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Biomedical subjects

G R Frank

Publications and source records attributed to G R Frank.

At least 37 records · Page 2Linked to original sources

Antibody to the Dirofilaria immitis aspartyl protease inhibitor homologue is a diagnostic marker for feline heartworm infections.

Feline heartworm disease, caused by the filarial nematode Dirofilaria immitis, has been diagnosed with increased frequency in areas endemic for canine heartworm infection. The routine methods for determining the infection status of dogs, such as identification of circulating microfilariae in blood or identification of circulating antigen in serum, plasma or blood, have proven inadequate for screening cats. The inadequacies are due to the likelihood of single-sex infections and clinical disease during prepatent infections. Current antibody detection methodologies rely on crude or partially purified worm antigen preparations that may result in poor specificity. This report describes the cloning, expression, and diagnostic utility of the D. immitis homologue (PDi33) of the Onchocerca volvulus aspartyl protease inhibitor (Ov33). PDi33 is present in all stages that occur in the mammalian host (microfilariae, L3, L4, adult males, and females) and is released by adults cultured in vitro. An indirect enzyme-linked immunosorbent assay (ELISA) using antibody to recombinant PDi33 as a diagnostic marker for infection in cats was very sensitive and was useful for identifying prepatent infections. Testing of sera from cats infected with common gastrointestinal parasites also indicated excellent specificity. The same ELISA in dogs, although demonstrating reasonable sensitivity and specificity, appeared to be of less value as compared with the currently accepted antigen detection methodologies.

Animals↗

Progesterone-dependent decidualization of the human endometrium is mediated by cAMP.

Progesterone is a key factor in regulating endometrial cell decidualization, but the signal transduction pathways involved in mediating the effects of progesterone are not known. A role of the cAMP pathway in decidualization has been suggested by in vitro studies demonstrating that cAMP agonists can stimulate decidualization, in the absence of sex steroids. In this article, we have used an in vitro culture model of progesterone-dependent decidualization of human endometrial stromal cells to examine whether progesterone-induced decidualization is associated with activation of the cAMP signal transduction pathway in which the prolactin gene expression is a marker of decidualization. Following a lag period of approx 3 d, progesterone induced prolactin secretion and elevated intracellular cAMP levels. By d 15, cAMP and prolactin levels were approx 10- and 60-fold greater, respectively, than those on d 3. Changes in cAMP levels showed a positive correlation with prolactin secretion. Prostaglandin E2 (PGE2), which enhances progesterone-dependent decidualization, also increased both prolactin secretion and cAMP levels approx two- to fourfold on d 15 compared with d 3, whereas PGE2 alone, which does not induce decidualization, did not stimulate prolactin secretion or intracellular cAMP accumulation. Conversely, all-trans retinoic acid, which attenuates progesterone-dependent decidualization, significantly (p < 0.05) decreased both prolactin secretion and cAMP levels. Furthermore, the protein kinase A (PKA) inhibitor, 8-bromoadenosine-3',5'-cyclic monophosphorothioate, significantly (p < 0.05) suppressed progesterone-dependent prolactin expression. Since activation of the PGE2 receptor subtype EP2 stimulates adenylate cyclase, reverse transcription-polymerase chain reaction (RT-PCR) analysis of endometrial cells was undertaken. Expression of EP2 mRNA was induced in cells treated with progesterone and estradiol alone or with PGE2, compared with untreated controls. The data suggest that the cAMP signal transduction cascade is activated during progesterone-dependent decidualization.

8-Bromo Cyclic Adenosine Monophosphate↗

Phantoms and automated system for testing the resolution of ultrasound scanners.

