Differentiation of dental pulp stem cells into islet-like aggregates

The post-natal dental pulp tissue contains a population of multipotent mesenchymal progenitor cells known as dental pulp stromal/stem cells (DPSCs), with high proliferative potential for self-renewal. In this investigation, we explored the potential of DPSCs to differentiate into pancreatic cell lineage resembling islet-like cell aggregates (ICAs). We isolated, propagated, and characterized DPSCs and demonstrated that these could be differentiated into adipogenic, chondrogenic, and osteogenic lineage upon exposure to an appropriate cocktail of differentiating agents. Using a three-step protocol reported previously by our group, we succeeded in obtaining ICAs from DPSCs. The identity of ICAs was confirmed as islets by dithiozone-positive staining, as well as by expression of C-peptide, Pdx-1, Pax4, Pax6, Ngn3, and Isl-1. There were several-fold up-regulations of these transcription factors proportional to days of differentiation as compared with undifferentiated DPSCs. Day 10 ICAs released insulin and C-peptide in a glucose-dependent manner, exhibiting in vitro functionality. Our results demonstrated for the first time that DPSCs could be differentiated into pancreatic cell lineage and offer an unconventional and non-controversial source of human tissue that could be used for autologous stem cell therapy in diabetes.

Seasonal variations, and the intra-household distribution of food in a Bangladeshi village

Individual food intakes and body weights were measured in 53 rural Bangladeshi households at four seasons. Energy and protein intakes (kcal/kg/d) showed significant seasonal differences for adults and young children (1-4 yr). Energy intakes of women and children were expressed as a proportion of the male household heads', to give an indicator of food allocation. Women's and older children's proportional energy intakes remained constant through the year, and in line with expected values. Young children's proportional intakes were low, girls' being lower than boys'. The only seasonal variation was an increase in young girls' proportional energy intake when household food supplies were lowest. It is concluded that women's proportional intakes are not depressed when family food intake decreases. There is evidence that young girls receive particularly low intakes.

SLC2A2 mutations can cause neonatal diabetes, suggesting GLUT2 may have a role in human insulin secretion

AIMS

The gene SLC2A2 encodes GLUT2, which is found predominantly in pancreas, liver, kidney and intestine. In mice, GLUT2 is the major glucose transporter into pancreatic beta cells, and biallelic Slc2a2 inactivation causes lethal neonatal diabetes. The role of GLUT2 in human beta cells is controversial, and biallelic SLC2A2 mutations cause Fanconi-Bickel syndrome (FBS), with diabetes rarely reported. We investigated the potential role of GLUT2 in the neonatal period by testing whether SLC2A2 mutations can present with neonatal diabetes before the clinical features of FBS appear.

METHODS

We studied SLC2A2 in patients with transient neonatal diabetes mellitus (TNDM; n = 25) or permanent neonatal diabetes mellitus (PNDM; n = 79) in whom we had excluded the common genetic causes of neonatal diabetes, using a combined approach of sequencing and homozygosity mapping.

RESULTS

Of 104 patients, five (5%) were found to have homozygous SLC2A2 mutations, including four novel mutations (S203R, M376R, c.963+1G>A, F114LfsX16). Four out of five patients with SLC2A2 mutations presented with isolated diabetes and later developed features of FBS. Four out of five patients had TNDM (16% of our TNDM cohort of unknown aetiology). One patient with PNDM remains on insulin at 28 months.

CONCLUSIONS

SLC2A2 mutations are an autosomal recessive cause of neonatal diabetes that should be considered in consanguineous families or those with TNDM, after excluding common causes, even in the absence of features of FBS. The finding that patients with homozygous SLC2A2 mutations can have neonatal diabetes supports a role for GLUT2 in the human beta cell.

