1
|
Low prevalence of scabies and impetigo in Dakar/Senegal: A cluster-randomised, cross-sectional survey. PLOS GLOBAL PUBLIC HEALTH 2024; 4:e0002942. [PMID: 38417092 PMCID: PMC10901544 DOI: 10.1371/journal.pgph.0002942] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Accepted: 01/25/2024] [Indexed: 03/01/2024]
Abstract
BACKGROUND Scabies, a parasitic infection caused by Sarcoptes scabiei var. hominis, is a public health problem with significant morbidity worldwide, particularly in low-resource countries. Impetigo, a complication of scabies infection, is a risk factor for sepsis, glomerulonephritis and possibly acute rheumatic fever. Currently, the majority of epidemiological data has been collected in rural populations in the Pacific with limited applicability to urban populations in sub-Saharan Africa, where scabies is also believed to be a problem. To inform future public health programs, more reliable information about the burden of disease is required. METHODOLOGY/PRINCIPAL FINDINGS In July/August 2022, we conducted a cross sectional, cluster-randomised, household survey in Pikine/Dakar using the 'International Association for the Control of Scabies (IACS)' criteria to diagnose scabies and impetigo. All participants underwent a standardised clinical examination by post-graduate dermatology students. For those diagnosed with scabies, an age-adapted 'Dermatology Life Quality Index (DLQI)' questionnaire was filled. We recruited and examined 1697 participants to detect 27 cases of scabies (prevalence: 1.6%, 95% CI 0.8-3.2), mostly in school aged children. Ten participants suffered from impetigo (prevalence: 0.6%, 95% CI 0.3-1.3), 5 of which were dually infected with scabies. Risk factors for scabies infection were young age, male gender and Koranic school attendance. Of those found to have scabies, in 7 out of 22 cases (31.8%) it had a large effect on their lives according to the DLQI questionnaires filled. CONCLUSIONS/SIGNIFICANCE This study adds to the mapping of the burden of scabies across Africa to support public health action. With a low prevalence of scabies that is concentrated amongst poor households and children attending Koranic schools, a focused public health approach targeting Koranic schools and poor households seems to be most appropriate in this community.
Collapse
|
2
|
Challenges of implementing the Paediatric Surviving Sepsis Campaign International Guidelines 2020 in resource-limited settings: A real-world view beyond the academia. ANDES PEDIATRICA : REVISTA CHILENA DE PEDIATRIA 2021; 92:954-962. [PMID: 35506809 DOI: 10.32641/andespediatr.v92i6.4030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Accepted: 09/28/2021] [Indexed: 06/14/2023]
Abstract
The Surviving Sepsis Campaign International Guidelines for the Management of Septic Shock and Sepsis-associated Organ Dysfunction in Children was released in 2020 and is intended for use in all global settings that care for children with sepsis. However, practitioners managing children with sep sis in resource-limited settings (RLS) face several challenges and disease patterns not experienced by those in resource-rich settings. Based upon our collective experience from RLS, we aimed to reflect on the difficulties of implementing the international guidelines. We believe there is an urgent need for more evidence from RLS on feasible, efficacious approaches to the management of sepsis and septic shock that could be included in future context-specific guidelines.
