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Purpose The aim of the present study was to investigate the effect of glutathione ethyl ester (GSH‐OEt) in the recovery medium on the developmental competence of mouse vitrified‐warmed MII oocytes. Methods Vitrified‐warmed oocytes were incubated for 1 h in recovery medium in the presence or absence of 0.5 mM GSH‐OEt. The authors examined the effects of GSH‐OEt, first on the levels of glutathione (GSH) and reactive oxygen species (ROS) in vitrified‐warmed oocytes, and second, on in vitro blastocyst development, division speed to blastocysts, and total cell numbers of blastocysts from vitrified‐warmed oocytes fertilized by Intracytoplasmic sperm injection (ICSI). Results Adding GSH‐OEt to the recovery medium significantly (p

Our aim is to clarify the association of the bioelectrical impedance-derived 50-kHz phase angle (φ50 ) with electrical parameters regarding the Cole-Cole model and clinical parameters. A total of 440 sets of bioelectrical impedance data from pre- and post-hemodialysis from 157 patients were used. Resistance at infinite frequency (Rinf ), resistance at 0 frequency (R0 ), capacitance of the cell membrane (Cm), and a parameter for the distribution of the time constant (α) were examined as electrical parameters. Normally hydrated lean tissue mass as a percentage of the dry weight (PNHLT ), excess fluid mass as a percentage of the dry weight (PExF ), body mass index (BMI), age, and sex (Nsex , 0 for male, 1 for female) were examined as clinical parameters. φ50 increased with the decrease in Rinf /R0 and α and also with the increase in Cm (multiple regression coefficients [β]: pre/post, -0.886/-0.936, -0.175/-0.212, and 0.167/0.141), which determined the ratio of intra- to extracellular fluid volume (ICV/ECV), tissue homogeneity, and total cell mass. φ50 increased with an increase in PNHLT and BMI and decrease in PExF , Nsex , and age (β: pre/post, 0.654/0.581, 0.466/0.412, -0.483/-0.473, -0.216/-0.154, and -0.145/-0.127). The concordance correlation coefficient between φ50 for pre- and post-hemodialysis (ρ = 0.772) may be improved (ρ = 0.950) by adding a multiplication of 0.2 and PExF to φ50 for correction. φ50 may be used to estimate body composition through the association with ICV/ECV, tissue homogeneity, and total cell mass. The correction for excess fluid is essential in order to use φ50 as a marker of body composition related to nutrition.

We investigated shifts in growth rates and cell size reduction-restoration processes in two species of diatoms, Skeletonema japonicum and Skeletonema dohrnii. Growth rates greatly fluctuated from 1.0 to 2.1 per day, even under the same conditions. Rates increased from 1.1 to 2.1 per day with decreasing valve diameter; however, rates quickly decreased to 1.0 per day when cell size reached the threshold for initiating auxosporulation. We also conducted co-culture experiments using different size combinations of the two species. The experiment was started using the same cell densities (75 cells · mL-1 ) of both species, and when batch cultures reached late exponential phase, the cultures were reinoculated twice into new medium. When large (valve diameter of 17 μm) S. japonicum cells and small (6 μm) S. dohrnii cells were co-cultured, the S. dohrnii contributed 99% of the total cell density on day 16 (S. dohrnii: 263,900 cells · mL-1 ; S. japonicum: 2,000 cells · mL-1 ). In contrast, when small (9 μm) S. japonicum cells and large (15 μm) S. dohrnii cells were co-cultured, small S. japonicum cells accounted for 97% of the total cell density after only 13 d (S. dohrnii: 1,900 cells · mL-1 ; S. japonicum: 62,500 cells · mL-1 ). This study demonstrated that diatom growth rates covary with cell size, and this phenomenon potentially determines the outcome of competition between species.

The monitoring and control of bioprocesses is of the utmost importance in order to provide a consistent, safe, and high-quality product for consumers. Current monitoring and control schemes rely on infrequent and time consuming offline sampling methods, which inherently leads to some variability in the process which may impact the product quality profile. As part of Lonza's dedication to process analytical technology (PAT) initiatives this study evaluated the ability to generate generic calibration models, which are independent of the cell line, using Raman probes to monitor changes in glucose, lactate, glutamate, ammonium, viable cell concentration (VCC), total cell concentration (TCC) and product concentration. Calibration models were developed from cell culture using two different CHOK1SV GS-KOTM cell lines producing different monoclonal antibodies (mAbs). Developed predictive models, measured changes in glucose, lactate, ammonium, VCC, and TCC with average prediction errors of 0.44, 0.23, 0.03 g L-1 , 1.90 × 106 cells mL-1 , and 1.85 × 106 cells mL-1 , respectively over the course of cell culture with minimal cell line dependence. The development of these generic models allows the application of spectroscopic PAT techniques in clinical and commercial manufacturing environments, where processes are typically run once or twice in GMP manufacturing based on a common platform process. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 34:730-737, 2018.

Contents The purpose of this study was to investigate the effect of seminal plasma (SP) from bulls of known fertility on bovine endometrial epithelial cells (bEEC) in culture. The bEEC from passage 5, approximately 5.0–13 × 105 cells per flask, were challenged with SP from bulls of high or low fertility (n = 3 and 2, respectively) or PBS (control), at 1% (75 μl) or 4% (300 μl) and were incubated for 72 hr (n = 13 per challenge). Total cell number and viability of bEEC after challenge with 1% SP from either high- or low-fertility bulls (75H or 75L, respectively) did not differ from controls. In contrast, challenge with 4% of SP from high- or low-fertility bulls (300H or 300L) negatively affected bEEC cell number and viability. Challenge with 300 L had a greater adverse effect than 300H. These results suggest that the negative effect of bovine SP on bEEC is both dose-dependent and fertility-dependent.

Wheat bran and rice bran were concentrated in terms of dietary fiber and were dephytinized by two different methods (fermentation and hydrothermal). Untreated, concentrated, concentrated-dephytinized by fermentation method, and concentrated-dephytinized by hydrothermal method bran samples were each incorporated into flour at levels of 0, 10, 15, and 20%, and their effects on bread properties were investigated. Unprocessed wheat bran and rice bran addition decreased the volume yield, and the specific volume of the bread depends on the incorporation level. A further decrease was observed with the addition of concentrated bran. However, the dephytinization treatments slightly improved these values. The same pattern was observed for the total number of cells and the total cell area of bread crumbs. Both wheat bran and rice bran were observed to cause a darker crumb color, and the effects of bran samples on crumb color were more pronounced after the dephytinization treatment. The addition of concentrated wheat bran and rice bran significantly increased hardness, as well as decreasing springiness, cohesiveness, and resilience of the bread, depending on the bran levels. Although dephytinization treatments enhanced the textural properties of bread, these results were still inferior to those obtained using bread produced with untreated bran. Regarding the dephytinization treatments, the influence of fermentation treatment on bread properties was slightly beneficial compared to hydrothermal treatment.Consumption of dietary fiber offers a range of health benefits. Cereal bran has great potential as a dietary fiber source. However, this bran's high phytic acid content and adverse effects on bread quality limit that potential. It is possible to obtain high dietary fiber and low phytic acid bran samples through bran concentration and dephytinization treatments. The dephytinization treatment is an effective method for degradation of phytic acid. The negative effects of wheat bran and rice bran on bread quality decreased significantly following the dephytinization treatments. This study demonstrated that fiber-enriched bread with low phytic acid content and acceptable texture can be produced using concentrated and dephytinized bran.

