[Clinical and epidemiologic description of a severe outbreak of Salmonellosis in an urban nursery school]. / Descripción clínica y epidemiológica de un brote grave de salmonelosis en una escuela infantil urbana.

OBJECTIVE: We describe clinically and epidemiologically an outbreak of gastrointestinal infection by Salmonella enterica ser. (serotype) Enteritidis in an urban infant school, which led to high morbidity and significant social alarm. The immediate communication, as well as the adequate study of the outbreak, in both aspects, allowed identifying the pathogen and establishing control measures in a reasonable period of time. Controversial aspects such as the indication of antibiotherapy or the moment of closing the center are discussed. METHODS: We retrospectively collected clinical, analytical and epidemiological information and we reviewed the methodology of the outbreak study and its results. RESULTS: A total of 57 children (3-45 months), were affected and had microbiological confirmation. Diarrhea and fever were the main symptoms. 74% went to the hospital and 37% were admitted (mean stay 3.3 days). Factors associated with admission were: dehydration, significant elevation of acute phase reactants and coagulopathy. Twelve patients received parenteral cefotaxime. There were 2 complications: 1 bacteremia and 1 readmission. The initial suspicion of the origin of the outbreak was food, but the analysis of the control samples was negative. Five workers were positive (2 symptomatic). Epidemiologic Surveillance concluded that the probable origin of the outbreak was an asymptomatic carrier and improper diapers handling. The center was closed for 8 days. Cleaning and disinfection measures were carried out, as well as instruction on diaper changing, and the carriers were followed. CONCLUSIONS: Clustering in time and space of cases should be reported immediately for early control of the outbreak. Children may present severe forms of Salmonella gastroenteritis.

[Cost-utility analysis of two formulations of botulinum toxin type A in the treatment of blepharospasm and cervical dystonia in Spain]. / Analisis coste-utilidad de dos formulaciones de toxina botulinica de tipo A en el tratamiento del blefaroespasmo y la distonia cervical en España.

INTRODUCTION: Studies on focal dystonia showed that the formulations of botulinum toxin type A, incobotulinumtoxin-A (Inco-BTA) and onabotulinumtoxin-A (Ona-BTA), have equivalent efficacy and safety. AIM: To carry-out a cost-utility analysis of Inco-BTA administered on flexible intervals vs. Ona-BTA on a fixed interval, in the treatment of blepharospasm and cervical dystonia. PATIENTS AND METHODS: A probabilistic Markov model was designed to estimate costs (euros, 2017) and benefits (quality-adjusted life years, QALY), from the Spanish National Health Service perspective and on a 5-year time horizon, of treatment of blepharospasm and cervical dystonia with Inco-BTA (6-12 month flexible intervals) versus Ona-BTA (12-month fixed intervals). It is assumed that symptoms will re-emerge some time later in both options. Result was expressed as incremental cost-utility ratio (ICUR). RESULTS: Inco-BTA and Ona-BTA costs were 3,742 and 3,366 euros respectively, in blepharospasm, and 6,673 and 6,419 euros in cervical dystonia. Patients treated with Inco-BTA remained asymptomatic for 22.12, and 21.34 more weeks than those treated with Ona-BTA, leading in 3.040 and 3.012 QALY, respectively, in blepharospasm, and 3.471 and 3.401 QALY, respectively, in cervical dystonia. Differences showed statistical significance in all cases. ICUR was estimated as 13,576 and 4,158 euros/QALY in blepharospasm and cervical dystonia, respectively. CONCLUSIONS: Treatment of blepharospasm and cervical dystonia with Inco-BTA is a cost-effective therapeutic alternative in Spain, based on the flexibility of their administration.

