Hb Santa Juana (ß 108(G10) Asn > Ser): a low oxygen affinity hemoglobin variant in a family of Bosnian background.

We present a family that carries the ß-hemoglobin variant Hb Santa Juana (HBB:c.326A>G, ß 108(G10) Asn>Ser), also known as Hb Serres, in three generations. All affected family members had an anomal hemoglobin fraction as detected by HPLC but normal blood count without evidence of anemia or hemolysis. Oxygen affinity (p50 (O2) = 31.9-40.4 mmHg) was decreased in all probands, compared to 24.9-28.1 mmHg in unaffected individuals. Clinical symptoms likely related to the hemoglobin variant were cyanosis during anaesthesia, while other complaints such as shortness of breath or dizziness were less clearly linked with the hemoglobin variant.

Vital Signs: Health Care-Associated Legionnaires' Disease Surveillance Data From 20 States and a Large Metropolitan Area-United States, 2015.

BACKGROUND: Legionnaires' disease, a severe pneumonia, is typically acquired through inhalation of aerosolized water containing Legionella bacteria. Legionella can grow in the complex water systems of buildings, including health care facilities. Effective water management programs could prevent the growth of Legionella in building water systems. METHODS: Using national surveillance data, Legionnaires' disease cases were characterized from the 21 jurisdictions (20 U.S. states and one large metropolitan area) that reported exposure information for ≥90% of 2015 Legionella infections. An assessment of whether cases were health care-associated was completed; definite health care association was defined as hospitalization or long-term care facility residence for the entire 10 days preceding symptom onset, and possible association was defined as any exposure to a health care facility for a portion of the 10 days preceding symptom onset. All other Legionnaires' disease cases were considered unrelated to health care. RESULTS: A total of 2,809 confirmed Legionnaires' disease cases were reported from the 21 jurisdictions, including 85 (3%) definite and 468 (17%) possible health care-associated cases. Among the 21 jurisdictions, 16 (76%) reported 1-21 definite health care-associated cases per jurisdiction. Among definite health care-associated cases, the majority (75, 88%) occurred in persons aged ≥60 years, and exposures occurred at 72 facilities (15 hospitals and 57 long-term care facilities). The case fatality rate was 25% for definite and 10% for possible health care-associated Legionnaires' disease. CONCLUSIONS AND IMPLICATIONS FOR PUBLIC HEALTH PRACTICE: Exposure to Legionella from health care facility water systems can result in Legionnaires' disease. The high case fatality rate of health care-associated Legionnaires' disease highlights the importance of case prevention and response activities, including implementation of effective water management programs and timely case identification.

Genomic profiling of Acute lymphoblastic leukemia in ataxia telangiectasia patients reveals tight link between ATM mutations and chromothripsis.

Recent developments in sequencing technologies led to the discovery of a novel form of genomic instability, termed chromothripsis. This catastrophic genomic event, involved in tumorigenesis, is characterized by tens to hundreds of simultaneously acquired locally clustered rearrangements on one chromosome. We hypothesized that leukemias developing in individuals with Ataxia Telangiectasia, who are born with two mutated copies of the ATM gene, an essential guardian of genome stability, would show a higher prevalence of chromothripsis due to the associated defect in DNA double-strand break repair. Using whole-genome sequencing, fluorescence in situ hybridization and RNA sequencing, we characterized the genomic landscape of Acute Lymphoblastic Leukemia (ALL) arising in patients with Ataxia Telangiectasia. We detected a high frequency of chromothriptic events in these tumors, specifically on acrocentric chromosomes, as compared with tumors from individuals with other types of DNA repair syndromes (27 cases total, 10 with Ataxia Telangiectasia). Our data suggest that the genomic landscape of Ataxia Telangiectasia ALL is clearly distinct from that of sporadic ALL. Mechanistically, short telomeres and compromised DNA damage response in cells of Ataxia Telangiectasia patients may be linked with frequent chromothripsis. Furthermore, we show that ATM loss is associated with increased chromothripsis prevalence in additional tumor entities.

Identification of a genetically defined ultra-high-risk group in relapsed pediatric T-lymphoblastic leukemia.

