Vaccine-associated varicella and rubella infections in severe combined immunodeficiency with isolated CD4 lymphocytopenia and mutations in IL7R detected by tandem whole exome sequencing and chromosomal microarray

In areas without newborn screening for severe combined immunodeficiency (SCID), disease-defining infections may lead to diagnosis, and in some cases, may not be identified prior to the first year of life. We describe a female infant who presented with disseminated vaccine-acquired varicella (VZV) and vaccine-acquired rubella infections at 13 months of age. Immunological evaluations demonstrated neutropenia, isolated CD4 lymphocytopenia, the presence of CD8(+) T cells, poor lymphocyte proliferation, hypergammaglobulinaemia and poor specific antibody production to VZV infection and routine immunizations. A combination of whole exome sequencing and custom-designed chromosomal microarray with exon coverage of primary immunodeficiency genes detected compound heterozygous mutations (one single nucleotide variant and one intragenic copy number variant involving one exon) within the IL7R gene. Mosaicism for wild-type allele (20-30%) was detected in pretransplant blood and buccal DNA and maternal engraftment (5-10%) demonstrated in pretransplant blood DNA. This may be responsible for the patient's unusual immunological phenotype compared to classical interleukin (IL)-7Rα deficiency. Disseminated VZV was controlled with anti-viral and immune-based therapy, and umbilical cord blood stem cell transplantation was successful. Retrospectively performed T cell receptor excision circle (TREC) analyses completed on neonatal Guthrie cards identified absent TREC. This case emphasizes the danger of live viral vaccination in severe combined immunodeficiency (SCID) patients and the importance of newborn screening to identify patients prior to high-risk exposures. It also illustrates the value of aggressive pathogen identification and treatment, the influence newborn screening can have on morbidity and mortality and the significant impact of newer genomic diagnostic tools in identifying the underlying genetic aetiology for SCID patients.

Mycophenolic Acid Production by Penicillium brevicompactum on Solid Media

When grown on Czapek-Dox agar, Penicillium brevicompactum produced mycophenolic acid after a vegetative mycelium had been formed and as aerial hyphae were developing. Nutrients were still plenteous in the agar when the synthesis began. If aerial hyphal development was prevented by placing a dialysis membrane over the growing fungus, no mycophenolic acid was produced. When the dialysis membrane was peeled back and, as a consequence, production of aerial hyphae began, mycophenolic acid biosynthesis was observed. We concluded that mycophenolic acid was produced only by P. brevicompactum colonies that possessed an aerial mycelium.

Assessment of the estrogenic activity of phytoestrogens isolated from bourbon and beer

Phytoestrogenic substances have previously been isolated and identified in two alcoholic beverages: bourbon and beer. To delineate the relative potencies of the estrogenic substances of plant origin thus far identified in these commonly consumed alcoholic beverages, we evaluated the ability of biochanin A, beta-sitosterol, genistein, and daidzein to bind to cytosolic estrogen receptor binding sites. The in vitro studies demonstrated that each of the contained substances was capable of effectively competing for cytosolic estrogen receptor binding sites of rat liver and uterus. Further, the two phytoestrogenic constituents of bourbon, beta-sitosterol and biochanin A, were less potent than those present in beer. Given the high concentration of beta-sitosterol in bourbon, we chose to evaluate the estrogenicity of beta-sitosterol in vivo using ovariectomized rats. beta-sitosterol was administered either daily or intermittently at 3 doses, based on amounts previously determined to be present in bourbon. The in vivo studies demonstrated that beta-sitosterol is capable of producing a weak estrogenic effect only at the lowest dose (6.2 micrograms/dl) administered intermittently. These responses suggest that beta-sitosterol may be weakly estrogenic at low doses, but is unable to maintain such an effect at higher doses.

Isolation and identification of phytoestrogens from beer

Two estrogenic substances of plant origin have been identified in beer using gas chromatography/mass spectrometry. These phytoestrogens, daidzein and genistein, have previously been shown to be biologically active in animals. Confirming the presence of biologically active phytoestrogens in beer and their possible presence in other beverages, suggests that there may be clinically significant effects related to sustained exposure to phytoestrogens contained in alcoholic beverages.

