Palaeoclimatic changes resulted in range expansion and subsequent divergence in brown fur seals, Arctocephalus pusillus.

Past climatic change as a driving force of marine diversification is still largely unclear, particularly for Southern Hemisphere species. Here, we present a case using the brown fur seal, Arctocephalus pusillus, assessing the geographical structure and demographic history using mitochondrial and nuclear data. Results show the two previously defined subspecies (one from Australia and the other from southern Africa) are phylogeographically distinct. Migration analyses based on nuclear data suggest the absence of migrants among the two genetically close assemblages. The demographic history of A. pusillus is characterized by a glacial population expansion (approx. 18 kya) in the southern African lineage, which coincides with time estimates of population expansion of prey species of seals. Approximate Bayesian calculations support an eastward dispersal event during the Last Glacial Maximum when sea levels were lower, followed by a postglacial divergence event, approximately 13 kya. The demographic history of the brown fur seal in the Southern Oceans provides support that recent palaeoclimatic changes could have facilitated expansions in some marine species and that postglacial sea-level rise may have acted as a dispersal barrier for species mostly confined to continental shelves.

How many daddies: microsatellite genotyping reveals polyandry in a live-bearing clinid fish Muraenoclinus dorsalis.

Fishes belonging to the family Clinidae in South Africa display super-embryonation, a rare reproductive mode were females gestate broods at different gestational stages, but little is known regarding the mating systems of this family. Here we tested the hypothesis that multiple males would contribute not only to the offspring of each female, but that several males would contribute to each brood, by sampling Muraenoclinus dorsalis from three sampling locations along the west and south-west coast of South Africa. Larval (n = 97) and maternal (n = 14) genotpyes, generated with newly developed microsatellites, were used to estimate the number of potential mates per female. Our results show that up to 78% of females displayed multiple mating with an average of 2·1-2·2 males. In addition, 39-42% of females displayed polyandry with an average of 1·5-1·6 sires per brood. This study provides the evidence for multiple mating and polyandry within a clinid fish characterized by super-embryonation that offers important baseline information regarding rare reproductive strategies, highlighting several gaps in our knowledge concerning clinid reproduction and mating systems.

Phylogeny of Parablennius Miranda Ribeiro, 1915 reveals a paraphyletic genus and recent Indo-Pacific diversification from an Atlantic ancestor.

A molecular phylogeny of 15 (out of 26 recognized) species of Parablennius Miranda Ribeiro, 1915 was constructed based on two mitochondrial and two nuclear gene fragments, and using maximum parsimony, maximum likelihood and Bayesian approaches. The closely related genera Hypleurochilus, Salaria and Scartella were also studied to ascertain their relationship with Parablennius. Phylogenetic analyses were compared with morphology-based taxonomical studies. Hypleurochilus, Salaria and Scartella appear well supported within a clade including all Parablennius, indicating that this genus is paraphyletic. The species pairs P. parvicornis-P. sanguinolentus and P. gattorugine-P. ruber are well-supported and relatively distant from remaining Parablennius. Remaining Parablennius form two distinct well-supported groups: (1) a clade of Atlantic-Mediterranean Parablennius (P. pilicornis, P. marmoreus, P. rouxi, P. salensis and P. tentacularis); (2) a clade including Hypleurochilus, the Indo-Western Pacific Parablennius (P. cornutus, P. intermedius, P. tasmanianus and P. yatabei) and the Atlantic-Mediterranean P. incognitus and P. zvonimiri. Use of a relaxed molecular clock suggests that Indo-Pacific Parablennius originated recently from an Atlantic Parablennius that may have dispersed via southern Africa, rather than via the Tethys seaway.

Multilocus phylogenetic analysis of the genus Atherina (Pisces: Atherinidae).

Sand-smelts are small fishes inhabiting inshore, brackish and freshwater environments and with a distribution in the eastern Atlantic and Mediterranean Sea, extending south into the Indian Ocean. Here, we present a broad phylogenetic analysis of the genus Atherina using three mitochondrial (control region, 12S and 16S) and two nuclear markers (rhodopsin and 2nd intron of S7). Phylogenetic analyses fully support the monophyly of the genus. Two anti-tropical clades were identified, separating the South African Atherina breviceps from the north-eastern Atlantic and Mediterranean Atherina' species. In European waters, two groups were found. The first clade formed by a well supported species-pair: Atherina presbyter (eastern Atlantic) and Atherina hepsetus (Mediterranean), both living in marine waters; a second clade included Atherina boyeri (brackish and freshwater environments) and two independent lineages of marine punctated and non-punctated fishes, recently proposed as separate species. Sequence divergence values strongly suggest multiple species within the A. boyeri complex.

