Low Molecular Mass Substances Research Articles

Selective, Intrinsically Fluorescent Trk Modulating Probes.

Neurotrophins (NTs) elicit the growth, survival, and differentiation of neurons and other neuroectoderm tissues via activation of Trk receptors. Hot spots for NT·Trk interactions involve three neurotrophin loops. Mimicry of these using "cyclo-organopeptides" comprising loop sequences cyclized onto endocyclic organic fragments accounts for a few of the low molecular mass Trk agonists or modulators reported so far; the majority are nonpeptidic small molecules accessed without molecular design and identified in random screens. It has proven difficult to verify activities induced by low molecular mass substances are due to Trk activation (rather than via other receptors), enhanced Trk expression, enhanced NT expression, or other pathways. Consequently, identification of selective probes for the various Trk receptors (e.g., A, B, and C) has been very challenging. Further, a key feature of probes for early stage assays is that they should be easily detectable, and none of the compounds reported to date are. In this work, we designed novel cyclo-organopeptide derivatives where the organic fragment is a BODIPY fluor and found ones that selectively, though not specifically, activate TrkA, B, or C. One of the assays used to reach this conclusion (binding to live Trk-expressing cells) relied on intrinsic fluorescence in the tested materials. Consequently, this work established low molecular mass Trk-selective probes exhibiting neuroprotective effects.

Determination of Biogenic Amines in Some Cheese Consumed in Hatay Region

Biogenic amines are biologically active, nitrogen based, low molecular mass substances and they consider as quality and toxicity indicators of foods. The amount of biogenic amines indicates also the freshness of the food products. These compounds form during production or storage of protein rich foods under unhygienic conditions. These amines are usually formed in protein rich foods by the act of microorganisms which has decarboxylase activity under inappropriate technological processing conditions especially while fermentation processes. Cheese, yogurt, kefir are among the most consumed fermented foods. Since these products are much consumed food products, the analysis of biogenic amines in them is very important in terms of consumer health and product quality. Biogenic amines taken in high amounts are known to cause headache, nausea and more serious food poisoning. There are studies both abroad and in our country on cheese varieties where biogenic amine formation is frequently observed. However, there is no study conducted in the Hatay region, which is extremely rich in terms of cheese varieties. Within the scope of this study, biogenic amine analyzes were performed on 20 cheese samples produced and consumed in the Hatay region after they were kept in the refrigerator at 4 ºC for 30 days. Total biogenic amine concentrations were determined between 57.00–432.41 mg kg-1. The samples with the highest total biogenic amine concentrations were blue-veined cheese (432.41 mg kg-1) and moldy cheese (314.45 mg kg-1). Total biogenic amine concentrations were the lowest in aged cheddar cheese (57.00 mg kg-1) and knitted cheese (97.57 mg kg-1). All of the biogenic amines (spermidine, putrescine, cadaverine, histamine, tryptamine, tyramine, phenylethyl amine) were detected in all cheese samples examined.

Plants with anticancer potency for breast cancer treatment

Breast cancer is the most common fast growing leading cause of morbidity and mortality in female patients across the worldwide including developed as well as developing countries. The worldwide weight of breast cancer malignancy is relied upon to cross 2 million constantly 2030across the globe. The increased mortality rate of breast cancer is due to the late diagnosis, low levels of awareness, socio-economic condition, educational background, low effectiveness of the treatment and incomplete treatment regimens. Although various advancement was made in treatment of breast cancer but still there are a space for the effective treatment. This space is the undesirable effect of chemotherapy. Plants are the indispensible source of medicinal lead molecule for the remedy of breast cancer. The curative properties of these lead molecules are present in various parts of the plant in the form of low molecular mass substance known as secondary metabolites. These secondary metabolites are glycosides, alkaloids, flavonoids, terpenoids, phenolics and compounds containing sulphur element. The mechanism behind these secondary metabolites is the inhibition of initiation of apoptosis, arrest of cell cycle at G1/G2, M phase, up/down regulation of various gene and DNA damage. The present chapter provide updated information about the mechanism of breast cancer and therapies including natural plant extract and isolated lead molecules.

