Serum vitamin B12, distal symmetrical polyneuropathy and anaemia in type 2 diabetes: the Fremantle Diabetes Study Phase 2

BACKGROUND

There are limited data relating to the effects of metformin-associated vitamin B12 deficiency on the risk of distal symmetrical polyneuropathy (DSPN) and megaloblastic anaemia in well-characterised community-based cohorts.

AIMS

To assess inter-relationships between metformin therapy, vitamin B12 deficiency assessed using serum active B12 concentrations, and DSPN and anaemia in 1492 Fremantle Diabetes Study Phase 2 (FDS2) participants with type 2 diabetes.

METHODS

Prevalence rates of vitamin B12 deficiency (total <80 pmol/L, active <23 pmol/L) and borderline deficiency (total ≥80 and ≤200 pmol/L, active ≥23 and ≤35 pmol/L) were determined using baseline sera. The relationship between vitamin B12 status and both DSPN and anaemia was assessed using multivariable analyses.

RESULTS

Most FDS2 participants (94.4%) were vitamin B12 replete (total serum concentration >200 pmol/L, active >35 pmol/L), 2.0% were deficient (total <80 pmol/L, active <23 pmol/L) and the remainder (3.6%) borderline. Although metformin treatment increased the odds of deficiency (4.2%, 3.1% borderline) in a dose-dependent fashion (odds ratio (95% confidence interval) 39.4 (4.90-316) for >2000 mg daily compared with no treatment; P < 0.001), there was no significant association between vitamin B12 status and DSPN, anaemia (haemoglobin ≤130 g/L males, ≤120 g/L females), haemoglobin concentration or mean corpuscular volume (P ≥ 0.147). Metformin increased the likelihood of anaemia, especially at high doses, independent of vitamin B12 deficiency.

CONCLUSIONS

Since nutritional sources likely attenuate metformin-associated vitamin B12 malabsorption and its clinical sequelae in developed countries such as Australia, there is no need for routine/opportunistic serum vitamin B12 screening in metformin-treated patients.

Use of a type 1 genetic risk score for classification of diabetes type in young Australian adults: the Fremantle Diabetes Study Phase II

The applicability of a UK-validated genetic risk score (GRS) was assessed in 158 participants in the Fremantle Diabetes Study Phase II diagnosed between 20 and <40 years of age with type 1 or type 2 diabetes or latent autoimmune diabetes of adults (LADA). For type 1 versus type 2/LADA, the area under the receiver operating characteristic curve (AUC) was highest for serum C-peptide (0.93) and lowest for the GRS (0.66). Adding age at diagnosis and body mass index to C-peptide increased the AUC minimally (0.96). The GRS appears of modest diabetes diagnostic value in young Australians.

Canagliflozin Attenuates PromarkerD Diabetic Kidney Disease Risk Prediction Scores

PromarkerD is a biomarker-based blood test that predicts kidney function decline in people with type 2 diabetes (T2D) who may otherwise be missed by current standard of care tests. This study examined the association between canagliflozin and change in PromarkerD score (Δ score) over a three-year period in T2D participants in the CANagliflozin cardioVascular Assessment Study (CANVAS). PromarkerD scores were measured at baseline and Year 3 in 2008 participants with preserved kidney function (baseline eGFR ≥60 mL/min/1.73 m²). Generalized estimating equations were used to assess the effect of canagliflozin versus placebo on PromarkerD scores. At baseline, the participants (mean age 62 years, 32% females) had a median PromarkerD score of 3.9%, with 67% of participants categorized as low risk, 14% as moderate risk, and 19% as high risk for kidney function decline. After accounting for the known acute drop in eGFR following canagliflozin initiation, there was a significant treatment-by-time interaction (p < 0.001), whereby participants on canagliflozin had decreased mean PromarkerD scores from baseline to Year 3 (Δ score: -1.0% [95% CI: -1.9%, -0.1%]; p = 0.039), while the scores of those on placebo increased over the three-year period (Δ score: 6.4% [4.9%, 7.8%]; p < 0.001). When stratified into PromarkerD risk categories, participants with high risk scores at baseline who were randomized to canagliflozin had significantly lower scores at Year 3 (Δ score: -5.6% [-8.6%, -2.5%]; p < 0.001), while those on placebo retained high scores (Δ score: 4.5% [0.3%, 8.8%]; p = 0.035). This post hoc analysis of data from CANVAS showed that canagliflozin significantly lowered PromarkerD risk scores, with the effect greatest in those T2D participants who were classified at study entry as at high risk of a subsequent decline in kidney function.

The relationship between thyroid dysfunction, cardiovascular morbidity and mortality in type 2 diabetes: The Fremantle Diabetes Study Phase II

AIMS

It is uncertain whether subclinical thyroid dysfunction is associated with cardiovascular disease (CVD) events and mortality in people with type 2 diabetes. The aim of this study was to determine whether undetected thyroid disease increases the risk of incident CVD and death in type 2 diabetes.

METHODS

One thousand two hundred fifty participants with type 2 diabetes (mean age 65.3 years, 56.5% males, median diabetes duration 8.0 years) without known thyroid disease and not taking medications known to affect thyroid function were categorised, based on baseline serum free thyroxine (FT4) and thyrotropin (TSH) concentrations, as euthyroid, overt hypothyroid (increased TSH, low FT4), subclinical hypothyroid (increased TSH, normal FT4), overt thyrotoxic (decreased TSH, raised FT4) or subclinical thyrotoxic (decreased TSH, normal FT4). Incident myocardial infarction, incident stroke, all-cause and cardiovascular mortality were ascertained during a mean 6.2-6.7 years of follow-up.

RESULTS

Most participants with newly-detected thyroid dysfunction had subclinical hypothyroidism (77.2%) while overt/subclinical thyrotoxicosis was infrequent. Compared to participants with TSH 0.34-2.9 mU/L, those with TSH > 5.1 mU/L were not at increased risk of incident myocardial infarction (adjusted hazard ratio (95% confidence limits) 1.77 (0.71, 2.87)), incident stroke (1.66 (0.58, 4.78)), all-cause mortality (0.78 (0.44, 1.37)) or cardiovascular mortality (1.16 (0.38, 3.58)). Independent baseline associates of subclinical hypothyroidism included estimated glomerular filtration rate and systolic blood pressure.

CONCLUSIONS

Subclinical hypothyroidism was not independently associated with CVD events or mortality in community-dwelling people with type 2 diabetes despite its associations with CVD risk factors, questioning strategies to identify and/or treat mild thyroid dysfunction outside usual care.

Changes in the Epidemiology of Hepatobiliary Disease Complicating Type 2 Diabetes over 25 Years: The Fremantle Diabetes Study

OBJECTIVE

To determine whether the incidence/outcome of hepatobiliary disease (HBD) has increased over recent decades in community-based Australians with and without type 2 diabetes (T2D).

