Early indicators of primary brain tumours: a population-based study with 10 years' follow-up.

BACKGROUND AND PURPOSE: To improve diagnoses of primary brain tumours, knowledge about early indicators is needed. Nationwide Danish health registries were used to conduct a population-based case-control study including all persons diagnosed with a primary brain tumour between 2005 and 2014 in Denmark. METHODS: All 5135 adults diagnosed with a primary brain tumour in the Danish Cancer Registry were matched to 19 572 general population comparisons from the Danish Civil Registration System. Conditional logistic regression analyses were applied to estimate age- and multivariable-adjusted odds ratios (ORs) for the occurrence of a primary brain tumour up to 10 years after hospital diagnoses or prescription of medications related to nervous system diseases and mental and behavioural disorders. RESULTS: Increased odds for primary brain tumour after nervous system diseases and mental and behavioural disorders manifested up to 10 years before tumour diagnosis were found. Increased odds were seen especially for hospital contacts for inflammatory nervous system diseases [OR 11.3; 95% confidence interval (CI) 6.5-19.7], epilepsy (OR 9.0; 95% CI 7.6-10.7) and antiepileptic medications (OR 3.6; 95% CI 3.2-4.0), whilst antidementia medications provided a strong, protective association for primary brain tumours (OR 0.5; 95% CI 0.3-0.8). CONCLUSIONS: Sub-groups of patients diagnosed with or being prescribed certain medications targeting nervous system diseases and mental and behavioural disorders may be at increased risk of being diagnosed with a primary brain tumour. Further studies should disentangle the potential underlying common pathogenetic pathways. The results are important for the development of systematic clinical approaches to ensure early diagnosis of primary brain tumours.

Benefit from extended surveillance interval on colorectal cancer risk in Lynch syndrome.

AIM: Although patients with Lynch syndrome have an increased risk of developing colorectal cancer, surveillance can reduce morbidity and mortality. Whether or not affected individuals benefit from lifetime surveillance depends on individual factors and patient adherence, and these may vary, complicating risk modelling. The aim of this study was to identify individual factors which influence patient adherence to surveillance programmes and whether extended surveillance interval influenced their risk of developing colorectal cancer. METHOD: Demographics and survival data were obtained from patients (n = 1223) with Lynch syndrome, identified by interrogating the Danish Hereditary Non-Polyposis Colorectal Cancer Register. These data were linked to patient surveillance interval data which had been divided into three subsets (< 27 months, adherent to the recommended biennial programme; > 27 months, extended surveillance interval; and no surveillance) to estimate the cumulative risks and hazard ratios (HRs) for colorectal cancer. RESULTS: In all, 147 colorectal cancers (99 first; 48 metachronous) were identified in 1223 patients. Factors associated with adherence to surveillance were female sex, a previous history of cancer and age < 75 years. The cumulative incidence for colorectal cancer was 38% (95% CI 27%-50%) for surveillance intervals < 27 months, 48% (95% CI 29%-67%) for intervals > 27 months and 72% (95% CI 61%-83%) with no surveillance. Adjusted HRs were 0.22 for surveillance intervals < 27 months and 0.32 for surveillance intervals > 27 months. Extended surveillance intervals > 27 months had a non-significant benefit with an HR of 1.51 (95% CI 0.83-2.75) compared to surveillance intervals < 27 months. CONCLUSION: This study demonstrates that adherence to colonoscopic surveillance in Lynch syndrome varies with age, sex and cancer history and demonstrates a consistent benefit from colorectal cancer surveillance, though it might be lower for individuals with extended intervals.

Stroke case-fatality and marital status.

