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Biomedical subjects

J Paul

Publications and source records attributed to J Paul.

392 records · Page 22Linked to original sources
PubMedDate not supplied

Molecular changes in Entamoeba histolytica in response to bacteria.

Entamoeba histolytica, the protozoan parasite, is the causative agent of amoebiasis. The degree of virulence, as inferred from invasiveness, of potentially pathogenic strains may be regulated by both host and parasite factors that determine the gut environment. One such factor that plays an important role is the bacterial flora in the gut. Previous studies have clearly shown that bacterial flora is an important determinant of virulence in E. histolytica. However, the exact nature of changes induced in E. histolytica in response to bacteria and their role in virulence is not clear. In this study the levels of a number of molecules potentially important in virulence mechanisms were determined in E. histolytica cells grown with and without normal human bacterial flora, using enzyme-linked immunosorbent assay. Significant changes were observed only after the E. histolytica cells had been adapted to grow with bacterial flora for a number of generations, and not in short term culture.

Animals↗
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Failure of short-term nutritional convalescence to reverse the adverse hemodynamic effects of protein-calorie malnutrition in dogs.

We previously reported that protein-calorie malnutrition (PCM) exerts adverse hemodynamic effects on left ventricular (LV) structure and function. In the present experiments, we tried to determine the duration of these adverse effects by inducing significant weight loss in matched beagle dogs followed by a short-term course of nutritional repletion. Following restitution of initial body weight, the animals were placed on total cardiopulmonary bypass and an isovolumetric LV preparation was established to determine baseline LV function compared with matched animals that remained normally-nourished, and with a third group in which the effects of PCM were not reversed. Decreases in LV compliance persisted following refeeding as did the decreases in the first derivative of LV pressure (LV dp/dt). Although animals re-fed ordinary diets following acute weight loss restored normal concentrations of myocardial glycogen, cardiac abnormalities persited for more than one month following refeeding. These results suggest that the adverse effects of semistarvation on LV functions cannot be completely reversed by short-term refeeding.

Animals↗
PubMedDate not supplied

Loss of motion after anterior cruciate ligament reconstruction.

We did a retrospective review and follow-up examination to investigate the incidence, risk factors, and outcome of patients who developed loss of motion after arthroscopic anterior cruciate ligament reconstruction. Two hundred forty-four patients with a minimum followup of 1 year were reviewed. Loss of motion (defined as a loss of extension of more than 10 degrees or flexion of less than 125 degrees) was identified in 27 patients for an overall incidence of 11.1%. Factors associated with loss of motion included acute reconstruction (less than 1 month from initial injury), male sex, and concomitant medial collateral ligament repair or posterior oblique ligament reefing or both. Twenty-one patients required surgery to regain their motion; three patients required a second procedure. Twenty-one of 27 patients with loss of motion underwent a detailed followup and were compared with 24 randomly chosen controls who had a normal range of motion after anterior cruciate ligament reconstruction. At followup, patients who experienced loss of motion had a significant decrease in noninvolved to involved knee extension and flexion compared to the control patients. There was no difference between our patients and the controls regarding patellofemoral problems, anterior knee laxity, and functional strength. Sixty-seven percent of patients with loss of motion had a good or excellent result in comparison to 80% of the controls.

Adolescent↗
PubMedDate not supplied

Pressure induced structural fluctuations in hemoglobin, studied by EPR-spectroscopy.

A quartz based cavity for pressure dependent EPR measurements on liquid samples allowing pressures up to 0.6 GPa was constructed. First investigations with this setup were done on spin labeled horse hemoglobin derivatives both in ferric and ferrous state of oxidation. The second derivative EPR spectra show changes of the label's mobility, which are not correlated with spin state changes of the Fe-porphyrin complex, but which point out structural fluctuations inside the globin protein matrices.

Cyclic N-Oxides↗
PubMedDate not supplied

Primary bacterial colonization of implant surfaces.

The purpose of this study was to assess the effects of modifying titanium surfaces, in terms of wettability, roughness, and mode of sterilization, on the ability of the oral bacterium Streptococcus sanguis to colonize. An in vitro model system was developed. All surfaces were colonized by the bacteria, but to significantly different levels. Titanium samples that exhibited rough or hydrophobic (low wettability) surfaces, along with all autoclaved surfaces, were preferentially colonized (P < .01). Titanium surfaces that had been repeatedly autoclaved were colonized with the levels of bacteria 3 to 4 orders of magnitude higher than other modes of sterilization. This may have implications relative to the commonly used method of autoclaving titanium implants, which may ultimately enhance bacterial biofilm formation on these surfaces.

Bacterial Adhesion↗
PubMedDate not supplied

Educating men about prostate cancer screening. A randomized trial of a mailed pamphlet.

