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Biomedical subjects

C Franklin

Publications and source records attributed to C Franklin.

At least 37 records · Page 2Linked to original sources
PubMed1998

A comparison of intraoral Candida carriage in Sjögren's syndrome patients with healthy xerostomic controls.

OBJECTIVE: Determination of the incidence of Candida carriage in patients with Sjögren's syndrome (SS) and xerostomic controls to assess the influence of immunologic disturbances in SS on carriage. STUDY DESIGN: A total of 16 primary SS patients, 12 secondary SS patients, and 14 xerostomic controls were included in the study. Sampling was performed using an oral rinse method. Aliquots (100 microliters) were spread onto CHROMagar* and incubated for 48 hours. Species identification was confirmed by the germ tube test and API ID32C. Total colony-forming units per milliliter (CFU/ml) were counted and statistical analyses performed by the Kruskal-Wallis test. RESULTS: Candida carriage in primary SS, secondary SS, and xerostomic patients was 81.25%, 66.7%, and 71.4%, respectively. There were no statistically significant differences in total CFU/ml. A wide range of species was isolated in each group. CONCLUSION: The immunologic disturbances seen in SS do not significantly influence the intraoral Candida carriage in patients with a dry mouth.

Adult↗
PubMed1997

A primitive enzyme for a primitive cell: the protease required for excystation of Giardia.

Protozoan parasites of the genus Giardia are one of the earliest lineages of eukaryotic cells. To initiate infection, trophozoites emerge from a cyst in the host. Excystation is blocked by specific cysteine protease inhibitors. Using a biotinylated inhibitor, the target protease was identified and its corresponding gene cloned. The protease was localized to vesicles that release their contents just prior to excystation. The Giardia protease is the earliest known branch of the cathepsin B family. Its phylogeny confirms that the cathepsin B lineage evolved in primitive eukaryotic cells, prior to the divergence of plant and animal kingdoms, and underscores the diversity of cellular functions that this enzyme family facilitates.

Animals↗
PubMed1997

A comparison of the kinetics of low-density lipoprotein oxidation initiated by copper or by azobis (2-amidinopropane).

This article describes the kinetics of low density lipoprotein (LDL) oxidation catalyzed by azobis (2-amidinopropane) dihydrochloride, ABAP, or by copper. The LDLs were isolated from nonhuman primates fed diets enriched in one of three types of fatty acids: saturated fatty acids, monounsaturated fatty acids, predominantly, oleic acid, or polyunsaturated fatty acids, predominantly linoleic acid. Oxidation was followed by monitoring the formation of conjugated diene hydroperoxides from polyunsaturated fatty acids (PUFA). For both copper and ABAP-initiated oxidation, the rate of LDL oxidation depended on the concentrations of initiator, PUFA, and LDL. Except for the dependence on PUFA concentration the rate of LDL oxidation was not directly influenced by the fatty acid composition of the LDL particle. The two initiators had very different dependence on initiator concentration. Because LDL particles are essentially small, lipid-rich droplets, the kinetic descriptions of LDL oxidation assumed: (1), that there was only one chain per particle, and (2) that the radical chain was terminated when a second radical either entered or was formed in the particle. When two LDL samples having very different lag times were mixed, the oxidation profile was bimodal. This finding demonstrated that the oxidation of native LDL particles was independent of the oxidation state of the other native LDL particles in solution, i.e., LDL particles do not rapidly exchange radicals, for example, hydroperoxyl radicals. Oxidation initiated by ABAP was proportional to [ABAP]0.5, suggesting that hydroperoxyl radical recombination between the lipid hydroperoxyl radical and the ABAP-hydroperoxyl radical was the chain-terminating step. The reciprocal of the rate of copper oxidation was linearly related to the reciprocal copper concentration, demonstrating that the binding of copper to LDL was necessary to initiate oxidation. This binding constant showed considerable variability among LDL samples. The kinetic descriptions of LDL oxidation reflect the differences in the mechanisms of initiation and termination.

Amidines↗
PubMed1997

Comparison of train-of-four and best clinical assessment during continuous paralysis.