OBJECTIVES: Most studies show that marriage conveys a survival advantage. Whether this is valid also for stroke patients is unclear. Results of studies have been inconsistent and conflicting. MATERIAL & METHODS: We studied 1-week and 1-month stroke case-fatality in relation to marital status (married, unmarried, divorced, and widowed) in all patients admitted to hospital for incident stroke in Denmark during 2003-2012. We used information from Danish registries on stroke merged to information on age, sex, marital status, stroke severity, stroke subtype, socioeconomic status, cardiovascular risk profile, and causes of death. We studied deaths due to the index stroke within the first week and month after stroke. Multivariate Cox regression models were applied to estimate cause-specific hazards and relative risks. RESULTS: We included 60507 patients with an incident stroke of which 51.19% were married, 9.47% were unmarried, 13.29% were divorced, and 26.05% were widowers. Death within the first week and first month was caused by stroke in 2110 (3.5%) and 3423 (5.7%) patients, respectively. Compared to married stroke patients, 1-week/1-month case-fatality (by stroke) was lower for the unmarried (HR (hazard ratio):0.69/0.74), divorced (HR:0.69/0.72), and widowed (HR:0.80/0.74) men and the unmarried (HR:0.84/0.86), divorced (HR:0.82/0.80), and widowed (HR:0.87/0.88) women with stroke. CONCLUSIONS: One-week and one-month case-fatality by stroke was lower among the unmarried, divorced, and widowed than among the married stroke patients. Selection by so-called mortality displacement linked to shorter life expectancy among divorced, widowed, and singles may explain our findings.

Married, unmarried, divorced, and widowed and the risk of stroke.

OBJECTIVES: Most studies report that marriage carries a lower risk of stroke than single living. Whether the marriage advantage is applicable with respect to all other marital status categories (unmarried, divorced, widow) remains unclear. We studied marital status and its association with incident stroke. MATERIAL AND METHODS: We included all patients > 40 years of age admitted to hospital for stroke in Denmark during 2003-2012 and compared marital status to the general Danish population (5.5 millions). Relative risks (RR) for stroke were estimated in log-linear Poisson regression models adjusting for age, sex, calendar year, income, and length of education. RESULTS: A total of 58 847 patients with incident stroke were included. Crude incidence rates of stroke (per 1000 per year) among the four marital status categories were as follows: 1.96 (married), 1.52 (unmarried), 2.36 (divorced), and 5.43 (widowed). Compared to married persons, adjusted risk of stroke was significantly increased for divorced (RR 1.23; CI 1.19-1.27) and unmarried men (RR 1.07; CI 1.03-1.11) but not for widowed men (RR 1.02; CI 0.98-1.06); risk was slightly increased for divorced women (RR 1.10; CI 1.06-1.15) while not for widowed (RR 1.0; CI 0.97-1.03) and unmarried women (RR 0.97; CI 0.97-1.03). CONCLUSIONS: Divorce was associated with higher risk of stroke, especially in men. Living in marriage or as unmarried or widower had only little or no impact on the risk of stroke.

Prediction of treatment response to adalimumab: a double-blind placebo-controlled study of circulating microRNA in patients with early rheumatoid arthritis.

At least 30% of patients with rheumatoid arthritis (RA) do not respond to biologic agents, which emphasizes the need of predictive biomarkers. We aimed to identify microRNAs (miRNAs) predictive of response to adalimumab in 180 treatment-naïve RA patients enrolled in the OPtimized treatment algorithm for patients with early RA (OPERA) Study, an investigator-initiated, prospective, double-blind placebo-controlled study. Patients were randomized to adalimumab 40 mg (n=89) or placebo-adalimumab (n=91) subcutaneously in combination with methotrexate. Expressions of 377 miRNAs were determined using TaqMan Human MicroRNA LDA, A Card v2.0 (Applied Biosystems). Associations between miRNAs and treatment response were tested using interaction analyses. MiRNAs with a P-value <0.05 using three different normalizations were included in a multivariate model. After backwards elimination, the combination of low expression of miR-22 and high expression of miR-886.3p was associated with EULAR good response. Future studies to assess the utility of these miRNAs as predictive biomarkers are needed.

Microcirculatory dysfunction and tissue oxygenation in critical illness.

