Enclosed afferent reservoir breathing systems. Description and clinical evaluation

A new group of breathing systems, namely the Enclosed Afferent Reservoir (EAR) systems, is described. They allow for the selective elimination of alveolar gas in association with both spontaneous and controlled ventilation. A comparison with the Bain system in controlled ventilation demonstrates greater efficiency in eliminating carbon dioxide. A fresh gas flow (VF) of 70 ml kg-1 min-1 using an EAR system gave mild hypocarbia which equated to a VF of 100 ml kg-1 min-1 using the Bain system. Smaller minute volumes of ventilation are required for optimal performance than with the Bain system. The minimum recommended minute volume of ventilation (VI) should equal VF plus anatomical deadspace ventilation (VDanat). The pattern of ventilation appears to have little influence upon the efficiency of carbon dioxide elimination when using an EAR system, whereas the Bain system does appear to be affected.

Inhibition of 2-aminofluorene mutagenesis in bacteria by inducers of cytochrome P-450d

Certain chemical inducers of rat liver microsomal cytochrome P-450d are tightly bound to the cytochrome. We investigated the ability of two inducers of cytochrome P-450d, Aroclor 1254 and isosafrole, to inhibit the microsomal activation of 2-aminofluorene to a mutagen as measured in Salmonella typhimurium. Butanol treatment of microsomes from isosafrole-treated rats removed an inhibitory metabolite of isosafrole and increased 2-aminofluorene mutagenesis by approximately 2-fold over controls. Butanol treatment of microsomes from Aroclor 1254-treated rats failed to either remove any of the Aroclor 1254 associated with microsomal cytochrome P-450 or affect 2-aminofluorene-induced mutagenesis. However, addition of Aroclor 1254 to butanol-treated microsomes from isosafrole-treated rats almost completely inhibited 2-aminofluorene mutagenesis. Aroclor 1254 completely inhibited the cytochrome P-450d-dependent estradiol 2-hydroxylase activity of butanol-treated microsomes from isosafrole-treated rats. Thus, we suspect that certain congeners from Aroclor 1254, a widely used mixture for induction of cytochrome P-450 activities, could inhibit cytochrome P-450d and partially mask its ability to metabolize some chemicals to mutagens.

Mithramycin selectively inhibits transcription of G-C containing DNA

Mithramycin induces a reversible inhibition of cellular RNA synthesis without affecting DNA synthesis. The authors have shown this drug induces myeloid differentiation of HL-60 promyelocytic leukemia cells and is an effective agent in certain patients with chronic granulocytic leukemia. In order to investigate the mechanism by which this drug inhibits RNA synthesis we have compared the effect of mithramycin on RNA synthesis by whole cells, isolated nuclei, and RNA synthesis by isolated E. coli RNA polymerase and eukaryotic RNA polymerase II. Exposure of HL-60 cells to mithramycin at concentrations of 4.6 X 10(-7) m or higher for 48 hours causes an almost immediate inhibition of RNA synthesis (up to 85% at 4 hours) with only modest cytotoxicity at these concentrations. Endogenous RNA synthesis by isolated nuclei can be inhibited by mithramycin only at high concentrations (greater than 10(-5) m), suggesting that mithramycin primarily may inhibit initiation, rather than elongation. Mithramycin inhibits in vitro transcription of salmon sperm DNA by E. coli RNA polymerase at DNA:drug ratios similar to those required for RNA synthesis inhibition in whole cells. Similar DNA binding studies with synthetic oligonucleotides demonstrate that mithramycin is a potent inhibitor of transcription of Poly dG.dC by E. coli RNA polymerase but has no effect on transcription of Poly dA.dT. The rapid inhibition of whole cell and isolated RNA polymerase transcription, and the relative insensitivity of isolated nuclei, suggest mithramycin may interact with specific DNA sequences in order to inhibit the initiation of RNA synthesis in intact cells.

Errors in the Measurement of Root Pressure and Exudation Volume Flow Rate Caused by Damage during the Transfer of Unsupported Roots between Solutions

Plants of Zea mays were grown with their roots confined to growing tubes, consisting of cylindrical or spherical glass tubes fitted at the bottom with a stopcock. Nutrient solution was circulated past the roots, and when a plant was 21 to 25 days old, the stopcock was closed, the root excised from the plant and connected to an apparatus which measured root pressure and exudation volume flow rate. The stopcock was opened and solution was again circulated through the growing tube without dropping the level of the liquid bathing the root in the process. Measurements of pressure and flow rate were made continuously during a period in which the solution was replaced, first by draining and refilling the tube in situ, and second by replacing the growing tube with a beaker of solution. Both these manipulations caused at least temporary and frequently permanent drops in root pressure and flow rate. Plants were also grown in cylindrical tubes with a support medium of either glass beads or Raschig rings which filled the growing tubes. It is shown that the solution bathing these roots could be repeatedly replaced by draining and refilling with no visible effect on the measurements. It is recommended, therefore, that in future, support be provided for the roots of all experimental plants grown by solution culture.

The results of cryosurgical treatment of cervical intraepithelial neoplasia at one, five, and ten years

The results after cryosurgical treatment of cervical intraepithelial neoplasia at 1, 5, and 10 years are reported. Ninety-four percent of the 1675 patients eligible for assessment at 1 year were successfully treated, with only 5.6% lost to follow-up. After 5 years, 14% of patients were lost to follow-up, but the corrected success rate remained essentially unchanged. No major differences in success rates were noted for the various histologic grades of cervical intraepithelial neoplasia treated. A small but definite percentage of patients developed further disease over the ensuing years, indicating the need for long-term, continued surveillance of these patients.

