Nrf2 deficiency in mice attenuates erythropoietic stress-related macrophage hypercellularity.

Erythropoiesis in the bone marrow and spleen depends on intricate interactions between the resident macrophages and erythroblasts. Our study focuses on identifying the role of nuclear factor erythroid 2-related factor 2 (Nrf2) during recovery from stress erythropoiesis. To that end, we induced stress erythropoiesis in Nrf2+/+ and Nrf2-null mice and evaluated macrophage subsets known to support erythropoiesis and erythroid cell populations. Our results confirm macrophage and erythroid hypercellularity after acute blood loss. Importantly, Nrf2 depletion results in a marked numerical reduction of F4/80+/CD169+/CD11b+ macrophages, which is more prominent under the induction of stress erythropoiesis. The observed macrophage deficiency is concomitant to a significantly impaired erythroid response to acute stress erythropoiesis in both murine bone marrow and murine spleen. Additionally, peripheral blood reticulocyte count as a response to acute blood loss is delayed in Nrf2-deficient mice compared with age-matched controls (11.0 ± 0.6% vs. 14.8 ± 0.6%, p ≤ 0.001). Interestingly, we observe macrophage hypercellularity in conjunction with erythroid hyperplasia in the bone marrow during stress erythropoiesis in Nrf2+/+ controls, with both impaired in Nrf2-/- mice. We further confirm the finding of macrophage hypercellularity in another model of erythroid hyperplasia, the transgenic sickle cell mouse, characterized by hemolytic anemia and chronic stress erythropoiesis. Our results revealed the role of Nrf2 in stress erythropoiesis in the bone marrow and that macrophage hypercellularity occurs concurrently with erythroid expansion during stress erythropoiesis. Macrophage hypercellularity is a previously underappreciated feature of stress erythropoiesis in sickle cell disease and recovery from blood loss.

Diagnostic Utility of Isolated Tube C Positivity in T-Cell Receptor ß Testing Using BIOMED-2 Primers.

OBJECTIVES: T-cell receptor (TCR) gene rearrangement studies are widely used for assessing T-cell clonality. The frequency and significance of clonal peaks restricted to TCR ß (TCRB) tube C are uncertain. We retrospectively reviewed 80 TCR studies performed on bone marrow/peripheral blood. METHODS: TCRB and TCR γ (TCRG) analyses were performed using BIOMED-2 primers. A peak was considered clonal or atypical if it was reproducible and 5× or more or 3× to 5× polyclonal background, respectively. RESULTS: TCRB analysis demonstrated 12 (15%) of 80 cases with one to four isolated peaks in tube C (>3×) with polyclonal pattern in tubes A and B. TCRG analysis was monoclonal in two cases (both definite T-cell neoplasms), polyclonal in four, and oligoclonal in six. Of the 10 cases without clone in TCRG, six had autoimmune disorder and none had T-cell neoplasm. CONCLUSIONS: Peaks restricted to TCRB tube C in the TCR analysis may be misleading, as it is often not indicative of an overt T-cell neoplasm.

Radon monitoring in sites of economical importance in Jamaica.

The main task was to evaluate possible radon risk to the public and workers in four caves of economical importance. Green Grotto Cave is a large labyrinthine limestone cave, open to the tourism; kept Rn concentration in the range 30-40 Bq m(-3). Xtabil a coral limestone sea cave is part of a beach resort resulted in very low radon concentration of 10 Bq m(-3). Windsor is an intricate limestone cave system showed Rn concentration in the range 250-350 Bq m(-3). Whereas the Oxford caves, is situated in a region of high radioactivity in soil due to the bauxite mines, reached a maximum of 2592 Bq m(-3).

Epidemiology of multiple myeloma and the role of M-band detection on serum electrophoresis in a small developing country. A retrospective study.