An adult human retinal pigment epithelial layer (ahRPE) model derived from stem cells isolated from native RPE monolayers (ahRPE-SCs) exhibits key physiological characteristics of native tissue and therefore provides the means to create a human "disease in a dish" model to study RPE diseases. Traditionally, RPE lines are established from whole globes dedicated to research. Here we describe a new technique for establishing primary RPE lines from the posterior poles of globes used for corneal transplants. Since tissues from corneal transplants are derived from younger and healthier donors than those used for research, we have hypothesized that RPE cells isolated from corneal transplantation globes will result in improved primary RPE line establishment. Our new procedure increases the rate of establishing successful RPE cultures and improves the total cell number yield. Use of this advanced methodology can provide a new source of high-quality primary RPE line cultures. © 2018 by John Wiley & Sons, Inc.

Marijuana (cannabis sativa), a schedule 1 drug has been recently approved by some of states in the US for its therapeutic benefit. Although few reports discuss about its anti-cancer potential, curr...

Background Rapid and precise measurement of total and differential nucleated cell counts is a crucial diagnostic component of cavitary and synovial fluid analyses. Objectives The objectives of this study included (1) evaluation of reliability and precision of canine and equine fluid total nucleated cell count (TNCC) determined by the benchtop Abaxis VetScan HM5, in comparison with the automated reference instruments ADVIA 120 and the scil Vet abc, respectively, and (2) comparison of automated with manual canine differential nucleated cell counts. Methods The TNCC and differential counts in canine pleural and peritoneal, and equine synovial fluids were determined on the Abaxis VetScan HM5 and compared with the ADVIA 120 and Vet abc analyzer, respectively. Statistical analyses included correlation, least squares fit linear regression, Passing–Bablok regression, and Bland–Altman difference plots. In addition, precision of the total cell count generated by the VetScan HM5 was determined. Results Agreement was excellent without significant constant or proportional bias for canine cavitary fluid TNCC. Automated and manual differential counts had R2

Objective The aim of this work was to evaluate the biofilm formation of Porphyromonas gingivalis on disks of titanium (Ti) grade 4 (G4) and Ti-6Al-4V alloy grade 5 (G5) with different surface topographies. Materials and methods Porphyromonas gingivalis ATCC 33277 was used to develop an in vitro mature biofilm on a total of 96 disk-shaped specimens of laser-treated (L), sandblasted (S), and machined (M) surfaces of Ti G4 and Ti G5. Surface roughness (Ra) and the wettability contact angle (WCA) were measured to characterize the surface of the specimens. The bacterial biofilm was evaluated by biomass quantification, bacterial viability, visualization of the biofilm extracellular matrix, and bacterial cell count. Data were analyzed using one-way ANOVA and Holm–Sidak tests and expressed as mean ± standard deviation. Results The Ra for the L group was 0.10 (±0.07) μm inside the craters and 0.40 (±0.08) μm in the area surrounding the craters resulting the smoothest (P

The aim of this study was to estimate the total number of Sertoli and Leydig cells in testes from male subjects across the human lifespan, using an optimized stereological method for cell-counting. In comparison with many other organs, estimation of the total cell numbers in the testes is particularly sensitive to methodological problems. Therefore, using the optical fractionator technique and a sampling design specifically optimized for human testes, we estimated the total number of Sertoli and Leydig cells in the testes from 26 post mortem male subjects ranging in age from 16 to 80 years. The mean unilateral total number of Sertoli cells was 407 × 10(6) [range: 86 × 10(6) to 665 × 10(6) , coefficient of variation (CV) = 0.33], and the mean unilateral total number of Leydig cells was 99 × 10(6) (range: 47 × 10(6) to 245 × 10(6) , CV = 0.48). There was a significant decline in the number of Sertoli cells with age; no such decline was found for Leydig cells. Quantitative stereological analysis of post mortem tissue may help understand the influence of age or disease on the number of human testicular cells.

In the present study, we examined the development to blastocysts of large and small blastomeres from unevenly cleaved 2-cell embryos (uneven 2-cell embryos) in pigs. Proportion of blastocysts derived from large blastomeres (52.8 ± 6.4%) was significantly higher (P

The osmotic responsiveness of cell water has been re-evaluated of reports on the osmotic behaviour of cells. In seven animal cell types, the osmotically unresponsive water (OUR) fraction values ranged from 0.75 to 2.41 g water/g dry mass (g/g), and from 25 to 92% of the total cell water. Protein confirmation, aggregation and crowding play a major, but under-recognised, role in determining the extent of OUR and the regulation of cell volume. Volume regulation studies that do not take into account the role of OUR must be judged incomplete.

Summary Background The diagnosis of non-alcoholic fatty liver disease (NAFLD), non-alcoholic steatohepatitis (NASH) and fibrosis relies on liver biopsy. Non-invasive assessments are urgently needed. Aim To evaluate cell apoptotic marker cytokeratin-18 M30 and total cell death markers cytokeratin-18 M65/M65ED for the assessment and monitoring of NAFLD. Methods A cohort of 147 patients with biopsy-proven NAFLD and 73 controls were enroled, including 51 patients who received paired liver biopsies 36 months apart. Biomarkers were determined by enzyme-linked immunosorbent assay. Results M30, M65 and M65ED increased in a stepwise fashion in control subjects, patients with non-NASH, NAFLD and NASH (all P

Summary Introduction: Cerebrospinal fluid (CSF) cell counts are traditionally performed by manual microscopy using the Fuchs–Rosenthal counting chamber. This procedure is time-, labour- and cost-intensive and requires experienced laboratory staff. Methods: The Sysmex XE-5000 haematology analyzer offers a channel to quantify the total cell count of body fluids. We compared technical sensitivity and specificity, intra-assay variability, turn-around time (TAT) and costs for the determination of CSF cell counts between both methods. Results: The mean coefficients of variation (CV) for total cell counts in CSF of the Fuchs–Rosenthal chamber and the XE-5000 were 15.2% (range: 2.8–47.5%) and 12.5% (range: 1.9–50.6%). Setting the Fuchs–Rosenthal chamber as ‘gold standard’, our results revealed a sensitivity of 100% and a specificity of 75% for the XE-5000 to detect a pathological cell count (≥6 cells/μL), whereas the sensitivity and specificity to detect a severely pathological cell count (≥20 cells/μL) were 100% for both. Bland and Altman analysis revealed slightly higher cell counts with the XE-5000. The approximate duration of a single CSF cell count analysis was 635 s for the manual vs. 85 s for the automated method. Total analytical performance costs for the counting chamber were 6.74 EUR per mean analysis and 1.22 EUR for the XE-5000. Conclusion: Our study revealed a lower mean CV for the total cell count for the XE-5000 method. The fully automated CSF cell count results in a 7.5-fold reduction in TAT and leads to a significant decrease in total analytical performance costs.

