (K1/2 approximately equal to 0.7 microM; Bmax approximately equal to 2.5 pmol/mg protein) than do bronchial membranes (K1/2 approximately equal to 3.5 microM; B(max) approximately equal to 7.5 pmol/mg). In both cases, saturable binding is reduced by greater than 65% when either Na, K, or Cl is removed from the medium. In primary cultures, saturable [3H]bumetanide binding (inhibited by a 30-fold excess of unlabeled bumetanide) occurs when [3H]bumetanide (1.0 microM) is added to the solution bathing the basolateral side of tracheal (1.20 +/- 0.10 pmol bound/mg total cell protein) and bronchial (1.79 +/- 0.52 pmol/mg) cultures; minimal binding is seen with apical [3H]bumetanide. Isoproterenol (10(-5) M; basolateral exposure) produces approximately 100% increase in saturable basolateral [3H]bumetanide binding to tracheal cultures and approximately 30% increase in bronchial cultures. Similar augmentation of binding is seen when apical Cl is reduced from 134 to 4 mM and when both apical and basolateral media are made hypertonic by addition of 100 mM sucrose. Under these latter two conditions, isoproterenol produces little or no additional increase in binding. Our results indicate that the increase in basolateral Cl influx via Na-K-Cl cotransport that must occur during beta-adrenergic stimulation of net salt secretion in canine airway epithelia is related to an actual increase in the number of functioning cotransporters in the basolateral membrane and is not simply due to a change in ion gradients. The increase in cotransport sites, however, may be secondary to initial stimulation of apical Cl channels, with resultant cell shrinkage.

Frequent mutations in the p53 tumor suppressor gene in human leukemia T-cell lines

Human T-cell leukemia and T-cell acute lymphoblastic leukemia cell lines were studied for alterations in the p53 tumor suppressor gene. Southern blot analysis of 10 leukemic T-cell lines revealed no gross genomic deletions or rearrangements. Reverse transcription-polymerase chain reaction analysis of p53 mRNA indicated that all 10 lines produced p53 mRNA of normal size. By direct sequencing of polymerase chain reaction-amplified cDNA, we detected 11 missense and nonsense point mutations in 5 of the 10 leukemic T-cell lines studied. The mutations are primarily located in the evolutionarily highly conserved regions of the p53 gene. One of the five cell lines in which a mutation was detected possesses a homozygous point mutation in both p53 alleles, while the other four cell lines harbor from two to four different point mutations. An allelic study of two of the lines (CEM, A3/Kawa) shows that the two missense mutations found in each line are located on separate alleles, thus both alleles of the p53 gene may have been functionally inactivated by two different point mutations. Since cultured leukemic T-cell lines represent a late, fully tumorigenic stage of leukemic T cells, mutation of both (or more) alleles of the p53 gene may reflect the selection of cells possessing an increasingly tumorigenic phenotype, whether the selection took place in vivo or in vitro. Previously, we have shown that the HSB-2 T-cell acute lymphoblastic leukemia cell line had lost both alleles of the retinoblastoma tumor suppressor gene. Taken together, our data show that at least 6 of 10 leukemic T-cell lines examined may have lost the normal function of a known tumor suppressor gene, suggesting that this class of genes serves a critical role in the generation of fully tumorigenic leukemic T cells.

The physics of spinal manipulation. Part IV. A theoretical consideration of the physician impact force and energy requirements needed to produce synovial joint cavitation

The critical force and energy required to facilitate synovial joint cavitation are presented as functions of seven parameters: joint and patient stiffnesses, joint and patient elasticities, the proportion of impacting energy entering the joint and patient, and the critical joint distraction at which cavitation occurs. These parameters are governed by numerous properties of the patient, doctor, joint, and the adjustive process. Equations for the critical force and energy are derived and the seven parameters and their governing factors are discussed.

The physics of spinal manipulation. Part III. Some characteristics of adjusting that facilitate joint distraction

The role of quickness, adjustive amplitude, preadjustive tension, and countertension in facilitating joint distraction to cavitation is investigated. These characteristics are further shown to contribute to joint isolation, protection of joints from injury, and enhanced adjustive efficiency. Block and spring "slinky dog" models aid in illustrating the physics principles involved. The complete role of mass and acceleration in the adjustive process is discussed.