Computerized axial tomography (CT) as an aid in the diagnosis of hepatic portal venous gas: a case report

The radiologic finding of hepatic portal venous gas and its surgical implications have been documented previously in the literature. More than 67 cases have been reported. Branching tubular lucencies that extend from the porta hepatis to the edge of the liver are characteristic. In general, air in the biliary tree is central in location, but the distinction may not always be clear. We present a case in which computerized axial tomography was extremely helpful in localizing extraluminal gas to the liver and differentiating between air in the biliary tree and hepatic portal venous gas.

Modulation of immune responses in mice by d-limonene

The immunotoxicologic effects of d-limonene were determined. This naturally occurring substance is widely used in food flavorings and is a common additive in cosmetics. In the present study, BALB/c mice were treated with d-limonene for 9 wk. Effects on T- and B-cell responses were determined after 4 and 8 wk of treatment. Concanavalin-A responses at 8 wk, but not 4 wk, were suppressed in treated mice. A similar trend was observed for phytohemagglutinin and lipopolysaccharide responses. Evidence was presented that d-limonene had polyclonal activator action. Mice primed with keyhole limpet hemocyanin (KLH) prior to initiation of d-limonene treatment had suppressed primary and secondary anti-KLH responses. Mice treated with d-limonene prior to KLH priming produced significant increased antibody responses. Additional evidence for polyclonal stimulation was obtained by histopathologic examination of secondary lymphoreticular tissue. Significant secondary follicle development and prominent lymphoid nodules and aggregates were found in the pancreas and intestinal mucosa, particularly apparent in mice receiving the highest d-limonene dosage. A subchronic LD50 study was conducted wherein BALB/c mice received 16 daily doses of d-limonene. An LD50 of approximately 0.0850 mg d-limonene/kg (corrected for 82% purity) was determined.

Preliminary observations on the therapy of the myeloid blast phase of chronic granulocytic leukemia with plicamycin and hydroxyurea

We observed a dramatic improvement in the peripheral blood counts of a patient in the myeloid blast phase of chronic granulocytic leukemia after plicamycin (mithramycin) therapy of concurrent hypercalcemia. We then treated eight additional patients in the blast phase of chronic granulocytic leukemia with a combination of alternate-day plicamycin and daily hydroxyurea. All six patients with myeloid morphology at the time of blast crisis responded with a return to a chronic phase without an intervening pancytopenic period. Of three patients with lymphoid morphology at the time of treatment, only one responded (this patient had recently relapsed and converted from myeloid to lymphoid morphology). Another patient with nonmyeloid, nonlymphoid blast morphology also did not respond. Continual therapy with the two-drug combination appeared to be necessary, since early relapses were seen in responding patients whose therapy was interrupted. These data are preliminary and will need further confirmation, but they suggest that the combination of alternate-day plicamycin and daily hydroxyurea may be effective in the myeloid blast phase of chronic granulocytic leukemia.

Basic mechanisms of metastasis

Metastatic disease is responsible for the majority of deaths caused by cancer. The process of metastasis is an orderly, stepwise process that results in the selection of cells that possess the capability to establish viable metastases. These cells must be locally invasive and be able to survive the physical traumas of dissemination and normal host defenses. Once metastatic cells have been arrested in a capillary bed, they must be able to invade the host organ parenchyma and survive in that milieu. Studies in a number of model systems have documented the phenotypic alterations in cells that have "metastatic potential." These differences may stem from normal tumor cell heterogeneity and surprisingly reflect only minor differences in gene expression. The role of activated oncogenes in metastasis is unclear, but a number of laboratories have documented that transfection with activated Ha-Ras results in increased metastatic potential. An increased understanding of the genetic basis of metastatic potential may suggest new directions for intervening in this deadly process.

Gall bladder anomaly in a young chicken

A multi-cystic gall bladder was observed at necropsy in a 7-week-old broiler cockerel. Cystic lumina contained multiple elongated papillary epithelial projections and plicae composed of epithelium and lamina propria, abutting normal lining epithelium.

A review of protonephridial excretory systems in Acanthocephala

Our present understanding of the excretory system of Acanthocephala is largely the result of work done by 5 German scholars: Kaiser, Schepotieff, Meyer, Kilian, and von Haffner. Present studies indicate that a protonephridial system is restricted to the family Oligacanthorhynchidae. However, many members of this family have not had a protonephridial system described. Three nephridial designs have been described: 1) dendritic type, organized as branches of a tree where each final branch terminates in a ciliated bulb; 2) capsular type, in which all ciliated bulbs empty directly into a common chamber; and 3) rudimentary type, consisting of a single cell with a patent ciliary pouch but no ducts to the outside. The first 2 types are a syncytia with 3 nuclei located in the capsule or stem wall and none in the flame bulbs. These excretory systems consist of 2 clusters of flame bulbs that empty separately into an expandable excretory bladder which in turn empties into ducts of the reproductive system. This urogenital system empties to the outside through a gonopore located at the tip of the penis in males and the posterior terminus of the vagina in females. Cilia occur in certain excretory tubes, depending on sex and species, but are unknown in the excretory bladder or ducts leading into it. The rudimentary type consists of a cell whose posterior extension terminates near the bursal lumen, but it is not known if this is significant for the discharge of material. There is no information on the physiology or biochemistry of the excretory system or its products.

Burn depth evaluation with fluorometry: is it really definitive?