Quantitation of beta-sitosterol in bourbon

Four phytoestrogens have previously been isolated and identified in alcoholic beverages. Before studies to evaluate the degree of estrogenicity of these substances can be performed, it is necessary to determine appropriate doses to be administered to experimental animals. Because beta-sitosterol is the most plentiful, being present in bourbon at microgram/dl quantities, we have chosen to begin our quantitation work with this compound. The variability of the amount of beta-sitosterol contained in various brands of bourbon and in different lots of the same brand of bourbon have been assessed using combined gas chromatography/mass spectrometry (GC/MS) for quantitation following a simplified procedure to extract compounds of interest from bourbon.

Assessment of articulated thoughts in social anxiety: modification of the ATSS procedure

In the present study an assessment strategy was developed which adapted the Articulated Thoughts during Simulated Situations (ATSS) paradigm devised by Davison, Robins & Johnson (1983). That strategy was applied to the assessment of social anxiety. Responses of 10 socially anxious and 10 non-anxious males were compared as they imagined themselves participating in videotaped simulations of heterosocial interactions. Each time the subject was aware of a reaction to the events depicted, he stopped the videotape, and then articulated his thoughts. Consistent with cognitive conceptualizations of social anxiety, the articulated thoughts of anxious males were distinguished by a greater focus upon the self in general and by a concentration upon irrational concerns in particular. In contrast, non-anxious males provided larger proportions of thoughts directed towards the environment and in particular, provided more positive thoughts both about other persons and their interactions in general. The theoretical and methodological implications of the data are discussed.

Negative symptoms and social skills performance in schizophrenia

The present study aimed to determine whether the negative symptoms of patients with schizophrenia were better predictors of social competence than a range of other variables pertaining to demographics, illness, hospitalization, and premorbid functioning. Independent raters assessed social skills performance on a video-taped role-play test and 5 min conversation in 53 inpatients with a DSM-III diagnosis of schizophrenia. Patients' social skills were also assessed by ward nurses. Project clinicians assessed depression, medication side effects and positive and negative symptoms. Multiple-regression analyses demonstrated that, generally, negative symptoms were the best predictors of social skills performance.

Is social skills performance a correlate of schizophrenia subtypes?

53 inpatients with a DSM-III diagnosis of schizophrenia were assessed in the week prior to discharge from hospital on measures of social skills performance and on severity of positive and negative symptoms. A cluster analysis based on the total positive and negative symptom scores resulted in three groups. The group with the least negative symptoms exhibited the best social skills performance. The findings add a further dimension to the validity of the subtyping of schizophrenia on the basis of positive and negative symptoms.

Utility of the Gd scale for the measurement of Gender-Dysphoria in males

Responses on the 31-item Gender Dysphoria ( Gd) scale of the MMPI of 104 primary gender-dysphoric males who had undergone or were about to undergo gender-reassignment surgery, 25 secondary gender-dysphoric patients from the same clinics, and 563 male psychiatric outpatients were tabulated and specificities and sensitivities calculated. The scale had satisfactory specificity, correctly identifying 98.1% of subjects. Sensitivity was unsatisfactory (40%) in distinguishing secondary gender-dysphorics in the Gender Clinic samples but adequate (88.4%) in the combined psychiatric outpatient and Gender Clinic samples. Factor analysis yielded 8 dimensions, but only 2 of these were easily interpretable or had sufficient items to ensure reliability, suggesting that there was little possibility of utilizing subscales. It is concluded that the Gd scale is an appropriate instrument for excluding primary gender dysphoria when used in conjunction with conventional diagnostic assessments.

The role of interpersonal perception in dyadic adjustment

The discrepancy between the way individuals perceive themselves and the way they are perceived by their partners has been proposed as an indicator of dyadic adjustment. The present study employed the CPI to investigate the relation of interpersonal perception within dyads and real similarity of spouses to marital satisfaction. The subjects were 20 married couples. Support was provided for the use of the real similarity-assumed similarity-accuracy paradigm in studies of interpersonal perception. No sex differences were found in the ability of individuals to predict their spouse's responses on the CPI. Accuracy of prediction was correlated significantly with scores on the Hogan Empathy scale for males, but not for females. Conversely, accuracy was related significantly to dyadic adjustment in the case of females, but not males. Real similarity also was correlated positively with dyadic adjustment. Avenues for further research are suggested.

