Iodothyronine deiodinase activity in methionine-deficient rats fed selenium-deficient or selenium-sufficient diets

We examined the effect of methionine deficiency on iodothyronine 5'-deiodinase activity in selenium-deficient rats or selenium-sufficient rats fed sodium selenate or selenomethionine. Forty-two weanling male Wistar rats were divided into six groups and pair fed the respective purified L-amino acid-based diets for 4 wk. L-methionine concentrations in the diet were 8.0 g/kg for sufficient rats, and 2.0 g/kg for deficient rats. Selenium concentrations in the diet were 0.5 mg/kg (as sodium selenate or selenomethionine) for selenium-sufficient rats and less than 0.005 mg/kg for selenium-deficient rats. Type I 5'-deiodinase activities were significantly lower in liver and higher in kidney of methionine-deficient rats than in those of methionine-sufficient rats fed either the selenium-sufficient or the selenium-deficient diets. The type I 5'-deiodinase activity in brain was significantly lower in the methionine-deficient rats than in the methionine-sufficient rats fed the selenium-deficient diet. Type II 5'-deiodinase activity in brain was significantly higher in the methionine-deficient rats than in the methionine-sufficient rats fed selenium-sufficient diet as sodium selenate. Both thyroxine and 3,3',5-triiodothyronine concentrations in plasma were significantly higher in the methionine-deficient rats than in the methionine-sufficient rats. It is suggested that the methionine deficiency affects the 5'-deiodinase activity and thyroid hormones level in the rats.

Transforming growth factor beta 1 modulates angiotensin II-induced calcium influx in vascular smooth muscle

The modulatory effects of transforming growth factor beta 1 (TGF beta 1) on the angiotensin II (Ang II)-induced increase in cytosolic free calcium concentration ([Ca2+]i) were investigated in vascular smooth muscle cells (VSMC) from spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto rats (WKY). [Ca2+]i in VSMC was measured using the fluorescent dye fura-2. When TGF beta 1 was applied 30s prior to Ang II, the Ang II-induced [Ca2+]i increase was significantly enhanced in VSMC from SHR (P < 0.05 compared to control), whereas after the preincubation with TGF beta 1 for 30 min, the Ang II-induced [Ca2+]i increase was significantly reduced in VSMC from both strains. Using the manganese-quenching technique, it was confirmed that short-term exposure to TGF beta 1 enhanced the Ang II-induced trans-plasma-membrane calcium influx in SHR. The inhibition of protein kinase C by calphostin C abolished the stimulatory effect of TGF beta 1 on the Ang II-induced [Ca2+]i increase. It is concluded that TGF beta 1 modulates the Ang II-induced calcium handling in VSMC.

Infection of cells by varicella zoster virus: inhibition of viral entry by mannose 6-phosphate and heparin

Envelope glycoproteins of varicella zoster virus (VZV) contain mannose 6-phosphate (Man6P) residues. We now report that Man6P competitively and selectively inhibits infection of cells in vitro by cell-free VZV; furthermore, dephosphorylation of VZV by exposure to alkaline phosphatase rapidly destroys infectivity. Cells are also protected from VZV in a concentration-dependent manner by heparin (ED50 = 0.23 micrograms/ml; 95% confidence limits = 0.16-0.26 microgram/ml) but not by chondroitin sulfate. Both heparin and Man6P are protective only when present about the time of inoculation. Heparin but not Man6P interferes with the attachment of VZV to cell surfaces; moreover, VZV binds to heparin-affinity columns. These data are compatible with a working hypothesis, whereby VZV attaches to cell surfaces by binding to a heparin sulfate proteoglycan. This binding stabilizes VZV, making possible a low-affinity interaction with another Man6P-dependent receptor, which is necessary for viral entry.

Inhibition of Epstein-Barr-virus-transformed human chronic lymphocytic leukaemic B cells with monoclonal-antibody-adriamycin (doxorubicin) conjugates

The anthracyclin antineoplastic agent doxorubicin (Adriamycin) was linked by four different methods of linkage to DalB02, an IgG1 kappa murine monoclonal antibody (mAb) against surface-associated antigens on human chronic lymphocytic leukaemia (CLL) B cells. All the four conjugates fully retained the immunoreactivity of the parent DalB02. When the inhibitory effect of these conjugates was evaluated in vitro against the target D10-1 cells (a clone derived from an Epstein-Barr-virus-transformed human CLL B cell line that binds DalB02) it was observed that one conjugate was more potent than the free drug but the others were not. When 131I-labelled unmodified DalB02 and the 131I-labelled DalB02-containing conjugate that was found to be potent were injected i.v. into nude mice bearing a subcutaneous D10-1 xenograft, the percentages of the injected dose (%ID) of both 131I-DalB02 and the 131I-DalB02-containing conjugate that localized in the tumour were much higher than the %ID of the respective preparations that localized in normal tissues of D10-1-xenografted mice. The systemic toxicity of the conjugate was less than that of the free drug. At an equitoxic dose level, this conjugate was a more effective inhibitor of established D10-1 xenografts than the free drug.

Uptake and distribution of sodium selenite in rat brain tumor

Eighteen weanling male Wistar rats with brain gliomas were divided into three groups, which received 0., 2.0, 5.0 ppm selenium (Se) in their drinking water. The accumulation and retention of selenium in the brain bearing tumor was investigated. Significantly higher concentrations of Se were observed in tumor tissue than normal brain tissue after exposure to sodium selenite. Tumors were observed in the 2.0 micrograms/g selenium group. The difference in selenium concentration between the tumor tissue and contralateral normal brain tissue was not influenced by the weight of brain or body, and water consumption. We observed that selenium accumulated in tumor tissue more than in normal brain tissue.

An exploratory study of arm-reach reaction time and eye-hand coordination

The study examined the time taken to reach and touch keys positioned both within and just outside the traditional reach envelope, as well as within and just outside the region of easy visibility, defined as being within a 30 degrees cone centered on the line of sight. Movements were required from a start key positioned in front of the subject to a response key positioned at one of 140 positions, defined by seven heights (from 360 to 1080 mm above the seat reference point (SRP), five angles (in vertical planes positioned from 30 degrees across the body to 90 degrees ipsilaterally) and four radii (from 200 mm closer to the body than the normal reach boundary to 100 mm further away than the normal reach boundary). The time taken was divided into detection time (the time from illumination of response signal to release of start key), and movement time (the time from release of start key to contact with response key). Results suggested that the visual cone should be extended downwards, as detection time increased rapidly to keys positioned outside the visual cone upwards, but not in the downwards direction. In general, responses to keys positioned anywhere that was both within the reach envelope and also within the visual cone took approximately the same time, from 371 to 420 ms. Movement time increased with distance moved, but disproportionately so, up to 595 ms, when movement was required to positions that were at one or more of the extremes of height, angle or radius.

