Genetic analysis of iron, zinc and grain yield in wheat-Aegilops derivatives using multi-locus GWAS

BACKGROUND

Wheat is a major staple crop and helps to reduce worldwide micronutrient deficiency. Investigating the genetics that control the concentrations of iron (Fe) and zinc (Zn) in wheat is crucial. Hence, we undertook a comprehensive study aimed at elucidating the genomic regions linked to the contents of Fe and Zn in the grain.

METHODS AND RESULTS

We performed the multi-locus genome-wide association (ML-GWAS) using a panel of 161 wheat-Aegilops substitution and addition lines to dissect the genomic regions controlling grain iron (GFeC), and grain zinc (GZnC) contents. The wheat panel was genotyped using 10,825 high-quality SNPs and phenotyped in three different environments (E1-E3) during 2017-2019. A total of 111 marker-trait associations (MTAs) (at p-value < 0.001) were detected that belong to all three sub-genomes of wheat. The highest number of MTAs were identified for GFeC (58), followed by GZnC (44) and yield (9). Further, six stable MTAs were identified for these three traits and also two pleiotropic MTAs were identified for GFeC and GZnC. A total of 1291 putative candidate genes (CGs) were also identified for all three traits. These CGs encode a diverse set of proteins, including heavy metal-associated (HMA), bZIP family protein, AP2/ERF, and protein previously associated with GFeC, GZnC, and grain yield.

CONCLUSIONS

The significant MTAs and CGs pinpointed in this current study are poised to play a pivotal role in enhancing both the nutritional quality and yield of wheat, utilizing marker-assisted selection (MAS) techniques.

Application of CRISPR-Mediated Gene Editing for Crop Improvement

Plant gene editing has become an important molecular tool to revolutionize modern breeding of crops. Over the past years, remarkable advancement has been made in developing robust and efficient editing methods for plants. Despite a variety of available genome editing methods, the discovery of most recent system of clustered regularly interspaced short palindromic repeats-CRISPR-associated proteins (CRISPR-Cas) has been one of the biggest advancement in this path, with being the most efficient approach for genome manipulation. Until recently, genetic manipulations were confined to methods, like Agrobacterium-mediated transformations, zinc-finger nucleases, and TAL effector nucleases. However this technology supersedes all other methods for genetic modification. This RNA-guided CRISPR-Cas system is being rapidly developed with enhanced functionalities for better use and greater possibilities in biological research. In this review, we discuss and sum up the application of this simple yet powerful tool of CRISPR-Cas system for crop improvement with recent advancement in this technology.

Identification, expression analysis, and molecular modeling of Iron-deficiency-specific clone 3 (Ids3)-like gene in hexaploid wheat

Graminaceous plants secrete hydroxylated phytosiderophores encoded by the genes iron-deficiency-specific clone 2 (Ids2) and iron-deficiency-specific clone 3 (Ids3). An effort was made to identify a putative ortholog of Hodeum vulgare Ids3 gene in hexaploid wheat. The protein structure of TaIDS3 was modeled using homology modeling and structural behavior of modeled structure was analyzed at 20 ns. The simulation trajectory using molecular dynamics simulation suggested the model to be stable with no large fluctuations in residues and local domain level RMSF values (< 2.4 Å). In addition, the ProFunc results also predict the functional similarity between the proteins of HvIDS3 and its wheat ortholog (TaIDS3). The TaIds3 gene was assigned to the telomeric region of chromosome arm 7AS which supports the results obtained through bioinformatics analysis. The relative expression analysis of TaIds3 indicated that the detectable expression of TaIds3 is induced after 5th day of Fe starvation and increases gradually up to 15th day, and thereafter, it decreases until 35th day of Fe-starvation. This reflects that Fe deficiency directly regulates the induction of TaIds3 in the roots of hexaploid wheat. The identification of HvIds3-like gene in wheat has opened up new opportunities to enhance the nutrient quality in wheat through biofortification program.

Transfer of HMW glutenin subunits from Aegilops kotschyi to wheat through radiation hybridization

High molecular weight glutenin subunits (HMWGS) are responsible for dough elasticity and bread making quality of bread wheat. Related wild non-progenitor species, Aegilops kotschyi possesses higher molecular weight x and y glutenin subunits than the bread wheat cultivars. A wheat-Aegilops substitution line with 1U chromosome was used for the transfer of (HMWGS) of 1U to wheat by using pollen radiation hybridization approach. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis profiling showed different patterns of allelic variations with either the presence or absence of HMWGS, Glu-1A (1, null), Glu-1B (7, 7 + 8, 17 + 18) and Glu-1D (5 + 10, 2 + 12, null). The pollen irradiated wheat-Aegilops derivatives, B-56-1-4-2, B-56-1-4-3, B-14-1 and B-14-2 with Glu1Ux and 1Uy and absence or presence of some Glu-1A and Glu-1B HMWGS showed high micro SDS sedimentation test (MST) values while B-16-1 and B-16-2 had moderate MST values and high protein content. However, B-58-3 with transfer of Glu-1Ux + 1Uy for Glu-1D showed very low MST values indicating that Glu-1Ux + 1Uy enhance MST value only in the presence of Glu1D HMWGS. The transfer/substitution of alien HMW-GS for Glu-1A and or Glu-1B loci only can lead to improved bread making quality of wheat.

Introgression of a leaf rust resistance gene from Aegilops caudata to bread wheat

Rusts are the most important biotic constraints limiting wheat productivity worldwide. Deployment of cultivars with broad spectrum rust resistance is the only environmentally viable option to combat these diseases. Identification and introgression of novel sources of resistance is a continuous process to combat the ever evolving pathogens. The germplasm of nonprogenitor Aegilops species with substantial amount of variability has been exploited to a limited extent. In the present investigation introgression, inheritance and molecular mapping of a leaf rust resistance gene of Ae. caudata (CC) acc. pau3556 in cultivated wheat were undertaken. An F(2) population derived from the cross of Triticum aestivum cv. WL711 - Ae. caudata introgression line T291-2 with wheat cultivar PBW343 segregated for a single dominant leaf rust resistance gene at the seedling and adult plant stages. Progeny testing in F(3) confirmed the introgression of a single gene for leaf rust resistance. Bulked segregant analysis using polymorphic D-genome-specific SSR markers and the cosegregation of the 5DS anchored markers (Xcfd18, Xcfd78, Xfd81 and Xcfd189) with the rust resistance in the F(2) population mapped the leaf rust resistance gene (LrAC) on the short arm of wheat chromosome 5D. Genetic complementation and the linked molecular markers revealed that LrAC is a novel homoeoallele of an orthologue Lr57 already introgressed from the 5M chromosome of Ae. geniculata on 5DS of wheat.