In the search for genes that define critical steps of relapse in pediatric T-cell acute lymphoblastic leukemia (T-ALL) and can serve as prognostic markers, we performed targeted sequencing of 313 leukemia-related genes in 214 patients: 67 samples collected at the time of relapse and 147 at initial diagnosis. As relapse-specific genetic events, we identified activating mutations in NT5C2 (P=0.0001, Fisher's exact test), inactivation of TP53 (P=0.0007, Fisher's exact test) and duplication of chr17:q11.2-24.3 (P=0.0068, Fisher's exact test) in 32/67 of T-ALL relapse samples. Alterations of TP53 were frequently homozygous events, which significantly correlated with higher rates of copy number alterations in other genes compared with wild-type TP53 (P=0.0004, Mann-Whitney's test). We subsequently focused on mutations with prognostic impact and identified genes governing DNA integrity (TP53, n=8; USP7, n=4; MSH6, n=4), having key roles in the RAS signaling pathway (KRAS, NRAS, n=8), as well as IL7R (n=4) and CNOT3 (n=4) to be exclusively mutated in fatal relapses. These markers recognize 24/49 patients with a second event. In 17 of these patients with mostly refractory relapse and dire need for efficient treatment, we identified candidate targets for personalized therapy with p53 reactivating compounds, MEK inhibitors or JAK/STAT-inhibitors that may be incorporated in future treatment strategies.

The clinical relevance of birch pollen profilin cross-reactivity in sensitized patients.

BACKGROUND: Overlapping seasons and cross-reactivity, especially to grass pollen profilin, can hamper the diagnosis of birch pollen allergy. To identify the primary sensitizing allergen and the clinical relevance of cross-sensitization, we correlated sensitization profiles with in vitro and in vivo tests, symptom scores, and pollen counts. METHODS: A total of 433 patients with positive skin prick test (SPT) to birch pollen were analyzed regarding IgE to major birch and grass pollen allergens Bet v 1 and Phl p 1/p 5 and the profilins Bet v 2 and Phl p 12. Subgroups were analyzed by basophil activation test (BAT) and CAP-FEIA-based cross- and self-inhibition tests. RESULTS: A total of 349 patients were sensitized to Bet v 1, 44 patients to both Bet v 1 and Bet v 2, and 15 patients to Bet v 2 only. From Bet v 2-sensitized patients, 40 were also sensitized to Phl p 12. Ex vivo, Bet v 2 and Phl p 12 induced dose-dependent activation in basophils of these patients. Cross- and self-inhibition tests with both allergens confirmed cross-reactivity. However, semiquantitative analysis of SPTs demonstrated markedly increased reactivity to grass compared to birch pollen extract in Bet v 2 only sensitized patients. Accordingly, in most of those patients, clinical symptoms precisely correlated with grass pollen counts. CONCLUSION: Identification of the clinically relevant and sensitizing allergen needs correlation of actual pollen counts with clinical symptoms and sensitization status to major allergens. Semiquantitative analysis of SPT or BAT and determining profilin-specific IgE can contribute to making the diagnosis.

Perfil bioquímico sérico de equinos clinicamente sadios da raça Campeiro / Serum biochemical profile from clinically healthy Campeiro horses

Amostras de sangue foram obtidas de 138 equinos registrados da raça Campeiro, com idade média de 9,7±5,4 anos, sendo 14 machos (10,15%) e 124 fêmeas (89,85%). Observaram-se valores médios da atividade sérica de GGT: 13,73±4,08 U/L; AST: 246,34±72,87U/L; ALT: 5,13±1,18U/L; FA: 284,32±53,33UI/L; CK: 132,54±72,25U/L; LDH: 511,38±143,65U/L; e das concentrações séricas de ureia: 38,65±12,62mg/dL e de creatinina: 1,24±0,24mg/dL. Os valores médios de AST, FA, ALT, ureia e creatinina foram semelhantes aos propostos na literatura para outras raças. Os valores de CK, GGT e LDH foram superiores aos comumente utilizados como referências. Não houve diferença nas concentrações de nenhum dos componentes séricos avaliados nas diferentes idades analisadas. Maiores valores médios nas concentrações de ureia e menores de creatinina foram observados nas fêmeas em relação aos machos, assim como a maior atividade sérica de FA em fêmeas gestantes em relação às éguas vazias. O perfil bioquímico sérico de equinos sadios da raça Campeiro apresenta variações peculiares que devem ser levadas em consideração na interpretação de exames laboratoriais.(AU)