Phylogeographic patterns and cryptic speciation across oceanographic barriers in South African intertidal fishes.

Biogeographic boundaries are the meeting zone of broadly distributed faunas, or the actual cause of a faunal break. In the latter case, closely related sister species should be found across such a boundary. To achieve such a situation, preliminary stages are expected, where phylogeographic breaks followed by genetic cryptic speciation would be observed. Biogeographic boundaries, in the Cape Point/Cape Agulhas region of southern Africa, offer an ideal system to test such predictions. Here, we studied two intertidal clinid fish species that are endemic to southern Africa, Clinus superciliosus (n = 127) and Muraenoclinus dorsalis (n = 114). Using mitochondrial control region, 16S rRNA, 12S rRNA and NADH2 genes and the nuclear rhodopsin and the first intron of the S7 ribosomal protein gene, we show both phylogeographic breaks and likely cryptic speciation in each species. Pairwise Φ(st) results suggest population genetic structuring for both species, with higher levels for M. dorsalis (Φ(st) = 0.34-0.93) than for C. superciliosus (Φ(st) = 0.1-0.74). Further, we recover two and three distinct lineages within M. dorsalis and C. superciliosus, respectively. Phylogenetic topologies, concordance between nuclear and mitochondrial markers and levels of sequence divergence, which are consistent with closely related sister species pairs, suggest the presence of cryptic species. Our results therefore meet the expectation for reduced gene flow at a biogeographic barrier, which translates into significant genetic breaks and cryptic sister species.

The influence of modulation of P-glycoprotein and /or cytochrome P450 3A on the pharmacokinetics and pharmacodynamics of orally administered morphine in dogs.

The influence of pretreatment with ketoconazole [cytochrome P450 3A (CYP3A) + P-glycoprotein (P-gp) inhibitor], elacridar (selective P-gp inhibitor) and rifampicin (CYP3A + P-gp inducer) on oral morphine pharmacokinetics and pharmacodynamics was investigated in experimental dogs. Seven beagles were used in a four-way crossover design. Morphine hydrochloride was administered orally (2.5 mg/kg) alone (control group CON) or after pretreatment with ketoconazole (group KETO), elacridar (group ELA) or rifampicin (group RIF). Morphine plasma concentrations were analysed by liquid chromatography-tandem mass spectrometry. Sedation scores (none, mild, moderate or severe) were evaluated subjectively. Dogs were significantly (P < 0.05) more sedated after ketoconazole pretreatment. There were no significant differences between group CON and the other pretreatment groups in pharmacokinetic parameters taking both sexes into account. Sex differences were apparent in some pharmacokinetic parameters of morphine. The area under the plasma concentration time curve (AUC(0-∞) ) was significantly higher, and the total body clearance was significantly lower in male compared to female dogs in all treatment groups. Ketoconazole, rifampicin and elacridar pretreatment had no significant effects on morphine pharmacokinetics, although dogs in the ketoconazole group showed higher sedation scores.

Functional optimality of the sulcus pattern of the human brain.

We develop a mathematical model of information transmission across the biological neural network of the human brain. The overall function of the brain consists of the emergent processes resulting from the spread of information through the neural network. The capacity of the brain is therefore related to the rate at which it can transmit information through the neural network. The particular transmission model under consideration allows for information to be transmitted along multiple paths between points of the cortex. The resulting transmission rates are governed by potential theory. According to this theory, the brain has preferred and quantized transmission modes that correspond to eigenfunctions of the classical Steklov eigenvalue problem, with the reciprocal eigenvalues quantifying the corresponding transmission rates. We take the model as a basis for testing the hypothesis that the sulcus pattern of the human brain has evolved to maximize the rate of transmission of information between points in the cerebral cortex. We show that the introduction of sulci, or cuts, in an otherwise smooth domain indeed increases the overall transmission rate. We demonstrate this result by means of numerical experiments concerned with a spherical domain with a varying number of slits on its surface.

Concurrent atypical myopathy and equine dysautonomia in two horses.

This report concerns 2 horses that suffered typical clinical signs of atypical myopathy (AM) and equine grass sickness (EGS) concurrently. Clinical details and pathological lesions of the cases are described. EGS and AM are relatively rare diseases and the concurrency of the diseases in the same animals is therefore considered unlikely to be a coincidence. However, it is not suggested that the evidence shows a common aetiology but rather the existence of common predisposing causes.

Serum retinol and risk of subsequent cancer: extension of the Evans County, Georgia, study.