Development of multiple embryos in polyembryonic insertional mutant OsPE of rice

A T-DNA insertional mutant OsPE of rice gives twin and triplet seedlings in up to 20 % of the seeds. Detailed cytological and histological analysis of OsPE indicated normal male and female gametogenesis in the OsPE mutant. Confocal laser scanning microscopic (CLSM) analysis of the developing seeds of OsPE showed multiple embryo development in up to 60 % of the ovules. The multiple embryos, mostly twins and triplets, and rarely quadruplets, developed through sequential cleavage from a single zygotic embryo in each ovule. The reduced number of multiple seedlings compared with multiple embryos observed in CLSM study may be attributed to their inability to develop further due to competition in a single embryo sac. Key message Multiple seedlings in the OsPE mutant are due to sequential proliferation and cleavage of the zygotic embryos. The nucellar tissue was not involved in multiple embryo development.

Abnormal endosperm development causes female sterility in rice insertional mutant OsAPC6

A T-DNA insertional mutant OsAPC6 of rice, with gibberellic acid insensitivity and reduced height, had up to 45% reduced seed set. The insertion occurred on chromosome 3 of rice in the gene encoding one of the subunits of anaphase promoting complex/Cyclosome APC6. The primary mother cells of the mutant plants had normal meiosis, male gametophyte development and pollen viability. Confocal laser scanning microscopic (CLSM) studies of megagametophyte development showed abnormal mitotic divisions with reduced number or total absence of polar nuclei in about 30-35% megagametophytes of OsAPC6 mutant leading to failure of endosperm and hence embryo and seed development. Abnormal female gametophyte development, high sterility and segregation of tall and gibberellic acid sensitive plants without selectable marker Hpt in the selfed progeny of OsAPC6 mutant plants indicate that the mutant could be maintained in heterozygous condition. The abnormal mitotic divisions during megagametogenesis could be attributed to the inactivation of the APC6/CDC16 of anaphase promoting complex of rice responsible for cell cycle progression during megagametogenesis. Functional validation of the candidate gene through transcriptome profiling and RNAi is in progress.

QTL mapping of 1000-kernel weight, kernel length, and kernel width in bread wheat (Triticum aestivum L.)

Kernel size and morphology influence the market value and milling yield of bread wheat (Triticum aestivum L.). The objective of this study was to identify quantitative trait loci (QTLs) controlling kernel traits in hexaploid wheat. We recorded 1000-kernel weight, kernel length, and kernel width for 185 recombinant inbred lines from the cross Rye Selection 111 &times; Chinese Spring grown in 2 agro-climatic regions in India for many years. Composite interval mapping (CIM) was employed for QTL detection using a linkage map with 169 simple sequence repeat (SSR) markers. For 1000-kernel weight, 10 QTLs were identified on wheat chromosomes 1A, 1D, 2B, 2D, 4B, 5B, and 6B, whereas 6 QTLs for kernel length were detected on 1A, 2B, 2D, 5A, 5B and 5D. Chromosomes 1D, 2B, 2D, 4B, 5B and 5D had 9 QTLs for kernel width. Chromosomal regions with QTLs detected consistently for multiple year-location combinations were identified for each trait. Pleiotropic QTLs were found on chromosomes 2B, 2D, 4B, and 5B. The identified genomic regions controlling wheat kernel size and shape can be targeted during further studies for their genetic dissection.

Effect of pre-harvest calcium sprays on post-harvest life of winter guava (Psidium guajava L.)

Influence of pre-harvest foliar application of calcium nitrate on quality attributes of winter guava cv. 'Sardar' during different interval of cold storage and post cold storage shelf-life under ambient conditions was investigated. Plants were sprayed with calcium nitrate solutions (0.5, 1.0 and 1.5%) at colour break stage of fruit and a fruit with no treatment was control. The fruits were harvested at optimum maturity. Bruise and disease free fruits were packed in corrugated fibre board boxes with newspaper lining and stored at 6-8 °C and 90-95% RH. The fruits were evaluated after 10, 20, 30 and 40 days of storage and during shelf-life at 2 and 4 days interval. Physiological loss in weight and spoilage of fruits increased and firmness, ascorbic acid and acidity decreased continuously during storage. Fruits treated with 1% Ca(NO3)2 effectively reduced spoilage, maintained higher firmness, total soluble solid and ascorbic acid up to 2 days under ambient conditions after 30 days of cold storage and remained moderately acceptable up to the 40 days of storage.

Studies on optimization of ripening techniques for banana

Fruits of banana (Musa spp) cultivar 'Grand Naine' were harvested at physiological green mature stage. The first lot of fruit was exposed to ethylene gas (100 ppm) for 24 h in ripening chamber. The second lot was treated with different concentrations of aqueous solution of ethephon (250, 500, 750, 1000 ppm) each for 5 min. The fruits were packed in plastic crates and stored in ripening chamber maintained at 16-18°C and 90-95% RH. Treatment with ethylene gas (100 ppm) or ethephon (500 ppm) resulted in adequate ripening of fruits after 4 days with uniform colour, pleasant flavour, desirable firmness and acceptable quality and better shelf-life. The untreated control fruits were hard textured and poor in colour and quality. The ripening with ethylene gas or ethephon treatment seems to hold promise in reducing postharvest losses and boosting the economy of banana growers and traders.

