Barriers and facilitators to community acceptability of integrating point-of-care testing to screen for sickle cell disease in children in primary healthcare settings in rural Upper East Region of Northern Ghana

INTRODUCTION

Sickle cell disease (SCD) remains a public health problem especially in sub-Saharan Africa including Ghana. While pilot initiatives in Africa have demonstrated that neonatal screening coupled with early intervention reduces SCD-related morbidity and mortality, only 50-70% of screen-positive babies have been successfully retrieved to benefit from these interventions. Point-of-care testing (POCT) with high specificity and sensitivity for SCD screening can be integrated into existing immunization programs in Africa to improve retrieval rates. This study explored community acceptability of integrating POCT to screen for SCD in children under 5 years of age in primary healthcare facilities in Northern Ghana.

METHOD

This was an exploratory study using qualitative research approach where 10 focus group discussions and 20 in-depth interviews were conducted with community members and health workers between April and June 2022. The recorded interviews were transcribed verbatim after repeatedly listening to the recordings. Data was coded into themes using QSR Nvivo 12 software before thematic analysis.

RESULTS

Most participants (70.9%) described SCD as serious and potentially life-threatening condition affecting children in the area. Of 148 community members and health workers, 141 (95.2%) said the screening exercise could facilitate diagnosis of SCD in children for early management. However, discrimination, fear of being tested positive, stigmatization, negative health worker attitude linked with issues of maintaining confidentiality were reported by participants as key factors that could affect uptake of the SCD screening exercise. Most participants suggested that intensive health education (78.3%), positive attitude of health workers (69.5%), and screening health workers not being biased (58.8%) could promote community acceptability.

CONCLUSION

A large majority of participants viewed screening of SCD in children as very important. However, opinions expressed by most participants suggest that health education and professionalism of health workers in keeping patients' information confidential could improve the uptake of the exercise.

The societal impact of early intensified treatment in patients with type 2 diabetes mellitus

Aim: The current study estimates the societal impact of early intensified treatment compared with initial monotherapy with subsequent treatment intensification in newly diagnosed adults with type 2 diabetes mellitus in Mexico. Methods: An individual patient-level simulation and a static cohort model were employed to simulate the treatment pathway and the probability of experiencing complications of diabetes. The avoided number of events was translated into avoided productivity losses, which were monetized using wages. Results: Patients on early intensified treatment experienced approximately 13,000 fewer complication events over 10 years. This was translated into a societal impact of $54 million (USD). Conclusion: Early treatment intensification is likely to be of particular benefit to health outcomes and productivity losses.

Establishment of transplantation tolerance via minimal conditioning in aged recipients

Mixed hematopoietic chimerism is a powerful means of generating donor-specific tolerance, allowing long-term graft acceptance without lifelong dependence on immunosuppressive drugs. To avoid the need for whole body irradiation and associated side effects, we utilized a radiation-free minimal conditioning regime to induce long-term tolerance across major histocompatibility barriers. We found that low-dose busulfan, in combination with host T cell depletion and short-term sirolimus-based immunosuppression, facilitated efficient donor engraftment. Tolerance was achieved when mice were transplanted with whole or T cell-depleted bone marrow, or purified progenitor cells. Tolerance induction was associated with an expansion in regulatory T cells and was not abrogated in the absence of a thymus, suggesting a dominant or compensatory peripheral mode of tolerance. Importantly, we were able to generate durable chimerism and tolerance to donor skin grafts in both young and aged mice, despite age-related thymic atrophy and immune senescence. Clinically, this is especially relevant as the majority of transplant recipients are older patients whose immune recovery might be dangerously slow and would benefit from radiation-free minimal conditioning regimes that allow efficient donor engraftment without fully ablating the recipient immune system.

Comparison of the dipeptidyl peptidase-4 inhibitor vildagliptin and the sulphonylurea gliclazide in combination with metformin, in Muslim patients with type 2 diabetes mellitus fasting during Ramadan: results of the VECTOR study

OBJECTIVE

To compare the incidence of hypoglycaemic events (HEs) in a real-world setting in Muslim patients with type 2 diabetes mellitus fasting during Ramadan.

