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In flowering plants, two cells are fertilized in the haploid female gametophyte. Egg and sperm nuclei fuse to form the embryo. A second sperm nucleus fuses with the central cell nucleus that replicates to generate the endosperm, which is a tissue that supports embryo development. MEDEA (MEA) encodes an Arabidopsis SET domain Polycomb protein. Inheritance of a maternal loss-of-function mea allele results in embryo abortion and prolonged endosperm production, irrespective of the genotype of the paternal allele. Thus, only the maternal wild-type MEA allele is required for proper embryo and endosperm development. To understand the molecular mechanism responsible for the parent-of-origin effects of mea mutations on seed development, we compared the expression of maternal and paternal MEA alleles in the progeny of crosses between two Arabidopsis ecotypes. Only the maternal MEA mRNA was detected in the endosperm from seeds at the torpedo stage and later. By contrast, expression of both maternal and paternal MEA alleles was observed in the embryo from seeds at the torpedo stage and later, in seedling, leaf, stem, and root. Thus, MEA is an imprinted gene that displays parent-of-origin-dependent monoallelic expression specifically in the endosperm. These results suggest that the embryo abortion observed in mutant mea seeds is due, at least in part, to a defect in endosperm function. Silencing of the paternal MEA allele in the endosperm and the phenotype of mutant mea seeds supports the parental conflict theory for the evolution of imprinting in plants and mammals.

Background: The pharmacodynamics and dose-response relationship of repaglinide, a novel oral hypoglycemic agent, were evaluated in steady-state treatment of patients with type 2 diabetes., Methods: Efficacy of repaglinide (0.25 mg, 0.5 mg, 1 mg, 2 mg, and 4 mg) was compared to that of placebo in a double-blind, randomized, parallel-group, 4-week dose-response clinical trial in 143 patients. Repaglinide was administered 15 minutes before meals (breakfast, lunch, and dinner). Efficacy of repaglinide therapy was assessed by measuring changes from baseline in mean levels of blood glucose (BGmean), fasting serum glucose (FSG), and mean levels of serum insulin (INSmean)., Results: Blood concentrations of repaglinide were proportional to the dose administered. INSmean values increased in all repaglinide treatment groups (by 6.7 to 12.9 microU/mL). All doses of repaglinide significantly decreased values of BGmean and FSG as compared with the placebo group. BGmean values stabilized between the second and third week of repaglinide treatment. A well-defined dose-response relationship was observed for BGmean and FSG values. All doses of repaglinide were well tolerated, and there were no serious adverse events., Conclusions: These findings show that the therapeutic reduction of serum glucose levels produced by repaglinide is dose-dependent for the 0.25- to 4-mg dose range. All doses of repaglinide tested were effective and well tolerated in patients with type 2 diabetes.

Higher plant reproduction is unique because two cells are fertilized in the haploid female gametophyte. Egg and sperm nuclei fuse to form the embryo. A second sperm nucleus fuses with the central cell nucleus that replicates to generate the endosperm, a tissue that supports embryo development. To understand mechanisms that initiate reproduction, we isolated a mutation in Arabidopsis, f644, that allows for replication of the central cell and subsequent endosperm development without fertilization. When mutant f644 egg and central cells are fertilized by wild-type sperm, embryo development is inhibited, and endosperm is overproduced. By using a map-based strategy, we cloned and sequenced the F644 gene and showed that it encodes a SET-domain polycomb protein. Subsequently, we found that F644 is identical to MEDEA (MEA), a gene whose maternal-derived allele is required for embryogenesis [Grossniklaus, U., Vielle-Calzada, J.-P., Hoeppner, M. A. & Gagliano, W. B. (1998) Science 280, 446-450]. Together, these results reveal functions for plant polycomb proteins in the suppression of central cell proliferation and endosperm development. We discuss models to explain how polycomb proteins function to suppress endosperm and promote embryo development.

A fundamental problem in biology is to understand how fertilization initiates reproductive development. Higher plant reproduction is unique because two fertilization events are required for sexual reproduction. First, a sperm must fuse with the egg to form an embryo. A second sperm must then fuse with the adjacent central cell nucleus that replicates to form an endosperm, which is the support tissue required for embryo and/or seedling development. Here, we report cloning of the Arabidopsis FERTILIZATION-INDEPENDENT ENDOSPERM (FIE) gene. The FIE protein is a homolog of the WD motif-containing Polycomb proteins from Drosophila and mammals. These proteins function as repressors of homeotic genes. A female gametophyte with a loss-of-function allele of fie undergoes replication of the central cell nucleus and initiates endosperm development without fertilization. These results suggest that the FIE Polycomb protein functions to suppress a critical aspect of early plant reproduction, namely, endosperm development, until fertilization occurs.

Insulin resistance and hyperinsulinemia can induce overproduction of triglyceride (TG) rich VLDL in the liver by increasing the availability of free fatty acids (FFA). Conversely, apolipoprotein C-III (apoC-III) is an inhibitor of the catabolism of TG-rich lipoproteins. To explore the relationship among FFA, apo C-III and TG in hyperinsulinemic subjects, we studied 103 individuals (63 women and 40 men) with a body mass index (BMI) 25 Kg/m2: 59 subjects with normal glucose tolerance (NGT), and 44 with newly diagnosed type 2 diabetes. After adjustment for age, BMI, fasting insulin and TG, FFA were significantly higher in women than in men and in subjects with diabetes compared with NGT. Subjects with diabetes had higher apo C-III levels compared to NGT, adjusted for age, sex and BMI, and that was largely accounted for by differences in insulin and TG levels. In addition, regression analysis in subjects with diabetes showed that TG were strongly associated with apo C-III in both men and women (r = 0.90 and 0.79, respectively; p < 0.001), while the association tended to be smaller between TG and FFA (r = 0.48, p < 0.05 in men and r = 0.45, p = 0.06 in women). Conversely, in individuals with NGT fasting TG was strongly associated with apo C-III in men (r = 0.83, p < 0.01) but not with FFA, while in women TG was associated with FFA (r = 0.39, p < 0.05) but not with apo C-III. In summary, elevated apo C-III was a predominant factor associated with elevated TG levels in NGT men and all subjects with type 2 diabetes, while FFA were more closely related with TG levels in NGT women.