[Storage temperature and skin xenograft survival]

Pieces of guinea pig skin, 0.3-0.4mm in thickness, 1.5cm in diameter, were stored at different temperatures. The skin fragments were divided into five groups: (1) fresh skin; (2) skin stored at 4 degrees C for 48hr; (3) skin stored at -20 degrees C for 48hr; (4) skin stored at -80 degrees C for 48hr; (5) skin stored at -196 degrees C for 48hr. The cryoprotective agent was the same in all groups except group 2. The experimental skin was grafted on both sides of the back of anesthetized mice, two pieces of skin of the same group for one mouse. The grafted skin survival was determined by daily observation. The skin was considered as rejected if necrosis took place in 80% of the grafted skin. Grafted skin biopsy was performed for pathological examination. The results showed that the survival days of stored skin xenografts were prolonged as the stored temperature lowered. The pathological changes (neutrophil infiltration, thrombosis of small vessels, necrosis of epidermal and dermal cells) were mild and delayed as the stored temperature lowered. So low temperature may decrease the antigenicity of the stored skin.

[Establishment of three-dimensional finite element models by using a series of plane section images processed with an image analysis system]

The geometric similarity and mesh dividing of finite element models directly create an effect on the results of analysis when a theoretical stress analysis is performed by the use of finite element method. The model is routinely established by means of sectioning the specimen. In this paper, a series of plane section CT images of the teeth and mandible, an image analysis system and a specially designed software for modeling three-dimensional finite element were used to establish a three-dimensional finite element model. It is a new preprocessing method for finite element applications in the field of oral biomechanism. The technique is characterized by the advantages of high similarity of the model to specimens and no damage to specimens; it is simple and easy. The images and figures can be repetitively used.

Effect of extracellular Mg2+ concentration on agonist-induced cytosolic free Ca2+ transients

The modulating effects of extracellular Mg2+ concentration ([Mg2+]o) on vascular contraction are well known. In the present study it was tested how the changes in cytosolic free Ca2+ concentration ([Ca2+]i) induced by various agonists are modified by changes in [Mg2+]o. Extracellular Mg2+ deprivation increased the [Ca2+]i response to arginine vasopressin, to angiotensin II and to thapsigargin, but not to 5-hydroxytryptamine and noradrenaline. Withdrawal of extracellular Ca2+ revealed that extracellular Mg2+ deprivation increased Ca2+ influx, but not Ca2+ release from cellular stores. The findings demonstrate that different responses of [Ca2+]i to agonists may underlie the modulating effect of [Mg2+]o on vascular contraction.

Nonlinear behavior of a liquid containing uniform bubbles: comparison between theory and experiments

Bubbles oscillating at resonance frequency dramatically enhance nonlinearity of a bubbly liquid. A second-order nonlinear wave equation taking account of bubble pulsation is solved. Numerical calculations based on the equation are compared favorably with experimental results. Possible biological significance of the highly nonlinear medium is also discussed.

U.S. farm women's participation in breast cancer screening practices

BACKGROUND

Surveys of women in the general population indicate that women are being screened for breast cancer at a much lower rate than recommended. There has been a concern that women living in rural areas may be screened for breast cancer even less often than women in urban or suburban areas because of reduced access to health practitioners.

METHODS

A random sample of farm women age 40 years or older from 4 rural counties in Michigan was surveyed on knowledge, attitudes, and use of breast cancer screening.

RESULTS

Six hundred eighty farm women completed a questionnaire. This was a response rate of 63.8%. The percentages of farm women who reported ever having had a mammogram, having had a mammogram in the past 3 years, and having had a mammogram in the last year were 80.6, 73.7, and 51.9%, respectively. The frequency of clinical breast examinations parallelled mammography usage at slightly higher percentages. Mammogram usage increased with higher education, income, and insurance coverage. Usage decreased in women age 75 years or older (ever 63.1%, in the last 3 years 58.2%, and in the last year 40.4%). Farm women were generally knowledgeable about symptoms and signs of breast cancer and understood the benefit of screening. There was, however, a range of answers on when to start or stop having a mammogram. Among farm women who reported not having a mammogram recently, the most important reasons were: haven't had any problems (29.4%), wasn't recommended by a doctor (14.3%), and procrastinated (11.3%).

CONCLUSIONS

Farm women in this survey reported having had breast cancer screening at rates similar to or above those in the general population. Because of a limited response rate (63.5%) and the relative affluence of the farming community in the 4 counties surveyed, these results are probably not generalizable to all populations of farm or rural women.

Pneumoconiosis and associated medical conditions

Hospital discharge data from Michigan for the years 1990 and 1991 were used to examine potential associations between pneumoconiosis and pulmonary hypertension, lung cancer, obstructive lung disease, and connective tissue disease among both men and women. Lung cancer, pulmonary hypertension, and obstructive lung disease were associated with coal workers' pneumoconiosis. Pulmonary hypertension and obstructive lung disease were associated with asbestosis and silicosis. Rheumatoid arthritis was associated with silicosis. The potential is suggested that misdiagnosis is the cause of the association between lung cancer and coal workers' pneumoconiosis.

Respiratory rate and signs in roentgenographically confirmed pneumonia among children in China

A clinical study was conducted in three Chinese community hospitals to investigate the reliability of respiratory rate and various clinical signs in the diagnosis of pneumonia among 54 children less than 5 years of age. Anteroposterior chest film was used as the diagnostic standard. The cutoff criterion for rapid breathing was 50 breaths/minute for infants ages 2 to 11 months and 40/minute in children 1 to 5 years old. Rapid breathing was a better predictor of pneumonia than rales (positive predictive values of 74.5 and 66.9%). Nasal flaring, chest indrawing, stridor and cyanosis of the tongue had predictive values of > 86%, but these clinical signs were observed in only a small proportion of patients. We recommend that village health workers use rapid breathing for diagnosis of pneumonia, rather than auscultation which is difficult and has proved unreliable. Sensitivity, specificity and positive and negative predictive values are presented for seven signs and symptoms of pneumonia.

Mammography usage and knowledge about breast cancer in a Michigan farm population before and after an educational intervention

The purpose of this study was to identify factors associated with the use of mammography screening in a farm population, before and after a community-based educational intervention. The educational intervention included sending individual mailings containing information about breast cancer risk and community sources for screening, and providing information and screening at local county fairs and agricultural community fairs. The authors used multivariate analytic methods to analyze the responses, reported by 1,545 women, to discern the roles of sociodemographic, attitudinal, and knowledge variables in this population's breast cancer screening practices. Results showed that the rural participants in both the intervention and the control communities demonstrated significant changes in knowledge and attitudes about breast cancer. Mammography usage was significantly higher among women who had higher scores on the knowledge and awareness assessments. Education--rather than income, insurance coverage, or family history of breast cancer--emerged in multivariate analyses as the most significant predictor of knowledge and awareness score levels associated with greater use of mammography. Implications of this study include support for education that emphasizes the benefits of early detection of breast cancer for all women.