RESEARCH DESIGN AND METHODS

We performed a ≤16-week prospective, non-interventional, two-cohort study. Data were collected 1-6 weeks before and ≤6 weeks after fasting. Patients were enrolled who had been receiving vildagliptin (50 mg twice daily) or sulphonylurea (SU) as add-on to metformin at least 4 weeks prior to fasting.

MAIN OUTCOME MEASURES

The primary efficacy endpoint was incidence of HEs during the Ramadan fast. Changes in glycated haemoglobin (HbA(1c)) and body weight, as well as adherence to treatment, were also assessed.

RESULTS

Seventy-two patients were enrolled (vildagliptin, n = 30; SU, n = 41; no treatment, n = 1), of whom 23 (76.7%) and 36 (87.8%), respectively, completed the study. With vildagliptin, there were no HEs or severe HEs, compared with 34 HEs (15 patients, 41.7%) and one severe (grade 2) HE with SU. The mean between-group difference in the proportion who experienced at least one HE was -41.7% (95%CI -57.8%, -25.6%), p = 0.0002. Vildagliptin lowered mean HbA(1c) from 7.6% (SD 0.9%) at baseline to 7.2% (SD 0.7%) post-Ramadan, whereas SU had no effect (7.2% [SD 0.6%] vs 7.3% [SD 0.7%]; mean between-group difference -0.5% [95% CI -0.9%, -0.1%], p = 0.0262). The mean number of missed doses was markedly lower with vildagliptin (0.2 [SD 0.8] vs 7.6 [SD 14.9]; mean between-group difference -7.4 [95% CI -13.7, -1.20] doses; p = 0.0204). Body weight remained unchanged in both groups.

CONCLUSION

Vildagliptin caused no hypoglycaemia, was well adhered to and improved HbA(1c), making it a suitable treatment option for managing fasting. Study limitations are the sample size and the lack of diet and exercise data. When extrapolated to the global Muslim population with a similar clinical background, these findings could have considerable public health and clinical implications.

Pharmacokinetics, safety, and tolerability of ascending doses of sublingual fentanyl, with and without naltrexone, in Japanese subjects

This open-label, nonrandomized study assessed single and repeat ascending doses of a new sublingual fentanyl (SLF) formulation in 48 healthy Japanese opiate-naïve subjects (47 completed). Subjects received single-dose SLF 100, 200, 400, or 800 µg followed by 13 doses 6 hourly, at their dose level. Subjects taking repeat-dose 400 and 800 µg were pretreated with naltrexone in order to block opiate-receptor-mediated effects on respiration, monitored by pulse oximetry and transcutaneous pco(2). Sublingual fentanyl was rapidly and consistently absorbed. After single doses, median t(first) was 0.08 to 0.25 hours and t(max) 0.50 to 1.00 hours. After repeat dosing, median t(max) (t(max,ss)) was 0.50 to 2.00 hours. Plasma concentrations were dose proportional both after single and repeat dosing, and naltrexone appeared to have no effect on SLF pharmacokinetics. Plasma fentanyl reached steady state within the 72-hour dosing period and accumulation was approximately 2-fold. After single doses, effects on respiratory variables were evident after the 400-µg and 800-µg doses. Transcutaneous pco(2) was not helpful in detecting respiratory depression. Thus, SLF yielded rapid absorption of fentanyl and dose-proportional plasma concentrations that, for 400 µg and 800 µg, were within the typical analgesic range. Respiratory depression in these opioid-naïve volunteers was manageable with simple clinical measures.

Association between risk of acquiring HIV and beliefs and perceptions about the lived experience of HIV/AIDS among HIV-negative or untested men who have sex with men

The study aim was to assess whether the sexual behaviour of HIV-negative or untested men who have sex with men (MSM) was related to their perceptions of what it is like to live with HIV/AIDS, their beliefs or their attitudes to highly active antiretroviral treatments. Any unprotected anal intercourse (UAI) with casual partners was used as the sexual-risk indicator. The study enrolled 261 MSM. There were no significant differences between beliefs, attitudes and perceptions about HIV/AIDS, knowledge of post-exposure prophylaxis (PEP) or exposure to the HIV/AIDS epidemic among those who had had UAI with casual partners and those that had not (P>0.12). Those who considered that low levels of viral load and withdrawing before ejaculation reduced the risk of HIV transmission were significantly more likely to have had UAI with a casual partner (P=0.03). Only a minority of MSM engaging in UAI were optimistic about antiretroviral therapy. The study participants were in general pessimistic about life with HIV/AIDS despite their risk-taking sexual behaviour.