TITLE: Analisis coste-utilidad de dos formulaciones de toxina botulinica de tipo A en el tratamiento del blefaroespasmo y la distonia cervical en España.Introduccion. Las formulaciones de toxina botulinica de tipo A, incobotulinumtoxinA (Inco-TBA) y onabotulinumtoxinA (Ona-TBA), han demostrado eficacia y seguridad similar en los estudios de distonias focales en los que se han comparado. Objetivo. Realizar un analisis coste-utilidad de Inco-TBA, administrada en intervalos flexibles, frente a Ona-TBA, administrada en intervalos fijos, en el tratamiento del blefaroespasmo y la distonia cervical. Pacientes y metodos. Un modelo de Markov probabilistico estimo, desde la perspectiva del Sistema Nacional de Salud español y en un horizonte de cinco años, el coste (euros, 2017) y el resultado (años de vida ajustados a calidad, AVAC) del tratamiento del blefaroespasmo y la distonia cervical mediante intervalos flexibles con Inco-TBA (6-20 semanas) y fijos con Ona-TBA (12 semanas). Se asume que los sintomas reapareceran despues de un tiempo en ambos. El resultado se expreso como ratio coste-utilidad incremental (RCUI). Resultados. El coste de la Inco-TBA y la Ona-TBA fue, respectivamente, de 3.742 y 3.366 euros en el blefaroespasmo y de 6.673 y 6.419 euros en la distonia cervical. Los pacientes tratados con Inco-TBA permanecieron asintomaticos 22,12 y 21,34 semanas mas que los tratados con Ona-TBA, lo que resulto 3,040 y 3,012 AVAC, respectivamente, en el blefaroespasmo, y 3,471 y 3,401 AVAC, respectivamente, en la distonia cervical. En todos los casos, las diferencias presentaron significacion estadistica. La RCUI fue de 13.576 y 4.158 euros/AVAC, respectivamente. Conclusiones. El tratamiento del blefaroespasmo y la distonia cervical con Inco-TBA, administrada siguiendo un esquema posologico de intervalos flexibles, constituye una alternativa terapeutica eficiente en España.

Identification of genes involved in imatinib resistance in CML: a gene-expression profiling approach.

The use of the tyrosine kinase inhibitor imatinib, which blocks the enzymatic action of the BCR-ABL fusion protein, has represented a critical advance in chronic myeloid leukemia (CML) treatment. However, a subset of patients initially fails to respond to this treatment. Use of complementary DNA (cDNA) microarray expression profiling allows the identification of genes whose expression is associated with imatinib resistance. Thirty-two CML bone marrow samples, collected before imatinib treatment, were hybridized to a cDNA microarray containing 6500 cancer genes, and analyzed using bootstrap statistics. Patients refractory to interferon-alpha treatment were evaluated for cytogenetic and molecular responses for a minimum of 12 months. A set of 46 genes was differentially expressed in imatinib responders and non-responders. This set includes genes involved in cell adhesion (TNC and SCAM-1), drug metabolism (cyclooxygenase 1), protein tyrosine kinases and phosphatases (BTK and PTPN22). A six-gene prediction model was constructed, which was capable of distinguishing cytogenetic response with an accuracy of 80%. This study identifies a set of genes that may be involved in primary resistance to imatinib, suggesting BCR-ABL-independent mechanisms.

Variaciones en la incidencia de bronquiolitis tras la aparición del SARS-CoV-2 / Variations in the incidence of bronchiolitis after the onset of SARS-CoV-2

Introducción. Durante la temporada 2020-2021 se ha asistido a una disminución de la incidencia de hospitalizaciones por bronquiolitis. Los cambios en la evolución de la pandemia de SARS-CoV-2 y en la aplicación de medidas preventivas podrían relacionarse con un aumento de la incidencia de bronquiolitis grave durante la temporada 2021-2022. Objetivo. Determinar la incidencia de hospitalizaciones por bronquiolitis en un hospital terciario durante la temporada 2021-2022 y compararla con temporadas previas. Método. Estudio epidemiológico de tipo observacional, descriptivo y ambispectivo. A través de la base de datos de un hospital terciario, se compararon la incidencia, la etiología y los indicadores de gravedad de las hospitalizaciones por bronquiolitis. Se analizaron 3 cohortes en época epidémica: la temporada 2020-2021 y la 2021-2022 (prospectivas); y la temporada 2018-2019 (retrospectiva). También se analizó una cohorte prospectiva entre los meses de abril y octubre de 2021. Resultados. La incidencia acumulada de hospitalizaciones fue de 113,6/10.000 niños menores de 2 años en la temporada pre-covídica; de 3,6/10.000 en la temporada 2020-2021; y de 65,7/10.000 en la temporada 2021-2022. El porcentaje de ingresos en UCIP fue de 36,6%, 0 % y 30,8%, respectivamente. La incidencia acumulada de hospitalizaciones en el periodo no epidémico fue de 60,8/10.000, precisando ingreso en UCIP el 19%. El microorganismo más frecuente fue el virus respiratorio sincitial en todas las cohortes. Conclusiones. La incidencia durante los meses típicamente epidémicos de bronquiolitis bajó drásticamente la temporada en la que apareció el SARS-CoV-2, aumentando notablemente el año posterior, aunque sin alcanzar la incidencia previa a la pandemia. Se ha observado una incidencia alta de casos de bronquiolitis entre abril y octubre de 2021 (AU)