Summary Plasma volume (PV) and red-cell volume (CV) were determined using Evans blue dye (T-1824) and 51Cr-labelled erythrocytes, respectively, before splenectomy in five horses and, in four of them, once to three times post-operatively. The red-cell volume determined in this way (CVCr) was compared with the corresponding red-cell volume (CVEB) calculated from PV and venous haematocrit before and after intravenous adrenalin injection. After splenectomy, CVCr and CVEB coincided both basally and after adrenalin injection. This also occurred in the intact state after adrenalin, whereas CVEB was much lower than CVCr during basal conditions with the spleen in situ. The difference between the total (CVCr) and the circulating cell volume (CVEB) amounted to more than half the available red-cell mass. This “non-circulating” part of the cell volume was accumulated in the spleen, since splenectomy abolished the difference between CVCr and CVEB. As this difference was obliterated by intravenous injection of adrenalin in the intact horse, a total mobilization of the stored erythrocytes must have occurred. There was no indication that other organs or tissues took over the erythrocyte-storing function during the first ten post-splenectomy months. The size of the splenic red-cell reservoir seemed to be dependent on the total cell volume and on the net splenic weight but independent of body-weight. The weight of the exsanguinated spleen was correlated to the total cell volume, but, independent of body-weight. More than half the splenic weight was due to the blood content. The mean time required for complete distribution was considerably longer for the labelled cells than for the dye. It was markedly reduced to about the same value for both indicators by splenectomy. The externally registered activity of 51Cr over the site of the spleen decreased notably from a relatively high level within 2–4 minutes after adrenalin injection in the intact horse and then increased gradually, reaching the initial level in about 15–25 minutes. After splenectomy the initial activity was much lower and unaffected by adrenalin injection. Zusammenfassung Der Einflus der Splenektomie auf den Blutkreislauf II. Einflus auf das Plasmavolumen und das totale zirkulierende Erythrozytenvolumen Plasmavolumen (PV) und Erythrozytenvolumen (CV) wurden mittels Evans blue (T-1824) und 51Cr-markierten Erythrozyten bestimmt, und zwar bei 5 Pferden vor der Milzexstirpation und bei 4 Pferden dieser Gruppe ein bis 3mal nach der Operation. Das so erhaltene Erythrozytenvolumen (CVCr), wurde mit dem entsprechenden Erythrozytenvolumen (CVEB), berechnet aus dem PV und dem venosen Haematokrit, vor und nach intravenoser Adrenalininjektion verglichen. Nach Splenektomie stimmten CVCr und CVEB sowohl in Ruhe wie auch nach Adrenalingabe uberein. Mit der Milz in situ traf dies ebenfalls nach Adrenalingabe zu, wahrend aber vor der Adrenalingabe CVEB viel tiefer als CVCr war. Die Differenz zwischen totalem (CVCr) und dem stromenden (CVEB) Zellvolumen betrug bis mehr als die Halfte der verfugbaren Masse der Erythrozyten. Dieser „nicht stromende” Teil des Zellvolumens wurde in der Milz angehauft, da Splenektomie den Unterschied zwischen CVCr und CVEB aufhebt. Da diese Differenz ebenfalls bei intravenoser Injektion von Adrenalin verschwand, muste eine totale Mobilisierung der eingelagerten Erythrozyten stattgefunden haben. Es gab keinen Hinweis, das andere Organe oder Gewebe die erythrozytenspeichernde Funktion der Milz wahrend der ersten 10 Monate nach Splenektomie ubernahmen. Die Grose des Erythrozytenreservoirs der Milz schien vom gesamten Zellvolumen und vom Milzgewicht, nicht aber vom Korpergewicht abhangig zu sein. Das Gewicht der entbluteten Milz war mit dem gesamten Zellvolumen, aber nicht mit dem Korpergewicht, korreliert. Mehr als die Halfte des Milzgewichts war dem Blutgehalt zuzuschreiben. Der Mittelwert fur die gleichmasige Verteilung war fur die markierten Zellen betrachtlich langer als fur den Farbstoff. Durch die Milzexstirpation wurde er fur beide Indikatoren auf ungefahr denselben Wert reduziert. Die auf der Korperoberflache festgestellte Aktivitat des 51Cr uber der Milz nahm beim intakten Pferd nach Adrenalininjektion innerhalb 2–4 Min. stark ab und stieg anschliesend sukzessive wieder an und erreichte den Ausgangswert nach ungefahr 15–25 Min. Nach Splenektomie war die Ausgangsaktivitat deutlich geringer und durch Adrenalingabe nicht beeinflusbar. Resume Influence de la splenectomie sur la circulation sanguine II. Influence sur le colume plasmatique et le volume erythrocytaire circulant total On determine le volume du plasma (PV) et le volume des globules rouges (CV) a l'aide d'une coloration au bleu d'Evans (T-1824) et d'un marquage des erythrocytes au 51Cr, chez cinq chevaux avant splenectomie et chez quatre d'entre eux 1 a 3 fois apres splenectomie. Le volume erythrocytaire ainsi obtenu (CVCr) est compare au volume erythrocytaire correspondant (CVEB) (calcule a partir du PV et de l'hematocrite veineux), avant et apres injection intraveineuse d'adrenaline. Apres splenectomie, les valeurs du CVCr et CVEB correspondent, que ce soit au repos ou apres injection d'adrenaline. Ces resultats sont egalement valables chez l'animal intact, apres administration d'adrenaline, alors que sans adrenaline, le CVEB est beaucoup plus bas que le CVCr. La difference entre le volume cellulaire total (CVCr) et le volume cellulaire circulant (CVEB) s'eleve a plus de la moitie de la masse des globules rouges disponibles. Cette partie «non circulante» du volume cellulaire s'est accumulee dans la rate, puisque la splenectomie annule la difference entre CVCr et CVEB. Comme cette difference disparait egalement apres injection intraveineuse d'adrenaline chez l'animal intact, il doit se produire une mobilisation totale des erythrocytes stockes. Il ne semble pas que d'autres organes ou tissus puissent assumer la fonction de stockage erythrocytaire pendant les dix premiers mois suivant la splenectomie. L'importance du reservoir erythrocytaire splenique semble dependre du volume cellulaire total et du poids de la rate, mais non du poids du corps. Le poids de la rate exsangue est mis en correlation avec le volume cellulaire total, sans tenir compte du poids du corps. Le sang contenu dans la rate represente plus de la moitie du poids de cet organe. La duree moyenne requise pour une distribution complete est nettement plus longue pour les cellules marquees que pour le colorant. Apres splenectomie, elle se trouve reduite et presque identique pour les deux indicateurs. L'activite du 51Cr mise en evidence a la surface du corps, du cote de la rate, diminue fortement en 2 a 4 minutes apres injection d'adrenaline chez l'animal intact et augmente a nouveau progressivement, atteignant la valeur initiale apres 15–25 minutes environ. Apres splenectomie, l'activite initiale est nettement plus faible et n'est pas influencee par une injection d'adrenaline. Resumen El influjo de la esplenectomia sobre la circulacion sanguinea II. Influjo sobre el volumen plasmatico y el volumen eritrocitico total circulante Se determinaron el volumen plasmatico (VP) y el volumen eritrocitico (VC) mediante azul de Evans (T-1824) y eritrocitos marcados con 51Cr, en cinco caballos antes de la extirpacion del bazo y en cuatro caballos de este grupo de una a tres veces despues de la operacion. El volumen eritrocitico (VCCr) obtenido asi se comparo con el volumen eritrocitico correspondiente (VCEB) — calculado del VP y del hematocrito venoso — antes y despues de la inyeccion intravenosa de adrenalina. Despues de la esplenectomia coincidian el VCCr y el VCEB tanto durante el reposo como despues de administrar la adrenalina. Con el bazo intacto tambien ocurria esto despues de la inyeccion de adrenalina, pero antes de la misma el VCEB era mucho mas bajo que el VCCr. La diferencia entre el volumen celular (VCCr) y el circulante VCEB ascendia a mas de la mitad de la masa disponible de los eritrocitos. Esta parte «no circulante» del volumen celular se acumulaba en el bazo, ya que la esplenectomia abule la diferencia entre VCCr y VCEB. Puesto que esta diferencia tambien desaparecia con la inyeccion intravenosa de adrenalina, tuvo que haber ocurrido una movilizacion total de los hematies almacenados. No hubo indicacion alguna de que otros organos o tejidos se hicieran cargo de la funcion almacenadora de los eritrocitos del bazo durante los 10 meses primeros despues de la esplenectomia. El tamano del deposito esplenico de globulos rojos parecia depender del volumen celular total y del peso del bazo, pero no del peso corporal. El peso del bazo desangrado se correlaciono con el del volumen celular total, sin tener en cuenta el peso del organismo. Mas de la mitad del peso del bazo correspondia al contenido en sangre. El valor medio requerido para la distribucion uniforme completa era bastante mas amplio para las celulas marcadas que para el colorante. Mediante esplenectomia se redujo marcadamente para ambos indicadores a casi el mismo valor. La actividad del 51Cr sobre el bazo registrada externamente decrecia de forma notable en el caballo intacto despues de inyectar adrenalina dentro de 2–4 min. y aumentaba a continuacion de manera gradual, alcanzando el nivel inicial al cabo de unos 15–25 minutos. Tras la esplenectomia era mucho menor la actividad inicial, no siendo afectada por la aplicacion de adrenalina.