Increased acute GvHD and higher transplant-related mortality in non-caucasians undergoing standard sibling allogeneic stem cell transplantation

We conducted a retrospective study to compare outcome in Caucasians and non-Caucasians undergoing standard sibling allogeneic SCT. End points of the study were to compare graft-versus-host disease (GvHD) occurrence and transplant-related mortality (TRM). There were 251 patients, 43 non-Caucasian and 208 Caucasian. A higher proportion of non-Caucasian patients developed acute GvHD (aGvHD) grade 2 or greater as compared to the Caucasian group (48 vs 26%, respectively) P = 0.02. With a median follow-up of 27 months, 26% (11/43) of non-Caucasians and 14% (29/208) of Caucasian patients had died from TRM, which accounted for 55% of all deaths in the non-Caucasian group compared to 33% in Caucasians, P = 0.02. Overall survival 12 months post transplant was 64 vs 69% in the non-Caucasian and Caucasian groups, respectively (P = 0.43). Although there were higher numbers of CMV-positive patients in the non-Caucasian group, there were no deaths from CMV reactivation in this subgroup. We conclude that there is increased TRM and aGvHD following standard sibling allograft in the non-Caucasian population and this could be due to either differences in tumour biology or extrinsic factors such as socio-economic factors, nutritional status, post transplant care or presenting with late stage disease.

Identification of a candidate membrane protein for the basolateral peptide transporter of rat small intestine

A candidate protein for the basolateral peptide transporter of rat jejunum is described. Vascular perfusion of the photoaffinity label, [4-azido-D-phe]-L-ala (2.5mM), had no effect on the transepithelial transport of the non-hydrolysable dipeptide D-phe-L-gln (1mM) from the lumen, its mucosal accumulation or wash-out into the vascular perfusate. When the label was perfused luminally, the transepithelial transport of D-phe-L-gln was inhibited by 38% (P<0.001) and accumulation increased by 62% (P<0.05). These data are consistent with those of a basolateral transporter that is strongly asymmetric in its substrate binding and transport properties. Labelling of basolateral membrane vesicles with [4-azido-3,5-3H-D-phe]-L-ala revealed that the majority of label was incorporated into a single protein of M(r)112+/-2 kDa and pI 6.5. MALDI-TOF analysis of tryptic digests of the protein followed by database searches established that this protein was novel with no obvious similarity to PepT1, the apical membrane transporter.

The influence of luminal pH on transport of neutral and charged dipeptides by rat small intestine, in vitro

Four hydrolysis-resistant dipeptides (D-phenylalanyl-L-alanine, D-phenylalanyl-L-glutamine, D-phenylalanyl-L-glutamate and D-phenylalanyl-L-lysine) were synthesized to investigate the effects of net charge on transmural dipeptide transport by isolated jejunal loops of rat small intestine. At a luminal pH of 7.4 and a concentration of 1 mM the two dipeptides with a net charge of -1 and +1 were transported at substantially slower rates (18 +/- 1.3 and 8.4 +/- 1.3 nmol min(-1)(g dry wt.)(-1), respectively) than neutral D-phenylalanyl-L-alanine and D-phenylalanyl-L-glutamine (87 +/- 0.2 and 197 +/- 14 nmol min(-1)(g dry wt.)(-1), respectively). We investigated the effects of luminal pH on dipeptide transport by varying the NaHCO3 content of Krebs Ringer perfusate equilibrated with 95% 02/5% CO2. The pH changes did not affect water transport, but serosal glucose appearance increased significantly at pH 6.8. Transmural transport of D-phenylalanyl-L-alanine and D-phenylalanyl-L-glutamine at pH 6.8 was stimulated (P < 0.01) by 61% and 49%, respectively, whereas the lower pH increased the rate for negatively charged D-phenylalanyl-L-glutamate by 306% (P < 0.01) and decreased that for positively charged D-phenylalanyl-L-lysine by 46% (P < 0.05). Increasing luminal pH to 8.0 inhibited D-phenylalanyl-L-alanine transport by 60%, whereas D-phenylalanyl-L-lysine transport was 60% faster.