METHODS

Longitudinal data from the Fremantle Diabetes Study Phase I (FDS1; recruitment 1993-1996; n = 1291 with T2D) and Phase II (FDS2; 2008-2011; n = 1509) were analyzed. Participants with T2D from both Phases were age-, sex-, and postcode-matched 1:4 to people without diabetes. Incident HBD and associated mortality were ascertained from hospitalization, cancer registration, and/or death certification codes. Incidence rates (IRs) and IR ratios (IRRs) for those with versus without diabetes in FDS1 and FDS2 were calculated.

RESULTS

HBD IRs for people without diabetes did not change between Phases. The IRR (95% CI) for people with T2D in FDS2 versus FDS1 was 1.30 (1.01-1.68) with the highest IRRs in participants aged <65 years. Non-alcoholic fatty liver disease/steatohepatitis (NAFLD/NASH) events were 54% greater in FDS2 than FDS1 in the presence of greater abdominal adiposity. NAFLD/NASH was coded in one in 11 HBD events in FDS2 and in 10% of HBD deaths (<4% of total mortality).

CONCLUSIONS

HBD is more frequent in people with versus without T2D and this discrepancy is increasing. Hospitalizations/deaths due to NAFLD/NASH remain uncommon.

Prevalence and incidence of thyroid dysfunction in type 1 diabetes, type 2 diabetes and latent autoimmune diabetes of adults: The Fremantle Diabetes Study Phase II

OBJECTIVE

Since the results of published studies assessing thyroid dysfunction complicating diabetes have been variable in quality, inconsistent and may not reflect contemporary clinical care, the aim of this study was to determine its prevalence and incidence in a large, well-characterized, representative cohort.

DESIGN

Community-based, longitudinal, observational study.

PATIENTS

A total of 1617 participants from the Fremantle Diabetes Study Phase II (FDS2), including 130 (8.0%) with type 1 diabetes, 1408 (87.1%) with type 2 diabetes, and 79 (4.9%) with latent autoimmune diabetes of adults (LADA).

MEASUREMENTS

Serum thyrotropin (TSH) and free thyroxine (FT4) at baseline between 2008 and 2011 and in those attending Year 4 follow-up.

RESULTS

The prevalence of known thyroid disease (ascertained from baseline self-reported thyroid medication use or hospitalization data) was 11.7% (189/1617). Of the remaining 1428 participants, 5.1% (73/1428) had biochemical evidence of subclinical hypothyroidism, 1.1% (15/1428) overt hypothyroidism, 0.1% (2/1428) subclinical hyperthyroidism and 0.2% (3/1428) overt hyperthyroidism, representing an overall baseline prevalence of thyroid disease of 17.4% (282/1617). During 5694 patient-years of follow-up, 25 (3.0%) of the 844 with a normal baseline TSH and follow-up data developed known thyroid disease. Of the remaining 819, 3.4% developed subclinical hypothyroidism, 0.2% overt hypothyroidism and 0.5% subclinical hyperthyroidism. There were no statistically significant differences in the prevalence or incidence of thyroid dysfunction by diabetes type.

CONCLUSIONS

Thyroid dysfunction, known or detected through screening, is common in diabetes. These data suggest the need for periodic clinical and biochemical screening for thyroid disease in all types of diabetes.

Validation of a protein biomarker test for predicting renal decline in type 2 diabetes: The Fremantle Diabetes Study Phase II

AIMS

To validate the prognostic utility of a novel plasma biomarker panel, PromarkerD, for predicting renal decline in an independent cohort of people with type 2 diabetes.

METHODS

Models for predicting rapid estimated glomerular filtration rate (eGFR) decline defined as i) incident diabetic kidney disease (DKD), ii) eGFR decline ≥30% over four years, and iii) annual eGFR decline ≥5 mL/min/1.73 m² were applied to 447 participants from the longitudinal observational Fremantle Diabetes Study Phase II. Model performance was assessed using discrimination and calibration.

RESULTS

During 4.2 ± 0.3 years of follow-up, 5-10% of participants experienced a rapid decline in eGFR. A consensus model comprising apolipoprotein A-IV (apoA4), CD5 antigen-like (CD5L), insulin-like growth factor-binding protein 3 (IGFBP3), age, serum HDL-cholesterol and eGFR showed the best performance for predicting incident DKD (AUC = 0.88 (95% CI 0.84-0.93)); calibration Chi-squared = 5.6, P = 0.78). At the optimal score cut-off, this model provided 86% sensitivity, 78% specificity, 30% positive predictive value and 98% negative predictive value for four-year risk of developing DKD.

CONCLUSIONS

The combination of readily available clinical and laboratory features and the PromarkerD biomarkers (apoA4, CD5L, IGFBP3) proved an accurate prognostic test for future renal decline in an independent validation cohort of people with type 2 diabetes.

Cervical cancer screening decentralized policy adaptation: an African rural-context-specific systematic literature review

Background: Worldwide, nearly 570,000 women are diagnosed with cervical cancer each year, with 85% of new cases in low- and middle-income countries. The African continent is home to 35 of 40 countries with the highest cervical cancer mortality rates. In 2014, a partnership involving a rural region of Senegal, West Africa, was facing cervical cancer screening service sustainability barriers and began adapting regional-level policy to address implementation challenges.

Objective: This manuscript reports the findings of a systematic literature review describing the implementation of decentralized cervical cancer prevention services in Africa, relevant in context to the Senegal partnership. We report barriers and policy-relevant recommendations through Levesque’s Patient-Centered Access to Healthcare Framework and discuss the impact of this information on the partnership’s approach to shaping Senegal’s regional cervical cancer screening policy.

Methods: The systematic review search strategy comprised two complementary sub-searches. We conducted an initial search identifying 4272 articles, then applied inclusion criteria, and ultimately 19 studies were included. Data abstraction focused on implementation barriers categorized with the Levesque framework and by policy relevance.

Results: Our findings identified specific demand-side (clients and community) and supply-side (health service-level) barriers to implementation of cervical cancer screening services. We identify the most commonly reported demand- and supply-side barriers and summarize salient policy recommendations discussed within the reviewed literature.

Conclusions: Overall, there is a paucity of published literature regarding barriers to and best practices in implementation of cervical cancer screening services in rural Africa. Many articles in this literature review did describe findings with notable policy implications. The Senegal partnership has consulted this literature when faced with various similar barriers and has developed two principal initiatives to address contextual challenges. Other initiatives implementing cervical cancer visual screening services in decentralized areas may find this contextual reporting of a literature review helpful as a construct for identifying evidence for the purpose of guiding ongoing health service policy adaptation.

Prevalence of diabetes in Australia: insights from the Fremantle Diabetes Study Phase II

BACKGROUND

Accurate diabetes prevalence estimates are important for health service planning and prioritisation. Available data have limitations, suggesting that the contemporary burden of diabetes in Australia is best assessed from multiple sources.

AIMS

To use systematic active detection of diabetes cases in a postcode-defined urban area through the Fremantle Diabetes Study Phase II (FDS2) to complement other epidemiological and survey data in estimating the national prevalence of diabetes and its types.