Tissue-mimicking phantoms and an automated system have been developed for testing the resolution performance of ultrasound scanners by determining detectability of low to higher contrast spherical lesions over the entire depth of field. Axial, lateral and elevational resolutions are accounted for simultaneously and equally. Tissue-mimicking spherical simulated lesions are either 3 or 4 mm in diameter and have one of four different intrinsic material contrasts. For each diameter and contrast, there is a set of 109 lesions in a regular array with coplanar centers extending from 0.5-15.5 cm in depth. With the scan slice superimposed on the spheres, the image is frame-grabbed for automated analysis. A diameter-dependent lesion signal-to-noise ratio is computed for each pixel position in the image, excluding a 5-mm boundary. Two universal thresholds, resulting from maximization of agreement between the automated system and human observers, give rise to a depth range, or "resolution zone", over which detection exists for each type lesion.

Image Enhancement↗

Effect of dietary energy source and immunological challenge on growth performance and immunological variables in growing pigs.

Forty-eight growing pigs (23 kg BW) were assigned to four treatments (n = 12) arranged as a 2 x 2 factorial. Dietary energy source (conventional [CON] vs high-oil corn [HOC]), with or without an immunological challenge (IC) regimen constituted main effects. The IC regimen consisted of injection of endotoxin (E. coli lipopolysaccharide [LPS]) and vaccination for porcine respiratory and reproductive syndrome (PRRS). Growth performance data were collected over a 5-wk period and are presented as prechallenge (d 1 to 14; d 1 was the 1st d of the study), challenge (d 15 to 21), and postchallenge (d 22 to 36) periods, and overall. Overall, the pigs fed HOC consumed less feed (P < .11) and gained more efficiently (P < .03). During the immunological challenge period, ADG was depressed 21% and feed intake 15% (P < .01). The IC resulted in lower (P < .01) serum alpha-1-acid glycoprotein (AGP) concentrations on d 22, and the magnitude of the reduction was greater in the pigs fed the CON diet (energy source x immune challenge, P < .10). Serum AGP concentrations remained lower (P < .08) in challenged pigs on d 36. Immunoreactive prostaglandin concentrations were higher (55%, P < .08) in the pigs fed HOC immediately following the IC period (d 22). The data reported herein indicate that the performance of pigs fed HOC is satisfactory, and that feeding HOC does not compromise growth performance during or after an immunological challenge.

Acute-Phase Proteins↗

Purification and characterization of three larval excretory-secretory proteins of Dirofilaria immitis.

Two proteins were previously described in the excretory-secretory products (ES) collected from Dirofilaria immitis during the molt from the third stage to the fourth stage in vitro. The two proteins were purified using cation exchange and reverse phase HPLC. During the purification of these two proteins, a third protein was identified that co-migrated with one of the others during previous gel analysis. All three had molecular masses of 20-23 kDa as determined by Tris-glycine SDS-PAGE and have been designated 20, 22L and 22U kDa proteins. The three proteins were digested with trypsin. Amino acid sequences were subsequently determined for four peptides and the N-terminus of the 20 kDa protein, five peptides of the 22L kDa protein and three peptides of the 22U kDa protein. The 20 and 22L kDa proteins were quite similar based on sequence and purification characteristics. The 22U kDa protein, but not the 20 and 22L kDa proteins, was also identified in adult worms using tryptic mapping and amino acid sequencing techniques. Immunoblot analysis demonstrated that the 20 and 22L kDa proteins were specifically recognized by sera from dogs immune to infection by D. immitis but not by sera from infected non-immune dogs. The 22U kDa protein was weakly recognized by the same immune sera but not by the infected non-immune dog sera. Since the 20 and 22L kDa proteins appear to be larval specific, associated in time with the molt from L3 to L4 and are specifically recognized by immune dog sera, they are good vaccine candidates.

Amino Acid Sequence↗

Molecular cloning of a developmentally regulated protein isolated from excretory-secretory products of larval Dirofilaria immitis.