Background: Although diabetes is a major risk factor for coronary heart disease (CHD), little information is available on the effects of lipid lowering in diabetic patients. We determined whether lipid-lowering treatment with pravastatin prevents recurrent cardiovascular events in diabetic patients with CHD and average cholesterol levels., Methods and Results: The Cholesterol And Recurrent Events (CARE) trial, a 5-year trial that compared the effect of pravastatin and placebo, included 586 patients (14.1%) with clinical diagnoses of diabetes. The participants with diabetes were older, more obese, and more hypertensive. The mean baseline lipid concentrations in the group with diabetes--136 mg/dL LDL cholesterol, 38 mg/dL HDL cholesterol, and 164 mg/dL triglycerides--were similar to those in the nondiabetic group. LDL cholesterol reduction by pravastatin was similar (27% and 28%) in the diabetic and nondiabetic groups, respectively. In the placebo group, the diabetic patients suffered more recurrent coronary events (CHD death, nonfatal myocardial infarction [MI], CABG, and PTCA) than did the nondiabetic patients (37% versus 25%). Pravastatin treatment reduced the absolute risk of coronary events for the diabetic and nondiabetic patients by 8.1% and 5.2% and the relative risk by 25% (P=0.05) and 23% (P<0.001), respectively. Pravastatin reduced the relative risk for revascularization procedures by 32% (P=0.04) in the diabetic patients. In the 3553 patients who were not diagnosed as diabetic, 342 had impaired fasting glucose at entry defined by the American Diabetes Association as 110 to 125 mg/dL. These nondiabetic patients with impaired fasting glucose had a higher rate of recurrent coronary events than those with normal fasting glucose (eg, 13% versus 10% for nonfatal MI). Recurrence rates tended to be lower in the pravastatin compared with placebo group (eg, -50%, P=0.05 for nonfatal MI)., Conclusions: Diabetic patients and nondiabetic patients with impaired fasting glucose are at high risk of recurrent coronary events that can be substantially reduced by pravastatin treatment.

Type 2 diabetes is a major cause of morbidity and mortality resulting from its microangiopathic and macroangiopathic complications. Current approaches to its management and to the prevention of diabetic complications are difficult to implement effectively, and there is little evidence to date that these approaches are reducing the impact of this disease. The recognition that type 2 diabetes usually has a prolonged prediabetic phase raises the possibility that the emergence of hyperglycemia and the atherosclerotic complications associated with diabetes may be preventable by the institution of early treatment modalities. Sufficient data suggest that life-style modification or pharmacotherapy directed at improving insulin sensitivity or insulin secretion in subjects with impaired glucose tolerance may reduce progression to diabetes. Two long-term prospective, controlled trials have been initiated to test this hypothesis.

The Arabidopsis LEAFY COTYLEDON1 (LEC1) gene is required for the specification of cotyledon identity and the completion of embryo maturation. We isolated the LEC1 gene and showed that it functions at an early developmental stage to maintain embryonic cell fate. The LEC1 gene encodes a transcription factor homolog, the CCAAT box-binding factor HAP3 subunit. LEC1 RNA accumulates only during seed development in embryo cell types and in endosperm tissue. Ectopic postembryonic expression of the LEC1 gene in vegetative cells induces the expression of embryo-specific genes and initiates formation of embryo-like structures. Our results suggest that LEC1 is an important regulator of embryo development that activates the transcription of genes required for both embryo morphogenesis and cellular differentiation.

Objectives: To test the safety and effects of exercise conditioning on cardiorespiratory fitness, body composition, muscle strength, glucose regulation, and lipid/cholesterol levels., Subjects: Ten male adolescents with insulin-dependent diabetes mellitus (IDDM) and 10 adolescent nondiabetic (ND) subjects., Design: Pretest, posttest intervention trial with control group., Setting: University-based human performance laboratory., Intervention: Mixed endurance and calisthenic/strength activities performed at a rapid pace three times weekly for 12 weeks., Results: Only one subject with IDDM experienced hypoglycemia after a single exercise session. Both subject groups improved their cardiorespiratory endurance (p < .05). Lean body mass of IDDM subjects increased by 3.5% (p < .05). Subjects with and without IDDM lowered their percent body fat (p < .05 and .001, respectively). Strength improvement of IDDM subjects ranged from 13.7% (p < .001) to 44.4% (p < .01), depending upon the maneuver. Fasting blood plasma glucose for all subjects was unchanged by training, but glycosylated hemoglobin A1c of IDDM subjects was reduced by .96 percentage point (p < .05). Reductions of HbA1c benefitted subjects exhibiting poor preconditioning glycemic control. Low-density lipoprotein cholesterol was decreased in subjects with IDDM (p < .05), but not total cholesterol or triglycerides., Conclusion: Adolescents with IDDM undergoing aerobic circuit training improve their cardiorespiratory endurance, muscle strength, lipid profile, and glucose regulation. Aerobic circuit training is safe for properly trained and monitored adolescent diabetics.