Crosstolerant Effect of Salt Priming and Viral Infection on Nicotiana Benthamiana

Currently, the salinization of soil one of the factors, which determine the productivity of crop plants. Under severe conditions, plants reveal the retardation in growth of shoots and roots,the decrease of productivity, because of biochemical and physiologicaleffects of salt high concentrations. To avoid any severe effect of biotic and abiotic stress is applied to the method of seed priming. Primed seed preserves the resistance signaling pathway for upcoming stress conditions. During biotic and biotic stress firstly accumulates reactive oxygen species which are the secondary messenger molecules in many signaling pathway of plant organisms. Excessive amounts of reactive oxygen species lead to macromolecules damage, such as lipids of cell walls, proteins, nucleic acids. To overcome the severe effect, plants evolved enzymatic and non-enzymatic systems of protection. The crucial enzymes are catalase, aldehyde oxidase, superoxide dismutase. The main components of the non-enzymatic antioxidant system are vitamins, low molecular mass substances such as glutathione. The phenomenon “cross-tolerance” suggests the resistance of plant organism to one stress by the exposure to another one. Early exposure salt stress to Nicotiana benthamiana leads to resistance to viral infection, change the activity of antioxidant enzymes (catalase, aldehyde oxidase). The analysis of viral particles revealed the decrease of viral particles content in salt primed plants.

Phase diagram of the low-density polyethylene – dimethyl terephthalate system: A new topology

A new type of phase diagram semicrystalline polymer – low molecular mass substance is found for the low-density polyethylene – dimethyl terephthalate mixture. Exploiting an original optical method and differential scanning calorimetry, we demonstrate that the studied system combines the features of polymer – poor solvent and polymer – high-melting substance mixtures. Its diagram also contains a curve describing the solubility of the low molecular mass component in the polymer, which is often missing in the literature. An experimental phase diagram enables us to perform a detailed analysis of the differential scanning calorimetry, optical and scanning electron microscopy data on the cooling of homogenized mixtures of different compositions, which leads to the formation of capillary-porous polyethylene bodies via thermally induced phase separation and following removal of dimethyl terephthalate crystals.

Physicochemical Grounds for Application of Schungite for Neutralization of 1,1-Dimethylhydrazine in Wastewater

Chromatography–mass spectrometry and MALDI mass spectrometry have been used to study the interaction of 1,1-dimethylhydrazine and products of its oxidation with the surface of mineral schungite in aqueous solutions. A comparative analysis has been performed for organic compounds contained in initial and equilibrium 1,1-dimethylhydrazine solutions brought in contact with schungite, as well as compounds desorbed from the modified surfaces of the mineral and its inorganic components. The analysis has revealed the efficiency of schungite as a low-cost and environmentally friendly sorbent capable of catalyzing the profound oxidation of 1,1-dimethylhydrazine and products of its transformation to nontoxic low-molecularmass substances. Environmentally safe methods have been proposed for the regeneration of used schungite.

Poly[3,3-bis(azidomethyl)oxetane]–2,4-dinitro-2,4-diazapentane

Constructing phase diagrams for the mixtures of semicrystalline polymers and low molecular mass substances by DSC can meet with difficulties in the case of slow polymer crystallization. A problem of this kind is encountered for high-energy compositions poly[3,3-bis(azidomethyl)oxetane] (PBAMO)–2,4-dinitro-2,4-diazapentane (DNAP). In this study, the experimental phase diagram PBAMO–DNAP is constructed by an optical method, which makes it possible to visualize structural transformations. The kinetic studies by DSC and XRD reveal that 30–50 days of storing a homogenized PBAMO–DNAP mixture at room temperature are needed to attain stationary values of the crystallinity degree and heat of fusion. Even after that, the DSC method cannot deliver a solubility curve of DNAP in PBAMO, which is naturally generated by the optical method. This curve separates a domain of physical gels, effectively crosslinked by polymer crystallites and swollen with the plasticizer molecules, from a two-phase domain, in which the above gel reaches osmotic equilibrium with the pure plasticizer. It is also shown that the melting temperature of DNAP drops with growing the PBAMO content in the mixture, which is consistent with a decrease in the mean size of plasticizer crystals formed in polymer pores during the previous cooling.

