Effect of 200 µg of gonadorelin hydrochloride at the first GnRH of a CIDR Synch program on ovulation rate and pregnancies per AI in Holstein heifers.

The initial ovulatory response during synchronization programs is often low in dairy heifers, largely due to follicular dynamics and hormonal dynamics. Specifically, the progesterone concentration (P4) at the time of the first GnRH treatment in a breeding program can influence the LH response, often resulting in a suboptimal ovulatory response. The objective of this study was to determine the effect of the highest label dose 200 µg (100 µg vs. 200 µg) of GnRH (50 µg gonadorelin hydrochloride per mL; Factrel®; Zoetis Inc. Madison, NJ) at the first GnRH of a 6-d CoSynch plus P4 device program on ovulatory response and pregnancy per AI (P/AI) in first service in Holstein heifers. A total of 1308 Holstein heifers were randomly allocated at the beginning of a 6-d CIDR-Synch program, Day 0, to receive either i.m. treatment of 100 µg (2CC, n = 655) or 200 µg (4CC, n = 653) of GnRH. Also, at Day 0, heifers received an intravaginal insert with 1.38 g of P4 (Eazi-Breed CIDR® Cattle Insert; Zoetis Inc., Madison, NJ). On Day 6, the insert was removed, and i.m. treatment of 25 mg of PGF2α (12.5 mg dinoprost tromethamine/mL; Lutalyse® HighCon Injection Zoetis) was administered. On Day 7, a second i.m. treatment of 25 mg of PGF2α was given, followed on Day 9 by concurrent i.m. treatment of 100 µg of GnRH and timed AI (TAI). A subset of 396 heifers had their ovaries scanned to evaluate ovulatory response, and blood samples were collected to measure the serum concentration of P4 at Day 0 and Day 6 of the study. The P4 concentrations at Day 0 were categorized as Low (≤3ng/mL) or High (>3ng/mL). The ovulatory response was greater for heifers receiving 4CC than 2CC at Day 0 (54.7% vs. 42.8%). The ovulatory response was greater for Low P4 than High P4 at Day 0 (54.3% vs. 37.8%). However, there was not an interaction between treatment and P4 concentrations (Low P4 2CC = 48.6% vs. High P4 2CC = 30.0%; Low P4 4CC = 60.0% vs. High P4 4CC = 45.5%). The ROC curve analysis indicates that P4 concentrations at Day 0 treatment could predict the ovulatory response, although the area under the curve was only 0.6. As expected, heifers that ovulated had increased P/AI (No = 55.6% vs. Yes = 67.7%); however, there was no effect of treatment on P/AI (2CC = 63.3% vs. 4CC = 59.6%), nor interactions between treatment and ovulation and treatment and P4 (HIGH vs LOW) for pregnancy outcomes. In summary, P4 concentration and increasing the dose of GnRH at Day 0 positively impacted ovulatory response in Holstein heifers. However, there was no interaction between treatment and P4 on ovulation and no subsequent impact of GnRH dose on P/AI.

Safety of Low-Dose Oral Minoxidil in Patients With Hypertension and Arrhythmia: A Multicenter Study of 264 Patients / Seguridad de minoxidil oral a dosis bajas en pacientes con hipertensión o arritmias: estudio multicéntrico de 264 pacientes

Background and objective Systemic adverse effects (AE) are a major concern of low-dose oral minoxidil (LDOM) treatment, especially in patients with arterial hypertension or arrhythmia. The objective of this study was to evaluate the safety of LDOM in patients with hypertension or arrhythmia. Patients and methods Retrospective multicenter study of patients with hypertension or arrhythmia treated with LDOM for any type of alopecia. Results A total of 254 patients with hypertension [176 women (69.3%) and 78 men (30.7%)] with a mean age of 56.9 years (range 19–82) were included. From them, the dose of LDOM was titrated in 128 patients, allowing the analysis of 382 doses. Patients were receiving a mean of 1.45 (range 0–5) antihypertensive drugs. Systemic AE were detected in 26 cases (6.8%) and included lightheadedness (3.1%), fluid retention (2.6%), general malaise (0.8%), tachycardia (0.8%) and headache (0.5%), leading to LDOM discontinuation in 6 cases (1.5%). Prior treatment with doxazosin (P<0.001), or with three or more antihypertensive drugs (P=0.012) was associated with a higher risk of discontinuation of LDOM. Conclusions LDOM treatment showed a favorable safety profile in patients with hypertension or arrhythmia, similar to general population (AU)