METHODS

People with known diabetes in a population of 157 000 were identified (n = 4639) from a variety of sources and those providing informed consent (n = 1668 or 36%) were recruited to the FDS2 between 2008 and 2011. All FDS2 participants were assigned a type of diabetes based on clinical and laboratory (including serological and genetic) features. Data from people identified through the FDS2 were used to complement Australian Health Survey and National Diabetes Services Scheme prevalence estimates (the proportions of people well controlled on no pharmacotherapy and registering with the National Diabetes Services Scheme respectively) in combination with Australian Bureau of Statistics data to generate the prevalence of diabetes in Australia.

RESULTS

Based on data from multiple sources, 4.8% or 1.1 million Australians had diabetes in 2011-2012, of whom 85.8% had type 2 diabetes, 7.9% type 1 diabetes and 6.3% other types (latent autoimmune diabetes of adults, monogenic diabetes and secondary diabetes).

CONCLUSIONS

Approximately 1 in 20 Australians has diabetes. Although most have type 2 diabetes, one in seven has other types that may require more specialised diagnosis and/or management.

The relationship between circulating adiponectin, ADIPOQ variants and incident cardiovascular disease in type 2 diabetes: The Fremantle Diabetes Study

AIMS

To investigate the relationship between serum adiponectin, ADIPOQ variants and haplotypes, and cardiovascular disease (CVD) in type 2 diabetes (T2D).

METHODS

Baseline data including serum total adiponectin and 21 ADIPOQ polymorphisms were available for 1076 participants (mean age 64.0 years, 49.4% males) in a community-based cohort followed for an average of 12 years.

RESULTS

During 8843 patient-years of follow-up for coronary heart disease (CHD), 13,494 patient-years for ischaemic stroke (IS) and 12,028 patient-years for heart failure (HF), 40.4%, 11.8% and 31.9% of patients experienced a first episode of CHD, IS or HF, respectively. In Cox regression after adjustment for the most parsimonious models, log_e(serum adiponectin) and the ADIPOQ variant rs12495941 were inversely associated with incident CHD (hazard ratio [95% confidence interval] 0.79 [0.65-0.98] and 0.64 [0.44-0.94], respectively), while rs1648707 was positively associated with incident IS (2.05 [1.37-3.06]; all P ≤ 0.028). In males, rs9860747 and rs17366568 predicted CHD (0.22 [0.05-0.92] and 1.50 [1.01-2.20]; P ≤ 0.042), while rs1648707 and rs1063537 predicted IS (2.36 [1.32-4.23] and 2.09 [1.17-3.72]; P ≤ 0.012). In females, rs10937273 predicted CHD via an interaction with serum adiponectin (0.43 [0.21-0.91]; P = 0.027), while rs864265 predicted IS (0.43 [0.21-0.88], P = 0.021). The associations between ADIPOQ variants and outcomes were supported by haplotype block analysis. Neither serum adiponectin nor ADIPOQ variants predicted HF.

CONCLUSIONS

Serum total adiponectin and gender-specific ADIPOQ variants predict CHD and IS, but not HF, independently of other risk factors in community-based patients with T2D. In contrast to some previous studies, there was no relationship between a high serum total adiponectin and CVD.

Plasma Amyloid-β Peptides in Type 2 Diabetes: A Matched Case-Control Study

BACKGROUND

Plasma amyloid-β (Aβ) levels have rarely been investigated in type 2 diabetes despite its known associations with Alzheimer's disease.

OBJECTIVE

To compare blood plasma Aβ concentrations (Aβ40 and Aβ42) in cognitively normal individuals with and without type 2 diabetes.

METHODS

Plasma Aβ40 and Aβ42 were measured in 194 participants with diabetes recruited from the community-based Fremantle Diabetes Study Phase II cohort (mean age 71 years, 59% males) and 194 age-, sex-, and APOEɛ4 allele-matched, control subjects without diabetes from the Australian Imaging, Biomarkers and Lifestyle Study using a multiplex microsphere-based immunoassay.

RESULTS

Plasma Aβ40 and Aβ42 were normally distributed in the controls but were bimodal in the participants with diabetes. Median Aβ40 and Aβ42 concentrations were significantly lower in those with type 2 diabetes (Aβ40 median [inter-quartile range]: 125.0 [52.6-148.3] versus 149.3 [134.0-165.6] pg/mL; Aβ42: 26.9 [14.5-38.3] versus 33.6 [28.0-38.9] pg/mL, both p < 0.001) while the ratio Aβ42:Aβ40 was significantly higher (0.26 [0.23-0.32] versus 0.22 [0.19-0.25], p < 0.001). After adjustment, participants with diabetes and plasma Aβ40 levels in the low peak of the bimodal distribution were significantly more likely to have normal to high estimated glomerular filtration rates (odds ratio (95% CI): 2.40 (1.20-4.80), p = 0.013) although the group with diabetes had lower renal function overall.

CONCLUSION

Type 2 diabetes is associated with altered plasma concentrations of Aβ peptides and is an important source of variation that needs to be taken into account when considering plasma Aβ peptides as biomarkers for Alzheimer's disease.

Identification of Novel Circulating Biomarkers Predicting Rapid Decline in Renal Function in Type 2 Diabetes: The Fremantle Diabetes Study Phase II

OBJECTIVE

To assess the ability of plasma apolipoprotein (apo) A-IV (apoA4), apo C-III, CD5 antigen-like (CD5L), complement C1q subcomponent subunit B (C1QB), complement factor H-related protein 2, and insulin-like growth factor binding protein 3 (IBP3) to predict rapid decline in estimated glomerular filtration rate (eGFR) in type 2 diabetes.

RESEARCH DESIGN AND METHODS

Mass spectrometry was used to measure baseline biomarkers in 345 community-based patients (mean age 67.0 years, 51.9% males) from the Fremantle Diabetes Study Phase II (FDS2). Multiple logistic regression was used to determine clinical predictors of rapid eGFR decline trajectory defined by semiparametric group-based modeling over a 4-year follow-up period. The incremental benefit of each biomarker was then assessed. Similar analyses were performed for a ≥30% eGFR fall, incident chronic kidney disease (eGFR <60 mL/min/1.73 m²), and eGFR decline of ≥5 mL/min/1.73 m²/year.

RESULTS

Based on eGFR trajectory analysis, 35 participants (10.1%) were defined as "rapid decliners" (mean decrease 2.9 mL/min/1.73 m²/year). After adjustment for clinical predictors, apoA4, CD5L, and C1QB independently predicted rapid decline (odds ratio 2.40 [95% CI 1.24-4.61], 0.52 [0.29-0.93], and 2.41 [1.14-5.11], respectively) and improved model performance and fit (P < 0.001), discrimination (area under the curve 0.75-0.82, P = 0.039), and reclassification (net reclassification index 0.76 [0.63-0.89]; integrated discrimination improvement 6.3% [2.1-10.4%]). These biomarkers and IBP3 contributed to improved model performance in predicting other indices of rapid eGFR decline.