Collapse
|
3
|
Application of systems dynamics and group model building to identify barriers and facilitators to acute care delivery in a resource limited setting. BMC Health Serv Res 2021; 21:26. [PMID: 33407458 PMCID: PMC7787401 DOI: 10.1186/s12913-020-06014-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 12/10/2020] [Indexed: 11/17/2022] Open
Abstract
Background Group model building (GMB) is a method to facilitate shared understanding of structures and relationships that determine system behaviors. This project aimed to determine the feasibility of GMB in a resource-limited setting and to use GMB to describe key barriers and facilitators to effective acute care delivery at a tertiary care hospital in Malawi. Methods Over 1 week, trained facilitators led three GMB sessions with two groups of healthcare providers to facilitate shared understanding of structures and relationships that determine system behaviors. One group aimed to identify factors that impact patient flow in the paediatric special care ward. The other aimed to identify factors impacting delivery of high-quality care in the paediatric accident and emergency room. Synthesized causal maps of factors influencing patient care were generated, revised, and qualitatively analyzed. Results Causal maps identified patient condition as the central modifier of acute care delivery. Severe illness and high volume of patients were identified as creating system strain in several domains: (1) physical space, (2) resource needs and utilization, (3) staff capabilities and (4) quality improvement. Stress in these domains results in worsening patient condition and perpetuating negative reinforcing feedback loops. Balancing factors inherent to the current system included (1) parental engagement, (2) provider resilience, (3) ease of communication and (4) patient death. Perceived strengths of the GMB process were representation of diverse stakeholder viewpoints and complex system synthesis in a visual causal pathway, the process inclusivity, development of shared understanding, new idea generation and momentum building. Challenges identified included time required for completion and potential for participant selection bias. Conclusions GMB facilitated creation of a shared mental model, as a first step in optimizing acute care delivery in a paediatric facility in this resource-limited setting.
Collapse
|
4
|
Survey of resources available to implement severe pediatric traumatic brain injury management guidelines in low and middle-income countries. Childs Nerv Syst 2020; 36:2647-2655. [PMID: 32300872 DOI: 10.1007/s00381-020-04603-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Accepted: 03/30/2020] [Indexed: 12/24/2022]
Abstract
PURPOSE Traumatic brain injury (TBI) is a leading cause of death and disability worldwide, with a disproportionately high burden in low-middle income countries. Guideline implementation has been associated with mortality reduction in high-income countries (HIC), but it is not known if hospitals in low and middle-income countries possess the resources to implement the pre-hospital TBI guidelines and the guidelines for the management of severe pediatric traumatic brain injury. METHOD An anonymous online survey was undertaken by a range of health care professionals currently managing children with severe TBI in low to middle-income countries. A variety of international and national pediatric, intensive care, and neurological societies assisted in the survey distribution. Thirty-eight questions were included to evaluate patient care and the provider's perceptions of their resources available to implement the pre-hospital specific TBI and current pediatric severe TBI guidelines. RESULTS Two hundred and forty-seven hospitals were represented from 68 countries. Fifty percent of LMIC hospitals that responded had the resources to implement 13 of 15 guidelines for the pediatric component of pre-hospital management for TBI and all baseline care recommendations. First tier therapies including the intracranial pressure (ICP) and cerebral perfusion pathways (CPP), however, demonstrated low capacity for uptake with 21.5% and 38.5% of surveyed hospitals possessing sufficient resources to follow the recommended pathways. CONCLUSION Pediatric TBI ICP/CPP management guidelines require numerous resources not widely sourced in LMIC. The creation of international guidelines that outline recommendations of care for LMIC may benefit patient care and outcomes in these settings.
Collapse
|
5
|
Review of supplemental oxygen and respiratory support for paediatric emergency care in sub-Saharan Africa. Afr J Emerg Med 2017; 7:S10-S19. [PMID: 30505669 PMCID: PMC6246869 DOI: 10.1016/j.afjem.2017.10.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
INTRODUCTION In African countries, respiratory infections and severe sepsis are common causes of respiratory failure and mortality in children under five years of age. Mortality and morbidity in these children could be reduced with adequate respiratory support in the emergency care setting. The purpose of this review is to describe management priorities in the emergency care of critically ill children presenting with respiratory problems. Basic and advanced respiratory support measures are described for implementation according to available resources, work load and skill-levels. METHODS We did a focused search of respiratory support for critically ill children in resource-limited settings over the past ten years, using the search tools PubMed and Google Scholar, the latest WHO guidelines, international 'Advanced Paediatric Life Support' guidelines and paediatric critical care textbooks. RESULTS The implementation of triage and rapid recognition of respiratory distress and hypoxia with pulse oximetry is important to correctly identify critically ill children with increased risk of mortality in all health facilities in resource constrained settings. Basic, effective airway management and respiratory support are essential elements of emergency care. Correct provision of supplemental oxygen is safe and its application alone can significantly improve the outcome of critically ill children. Non-invasive ventilatory support is cost-effective and feasible, with the potential to improve emergency care packages for children with respiratory failure and other organ dysfunctions. Non-invasive ventilation is particularly important in severely under-resourced regions unable to provide intubation and invasive mechanical ventilation support. Malnutrition and HIV-infection are important co-morbid conditions, associated with increased mortality in children with respiratory dysfunction. DISCUSSION A multi-disciplinary approach is required to optimise emergency care for critically ill children in low-resource settings. In this context, it is important to consider aspects of training of staff, technical support and pragmatic research.