Two new types of assays to determine protein concentrations in biological fluids using mass spectrometry of intact proteins with cystatin C in spinal fluid as an example

There is no reference method that is generally acknowledged to be unbiased for the determination of the concentration of any protein in biological fluids. This is probably because mass spectrometry (MS) methods acknowledged as reference methods for determination of low molecular mass substances in biological fluids, e.g. creatinine, have been difficult to adapt for proteins. Here we suggest two tentative MS methods, which might be used as reference methods for the determination of protein concentrations in biological fluids. One is based upon the addition to the fluid of a non-proteome reference protein, very similar to the one to be measured, and analyzing the ratio between the corresponding peaks in a selected ion monitoring (SIM) chromatogram. We call this method LC-MS-NPRP (NPRP, Non-Proteome Reference Protein). The other method is based upon the classical standard addition assay for low molecular mass substances. The results of these assays for cystatin C in spinal fluid were compared to those obtained by an immunoassay. Both methods indicated lower concentration than the immunoassay. This was found to be due to the presence of a significant fraction of monohydroxylated cystatin C in spinal fluid. It turned out that the sum of the unhydroxylated and hydroxylated cystatin C concentrations, determined by either of the two MS methods, were close to the results obtained by the immunoassay. These MS-based methods analyze intact proteins and therefore seem more suitable for the determination of protein concentrations in biological fluids than other MS-based methods requiring proteolytic degradation with its inherent lack of precision.

Organoclays with hexagonal rotator order for the paraffinic chains of the compensating cation. Implications on the structure of clay polymer nanocomposites

Organically modified clays (OC) were prepared by reacting montmorillonite (Mt) and dimethyl ditallow ammonium chloride (2HTCl), optionally adding either stearic acid (SA) or 2-stearamidoethyl stearate (SAES). Reactions were performed either at the solid state, in the absence of any other chemical substance, or with the help of solvents such as water and alcohol, or in poly(1,4-cis-isoprene) as the reaction medium. Characterization was performed by means of TGA, XRD, DSC, IR analyses. Two types of OC were identified, with 3.6–4.0nm and about 6nm as d001 basal spacing, independently of the synthetic route. The 3.6–4nm value could be explained with the bilayer placement of the tilted paraffinic chains of the ammonium cation. The 6nm value could arise from the perpendicular placement of the paraffinic chains, associated with the presence in the interlayer space of either the acid or the amide. For the first time, it is documented the occurrence of hexagonal rotator order in the packing of the long hydrocarbon tails of the 2HT compensating cation. SA and, in particular, SAES were found to enhance this type of order. A third type of OC, with 2.5nm as d001 basal spacing was obtained through solvent extraction of the above mentioned OC. Results reported in this work show that the crystalline structure of an OC depends on type and amount of low molecular mass substances present in the interlayer space: compensating cations and guests such as an acid and/or an amide. For a given compensating cation, the interlayer distance can be varied by changing the amount of the cation and by adding a guest. The Mt/2HT organoclay studied in this work reveals 2.5, 3.6–4.0 and 6.0nm as the interlayer distances of the minima of energy. Polymer chains are not involved in the OC crystalline structure, even if the OC synthesis is performed in the polymer matrix. This work strongly suggests that the best explanation for most interlayer spacing variation observed for clays in polymer nanocomposites is the different placement of intercalated low molecular mass substances, rather than the generally assumed polymer chain intercalation. Moreover, it presents the synthesis of OC at the solid state as a versatile method for preparing a large variety of clay polymer nanocomposites.

Sensors based on surface plasmon resonance in a plastic optical fiber for the detection of trinitrotoluene

The objective of this study is to present an optical chemical sensor based on surface plasmon resonance (SPR) in a plastic optical fiber (POF) for the selective detection and analysis of trinitrotoluene (TNT) in aqueous solution.The fabricated optical chemical sensor was realized removing the cladding of a plastic optical fiber along half the circumference, spin coating on the exposed core a buffer of Microposit S1813 photoresist, and finally sputtering a thin gold film. A molecularly imprinted polymer (MIP) film was, then, deposited on the thin gold film to allow the selective detection of TNT. The film was a methacrylic acid-divinyl benzene copolymer obtained by radicalic polymerization at high temperature.The experimental results show that the use of MIP layer is suitable for highly selective detection of TNT, down to about 50μM (i.e. ∼11μg/ml). This shows that the direct detection of a low molecular mass substance is possible by SPR transduction, even at low concentration. Furthermore, the proposed sensing head is low cost and relatively easy to realize, and may be very attractive for the detection and analysis of trinitrotoluene (TNT), in particular considering that it does not involve the use of any electrical devices and it can be used for remote/online monitoring exploiting, f.i., a fiber optic link.

