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Freeze resistance is critical to successful dormant bud (DB) cryopreservation, and is affected by genotype, environmental conditions, dormancy phase and processing techniques. Pretreatment induced freeze resistance may contribute to more successful and efficient protocols for cryopreserving DB. Differential thermal analysis (DTA) was used to quantify the effects of cryopreservation pretreatments on freeze resistance of dormant budwood. Low temperature exotherm (LTE) profiles created by DTA could rapidly identify pretreatments that are contributing to increased freeze resistance in tree fruit species. In this study, DTA was used to help elucidate the effects of varying pretreatments (sucrose, desiccation and their combination) on peach, a model crop in tree fruit physiology that has shown little cryosurvival using the DB method in the past. Post cryopreservation recovery trials using an antimicrobial forced bud development (AFBD) protocol evaluated the ability of selected pretreatments, that improved freeze resistance based on DTA, to improve recovery of dormant budwood of various deciduous tree fruit and nut species. Precryogenic exposure to sucrose solution (5.0 M, 96 h), desiccation to 30% moisture content (MC) and their combination tested for their efficacy on improving postcryogenic viability in peach, apricot, sweet cherry, little walnut, black walnut, English walnut, apple, and pear. Among the different pretreatments tested, desiccation to 30% MC had the greatest impact on increasing freeze resistance and cryosurvival across most fruit species tested and little walnut. Gradual reduction of MC (from 40 to 25%) levels increased freeze resistance in peach (R 2 =0.95) and increased some recovery outcomes (leaf, shoot and bud swell), however, this was not correlated with equal cryorecovery outcomes as severe bud cracking was observed. Overall, our approach linking freeze resistance and preconditioning treatments could help establish efficient species-specific cryopreservation protocols for a number of important temperate woody crops which could be recovered as complete plants by coupling AFBD and plant tissue culture., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Dormant bud cryogenic preservation is a cost- and labor-efficient method of genetic resource backup compared to in vitro derived meristem shoots cryopreservation. While protocols have been developed for cryopreserving apple dormant buds, effective and reproducible protocols are yet to be developed for several temperate fruit and nut species. Dormant bud cryopreservation typically requires material to be grafted to evaluate viability and recover a plant. Forced bud development has been used on a very limited scale for cryostored dormant budwood recovery, however, it provides a labor-efficient alternative viability assessment. To increase the utility of this approach, regrowth must be optimized to allow complete plant recovery. We hypothesized that bacterial attacks are limiting regrowth, thus, an antimicrobial forcing solution can maximize regrowth potential. This study examined the effects of an antimicrobial forcing solution (8-hydroxyquinoline citrate and sucrose, 8-HQC) on the cryosurvival and recovery of dormant buds of fruit (Malus x domestica, Prunus armeniaca, Prunus avium, Prunus persica, Pyrus communis), and nut species (Juglans regia, Juglans nigra, Juglans microcarpa). Recovery and shoot development were significantly improved for all the fruit and one nut species (J. microcarpa) treated with the 8-HQC, compared to standard recovery under high humidity alone (P < 0.001). Additionally, this post cryo recovery approach led to successful in vitro shoot tip establishment across all surviving fruit species. 8-HQC embedded forced bud development method increased viability and efficiency for existing cryostored material and can be used as a benchmark to develop protocols for different crops that could potentially lead to complete plant recovery., (Copyright © 2020 Elsevier Inc. All rights reserved.)

The present study was undertaken to further explore the potential neuropsychological information associated with baseline plasma levels of catecholamines and dopamine D3 receptor (DRD3) mRNA expression in peripheral blood lymphocytes (PBL). Baseline plasma norepinephrine and epinephrine levels and PBL DRD3 mRNA expression were compared with performance in the Wisconsin Card Sorting Test (WCST) in n=79 healthy volunteers (mean+/-S.D. age: 24.1+/-3.2 years, 34 males). After correction for multiple testing, we found that baseline plasma epinephrine levels predicted WCST total number of errors (Spearman's rho=-0.36, p<0.05), number of perseverative responses (Spearman's rho=-0.36, p<0.05) and percent conceptual level responses (Spearman's rho=0.37, p<0.05). Plasma norepinephrine levels and PBL DRD3 mRNA expression did not predict WCST scores, but PBL DRD3 mRNA expression correlated negatively with plasma epinephrine levels (Spearman's rho=-0.45, p<0.001). Further studies should be undertaken to explore possible neurophysiological links between plasma epinephrine levels and the neurobiology underlying cognitive performance.