Summary Artificial E. coli endotoxin mastitis was induced in one gland (homolateral gland) of lactating goats. Mammary blood flow (MBF) was always measured in the heterolateral gland and sometimes in the homolateral gland as well, using the electromagnetic flow technique. In the homolateral gland two conspicuous MBF peaks, separated by an intervening period of low flow, swelling and pain and gross alterations in milk composition were observed. The clinical aspect, chloride concentration and total cell count in milk were not significantly altered in the heterolateral gland, but 3 types of responses could be distinguished in its MBF. In type I (56 %) there was only one MBF peak, which coincided in time with MBF peak II of the homolateral side and which remained unaffected by severing the anastomoses between the two glands. In type II (10 %), the heterolateral MBF showed 2 distinctly separated peaks which coincided with MBF peaks I and II of the homolateral gland. MBF peak I disappeared after suturing the anastomoses between the two udder halves. In type III (33 %) no heterolateral peaks were present, but in most cases a fall of MBF, coinciding with the intervening period of low flow at the homolateral side, was observed. It is concluded that during experimental endotoxin mastitis MBF peak I is induced by locally formed mediators; the subsequent low MBF value and MBF peak II are at least partially due to systemic phenomena e. g. fever. Zusammenfassung Einflus einer experimentell induzierten Mastitis auf den Blutflus in der kontralateralen Milchdruse von laktierenden Ziegen Bei laktierenden Ziegen wurde in einer Drusenhalfte (ipsilaterale Druse) mittels E. coli-Endotoxin eine Mastitis induziert. Elektromagnetische Blutflusbestimmungen (MBF) erfolgten stets in der kontralateralen und vereinzelt auch in der ipsilateralen Druse. In der ipsilateralen Druse wurden zwei deutliche MBF-Peaks beobachtet, zwischen denen sich eine Phase mit herabgesetztem Blutflus, Schwellung, Schmerz und Auftreten grobsinnlicher Milchveranderungen befand. In der kontralateralen Druse waren die klinischen Befunde sowie der Chloridgehalt und die Zellzahl im Sekret nicht signifikant verandert. Dagegen konnten bezuglich des MBF drei Verlaufsformen unterschieden werden. Typ I (56 %) wies nur einen einzigen MBF-Peak auf, welcher mit dem MBF-Peak II der ipsilateralen Seite koinzidierte und der durch Unterbindung der Anastomosen zwischen den beiden Euterhalften nicht beeinflust wurde. Beim Typ II (10%) traten synchron mit den beiden MBF-Peaks der ipsilateralen Seite zwei deutlich voneinander getrennte MBF-Peaks auf. Peak I der kontralateralen Seite verschwand nach Unterbindung der Anastomosen zwischen den beiden Drusenhalften. Beim Typ III (33%) traten keine kontralateralen Peaks auf; in den meisten Fallen wurde jedoch ein Ruckgang des MBF, synchron mit der Zwischenphase der ipsilateralen Seite, beobachtet. Es wird angenommen, das im Verlaufe einer experimentellen Endotoxin-Mastitis eine erste MBF-Erhohung eintritt infolge von lokalen Entzundungsmediatoren. Der anschliesende erniedrigte Blutflus und der zweite MBF-Peak sind zumindest teilweise die Folge systemischer Reaktionen (z. B. Fieber). Resume Influence d'une mastite induite experimentalement sur l'irrigation sanguine dans la glande mammaire contra-laterale de chevres en lactation Une mastite a ete provoquee avec une endotoxine d'E. coli dans une mamelle (glande ipsilaterale) chez des chevres en lactation. Des determinations electromagnetiques du flux sanguin (MBF) ont ete faites constamment dans la glande contra-laterale et parfois egalement dans la glande ipsilaterale. On a observe deux pics marques MBF dans la glande ipsilaterale entre lesquels on notait une phase avec flux sanguin diminue, enflure, douleur et apparition d'alterations grossieres du lait. Les examens cliniques, le taux du chlorure et le nombre de cellules n'ont pas ete modifies de facon significative dans la glande contra-laterale. On a pu par contre differencier trois formes d'evolution de MBF. Le type I (56 %) a montre un seul pic MBF qui coincida avec le MBF-pic II du cote ipsilateral et qui ne fut pas influence par la ligature des anastomoses entre les deux moities de la mamelle. Deux pics MBF nettement separes sont apparus synchroniquement lors du type II (10%) avec les deux pics MBF du cote ipsilateral. Le pic I du cote contralateral a disparu apres une ligature des anastomoses entre les deux de la glande mammaire. Il n'y a pas eu de pics contra-lateraux avec le type III (33 %). On a cependant observe dans la plupart des cas un recul de MBF, en synchronisation avec la phase intermediaire du cote ipsilateral. On suppose qu'une premiere augmentation du flux sanguin intervient au cours d'une mastite a endotoxine experimentale a la suite de mediateurs d'inflammation locaux. Le flux sanguin abaisse qui suit et le second pic sont au moins en partie la consequence de reactions systematiques (fievre p. ex.). Resumen El influjo de una mastitis inducida experimentalmente sobre la irrigacion sanguinea en la glandula mamaria contralateral en cabras lactantes Se indujo en cabras lactantes una mastitis en una mitad de la glandula mamaria (glandula ipsilateral) mediante endotoxina de E. coli. De forma continua se llevaron a cabo valoraciones electromagneticas del flujo sanguineo (MBF) en la glandula contralateral y, a veces, en la ipsilateral. En la glandula ipsilateral se observaron dos cuspides MBF pronunciadas, entre las cuales se hallaba un periodo intermedio de flujo reducido, tumefaccion, dolor y alteraciones manifiestas en la composicion de la leche. En la glandula contralateral no estaban modificados los hallazgos clinicos ni la concentracion de cloruros ni la cantidad de celulas en la secrecion. Sin embargo, con respecto a las MBF se pudieron distinguir tres formas de respuesta. El tipo I (56 %) mostraba una sola cuspide MBF, la cual coincidia con la cuspide MBF II de la parte ipsilateral y no era influenciada por la interrupcion de las anastomosis entre las dos glandulas. En el tipo III (33%) no aparecen cuspides contralaterales; sin embargo, en la mayoria de los casos se observo un retroceso del MBF, en sincronizacion con la fase intermediaria del lado ipsilateral. Se supone que en el curso de una mastitis experimental a base de endotoxina se produce un aumento primero del flujo lacteo como consecuencia de mediadores de la inflamacion locales. El flujo sanguineo disminuido acto seguido y la cuspide MBF II son, al menos en parte, la consecuencia de reacciones sistemicas (fiebre, por ej.).