Mapping of adult plant stripe rust resistance genes in diploid A genome wheat species and their transfer to bread wheat

Stripe rust, caused by Puccinia striiformis West. f.sp. tritici, is one of the most damaging diseases of wheat worldwide. Forty genes for stripe rust resistance have been catalogued so far, but the majority of them are not effective against emerging pathotypes. Triticum monococcum and T. boeoticum have excellent levels of resistance to rusts, but so far, no stripe rust resistance gene has been identified or transferred from these species. A set of 121 RILs generated from a cross involving T. monococcum (acc. pau14087) and T. boeoticum (acc. pau5088) was screened for 3 years against a mixture of pathotypes under field conditions. The parental accessions were susceptible to all the prevalent pathotypes at the seedling stage, but resistant at the adult plant stage. Genetic analysis of the RIL population revealed the presence of two genes for stripe rust resistance, with one gene each being contributed by each of the parental lines. A linkage map with 169 SSR and RFLP loci generated from a set of 93 RILs was used for mapping these resistance genes. Based on phenotypic data for 3 years and the pooled data, two QTLs, one each in T. monococcum acc. pau14087 and T. boeoticum acc. pau5088, were detected for resistance in the RIL population. The QTL in T. monococcum mapped on chromosome 2A in a 3.6 cM interval between Xwmc407 and Xwmc170, whereas the QTL from T. boeoticum mapped on 5A in 8.9 cM interval between Xbarc151 and Xcfd12 and these were designated as QYrtm.pau-2A and QYrtb.pau-5A, respectively. Based on field data for 3 years, their R2 values were 14 and 24%, respectively. T. monococcum acc. pau14087 and three resistant RILs were crossed to hexaploid wheat cvs WL711 and PBW343, using T. durum as a bridging species with the objective of transferring these genes into hexaploid wheat. The B genome of T. durum suppressed resistance in the F1 plants, but with subsequent backcrossing one resistance gene could be transferred from one of the RILs to the hexaploid wheat background. This gene was derived from T. boeoticum acc. pau5088 as indicated by co-introgression of T. boeoticum sequences linked to stripe rust resistance QTL, QYrtb.pau-5A. Homozygous resistant progenies with 40-42 chromosomes have been identified.

An integrated molecular linkage map of diploid wheat based on a Triticum boeoticum x T. monococcum RIL population

Diploid A genome species of wheat harbour immense variability for biotic stresses and productivity traits, and these could be transferred efficiently to hexaploid wheat through marker assisted selection, provided the target genes are tagged at diploid level first. Here we report an integrated molecular linkage map of A genome diploid wheat based on 93 recombinant inbred lines (RILs) derived from Triticum boeoticum x Triticum monococcum inter sub-specific cross. The parental lines were analysed with 306 simple sequence repeat (SSR) and 194 RFLP markers, including 66 bin mapped ESTs. Out of 306 SSRs tested for polymorphism, 74 (24.2%) did not show amplification (null) in both the parents. Overall, 171 (73.7%) of the 232 remaining SSR and 98 (50.5%) of the 194 RFLP markers were polymorphic. Both A and D genome specific SSR markers showed similar transferability to A genome of diploid wheat species. The 176 polymorphic markers, that were assayed on a set of 93 RILs, yielded 188 polymorphic loci and 177 of these as well as two additional morphological traits mapped on seven linkage groups with a total map length of 1,262 cM, which is longer than most of the available A genome linkage maps in diploid and hexaploid wheat. About 58 loci showed distorted segregation with majority of these mapping on chromosome 2A(m). With a few exceptions, the position and order of the markers was similar to the ones in other maps of the wheat A genome. Chromosome 1A(m) of T. monococcum and T. boeoticum showed a small paracentric inversion relative to the A genome of hexaploid wheat. The described linkage map could be useful for gene tagging, marker assisted gene introgression from diploid into hexaploid wheat as well as for map based cloning of genes from diploid A genome species and orthologous genes from hexaploid wheat.

Identification and mapping of a tiller inhibition gene (tin3) in wheat

Tillering is one of the most important agronomic traits in cereal crops because tiller number per plant determines the number of spikes or panicles per plant, a key component of grain yield and/or biomass. In order to characterize the underlying genetic variation for tillering, we have isolated mutants that are compromised in tillering ability using ethyl methanesulphonate (EMS)-based mutagenesis in diploid wheat (Triticum monococcum subsp. monococcum). The tillering mutant, tiller inhibition (tin3) produces only one main culm compared to the wild type with many tillers. The monoculm phenotype of tin3 is due to a single recessive mutation. Genetic and molecular mapping in an F(2) population of diploid wheat located the tin3 gene on the long arm of chromosome 3A(m). One codominant RFLP marker Xpsr1205 cosegregated with tin3 in the F(2) population. Physical mapping of PSR1205 in a set of Chinese Spring deletion lines of group-3 chromosomes placed the tin3 gene in the distal 10% of the long arm of chromosome 3A, which is a recombination-rich region in wheat. The implications of the mapping of tin3 on chromosome arm 3A(m)L are discussed with respect to putative orthologs of tin3 in the 3L colinear regions across various cereal genomes and other tillering traits in grasses.

Patterns of antifungal prescribing in general dental practice

OBJECTIVE

To examine the current practice of antifungal prescribing by GDPs in the United Kingdom. Design A postal questionnaire circulated to a random selection of 400 dentists.

OUTCOME MEASURES

The questionnaires were analysed and the responses expressed as absolute and relative frequencies.

RESULTS

Responses to the questionnaire were received from 297 (74.3%) GDPs. Nystatin was the most popular choice of antifungal agent that GDPs would use, followed by miconazole, amphotericin B and fluconazole. The likelihood of use of miconazole was positively linked to recent date of graduation. Lack of knowledge regarding contraindications and problems with azole antibiotics was found in a significant minority of practitioners (36%).

CONCLUSIONS

The present study indicates that azole antifungal agents (especially miconazole) are becoming more widely used by GDPs, but that knowledge regarding potential problems with their use is sub-optimal. Nystatin remains the most popular choice of antifungal agent.

QTL analysis for grain protein content using SSR markers and validation studies using NILs in bread wheat

QTL interval mapping for grain protein content (GPC) in bread wheat was conducted for the first time, using a framework map based on a mapping population, which was available in the form of 100 recombinant inbred lines (RILs). The data on GPC for QTL mapping was recorded by growing the RILs in five different environments representing three wheat growing locations from Northern India; one of these locations was repeated for 3 years. Distribution of GPC values followed normal distributions in all the environments, which could be explained by significant g x e interactions observed through analyses of variances, which also gave significant effects due to genotypes and environments. Thirteen (13) QTLs were identified in individual environments following three methods (single-marker analysis or SMA, simple interval mapping or SIM and composite interval mapping or CIM) and using LOD scores that ranged from 2.5 to 6.5. Threshold LOD scores (ranging from 3.05 to 3.57), worked out and used in each case, however, detected only seven of the above 13 QTLs. Only four (QGpc.ccsu-2B.1; QGpc.ccsu-2D.1; QGpc.ccsu-3D.1 and QGpc.ccsu-7A.1) of these QTLs were identified either in more than one location or following one more method other than CIM; another QTL (QGpc.ccsu-3D.2), which was identified using means for all the environments, was also considered to be important. These five QTLs have been recommended for marker-assisted selection (MAS). The QTLs identified as above were also validated using ten NILs derived from three crosses. Five of the ten NILs possessed 38 introgressed segments from 16 chromosomes and carried 42 of the 173 markers that were mapped. All the seven QTLs were associated with one or more of the markers carried by the above introgressed segments, thus validating the corresponding markers. More markers associated with many more QTLs to be identified should become available in the future by effective MAS for GPC improvement.