Introduction. A decrease has been observed during the 2020-2021 season in the incidence of hospitalizations for bronchiolitis. Changes in the evolution of the SARS-CoV-2 pandemic and in the application of preventive measures could be related to an increase in the incidence of severe bronchiolitis during the 2021-2022 season. Objective. To determine the incidence of bronchiolitis hospitalizations in a tertiary hospital during the 2021-2022 season and to compare it with previous seasons. Method. An observational, descriptive and ambispective epidemiological study. A tertiary hospital database was used to compare the incidence, etiology, and severity indicators of bronchiolitis hospitalizations. 3 cohorts were analyzed in epidemic times: the 2020-2021 season and the 2021-2022 season (prospective); and the 2018-2019 season (retrospective). A prospective cohort between the months of April and October 2021 was also analyzed. Results. The cumulative incidence of hospitalizations was 113.6/10,000 children under 2 years of age in the pre-covid season; 3.6/10,000 in the 2020-2021 season; and 65.7/10,000 in the 2021-2022 season. The percentage of admissions in PICU was 36.6%, 0% and 30.8%, respectively. The cumulative incidence of hospitalizations in the non-epidemic period was 60.8/10,000, with 19% requiring admission to the PICU. The most frequent microorganism was the respiratory syncytial virus in all cohorts. Conclusions. The incidence during the typically epidemic months of bronchiolitis drastically decreased the season in which SARS-CoV-2 appeared, noticeably increasing the next year, although without reaching the pre-pandemic incidence. A high incidence of bronchiolitis cases was observed between April and October 2021 (AU)

Malformaciones ano-rectales: cambios en el manejo neonatal en los últimos 22 años / Anorectal malformations: changes in neonatal management in the last 22 years

Introducción y objetivos. Una inspección perineal alterada o el retraso en la expulsión meconial debe hacernos sospechar una malformación anorrectal. El objetivo de este estudio es conocer la incidencia de estas malformaciones, así como el estudio de las características obstétricas y neonatales, diagnósticas y terapéuticas de estos pacientes, y sus complicaciones en los últimos 22 años. Material y método. Estudio descriptivo y retrospectivo incluyendo pacientes con diagnóstico en periodo neonatal de malformaciones anorrectales, excluyendo enfermedad de Hirschsprung, entre 2000-2021. Se establecieron dos periodos temporales para ver posibles cambios (2000-2010 versus 2011-2021). Resultados. 27 pacientes, 92,6% varones. Incidencia de 1 caso por cada 5.895 recién nacidos en nuestra región. El 88,9% fueron intervenidos con una mediana de edad de 2 días, precisando ingreso todos ellos durante una mediana de 15 días. El 95,8% recibió antibioterapia (mediana de 6 días), siendo la pauta más utilizada la asociación ampicilina, gentamicina y clindamicina; el 25% precisó ventilación mecánica invasiva (mediana de 1 día) y el 25% sedoanalgesia, tras la intervención; y 17 pacientes precisaron nutrición parenteral (media de 7,6 días). El 16,7% presentó complicaciones a corto plazo (75% infecciosas). A mediolargo plazo, el 37,5% precisó reintervención. No hemos encontrado diferencias significativas en las características clínicas ni diagnósticas entre los dos periodos temporales analizados. Conclusiones. Las malformaciones anorrectales son una causa relativamente frecuente de obstrucción intestinal en periodo neonatal que requiere un tratamiento multidisciplinar. En los últimos 22 años no hemos encontrado diferencias en cuanto a su incidencia ni en su manejo y resultado (AU)