CONCLUSIONS

The current study has identified novel plasma biomarkers (apoA4, CD5L, C1QB, and IBP3) that may improve the prediction of rapid decline in renal function independently of recognized clinical risk factors in type 2 diabetes.

Serum bicarbonate concentration and the risk of cardiovascular disease and death in type 2 diabetes: the Fremantle Diabetes Study

Background

Serum bicarbonate is associated with mortality, heart failure (HF) and progression of renal failure in studies of healthy people and patients with chronic kidney disease, but the significance of these observations in unselected patients with diabetes in the general population is unknown. The aim of this study was to determine whether serum bicarbonate was associated with mortality and cardiovascular disease risk in type 2 diabetes.

Methods

Baseline serum bicarbonate was available for 1283 well-characterized community-based patients (mean ± SD age 64.1 ± 11.3 years, 48.7 % males) from the longitudinal observational Fremantle Diabetes Study followed for a mean of 12 years. Associations between serum bicarbonate and mortality, coronary heart disease (CHD) and incident HF were analysed using Cox proportional hazards regression.

Results

Serum bicarbonate was independently and negatively associated with incident CHD. For each 1 mmol/L increase in bicarbonate, the hazard ratio for CHD was 0.95 (95 % confidence interval 0.92–0.99) after adjustment for age as time scale, age at baseline, sex, English fluency, diabetes duration, log_e(serum triglycerides), log_e(urinary albumin: creatinine ratio), peripheral sensory neuropathy and peripheral arterial disease. There were no independent associations between serum bicarbonate and all-cause mortality [0.98 (0.95–1.004)] or incident HF [0.99 (0.95–1.03)].

Conclusions

Serum bicarbonate was a significant independent predictor of incident CHD but not death or HF in community-based patients with type 2 diabetes. This supports intervention trials of bicarbonate replacement in type 2 patients at risk of CHD and who have a low serum bicarbonate concentration.

Electronic supplementary material

The online version of this article (doi:10.1186/s12933-016-0462-x) contains supplementary material, which is available to authorized users.

Prevalence and prognosis of a low serum testosterone in men with type 2 diabetes: the Fremantle Diabetes Study Phase II

BACKGROUND

Because published studies have usually involved imprecise assays and selected patients with limited additional data and follow-up, the consequences of a low serum testosterone in diabetes are unclear. This study assessed the prevalence, associates and prognosis of a low testosterone in community-dwelling men with type 2 diabetes.

DESIGN

Longitudinal observational study.

PATIENTS

788 men (mean ± SD age: 65·8 ± 11·3 years) followed for 4·0 ± 1·1 years.

MEASUREMENTS

Serum testosterone, SHBG, erectile dysfunction (ED; Sexual Health Inventory for Men score <22), anaemia (haemoglobin <130 g/l), all-cause mortality.

RESULTS

The mean ± SD total serum testosterone by liquid chromatography/mass spectrometry was 13·1 ± 5·9 nmol/l (30·6% <10 nmol/l). Most men with a total testosterone <10 nmol/l (67·0%) had a normal/low serum LH. Serum testosterone was independently associated with anaemia (P < 0·001), but not ED (P = 0·80), in logistic regression models. The optimal cut-point (Youden Index) for anaemia was 9·8 nmol/l (sensitivity 53·6%, specificity 75·4%). During the follow-up, 102 men (12·9%) died. There was a U-shaped relationship between total serum testosterone quintiles and death (P = 0·003, log rank test). The middle quintile (>11·1 to ≤13·7 nmol/l) had the lowest risk and there was a 78% increased risk for highest (>16·9 nmol/l) vs lowest (≤8·6 nmol/l) quintile in Cox proportional hazards modelling (P = 0·036). Free serum testosterone and SHBG quintiles were not associated with death.

CONCLUSIONS

These data provide some support for the general conventional serum testosterone <10 nmol/l cut-point in identifying an increased risk of anaemia and the subsequent death in men with type 2 diabetes, but indicate that high-normal levels are also an adverse prognostic indicator.

Lifetime depression history and depression risk in type 2 diabetes: A case-control study

AIMS

To assess whether a personal history of depression assists in risk prediction for depression in type 2 diabetes.

METHODS

Age- and sex-matched participants with and without diabetes from the Busselton Health Survey were assessed for current and previous depression using the 9-item Patient Health Questionnaire and the Brief Lifetime Depression Scale (BLDS). In the diabetic participants, the temporal relationship between first depression episode and diabetes onset was also explored.

RESULTS

In 184 paired participants (age 70.2±10.1years, 50% female), those with diabetes had a higher prevalence of any current depression (12.5% vs 4.3%, P<0.01) and lifetime history of major depression (30.6% vs 21.1%, P=0.06) compared to those without diabetes. After adjustment, lifetime major depression history was independently associated with any current depression in the combined sample (odds ratio (95% CI): 5.55 (3.09-9.98), P<0.001), in those with diabetes (4.17 (2.00-8.71), P<0.001), in those without diabetes (8.29 (3.24-21.23), P<0.001) and in diabetes whether sub-divided by depression first occurring before or after diabetes onset (before: 3.16 (1.38-7.24), P=0.007; after: 2.77 (1.00-7.70), P=0.051).

CONCLUSIONS

Obtaining a lifetime history of major depression using the BLDS assists in depression risk prediction in type 2 diabetes regardless of whether depression preceded diabetes onset or not.

Effect of continuous positive airway pressure therapy on sexual function and serum testosterone in males with type 2 diabetes and obstructive sleep apnoea

OBJECTIVE

There have been no studies of the effect of continuous positive airway pressure (CPAP) therapy on erectile dysfunction (ED) and serum testosterone in men with type 2 diabetes and obstructive sleep apnoea (OSA), a patient group at increased risk of ED and hypogonadism. The aim of this study was to determine whether CPAP improves sexual and gonadal function in males with type 2 diabetes and a pre-CPAP apnoea-hypopnoea index >15/h.

DESIGN

Substudy of a trial assessing the effect of 3 months of CPAP on cardiovascular risk in type 2 diabetes.

PATIENTS

Of 35 males starting CPAP, 27 (mean ± SD age 65.4 ± 9.6 years, median [interquartile range] diabetes duration 12.1 [5.2-15.3] years) completed the trial.

MEASUREMENTS

Serum total and free testosterone, responses to the Androgen Deficiency in the Aging Aale (ADAM) and Sexual Health Inventory for Men (SHIM) questionnaires.

RESULTS

There were no significant changes in mean total or free testosterone (baseline concentrations 12.7 ± 4.5 nm and 0.26 ± 0.07 pm, respectively), or SHIM score (baseline 13 [5-17]), after 3 months of CPAP (P > 0.20). The ADAM score (baseline 6.2 ± 2.1) fell after 1 month (to 5.0 ± 2.6) and was maintained at this level at 3 months (P = 0.015). The Epworth Sleepiness Scale score decreased and self-reported physical activity increased over 3 months (P ≤ 0.017) without a change in body mass index (P = 1.00).

