Lipid and lipoprotein levels in adults receiving Liposyn II

Lipid and lipoprotein levels were measured in 45 adult patients receiving parenteral nutrition for 10-14 days who were administered 20-50% of their daily total calorie requirement as Liposyn II. The study was an unblinded noncomparative multicenter investigation. Measurements were made on days 1, 3, 7, 10, and 14. Patients gained an average of 1.2 +/- 0.5 kg body wt during the study. No patient had to be removed from the study due to clinically significant adverse effects. Some changes in hematology, blood chemistry, and liver function parameters occurred, but these changes were consistent with alterations typically observed in patients receiving total parenteral nutrition. Total protein levels increased by an average of 0.30 +/- 0.13 g/dl (p less than 0.03). Plasma levels of phospholipid, triglycerides, total free fatty acids, very-low-density lipoprotein (VLDL) cholesterol and high-density-lipoprotein (HDL) cholesterol were normal or below normal at all times and did not change during the study. Significant increases occurred in total cholesterol (p less than 0.03) and low-density-lipoprotein (LDL) cholesterol (p less than 0.02) that were consistent with the mobilization of tissue cholesterol during intravenous lipid infusions. These increases do not infer any increased risk of coronary heart disease. The ratio of HDL to LDL cholesterol was 0.24-0.28 at all times.

Acoustic reflectometry for assessment of hearing loss in children with middle ear effusion

We sought associations between acoustic reflectometry and hearing loss in ears with and without middle ear effusion in 137 New Zealand children ages 3 to 16 years. Reflectometry was significantly associated with conductive hearing loss. These associations were present in the entire sample; correlation coefficients varied between 0.31 at 2000 Hz (P less than 0.001) and 0.55 for a three frequency pure tone average (P less than 0.001). The associations persisted for the sample of ears deemed to be filled entirely by effusion; correlation coefficients varied between 0.27 at 4000 Hz (P = 0.026) and 0.47 at 500 Hz (P less than 0.001). Using a reflectivity of 6.0 or greater to detect a three frequency pure tone average loss of 30 dB or more, the sensitivity was 88% and the specificity was 44%. The technique of acoustic reflectometry should be explored and extended to permit rational decisions about management of middle ear effusions.

Dorsal lunate tilt (DISI configuration): sign of scaphoid fracture displacement

Excessive dorsiflexion (dorsal tilting) of the lunate on a lateral wrist radiograph can be an important sign of carpal injury. Lunate dorsiflexion is a well-recognized sign of an intercarpal ligamentous injury pattern known as dorsal intercalated segment instability (DISI). It is less well recognized that excessive dorsal tilting of the lunate (DISI configuration) can also be produced by displacement of a scaphoid waist fracture. Since the management and prognosis of displaced scaphoid fractures may be quite different from those for nondisplaced fractures, radiologists can make an important contribution by recognizing dorsal tilting of the lunate and appreciating that it may be an important, indirect sign of scaphoid fracture displacement, which may not be directly visualized with standard wrist radiography. In this setting, computed tomography or complex motion tomography may be helpful for further evaluation of the scaphoid fracture.

The knee after partial meniscectomy: MR imaging features

The magnetic resonance (MR) examinations of 51 menisci treated by means of partial meniscectomy were reviewed. Menisci were divided into three groups: group 1, near normal length without osteoarthritis; 2, substantially shortened without osteoarthritis; and 3, any length with osteoarthritis. Group 1 menisci resembled normal menisci except for mild shortening and frequent signal inhomogeneity (56%). Group 2 menisci varied in appearance, with marked contour irregularity simulating fragmentation in 40% of segments despite a normal postoperative appearance at follow-up arthroscopy. Group 3 menisci appeared similar to menisci of the same length without osteoarthritis. Arthroscopic correlation, available for 23 menisci (45%), confirmed the MR diagnosis of a tear in 11 and no tear in 49 and revealed an unsuspected tear in three meniscal segments. There is a spectrum of normal MR appearances after partial meniscectomy. Standard MR criteria can be used to diagnose tears in the absence of marked contour irregularity; however, the diagnosis of tears of segments with marked contour irregularity must be made cautiously, since this irregularity can mimic a tear and was not predictive of an arthroscopically visible tear.