Collapse
|
6
|
Renale kortikale Nekrose: Verlaufskontrollen mittels kontrastmittelunterstütztem Ultraschall (CEUS). ROFO-FORTSCHR RONTG 2016; 188:1070-1072. [PMID: 27486694 DOI: 10.1055/s-0042-110860] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
7
|
|
8
|
Imaging assessment of desmoid tumours in familial adenomatous polyposis: is state-of-the-art 1.5 T MRI better than 64-MDCT? Br J Radiol 2012; 85:e254-61. [PMID: 22215881 DOI: 10.1259/bjr/42420290] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
OBJECTIVE Desmoid tumour is a common extraintestinal manifestation of patients with familial adenomatous polyposis (FAP) who have undergone prophylactic colectomy. We aimed to determine whether MRI provides equivalent or better assessment of desmoid tumours than CT, the current first-line investigation. METHODS Following ethics approval and informed consent, FAP patients with known desmoid tumour underwent contrast-enhanced 64-slice multidetector CT (MDCT) and 1.5 T MRI (incorporating T(1) weighted, T(2) weighted, short tau inversion-recovery and T(1) weighted with contrast, axial, sagittal and coronal sequences). The number, site, size, local extent, tumour signal intensity and desmoid-to-aorta enhancement ratio were analysed. RESULTS MRI identified 23 desmoid tumours in 9 patients: 9 intra-abdominal desmoid (IAD) tumours, 10 abdominal wall desmoid (AWD) tumours and 4 extra-abdominal desmoid (EAD) tumours. CT identified only 21 desmoids; 1 EAD and 1 AWD were not identified. The two modalities were equivalent in terms of defining local extent of desmoid. Five IAD tumours involved the bowel, six caused ureteric compression and none compromised the proximal superior mesenteric artery. There was no difference in median desmoid size: 56.7 cm(2) (range 2-215 cm(2)) on MDCT and 56.3 cm(2) (3-215 cm(2)) on MRI (p=0.985). The mean MRI enhancement ratio, at 1.12 (standard deviation 0.43), was greater than the CT enhancement ratio, which was 0.48 (0.16) (p<0.0001). High signal intensity on T(2) MRI was associated with increased MRI enhancement ratio (p=0.006). CONCLUSIONS MRI is at least equivalent (and may be superior) to MDCT for the detection of desmoid tumours in FAP. Coupled with the advantage of avoiding radiation, it should be considered as the primary imaging modality for young FAP patients.
Collapse
|
9
|
Adrenal incidentaloma in familial adenomatous polyposis: a long-term follow-up study and schema for management. Dis Colon Rectum 2009; 52:1637-44. [PMID: 19690494 DOI: 10.1007/dcr.0b013e3181a876d6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
PURPOSE Adrenal incidentaloma is often diagnosed in patients with familial adenomatous polyposis, because they frequently undergo abdominal imaging and have a raised incidence of adrenal incidentaloma. This study investigates the natural history of adrenal incidentaloma in familial adenomatous polyposis, and suggests a schema for management. METHODS An original cohort of 14 familial adenomatous polyposis patients with adrenal incidentaloma, identified prospectively 12 years ago, was followed up clinically and radiologically. A further group of 16 patients was also identified. All had lesions >1 cm. For both cohorts, characteristics of patients (genotype, age at diagnosis, concomitant diagnoses) and incidentaloma (size, laterality, rate of growth, outcome) are described. RESULTS Overall, 3 of 30 patients underwent adrenalectomy; one patient had pheochromocytoma and another had an adenoma of borderline malignancy. A further three lesions were radiologically suspicious for malignancy at the time of diagnosis; one was in a patient who was unfit for surgery but died of nonadrenal causes after nine years. None of the lesions radiologically benign at diagnosis showed an aggressive course, but one patient required referral for surgery after 12 years because of a slow increase in size of the lesion. There were no associations with genotype. CONCLUSIONS Familial adenomatous polyposis-associated adrenal incidentaloma may warrant long-term follow-up. Although the natural history is similar to lesions occurring sporadically, these patients have concomitant familial adenomatous polyposis-associated manifestations under radiologic surveillance. In this rare condition, development of a robust protocol will require evidence from worldwide patient cohorts. However, a tailored schema is suggested as a consistent basis for future modification.
