Atypical cofilin signaling drives dendritic cell migration through the extracellular matrix via nuclear deformation

To mount an adaptive immune response, dendritic cells must migrate to lymph nodes to present antigens to T cells. Critical to 3D migration is the nucleus, which is the size-limiting barrier for migration through the extracellular matrix. Here, we show that inflammatory activation of dendritic cells leads to the nucleus becoming spherically deformed and enables dendritic cells to overcome the typical 2- to 3-μm diameter limit for 3D migration through gaps in the extracellular matrix. We show that the nuclear shape change is partially attained through reduced cell adhesion, whereas improved 3D migration is achieved through reprogramming of the actin cytoskeleton. Specifically, our data point to a model whereby the phosphorylation of cofilin-1 at serine 41 drives the assembly of a cofilin-actomyosin ring proximal to the nucleus and enhances migration through 3D collagen gels. In summary, these data describe signaling events through which dendritic cells deform their nucleus and enhance their migratory capacity.

FIRRM/C1orf112 is synthetic lethal with PICH and mediates RAD51 dynamics

Joint DNA molecules are natural byproducts of DNA replication and repair. Persistent joint molecules give rise to ultrafine DNA bridges (UFBs) in mitosis, compromising sister chromatid separation. The DNA translocase PICH (ERCC6L) has a central role in UFB resolution. A genome-wide loss-of-function screen is performed to identify the genetic context of PICH dependency. In addition to genes involved in DNA condensation, centromere stability, and DNA-damage repair, we identify FIGNL1-interacting regulator of recombination and mitosis (FIRRM), formerly known as C1orf112. We find that FIRRM interacts with and stabilizes the AAA⁺ ATPase FIGNL1. Inactivation of either FIRRM or FIGNL1 results in UFB formation, prolonged accumulation of RAD51 at nuclear foci, and impaired replication fork dynamics and consequently impairs genome maintenance. Combined, our data suggest that inactivation of FIRRM and FIGNL1 dysregulates RAD51 dynamics at replication forks, resulting in persistent DNA lesions and a dependency on PICH to preserve cell viability.

5-Ethynyluridine: A Bio-orthogonal Uridine Variant for mRNA-Based Therapies and Vaccines

The identification of pseudo- and N¹ -methylpseudo-uridine (Ψ and mΨ, respectively) as immunosilent uridine analogues has propelled the development of mRNA-based vaccines and therapeutics. Here, we have characterised another uridine analogue, 5-ethynyluridine (EU), which has an ethynyl moiety. We show that this uridine analogue does not cause immune activation in human macrophages, as it does not induce interleukin-6 secretion or expression of the inflammatory and antiviral genes MX1, PKR, and TAP2. Moreover, EU allows for prolonged expression, as shown with mRNA coding for yellow fluorescent protein (YFP). Side-by-side comparisons of EU with unmodified, Ψ, and mΨ revealed that EU-modified mRNA is expressed at lower levels, but confers similar stability and low immunogenicity to the other uridine analogues. Furthermore, structure analysis of modified mRNAs suggests that the observed phenotype is largely independent of RNA folding. Thus, EU is a potential candidate for RNA-based vaccines and therapeutics.

Rerouting trafficking circuits through posttranslational SNARE modifications

Soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) are membrane-associated trafficking proteins that confer identity to lipid membranes and facilitate membrane fusion. These functions are achieved through the complexing of Q-SNAREs with a specific cognate target R-SNARE, leading to the fusion of their associated membranes. These SNARE complexes then dissociate so that the Q-SNAREs and R-SNAREs can repeat this cycle. Whilst the basic function of SNAREs has been long appreciated, it is becoming increasingly clear that the cell can control the localisation and function of SNARE proteins through posttranslational modifications (PTMs), such as phosphorylation and ubiquitylation. Whilst numerous proteomic methods have shown that SNARE proteins are subject to these modifications, little is known about how these modifications regulate SNARE function. However, it is clear that these PTMs provide cells with an incredible functional plasticity; SNARE PTMs enable cells to respond to an ever-changing extracellular environment through the rerouting of membrane traffic. In this Review, we summarise key findings regarding SNARE regulation by PTMs and discuss how these modifications reprogramme membrane trafficking pathways.