Possibility to use Ademetionine for the treatment of psoriaticpatients with a pathology of the hepatobiliary system

The endogenous intoxication syndrome manifested in the form of excessive accumulation of low and mean molar mass substances in plasma and urine as well as increased blood plasma concentrations of malonic dialdehyde against the background of reduced alpha-tocopherol was revealed in psoriatic patients with the concomitant hepatobiliary system pathology. Application of Ademetionine in the dose of 800 mg per day for 15 days as a part of the complex therapy for such patients as opposed to the patients receiving standard therapy resulted in reliable reduction in the severity of clinical manifestations of the disease and PASI value as well as decrease in the concentration of low and mean molecular mass substances in plasma and erythrocytes, reduction in the blood plasma malonic dialdehyde concentration and increase in alpha-tocopherol.

5 ASSOCIATION BETWEEN RENAL FUNCTION AND CANCER INCIDENCE IN A LARGE, POPULATION-BASED COHORT

You have accessJournal of UrologyGeneral & Epidemiological Trends & Socioeconomics: Evidence-based Medicine & Outcomes I1 Apr 20105 ASSOCIATION BETWEEN RENAL FUNCTION AND CANCER INCIDENCE IN A LARGE, POPULATION-BASED COHORT Anders Christensson, Caroline Savage, Angel Cronin, M. Frank O'Brien, Peter Nilsson, Jonas Manjer, Andrew Vickers, Paul Russo, and Hans Lilja Anders ChristenssonAnders Christensson Malmo, Sweden More articles by this author , Caroline SavageCaroline Savage New York, NY More articles by this author , Angel CroninAngel Cronin New York, NY More articles by this author , M. Frank O'BrienM. Frank O'Brien New York, NY More articles by this author , Peter NilssonPeter Nilsson Malmo, Sweden More articles by this author , Jonas ManjerJonas Manjer Malmo, Sweden More articles by this author , Andrew VickersAndrew Vickers New York, NY More articles by this author , Paul RussoPaul Russo New York, NY More articles by this author , and Hans LiljaHans Lilja New York, NY More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2010.02.048AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES There are reports that impaired renal function increases the risk of several types of cancer. We evaluated whether moderately impaired renal function influenced risk of developing cancer in a large, population-based cohort. METHODS We used data from Malmö Preventative Medicine Project, a large, population-based cohort (74% participation) containing demographic data and blood samples collected from 33,346 persons aged 33-50 during 1974-86 in Malmö, Sweden. Incident cancers were identified from the Swedish Cancer Registry, updated to 12/31/2006. Glomerular filtration rate (GFR) was estimated using the Modified Diet and Renal Disease formula. Patients were classified as having normal kidney function (GFR≥90 mL/min/1.73m2), mild kidney disease (GFR 60-89 mL/min/1.73m2) or moderate kidney dysfunction (GFR<60 mL/min/1.73m2). We calculated the risk of being diagnosed with cancer using the cumulative incidence function in the presence of a competing risk (death without cancer diagnosis). RESULTS 7,577 patients were diagnosed with cancer and 4,588 died with no cancer diagnosis. The median age at baseline was 47 (IQR 40, 49). 22,183 (69%) participants were male; prostate cancer was the most common cancer diagnosis (n=1,579). Most subjects had mild kidney disease (n=22,336; 70%); 3% (n=1,015) had moderate renal dysfunction and 27% (n=8,621) had normal renal function. The cumulative incidence of cancer was highest for those with the most severely impaired renal function: 20-year cumulative incidence of cancer was 17.3% (95% CI: 15.1%, 19.8%) for those with GFR<60 versus 13.5% (95% CI: 13.0%, 13.9%) and 11.6% (95% CI: 10.9%, 12.3%) for those with GFR 60-89, and ≥90 mL/min/1.73m2, respectively (p<0.001; Figure). This association remained significant after adjustment for age (p<0.001). CONCLUSIONS The mechanism by which cancer risk is associated with renal impairment is unclear but could be due to changes in the accumulation of low molecular mass substances due to decreased GFR. It will be critical to determine which types of cancer are elevated with renal dysfunction. © 2010 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 183Issue 4SApril 2010Page: e2-e3 Advertisement Copyright & Permissions© 2010 by American Urological Association Education and Research, Inc.MetricsAuthor Information Anders Christensson Malmo, Sweden More articles by this author Caroline Savage New York, NY More articles by this author Angel Cronin New York, NY More articles by this author M. Frank O'Brien New York, NY More articles by this author Peter Nilsson Malmo, Sweden More articles by this author Jonas Manjer Malmo, Sweden More articles by this author Andrew Vickers New York, NY More articles by this author Paul Russo New York, NY More articles by this author Hans Lilja New York, NY More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Reinforcement of diene elastomers by organically modified layered silicates

