Unusual pathogenicity of a common metacercaria of fish

The metacercaria of Posthodiplostomum minimum centrarchi Hoffman, 1958, is reported from an unusual host, Roccus saxatilis, from North Carolina. Although few dead or moribund fish were observed, there were many deformed fish, few of which survived. The metacercariae were in the musculature and orbit of the eye instead of in the usual location in the centrarchid hosts.

Report of the Task Force on Residency Training Information (2000-2001), American Board of Emergency Medicine

The American Board of Emergency Medicine gathers extensive background information on emergency medicine residents and the programs in which they train. We present the fourth annual report on the status of US emergency medicine residency programs.

Report of the Task Force on Residency Training Information (1999-2000), American Board of Emergency Medicine

The American Board of Emergency Medicine gathers extensive background information on emergency medicine residents and the programs in which they train. We present the third annual report on the status of US emergency medicine residency programs. [American Board of Emergency Medicine. Report of the Task Force on Residency Training Information (1999-2000), American Board of Emergency Medicine. Ann Emerg Med. May 2000;35:481-498.]

Report of the Task Force on Residency Training Information (1998-1999), American Board of Emergency Medicine

The American Board of Emergency Medicine gathers extensive background information on emergency medicine residents and the programs in which they train. We present the second annual report on the status of US emergency medicine residency programs. [American Board of Emergency Medicine: Report of the Task Force on Residency Training Information (1998-1999), American Board of Emergency Medicine. Ann Emerg Med May 1999;33:529-545.]

Report of the Task Force on Residency Training Information, American Board of Emergency Medicine

The American Board of Emergency Medicine gathers extensive background information on emergency medicine residents and the programs in which they train. Before the compilation of this report, this information has not been widely available.

Improved precision of newborn screening for congenital adrenal hyperplasia using weight-adjusted criteria for 17-hydroxyprogesterone levels

OBJECTIVE

To evaluate the efficacy and efficiency of weight-adjusted threshold levels for 17-hydroxyprogesterone (17-OHP) in screening newborn infants for 21 hydroxylase deficiency-congenital adrenal hyperplasia (21-OH-D-CAH).

DESIGN

Analysis of the number of false-positive reports and diagnoses in infants, of 21-OH-D-CAH with the use of two strategies. Before October 1993, separate criteria for definite abnormal 17-OHP levels were established and implemented for 41,846 infants on the basis of birth weight: either less than 2200 gm (17-OHP level, 90 ng/ml) or 2200 gm or more (40 ng/ml). To reduce the burden of follow-up testing in low birth weight infants, criteria for definite abnormal 17-OHP results were statistically determined for four, rather than two, birth weight divisions: 1299 gm or less (17-OHP level > or = 165 ng/ml), 1300 to 1600 gm (> or = 135 ng/ml), 1700 to 2200 gm (> or = 90 ng/ml), and more than 2200 gm (> or = 40 ng/ml). These criteria were applied to the next 149,684 infants screened, and rates of false-positive test results and of false-positive diagnoses of 21-OH-D-CAH were compared.

RESULTS

Before implementation of four-tiered weight-adjusted 17-OHP criteria, 205 definite abnormal reports yielded four confirmed cases of 21-OH-D-CAH (positive predictive value = 2%; incidence of 21-OH-D-CAH = 1 in 10,461). With the revised criteria, 61 of 149,684 infants had definite abnormal results and 14 cases of 21-OH-D-CAH were confirmed (positive predictive value, 20%; incidence of 21-OH-D-CAH, 1 in 10,692). No undetected severe cases of 21-OH-D-CAH have been subsequently reported.

CONCLUSIONS

Weight-adjusted criteria for 17-OHP levels in screening for 21 -OH-D-CAH markedly reduced the number of false-positive results requiring immediate follow-up testing, particularly among low birth weight infants. Increased specificity afforded by these criteria was not accompanied by diminished sensitivity in detecting severe cases. Long-term follow-up of this screened cohort will determine whether the goals of newborn screening for 21-OH-D-CAH are adequately and efficiently fulfilled by this approach.