Blood samples were obtained from 138 equines of the Campeiro breed with mean ages of 9.7±5.4 years, including 14 males (10.15%) and 124 mares (89.85%). Mean values of serum of GGT: 13.73 ± 4.08U/L; AST: 246.34±72.87U/L; ALT 5.13±1.18U/L; FA: 284.32±53.33IU/L; CK: 132.54±72.25U/L; LDH: 511.38±143.65U/L; and serum urea: 38.65±12.62mg/dL and creatinine: 1.24±0.24mg/dL were observed. The mean values of AST, FA, ALT, urea and creatinine were similar to those proposed in the literature for other breeds. The CK values, GGT, and LDH were higher than those commonly used as references. There was no difference in the concentrations of any of the serum components evaluated at different ages analyzed. Further average values in the lower urea concentrations and creatinine were observed in females compared to males, as well as the higher serum activity of FA in pregnant mares in relation to non-pregnant. Serum biochemical profile of healthy horses of the Campeiro breed presents peculiar variations that must be taken into consideration in the interpretation of laboratory tests.(AU)

Biometrics of hoof balance in equids / Biometria do equilíbrio podal de equídeos

Differences in hoof balance between horses, mules and donkeys were identified in order to form more specific considerations for proper management of the animals. Measurements of the natural dimensions of hooves in sixty animals were used: 20 horses from the Crioulo breed, 20 mules and 20 donkeys from the Pêga breed. Liveweight was estimated using the correlation equations in each species by heart girth. Using a caliper rule, tape measure and hoof gauge, measurements of the length and width of the frog, hoof height, angle of heel, medial and lateral dorsal length, angle of the toe and crown circumference of the hooves of forelimbs and hindlimb were taken. Within each group the hooves of the hindlimbs exhibited narrower measurements than the hooves of the forelimbs and no difference was observed between the hoof angle of both members of groups. The conformation of the hooves of donkeys is shown to be substantially different from that observed in horses, the mules being in an intermediate condition, being smaller, angled and robust frog and proportionally more developed. Similarly, the hooves of donkeys provide greater support area compared to mules and horses, in descending order, even being dimensionally smaller. We conclude that the hooves of horses, mules and donkeys, have specific patterns of geometric balance that must be taken into consideration at the time of trimming and imbalance inferences.(AU)

O objetivo deste trabalho foi determinar o equilíbrio dos cascos de equídeos. Foram utilizados 60 animais, sendo estes: 20 equinos da raça Crioula, 20 muares e 20 asininos da raça Pêga. O peso vivo foi estimado por meio de equações de correlação com o perímetro torácico específico a cada espécie. Utilizando-se paquímetro, fita métrica e podogoniômetro, foram mensurados comprimento e largura da ranilha e do casco, altura e ângulo dos talões medial e lateral, comprimento dorsal e ângulo da pinça e perímetro da banda coronária dos cascos dos membros torácicos e pélvicos. Dentro de cada grupo, observou-se que os cascos dos membros pélvicos exibem-se mais estreitos que os cascos dos membros torácicos, e não houve diferença entre o ângulo das pinças de ambos os grupos de membros. A conformação dos cascos dos asininos mostra-se substancialmente divergente do observado nos equinos, estando os muares numa condição intermediária, sendo aqueles menores, mais angulados e com ranilha robusta e proporcionalmente mais desenvolvida. Da mesma forma, os cascos dos asininos proporcionam maior área de apoio em relação aos muares e equinos, em ordem decrescente, mesmo sendo dimensionalmente menores. Conclui-se que os cascos de equinos, muares e asininos apresentam padrões de equilíbrio geométrico específicos, que devem ser levados em consideração no momento do casqueamento e na inferência de desequilíbrios.(AU)

Simultaneous computed tomography-guided biopsy and radiofrequency ablation of solitary pulmonary malignancy in high-risk patients.

BACKGROUND: In recent years experience has been accumulated in percutaneous radiofrequency ablation (RFA) of lung malignancies in nonsurgical patients. OBJECTIVES: In this study, we retrospectively evaluated a simultaneous diagnostic and therapeutic approach including CT-guided biopsy followed immediately by RFA of solitary malignant pulmonary lesions. METHODS: CT-guided transthoracic core needle biopsy of solitary pulmonary lesions suspicious for malignancy was performed and histology was proven based on immediate frozen sections. RFA probes were placed into the pulmonary tumors under CT guidance and the ablation was performed subsequently. The procedure-related morbidity was analyzed. Follow-up included a CT scan and pulmonary function parameters. RESULTS: A total of 33 CT-guided biopsies and subsequent RFA within a single procedure were performed. Morbidity of CT-guided biopsy included pulmonary hemorrhage (24%) and a mild pneumothorax (12%) without need for further interventions. The RFA procedure was not aggravated by the previous biopsy. The rate of pneumothorax requiring chest tube following RFA was 21%. Local tumor control was achieved in 77% with a median follow-up of 12 months. The morbidity of the CT-guided biopsy had no statistical impact on the local recurrence rate. CONCLUSIONS: The simultaneous diagnostic and therapeutic approach including CT-guided biopsy followed immediately by RFA of solitary malignant pulmonary lesions is a safe procedure. The potential of this combined approach is to avoid unnecessary therapies and to perform adequate therapies based on histology. Taking the local control rate into account, this approach should only be performed in those patients who are unable to undergo or who refuse surgery.