Biologically active phytoestrogens are present in bourbon

The nonethanol congeners of bourbon have been found to possess estrogenic activity when tested using an in vivo oophorectomized rat bioassay, as well as an in vivo estrogen receptor assay system. The phytoestrogen, biochanin A, as well as the plant sterol, beta-sitosterol, were identified in the bourbon preparation using gas chromatography/mass spectrometry. These findings, using three methodological approaches, demonstrate that bourbon contains at least one biologically active phytoestrogen and suggest that the effects of alcoholic beverage use or abuse, particularly as they relate to endocrine systems, should not be viewed as resulting solely from exposure to ethanol.

Discriminant validity of the Crown-Crisp Experiential Index

The discriminative power of the CCEI subscales was examined. Several approaches were undertaken on the responses from subjects in three neurotically disturbed groups and a normal control group. Analyses indicated that simple cut-off points could discriminate effectively an 'adjusted-neurotic' dimension; simple cut-off points were relatively more difficult to develop for discrimination among the three neurotically disturbed groups. Discriminant analysis of the CCEI subscales indicated that approximately 74 per cent of all subjects could be classified correctly. The OBS and HYS subscales were not found to be effective discriminators among the four groups. While that finding may question the utility of those scales, an alternative explanation was proposed in terms of the characteristics of the present samples.

Effect of hypobaric oxygen and oleic acid on respiration of Staphylococcus aureus

The effect of hypobaric oxygen, with oleic acid in the nutrient substrate, on respiration and slime production by a pulmonary isolate of Staphylococcus aureus was investigated. Under hypobaric, but not normal oxygen pressure, the addition of oleic acid to the nutrient broth caused the bacteria to drastically diminish their demand for oxygen and initiate the secretion of extrapolymeric substances (slime). The decrease in oxygen demand was found to result from impairment of the capacity to reduce and oxidize the coenzyme NAD. Prior to the initiation of slime production, the rate of oxidation exceeded the rate of reduction of the coenzyme, whereas with slime production the rate of reduction was greatest. This could result in elevation of the cellular NADH, which could stimulate gluconeogenesis and thereby increase the synthesis of the carbohydrate component of the slime. The results suggest that staphylococcal infections, such as those of the pulmonary tract in cystic fibrosis and essential fatty acid deficiency, may occur in response to a peculiar chemical environment.

A manifest anxiety scale from the MMPI-168

An established measurement of anxiety that uses MMPI items is Taylor's Manifest Anxiety Scale (MAS). Because the items on the MAS are distributed over the entire MMPI, this measure is not available from a popular short form, the MMPI-168. A new composite anxiety scale that comprises items on the MMPI-168 is described, together with relevant normative statistics and its relationship with other MMPI scales.

Vitamin K (menaquinone) biosynthesis in bacteria: purification and probable structure of an intermediate prior to o-succinylbenzoate

The first aromatic intermediate in the menaquinone biosynthetic pathway is o-succinylbenzoate (OSB); it is formed from chorismate/isochorismate and 2-ketoglutarate. Cell-free extracts of menD+ E. coli strains synthesize an intermediate, "X", which is converted to OSB by extracts of menC+ cells. "X" has been purified to near homogeneity by HPLC. On treatment with acid, it yields both OSB and succinylbenzene (SB). This and other data, suggest that "X" has the structure, 2-succinyl-6-hydroxy-2,4-cyclohexadiene-1-carboxylate (I).

A factorial analysis of BDI scores

Undertook a factorial analysis of the BDI on a sample of 214 male cardiac outpatients. The factor structure yielded three psychologically distinct dimensions interpreted as negative self-attitudes, physiological symptoms and sadness. The sample was divided into depressed and nondepressed subgroups in order to investigate whether the BDI factor structure is dependent on the range of BDI scores selected. While the first two factors from the nondepressed group's scores mimicked those for the full sample, in general the subgroups' factor structures provided no clear interpretation.