Mapping of a resistance gene effective against Karnal bunt pathogen of wheat

A set of 130 wheat recombinant inbred lines (RILs) developed from a cross between parents susceptible (WL711) and resistant (HD29) to Karnal bunt (caused by Tilletia indica), were screened for 3 years with the pathogen populations prevalent in northern India. When 90 simple sequence repeats (SSRs) and 81 amplified fragment length polymorphism (AFLP) loci were mapped on the RILs, markers on chromosomes 2A, 4B and 7B accounted collectively for about one-third of the variation in the disease reaction. The genomic region of largest effect, identified on the long arm of chromosome 4B, reduced Karnal bunt disease by half in three different experiments and accounted for up to 25% of the phenotypic variation for KB reaction. A closely linked SSR marker, GWM538, may be useful in marker-assisted selection for Karnal bunt resistance in wheat.

Molecular marker analysis of protein content using PCR-based markers in wheat

Grain protein concentration (GPC) of hexaploid wheat is one of the important factors that determines the end-product quality as well as playing a pivotal role in human nutrition. In an attempt to identify PCR-based DNA markers linked to GPC, 106 recombinant inbred lines (RILs) were developed from a cross between two wheat cultivars PH132 and WL711, which differ significantly in GPC, by the single seed descent method. The RILs were phenotyped for GPC at two diverse agroclimatic locations, namely Pune and Ludhiana, to study the influence of genotype and environment interactions on this trait. The parents were screened with 85 inter simple sequence repeat (ISSR) primers and 350 random primers. The selective genotyping and whole population analysis revealed nine DNA markers associated with the trait. Three markers (UBC8441100, UBC8801000, and OPA4800) were observed to be associated with the trait in both locations, whereas two markers (OPH41400) and UBC873750) werefound to be specific to Pune, and four markers (OPM5870, OPO10870, OPV141200, and UBC8251000) were specific to Ludhiana. Together five markers at the Pune location representing five QTLs and seven markers at Ludhiana representing four QTLs accounted for 13.4 and 13.5% of total phenotypic variation, respectively. This study clearly demonstrates that GPC is highly influenced by the environment, and the applicability of ISSR and RAPD markers in finding regions on chromosomes associated with quantitative characters in wheat such as GPC.

Microsatellite markers reveal chimeric origin of redesignated chromosome 4A of wheat from Triticum urartu and other species

Although a new nomenclature has been adopted for wheat in which chromosome 4A (4AO) has been renamed 4B (4BN) and chromosome 4B (4BO) has been renamed 4A (4AN), their specific origin remains uncertain. The use of wheat microsatellite (WMS) markers mapped to chromosomes 4AN and 4BN in a set of polyploid wheats and diploid genome donors has unequivocally indicated that the entire short arm of 4AN, some part of 4ANL. and a segment of 4BNL were derived from Triticum urartu. The presence of a T. urartu-specific allele at locus gwm368 on 4BNL and of an Aegilops speltoides allele at locus gwm397 on 4ANL suggests the possibility of a reciprocal translocation between 4ANL and 4BNL. The subcentromeric and telomeric regions of 4ANL corresponding to heterochromatic C-bands were derived neither from diploid wheats nor from Ae. speltoides or Aegilops longissima.

Values of electroretinogram responses according to axial length

Accurate interpretation of electroretinograms (ERGs) requires knowledge of effects of axial myopia on ERG responses. Our purpose was to derive expected changes of ERG responses according to axial length, to stimulus conditions that conform to the International Society for Clinical Electrophysiology of Vision (ISCEV) Standard for Electroretinography. ERGs from 60 subjects were recorded. The subjects were assigned to one of three groups according to the level of myopia. Thirty-three subjects had high myopia (-6.00 D to -14.50 D; mean age, 31 years), eight had mild myopia (-3.00 D to -5.00; mean age, 28 years), and 19 had a small refractive error (+0.75 D to -2.75 D; mean age, 27 years). No subjects had myopic retinopathy. Stimulus-response curves were fitted to dark-adapted b-wave amplitudes and maximum amplitude and semi-saturation constants derived. Axial lengths, measured with A scan ultrasound, ranged from 22.2 mm to 30.0 mm. Analysis of variance and post hoc t-tests revealed significant difference between subjects with high myopia and subjects with small refractive error for ERG amplitude data. There were no significant differences between the three groups for implicit times, the ratio of b- to a-wave and semi-saturation constant. There is linear reduction in the logarithmic transform of ERG amplitude with increasing axial length, related more to axial length than refractive error. We provide relative slope and intercept values, allowing labs to derive expected ERG amplitudes according to axial length. These derivations are valid for persons with no retinopathy.

Ph1 gene derived from Aegilops speltoides induces homoeologous chromosome pairing in wide crosses of Triticum aestivum

The present study was conducted to investigate the effectiveness of the PhI gene transferred from Aegilops speltoides into bread wheat cultivar Chinese Spring (CS) in inducing homoeologous chromosome pairing in interspecific crosses using the Chinese Spring line, CS(PhI), carrying the gene. Chinese Spring, as well as CS(PhI), were crossed as female parents with three accessions of Ae. kotschyi (UUSS), one accession of Secale cereale (RR), two amphiploids of Triticum durum-Ae. caudata (AABBCC), and one amphiploid of Triticum durum-Ae. umbellulata (AABBUU). Meiotic metaphase I chromosome pairing was studied in all the interspecific crosses with CS as well as CS(PhI). There was significant increase in chiasma frequency in all the crosses with CS(PhI) over those with CS. The extent of induced homoeologous chromosome pairing by PhI in crosses of CS(PhI) with S. cereale was higher than with those of Ae. kotschyi, as indicated by higher chiasma frequency per pollen mother cell. Significant reduction in frequency of univalents and increase in bivalents (>14), multivalents, and chiasma frequency in crosses of amphiploids with CS(PhI) as compared to those of CS indicated induced homoeologous pairing between C and D, D and U, and C, D, and U genomes with AB genomes in the presence of PhI. The results of the present study unequivocally demonstrate the effectiveness of PhI gene transferred from Ae. speltoides in hexaploid wheat in inducing homoeologous chromosome pairing and suggest that the line CS(PhI) can be effectively used for precise transfer of useful alien genetic variations with least linkage drag.