Mitochondrial interaction of fibrosis-protective 5-methoxy tryptophan enhances collagen uptake by macrophages

5-methoxy tryptophan (5-MTP) is an anti-fibrotic metabolite made by fibroblasts and epithelial cells, present in a micromolar concentrations in human blood, and is associated with the progression of fibrotic kidney disease, but the mechanism is unclear. Here, we show by microscopy and functional assays that 5-MTP influences mitochondria in human peripheral blood monocyte-derived macrophages. As a result, the mitochondrial membranes are more rigid, more branched, and are protected against oxidation. The macrophages also change their metabolism by reducing mitochondrial import of acyl-carnitines, intermediates of fatty acid metabolism, driving glucose import. Moreover, 5-MTP increases the endocytosis of collagen by macrophages, and experiments with inhibition of glucose uptake showed that this is a direct result of their altered metabolism. However, 5-MTP does not affect the macrophages following pathogenic stimulation, due to 5-MTP degradation by induced expression of indole-amine oxygenase-1 (IDO-1). Thus, 5-MTP is a fibrosis-protective metabolite that, in absence of pathogenic stimulation, promotes collagen uptake by anti-inflammatory macrophages by altering the physicochemical properties of their mitochondrial membranes.

Control of adhesion and protrusion in cell migration by Rho GTPases

Cell migration is a critical process that underpins a number of physiological and pathological contexts such as the correct functioning of the immune system and the spread of metastatic cancer cells. Central to this process are the Rho family of GTPases, which act as core regulators of cell migration. Rho GTPases are molecular switches that associate with lipid membranes and act to choreograph molecular events that underpin cell migration. Specifically, these GTPases play critical roles in coordinating force generation through driving the formation of cellular protrusions as well as cell-cell and cell-matrix adhesions. Here we provide an update on the many roles of Rho-family GTPases in coordinating protrusion and adhesion formation in the context of cell migration, as well as describing how their activity is controlled to by a variety of complex signalling networks.

Iliad: Moving Medical Decision-Making into New Frontiers

If the essence of clinical practice is a process of sequential problem-solving, whereby a physician works with a patient to formulate a series of decisions about diagnostic treatment, then it would naturally follow that the essence of medical education should evolve around the training of would-be clinicians in the difficult art of diagnostic decisionmaking. Yet this is not often the case.

Can Health/Medical Informatics be Regarded as a Separate Discipline?

The participants of the panel on education and training in Medical Informatics, concurred that health/medical informatics is today thriving as a separate discipline, despite inevitable uncertainties regarding the future. Conferees discussed the distinctions between physician-built systems and those designed by medical informaticians, focusing on methodology as critical to medical informatics.

Acceptability of Queso Fresco Cheese by Traditional and Nontraditional Consumers

Four replicate batches of high- and low-salt queso fresco cheeses were made to comnpare consumer preferences. Seven trained panelists judged specific attributes of the eight cheeses. Untrained consumers (395) at three Washington state locations noted how much they liked or disliked the same cheeses. Thirty-three percent of the surveyed population was Hispanic, and 45% were familiar with queso fresco. All cheeses, except the one containing the highest percent salt and the highest pH, were liked slightly to moderately. Traditional consumers (either Hispanic or those familiar with queso fresco) preferred high-saltlhigh-pH cheeses to a greater extent than nontraditional consumers. Nontraditional consumers preferred low-salt/low-pH cheeses. The same preference trends were noted for all ages and at all three geographical locations. Queso fresco with 1.4-2.4% salt and a pH between 5.4-6.1 was most acceptable to the widest range of consumers.

The Rotational Spectra, Structure, Internal Dynamics, and Electric Dipole Moment of the Argon-Ketene van der Waals Complex