Train-of-four (TOF) monitoring is recommended in published guidelines during use of continuous-infusion neuromuscular blocking agents (NMB) in the intensive care unit (ICU). To test that recommendation, dual protocols were established in a medical ICU after intensive nursing education. Paralyzed patients received either TOF monitoring with a goal of three twitches or best clinical assessment while receiving atracurium by continuous infusion. Demographics and mean duration of paralysis of 20 patients in the TOF group were no different than that of the 16 patients in the best clinical assessment group. Although most patients demonstrated atracurium tolerance over time, there was no difference between groups in total mg (+/- SEM) infused (10,460 +/- 2,409 versus 9,201 +/- 3,237) or mean microgram/kg/min (15.2 +/- 1.5 versus 12.0 +/- 1.1). The time to clinical recovery was no different between groups (50 +/- 10 versus 45 +/- 12 min). Two complications occurred in the TOF group, with pulmonary emboli despite prophylaxis and an unrecognized cerebrovascular accident in one patient each. We conclude that careful titration of NMB using clinical bedside markers should remain the standard of care with these drugs.

Adult↗
PubMed1997

Muscle power output during escape responses in an Antarctic fish

Escape responses (C-shaped fast-starts) were filmed at 500 frames s-1 in the Antarctic rock cod (Notothenia coriiceps) at 0 °C. The activation and strain patterns of the superficial fast myotomal muscle were measured simultaneously using electromyography and sonomicrometry respectively. In order to bend the body into the initial C-shape, the muscle fibres in the rostral myotomes (at 0.35L, where L is total length) shortened by up to 13 % of their resting length at a maximum velocity of 1.68 fibre lengths s-1. During the contralateral contraction, muscle fibres were stretched (by 5 % and 7 % at 0.35L and 0.65L, respectively) and were activated prior to the end of lengthening, before shortening by up to 12 % of resting fibre length (peak-to-peak strain). Representative strain records were digitised to create cyclical events corresponding to the C-bend and contralateral contraction. Isolated fibres were subjected to the abstracted strain cycles and stimulated at the same point and for the same duration as occurs in vivo. During the early phase of shortening, muscle shortening velocity (V) increased dramatically whilst the load was relatively constant and represented a substantial fraction of the maximum isometric stress. Pre-stretch of active muscle was associated with significant force enhancement. For the contralateral contraction, V exceeded that predicted by the steady-state force­velocity relationship for considerable periods during each tailbeat, contributing to relatively high maximum instantaneous power outputs of up to 290 W kg-1 wet muscle mass. In vitro experiments, involving adjusting strain, cycle duration and stimulation parameters, indicated that in vivo muscle fibres produce close to their maximum power. During escape responses, the maximum velocity and acceleration recorded from the centre of gravity of the fish were 0.71±0.03 m s-1 and 17.1±1.4 m s-2, respectively (mean ± s.e.m., N=7 fish). Muscle performance was sufficient to produce maximum velocities and accelerations that were within the lower end of the range reported for temperate-zone fish.

Journal Article↗
PubMed1997

The sub-pulmonary conus and the arterial anastomosis as important sites of cardiovascular regulation in the crocodile Crocodylus porosus

We present evidence to support the hypothesis that the arterial anastomosis and the cogteeth-like valves located in the sub-pulmonary conus in the right ventricle are important sites of cardiovascular regulation in the crocodile Crocodylus porosus. The influence of the arterial anastomosis on the development of the 'foramen spike' in the left aortic pressure trace, which occurs at the onset of diastole when the pressures in the right and left aortas become equal, and on gastrointestinal blood flow was examined in unanaesthetised C. porosus using blood vessel occluders. Measurements of blood flow in the arterial anastomosis showed that, during non-shunting conditions, there was a substantial systolic blood flow from the right aorta into the coeliac artery. The total coeliac artery blood flow was the sum of the anastomosis flow from the right aorta plus the left aortic flow originating from the right aorta via the foramen of Panizza during diastole. During mechanically induced pulmonary-to-systemic shunting, the anastomosis blood flow was reversed, with blood flowing from the left to the right aorta. The magnitude of the 'foramen spike' was directly related to the vascular resistance in the anastomosis. When vascular resistance in the anastomosis was high, such as during mechanical occlusion, there was an increase in the right aortic to left aortic pressure gradient during systole which resulted in an increase the foramen spike amplitude. Recordings of right intraventricular pressure in unanaesthetised C. porosus showed spontaneous changes in right intracardiac systolic pressure. The pressure recordings were biphasic, with the second contraction (isometric) being highly variable in size, indicating the control of pulmonary outflow resistance, possibly via the 'cogteeth valves' located in the sub-pulmonary conus in the right ventricle.