An ergonomic perspective on accommodation in accessibility for people with disability

While accessibility has increasingly become a concern in today's society, the implementation of this concern has failed to address many issues. This paper discusses the components of exclusivity, safety, and reasonability in accessibility. Common problems in the implementation of these factors are addressed. These elements in both design for accessibility and evaluation of accessibility, constitute the principle of accommodation in accessibility. The application of ergonomic principles to improve the accommodation of accessibility is proposed.

Randomized multicenter trial comparing synchronized and conventional intermittent mandatory ventilation in neonates

OBJECTIVE

To compare synchronized intermittent mandatory ventilation (SIMV) and conventional intermittent mandatory ventilation (IMV) in neonates.

STUDY DESIGN

Prospective, multicenter, randomized clinical trial.

SETTING

Level III neonatal intensive care units at six university or children's hospitals.

PATIENTS

Three hundred twenty-seven infants receiving conventional IMV for respiratory distress syndrome, pneumonia, or meconium aspiration pneumonitis were randomly assigned a 7.5 +/- 6 hours of age to either continue with IMV or change to SIMV. Infants assigned to each mode of ventilation had similar birth weight (BW), gestational age, and Apgar scores at birth, and similar oxygenation indexes at randomization. They received similar surfactant therapy and had similar incidence of sepsis, seizures, secondary pneumonia, and necrotizing enterocolitis. In the infants with BW less than 1000 gm, more infants receiving IMV had surgical ligation of their patent ductus arteriosus than did those receiving SIMV (27 vs. 7 %; p = 0.02).

ANALYSIS

Data was analyzed overall for all infants and also separately within three BW groups: less than 1000 gm, 1000 to 2000 gm, and more than 2000 gm. The 1000 to 2000 gm BW group was further analyzed in subgroups weighing 1000 to 1499 gm and 1500 to 2000 gm.

RESULTS

In all infants, at 1 hour after randomization, the infants receiving SIMV had a lower mean airway pressure than those receiving IMV (8.08 +/- 2.15 vs. 8.63 +/- 2.59; p<0.05), with similar fractions of inspired oxygen and oxygenation indexes. Infants whose BW was 1000 to 2000 gm at 0.5 hour required a lower fraction of inspired oxygen with SIMV than with IMV (0.52 +/- 0.20 vs. 0.62 +/- 0.27; p<0.05) and had better oxygenation at 1 hour, as shown by lower oxygenation indexes with SIMV than with IMV (6.14 +/- 4.17 vs. 9.42 +/- 8.41; p = 0.01). Infants whose BW was 1000 to 2000 gm received a lower number of unit doses of sedative/analgesic drugs per infant during the first 4 days of SIMV than did infants receiving IMV (3.8 +/- 3.4 vs 6.3 +/- 5.5 unit doses; p = 0.02). Infants whose BW was more than 2000 gm had a shorter duration of mechanical ventilation with SIMV than with IMV (median, 72 vs 93 hours; p = 0.02). Three of the forty-six infants receiving IMV but none of the 47 infants receiving SIMV required extracorporeal membrane oxygenation. In the infants with BW less than 1000 gm, fewer infants treated with SIMV required supplemental oxygen at 36 weeks of postconceptional age than did those treated with IMV (47 vs 72%; p<0.05). In 83 infants whose lungs were mechanically ventilated for 14 days or longer, all with BW less than 2000 gm, those treated with SIMV regained their BW earlier than those treated with IMV (median, 21.5 vs 29 days; p<0.01). There were no differences in the rates of death, intraventricular hemorrhage (grades III and IV), air leak, need for pharmacologic paralysis, or need for supplemental oxygen at 28 days.

CONCLUSIONS

We found that SIMV was at least as efficacious as conventional IMV, and may have improved certain outcomes in BW-specific groups.