In a double diffusion chamber (DC) culture system bone marrow cells elaborated diffusible factor(s) that prevented spleen colony-forming cells (CFU-S), but not PHA stimulated lymphocytes, from entering cell cycle. Mature granulocytes and macrophages did not produce such factor(s). Various numbers of steady-state or regenerating mouse bone marrow cells were cultured in single diffusion chambers for periods up to 7 d. After the initial cell loss, the net growth of CFU-S was inversely related to both total cell number and CFU-S number in DC. Diffusible factors rather than cell-to-cell contact appeared to be involved in the inhibition, even though we were not able to demonstrate inhibition of net growth of CFU-S with the double chamber approach.

To determine variations in stomatal density and distribution in individual leaves of vine species with different growth/life forms and different habitat types, we quantified and compared leaf-area-based stomatal density, epidermal cell density and stomatal index (percentage of stoma on the epidermis to the total cell number, including epidermal and stomatal cells on the epidermis) of 53 species comprising 19 woody species (lianas) and 34 herbaceous vines growing in Japan. We counted the numbers of stomata on both the adaxial and abaxial leaf surfaces using a light microscope. Stomatal density and distribution on the leaf surfaces varied greatly among species. Most of the creeping herbaceous species had stomata on both the adaxial and abaxial leaf surfaces (amphistomatous); however, lianas had no stomata on the adaxial leaf surface. Species from coastal (probably drier) habitats had greater adaxial to abaxial ratios of stomatal density and stomatal indices compared with species from inland habitats. A positive correlation between stomatal density and epidermal cell density was found on the abaxial/adaxial leaf surfaces of the examined species. This suggests that there is a developmental similarity among vine species in which stomata are developed with differentiation of epidermal cells on the leaf surface. Thus, leaf stomatal density and distribution appear to vary among species with different growth/life forms from different habitats under a developmental constraint of leaf surface in vine plants in Japan.

Proteome profiling techniques rely on the separation of proteins or peptides and their subsequent quantification. The reliability of this technique is still limited because a proteome profiling result does not necessarily represent the true protein composition of the analysed sample, thus seriously hampering proper data interpretation. Many experimentally observed proteome alterations are biologically not significant. It was the aim of this study to use the knowledge of the biological context of proteins in order to establish optimised proteome profiling protocols. While 2-D spot patterns of total cell protein fractions were found to poorly represent the true protein composition, purified subcellular protein fractions were found to better represent the protein composition of the analysed sample. The application of a standardised protocol to different kinds of cells revealed several striking observations. Firstly, the protein composition of cultured cells of various origins is very similar. Secondly, proteome alterations observed with the described protocols do make sense from a biologic point of view and may thus be considered as truly representative for the analysed samples. Thirdly, primary white blood cells isolated from different donors were found to show minor, but reproducible and significant individual differences. We designate the consideration of known properties of identified proteins in proteome profiles as a knowledge-based approach. The present data suggest that this approach may tremendously help to improve the applied techniques and assess the results. We demonstrate that the fulfilment of well-defined criteria of proteome profiles eventually results in reliable and biologically relevant data.

The Effects of Carbon Fibre and Carbon Fibre Composite Dusts on Bronchoalveolar Lavage Component of Rats: Zhongyi ZHANG, et al. Department of Occupational Health, School of Public Health, Harbin Medical University, People''s Republic of China—Carbon fibre (CF) and carbon fibre composite (CFC) as new materials have increasing industrial application. The People''s Republic of China now manufactures CF and CFC. This paper predicted their potential toxicity to human using bronchoalveolar lavage technique on the basis of comparisons with positive reference materials (quartz and chrysotile) and negative reference materials (titanium dioxide and alumina (SAFFIL) fibre). All rats dosed with dust showed some increase in lung weight relative to the saline control, though the only significant differences were seen between the rats dosed with quartz or chrysotile and those dosed with saline. From the morphological observation of lavage cells, a benign reaction of macrophages to CF and CFC was observed, whereas a series of changes in macrophages was involved in rats dosed with quartz and chrysotile. CF and CFC did not induce a significant increase in the total cell count or percentages of neutrophils and lymphocytes in bronchoalveolar lavage. The two materials tested had much lower toxicity than that of quartz and chrysotile, and were comparable with the effect induced by titanium dioxide and SAFFIL fibre which had minimal toxicity. The present work provides a scientific basis for the setting of occupational health standards for carbon fibre and carbon fibre composite dust in the workplace. (J Occup Health 2001; 43: 75-79)

Despite extensive clinical experience, the effects of different reuse procedures have not been fully evaluated. The available data suggest that the effect of reuse on dialyzer performance depends upon the type of chemicals employed, the membrane type, and the size of the solute whose removal is being assessed. The effect of reuse on urea clearance is essentially defined by the residual cell volume with a total cell volume of > 80% associated with a dialyzer clearance that is within 10% of its original value. The effect of reuse on large solute clearance can be dramatic, with the procedure resulting in substantial changes in the beta2-microglobulin clearance of different dialyzers. Of note is the limited data available regarding the effect of reuse procedures on dialyzers processed more than 20 times.

The effect of additives and processing parameters on wheat bread were investigated objectively using image analysis (IA). Five different bread types were produced by varying the ingredients (standard, standard with fat, standard with emulsifiers) and changing the mixing times (90, 150, and 240 sec). A digital IA system for wheat bread was developed from generic commercial software. The system yielded reproducible results for a variety of bread crumb grain image features. Bread slices were scanned and evaluated using the IA system. Image characteristics were determined for each bread type. All data was statistically evaluated to detect significant differences between bread types. It was shown quantitatively that inclusion of fat or emulsifiers or extension of mixing time had a significant effect on crumb grain features such as mean cell area, total cell area, and number of cells/cm2. The five bread types could be distinguished solely by crumb grain characteristics.