CONCLUSIONS

These findings imply that CPAP therapy improves somnolence and promotes exercise in men with type 2 diabetes, but that there is no direct benefit for gonadal or sexual function.

A comprehensive investigation of variants in genes encoding adiponectin (ADIPOQ) and its receptors (ADIPOR1/R2), and their association with serum adiponectin, type 2 diabetes, insulin resistance and the metabolic syndrome

Background

Low levels of serum adiponectin have been linked to central obesity, insulin resistance, metabolic syndrome, and type 2 diabetes. Variants in ADIPOQ, the gene encoding adiponectin, have been shown to influence serum adiponectin concentration, and along with variants in the adiponectin receptors (ADIPOR1 and ADIPOR2) have been implicated in metabolic syndrome and type 2 diabetes. This study aimed to comprehensively investigate the association of common variants in ADIPOQ, ADIPOR1 and ADIPOR2 with serum adiponectin and insulin resistance syndromes in a large cohort of European-Australian individuals.

Methods

Sixty-four tagging single nucleotide polymorphisms in ADIPOQ, ADIPOR1 and ADIPOR2 were genotyped in two general population cohorts consisting of 2,355 subjects, and one cohort of 967 subjects with type 2 diabetes. The association of tagSNPs with outcomes were evaluated using linear or logistic modelling. Meta-analysis of the three cohorts was performed by random-effects modelling.

Results

Meta-analysis revealed nine genotyped tagSNPs in ADIPOQ significantly associated with serum adiponectin across all cohorts after adjustment for age, gender and BMI, including rs10937273, rs12637534, rs1648707, rs16861209, rs822395, rs17366568, rs3774261, rs6444175 and rs17373414. The results of haplotype-based analyses were also consistent. Overall, the variants in the ADIPOQ gene explained <5% of the variance in serum adiponectin concentration. None of the ADIPOR1/R2 tagSNPs were associated with serum adiponectin. There was no association between any of the genetic variants and insulin resistance or metabolic syndrome. A multi-SNP genotypic risk score for ADIPOQ alleles revealed an association with 3 independent SNPs, rs12637534, rs16861209, rs17366568 and type 2 diabetes after adjusting for adiponectin levels (OR=0.86, 95% CI=(0.75, 0.99), P=0.0134).

Conclusions

Genetic variation in ADIPOQ, but not its receptors, was associated with altered serum adiponectin. However, genetic variation in ADIPOQ and its receptors does not appear to contribute to the risk of insulin resistance or metabolic syndrome but did for type 2 diabetes in a European-Australian population.

Effect of continuous positive airway pressure therapy on cardiovascular risk factors in patients with type 2 diabetes and obstructive sleep apnea

CONTEXT

Few prospective intervention studies have examined the effect of continuous positive airway pressure (CPAP) therapy on cardiovascular disease (CVD) risk factors in diabetes.

OBJECTIVE

Our objective was to determine whether CPAP improves CVD risk factors in patients with type 2 diabetes and obstructive sleep apnea (OSA).

DESIGN AND SETTING

This was a randomized parallel group intervention trial in an urban Australian community.

PATIENTS

Fifty-nine participants of the Fremantle Diabetes Study Phase II at high risk for OSA consented to confirmatory polysomnography followed by randomization to a 3-month CPAP intervention initiated early (<1 wk) or late (1-2 months).

MAIN OUTCOME MEASURES

Patients were assessed before and 1 and 3 months after CPAP started. Tests for repeated measures were used to compare variables of interest over time.

RESULTS

Forty-four patients (75%) completed the study. Their mean ± sd age was 66.1 ± 8.8 yr, and 61.4% were male. Completers and noncompleters had similar age, sex, diabetes duration, apnea-hypopnea index, and Epworth Sleepiness Scale (P ≥ 0.29). There were no differences in outcome between early and late randomization, and the data were pooled. The Epworth Sleepiness Scale decreased between entry and 1 month [-4.8 (-6.5 to -3.1), P < 0.001]. Blood pressure improved between entry and 3 months (from 149 ± 23/80 ± 12 to 140 ± 18/73 ± 13 mm Hg; P ≤ 0.007). Pulse rate declined within the first month [-6 (-10 to -2) beats/min, P = 0.002]. Glycemic control and serum lipids, which were mostly within recommended target ranges at entry, did not change.

CONCLUSIONS

Three months of CPAP in community-based people with type 2 diabetes significantly decreased blood pressure and pulse rate but did not influence metabolic control.

Prevalence, incidence, and prognosis of hepatobiliary disease in community-based patients with type 2 diabetes: the Fremantle Diabetes Study

CONTEXT

Few studies have examined morbidity and mortality associated with hepatobiliary disease in diabetes. Most have used administrative databases and/or have had limited/incomplete data including recognized risk factors for hepatobiliary disease.

OBJECTIVE

The objective of the study was to explore the relationship between type 2 diabetes and hepatobiliary disease in well-characterized patients with detailed risk factor data including viral hepatitis status and hemochromatosis genotype.

DESIGN

This was a community-based longitudinal observational study.

SETTING

The study was conducted in an urban Australian community.

PATIENTS

The study included 1294 patients of mean ± SD aged 64.1 ± 11.3 yr and 5156 age-, gender-, and ZIP code-matched nondiabetic controls.

MAIN OUTCOME MEASURES

Prevalent and incident hepatobiliary disease and hepatobiliary disease-related death were measured. Competing risks proportional hazard models provided independent associates of these end points.

RESULTS

During 13,705 patient-years (mean 11.5 yr), 144 patients had an initial hepatobiliary disease-related hospitalization/cancer registration vs. 403 controls during 63,937 person-years of follow-up, an incidence rate ratio of 1.66 (95% confidence interval 1.37-2.02). Incident hepatobiliary disease was associated with a lower glycosylated hemoglobin and higher urinary albumin to creatinine ratio. Nearly half of the patients (49.9%) died during follow-up [crude mortality ratio vs. nondiabetic controls 1.97 (1.16-3.32)], and 21 (3.3%) from hepatobiliary disease including two cases of cirrhosis attributable to nonalcoholic steatohepatitis. Hepatobiliary disease-related death was independently predicted by prior hepatobiliary disease, hepatitis C seropositivity, retinopathy, and peripheral neuropathy; higher educational level and higher fasting serum glucose were protective.

CONCLUSIONS

Hepatobiliary disease and associated mortality are increased in type 2 diabetes. Multiple factors including fatty infiltration, microangiopathy, and direct glucotoxicity are likely to contribute, but hospitalization and death due to cirrhosis from nonalcoholic steatohepatitis appear uncommon.