Microtuberization in potato (Solanum tuberosum L.)

Twenty-two genotypes of potato (Solanum tuberosum L.) were induced to form microtubers under six in vitro culture conditions. Cultures maintained under a short photoperiod (10 h of 6-12 μmol m^-2 s^-1) and low temperatures (day 20°±2°C and night 18°±2°C) had both a higher yield (255 mg/plantlet) and a greater number (2/plantlet) of microtubers than those maintained under long days (16 h of 38-50 μmol m^-2 s^-1) combined with high temperatures (day 28°±2°C and night 25°±2°C) (yield 207 mg/plantlet; microtuber number, 0.9/plantlet), over a wide range of genotypes. After the plantlets had been cultured under long days for an initial period of 60 days, continuous darkness advanced microtuberization by 2-3 months in various genotypes. Under short-day and low-temperature conditions the addition of 6-benzylaminopurine increased microtuber yield from 255 mg/plantlet to 645 mg/plantlet and average microtuber weight from 115 mg to 364 mg. A similar pattern was observed under conditions of long days and high temperature, and continuous darkness and low-temperature. Microtubers produced under light had a greater number of eyes (maximum average: 5.96/microtuber) than those produced in the dark (maximum average: 3.50/plantlet). The genotype × cultural conditions interactions were significant indicating the importance of developing genotype-specific protocols to maximize microtuberization.

Phase III placebo-controlled trial of capsaicin cream in the management of surgical neuropathic pain in cancer patients

PURPOSE

A minority of cancer survivors develops long-term postsurgical neuropathic pain. Based on evidence that capsaicin, the pungent ingredient in hot chili peppers, might be useful for treating neuropathic pain, we developed the present clinical trial.

PATIENTS AND METHODS

Ninety-nine assessable patients with postsurgical neuropathic pain were entered onto this study. After stratification, patients were to receive 8 weeks of a 0.075% capsaicin cream followed by 8 weeks of an identical-appearing placebo cream, or vice versa. A capsaicin/placebo cream was to be applied to the painful site four times daily. Treatment evaluation was performed by patient-completed weekly questionnaires.

RESULTS

During the first 8-week study period, the capsaicin-cream arm was associated with substantially more skin burning, skin redness, and coughing (P < .0001 for each). Nonetheless, treatment was stopped for patient refusal or toxicity just as often while patients were receiving the placebo as compared with the capsaicin. The capsaicin cream arm had substantially more pain relief (P = .01) after the first 8 weeks, with an average pain reduction of 53% versus 17%. On completion of the 16-week study period, patients were asked which treatment period was most beneficial. Of the responding patients, 60% chose the capsaicin arm, 18% chose the placebo arm, and 22% chose neither (P = .001).

CONCLUSION

A topical capsaicin cream decreases postsurgical neuropathic pain and, despite some toxicities, is preferred by patients over a placebo by a three-to-one margin among those expressing a preference.

Signal-detection, threshold, and dual-process models of recognition memory: ROCs and conscious recollection

Threshold- and signal-detection-based models have dominated theorizing about recognition memory. Building upon these theoretical frameworks, we have argued for a dual-process model in which conscious recollection (a threshold process) and familiarity (a signal-detection process) contribute to memory performance. In the current paper we assessed several memory models by examining the effects of levels of processing and the number of presentations on recognition memory receiver operating characteristics (ROCs). In general, when the ROCs were plotted in probability space they exhibited an inverted U shape; however, when they were plotted in z space they exhibited a U shape. An examination of the ROCs showed that the dual-process model could account for the observed ROCs, but that models based solely on either threshold or signal-detection processes failed to provide a sufficient account of the data. Furthermore, an examination of subjects' introspective reports using the remember/know procedure showed that subjects were aware of recollection and familiarity and were able to consistently report on their occurrence. The remember/know data were used to accurately predict the shapes of the ROCs, and estimates of recollection and familiarity derived from the ROC data mirrored the subjective reports of these processes.

Randomized evaluation of controlled-release codeine and placebo in chronic cancer pain

Codeine is widely used in combination with acetaminophen and aspirin for the management of mild to moderate pain. However, there are few controlled clinical trials of single-entity codeine in chronic cancer pain. The purpose of this study was to evaluate the clinical efficacy and safety of controlled-release codeine given every 12 hr in patients with cancer pain. Thirty-five patients with chronic cancer pain were randomized in a double-blind crossover study to controlled-release (CR) codeine or placebo, for 7 days each. Pain intensity was assessed at 0800 hr and 2000 hr using a visual analogue scale (VAS) and a five-point categorical scale, and the use of "rescue" acetaminophen-plus-codeine (300 mg/30 mg every 4 hr as needed) was recorded. Thirty patients completed the study (17 male, 13 female; mean age, 64.4 +/- 9.8 years) with a mean daily CR codeine dose of 277 +/- 77 mg (range, 200-400 mg). CR codeine treatment resulted in significantly lower overall VAS pain intensity scores (22 +/- 18 mm versus 36 +/- 20 mm, P = 0.0001), categorical pain intensity scores (1.2 +/- 0.8 versus 1.8 +/- 0.8, P = 0.0001), and pain scores when assessed by day of treatment and by time of day. Daily "rescue" analgesic consumption was significantly lower on CR codeine, compared to placebo treatment (2.2 +/- 2.3 versus 4.6 +/- 2.8 tablets per day, P = 0.0001). Both patients and investigators preferred CR codeine to placebo (80% versus 3%, P = 0.0014 and 73% versus 7%, P = 0.0160, respectively). These data indicate that CR codeine, given every 12 hr results in significant reductions in pain intensity and the use of "rescue" acetaminophen-plus-codeine in patients with cancer pain. CR codeine provides the benefits of a flexible single entity codeine formulation and the convenience of 12-hr duration of action, which allows patients uninterrupted sleep and improved compliance.