Background: Agenesis of the dorsal pancreas is a very rare congenital pancreatic malformation and is associated with some other diseases., Methods: A PubMed search revealed 53 cases of agenesis of the dorsal pancreas., Results: In 28 patients with this congenital malformation hyperglycemia was demonstrated, 27 had abdominal pain, 16 had pancreatitis, 14 had an enlarged or prominent pancreatic head visible on computed tomography, and in a few cases, polysplenia, which may occur with various congenital anomalies of visceral organs, was described., Conclusions: Difficulties involved in obtaining a firm diagnosis have led to a variety of terms being used to describe this congenital disease. Diagnosis of agenesis of the dorsal pancreas is inconclusive without demonstration of the absence of the dorsal pancreatic duct. Here we describe the embryological development of the pancreas, the so-far known cases of agenesis of the dorsal pancreas with associated medical problems, and the diagnostic measures to find the right conclusions.

The optical device LIPOMETER enables the non-invasive, quick, and save determination of the thickness of subcutaneous adipose tissue layers at any given site of the human body. The specification of 15 evenly distributed body sites allows the precise measurement of subcutaneous body fat distribution, so-called subcutaneous adipose tissue topography (SAT-Top). In the present paper we focus on SAT-Top of male type-2 diabetes patients (N=21), describing very precisely their special SAT development and their SAT-Top deviation from a healthy control group (N=111), applying factor analysis and ROC curves. Factor analysis revealed three independent subcutaneous body fat compartments, which can be summarised as "upper body", "lower trunks" and "legs". The upper body SAT-Top is much more pronounced in diabetic men compared to their healthy controls (p<0.001). Furthermore, high diagnostic power by ROC curve analysis was achieved by different measurement sites of the upper body and summary measures of upper body obesity (sum2, which is the sum of neck and biceps, provides: area index =0.86, sensitivity =81%, specificity =90.1%, at an optimal cutoff value of 18.8 mm), ascribing a higher diabetes probability to subjects with a more upper body SAT-Top pattern. Calculating new ROC curves for diabetic patients with HBA1C values >8 (N=17) and their healthy controls (N=111) we received improved discrimination power for several SAT-Top body sites, especially for sum2, showing an area index of 0.91, a sensitivity of 94.1%, and a specificity of 90.1% at the optimal cutoff value of 18.8 mm. Concluding, the exact and complete description of the especial type 2 diabetic SAT pattern, which differs strongly from the SAT-Top of healthy controls, suggests the LIPOMETER technique combined with advanced statistical methods such as factor analysis and ROC curve analysis as a possible detecting tool for this disease.

The aim of this study was to investigate whether subcutaneous adipose tissue topography (SAT-Top) is different in female CHD patients (n=26) and healthy controls (n=36) matched to age, body size, weight, and BMI. The thicknesses of SAT layers were measured by LIPOMETER at 15 specified body sites. To calculate the power of the different body sites to discriminate between CHD women and healthy controls, receiver operating characteristic (ROC) curve analysis was performed. For each parameter, sensitivity and specificity were calculated at different cutoff points. CHD women showed a significant decrease to 78.36% (p=0.012) at body site 11-front thigh, 73.10% (p=0.012) at 12-lateral thigh, 72.20% (p=0.009) at 13-rear thigh, 66.43% (p<0.001) at 14-inner thigh, and 49.19% (p<0.001) at 15-calf. The best discriminators analysed by ROC curves between female CHD patients and healthy controls turned out to be calf and inner thigh (optimal cut off values: calf: 3.85 mm and inner thigh: 11.15 mm). Stepwise discriminant analysis identified the body sites calf, lateral chest, and inner thigh as significant. In conclusion, information was obtained on the extent to which SAT thickness at each measured body site is able to discriminate between the two subject groups. The good discrimination results obtained for the present dataset are encouraging enough to recommend applying LIPOMETER SAT-Top measurements in further studies to investigate individual risks for CHD.