Pulsed-beam Fourier transform microwave spectroscopy was used to observe and assign the rotational spectra of the argon-ketene van der Waals complex. Tunneling of the hydrogen or deuterium atoms splits the a- and b-type rotational transitions of H(2)CCO-Ar, H(2)(13)CCO-Ar, H(2)C(13)CO-Ar, and D(2)CCO-Ar into two states. This internal motion appears to be quenched for HDCCO-Ar where only one state is observed. The spectra of all isotopomers were satisfactorily fit to a Watson asymmetric top Hamiltonian which gave A=10 447.9248(10) MHz, B=1918.0138(16) MHz, C=1606.7642(15) MHz, Delta(J)=16.0856(70) kHz, Delta(JK)=274.779(64) kHz, Delta(K)=-152.24(23) kHz, delta(J)=2.5313(18) kHz, delta(K)=209.85(82) kHz, and h(K)=1.562(64) kHz for the A(1) state of H(2)CCO-Ar. Electric dipole moment measurements determined &mgr;(a)=0.417(10)x10(-30) C m [0.125(3) D] and &mgr;(b)=4.566(7)x10(-30) C m [1.369(2) D] along the a and b principal axes of the A(1) state of the normal isotopomer. A least squares fit of principal moments of inertia, I(a) and I(c), of H(2)CCO-Ar, H(2)(13)CCO-Ar, and H(2)C(13)CO-Ar for the A(1) states give the argon-ketene center of mass separation, R(cm)=3.5868(3) Å, and the angle between the line connecting argon with the center of mass of ketene and the C=C=O axis, θ(cm)=96.4 degrees (2). The spectral data are consistent with a planar geometry with the argon atom tilted toward the carbonyl carbon of ketene by 6.4 degrees from a T-shaped configuration. Copyright 2001 Academic Press.

Modeling empiric antibiotic therapy evaluation of QID

At AMIA 1997, we reported on the design and development of a new computer-based tool, called QID, for empiric antibiotic decision support. QID was designed to help physicians identify the antibiotic regimens with the highest probability of covering the pathogens that are most likely to be present in individual patients. QID creates a list of antibiotics, ordered by potential benefit in treatment, for a patient with a suspected infection before culture results are available. Since our initial publication, a "before and after" study has been done using 20 internal medicine residents and the same number of internal medicine attendings. In order to test the hypothesis that physician's would make more appropriate empiric antibiotic choices with the aid of QID, we chose University of Utah physicians and had each evaluate four infectious disease cases that were abstracted from medical record infectious disease cases. Immediately following their initial review and determination of antibiotic therapy for each case, the study participants were presented with QID's antibiotic recommendations on the same case to see if this information would change their initial drug regimen. The tool was shown to have a greater impact on the most difficult cases but statistically improved scores overall (p < .001). Details of our study design and results are presented.

Ion-exchange column chromatographic method for assaying purine metabolic pathway enzymes

High energy phosphate levels fall rapidly during cardiac ischemia and recover slowly (more than one week) during reperfusion. The slow recovery of ATP may reflect a lack of purine metabolic precursors and/or increased activity of purine catabolic enzymes such as 5'-nucleotidase (5'-NT, EC 3.1.3.5) and adenosine deaminase (ADA, EC 3.5.4.4). The activity of enzymes involved in both the catabolism of ATP precursors (5-NT and ADA) and the restoration of ATP from slow synthetic pathways [adenosine kinase (AK, EC 2.7.1.20), adenine phosphoribosyl transferase (APRT, EC 2.4.2.7) and hypoxanthine phosphoribosyl transferase (HPRT, EC 2.4.2.8)] may directly affect the rate of ATP recovery. Strategies to enhance recovery will depend on the relative activity of these enzymes following ischemia. Their activity in different species and their response to ischemia are not well characterized. Hence, rapid assay methods for these enzymes would facilitate detailed time course studies of their activities in postischemic myocardium. We modified a single ion-exchange column chromatographic method using DEAE-Sephadex to determine the products of incubation of 5'-NT, AK, APRT and HPRT with their respective substrates. The uniformity of the final product measurement procedure for all assays permits the activities of the four enzymes to be rapidly determined in a single tissue sample and facilitates the study of a large number of samples. This technique should also be useful for enzymes of the pyrimidine metabolic pathway.

New computer-based tools for empiric antibiotic decision support

Since 1995 we have been developing a decision-support model, called Q-ID, which uses a series of infectious disease knowledge bases to make recommendations for empirical treatment or to check the appropriateness of current antibiotic therapy. From disease manifestations and risk factors, a differential diagnosis for the patient is generated by a diagnostic medical expert system. The resulting probability of each: disease is multiplied by the expected benefit in improved mortality and morbidity from optimal antibiotic treatment of each disease. To generate empirical treatment recommendations, site-specific data on sensitivity to antibiotics of each organism is used as an estimate of the likelihood of achieving maximum benefit for each disease on the patient's differential. Combining this data with drug and patient specific factors, the model recommends the antibiotic(s) most likely to produce the optimal benefit in this patient with the least risk and expense. In this paper the model is described, excerpts from each of the knowledge bases are presented, and performance of the model in a real case is shown for illustration.