OBJECTIVE: The objective of the study was to determine the role of M-band component on serum protein electrophoresis and bone marrow biopsy in the diagnosis. METHODS: Data was collected on 34 patients with MM diagnosed and/or treated. RESULTS: There were equal numbers of men 17 (50%) and women 17 (50%). All patients were first screened for the presence of M-Band using serum protein electrophoresis (SPE) followed by bone marrow biopsy as the confirmatory test. Only two patients screened negative by SPE. On the other hand six patients who tested positive by SPE were negative on biopsy. Thus the sensitivity of the SPE was 96% and specificity 71%. This means that 29 patients had an established diagnosis of MM. There was a slight male predominance when compared to females. CONCLUSION: The data showed that the SPE and bone biopsy are the important tools in the diagnosis of multiple myeloma in a small developing country.

Elements in human placentae in Jamaica / Elementos en las placentas humanas en Jamaica

AIM: To investigate the relationships, if any, between elemental content of the placenta with age of mother, birthweight and the Apgar scores of a neonate. METHODS: Placental samples were collected, stored at -20ºC and then dried and analysed using neutron activation with the SLOWPOKE II reactor at the International Centre for Environmental and Nuclear Sciences (ICENS). A questionnaire was administered at the time of delivery to determine the level of fish consumption, numbers of dental amalgam fillings and use of cough syrups. Placental concentrations of bromine, calcium, chlorine, iron, mercury, potassium, rubidium, selenium, sodium and zinc were determined. RESULTS: The placentae of 52 Jamaican mothers with a mean age 29 years (range 18-42 years) delivering singleton neonates with a mean birthweight of 3.1 kg (1.3 - 5.5 kg) at term were collected. With the exception of iron and bromine, all results for elemental determinations are very similar to those found elsewhere. Correlation was observed for Apgar 2 (5 minutes), calcium and zinc with birthweight, with p-values of 0.002, 0.007 and 0.07, respectively. Negative correlation was observed for the Apgar 2 and potassium (p = 0.056) and age of mother at birth and bromine (p = 0.02). The mercury concentration in the measured placentae (7.29 ±9.1 µg/kg w/w) was slightly lower than the mean concentration found in the literature (8 µg/kg w/w). Approximately 93% of the measured placentae in this study are below the derived placentae upper limit of 22 µg/kg. Of the 7% above the upper limit none exceeded the conservative estimated limit of 115 /µg/kg at which neural developmental problems start. CONCLUSION: The significant associations noted are of unknown clinical relevance and need further study.

OBJETIVO: Investigar las relaciones que pudieran existir entre el contenido elemental de la placenta y la edad de la madre, el peso al nacer, y la puntuación Apgar del neonato. MÉTODOS: Muestras de placenta fueron recogidas, almacenadas a -20ºC y entonces secadas y analizadas usando la activación neutrónica con el reactor SLOWPOKE II del Centro Internacional de Ciencias Medioambientales y Nucleares (ICENS). A la hora del parto se aplicó una encuesta para determinar el nivel de consumo de pescado, el número de amalgamas dentales y el uso de jarabes para la tos. Se determinaron las concentraciones placentales de bromo, calcio, cloro, hierro, mercurio, potasio, rubidio, selenio, sodio y cinc. RESULTADOS: Se recogieron las placentas de 52 madres jamaicanas con una edad promedio de 29 años (rango 18-42 años) que parieron neonatos únicos con un peso promedio de 3.1 kg (1.3-5.5 kg) a término. Con la excepción del hierro y el bromo, todos los resultados para las determinaciones elementales son muy similares a los hallados en otras partes. Se observó una correlación de Apgar 2 (5 minutos), el calcio y el cinc con el peso al nacer, los valores p de 0.002, 0.007 y 0.07 respectivamente. Se observó una correlación negativa de Apgar 2 y el potasio (p = 0.056) y la edad de la madre a la hora del alumbramiento, con el bromo (p = 0.02). La concentración de mercurio en las placentas medidas (7.29 ± 9.1 w/w de µg/kg) fue ligeramente más baja que la concentración promedio hallada en la literatura (8 µg/kg w/w). Aproximadamente 93% de las placentas evaluadas en este estudio están por debajo del límite superior de 22 µg/kg. Del 7% por encima del límite superior, ninguna excedió el límite conservador estimado de 115 µg/kg en el cual comienzan los problemas del desarrollo neural. CONCLUSIÓN: Se desconoce la importancia clínica de las asociaciones significativas observadas y se requiere más estudio.

Elements in human placentae in Jamaica.