Radiographic features of hand and wrist surgery excluding arthroplasties

The normal and abnormal radiographic appearances of various hand and wrist surgical procedures have been presented. It is hoped that increased familiarity with these procedures and their radiographic features will lead to more meaningful radiographic interpretations by consulting radiologists.

Subtalar arthrosis: evaluation with CT

The surgical implantation of a Silastic wedge into the lateral subtalar joint (subtalar arthrosis) is designed to restrict the osseous malalignment associated with a flexible or neurogenic flatfoot deformity. We used CT to examine patients who had persistent pain after a subtalar arthrosis and retrospectively reviewed our experience with CT scans of 13 subtalar implants (seven patients) during a 3.5-year period. The CT scans of four asymptomatic subtalar implants showed each implant in the expected position and orientation, and the findings were considered normal. Conversely, the findings on CT scans of all nine painful implants (seven patients) were interpreted as abnormal. The scans showed oblique orientation of four implants (44%), loosening of three implants (33%), extruded methyl methacrylate in the subtalar joint in two implants (22%), and abnormal calcaneal recession in two implants (22%). Five of the nine painful implants were revised with improvement or resolution of symptoms. Our experience suggests that CT scanning of the subtalar joint can show the position and orientation of a subtalar implant and identify causes of persistent pain after a subtalar arthrosis.

External fixation of high-energy upper extremity injuries

Forty patients with high-energy upper extremity injuries involving the humerus and forearm bones were treated by primarye external fixation. Concomitant soft tissue or neurovascular injuries were rated by the Gustilo classification, and this rating correlated well with the final results: three fractures were Gustilo type I, two fractures were type II, and 35 were type III (IIIA, nine fractures; IIIB, eight; and IIIC, 18). Immediate external fixation, open wound treatment, delayed bone grafting, and late internal fixation led to good to excellent results in 73%. Complications were either minor (related to the external fixation and included pin loosening, 20%) or significant (osteomyelitis, 3%).

Radiographic features of hand and wrist arthroplasties

The normal and abnormal radiographic appearances of various arthroplasties of the hand and wrist have been presented. It is hoped that increased familiarity with these procedures and their radiographic features will lead to more meaningful radiographic interpretations by consulting radiologists.

Topical zinc and delayed hypersensitivity responsiveness

The ability of topical zinc to enhance the DHR to skin test antigens may be a simple method of evaluating functional zinc status. Additional testing is required to determine the sensitivity and specificity of this technique. In addition to zinc, other nutrient deficiencies such as protein deficiency may suppress DHR. Because of this and because of the variability among individuals in degree of reactiveness, each patient should serve as his/her own control, with zinc-treated and nontreated skin test sites being evaluated simultaneously.

Phylogenetic comparative analysis and the secondary structure of ribonuclease P RNA--a review

The most incisive a priori approach to inferring the higher order structure of large RNAs has proven to be the use of phylogenetic comparisons. This article provides guidelines to the method, using as an illustration the elucidation of the secondary structure of the catalytic RNA subunit of ribonuclease P (RNase P). The resultant structure is compared to the possibilities that are predicted thermodynamically for the RNase P RNA sequences of nine eubacteria.

Scaphoid anatomy: evaluation with complex motion tomography

Complex motion tomography was used to study the normal orientation of the axes of the proximal and distal scaphoid poles as a basis for comparison with displaced or malunited scaphoid fractures. Biplanar tomograms of 10 normal wrists were evaluated by seven physicians with the use of two standardized measurement techniques. The reference planes used for the first technique were the volar cortical surface of the proximal scaphoid and the dorsal cortical surface of the distal scaphoid. The apparent angulation between the reference planes with this technique averaged 32 degrees +/- 5 degrees on the sagittal view and 40 degrees +/- 3 degrees on the coronal view. The second technique used the orientation of the proximal articular surface relative to the distal articular surface of the scaphoid. The angulation between the axes averaged 24 degrees +/- 5 degrees in the sagittal plane and 40 degrees +/- 4 degrees in the coronal plane.