Can health/medical informatics be regarded as a separate discipline?

The participants of the panel on education and training in Medical Informatics, concurred that health/medical informatics is today thriving as a separate discipline, despite inevitable uncertainties regarding the future. Conferees discussed the distinctions between physician-built systems and those designed by medical informaticians, focusing on methodology as critical to medical informatics.

Implementation of practice guidelines in a clinical setting using a computerized knowledge base (Iliad)

We present the implementation of the indications for surgery for three surgical operations--cholecystectomy, cataract extraction, and knee arthroscopy--in a medical expert system, called Iliad. This implementation operates in the preauthorization service of IHC Health Plans (an insurance company in Salt Lake City) as a basis for reimbursement of services. Patient data collection forms, derived from Iliad knowledge base, were used by 13 participating surgeons to document the objective patient observations that justify the surgery and, then were faxed to IHC where a trained nurse input the data in Iliad. Iliad's decisions and reports on any deviations from guidelines are communicated back to the care provider. The study evaluates the impact of the computerized implementation on process, as measured by a questionnaire, and on outcome as measured by rate of approvals, documentation level, rate of requests, and average cost. The prospective implementation of the computerized guidelines has performed reliably, has been perceived as a preferred alternative to the old preauthorization system, and, most importantly, has enhanced significantly the level of documentation permitting evaluation and determination of appropriateness before surgery.

Iliad training effects: a cognitive model and empirical findings

Iliad is a diagnostic expert system consisting of an "inference engine" (collection of rules and procedures for making decisions) and a "knowledge base" (collection of medical facts). Iliad's internal medicine knowledge base recognizes 5000 medical findings and covers 1150 diagnostic conditions in 10 subspecialty fields. We used Iliad's simulator mode to train diagnostic skills in junior-year medical students. The results corroborate previous findings documenting Iliad's teaching efficacy. Recent developments in cognitive psychology provide a framework for explaining Iliad's training effects.

Estimating frequency of disease findings from combined hospital databases: a UMLS project

Merging data from the Salt Lake VA hospital database and the LDS hospital HELP system into a UMLS sponsored unified patient database has demonstrated that distribution of variables within a disease is hospital independent. Although disease prevalence is clearly not the same among hospitals, analysis of data within a disease group across hospitals can be done using such a merged database. This unified patient database would allow study of unusual diseases not possible using data from a single institution.

Electroejaculation in spinal cord injury patients: simplified new equipment and technique

A new simplified electrostimulation system for rectal probe electroejaculation has been developed and tested 17 times in 13 patients. Seminal emissions were obtained easily from 13 of 17 studies and partial emissions were obtained in 4. Patients with cauda equina and conus lesions with partial intact sensorium also could achieve successful ejaculation by longer stimulation from 2 to 5 minutes with lower currents that could be maintained easily and were tolerated by the patient--a feature unique to our new computerized equipment. The simplicity of operation reduces the number of trained personnel for an electrostimulation procedure, which can be done even in an outpatient setting.

Electrostimulation of erection and ejaculation and collection of semen in spinal cord injured humans

An electrostimulation system developed for early research with humans and the great apes, and a new constant-current stimulator specifically developed for human use, have been employed in studies with paraplegic men to produce erection and semen release by rectal probe electrostimulation (RPE). Catheter techniques for antegrade collection of the semen, uncontaminated by urine, have also been applied with moderate success. Details of the electronic instrumentation and catheter techniques are given. The procedure used with the patients and electrostimulation and semen collection results are presented.

Reproductive biology of paraplegics: results of semen collection, testicular biopsy and serum hormone evaluation