Improving estimates of HIV-1 seroprevalence among childbearing women: use of smaller blood spots

OBJECTIVES

Nationwide, human immunodeficiency virus type 1 (HIV-1) seroprevalence surveys using dried neonatal blood specimens are critical to estimating HIV-1 seroprevalence among childbearing women. However, the noninclusion of blood specimens deemed "quantity not sufficient" (QNS) for HIV-1 antibody testing potentially introduces bias. In Wisconsin beginning in 1990, we modified the survey protocol to reduce QNS rates and assess bias introduced by QNS specimens.

METHODS

The HIV-1 antibody assay was modified to use four 1/8-in blood spots when a single 1/4-in blood spot could not be obtained. Both methods obtain identical blood volumes for testing.

RESULTS

During a 27-month period, 7396 (4.8%) of 154,683 specimens were deemed QNS using 1/4-in blood spots. Of these, 6590 (89%) were of sufficient quantity to be tested using four 1/8-in blood spots; 6 (0.09%) specimens tested with 1/8-in blood spots were HIV-1 Western blot assay positive compared with 44 (0.03%) of 147,287 1/4-in specimens (odds ratio = 3.0; 95% confidence interval = 1.2, 7.4).

CONCLUSIONS

Because noninclusion of QNS specimens potentially introduces bias, incorporating the results of HIV-1 antibody testing of QNS specimens using four 1/8-in blood spots can improve the accuracy of HIV-1 seroprevalence estimates in these serologic surveys.

Laboratory quality control issues related to screening newborns for cystic fibrosis using immunoreactive trypsin

We have incorporated the IRT assay for CF to our newborn screening program, relying heavily on electronic data processing to optimize the test results in order to provide the most reliable data possible from the specimen at hand. We have established an internal cut-off of 100 ng/mL and an external referral of 180 ng/mL; this virtually eliminates the possibility that analytical imprecision will result in misidentifying a positive patient specimen. The relationship between IRT levels and various mutant forms of CF are not well established, and it is possible that various forms of CF may exhibit different levels of IRT in the first few days of life. We believe that IRT screening for CF could be a useful procedure for early identification of potential CF. However, by comparison with other newborn screening tests, its sensitivity, 90%, presents a concern. The expectation for PKU, hypothyroidism, MSUD, and galactosemia screening is 100% sensitivity. A false-negative usually results in litigation. The use of IRT in routine newborn screening will require considerable education of the general public and physicians receiving test results. Our program, along with many others, is anxiously watching the developments in the area of gene testing. We feel the relatively inexpensive IRT, used for mass screening can be successfully coupled with the more definitive (and expensive) gene test on a selected population to identify CF at the earliest possible age in a more effective manner. It is possible that in the near future gene probe tests will be applied in a cost effective manner to the initial filter paper specimen.

A study of Enterogyrus sp. (Monogenea) parasitizing the foregut of captive Pomacanthus paru (Pomacanthidae) in Georgia

A species of Enterogyrus Paperna, 1963 (Monogenea: Ancyrocephalidae) parasitizing the foregut of a captive Pomacanthus paru (Pomacanthidae) in Georgia was studied in situ both histologically and with scanning electron microscopy. The worms are found at the junction of the esophagus and stomach and arrange themselves with their main body axis directed perpendicular to longitudinal folds in the foregut wall. They cling to host tissue principally by blades of the pair of large dorsal hamuli and apparently rely little on the action of the pair of small ventral hamuli and the 14 marginal hooks. It is argued that this adhesive attitude allows unrestricted movement when peristaltic waves move along the gut and the worm thereby maintains a stable footing. The body tegument is unusually thick (2 to 5 μm) for the worm's size. Dorsally it is smooth and devoid of microvilli. Ventrally it is thrown into transverse folds having small microvilli and unique round to oval papillae that measure up to 7 μm in diameter. Evidently the modified tegument is an adaptation to life in the foregut, possibly serving to protect worms from digestive enzymes. The study represents the first report of Enterogyrus from a marine host.