Antecedentes y objetivo Los efectos adversos sistémicos son una de las principales limitaciones del uso de minoxidil oral a dosis bajas (MODB), especialmente en pacientes con hipertensión arterial o arritmias. El objetivo de este estudio fue evaluar la seguridad de MODB en estos pacientes. Material y método Estudio retrospectivo multicéntrico con pacientes con antecedentes de hipertensión o arritmias tratados con MODB para cualquier tipo de alopecia. Resultados Se incluyó un total de 254 pacientes con hipertensión (176 mujeres [69,3%] y 78 hombres [30,7%]) con una edad media de 56,9 años (rango 19 – 82). La dosis de MODB se incrementó gradualmente en 128 pacientes, obteniendo un total de 382 dosis analizadas. Los sujetos estaban tomando de media 1,45 fármacos antihipertensivos (rango 0 – 5). Se detectaron EA sistémicos en 26 casos (6,8%), incluyendo mareo (3,1%), retención de líquidos (2,6%), malestar general (0,8%), taquicardia (0,8%) y cefalea (0,5%), requiriendo suspensión del MODB en seis casos (1,5%). Los pacientes en tratamiento con doxazosina (p < 0,001) o con tres o más antihipertensivos (p = 0,012) presentaron mayor riesgo de suspensión de MODB. Conclusión El tratamiento con MODB mostró un perfil de seguridad favorable en pacientes con hipertensión o arritmias, similar al de la población general (AU)

[Artíulo traducido] Seguridad de minoxidil oral a dosis bajas en pacientes con hipertensión o arritmias: estudio multicéntrico de 264 pacientes / Safety of Low-Dose Oral Minoxidil in Patients With Hypertension and Arrhythmia: A Multicenter Study of 264 Patients

Antecedentes y objetivo Los efectos adversos sistémicos son una de las principales limitaciones del uso de minoxidil oral a dosis bajas (MODB), especialmente en pacientes con hipertensión arterial o arritmias. El objetivo de este estudio fue evaluar la seguridad de MODB en estos pacientes. Material y método Estudio retrospectivo multicéntrico con pacientes con antecedentes de hipertensión o arritmias tratados con MODB para cualquier tipo de alopecia. Resultados Se incluyó un total de 254 pacientes con hipertensión (176 mujeres [69,3%] y 78 hombres [30,7%]) con una edad media de 56,9 años (rango 19 – 82). La dosis de MODB se incrementó gradualmente en 128 pacientes, obteniendo un total de 382 dosis analizadas. Los sujetos estaban tomando de media 1,45 fármacos antihipertensivos (rango 0 – 5). Se detectaron EA sistémicos en 26 casos (6,8%), incluyendo mareo (3,1%), retención de líquidos (2,6%), malestar general (0,8%), taquicardia (0,8%) y cefalea (0,5%), requiriendo suspensión del MODB en seis casos (1,5%). Los pacientes en tratamiento con doxazosina (p < 0,001) o con tres o más antihipertensivos (p = 0,012) presentaron mayor riesgo de suspensión de MODB. Conclusión El tratamiento con MODB mostró un perfil de seguridad favorable en pacientes con hipertensión o arritmias, similar al de la población general (AU)

Background and objective Systemic adverse effects (AE) are a major concern of low-dose oral minoxidil (LDOM) treatment, especially in patients with arterial hypertension or arrhythmia. The objective of this study was to evaluate the safety of LDOM in patients with hypertension or arrhythmia. Patients and methods Retrospective multicenter study of patients with hypertension or arrhythmia treated with LDOM for any type of alopecia. Results A total of 254 patients with hypertension [176 women (69.3%) and 78 men (30.7%)] with a mean age of 56.9 years (range 19–82) were included. From them, the dose of LDOM was titrated in 128 patients, allowing the analysis of 382 doses. Patients were receiving a mean of 1.45 (range 0–5) antihypertensive drugs. Systemic AE were detected in 26 cases (6.8%) and included lightheadedness (3.1%), fluid retention (2.6%), general malaise (0.8%), tachycardia (0.8%) and headache (0.5%), leading to LDOM discontinuation in 6 cases (1.5%). Prior treatment with doxazosin (P<0.001), or with three or more antihypertensive drugs (P=0.012) was associated with a higher risk of discontinuation of LDOM. Conclusions LDOM treatment showed a favorable safety profile in patients with hypertension or arrhythmia, similar to general population (AU)

Safety of Low-Dose Oral Minoxidil in Patients With Hypertension and Arrhythmia: A Multicenter Study of 264 Patients.