Collapse
|
10
|
Neonatale Alveolarproteinose durch homozygote 121ins2-Mutation des Surfactant-Protein-B-Gens – ein Fallbericht. Z Geburtshilfe Neonatol 2008. [DOI: 10.1055/s-2008-1078915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
11
|
Abstract
BACKGROUND Peutz-Jeghers syndrome (PJS) is caused by germline STK11 mutations and characterised by gastrointestinal polyposis. Although small bowel intussusception is a recognised complication of PJS, risk varies between patients. OBJECTIVE To analyse the time to onset of intussusception in a large series of PJS probands. METHODS STK11 mutation status was evaluated in 225 PJS probands and medical histories of the patients reviewed. RESULTS 135 (60%) of the probands possessed a germline STK11 mutation; 109 (48%) probands had a history of intussusception at a median age of 15.0 years but with wide variability (range 3.7 to 45.4 years). Median time to onset of intussusception was not significantly different between those with identified mutations and those with no mutation detected, at 14.7 years and 16.4 years, respectively (log-rank test of difference, chi(2) = 0.58, with 1df; p = 0.45). Similarly no differences were observed between patient groups on the basis of the type or site of STK11 mutation. CONCLUSIONS The risk of intussusception in PJS is not influenced by STK11 mutation status.
Collapse
|
12
|
Abstract
BACKGROUND AND OBJECTIVE Colonoscopy is the gold standard for the diagnosis of colonic neoplasia. Because of the low compliance, the discomfort of bowel preparation and the procedure itself and the (albeit small) risk of perforation or bleeding alternative procedures such as stool tests are being focused on. PATIENTS AND METHODS After informed consent stool samples of 116 patients (44 male, 72 female, median age 47 years), scheduled for colonoscopy and 22 patients (17 m, 5 f, 69 y) with known colorectal cancer stool samples were collected. The samples were investigated by three methods: a biochemical (Guajak) test for fecal occult blood, an immunological test for fecal occult blood and a test determining the dimer pyruvat kinase M2 (tumor M2-PK). RESULTS Sensitivity for detection of colorectal cancer or polyps was 27 % and 10 % for the biochemical test, 91 % and 19 % for the immunological test and 77 % and 48 % for the M2-PK-test, respectively. Specificity was 89 %, 94 % and 72 %, respectively. CONCLUSIONS Both methods for detection of occult blood had a similar specificity. The sensitivity of the immunological test for the detection of colorectal cancer was significantly higher. The M2-PK-test had a markedly lower specificity in diagnosing cancer. Because of the low sensitivity for polyps the usefulness of stool tests is questionable. Reducing incidence and mortality of colorectal cancer should be achieved by colonoscopy, a recommendation that requires specific communication to the public.