Introduction and objectives. An altered perineal inspection or the delay in meconium expulsion should lead us to suspect an anorectal malformation. This study has aimed to know the incidence of these malformations and to study the obstetric and neonatal, diagnostic and therapeutic characteristics of these patients, and their complications in the last 22 years. Material and methods. A descriptive and retrospective study including patients having a diagnosis in the neonatal period of anorectal malformations, excluding Hirschsprung’s disease, between 2000-2021. Two time periods were established to see possible changes (2000-2010 versus 2011-2021). Results. 27 patients, 92.6% males, there being an incidence of one case per 5,895 newborns in our region. 88.9% underwent surgery with a median age of 2 days, admission being required for a median of 15 days. 95.8% received antibiotic therapy (median of 6 days), the regimen used most being the association of ampicillin, gentamicin and clindamycin; 25% required invasive mechanical ventilation (median of 1 day) and 25% sedated analgesia after the intervention. 17 patients required parenteral nutrition (mean 7.6 days). 16.7% had short-term complications (75% infectious). In the medium to long term, 37.5% required reoperation. We did not find any significant differences in the clinical or diagnostic characteristics between the two time periods analyzed. Conclusions. Anorectal malformations are a relatively frequent cause of intestinal obstruction in the neonatal period that requires multidisciplinary treatment. We have not found differences in terms of its incidence or in its management and outcome regarding the last 22 years (AU)

The spectral sensitivity of single units in the nucleus rotundus of pigeon, Columba livia.

Responses to diffuse monochromatic light were recorded from single units in the diencephalon of pigeon. Units were both excited and inhibited by light stimulation. Intensity-response functions based on latency measures to the first spike after stimulation were used to generate action spectra. One class of spectral sensitivity functions presumably from rods, showed peak sensitivities near 500 nm: these functions were unaffected by changing criterion values used to generate the functions. A second class of cone functions showed multiple peak sensitivities at 540 nm and 600-620 nm. These units shifted their peak sensitivities with a change in criterion values. Unit response types tended to be localized differentially in the nucleus rotundus. Excitatory units were located in the dorsal half of the nucleus, while inhibitory units were located in the ventral half, with a few exceptions. An attempt was made to integrate the present findings with previous behavioral, electrophysiological, photochemical, and anatomical data in the pigeon.

Sedoanalgesia para procedimientos en Unidad de Cuidados Intensivos Pediátricos (UCIP). Farmacología, efectos secundarios y control de calidad / Sedoanalgesia for procedures in Pediatric Intensive Care Unit (PICU). Pharmacology, side effects and quality control

OBJETIVOS: Analizar los fármacos más utilizados para sedoanalgesia en procedimientos realizados en una Unidad de Cuidados Intensivos Pediátricos (UCIP), medir su efectividad (nivel de sedación), efectos secundarios y control de calidad. MATERIAL Y MÉTODOS: Estudio prospectivo, observacional y descriptivo. Se recogieron datos epidemiológicos y clínicos, fármaco/s utilizado/s, nivel de sedación alcanzado, incidencias o efectos adversos y escalas de satisfacción, de pacientes de 0 a 18 años sometidos a procedimientos que precisaron sedoanalgesia. RESULTADOS: Se incluyeron 112 pacientes con una edad media de 8,3 años. El fármaco más utilizado fue el propofol (64,3%), seguido de la asociación de ketamina con midazolam (16,1%) y del sevofluorano (12,5%). En el 70,5% de los pacientes se alcanzó un nivel de sedación profunda, sin diferencias estadísticamente significativas entre los distintos fármacos. Se registraron efectos adversos en un 51,8% de pacientes, principalmente desaturación, con una frecuencia mayor al emplear propofol (p< 0,05). La puntuación en la satisfacción alcanzó el valor máximo en todos los padres encuestados, sin hallarse diferencias significativas en función del procedimiento, fármaco, nivel de sedación o efectos adversos. En el 80% de los profesionales la puntuación alcanzó ese mismo valor. CONCLUSIONES: El fármaco más utilizado y con mayor eficacia es el propofol, aunque se asocia más frecuentemente con efectos adversos. El nivel de sedoanalgesia fue adecuado en el momento de iniciar los procedimientos. El grado de satisfacción es óptimo en la mayor parte de los encuestados, aunque fue registrado en menos de la mitad de los procedimientos