Shprintzen-Goldberg syndrome is one of a group of disorders characterized by craniosynostosis and marfanoid habitus. Eleven cases were reported previously. We present 4 new patients and review one of the patients of the original report of Shprintzen and Goldberg [1982: J Craniofac Genet Dev Biol 2:65-74], 15 years later. The clinical and radiologic findings on our patients are compared with those of the previously reported patients and also with those of Furlong et al. [1987: Am J Med Genet 26:599-604] and Lacombe and Battin [1993: Clin Dysmorphol 2: 220-224], who share many of the characteristics of Shprintzen-Goldberg syndrome. Some of the clinical data are helpful in determining if the patients of Furlong et al. [1987: Am J Med Genet 26:599-604] and Lacombe and Battin [1993: Clin Dysmorphol 2: 220-224] have a separate syndrome or represent a variant of Shprintzen-Goldberg syndrome. However, radiologic investigations appear to be more specific, since an abnormality of the first and second cervical vertebrae, hydrocephalus, dilatation of the lateral ventricles, and a Chiari-I malformation of the brain were found only in the patients with Shprintzen-Goldberg syndrome. The apparently diagnostic findings of the 15 patients with this syndrome may be helpful in differentiating between Shprintzen-Goldberg syndrome and other syndromes with craniosynostosis and marfanoid habitus.

The clinical stereotype that divides diabetic patients into those who are thin and need insulin and those who are obese and do not need insulin can be misleading. Some patients with type 2 diabetes present with ketoacidosis and require insulin treatment. Many of them can be weaned from insulin, although they may require hypoglycemic therapy.

A number of coronary heart disease risk factors have been identified that often cluster together to increase the risk of macrovascular disease. This cluster is referred to as the insulin resistance syndrome, and the risk factors commonly include dyslipidemia, elevated blood pressure, an android pattern of body fat distribution, and glucose intolerance. Whether hyperinsulinemia or insulin resistance per se provides a common pathway for these metabolic abnormalities is unclear. The authors studied 50 nondiabetic persons who had completed a euglycemic hyperinsulinemic clamp protocol in addition to a 75-g oral glucose tolerance test and other measures of the coronary risk profile. Using principal-component analysis, we reduced nine coronary risk factors to two uncorrelated factors that explained 54.5% of the variance. Factor 1 consisted of positive loadings for uric acid, systolic and diastolic blood pressure, triglyceride concentration, and waist girth and negative loadings for HDL cholesterol and the rate of insulin-mediated glucose disposal (M, in milligrams per kilogram of body weight per minute). M also loaded on factor 2, along with fasting insulin and glucose concentrations, diastolic blood pressure, and waist girth. The observation that M loaded on both factors suggests that a resistance to insulin action may provide the mechanism uniting the features of the insulin resistance syndrome. Hyperinsulinemia with concomitant insulin resistance may be necessary to produce this metabolic derangement, as well as the increased risk of macrovascular complications.

As many as 25 percent of patients with diabetes mellitus may also have depressive symptoms. Tricyclic antidepressants (TCAs) may produce increased appetite and weight gain with adverse consequences for diabetes. The selective serotonin reuptake inhibitors (SSRIs), however, may improve fasting blood sugar in laboratory studies. In an initial application, sertraline was administered at a dose of 50 mg/day in a 10-week open study to 28 non-insulin-dependent diabetes mellitus (NIDDM) patients with DSM-III-R major depression after a 2-week single-blind placebo washout period with a minimum 17-Item Hamilton Rating Scale for Depression (HAM-D) score of 18. The patient group included 16 males and 12 females with a mean age of 54.2 +/- 8.8 years. Results indicated (1) significant improvement in mean HAM-D (22.6 +/- 3.4 to 4.9 +/- 5.9, p < .001) and in mean Beck Depression Inventory (BDI) scores (21.9 +/- 10.5 to 12.7 +/- 8.3, p < .001); (2) fall in platelet serotonin (5-HT) content (79.7 +/- 22.5 to 13.6 +/- 12.7 ng/10(8) platelets, p < .001); (3) correlation of baseline platelet 5-HT content with response to sertraline by BDI scores (r = 0.51, p < .05); (4) improved dietary compliance for those with baseline value below 70 percent (59.7% to 69.1%, p < .005); and (5) 13 of 17 patients with baseline glycosylated hemoglobin A (HbA1c) levels greater than 8.0, showed a reduction (p = .018). Sertraline may be an effective antidepressant in patients with diabetes mellitus and response may be predictable by higher baseline platelet 5-HT content, with the potential to improve dietary compliance and reduce HbA1c measures. As with all open studies, replication is essential.

The processes controlling the differentiation of plant cells are not well understood. Two alternative, but not mutually exclusive, mechanisms probably play a major role in plant-cell differentiation. One mechanism utilizes a position-independent, cell-autonomous differentiation process. The other, employs a position-dependent, cell-cell interaction process that requires signals from neighbouring cells. Cell ablation studies can be used to distinguish between these two models of plant-cell differentiation. In this article we outline a new cell-ablation strategy that utilizes promoters with distinct, but overlapping, cell specificities that are fused with cytotoxic and anticytotoxic structural genes. We present preliminary observations on how this strategy can be used to dissect the events controlling anther development.