BACKGROUND AND OBJECTIVE: Systemic adverse effects (AE) are a major concern of low-dose oral minoxidil (LDOM) treatment, especially in patients with arterial hypertension or arrhythmia. The objective of this study was to evaluate the safety of LDOM in patients with hypertension or arrhythmia. PATIENTS AND METHODS: Retrospective multicenter study of patients with hypertension or arrhythmia treated with LDOM for any type of alopecia. RESULTS: A total of 254 patients with hypertension [176 women (69.3%) and 78 men (30.7%)] with a mean age of 56.9 years (range 19-82) were included. From them, the dose of LDOM was titrated in 128 patients, allowing the analysis of 382 doses. Patients were receiving a mean of 1.45 (range 0-5) antihypertensive drugs. Systemic AE were detected in 26 cases (6.8%) and included lightheadedness (3.1%), fluid retention (2.6%), general malaise (0.8%), tachycardia (0.8%) and headache (0.5%), leading to LDOM discontinuation in 6 cases (1.5%). Prior treatment with doxazosin (P<0.001), or with three or more antihypertensive drugs (P=0.012) was associated with a higher risk of discontinuation of LDOM. CONCLUSIONS: LDOM treatment showed a favorable safety profile in patients with hypertension or arrhythmia, similar to general population.

Safety of Low-Dose Oral Minoxidil in Patients With Hypertension and Arrhythmia: A Multicenter Study of 264 Patients. / [Artíulo traducido] Seguridad de minoxidil oral a dosis bajas en pacientes con hipertensión o arritmias: estudio multicéntrico de 264 pacientes.

BACKGROUND AND OBJECTIVE: Systemic adverse effects (AE) are a major concern of low-dose oral minoxidil (LDOM) treatment, especially in patients with arterial hypertension or arrhythmia. The objective of this study was to evaluate the safety of LDOM in patients with hypertension or arrhythmia. PATIENTS AND METHODS: Retrospective multicenter study of patients with hypertension or arrhythmia treated with LDOM for any type of alopecia. RESULTS: A total of 254 patients with hypertension [176 women (69.3%) and 78 men (30.7%)] with a mean age of 56.9 years (range 19-82) were included. From them, the dose of LDOM was titrated in 128 patients, allowing the analysis of 382 doses. Patients were receiving a mean of 1.45 (range 0-5) antihypertensive drugs. Systemic AE were detected in 26 cases (6.8%) and included lightheadedness (3.1%), fluid retention (2.6%), general malaise (0.8%), tachycardia (0.8%) and headache (0.5%), leading to LDOM discontinuation in 6 cases (1.5%). Prior treatment with doxazosin (P<0.001), or with three or more antihypertensive drugs (P=0.012) was associated with a higher risk of discontinuation of LDOM. CONCLUSIONS: LDOM treatment showed a favorable safety profile in patients with hypertension or arrhythmia, similar to general population.

Effect of rumen-protected choline on dairy cow metabolism, immunity, lactation performance, and vaginal discharge microbiome.