AIM: To investigate the relationships, if any, between elemental content of the placenta with age of mother birthweight and the Apgar scores of a neonate. METHODS: Placental samples were collected, stored at -20 degrees C and then dried and analysed using neutron activation with the SLOWPOKE II reactor at the International Centre for Environmental and Nuclear Sciences (ICENS). A questionnaire was administered at the time of delivery to determine the level of fish consumption, numbers of dental amalgam fillings and use of cough syrups. Placental concentrations of bromine, calcium, chlorine, iron, mercury, potassium, rubidium, selenium, sodium and zinc were determined. RESULTS: The placentae of 52 Jamaican mothers with a mean age 29 years (range 18-42 years) delivering singleton neonates with a mean birthweight of 3.1 kg (1.3-5.5 kg) at term were collected. With the exception of iron and bromine, all results for elemental determinations are very similar to those found elsewhere. Correlation was observed for Apgar 2 (5 minutes), calcium and zinc with birthweight, with p-values of 0.002, 0.007 and 0.07, respectively. Negative correlation was observed for the Apgar 2 and potassium (p = 0.056) and age of mother at birth and bromine (p = 0.02). The mercury concentration in the measured placentae (7.29 +/- 9.1 microg/kg w/w) was slightly lower than the mean concentration found in the literature (8 microg/kg w/w). Approximately 93% of the measured placentae in this study are below the derived placentae upper limit of 22 microg/kg. Of the 7% above the upper limit none exceeded the conservative estimated limit of 115 microg/kg at which neural developmental problems start. CONCLUSION: The significant associations noted are of unknown clinical relevance and need further study.

Trace elements in Jamaican tobacco.

The concentrations of 28 elements, in hand-made cigars, "rope" tobacco and freshly picked tobacco leaves from the parish of Manchester in central Jamaica, were compared with locally packaged and imported cigarettes and cigars. Except for chromium and vanadium, which are lower in the imported products, the elemental concentrations of all the brands sold in Jamaica are rather similar. The means for aluminium, cadmium, caesium, cerium, chromium, iron, thorium, uranium, vanadium and zinc for the Manchester material exceed the maximum values of the other tobaccos. The significant concentrations of heavy metals, and especially cadmium, which is about 50 times that of commercial cigarettes, reflect the known high concentrations in the soils in the region. This tobacco is not filtered and the smoke contains 50% of the cadmium. This, and the concentrations of radioactive elements, may indicate an additional health risk compared with commercial cigarettes. A study of three samples of marijuana indicates a similar level of risk from heavy metals.

Trace elements in Jamaican tobacco

The concentrations of 28 elements, in hand-made cigars, [quot ]rope[quot ] tobacco and freshly picked tobacco leaves from the parish of Manchester in central Jamaica, were compared with locally packaged and imported cigarettes and cigars. Except for chromium and vanadium, which are lower in the imported products, the elemental concentrations of all the brands sold in Jamaica are rather similar. The means for aluminium, cadmium, caesium, cerium, chromium, iron, thorium, uranium, vanadium and zinc for the Manchester material exceed the maximum values of the other tobaccos. The significant concentrations of heavy metals, and especially cadmium, which is about 50 times that of commercial cigarettes, reflect the known high concentrations in the soils in the region. This tobacco is not filtered and the smoke contains 50 of the cadmium. This, and the concentrations of radioactive elements, may indicate an additional health risk compared with commercial cigarettes. A study of three samples of marijuana indicates a similar level of risk from heavy metals

Thermoluminescence dosimetry in the Caribbean.

The results of five years of radiation monitoring of 590 radiation workers in Jamaica and an additional 88 in Barbados and The Turks and Caicos Islands show that the annual dose absorbed by Caribbean radiation workers is, with a single exception, well within the internationally accepted limits of 20 mSv per year. There were few cases of relatively high exposures. The dose equivalent of the radiation workers by category agrees with international trends; workers in nuclear medicine receive the highest doses and dental radiologists the lowest. The collective Effective Dose Equivalent has been calculated for each of the monitored populations and certain trends identified. The risk for development of fatal cancers from the occupational doses reported was very low. Consistent monitoring will identify aberrant conditions quickly and help maintain that record.