[Update on diabetic macroangiopathy]. / Aktuelles zur diabetischen Makroangiopathie.

Current findings from the literature on the multifactorial genesis of macroangiopathy of diabetes mellitus (DM) were compiled using the PubMed database. The primary aim was to find an explanation for the morphological, immunohistochemical and molecular characteristics of this form of atherosclerosis. The roles of advanced glycation end products (AGE), defective signal transduction and imbalance of matrix metalloproteinases in the increased progression of atherosclerosis in coronary and cerebral arteries as well as peripheral vascular disease are discussed. The restricted formation of collateral arteries (arteriogenesis) in diabetic patients with postischemic lesions is also a focus of attention. The increased level of prothrombotic factors and the role of diabetic neuropathy in DM are also taken into account. Therapeutic influences of AGE-RAGE (receptor of AGE) interactions on the vascular wall and the effects of endothelial progenitor cells in the repair of diabetic vascular lesions are additionally highlighted.

Tetrasomy 9p mosaicism associated with a normal phenotype in two cases.

Tetrasomy 9p is a rare chromosomal syndrome and about 30% of known cases exhibit mosaicism. Approximately 50 of the reported cases with tetrasomy 9p mosaicism show a characteristic facial appearance, growth failure, and developmental delay. However, 3 patients with mosaicism for isochromosome 9p and a normal phenotype have also been reported. We report 2 additional cases of clinically normal young females with tetrasomy 9p mosaicism, one of whom also exhibited X chromosome aneuploidy mosaicism leading to an overall of 6 different cell lines. STR analysis performed on this complex mosaic case indicated that the extra isochromosome was of maternal origin while the X chromosome aneuploidy was of paternal origin, indicating a postzygotic event.

[18-year-old woman with an ovarian tumour detected by coincidence]. / 18-jährige Frau mit zufällig entdecktem Ovarialtumor.

Massive ovarian edema (MOE) is a rare, benign disease of young women. Because preoperatively in most cases the differential diagnosis primarily appears to indicate the presence of a malignant tumour, there is a risk that these patients will be subjected to unnecessary overtreatment. In the case of the 18-year-old patient described here, on the basis of the preoperative data the suspected clinical diagnosis was polycystic ovarian (PCO) syndrome. In the MRI the enlarged ovary was interpreted as a mucous tumour. The laparotomy showed a smooth-walled, opalescent ovarian tumour with adnexal torsion. Histopathological examination of the adnexectomy specimen gave the diagnosis of a massive ovarian edema (MOE). Therapeutically, a wedge-shaped excision, immediate-section histology and derotation and suspension of the ovary would have been sufficient. Unnecessary overtreatment can be avoided in young women with enlarged ovaries, if MOE is included in the differential diagnosis and if the characteristic sonography, MRI and macroscopy findings are known.

Tetrasomy 12p (Pallister-Killian syndrome): difficulties in prenatal diagnosis.

PURPOSE: We report a rare case of Pallister-Killian syndrome diagnosed prenatally with increased nuchal translucency during screening for trisomy 21. MATERIALS AND METHODS: Echografic and postmortem examination of the fetus, G-banded chromosome and FISH analysis on short- and long-term chorion villous sampling (CVS) culture. RESULTS AND DISCUSSION: Cytogenetic analysis revealed a supernumerary isochromosome 12p after long-term culture whereas a normal cell line was detected in short-term culture only. Sonografic examination in 17-weeks' gestation showed further increase of the NT and the additional presence of brachymelia, diaphragmatic hernia and a marked dextroposition of the heart. Termination of the pregnancy was performed. The cases of PKS karyotypically confirmed on CVS are reviewed, and cytogenetic and sonographic aspects of the prenatal diagnosis of PKS are discussed.

Diagnosis of pulmonary metastases with helical CT: the effect of imaging techniques.