Scaphoid malunion

Forty-five patients with 46 scaphoid fractures were studied more than 6 months after union by clinical examination and trispiral tomography. Twenty had normal scaphoid alignment with lateral intrascaphoid angles less than 35 degrees; the rest had varying degrees of increased flexion angulation of the scaphoid, ranging from 36 degrees to 60 degrees. Increasing lateral scaphoid angulation, eventually resulting in a "humpback" deformity, was associated with progressively poor clinical and radiographic results. There were satisfactory clinical outcomes in 83% and posttraumatic arthritis in only 22% of those with normal scaphoid anatomy. Those with greater than 45 degrees of lateral intrascaphoid angulation present at the time of union had a satisfactory clinical outcome in 27% and posttraumatic arthritis in 54%. Union alone is an insufficient criterion for success in treating scaphoid fractures.

Trace element status in multiple sclerosis

We compared trace element status in multiple sclerosis (MS) patients (n = 27) with and without treatment with corticosteroids and groups of healthy subjects. Concentrations of plasma ceruloplasmin, selenium, and zinc and erythrocyte (RBC) glutathione peroxidase, Se, and Zn were similar in all groups. RBC copper concentrations were significantly lower in MS patients than in control subjects (mean +/- SEM: 0.048 +/- 0.005 vs 0.060 +/- 0.002 mumol/g Hb) because of decreased RBC Cu with steroid therapy. RBC Zn-Cu ratios were significantly higher (14.9 +/- 1.0 vs 10.1 +/- 0.3) in MS patients than in control subjects, differing in both groups of MS patients. In MS and control subjects, RBC Cu correlated significantly with RBC Zn (r = 0.56, 0.49). Disease acuity and disability had no effect on trace-mineral status. These data suggest that in MS there is altered Cu and Zn homeostasis that may cause or result from the disease and is influenced by corticosteroid therapy. Systemic trace element alterations might provide clinically useful markers of MS.

Validation of three-dimensional reconstructions of knee anatomy: CT vs MR imaging

This is the first investigation to validate the accuracy of spatial measurements based on computer-generated three-dimensional (3D) reconstructions of CT and magnetic resonance (MR) scans. Standard 3D reconstructions of one fresh frozen cadaveric knee specimen with implanted stereotactic reference markers were created. These reconstructions were based on the data from CT and MR scans performed before and after the resection of extraosseous soft tissues. The distances between the stereotactic reference markers in the 3D reconstructions were compared with the same measurements of the specimen using a Bridgeport milling machine as a precision 3D digitizer. The accuracy of intermarker distance measurements averaged 99% for CT-based reconstructions compared with 97.5% for MR-based reconstructions. Planar slices at a predetermined level and orientation through the femoral condyles were created by sequential milling of the specimen and were compared with reconstructed oblique planar CT and MR slices at the same level and orientation. The accuracy of condylar dimensional measurements was 94% for CT and 93% for MR compared with measurements of the milled slices. Three-dimensional reconstructions based on CT and MR scan data were of equally high quality and were unaffected by the status of the soft tissues.

The effects of simulated unstable scaphoid fractures on carpal motion

The kinematics of five fresh frozen wrist specimens were studied before and after a simulated scaphoid waist fracture. To determine the change in wrist motion and fracture site characteristics associated with an unstable wrist, the relative motion of each carpal bone was determined from the movement of implanted carpal markers on biplanar radiographs obtained in neutral and the four extreme wrist positions. The kinematics of the wrist in our specimens before the osteotomy were similar to previous studies. After the osteotomy, the proximal and distal segments of the scaphoid moved independently. The distal scaphoid assumed a relatively flexed stance and displayed increased motion. The proximal scaphoid fragment and lunate assumed a relatively extended stance and displayed less motion after the osteotomy. These kinematic abnormalities produced significant interfragmentary motion that would be expected to complicate normal fracture healing. The spontaneous collapse of the two scaphoid fragments produced a dorsal angulation or "humpback" deformity that simulated the clinical situation of displaced scaphoid nonunions. The scaphoid serves an important role maintaining normal alignment of the carpal bones and producing normal wrist motion.