Clinical evaluation of burn depth soon after injury is subjective, based on gross visual assessment. Previous investigators have quantified this process using fluorometry. Their studies show fluorescein levels in full-thickness burns to be far below control levels and partial-thickness burns to be about 60% of nonburned skin. In both rat and human models, 59 burn sites (eight rats) and 37 burn sites (seven patients) were assessed. Readings were taken for three hours on the rats and one hour on the patients during the first 48 hours, and the procedure was repeated for five days postburn. Maximum values during these periods were determined for burn and nonburn sites, and background levels were subtracted from these values. The rate of fluorescein uptake and the peak times for burn and nonburn sites were then compared. Actual depth of burn was determined by whether or not healing had occurred. The results showed no significant difference between partial-thickness and full-thickness burns using fluorometry, as standard deviations in both models for both depths of burn were large. Therefore, fluorometry did not provide a definitive evaluation of burn depth. These results differ from those reported by previous investigators.

Categorization Methodology: an Approach to the Collection and Analysis of Certain Classes of Qualitative Information

A new methodology has been developed for the study of certain classes of qualitative information. The methodology is composed of two major techniques: the F-sort task for data collection and latent partition analysis for data summarization. In this paper, similarities and differences of the methodology in relation to existing techniques are discussed. This includes a review of the historical antecedents and development of the methodology as well as a listing of recent applications of the methodology, which have been in several fields of psychology and education. Following that review, a detailed presentation is given of how the methodology was applied to studying teachers' views of facilitating student learning in the classroom. In the data analysis, some previously unpublished enhancements of latent partition analysis are introduced -- for basic categorization statistics, recovery of subgroup information, and linkage to multidimensional scaling. This complete and substantively intriguing example is intended to illustrate the power and utility of the methodology in exploring important research topics. Then, examinations are made of the main components of the F-sort technique and of latent partition analysis. The intent is to lay out detailed frameworks for designing and interpreting research that applies the categorization methodology. The methodology has not previously been given an integrated description. Finally, discussion concerns the uses of the methodology and the importance of standardized application of the procedures.

Trichosporon infection in a cat

A protruding nasal mass in a domestic shorthair cat with nasal discharge and recurrent fever was determined to be caused by infection with the fungus Trichosporon pullulans, as determined by cytologic, histologic, and fungal culture methods. Initially, the cat was treated orally with ketoconazole and the mass decreased in size. When signs of hepatotoxicosis developed, treatment was reduced to an alternate-day basis. However, the nasal mass increased in size with this regimen, and therapy with amphotericin B and 5-flucytosine was begun. It also was unsuccessful.

Identification of myosin heavy chain in Saccharomyces cerevisiae

Motility in biological systems is expressed in a variety of ways, such as cytoplasmic streaming, cell shaping, nuclear migration and muscle contraction. These functions are thought to be mediated by structural proteins, for example, myosin, actin and tubulin. The involvement of myosin in muscle contraction is well documented and this protein is implicated in generating the cleavage forces during cytokinesis in some non-muscle cells. Here, we report the isolation of a protein similar to myosin as judged by its biochemical and immunological properties, from the yeast Saccharomyces cerevisiae. Parts of the protein have been conserved through evolution at the protein and DNA sequence levels. The presence of this protein in the region bordering mother cell and bud, as revealed by immunofluorescence, suggests that it is involved in cell division.

In vivo differentiation of blast-phase chronic granulocytic leukemia. Expression of c-myc and c-abl protooncogenes

A patient with chronic granulocytic leukemia in acute blastic transformation was treated with mithramycin, an RNA synthesis inhibitor, after in vitro exposure of her leukemic cells to mithramycin showed differentiation to normal appearing granulocytes. Mithramycin therapy in vivo resulted in a prompt and dramatic hematologic response. Before therapy, the patient's leukemic cells had high levels of transcription of the cellular myc and abl protooncogenes. After initiation of therapy, protooncogene mRNA decreased rapidly. These observations indicate that mithramycin can induce differentiation both in vitro and in vivo and suggest that such changes may be associated with altered oncogene expression.

Control of lysozyme gene expression in differentiating HL-60 cells

We have investigated the control of lysozyme gene expression in HL-60 cells induced to differentiate into macrophage-like cells with phorbol myristate acetate (PMA). Differentiation, as evidenced by cellular adherence, and morphological changes corresponded temporally to an increase in nonspecific esterase activity. The lysozyme concentration in the medium of uninduced HL-60 cells was 10 micrograms/10(7) cells, increasing to a maximum of 46 micrograms/10(7) cells after 48 h incubation with PMA (16 nM). At 72 h the lysozyme concentration decreased to 16 micrograms/10(7) cells. Intracellular lysozyme activity remained constant throughout differentiation. If HL-60 cells were exposed to PMA for 24 h, washed, then maintained in normal medium, they differentiated normally, confirming their irreversible commitment to differentiate. The increase in lysozyme secretion by these cells, however, is markedly blunted suggesting that continued PMA treatment of differentiated cells is required for their secretion of lysozyme. There is no change in the rate of extracellular degradation of lysozyme during differentiation. The level of lysozyme mRNA does not correlate directly with the amount of lysozyme secreted into the medium. Hybridization of uninduced HL-60 cell RNA with a chicken lysozyme cDNA probe demonstrates moderate hybridization. There is a modest (five-fold) increase in lysozyme mRNA between 0 and 36 h of exposure to PMA, corresponding to the burst of lysozyme secretion by these cells. The lysozyme mRNA decreases to a level which is lower than the original baseline by 72 h, when the cells are still secreting substantial amounts of lysozyme. These data suggest that both transcriptional and post-transcriptional controls are operative in the control of lysozyme gene expression during the differentiation of HL-60 cells. They also imply that lysozyme secretion is not a necessary component in the macrophage-monocyte differentiation of these cells.