Three proteins isolated from the excretory-secretory products (ES) of larval Dirofilaria immitis have been previously characterized and termed the 20, 22L and 22U kDa proteins. Two of the proteins (20 and 22L) were produced and released around the time of the third molt and were specifically recognized by immune dog sera. An amino acid sequence common to both proteins was used to synthesize a DNA probe to molecularly clone these molecules from a 48-h third stage larval cDNA library. The DNA sequence of the isolated clones encoded a 17.5 kDa protein with a 21 amino acid hydrophobic leader sequence that when removed yielded a 15.3 kDa protein starting with the N-terminal sequence obtained from the 20 kDa protein and containing all sequences obtained from tryptic peptides of the 20 and 22L kDa proteins. It was hypothesized that the 20 and 22L kDa proteins were the same, differing only by a 21 amino acid hydrophobic leader sequence which was later cleaved. The calculated molecular masses were consistent with those determined by reducing Tris-tricine SDS-PAGE. Expression of the protein without the leader sequence was accomplished in Escherichia coli. Antiserum raised against the expressed protein demonstrated the presence of the protein in L3 and L4, but not in adults or microfilariae. Expression of the protein with the leader sequence using a baculovirus system demonstrated processing of the signal sequence at the same time as found in larval D. immitis ES. Sera from dogs immune to infection were reactive with the D. immitis proteins expressed in either E. coli or insect cells.

Amino Acid Sequence↗

Linear growth in response to growth hormone treatment in children with short stature associated with intrauterine growth retardation: the National Cooperative Growth Study experience.

Short stature commonly follows intrauterine growth retardation (IUGR). Most patients are not growth hormone (GH)-deficient, but GH therapy has been used in IUGR. Early studies found a heterogeneous increase in initial growth rate that could not be maintained. Results of more recent studies with higher doses are more encouraging but do not establish whether final height is increased. Data from a large number of patients in the National Cooperative Growth Study were reviewed to evaluate the response to GH treatment in patients with IUGR-associated short stature. Two hundred seventy such patients were identified and were categorized as those with unclassified IUGR and those with Russell-Silver syndrome/primordial short stature (RSS/PSS). Patients were treated with standard doses of recombinant human GH (approximately 0.3 mg/kg per week) and were assessed periodically for up to 4 years. The height SD score at baseline in patients with unclassified IUGR was -3.49 +/- 1.16, and their relative height improved with each year of therapy. Patients who completed 4 years of treatment reached a height SD score of -1.32 +/- 0.79. Results were similar in patients with RSS/PSS; their baseline height SD score was -3.83 +/- 1.05 and improved to -2.10 +/- 0.99 by year 4. Despite these encouraging results, no change occurred in predicted adult heights. Furthermore the number of patients who remained in treatment for 4 years decreased substantially, thus limiting the interpretation of the data. These data suggest that a beneficial response to GH occurs in some patients with IUGR-associated short stature and that little difference exists in the responses in patients with RSS/PSS compared with those in patients with unclassified IUGR.

Adolescent↗

Predicting the growth response to growth hormone in patients with intrauterine growth retardation.