Collapse
|
13
|
Baseline plasma viral load and CD4 cell percentage predict survival in HIV-1- and HIV-2-infected women in a community-based cohort in The Gambia. J Acquir Immune Defic Syndr 2005; 38:335-41. [PMID: 15735454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
Abstract
OBJECTIVES To estimate and compare the all-cause mortality rates among HIV-1-infected, HIV-2-infected, and uninfected women and to assess the predictive value of baseline plasma viral load (PVL) and CD4 cell percentage (CD4%) for mortality. DESIGN Cohort study. METHODS At presentation to antenatal clinics in The Gambia in 1993-1995, pregnant women were screened for antibodies to HIV-1 and HIV-2. Seropositive subjects and a similar number of seronegative controls were enrolled, and baseline PVL and CD4% were measured. Participants were visited regularly by field-workers until 18 months after delivery and again 4-7 years later. RESULTS Thirty-two of 101 women infected with HIV-1, 23 of 243 infected with HIV-2, and 9 of 468 seronegative women died during a median follow-up of 6.9 years. The mortality rate was 56 deaths per 1000 person years of observation (pyo) for HIV-1-infected, 16 deaths per 1000 pyo for HIV-2-infected, and 3.1 deaths per 1000 pyo for HIV-uninfected women. After 8 years of follow-up, >50% of HIV-1-infected women were still alive. In multivariate analysis, a 1-log increase of HIV-1 PVL was associated with a 1.8-fold higher rate of mortality (95% confidence interval [CI], 0.9-3.4). In HIV-2 infection, women with a high PVL (>10,000 copies/mL) had an 8.7-fold (95% CI, 2.8-28) higher rate of mortality than did those with a low PVL (<1000 copies/mL). A 10% decrease in CD4% was associated with higher mortality rates among HIV-1-infected (1.6-fold; 95% CI, 1.1-2.3) and HIV-2-infected (1.5-fold; 95% CI, 1.0-2.3) subjects. DISCUSSION Survival of HIV-1-infected women in The Gambia is similar to that in industrialized countries before the introduction of antiretroviral treatment. Survival of HIV-2-infected women is much better. However, women with high PVLs die as quickly as their HIV-1-infected counterparts.
Collapse
|
14
|
No observed effect of GB virus C coinfection on disease progression in a cohort of African woman infected with HIV-1 or HIV-2. Clin Infect Dis 2005; 40:876-8. [PMID: 15736023 DOI: 10.1086/428123] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2004] [Accepted: 11/04/2004] [Indexed: 11/03/2022] Open
Abstract
We studied mortality among subjects with human immunodeficiency virus (HIV)-1 and HIV-2 infection in relation to GB virus (GBV)-C coinfection. No significant differences in mortality were seen between subjects with and subjects without GBV-C coinfection who also had either HIV-1 or HIV-2 infection. No association between GBV-C and HIV plasma virus loads or CD4 cell count was observed.
Collapse
|
15
|
Abstract
BACKGROUND The risk of mother-to-child transmission (MTCT) of HIV-2 is much lower than that of HIV-1, but the long-term prognosis of perinatally infected HIV-2 children is unknown. We re-visited children who were part of a large MTCT study in The Gambia (conducted during 1993-1997), in order to compare the long-term survival of children perinatally infected with HIV-2 with that of seronegative and of HIV-1 infected children. METHODS Five to eight years' follow-up of a cohort of children born to HIV-negative, HIV-1 positive, and HIV-2 positive mothers. RESULTS Seven hundred and seventy-four children were followed up for a median of 6.6 years. Of 17 perinatally HIV-1 infected children, three were still alive on 1 July 2001, two had been lost to follow-up, and 12 had died. The median survival was 2.5 years. Of eight HIV-2 infected children five were still alive, none were lost to follow-up and three had died. The mortality hazards ratio of both HIV-1 [9.9; 95% confidence interval (CI), 5.2-19], and of HIV-2 infected children (3.9; CI, 1.2-12) was significantly increased compared with children of seronegative mothers. The mortality hazards ratio of HIV uninfected children of HIV-1 or HIV-2 infected mothers was not significantly increased compared to that of children of seronegative mothers (P = 0.17 and P = 0.5 respectively). CONCLUSIONS Children with perinatally acquired HIV-2 infection have a higher mortality than children of seronegative mothers. Guidelines for treatment of HIV-1 infected children should be used for treatment of HIV-2 infected children.
Collapse
|
16
|
Abstract
Appendices of children operated on because of clinical signs of acute appendicitis and presenting normal histological findings were revised by means of special assays. These findings were then compared with appendectomies during abdominal surgery, catarrhal and early phlegmonous appendicitis. We found pathological changes of the epithelium and the lymphatic tissue in more than two thirds of the specimens originally classified as normal. Therefore the term of "negative appendectomy" has to be redefined.