Severe sepsis is defined by organ failure, often of the kidneys, heart, and brain. It has been proposed that inadequate delivery of oxygen, or insufficient extraction of oxygen in tissue, may explain organ failure. Despite adequate maintenance of systemic oxygen delivery in septic patients, their morbidity and mortality remain high. The assumption that tissue oxygenation can be preserved by maintaining its blood supply follows from physiological models that only apply to tissue with uniformly perfused capillaries. In sepsis, the microcirculation is profoundly disturbed, and the blood supply of individual organs may therefore no longer reflect their access to oxygen. We review how capillary flow patterns affect oxygen extraction efficacy in tissue, and how the regulation of tissue blood flow must be adjusted to meet the metabolic needs of the tissue as capillary flows become disturbed as observed in critical illness. Using the brain, heart, and kidney as examples, we discuss whether disturbed capillary flow patterns might explain the apparent mismatch between organ blood flow and organ function in sepsis. Finally, we discuss diagnostic means of detecting capillary flow disturbance in animal models and in critically ill patients, and address therapeutic strategies that might improve tissue oxygenation by modifying capillary flow patterns.

Increased risk of antidepressant use in childhood cancer survivors: a Danish population-based cohort study.

AIM: Childhood cancer survivors are at risk of both somatic and mental late effects, but large population-based studies of depression are lacking. METHODS: Risk of antidepressant use was evaluated in a population-based cohort of 5452 Danish children treated for cancer in 1975-2009 by linkage to the National Prescription Drug Database, which worldwide is the oldest nationwide registry of prescription medication. Hazard ratios (HRs) for antidepressant use were estimated in a Cox proportional hazards model stratified on sex, with population comparisons as referents. RESULTS: Overall, childhood cancer survivors were at increased risk of having antidepressants prescribed (HR, 1.4; 95% confidence interval (CI), 1.3-1.5). The excess absolute risk of antidepressant use was 2.5 per 1000 person-years (95% CI, 1.7-3.3), equivalent to an excess of 2.5 survivors for every 100 survivors followed for 10years. Increased HRs of 30-50% were seen for survivors of cancers of all main groups (haematological malignancies, central nervous system (CNS) and solid tumors); the highest risk was among children treated with haematopoietic stem cell transplantation (HR, 1.9; 95% CI, 1.2-3.1). Our data suggested that the risk was most pronounced for children treated in the most recent calendar periods (test for interaction between cancer and calendar periods: P<0.001), especially for survivors of haematological cancers (P=0.007). Interaction analysis of the effect of parental socioeconomic position and psychiatric disease on the association between childhood cancer and antidepressant use indicated no modifying effect. CONCLUSION: Childhood cancer survivors should be followed-up for depression. Our results indicate an increasing need for follow-up especially in survivors treated by more recent, intensive anticancer treatment.

Screening for carcinoma in situ in the contralateral testicle in patients with testicular cancer: a population-based study.

BACKGROUND: Screening programmes for contralateral carcinoma in situ (CIS) testis in patients with unilateral germ-cell cancer (GCC) have never been evaluated. We investigated the effect of screening for contralateral CIS in a large nation-wide, population-based study. PATIENTS AND METHODS: A contralateral single-site biopsy was offered to 4130 patients in whom GCC had been diagnosed in 1984-2007 (screened cohort); 462 patients in whom GCC was diagnosed in 1984-1988 comprised the unscreened cohort. Cases with CIS were offered radiotherapy. Initially CIS-negative biopsies in patients with metachronous GCC were revised according to today's standards. Risk for metachronous GCC was estimated using cumulative incidence and the Cox proportional hazards model. RESULTS: In the screened cohort, contralateral CIS was found in 181 (4.4%) patients. The cumulative incidence of metachronous GCC after 20 years was 1.9% in the screened cohort and 3.1% in the unscreened cohort (P = 0.097), hazard ratio (HR) for the unscreened cohort: 1.59 (P = 0.144). Expert revision with contemporary methodology of CIS-negative biopsy samples from patients with metachronous cancer revealed CIS in 17 out of 45 (38%) cases. Decreased risks for metachronous GCC were related to older age at diagnosis (HR 0.52 per 10 years, P < 0.001) and chemotherapy (HR 0.35, P = 0.002). Limitations include the small number of patients in the unscreened cohort and the retrospective study design. CONCLUSIONS: Our evaluation of a national population-based screening programme for contralateral CIS in patients with testicular cancer showed no significant difference in the risk for metachronous GCC between a screened and an unscreened cohort. Single-site biopsy including modern immunohistochemistry does not identify all cases of CIS.