Rumen-protected choline (RPC) promotes benefits in milk production, immunity, and health in dairy cows by optimizing lipid metabolism during transition period management and early lactation. However, the RPC success in dairy cows depends on choline bioavailability, which is affected by the type of protection used in rumen-protected choline. Therefore, our objectives were to determine the effects of a novel RPC on dry matter intake (DMI), identify markers of metabolism and immunity, and evaluate lactation performance. Dry Holstein (n = 48) cows at 245 ± 3 d of gestation were blocked by parity and assigned to control or RPC treatment within each block. Cows enrolled in the RPC treatment received 15 g/d of CholiGEM (Kemin Industries, Cavriago RE, Italy) from 21 d prepartum and 30 g/d of CholiGEM from calving to 21 d postpartum. During the transition period, DMI was measured daily, and blood was sampled weekly for energy-related metabolites such as ß-hydroxybutyrate (BHB), glucose, and nonesterified fatty acids (NEFA), as well as immune function markers such as haptoglobin (Hp) and lipopolysaccharide-binding protein (LPB). Vaginal discharge samples were collected at the calving and 7 d postpartum and stored in microcentrifuge tubes at -80°C until 16S rRNA sequencing. The main responses of body condition score, body weight, DMI, milk yield, milk components, and immune function markers were analyzed using the GLIMMIX procedure of SAS with the effects of treatment, time, parity, and relevant covariates added to the models. The relative abundance of microbiome α-diversity was evaluated by 3 indexes (Chao1, Shannon, and Simpson) and ß-diversity by principal coordinate analysis and permutational multivariate ANOVA. We found no differences in DMI in the pre- and postpartum periods. Cows fed RPC increased the yields of energy- and 3.5% fat-corrected milk and fat yield in primiparous and multiparous cows, with an interaction between treatment and parity for these lactation variables. However, we found no differences in milk protein and lactose up to 150 DIM between treatments. Glucose, NEFA, and BHB had no differences between the treatments. However, RPC decreased BHB numerically (control = 1.07 ± 0.13 vs. RPC = 0.63 ± 0.13) in multiparous on the third week postpartum and tended to reduce the incidence of subclinical ketosis (12.7% vs. 4.2%). No effects for Hp and LPB were found in cows fed RPC. Chao1, Shannon, and Simpson indexes were lower at calving in the RPC treatment than in the Control. However, no differences were found 7 d later for Chao1, Shannon, and Simpson indexes. The vaginal discharge microbiome was altered in cows fed RPC at 7 d postpartum. Fusobacterium, a common pathogen associated with metritis, was reduced in cows fed RPC. Rumen-protected choline enhanced lactation performance and health and altered the vaginal discharge microbiome which is a potential proxy for uterine healthy in dairy cows. The current study's findings corroborate that RPC is a tool to support adaptation to lactation and shed light on opportunities for further research in reproductive health.

Association study between ceftriaxone and a synthetic amide against strains of Pseudomonas aeruginosa.

Pseudomonas aeruginosa is a non-lactose fermenting Gram-negative bacteria responsible for causing numerous nosocomial infections. The present research aimed to analyze the anti-Pseudomonas aeruginosa potential of 2-Chloro-N-(4-fluoro-3-nitrophenyl)acetamide (A8). The antibacterial potential of A8 was evaluated from the Minimum Inhibitory Concentration (MIC), Minimum Bactericidal Concentration (MBC) and Association using the checkerboard method. MIC and MBC values were 512 µg/mL for all P. aeruginosa strains evaluated, demonstrating predominantly bactericidal activity. Furthermore, when A8 was associated with the drug ceftriaxone, pharmacological additivity and indifference were evidenced. In this sense, the synthetic amide was interesting, since it demonstrates the potential to become a possible candidate for an antimicrobial drug.

Interstitial incisional hernia of greater omentum: An incidental finding during routine cadaveric dissection.

Omental herniation, located between the rectus abdominis muscle and the anterior blade of the rectus sheath, can be triggered after a transverse suprapubic incision. It causes the development of an incisional interstitial hernia (IIH), which is an extremely rare and poorly understood condition. Based on this information, our work presents the first anatomical description of incisional interstitial hernia found during routine dissection at the Human Anatomy Laboratory of the Federal University of Ceará in a formalized female corpse.

The spectrum of focal epithelial hyperplasia-a report of two cases.

Focal epithelial hyperplasia is a rare, benign, and asymptomatic disorder, characterized by soft papules on the oral cavity. It is primarily associated with human papillomavirus genotypes 13 and 32. It most commonly affects children and young adults. When it affects young adults, it is important to differentiate it from oral condyloma acuminata. Its diagnosis may be made clinically, but histologic examination and PCR genotyping are often useful. Treatment is not always mandatory.

Probiotic properties of yeasts isolated from Brazilian fermented table olives.