Steady-state pharmacokinetics of hydromorphone and hydromorphone-3-glucuronide in cancer patients after immediate and controlled-release hydromorphone

Although the pharmacokinetics of oral hydromorphone has been evaluated in healthy volunteers after small single oral doses, data are not available regarding the disposition of hydromorphone and its principal metabolite, hydromorphone-3-glucuronide (H3G), at steady-state and after large oral doses. The authors studied the pharmacokinetics of hydromorphone and H3G after oral administration of an immediate-release (IR) and controlled-release (CR) formulation of hydromorphone at a daily dose of 48 +/- 11 mg (range 6-216 mg) in a randomized, double-blind, steady-state, two-way crossover evaluation in 18 patients with chronic cancer pain. Controlled-release hydromorphone demonstrated equivalent bioavailability and acceptable CR characteristics, when compared with IR hydromorphone (CR vs. IR: AUC0-12 123.10 +/- 20.38 vs. 118.98 +/- 20.92 ng.hr.mL-1, P = NS, Cmax 17.76 +/- 3.07 vs. 19.70 +/- 4.04 ng.mL-1, P = NS, Cmin 6.04 +/- 1.01 vs. 5.28 +/- 1.000 ng.mL-1, P = NS, and Tmax 4.78 +/- 0.78 vs. 1.47 +/- 0.22 hr, P = 0.0008). A significant linear relationship existed between hydromorphone dose and hydromorphone AUC (r = 0.8315, P = 0.0001) and between hydromorphone AUC and H3G AUC (r = 0.8048, P = 0.0001) over a wide dose range. The steady-state molar ratio of H3G to hydromorphone was 27:1. The authors conclude that CR hydromorphone provides a pharmacokinetic profile consistent with 12 hourly dosing and that at steady state, oral hydromorphone is extensively metabolized to H3G, although the pharmacologic activity of this metabolite remains unknown.

Combination chemotherapy for intermediate and high grade non-Hodgkin's lymphoma

One hundred and eighteen consecutive adults with newly diagnosed intermediate and high-grade non-Hodgkin's lymphoma were treated with chemotherapy comprising Doxorubicin, Cyclophosphamide, Vincristine and Prednisolone with mid-cycle Methotrexate (MTX) and leucovorin rescue ('CHOP-M'). Intrathecal MTX was given with each treatment cycle as central nervous system (CNS) prophylaxis. 'Clinical remission' was achieved in 70/110 evaluable patients (64%), complete remission: 45/110, (41%), good partial remission: 25/110 (23%). Twenty two patients (19%) died prior to completion of therapy, 18 patients had persistent disease. Hyponatremia (< 137 mmol l-1), advanced age and hypoalbuminaemia (< 32 g l-1) correlated adversely with achievement of CR (P = 0.0007, 0.0005 and 0.04 respectively). With a minimum follow up of 41 years, 47 of the seventy patients (67%) in whom clinical remission was achieved remain well, 19 have developed recurrent disease, resulting in an actuarial projected remission duration of 70% at 8 years. Four died in CR. There has been only one isolated CNS recurrence. On univariate analysis, hypoalbuminaemia, hyponatremia and beta 2 microglobulin (> 3) correlated with unfavourable outcome in terms of duration of remission (P = 0.0009, 0.007 and 0.04 respectively). On multivariate analysis, only the serum sodium (0.002) and advanced age (0.01) were predictive for remission duration. Fifty patients (45%) are alive, the overall actuarial projected survival is thus 42% at 8 years. On univariate analysis, age, hypoalbuminaemia, hyponatraemia, liver involvement and the presence of B symptoms correlated unfavourably with survival. On multivariate analysis, hypoalbuminaemia, advanced age, hyponatraemia, male gender (aged > 50) and diffuse large cell or large cell, immunoblastic histology (Working Formulation) had an adverse effect (P = 0.003, < 0.0001, < 0.0001, 0.002, and 0.03). It was further possible, using cut-off points of 32 g l-1 and 136 mmol l-1 for albumin and sodium respectively to define prognostic categories for patients who differed significantly in terms of survival.

Molecular cytogenetic analysis of Agropyron elongatum chromatin in wheat germplasm specifying resistance to wheat streak mosaic virus

Three lines derived from wheat (6x) x Agropyron elongatum (10x) that are resistant to wheat streak mosaic virus (WSMV) were analyzed by chromosome pairing, banding, and in situ hybridization. Line CI15321 was identified as a disomic substitution line where wheat chromosome 1D is replaced by Ag. elongatum chromosome 1Ae-1. Line 87-94-1 is a wheat-Ag. elongatum ditelosomic addition 1Ae-1L. Line CI15322 contains an Ag. elongatum chromosome, 1Ae-2, that substitutes for chromosome 1D. The short arm of 1Ae-2 paired with the short arm of 1Ae-1 at metaphase I (MI) in 82% of the pollen mother cells (PMCs). However, the long arms of these two chromosomes did not pair with each other. In CI15322, the long arm of chromosome 4D has an Agropyron chromosome segment which was derived from the distal part of 1Ae-1L. This translocation chromosome is designated as T4DS·4DL-1L. T4DS·4DL-1Ae-1L has a 0.73 μm distal part of the long arm of 4D replaced by a 1.31 μm distal segment from 1Ae-1L. The major WSMV resistance gene(s) in these lines is located on the distal part of 1Ae-1L.

Identification of alien chromatin specifying resistance to wheat streak mosaic and greenbug in wheat germ plasm by C-banding and in situ hybridization

The chromosome constitutions of eight wheat streak mosaic virus (WSMV)-resistant lines, three of which are also greenbug resistant, derived from wheat/ Agropyron intermedium/Aegilops speltoides crosses were analyzed by C-banding and in situ hybridization. All lines could be traced back to CI15092 in which chromosome 4A is substituted for by an Ag. intermedium chromosome designated 4Ai-2, and the derived lines carry either 4Ai-2 or a part of it. Two (CI17881, CI17886) were 4Ai-2 addition lines. CI17882 and CI17885 were 4Ai-2-(4D) substitution lines. CI17883 was a translocation substitution line with a pair of 6AL.4Ai-2S and a pair of 6AS.4Ai-2L chromosomes substituting for chromosome pairs 4D and 6A of wheat. CI17884 carried a 4DL.4Ai-2S translocation which substituted for chromosome 4D. CI17766 carried a 4AL.4Ai-2S translocation substituting for chromosome 4A. The results show that the 4Ai-2 chromosome is related to homoeologous group 4 and that the resistance gene(s) against WSMV is located on the short arm of 4Ai-2. In addition, CI17882, CI17884, and CI17885 contained Ae. speltoides chromosome 7S substituting for chromosome 7A of wheat. The greenbug resistance gene Gb5 was located on chromosome 7S.