Hypercholesterolemia is common following renal transplantation and undoubtedly contributes to morbidity and mortality due to occlusive atherosclerosis in these patients. Although 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors are more tolerable as low density lipoprotein cholesterol (LDL-C)-lowering agents than other classes of drugs, their use in transplant patients has been limited due to potentially serious interactions with cyclosporine. Fluvastatin is the first wholly synthetic HMG-CoA reductase inhibitor. Because it has a shorter half-life and greater protein-binding capacity than other drugs of this class and has no active circulating metabolites, fluvastatin may be safer than other HMG-CoA reductase inhibitors in this group of patients. To study this question, 19 renal transplant recipients (age, 21-70 years) with hypercholesterolemia (LDL-C > 180 mg/dL; triglycerides < 400 mg/liter) were entered into a 14-week active-treatment period with fluvastatin at 20 mg/day following dietary stabilization and a 3-week placebo washout period. Changes in LDL-C levels were compared with those obtained in control hypercholesterolemic subjects treated in the same way. The lipid-lowering ability of fluvastatin was not imparied in these patients, indicating a lack of interaction with cyclosporine. Mean liver enzyme levels, creatine phosphokinase (CPK), and creatine did not change significantly from baseline. Two subjects experienced myalgias without CPK elevations, and another subject experienced an asymptomatic increase in CPK to > 10 times the upper limit of normal, related to exercise. In conclusion, fluvastatin safely and effectively lowers elevated LDL-C levels in renal transplant recipients.

The objective of this study was to compare the lipid-altering efficacy and safety of simvastatin with that of gemfibrozil in hypercholesterolemic patients with non-insulin-dependent diabetes mellitus (NIDDM). The study was a 24-week, double-blind, randomized, multicenter trial conducted at clinics and hospitals in the United States, Austria, Germany, Brazil, and New Zealand. The study population included 168 men and women aged 34 to 78 years with NIDDM and primary hypercholesterolemia (low-density lipoprotein cholesterol [LDL-C] level at screening was > or = 4.9 mmol/L with no other risk factor or > or = 4.1 mmol/L with one or more other risk factors). All patients had been under moderate-to-good diabetic control (hemoglobin A1c [HbA1c] < or = 10.0%) for at least 6 months with diet alone, oral hypoglycemic agents, or insulin therapy. Patients meeting eligibility criteria were randomized to receive either simvastatin 10 mg (titrated up to 40 mg to achieve an LDL-C level < 3.4 mmol/L) once in the evening or gemfibrozil 600 mg twice daily. There were 81 patients in the simvastatin group and 87 patients in the gemfibrozil group. After 17 weeks of treatment, simvastatin significantly reduced levels of total cholesterol, LDL-C, and very-low-density lipoprotein cholesterol (VLDL-C) by approximately 25%, 33%, and 20%, respectively (P < or = 0.001), and triglycerides by about 9% (P < or = 0.05). The drug increased high-density lipoprotein cholesterol (HDL-C) levels by about 6% (P < 0.01). Gemfibrozil significantly reduced total cholesterol, VLDL-C, and triglyceride levels by approximately 8%, 38%, and 27%, respectively (P < 0.001); it significantly increased HDL-C values by about 12% (P < 0.001). Gemfibrozil lowered LDL-C levels by 4% but not significantly. The decreases in total cholesterol and LDL-C were significantly greater (P < 0.001) in the simvastatin group, and decreases in VLDL-C and triglycerides were significantly greater in the gemfibrozil group (P < 0.01). The changes in HDL-C were not significantly different between groups. LDL-C values of < 3.4 mmol/L were achieved in 60% of the simvastatin patients and 14% of the gemfibrozil patients. There were no significant between-group differences in fasting serum glucose or HbA1c at any time point. Glycemic profiles (performed at baseline and after 17 weeks of treatment) and glucose area under the curve (at baseline and after 17 weeks of treatment) were not significantly different between treatment groups. Both drugs were generally well tolerated.(ABSTRACT TRUNCATED AT 400 WORDS)

Most differentiation events in higher plants occur continuously in the postembryonic adult phase of the life cycle. Embryogenesis in plants, therefore, is concerned primarily with establishing the basic shoot-root body pattern of the plant and accumulating food reserves that will be used by the germinating seedling after a period of embryonic dormancy within the seed. Recent genetics studies in Arabidopsis have identified genes that provide new insight into how embryos form during plant development. These studies, and others using molecular approaches, are beginning to reveal the underlying processes that control plant embryogenesis.

We identified a tobacco stigma-specific gene, designated STIG1. The STIG1 gene is developmentally regulated and expressed specifically in the stigmatic secretory zone. We used a chimeric STIG1-GUS gene to show that the stigma-specific STIG1 gene expression pattern is controlled primarily at the transcriptional level. We constructed a stigma-specific cytotoxic gene by fusing the STIG1 gene 5' regulatory region with the coding sequence of the Bacillus amyloliquefaciens barnase gene, to assess the role of the stigmatic secretory zone in the pollination process. Pistils of transgenic STIG1-barnase tobacco plants undergo normal development, but lack the stigmatic secretory zone and are female sterile. Pollen grains germinate on the ablated 'stigmatic' surface, but are unable to penetrate the transmitting tissue of the style. Application of stigmatic exudate from wild-type pistils to the ablated surface increases the efficiency of pollen tube germination and growth and restores the capacity of pollen tubes to penetrate the style. Our data demonstrate the importance of the stigmatic secretory zone in the pollination process and provide an approach to identify compounds produced by the stigma that are critical for successful pollination and fertilization to occur.