Journal Article↗
PubMed1997

Evaluation of a stage-specific proteolytic enzyme of Schistosoma mansoni as a marker of exposure.

Cercarial elastase (CE) is one of the first proteins released in the host by invading schistosome cercariae. An enzyme-linked immunosorbent assay (ELISA)-formatted immunoassay has been developed to detect antibodies to the stage-specific CE antigen of Schistosoma mansoni as marker of exposure. We have evaluated this test system as an epidemiologic tool, using well-characterized sera collected from S. mansoni- and S. haematobium-infected subjects residing in endemic areas and from control subjects living in nonendemic areas in Egypt. Urine, stool specimens, and blood samples were collected from a sample of 272 endemic subjects randomly selected to represent different age groups in the range of 2-20 years of age. Of 47 S. mansoni-infected subjects, 41 (87.2%) had anti-CE IgG antibodies. Of 52 S. haematobium-infected cases, 38 (73.0%) had IgM antibodies to CE and 43 (82.7%) had IgG antibodies to CE. Of 173 egg-negative people in the endemic area, 84 (48.6%) were IgM positive and 99 (57.2%) were IgG positive. The mean IgM and IgG antibody levels were similar in the infected groups but were significantly lower in the egg-negative group (P = 0.001). All sera from young children (2-3 years of age) were uniformly ELISA negative. The prevalence of IgM and IgG antibodies to CE in children less than six years of age were significantly lower than in other age groups. There was no significant difference in prevalence rates of IgM and IgG anti-CE antibodies between subjects having other parasites present in the endemic area (Ascaris lumbricoides, Entrobius vermicularis, Hymenolepis nana, H. diminuta, Trichostrongylus spp., and Entamoeba histolytica) and those without any parasitic infection. All nonendemic sera (58), including those with other helminth infections, were uniformly ELISA negative for antibodies to CE. These findings suggest that antibodies to elastase indicate exposure, but not necessarily active schistosome infection.

Adolescent↗
PubMed1996

A comparison of the effect of universal use of gloves and gowns with that of glove use alone on acquisition of vancomycin-resistant enterococci in a medical intensive care unit.