OBJECTIVE: Human GH treatment of short children who had intrauterine growth retardation (IUGR) results in a highly variable growth response. The object of this study was to test the hypothesis that differences in responsiveness to exogenously administered GH might reflect differences in endogenous GH secretion or sensitivity. DESIGN: Prospective study evaluating th growth response to GH therapy in short individuals with prior IUGR. PATIENTS: Ten short, prepubertal children with prior IUGR were studied. Mean age was 6 years (3.39-8.61). Mean bone age was 4.6 years (2.3-8.3). Mean body mass index was 13.2 kg/m2 (9.9-14.0; normal 13.5-19.0). MEASUREMENTS: Overnight spontaneous GH release was measured using a constant withdrawal pump and stimulated GH release was measured following clonidine (0.15 mg/m2) administration. IGF-I concentrations were measured at baseline and 12, 24, 36 and 48 hours after sequential doses of GH (0.05 and 0.2 mg/kg/dose) given 48 hours apart. Patients were treated with GH (0.125 mg/kg three times a week) and growth response was assessed. In the second and third year, attempts were made to improve the growth rate by nutritional supplementation and increasing the dose of GH to 0.25 mg/kg three times a week. RESULTS: All patients had normal integrated nocturnal GH secretion (> 3 micrograms/l, 6mU/l) and normal peak GH secretion in response to clonidine (> 7 micrograms/l). In the first year of the trial, mean growth velocity (GV) increased from 5.39 cm/year +/- 0.29 to 7.32 cm/year +/- 0.39 (P = 0.004). Changes in GV correlated inversely with integrated GH (r = -0.69; P = 0.038), baseline IGF-I concentration (r = -0.88; P = 0.002) and baseline GV-SDS (r = -0.68; P = 0.043). There was no correlation between change in GV and GH binding protein, baseline height SDS or age. The effect of GH waned in the second year, but tended to remain greater than the pretreatment growth rate (6.54 +/- 0.49 vs 5.53 cm/year +/- 0.29; P = 0.09). No significant advancement of bone age over chronological age was observed over the first 2 years. Increasing nutritional intake by 17% did not result in significant weight gain nor increase in height velocity. Doubling the dose of GH in the second or third year did not result in a significant increase in GV. CONCLUSION: The variable response to GH therapy in short children with a history of intrauterine growth retardation may partly reflect relative sufficiency or insufficiency of GH. Baseline IGF-I levels and baseline growth velocity appear to be useful and practical predictors of response to GH.

Body Height↗

Laminin decreases PRL and IGFBP-1 expression during in vitro decidualization of human endometrial stromal cells.

The expression of laminin, a major constituent of endometrial cell basement membranes, is increased during differentiation of human endometrial stromal cells (decidualization). To determine whether laminin plays a role in decidualization, we studied the effects of laminin substrate on the synthesis and release of prolactin (PRL) and insulin-like growth factor binding protein-1 (IGFBP-1), two major secretory proteins of decidualized stromal cells. Endometrial stromal cells were plated on laminin as well as several other extracellular matrix (ECM) proteins (types 1 and IV collagen or fibronectin) and on plastic, and cultured in media containing medroxyprogesterone acetate (MPA) and estradiol. Cells cultured on plastic or ECM proteins displayed similar morphological changes indicative of decidualization. However, the release of PRL and IGFBP-1 from cells cultured on plastic and ECM proteins (types 1 and IV collagen and fibronection) was approximately 2.1-fold and 2.8-fold greater respectively, than from cells cultured on laminin. The decrease in PRL and IGFBP-1 expression in cells cultured on laminin was not due to differences in initial cell attachment efficiency or final DNA content. In addition, laminin had no effect on the content of laminin protein or fibronectin mRNA levels, indicating that the effects of laminin on PRL and IGFBP-1 were specific. PGE2 stimulated the release of PRL and IGFBP-1 from cells cultured on laminin to levels comparable to those from cells cultured on plastic or other ECM proteins. This indicates that the decrease in PRL and IGFBP-1 release by laminin was not due to a generalized unresponsiveness. In contrast to the effects of laminin during decidualization, PRL expression was not altered by laminin in terminally differentiated decidual cells isolated at term. Our results support a role for laminin in selectively regulating PRL and IGFBP-1 gene expression during in vitro decidualization of human endometrial stromal cells.

Carrier Proteins↗

Vaccine research and development for the prevention of filarial nematode infections.