We present a novel solar cell structure, the “buried emitter solar cell”. This concept is designed for decoupling the metallisation geometry from the geometry of the carrier collecting p–n junction in back-contacted (and in particular back-junction) solar cells without requiring electrical insulation by dielectric layers. The most prominent features of this device structure are a carrier collecting emitter that covers close to 100% of the total cell area and an effective electrical insulation between emitter and base metallisation via a p+–n+ junction. The experimental results presented in this paper report a 19.5% efficient “buried emitter solar cell”, where 50% of the solar cell's rear side exhibit a p+–n+ junction. This preparation technique implies covering a boron-doped p-type emitter with an n-type surface layer that can be efficiently surface-passivated by thermal oxidation. All structuring of this cell has been performed by laser processing without any photo-lithography. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

The corneal endothelium is often described as a mosaic of hexagonal cells, despite numerous reports that the relative number of 'hexagonal' cells is often only around 65%. Such estimates also cannot define the relative area contribution to the cell mosaic of either these cells, or those that are not 6-sided. Specular micrographs were therefore taken of 20 healthy young Caucasian adults aged 21 to 34 years and the apical surface areas of at least 105 contiguous cells from each central corneal endothelium measured by planimetry. The numbers of each cell type and their surface areas were assessed so that the summated area occupied by each cell type could be calculated. The results reveal that endothelia that show only modest variance in cell areas are usually composed of 4-, 5-, 6-, 7- and 8-sided cells. Assessments of relative contribution of each cell type to the mosaic indicates that the 6-sided cells can be expected to constitute just over 60% of the total cell area. Increases in the variance in the areas across all the cells can be strongly correlated with a reduction in the 6-sided cells and increases in the 5- and 7-sided cells. Each cell type (4-, 5-, 6-sided etc) has a preferred area that is proportional to other cells. The results firmly indicate that the mosaic is not random and follows a specific order that is presumably dictated by the physics of cell packing. These methods of comparing endothelia should allow distinctions to be made between endothelia that are different, versus being abnormal (i.e. with disease).

PURPOSE To investigate the frequency of snake-like chromatin in the conjunctival epithelial cells (SLC) of a population from Copenhagen City. METHODS A questionnaire was mailed to 504 persons aged 30-60 years. Persons with symptoms of ocular/oral dryness and a control group without symptoms were examined by the conjunctival imprint technique. RESULTS According to this material the frequency of SLC in persons 30-60 years living in Copenhagen may be estimated to 47%, which is considerably higher than earlier reported. In most cases SLC was, however, occupying less than 1% of the total cell area. No significant association was found to abnormal results of the Schirmer test, tear film break up time, rose bengal score or tear film lipid layer thickness. The frequency of SLC in persons with KCS was 53%, however, only few cases of KCS were found in the material. CONCLUSION Results indicate that SLC is a quite frequent and unspecific finding, probably reflecting chronic irritation of the ocular surface.

We have studied the synthesis and stability of the monooxygenase AlkB of Pseudomonas oleovorans in its natural host and in recombinant Escherichia coli. Three strains were investigated: the prototype strain P. oleovorans and the E. coli alk+ recombinants HB101 (pGEc47) and W3110 (pGEc47). Plasmid pGEc47 allows regulated expression of alkB and synthesis of active AlkB in E. coli. The E. coli strains were selected because E. coli HB101 (pGEc47) produces similar amounts of AlkB as P. oleovorans (1.5-2% of total cell protein), whereas E. coli W3110 (pGEc47) is able to make substantially (about fivefold) more AlkB. The AlkB synthesis and degradation rates in batch cultures of the three strains were determined by means of isotopic-labeling and immunological techniques. The mean specific AlkB synthesis rates in P. oleovorans, E. coli HB101 (pGEc47) and E. coli W3110 (pGEc47) were approximately 7, 12.5 and 45 microg x mg protein(-1) x h(-1), respectively. The half-lives of AlkB were estimated to be 80, 3 and 15 for P. oleovorans, E. coli HB101 (pGEc47) and E. coli W3110 (pGEc47), respectively. Thus, the intracellular AlkB level in each of the three strains was the result of their AlkB synthesis and degradation rates. The AlkB level during batch growth was modelled by means of experimentally derived parameters for AlkB synthesis and degradation, and showed good agreement with AlkB levels determined by means of immunoblotting in all strains investigated.

OBJECTIVES: The purpose of this in vivo study was to histopathologically evaluate the inflammatory reaction incited by Vicryl in rats and compare this material with various suture materials that are widely used in the clinic. SUBJECTS AND METHODS: Four different suture materials, catgut, silk, polypropylene, and Vicryl were used in soft tissues of 32 Sprague‐Dawley rats. Incisions performed were sutured by a standard technique. Eight rats were killed at the first, third, fifth, and seventh days. Histopathological evaluation of the en bloc samples was performed by determining the density of seven cell-types. A numerical grading from one to three was used. The data were statistically analysed by Kruskal‐Wallis one way ANOVA and Dunn’s tests. RESULTS: Vicryl has produced the mildest tissue reaction among the test materials at all experimental periods (P < 0.05). Total cell number value in Vicryl group was found to be significantly lower than the one in catgut group (P < 0.05). CONCLUSION: Under the conditions of this study, the results demonstrated that Vicryl as a suture material produced the mildest tissue reaction during early healing period. Oral Diseases (2003) 9, 284–286

The effectiveness of the hok/sok plasmid stability locus and mechanism of cloned-gene loss was evaluated in shake-flask cultures. Addition of the hok/sok locus dramitically increasedapparent plasmid segregational stability to the hok/sok(-) control. In terms of the number of generations before 10%of the population became plasmid-free, segregational stability was increased by 11- to 20-fold in different media in the absence of induction of the cloned-gene (hok/sok(+) plasmid stable for over 200 generations in all media tested). With constant expression of beta-galactosidase in the absence of an tibiotic, the segregational stability of the plasmid containing hok/sok was incresed more than 17- to 30-fold when beta-galactosidase was expressed at 7-15 wt % of total cell protein. Although the hok/sok system stabilized the plasmid well infour different media (Luria-Bertani (LB), LB glucose, M9C Trp, and a representative fedbatch medium), the ability of hok/sok to maintain the plasmid with induction of the cloned gene decreased as the complexity of the media increased. This result is better interpreted in terms of the influence of cloned-gene expression on plasmidmaintenance; plasmid segregational stability decreased linearly as specificbeta-galactosidase activity increased. (c) 1994 John Wiley & Sons, Inc.

In recent studies, sputum smear cell counts were found to be reproducible and usefully applied to research in asthma and other airway conditions. However, cell definition on the smears is poor, and the procedure is tedious and has limited utility. The objective of this study is to improve the methods of sputum examination. The subjects used in this study were people with bronchitis or asthma from whom sputum could be obtained. By inverted microscopy, portions of fresh sputum were selected to exclude salivary contamination. These portions were exposed to different volumes of dithiothreitol for varied time intervals. We used the resulting cell suspensions to perform total cell counts and prepare cytospins for differential cell counts and immunohistochemical stains for GM-CSF, EG2, TNF alpha and IL-8. Cytospins were compared with smears for differential cell counts on the same sputum specimens. Excellent cell dispersion and definition in cytospins could be observed. The time required for differential cell counting on cytospins was reduced and cytospin counts were more reproducible than smears. Greater duration of treatment of sputum with dithiothreitol tended to increase total cell counts and significantly decreased EG2 staining but had no effect on differential cell counts or the cytokine cell components. Therefore the proposed method of sputum examination involving cell dispersion and use of cytospins overcomes a number of the disadvantages of the examination of smears.