Conservative treatment for adenocarcinoma of the pancreas

The records of 71 patients with the diagnosis of adenocarcinoma of the pancreas were reviewed. Seventeen patients were treated without surgery, 13 underwent exploratory laparotomy for diagnosis with no further palliative or curative operative procedure, six underwent pancreaticoduodenal resection, and 35 patients had a palliative gastric and/or biliary bypass procedure at initial operation. No preoperative signs or symptoms, routine laboratory tests, or radiologic evaluation were helpful as early diagnostic or prognostic indicators. Surgical mortality rates were not significantly different among the four groups; however, the survival time differences between the palliative group (4.8 mo) and the medically managed group (2.0 mo) was significant (p = 0.01 chi 2). Surgical morbidity did not differ significantly among the four groups of patients. The implications of these data in the treatment of patients with adenocarcinoma of the pancreas are discussed.

Effects of a scaphoid waist osteotomy on carpal kinematics

The effects of a scaphoid osteotomy on the kinematics of the carpal bones were determined in five cadaveric wrist specimens. Minute radiographic markers were inserted into the distal radius and selected carpal bones through limited arthrotomies between the intercarpal ligaments. Simultaneous biplanar radiographs were obtained in neutral and the extreme wrist positions of extension, flexion, radial deviation, and ulnar deviation, both before and after a scaphoid waist osteotomy. The positions of each of the carpal markers and their corresponding carpal bones were digitized for each wrist position , and a computer-assisted motion analysis was performed for each specimen before and after transverse scaphoid waist osteotomy. Following the osteotomy, there was a tendency for the scaphoid osteotomy to collapse into a dorsally angulated or "humpback collapse" deformity during each extreme wrist position. There was also multiplanar osteotomy site motion as well as complex collapse deformities of the midcarpal joint associated with loss of the mechanical tie-rod function of the scaphoid. These findings reveal the importance of the scaphoid in maintaining normal kinematics and the inherent instability of these fractures with loss of scaphoid integrity.

Epidemiology of human bites to children in a day-care center

The purpose of this study was to examine the epidemiology of human bites to children in a day-care center over a one-year period. This was a cohort study based on the injury log maintained on a daily basis by staff of the day-care center, as required by state II-censure law. A total of 224 children was enrolled in the center during the study period: 29 infants (ages 0 to 16 months), 62 toddlers (16.1 to 30 months), and 133 preschoolers (30.1 to 72 months). One hundred four children were bitten one or more times by other children in the center, with a total of 347 bites. The bite rates (defined as number of bites per 100 child days of enrollment in the center) varied significantly by age group but not by gender for initial or first-time bites, with toddlers having the highest rate and preschoolers the lowest (infants, 0.7129; toddlers, 1.3672; preschoolers, 0.4193). Total bite rates (which took into account multiple bites per child over the 12-month study period) varied significantly by age group, with toddlers having the highest rate per 100 days of enrollment and preschoolers the lowest (infants, 2.1931; toddlers, 3.1300; preschoolers, 0.5611). Males and females differed significantly in total bite rates per 100 enrollment days within the toddler age group (males, 3.6683; females, 2.3096) but not within the other two age groups. None of the demographic characteristics available in this study distinguished between children who were bitten compared with those who were not bitten with the exception of number of days of enrollment. The circumstances surrounding the biting events were examined with respect to the activity of the child when bitten, the victim's location when bitten, body part bitten, and treatment by staff. The results of this study raise policy questions about treatment protocols for human bites of children in group child-care settings, the routine recording of biting events, and the ethics and practice of reporting such events to parents.

Comparison of K-ABC performance between at-risk and normal preschool children

This study examined differences in K-ABC performance between at-risk (n = 44) and normal (n = 49) preschool children. For the group at-risk, all of the mean global scores on the K-ABC clustered around a standard score of approximately 90. The normal group's mean scores were 15 to 21 standard-score points higher and clustered near 110. The results of t tests for independent samples indicated that the normal group's scores on both the global scales and K-ABC subtests were significantly higher than the at-risk group's scores in nearly every instance. Correlations among scores were consistent with previous findings for preschoolers on the K-ABC. For the normal group, correlations obtained among the global scales were nearly identical to those reported for the standardization sample. For the at-risk group, however, the correlation of .75 between Sequential processing and Achievement was higher than that (.58) between Simultaneous processing and Achievement.