Management of gastrointestinal bleeding induced by gastrointestinal endoscopy

Therapeutic gastrointestinal endoscopy has a much greater risk of inducing gastrointestinal hemorrhage than diagnostic endoscopy. For example, colonoscopic polypectomy has a risk of approximately 1.6% of inducing bleeding, compared with a risk of approximately 0.02% for diagnostic colonoscopy. Higher-risk procedures include colonoscopic polypectomy, endoscopic biliary sphincterotomy, endoscopic dilatation, endoscopic variceal therapy, percutaneous endoscopic gastrostomy, and endoscopic sharp foreign body retrieval. The risk of inducing hemorrhage is decreased by meticulous endoscopic technique. Hemorrhage from endoscopy may be immediate or delayed. Immediate hemorrhage should be immediately treated by endoscopic hemostatic therapy, including injection therapy, thermocoagulation, or electrocoagulation. Delayed hemorrhage generally requires repeat endoscopy for diagnosis and for therapy, using the same hemostatic techniques.

Identification of rat testis galactosyl receptor using antibodies to liver asialoglycoprotein receptor: purification and localization on surfaces of spermatogenic cells and sperm

We have found that the rat testis contains a cell surface galactosyl receptor that is antigenically related to the minor species of rat liver asialoglycoprotein receptor (ASGP-r) and has binding affinity for galactose coupled to agarose. In immunoblotting experiments, rat testis galactosyl receptor (RTG-r) is recognized by antiserum raised against the minor ASGP-r species of rat liver (designated rat hepatic lectin-2/3, RHL-2/3). Antiserum raised against the major species RHL-1 does not recognize an antigenic protein equivalent to RTG-r. Triton X-100-extracted rat liver and testes preparations fractionated by affinity chromatography on galactose-agarose and resolved by SDS-PAGE under reducing conditions, show that rat liver contains both the major (RHL-1) and minor (RHL-2/3) ASGP-r species whereas rat testis displays only a receptor species comigrating with RHL-2/3. RTG-r was present throughout testicular development. The receptor was found in seminiferous tubules, cultured Sertoli and spermatogenic cells, and epididymal sperm. Indirect immunofluorescent studies show RHL-2/3-like immunoreactivity on the surface of Sertoli cell, meiotic prophase spermatocytes, spermatids, and epididymal sperm. In spermatids and sperm, the immunoreactivity is restricted to the plasma membrane overlying the dorsal portion of the head. Because of RTG-r has galactose binding affinity, is present on surfaces of Sertoli and developing meiotic and postmeiotic spermatogenic cells, and overlies a region of the intact acrosome on epididymal sperm, RTG-r may have a role in spermatogenesis and in events leading to sperm-egg recognition.

Making EmOC a reality--CARE's experiences in areas of high maternal mortality in Africa

OBJECTIVE

This paper describes the package of interventions undertaken by the CARE/AMDD program collaboration to increase the availability and quality of emergency obstetric care for 3 high maternal mortality countries in Africa.

METHODS

Project implementation over 4 years focused on enhancing the capacity of 10 district hospitals in 3 countries - Tanzania, Rwanda and Ethiopia. Interventions were designed to create functional health facilities with trained and competent staff, working in an enabling environment supporting EmOC service delivery.

RESULTS

By keeping a clear focus on EmOC, the project achieved modest improvements in services, even in the face of the considerable constraints of rural district hospitals. Availability and utilization of EmOC increased in Tanzania; the met need for EmOC increased slightly from 14% in year 1 to 19% in year 4, while in Rwanda it increased from 16% to 25% over 4 years. Case fatality rates (CFR) declined by 30-50% in all 3 countries. While still well below UN recommendations, in all 3 countries there was also a progressive increase in the cesarean section rates, a life saving obstetric intervention.

CONCLUSIONS

The increases in met need and decreases in case fatality suggest that project interventions improved the quality and use of EmOC, a critical component for saving women's lives.