Noncaseating pulmonary granulomas associated with small cell carcinoma of the lung

Noncaseating pulmonary granulomas are rarely associated with primary carcinoma of the lung. The patient described herein presented with constitutional symptoms and nodular pulmonary infiltrates associated with noncaseating granulomas without evident neoplasm in both transbronchial and open lung biopsy specimens. Despite corticosteroid therapy for presumed sarcoidosis, chest roentgenographic findings worsened and repeated transbronchial biopsy 12 months after the onset of initial symptoms revealed small cell carcinoma of the lung. Twenty-two months after initiation of chemotherapy, the patient is well with no evidence for carcinoma.

Myosin and paramyosin are organized about a newly identified core structure

Myosin isoforms A and B are differentially localized to the central and polar regions, respectively, of thick filaments in body wall muscle cells of Caenorhabditis elegans (Miller, D. M. III, I. Ortiz, G. C. Berliner, and H. F. Epstein, 1983, Cell, 34:477-490). Biochemical and electron microscope studies of KCl-dissociated filaments show that the myosin isoforms occupy a surface domain, paramyosin constitutes an intermediate domain, and a newly identified core structure exists. The diameters of the thick filaments vary significantly from 33.4 nm centrally to 14.0 nm near the ends. The latter value is comparable to the 15.2 nm diameter of the core structures. The internal density of the filament core appears solid medially and hollow at the poles. The differentiation of thick filament structure into supramolecular domains possessing specific substructures of characteristic stabilities suggests a sequential mode for thick filament assembly. In this model, the two myosin isoforms have distinct roles in assembly. The behavior of the myosins, including nucleation of assembly and determination of filament length, depend upon paramyosin and the core structure as well as their intrinsic molecular properties.

Evidence for two isozymes of leukocyte alkaline phosphatase in leukemic leukocytes

Leukocyte alkaline phosphatase (LAP) is a granulocyte enzyme whose level of expression is markedly altered in various disease states. We have characterized LAP from normal cells and leukemic cells with a high level of LAP activity in order to determine whether increased enzyme levels are caused by increased levels of the same enzyme or induction of a different alkaline phosphatase. Leukocyte alkaline phosphatase was purified from normal granulocytes and from leukemic cells of a patient with chronic granulocytic leukemia (CGL) in blast phase with an elevated LAP level. LAP was partially purified utilizing diethylaminoethyl (DEAE)-cellulose ion exchange chromatography, gel filtration, and preparative electrophoresis. The sample prepared from normal granulocytes contained a single protein with LAP activity having a molecular weight of 61,000 as determined by SDS gel electrophoresis. The sample from the CGL blast-phase cells, however, demonstrated two proteins with alkaline phosphatase activity, one with a molecular weight of 61,000 (LAPs) and one with a molecular weight of 45,000 (LAPf). Differential heat inactivation and distinct isoelectric points of the two isozymes suggest that they are different proteins. We interpret our data to suggest two closely related LAP alleles whose expression is controlled independently. This may represent either genetic heterogeneity or induction of "tumor marker" gene expression.

Multipurpose central venous access in the immunocompromised pediatric patient

During a 21-month period, 50 consecutive pediatric oncology patients undergoing bone marrow transplantation and/or cytoreductive chemotherapy had 61 silastic central venous catheters placed to facilitate their therapy. All catheters were used for medications, routine blood sampling, and transfusions, with 45% also used for hyperalimentation and 57% used for bone marrow transplantation. Catheters were utilized during both inpatient and outpatient therapy periods. Total catheter days numbered 8455, an average of 139 days per catheter. Forty-seven catheters (77%) were removed electively or were in place at time of patient death. Seven were removed for mechanical complications (1/1409 catheter days). Four additional episodes of presumed catheter sepsis were managed with antibiotics and did not require catheter removal (40% of septic episodes). One catheter is still in place after 585 days. Complication rates were not influenced by this multiple use protocol. With standardized catheter care and surveillance, multipurpose, long-term central venous access can be safely utilized in the immunosuppressed pediatric patient.

Studies of Root Function in Zea mays: III. Xylem Sap Composition at Maximum Root Pressure Provides Evidence of Active Transport into the Xylem and a Measurement of the Reflection Coefficient of the Root

The cut ends of excised Zea mays roots were sealed to a pressure transducer and their root pressures recorded. These rose approximately hyperbolically to a maximum value of 4.21 +/- 0.34 bar after 30 to 40 minutes. Xylem exudate could not be collected at this pressure since the flow rate was zero. Samples of exudate were collected at lower applied pressures (DeltaP), however, and Deltapi, the osmotic pressure difference between them and the solution bathing the root, was measured by freezing point depression. A plot of DeltaP/Deltapi against J(v)/Deltapi, where J(v) is the volume flux, proved to be a straight line whose intercept, equal to sigma, the reflection coefficient, was 0.853 +/- 0.016. The maximum xylem concentrations of various chemical species were found by a similar extrapolative method and compared with those in the cell sap. This indicated that (a) Ca(2+), Mg(2+), NO(3) (2-), SO(4) (2-), and most amino acids move from the cells to the xylem down an electrochemical potential gradient; (b) relative to these ions H(+), NH(4) (+), glutamine and asparagine are actively transported into the xylem; and (c) H(2)PO(4) (-), and K(+) are actively retained in the symplasm.

Purification of functional RNA from human granulocytes

The presence, in granulocytes, of high levels of nuclease activity makes it difficult to isolate intact RNA from these cells. We have developed a method that allows purification of functional RNA from normal granulocytes as determined by capability for reverse transcription and in vitro translation. We have shown that a considerable amount of ribonuclease activity remains in granulocyte lysates, even after the addition of heparin or vanadyl ribonucleoside complexes. RNA isolated from such lysates demonstrates only minimal binding to oligothymidylic-cellulose and does not serve as a template for reverse transcription or in vitro translation. However, the extraction of frozen granulocytes into phenol in the presence of both heparin and vanadyl ribonucleoside allows the purification of relatively large quantities of RNA, which serves as an excellent template for reverse transcription and in vitro translation. Purification of granulocyte RNA by this method will facilitate study of granulocyte gene expression.