Intracellular localization of the herpes simplex virus type 1 major transcriptional regulatory protein, ICP4, is affected by ICP27

Infected-cell protein 4 (ICP4) is the major transcriptional activator of herpes simplex virus (HSV) gene expression during productive infection. ICP0 has broad transactivating activity for all classes of HSV genes as well as cellular genes and genes of heterologous viruses. Together, the transactivating activities of ICP4 and ICP0 are synergistic. ICP27, which alone does not exhibit major transregulatory activity, is able to differentially activate and repress viral gene expression induced by ICP4 and ICP0. Thus, ICP27 plays a modulatory role in viral gene expression. In order to explore the functional relationships among ICP4, ICP0, and ICP27 in the regulation of viral gene expression, we have used indirect immunofluorescence to examine the intracellular localization of ICP4 in cells infected with wild-type virus or with mutant viruses that did not express functional forms of ICP0 or ICP27. Although ICP4 localized to both the nuclei and cytoplasm of cells infected with either the wild-type virus or an ICP0 null mutant virus, this protein was present exclusively in the nuclei of cells infected with an ICP27 null mutant virus, suggesting that ICP27 is able to inhibit the nuclear localization of ICP4 during virus infection. Transient expression assays with pairs of plasmids that express wild-type forms of ICP4 and ICP0 or of ICP4 and ICP27 demonstrated that ICP27 has a significant inhibitory effect on the nuclear localization of ICP4, confirming the observations made with the mutant-virus-infected cells. By using a plasmid expressing wild-type ICP4 and a series of ICP27 mutant plasmids in transient expression assays, the C-terminal half of ICP27 was shown to be required for its inhibitory effect on the nuclear localization of ICP4. In similar studies using a series of ICP4 mutant plasmids, the region of ICP4 responsive to wild-type ICP27 was mapped to the C-terminal portion of the molecule between amino acid residues 820 and 1029. The level of expression of ICP27 was shown to have a significant effect on the intracellular localization of ICP4 in transient assays. These findings are consistent with previous studies in which ICP27 was shown to have an inhibitory effect on the nuclear localization of ICP0 (Z. Zhu, W. Cai, and P. A. Schaffer J. Virol. 68:3027-3040, 1994). Thus, ICP27 has a significant inhibitory effect on the ability of the two major HSV type 1 (HSV-1) regulatory proteins to localize to the nucleus. Collectively, these findings indicate that cooperative regulation of HSV-1 gene expression may well involve intracellular compartmental constraints.

[The effects of different storage temperatures on epidermal Langerhans cells]

The skin from fresh human cadavers and guinea pigs was stored in 4 degrees C, -20 degrees C, -80 degrees C and -196 degrees C deep freezing for six different periods (1, 2, 3, 5, 7 and 14 days). The number and morphology of Langerhans cells (LC) were observed using Juhlin's ATP-ase dye method. It was found that the epidermal LC of cryopreserved skin decreased significantly in number, and there was a marked change in shape, as compared with fresh skin grout (P < 0.01), except for those in 4 degrees C groups (for 1, 2, 3 days). The mean value of LC in -196 degrees C group, which was 40%-50% of that of fresh skin, was the lowest among all the groups. The number of LC dropped most rapidly in the -196 degrees C group after one day freezing. The changes in LC in the stored skin may play an important role in prolongation of rejection time after transplantation.

Tumor localization and therapeutic potential of an antitumor-anti-CD3 heteroconjugate antibody in human renal cell carcinoma xenograft models

A heteroconjugate (HC) antibody, constructed with the monoclonal antibody (MoAB) Dal K29 to human renal cell carcinoma (RCC) and an anti-CD3 MoAb, could induce a very high level of lysis of human RCC cells when incubated with human peripheral blood lymphocytes (PBL) in vitro (Kerr et al., 1990, J. Immunol., 144, 4060-4067). We now report that this HC antibody selectively localizes in RCC xenografts in nude mice and could inhibit RCC in an ascites tumor xenograft model when administered intraperitoneally together with PBL.

Intracellular transport of newly synthesized varicella-zoster virus: final envelopment in the trans-Golgi network

The maturation and envelopment of varicella-zoster virus (VZV) was studied in infected human embryonic lung fibroblasts. Transmission electron microscopy confirmed that nucleocapsids acquire an envelope from the inner nuclear membrane as they enter the perinuclear-cisterna-rough endoplasmic reticulum (RER). Tegument is not detectable in these virions; moreover, in contrast to the mature VZV envelope, the envelope of VZV in the RER is not radioautographically labeled in pulse-chase experiments with [3H]mannose, and it lacks gpI immunoreactivity and complex oligosaccharides. This primary envelope fuses with the RER membrane (detected in cells incubated at 20 degrees C), thereby releasing nucleocapsids to the cytosol. Viral glycoproteins, traced by transmission electron microscopy radioautography in pulse-chase experiments with [3H]mannose, are transported to the trans-Golgi network (TGN) by a pathway that runs from the RER through an intermediate compartment and the Golgi stack. At later chase intervals, [3H]mannose labeling becomes associated with enveloped virions in post-Golgi locations (prelysosomes and plasma membrane). Nucleocapsids appear to be enveloped by wrapping in specialized cisternae, identified as the TGN with specific markers. Tegument-like material adheres to the cytosolic face of the concave surface of TGN sacs; nucleocapsids adhere to this protein, which is thus trapped between the nucleocapsid and the TGN-derived membrane that wraps around it. Experiments with brefeldin A suggest that tegument may bind to the cytosolic tails of viral glycoproteins. Fusion and fission convert the TGN-derived wrapping sacs into an inner enveloped virion and an outer transport vesicle that carries newly enveloped virions to cytoplasmic vacuoles. These vacuoles are acidic and were identified as prelysosomes. It is postulated that secreted virions are partially degraded by their exposure to the prelysosomal internal milieu and rendered noninfectious. This process explains the cell-associated nature of VZV in vitro; however, the mechanism by which the virus escapes diversion from the secretory pathway to the lysosomal pathway in vivo remains to be determined.

Radioimmunotherapy of human B-cell chronic lymphocytic leukemia in nude mice

After i.v. or i.p. inoculation of 5 x 10(6) D10-1 cells, a subclone of an Epstein-Barr virus transformed human B-cell chronic lymphocytic leukemia (CLL) line, 100% of nude mice developed solid or ascites tumors and died within 17-60 days of tumor inoculation. There was significant tumor inhibition, including tumor cure, when these tumor-inoculated mice were treated with either unmodified or 131I (300 microCi)-linked Dal B02 (50 micrograms/mouse), a monoclonal antibody directed against surface-associated antigens on human CLL B-cells and several histological types of B-lymphoma cells. There was no significant difference between the antitumor activity of unmodified Dal B02 and 131I-linked Dal B02 when the treatment was given 3 days after i.p. or i.v. inoculation of 5 x 10(6) D10-1 cells. However, when the mice were treated 3 days after i.p. inoculation of 15 x 10(6) D10-1 cells, or 7 days after the i.v. inoculation of 5 x 10(6) D10-1 cells, 131I-linked Dal B02 was a more potent tumor inhibitor than was unmodified Dal B02 (P < 0.05 and P < 0.01, respectively). Two injections of 131I (500 microCi) linked to 100 micrograms of a Dal B02 F(ab')2 fragment preparation also prolonged the survival of i.p. or i.v. tumor-inoculated mice (P < 0.05 and P = 0.05, respectively). In nude mice with established s.c. xenografts of D10-1 cells, two injections of 131I (300 microCi) linked to 50 micrograms of Dal B02 led to complete tumor cure in 3 of 4, mice, but two injections of 50 micrograms of unmodified Dal B02 had no effect on the s.c. xenografts. Two injections of 131I (500 microCI) linked to 100 micrograms of Dal B02 F(ab')2 fragment caused significant tumor inhibition but no tumor cure. 131I (300 microCi) linked to 50 micrograms of a nonspecific IgG1 only led to minor tumor inhibition. A mixture of unmodified Dal B02 and 131I-linked nonspecific IgG1 was not a more potent tumor inhibitor than the 131I-linked nonspecific IgG1 preparation by itself. These results suggest that Dal B02 may be an effective carrier for the radioimmunotherapy of human B-cell CLL and other appropriate B-cell lymphomas, especially in the progressive phase of B-cell CLL, which is usually not amenable to currently available therapeutic modalities.