A statistical audit of the clinical utility of the 168 version of MMPI

Measured MMPI protocols from 347 female and 563 male psychiatric patients according to the standard form and the 168 version. Clinical scales were derived and profiles were classified using the procedure of Marks, Seeman, and Haller (1978). Approximately 50% agreement between MMPI-168 and full scale profiles was obtained. Most disagreements tended to be clinically important. On a simple psychopathology/nonpsychopathology dichotomy, between 75 and 80% agreement occurred.

Face validity vs. item subtlety in the MMPI D scale

The distinction between item subtlety and face validity ( Holden & Jackson, 1979) provided the basis to reevaluate findings for subtle items in the MMPI D scale (N = 214). Results indicated that the inclusion of nonpathological items in the D scale did not lead to greater predictive validity of depression criteria. The need for substantive considerations in scale construction was emphasized further.

Homogeneous scales for the neurotic triad of the MMPI

This study used item statistics for the nonduplicated items of the MMPI and the CPI to develop homogeneous scales for the neurotic triad (Hs, D, Hy) of the MMPI. The construction and partial cross-validation of scales were based on data from a predominantly clinical sample of 563 male subjects and 347 female subjects. Two non-overlapping scales of high internal consistency were developed which contained embedded subscales designed to be relatively independent of factor dimensions previously identified in the data. The first of the two scales comprised items exclusively related to health concern, and the second was a more concentrated measure of poor morale than the MMPI Depression scale. The nature of the revised scales was analyzed in relation to the standard MMPI scales and factor dimensions from previous research. Implications of the study for development of an hierarchical inventory were discussed.

In vitro response of Staphylococcus aureus from cystic fibrosis patients to combinations of linoleic and oleic acids added to nutrient medium

The effect of supplementing nutrient substrate with various combinations of concentrations of oleic and linoleic acids on the growth of 11 strains of Staphylococcus aureus was assessed. Whereas increasing the concentration of linoleic acid by itself greatly diminished the growth of all 11 strains, concomitant increases in oleic acid greatly diminished the inhibitory effect of linoleic acid. With oleic acid in the nutrient substrate, most of the strains were induced to produce slime which surrounded the cells. Since the slime incorporated oleic but not linoleic acid, such slime production isolated the cells from direct contact with the growth inhibitor, linoleic acid.

Effects of 20,25-diazacholesterol on cholesterol synthesis in cultured chick muscle cells: a radiogas chromatographic and mass spectrometric study of the post-squalene sector

Radiogas chromatography, used in conjunction with mass spectrometry, has been used to analyze the sterol content of cultured chick muscle cells. Seven sterols, plus lanosterol, were detected. These sterols conformed to a linear biosynthetic pathway linking lanosterol and cholesterol. The reaction sequence is: C-14 demethylation, C-4 demethylation, delta 8 leads to delta 5 double bond rearrangement, delta 24 double bond reduction. When chick cells were treated with increasing concentrations of 20,25-diazacholesterol, components of this pathway and aberrant products accumulated. These accumulations suggest that diazacholesterol affects reductases, double bond isomerases and the C-14 demethylation enzymes of sterol biosynthesis.

Reversible cryogenic alteration of the ultraviolet absorption spectra of the olefinic bonds in lipid membranes

In earlier studies it was found that the association of basic polypeptides with lipid vesicles drastically altered ultraviolet absorption by the olefinic bonds of the lipid. Such an effect suggested that the polypeptide was increasing the polarity of the chromophore environment by either direct interaction with the acyl chains or by inducing their hydration. It is reported here that freeze-thaw cycling, which was expected to allow hydration of the olefinic-bond region of the membranes, caused the same spectral alteration as vesicle interaction with basic polypeptides. When these vesicles were subsequently placed under conditions that would be expected to accelerate the escape of water entrapped within the membranes (i.e., by placing them under vacuum or adding sucrose to establish a high osmotic gradient to their exterior), the absorption spectrum was rapidly restored to that for olefinic bonds in a nonpolar environment. Since placing the polylysine- dioleoylphosphatidylcholine (DOPC) vesicle interaction product under the same conditions restored the spectral intensity, at 190 nm, to between 80 and 85% of that for the lipid in a nonpolar environment, it seems that a major effect of polylysine on DOPC membranes may be though induction of hydration of their interior.