The galaxy luminosity function and the redshift-distance controversy (A Review)

The mean relation between distance and redshift for galaxies is reviewed as an observational question. The luminosity function for galaxies is an important ingredient and is given explicitly. We discuss various observational selection effects that are important for comparison of the linear and quadratic distance-redshift laws. Several lines of evidence are reviewed, including the distribution of galaxy luminosities in various redshift ranges, the luminosities of brightest galaxies in groups and clusters at various redshifts, and the Tully-Fisher correlation between neutral hydrogen velocity widths and luminosity. All of these strongly favor the linear law over the quadratic.

Glugea pimephales Fantham, Porter and Richardson, 1941, n. comb. (Microsporidia, Glugeidae) in the fathead minnow, Pimephales promelas

A microsporidan parasite, fitting the description of Nosema pimephales Fantham, Porter and Richardson, 1941, was found in fry of the fathead minnow, Pimephales promelas Rafinesque, from the Wray Fish Hatchery near Fort Morgan, Colorado. More detailed studies proved it to be a typical species of Glugea Thélohan, 1891, to which genus it was transferred. Presence of a delicate sporophorous vesicle, like that recently demonstrated in the type species, was observed. A sequence of three distinct kinds of divisions within that membrane, beginning with the plasmodium and ending with sporoblasts, was recognized. These were plasmotomy, multiple fission, and binary fission. The first two kinds, under the one name or the other, have been treated as one process in previous studies on species of Glugea. Results of this, a well as of recent studies, compel us to reconsider our concepts of "sporont" and "sporogony."

Dual-channel continuous-flow system for determination of phenylalanine and galactose: application to newborn screening

We describe a dual-channel AutoAnalyzer (Technicon) system for the simultaneous measurement of phenylalanine and galactose from blood specimens on filter-paper. Using a single 1/4-in.-diameter (6-mm) specimen, we measure both components fluorometrically at a rate of 70/h. Analytical recovery with the method and the linearity of measurements vs sample concentration are excellent through the ranges of interest, 0-200 mg/L for phenylalanine and 0-800 mg/L for galactose. Carryover at the critical values during screening, 40 mg/L for phenylalanine and 100 mg/L for galactose, is essentially zero. The dual-channel system provides the means to incorporate a low-incidence test, i.e., galactosemia (incidence 1/70 000), into an existing program for phenylalanine analysis, for which the higher rates (phenylketonuria, incidence 1/11 500) easily justify the cost of mass screening.

Dual-channel continuous-flow system for determination of phenylalanine and galactose: application to newborn screening

We describe a dual-channel AutoAnalyzer (Technicon) system for the simultaneous measurement of phenylalanine and galactose from blood specimens on filter-paper. Using a single 1/4-in.-diameter (6-mm) specimen, we measure both components fluorometrically at a rate of 70/h. Analytical recovery with the method and the linearity of measurements vs sample concentration are excellent through the ranges of interest, 0-200 mg/L for phenylalanine and 0-800 mg/L for galactose. Carryover at the critical values during screening, 40 mg/L for phenylalanine and 100 mg/L for galactose, is essentially zero. The dual-channel system provides the means to incorporate a low-incidence test, i.e., galactosemia (incidence 1/70 000), into an existing program for phenylalanine analysis, for which the higher rates (phenylketonuria, incidence 1/11 500) easily justify the cost of mass screening.

Two new species of Myxozoa, Myxobolus inaequus sp. n. and Henneguya theca sp. n. from the brain of a South American knife fish, Eigemannia virescens (V.)

Two new species of Myxozoa from the brain of the green knife fish Eigemannia virescens are described: Myxobolus inaequus sp. n. has an unusually large spore body and extremely unequal polar capsules, and Henneguya theca sp. n. has an attenuated spore encased in a sheath not previously described in other Myxozoa . Only spores of the two species were observed, and infections caused no obvious pathological changes in the brain.