Lack of association of the CD14 promoter polymorphism--159C/T with Caucasian inflammatory bowel disease

OBJECTIVE

The inflammatory bowel diseases (IBDs), including Crohn's disease (CD) and ulcerative colitis (UC), are multifactorial diseases resulting from a complex interaction of genetic and environmental factors. The recently described CARD15 and TNF-alpha risk alleles are believed to be contributors to disease by disrupting inflammatory pathways via impaired response to bacteria. Other bacterial receptors, such as CD14, may also have a role in disease. A promoter polymorphism (-159C/T) in CD14 has been implicated in IBD in a number of studies.

MATERIAL AND METHODS

We have analysed this CD14 promoter polymorphism in probands from 206 multiplex IBD families, 110 sporadic IBD individuals and 189 healthy controls from the Australian population, all of whom are Caucasian.

RESULTS

We could not replicate the described association between the CD14-159T allele and CD or UC, nor did we find any evidence for an interaction between the CARD15 or TNF-alpha risk alleles and the CD14-159T allele.

CONCLUSIONS

It is possible that the association seen in other studies may be due to population stratification or to the CD14 polymorphism being in linkage with the real disease-causing variant(s).

Peer intervention in case management practice

Using peers as case managers in dealing with current and chronic public health problems such as substance abuse, gang violence, or the HIV/AIDS crisis has been shown to improve outreach efforts, monitoring, and outcomes in hard-to-reach populations. This article focuses on a case management strategy that uses peer modeling interventions to assist people in renegotiating their present life circumstances. Peer modeling engages peers of the client population as case managers and employs group-mediated, social control intervention strategies in the community to bring about positive changes in lifestyle and living conditions. The peer approach is an enhanced version of case management, utilizing the core activities of outreach, assessment, planning, linking, monitoring, and advocacy but adding peer-led, skill-based training activities, coupled with a system of positive incentives designed to encourage a more healthful lifestyle. To clarify this enhanced approach to case management, the authors present a matrix to illustrate how key case management activities might be enhanced through peer modeling interventions. We conclude by suggesting the circumstances in which an organization responsible for service delivery might consider using peer modeling in addressing difficult public health problems, and we discuss the advantages and disadvantages of such a strategy.

Changing dose of progesterone results in sudden changes in frequency of luteinizing hormone pulses and secretion of 17 beta-estradiol in bovine females

The aim of the present study was to elucidate the time course according to which changes in circulating concentrations of progesterone influence pulsatile secretion of LH and secretion of 17 beta-estradiol. Our working hypothesis was that changing the dose of progesterone would result in changes in frequency of LH pulses and secretion of 17 beta-estradiol within 72 h. Five days after behavioral estrus, thirty-three cows were randomly assigned to one of five groups: 1) control, no treatment (CONT, n = 5); 2) treatment with two progesterone-releasing intravaginal devices (PRIDs) for 11 days (2PRID, 5-6 ng/ml plasma progesterone, n = 7); 3) treatment with a 0.5 PRID for 11 days (0.5PRID, 1-2 ng/ml plasma progesterone, n = 7); 4) treatment with 2 PRIDs for 8 days followed by treatment with a 0.5 PRID for 3 days (2-0.5PRID, n = 7); and 5) treatment with a 0.5 PRID for 8 days followed by treatment with 2 PRIDs for 3 days (0.5-2PRID, n = 7). Cows subject to PRID treatments received injections of prostaglandin F2 alpha on Days 1 and 2 (Day 0 = day of initiation of PRID treatments, fifth day of the estrous cycle in CONT cows) to lyse the existing corpus luteum. Cows were bled for 12 h at 15-min intervals on Day 7.5 of the treatment period (twelfth day of the estrous cycle in CONT cows). The dose of progesterone was changed on Day 8 in cows that were assigned to the 2-0.5PRID and 0.5-2PRID groups, and blood collections continued an additional 72 h to characterize profiles of circulating concentrations of LH and 17 beta-estradiol. Cows treated with a 0.5 PRID had a greater (p < 0.05) number of LH pulses and higher (p < 0.05) concentrations of 17 beta-estradiol throughout the entire blood collection period than cows in the 2PRID and CONT groups. An increase in the number of LH pulses was detected within 6 h after the change from the high to the low dose of progesterone (2-0.5PRID), and frequency of LH pulses was similar to that of cows in the 0.5PRID group for the remainder of the period of blood collection. LH pulse frequency declined within 6 h after the shift from the low to the high dose of progesterone (0.5-2PRID) and was similar to that of cows in the 2PRID group by 12 h after the dose was changed. Within 6 h after the dose of progesterone was changed, circulating concentrations of 17 beta-estradiol increased (p < 0.05) in cows shifted from the high to low dose (2-0.5PRID) and declined (p < 0.05) after the dose of progesterone was changed from low to high (0.5-2PRID). We conclude that changing the circulating concentrations of progesterone concurrently affects frequency of pulsatile LH release and secretion of 17 beta-estradiol within 6-24 h.

Dosage of the synthetic progestin, norgestomet, influences luteinizing hormone pulse frequency and endogenous secretion of 17 beta-estradiol in heifers

The objective of this study was to determine whether there were doses at which the synthetic progestin, norgestomet, could mimic midluteal phase concentrations of progesterone in regulating the secretion of LH and 17 beta-estradiol in bovine females. Heifers were randomly assigned to one of five groups to receive: 1) one (1Norg, n = 5), 2) two (2Norg, n = 5), 3) four (4Norg, n = 5), or 4) eight (8Norg, n = 5) norgestomet implants or to serve as untreated control heifers (control, n = 5). On Day 7 (Day 0 = behavioral estrus), implants containing norgestomet were inserted, and they remained in place for 10 days. All heifers implanted with norgestomet were treated with 25 mg prostaglandin F2 alpha (PGF2 alpha) on Days 7 and 8 to lyse the CL. Controls were treated with 25 mg PGF2 alpha at the time norgestomet implants were removed from heifers of the other treatment groups. Blood samples were collected every 15 min for 24 h on Days 10 and 16 to determine the frequency of LH pulses. Beginning 24 h after removal of implants, samples of blood were collected at 4-h intervals for 96 h to determine the time of the preovulatory surge of LH. Daily blood samples were collected from Day 2 to Day 48 to determine concentrations of progesterone, and samples collected between Days 2 and 17 were used to determine concentrations of 17 beta-estradiol. Ultrasonography was performed daily from Day 2 until Day 23 to evaluate ovarian follicular development.(ABSTRACT TRUNCATED AT 250 WORDS)

Luteinizing hormone has a role in development of fully functional corpora lutea (CL) but is not required to maintain CL function in heifers