Selenium status of malnourished hospitalized patients

We evaluated selenium (Se) status of 44 hospitalized patients with protein-energy malnutrition. The patients were assigned to "normal" or "low" Se groups-1 and 2, respectively-based on whether the plasma Se level exceeded or was below the value of the mean-2SD of healthy Georgians'. Plasma and erythrocyte Se levels correlated significantly (r = .52, P less than .01). Erythrocyte glutathione peroxidase activity was highly correlated with plasma Se (r = .68) in group 2; there was no significant correlation between these parameters in group 1. In group 2 the mean plasma prealbumin level was significantly lower, and the mean corpuscular volume and serum glutamic oxaloacetic transaminase level were significantly higher compared to group 1. Other nutritional parameters did not correlate with Se status. Concomitant deficiencies of other nutrients were common in both patient groups. Se levels may relate to protein status, and abnormal hematologic and hepatic parameters may reflect low Se status and/or protein-energy malnutrition. Low Se status is common in malnourished patients from a low Se area, and Se supplementation should be included in their nutritional-repletion regimens.

Effects of N-ethylmaleimide on ouabain-insensitive cation fluxes in human red cell ghosts

In red cells of several species, the sulfhydryl reagent N-ethylmaleimide activates a Cl- -dependent, ouabain-resistant K+ transport pathway. Here we report our attempts to demonstrate ouabain-resistant Cl- -dependent K+ fluxes stimulated by N-ethylmaleimide in resealed human red cell ghosts using Rb+ as a K+ analogue. In contrast to intact cells, the rate constants of the base level Rb+ efflux in ghosts were similar in NaNO3 and NaCl (okRb = 0.535 +/- 0.079 h-1 and 0.534 +/- 0.085 h-1, respectively), while 1 mM N-ethylmaleimide stimulated Rb+ efflux strongly in NaNO3 (okRb = 14.26 +/- 1.32 h-1) and moderately in NaCl (okRb = 2.73 +/- 0.54 h-1). This effect was dependent on the presence of internal ATP. Stimulation of Rb+ efflux was observed in the presence of greater than or equal to 0.2 mM N-ethylmaleimide and increased at pH values approaching 8.0, consistent with titration of SH groups. N-Ethylmaleimide-stimulated Rb+ efflux was approx. 50% inhibited by 100 microM quinine sulfate whereas 1 microM bumetanide had no effect. In NaCl the N-ethylmaleimide-stimulated efflux saturated with initial internal ghost Rb+ concentration, but rates increased linearly in NaNO3. Replacement of external Na+ with glucamine or choline decreased the N-ethylmaleimide-stimulated Rb+ efflux, suggesting a role for external Na+. N-Ethylmaleimide-stimulated Rb+ efflux was greater in buffers with lipophilic anions such as SCN- or NO3- than in solutions with Cl- or acetate. However, the cation selectivity of the pathway studied was low, as Li+ efflux was also stimulated by N-ethylmaleimide. We conclude that the effect of N-ethylmaleimide on ouabain-resistant cation effluxes of human red cell ghosts is very different from the selective action of N-ethylmaleimide on Rb+ influxes in intact red cells.

Effect of age, sex, and race on selenium status of healthy residents of Augusta, Georgia

In this study we determined the possible effects of age, sex, and race on selenium (Se) concentration in plasma and erythrocytes and on glutathione peroxidase (GSH-Px) activity in erythrocytes. Two hundred six healthy blacks, whites, males, and females ranging in age from 11 to 60 yr were studied. For the entire population, mean±SDM Se concentrations were 0.104±0.021 μg/mL for plasma and 0.158±0.035 μg/mL for erythrocytes. Mean concentration of Se in plasma was higher in white subjects compared to black subjects (P<0.02). This difference was due exclusively to higher values in young adult white males (age, race, sex interaction). Neither plasma nor erythrocyte Se concentration nor erythrocyte GSH-Px activity were otherwise affected by age. In all groups plasma Se was correlated with erythrocyte Se (P<0.001), but not with glutathione peroxidase. Erythrocyte Se also was correlated inversely with years of smoking (P<0.033) and coffee intake (p<0.01). These results have defined the Se status in this healthy population in Augusta, Georgia as below the reported US mean. The factors underlying the age, race, sex interaction and the health significance of the low Se status in this population should be investigated.