Melatonin mitigates cadmium and aluminium toxicity through modulation of antioxidant potential in Brassica napus L

Melatonin has emerged as an essential molecule in plants, due to its role in defence against metal toxicity. Aluminium (Al) and cadmium (Cd) toxicity inhibit rapeseed seedling growth. In this study, we applied different doses of melatonin (50 and 100 µm) to alleviate Al (25 µm) and Cd (25 µm) stress in rapeseed seedlings. Results show that Al and Cd caused toxicity in rapeseed seedling, as evidenced by a decrease in height, biomass and antioxidant enzyme activity. Melatonin increased the expression of melatonin biosynthesis-related Brassica napus genes for caffeic acid O-methyl transferase (BnCOMT) under Al and Cd stress. The genes BnCOMT-1, BnCOMT-5 and BnCOMT-8 showed up-regulated expression, while BnCOMT-4 and BnCOMT-6 were down-regulated during incubation in water. Melatonin application increased the germination rate, shoot length, root length, fresh and dry weight of seedlings. Melatonin supplementation under Al and Cd stress increased superoxide dismutase, catalase, peroxidase, ascorbate peroxidase, proline, chlorophyll and anthocyanin content, as well as photosynthesis rate. Both Cd and Al treatments significantly increased hydrogen peroxide and malondialdehyde levels in rapeseed seedlings, which were strictly counterbalanced by melatonin. Analysis of Cd and Al in different subcellular compartments showed that melatonin enhanced cell wall and soluble fractions, but reduced the vacuolar and organelle fractions in Al- and Cd-treated seedlings. These results suggest that melatonin-induced improvements in antioxidant potential, biomass, photosynthesis rate and successive Cd and Al sequestration play a pivotal role in plant tolerance to Al and Cd stress. This mechanism may have potential implications in safe food production.

Percutaneous catheter closure of the ductus arteriosus in children and young adults

The double-disk occluding device suitable for use in infants and children with patent ductus arteriosus, developed by Rashkind and Mullins, has been available to this institution since December 1987 on an investigational basis. Results of 43 nonsurgical ductal closure attempts using this device in children and young adults between December 1987 and October 1988 are presented. Successful implantation was achieved in 42 patients (98%). In 25 patients a residual shunt was seen on angiography immediately after implantation. In 12 patients a residual ductal shunt was detected by Doppler 24 hours after implantation; 6-week follow-up studies showed a small residual shunt in only 3 patients. After a second occluder device was implanted in 2 of these patients, complete closure of the patient ductus arteriosus was achieved. In 1 patient, early in the series, the occluder device embolized to the left pulmonary artery, necessitating surgical removal at the time of ductus division. This event was the only serious complication; there were no deaths.

Comparison between single (Inoue) and double balloon mitral valvuloplasty: immediate and short-term results

This study compared the results in 60 consecutive patients with severe rheumatic mitral stenosis, who underwent percutaneous double-balloon mitral valvuloplasty by means of a combination of 20 mm + 20 mm diameter balloon catheters (group A), with a similar group of 60 consecutive patients who underwent single (Inoue) balloon mitral valvuloplasty (group B). After balloon mitral valvuloplasty the hemodynamic measurements showed significant improvement in both groups: in groups A and B, respectively, mitral valve area calculated with the Gorlin formula increased from 0.9 +/- 0.2 to 2.1 +/- 0.5 cm2 (p less than 0.001) and from 0.8 +/- 0.2 to 1.9 +/- 0.4 cm2 (p less than 0.001). There was a significant improvement in cardiac functional status in both groups. There was no significant difference between the groups with regard to clinical or hemodynamic improvement, technical failure rate, inadequacy of dilatation, or complications. However, the double-balloon technique was more complex and involved a longer screening time--group A, 40 +/- 12 minutes; group B, 21 +/- 10 minutes (p less than 0.001). In our institution the disposable supplies used for the Inoue balloon technique were 40% more expensive than those used for the double-balloon technique.

Insulin storage in hot climates without refrigeration: temperature reduction efficacy of clay pots and other techniques

AIM

Insulin loses potency when stored at high temperatures. Various clay pots part-filled with water, and other evaporative cooling devices, are used in less-resourced countries when home refrigeration is unavailable. This study examined the cooling efficacy of such devices.