The fertility and urological status of 30 male paraplegics between 20 and 47 years old with lesions between the T2 and L3 levels were examined by studying serum hormone levels (estradiol-17 beta, testosterone, prolactin, and follicle-stimulating and luteinizing hormones), sperm and semen characteristics via testicular biopsy and rectal probe electrostimulation, and urodynamic evaluation. Of the patients 13 had reflexic, 4 hyperreflexic and 13 areflexic bladders. Nine of the 13 patients with reflexic and all 4 with hyperreflexic bladders had a positive external sphincter electromyogram with detrusor-sphincter dyssynergia. When catheters were not used to collect semen during rectal probe electrostimulation, retrograde semen flow into the bladder was the rule. A total of 22 patients could tolerate rectal probe electrostimulation, while 6 who could not were injured at the T12 level or lower. Seminal emissions were obtained from 35 to 42 studies in these 22 patients. Total sperm count was variable; in 22 studies it was greater than 20 million. Progressive motility usually was low; 77 per cent of the patients had less than 20 per cent motility. Of 13 biopsy specimens obtained 6 suggested normal testicular morphology, with tubule atrophy and spermatogenic activity only mildly reduced in 6 of the remaining 7. Serum testosterone and luteinizing hormone values were significantly higher (p less than 0.05) among the paraplegic patients than among intact male volunteers of the same age range. Other serum hormone levels were unchanged. Outcome of rectal probe electrostimulation and biopsy did not relate to the number of years of patient injury. Thus, the principal deterrent to the use of semen collected by rectal probe electrostimulation from paraplegics for artificial insemination resides in a predominantly low sperm motility. Suggestions for improvement of motility include 1) great care to minimize or prevent urinary tract infections, 2) selection of medications for urinary tract care that do not compromise sperm survival and 3) prevention of sperm stagnation in lower tract storage sites, perhaps by use of periodical rectal probe electrostimulation.

Initiation of erection and semen release by rectal probe electrostimulation (RPE)

Instrumentation and methodology are described for rectal probe electrostimulation (RPE) in human males to elicit erection and allow semen collection. This system virtually eliminates shock hazard; the simultaneous monitoring of current, voltage and impedance ensures reliability and repeatability. It was tested with 8 neurologically intact subjects, and 12 paraplegic patients with lesions between T4 and L2. Platinum electrodes delivered current (density never exceeding 0.37 mA per mm. at the electrode) at frequencies of 60 Hz, 20 Hz, and 0.25 Hz. Erection was elicited repeatably in only 1 of the intact subjects, and no seminal emissions or ejaculations occurred. Discomfort prevented current delivery beyond levels even 50 per cent of those safely acceptable. Six of 10 paraplegic patients (2 others had penile implants) developed erections with 20 Hz; the other 2 frequencies were much less effective. The extent of RPE-induced penile tumescence varied directly with electrode surface area and applied current intensity. Discomfort was minimal. Retrograde seminal emission in 5 of the 12 paraplegics was verified by post-stimulation recovery of sperm via voiding or bladder irrigation via catheter. Although motility was very low, 4 of 8 recovered bladder-urine/seminal fluid specimens indicated sperm counts and morphology consonant with use in artificial insemination. Thus, RPE, if combined with techniques to allow antegrade semen collection, may be a useful technique for spinal cord-injured men who, as part of their sexual rehabilitation, are interested in siring children.

Partial purification and characterization of a uracil-DNA glycosylase from wheat germ

A uracil-DNA glycosylase has been purified over 1,000-fold from wheat germ, the first such repair activity isolated from a higher plant. The enzyme has a molecular weight of approximately 27,000 and is resistant to metal ion chelators, but inhibited by high concentrations of either mono or divalent cations. This glycosylase is unable to release uracil from the mononucleotides dUMP and dUTP or from wheat germ RNA. Twelve pyrimidine analogues which closely mimic uracil structurally and the nucleoside uridine were examined for their ability to inhibit glycosylase activity. However, only 5-azauracil and 6-aminouracil inhibited enzymatic release of uracil to the same degree as uracil itself. An inhibitor induced by bacteriophage T5 which inhibits Escherichia coli uracil-DNA glycosylase has been shown not to affect the glycosylase isolated from wheat germ, indicating that these two enzymes differ. The ability of the wheat germ uracil-DNA glycosylase to completely remove available uracil from synthetic DNA substrates in which thymine had been replaced by uracil in varying percentages was also examined and found not to depend on percentage of uracil in the substrates.