A previous report from the Evans County, Ga., cohort correlated low base-line retinol levels in 1960-62 to an increased risk of cancer developing in the following 12-14 years. So that this inverse association could be retested, retinol determinations were performed on sera in 135 incident cancer cases, identified during a vital status follow-up in 1981, and in 237 controls matched by race, sex, age, and date of venipuncture. The serum was drawn during the second cohort examination between 1967 and 1969 and stored at -20 degrees C until analysis by high-pressure liquid chromatography in January 1982. Eligible for the study were patients whose initial cancer diagnosis was established more than 24 months after venipuncture. Base-line retinol levels of subsequent cancer cases and their matched controls were similar in the 4 race-sex groups. The risk of cancer at all sites associated with the lowest retinol quintile was similar to that associated with the highest quintile. In multivariate analysis, with control for age, cholesterol, body mass, smoking status, and social class, no significant relationship of serum retinol and case status was found. In summary, these data fail to confirm the strong dose-response relationship between baseline retinol levels and subsequent cancer reported in the previous study.

Coffee consumption and mortality. Total mortality, stroke mortality, and coronary heart disease mortality.

Total mortality showed no association with coffee usage in the four race-sex groups of Evans County, Georgia. Deaths of coronary heart disease (CHD) in white men and women and black men showed no statistically significant difference between high and low coffee consumers. In an area that has been designated as the "Stroke Belt," neither CHD nor cerebrovascular death rates seem related to coffee-drinking habits. However, to refute or confirm the allegations of a detrimental influence of high coffee intake, larger samples are needed. Nevertheless, our finding that mortality from all causes is not increased in the high coffee-consuming group means that a finding of increased CHD mortality with high coffee consumption would have to be compensated by a protective lower rate for other causes of death.

Listeria monocytogenes and recurrent mycobacterial infections in a child with complete interferon-gamma-receptor (IFNgammaR1) deficiency: mutational analysis and evaluation of therapeutic options.

We describe the history of a girl with interferon-gamma-receptor (IFNgammaR1) deficiency and studies performed to identify the molecular and clinical characteristics of this recently discovered disorder. This is the first report of a child from Northern Europe with IFNgammaR1 deficiency. The patient, now 7 years old, first presented with swelling and reddening at the Bacille Calmette-Guerin (BCG) vaccination site, swelling of lymph nodes, hepatomegaly, and an unusually severe varicella rash at the age of 4 months. At that time, she was diagnosed with BCG histiocytosis without typical granuloma formation and was treated with antituberculous agents. During the clinical course of her illness, several different types of atypical mycobacteria and (for the first time in an IFNgammaR1-deficient patient) Listeria monocytogenes were detected. Flow cytometric analysis showed that the patient's monocytes could not bind a monoclonal antibody specific for the IFNgamma-receptor. Our analysis of mRNA derived from the alpha-chain (IFNgammaR1) gene of this receptor revealed deletions of 173 bp and 4 bp in cDNA sequences originating from individual alleles. The 173 bp deletion was located between nucleotide positions 200 and 372, exactly matching those of exon 3, and the 4 bp deletion was located between nucleotide positions 561 and 564 of the coding region of the cDNA. Analysis of genomic DNA revealed the presence of a G to T transition at the 5'end of the splice consensus sequence of intron 3, which explains the absence of exon 3. The other allele carried the 4-base-pair deletion (ACTC) at nucleotide positions 15-18 of exon 5. Twelve months after an allo\geneic bone marrow transplantation, the patient had clinically improved.

Uncommon missense and splice mutations and resulting biochemical phenotypes in German patients with X-linked chronic granulomatous disease.

Chronic granulomatous disease is an inherited disease characterized by the inability of phagocytes to generate normal amounts of superoxide, leaving patients susceptible to opportunistic, life-threatening infections. In the majority of cases, cytochrome b558 is absent in the X-chromosomal form of CGD. However, the neutrophils from six of nine X-linked CGD patients, reported here, expressed normal or decreased amounts of this cytochrome and are referred to as "variant" forms. In three of these six variant patients, a roughly proportional decrease in cytochrome b558 expression and production of H2O2 were found. In two cases this phenotype could be well explained by special splice mutations, whereas in the third case it was caused by a missense mutation, predicting Ser 193-->Phe. In the other three variant patients, cytochrome b558 expression and H2O2 production were clearly disproportionate as the generation of H2O2 was much more decreased than cytochrome expression. Missense mutations also were found in these cases. One of these mutations, predicting Leu 546-->Pro and affecting the putative nicotinamide adenine dinucleotide phosphate binding site, led to normal levels of cytochrome b558 expression and reduced H2O2 production. In the other two mutations, predicting Pro 339-->His and His 338-->Tyr, the putative flavin adenine dinucleotide binding site was affected. This could explain the corresponding uncommon phenotypes, characterized by zero or trace amounts of H2O2 production and the expression of relatively high amounts of nonfunctional or low functional cytochrome b558, respectively. The only missense mutation found that prevented the expression of any cytochrome b558 was caused by a predicted His 222-->Arg exchange in one of the three classic cases. The two other classic phenotypes were caused by splice mutations.

