Linking physiology and biomineralization processes to ecological inferences on the life history of fishes.

Biomineral chemistry is frequently used to infer life history events and habitat use in fishes; however, significant gaps remain in our understanding of the underlying mechanisms. Here we have taken a multidisciplinary approach to review the current understanding of element incorporation into biomineralized structures in fishes. Biominerals are primarily composed of calcium-based derivatives such as calcium carbonate found in otoliths and calcium phosphates found in scales, fins and bones. By focusing on non-essential life elements (strontium and barium) and essential life elements (calcium, zinc and magnesium), we attempt to connect several fields of study to synergise how physiology may influence biomineralization and subsequent inference of life history. Data provided in this review indicate that the presence of non-essential elements in biominerals of fish is driven primarily by hypo- and hyper-calcemic environmental conditions. The uptake kinetics between environmental calcium and its competing mimics define what is ultimately incorporated in the biomineral structure. Conversely, circannual hormonally driven variations likely influence essential life elements like zinc that are known to associate with enzyme function. Environmental temperature and pH as well as uptake kinetics for strontium and barium isotopes demonstrate the role of mass fractionation in isotope selection for uptake into fish bony structures. In consideration of calcium mobilisation, the action of osteoclast-like cells on calcium phosphates of scales, fins and bones likely plays a role in fractionation along with transport kinetics. Additional investigations into calcium mobilisation are warranted to understand differing views of strontium, and barium isotope fractionation between calcium phosphates and calcium carbonate structures in fishes.

Disease burden in four populations of dog and cat breeds compared to mixed-breed dogs and European shorthair cats.

Current public and professional opinion is that many dog breeds suffer from health issues related to inherited diseases or extreme phenotypes. The aim of this historical comparative observational study was to evaluate the breed-related disease burden in three purebred dog populations (Chihuahua, French bulldog, Labrador retriever) and one purebred cat breed (Persian cats) in the Netherlands by comparison to a control population of mixed-breed dogs and European Shorthair cats. A qualitative query was performed, consisting of a literature review and collecting the expert opinions of University veterinary specialists, to gather insight into potential diseases of the study population. Next, a referral clinic case control study of the patients referred to specific medical disciplines in the University Clinic was performed. The odds ratio (OR) was calculated to determine the likelihood of a patient referred to a particular medical discipline being a certain breed. Together, the qualitative query and the case control study resulted in a list of potentially relevant diseases limited to five organ systems per breed. These were analysed in data from primary practices. Patient files from ten primary practices over a period of two years were manually extracted and examined. Four-hundred individual patient records per breed as well as 1000 non-breed records were randomly selected from the 10 practices, weighted per practice size. Records were then examined and the presence or absence of certain diseases was identified. To evaluate the disease burden per breed, proportional difference (PD) was estimated, as well as the animal's age at presentation in months. The results of the referral clinic case control study showed an overrepresentation (Odds Ratio>1.5) of the selected breeds in several medical specialties, while median age at presentation was in some cases significantly lower than in the non-breed animals. Results of the practice-based extended cross-sectional study showed that only a few of the selected diseases contribute to the disease burden in these purebred populations, which was different from the expectations derived from the literature or expert opinion. Additional results included age difference at presentation, which may be interpreted as age of onset, and could indicate a higher disease burden for the individual animal. Also, only a small percentage of purebred dogs was registered with the national kennel club. Our final recommendation is that population-based data mining is needed to evaluate country-specific companion animal health and welfare.

Effects of benzyl alcohol on enzyme activities and D-glucose transport in kidney brush-border membranes.

Addition of increasing amounts of benzyl alcohol progressively reduced the steady-state anisotropies of diphenylhexatriene and trimethylammoniumdiphenylhexatriene in brush-border membranes from rat kidney. The decrease in order of membrane lipids, equivalent for 50 mM benzyl alcohol to that produced by a rise in temperature of approx. 6 degrees C, had no effect on the activities of alkaline phosphatase or gamma-glutamyltranspeptidase. On the other hand, benzyl alcohol markedly inhibited the D-glucose uptakes measured in the presence of a 100 mM sodium gradient. For concentrations less than 30 mM, benzyl alcohol reduced the Jmax without significant effects on Km, 22Na+ uptake or the vesicular volume of brush-border preparations. Comparable results were obtained substituting octanol for benzyl alcohol. Our data strongly suggest that, at constant temperature, the D-glucose carrier present in renal brush-border membranes is extremely sensitive to variations in membrane physical state.