The development of vaccines for the prevention of filarial nematode infections is in a state of relative infancy in comparison to vaccines for other parasitic diseases, such as schistosomiasis and malaria. There are many reasons for this slow start. Some of the principal problems are: (1) the lengthy and complex life cycle of these organisms with attendant complex immune responses, (2) the unique characteristics associated with a relatively large number of different pathogens, (3) the lack of suitable model systems for study of medically important infections, (4) the paucity of parasite material for antigen discovery and recombinant library construction, (5) the lack of substantial evidence suggesting the natural occurrence of protective immune responses, and (6) the limited data on mechanisms responsible for protective immunity. As technical hurdles are considered, it is also critical to focus on the characteristics of a vaccine necessary for its eventual utility. In the case of a vaccine for D. immitis a completely successful product will need to approach a 99+% efficacy. This is because of the 99+% efficacy of competitive chemotherapeutic products and the fact that microfilaremia observed on blood examination, resulting from as few as two worms, would present as a vaccine failure. Although very low worm burdens in large dogs could be perceived as success in the context of protection from clinical disease, because of the option of virtually complete chemoprophylactic protection, the typical veterinary practitioner would probably fail to appreciate less than complete vaccine protection. In contrast, a vaccine that produced a reduction in adult worm burdens without complete protection in either lymphatic filariasis or onchocerciasis would be very important. Highly effective chemoprophylactic agents are not widely available for prevention of the human filariases, and dramatically reduced clinical disease provided by less than a completely effective vaccine could occur as the result of fewer adult worms. The importance of developing these vaccines has outweighed the obstacles to this research. There has been a great deal of epidemiological and experimental evidence to suggest a vaccine is feasible and antigen discovery has progressed relatively rapidly within just the past few years. Efforts to generate appropriate larval cDNA libraries are beginning to yield dividends and a variety of fascinating vaccine candidates have been cloned. Additional antigen discovery, research on appropriate modalities for overexpression of genes from these parasites, and the complex tasks associated with vaccinology remain as significant research and development obstacles.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

Gliding bacterial adjuvant stimulates feline cytokines in vitro and antigen-specific IgG in vivo.

Gliding bacterial adjuvant (GBA) has been previously characterized as a potent immune modulator, stimulating the growth of murine B lymphocytes, inducing murine NK cell activity, and promoting the release of several murine cytokines. Based on these studies and our interest in potentiating the effectiveness of feline vaccines, GBA was tested for its ability to stimulate feline T cells in vitro and act as a vaccine adjuvant in vivo. In vitro, GBA stimulated feline PBLs to proliferate and release interferon (IFN) and IL-2. Unlike IFN, the release of IL-2 appeared to be unaffected by prior depletion of macrophages, indicating GBA directly stimulated feline T cells. In vivo GBA was co-administered with Keyhole Limpet Hemacyanin (KLH) and the anti-KLH antibody response was compared to cats receiving KLH emulsified in complete Freund's adjuvant (CFA). Fourteen days after the third immunization and continuing for a 30-day observation period, KLH-specific IgG titers in cats receiving GBA were significantly higher than those given CFA. However, when cats were subsequently boosted with KLH alone, those cats receiving CFA demonstrated significantly higher antibody titers throughout a second 30-day observation period. The anti-KLH antibody memory response was greatly enhanced when GBA was emulsified with incomplete Freunds adjuvant (IFA) prior to injection. Serum titers of cats given KLH in an oil-based GBA preparation were significantly higher than cats receiving KLH adjuvanted with IFA or CFA, an effect which persisted 38 days after boosting with KLH alone. Finally, GBA significantly enhanced the feline humoral response to a recombinant protein of Dirofilaria immitis, the causative agent of feline heartworm. Serum titers of cats inoculated with recombinant antigen in GBA were significantly greater than cats given recombinant antigen adjuvanted with Titermax, alum, or NAGO. These studies indicate that GBA induces T cell proliferation and the release of IL-2 and IFN in vitro and can be used to enhance the recall antibody response to both a T cell dependent antigen and an immunogen derived from Dirofilaria immitis.

Adjuvants, Immunologic↗

Interleukin-1 beta and the endometrium: an inhibitor of stromal cell differentiation and possible autoregulator of decidualization in humans.