Plasma lipid measurements were obtained at the time that 545 subjects were screened for diabetes mellitus. Both the women and men diagnosed with diabetes had significantly higher triglyceride levels (p < 0.05) and lower high-density-lipoprotein cholesterol (HDL-cholesterol) levels (p < 0.05) than those with normal glucose tolerance. Low-density-lipoprotein cholesterol (LDL-cholesterol) levels were only higher in the diabetic women (p < 0.001). Differences in lipid values were diminished somewhat with allowances for the waist-hip ratio. HDL-cholesterol values were inversely related to fasting insulin levels in the normoglycaemic men and women (p < 0.01), but not in the diabetic individuals. Triglyceride levels were strongly positively related to insulin values in the normoglycaemic men and women (p < 0.001 for both), while associations tended to be smaller in the diabetic subjects. In 13 of the diabetic individuals who were not medicated for diabetes over a period of 17.5 +/- 4.6 months, changes in HDL-cholesterol levels were positively related (p = 0.80, < 0.001) and changes in triglyceride levels inversely related (r = -0.70, p < 0.01) to changes in insulin values. These data indicate that at diagnosis Type 2 diabetic patients have an atherogenic lipid pattern that may be related in part to differences in adipose distribution. In addition, the data suggest that HDL-cholesterol is positively related and triglyceride inversely related to insulin action.

This study sought to compare the efficacy and safety of glyburide and glipizide in elderly patients with well-controlled non-insulin-dependent diabetes mellitus (NIDDM). One hundred forty-five patients aged > or = 65 years with NIDDM that was controlled for at least 3 months with oral sulfonylurea therapy were enrolled. After a washout phase, 139 patients were randomized to receive glyburide, 1.25 or 2.5 mg/day, or glipizide, 2.5 or 5 mg/day. During a 4- to 8-week titration phase, doses were adjusted according to prescribing guidelines. Patients who achieved glycemic control (fasting plasma glucose of < or = 8.9 mmol/L, or 160 mg/dl, on two consecutive occasions) entered a maintenance phase, for a total treatment period of 4 months. Hypoglycemia was defined as a fasting plasma glucose of < 3.3 mmol/L (60 mg/dl) or a random plasma glucose of < 2.8 mmol/L (50 mg/dl), with associated signs and symptoms. Most patients in both the glyburide and glipizide groups achieved satisfactory glycemic control; there were no significant differences between groups in fasting plasma glucose or hemoglobin A1c levels at any time. Of note, the mean dose of glyburide (8.5 mg/day) was approximately half that of glipizide (15.4 mg/day) at the end of the maintenance period (P = 0.009). Both regimens were well tolerated and were associated with a similarly low incidence of hypoglycemia. It was concluded that both glyburide and glipizide are suitable for the treatment of NIDDM in properly selected elderly patients.

We compared the accuracies of adiposity distribution measures (waist and hip circumferences, subscapular and triceps skinfold thicknesses, waist-hip and subscapular-triceps ratios) with a measure of adiposity extent (body mass index) for screening non-insulin dependent diabetes mellitus (NIDDM). Of 521 subjects (218 men and 303 women) who had 2 h oral glucose tolerance tests, 43 men and 28 women were found to have NIDDM. Allowing for age, ethnicity, and family history in analyses of covariance, the subscapular skinfold thickness and the ratio of the subscapular to triceps skinfold thicknesses were significantly higher (P < 0.05) in both the men and women found to have diabetes than in their non-diabetic counterparts. The waist-hip ratio was also significantly higher in diabetic women; however, the elevation was not as marked in diabetic men (P = 0.06). The body mass index did not differ between diabetic and non-diabetic men and was only moderately elevated in diabetic women (P = 0.04). Receiver-operator curves were employed to examine the relative accuracies of the body mass index, waist-hip ratio, and subscapular skinfold thickness for screening NIDDM. In both men and women, the waist-hip ratio and subscapular thickness were superior to the body mass index. These data suggest that certain measures of adiposity distribution are more accurate than measures of overall adiposity extent for screening NIDDM and that they may be useful in screening programmes.

Velo-cardio-facial syndrome (VCFS), an autosomal dominant disorder, is characterized by cleft palate, cardiac defects, learning disabilities and a typical facial appearance. Less frequently, VCFS patients have manifestations of the DiGeorge complex (DGC) including hypocalcemia, hypoplastic or absent lymphoid tissue and T-cell deficiency suggesting that these 2 conditions share a common pathogenesis. Here, we report the results of cytogenetic and molecular studies of 15 VCFS patients. High-resolution banding techniques detected an interstitial deletion of 22q11.21-q11.23 in 3 patients. The remaining 12 patients had apparently normal chromosomes. Molecular analysis with probes from the DiGeorge Chromosome Region (DGCR) within 22q11 detected DNA deletions in 14 of 15 patients. In 2 families, deletions were detected in the affected parent as well as the propositus suggesting that the autosomal dominant transmission of VCFS is due to segregation of a deletion. Deletions of the same loci previously shown to be deleted in patients with DGC explains the overlapping phenotype of VCFS and the DGC and supports the hypothesis that the cause of these two disorders is the same.

We compared the plasma lipid profiles of Cuban Americans and other Hispanic-American subgroups with those of non-Hispanics. High-density lipoprotein cholesterol levels were lower and triglyceride levels were higher when Hispanic women were compared with non-Hispanic women, and this pattern was also apparent for men. The lower high-density lipoprotein cholesterol and higher triglyceride levels were consistent for both Cuban and non-Cuban Hispanics. There were higher waist-hip ratios and insulin levels in both Hispanic men and women. When allowances were made for these attributes in covariance analyses, the lipid differences were markedly diminished. These data suggest the lower high-density lipoprotein cholesterol and higher triglyceride levels are consistent across Hispanic subgroups and that this lipid pattern may be attributable at least in part to increased insulin resistance in Hispanics.