OBJECTIVE: Survival in patients after surgical resection of pulmonary metastases correlates with the complete resection of all metastatic deposits. The purpose of this study was to evaluate the additional value of helical CT to see whether the slice thickness and the reading environment was a factor determining the accuracy of helical scans. METHODS: Between 2004 and 2007, 93 patients (62 men, 31 women) underwent complete resection of pulmonary metastases by open thoracotomy. A total of 125 thoracotomies were performed with manual palpation of the involved lung. We retrospectively examined the helical CT findings obtained using a 5-mm slice thickness in a routine preoperative analysis, and within this study a second reading was performed independently, using 3-mm slice thickness image sets. The CT images were evaluated in a consensus between two radiologists. RESULTS: Computed tomography scanning was performed a median of 12 days before thoracotomy (range 1-121 days). Analysis of helical CT in 5-mm slice thickness detected metastases with a sensitivity of 83.7 % whereas a 3-mm slice thickness had a sensitivity of 88.8 %. There were statistically significantly more lesions using helical CT and a 3-mm slice thickness technique than with the 5-mm slice thickness technique, compared to the surgical results ( P = 0.002). This was also found with regard to nodules which were finally histologically confirmed as lung metastases ( P = 0.014). CONCLUSIONS: We conclude that a reduced slice thickness may have an important positive impact on the treatment and outcome of patients with pulmonary metastases. The use of 3-mm slice thickness helical CT may raise the sensitivity for pulmonary metastases detection compared to 5-mm images, but the rate of false positive results may also increase.

[Placental site trophoblastic tumor: case report and review of literature]. / Placental site trophoblastic tumor--Ein Fallbericht und Literaturübersicht.

A 32-year-old para 3 patient is presented having suffered from a silent uterine rupture on the occasion of her second and third Caesarean sections. After the third Caesarean section, there was light uterine bleeding whilst the patient breastfed for five months. Amenorrhoea then ensued due to oral contraception. Regular clinical and ultrasound checks revealed negative serum beta-HCG values and retrovesicular resistance, which increased in size after 18 months and became symptomatic. Because the patient's family was complete, abdominal hysterectomy without adnexectomy was performed. Histology revealed a placental site trophoblastic tumour (PSTT). This is a rare tumour with malignant potential, whose prognosis depends on the stage of the primary tumour, the period of time between the last pregnancy and onset of disease, the patient's age, and the rate of mitosis, and whose progress cannot be assessed using the WHO Prognostic Index Score for Gestational Trophoblastic Disease. In therapeutic terms, hysterectomy is recommended. Chemosensitivity is low and, due to the infrequency of the tumours, the most suitable chemotherapy scheme is unknown. In the case of metastasising or recurrent PSTT, the EP/EMA regime has proved to be most effective.

[Uterine tumor resembling ovarian sex cord tumor: case report and review of literature]. / Uteriner Tumor mit keimstrang-ahnlicher Differenzierung (UTROSCT): Fallbericht und Literaturübersicht.

Uterine tumours with sex cord-like differentiation are rare. They are observed, pre- and post-menopausal women between the fourth and the sixth decade and manifest themselves by haemorrhagic anomalies and usually enlarged uteri, misinterpreted as uterus myomatosus. One distinguishes between two groups on account of the share of sex cord-like elements, i.e. tumours with only focal sex cord-like differentiation with a tendency to relapses and metastatic spread, and tumours with predominant differentiation in the sense of ovarian sex cord tumours with a good prognosis because surgical treatment alone often leads to relapse-free survival. Because of the tumours' rarity, there are no randomized studies as to an optimal therapy. Since there have been reports on endometrial stromal sarcoma with low malignant potential in adjuvant therapy of breast cancer with Tamoxifen, one can assume that this entity will occur more frequently in future.

Efficacy and safety of a low-dose 21-day combined oral contraceptive containing ethinylestradiol 20microg and drospirenone 3mg.