Disposition of Mycophenolic Acid, Brevianamide A, Asperphenamate, and Ergosterol in Solid Cultures of Penicillium brevicompactum

When Penicillium brevicompactum was grown between layers of dialysis membrane on Czapek-Dox agar for 3 days, no synthesis of mycophenolic acid, brevianamide A, asperphenamate, or ergosterol occurred. After removal of the uppermost membrane layer, aerial mycelium developed and all four metabolites were formed. The bulk of the mycophenolic acid that was formed was excreted into the medium, the bulk of the brevianamide A and asperphenamate was found in the aerial hyphae, and ergosterol was found in both vegetative and aerial mycelia.

Brevianamides A and B Are Formed Only After Conidiation Has Begun in Solid Cultures of Penicillium brevicompactum

In cultures of Penicillium brevicompactum grown on Czapek-Dox agar or on circles of dialysis membrane placed on Czapek-Dox agar, brevianamides A and B first appeared after conidiation had begun. The presence of these brevianamides imparted a yellow-green fluorescence to the penicilli and to the upper section of the conidiophores of actively conidiating cultures. Experiments with replacement cultures indicated that medium nutrient levels had little direct effect on brevianamide production. If P. brevicompactum was grown between two circles of dialysis membrane, no aerial hyphae were formed, and brevianamide production was not observed. Three brevianamide-minus mutants of P. brevicompactum were isolated.

6-Methylsalicylic Acid Production in Solid Cultures of Penicillium patulum Occurs Only When an Aerial Mycelium Is Present

When Penicillium patulum was grown on Czapek-Dox agar, 6-methylsalicylic acid was produced as an aerial mycelium was forming. Nutrients were often plentiful in the medium when biosynthesis began. If the formation of an aerial mycelium was prevented by growing the fungus between two sheets of dialysis membrane, no 6-methylsalicylic acid was produced even when nutrients were completely consumed. If the upper sheet of dialysis membrane was stripped off cultures of the latter type, an aerial mycelium formed; concomitantly, 6-methylsalicylic acid biosynthesis was observed. We conclude that 6-methylsalicylic acid was produced only by P. patulum colonies that possessed an aerial mycelium.

Vesicle surface charge and polylysine modification of ultraviolet absorption by the olefinic bonds in charged lipid

The results of electrical conductivity and ultraviolet absorption studies on bilayer vesicles, composed of various mixtures of saturated dipalmitoylphosphatidylcholine (DPPC)and unsaturated bovine brain phoaphatidylserine (PS), in the presence and absence of polylysine indicate the following. (i) The two kinds of lipid maintain a strong transbilayer segregation over a wide range of proportions. The charged lipid (PS) preferentially locates in the inner, at PS proportions of 33% or less, and in the outer layer of the membranes when its proportion is increased to 50%. (ii) At PS proportions of 33% of less, where DPPC is the major component of the outer layer, the ability of polylysine to modify ultraviolet absorption by the olefinic bonds in the PS depends on the fluidity of the phosphatidylcholine. At higher PS proportions, where PS preferentially locates in the outer layer, modification of the ultraviolet absorption spectrum of the lipid by polylysine occurs only when the surface charge of the vesicles is diminished by the addition of bivalent metal ions. (iii) The polylysine-induced change in the ultraviolet absorption spectrum of the olefinic bonds in the vesicles was found to be very similar to that induced by dispersing unsaturated fatty acids in water rather than dissolving them in a nonpolar solvent. This suggests that polylysine modification of the vesicles spectrum may be the result of deep hydrophobic penetration by the polypeptide causing hydration and(or) parallel alignment of the dipole moments of the absorbing chromophores.

Radiogas chromatography mass spectrometry in the selected ion monitoring mode

The value of selected ion monitoring in analyzing biological radio isotope incorporation experiments by radiogas chromatography mass spectrometry is illustrated with reference to the biosynthesis of the mycotoxin mycophenolic acid and the mode of action of the anticholesterolemic drug 20,25-diazacholesterol. It is shown that the increased sensitivity and specificity of the selected ion monitoring mode detector permits straightforward detection and identification of the relatively small cellular pools associated with metabolic intermediates. The computer program RADSIM is described. Problems that still exist in using radiogas gas chromatography mass spectrometry technology to analyse isotope incorporation experiments are discussed.