We describe an algorithm for fully automated flow cytometric DNA histogram classification and analysis that provides rapid, reproducible determination of DNA index and S-phase fraction (SPF). Automated classification agreed with subjective assessment of DNA ploidy in 96–98% of DNA histograms. Automated and conventional analyses of DNA index (r = 0.95) and SPF (r = 0.89) were also highly correlated with one another. In a series of 86 node-negative breast carcinomas, SPF calculated with the fully automated method was a significant predictor of 10 year survival (P = 0.009). Automation greatly increased the speed of DNA histogram analysis, allowing evaluation of the same set of histograms with different methods. In a preliminary study exploring the optimization of DNA histogram analysis, the best association between SPF and prognosis of breast cancer patients was achieved using sliced nuclei debris modeling, reporting only the aneuploid SPF (in aneuploid histograms), while excluding small aneuploid clones (

Immer wieder taucht bei der Bearbeitung mikrobieller Probleme die Frage auf, ob die Mikroorganismen physiologisch aktiv sind oder nicht. Es wird eine Methode vorgestellt, die eine direkte Quantifizierung atmungsaktiver Bakterien in Wasser- und Biofilmproben zulast. Die Bestimmung wird mit einem fluoreszierenden Redoxfarbstoff (5-Cyano-2,3-Ditolyltetrazoliumchlorid [CTC]) durchgefuhrt. Durch die Fluoreszenz ist ein empfindlicher Nachweis sowohl im Wasser als auch auf undurchsichtigen Oberflachen moglich. Die Biomasse-Aktivitat kann summarisch bestimmt werden, es last sich aber auch die Aktivitat einzelner Zellen uber die Lichtausbeute mikroskopisch feststellen, denn bei der Reaktion entsteht ein sehr gut detektierbarer fluoreszierender Formazan-Kristall. Das Verfahren ist einfach und in kurzer Zeit (1–2 h) durchzufuhren. Es liefert die Anzahl physiologisch aktiver Zellen und kann mit Farbemethoden zur Ermittlung der Gesamtzellzahl kombiniert werden. Der CTC-Test bietet sich damit fur Routineuntersuchungen und fur die Eigenkontrolle an, nicht zuletzt, um die Wirksamkeit von keimtotenden Masnahmen zu uberprufen. Microbial deterioration of materials – biofilm and biofouling: Quantification of respiratory active bacteria in water and in biofilms by means of a fluorescent redox dye The question of physiological activity of microorganisms is in many microbially caused problems of strong interest. A method is presented which allows the direct quantification of respiratory active bacteria in water and biofilm samples. The determination is performed with a fluorescent redox dye (5-cyano-2,3-ditolyltetrazolium chloride [CTC]). By means of the fluorescence a very sensitive detection of reducing activity can be achieved, even on opaque surfaces. The activity of the biomass can be determined as well as the activity of single cells. The latter can be performed microscopically by determination of the light yield, because a readily detectible, fluorescent crystal is formed inside the cell by its reductive activity. The method is easy to carry out and takes only 1–2 h. It gives the number of physiologically active cells and can be combined with other methods, giving the total cell number. The CTC test is suitable for routine measurements as well as for monitoring. It is also useful to assess the effectivity of biocide application.

SUMMARY 1. The effect of storm-flow on light- and dark-grown biofilms from a North Wales river was monitored using electron transport system (ETS) activity and epifluorescence cell counts. 2. Artificial substrata were colonized in the river, exposed to ambient-flow (60 cms−1) or storm-flow (235 cms−1 with suspended sediment addition) for 12h in a laboratory flow tank, and returned to the river to monitor the recovery period. 3. Total cell densities decreased in both the light- and dark-grown biofilms as a result of storm-flow. In addition, storm-flow ETS activity per cell increased significantly in the light-grown samples (2.7 times) but did not increase significantly in the dark-grown samples (1.6 times). 5. Within 48 h, storm-flow total cell densities and ETS activity levels had returned to ambient-flow levels in both light- and dark-grown biofilms. 6. Within each light regime, despite their different histories, both ambient and storm-flow samples responded the same to daily changes in the river environment, including a second disruption by natural causes, for the remainder of the 24-day experiment.

The variance of observed cell counts using a hemacytometer was analyzed. The variance was found to be greater than expected under the normally assumed Poisson distribution because of variations in the volume of the counting area. Furthermore, counts from the two sides of the hemacytometer were found to be correlated. Total cell count on a hemacytometer was better described using a normal distribution with quadratic variance, N(lambda, lambda + sigma-lambda-2), with sigma = 0.012. Because hemacytometer cell counts are not Poisson distributed, modified counting protocols are recommended.

This unit describes techniques, based on recent advances in stereological methods, to obtain unbiased estimates of total cell or synapse number in discrete structures of the central nervous system. They combine unbiased counting frames, unbiased systematic random sampling, and unbiased estimates of the structure volume to produce the final estimate of number.

Dialyzer reprocessing systems “accept” dialyzers for reuse if their total cell volume (TCV) is well maintained. What nephrologists mainly care about, however, is the dialyzer's urea clearance. How well documented is the TCV-urea clearance relationship for dialyzers in current use?

Seasonal changes in the specialized skin glands of the forehead, metatarsal gland and interdigital regions of Roebucks are described and compared with glands of the general body surface. In both the forehead region and dorsal skin the sebaceous and apocrine glands enlarge as the testes enlarge and regress after the rut, but the glands of the forehead region are at least three times larger than those of the general body surface. The apocrine glands of the forehead region discharge by exocytosis except at the time of maximum secretion, which precedes total cell breakdown. In the metatarsal and interdigital regions the skin glands are enlarged throughout the year.

Direct morphometric estimation of the number of intestinal crypts per 10 mm length of jejunum, the total number of cells per crypt, and the number of Paneth cells per crypt was performed using Zenker-fixed, serially sectioned small intestines from adult BALB/c mice. The mean volume of a crypt cell was estimated to be in the order of 6.6 plus or minus 0.1 times 10-4 mm-3, while the total volume of all cells in a single crypt was 1.833 plus or minus 0.02 times 10-1 mm-3. The cell population per crypt was 278 plus or minus 7 cells, of which 44 plus or minus 10 were Paneth cells. It was estimated further that 265 plus or minus 30 crypts per 10 mm length of jejunum contained 7.4 plus or minus 0.1 times 10-4 cells, including 1.2 plus or minus 0.24 times 10-3 Paneth cells. The volume of all crypt and Paneth cells per 10 mm length of jejunum was in the order of 49 plus or minus 1.2 and 8 plus or minus 1.8 mm-3, respectively. The volume of the tunica muscularis and the surface area of the crypt's lumina were estimated to be 33.5 plus or minus 2.2 mm-3 and 118 plus or minus 19 mm-2, respectively.