[Antigenic changes in skin after cryopreservation]

It is well accepted impression that antigenic properties of skin are lowered after cryopreservation. In order to prove it, this experiment was done. Fresh guinea pig and cadaveric skin homogenates with appropriate adjuvants were injected hypodermically separately to rabbits once a week. Five week later, blood was withdrawn from rabbits, thus anti-guinea pig skin serum (AGS) and anti-cadaveric skin serum (ACS) were obtained. Homogenates of fresh guinea pig skin (FG) and guinea pig skin stored at -196 degrees C (SG), homogenates of fresh cadaveric skin (FC) and cadaveric skin stored at -196 degrees C (SC) were used as antigens. Microimmunoelectrophoresis and rocket immunoelectrophoresis were performed between related antigens and antibodies. The results of microimmunoelectrophoresis showed that there were four dense and wide precipitated are lines in AGS vs FG and ACS vs FC groups, while only two light and thin precipitated are lines in AGS vs SG and ACS vs SC groups. Rocket immunoelectrophoresis showed that the rocket precipitated area in AGS vs FG and ACS vs FC groups are larger (longer in axis, and broader in width) than in AGS vs SG and ACS vs SC groups. The antigenicity of skin is lowered after being stored at -196 degrees C as compared with that of the fresh one as shown by electrophoresis method.

Captopril inhibits the agonist-induced increase of cytosolic free Ca2+ in glomerular mesangial cells

To evaluate the underlying mechanism of the putative renal protective effects of angiotensin converting enzyme (ACE) inhibitors, the modulatory action of captopril on the angiotensin II (Ang II) and platelet-derived growth factor (PDGF)-induced increase of cytosolic free calcium concentration ([Ca2+]i) was investigated in cultured glomerular mesangial cells (MC) from spontaneously hypertensive rats from the Münster strain (SHR) and normotensive Wistar-Kyoto rats (WKY). Resting [Ca2+]i was not affected by captopril in MC from either SHR or WKY. Captopril inhibited the Ang II-induced [Ca2+]i increase in MC from both SHR and WKY in a dose-dependent and time-dependent fashion. The preincubation of MC with 1 mumol/liter captopril for 40 minutes significantly reduced the Ang II-induced [Ca2+]i increase in SHR from 167 +/- 30 nmol/liter (N = 17) to 74 +/- 20 nmol/liter (N = 8, P < 0.05) and in WKY from 102 +/- 42 nmol/liter (N = 14) to 43 +/- 12 nmol/liter (N = 7, P < 0.05). After removal of external calcium there was no significant effect of captopril on the Ang II-induced [Ca2+]i increase. With the Mn2+ quenching technique, it was confirmed that captopril affects Ca2+ influx. Phospholipase C activity as estimated by diacylglycerol formation was not changed by captopril. The preincubation of MC with 1 mumol/liter captopril for 40 minutes significantly reduced the PDGF-induced [Ca2+]i increase in SHR from 166 +/-54 nmol/liter (N = 9) to 31 +/- 19 nmol/liter (N = 6, P < 0.01) and in WKY from 127 +/- 31 nmol/liter (N = 11) to 61 +/- 32 nmol/liter (N = 5, P < 0.05). Similarly captopril reduced the [Ca2+]i increase induced by endothelin and vasopressin. The results indicate that the actions of Ang II and PDGF on MC are modulated by captopril, probably resulting in the impairment of the calcium dependent contractile response of mesangial cells.

Effect of Na,K-ATPase inhibition on cytosolic free calcium ions in vascular smooth muscle cells of spontaneously hypertensive and normotensive rats

OBJECTIVE

To investigate the role of Na(+)-Ca2+ exchange in the regulation of cytosolic free Ca2+ and the pathogenesis of primary hypertension.

METHOD

Cytosolic free Ca2+ ([Ca2+]i) in cultured vascular smooth muscle cells from normotensive and spontaneously hypertensive rats of the Münster strain was measured using the fluorescent dye fura-2 after inhibition of Na+,K+ATPase by ouabain and after addition of angiotensin II.

RESULTS

[Ca2+]i showed a rapid increase together with a depolarization of membrane potential as measured by merocyanine 540. The ouabain-induced increase in [Ca2+]i was blocked in Ca(2+)-free medium and by nifedipine, but incubation with the inhibitor of the Na(+)-Ca2+ exchange, NiCl2, did not diminish the effect of ouabain. Likewise, in Na(+)-free medium the response to ouabain was not suppressed. The angiotensin II-induced changes in [Ca2+]i were diminished in Ca(2+)-free medium and by nifedipine, but enhanced by NiCl2.

CONCLUSION

The increase in [Ca2+]i after Na+,K+ ATPase inhibition is not due to a modulation of Na(+)-Ca2+ exchange, but to a Ca2+ influx through Ca2+ channels. Changes in Na(+)-Ca2+ exchange caused by Na+,K+ ATPase inhibition may not play an important role in vascular smooth muscle cells of spontaneously hypertensive rats.

Mechanism of the action of angiotensin-converting enzyme inhibitors on agonist-induced Ca2+ influx

To evaluate the direct effects of the angiotensin-converting enzyme (ACE) inhibitors, captopril, enalaprilat, enalapril (a prodrug without therapeutically significant ACE inhibitory effect) and ramiprilat, on cellular calcium metabolism, the cytosolic free calcium concentration was measured in cultured rat vascular smooth muscle cells using the fluorescent dye, fura-2. Preincubation with captopril, enalaprilat, enalapril, or ramiprilat for 40 min significantly reduced the angiotensin II-induced transplasma membrane calcium influx but did not influence the angiotension II-induced calcium release from internal stores. Captopril and ramiprilat also inhibited arginine vasopressin, but not the thapsigargin-, norepinephrine-, or the BayK 8644-induced changes in cytosolic calcium. Phorbol 12-myristate 13-acetate pretreatment for 30 s caused an increase in the angiotensin II-induced rise in cytosolic calcium. Although both captopril and verapamil reduced responses to angiotensin II to similar extents, only verapamil blocked the ability of phorbol 12-myristate 13-acetate to enhance responses to angiotensin II. It is concluded that ACE inhibitors modulate the effects of some but not all agonist-induced transplasma membrane calcium influx.