Arsenic uptake and loss in the American oyster, Crassostrea virginica

In addition to a control Crassostrea virginica was treated with 3 and 5 μg As kg(p-1) for 16 wks at ambient seawater salinity and temperature to determine the potential of C. virginica as an indicator of arsenic pollution. Prior to spawning, as much as 10.3±1.5, 12.7±2.7, and 14.1±3.7 μg As g(p-1) dry weight were accumulated in the total soft parts of oysters after treatment with ambient (control), 3 and 5 μg As kg(-1), respectively. Immediately after spawning, an increase in tissue arsenic concentration was observed in all treatments up to week 12, after which a decrease in tissue arsenic concentrations occurred despite continuous addition of arsenic to the seawater. During the uptake period, a significant inverse relationship existed between dry weight and tissue arsenic concentration, whereas a significant direct relationship was apparent between dry weight and tissue content. Arsenic concentration in the total soft parts is not significantly related to seawater arsenic concentration over the range of concentrations used in this study. In all three treatments, arsenic uptake as concentration (μg g(p-1)) is not a significant linear function of time. Weight loss was significant but gradual during the first 16 wks of treatment and did not change significantly during the depuration period (wks 17-25). Tissue arsenic concentrations increased significantly in oysters from all three treatments during the depuration period. Generally, arsenic body burdens increased with increases in phytoplankton concentration and it appears that food contributes more to arsenic uptake than seawater arsenic concentrations. Since a relationship between tissue arsenic concentration and seawater arsenic concentration does not appear to exist, C. virginica would not be a good biological indicator of arsenic concentration in its environment.

Pathogenicity and histopathology of an unusually intense infection of white grubs (Posthodiplostomum m. minimum) in the fathead minnow (Pimephales promelas)

A massive infection of metacercariae, particularly of the white grub (Posthodiplostomum m. minimum), was found in fathead minnows (Pimephales promelas) taken in November, 1979 from a commercial baitfish farm in Missouri. More than 2000 metacercariae were found in one fish 6 cm long. Low-grade mortality was occurring, and histologic sections showed that an intensive inflammatory response had resulted from the infection. The body cavity also contained a large volume of ascitic fluid with many blood cells, of which 92% were leucocytes. Moderate numbers of metacercariae caused a lesser inflammatory response.

Characterization of a C3/C3b regulatory protein in normal human serum

A protein which alters the activity of C3 and C3b has been isolated from normal human serum by sequential column chromatography. In purified form, at normal serum concentration, this protein fixes to cell-bound C3b. It cannot bind to C3d. After fixation, it prevents the inactivation of C3b by beta 1H and C3bINA in both the classical and alternative pathway C5 convertases. Independent of this action, fixation to C3b also markedly enhances the subsequent activity of C5. At higher concentrations, however, this protein is capable of blocking the activation of C3 by both pathway C3 convertases. This material, therefore, appears to represent a potent means of regulating several critical aspects of the biologic activity of the complement system.

A comparison of hard and soft glass blood-drawing tubes

The authors examined both hard and soft glass evacuated blood-drawing tubes for possible effects on clinical chemistry measurements. Using routine laboratory procedures, no clinically or statistically significant difference could be detected in 34 analytes using 66 different methods. A special high-precision study utilizing an adaption of the NBS round-robin procedures for calcium, magnesium, sodium, and potassium detected no difference between paired sera when drawn or stored for 72 hours, or both, in the two types of glass. The authors conclude that the type of glass used in production of the evacuated blood-drawing tubes does not affect the clinical chemistry results obtained.

The parasitic coelenterate, Polypodium hydriforme USSOV, from the eggs of the American acipenseriform Polyodon spathula

No significant differences in macro- and micromorphology were found between the parasitic stolon and free-living polyps of Polypodium sp. obtained from infected eggs of the North American acipenseriform fish Polyodon spathula and corresponding developmental stages of Polypodium hydriforme Ussov, parasitic in the Volga sterlet (Acipenser ruthenus). Therefore, both the American and the European forms of Polypodium belong to the species P. hydriforme Ussov.