The effect of polypeptide-lipid interactions on the ultraviolet spectrum of the olefinic bonds of the lipid

The effect of associating acidic and basic polypeptides with dilute suspensions of vesicles composed of various unsaturated phospholipids was assessed with regard to optical density and ultraviolet absorption. Associating basic polypeptides with phosphatidylserine, phosphatidylethanolamine, and phosphatidylglycerol vesicles, or acidic polypeptide with phosphatidylcholine vesicles, caused an increase in the optical density of the preparations, with no measurable effect on the intensity of the ultraviolet spectrum of the olefinic bonds of the lipid. Associating basic polypeptides with phosphatidylcholine vesicles, in addition to causing similar increases in optical density, resulted in a large decrease in the intensity of ultraviolet absorption by the olefinic bonds. This implies that the interaction between the basic polypeptides and phosphatidylcholine vesicles results in major alterations in the microenvironment of the olefinic bonds, which would require intimate association of the polypeptide with the ninth carbon region of the acyl chains. These observations support the conclusion, drawn from our earlier studies, that the association of basic polypeptides and liquid crystalline phase phosphatidylcholine vesicles is peculiar in that it involves a major hydrophobic component.

Mycophenolic acid production by Penicillium brevicompactum in two media

Penicillium brevicompactum produces mycophenolic acid as it grows vegetatively, not only on a simple medium where growth is slow but also on a richer medium where growth is less restricted. The implications of this finding on the association of fungal secondary metabolism with the idiophase in liquid and solid culture are discussed.

Temperature-dependent interactions between poly-L-lysine and phosphatidylcholine vesicles

Studies on the effect of temperature on the optical density of suspensions of dipalmitoyl phosphatidylcholine vesicles, in the presence of polylysine, indicate that the polypeptide can undergo two different kinds of interactions with the vesicles. At temperatures below the phase transition there seems to be a small surface–polar interaction, which maximizes at about 36 °C (i.e., about 5 °C below the phase transition). Upon transition of the lipid membranes to the liquid crystalline phase, there is a much larger rapid interaction, which seems to be hydrophobic. Whereas the first interaction is not temperature reversible, the second interaction rapidly reverses when the temperature is decreased below the phase transition of dipalmitoyl phosphatidylcholine. Incorporation of as little as 5% unsaturated lecithin, either dioleoyl or dilinoleoyl, into the dipalmitoyl vesicles, stabilizes the liquid phase interaction, so that it does not readily reverse when the temperature is decreased below that of the phase transition. Whereas dioleoyl only partially and temporarily interferes with the temperature reversal, dilinoleoyl almost completely stabilizes the interaction. Associated studies using dilatometry and electron microscopy show that the liquid phase interaction between polylysine and phosphatidylcholine vesicles results in the formation of a complex which is of high molecular and electron density.

Changes in the osmotic behaviour of phosphatidylcholine vesicles induced by interaction with polyamino acids

The permeability of synthetic phosphatidylcholines has been studied with stopped-flow spectrometry by monitoring the initial shrinkage or swelling velocity of the sonicated vesicles. It was observed that aqueous diffusion was more rapid through dilinoleoyl- than through dioleoyl- which in turn was faster than through dipalmitoyl-phosphatidylcholine membranes. In contrast, when the vesicles were associated with poly-L-lysine, aqueous diffusion through dioleoyl- was greatly enhanced, whereas that through dilinoleoyl- and dipalmitoyl-phosphatidylcholine was diminished. When the vesicles were associated with polyglutamic acid, the permeability of dipalmitoyl decreased, that of dioleoyl increased, and there was little or no effect on dilinoleoyl vesicles. Measurements on the initial rate of optical density increase by dioleoyl- and dilinoleoyl-phosphatidylcholine vesicles, when they were mixed with polylysine solutions, showed that the rates of interaction by the two kinds of vesicles with the polypeptide were very different, dilinoleoyl reacting much more rapidly than dioleoyl. The observations indicate that phosphatidylcholine vesicles can interact with both acidic and basic polypeptides, and the reaction differs not only in relation to the charge on the polypeptide but also on the fatty acid composition of the lipid.