Directly labeled DNA probes using fluorescent nucleotides with different length linkers

Directly labeled fluorescent DNA probes have been made by nick translation and PCR using dUTP attached to the fluorescent label, Cy3, with different length linkers. With preparation of probes by PCR we find that linker length affects the efficiency of incorporation of Cy3-dUTP, the yield of labeled probe, and the signal intensity of labeled probes hybridized to chromosome target sequences. For nick translation and PCR, both the level of incorporation and the hybridization fluorescence signal increased in parallel when the length of the linker arm is increased. Under optimal conditions, PCR yielded more densely labeled probes, however, the yield of PCR labeled probe decreased with greater linear density of labeling. By using a Cy3-modified dUTP with the longest linker under optimal conditions it was possible to label up to 28% of the possible substitution sites on the target DNA with reasonable yield by PCR and 18% by nick translation. A mechanism involving steric interactions between the polymerase, cyanine-labeled sites on template and extending chains and the modified dUTP substrate is proposed to explain the inverse correlation between the labeling efficiency and the yield of DNA probe synthesis by PCR.

Optical threshold-decomposed Boolean-based gray-scale filter

Because of the advances made in optical technology, an extension can be made from the well-known stack filter to a new kind of gray-scale filter by using arbitrary Boolean functions instead of positive Boolean functions in the second step of a three-step process. Applications of these threshold-decomposed Boolean-based gray-scale filters in image processing include image smoothing and feature detection. A general optical implementation approach of nonlinear threshold-decomposed Boolean-based gray-scale filters is also described that utilizes area coding, gray scale correlation and lookup table thresholding techniques. Some experimental results are demonstrated.

Sequential proton resonance assignments and metal cluster topology of lobster metallothionein-1

NMR studies of 111Cd6-MT 1 from lobster have been conducted to determine coordination structure of Cd-thiolate binding in the protein. Sequential proton resonance assignments were made using standard two-dimensional 1H NMR methods. Two-dimensional 1H-111Cd HMQC experiments were then carried out to determine the cadmium-cysteine connectivities in the protein. With this information, it was established that the six Cd ions exist in two different Cd3S9 clusters, each involving three bridging and six terminal thiolate ligands. Sequential cysteines in the sequence provide the sulfhydryl ligands for each cluster and do not overlap, as has been found in mammalian metallothionein. Comparison of the N-terminal, Cd3S9 B-type cluster of lobster MT 1 with the Cd3S9 cluster from rabbit MT 2 shows that while eight of the nine cysteine residues occupy homologous positions in their sequences, three of the 12 Cd-thiolate connectivities are different. Similarly, the C-terminal B-cluster of lobster MT 1 was compared with the Cd4S11 cluster of mammalian MT 2, excluding the two terminal cysteine sulfhydryl groups that convert this cluster from A- to B-type. As above, eight of nine cysteine positions are identical, yet five of 12 Cd-sulfhydryl connections are different. These differences are expanded when the role of each cysteine as bridging or terminal ligands in the clusters is considered.

Immunoreactivity, stability, pharmacokinetics and biodistribution of a monoclonal antibody to human leukemic B cells after three different methods of radioiodination

Dal B02, a murine monoclonal antibody against human chronic lymphocytic leukemia (CLL) was radioiodinated using chloramine T (Chl.T), Bolton-Hunter (B-H) or N-succinimidyl-p-iodobenzoate (PIB). The preparations had comparable radiochemical purity (> 97%) and immunoreactive fraction (65-80%) but the Chl.T-based product was most susceptible to deiodination and loss of immunoreactivity. After i.v. injection into CLL-xenografted nude mice, the preparations had identical patterns of clearance from the blood but the PIB-based product led to more radioactivity in liver and spleen and less in the thyroid compared to the other preparations. The Chl.T-based product showed loss of immunoreactivity in circulation and less tumor-localized radioactivity 168 h after administration. The differences between the B-H-based and PIB-based products were less impressive than between PIB-based and Chl.T-based products.

[Biochemical analysis of protein homogenates in skin stored at different temperatures]

The amount and constitution of protein, its ultraviolet photo-absorption ability, and the amount of esterase of homogenates of cadaver, guinea pig and mouse skin, which were stored under various temperatures of 4 degree C, -20 degree C, -80 degree C and -196 degree C, were assayed by using ultraviolet spectrophotometer and polyacrylamide gel electrophoresis. The results show that there are changes in various degree in biochemical components of skin protein and esterase after being stored at different temperatures as compared with fresh skin.

Reduced cytosolic free sodium concentration in vascular smooth muscle cells from spontaneously hypertensive rats

1. Cytosolic free sodium concentration and sodium transport systems were measured in intact cultured vascular smooth muscle cells from spontaneously hypertensive rats of the Münster strain and from normotensive Wistar-Kyoto rats using the sodium-sensitive fluorescent dye sodium-binding benzofuran isophthalate. 2. Resting cytosolic free sodium concentration was significantly lower in vascular smooth muscle cells from spontaneously hypertensive rats than from Wistar-Kyoto rats (10.2 +/- 1.5 mmol/l, n = 26, versus 19.4 +/- 2.5 mmol/l, n = 20, P < 0.01). 3. Inhibition of Na+, K(+)-ATPase by ouabain caused a dose-dependent increase in cytosolic free sodium concentration in spontaneously hypertensive rats and Wistar-Kyoto rats. 4. Activation of Na(+)-Ca2+ exchange by ionomycin increased cytosolic free sodium concentration in both strains. However, the ionomycin-induced increase in cytosolic free sodium concentrations was significantly higher in vascular smooth muscle cells from spontaneously hypertensive rats than from Wistar-Kyoto rats (220 +/- 35% of the resting cytosolic free sodium concentration versus 148 +/- 27%; P < 0.05). The ionomycin-induced increase in cytosolic free sodium concentration was prevented in the absence of external sodium or by inhibition of Na(+)-Ca2+ exchange by NiCl2. 5. Activation of Na(+)-H+ exchange by intracellular acidification of vascular smooth muscle cells with propionic acid increased cytosolic free sodium concentration in each strain (19.6 +/- 5.7 versus 16.3 +/- 3.2 mmol/l). 6. It is concluded that concepts concerning the role of cytosolic free sodium concentration in the pathogenesis of primary hypertension need to be reinvestigated.(ABSTRACT TRUNCATED AT 250 WORDS)

Over-representation of the disease associated (CAG) and (CGG) repeats in the human genome

Expansion of trimer repeats has recently been described as a new type of human mutation. Of the 64 possible trimer compositions, only the CGG and CAG repeats have been implicated in genetic diseases. This study intends to address two questions: (1) What makes the CGG and CAG repeats unique? (2) Could other trimer repeats be involved in this type of mutation? By computer analysis of trimer and hexamer frequency distributions in approximately 10 Mb of human DNA, twenty trimer motifs (ten complementary pairs) have been identified that are the most likely to be expanded. The frequency distribution study also indicated that the expanded trimer motif in Fragile-X syndrome is GGC instead of CGG. DNA linguistics studies revealed that the GGC/GCC and CAG/CTG repeats were over-represented in the human genome. Further analysis of base composition suggested that the CCA/TGG repeats may be involved in the trimer expansion mutation since they possessed many similar characteristics to GGC/GCC and CAG/CTG. The computer aided sequence analysis studies reported here may help to understand the molecular mechanisms of trimer repeat expansion.