Collapse
|
17
|
The expression of insulin-like growth factor binding proteins is tissue specific during human fetal life and early infancy. ACTA ENDOCRINOLOGICA 1992; 127:107-14. [PMID: 1382347 DOI: 10.1530/acta.0.1270107] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The insulin-like growth factors (IGFs) are bound to multiple IGF binding proteins (IGFBPs) that are present both in the circulation and in extracellular fluids. There are at least six different IGFBP species that have been fully characterized in terms of molecular structure and amino acid sequence. The tissue distribution and local production of these proteins as well as the regulation of IGFBP production in different tissues have not been elucidated. We have studied the distribution of multiple IGFBP species in protein extracts from human kidney, skeletal muscle, lung, liver and brain by ligand blotting employing [125I]IGF-2 as the radiolabeled hormone. Five distinct IGFBP species with a respective molecular weight of 43, 38, 34, 30 and 20 kDa were detected on the ligand blots in tissues from human fetuses and infants (23 weeks of gestation till 24 months of postnatal age). The 34 kDa species and a 30-32 kDa IGFBP species were predominant in brain, whereas a 30 kDa IGFBP species was mainly detected in skeletal muscle. Immunoblotting experiments using an anti IGFBP-2 antiserum showed that the 34 kDa IGFBP species from human brain was presumably related to IGFBP-2. We conclude that IGFBPs are differentially expressed in different tissues throughout human fetal life and early infancy. Local production or accumulation of the different IGFBPs could modulate IGF action at a local level or alternatively have differential functions during development.
Collapse
|
18
|
Expression of the insulin-like growth factor-II/mannose-6-phosphate receptor in multiple human tissues during fetal life and early infancy. J Clin Endocrinol Metab 1992; 75:424-31. [PMID: 1379254 DOI: 10.1210/jcem.75.2.1379254] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The insulin like growth factor-II/mannose-6-phosphate (IGF-II/M6P) receptor has been detected in many cells and tissues. In the rat, there is a dramatic developmental regulation of IGF-II/M6P receptor expression, the receptor being high in fetal and neonatal tissues and declining thereafter. We have systematically studied the expression of the human IGF-II/M6P receptor protein in tissues from 10 human fetuses and infants (age 23 weeks gestation to 24 months postnatal). We have asked 1) whether there is differential expression among different organs, and 2) whether or not the human IGF-II/M6P receptor is developmentally regulated from 23 weeks gestation to 24 months postnatal. Protein was extracted from human tissues using a buffer containing 2% sodium dodecyl sulfate and 2% Triton X-100. Aliquots of the protein extracts were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting using an anti-IGF-II/M6P receptor antiserum (no. 66416) and 125I-protein A or an immunoperoxidase stain. IGF-II/M6P receptor immunoreactivity was detected in all tissues studied with the highest amount of receptor being expressed in heart, thymus, and kidney and the lowest receptor content being measured in brain and muscle. The receptor content in ovary, testis, lung, and spleen was intermediate. The apparent molecular weight of the IGF-II/M6P receptor (220,000 kilos without reduction of disulfide bonds) varied among the different tissues: in brain the receptor was of lower molecular weight than in other organs. Immunoquantitation experiments employing 125I-protein A and protein extracts from human kidney at different ages revealed a small, albeit not significant, difference of the receptor content between fetal and postnatal tissues: as in other species, larger amounts of receptor seemed to be present in fetal than in postnatal organs. In addition, no significant difference of the receptor content between human fetal liver and early postnatal liver was measured employing 125I-protein A-immunoquantitation in three fetal and five postnatal liver tissue samples. The distribution of IGF-binding protein (IGEBP) species, another abundant and major class of IGF binding principles, was also measured in human fetal and early postnatal lung, liver, kidney, muscle, and brain using Western ligand blotting with 125I-IGF-II: as with IGF-II/M6P receptor immunoreactivity there was differential expression of the different classes of IGFBPs in the various organs.(ABSTRACT TRUNCATED AT 400 WORDS)
Collapse
|