Seasonal variation in the composition and melting behavior of milk fat.

Dairy bulk tank milk was sampled during 1yr from 2 conventional (C1 and C2) and 1 organic dairy (O1) for studying the seasonal variation as well as the variation between dairies in the composition and properties of milk fat. The composition of fatty acids (FA) as well as triglycerides (TAG) in milk fat was analyzed, and the melting properties of milk fat were analyzed by use of differential scanning calorimetry. The main differences in fat content and composition of FA in milk fat between dairies included a higher fat content, greater proportion of C18:0, and smaller proportion of C16:0 in milk from dairy C2, which could be associated with a higher frequency of Jersey herds supplying milk to this dairy. The organic milk was characterized by a higher proportion of C18:3n-3, C18:2 cis-9,trans-11, C6 to C14, a lower proportion of C18:1 cis-9, and a higher melting point of the low-melting fraction. The TAG composition showed a greater proportion of C24 to C38 TAG in milk fat from dairy O1 and a greater proportion of C52 to C54 TAG in milk fat from dairy C2, which was in accordance with the differences in FA composition. Melting point of the low-melting fraction was higher for milk fat from dairy O1 compared with dairies C1 and C2, whereas no differences between dairies were observed with respect to melting points of the medium- and high-melting fractions. The seasonal variation in FA composition was most pronounced for dairy O1 although similar patterns were observed for all dairies. During the summer, the content of C18:0 and C18:1 cis-9 in milk fat was greater, whereas the content of C14:0 and C16:0 was lower. In addition, the content of C18:2 cis-9,trans-11 and C18:1 trans-11 increased in late summer for dairy O1. The differential scanning calorimetry thermograms of individual milk fat samples could be divided into 3 groups by principal component analysis. For dairy O1, summer samples belonged to group 1, spring and autumn samples to group 2, and winter samples to group 3. For dairy C1 winter samples (group 2), were separated from other samples (group 1), and for dairy C2 all samples were in group 1. Individual melting points were related to FA composition, and the melting point of the low-melting fraction was positively correlated to the content of C14:0 and C16:0 in milk fat and negatively correlated to the content of C18:1 cis-9 and C18:0.

The effects of multidisciplinary rehabilitation: RePCa-a randomised study among primary prostate cancer patients.

BACKGROUND: The objective of this study is the effectiveness of multidisciplinary rehabilitation on treatment-related adverse effects after completed radiotherapy in patients with prostate cancer (PCa). METHODS: In a single-centre oncology unit in Odense, Denmark, 161 PCa patients treated with radiotherapy and androgen deprivation therapy were randomly assigned to either a programme of two nursing counselling sessions and two instructive sessions with a physical therapist (n=79) or to usual care (n=82). Primary outcome was Expanded Prostate Cancer Index Composite (EPIC-26) urinary irritative sum-score. Before radiotherapy, pre-intervention 4 weeks after radiotherapy, and after a 20-week intervention, measurements included self-reported disease-specific quality of life (QoL; EPIC-26, including urinary, bowel, sexual, and hormonal symptoms), general QoL (Short-form-12, SF-12), pelvic floor muscle strength (Modified Oxford Scale), and pelvic floor electromyography. Intension-to-treat analyses were made with adjusted linear regression. RESULTS: The intervention improved, as compared with controls, urinary irritative sum-score 5.8 point (Cohen's d=0.40; P=0.011), urinary sum-score (d=0.34; P=0.023), hormonal sum-score (d=0.19; P=0.018), and the SF-12 Physical Component Summary, d=0.35; P=0.002. Patients with more severe impairment gained most. Pelvic floor muscle strength measured by electromyography declined in both groups, P=0.0001. CONCLUSION: Multidisciplinary rehabilitation in irradiated PCa patients improved urinary and hormonal symptoms, and SF-12 physical QoL.