The importance of body composition measurements to elucidate the dynamics of related diseases in pediatrics is gaining recognition. The methods used should not expose subjects to high doses of radiation and require substantial cooperation. The Lipometer is a new optical device that enables the non-invasive, quick and safe determination of the thickness of subcutaneous adipose tissue (SAT) layers (in mm) at any site of the human body. The topographic specification of 15 evenly distributed body sites, which makes it possible to precisely measure subcutaneous body fat distribution, is called subcutaneous adipose tissue topography (SAT-Top). SAT-Top was determined in more than 1000 children and young adults between the ages of 7 and 21. In this paper we describe the SAT-Top development of these subjects through different age groups and the differences between male and female SAT-Top development in each age group. SAT layer profiles (medians of the 15 body sites) for boys and girls in age group 1 (7-9 yrs) show a very similar pattern for both sexes, followed by slightly decreasing SAT layer thicknesses in boys and increasing values in girls in the subsequent age groups. Between age group 3 (11-13 yrs) and age group 7 (19-21 yrs) male and female SAT-Top is significantly different. The discriminating power between male and female SAT-Top was investigated by stepwise discriminant analysis, which provided no significant results for age group 1 (7-9 yrs), about 73% correct classification for age group 2 (9-11 yrs) and 3 (11-13 yrs), 83% for age group 4 (13-15 yrs), and about 91-93% for the following age groups (15-21 yrs). It is known that SAT development is the same in both sexes until puberty, when girls gain relatively more fat mass than boys to reach a higher body-fat percentage as adults. This paper presents a precise description of SAT development in boys and girls from childhood to adolescence, which provides a basis for further investigations.

The aim of this study was to examine the relationships between body fat measured by DXA and subcutaneous adipose tissue layers (SAT-layers) measured by LIPOMETER in adult males (n=28) and females (n=53). Body height and mass were measured and BMI was calculated (kg/m2). Measurements of the thicknesses of SAT-layers by LIPOMETER were performed at 15 original body sites. Body composition was measured using DXA. Total body fat % measured by DXA was highly dependent on the SAT-layers in the upper back and inner thigh in males (87.1%, R(2)x100) and the lateral chest, biceps, and calf in females (78.5%, R(2)x100). There were gender differences in trunk fat mass and right hand and leg fat mass calculation using specific SAT-layers. In conclusion, our results indicate that there are close relationships between SAT-layers and body fat measured by DXA. However, there are big differences between genders.

Background: Evaluation of conditions associated with glycated hemoglobin (HbA1c) values below the reference range in HbA1c determinations., Methods: Over a time period of 5 years, HbA1c results were determined with the ion-exchange high-performance liquid chromatography (HPLC) method HA-8140 Menarini., Results: Of approximately 20 000 HbA1c results analyzed, 9 were below the reference range. The reason for HbA1c values below the reference range was found to be liver cirrhosis in 6 patients, anemia with hematological neoplasms in 2 patients, and elevated fetal hemoglobin > 1.5% in one patient. The silent hemoglobin (Hb) variant Hb Graz in 6 patients, Hb Sherwood Forest in 1 patient, homozygote HbS in one patient, and gross hypertriglyceridemia in one patient demonstrated no HbA1c result., Conclusions: In patients with liver cirrhosis, HbA1c measurements should be used with caution when evaluating long-term glucose control, and samples with suspected Hb variants should be analyzed by hemoglobin electrophoresis. Our study underscores the need for clinical laboratories and physicians to be aware of the limitations of their HbA1c assay methods as well as of the importance of visual inspection of ion-exchange chromatograms to detect HbA1c values below the reference range and abnormalities caused by the interference factors described here.

Glycated hemoglobin (GHb) measured as HbA1c in diabetic patients, is used to evaluate long-term control of diabetes mellitus, and most accurately reflects the previous 2-3 months of glycemic control. Liver disease is one of the leading causes of death in persons with type 2 diabetes mellitus. Diabetic patients can present with abnormal liver chemistries, from benign nonalcoholic fatty liver disease to severe cirrhosis of the liver. Because liver disease is associated with impaired glucose tolerance and diabetes mellitus, tools are needed to measure long-term glycemic control. In this review we discuss current information on glycated hemoglobin, HbA1c assay methods, attempts to standardize HbA1c assay methods, fructosamine and interferences caused by liver disease. We aim to alert the reader to current problems in determining long-term glycemic control parameters, HbA1c and fructosamine, and describe the measures necessary for proper interpretation of HbA1c.

Objectives: Evaluation of HbA1c determination with an automated ion-exchange high-performance liquid chromatography (HPLC) method in patients with clinically silent hemoglobin (Hb) variants., Design and Methods: HbA1c values were determined with the Arkray HA-8160 ion-exchange HPLC using the high-resolution, 4.2-min beta-thalassemia screening mode in patients with silent hemoglobin (Hb) variants, namely, Hb Graz, Hb Sherwood Forest, Hb O Padova, and HbD., Results: All of these hemoglobin variants caused additional peaks in the chromatograms, without HbA1c results in patients with Hb Graz and Hb Sherwood Forest, and demonstrated extra peaks with HbA1c results that were clinically too low for patients with Hb O Padova and in the patient with HbD., Conclusions: The development of this automated HPLC method modification with high-resolution beta-thalassemia screening mode aids identification of interference due to some clinically silent Hb variants in HbA(1c) determination.