AIMS: To investigate the probiotic potential of yeasts isolated from naturally fermented Brazilian table olives. METHODS AND RESULTS: Eighteen yeast strains were tested in terms of: safety; survival of gastrointestinal and digestion conditions; antimicrobial activity; cellular hydrophobicity; autoaggregation ability and adhesion to epithelial cells; coaggregation and inhibition of pathogenic bacteria adhesion. Six yeasts showed favourable results for all probiotic attributes: Saccharomyces cerevisiae CCMA 1746, Pichia guilliermondii CCMA 1753, Candida orthopsilosis CCMA 1748, Candida tropicalis CCMA 1751, Meyerozyma caribbica CCMA 1758 and Debaryomyces hansenii CCMA 1761. These yeasts demonstrated resistance to 37°C, pH 2·0 and bile salts, and survived in vitro digestion (≥106  CFU per ml). Furthermore, the yeasts exhibited a hydrophobic cell surface (42·5-92·2%), autoaggregation capacity (41·0-91·0%) and adhesion to Caco-2 (62·0-82·8%) and HT-29 (57·6-87·3%) epithelial cell lines. Also, the strains showed antimicrobial activity against Salmonella Enteritidis as well as the ability to coaggregate and reduce the adhesion of this pathogen to intestinal cells. CONCLUSIONS: Autochthonous yeasts from naturally fermented Brazilian table olives have probiotic properties, with potential for development of new probiotic food products. SIGNIFICANCE AND IMPACT OF STUDY: These data are important and contribute to the knowledge of new potential probiotic yeasts capable of surviving gastrointestinal tract conditions and inhibiting pathogenic bacteria.

Behavioral aspects of waterbirds / Aspectos comportamentais de aves aquáticas

Abstract Estuaries are used by waterbirds as foraging, resting and nesting sites, serving also as shelter for migratory birds. The dynamics of this avifauna in an aquatic environment may be associated with the differences of time of day, tide height, temperature, wind speed and use of the site by different species. This study had the objective of evaluating behavioral aspects of aquatic birds, relating the influence of environmental variables with their activities. Bird counts were performed at the mouth of two important rivers of the state of Santa Catarina, Brazil, during two-hour intervals throughout the day in monthly samplings between June (2015) and May (2016). A total of 44 species were recorded, ten of which were migratory. The most recorded behaviors were foraging and resting. The Kruskal-Wallis analysis indicated no significant difference in behavior between the sampling intervals. The Bray-Curtis similarity test resulted in three groups: 1) - species that foraged most of the time; 2) - species that rested most of the time; and 3) - same time in both activities. The Indicator Species Analysis showed that 17 species were associated with only one microhabitat and 15 species with more than one. The Canonical Correlation Analysis indicated that only tide height, temperature and rainfall variables were correlated with the behaviors performed and only the resting activity was positively correlated with all variables. This may be associated with thermoregulation and the ability of some species to stay in midlitoral at high tide. The results demonstrate that different waterbird species used the studied areas in different ways. Thus, the heterogeneity of microhabitats in an aquatic environment of extreme importance for the coexistence and maintenance of the diversity of waterbirds.

Resumo Estuários são utilizados por aves aquáticas como locais de forrageio, descanso e nidificação, servindo, também, como pontos de parada para aves migratórias. A dinâmica dessa avifauna em um ambiente pode estar associada a diferenças entre horários do dia, altura da maré, temperatura, velocidade do vento e uso do local. Esse trabalho teve o objetivo de avaliar aspectos comportamentais de aves aquáticas, relacionando a influência de variáveis ambientais com suas atividades. Amostragens mensais foram realizadas na foz de dois importantes rios do Estado de Santa Catarina, Brasil, entre junho de 2015 e maio de 2016, em intervalos de duas horas no decorrer do dia. Um total de 44 espécies foram registradas, dez das quais foram migratórias. Os comportamentos mais observados foram forrageio e descanso. A análise de Kruskall-Wallis não indicou diferenças significativas no comportamento entre os horários de amostragem. O teste de similaridade Bray-Curtis resultou em três agrupamentos: 1) - espécies que forragearam na maior parte do tempo; 2) - espécies que descansaram na maior parte do tempo; e 3) - mesma quantidade de tempo em ambas atividades. A Análise de Espécies Indicadoras mostrou que 17 espécies estiveram associadas com apenas um microhabitat e 15 espécies com mais de um. A Análise de Correlação Canônica indicou que apenas as variáveis maré, temperatura e precipitação foram significativamente correlacionadas com os comportamentos demonstrados e apenas a atividade de descanso foi positivamente correlacionada com as todas as variáveis. Isso pode estar associado com a termorregulação e com a habilidade de algumas espécies de permanecer no mediolitoral durante a maré cheia. Os resultados demonstram que diferentes espécies de aves aquáticas utilizaram as áreas estudadas de diferentes maneiras. Assim, a heterogeneidade de microhabitats em um ambiente aquático é de extrema importância para a coexistência e a manutenção da diversidade de aves.

Behavioral aspects of waterbirds.

