Knowledge, Attitude, and Practice of using Antibiotics among the Community in Eastern Province, Saudi Arabia

Objectives

The purpose of this study is to explore and evaluate the knowledge, attitude, and practice of using antibiotics among the community in the Eastern Province, of Saudi Arabia.

Methods

A cross-sectional study was conducted, from February 2022 through March 2022, among people in Eastern Province, Saudi Arabia.

Results

The study population was 753 of the Saudi community. The questionnaire used open-ended and multiple-choice questions. Out of 753 participants, only 254 (55.6%) think that antibiotics can treat a bacterial infection, whereas 163 (35.7%) and 82 (17.9%) think it treats viral and fungal infections respectively. 26 (5.7%) of the respondents think that they should be stopped when the antibiotics are finished, while 72 (15.8%) think that they should be stopped when the symptoms disappear. The most common side effect in the respondent's opinion was diarrhea 183 (40%), followed by 168 (36.76%) antibiotics resistance. The major reason for taking antibiotics without a prescription was found to be mild symptoms 28 (50.90%), adequate information 21 (38.18%), difficulty in taking appointments 17 (30.90%), long waiting hours during the hospital visits 15 (27.27%). 169 (36.9%) kept the leftover antibiotics for reuse. The most common antibiotics used for self-medication were found to be Amoxicillin and clavulanic acid 23 (41.8%), followed by Amoxicillin 9 (16.36%). Knowledge of antibiotic resistance was highest in the age group 20-30 (62.7%) (P < 0.05).

Conclusion

People in Saudi Arabia show a high awareness of antibiotics' proper usage, and this returns to the great awareness campaign held by The Ministry of Health (MoH).

Prevalence of side-effects associated with the booster dose of Pfizer-BioNTech (BNT162b2) of COVID-19 Vaccine among vaccinated adults in the Eastern province of Saudi Arabia

Background

Reports of local and systemic side-effects of COVID-19 vaccination may play an important role in public confidence in the acceptance of the COVID-19 vaccine booster dose.

Methods

We conducted a retrospective cross-sectional study among adults living in Eastern Province of Saudi Arabia. A link to the survey was distributed to community members via WhatsApp, SMS, or e-mail. Participants' general and demographic information was also collected, as well as information about any local and systemic side-effects reported following vaccination.

Results

A total of 370/390 (94.87%) of respondents reported one or more side-effects. Pain or redness at the site of injection (88.92%), fatigue (43.78%), body pain fever (37.84%), and headache (15.95%) were the most commonly reported side-effects. Moreover, 2.43% of the participants reported side-effects needed to see a physician; only four were admitted to the hospital. The non-healthcare respondents (n=273 (97.15%), OR (95% CI) = 5.22 (2.02, 13.48, P <0.001) were more likely to report side-effects compared to the healthcare related respondents (n=36 (85.71%), OR (95% CI) = 0.25 (0.10, 0.70), P=0.013).

Conclusion

According to this study, the Pfizer-BioNTech (BNT162b2) COVID-19 vaccine was safe when given to Saudi Arabian adults. All reported side-effects were mild to moderate. The findings will likely persuade vaccine-hesitant individuals and pessimists to accept booster dose of COVID-19 vaccine.

Evaluation of Prevalence of Side-Effects Associated with Booster Dose of mRNA-Based COVID-19 Vaccine Among Healthcare Workers in Eastern Province, Saudi Arabia: A Descriptive Cross-Sectional Study

Background

The purpose of this study was to examine the mild and moderate side-effects experienced by the healthcare workers (HCWs) in the Eastern Province of Saudi Arabia after receiving the booster dose of the Pfizer-BioNTech/BNT162b2 COVID-19 vaccine.

Methods

We directed a descriptive cross-sectional study among adults living in the Eastern Province of Saudi Arabia. A survey link was distributed through WhatsApp, SMS, or e-mail to HCWs. Participants' general and demographic information were also collected, as well as information about any local and systemic side-effects reported following vaccination.

Results

The results of this study showed that 81.84% (401/490) of the HCWs who contributed to this study reported the minimum COVID-19 post-vaccination side-effect. Body pain (89%) and pain at the site of injection (88.73%) were the most frequent frequently reported side-effects, followed by headache (28.68%), joint or bone pain (27.18%), muscle pain (26.43%), nausea or vomiting (21.2%), fever (18.95%), skin rashes (10.22%). History of chronic diseases had a 0.44-fold increased risk of side-effects compared to no history of chronic diseases HCWs (adjusted odds ratio (aOR) = 0.44; 95% CI = 0.224, 0.880), and significant association of occupation with side-effects was also 1.61-fold increased risk compared to nonmedical ((aOR) = 1.61; 95% CI = 1.037, 2.513).

Conclusion

According to this study, the Pfizer-BioNTech/BNT162b2 COVID-19 vaccine was safe when given to Saudi Arabian HCWs. All reported side-effects were mild to moderate. The outcomes indicated that most participants had body pain and pain at the site of injection and fatigue is among the least reported side-effect post-booster dose. Healthcare was highly connected with more reporting of side-effects.