Studies of Root Function in Zea mays: IV. Effects of Applied Pressure on the Hydraulic Conductivity and Volume Flow through the Excised Root

The volume flux, J(v), and the osmotic driving force, sigma big up tri, openpi, across excised root systems of Zea mays were measued as a function of big up tri, openP, the hydrostatic pressure difference applied across the root, using the pressure jump method previously described (Miller DM 1980 Can J Bot 58: 351-360). J(v) varied from 5.3% to 142% of its value in intact transpiring plants as a result of the application of pressure differences from -2.4 to 2.4 bar. The calculated hydraulic conductivity was 5.9 x 10(-4) cubic centimeters per second per bar per gram root and was independent of pressure. A model of root function similar to those appearing in the literature failed to provide quantitative accord with the data. A proposed model, which includes the effect of volume flux on the distribution of solutes in the symplasm, predicts accurately J(v) big up tri, openpi, and the xylem solute concentration as a function of big up tri, openP.

Interactions of maitotoxin with voltage-sensitive calcium channels in cultured neuronal cells

The dinoflagellate toxin maitotoxin (MTX) stimulated 45Ca2+ uptake in cultured NG108-15 neuroblastoma X glioma cells. Depolarizing stimuli (e.g., 50 mM K+) produced an immediate stimulation in Ca2+ uptake, whereas that produced by MTX occurred only after a lag period of about 2 min. MTX did not stimulate Ca2+ uptake into fibroblasts. Both 50 mM K+- and MTX-stimulated Ca2+ uptake was blocked by organic calcium channel antagonists (nitrendipine, D-600, diltiazem) at very low concentrations. Cd2+ was also a potent blocker. The novel dihydropyridine BAY K8644 enhanced Ca2+ uptake in the presence of 50 mM K+ but had no effect in 5 mM Ca2+. However, in the presence of MTX, BAY K8644 stimulated Ca2+ uptake in 5 mM K+. The effects of MTX were not blocked by tetrodotoxin but were decreased in Na+-free medium. MTX did not stimulate Na+ uptake into NG108-15 cells and did not alter [3H]nitrendipine binding to rat brain cortical synaptosomes. It is concluded that MTX may alter the voltage dependence of calcium-channel activation.

Cellular transformation by coordinated action of three peptide growth factors from human platelets

Platelet-derived growth factor (PDGF) is known to be involved in regulating the mitosis of connective tissue cells, and recent studies have also shown that it may function in mediating cellular transformation. The oncogene carried by simian sarcoma virus, sis, is homologous to one chain of PDGF, and treatment of non-neoplastic cells with this growth factor results in increased transcription of another oncogene, myc (ref. 9). PDGF also stimulates the synthesis of proteins that are characteristic of transformed cells. However, phenotypic transformation does not appear to result from the action of PDGF alone. For example, expression of myc does not transform cells in the absence of other oncogene expression. We have recently shown that platelets contain another peptide growth factor, transforming growth factor-beta (TGF-beta)12,13, in addition to PDGF. We report here that extracts of human platelets can induce anchorage-independent growth of nonneoplastic rat kidney (NRK) fibroblasts, but that purified PDGF alone does not elicit this effect. Rather, the transforming activity of the platelet extract is due to a concerted action of three distinct peptides: PDGF, TGF-ss and a newly identified analogue of epidermal growth factor (EGF).

Caprine aflatoxicosis: experimental disease and clinical pathologic changes

Groups of 8 male crossbreed domestic goats were given 3 dosage levels of aflatoxin B1 [(AFB1) mg/kg of body weight/day] orally: 0.1 for 34 days; 0.2 for 18 days; or 0.4 for 10 days. Clinical condition, feed consumption, and selected blood values were determined. Clinical signs of toxicosis included decreased feed consumption, slight-to-moderate loss of body weight, mucopurulent nasal discharge, dyspnea, coughing, lethargy, icterus, diarrhea (4 goats), and subnormal body temperature 24 to 48 hours before death. Clinicopathologic changes included increases in total RBC count, PCV, hemoglobin concentration, serum bilirubin concentration, and serum activities of aspartate aminotransferase, isocitric dehydrogenase, and ornithine carbamyl transferase. Goats given the 2 smaller dosage levels of AFB1 had slight increases of serum total protein (TP) concentration compared with control goats, but goats given the larger dosage levels of AFB1 initially had a slight decrease in TP. Aflatoxin had little effect on total WBC count. Serum alanine aminotransferase (ALT) activities in goats given the 2 larger dosage levels of AFB1 were similar to those of control goats, but goats given the smallest dosage level of AFB1 had increased serum ALT activities. Aflatoxin did not produce consistent dose-related changes in serum alkaline phosphatase activities. Seemingly, goats are susceptible to aflatoxin. Onset of clinical signs was dose-related. Onset and magnitude of increases in PCV, hemoglobin concentration, serum bilirubin concentration, and activities of serum aspartate aminotransferase, ornithine carbamyl transferase, and isocitric dehydrogenase were dose-related. Changes in TP and activities of serum ALT and alkaline phosphatase were neither dose-related nor were they potentially useful indicators of toxicosis.