Cooperativity among herpes simplex virus type 1 immediate-early regulatory proteins: ICP4 and ICP27 affect the intracellular localization of ICP0

The results of transient expression assays and studies of viral mutants have shown that three of the five immediate-early proteins of herpes simplex virus type 1 (HSV-1) perform regulatory functions, individually and cooperatively. As part of efforts designed to explore the molecular basis for the functional cooperativity among ICP0, ICP4, and ICP27 in the regulation of HSV gene expression, we have examined the intracellular localization of ICP0 in cells infected with ICP4 and ICP27 null mutant viruses by indirect immunofluorescence. Although ICP0 was localized predominantly to the nuclei of wild-type virus-infected cells, it was found exclusively in the nuclei of ICP27 mutant-infected cells and in both the cytoplasm and nuclei of ICP4 mutant-infected cells, the cytoplasmic component being especially strong. These observations indicate that both ICP4 and ICP27 can affect the intracellular localization of ICP0. Transient expression assays with plasmids that express wild-type and mutant forms of ICP0, ICP4, and ICP27 confirmed that ICP4 promotes and that ICP27 inhibits the nuclear localization of ICP0. These results confirm the observations made for mutant virus-infected cells and indicate that the localization pattern seen in infected cells can be established by these three immediate-early proteins exclusive of other viral proteins. The C-terminal half of ICP27 was shown to be required to achieve its inhibitory effect on the nuclear localization of ICP0. The region of ICP0 responsive to ICP27 was mapped to the C terminus of the molecule between amino acid residues 720 and 769. In addition, the concentration of ICP27 was shown to have a significant effect on the intracellular localization of ICP0. Because the major regulatory activities of ICP0, ICP4, and ICP27 are expressed in the nucleus, the ability of these three proteins collectively to determine their own localization patterns within cells adds a new dimension to the complex process of viral gene regulation in HSV.

Different calcium storage pools in vascular smooth muscle cells from spontaneously hypertensive and normotensive Wistar-Kyoto rats

OBJECTIVE

To evaluate whether the distribution of intracellular free calcium may be impaired in primary hypertension.

DESIGN

Cytosolic free calcium and stored calcium were investigated in cultured vascular smooth muscle cells from spontaneously hypertensive rats (SHR).

METHODS

The concentrations of intracellular and stored calcium were investigated in cultured vascular smooth muscle cells from spontaneously hypertensive rats aged 6 months from the Münster strain (SHR) and from age-matched normotensive Wistar-Kyoto (WKY) rats. Vascular smooth muscle cells were grown on coverslips, and fluorescence measurements of the intracellular calcium concentration were performed using fura-2. The different effects of thapsigargin, a selective Ca-ATPase inhibitor, and of angiotensin II (Ang II) on the calcium storage pools were investigated.

RESULTS

In the absence of external calcium thapsigargin produced a dose-dependent transient increase in the concentration of intracellular calcium in vascular smooth muscle cells. The thapsigargin-induced maximum peak increase in the concentration of intracellular calcium was not significantly different in SHR and WKY rats. After depletion of the thapsigargin-sensitive calcium pools the addition of 100 nmol/l Ang II produced a rise in the concentration of intracellular calcium in vascular smooth muscle cells from SHR and WKY rats. Using vascular smooth muscle cells from the SHR the Ang II-induced increase in the concentration of intracellular calcium was not significantly different in the presence and absence of thapsigargin, indicating that the calcium pools depleted by thapsigargin and Ang II do not overlap significantly in vascular smooth muscle cells from SHR. In contrast, in the WKY rats the response to Ang II was significantly diminished after depletion of the thapsigargin-sensitive pool. When Ang II and thapsigargin were administered in the reverse order, i.e. Ang II before thapsigargin, the thapsigargin response was diminished in the WKY rats but not in the SHR.

CONCLUSION

SHR differ from WKY rats in having vascular smooth muscle cells that contain thapsigargin-sensitive calcium storage pools that are distinct from the Ang II-sensitive calcium pools.

Mechanisms of heterologous agonist-stimulated phosphorylation of cholecystokinin receptor

The phosphorylation of one receptor that occurs as a result of the stimulation of a different receptor on a cell is a common mechanism for heterologous regulation or "cross-talk," which has been implicated in desensitization. In this work, we focus on the mechanisms of phosphorylation of the rat pancreatic acinar cell cholecystokinin (CCK) receptor that occur upon stimulation of this cell by various agonists. Phosphorylation was allowed to occur in dispersed intact acinar cells in response to the experimental manipulation, and the phosphoreceptor was subsequently purified and quantified as an indication of response. Agonists such as vasoactive intestinal polypeptide and secretin, which act via activation of adenylate cyclase, had no effect on CCK receptor phosphorylation, whereas carbamylcholine and bombesin stimulated increased phosphorylation of the CCK receptor. Because these agents would be expected to activate protein kinase C (PKC) as well as a number of calcium-sensitive kinases and phosphatases, these activities were further dissociated by using more direct activators and inhibitors acting intracellularly. Manipulation of calcium independent of PKC by using a calcium ionophore, inhibition of calcium/calmodulin-dependent kinase II, and inhibition of calcium-dependent protein phosphatase type 2B had no effect on the state of CCK receptor phosphorylation.(ABSTRACT TRUNCATED AT 250 WORDS)

Role of Na(+)-Ca2+ exchange in agonist-induced changes in cytosolic Ca2+ in vascular smooth muscle cells

Changes in cytosolic free calcium concentration ([Ca2+]i) induced by angiotensin II (ANG II), arginine vasopressin (AVP), angiotensin III (ANG III), norepinephrine (NE), or thapsigargin were investigated after inhibition of the Na(+)-Ca2+ exchange in vascular smooth muscle cells (VSMC) from Wistar-Kyoto rats by use of the fluorescent dye technique. The ANG II-induced peak [Ca2+]i increase was significantly enhanced after inhibition of Na(+)-Ca2+ exchange by NiCl2 or 1,3-dimethyl-2-thiourea (DMTU): control, 99 +/- 9 (SE) nM (n = 64); NiCl2, 181 +/- 23 nM (n = 23; P < 0.01); DMTU, 182 +/- 35 nM (n = 10; P < 0.05). In the absence of external calcium, the inhibition of the Na(+)-Ca2+ exchange by NiCl2 also enhanced the ANG II-induced [Ca2+]i increase. Inhibition of Na(+)-Ca2+ exchange by removal of external sodium, which was replaced by choline, augmented the ANG II-induced [Ca2+]i increase to 174 +/- 26 nM (n = 11; P < 0.05 compared with control). The inhibition of the protein kinase C activity by isoquinoline-sulfonyl-O-2-methylpiperazine blocked the enhancing effect of NiCl2 on ANG II-induced [Ca2+]i increase. The inhibition of the Na(+)-Ca2+ exchange did not enhance the increase in [Ca2+]i induced by ANG III, NE, or thapsigargin. The AVP-induced changes in [Ca2+]i were not significantly different in the presence or absence of NiCl2. It is concluded that the recovery of resting [Ca2+]i after stimulation by ANG II is mediated by calcium efflux via the Na(+)-Ca2+ exchange.(ABSTRACT TRUNCATED AT 250 WORDS)