Estuaries are used by waterbirds as foraging, resting and nesting sites, serving also as shelter for migratory birds. The dynamics of this avifauna in an aquatic environment may be associated with the differences of time of day, tide height, temperature, wind speed and use of the site by different species. This study had the objective of evaluating behavioral aspects of aquatic birds, relating the influence of environmental variables with their activities. Bird counts were performed at the mouth of two important rivers of the state of Santa Catarina, Brazil, during two-hour intervals throughout the day in monthly samplings between June (2015) and May (2016). A total of 44 species were recorded, ten of which were migratory. The most recorded behaviors were foraging and resting. The Kruskal-Wallis analysis indicated no significant difference in behavior between the sampling intervals. The Bray-Curtis similarity test resulted in three groups: 1) - species that foraged most of the time; 2) - species that rested most of the time; and 3) - same time in both activities. The Indicator Species Analysis showed that 17 species were associated with only one microhabitat and 15 species with more than one. The Canonical Correlation Analysis indicated that only tide height, temperature and rainfall variables were correlated with the behaviors performed and only the resting activity was positively correlated with all variables. This may be associated with thermoregulation and the ability of some species to stay in midlitoral at high tide. The results demonstrate that different waterbird species used the studied areas in different ways. Thus, the heterogeneity of microhabitats in an aquatic environment of extreme importance for the coexistence and maintenance of the diversity of waterbirds.

Surface and finite-size effects on N-Sm-A-Sm-C phase transitions in free-standing films.

The present study is devoted to the investigation of surface anchoring and finite-size effects on nematic-smectic-A-smectic-C (N-Sm-A-Sm-C) phase transitions in free-standing films. Using an extended version of the molecular theory for smectic-C liquid crystals, we analyze how surface anchoring and film thickness affect the thermal behavior of the order parameters in free-standing smectic films. In particular, we determine how the transition temperature depends on the surface ordering and film thickness. We show that the additional orientational order imposed by the surface anchoring may lead to a stabilization of order parameters in central layers, thus modifying the nature of the phase transitions. We compare our results with experimental findings for typical thermotropic compounds presenting a N-Sm-A-Sm-C phase sequence.

Immature Stages, Natural History, Systematics and Conservation of an Endangered Neotropical Butterfly: the Case of Scada karschina delicata (Nymphalidae: Ithomiini).

The endangered butterfly Scada karschina delicata Talbot, 1932 (Nymphalidae: Danainae: Ithomiini) is endemic to northeastern Brazil, occurring in very few forest remnants of the 'Pernambuco Center of Endemism'. Larvae feed on Solanaceae and are very similar to those of other species in the subtribe Mechanitina, with lateral projections on body, one of the main synapomorphies of this subtribe. Based on molecular data, S. k. delicata clustered together with S. karschina karschina, as a monophyletic group sister to the amazon clade of S. reckia. Based on all available data, S. k. delicata is known from only five localities of mid- to high-altitude forests (from 500 to 1000 m of altitude) in northeastern Brazil. Grounded on available data, a new assessment of extinction risk is proposed, and S. k. delicata is now considered Vulnerable (VU) taxon.

Eurados review of retrospective dosimetry techniques for internal exposures to ionising radiation and their applications.

This work presents an overview of the applications of retrospective dosimetry techniques in case of incorporation of radionuclides. The fact that internal exposures are characterized by a spatially inhomogeneous irradiation of the body, which is potentially prolonged over large periods and variable over time, is particularly problematic for biological and electron paramagnetic resonance (EPR) dosimetry methods when compared with external exposures. The paper gives initially specific information about internal dosimetry methods, the most common cytogenetic techniques used in biological dosimetry and EPR dosimetry applied to tooth enamel. Based on real-case scenarios, dose estimates obtained from bioassay data as well as with biological and/or EPR dosimetry are compared and critically discussed. In most of the scenarios presented, concomitant external exposures were responsible for the greater portion of the received dose. As no assay is available which can discriminate between radiation of different types and different LETs on the basis of the type of damage induced, it is not possible to infer from these studies specific conclusions valid for incorporated radionuclides alone. The biological dosimetry assays and EPR techniques proved to be most applicable in cases when the radionuclides are almost homogeneously distributed in the body. No compelling evidence was obtained in other cases of extremely inhomogeneous distribution. Retrospective dosimetry needs to be optimized and further developed in order to be able to deal with real exposure cases, where a mixture of both external and internal exposures will be encountered most of the times.