Plasma immunoreactive relaxin levels in pregnant and nonpregnant women.

Immunoreactive relaxin was measured in plasma samples obtained from human volunteers utilizing the RIA procedure of Sherwood et al., as modified by O'Byrne and Steinetz for heterologous plasma samples. Immunoreactive hormone was not detected in samples obtained from men, and only rarely in plasma of nonpregnant women. Immunoreactive relaxin was present as early as the fourth week of pregnancy and was detectable throughout the course of gestation. Immunoreactive relaxin tended to be higher early in pregnancy, and there was no peak just before parturition as occurs in many other species. Our results are at variance with those of Bryant and coworkers, who reported high levels of immunoreactive relaxin in men and nonpregnant as well as pregnant women. The possible reasons for this discrepancy are presented.

The in vivo metabolism of 7 beta, 17-dimethyltestosterone-6,7-3H.

7 beta, 17-Dimethyltestosterone (17 beta-hydroxy-7 beta, 17-dimethyl-4-androsten-3-one) (I) was given to three subjects in oral doses of 400 mg per day for ten days. The initial dose contained the steroid tritiated in the 6 and 7 positions. Plasma levels and urinary excretion patterns were followed in all three subjects. Isolations were done on the urine, plasma, and stools of one patient. From the urine 7 beta, 17-dimethyl- 5 alpha-androstane-3 beta,17 beta-diol (VI) was isolated from the nonhydrolyzed fractions. Unchanged (I), 7 beta,17-dimethyl-5 beta-androstane-3 alpha,17 beta-diol (III) and 7 beta, 17-dimethyl-5 beta-androstane-3 beta,17 beta-diol (IV) were isolated from the nonhydrolyzed and enzyme-hydrolyzed fractions. 7 beta,17-dimethyl-5 alpha-androstane-3 alpha,17 beta-diol (V) was isolated from the enzymatic fractions. From the stools were isolated unchanged (I), (III), (IV), (V), and (VI). Unchanged (I) and its 5 alpha-dihydro derivative (17 beta-hydroxy-7 beta,17-dimethyl-5 alpha-androstan-3-one) (II) were identified in the plasma. The total recovery of radioactivity in the one patient on whom the isolations were done was 57%; 40% from the urine and 17% from the stools.

[Depression in rheumatic diseases or somatic symptoms in depression]. / Depression bei rheumatischen Erkrankungen oder körperliche Beschwerden bei Depression.

Depression can be produced in many different ways. Via cerebral nuclear-specific imbalance a depression can be associated with disturbances in nuclear regions regulating muscular tone. Such syndromes appear chiefly as syndromes of the cervical vertebral column or lumbal vertebral column or as a general "non-specific-pain-syndrome". Depression may also cause manifestations of "latent" rheumatic complaints by lowering the pain threshold. Chronic physical diseases may be assumed to produce depression via the "common pathway" (nuclear-specific imbalance of biogenic amines). Masked depression can assume the pattern of rheumatic pain syndrome and might be treated as such for a long time purely somatically (i.e. non-effectively because non-specifically).

Vertebral fractures as initial signs for acute lymphoblastic leukemia.

Common presenting symptoms of acute lymphoblastic leukemia in children are well known and include pallor, fatigue, and loss of appetite. Limb pain is sometimes described and can be misleading. We describe two recent cases seen in our emergency department, where vertebral fractures, a much rarer finding, were the only presenting symptoms that led to the diagnosis. One case had been thoroughly evaluated only 5 weeks prior to the diagnosis and included magnetic resonance imaging. The second patient was rapidly referred to our center with a history of acute lumbar pain. Emergency physicians caring for children must be aware of this rare type of presentation of leukemia.

Membrane fluidity and enzyme activities in brush border and basolateral membranes of the dog kidney.