Caprine aflatoxicosis: serum electrophoresis and pathologic changes

Pathologic changes and serum electrophoretic patterns were determined in 30 male goats given aflatoxin B1 (AFB1) orally at 4 dosage levels (mg/kg of body weight/day): 0.1 for 34 days; 0.2 for 18 days; 0.4 for 10 days; or 0.0 for 29 days. Goats given AFB1 had increased mean concentrations of gamma-globulins and most had decreased mean concentrations of beta-globulins, although these changes in serum proteins were not significant (P greater than 0.05). At necropsy, ascites, pale livers, petechial hemorrhages, nasal discharge, and icterus were present. Microscopic changes included bile ductule proliferation, hepatocytic karyomegaly, hepatocellular degeneration, pneumonia, rhinitis, and proximal renal tubular nephrosis. Goats given the 2 smaller dosage levels of AFB1 lived longer and had more severe lesions. Goats may be a good model for the study of ruminant aflatoxicosis.

Altered isozyme patterns of leucocyte alkaline phosphatase in disease states

Leucocyte alkaline phosphatase (LAP) is a granulocyte enzyme whose concentration varies in disease states. In order to determine whether the pattern of expression is altered in leukaemic granulocytes, we have analysed the LAP isozyme pattern of a series of normal subjects and patients with various haematological diseases. Electrophoretic patterns of partially purified LAP samples were determined by polyacrylamide gel electrophoresis in the presence of Triton X-100. These patterns were reproducible on repeated samples from the same patient. Presence of the LAPf and LAPs isozymes were determined after staining with the dye Fast Blue BB. Granulocytes were obtained from 15 normal subjects. Thirteen of these samples had only the LAPs isozyme. The other two had LAPs, plus a small amount (less than or equal to 10% of total) of LAPf activity. Eight patients with stable phase chronic myelogenous leukaemia (CML) had only small amounts of the normal LAPs isozyme and no evidence of LAPf . Of 11 patients with CGL who clinically had blast crisis. 10 had both LAPs and LAPf . The eleventh patient who was Ph1 negative had only LAPs. Three of five patients with polycythaemia vera had only the LAPs isozyme while two had both isozymes. Six patients with non-malignant leucocytosis had only LAPs. We interpret this data to indicate that the increased levels of LAP activity in some CGL blast crisis patients are primarily related to synthesis of the LAPf isozyme.

Hematologic and immunologic responses of Holstein calves to a fire ant toxicant

Holstein calves (3 to 5 months of age) were used to develop an animal model sensitive to environmental toxicants. In the present study, the fire ant toxicant AMDRO was fed (113.5 g/day/calf) to weanling castrated calves (9 test and 9 controls) for 7 weeks. As early as 14 days after the start of the AMDRO feeding, leukopenia was observed. Differential counts revealed significant non-transient decreases in lymphocytes and eosinophils. Eosinopenia was observed from days 21 to 49 of AMDRO treatment. Variability in hematocrit and hemoglobin values in treated and control calves precluded making a determination of trends due to toxicant exposure. The AMDRO treatment did not produce significant decreases in primary or secondary antibody responses to keyhole limpet hemocyanin or to Brucella abortus vaccination. It also did not produce suppression of cellular immunity, as determined by delayed-type hypersensitivity response to bacille Calmette-Guérin. Potential effects of AMDRO on thermoregulatory mechanisms were indicated by significant depressions of rectal temperature observed after 25, 32, and 39 days' treatment.

Transforming growth factor-beta controls receptor levels for epidermal growth factor in NRK fibroblasts

NRK fibroblasts exposed to transforming growth factor-beta (TGF-beta) show increased binding of radiolabeled epidermal growth factor (EGF) relative to untreated cells. The binding of another growth factor, rat insulin-like growth factor-II, is unaffected. The increase in EGF binding induced by TGF-beta is not due to inhibition of EGF processing nor to an alteration in the affinity of plasma membrane EGF receptors. However, treatment of the cells with TGF-beta does cause a rapid increase in the number of plasma membrane receptors for EGF. TGF-beta has little effect on the rate of overall protein synthesis, but the increase it induces in EGF binding can be completely inhibited by cycloheximide and tunicamycin. Thus a selective synthetic mechanism underlies TGF-beta action. Cells incubated with TGF-beta also show altered down regulation of their EGF receptors in response to the ligand; concentrations of EGF that can induce strong biological responses no longer decrease the plasma membrane receptor level below the basal state. These results agree well with the known specificity and synergism of the interaction between TGF-beta and EGF. Moreover, they describe a mechanism of growth control in which bioactive peptides act coordinately through a regulatory effect on the number of cell-surface receptors.

Rates of ligand binding to periplasmic proteins involved in bacterial transport and chemotaxis

The ligand reactions of three binding proteins involved in bacterial transport and chemotaxis have been examined by stopped flow, rapid mixing techniques. The processes measured were: L-arabinose, D-galactose, and D-fucose binding to the Escherichia coli L-arabinose-binding protein; L-histidine binding to the Salmonella typhimurium L-histidine-binding protein; and D-maltose, maltotriose, cyclic maltohexaose, and cyclic maltoheptaose binding to the E. coli D-maltose-binding protein. Changes in tryptophan fluorescence were monitored, and the resultant time courses were analyzed quantitatively in terms of a simple one-step binding process. The fitted association rate constants for sugar binding are all about 1-3 X 10(7) M-1 s-1; variation in the affinity constants is expressed primarily by changes in the dissociation rate constants, 1-100 s-1. The sugar-binding proteins react at equal rates with the alpha and beta anomeric forms of their substrates. The ligand dissociation rates measured in vitro are consistent with the corresponding Vmax values observed for in vivo active transport. The association rate constant for the L-histidine-binding protein is 5-10 times greater than the corresponding rate constants for the sugar-binding proteins. A similar, large bimolecular rate, approximately 1 X 10(8) M-1 s-1, has been observed for the E. coli L-glutamine-binding protein (Weiner, J. H., and Heppel, L. A. (1971) J. Biol. Chem. 246, 6933-6941) and appears to reflect favorable electrostatic interactions between the charged amino acid and the surface of the protein molecule.