OBJECTIVE: To determine the efficacy of the use of gloves and gowns compared with that of the use of gloves alone for the prevention of nosocomial transmission of vancomycin-resistant enterococci. DESIGN: Epidemiologic study and controlled, nonrandomized clinical trial. SETTING: University-affiliated, 900-bed, urban teaching hospital in which vancomycin-resistant enterococci are endemic. PATIENTS: 181 consecutive patients admitted to the medical intensive care unit for 48 hours or more. INTERVENTION: It was determined that all hospital employees would always use gloves and gowns when attending 8 particular beds in the medical intensive care unit and would always use gloves alone when attending 8 others. Compliance with precautions was monitored weekly. Rectal surveillance cultures were taken from patients daily. Cultures of environmental surfaces, such as those of bed rails, bedside tables, and other frequently touched objects in patient rooms and common areas, were taken monthly. Pulsed-field gel electrophoresis was used for molecular epidemiologic typing of vancomycin-resistant enterococci. MEASUREMENTS: The number of patients becoming colonized by vancomycin-resistant enterococci; the number of days to acquisition of vancomycin-resistant enterococci; and other measurements, including nosocomial infections, length of hospital stay, and mortality rates. RESULTS: The 93 patients in glove-and-gown rooms and the 88 patients in glove-only rooms had similar demographic and clinical characteristics. Fifteen (16.1%) patients in the glove-and-gown group and 13 (14.8%) in the glove-only group had vancomycin-resistant enterococci on admission to the medical intensive care unit. Twenty-four (25.8%) patients in the glove-and-gown group and 21 (23.9%) in the glove-only group acquired vancomycin-resistant enterococci in the medical intensive care unit. The mean times to colonization among the patients who became colonized were 8.0 days in the glove-and-gown group and 7.1 days in the glove-only group. None of these comparisons were statistically significant. Risk factors for acquisition of vancomycin-resistant enterococci induced length of stay in the medical intensive care unit, use of enteral feeding, and use of sucralfate. Compliance with precautions was 79% in glove-and-gown rooms and 62% in glove-only rooms (P < 0.001). Only 25 of 397 (6.3%) environmental cultures were positive for vancomycin-resistant enterococci. Nineteen types of vancomycin-resistant enterococci were documented by pulsed-field gel electrophoresis during the study period. CONCLUSIONS: Universal use of gloves and gowns was no better than universal use of gloves only in preventing rectal colonization by vancomycin-resistant enterococci in a medical intensive care unit of a hospital in which vancomycin-resistant enterococci are endemic. Because the use of gowns and gloves together may be associated with better compliance and may help prevent transmission of other infectious agents, this finding may not be applicable to outbreaks caused by single strains or hospitals in which the prevalence of vancomycin-resistant enterococci is low.

Adult↗
PubMed1996

Anticipatory grief and AIDS: strategies for intervening with caregivers.

Anticipatory grief may have beneficial effects for caregivers of people with HIV infection or AIDS. However, the duration of the illness and the stigmatization and multiple losses associated with the disease may impede the caregiver's ability to effectively engage in the grief process. This article discusses the impact of these aspects of the disease on the anticipatory grief process and mourning tasks for caregivers at each stage of the illness. Intervention strategies developed to help the caregiver remain actively involved with the patient and simultaneously grieve losses and prepare for death are specified.

Acquired Immunodeficiency Syndrome↗
PubMed1996

p53 protein expression in malignant, pre-malignant and non-malignant lesions of the lip.

AIM: To elucidate the role of the p53 tumour suppressor gene in the pathogenesis of lip cancer. METHODS: Expression of p53 was evaluated immunocytochemically in a retrospective study of formalin fixed, paraffin wax embedded tissue. Five cases each of four types of lip lesions were studied; these comprised squamous cell carcinoma (SCC), solar keratosis (SK), chronic hyperplastic candidosis (CHC), and lichen planus (LP). Five cases each of normal lip mucosa, SCC, and SK from sun exposed facial skin as well as LP, CHC, and SCC from buccal mucosa were also analysed. Immunolocalisation of p53 was scored semiquantitatively. The degree of apoptosis was also assessed in selected lesions by determining cell nuclear fragmentation. RESULTS: All SCCs from lip lesions were immunopositive for p53. All cases of SK and two of five CHC lip lesions were also p53 positive. Normal lip mucosa samples were p53 negative. Sun exposed skin lesions of SCC and SK were all positive for p53, but only three of five cases of SCC from the buccal mucosa had detectable levels of p53. p53 expression was not detected in CHC and LP lesions of the buccal mucosa. CONCLUSIONS: The aberrant expression of p53 is likely to occur early in the pathogenesis of lip cancer and may be related to exposure to the sun. The immunopositive p53 cells identified in the benign LP lesions do not necessarily correlate with commitment of cells within the lesion to programmed cell death. In light of the prior reports which indicate that p53 positive cells may progress to form malignant tumours, it is suggested that patients with p53 positive but otherwise benign lesions should be followed more closely.