Effects of glucose on insulin release and on intermediary metabolism of isolated perifused pancreatic islets from fed and fasted rats

We examined the relationship between glucose-induced insulin release and the intermediary metabolism of islets from fed and fasted rats. Isolated islets were perifused and insulin release measured in the effluent. At various times after switching islets from 2.4 to 8.6 or 14.5 mM glucose or from 2.4 to 14.5 and back to 2.4 mM glucose, islets were quickly frozen, freeze dried, and subsequently analyzed for tissue content of glucose-6-P, fructose-1,6-P2 plus triose-P, Pi, ATP, ADP, 5'-AMP, NADH, NADPH, total NAD, and total NADP using enzymatic fluorometric procedures. When islets from fed rats were exposed to high glucose, there were concomitant increases of insulin release and islet content of glucose-6-P, fructose-1,6-P2 plus triose-P, NADH, and NADPH. During stimulation Pi and 5'-AMP content fell markedly. The total adenine nucleotide content remained constant. Similar secretory and metabolic changes occurred when 1.5 mM Pi was added to the perifusion fluid. When glucose-stimulated islets were switched back to low glucose for 10 min, all substances but fructose-1,6-P2 plus triose-P, 5'-AMP, NADPH, and possibly ATP returned to the prestimulatory level. Starvation of rats for 3 days blocked the secretory response to 8.6 mM glucose. Fructose-1,6-P2 plus triose-P rose but it did not attain the level existing in islets from fed rats. The ratios (ATP)/(5'-AMP) and (ATP)/(Pi)(adp) increased to the values observed in glucose-stimulated islets of fed rats. The metabolic changes in islets from fed rats exposed to high glucose are consistent with an activation of glycolysis occurring concomitantly with stimulated rates of insulin release. This occurs despite the decrease of important activators of glycolysis--Pi and 5'-AMP. The enhanced glycolysis possibly results from P-fructokinase activation by increased fructose-6-P levels. Activation of glycolysis with 8.6 mM glucose was not as pronounced in islets from starved rats. Despite the different secretory response of islets from fet and fasted rats, the changes of phosphorylation state in the islets, in particular, Pi and 5'-AMP levels, were similar.

Myocardial infarct imaging with 99mTc-pyrophosphate and 99mTc-methylene diphosphonate: lack of correlation

A prospective study of eight patients with recent transmural myocardial infarction was performed using 99mTc-Sn-pyrophosphate and 99mTc-Sn-methylene diphosphonate in each patient. All pyrophosphate scans were strongly positive whereas the diphosphonate scan was strongly positive in only one case. We conclude that 99mTc-Sn-pyrophosphate is preferable to 99mTc-Sn-methylene diphosphonate for myocardial imaging.

Relationship between diazepam dose, plasma level, age, and central nervous system depression

Patients undergoing elective cardioversion for treatment of arrhythmias were premedicated with diazepam. The dose was individualized to achieve a degree of central nervous system CNS) depression characterized by response to painful but not vocal stimulation. Promptly following each cardioversion, blood was drawn and the plasma diazepam concentration was measured by gas chromatography. The plasma levels varied as widely as the diazepam doses so that there was no fixed plasma level of diazepam associated with the degree of CNS depression produced in these patients. However, both the dose of diazepam and the resulting plasma level were inversely correlated to age, indicating that age is a critical factor in the use of diazepam for cardioversion premedication; elderly are more sensitive to the depressant effects of this drug than the young.

Rectal probe electroejaculation of primates

The technique of rectal probe electroejaculation has been developed to permit collection of semen using equipment proven safe, simple, and effective on the 30 primate species so far tested. This paper provides information on the construction and operation of this equipment, together with electrical parameters applicable to primate species. Seminal emission or ejaculation occurs in all species when alternating current is delivered at 0.25 mA/mm2 electrode area. The most effective frequency is 20 Hz, and the most acceptable anesthetic is ketamine hydrochloride.

The association between basal body temperature, sexual swelling and urinary gonadal hormone levels in the menstrual cycle of the chimpanzee

Basal body temperature (BBT) was measured continuously by radiotelemetry throughout 14 chimpanzee menstrual cycles and correlated with daily observations of the sexual skin swelling. A biphasic BBT shift from a pre-nadir mean of 36-12 degrees C to a post-nadir mean of 36-67 degrees C was observed in 12 cycles. The temperature nadir showed a close temporal relationship with detumescence of the sexual skin swelling (an early luteal event), but the rate of temperature rise after the nadir was variable. In 3 normal cycles studied, the temperature nadir occurred the day after a urinary oestrone peak, but there was no consistent temporal association between BBT rise and pregnanediol increment. Progesterone secretion is therefore probably not the sole determinant of the BBT shift; the changing oestrogen/progestin ratio may be the more important factor regulating body temperature during the luteal phase.