Differential localization of two myosins within nematode thick filaments

The body wall muscle cells of the nematode, Caenorhabditis elegans, contain two unique types of myosin heavy chain, A and B. We have utilized an immunochemical approach to define the structural location of these two myosins within body wall muscle thick filaments. By immunofluorescence microscopy, myosin B antibodies label the thick filament-containing A-bands of body wall muscle with the exception of a thin gap at the center of each A-band, and myosin A antibodies react to form a medial fluorescent stripe within each A-band. The complexes of these monoclonal antibodies with isolated thick filaments were negatively stained and studied by electron microscopy. The myosin B antibody reacts with the polar regions of all filaments but does not react with a central 0.9 micron zone. The myosin A antibody reacts with a central 1.8 micron zone in all filaments but does not react with the polar regions.

Leukocyte alkaline phosphatase: another organ-specific alkaline phosphatase

We have used enzyme specific inhibitors and heat inactivation to distinguish Leukocyte alkaline phosphate (LAP) from other organ-specific alkaline phosphatases as well as to compare LAP from normal granulocytes and leukemic cells with elevated LAP. The heat inactivation and inhibition curves of LAP are quite different from those of other organ-specific alkaline phosphatases. The inhibition curves and heat inactivation characteristics of LAP from normal granulocytes and that obtained from chronic granulocytic leukemia (CGL) blast phase cells with elevated LAP are identical. These data suggest that LAP is distinct from other organ-specific alkaline phosphatases, particularly placental alkaline phosphatase. We also conclude that the LAP present in cells with elevated levels is very similar or identical to that of normal granulocytes.

Transforming growth factor-beta in human platelets. Identification of a major storage site, purification, and characterization

Acidic ethanol extracts of human platelets induced non-neoplastic normal rat kidney fibroblasts to undergo anchorage-independent growth. Less than 100 ng/ml of the crude extract elicits 50% of the maximal biological response when assayed in the presence of epidermal growth factor (2.5 ng/ml). In the absence of epidermal growth factor, the potency of the extract decreased 1,000-fold. These results show that platelets contain a type beta transforming growth factor. The specific activity of the platelet extract is 100-fold greater than that of other non-neoplastic tissues. The growth factor was purified to homogeneity by sequential gel filtration on Bio-Gel P-60 columns, first in the absence and then in the presence of urea. As determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, this transforming growth factor-beta is a protein of 25,000 daltons. It is composed of two 12,500-dalton subunits held together by disulfide bonds. These results, as well as its amino acid composition and its lack of strong mitogenic activity, show that this protein is distinct from platelet-derived growth factor. When completely purified, transforming growth factor-beta elicits 50% of its maximal biological response at concentrations less than 5 x 10(-12) M.

Comparison of the fresh gas flow requirements and resistance of the Preferential Flow System with those of the Magill system

The fresh gas flow requirements of the Preferential Flow System have been compared with those of the Magill system in spontaneously breathing volunteers and found to be similar. A lower resistance to expiration was found with the Preferential Flow System and the effectiveness of the valveless method of flow direction was demonstrated.

Progress in cerebrovascular disease: local cerebral blood flow by xenon enhanced CT

A noninvasive technique for measuring local cerebral blood flow (LCBF) by xenon enhanced x-ray transmission computed tomography (CT) has been developed an reported quite extensively in recent years. In this method, nonradioactive xenon gas in inhaled and the temporal changes in radiographic enhancement produced by the inhalation are measured by sequential computed tomography. Time dependent xenon concentrations within various tissue segments in the brain are used to derive both local partition coefficient (lambda) and LCBF. An assessment of this method reveals that although it provides functional mapping of blood flow with excellent anatomic specificity, there are distinct limitations. The assumptions underlying this methodology are examined and problems associated with various potential applications of this technique are discussed.

Aflatoxicol and aflatoxins B1 and M1 in the tissues of pigs receiving aflatoxin

Aflatoxicol (AFL) and aflatoxins B1 and M1 were found in tissues (kidney, liver, and muscle) of feeder pigs given an estimated LD50 oral dose of B1 (1.0 mg/kg body weight) provided as a rice culture of Aspergillus flavus and of market-weight pigs fed a naturally contaminated feed, containing aflatoxin B1 at a level of 400 ng/g from corn, for 14 days. The residues in all tissues decreased with time after treatment in both groups, with no detectable residues (approximate detection limits, ng/g, B1 0.03, M1 0.05, AFL 0.01) in pig tissues from the feeding experiment 24 h after withdrawal of aflatoxin-contaminated feed. B1 and M1, when found in the feeding experiment, were at about the same levels in all tissues except the kidney, in which M1 was the dominant aflatoxin. The level of AFL, when detected, was about 10% of the B1 level.