The physical state of membrane lipids and relationships with the activity of Na+-K+-ATPase and alkaline phosphatase were studied in basolateral and brush border membranes of the dog kidney. Fluorescence polarization and electron spin resonance experiments demonstrate that basolateral membranes are much more fluid than brush border membranes. This can be accounted for by a difference in fluidity of the lipid part of the membranes. Broad (43-17 degrees C) thermotropic transitions are observed in liposomes made from total lipid extracts of brush border and basolateral membranes. Fluorescence data strongly suggest that thermotropic transitions also occur in intact membranes and that a change in membrane physical state may take place around the physiological temperature. A nonlinear Arrhenius plot for the Na+-K+-ATPase activity in basolateral membranes (breakpoint 21 degrees C) provides additional support for the existence of a lipid liquid leads to gel transition in antiluminal plasma membranes. A break in the Arrhenius plot of alkaline phosphatase activity is also observed but at a temperature significantly higher (26 degrees C) than that of the end of the thermotropic transition. "Room temperature" appears as a critical zone for lipid physical state and activities of both enzymes.

Gamma interferon can prevent herpes simplex virus type 1 reactivation from latency in sensory neurons.

We recently demonstrated that CD8(+) T cells could block herpes simplex virus type 1 (HSV-1) reactivation from latency in ex vivo trigeminal ganglion (TG) cultures without destroying the infected neurons. Here we establish that CD8(+) T-cell prevention of HSV-1 reactivation from latency is mediated at least in part by gamma interferon (IFN-gamma). We demonstrate that IFN-gamma was produced in ex vivo cultures of dissociated latently infected TG by CD8(+) T cells that were present in the TG at the time of excision. Depletion of CD8(+) T cells or neutralization of IFN-gamma significantly enhanced the rate of HSV-1 reactivation from latency in TG cultures. When TG cultures were treated with acyclovir for 4 days to insure uniform latency, supplementation with recombinant IFN-gamma blocked HSV-1 reactivation in 80% of cultures when endogenous CD8(+) T cells were present and significantly reduced and delayed HSV-1 reactivation when CD8(+) T cells or CD45(+) cells were depleted from the TG cultures. The effectiveness of recombinant IFN-gamma in blocking HSV-1 reactivation was lost when its addition to TG cultures was delayed by more than 24 h after acyclovir removal. We propose that when the intrinsic ability of neurons to inhibit HSV-1 gene expression is compromised, HSV-specific CD8(+) T cells are rapidly mobilized to produce IFN-gamma and perhaps other antiviral cytokines that block the viral replication cycle and maintain the viral genome in a latent state.

Calcium oxalate stone agglomeration reflects stone-forming activity: citrate inhibition depends on macromolecules larger than 30 kilodalton.

To evaluate the clinical utility of in vitro calcium oxalate monohydrate (COM) crystallization kinetics measurements and to determine the effect of quantitative removal of urinary Tamm-Horsfall glycoprotein on such measurements, we examined 24-hour, room temperature urine collections of patients from our Stone Clinic and of normal subjects from our research laboratories at Ochsner Medical Institutions in New Orleans, LA, and compared their COM kinetic parameters in vitro before and after urine ultrafiltration (30 kd). Data from 53 calcium oxalate stone-forming patients (26% women; mean age, 47 years) who demonstrated radiographic or other evidence of forming at least one stone were compared with data from 22 healthy volunteers (25% women; mean age, 40 years). Hypercalciuria (> 7.5 mm/24 hr), hyperoxaluria (> 0.5 mm/24 hr), and hypocitraturia (< 2.0 mm/24 hr) were present in 38%, 26%, and 26% of the patient population, respectively. Urinary creatinine, urate, calcium, citrate, phosphate, oxalate, pH, volume, total immunoreactive-disaggregated Tamm-Horsfall glycoprotein, and the urine's effects on COM solubility, percent crystal growth inhibition, and crystal agglomeration inhibition [tm] were determined. Calcium oxalate monohydrate agglomeration inhibition, [tm], was reduced in stone-forming patients. It decreased with increasing stone frequency, making [tm] a useful tool for measuring the risk of stone recurrence. Urinary Tamm-Horsfall glycoprotein and citrate concentrations were linearly related to COM agglomeration inhibition. Their effects were synergistic. Tamm-Horsfall glycoprotein removal from urine reduced COM agglomeration inhibition dramatically. Alkali therapy increased urinary citrate concentration and increased [tm].(ABSTRACT TRUNCATED AT 250 WORDS)