CONTEXT: Although evidence-based guidelines recommend that physicians inform men about prostate cancer screening, the most efficient way to do this is not known. OBJECTIVE: To evaluate whether a mailed educational pamphlet affected men's knowledge about early detection of prostate cancer. DESIGN: Randomized, controlled trial. SETTING: Primary care clinic of the Minneapolis VA Medical Center. PATIENTS: 342 men at least 50 years of age who responded to a mailed survey (overall response rate, 68%) and did not report a history of prostate cancer. INTERVENTION: "Early Prostate Cancer" pamphlet mailed to patients in the intervention group 1 week before their scheduled clinic appointments. OUTCOME MEASURES: Patients' responses to a survey mailed 1 week after their clinic appointments; prostate-specific antigen (PSA) testing determined from electronic medical records. RESULTS: Respondents were predominantly elderly white men (mean age, 71 years; 90% white) with chronic illnesses (48% described their health as "fair" or "poor"). Men who received the educational pamphlet were better informed than men in the usual care group, as measured by correct responses to the following three questions about prostate cancer screening: the natural history of prostate cancer (32% vs. 24%; P = 0.10), whether treatment lengthens lives of men with early prostate cancer (56% vs. 44%; P = 0.04), and accuracy of PSA testing (46% vs. 27%; P < 0.008). The overall proportion of correctly answered questions was greater in the intervention group (45% vs. 32%; P < 0.001). Testing for PSA in the year after the index clinic appointments did not differ significantly between the intervention group and the usual care group (31% vs. 37%; P > 0.2). CONCLUSIONS: Male veterans are poorly informed about the potential benefits and risks of prostate cancer screening. Although our mailed educational pamphlet enhanced knowledge only modestly, it was an inexpensive and easily implemented intervention.

Aged↗
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Pharmacological comparison of CK-2289, an inodilator agent, with milrinone and enoximone.

CK-2289 is an inhibitor of type III cyclic 3'5'-adenosine monophosphate phosphodiesterase with potential utility in the treatment of congestive heart failure. We compared CK-2289 to milrinone and enoximone in several pharmacological models. Intravenous administration of CK-2289 to pentobarbital-anesthetized dogs (0.03 to 1 mg/kg) produced dose-related increases in myocardial dP/dTmax and decreased mean arterial blood pressure, similar to milrinone and enoximone. However, CK-2289 was 3-9 times more potent than either agent as a positive inotrope. Intraperitoneal and oral administration of CK-2289 and milrinone to mice produced central nervous system depression. Administered intravenously. CK-2289 and milrinone (1 mg/kg) inhibited, whereas enoximone (1 mg/kg) enhanced, guinea-pig gastric acid secretion. CK-2289 (0.01 to 0.3 mg/kg) and milrinone (0.03 to 1 mg/kg), given intravenously, did not affect neurotransmission to the rabbit sciatic nerve-gastrocnemius muscle preparation. Neither CK-2289 nor milrinone (100 microM) inhibited sympathetic neurotransmission, alpha 1-, muscarinic and thromboxane receptors. Both compounds relaxed canine arteries and veins. CK-2289 was devoid of effects on non-vascular smooth muscles of guinea-pig vas deferens and uteri and rabbit bronchi. CK-2289 (1 to 100 microM), milrinone and enoximone inhibited human platelet aggregation produced by adenosine diphosphate and sodium arachidonate. These data suggest that CK-2289 should be devoid of adverse renal, neural, smooth or skeletal muscle or gastrointestinal side effects associated with milrinone and enoximone therapy.

Animals↗
PubMedDate not supplied

[Nutritional status and plasma amino acid levels in hemodialysis].

The objective of this work is to study the relation between the variations of the plasmatic aminogram, and the nutritional state of the patient with chronic kidney failure on hemodialysis. We studied 79 patients with chronic kidney failure undergoing hemodialysis treatment, with and evolution of 46 +/- 37 months. They were subjected to a dietary questionnaire, and anthropometric study after dialysis (body mass index, triceps skin fold, muscular circumference of the arm), and determination of the levels of serum amino acids after a pre-dialysis nocturnal fast half way through the week, and finally a record is made of the number of times each patient was hospitalized in the 6 months prior to the study. In the amino acids with a pyruvate origin, there is a significant reduction of alanine (p: 0.002), serine (p: 0.004), and methionine (p: 0.001), and a significant increase of glycine, cystathionine, and cystine (p: 0.0001), with the Glycine/Serine coefficient being elevated (p: 0.001). All amino acids with a ketoglutarate origin are increased significantly (p < 0.007), except glutamine which is decreased (p: 0.0009), and arginine which does not show any significant differences. The essential amino acids are decreased in relation to the non-essential ones (p: 0.0001), although if they are compared with the normal values, only threonine is decreased (p: 0.001). Of the rest, histidine, isoleucine (p: 0.0001) and phenylalanine (p: 0.001) are significantly increased. The tyrosine/phenylalanine coefficient is decreased (p: 0.001). The daily ingestion of protein is correlated negatively with alanine, proline, hydroxyproline, and aspartic acid. The anthropometric parameters are correlated positively with the branched amino acids, alanine and proline. Finally, the number of hospital admissions in the last 6 months, is correlated positively with valine, leucine, phenylalanine, and glutamic acid. In conclusion, we consider that the increase of the glycine/serine, phenylalanine/serine and non essential/essential coefficients, is related to alterations of the metabolism, intrinsic to the condition of uremia, while the alterations of the levels of branched amino acids is related to the nutritional condition of the patients.

Adult↗