Inhibition of human B-cell chronic lymphocytic leukemia by a monoclonal antibody in xenograft models

To establish xenograft models of human B-cell chronic lymphocytic leukemia (CLL), we inoculated 5 x 10(6) D10-1 cells, a subline of Epstein-Barr virus (EBV)-transformed human B-cell CLL with a marker chromosomal anomaly, into SCID or irradiated nude mice by the intravenous (i.v.) or intraperitoneal (i.p.) route. All i.p. tumor-inoculated mice developed rapidly progressive, lethal ascites tumor, and 100% of i.v. tumor-inoculated mice developed disseminated CLL. All mice died of tumor within 8 weeks of tumor inoculation. Tumor-inoculated SCID mice died earlier with wider tumor dissemination than the tumor-inoculated nude mice. All the tumor-inoculated mice had histologically confirmed metastases in lymph nodes, and most of them also had metastases in one or more internal organs. Cytogenetic analysis confirmed the origin of these tumors from the xenografted D10-1 cells. The D10-1 cells harvested from the xenografts did not differ from the parent D10-1 cells as regards (i) reactivity with 2 monoclonal antibodies (MAbs) directed against CLL-associated cell-surface antigens; (ii) rate of proliferation in vitro; and (iii) sensitivity to the 2 chemotherapeutic agents, methotrexate and adriamycin. Administration of 50 micrograms/mouse of Dal B02, an IgG1 (kappa) MAb directed against surface-associated antigens of human B-cell CLL, significantly prolonged the survival of D10-1-inoculated nude and SCID mice. The MAb was more effective in D10-1-inoculated nude mice than in SCID mice. In all the D10-1 xenograft models, the effectiveness of Dal B02 decreased with higher tumor load but increased with the amount of MAb injected. Dal B02 F(ab)'2 fragment failed to demonstrate any anti-tumor activity in D10-1-inoculated nude mice. In vitro assays revealed that Dal B02 had no direct inhibitory effect on D10-1 cells, but could be cytotoxic towards D10-1 cells in the presence of splenic cells or peritoneal macrophages from nude and SCID mice, or together with rabbit complement.

Pharmacokinetics, biodistribution and tumor localization of two anti-human B-cell chronic lymphocytic leukemia monoclonal antibodies and their F(ab)'2 fragments in a xenograft model

We investigated the pharmacokinetics, biodistribution and tumor localization of intravenously injected Dal B01 and Dal B02, two monoclonal antibodies (MoAbs) directed against tumor associated antigens on human chronic lymphocytic leukemia (CLL) B cells, and their F(ab)'2 fragments in nude mice bearing xenografts of the human B cell CLL line D10-1. More of the percentages of the injected dose (% ID) of these two MoAbs and their F(ab)'2 fragments specifically localized in the tumor xenografts than in normal tissues. Compared to intact MoAbs, their F(ab)'2 fragments had lower % ID in tumors and were cleared from circulation faster. Well-defined tumor images were obtained at 24 and 48 h after administration of [131I]Dal B02 F(ab)'2 fragment and at 96-192 h after administration of [131I]Dal B02. A comparison between intravenous and intraperitoneal routes of administration of [131I]Dal B02 did not reveal any difference in the localization of % ID in tumor or normal tissues.

Effect of genetically determined host factors on the efficacy of vidarabine, acyclovir and 5-trifluorothymidine in herpes simplex virus type 1 infection

The susceptibility of Herpes simplex virus (HSV) to acyclovir (ACV), 5-trifluorothymidine (TFT) and vidarabine (Ara-A) in HSV-infected embryo fibroblasts from BALB/c and C57BL/6 mice as well as Vero cells were measured. Ara-A and TFT (at its highest concentration) were more effective in Vero cells and BALB/c mouse embryo fibroblasts (MEF) than in C57BL/6 MEF. In contrast, ACV was more effective in C57BL/6 MEF than BALB/c MEF and Vero cells. These data suggest that genetically determined differences in the ability of host cells to support the replication of HSV influence the activity of antiviral drugs.

Selection of antisense oligonucleotides on the basis of genomic frequency of the target sequence

Antisense oligonucleotides (ASOs) are capable of blocking the expression of targeted genes and are potential antitumor and antiviral therapeutic agents. The specificity of ASO gene inhibition is compromised when homology to other sequences allows the selected ASO to bind to nontargeted mRNAs. To reduce this nonspecific activity, an ASO should target a sequence that is predicted to be unlikely to occur in other mRNAs. The probability of a sequence being unique can be predicted by determining the genomic frequency of short stretches of sequences contained within the target sequence. Two computer programs, OLIGOMER and HEXAGRAPH, were developed for this analysis. OLIGOMER was used to analyze the genomic frequencies of di-, tri-, and hexamers in more than 24 million nucleotides from 8 different genomes in GenBank. A mathematical model was developed that predicts the genomic frequency of longer oligomers on the basis of the observed frequencies of shorter oligomers. The second program, HEXAGRAPH, was used to graphically display the genomic frequency data of a selected target gene. The computational tools developed in this study may help to design more efficient ASOs by decreasing their nonspecific binding activity.

Effect of captopril on vasoconstriction and Ca2+ fluxes in aortic smooth muscle

The effects of captopril on the response of cytosolic free Ca2+ concentration in cultured vascular smooth muscle cells of aortas from Wistar-Kyoto and spontaneously hypertensive rats to angiotensin II (Ang II) and bradykinin were studied using fura 2. Incubation with captopril for longer than 10 minutes caused a decreased response of cytosolic free Ca2+ to Ang II and bradykinin. Maximal effects of captopril were observed after a 40-minute incubation. The inhibitory effect of captopril was abolished in Ca(2+)-free medium, suggesting that captopril acts by blocking Ca2+ influx. Similar effects were observed with enalaprilat. Isometric contraction of aortic strips induced by Ang II in normotensive rats was reduced from 6.5 +/- 2.5 to 1.8 +/- 0.6 mN by a 40-minute incubation with 1 mumol/L captopril (P = .016). Enalaprilat similarly decreased the Ang II-induced contraction. Besides the inhibition of the angiotensin converting enzyme, direct effects of Ang II converting enzyme inhibitors on vascular contraction and Ca2+ influx in vascular smooth muscle cells may be of therapeutic relevance.