Sulfhydryl reagents induce altered spectrin self-association, skeletal instability, and increased thermal sensitivity of red cells

Incubation of erythrocytes with the sulfhydryl reagent N-ethyl-maleimide (NEM) results in altered spectrin self-association and formation of dimers on the membrane. Skeletons isolated from these cells exhibit marked skeletal instability. In addition, NEM treatment induces increased thermal sensitivity of both cells and purified spectrin. These effects were not produced in aerobically incubated glucose-6-phosphate dehydrogenase deficient cells and were therefore presumably not due to depletion of intracellular reduced glutathione. These effects were produced by another permeant sulfhydryl reagent, monobromobimane, but not by its membrane-impermeant derivative. We conclude that spectrin sulfhydryl groups play an important role in spectrin self-association and thermal stability.

Hypothermia in a patient with anorexia nervosa

A young woman with anorexia nervosa had severe recurrent hypothermia. Initial evaluation revealed a thiamine deficiency. Administration of pharmacologic doses of thiamine improved voluntary food intake, and her temperature normalized. Following the restoration of body weight, withdrawal of supplemental thiamine produced a clinical relapse. After reinstitution of supplemental thiamine, the patient again became asymptomatic until she chose to consume a calorically-restricted diet. With progressive weight loss, hypothermia recurred and was unresponsive to thiamine therapy. Fortuitously, the patient's intake of sucrose was abruptly increased, and her body temperature normalized within seven days. The potential roles of thiamine and carbohydrate in thermoregulation are discussed.

Fear of death, death attitudes, and religious conviction in the terminally ill

The way in which an individual's belief system about death affects fear of death (FOD) has been largely neglected in the thanatology literature. The present study addresses the dimension of certainty or uncertainty with which beliefs about death are held and examines the way in which such attitudes might affect the FOD in dying patients. Twenty terminally ill patients were administered three FOD measures and a death perspective scale which assessed eight death attitudes. FOD among the terminally ill at both the conscious and fantasy level was low. Increased age was associated with declining conscious FOD, independent of life expectancy. Of the eight death perspectives, the attitudes toward death as afterlife-of-reward most directly tap the dimension of certainty or uncertainty. A significant curvilinear relationship emerged between this death perspective and FOD, suggesting that beliefs are a less critical determinant of death fear than is the certainty with which these beliefs are held. The study raises research and clinical issues pertinent to understanding FOD in dying patients.

Antimicrobial resistance among Pasteurella spp recovered from Missouri and Iowa cattle with bovine respiratory disease complex

A retrospective study was conducted to determine the prevalence of antimicrobial resistance among Pasteurella spp recovered from cattle with bovine respiratory disease complex. The study extended from January 1976 through May 1980, and included a review of the necropsy records of 386 beef cattle. Susceptibility or resistance of the Pasteurella isolants was determined by using the standard disk diffusion susceptibility test. Each isolant was tested for susceptibility with 15 different antimicrobial agents. A high prevalence of resistance (greater than 80%) was found when Pasteurella was tested with triple sulfonamides. For P haemolytica isolants, 57% to 70% were resistant to ampicillin (56/97), penicillin (58/101), and streptomycin (70/100); for unidentified Pasteurella spp isolants, 64% to 91% were resistant to ampicillin (83/129), penicillin (89/129), and streptomycin (118/129). For P haemolytica (21/100) and P multocida (34/146) isolants, 21% to 23% were resistant to tetracycline. Most of the P multocida isolants did not show marked antimicrobial resistance to 9 of the 15 drugs tested. However, 58% of the P multocida isolants (84/145) were resistant to streptomycin and 88% of them were resistant to three combined sulfonamides (126/144).

Closed form bandlimited image extrapolation

Digital implementations of a closed form 2-D bandlimited image extrapolation algorithm are presented for a number of elementary target images. The resulting figures of merit empirically verify the assumption that extrapolation is better near to where the image is known. Results of extrapolating a truncated image perturbed by white Gaussian noise suggest a required SNR of the order of 10(10).