METHODS

Thirteen devices used in Sudan, Ethiopia, Tanzania, Mali, India, Pakistan and Haiti (10 clay pots, a goat skin, a vegetable gourd and a bucket filled with wet sand), and two identical commercially manufactured cooling wallets were compared. Devices were maintained according to local instructions. Internal and ambient temperature and ambient humidity were measured by electronic loggers every 5 min in Khartoum (88 h), and, for the two Malian pots, in Bamako (84 h). Cooling efficacy was assessed by average absolute temperature difference (internal vs. ambient), and % maximal possible evaporative cooling (allowing for humidity).

RESULTS

During the study period, mean ambient temperature and humidity were 31.0°C and 32.0% in Khartoum and 32.9°C and 39.8% in Bamako. All devices reduced the temperature (P < 0.001) with a mean (sd) reduction from 2.7 ± 0.5°C to 8.3 ± 1.0°C, depending on the device. When expressed as % maximal cooling, device efficacy ranged from 20.5% to 71.3%. On cluster analysis, the most efficacious devices were the goat skin, two clay pots (from Ethiopia and Sudan) and the suspended cooling wallet.

CONCLUSIONS

Low-cost devices used in less-resourced countries reduce storage temperatures. With more efficacious devices, average temperatures at or close to standard room temperature (20-25°C) can be achieved, even in hot climates. All devices are more efficacious at lower humidity. Further studies are needed on insulin stability to determine when these devices are necessary.

Cardiovascular autonomic neuropathy in HIV infected patients

OBJECTIVE

To evaluate the presence and extent of autonomic dysfunction in HIV infected individuals of one ethnic group.

DESIGN

Prospective, age-sex matched study.

METHODS

25 patients (seven asymptomatic (HIV), eight AIDS related complex (ARC), 10 AIDS) and 25 controls were recruited from patients and staff at the Aga Khan Hospital, Nairobi. Autonomic function was assessed by measurement of pulse rate variability on standing, rest, deep breathing, Valsalva manoeuvre, isometric exercise, cold face test, and mental stress. Blood pressure was measured during standing, supine resting, and on Valsalva manoeuvre. CD4 count was correlated with number of abnormal test results.

RESULTS

21 patients had at least one abnormal test of autonomic function compared with one control (p < 0.0001). There were significant differences between AIDS patients and controls for supine heart rate (p < 0.001), Valsalva ratio (p = 0.05), and cold face test (p = 0.05), and almost significant results for mental stress (p = 0.051). Evidence of autonomic hypersensitivity was found in response to exercise and/or mental stress in some patients with HIV or ARC. No difference was found in blood pressure measurements. Abnormalities in autonomic function occurred at all CD4 counts and all patients with four abnormal tests of heart rate variation had a CD4 count less than 300 x 10(6)/l.

CONCLUSIONS

There is evidence of substantial autonomic dysfunction in AIDS patients compared with controls and mild abnormalities in the majority of HIV infected patients studied irrespective of CD4 count. Autonomic hypersensitivity may precede loss of function in some cases.

Pulmonary artery pressure and pulmonary vascular resistance before and after mitral balloon valvotomy in 100 patients with severe mitral valve stenosis