Cytogenetic identification of Aegilops squarrosa chromosome additions in durum wheat

A set of four normal chromosomes (1D, 2D, 3D, and 6D), and three translocation chromosomes (4DS·5DS, 5DL·7DS, and 7DL·4DL) involving all 14 chromosome arms of the D-genome were obtained as monosomic additions from Aegilops squarrosa (genome D, n=7) in Triticum durum Desf. cv 'PBW114' (genome AB, n=14). The cyclical translocation occurred during the synthesis of the amphiploid probably as a result of misdivision and reunion of the univalents during meiosis of the F1 hybrid T. durum x A. Squarrosa. The amphiploid was backcrossed twice with the durum parent to obtain monosomic addition lines. The monosomic addition chromosomes were identified by C-banding and associated phenotypic traits. All monosomic addition lines were fertile. The development of disomic and ditelosomic addition lines is underway, which will be useful for cytogenetic analysis of individual D-genome chromosomes in the background of T. Durum.

Lymphoplasmacytoid and small cell centrocytic non-Hodgkin's lymphoma--a retrospective analysis from St Bartholomew's Hospital 1972-1986

Lymphoplasmacytoid (lpc) and small cell centrocytic (scc) lymphoma are the two major sub-types of diffuse low grade non-Hodgkin's Lymphoma (NHL) within the Kiel classification. The presentation features and outcome for all 112 patients with these diagnoses (60 lpc, 52 scc) managed at St Bartholomew's Hospital between 1972 and 1986 are presented. The outcome for these patients is compared with that for patients with follicular and high grade lymphomas managed at this hospital during the same period. Nineteen of the 112 patients had localized (stages I-IIE) disease. In 18 of these cases the primary site of disease was extranodal, the gastrointestinal tract being involved in 12 cases. The survival for patients with localized disease was excellent. Eighteen are currently alive with median follow-up of 8 years. Ninety-three patients had advanced disease. A high incidence of splenomegaly, hepatomegaly, bone marrow and peripheral blood involvement was observed in both histological subgroups. A monoclonal paraprotein band was detected in the serum of nearly 50 per cent of patients with advanced lpc lymphoma. Patients with advanced disease were treated with either chlorambucil or cyclophosphamide, vincristine and prednisolone (CVP). The outcome was similar for both histological groups. Survival for these patients was poor (median 40 months) with less than 20 per cent surviving 5 years. Advanced age, elevated aspartate transaminase and failure to respond to treatment were identified by multivariate regression analysis as adverse prognostic factors.

Management of localized non-Hodgkin's lymphoma: the experience at St. Bartholomew's Hospital 1972-1985

A retrospective study of 202 patients with clinical stage I and II non-Hodgkin's lymphoma managed at St. Bartholomew's Hospital between 1972 and 1985 was conducted. Patients were treated either with radiotherapy alone, radiotherapy and adjuvant chemotherapy, or chemotherapy (with or without adjuvant radiotherapy). At the onset of the study it was intended that all patients with localized NHL should be treated with involved field radiotherapy and adjuvant 'CVP'. As it became apparent that this was inadequate for some patients and too toxic for others a flexible approach was later adopted. Treatment selection depended on age, volume, distribution of disease and histological subtype. The actuarial 5 year overall survival for the whole group was 70 per cent. Death from lymphoma after 5 years was very rare. Increasing age and high grade histology were highly significant adverse prognostic factors by multivariate analysis. The results for patients with high grade and low grade histology were therefore analysed separately, as was the outcome for patients presenting with either gastrointestinal or skin lymphomas. During the latter part of the study period intensive chemotherapy was given as the initial treatment to patients with high grade histology and bulky, or stage II disease. Twenty out of 24 patients so treated achieved complete remission and only one has relapsed to date. These results are encouraging and probably explain the absence of a difference in prognosis between patients with stage I and IE disease and those with stage II and IIE disease observed over the whole period of the study. Remission was achieved in the overwhelming majority of patients with low grade histology for whom radiotherapy was selected as primary therapy. Duration of remission was better in patients who received adjuvant chemotherapy than in those treated with radiation alone, but no difference in overall survival was observed between these groups. Neither stage nor the presence of a follicular histological pattern correlated with prolonged survival in patients with low grade histology.

Short-course etoposide, bleomycin and cisplatin in the treatment of metastatic germ cell tumours. Appraisal of its potential as adjuvant chemotherapy for stage 1 testis tumours

Prompted by recent reports of the increasing incidence of late relapses in Stage 1 patients with both malignant teratoma and seminoma on surveillance, a low toxicity regimen combining etoposide, bleomycin and cisplatin [EBCi(3)] with prolonged infusion of bleomycin, given daily for 3 days, has been developed for possible use as adjuvant treatment. Forty of 44 patients treated remain free of disease with a median follow-up of 21 months and actuarial disease free survival at 2 years of 91%. There have been no respiratory problems attributable to bleomycin lung toxicity in this study compared with four (3 associated with patient deaths) seen in 91 previously treated patients. The relatively low toxicity and high efficacy of this regime indicate that it may be suitable as adjuvant treatment.

Angio-immunoblastic lymphadenopathy: a clinical, immunological and molecular study

Twenty four patients with angio-immunoblastic lymphadenopathy (AILD) presenting between 1974 and 1985 have been reviewed. Clinical features at presentation included rash, fever, lymphadenopathy and hepatosplenomegaly in 75% of patients. Polyclonal hypergammaglobulinaemia was seen in 19/20 patients; 5 had normal immunoglobulin levels. Combination chemotherapy with MVPP was the optimal treatment with 6/7 patients achieving complete remission. Duration of remission ranged from 9 months to 4 years and was significantly longer in patients achieving complete as opposed to partial remission. In 6 patients phenotype studies were performed on single cell suspensions and immunoperoxidase studies on frozen sections of 7 lymph nodes. There was a reversal of the normal T suppressor/helper cell ratio with a predominance of T suppressor cells. Loss of normal B follicles was observed histologically in all except one lymph node. Germline configuration of the beta B-chain of the T cell receptor was observed in lymph nodes of 4 patients with AILD, and a rearranged T cell receptor was observed in 1 patient in whom a second lymph node biopsy had shown alteration of the histological picture to that of T-zone lymphoma. Frozen sera of 15 patients were screened for antibodies to HTLV I and III and were found to be negative.