Over thuty years ago it was proposed that the mttom of cells may be controlled by a negative feed- back mechanism [ 1,2], an idea winch was substantially apphed to the regulation of epidermal cell growth [3,4] These workers suggested that endogenous mitotic minbltors were produced by cells winch would mlublt only that speofic cell type Historically, these minbRors have been referred to as 'chalones', from the Greek word meanmg to brake or slow down. The Instory of the chalone concept has been rewewed [5] and is too vast to be treated here. The primary charac- tensUcs ofa classac chalone have been defmed as: (1) total cell specificity, (2) species non-specific, (3) revers- lble; and (4) non-cytotoxlc. Houck [6] covered the hter- ature up to 1976 m detml and summarized the major biological ewdence for the existence of chalones, a point whach has not been unequivocally estabhshed It is a general cntlclsm of chalone research that the theories have always been far m advance of the data. This has come about possibly because of the inherent difficulties m measunng cell minbltlon m a specific manner, as opposed to measurement of cell growth stmmlatlon However, it may not be justified to dis- card an attractive theory sunply due to techmcal dlf- ficullaes and weak supporting data Here we are not concerned with the phenomenol- ogy of ehalones and consider only recent develop- ments m several areas wluch show progress toward purification and understanchng the chemistry of van- ous ehalones Obvmusly, much of the biology and theory will not be relevant until the purified mlubttor is at hand Thus we do not present a comprehenrave review of the hterature and cite orfiy general or repre- sentatave papers m any area We consider two specific chalones in detail, lymphocyte and granulocyte, and several others briefly Considerable progress has been made with these two and they may be representative ofchalones m general We also mention some prob- lems reeogmzed m research on growth mlubttors

Friable callus tissue of Centaurea cyanus L. was grown on a solidified synthetic nutrient medium (EBM-1) to produce a tissue with a low frequency of differentiated tracheary elements. Tissues were then suspended in liquid nutrient medium with agitation to produce a suspension which was filtered and the single-cell suspension resulting was used as inoculum for either cell suspension cultures or for plating of cells into solidified medium in Petri plates. Media for the suspension cultures were selected to favor cytodifferentiation of tracheary elements. Differentiated tracheary elements formed as early as 10 days and numbers of tracheary elements increased with time roughly in relation to the increase in total cell number. From plating experiments it was shown conclusively that single isolated parenchyma cells differentiated directly into single isolated tracheary elements, although this event was rare. More usual was the division of isolated cells to form small colonies and then the differentiation of one, several or all of the cells into tracheary elements. Comparisons are made between results with cell plating experiments and cell suspension cultures. Optimism is expressed for finding a cell suspension culture system for studying cytodifferentiation.

Twenty-six species of phytoplankton were able to multiply in water collected from the surface at nine stations in the subarctic Pacific and enriched with nutrients. These species normally constitute 91 percent of the total cell numbers and 64 percent of the phytoplankton biomass in the collection area in the spring months. (auth)

The fastidious gram negative asaccharolytic rods Wolinella recta, Campylobacter concisus, Bacteroides gracilis, and Eikeneila corrodens have been isolated from lesions of advanced periodontal disease. In this investigation, three methods were compared for their ability to identify fresh isolates of these species: 1) biochemical tests and sensitivities to dyes and other inhibitors, 2) serological reactions, and 3) sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). SDS-PAGE of total cell proteins appeared to be the most sensitive and accurate method to identify isolates, although many strains were successfully identified using serology. Biochemical tests including sensitivities to inhibitors were the least reliable. W. recta, B. gracilis, and E. corrodens were found more frequently and in higher numbers in progressive (active) disease sites of many of the subjects. E. corrodens was also found to be significantly elevated in inactive sites of certain subjects. After successful treatment with Widman flap surgery and systemically administered tetracycline, the proportions of W. recta and E. corrodens were reduced, while those of C. concisus were elevated.

The effect of insulin on glucose entry has been studied in monolayer cultures of human diploid fibroblastic cells. Influence of insulin on total cell glucose incorporation was evaluated using [14C] glucose. Glucose incorporation was increased up to two-fold in the presence of insulin. Insulin action occurred within 30 minutes and could be observed with insulin concentrations as low as 10(-10) M (10 microU)ml). The action of insulin was enhanced by preincubation in glucose-free medium. After glucose starvation the cells converted glucose primarily to glycogen and nucleotides, and the stimulation by insulin was observed equally in both fractions. Influence of insulin on the kinetics of hexose transport was studied using 2-deoxyglucose and 3-0-methyl glucose. A large diffusion component was corrected using rho-chloromercuribenzoic acid or phloridzin. Km for facilitated diffusion averaged 1.9 mM for 2-deoxyglucose and 5.3 mM for 3-O-methyl glucose, and Vmax ranged from 10-24 nmoles/min/mg cell protein. Insulin resulted in a 150% increase in Vmax with no significant change in Km. The data suggest that human diploid fibroblasts can be a useful system for the study of insulin's glucoregulatory action.

The advantages of the concentrated system over conventional methods, as well as the disadvantages, are assessed. The batch method of concentrate production requiring a pure culture grown to a high total level is discussed and tables given showing total cell count and yield. The necessity for quality control of the concentrate to ensure meeting standards regarding species, strain type, cell numbers and acid producing activity is stressed. The design of process plant equipment is described in detail and the layout of the system evaluated. (Editor's summary.)

' Plotless ' techniques for determining population densities have been developed for, and applied to, higher plant populations. They can often be carried out more rapidly than techniques involving total counts of individuals in plots, or quadrants, but such plotless techniques have not been generally applied to the estimation of densities of bacterial cells. Direct microscopical counting of cell numbers in a field of view, an example of a plot-related method, has been traditionally used for microbial cell counts. In this study 'plot' and ' plotless ' methods on a variety of bacterial samples are compared. Estimates of bacterial cell density were obtained by measuring the distance of cells from a fixed point in a field of view. The values, which were more rapidly obtained, were directly correlated with total cell counts. Although there was some apparent deviation from a perfect 1:1 relationship with total counts, as indicated by a correlation coefficient less than 1.0, there were no significant differences between the replicated counts of bacteria on samples of tissue from the surface of Hypholoma basidiocarps (P less than 0.05). This indicated that the methods of enumeration were comparable. The distance-related estimates could readily be obtained from fields of view with cell densities varying over several orders of magnitude. It was more rapidly applied, particularly at high density, and the method was applicable not only to random cell distributions but also to the non-random distributions encountered when microbial cells aggregated into microcolonies. The method appears to be particularly well-suited for automated, digitized, direct counting procedures, as well as to estimating bacterial numbers on membrane filters and natural substrates.

SUMMARY The common methods of counting Azotobacter spp. in soil, colony counts and MPN, were compared using cell suspensions of densities determined by direct microscopic counts. A highly significant positive correlation was found between the surface-plate, MPN and total cell counts, but the MPN estimations approximated total cell counts much more closely. Inclusion of 1-1.5 g of agar/l of the liquid medium enhanced multiplication of azotobacters and facilitated the recording of growth in MPN estimations.

The influence of red cell age on their agglutin-obility by bloodgroup isoagglutinins was investigated in various ways. No definite differences between young and old red cells could be established although some experiments suggested a somewhat lesser agglutinability of the young cells in comparasion to the total cell population.