Dipeptide transport and hydrolysis in rat small intestine, in vitro

A range of natural and mixed D-/L-stereoisomer phenylalanine dipeptides was used to investigate peptide uptake and hydrolysis by isolated rings of rat jejunum. Characterisation of dipeptide hydrolysis by the brush border fraction revealed apparent Km values in the 0.1-1.0 mM range which, except for the charged dipeptides, were significantly higher than those for hydrolysis by the cytosolic fraction. Uptake of L-/L-dipeptides into jejunal rings, which was followed by HPLC, was unaffected by the presence of peptidase inhibitors in the incubation medium although the absorbed peptides were completely hydrolysed in the cytosol; comparison of the effects of excess leucine on dipeptide uptake and on the uptake of the two constituent amino acids were also consistent with absorption of intact dipeptide followed by cytosolic hydrolysis. The uptake of hydrolysis-resistant mixed D-/L-dipeptides was also studied and confirmed that peptide uptake preceded hydrolysis; D-alanyl-L-phenylalanine accumulated within the rings to twice the medium concentration.

Dipeptide transport and hydrolysis in isolated loops of rat small intestine: effects of stereospecificity

1. Isolated jejunal loops of rat small intestine were perfused by a single pass of bicarbonate Krebs-Ringer solution containing either D- or L-phenylalanine or one of eight dipeptides formed from D- or L-alanine plus D- or L-phenylalanine. 2. At 0.5 mM L-phenylalanyl-L-alanine increased serosal phenylalanine appearance to forty times the control rate giving a value similar to that found with 0.5 mM free L-phenylalanine. No serosal dipeptide could be detected. 3. Perfusions with the two mixed dipeptides with N-terminal D-amino acids (D-alanyl-L-phenylalanine and D-phenylalanyl-L-alanine) gave rise to the appearance of intact dipeptides in the serosal secretions although there were substantial differences in their rates of absorption and subsequent hydrolysis. 4. L-Alanyl-D-phenylalanine was absorbed from the lumen three to five times as fast as L-phenylalanyl-D-alanine. At 1 mM L-alanyl-D-phenylalanine transferred D-phenylalanine across the epithelial layer at more than seven times the rate found with the same concentration of the free D-amino acid. 5. Perfusions with D-alanyl-D-phenylalanine or D-phenylalanyl-D-alanine showed that these two dipeptides are poor substrates for both transport and hydrolysis by the rat small intestine. 6. Analysis of mucosal tissue extracts after perfusion with the two mixed dipeptides with N-terminal D-amino acids revealed that both dipeptides were accumulated within the mucosa and suggested that exit across the basolateral membrane was rate limiting for transepithelial dipeptide transport.

Tripeptide transport in rat lung

Transport of L-alanyl-D-phenylalanyl-L-alanine was investigated with an in situ vascular perfusion preparation of rat lung and brush border membrane vesicles prepared from type II pneumocytes. In the perfused lung 1 mM tripeptide was transported intact from the alveolar lumen to the vascular perfusate at a mean rate of 25.1 +/- 1.29 (3) nmol/min per g dry weight. D-Phenylalanine also appeared in the vascular perfusate at a rate of 21.9 +/- 1.74 (3) nmol/min per g dry weight indicating that 47% of the absorbed tripeptide was split during passage across the epithelial layer. No dipeptide could be detected in the vascular effluent during perfusions with tripeptide. Rapid L-alanyl-D-phenylalanyl-L-alanine uptake occurred with fresh apical membrane vesicles prepared from type II pneumocytes and this was abolished by treatment with 0.1% triton. The related tripeptide, D-alanyl-L-phenylalanyl-D-alanine, was taken up significantly more slowly by the vesicles. D-phenylalanyl-L-alanine and D-phenylalanyl-D-alanine, were also studied with the vascularly perfused preparation; the mixed dipeptide appeared in the vascular perfusate significantly faster than L-alanyl-D-phenylalanyl-L-alanine whereas D-phenylalanyl-D-alanine appeared more slowly and was not hydrolysed.