Treatment of acute lymphoblastic leukaemia in adults

Between 1972 and 1982, 112 consecutive previously untreated adults (aged 15-69 years, median 26) commenced therapy for acute lymphoblastic leukaemia (ALL) at St Bartholomew's Hospital. The first 63 patients entered into the study received initial treatment which comprised four cycles of adriamycin and vincristine, prednisolone and L-asparaginase with the first cycle (OPAL). In 1978, six cycles were given, with escalating doses of adriamycin and cyclophosphamide from cycle 3 (HEAV'D). Central nervous system (CNS) prophylaxis incorporated intrathecal methotrexate and cytosine arabinoside with cranial irradiation. Maintenance chemotherapy consisted of 6-mercaptopurine, cyclophosphamide and methotrexate for 3 years. Results obtained with the OPAL and HEAV'D regimens were not significantly different. The overall complete remission (CR) rate was 66% (73/111), factors correlating unfavourably with achievement of CR being advanced age (P less than 0.001) and L3 morphology/B-ALL immunophenotype (P less than 0.01). Fifty-three patients have relapsed, the bone marrow being the primary site in 43. Extramedullary relapse alone occurred in 10 (seven CNS, two testicular and one skin). Only three of the 64 patients who had complete CNS prophylaxis subsequently relapsed in the CNS as an isolated site. One patient died in CR, 19 remain in continuous CR between 2.5 and 10.5 years. The median duration of remission of the 73 patients who achieved CR was 18.5 months, factors correlating favourably with duration of CR being low blast cell count at presentation (P less than 0.002) and common ALL immunophenotype (P less than 0.04). Twenty-four patients remain alive, with a median survival of all patients of 18 months. Long-term survival is possible for approximately 20% of adults with ALL treated relatively intensively.

Follicular lymphoma: prognostic factors for response and survival

One hundred forty-eight patients with newly diagnosed follicular lymphoma were treated over a 12-year period. Twenty-two patients received radiotherapy for stage I and II disease, followed by adjuvant chemotherapy in 14 patients. One hundred thirteen were treated at presentation with short courses of chemotherapy, most often with single-agent chlorambucil for bulky stage II and stages III and IV disease. Thirteen patients were managed expectantly until there was evidence of disease progression. The median survival was 9 years. Patients treated with radiotherapy for stage I and II disease had an 83% relapse-free survival, but those with bulky stage II or stages III and IV disease treated with chemotherapy pursued a remitting and relapsing course with a 70% response rate at initial and subsequent retreatments, but a median duration of remission of 4 years in stage III and 1 year in stage IV disease (P = .041). Patients were observed in relapse and retreatment was administered as appropriate, once every 33 months on average. Poor prognosis patients could be identified by a combination of the presentation characteristics: B symptoms, hepatosplenomegaly, anemia, and abnormal liver function. These factors predicted a poor response to treatment and correlated with a short survival. Histologic subgroups were not associated with differences in survival, but transformation to a diffuse high-grade lymphoma was observed in 23 of the 72 patients (32%) at risk, with a median follow-up of 6 years and 6 months, and was associated with a very poor prognosis. The present treatment strategy has proved successful for most patients with localized disease and those older patients with indolent small volume disseminated follicular lymphoma. New approaches are being investigated for the younger poor prognosis patients.

Treatment of acute leukaemia with m-AMSA in combination with cytosine arabinoside

A series of 46 patients with acute leukaemia were treated with amsacrine (m-AMSA) and cytosine arabinoside (ara-C). Complete remission (CR) was achieved in 15 of 38 (40%) patients with acute myelogenous leukaemia (AML) and 4 of 8 (50%) patients with acute lymphoblastic leukaemia (ALL). The CR rate was significantly higher (P less than 0.05) for the younger, previously treated patients with AML (9/16) than for the older previously untreated ones (6/22), because of higher treatment mortality in the latter group. Myelosuppression was prolonged and profound. Major nonhaematological toxicity affected the gastrointestinal tract (nausea, vomiting, mucositis, bleeding and ileus associated with severe diarrhoea). Many patients also developed reversible hepatic dysfunction and two elderly patients died of cardiac arrhythmia. Further trials of this combination are justified in patients with relapsed or resistant leukaemia, but for older patients dose reduction is recommended.

Developmentally regulated rearrangement and expression of genes encoding the T cell receptor-T3 complex

Human leukemic cells corresponding to the earliest identifiable stages of intrathymic T cell differentiation lack cell surface expression of the T cell receptor(TCR alpha/beta)-T3 complex but transcribe TCR beta mRNA from either germ-line configuration (1/13) or partially (DJ) or fully (VDJ) rearranged (12/13) genes. These cells do not produce TCR alpha mRNA, but do contain T3 delta and T3 epsilon mRNA and accumulate T3 polypeptides, primarily in the perinuclear envelope. Equivalent normal T cells isolated from thymus have a predominantly germ-line configuration of TCR beta but contain intracellular T3 proteins. T3 gene expression is therefore a very early event in T cell differentiation. TCR alpha chain production appears to be the limiting maturation-linked event in the transport, assembly, and cell surface membrane insertion of the TCR alpha/beta-T3 complex.

Genetics of yellow berry in wheat (Triticum aestivum)

The inheritance of yellow berry, a grain disorder in durum and bread wheats, was studied in six intervarietal crosses in bread wheat. The trait was found to be controlled by either two or three dominant genes. Monosomic analysis using 'Chinese Spring' monosomic series showed the presence of two major dominant genes on chromosomes 1A and 7A, and four modifiers on 4A, 4B, 6A and 6D, which influence the expression of yellow berry in bread wheat.

Intensive therapy for life-threatening medical complications of haematological malignancy

The medical records of 22 consecutive adult admissions to an intensive care unit (ICU) with life-threatening complications of haematological malignancy, or its treatment, are reviewed. Twenty patients (91%) were in acute respiratory failure, and 17 of the 22 patients required intermittent positive pressure ventilation (IPPV). The in-unit mortality was 55%, but only 4 patients (18%) survived to leave the hospital. Although the unit mortality appeared to be related to the acute physiology score (APS), this small series did not demonstrate a clear relationship between the APS and long-term survival (discharge from hospital). There were, however, significant differences in the number of organ systems involved between those who died on the ICU and those who returned to the ward, as well as between those who survived to leave hospital and those who died. No patient with more than three systems involved became a long-term survivor. All long-term survivors had either reasonable peripheral white cell counts throughout or their bone marrow showed significant recovery prior to discharge from the ICU. Unresponsive malignant disease and a failure to recover bone marrow function were major factors in those patients who died shortly after discharge from the ICU. Although long-term survival rates are low and are probably largely determined by the progress of the underlying malignancy, intensive care was life-saving in four patients, three of whom are alive several years after discharge.