OBJECTIVE: The purpose of this study was to assess the efficacy and safety of a new low-dose oral contraceptive containing ethinylestradiol 20microg and drospirenone 3mg (EE 20microg/drsp 3mg). METHODS: This was an open-label, non-comparative, multicentre study conducted at 33 centres in Germany and Switzerland. The combined contraceptive was administered over 26 cycles of treatment, with each cycle consisting of once-daily treatment for 21 consecutive days followed by a 7-day hormone-free interval. RESULTS: A total of 527 women were randomised, of whom 516 (97.9%) started treatment and had at least one study observation. Two pregnancies occurred during 11 165 cycles of treatment, giving a Pearl Index of 0.23 (upper limit of 97.5% CI 0.84). The corresponding 2-year cumulative pregnancy rate was 0.44% (95% CIs 0, 1.05). One of the two pregnancies was attributed to non-compliance with treatment, giving an adjusted Pearl Index of 0.12 (upper limit of 97.5% CI 0.67) over 10 827 compliant cycles. Only three (0.6%) women discontinued treatment because of bleeding problems in this long-term study, suggesting an acceptable bleeding profile. Overall, the study drug was well tolerated and adverse events experienced were typical of hormonal contraceptive use. The majority of women who responded (435 of 501; 86.8%) were satisfied or very satisfied with the study treatment and most (367 of 501; 73.3%) would continue with it if given the choice. CONCLUSION: The EE 20microg/drsp 3 mg combined oral contraceptive is an effective and well tolerated contraceptive with an acceptable bleeding pattern.

[Primary adenocarcinoma of the appendix as differential diagnosis of advanced ovarian carcinoma]. / Das primäre Adenokarzinom der Appendix als Differentialdiagnose des fortgeschrittenen Ovarialkarzinoms.

Malignant tumours of the appendix are rare. They are usually carcinoid tumours that must be distinguished from extremely rare adenocarcinomas. Metastatic mucinous adenocarcinomas of the appendix are only reported as case histories. In clinical terms, the tumours usually manifest themselves as acute appendicitis, as ruptured appendicitis, as a tumour in the right lower abdominal quadrant or as a pelvic tumour, which are generally mistaken for an ovarian tumour with the same sonographic image. Advanced primary adenocarcinomas of the appendix with ovarian metastases cannot be distinguished intraoperatively from a FIGO III ovarian carcinoma. The pathologist makes the definitive diagnosis. These characteristics also apply to the case presented here. Surgical therapy of the isolated primary appendiceal carcinoma consists of a hemicolectomy--an appendectomy in favourable cases--and, in the case of a metastasised carcinoma, according to the guidelines for an advanced ovarian or colon carcinoma. The effect of chemotherapy is insufficiently documented.

[Uterine leiomyoma as cause of erythrocytosis]. / Uterus myomatosus als Ursache für Erythrozytose.

Myoma-induced erythrocytosis is a rare clinical picture which is probably largely misunderstood. Pre- and postmenopausal women are affected. The characteristics of this syndrome are raised haemoglobin and haematocrit values, erythrocytosis at normal plasma volumes and the fact that these values are promptly and permanently corrected by myomectomy or hysterectomy. Myomatous erythrocytosis syndrome (MES) can be the explanation of normal haematological parameters in patients with myoma-related hypermenorrhoea and menorrhagia.

Assessing contaminant sensitivity of endangered and threatened aquatic species: part I. Acute toxicity of five chemicals.

Assessment of contaminant impacts to federally identified endangered, threatened and candidate, and state-identified endangered species (collectively referred to as "listed" species) requires understanding of a species' sensitivities to particular chemicals. The most direct approach would be to determine the sensitivity of a listed species to a particular contaminant or perturbation. An indirect approach for aquatic species would be application of toxicity data obtained from standard test procedures and species commonly used in laboratory toxicity tests. Common test species (fathead minnow, Pimephales promelas; sheepshead minnow, Cyprinodon variegatus; and rainbow trout, Oncorhynchus mykiss) and 17 listed or closely related species were tested in acute 96-hour water exposures with five chemicals (carbaryl, copper, 4-nonylphenol, pentachlorophenol, and permethrin) representing a broad range of toxic modes of action. No single species was the most sensitive to all chemicals. For the three standard test species evaluated, the rainbow trout was more sensitive than either the fathead minnow or sheepshead minnow and was equal to or more sensitive than listed and related species 81% of the time. To estimate an LC50 for a listed species, a factor of 0.63 can be applied to the geometric mean LC50 of rainbow trout toxicity data, and more conservative factors can be determined using variance estimates (0.46 based on 1 SD of the mean and 0.33 based on 2 SD of the mean). Additionally, a low- or no-acute effect concentration can be estimated by multiplying the respective LC50 by a factor of approximately 0.56, which supports the United States Environmental Protection Agency approach of multiplying the final acute value by 0.5 (division by 2). When captive or locally abundant populations of listed fish are available, consideration should be given to direct testing. When direct toxicity testing cannot be performed, approaches for developing protective measures using common test species toxicity data are available.