Transport and metabolism of 6-thioguanine and 6-mercaptopurine in mouse small intestine

1. The transport of 6-thioguanine and 6-mercaptopurine has been studied with isolated jejunal loops of mouse small intestine. H.p.l.c. was used to identify and quantify the thiopurines and their metabolites in the serosal secretions. 2. When the lumen of the intestinal loops contained either 6-thioguanine or 6-mercaptopurine at a concentration of 1 mmol/l, the concentration of unmetabolized drug in the serosal secretions reached a maximum of 0.13 +/- 0.02 mmol/l (mean +/- SEM). 3. Analysis of the serosal secretions from the perfusions with either of the drugs revealed the appearance of an unknown compound which had the characteristics of a thiopurine and the same time course of appearance as the unmetabolized drug. Thus 6-thioguanine and 6-mercaptopurine are significantly metabolized during absorption in mouse intestine. 4. The unknown compound was identified as 6-thiouric acid, and with 1 mmol/l 6-thioguanine or 6-mercaptopurine in the lumen the concentration of this metabolite in the serosal secretions rose to a maximum of 0.13 +/- 0.01 and 0.18 +/- 0.03 mmol/l, respectively. At luminal drug concentrations of 0.1 mmol/l, the metabolite accounted for approximately 90% of the serosal thiopurine. 5. After an initial lag period of 20 min, linear rates of appearance in the serosal secretions were obtained for both the unmetabolized drugs and 6-thiouric acid. 6. Addition of the xanthine oxidase inhibitor oxypurinol at a luminal concentration of 0.3 mmol/l prevented the formation of 6-thiouric acid from 6-thioguanine. However, the inhibitor reduced the rate of 6-thioguanine appearance in the serosal secretions by 50%. 7. The conversion of 6-mercaptopurine to 6-thiouric acid was prevented when allopurinol or oxypurinol were added to the lumen. At a luminal drug concentration of 1 mmol/l, allopurinol increased the rate at which 6-mercaptopurine appeared in the serosal secretions by 90% compared with an increase of only 50% with oxypurinol. 8. The transport of water and glucose by the mouse intestinal loops was unaffected by 6-thioguanine or the xanthine oxidase inhibitors. However, 6-mercaptopurine caused significant reductions in the rate of water transport (30%) and glucose transport (39%). These effects were observed at a luminal drug concentration of 0.1 mmol/l and there was no further increase at a drug concentration of 1 mmol/l.

Absorption of 5-fluorouracil and related pyrimidines in rat small intestine

The transport of 5-fluorouracil, uracil and thymine has been studied with isolated jejunal loops of rat small intestine. High performance liquid chromatography was used to identify the pyrimidines and measure their concentrations. When the lumen of the intestine was perfused with 5-fluorouracil or uracil at 0.1 mmol/l or 0.2 mmol/l, the concentration in the serosal secretions was significantly higher than that in the lumen. For thymine the serosal concentration exceeded that in the lumen only at 0.1 mmol/l. Analysis of the mucosal tissue water at the end of the perfusion demonstrated that when the intestinal lumen was perfused with any one of the three pyrimidines at 0.1 mmol/l or 0.2 mmol/l the concentration within the tissue was significantly above that in the lumen. After an initial lag period linear rates of transport from the lumen to the serosal secretions were obtained for all three pyrimidines over a 10-fold concentration range from 0.1 mmol/l to 1 mmol/l. Uracil and thymine inhibited the transmural transport of 5-fluorouracil. The transport of 5-fluorouracil was also studied with a vascularly perfused preparation of rat small intestine. At 0.1 mmol/l the rate of transmural transport of the drug in this preparation was substantially higher than in the jejunal loops. This difference was eliminated by adding 5-fluorouracil to the vascular perfusate, suggesting that the higher transport rate in the vascularly perfused preparation was due to the lower serosal drug concentrations in the mesenteric circulation of the perfused intestine. At a concentration of 5 mmol/l 5-fluorouracil inhibited water transport in the isolated loops and transmural D-galactose transport in the vascular perfusions.