AbstractNanocomposites were prepared based on diene rubbers and layered clays modified with an alkyl quaternary ammonium cation (organoclay). A diene rubber, either polybutadiene, or synthetic or naturally occurring polyisoprene or styrene-butadiene copolymer, was melt blended with either a preformed organoclay or with a mixture of pristine clay and ammonium cation. Besides isolated lamellae, nanocomposites showed the presence of crystalline organoclays with intercalated organic layers made only by low molecular mass substances, essentially the ammonium cation, and no evidences for the intercalation of polymer chains were observed. Dynamic-mechanical properties of sulphur cured compounds with carbon black as the main filler and a minor amount of organoclay were investigated. The organoclay was found to bring about a reduction of Mooney viscosity, an increase of storage modulus at low temperature as well as an increase of thermoplasticity.

Characterization of dopamine-depleting activity of Nocardia asteroides strain GUH-2 culture filtrate on PC12 cells

Experimental infection of BALB/c mice with the Gram-positive bacterium Nocardia asteroides (strain GUH-2) results in life-long movement abnormalities including head shaking and spinning when held by the tail. The head shaking is temporarily inhibited by treatment with dopamine's precursor levodopa, suggesting that abnormalities in dopaminergic neurotransmission may be involved in these movement abnormalities. Cell-free filtrates from N. asteroides cultures induce >70% dopamine depletion in rat pheochromocytoma PC12 cells, suggesting that Nocardia's effects on dopamine neurons may result in part from secreted factors. The nature of this dopamine-depleting activity was examined in the present study. Dopamine-depleting activity in N. asteroides culture filtrate was resistant to heat (100 °C×30 min), proteases, and chloroform extraction, and was present in a low molecular mass (<3 kDa) fraction. It was partially inhibited by decreasing (to 4.0) or increasing (to 10.0) the filtrate pH. GUH-2 filtrate increased cellular lactate dehydrogenase release by only 2%, and induced apoptotic morphology in only 11% of PC12 cells, suggesting that dopamine-depleting activity was not due to either cell injury or induction of apoptosis. These results suggest that a protease-resistant, low molecular mass substance secreted by N. asteroides may be responsible for its dopamine-depleting effects.

Hydrolysis of ginger bagasse starch in subcritical water and carbon dioxide.

Ginger bagasse from supercritical extraction was hydrolyzed using subcritical water and CO(2) to produce reducing sugars and other low molecular mass substances. Response surface methodology was used to find the best hydrolysis conditions; the degree of hydrolysis and the yield were the two response variables selected for maximization. The kinetic studies of the hydrolysis were performed at 150 bar and temperatures of 176, 188, and 200 degrees C. The higher degree of hydrolysis (97.1% after 15 min of reaction) and higher reducing sugars yield (18.1% after 11 min of reaction) were established for the higher process temperature (200 degrees C). Different mixtures of oligosaccharides with different molecular mass distributions were obtained, depending on the temperature and on the reaction time. The ginger bagasse hydrolysis was treated as a heterogeneous reaction with a first-order global chemical kinetic, in relation to the starch concentration, which resulted in an activation energy of 180.2 kJ/mol and a preexponential factor of 5.79 x 10(17)/s.

SCTA Application to Polymers

In SCTA application to high polymers, we do not find remarkable and illustrative results such as found in multiple step dehydration processes of low molecular mass substances. However, some characteristic results were obtained in the application to high polymers, and three examples are described in this report.

Serum cystatin C for assessment of glomerular filtration rate in pregnant and non-pregnant women. Indications of altered filtration process in pregnancy

Serum cystatin C is believed to reflect the glomerular filtration rate (GFR) more closely than serum creatinine in many contexts and a reference interval for serum cystatin C in term pregnancy has been defined to enable its use also in pregnant women. However, serum cystatin C levels were not found to be decreased in term pregnancy, though GFR of low molecular mass substances is known to increase by at least 40% by the third trimester. The aim of this study was therefore to determine whether serum cystatin C is a reliable GFR marker also in pregnant women. GFR was determined by measurement of plasma clearance of iohexol in 48 previously healthy women in their third trimester and in 12 healthy nonpregnant women, and was compared with their serum levels of cystatin C and creatinine. Both serum cystatin C and creatinine levels were significantly related to GFR for both pregnant and non-pregnant women. However, the correlation between cystatin C and GFR was set at different levels for pregnant and nonpregnant women. Our results indicate a physiological difference between the filtration processes in kidneys of pregnant and non-pregnant women, whether it is size-dependent, configuration-dependent or charge-dependent. Nevertheless, serum cystatin C seems to reflect GFR reliably in both non-pregnant and pregnant, healthy and hypertensive women.