Thermoluminescence dosimetry in the Caribbean

The results of five years of radiation monitoring of 590 radiation workers in Jamaica and an additional 88 in Barbados and The Turks and Caicos Islands show that the annual dose absorbed by Caribbean radiation workers is, with a single exception, well within the internationally accepted limits of 20 mSv per year. There were few cases of relatively high exposures. The dose equivalent of the radiation workers by category agrees with international trends; workers in nuclear medicine receive the highest doses and dental radiologists the lowest. The collective Effective Dose Equivalent has been calculated for each of the monitored populations and certain trends identified. The risk for development of fatal cancers from the occupational doses reported was very low. Consistent monitoring will identify aberrant conditions quickly and help maintain that record

Is the management of acute otitis media in children by primary care physicians in Kingston consistent with evidenced-based medicine?

OBJECTIVE: to explore the knowledge and actual management practice of acute otitis media (AOM) by primary care physicians. METHODS: A 19-item questionnaire was administered to all Kingston-based general practitioners and pediatricians currently listed by two major pharmaceutical companies. Data obtained included knowledge, diagnostic and therapuetic practice, and reported involvment in continuing medical education. There were 91 responders, consisting of 53 percent of the general practitioners (GPs) and 90 percent of the paediatricians listed. RESULTS: All the physicians except three of the GPs were participating in some aspect of continuing medical education. Fifty-two different criteria were used for the diagnosis of AOM. Only 15 of these were consistent with current best management guidelines. There was no statistically significant difference in diagnostic ability between the two groups of physicians. The four major causative agents of AOM were correctly listed by 7 percent GPs and 23 percent pediatricians (p=0.05). Amoxicillin was prescribed as first line agent for treatment of AOM by 62 percent of pediatricians and 22 percent of GPs. Trimethoprimsulfmethoxazole was still being used as first line agent by 17 percent of GPs. All physicians considered the use of analgesics as appropriate and steroids inappropriate in the management of AOM. There was significant difference between groups concerning the use of antihistamines (84 percent GPs, 53 percent paediatricians) and decongestants (91 percent GPs, 52 percent paediatricians, p<0.001) in the management of AOM. Most physicians recommeneded routine follow-up of patients at the end of the course of antibiotic treatment. CONCLUSIONS: Factors other than evidence-based medicine influence the current management of otitis media by primary care physicians. Exploration of the factors that determine management practice is being proposed. The results under-score the need for a re-accreditation process for physicians in the Caribbean region. (AU)

Variation in coverage by ethnic group of neonatal (Guthrie) screening programme in south London.

OBJECTIVES: To determine whether coverage of the neonatal (Guthrie) screening programme in Britain is different for groups at highest risk of sickle cell disease and to identify possible reasons for incomplete coverage. DESIGN: Descriptive study of coverage of screening programme and its variation by mobility, district of residence, and ethnic group. SUBJECTS: 1727 infants born between 1 October and 31 December 1991. SETTING: Former West Lambeth and Camberwell District Health Authorities, London. MAIN OUTCOME MEASURE: Proportion of infants with an identifiable screening test result. RESULTS: Screening covered 1663/1727 (96.3%) infants overall (745/786 (94.8%) in West Lambeth; 918/941 (97.6%) in Camberwell). The relative odds ratio of an African infant not having been tested compared with a white infant was 3.05 (95% confidence interval 1.30 to 7.14) (2.08 (0.86 to 5.01) after adjustment for mobility and district of residence). For infants whose families moved into the districts after the birth compared with those born and resident in the districts the relative odds ratio of having been tested was 10.16 (4.85 to 21.29). The odds ratio of locally delivered infants in West Lambeth not having been tested compared with those in Camberwell was 2.12 (1.08 to 4.16) after adjustment for ethnic group. CONCLUSION: Coverage of the screening programme is incomplete and poorer in infants of African ethnic group than in white infants. Poorer coverage is also associated with mobility of the family around the time of birth. The findings have implications for using the neonatal programme for testing for sickle cell disease and other disorders. Arrangements for monitoring the existing screening programme are inadequate and an improved system should be established, similar to the scheme that monitors the immunisation programme.