Weight cycling may cause a redistribution of body fat to the upper body fat compartments. We investigated the distribution of subcutaneous adipose tissue (SAT) in 30 overweight women with a history of weight-cycling and age-matched controls (167 normal weight and 97 overweight subjects). Measurements of SAT were performed using an optical device, the Lipometer. The SAT topography describes the thicknesses of SAT layers at 15 anatomically well-defined body sites from neck to calf. The overweight women with a history of weight cycling had significantly thicker SAT layers on the upper body compared to the overweight controls, but even thinner SAT layers on their legs than the normal weight women. An android fat pattern was attributed to overweight females and, even more pronounced, to the weight cyclers. The majority of normal weight women showed a gynoid fat pattern. Using stepwise discriminant analysis, 89.0% of all weight cyclers and overweight controls could be classified correctly into the two groups. These findings show the importance of normal weight maintenance as a health-promoting factor.

VACTERL association is defined as a combination of vertebral, anal, cardiac, tracheoesophageal, renal and limb anomalies, in particular radial defects. In recent years hydrocephalus was observed in patients with apparent VACTERL association. This particular condition was recognized as a hereditary entity with poor prognosis. Both autosomal recessive and X-linked forms were described. Here we report prenatal, clinical and autopsy findings in 2 brothers with this syndrome, who had, in addition, branchial arch anomalies. The recurrence in this family suggests X-linked inheritance. Branchial arch defects have so far not been described as part of the VACTERL+H syndrome. This observation further supports that a variety of brain anomalies including hydrocephalus associated with VACTERL anomalies represents separate entities with a considerable recurrence risk. The use of the term VACTERL "association" for these conditions is misleading and is discouraged.

A 51-year-old patient with severe back pain had undergone resection of a benign cerebellar tumour when aged 15 years. In addition, polycystic kidney disease was diagnosed 24 years ago, bilateral phaeochromocytoma 2 years ago, and for 4 months before the present admission he had been on haemodialysis. The family history indicated autosomal dominant inheritance of the polycystic renal disease. His general condition was found to have deteriorated, he had pain on pressure over the upper thoracic and lower lumbar vertebrae, and the kidneys were enlarged on palpation. There were increased concentrations of calcium (3.01 mmol/l), parathormone (2.0 ng/l), carcinoembryonic antigen (13.5 micrograms/l) and TPA (69 U/l). Computed tomography demonstrated cystic and solid parts of much enlarged kidneys. Biopsy revealed a poorly differentiated clear-cell renal carcinoma. Further information concerning the previously removed brain tumour showed this to have been an haemangioblastoma of the cerebellar tonsils indicating the diagnosis of v. Hippel-Lindau disease. Nine other family members had been affected, but none had the full-blown picture of the disease. The patient died 3 weeks later from the rapidly advancing tumour. Autopsy showed the bilateral renal carcinoma, bilateral phaeochromocytoma and metastases to the sternum, femurs, vertebrae and liver.

Greenhouse-cultured, container-grown ponderosa pine (Pinus ponderosa var. scopulorum Engelm.), interior Douglas-fir (Pseudotsuga menziesii var. glauca (Beissn.) Franco), and Engelmann spruce (Picea engelmannii (Parry) Engelm.) were cold acclimated and deacclimated in growth chambers over 19 weeks. Cold hardiness was measured weekly by a whole-plant freeze test and by two quick tissue tests: freeze-induced electrolyte leakage of needles, and differential thermal analysis of buds. The whole-plant freeze test provided results in 7 days, and indicated differences in cold hardiness among stems, buds, and needles. Although the whole-plant freeze test could accurately measure cold hardiness, it was not precise, and it required destructive sampling. Results from freeze-induced electrolyte leakage and differential thermal analysis were available in 2 days and 1 hour, respectively. The freeze-induced electrolyte leakage test was a precise, sensitive and objective predictor of changes or differences in tissue cold hardiness. To determine actual cold hardiness, results could be calibrated to the response of the same tissue in the whole-plant freeze test. The speed and objectivity of differential thermal analysis made this test useful for rapid, general assessment of cold hardiness status, but calibration was difficult, and precision varied.