OmpA can form folded and unfolded oligomers.

The monomeric outer membrane protein OmpA from Escherichia coli has long served as a model protein for studying the folding and membrane insertion of ß-barrel membrane proteins. Here we report that when OmpA is refolded in limiting amounts of surfactant (close to the cmc), it has a high propensity to form folded and unfolded oligomers. The oligomers exist both in a folded and (partially) unfolded form which both dissociate under denaturing conditions. Oligomerization does not require the involvement of the periplasmic domain and is not strongly affected by ionic strength. The folded dimers can be isolated and show native-like secondary structure; they are resistant to proteolytic attack and do not dissociate in high surfactant concentrations, indicating high kinetic stability once formed. Remarkably, OmpA also forms significant amounts of higher order structures when refolding in the presence of lipid vesicles. We suggest that oligomerization occurs by domain swapping favored by the high local concentration of OmpA molecules congregating on the same micelle or vesicle. In this model, the unfolded oligomer is stabilized by a small number of intermolecular ß-strand contacts and subsequently folds to a more stable state where these intermolecular contacts are consolidated in a native-like fashion by contacts between complementary ß-strands from different molecules. Our model is supported by the ability of complementary fragments to associate with each other in vitro. Oligomerization is probably avoided in the cell by the presence of cellular chaperones which maintain the protein in a monomeric state.

pH regulation of the kinetic stability of the lipase from Thermomyces lanuginosus.

Thermomyces lanuginosus lipase (TlL) is a kinetically stable protein, resistant toward both denaturation and refolding in the presence of the ionic surfactant sodium dodecyl sulfate (SDS) and the nonionic surfactant decyl maltoside (DecM). We investigate the pH dependence of this kinetic stability. At pH 8, TlL remains folded and enzymatically active at multimillimolar surfactant concentrations but fails to refold from the acid urea-denatured state at submillimolar concentrations of SDS and DecM, indicating a broad concentration range of kinetic trapping or hysteresis. At pH 8, very few SDS molecules bind to TlL. The hysteresis SDS concentration range shrinks when moving to pH 4-6; in this pH range, SDS binds as micellelike clusters. Although hysteresis can be eliminated by reducing disulfide bonds, destabilizing the native state, and lowering the unfolding activation barrier, SDS sensitivity is not directly linked to intrinsic kinetic stability [its resistance to the general chemical denaturant guanidinium chloride (GdmCl)], because TlL unfolds more slowly in GdmCl at pH 6.0 than at pH 8.0. However, the estimated net charge drops from approximately -12 to approximately -5 between pH 8 and 6. SDS denatures TlL at pH 6.0 by nucleating via a critical number of bound SDS molecules on the surface of native TlL to form clusters. These results imply that SDS sensitivity is connected to the availability of appropriately charged regions on the protein. We suggest that conformational rigidity is a necessary but not sufficient feature of SDS resistance, because this has to be combined with sufficient negative electrostatic potential to avoid extensive SDS binding.

Distinct composition of bovine milk from Jersey and Holstein-Friesian cows with good, poor, or noncoagulation properties as reflected in protein genetic variants and isoforms.