Interleukin-1 beta (IL-1 beta), which modulates cell proliferation and differentiation in a number of cell types, is present in human endometrial stromal cells. However, both the function of IL-1 beta in endometrium and the factors that modulate its expression in endometrial stromal cells are unknown. To examine the effects of IL-1 beta on decidualization, human proliferative endometrial stromal cells were cultured for 12 days in medium (Dulbecco's Modified Eagle's medium with 2% fetal bovine serum) containing 1 microM medroxyprogesterone acetate, 10 nM estradiol, and 1 microM prostaglandin E2 (PGE2) with and without IL-1 beta (17 pg/ml). Morphologic changes as well as release of prolactin (PRL) and insulin-like growth factor binding protein-1 (IGFBP-1) were used as markers of decidualization. Morphologic analysis of cells exposed to IL-1 beta revealed incomplete decidualization. In addition, cells exposed to IL-1 beta released 40% less PRL and 85% less IGFBP-1 than cells cultured in the absence of IL-1 beta, and the PRL mRNA content of the IL-1 beta-exposed cells was decreased by 68%. A possible role for ovarian steroids in the modulation of IL-1 beta expression in the endometrium is suggested by the increase in IL-1 beta mRNA that occurs in late secretory endometrium and by the induction of IL-1 by estrogen and progesterone in the mouse uterus.(ABSTRACT TRUNCATED AT 250 WORDS)

Base Sequence↗

Fibroblast cells from term human decidua closely resemble endometrial stromal cells: induction of prolactin and insulin-like growth factor binding protein-1 expression.

Term decidual tissue consists of terminally differentiated decidual cells, bone marrow-derived cells, and fibroblast cells. Since undifferentiated decidual cells are fibroblast-like cells of the endometrial stroma, the possibility exists that the fibroblast cells in term decidua are undifferentiated decidual cells. To test this hypothesis, a purified population of fibroblast cells was isolated from term decidua and treated under conditions that are known to induce differentiation of endometrial stromal cells. By flow cytometry and immunocytochemistry, the fibroblast cells from term decidua were shown to be free of cells expressing bone marrow-derived cell-surface antigens and the epithelial cell marker cytokeratin. In addition, they tested positive for the cytoskeletal protein vimentin, thus establishing that they were mesenchymal cells. As with endometrial stromal cells, continuous treatment of the decidual fibroblast cells with the progesterone analog medroxyprogesterone acetate and estradiol in combination with either dibutyryl-cAMP or prostaglandin E2 induced cell aggregation and the expression of prolactin (PRL) and insulin-like growth factor-binding protein-1 (IGFBP-1). When cells were plated at an initial cell density of 0.25 x 10(6) cells/well in a 24-well culture dish with medium changes every three days, PRL was first detected on Days 4-6, and the peak of averaged 24 h-PRL release (30 ng/well) occurred on Days 26-28. The mRNA for decidual fibroblast PRL followed a temporal pattern corresponding to that of the released hormone. The size of the PRL mRNA was 1.15 kb, corresponding to the alternately spliced PRL mRNA reported for decidualized endometrial stromal cells and other extrapituitary sources of PRL.(ABSTRACT TRUNCATED AT 250 WORDS)

Antigens, Surface↗

The role of estrogen in pubertal skeletal physiology: epiphyseal maturation and mineralization of the skeleton.

The year 1994 is likely to be remembered by many endocrinologists as the year in which dramatic new light was shed on the role played by estrogen in human skeletal physiology. It was in 1994 that two new syndromes were described, each representing a human model in which estrogen action was lacking. The first case was a female with an aromatase defect and a resultant inability to synthesize estrogen, and the second case was a man with an estrogen receptor gene defect that resulted in a non-functioning estrogen receptor and complete estrogen resistance. By examining the phenotypes of these two individuals, we were able, for the first time, to see what pubertal skeletal changes occur in the absence of estrogen action and directly extrapolate the role of estrogen in skeletal physiology. What has become abundantly clear is that it is estrogen and not androgen that is responsible for pubertal epiphyseal maturation and skeletal mineralization.

Androgens↗

Estrogen resistance caused by a mutation in the estrogen-receptor gene in a man.