During exposure to 2 degrees C, pea (Pisum sativum) seedlings cold acclimated to a killing temperature of -6 degrees C. Associated with this increase in freezing resistance was an increase in the weight of cell walls and changes in wall composition. Arabinosyl content increased by 100%, while other cell wall glycosyl residues and cellulose increased by about 20%. The cell wall hydroxyproline content increased by 80%. Arabinose and hydroxyproline are both major components of the structural cell wall glycoprotein, extensin. The increase in these components indicates that the level of extensin in the cell wall increases during cold acclimation. Northern blot analysis, using the pDC5A1 genomic clone as a probe, revealed a more than three-fold increase in total extensin mRNA during exposure to cold temperature. Specific extensin transcripts of 6.0, 4.5, 3.5, 2.6, 2.3, 1.8, and 1.5 kilobases were identified. Those at 6.0, 2.6, and 1.5 kilobases were especially promoted by low temperature treatment. The rise in extensin during cold acclimation may be regulated, at least in part, at the gene level. The possible structural role of this protein in freezing protection is discussed.

The pipetting of pear (Pyrus communis cv Bartlett) suspension cultures was followed by a substantial but transient decrease in heat sensitivity. During a culture cycle, pear cells were most sensitive to heat at day 3, which coincided with the period of most active cell division. To minimize serious artifacts, the influence of culture handling and age on parameters such as heat sensitivity must be standardized.

Using cultured pear (Pyrus communis cv Bartlett) cells, heat tolerance induced by heat shock was compared to that developed during growth at high temperature. After growth at 22 degrees C, cells exposed to 38 degrees C for 20 minutes (heat shock) showed maximum increased tolerance within 6 hours. Cells grown at 30 degrees C developed maximum heat tolerance after 5 to 6 days; this maximum was well below that induced by heat shock. Heat shock-induced tolerance was fully retained at 22 degrees C for 2 days and was only partly lost after 4 days. However, pear cells acclimated at 30 degrees C lost all acquired heat tolerance 1 to 2 days after transfer to 22 degrees C. In addition, cells which had been heat-acclimated by growth at 30 degrees C showed an additional increase in heat tolerance in response to 39 degrees C heat shock. The most striking difference between heat shock and high growth temperature effects on heat tolerance was revealed when tolerance was determined using viability tests based on different cell functions. Growth at 30 degrees C produced a general hardening, i.e. increased heat tolerance was observed with all three viability tests. In contrast, significantly increased tolerance of heat-shocked cells was observed only with the culture regrowth test. The two types of treatment evoke different mechanisms of heat acclimation.

Fully hydrated lettuce (Lactuca sativa L.) seeds showed dual freezing exotherms (-9 and -18 degrees C), even after 10 hours imbibition. Only the -9 degrees C exotherm was observed in seeds imbibed for 20 hours, but without external nucleation, all water in the embryo supercooled. Results indicate that the endosperm acts as a barrier to ice propagation. Other experiments suggest that the pericarp may also protect the embryo under certain freezing conditions.

The in vitro degradation of green tomato (Lycopersicon esculentum L.) cell walls by an extract of ripe fruits was characterized. The susceptibility of isolated walls to enzymolysis varied considerably among the different cultivars tested. Wall solubilization in vitro appeared to be nearly as extensive as that which accompanies fruit ripening. The solubilized material was primarily polyuronide; smaller amounts of neutral sugar were released. Gel filtration chromatography indicated that an endopolygalacturonase was the only enzyme in the citrate extract able to hydrolyze isolated cell walls. However, this polygalacturonase in vitro did not lead to the substantial (40-60%) decrease in wall galactose which was observed in situ. This difference between in vitro and in situ wall modification is discussed in terms of the possible involvement of other wall hydrolases in fruit softening.

Enzyme preparations were obtained from cell wall debris of tomato (Lycopersicon esculentum L. cv. Tropic) fruits at various stages of ripeness and were assayed for glycosidase and polysaccharidase activities. In addition to polygalacturonase (mol wt 40,000), ripening fruits contain beta-galactosidase (mol wt 63,000) and beta-1, 3-glucanase (mol wt 12,000). The beta-glycosidases, unlike polygalacturonase, are active in extracts of green fruits. Placental tissue shows very low polygalacturonase but increasing beta-galactosidase and beta-1, 3-glucanase activities as ripening proceeds. A large change in the susceptibility of the walls to hydrolase action occurs before the stage in which the greatest polygalacturonase activity occurs. The possibility that the beta-glycosidases contribute to the wall modifications that lead to fruit softening is discussed.