We studied the pulmonary vascular hemodynamics before and after mitral balloon valvotomy in 100 patients with severe mitral valve stenosis. Before balloon valvotomy 23 patients had a pulmonary artery systolic pressure of < 31 mm Hg (group 1), 54 patients had a pulmonary artery systolic pressure between 31 and 50 mm Hg (group 2), and 23 patients had a pulmonary artery systolic pressure of > 50 mm Hg (group 3). After balloon valvotomy the mean systolic pulmonary artery pressure in group 1 decreased from 28 +/- 3 to 26 +/- 5 mm Hg (p = NS). In group 2 the systolic pulmonary artery pressure after balloon valvotomy decreased from 41 +/- 5 to 33 +/- 7 mm Hg (p < 0.0001) and normalized to < 31mm Hg in 27 patients (50%). The mean left atrial pressure was abnormal (> or = 13 mm Hg) in 6 of 27 patients (22%) who had a systolic pulmonary artery systolic pressure of < 31 mm Hg and in 6 of 27 patients (22%) with a pulmonary artery systolic pressure of > or = 31 mm Hg. The pulmonary vascular resistance was abnormal in 36 of 54 patients (67%) after mitral balloon valvotomy; only 5 of 36 patients (14%) had a raised left atrial pressure (> or = 13 mm Hg). In group 3 the pulmonary vascular resistance was abnormal (> 125 dynes/sec/cm-5) in all 23 patients before and in 19 of 31 patients (91%) after balloon valvotomy.(ABSTRACT TRUNCATED AT 250 WORDS)

S1PR1 drives a feedforward signalling loop to regulate BATF3 and the transcriptional programme of Hodgkin lymphoma cells

The Hodgkin/Reed-Sternberg cells of classical Hodgkin lymphoma (HL) are characterised by the aberrant activation of multiple signalling pathways. Here we show that a subset of HL displays altered expression of sphingosine-1-phosphate (S1P) receptors (S1PR)s. S1P activates phosphatidylinositide 3-kinase (PI3-K) in these cells that is mediated by the increased expression of S1PR1 and the decreased expression of S1PR2. We also showed that genes regulated by the PI3-K signalling pathway in HL cell lines significantly overlap with the transcriptional programme of primary HRS cells. Genes upregulated by the PI3-K pathway included the basic leucine zipper transcription factor, ATF-like 3 (BATF3), which is normally associated with the development of dendritic cells. Immunohistochemistry confirmed that BATF3 was expressed in HRS cells of most HL cases. In contrast, in normal lymphoid tissues, BATF3 expression was confined to a small fraction of CD30-positive immunoblasts. Knockdown of BATF3 in HL cell lines revealed that BATF3 contributed to the transcriptional programme of primary HRS cells, including the upregulation of S1PR1. Our data suggest that disruption of this potentially oncogenic feedforward S1P signalling loop could provide novel therapeutic opportunities for patients with HL.

Pulmonary haptoglobin and CD163 are functional immunoregulatory elements in the human lung

BACKGROUND

The acute-phase protein haptoglobin (Hp) and its receptor CD163 serve as immunomodulators and possess anti-inflammatory besides antioxidant functions.

OBJECTIVES

To further understand the role of the recently described pulmonary Hp (pHp) and its receptor CD163 in case of inflammation and infection, pHp and CD163 were investigated on mRNA and protein level to gain insight into the cellular events taking place upon stimulation with the inflammatory mediators LPS, Pam3, cytokine IL-6 and dexamethasone, and upon infection with respiratory pathogens (Haemophilus influenzae, Streptococcuspneumoniae and Chlamydia pneumoniae) by use of a human ex vivo tissue culture model and cell cultures of A549 and alveolar epithelial cells type II. In addition, pHp and CD163 expression in COPD and sarcoidosis was assessed.

METHODS

We conducted experiments using 942 ex vivo cultured lung samples applying immunohistochemistry, immunocytochemistry, in situ hybridization, immunofluorescence, real-time PCR, RT-PCR, slot and Western immunoblot analyses with tissue lysates and culture supernatants as well as ELISA and cytometric bead array analyses.

RESULTS

This study describes for the first time the expression, regulation and secretion of pHp and its receptor CD163 in the human lung. The release of soluble mediators from A549 cell line and human monocyte-derived macrophages was observed indicating that Hp differentially activates the release of soluble mediators and major chemoattractants.

CONCLUSIONS

The findings indicate a native function of pHp and CD163 as functional pulmonary defense elements due to local expression, regulation and secretion during lung infection and as part of the inflammatory immune response of the respiratory system.