A body of epidemiological evidence suggests an association between residential or occupational exposure to extremely low frequency (ELF) electromagnetic fields (EMF) and an increased incidence of cancer in children and adults. Experimental studies at the whole-animal and cellular level are ambiguous; bioeffects suggestive of a carcinogenic effect have been reported, but a similar volume of negative reports can also be assembled. This literature is critically reviewed based on the hypothesis that the epidemiological results are correct, and asking what plausible mechanism could explain a small increase in the incidence of a range of tumors with a non-specific increased exposure to ELF EMF? We focus on four likely mechanisms: 1) disruption of cell communication, 2) modulation of cell growth via changes in calcium ion flux, 3) activation of specific oncogenic gene sequences, and 4) action as a stress factor operating through disruption of hormonal and immune system tumor control mechanisms. We discuss the implications of epidemiologic and experimental results in the context of hypothetical mechanisms of cancer induction, and suggest experiments likely to help define putative EMF hazards.

We constructed two chimaeric ribonuclease genes that are specifically expressed in anthers of tobacco and rapeseed plants. The expression of these genes affects the production of functional and viable pollen yielding plants that are male sterile. This dominant gene for nuclear male sterility should facilitate the production of hybrid seed in various crops.

We examined 14 patients from nine families referred with the diagnosis of Treacher Collins syndrome. We noted seven significant ocular findings including the following: a subnormal horizontal palpebral fissure length and inferomedial displacement of the lateral canthus in primary gaze; further medial displacement (4.0 mm or more) of the lateral canthus with resultant shortening of the horizontal fissure length on forced eyelid closure (fissure narrowing sign); partial-thickness eyelid colobomata localized to the nasal one half to two thirds of the lower eyelids; bilateral absence of the inferior lacrimal puncta; bilateral blepharoptosis; inferior displacement of the palpebral fissures; and regular astigmatism without any consistent orientation of the axis of astigmatism relative to the lower eyelid defects, blepharoptosis, or lateral canthus. The fissure narrowing sign correlates with known anatomic deficiencies in the Treacher Collins syndrome and may prove valuable in confirming the diagnosis in patients who lack certain typical features.

The correlations between lipid and lipoprotein measurements and other risk factors of coronary artery disease were evaluated in 101 men undergoing coronary angiography. Clinically significant disease was present in 75 patients, whereas 24 had no observable lesions and 2 had minimal lesions. Comparisons of individual lipid and lipoprotein levels were nearly all significantly different between patients with and patients without clinically significant disease; however, no single variable could predict the presence of disease among patients. Logistic regression analysis identified five factors: apolipoprotein A-I, apolipoprotein B, diabetes, age, and family history of heart disease, which account for most of the differences between the two patient groups. These results could have important implications for the evaluation and management of patients suspected of having coronary atherosclerosis.

Spondyloepiphyseal dysplasia congenita (SEDC) is an autosomal dominantly inherited chondrodysplasia characterized by disproportionate short stature (short trunk), abnormal epiphyses, and flattened vertebral bodies. Manifestations are present at birth. We ascertained a 4-generation family exhibiting the clinical manifestations of the disorder. Previous evidence suggesting defects of type II collagen associated with the SEDC phenotype led us to genotype the family for various COL2A1 gene-associated RFLPs. A total of 17 affected and unaffected members of this family were studied. The family was informative for a recently discovered HinfI RFLP. No recombinants between the marker and the phenotype were found in eight informative meioses. A maximum LOD score of 3.01 was obtained at a recombination fraction of .00. Our results indicate that the SEDC phenotype in this family is caused by mutations in or very close to the COL2A1 locus.

Relations between lipoprotein indices and the waist/hip ratio (WHR) were examined in normoglycemic subjects (124 women and 63 men). Among women, an atherogenic lipoprotein pattern was strongly associated with WHR. The relation was greater than that of the lipoprotein pattern with either the body mass index or the subscapular/triceps ratio, and was independent of these adiposity measures. The association between low-density-lipoprotein cholesterol (LDL-cholesterol) and WHR was much stronger in thinner women than in those more obese (r = 0.64 vs r = 0.22, p = 0.001 for difference). Men had a more atherogenic lipoprotein pattern than women; however, with allowances for WHR the lipoprotein patterns were similar. These findings suggest that: (1) WHR is more strongly related to plasma lipoproteins than other adiposity measures; (2) there is effect modification by the extent of adiposity for the relation between LDL-cholesterol and WHR; and (3) the adipose distribution may be important in explaining lipoprotein differences between men and women.

We investigated soybean lectin gene structure and expression in a genetic line that accumulates normal levels of seed lectin (Le+ line) and in a mutant line that produces no detectable seed lectin (Le- line). We found that the nuclear and cytoplasmic lectin RNA levels in Le- embryos are approximately 0.01% of those in Le+ embryos. Runoff transcription experiments with isolated nuclei showed that the reduced RNA levels are caused by decreased lectin gene transcription. Each genetic line contains two lectin genes, L1 and L2. L1 encodes seed lectin, while the function of L2 is unknown. We found that a 3.4 kb DNA segment, consisting of repeated sequences, has been inserted into the L1 gene of the Le- line. We conclude that this insertion results in reduced transcription of the mutant L1 gene, and leads to the lectinless phenotype.

Flowering plants are the most highly evolved and complex organisms within the plant kingdom. The flower consists of several distinct organ systems that are responsible for higher plant reproduction. Cells within specific floral organs differentiate into spores and gametes required by the plant to complete its life cycle. Flower development represents an excellent model for understanding the molecular and physiological processes that control organ differentiation in higher plants. Rapidly emerging gene tagging procedures are facilitating the isolation of genes that control flower morphogenesis.