Effects of activated carbon and bacteriostatic filters on microbiological quality of drinking water

Three activated carbon filters for point-of-use water treatment were tested in laboratory and field studies for chemical removal and microbiological effects on water. All removed free available chlorine in municipally treated water to below the limit of detection, but removed only about 50 to 70% of the total available chlorine and 4 to 33% of the total organic carbon. Standard plate count bacteria in the effluent increased steadily with time for 3 weeks and remained elevated over the 8-week period of the study. Total coliform bacteria were found to persist and proliferate on the filters for several days after transient contamination of the influent water. Silver-containing activated carbon filters suppressed total coliform but not total bacterial growth. Pseudomonas aeruginosa was recovered from the effluents of all filters at some time during the tests.

Enzymatic detection of Neisseria gonorrhoeae

In a study using a non-serological enzymatic approach for the detection of Neisseria gonorrhoeae in cervical and urethral swabs, the technique was shown to be technically feasible. The enzyme, 1, 2-propanediol oxidoreductase, was used as a presumptive diagnostic marker for N gonorrhoeae. Enzymatic activity was measured with a fluorometer. Two assay procedures were performed: (a) enzyme detection (two-tube and three-tube assays) requiring 60 minutes; and (b) enzyme inhibition (EI) (90-minute and modified 20-minute assays). Sensitivities of the two-tube, three-tube, and the 90-minute EI assays with male urethral specimens from a high-prevalence population were 80%, 84%, and 91% respectively. The specificities of these assays in a low-prevalence male population were not determined. Sensitivity of the 90-minute EI assay in a high-prevalence female group was 77% and specificity in a low-prevalence female group was 75%. The modified EI assay was tested only in a low-prevalence female group and had 87% specificity. Although the specificity of the assays needs improvement, several advantages--including early case detection, rapid availability of results, detection of current active infections, and the possibility of automation--are intrinsic in this enzymatic approach.

Radioiodination of an outer membrane protein in intact Rickettsia prowazekii

Intact Rickettsia prowazekii was radiolabeled with the glucose oxidase-lactoperoxidase method of iodination. Separation of the rickettsial extract into cytoplasmic, outer and inner membrane fractions demonstrated that the outer membrane was preferentially labeled. Analysis of the polypeptides of these fractions on high-resolution slab polyacrylamide gels showed that most of the 125I was in polypeptide T49, an outer membrane constituent. Additional outer membrane polypeptides were iodinated in broken envelope preparations, demonstrating that T49 is uniquely accessible to the external environment and the asymmetric polypeptide organization of the outer membrane.

The occurrence of 1,2-propanediol oxidoreductase in micro-organisms and its use as a possible diagnostic marker for Neisseria gonorrhoeae

The cervical microbial flora of 25 females and stock cultures of various micro-organisms which may be present in the human female cervix were examined using a fluorimetric assay for 1,2-propanediol oxidoreductase. Results indicated that only members of the genera Neisseria and Acinetobacter possess appreciable activities of the enzyme, whose physiological function is not yet known. The activity of this enzyme in N. gonorrhoeae appeared to be significantly higher than the activities observed in mot of the other Neisseria species and in the Acinetobacter species. These results indicated that it may be possible to utilize this enzyme as a presumptive diagnostic marker for N. gonorrhoeae in cervical secretions. 1,2-Propanediol oxidoreductase may also be of taxonomic significance for the classification of various bacterial species.

Clinical pharmacology of intermediate-dose oral methotrexate

The clinical pharmacology of intermediate-dose oral methotrexate (MTX) was studied in nine patients receiving 18 courses of treatment. Serum and urine MTX concentrations were measured by means of a competitive protein binding assay after oral aqueous solution (3 courses), 50-mg tablets (13 courses) or IV drug (2 courses) had been administered in four doses of 100 mg/m2 at 6-h intervals or in four doses of 200 mg/m2 at 6-h intervals and followed by citrovorum factor rescue. Levels above 150 ng/ml (3.3 x 10(-7) M) were maintained throughout all treatment cycles, with rapid disappearance of drug after the last dose. A 100% increase in administered dose resulted in only a 42% increase in the concentration-time level. Methotrexate was absorbed well from both aqueous solutions and 50-mg tablets, but serum levels after 50-mg tablets were only 20% of those achieved after IV administration. We conclude that significant serum MTX concentrations can be achieved for prolonged periods of time after oral administration of intermediate doses, but that the proportion of drug absorbed is much less than is seen with lower doses.