The objective of this study was to examine variation in overall milk, protein, and mineral composition of bovine milk in relation to rennet-induced coagulation, with the aim of elucidating the underlying causes of milk with impaired coagulation abilities. On the basis of an initial screening of 892 milk samples from 42 herds with Danish Jersey and Holstein-Friesian cows, a subset of 102 samples was selected to represent milk with good, poor, or noncoagulating properties (i.e., samples that within each breed represented the most extremes in regard to coagulation properties). Milk with good coagulation characteristics was defined as milk forming a strong coagulum based on oscillatory rheology, as indicated by high values for maximum coagulum strength (G'(max)) and curd firming rate (CFR) and a short rennet coagulation time. Poorly coagulating milk formed a weak coagulum, with a low G'(max) and CFR and a long rennet coagulation time. Noncoagulating milk was defined as milk that failed to form a coagulum, having G'(max) and CFR values of zero at measurements taken within 1h after addition of rennet. For both breeds, a lower content of total protein, total casein (CN) and κ-CN, and lower levels of minerals (Ca, P, Mg) were identified in poorly coagulating and noncoagulating milk in comparison with milk with good coagulation properties. Liquid chromatography/electrospray ionization-mass spectrometry revealed the presence of a great variety of genetic variants of the major milk proteins, namely, α(S1)-CN (variants B and C), α(S2)-CN (A), ß-CN (A(1), A(2), B, I, and F), κ-CN (A, B, and E), α-lactalbumin (B), and ß-lactoglobulin (A, B, and C). In poorly coagulating and noncoagulating milk samples of both breeds, the predominant composite genotype of α(S1)-, ß-, and κ-CN was BB-A(2)A(2)-AA, which confirmed a genetic contribution to impaired milk coagulation. Interestingly, subtle variations in posttranslational modification of CN were observed between the coagulation classes in both breeds. Poorly coagulating and noncoagulating milk contained a lower fraction of the least phosphorylated α(S1)-CN form, α(S1)-CN 8P, relative to total α(S1)-CN, along with a lower fraction of glycosylated κ-CN relative to total κ-CN. Thus, apparent variation was observed in the milk and protein composition, in the genetic makeup of the major milk proteins, and in the posttranslational modification level of CN between milk samples with either good or impaired coagulation ability, whereas the composition of poorly coagulating and noncoagulating milk was similar.

Thyroid cancer in Denmark 1943-2008, before and after iodine supplementation.

Thyroid cancer incidence has increased worldwide during the previous decades. In this nationwide study, we aimed to identify the overall incidence of thyroid cancer in Denmark during 66 years (1943-2008) and incidences of the four main histological types of thyroid cancer from 1978 to 2008. Data were obtained from the nationwide Danish Cancer Registry, and we focused especially on the period after implementation of compulsory iodine supplementation, which was established on a national level in 2000. We calculated age-standardized incidence rates per 100,000 person-years, and age-period-cohort models were fitted to describe trends in incidence. To quantify trends in incidence over time, log-linear Poisson models were used to estimate annual percentage change. From 1943 to 2008, 1,947 men (29%) and 4,682 women (71%) were diagnosed with thyroid cancer. The age-standardized incidence increased in both sexes; in men from 0.41 to 1.57 per 100,000 and from 0.90 to 4.11 per 100,000 in women, corresponding to a significant average annual percentage change of 1.7 and 1.8%, respectively. The incidence increased with younger birth cohorts. The rise was almost exclusively caused by papillary carcinomas, and it was particularly present during the last decades of the study period. It cannot be ruled out that iodine supplementation may play a role for the risk of thyroid cancer, but as the strongest increase in incidence began in the years before the implementation, it is likely that improvement in diagnostic modalities increased diagnostic activity, and/or new unknown risk factors are also important contributors to the increase.

HPV16 is associated with younger age in women with cervical intraepithelial neoplasia grade 2 and 3.

OBJECTIVE: To evaluate if women with HPV16 positive CIN2 and CIN3 are diagnosed at a younger age. METHODS: We conducted a population-based cohort study including more than 40,000 women having a liquid based cervical cytology sample taken as part of routine screening. HPV analysis was performed using Hybrid Capture 2 and LiPAv2. The study population was linked to the Danish Pathology Data Bank to retrieve information on subsequent cervical histology. We included HR HPV positive CIN2/3 samples, comprising 173 CIN2 and 467 CIN3 lesions. Due to a high number of multiple concurrent HPV infections, the causative HPV type was assigned to a hierarchically group. RESULTS: In CIN3, the estimated proportion of lesions positive for HPV16 was 68.1% among women aged 20 years and decreased to 38.9% among women aged 50 years. A decrease in HPV16 positivity with increasing age was also observed in CIN2. In a multinomial logistic regression analysis, young age was strongly associated with HPV16 positivity in CIN3 lesions (OR=0.46 per 10 year increase in age, 95% CI: 0.32-0.65). The proportion of HPV16 and/or 18 positive lesions among women diagnosed with CIN2 and CIN3 below 30 years of age was 44% and 75%, respectively. CONCLUSIONS: HPV16 positivity was significantly associated with younger age at diagnosis of CIN3. In a population vaccinated against HPV16 and 18, we will experience a shift to older ages in cervical precancerous lesions. These findings may imply that cervical cancer screening programs could start at an older age in HPV vaccinated populations.