Naphthalenone production in Aspergillus parvulus

The naphthalenones asparvenone and its 6-O-methyl ether are produced by Aspergillus parvulus during vegetative growth in batch-mode, shaken cultures in a glucose-glycine-salts medium. The secondary metabolites first appear around the time when hyphae of developing spores begin to make contact with each other, i.e. at a very early stage of culture development. Resuspension in new medium of mycelium that is producing the naphthalenones fails to inhibit production. When A. parvulus is grown in parallel on a glucose-glycine-salts medium and on a glucose-malt-peptone medium, the naphthalenones appear first in the richer medium despite the fact that biomass proliferation is relatively unrestricted in that medium. Radiolabelled [1-14C]-acetate is taken up quickly by the fungus (k = 0.09 min-1) and is incorporated effectively into the naphthalenones.

Spore germination, colony development, and secondary metabolism in Penicillium brevicompactum: a radiogas chromatographic and morphological study

A study of the first 76 h of development of spores of Penicillium brevicompactum in batch-mode shake culture indicates that mycophenolic acid biosynthesis begins when the hyphae of germinating spores aggregate to form pellets. Supplies of mycophenolic acid so produced augment a pre-existing pool of the material that is associated with the dormant spore. Although acetate metabolism is active at all stages of development, incorporation of [1-(14)C]acetate into 2,4-dihydroxy-6-(1',2'-dioxopropyl)benzoic acid, another secondary metabolite of the fungus, could not be demonstrated. The significance of these data are considered in terms of the function of mycophenolic acid and the substituted benzoic acid in the producing organism.

Labelled acetone and levulinic acid are formed when [14C]acetate is being converted to mycophenolic acid in Penicillium brevicompactum

Evidence is presented that is compatible with the hypothesis that the farnesyl unit involved in the biosynthesis of mycophenolic acid in Penicillium brevicompactum is degraded by two successive oxidative cleavages at the double bonds distal from the phthalide nucleus. Acetone and levulinic acid are two non-aromatic degradation products.

How valine deprivation and its reversal affect fatty acid metabolism in HeLa cells

A protocol based on radio gas chromatography demonstrates that when HeLa cells are deprived of valine for short periods of time (6-7.5 h), their overall fatty acid biosynthetic activity is depressed after a latency of a few hours. The transfer of newly synthesized fatty acyl units to phospholipids is curtailed much faster than their transfer to triacyglycerols. Despite the cut-back in fatty acid biosynthesis, valine deprivation causes a lipid accumulation in the cells. Valine deprivation appears to affect de novo synthesis of fatty acid units from acetate more rapidly than desaturation and elongation. When valine is returned to the valine-deprived culture, overall fatty acid biosynthesis is resumed well within 2 h. Newly synthesized fatty acyl units are transferred to both the phospholipids and the 1,2-diacylglycerols of the cells but not initially to the triacylglycerols.

Influence of valine deprivation and its reversal on fatty acid metabolism in HeLa cells

The effects that amino acid starvation and re-supplementation have on fatty acid metabolism in HeLa cells have been studied using radio gas chromatographic techniques. Deprivation of valine for 13.5 h caused fatty acid de novo biosynthesis, elongation and desaturation to cease. This effect was reversed within 5 h by adding valine back to the culture. During deprivation accumulation of triacylglycerol occurred. The return of valine to the culture caused compositional changes in the triacylglycerols and phosphatidylcholines.

Abnormal fatty acid composition and impaired oxygen supply in cystic fibrosis patients

Impaired oxygen supply and deteriorating health, in cystic fibrosis patients, correlates with abnormal changes in the fatty acid composition of blood lipids. As the proportion of oleates increases and that of linoleates decreases, erythrocyte membrane interference with the formation of intracellular oxyhemoglobin increases and arterial oxygen pressure decreases. The physical-chemical basis for these changes seems to be that oleic and linoleic acid differ in their ability to undergo reversible oxygenation in response to changes in oxygen pressure. The oxygen complex of linoleic acid dissociates at relatively high pressures, whereas that of oleic dissociates only at low pressures. Accordingly, excessive substitution of oleic for linoleic acid in membrane lipids would be expected to decrease the intracellular oxygen pressure to a level where hemoglobin oxygenation and any other oxygen-requiring processes would be impaired.