OBJECTIVES: To analyze the drugs most used for sedoanalgesia in procedures performed in a Pediatric Intensive Care Unit (PICU), to measure their effectiveness (level of sedation achieved), the main side effects and to carry out a quality control. MATERIAL AND METHODS: Prospective, observational and descriptive study. Epidemiological and clinical data, drug (s) used, level of sedation achieved, incidences or adverse effects, and satisfaction scales were collected from patients from 0 to 18 years of age who underwent procedures that required sedation and analgesia. RESULTS: 112 patients with an average age of 8.3 years were included. The most widely used drug was propofol (64.3%), followed by the association of ketamine with midazolam (16.1%) and sevofluorane (12.5%). In 70.5% of the patients, a level of deep sedation was reached, with no statistically significant differences between the different drugs used. Adverse effects were recorded in 51.8% of patients, mainly desaturation, with a higher frequency when using propofol (p <0.05). Satisfaction score was maximal in all the parents surveyed, without finding significant differences based on the procedure, drug, level of sedation or adverse effects. In 80% of the professionals the score was also maximal. CONCLUSION: The most used and with the highest efficacy in absolute values drug was propofol, although it was more frequently associated with adverse effects. The level of sedoanalgesia was adequate at the time of initiating the procedures. The degree of satisfaction was optimal in most of the respondents, although it was registered in less than half of the procedures

Functional morphologies of retinal ganglion cells in the turtle.

Retinal ganglion cells in the turtle, Pseudemys scripta elegans, were examined by intracellular recording with a protocol of stationary and moving lights. Responses were apportioned among OFF, ON, and ON-OFF categories, and directional selectivity. Cells were injected with Neurobiotin, then later conjugated with avidin-horseradish peroxidase in standard procedure. Morphological analysis of the stained cells included measurements of soma and dendritic field sizes, dendritic stratification, number of cell processes, dendritic branchings, and dendritic symmetry ratios. ON and ON-OFF cells are at least bistratified, sometimes tristratified, in both sublaminae A and B whether directionally selective or not. OFF cells, in contrast, are monostratified, or at least confined to sublamina A. Morphological parameters of somal and dendritic field areas, branch point densities, and dendritic field asymmetries do not predict directional selectivity. Membrane polarization accompanying moving stimulation is discussed in terms of shunting inhibition and recording site.

Allogeneic peripheral blood progenitor cell (PBPC) transplantation in children.

The use of peripheral blood as a source of hematopoietic precursors is an alternative to the bone marrow in allogeneic transplantation. Although pediatric allogeneic PBPC experience is limited, there is no reason to believe that the outcome and benefit with PBPC should be different than adults. We describe our initial experience in two children who received PBPC allogeneic transplantation in whom the donors were mobilized with filgrastim. Hematopoietic recovery was achieved on days 14 and 16, and the patients did not develop severe GVHD.

Pediatric experience with autologous peripheral blood progenitor cell transplantation: influence of CD34+ cell dose in engraftment kinetics.

The aim of this study was to analyze factors affecting mobilization and engraftment in 40 children undergoing autologous peripheral blood progenitor cell transplantation for different malignancies: 19 patients with haematological malignancies and 21 patients with solid tumors. Patients received 4-5 days of rhG-CSF (12 micrograms/kg/day) subcutaneously. Apheresis was performed by continuous flow blood cell separation beginning on the fifth day of rhG-CSF. For patients weighing < or = 25 kg, the extracorporeal line was primed with irradiated red blood cells. After myeloablative conditioning regimens, patients were grafted with 7.21 +/- 7.8 x 10(6)/kg CD34+ cells. Days to achieve an absolute neutrophil count > 0.5 x 10(9)/1 and a platelet count > 20 x 10(9)/1 without platelet support were 9.50 +/- 1.2 (range 7-13) and 18.1 +/- 8.3 (range 9-37), respectively. The number of CD34+ cells infused was highly correlated with engraftment kinetics (P = 0.0001). The patient's body weight and the number of previous chemotherapy courses had a negative influence on CD34+ cells collected.

Large-volume leukapheresis for peripheral blood stem cell collection in children: a simplified single-apheresis approach.

Large volume leukapheresis (LVL) defined as the processing of greater than three volumes of blood in a single session for peripheral blood stem cell (PBSC) collection was performed in 27 children, aged from 1 to 15 years, with various malignancies. Harvesting of PBSC was started after 4 days of cytokine (G-CSF 12 micrograms/kg s.c.) alone. With the exception of two cases the rest (92.5%) needed only a single apheresis to yield the minimum number of cells required for transplantation. No consistent side-effects were observed and the LVL were well tolerated by children. An average of 7.6 x 10(8) MNC/kg, 6.1 x 10(6)/kg CD34+ and 2.1 x 10(4)/kg CFU-GM were harvested. To date, 19 patients have been transplanted after myeloablative treatment and sustained engraftment was achieved in all cases. LVL can be safely and easily performed in children allowing adequate PBSC collection for transplantation with prompt hematological engraftment.

