Comparative study of two computerized semen motility analyzers

Semen analysis is one of the primary tests carried out to investigate the infertile male. Subjective evaluation of semen is often prone to observer bias and error. To eliminate this, a number of computerized semen analyzers have recently been introduced into the market and we have evaluated two of the more popular models, the Cell Soft Semen Analyzer and the Hamilton Thorn Motility Analyzer (HTM 2000). The Cell Soft identifies sperm on the basis of user defined values for cell size and luminosity whereas the Hamilton Thorn identifies sperm by motility, and then applies the computer-calculated average size and luminosity of all moving objects to non moving sperm cells. Semen samples from 25 normal donors and 25 subfertile patients were analyzed using these two models of computerized semen analyzers, and also by an experienced technician using both the Makler chamber and the hemocytometer. The results obtained from the two automated analyzers were compared with those obtained by subjective evaluation. Variation in sperm count and motility were analyzed according to the sperm density. Four groups, less than 30 million/ml with debris, less than 30 million/ml, 30-50 million/ml, and greater than 50 million/ml were studied. The majority of patients fit into the first two groups. We observed that the HTM 2000 is superior to the Cell Soft in evaluating sperm count within the patient population group. For our donor population with an average sperm count of greater than 85 million/ml both systems provide extremely accurate counts.(ABSTRACT TRUNCATED AT 250 WORDS)     

Structural characterization and magnetic properties of undoped and copper-doped cobalt ferrite nanoparticles prepared by the octanoate coprecipitation route at very low dopant concentrations

Nanoparticles of undoped and copper-doped cobalt ferrite Co_1−xCu_xFe₂O₄ at very low dopant concentrations (x = 0; 0.02; 0.04; 0.06; 0.08) were successfully synthesized by pyrolysis of the corresponding hetero metal octanoate precursors obtained via coprecipitation using the octanoate ligand as precipitating agent. The precursors were then characterized by FTIR, ICP-AES and TG-DTA analyses and the results reveal the formation of a copper-cobalt-iron hydroxooctanoate represented by the formula [Co_1−xCu_xFe₂(C₈H₁₅O₂)₆(OH)₂·2H₂O]. The decomposition products obtained upon pyrolysis in air at 400 °C for 3 h were characterized by FTIR, XRD, SEM, TEM, XPS and VSM analyses. FTIR and XRD analyses showed the formation of a single phase mixed spinel ferrite while TEM analysis showed that the particles have a spherical shape with a mean size of 20 nm and form spherical agglomerates with sizes reaching 500 nm in some cases as the SEM images show. The chemical states of the metallic species in the samples were revealed by XPS to be Cu²⁺, Co²⁺ and Fe³⁺. These results combined with XRD confirmed the mixed spinel structure, Co_1−xCu_xFe₂O₄ in which Cu²⁺ ions substitute Co²⁺ ions in tetrahedral sites for x lower than 0.06 and in octahedral sites for x between 0.06 and 0.08. Magnetic parameters such as saturation magnetization (M_s), coercivity (H_c), remanent magnetization (M_r), magnetocrystalline anisotropy constant (K) and reduced magnetization (M_r/M_s), obtained from magnetic hysteresis loops measured at room temperature, are in agreement with this mixed spinel structure and also indicate that these materials are ferromagnetic and could be good candidates for applications in biomedicine and in microwave devices.

Low level copper-doped CoFe₂O₄ has been synthesized and shows an increasing of saturation magnetization up to 6% Cu, subsequently decreasing above 6%.     