Coffee and cholesterol in epidemiological and experimental studies.

Twenty-two cross-sectional studies involving 130,000 persons from 8 different countries have reported their findings on the association between coffee consumption and cholesterol levels. Results of these reports display a variety of trends in the association between coffee intake and serum cholesterol concentrations: 8 (36%) studies demonstrated a significant positive association in both sexes, and 5 (23%) studies showed no association in men or women. In 3 other reports where both sexes were included, significant positive association was observed only in women. The remaining 6 investigations examined only men with 4 (18%) reporting a significant correlation between coffee and cholesterol. This unexplained incongruity of cross-sectional data points to a relationship between coffee and cholesterol in some populations, which needs to be further explored. In addition, HDL cholesterol levels appeared unrelated to coffee intake in the 11 studies in which it was measured. The 7 available human experiments showed the same low level of agreement in the results among small numbers of volunteers. Experiments involving different brewing methods suggest that a major part of the cholesterol-increasing effect can be explained by different brewing methods. A critical assessment of the published reports leads to the conclusion that the data are insufficient to warrant public health admonitions against coffee drinking, but that it may be of clinical importance in some hypercholesterolemic individuals.

Influence of race, sex and weight on blood pressure behavior in young adults.

This study is concerned with blood pressure behavior in young adults (aged 15 to 29 years) in the biracial community of Evans County, Ga., on two occasions 7 years apart. On the basis of casual blood pressure recordings the prevalence of systolic pressure equal to or greater than 140 mm Hg or diastolic pressure equal to or greater than 90 mm Hg, or both, showed race/sex differences as follows: white males 19.0 percent, white females 12.7 percent. black males 34.0 percent, black females 31.6 percent. Similar differences were noted in the incidence during the 7 year interval. The problem presented by the variability of the casual blood pressure recording is apparent in this interval study. Of particular interest is the association of weight with blood pressure in this youthful group, particularly among white males and females and black females, in relation to both initial and subsequent pressure levels. The data suggest that in this population under 30 years, weight is a risk factor for hypertension, and that maintenance of ideal weight, instituted in youth, may be a preventive measure.

Coronary heart disease in hypertensives: a need to reduce cholesterol.

Ten international long-term hypertension intervention trials between 1980 and 1987 have resulted in significant reduction in the incidence of stroke in the treatment groups. Yet, eight of these studies have shown disappointing results in the prevention of coronary heart disease (CHD). Five hypertension intervention trials revealed high average cholesterol values at baseline. No cholesterol treatment was provided and the incidence of CHD was high. In four other trials with stratification into 'low' and 'high' baseline cholesterol levels, the incidence of CHD was considerably less in the 'low' cholesterol groups. Only the 10th, the Gothenburg trial, has demonstrated a marked reduction in CHD by combining antihypertensive medication with cholesterol lowering treatment. Failure to reduce cholesterol in hypertensives with hypercholesterolaemia may be one explanation for the limited efficacy of antihypertensive treatment in the reduction of CHD. We postulate that successful treatment of hypercholesterolaemia will reduce the incidence of CHD in well-controlled hypertensive patients to the same extent as it lowers the incidence of CHD in normotensive people.

Raised lipoprotein(a) in hypercholesterolaemic black students compared to age-matched whites in North and South Carolina.