Aneurysms of extracranial carotid arteries

Twenty-three extracranial carotid artery aneurysms were encountered in 19 patients. Arteriosclerosis was evident in 16 aneurysms. Severe arterial hypertension affected all patients with arteriosclerotic lesions. Trauma, penetrating neck injury once, and blunt neck injury three times caused four aneurysms. Three aneurysms resulted from earlier carotid artery operations. All 19 patients were symptomatic. Neurologic symptoms affected 13 individuals. Local symptoms referable to the aneurysmal mass troubled 15 patients. Twenty-one aneurysms were treated operatively. There was no operative mortality. Aneurysmectomy with arterial reconstruction was performed 16 times. Aneurysmorrhaphy was undertaken on four occasions and carotid ligation once. Two strokes and multiple cranial nerve injury accounted for three operative complications. No neurologic complications occurred during follow-up totaling 360 man-months. These lesions may be successfully treated by a carefully performed, properly selected operation.

Whirling disease (Myxosoma cerebralis): control with ultraviolet irradiation and effect on fish

Water contaminated by Myxosoma cerebralis was disinfected with ultraviolet irradiation to control whirling disease. Irradiation at 18,000 microwatt seconds/cm2 (MWS/cm2) reduced infectivity of M. cerebralis by 31-86% and 27,650 MWS/cm2 reduced infectivity by 86-100%, even in the presence of a small amount of silt.

A disease of freshwater fishes caused by Tetrahymena corlissi Thompson, 1955, and a key for identification of holotrich ciliates of freshwater fishes

Tetrahymena corlissi, a free-living protozoan, apparently caused the death of large number of guppies (Poecilia reticulatus) and occasionally other fishes, in aquaria and hatcheries at several locations. Apparently the disease occurs when the fish and protozoan populations are both at a high level of density. The signs include white spots and epidermal damage. Histologically, T. corlissi could be seen in skin, muscle, and viscera; in some there was marked inflammation, in others there was little tissue reaction. A key is presented for the identification of invasive fish ciliates: Chilodonella, Hemiophrys, Ichthyophthirius, Ophryoglena, and Tetrahymena.

Atmospheric Trace Metals at Remote Northern and Southern Hemisphere Sites: Pollution or Natural?

The chemical composition of atmospheric particles collected near sea level over the North Atlantic indicates that Al, Sc, Mn, Fe, Co, Cr, Na, Mg, Ca, K, and Sr are derived from either crustal weathering or the ocean. The elements V, Zn, Cu, Cd, Pb, Sb, and Se are present in concentrations higher than expected from these sources. Although the V is probably derived from pollution sources on the North American continent, a comparison of enrichment factors relative to average crustal material for the remainder of these elements over the North Atlantic with enrichment factors for similar samples collected at the geographic South Pole suggests that the anomalously high enrichment factors may be due to natural rather than anthropogenic sources. A vapor phase for these metals may be involved at their source.

Variation in response of channel catfish to Henneguya sp. infections (Protozoa: Myxosporidea)

Infections in channel catfish (Ictalurus punctatus, Rafinesque) induced by the sporozoan Henneguya (Protozoa: Myxosporidea) result in seven known and diverse disease manifestations. Most outstanding is an interlamellar branchial form responsible for significant losses among immature catfish, and a unique papillomatous form. The question of whether or not the species of Henneguya involved in these cases is H. exilis remains to be resolved.

Incidental Aquatic Zoonoses

The following incidental aquatic zoonoses are discussed: eosinophilic mengingitis caused by Angiostrongylus cantonesis, the Guinea worm (Dracunculus medinesis), Anisakis infections, Cryptocotyle lingua, eye fluke (Philophthalmus), the tapeworm Diplogonoporus grandis, and shellfish-borne hepatitis.

Control Methods for Snail-Borne Zoonoses

All trematodes which cause infections and diseases in humans (zoonoses) require snails for their first intermediate host. Some have additional intermediate hosts such as crustaceans, fishes and frogs. In this paper I have discussed the use of various procedures for controlling snail populations thereby reducing the population of trematodes whose cercariae penetrate the skin of man, or which are acquired by eating raw aquatic vegetation such as watercress, or which cause pathology in fish. Biological, chemical, and physical snail control techniques are discussed. The most promising molluscucides are copper compounds, Bayluscide, biocidal rubber and molluscicidal bait.