Concentration-dependent effects of insulin on Ca2+ influx in vascular smooth muscle cells of normotensive and spontaneously hypertensive rats

1. The effect of insulin on cytosolic free Ca2+ concentration was measured using fura-2 in vascular smooth muscle cells of normotensive and spontaneously hypertensive rats. 2. In both strains, insulin increased cytosolic free Ca2+ concentration in a concentration range between 10(-6) and 10(-3) units/ml. The maximum increase in cytosolic free Ca2+ concentration was observed with 10(-5) units/ml insulin (107 +/- 25 and 82 +/- 27 nmol/l in spontaneously hypertensive rats and normotensive rats, respectively). 3. The effect of insulin was dependent on extracellular Ca2+ and was enhanced by stimulation of protein kinase C. 4. Thus insulin appears to induce a Ca2+ influx in vascular smooth muscle cells only over a certain range of concentrations. No significant difference in the response to insulin of cells from normotensive and hypertensive rats was observed.

Hormonal replacement therapy in fish:human growth hormone gene function in hypophysectomized carp

Transgenic common carp,Cyprinus carpio, produced by the microinjection of fertilized eggs with a linearized chimeric plasmid pMThGH, a human growth hormone (hGH) gene with a mouse metallothionein-1 (MT) gene promoter in pBR322, were used to produce F1 and F2 transgenics. Following hypophysectomy of the transgenic F2 common carp, non-transgenic common carp and non-transgenic crucian carp, growth was monitored for up to 110 days. In addition, recombinant hGH was injected subcutaenously into a group of the non-transgenic crucian carp. Growth rate analyses indicated that (1) hypophysectomy of non-transgenic common carp and crucian carp results in the cessation of growth, (2) hGH administration can stimulate the growth of hypophysectomized crucian carp and (3) hypophysectomized hGH-transgenic common carp continue to grow in the absence of their own growth hormone, suggesting that the hGH-transgene is being expressed in tissues other than the pituitary.

Optical cellular continuous logic array for gray-scale image processing

A new optical cellular continuous-logic array for gray-scale image processing is presented. The array involves two steps of multichannel neighborhood ranked-order operations and interimage threshold decomposition continuous-logic operation. Image processing transforms available from this array include gray-scale morphological transforms, stack-nonstack filters, and gray-scale hit-or-miss transforms. An area-coding technique is used to implement neighborhood operations in a correlation thresholding system. A similar one-channel grayscale-correlation and multithresholding system is used for interimage threshold decomposition continuous logic. Primary experimental results are given.

A gas monitoring system for ethylene oxide sterilizers with constant sample flow through a microwave cavity spectrometer

This paper reports a measurement system for monitoring the gas concentrations of ethylene oxide (EO) within sterilizers. It samples gas from the sterilizer chamber at a constant flow into a microwave cavity spectrometer. The pressure in the cavity of the spectrometer is linearly proportional to that in the sterilizer chamber, hence the partial pressure (i.e. gas concentration) of the EO gas is linearly proportional to that in the chamber. Measurement of the gas concentration in the chamber can therefore take place without the need to monitor and interpret the chamber pressure. As a consequence the reliability of the sterilization process may be improved, thus enabling a reduction in the in-chamber concentration of EO during sterilization and, hence, EO residues. The microwave cavity spectrometer operates under conditions of power saturation, and there is a good linear correlation between the output signal and the concentration of EO in the gas cell (to within a standard error of 4%).

Mineral status in selenium-deficient rats compared to selenium-sufficient rats fed vitamin-free casein-based or torula yeast-based diet

To clarify the mineral status in selenium (Se)-deficient rats fed a vitamin-free casein (VFC)-based or torula yeast (TY)-based diet, 24 weanling male Wistar rats were divided into 4 groups fed diets using VFC or TY as the protein source and containing Se at sufficient (0.5 microgram/g, +Se) or deficient (0.019 microgram/g for VFC-based and < 0.005 microgram/g for TY-based diets, -Se) level for 8 wk. TY supplied a larger amount of extra minerals (Na, K, Ca, Mg, Fe, Mn, Zn, and Cu) except Se than VFC. Se concentration and glutathione peroxidase activity were significantly lower in TY-fed rats than in VFC-fed rats, as well as in -Se rats compared to +Se rats. Compared to +Se rats, Fe concentration was higher in liver and muscle of -Se rats fed the VFC-based diet and in plasma, heart, liver, and tibia of -Se rats fed the TY-based diet. Compared to +Se rats, decreases of Mn concentration appeared in plasma, heart, and tibia of VFC-fed -Se rats and in brain, heart, liver and tibia of TY-fed -Se rats. There was also a little imbalance in Ca, Mg, Na, K, and Cu caused by Se deficiency. The results indicated that Se deficiency induced the mineral imbalance in rats, especially an increase in Fe and decrease in Mn, which was more severe in TY-fed rats than VFC-fed rats. However, TY cannot be used as a model for both Se and other mineral deficiency because of the extra minerals except Se found in TY. Instead, VFC can be employed, which contains fewer minerals except Se than TY and also can produce a severe degree of Se deficiency.

Selenium concentration and glutathione peroxidase activity in selenium and magnesium deficient rats

To clarify the effects of selenium (Se) and magnesium (Mg) deficiencies on Se and glutathione peroxidase (GSHPx) status, weanling male Wistar rats weighing 50-60 g were placed on four kinds of diets divided by two levels of Se (0.5 or 0.019 mg/kg) and Mg (500 or 50 mg/kg) for 8 wk. Magnesium deficiency had an influence on distribution of Se, which was increased in muscle and decreased in other tissues. The changes in GSHPx matched those in Se. The levels of Se and GSHPx in most tissues were lower in Se-Mg-deficient rats than in Se-deficient rats. Thus, selenium and Mg deficiencies would make oxidant lesion more serious than Se deficiency.

Effects of protein kinase C activation on intracellular Ca2+ distribution in vascular smooth muscle cells of spontaneously hypertensive rats

Protein kinase C is known to influence contraction in vascular smooth muscle cells by Ca(2+)-dependent and Ca(2+)-independent mechanisms. In the present study, the effect of protein kinase C activation by phorbol 12-myristate 13-acetate on resting cytosolic free Ca2+ and on cellular Ca2+ pools was assessed in cultured rat aortic muscle cells using fura 2. Cellular Ca2+ pools were evaluated with the selective inhibitor of the sarcoplasmic Ca2+ ATPase, thapsigargin. In normotensive vascular smooth muscle cells, protein kinase C activation caused a redistribution of Ca2+ from the thapsigargin-sensitive pool into the cytoplasm, whereas, in hypertensive cells, no significant effect of protein kinase C activity on cellular Ca2+ distribution was found. It is concluded that protein kinase C modulates the amount of Ca2+ stored in the thapsigargin-sensitive calcium stores. In hypertensive cells, the regulation of Ca2+ pools by protein kinase C is disturbed.