Comparison of palmitic acid and glucose metabolism in the rabbit urinary bladder

This study was designed to investigate the relative importance of carbohydrate and fatty acids as substrates for energy production in the urinary bladder and to obtain information about the kinetics involved in the oxidation of glucose and a representative fatty acid by rabbit bladder incubated in vitro. Isolated strips of rabbit bladder body were incubated in the presence of various concentrations of ¹⁴C-glucose or ¹⁴C-palmitate for different periods of time up to 90 minutes. The rate of ¹⁴CO₂ generation was measured. In addition, the effect of bethanechol on both glucose and palmitic acid metabolism was determined. The results can be summarized as follows: (1) The oxidation of glucose showed a distinct lag period with time lasting for about 30 minutes. From 30 to 90 minutes the rate of ¹⁴C₂-palmitate was linear over the entire 90-minute period of incubation. (2) Experiments in which the concentration of glucose was varied showed saturation kinetics. From a Lineweaver-Burk plot a V_max of 0.645 umol/g/hr was obtained with a k_m of 2.30 mM. (3) Preincubation of tissues without substrate caused a significant increase in the rate of glucose oxidation. (4) The rate of oxidation of ¹⁴C-palmitate increased with concentration of the fatty acid. (5) A Lineweaver-Burk plot showed a V_max of 30.0 nmol/g/hr and a k_m of 2.50 mM. Addition of unlabeled glucose to tissues oxidizing ¹⁴C-palmitate had no effect on ¹⁴CO₂ production. Similarly, the addition of non-radioactive palmitate to tissues incubated with ¹⁴C-glucose did not decrease glucose oxidation. When both radioactive substrates were present the rates of oxidation were additive. (6) Although bethanechol stimulated glucose oxidation, the drug had no significant effect on palmitate metabolism.     

Partial bladder outlet obstruction induces urethral smooth muscle hypertrophy and decreased force generation

PURPOSE: PBOO leads to increased urinary frequency, decreased void volume, hypertrophy of the detrusor SM, and alterations in contractile and regulatory proteins. This study was done to determine whether PBOO induced increases in urinary frequency and detrusor SM hypertrophy are associated with an alteration in the contractility and expression of myosin isoforms in urethral SM. MATERIALS AND METHODS: PBOO was surgically induced in male New Zealand White rabbits, and sham operated rabbits served as controls. After surgery, rabbits were kept 12 days, and prior to sacrifice, urine output and voiding frequency were monitored by keeping the animals in metabolic cages for 24 hours. Animals with increased urinary frequency (mean +/- SEM 43 +/- 12 voids per 24 hours) and sham operated rabbits (6 +/- 3 voids per 24 hours) were used for this study. Morphology of the urethra was studied using light and immunofluorescence microscopy. The expression of myosin isoforms was analyzed at the mRNA and protein levels by RT-PCR and Western blotting. RESULTS: The urethral wall and SM of PBOO rabbits showed hypertrophy. The force produced by the longitudinal muscle strips of PBOO animals in response to phenylephrine, KCl, or electrical field stimulation was decreased 50%, 37% and 40%, respectively. Immunofluorescence microscopy revealed a decrease in nerve density. RT-PCR and Western blotting showed a decrease in the expression of myosin isoform SM-B with a concomitant increase in SM-A at the mRNA and protein levels. CONCLUSIONS: Our data show hypertrophy of the urethral wall and SM, and alterations in contraction, innervation, and myosin isoforms in PBOO induced detrusor hypertrophy.     

Effect of partial outlet obstruction on 14C-adenine incorporation in the rabbit urinary bladder

Bladder outlet obstruction induces severe changes in urinary bladder function and metabolism. These changes are characterized by significant reductions in the ability of the in vitro whole bladder to generate pressure and to empty. Metabolically, partial outlet obstruction induces a shift from oxidative to anaerobic metabolism. The decreased oxidative metabolism is mediated in part by significant decreases in mitochondrial substrate metabolism, which in turn is correlated with decreased activity of 2 important mitochondrial enzymes: citrate synthase and malate dehydrogenase. The present study was designed to evaluate mitochondrial function by studying the incorporation of ¹⁴C-adenine into high-energy phosphates (ATP, AMP, and ADP). Mild partial outlet obstructions were created by surgically placing silk ligatures loosely around the bladder neck. The results of these studies demonstrate that after 60 min incubation in oxygenated medium containing glucose + uCi¹⁴C-adenine, 1) There was no significant differences in the total AMP, ADP, and ATP concentrations measured in bladders taken from controls, 7- and 14-day obstructed rabbits; 2) there was no effect of obstruction on either the concentration of ¹⁴C-AMP in the tissue or in the ratio of hot to cold AMP; and 3) there was a 50% decrease in the concentration of ¹⁴C-ADP and a 70% decrease in the concentration of ¹⁴C-ATP in the bladder smooth muscle obtained from obstructed tissue (from both 7- and 14-day obstructions) compared to concentration in the control bladder smooth muscle. These results confirm the previous finding that obstruction did not reduce the rate of incorporation of adenine to AMP within the obstructed bladder smooth muscle and extends these studies to identify a significant reduction in the synthesis of both ADP and ATP. These results support the hypothesis that partial outlet obstruction induce a major dysfunction in mitochondrial function, both in the ability to oxidize substrates and in the ability to generate ATP. Neurourol. Urodynam. 16:201–208, 1997. © 1997 Wiley-Liss, Inc.     