Acute aflatoxicosis in swine: clinical pathology, histopathology, and electron microscopy

Feeder pigs weighing 12 to 15 kg each were given a single oral dose of aflatoxin, 1.2 mg/kg of body weight. Liver-specific serum enzyme activities were compared with gross, microscopic, and ultrastructural hepatic changes in individual pigs euthanatized at 24, 48, and 72 hours after they were given aflatoxin. The greater the morphologic change in liver of the treated pigs, the greater the increase in liver-specific serum enzyme activities. Isocitric dehydrogenase, alkaline phosphatase, sorbitol dehydrogenase, and aspartate aminotransferase activities increased in 6 of 8 treated pigs by 24 hours. Increase in gamma-glutamyl transpeptidase activity was not significant. Microscopic and ultrastructural changes in centrilobular hepatocytes included glycogen deletion, mitochondrial and endoplasmic reticulum swelling, membrane disruption, and nuclear fragmentation at 24 hours. The centrilobular areas had marked extravasation of erythrocytes at 24 hours without basal lamina changes. At 72 hours, the centrilobular hepatocytes had increased lipid vacuoles and acceptable amounts of glycogen. Marked infiltrations of monocytes, plasma cells, and lymphocytes were also present at this time.

High performance liquid chromatographic determination and clearance time of aflatoxin residues in swine tissues

Liver, kidney, and muscle tissues from swine given a single oral dose of 1.2 mg aflatoxins/kg body weight and from young pigs fed an aflatoxin-contaminated diet (0,400, or 800 ng/g feed) for 10 weeks were analyzed for aflatoxin residues. Extraction was performed according to the method of Stubblefield and Shotwell. Aflatoxin residues were detected by high performance liquid chromatography (HPLC), and residue levels were correlated with withdrawal times. Residues were present in liver and kidney but not muscle by 12 h post-dosing; residues were detected in muscle by after 24 h. Residue levels decreased over the 72 h period in all tissues. No aflatoxin residues were detected in the muscle from any pig 72 h post-dosing or in those pigs fed the 400 ng/g diet, but were present in the muscle of pigs fed the 800 ng/g diet.

Anatomy of the cerebral ganglion in Oligacanthorhynchus tortuosa (Acanthocephala) from the opossum (Didelphis virginiana)

The anatomy of the cerebral ganglion from Oligacanthorhynchus tortuosa (Acanthocephala) resembles that previously described for large acanthocepalans from mammals. The cell population was equally distributed between each half of the ganglion, there were 38 cells on each side with seven cells centrally located. The core of the ganglion or neuropile occupied the central part of the ganglion and was the site for the crossover for many cell processes. Many of the axons from these cells exited from the side opposite the soma. The cell bodies predominated on the ventral surface while the dorsal surface was more of a mixture of cell bodies and neurites. The cytoarchitecture of these cells varied considerably but most had a large round nucleus with well-defined nucleoli. There were 83 cells, two of which were binucleate. The two binucleate cells were located at opposite extremes of the anteroposterior axis of the ganglion. The anterior binucleate cell was adjacent to the dorsal surface whereas the posterior cell was central and near the posterior terminal of the ganglion.

Experimental aflatoxicosis in swine: morphological and clinical pathological results

The morphological changes in livers of 30 feeder pigs fed diets containing corn contaminated by aflatoxins (0.0 microgram aflatoxins/g feed, 0.4 microgram aflatoxin/g feed, and 0.8 microgram aflatoxin/g feed) were compared with changes in hematology, liver specific serum enzymes, serum proteins, and lymphocyte stimulation indices. Histologically, the livers were classified into five groups. Pigs fed the 0.8 microgram/g diets had the most severe histological lesions of karyomegaly, bile ductule proliferation and hepatocellular degeneration plus elevated gamma-glutamyl transpeptidase, aspartate aminotransferase, and alkaline phosphatase. This group also had significantly lower total protein and albumin values compared to the control pigs. Variation in the severity of the histological lesions was seen in pigs fed 0.4 microgram/g diets as well as variation in lymphocyte indices, liver specific serum enzymes, and electrophoretic results in the affected pigs in that group.

Membrane potentials in an acanthocephalan worm (macracanthorhynchus hirudinaceus)

The resting membrane potential of the acanthocephalan rete system in Macracanthorhynchus hirudinaceus was -35 +/- 1.5 mV (n = 20) and was dependent upon the external potassium concentration. The membrane potential reached 0 mV when the external potassium concentration was 160 mM. Spontaneous spike potentials of 45 mV +/- 10 were dependent on calcium flux. The membrane potential was depolarized by acetylcholine, potassium-free medium, calcium ions and chloride-free medium but not by changes in the external sodium concentration. Spontaneous potentials were increased in number by acetylcholine and calcium at concentrations above 3 mM, but were decreased in number by chloride- and calcium-free medium. Hence the rete system potentials are very similar to smooth muscle potentials in many respects.

Fluorescence polarization immunoassay. II. Analyzer for rapid, precise measurement of fluorescence polarization with use of disposable cuvettes

This instrument, developed for quantitating fluorescence polarization immunoassays, automatically measures both polarization components and computes a polarization value corrected for background and optical bias. An electronically switched liquid crystal provides a nonmechanical means of rotating the plane of polarization in the excitation optics. The electronic design features digital integration and microprocessor controlled functions. Readings are made in disposable 12 X 75 mm round culture tubes. in less than 10 s. Results are precise to 0.001 polarization unit, linear from 10(-7) to 10(-10) mol of fluorescein per liter, and correlate well with those obtained with other "high-performance" instrumentation.

Fluorescence polarization immunoassay. II. Analyzer for rapid, precise measurement of fluorescence polarization with use of disposable cuvettes

This instrument, developed for quantitating fluorescence polarization immunoassays, automatically measures both polarization components and computes a polarization value corrected for background and optical bias. An electronically switched liquid crystal provides a nonmechanical means of rotating the plane of polarization in the excitation optics. The electronic design features digital integration and microprocessor controlled functions. Readings are made in disposable 12 X 75 mm round culture tubes. in less than 10 s. Results are precise to 0.001 polarization unit, linear from 10(-7) to 10(-10) mol of fluorescein per liter, and correlate well with those obtained with other "high-performance" instrumentation.