BACKGROUND AND METHODS: Mutations in the estrogen-receptor gene have been thought to be lethal. A 28-year-old man whose estrogen resistance was caused by a disruptive mutation in the estrogen-receptor gene underwent studies of pituitary-gonadal function and bone density and received transdermal estrogen for six months. Estrogen-receptor DNA, extracted from lymphocytes, was evaluated by analysis of single-strand-conformation polymorphisms and by direct sequencing. RESULTS: The patient was tall (204 cm [80.3 in.]) and had incomplete epiphyseal closure, with a history of continued linear growth into adulthood despite otherwise normal pubertal development. He was normally masculinized and had bilateral axillary acanthosis nigricans. Serum estradiol and estrone concentrations were elevated, and serum testosterone concentrations were normal. Serum follicle-stimulating hormone and luteinizing hormone concentrations were increased. Glucose tolerance was impaired, and hyperinsulinemia was present. The bone mineral density of the lumbar spine was 0.745 g per square centimeter, 3.1 SD below the mean for age-matched normal women; there was biochemical evidence of increased bone turnover. The patient had no detectable response to estrogen administration, despite a 10-fold increase in the serum free estradiol concentration. Conformation analysis of his estrogen-receptor gene revealed a variant banding pattern in exon 2. Direct sequencing of exon 2 revealed a cytosine-to-thymine transition at codon 157 of both alleles, resulting in a premature stop codon. The patient's parents were heterozygous carriers of this mutation, and pedigree analysis revealed consanguinity. CONCLUSIONS: Disruption of the estrogen receptor in humans need not be lethal. Estrogen is important for bone maturation and mineralization in men as well as women.

Adult↗

Transient erythroblastopenia in a child with Kawasaki syndrome: a case report.

PURPOSE: We describe for the first time the case of a child with Kawasaki syndrome and associated transient erythroblastopenia. PATIENTS AND METHODS: A 5 1/2-month-old infant with Kawasaki syndrome as evidenced by lymphadenopathy, fever, rash conjunctival injection, and extremity changes had associated anemia and reticulocytopenia requiring transfusion and thrombocytopenia. Bone marrow aspiration was consistent with a transient erythroblastopenia. She developed cardiac aneurysms despite therapy with i.v. immunoglobulin and aspirin. RESULTS: The anemia and reticulocytopenia resolved with normalization of her hemoglobin. The platelet count increased and she developed a thrombocytosis characteristic of this clinical entity. She completely recovered without recurrence of either the anemia or reticulocytopenia. CONCLUSIONS: We speculate that the cause of the erythroblastopenia and thrombocytopenia is an inflammatory insult of Kawasaki syndrome on the bone marrow and its various lineages causing the myriad hematological abnormalities now associated with Kawasaki syndrome. It is possible that the i.v. immunoglobulin aids in neutralizing the triggering agent and therefore shortening the duration of the marrow insult.

Female↗

Performance testing of transrectal US scanners.

PURPOSE: To test the performance of transrectal ultrasound (US) scanners in the detection of low-contrast focal lesions as a function of depth, size, and contrast. MATERIALS AND METHODS: US images of two phantoms were analyzed by three observers. One phantom was most suitable for US units allowing scanning in the transverse or longitudinal planes, while the other was suitable for any scanning situation. Both phantoms were made of tissue-mimicking material and had six sections. Five sections contained different sizes of low-contrast simulated lesions, which were of different echogenicities and were randomly distributed to a depth of 8 cm. The sixth section contained only background material and served as a reference. A resolution zone, corresponding to the depth range over which a given type of lesion was detectable, was determined for each of the five lesion-containing sections and a figure of merit equal to a weighted sum of resolution zone lengths computed. RESULTS: Data from 12 different scanner configurations were analyzed; a broad range of figures of merit were found. Agreement was found among the three observers regarding relative performance of the scanner configurations. CONCLUSION: The phantoms are useful for comparing performances of different transrectal US configurations.

Evaluation Studies as Topic↗