Hepatic synthesis of cholesterol in higher animals is normally markedly suppressed by dietary cholesterol. This feedback regulation has been shown to be absent in all experimental hepatomas studied, and also in the only 2 humans with primary hepatocellular cancer (PHC) who have been investigated. Another patient who presented with hypercholesterolaemia is described in whom cholesterogenesis in the tumour was not suppressed by cholesterol feeding. In order to determine the frequency with which hypercholesterolaemia occurs in PHC, serum cholesterol levels were measured in 132 Black patients with this tumour. Raised levels were found in 14 of the patients (11%). In only 2 of these was hypercholesterolaemia associated with obstructive jaundice.

We investigated soybean seed protein gene transcription during development. We found that seed protein genes are transcriptionally activated and then repressed during embryogenesis and that these genes are either inactive or transcribed at low levels in the mature plant. We further observed that genes encoding mRNAs with vastly different prevalences are transcribed at similar rates. DNA gel blot studies showed that transcriptionally active and inactive seed protein genes have indistinguishable methylation patterns. We conclude that both transcriptional and posttranscriptional processes regulate seed protein mRNA levels in the absence of detectable DNA methylation changes.

Pulsus paradoxus (PP) was measured in 35 patients with bronchial asthma. The presence and degree of PP correlated well with the clinical conditions of the patient and with peak expiratory flow rate (PEF). PP and PEF are useful bedside measurements in the assessment and management of patients with bronchial asthma. Although the degree of PP is usually directly related to the severity of the attack of asthma, it was absent in the one patient who remained severly ill with unreleived bronchospam when he became exhausted. Our experience with this patient, and with previous patients who are not included in the present analysis, emphasises the fact that PP must not be considered in isolation but in conjunction with the patient's clinical state and with other indices of the severity of the astmatic attack.

The inheritance of Robinow's syndrome has been thought to be autosomal dominant. However, since no cases of male-to-male transmission have been reported, it has been impossible to rule out X-linked dominant inheritance. We studied a case of male-to-male transmission in a father and son with Robinow's syndrome and cleft lip-cleft palate, confirming autosomal dominant inheritance in at least some cases.

Separation of labelled nuclei by sedimentation velocity at unit gravity (Staput method) was used to study the timing of histone synthesis and replacement by testis-specific basic nuclear protein (TSP) during spermatogenesis in the mouse. Animals were injected (intratesticularly) with 1.25 micronCi per testis 3H-arginine or 2.5 micronCi per testis 3H-lysine, testis nuclei were separated, and the acid extract of each nuclear fraction was analyzed by acrylamide gel electrophoresis. The distribution of labelled histones and TSP in separated nuclei was assessed 2 h after incorporation. Changes in the labelled histone and TSP content of nuclei during subsequent differentiation (1--34 days post-label) was followed in fractions of separated testis cell nuclei and in nuclei of cauda epididymal spermatozoa. Analysis of total histone and (TSP) content indicated quantitative changes during development. Nuclei from primary spermatocytes had relatively larger amounts of histones H1 and H4. Spermatid nuclei showed a relative reduction in histones H1 and H4, coincident with the appearance of TSP in these nuclei. These results suggested that synthesis and/or removal of certain histones must occur in late primary spermatocyte and early spermatid stages of spermatogenesis. Results of labelling experiments indicated several periods of histone synthesis during spermatogenesis: (1) closely associated with the last DNA synthesis(i.e., in early primary spermatocytes), (2) late in meiotic prophase (i.e., in pachytene primary spermatocytes) and (3) simultaneous with TSP synthesis (i.e., in late spermatids). Histone H1 was more heavily labelled toward the end of the primary spermatocyte period. Histone H4 was more heavily labelled in the early primary spermatocyte period, and again at the time of TSP synthesis in spermatids. Histones synthesized before the pachytene primary spermatocyte stage appeared to be replace, but histones synthesized later in spermatogenesis appeared to be at least partially retained in epididymal spermatozoa. These results suggested that repeated specific alterations in the protein complement of the nucleus are an integral part of spermatogenic differentiation in the mouse.

The arrangement of repetitive and nonrepetitive DNA sequences in the soybean genome was ascertained by a comparison of the reassociation kinetics of short (250 nucleotides) and long (2700 nucleotides) DNA fragments, the size distribution of S-1 nuclease resistant repetitive duplexes, and a direct assay of the spectrum of DNA sequences present on long DNA fragments enriched in repetitive DNA. These measurements reveal the following: (1) The 1N genome size of the soybean plant is 1.97 pg. (2) Approximately 40% of the soybean genome consists of nonrepetitive or single-copy DNA sequences, while 60% is repetitive DNA. (3) The repetitive DNA is partitioned into three discrete classes termed "very fast," "fast," and "slow," containing DNA sequences repeated an average of 290,000, 2800, and 19 times each. (4) Approximately 35--50% of the soybean genome is arranged in a short-period interspersion pattern of 250 nucleotide slow sequences and single-copy DNA averaging up to 2700 nucleotides in length. (5) From 30% to 45% of the soybean genome is organized into long stretches of repetitive DNA at least 1500 nucleotides in length. (6) Minimal interspersion of repetitive sequence classes occurs in soybean DNA.