Biomarkers↗
PubMed1996

Dynamic anatomical study of cardiac shunting in crocodiles using high-resolution angioscopy

Prolonged submergence imposes special demands on the cardiovascular system. Unlike the situation in diving birds and mammals, crocodilians have the ability to shunt blood away from the lungs, despite having an anatomically divided ventricle. This remarkable cardiovascular flexibility is due in part to three anatomical peculiarities: (1) an 'extra' aorta (the left aorta) that leaves the right ventricle and allows the blood from the right ventricle to take an alternative route into the systemic circulation instead of going to the lungs; (2) the foramen of Panizza, an aperture that connects the right and left aortas at their base immediately outside the ventricle; and (3) a set of connective tissue outpushings in the pulmonary outflow tract in the right ventricle. Using high-resolution angioscopy, we have studied these structures in the beating crocodile heart and correlated their movements with in vivo pressure and flow recordings. The connective tissue outpushings in the pulmonary outflow tract represent an active mechanism used to restrict blood flow into the lungs, thus creating one of the conditions required for a right-to-left shunt. We observed that the foramen of Panizza was obstructed by the medial cusp of the right aortic valve during most of systole, effectively differentiating the left and right aortic blood pressure. During diastole, however, the foramen remained open, allowing pressure equilibration between the two aortas. Contrary to current theories, we found that the left aortic valves were unable to cover the foramen of Panizza during any part of the cardiac cycle, supporting the reversed foramen flow hypothesis. This would ensure a supply of blood to the coronary and cephalic circulation during a complete shut-down of the left side of the heart, such as might occur during prolonged submergence.

Journal Article↗
PubMed1995

Improving long-term prognosis for survivors of mechanical ventilation in patients with AIDS with PCP and acute respiratory failure. Five-year follow-up of intensive care unit discharges.

BACKGROUND: Before 1987, the hospital survival of patients with acquired immunodeficiency syndrome, Pneumocystis carinii pneumonia, and acute respiratory failure receiving mechanical ventilation was less than 15%. Hospital survival has improved since then, but concerns have been raised that the post-hospital discharge survival of these patients remains extremely poor. This study evaluated the long-term survival of patients discharged alive after an acute episode of acute respiratory failure caused by P carinii pneumonia. METHODS: A prospective cohort study was conducted for the 5-year period from May 1987 through May 1992 in an urban teaching hospital. Forty-seven patients discharged from the hospital after receiving mechanical ventilation and/or continuous positive airway pressure for acquired immunodeficiency syndrome, P carinii pneumonia, and acute respiratory failure were followed up from their initial intensive care unit admission until death or termination of the study to measure the long-term survival and cumulative probability of survival of the study cohort. Actuarial life-table analysis was performed, and long-term cumulative probability of survival was calculated on the basis of the life-table analysis. Median survival was estimated by means of the product-limit method. RESULTS: During the 5-year follow-up of the 47 subjects, 31 patients died, 12 were unavailable for follow-up, and four were still alive at the end of the cutoff. The cumulative survival rate at 1 year was 80% (95% confidence interval, 92% to 68%); at 2 years, 49% (95% confidence interval, 65% to 34%); at 3 years, 18% (95% confidence interval, 32% to 4%); and at 4 years, 6% (95% confidence interval, 17% to 0%). Median survival time for all subjects was 602 days (1.65 years), and the longest survival time for a single patient was 1774 days (4.86 years). CONCLUSIONS: Post-hospital discharge survival of patients with acquired immunodeficiency syndrome, P carinii pneumonia, and acute respiratory failure has improved dramatically in the past decade. Patients can undergo intubation and mechanical ventilation with the hope of reasonable long-term survival.

AIDS-Related Opportunistic Infections↗
PubMed1995

Confirmation of spurious hypoxemia using continuous blood gas analysis in a patient with chronic myelogenous leukemia.

Patients with extreme leukocytosis or thrombocytosis who have hypoxemia on arterial blood gas analysis may demonstrate normal oxygen saturation using pulse oximetry. The most commonly invoked explanation for this phenomenon is oxygen consumption in the blood gas sample prior to analysis. However, others have challenged the premise that the hypoxemia is spurious. We describe a patient with extreme leukocytosis and hypoxemia in whom normoxia was confirmed by continuous blood gas analysis.

Adult↗