Separation of inner and outer membranes of Rickettsia prowazeki and characterization of their polypeptide compositions

Rickettsia prowazeki were disrupted in a French pressure cell and fractionated into soluble (cytoplasm) and envelope fractions. The envelope contained 25% of the cell protein, with the cytoplasm containing 75%. Upon density gradient centrifugation, the envelope fraction separated into a heavy band (1.23 g/cm3) and a lighter band (1.19 g/cm3). The heavy band had a high content of 2-keto-3-deoxyoctulosonic acid, a marker for bacterial lipopolysaccharide, but had no succinic dehydrogenase, a marker for cytoplasmic membrane activity, and therefore represented outer membrane. The lighter band exhibited a high succinate dehydrogenase activity, and thus contained inner (cytoplasmic) membrane. Outer membrane purified by this method was less than 5% contaiminated by cytoplasmic membrane; however, inner membrane from the gradient was as much as 30% contaminated by outer membrane. The protein composition of each cellular fraction was characterized by sodium dodecyl sulfate--polyacrylamide gel electrophoresis. The outer membrane contained four major proteins, which were also major proteins of the whole cell. The cytoplasmic membrane and soluble cytoplasm exhibited a more complex pattern on gels.

Inflammatory fibrous histiocytoma: response to non-surgical therapy: a case report

A case of inflammatory fibrous histiocytoma arising in soft tissue near the sacrum is presented. The patient's mode of presentation, clinical course, and tumor histology were typical of this disease. The tumor was inoperable, and radiotherapy combined with doxorubicin, cyclophosphamide, and intermediate-dose oral methotrexate produced a dramatic complete response lasting over 27 months. Favorable results with nonsurgical therapy have not previously been reported for this disease. The gratifying result obtained, although of relatively short duration to date, indicates that combined modality therapy may provide significant back-up to aggressive surgery. The use of these agents in an adjuvant setting merits study.

Characterization of a lysine-specific active transport system in Rickettsia prowazeki

Rickettsia prowazeki possesses an active transport system for lysine with a Kt of influx of 1 muM. Extraction and chromatographic analysis of the accumulated labeled material show the material to be lysine rather than a derivative. This intracellular lysine pool can be exchanged with external unlabeled substrates for at least 10 min; The lysine analogues L-aminoethyl cysteine, N-methyl lysine, hydroxylysine, and D-lysine competitively inhibit uptake of L-lysine, but cadaverine, diaminopimelate, arginine, ornithine, and epsilon-aminocaproate do not. Accumulation of lysine can be inhibited by the energy poisons potassium cyanide, triphenylmethyl phosphonium bromide, and 2,4-dinitrophenol. The effect of potassium cyanide, but not 2,4-dinitrophenol or triphenylmethyl phosphonium bromide, can be overcome by adenosine 5'-triphosphate. Both energy-dependent influx and energy-independent efflux are inhibited by the sulfhydryl reagents N-ethyl maleimide and p-chloromercuriphenyl sulfonic acid.

Bacterial culture longevity: control by inorganic phosphate and temperature

Death of cells in cultures of six species of gram-negative bacteria was accelerated by incorporation in the medium of 10-fold more inorganic phosphate than was needed for growth. Death induced by inorganic phosphate was independent of the carbohydrate employed and was enhanced by warm temperatures.

Iron Minerals Formed by a Nuclear Explosion in a Salt Bed

The nuclear event, Gnome, was carried out in halite in the Salado formation and yielded a varied mineral assemblage. The iron suppor members reacted in the salt melt and formed several iron oxide phases. The magnetite which formed during the fireball stage reached in various ways with the environment to form higher oxides and hydrated oxides.

Epidermophyton Infection

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