By a complex process involving methylation, partial hydrolysis with acid, reduction with sodium borodeuteride, ethylation, further hydrolysis and reduction, and subsequent capillary gas-liquid chromatography-mass spectrometry of the derived alditol acetates, it was established that the arabinogalactans of Mycobacterium leprae and Mycobacterium tuberculosis contain arabinofuranyosyl and galactofuranosyl residues exclusively. Thus, the covalently bound, highly immunogenic arabinogalactan of mycobacteria, and presumably of other actinomycetes, is highly unusual, in that all of the glycosyl residues are in the furanoid form. Furthermore, by establishing that the galactofuranosyl residues are either 5-, 6-, or 5,6-linked, their linkage pattern was established, and the literature is corrected on this point.

Changes in the galactose content of the noncellulosic polysaccharides of tomato (Mill) fruit cell walls were analyzed under various conditions. On the plant, galactan decreased gradually during fruit growth. As normal fruits ripened, the loss of galactan increased sharply; this was not observed in attached rin fruits beyond the fully mature stage. The ability to produce new wall galactan in vitro was retained in mature fruit tissue but declined with ripening. Normal tomatoes ripening on the plant showed a transient increase in galactan content at the climacteric. It is suggested that the decline in wall galactan is partly due to reduced synthesis in senescing, normal fruits and in detached rin tomatoes.

The response of suspension-cultured pear (Pyrus communis cv Bartlett) cells to heat stress was studied using three viability tests: regrowth (culture growth during 10 days after stress); triphenyltetrazolium chloride reduction; and electrolyte leakage. Critical (50% injury) temperatures for a 20-minute exposure were 42 degrees , 52 degrees , and 56 degrees C, respectively, for these viability tests. Electrolyte leakage had the lowest temperature coefficient. Heat stress inhibition of triphenyltetrazolium chloride reducing capacity was much greater if the viability test was conducted 3 days, rather than immediately, after the stress treatment. Consistent with a major role for indirect metabolic strain in heat injury, treatment with 3.6 micromolar cycloheximide and heat stress (20 minutes at 43 degrees C) affected culture regrowth similarly. We conclude that the measurements of direct response are not adequate substitutes for regrowth tests in assessing heat injury to cultured plant cells.

Changes in neutral sugar, uronic acid, and protein content of tomato (Lycopersicon esculentum Mill) cell walls during ripening were characterized. The only components to decline in amount were galactose, arabinose, and galacturonic acid. Isolated cell walls of ripening fruit contained a water-soluble polyuronide, possibly a product of in vivo polygalacturonase action. This polyuronide and the one obtained by incubating walls from mature green fruit with tomato polygalacturonase contained relatively much less neutral sugar than did intact cell walls. The ripening-related decline in galactose and arabinose content appeared to be separate from polyuronide solubilization. In the rin mutant, the postharvest loss of these neutral sugars occurred in the absence of polygalacturonase and polyuronide solubilization. The enzyme(s) responsible for the removal of galactose and arabinose was not identified; a tomato cell wall polysaccharide containing galactose and arabinose (6:1) was not hydrolyzed by tomato beta-galactosidase.

Greenhouse-cultured, container-grown ponderosa pine (Pinus ponderosa var. scopulorum Engelm.), interior Douglas-fir (Pseudotsuga menziesii var. glauca (Beissn.) Franco) and Engelmann spruce (Picea engelmannii (Parry) Engelm.) were cold acclimated and deacclimated in growth chambers over 19 weeks. Stem cold hardiness, total new root length at 14 days and days to bud break were measured weekly. Relationships among cold hardiness, root growth potential (RGP) and bud dormancy suggest that cold hardiness, which can be measured quickly, could provide a useful basis for estimating the two other parameters. During cold acclimation, there was a lag period in which stem cold hardiness remained at -15 degrees C and RGP was at a minimum, in all three species. Douglas-fir and Engelmann spruce buds remained fully dormant during this lag period. Ponderosa pine buds had no chilling requirement for the loss of dormancy, and reached quiescence during the lag period. Immediately following the lag period, as stem cold hardiness progressed to -22 degrees C, RGP increased to a high plateau in all three species, and Douglas-fir and Engelmann spruce buds approached quiescence. Cold deacclimation and bud development began immediately on exposure to warm, long days, but RGP remained high until stem cold hardiness returned to approximately -15 degrees C. At bud break, cold hardiness and RGP were at the minimum.