A mammalian sperm lectin related to rat hepatocyte lectin-2/3. Purification from rabbit testis and identification as a zona binding protein

In rat liver the asialoglycoprotein receptor is composed of three polypeptides, RHL-1, RHL-2 and RHL-3. In rat testis and spermatozoa a galactosyl receptor (RTG-r) which is immunologically related to RHL-2/3 has been described. We now report that in addition to its presence in the rat, an antigenic species of 54 kDa related to RHL-2/3 is present on rabbit, human, pig and mouse spermatozoa. Purified rabbit testis galactosyl receptor (RbTG-r) consists of two major proteins of 54 and 49 kDa, while purified rabbit liver galactose lectin consists of two major proteins of 43 and 40 kDa. In an ELISA the purified rabbit testis galactosyl receptor was shown to bind biotinylated heat solubilized rabbit zonae, while the purified liver galactose lectin did not. We conclude that one of the mammalian sperm's zona binding proteins is a galactose lectin of 54 kDa related to rat liver RHL-2/3.

Fetuin: a serum component associated with rat Sertoli and spermatogenic cells in coculture

Cocultures of rat Sertoli-spermatogenic cells plated in a culture medium supplemented with 10% fetal bovine serum for 6-12 h and then maintained in serum free, hormone/growth factor-supplemented medium accumulated an acidic glycoprotein of molecular weight of 68,000 dalton (68 kD) and isoelectric point range of about 4.2-3.5. Anion exchange chromatography has allowed the partial purification of this protein, which consists of a major protein band of 68 kD and two minor, low molecular weight components. A rabbit antiserum raised against the 68 kD component also crossreacts with the two low molecular weight components, thus suggesting that these two minor components are antigenically related to the 68 kD protein. The 68 kD protein has been identified as fetuin, the major component of fetal bovine serum, based on similar molecular weight, isoelectric point, immunoreactivity and trypsin inhibitory activity. Labeling experiments with [14C]amino acid mixture show that 68 kD protein is not synthesized by cocultured rat Sertoli and spermatogenic cells. Immunocytochemistry and Western blot approaches carried out under various experimental conditions support the view that the fetuin-68 kD protein is taken up from serum by both Sertoli cells and pachytene spermatocytes. Because fetuin 1) behaves as a carrier protein for growth factors, 2) has protease inhibitory activity, 3) is preferentially internalized by Sertoli cells and pachytene spermatocytes and 4) fetal bovine serum-supplemented medium impairs spermatogenic cell viability, there is a need to further define appropriate conditions for optimizing long-term viability and differentiation of spermatogenic cells in vitro.

Provocation and amplification of the transvalvular pressure gradient in rheumatic tricuspid stenosis

A low cardiac output and high compliance of the systemic venous system may mask a resting tricuspid diastolic gradient in patients with significant rheumatic tricuspid stenosis. Thirty-three patients (mean age 28 +/- 10 years) with rheumatic tricuspid stenosis evidenced by 2-dimensional echocardiography (doming and restricted motion of all 3 tricuspid valve leaflets) were studied to expose occult and to amplify borderline and basal tricuspid valve gradients. At cardiac catheterization, the right atrium and right ventricular pressures were recorded simultaneously in the basal state, after intravenous infusion of 200, 400, 500, 700 or 1,000 ml of normal saline until a mean right atrial pressure of 12 mm Hg was achieved, and after 0.6 mg of intravenous atropine. Eleven patients (33%) had a mean tricuspid diastolic gradient of greater than 2 mm Hg at rest (group 1). After 483 +/- 240 ml of saline infusion, the mean tricuspid diastolic gradient increased from 5 +/- 2 to 9 +/- 3 mm Hg (p less than 0.001), secondary to a marked rise in right atrial pressure from 8 +/- 3 to 12 +/- 2 mm Hg (p less than 0.001). Concomitantly, there was no increase in right ventricular end-diastolic pressure, although the heart rate increased from 76 +/- 13 to 79 +/- 12 beats/min (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)