The interrelationships between body weight, insulin secretion and serum lipids were studied in 40 young white patients (mean age 37 years) with established ischemic heart disease (IHD), living in Johannesburg. None was severely obese, hypertensive or overtly diabetic. In general, strong positive correlations were found between body weight and insulin concentrations and between insulin levels and fasting serum triglycerides. However, insulin levels were relatively low in 4 patients with marked hypertriglyceridemia (above 350 mg/dl). These data are consistent with the postulate that insulin promotes (hepatic) triglyceride synthesis, but when there is gross hypertriglyceridemia peripheral triglyceride clearance becomes defective. Insignificant correlations were observed between body weight and serum lipids and between cholesterol and other metabolic variables. We conclude that there is a sequential link between increasing body weight, insulin secretion and triglyceride levels in young patients with IHD, but that cholesterolemia is independent of this axis.

Twenty-one Caucasian renal transplant recipients with hyperlipidemia and normal renal function were assessed with regard to their diet. Their average daily intake of energy and cholesterol was lower and the ratio of polyunsaturated to saturated fat higher in their diet than in that of a comparable urban Caucasian South African population. Nevertheless modification of their diets in one year produced a significant lowering of their body weight and a statistically significant drop in the mean plasma cholesterol (9.2 +/- 0.5 mmoles/l to 7.6 +/- 0.5 mmoles/l, P less than 0.05). Although the fall in plasma triglyceride in the group as a whole was not statistically significant (3.8 +/- 0.6 mmoles/l to 3.2 +/- 0.5 mmoles/l) the level did decrease substantially in 13 of the 21 patients (4.2 +/- 0.9 mmoles/l to 2.5 +/- 0.5 mmoles/l, P less than 0.01). It is suggested that diet has a definite role in the control of post-transplant hyperlipidemia but should probably be introduced immediately after immunosuppression is started and be coupled with a suitable exercise program for optimal effect.

Although familial hypercholesterolemia (FH) has been well characterized in terms of the etiology of the major lipoprotein abnormality, that of low density lipoproteins (LDL), less information is available on changes in other lipoproteins which could influence the atherogenic process in this disorder. The present study has focused on such potential abnormalities by studying in detail the lipoprotein association of apolipoprotein E (apo E) in a large group of subjects homozygous for FH. Total plasma apo E levels in homozygous subjects were significantly elevated (p less than 0.001) relative to heterozygous subjects which were, in turn, significantly greater (p less than 0.001) than controls (137.6 micrograms/ml, 69.4 micrograms/ml, 46.5 micrograms/ml respectively). After separation of plasma lipoproteins by 4% agarose chromatography, an increased mass of apo E in lipoproteins of intermediate size was present; this may reflect the absence of LDL receptors that normally mediate their clearance. Homozygous FH subjects also demonstrated an increased mass of apo E-enriched high density lipoproteins (HDL) of large size, but a reduction in HDL cholesterol and apo A-I. The increase in the potentially atherogenic remnant lipoproteins and the decrease in HDL are associated with an increased risk for atherosclerosis, even in the absence of the LDL elevation, which is characteristic of FH. The increase in apo E-enriched HDL could reflect a compensatory mechanism that permits reverse cholesterol transport in the absence of LDL receptors.

Experiments are described that characterize the organization of DNA sequences in the water mold Achlya bisexualis. These experiments demonstrate that repetitive and single copy sequences in the Achlya genome are arranged in a long-period interspersion pattern. Estimates of the spacing intervals between repetitive and single copy DNA indicate, however, that the interspersion pattern in Achlya is longer than has been previously reported in other eukaryotes. These data and measurements of structural gene expression in Achlya [Timberlake, W.E., Shumard, D. S. & Goldberg, R. B. (1977) Cell 10, 623-632] make it difficult to propose a regulatory function for repeated DNA in this eukaryote.

Seed protein genes are highly regulated during the soybean life cycle. These genes encode prevalent mRNAs that accumulate and decay during embryogenesis, and are either undetectable or present at low levels in mature plant organ systems. Transcriptional activation and repression processes are important in regulating seed protein gene developmental expression programs. We started DNA binding protein studies with the soybean lectin gene to begin to identify trans-acting proteins and cis-regulatory sequences required for seed protein gene expression. We have identified an embryo DNA binding protein that interacts with specific sequences in the lectin gene 5' region. The DNA binding protein is undetectable in mature plant organ systems and its concentration parallels the lectin gene transcription rate during embryogenesis. The DNA binding protein activity corresponds to a 60,000 Mr (60K) nuclear protein, and a protein of similar size interacts with at least one other seed protein gene but not with a gene inactive during embryogenesis. Our data suggest that the 60K protein, and the DNA sequences that it interacts with, may be involved in regulating lectin gene expression.

We have characterized the structure and flanking region of genes representing two, coordinately expressed, soybean seed protein gene families. One family directs the synthesis of the major storage protean glycinin; the other encodes a 15.5 kd polypeptide of unknown function. DNA blot hybridization experiments showed approximately three, nonallelic genes in the glycinin family and two in the 15 kd protein family, and showed that these families are not selectively amplified or rearranged during embryogeny. R-loop and S1 nuclease mapping studies demonstrated no detectable introns in the 15 kd protein genes but at least one and possibly two in the glycinin genes. No interfamily clustering of these genes occurs within a 10-15 kb chromosomal domain. Nor are they contiguous to other genes expressed at moderate levels during embryogenesis. Each of them, however, is contiguous to a gene expressed at another developmental period in the leaf. These leaf genes encode rare class messages which constitute only 1 X 10(-5%) of the leaf mRNA, or about one molecule per cell. R-loop analysis of two leaf genes showed that one contains no detectable introns while the other possesses at least three. DNA gel blot studies showed that only one of the seed protein genomic clones contains an interspersed repetitive DNA element. Pairwise cross-hybridization studies did not detect any flanking sequences shared by the 15 kd protein, glycinin and leaf genes.