Surface biopassivation of replicated poly(dimethylsiloxane) microfluidic channels and application to heterogeneous immunoreaction with on-chip fluorescence detection.

Poly(dimethylsiloxane) (PDMS) appeared recently as a material of choice for rapid and accurate replication of polymer-based microfluidic networks. However, due to its hydrophobicity, the surface strongly interacts with apolar analytes or species containing apolar domains, resulting in significant uncontrolled adsorption on channel walls. This contribution describes the application and characterization of a PDMS surface treatment that considerably decreases adsorption of low and high molecular mass substances to channel walls while maintaining a modest cathodic electroosmotic flow. Channels are modified with a three-layer biotin-neutravidin sandwich coating, made of biotinylated IgG, neutravidin, and biotinylated dextran. By replacing biotinylated dextran with any biotinylated reagent, the modified surface can be readily patterned with biochemical probes, such as antibodies. Combination of probe immobilization chemistry with low nonspecific binding enables affinity binding assays within channel networks. The example of an electrokinetic driven, heterogeneous immunoreaction for human IgG is described.

Induction of apoptosis in HL-60 cells by skimmed milk digested with a proteolytic enzyme from the yeast Saccharomyces cerevisiae

Bovine skimmed milk digested with cell-free extract of the yeast Saccharomyces cerevisiae was found to exhibit proliferation inhibition activity towards human leukemia (HL-60) cells. The optimum pH for digestion of skimmed milk and production of the proliferation inhibition factor was pH 4.8. Nondigested skimmed milk exhibited little suppressive effect on the proliferation of HL-60 cells. An active enzyme involved in the production of cell proliferation inhibitory materials from skimmed milk was purified from the cell-free extract of S. cerevisiae by a series of column chromatographies: DEAE-Sephacel, d-tryptophan methyl ester-Sepharose 4B, Hiload Superdex G-200 and HPLC Mono Q. The homogeneous purified enzyme and exhibited a molecular mass of 33 kDa in sodium dodeceyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and was identified as protease B by N-terminal amino acid sequence analysis. Bovine skimmed milk digested with purified protease B was found to inhibit proliferation activity of HL-60 cells most strongly when digestion was conducted at pH 4.8. The cell proliferation inhibition activity induced by digested skimmed milk was shown to be due to the induction of apoptosis, demonstrated by the formation of apoptotic bodies and fragmentation of DNA in treated cells. The proliferation inhibition factors produced were recovered in the soluble fraction of 92% ethanol, suggesting that the factors were hydrophilic low molecular mass substances derived from skimmed milk.

Drug specific antibodies: T-cell epitope-lipopeptide conjugates are potent adjuvants for small antigens in vivo and in vitro

To generate conventional or monoclonal antibodies for the serological detection of drugs, antibiotics, toxins and other low molecular mass substances, a suitable and effective adjuvant is needed. Lipopeptides derived from a major component of the bacterial cell wall constitute potent nontoxic and nonpyrogenic immunoadjuvants when mixed with conventional antigens. Here we demonstrate that the synthetic lipopeptide N-palmitoyl- S-[2,3- bis(palmitoyloxy)-(2 R, S)-propyl]-( R)-cysteinyl-serine (P 3CS) coupled to a T h-cell epitope (P 3CS-T h) can efficiently enhance the specific immune response against low molecular weight compounds in different species. In the presence of the synthetic lipopeptide P 3CS-T h, the peptides which are per se non-immunogenic stimulated a specific humoral immune response in mice after intraperitoneal application. Mixtures containing adjuvants without the T h sequence showed no significant antibody induction. A marked enhancement of the humoral immune response was obtained with the low molecular mass antigens Iturin A L, Herbicolin A and Microcystin (MLR) coupled to poly-l-lysin (MLR-PLL), in rabbits and in chickens. Lipopeptide-T h cell epitope conjugates also constituted adjuvants for the in vitro immunization of either human mononuclear cells or mouse B-cells with MLR-PLL; after fusion of the immunized cultures with the heteromyeloma cell lines CB-F7 or the mouse myeloma cell line SP 2/0, respectively, we observed a significantly increased yield of antibody secreting hybridomas.