Composition and effect of blending of noncoagulating, poorly coagulating, and well-coagulating bovine milk from individual Danish Holstein cows.

The aim of the present investigation was to study the underlying causes of noncoagulating (NC) milk. Based on an initial screening in a herd of 53 Danish Holstein-Friesians, 20 individual Holstein-Friesian cows were selected for good and poor chymosin-induced coagulation properties; that is, the 10 cows producing milk with the poorest and best coagulating properties, respectively. These 20 selected cows were followed and resampled on several occasions to evaluate possible changes in coagulation properties. In the follow-up study, we found that among the 10 cows with the poorest coagulating properties, 4 cows consistently produced poorly coagulating (PC) or NC milk, corresponding to a frequency of 7%. Noncoagulating milk was defined as milk that failed to form a coagulum, defined as increase in the storage modulus (G') in oscillatory rheometry, within 45min after addition of chymosin. Poorly coagulating milk was characterized by forming a weak coagulum of low G'. Milk proteomic profiling and contents of different casein variants, ionic contents of Ca, P and Mg, κ-casein (CN) genotypes, casein micelle size, and coagulation properties of the 4 NC or PC samples were compared with milk samples of 4 cows producing milk with good coagulation properties. The studies included determination of production of caseinomacropeptide to ascertain whether noncoagulation could be ascribed to the first or second phase of chymosin-induced coagulation. Caseinomacropeptide was formed in all 8 milk samples after addition of chymosin, indicating that the first step (cleavage of κ-CN) was not the cause of inability to coagulate. Furthermore, the effect of mixing noncoagulating and well-coagulating milk was studied. By gradually blending NC with well-coagulating milk, the coagulation properties of the well-coagulating samples were compromised in a manner similar to titration. Milk samples from cows that consistently produced NC milk were further studied at the udder quarter level. The coagulation properties of the quarter milk samples were not significantly different from those of the composite milk sample, showing that poor coagulation traits and noncoagulation traits of the composite milk were not caused by the milk quality of a single quarter. The milk samples exhibiting PC or NC properties were all of the κ-CN variant AA genotype, and contained casein micelles with a larger mean diameter and a lower fraction of κ-CN relative to total CN than milk with good coagulation properties. Interestingly, the relative proportions of different phosphorylation forms of α-CN differed between well-coagulating milk and PC or NC milk samples. The PC and NC milk samples contained a lower proportion of the 2 less-phosphorylated variants of α-CN (α(S1)-CN-8P and α(S2)-CN-11P) compared with samples of milk that coagulated well.

Holocene thinning of the Greenland ice sheet.

On entering an era of global warming, the stability of the Greenland ice sheet (GIS) is an important concern, especially in the light of new evidence of rapidly changing flow and melt conditions at the GIS margins. Studying the response of the GIS to past climatic change may help to advance our understanding of GIS dynamics. The previous interpretation of evidence from stable isotopes (delta(18)O) in water from GIS ice cores was that Holocene climate variability on the GIS differed spatially and that a consistent Holocene climate optimum-the unusually warm period from about 9,000 to 6,000 years ago found in many northern-latitude palaeoclimate records-did not exist. Here we extract both the Greenland Holocene temperature history and the evolution of GIS surface elevation at four GIS locations. We achieve this by comparing delta(18)O from GIS ice cores with delta(18)O from ice cores from small marginal icecaps. Contrary to the earlier interpretation of delta(18)O evidence from ice cores, our new temperature history reveals a pronounced Holocene climatic optimum in Greenland coinciding with maximum thinning near the GIS margins. Our delta(18)O-based results are corroborated by the air content of ice cores, a proxy for surface elevation. State-of-the-art ice sheet models are generally found to be underestimating the extent and changes in GIS elevation and area; our findings may help to improve the ability of models to reproduce the GIS response to Holocene climate.