We tested the hypothesis that endogenous pulses of LH have a role in development and maintenance of CL during the estrous cycle of the bovine female. Twenty heifers were synchronized to estrus by treating two times with prostaglandin F2 alpha 11 days apart (Day 0 = behavioral estrus). Heifers were then randomly assigned to one of four treatments (n = 5/group). Heifers were treated with an antagonist to LHRH (LHRH-Ant; N-Ac-D-Nal[2]1,4Cl-D-Phe2,D-Pal[3]3,D-Cit6,D-Ala10- LHR H; 10 micrograms/kg body weight) or vehicle (5% mannitol) once every 24 h: 1) LHRH-Ant Days 2-7, 2) LHRH-Ant Days 7-12, 3) LHRH-Ant Days 12-17, 4) no LHRH-Ant (control). Blood samples were collected from the jugular vein twice daily on Days 0-24, and area under the profile of progesterone in circulation during the luteal phase of the estrous cycle was characterized from the start of each treatment period until the demise of CL or Day 24, whichever came first. Luteolysis was considered to have occurred when three consecutive samples contained less than 1 ng progesterone/ml plasma. Areas under the profile of progesterone in circulation during the luteal phase of the estrous cycle were compared to those of heifers from the control group for the same period. LHRH-Ant treatment diminished LH pulses in all treatment groups compared to control (p < 0.05). Treatment with LHRH-Ant on Days 2-7 diminished function of CL (3.72 +/- 0.93 vs. 7.36 +/- 1.02 units, respectively; p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Ovarian follicular development in prepubertal heifers is influenced by level of dietary energy intake

Objectives were twofold: 1) to determine the chronology of development of dominant ovarian follicles during the peripubertal period in heifers and 2) to determine whether feeding a diet with low energy content that delays onset of puberty alters chronology of dominant ovarian follicular development in peripubertal heifers. Ten heifers of composite breeding (1/4 Angus, 1/4 Hereford, 1/4 Red Poll, 1/4 Pinzgauer) were randomly assigned, at 8 mo of age, to receive a diet designed to produce 0.9 (n = 5) or 0.3 (n = 5) kg body weight gain per day for the duration of the experiment. To characterize changes in size of ovarian follicles, real-time linear ultrasonography of ovaries was conducted in all heifers every other day until puberty occurred. Blood samples were collected weekly to determine concentrations of progesterone and 17 beta-estradiol. Determination of time of puberty was based on increased concentrations of progesterone, ultrasound depiction of ovulation, and subsequent presence of a corpus luteum. Size of the dominant ovarian follicles differed prior to puberty (p < 0.03); diameter of the dominant ovarian follicle was greater in all heifers as the first ovulation approached as compared to earlier in prepuberty. Heifers fed the greater amount of energy exhibited larger dominant ovarian follicles at a younger age in comparison to heifers fed the lower amount of energy.(ABSTRACT TRUNCATED AT 250 WORDS)

Differential regulation of gonadotropin synthesis and release in ovariectomized ewes after treatment with a luteinizing hormone-releasing hormone antagonist

Our working hypothesis was that synthesis and release of LH, but not FSH, were solely dependent on LHRH. Twenty ovariectomized (OVX) ewes were randomly assigned to one of five treatments (n = 4 per group). Ewes were administered a low (10 micrograms/kg) or high (100 micrograms/kg) dose of LHRH antagonist (LHRH-Ant) at 24-h intervals for 3 or 6 days. Control ewes received vehicle (5% mannitol) at 24-h intervals for 6 days. Blood samples were collected every 15 min for 4 h before LHRH-Ant or vehicle and every 2 h during the period of treatment to determine concentrations of LH and FSH. Twenty-four hours after the last treatment with LHRH-Ant or vehicle, anterior pituitaries were collected and divided in half along the midsagittal plane; the number of receptors for LHRH, pituitary content of LH and FSH, and relative amounts of mRNA for alpha, LH beta, and FSH beta subunits were determined. Concentrations of LH in serum decreased (p < 0.05) from 25.4 +/- 4.3 ng/ml before LHRH-Ant to less than 0.5 ng/ml within 4 h after the first treatment of LHRH-Ant and remained low (< 0.5 ng/ml) throughout the study. Serum concentrations of FSH declined gradually during the 3- or 6-day period of treatment with LHRH-Ant, from 37.3 +/- 2.4 and 26.5 +/- 4.8 ng/ml to 19.9 +/- 1.8 and 13.7 +/- 2.1 ng/ml, respectively. The magnitude of decline in serum concentrations of LH and FSH did not differ among ewes treated with low or high doses of LHRH-Ant.(ABSTRACT TRUNCATED AT 250 WORDS)

Survival analysis and prognosis for dementia patients

How long a dementia patient is cared for in the home before admission to a nursing home depends on the state of the patient and the state of the caregiver. Using 5-year follow-up data, the times until entry to nursing home and until death are modeled using a Cox survival model in which patient and caregiver variables at entry to study as well as changes in these variables over the following 12 months are the regression variables. Treatment variables quantify the effects of a caregiver training program. Statistical methods used in fitting the Cox survival model and consequent predictions of survival rates are discussed.

Pregnancy rate is greater when the corpus luteum is present during the period of progestin treatment to synchronize time of estrus in cows and heifers

Our hypothesis was that conception in bovine females would be enhanced if the corpus luteum was present during the period of progestin treatment to synchronize estrus. In this study, 67 heifers (one replicate) and 124 cows (two replicates) were randomly assigned to one of two treatment groups. Seven days after estrus (Day 0), all animals were implanted with norgestomet and the implant remained in place for 10 days. All implants were removed on Day 17. Cows and heifers in one group received prostaglandin F2 alpha (PGF2 alpha) on Day 7 of the estrous cycle (PG 7; norgestomet without corpus luteum), and animals in the second group received PGF2 alpha on Day 17 (day of implant removal; PG 17; norgestomet with corpus luteum). All heifers and cows exhibiting behavioral estrus were artificially inseminated 12 h after estrus was detected during a 7-day period following removal of norgestomet. Blood samples were collected from cows of replicate 1 to determine serum concentrations of progesterone and 17 beta-estradiol. Percentage of females that had calves as a result of artificial insemination was greater (p < 0.01) in the PG 17 group (87% and 78% cows [two replicates] and 58% heifers) compared to the PG 7 group (31% and 44% cows [two replicates] and 41% heifers).(ABSTRACT TRUNCATED AT 250 WORDS)

Time until institutionalization and death in patients with dementia. Role of caregiver training and risk factors

OBJECTIVE

To determine which variables best predict prognosis--time to nursing home admission (NHA) and death--in patients with dementia.

DESIGN

Survival analysis employing the Cox proportional hazards model with the use of risk variables pertaining to dementia severity and its rate of progression and caregiver functioning.

SETTING

Patients and their caregivers participating in a controlled intervention study of training for caregivers in home management of dementia.

PARTICIPANTS

Patients with mild Diagnostic and Statistical Manual of Mental Disorders, Third Edition--defined dementia (N = 91; 68 patients with Alzheimer-type dementia, 20 with vascular dementia, and three with other types) and their caregivers.

FOLLOW-UP

All subjects had repeated assessments in the first year to determine rates of change and thereafter annually to determine the date of NHA and/or death. RISK VARIABLES: (1) Caregiver training; (2) dementia severity at index assessment; (3) caregiver stress, neuroticism, and socialization; (4) changes in patients and caregivers during the first 12 months; and (5) patient characteristics.