Quinton-Mahurkar catheter as short-term central venous access for PBSC collection: single-center experience of 370 aphereses in 110 patients.

We retrospectively analyzed our experience with the Quinton-Mahurkar dual-lumen hemodialysis catheter as short-term central venous access for harvesting peripheral blood stem cells (PBSC) for autologous transplantation. For intensification therapy for various malignancies 370 leukaphereses were performed in 110 candidates. The catheter was placed percutaneously under local anesthesia only for the time of blood collection and in no case was it used for the PBSC transplant. No systemic antithrombotic prophylaxis was administered. PBSC were collected using a continuous flow cell separator, COBE Spectra, after mobilization with chemotherapy followed by cytokine: rhGM-CSF and rhG-CSF s.c. (35 patients) or rhG-CSF s.c. alone (75 patients). The median number of aphereses was two (1-13). Eighty-nine patients (81.3%) required three or fewer sessions to collect the minimum mononuclear cell target number of 6 x 10(8) MNC/kg. The volume of blood per kg body weight processed for each apheresis was 240 ml (range 150-560 ml) equivalent to 13 l (6-30 l) and the median flow rate was 61 ml/min (range 30-90 ml/min). The total CD34+ cell yield per patient was 3.55 x 10(6)/kg (0.26-34.8) and the MNC yield was 6.1 x 10(8)/kg (2.96-12.6). We observed the following complications: local infection in four cases (3.6%), catheter occlusion for local thrombosis in two cases (1.8%) and pneumothorax in one case (0.97%). In our experience the Mahurkar-Quinton catheter, when placed specifically for apheresis sessions, was very effective and safe for PBSC harvesting with a low incidence of complications.

Comparison of peripheral blood progenitor cell mobilization in patients with multiple myeloma: high-dose cyclophosphamide plus GM-CSF vs G-CSF alone.

The best method for peripheral blood progenitor cell (PBPC) mobilization in patients with multiple myeloma (MM) remains controversial. We report the results of two different methods of PBPC collection for autologous transplantation in 40 patients with stage II or III MM. In group I (n = 18), HD-CY, 4 g/m2 i.v., was administered followed by GM-CSF, 8 microg/kg/day s.c., until the end of collection, starting the leukaphereses after hematological recovery (>1 x 10(9)/l WBC). In group II (n = 22), G-CSF, 10 microg/kg/day s.c., was used alone until the last day of collection, starting consecutive aphereses on the 5th day. A minimum of two aphereses were performed to collect at least 2 x 10(6)/kg CD34+ cells. Both patient groups were comparable for age, sex and clinical prognostic features as well as previous therapies. In group I, the median yields per pheresis were: MNC 1.47 (1.38-2.32) x 10(8)/kg, CFU-GM 0.82 (0.18-13.2) x 10(4)/kg and CD34+ cells 1.98 (0.96-6.96) x 10(6)/kg. In group II these results were: MNC 2.44 (2.06-3.6 x 10(8)/kg) (P = 0.03), CFU-GM 0.75 (0.16-7.8) x 10(4)/kg and CD34+ 1.05 (0.32-3.4) x 10(6)/kg (P = 0.02). The median number of aphereses performed in each group was 5 (4-12) with a median of 5.24 +/- 2.51 in group I and 3 (2-6) with a median of 3.1 (+/- 0.91) in group II (P = NS). Hospitalization for PBPC mobilization was required in all patients in group I and the treatment-related toxicity was greater in this group: 12 patients (66%) developed fever requiring antibiotics during the neutropenic period after HD-CY and six (33%) patients required transfusion support. After receiving busulfan 12 mg/kg p.o. and melphalan 140 mg/m2 i.v., as the conditioning regimen, the median periods to reach granulocytes (>0.5 x 10(9)/l) and platelet (>20 x 10(9)/l) engraftment were 12 and 11 days respectively (ranges 8-20 and 10-16) in group I (HD-CY plus GM-CSF group), and 11 and 13 days respectively (ranges 7-42 and 10-38) in group II (G-CSF group) (P = NS). In conclusion, these data suggest that although HD-CY plus GM-CSF is superior to G-CSF alone based on mean CD34+ cell yield per pheresis, adequate CD34+ cell collections can be achieved with G-CSF alone in most MM patients with less toxicity and with simplification of the procedure.