Nicotine and clozapine selectively reverse a PCP-induced deficit of PPI in BALB/cByJ but not NMRI mice: comparison with risperidone.

Schizophrenic patients have deficits in prepulse inhibition (PPI) that may be alleviated by smoking/nicotine. The effect of nicotinic agents on PPI in rodents is equivocal and few studies in mice have been reported. Thus, we assessed nicotine's (0.03-1mg/kg) effect on PPI in five mouse strains with no effects. We next determined if nicotine would reverse a phencyclidine (PCP)-induced deficit of PPI in BALB/cByJ and NMRI mice. BALB/cByJ mice have a low density of [(125)I]alpha-bungaratoxin binding in the hippocampus and poor inhibitory gating of auditory evoked potentials (AEPs), a model related to PPI. At 1mg/kg, nicotine selectively reversed the PCP-induced deficit of PPI in BALB/cByJ mice. The pharmacokinetic profile of nicotine (T(1/2), C(max), T(max) and AUC) was identical in both strains, obviating this as a factor for the strain-dependent effect observed. Moreover, 1mg/kg nicotine inhibited in vivo [(3)H]epibatidine binding with the same time-course in both strains, indicating no difference in brain "kinetics". Since high doses of nicotine were effective in BALB/cByJ mice a role for low-affinity nicotinic receptors, e.g. alpha(7) receptors, is plausible. Clozapine, but not risperidone, also only reversed the PCP deficit of PPI in BALB/cByJ. Clozapine and nicotine also enhance inhibitory gating of AEPs in DBA/2 mice, and clozapine's effect is antagonized by an alpha(7) antagonist. Our data and previous evidence possibly suggest a role for low-affinity nicotinic receptors in the effects of clozapine and nicotine. Furthermore, BALB/cByJ mice may represent a model to test the effects of nicotinic agents acting at low-affinity nicotinic receptors.

Global iron connections between desert dust, ocean biogeochemistry, and climate.

The environmental conditions of Earth, including the climate, are determined by physical, chemical, biological, and human interactions that transform and transport materials and energy. This is the "Earth system": a highly complex entity characterized by multiple nonlinear responses and thresholds, with linkages between disparate components. One important part of this system is the iron cycle, in which iron-containing soil dust is transported from land through the atmosphere to the oceans, affecting ocean biogeochemistry and hence having feedback effects on climate and dust production. Here we review the key components of this cycle, identifying critical uncertainties and priorities for future research.

High-resolution record of Northern Hemisphere climate extending into the last interglacial period.

Two deep ice cores from central Greenland, drilled in the 1990s, have played a key role in climate reconstructions of the Northern Hemisphere, but the oldest sections of the cores were disturbed in chronology owing to ice folding near the bedrock. Here we present an undisturbed climate record from a North Greenland ice core, which extends back to 123,000 years before the present, within the last interglacial period. The oxygen isotopes in the ice imply that climate was stable during the last interglacial period, with temperatures 5 degrees C warmer than today. We find unexpectedly large temperature differences between our new record from northern Greenland and the undisturbed sections of the cores from central Greenland, suggesting that the extent of ice in the Northern Hemisphere modulated the latitudinal temperature gradients in Greenland. This record shows a slow decline in temperatures that marked the initiation of the last glacial period. Our record reveals a hitherto unrecognized warm period initiated by an abrupt climate warming about 115,000 years ago, before glacial conditions were fully developed. This event does not appear to have an immediate Antarctic counterpart, suggesting that the climate see-saw between the hemispheres (which dominated the last glacial period) was not operating at this time.