RESULTS

By 5 years' follow-up, 76% of patients had entered a nursing home and 42% had died. Dementia severity and rate of deterioration ("how far" and "how fast") and caregiver psychological morbidity significantly influenced rates of NHA and death. Training of caregivers was significantly associated with delayed NHA and reduced mortality. Greater patient age, non-Alzheimer's dementia, and, unexpectedly, greater caregiver psychological morbidity were associated with shorter survival to death.

CONCLUSIONS

Both severity ("how far") and rate of deterioration ("how fast") influence time to NHA and death. Caregiver training may have important ameliorating effects on the prognosis of dementia.

Cost effectiveness of a training program for dementia carers

An intensive 10-day residential training program for dementia carers has previously been shown to be associated with increased patient survival at home and decreased psychological morbidity in carers (Brodaty & Gresham, 1989). Results from a further follow-up, about 39 months after entry into the trial, were even more impressive. Patients whose carers had trained in the program had much higher adjusted rates of survival at home (53% versus 13%) and, unexpectedly, fewer deaths (20% versus 41%) than those whose carers did not have training. Patients whose carers had delayed training achieved intermediate results (31% surviving at home and 21% dying). These results were achieved with an average saving of $A7,967 ($U.S.5975) per patient over the first 39 months.

Nuclear protein, matrix and structural changes in rooster liver after estrogenic induction of vitellogenesis

The estrogenic induction of vitellogenesis in avian and amphibian liver has been well characterized at the target gene level. Comparatively little however, is known about cognate nuclear events associated with the response, particularly those involving large-scale structural changes and the non-histone proteins (NHP). We have examined these aspects further in primary stimulated roosters. In the first 24 hr post induction with estradiol, hepatocyte nuclei enlarged by 50% and exhibited sharp rises in total protein and RNA content. In particular, the mass of residual NHP rose about 40%. Extensive internal reorganization was evident, including partial disaggregation of chromatin, proliferation of interchromatin components and de novo appearance of prominent "nuclear bodies". These changes were accompanied by quantitative fluctuations in nucleoplasmic and several matrix fraction proteins. A marked relative decrease was evident in all three lamins, as well as approximately 75 and approximately 175 kD proteins. Hn-RNP-associated polypeptides however, and various unidentified components became much more prominent. By 24 hr, cells were fully differentiated for bulk export of vitellogenin and low density lipoproteins. All changes persisted for several days before gradually regressing to normal over a 2-4 week period. Many key nuclear modifications, however, did not regress fully, including persistent enlargement, elevated NHP content and modified matrix fraction proteins. Collectively, these may reflect part of the "memory" effect, commonly observed in steroid target tissues, whereby a second, more pronounced response can be triggered long after primary induction has subsided.

Chinese hamster nuclear proteins. An electrophoretic analysis of interphase, metaphase and nuclear matrix preparations

A comparison, by two-dimensional gel electrophoresis, of total interphase nuclear, metaphase chromosomal and nuclear matrix proteins from Chinese hamster V-79 cells was undertaken to examine the distribution of these proteins during mitosis. We have found a number of differences among these populations, although the two-dimensional gel patterns are generally similar. The most striking observation is that a loose cluster of six interphase nuclear polypeptides, with isoelectric points in urea between 5.7 and 6.7 and molecular masses ranging from 53 to 75 kDa, is greatly enriched in chromosome preparations. Each of these species is prominent also in the nuclear matrix. Preliminary evidence suggests that one of these polypeptides is the intermediate filament protein, vimentin. In addition, two major polypeptides of interphase nuclear preparations, a basic 94-kDa species and an approximately 65-kDa species, are absent from chromosomes. The latter polypeptide is the nuclear pore-lamina complex lamin B. Actin is present in all of these fractions, but tubulin has not been observed. hnRNP particle polypeptides are major components of the nuclear matrix, but are markedly reduced in metaphase chromosomes. The intermediate and basic 65-75-kDa nuclear matrix polypeptides we have previously demonstrated to be major components of rat liver nuclear matrix, are reduced in Chinese hamster matrix preparations and at least one of these species, a minor, basic, 68-kDa polypeptide, is missing entirely from metaphase chromosomes. These results are discussed in relation to nuclear and chromosome structure and the possibility of contamination of nuclear protein preparations from cultured cell lines with intermediate filaments.

Two-dimensinal gel electrophoresis of rat liver nuclear washes, nuclear matrix, and hnRNA proteins

The proteins of rat liver cytoplasm, nuclear washes, matrix, membrane, heterogeneous nuclear (hn)RNA proteins and chromatin were examined by two-dimensional gel electrophoresis. The inclusion in the gels of six common protein standards of carefully selected molecular weight and isoelectric point allowed us to clearly follow the distribution of specific proteins during nuclear extraction. In the nuclear washes and chromatin, we observed five classes of proteins: (a) Exclusively cytoplasmic proteins, present in the first saline-EDTA wash but rapidly disappearing from subsequent washes; (b) ubiquitous proteins of 75,000, 68,000, 57,000, and 43,000 mol wt, the latter being actin, found in the cytoplasm, all nuclear washes and the final chromatin pellet; (c) proteins of 94,000, 25,000, and 20,500 mol wt specific to the nuclear washes; (d) proteins present in the nuclear washes and final chromatin, represented by species at 62,000, 55,000, 54,000, and 48,000 mol wt, primarily derived from the nuclear matrix; and (e) two proteins of 68,000 mol wt present only in the final chromatin. The major 65,000-75,000-mol wt proteins seen by one-dimensional gel electrophoresis of nuclear matrix were very heterogeneous and contained a major acidic, an intermediate, and a basic group. A single 68,000-mol wt polypeptide constituted the majority of the membrane-lamina fraction, consistent with immunological studies indicating that a distinct subset of matrix proteins occurs, associated with heterochromatin, at the periphery of the nucleus. Actin was the second major nuclear membrane-lamina protein. Two polypeptides at 36,000 and 34,000 mol wt constituted 60% of the hnRNP. Approximately 80% of the mass of the nonhistone chromosomal proteins (NHP) from unwashed nuclei is contributed by nuclear matrix and hnRNPs, and essentially the same patterns were seen with chromatin NHP. The concept of NHP being a distinct set of DNA-bound proteins is unnecessarily limiting. Many are derived from the nuclear matrix or hnRNp particles and vary in the degree to which they share different intracellular compartments.

Triple-spot proteins in two-dimensional gel electrophoresis

A triple-spot pattern of polypeptides occurring in two-dimensional gel electrophoresis of proteins is described. The presence of a mutant protein, Pc 1 Duarte, which results in a splitting of all three polypeptides, is evidence that they are produced by the same gene. This pattern is seen in about 1% of the proteins from a variety of sources. Typically, about 50% of the protein occurs as a single major spot, the remainder occurring as two polypeptides with an additional negative charge and slightly different molecular weight. The reproducibility of this pattern implies a functional significance which is presently unknown. The implication of this configuration for patterns seen by one-dimensional gel electrophoresis is discussed.