Visual properties of cells in anterior dorsal ventricular ridge of turtle.

Single units in the anterior dorsal ventricular ridge (ADVR), a structure in the major afferent visual pathway of turtle, were investigated electrophysiologically for response properties to varied light patterns. The majority of cells responded to a broad range of spatially, temporally, and chromatically varied stimuli over most of the monocular visual field. One category of cells, seemingly specialized for 'novelty' detection, indicates one possible role for ADVR in visual sensory processing.

Psychophysically derived visual mechanisms in turtle. II--Spatial properties.

Visual mechanisms isolated in Pseudemys by the two-color threshold technique of Stiles show peak wavelength sensitivities at 650 nm (red light) and 540 nm (green light). Ricco critical areas were measured for the two test wavelengths under three conditions: dark, moderate and intense backgrounds. As expected, critical spatial areas decreased with light adaptation. Under dark adaptation only rods and red-sensitive cones were operative, and one photon per 12 rods was sufficient for green-light threshold, as was one photon per four red-sensitive cones for red-light threshold. Rods apparently pool their information among the several receptors within the threshold area. Under light adaptation, rods were not functional and thresholds were determined by red-sensitive and green-sensitive cones alone. Cones did not share information over many receptors, requiring close to one photon per receptor to function at threshold.

Psychophysically derived visual mechanisms in turtle. I--Spectral properties.

Two-color increment thresholds were measured in turtle using a behavioral avoidance paradigm. Four visual mechanisms were isolated, and their spectral sensitivities were compared to action spectra of photoreceptors known to occur in this animal. One visual mechanism appears to be mediated by rods and red-sensitive cones at low background intensities, a second mechanism by coupled red- and green-sensitive cones at intermediate levels, a third and fourth mechanism by red-sensitive, and green-sensitive single cones, respectively, acting alone at high background intensities.

Photoreceptor input and temporal summation in turtle retinal ganglion cells.

The relation between photoreceptor input and temporal summation in ganglion cells was investigated in the optical nerve of fresh-water turtle, Pseudemys. Action spectra derived for constant, high-criterion responses showed most cells to be maximally sensitive to 620 nm light, indicating dominant input from red-sensitive cones. At a lower criterion, sensitivity to 520 nm light greatly increased indicating an increase in rod input. Temporal summation curves for these intensity-dependent cells showed reciprocity between flash intensity and duration up to 128 msec for high-criterion summation curves. Low-criterion summation curves showed reciprocity up to the critical duration of 285 msec. Cells maximally sensitive to 620 nm light at all intensities often showed secondary sensitivity to 560 nm light, and were fitted by action spectra taken from red- and green-sensitive cones. Temporal summation curves for these cells had critical durations near 100 msec. Some cells responded best to light near 520 nm at all intensities and demonstrated little or no input from red-sensitive cones. These cells were fitted well by the action spectrum of rods and showed the longest critical durations of all at 375 msec. Chromatic input and temporal characteristics are intimately related: red-cone-dominated ganglion cells have the shortest critical durations while rod-dominated cells shows much longer ones. These findings are in keeping with psychophysical determinations of critical durations in this same animal.

An automated apparatus for the determination of visual thresholds in turtles.

An automated apparatus is described that permits precise and reliable measurements of visual thresholds in turtles using a conditioned avoidance technique. The entire sequence of stimulus management and the collection of response data are under programmed control.

Multiplied functions unify shapes of ganglion-cell receptive fields in retina of turtle.

Retinal ganglion cells in the turtle were extracellularly recorded to define the shapes of their receptive fields by small moving light spots. To better define the geometries, spectral-light adaptations and vitreal injections of 2-amino-4-phosphonobutyric acid (APB) were used to disrupt balances in field organization along dimensions of wavelength, ON and OFF responses, and center/surround areas. Three-dimensional data plots were fit by Gaussian, Gabor, and cardioid functions to show that the shapes of receptive fields are predicted by combinations of these multiplied functions. Results indicate that Gaussian functions describe simple symmetrical receptive fields that are center-only; Gabor functions describe center/surround color-opponent receptive fields that have a ring of spike activity in the periphery; and directionally selective receptive fields, in contrast, which are asymmetrical, are described by cardioid functions adjoined to Gaussian or Gabor functions. The advantage of linking multiplied functions is that receptive fields are unified by a model that predicts progressively more complex field geometries derived from particular stimulating conditions.