BACKGROUND: North and South Carolina are the states with the highest coronary death rates and also belong to the Stroke Belt of the US. From a Reflotron cholesterol screening in North and South Carolina schools, students with cholesterol levels > or = 4.66 mmol/l (> or = 180 mg/dl) were tested for high density lipoprotein (HDL), low density lipoprotein (LDL) and lipoprotein(a) (Lp(a)). METHODS: The 923 students aged 12-19 with mild hypercholesterolaemia represented one-third of the high school population, of whom 30% are black. Of the hypercholesterolaemic white students, 96% took the additional tests, of the hypercholesterolaemic black students, 88% responded. Lp(a) levels were determined by electroimmunodiffusion. RESULTS: Most important was a three-fold elevation of the geometric mean of Lp(a) values among blacks compared to whites: white males 9, white females 10, black males 25, black females 26 mg/dl, respectively, independent of age and sex. Relationships between Lp(a) and four other lipids/lipoproteins were examined and proved non-significant except for total cholesterol and LDL in black males and white females. While 70% of the white students displayed Lp(a) levels < 20 mg/dl, 65-70% of the black students showed Lp(a) levels > 20 mg/dl. CONCLUSIONS: Early identification of high Lp(a) levels may be of importance for two groups, (1) black females who have a 20% higher coronary heart disease mortality rate than white females in spite of significantly higher HDL levels; and (2) for black males and black females who have a prevalence of cerebrovascular disease twice as high as in whites.

Prospective study of "fibrocystic breast disease" and caffeine consumption.

Conflicting reports have appeared in the recent literature on a presumed association between coffee intake and "fibrocystic breast disease." The hypothesis suggesting that abstention from coffee and caffeine consumption eliminates breast pain and resolves breast nodules was based on an uncontrolled clinical study. For a condition with a notorious reputation for "waxing and waning," it is essential to document the stability versus instability of clinical findings, keeping the methyl xanthine consumption constant. Seventy-two women, all with palpable breast nodules, were followed over a 6-month period with monthly examinations and questionnaires on intake of coffee, tea, soft drinks, chocolate, candies, and caffeine-containing drugs. The methyl xanthine consumption remained remarkably constant throughout the observation time. The examiner was uninformed as to previous examination findings and pain reports of each woman. In 21 (15%) breasts with nodularity, the nodules had completely disappeared by the termination of the study. A total of 125 (87%) breasts of the sample manifested a change in the number of nodules or a change in position. Forty-eight of the 72 women were menopausal. For a chronic condition with so much variety of subjective sensitivity and great variability of objective clinical palpation, it is difficult to relate the amount of methyl xanthine consumption to "fibrocystic breast disease."

Effect of coffee on cholesterol and apolipoproteins, corroborated by caffeine levels.

The possibility that coffee may increase cholesterol levels has created uncertainty among physicians. The confusion arose from cross-sectional studies, in which female coffee drinkers appeared to show a positive association more frequently than men. To clarify this relationship, we designed an intervention trial to reduce caffeine and coffee intake sequentially while measuring total cholesterol and the apolipoprotein A-I and B levels. We conducted the study among women who were coffee drinkers (n = 35) or not coffee drinkers (n = 28). The trial spanned seven months with caffeine-free and coffee-free intervals. Serum caffeine levels corroborated compliance with the dietary protocol. Analysis of the apolipoprotein levels confirms the absence of any influence of coffee on lipoproteins in normocholesterolemic persons. We observed no apparent causal association of coffee or caffeine consumption and cholesterol and apolipoproteins.

The workinghman's diet. II. Effect of weight reduction in obese patients with hypertension, diabetes, hyperuricemia and hyperlipidemia.

Weight reduction is almost always successful in cases of essential hypertension if and when the weight loss is accompanied by a drastic sodium reduction. (2) Weight normalization is of remarkable help in complete reversal of abnormal glucose tolerance, decrease in insulin requirement in manifest diabetes mellitus, and - in many patients with mild diabetes - discontinuation of oral hypoglycemic agents. (3) Weight loss will occasionally relieve gout patients of their symptoms. The majority of hyperuricemic patients will benefit with a lowering of serum uric acid levels. (4) An unresolved issue is the influence of weight reduction on the cholesterol metabolism - short- and long-term results are by no means predictable. Whereas the triglycerides in obese patients almost always return to lower serum concentrations, and with them the hyperlipoproteinemias of type IIB, III and IV, the type IIA is only rarely seen in association with obesity. Therefore, information on this lipid abnormality is very limited regarding the effect of weight loss.

Dietary effects on blood pressure.

Low density potassium intake, particularly among black hypertensive patients, appears to contribute significantly to this disease and its major sequellae. The high sodium intake of industrialized societies and the epidemic prevalence of hypertension must be considered in the light of a relatively greater urinary potassium excretion as compared to a low-sodium diet with a lower urinary potassium excretion. There is no reason to assume that weight reduction per se is the major contributor to lowering of elevated blood pressure levels although claims to this effect have been made. In general, a high-caloric diet is loaded with sodium while a low-energy diet has a drastically reduced sodium content. The hypothesis that a higher dietary linoleic acid intake via increased prostaglandin synthesis may lead to natriuresis and a drop in blood pressure levels is an interesting development which needs more testing.