Participation in medical research as a resource‐seeking strategy in socio‐economically vulnerable communities: call for research and action

The freedom to consent to participate in medical research is a complex subject, particularly in socio‐economically vulnerable communities, where numerous factors may limit the efficacy of the informed consent process. Informal consultation among members of the Switching the Poles Clinical Research Network coming from various sub‐Saharan African countries, that is Burkina Faso, The Gambia, Rwanda, Ethiopia, the Democratic Republic of Congo (DRC) and Benin, seems to support the hypothesis that in socio‐economical vulnerable communities with inadequate access to health care, the decision to participate in research is often taken irrespectively of the contents of the informed consent interview, and it is largely driven by the opportunity to access free or better quality care and other indirect benefits. Populations' vulnerability due to poverty and/or social exclusion should obviously not lead to exclusion from medical research, which is most often crucially needed to address their health problems. Nonetheless, to reduce the possibility of exploitation, there is the need to further investigate the complex links between socio‐economical vulnerability, access to health care and individual freedom to decide on participation in medical research. This needs bringing together clinical researchers, social scientists and bioethicists in transdisciplinary collaborative research efforts that require the collective input from researchers, research sponsors and funders.     

Hospitalizations for bacterial pneumonia after renal transplantation in the United States

PURPOSE: Bacterial pneumonia has been cited as the leading cause of infectious death in renal transplant recipients but has not been studied in a national transplant population. SUBJECT AND METHODS: Retrospective analysis of the incidence, risk factors and mortality of hospitalized bacterial pneumonia (ICD9 Code 481.x486.x) for 33,479 renal transplant recipients in the United States Renal Data System transplanted from 1 July 1994-30 June 1997. RESULTS: Among all transplant recipients, 4.7% were hospitalized for a primary discharge diagnosis of pneumonia in the study period (2.86 episodes per 100 person years). 9.9% had bronchoscopy and 4.8% had open lung biopsy. A specific etiology was not identified in 72.5% of patients. The hospitalization rate for pneumonia and hazard for mortality due to hospitalized pneumonia were both constant over time. In logistic regression analysis, pneumonia prior to transplant (odds ratio 1.73, 95% confidence interval, 1.32-2.26), older recipient age, diabetes, delayed graft function, rejection (occurring at any time after transplant during the time of the study), duration of pre-transplant dialysis, and positive recipient cytomegalovirus serology were associated with pneumonia. In Cox Regression, hospitalization for pneumonia was associated with greater risk of mortality (hazard ratio 1.64, 95% CI, 1.42-1.89). CONCLUSIONS: Renal transplant recipients with a previous history of pneumonia are at increased risk for subsequent pneumonia, which is associated with substantially decreased patient survival. Given the low rate of specific etiologies identified in this study, invasive diagnosis may be underutilized in this population.     

Sickle cell nephropathy at end-stage renal disease in the United States: patient characteristics and survival

BACKGROUND: The patient characteristics, including age at presentation to end-stage renal disease (ESRD) and mortality associated with sickle cell nephropathy (SCN) have not been characterized for a national sample of patients. METHODS: 375,152 patients in the United States Renal Data System were initiated on ESRD therapy between January 1, 1992 and June 30, 1997 and analyzed in an historical cohort study of SCN. RESULTS: Of the study population, 397 (0.11%) had SCN, of whom 93% were African-American. The mean age at presentation to ESRD was 40.68+/-14.00 years. SCN patients also had an independently increased risk of mortality (hazard ratio 1.52, 95% CI: 1.27-1.82) even after adjustment for placement on the renal transplant waiting list, diabetes, hematocrit, creatinine, and body mass index. However, when receipt of renal transplantation was also included in the model, SCN was no longer significant (p = 0.51, HR = 1.10, 95% CI: 0.82-1.48). SCN patients were much less likely to be placed on the renal transplant waiting list or receive renal transplants in comparison to age and race matched controls, and results of survival analysis were similar in this model. CONCLUSIONS: SCN patients were much less likely to be listed for or receive renal transplantation than other comparable patients with ESRD. SCN patients were at independently increased of mortality compared with other patients with ESRD, including those with diabetes, but this increased risk did not persist when models adjusted for their low rates of renal transplantation.