Conversations with a chimpanzee in a computer-controlled environment

The linguistic-type skills of a young chimpanzee (Pan) acquired in a computer-controlled language-training situation are reviewed. Those skills include facile acquisition of vocabulary, object naming, color naming, appropriate use of "yes" and "no" in response to certain questions, and conversation. In conversations the subject has formulated novel sentences and without special training has asked that objects be named, whereupon requests were made that they be given to her. These findings are interpreted in terms of how enriched environments can serve to bring forth novel communication skills in the chimpanzee, which is otherwise alinguistic; how the challenge of the environment can serve to limit manifest intelligence; and how a cognitive, rather than the traditional stimulus-response, framework is required for understanding the communication skills and psychological processes of the chimpanzee.

Assessment of ventricular function in coronary artery disease using nitroglycerin and computerized analysis of left ventriculograms

The ability to predict if abnormalities in regional wall motion are reversible would assist in selecting patients for aortocoronary bypass operation. This study shows that asynergic areas of the ventricle may be reversed by nitroglycerin. Thirty-four asynergic areas in 30 patients with coronary artery disease were studied before and after administration of nitroglycerin. Nineteen patients with previous infarction, diagnostic Q waves in their electrocardiogram, and akinetic areas in the left ventricle had no change in their akinetic areas after nitroglycerin administration. Nine of these patients did show increased motion in other hypokinetic areas of the myocardium. Five of 11 patients with no evidence of previous infarction showed a dramatic improvement in akinetic areas after nitroglycerin, while of the remaining 6, 5 showed mild improvement. This illustrates that recoverable asynergic areas may be recognized by nitroglycerin.

Cytochemical response of kidney, liver and nervous system of fluoride ions in drinking water

Morphological and cytochemical studies on the squirrel monkey have been made after maintaining the sujects on pure distilled water and fluoridated distilled water for 18 months with the objective of determining the effect of fluoride on the activity of some hydrolytic and oxidative enzymes in the kidney, liver and nervous system. Daily water intake by individual animals was measured over the final 10 months of the animal's exposure to 0,1 and 5 ppm fluoride. Water consumption was considerably higher in the animals on higher fluoride intake. Whereas the nervous system remained totally unaffected by this experimental procedure, the liver showed a slightly enhanced acivity of Krebs citric acid cycle enzymes. The kidneys, however, showed significant cytochemical changes, especially in the animals on 5 ppm fluoride intake in their drinking water. In these animals, the glomeruli showed an increase in the activity of acid phosphatase and the enzymes belonging to the citric acid cycle and the pentose shunt, whereas lactate dehydrogenase, a resentative of the anaerobic glyoclytic pathway, remained unchanged or only slightly changed. These observations suggest that fluoride in concentrations as low as 5 ppm interferes to some extent with the intracellular metabolism of the excretory system.

Polymorphic acetylation procainamide in man

N-Acetylprocainamide (NAPA) and procainamide plasma and urine concentrations were determined by thin-layer chromatography (TLC) densitometry in people of known acetylator phenotype (dapsone phenotyping) taking procainamide for more than 3 days. The plasma NAPA/procainamide ratio 3 hr after the last dose for fast acetylators (mean plus or minus SD) is 1.8 plus or minus 0.59 (N equal to 8) and for slow acetylators, 0.61 plus or minus 0.09 (N equal to 6) P smaller than 0.001). The renal clearance of NAPA averaged 1.2 times the simultaneously measured endogenous creatinine clearance, whereas procainamide clearance was approximately double the creatinine clearance. There was no difference between slow and rapid acetylators in the renal clearance of either drug or the urine pH, indicating that the difference in plasma NAPA/procainamide ratios between these two groups is due to differences in their rates of acetylation. Therefore, procainamide is probably acetylated by the polymorphic N-acetyltransferase in man. Reflecting the blood level differences, the NAPA/procainamide ratio in urine (collected 99 to 180 min after last dose) was found to be higher in rapid than in slow acetylators. The plasma protein binding of NAa and of procainamide are similar. Since NAPA seems to have an antiarrhythmic potency similar to procainamide, NAPA probably contributes to the antiarrhythmic activity of procainamide therapy, especially in genetic rapid acetylators.