Evaluation of wound healing potential and biochemical estimation of sage oil nanoemulsion on animal model

The study was aimed to design a nano emulsion formulations of Sage oil and to determine its effectiveness in healing the wound using rats as a model. Sage oil nanoemulsion (o/w) was formulated by a spontaneous emulsification method and tested for physicochemical parameters. The wound creation methods namely; circular excision and linear incision were utilized in the present study. Many specifications like tensile strength, DNA, total protein, Hexosamine and Uronic acid, were estimated from the tissues collected from incised wounds. The antioxidant and antimicrobial activity of the oil was estimated from the wound tissue homogenate. Finally epithelialization period and concentration of TNF-α were also measured. A Significant rise in collagen content by 77.52% and tensile strength by 56.20% were noticed in comparison to control. Reduction in period of epithelialization was noticed by 42.85% in comparison to control. The treatment groups confirmed significant antimicrobial activity in comparison to control. It was evident from the results that Sage oil nano emulsion could be the accelerator in wound healing process and it may be devoid of other drawbacks which would be possible with synthetic drug.

Drug utilization pattern and cost-effectiveness analysis of five most common antibiotics used in Saudi Arabia

Objectives

Inappropriate use of antibiotics is a matter of concern worldwide as that may lead to antimicrobial drug resistance. The objective of current study was to assess drug utilization pattern and cost-effectiveness. Studies are conducted to analyze the pattern of antibiotics prescribing their adherence to standard guidelines and economic impact on the patients in order to promote their rational use.

Methods

The study was designed as a single-centred, cross-sectional retrospective pharmacy database study of prescribing patterns and cost-utility analysis of five most common antibiotics used in Saudi Arabia. Data for the period from 1 January 2019 to 31 December 2019 were used in the study. Demographic characteristics were demonstrated as frequencies and percentages (with Wilson 95% confidence intervals for proportions). The chi-square test (for P-value calculation) was used to compare the adherence of National Antimicrobial Guidelines for prescribing antibiotics in Saudi Arabia.

Key findings

The maximum number of patients was recorded from the age group of 18–35 years (35.97%) and minimum from 72 to 88 years (1.82%). The number of units prescribed was highest for amoxicillin, clavulanic acid (22487) to 42.93% of patients and was lowest for ciprofloxacin (4215) with 8.04%. The longest duration of therapy was for Cefdenir (7.23 days) and lowest for azithromycin (3.58 days). The cost was highest for Cefdenir 38.66SR (10.31USD), and lowest cost was estimated for Cefuroxime 12.43SR (3.31USD).

Conclusions

Our study declared that (amoxicillin with clavulanic acid) was used the most as first-line agents in treating bacterial infections due to their broad coverage against different microbes. Conducting laboratory tests to identify the type of microbe before prescribing could prevent the development of drug resistance and save the antibiotic for future. The cost-to-benefit analysis studies of antibiotics must be conducted for each indication that may promote their rational use.

Immune checkpoint expression on peripheral cytotoxic lymphocytes in cervical cancer patients: moving beyond the PD-1/PD-L1 axis

Immune checkpoint therapy to reverse natural killer (NK) and T cell exhaustion has emerged as a promising treatment in various cancers. While anti-programmed cell death 1 (PD-1) pembrolizumab has recently gained Food and Drug Administration (FDA) approval for use in recurrent or metastatic cervical cancer, other checkpoint molecules, such as T cell immunoreceptor with immunoglobulin (Ig) and immunoreceptor tyrosine-based inhibition motif (ITIM) domains (TIGIT) and T cell immunoglobulin and mucin-domain containing-3 (Tim-3), have yet to be fully explored in this disease. We report expression of TIGIT, Tim-3 and PD-1 on subsets of peripheral blood NK (CD56^dim/neg CD16^{bright/dim/neg} and CD56^bright CD16^dim/neg ) and T cells. The percentages of these cells were increased in women with cervical cancer and pre-malignant lesions. PD-1⁺ NK and T cells were likely to co-express TIGIT and/or Tim-3. These cells, with an apparently 'exhausted' phenotype, were augmented in patients. A subset of cells were also natural killer group 2 member D (NKG2D)- and DNAX accessory molecule 1 (DNAM-1)-positive. PD-1^int and PD-1^high T cells were notably increased in cervical cancer. Soluble programmed cell death ligand 1 (PD-L1) was higher in cancer patient blood versus healthy donors and we observed a positive correlation between sPD-L1 and PD-1⁺ T cells in women with low-grade lesions. Within the cancer group, there were no significant correlations between sPD-L1 levels and cervical cancer stage. However, when comparing cancer versus healthy donors, we observed an inverse association between sPD-L1 and total T cells and a correlation between sPD-L1 and CD56^dim NK cells. Our results may show an overview of the immune response towards pre-cancerous lesions and cervical cancer, perhaps giving an early clue as to whom to administer blocking therapies. The increase of multiple checkpoint markers may aid in identifying patients uniquely responsive to combined antibody therapies.

A retrospective study on drug utilization pattern and cost utility analysis of antifungal drugs

Objectives

Fungal infections in humans are superficial or systemic and are found to be life threatening. They are common among the middle age group and particularly in females and immunocompromised patients.

Methods

This study was conducted to evaluate the prescription pattern of antifungal drugs and their economic burden on patients. The study was designed as a single centered, cross-sectional retrospective pharmacy database study of utilization of antifungal drug therapy and their cost analysis. Data for the period from 1 January 2019 to 31 December 2019 were retrieved from the inpatients and outpatient electronic pharmacy records along with the unit dose prices of antifungal drug in the study hospital.

Key findings

Antifungals use was more among females (67.05%) compared with males (34.91%). The use was predominant among middle age group (31–45) with Clotrimazole being the most utilized lower cost topical drug and fluconazole the next preferred systemic drug with least toxicity. Variconazole is a novel drug utilized the least among all age groups due to its adverse effects and higher cost. Clotrimazole is the drug of choice topically due to low cost and lesser absorption orally. Fluconazole is the next preferred drug that can be given systemically and its use remain unchanged due to lower cost and least toxicity in immunocompromised patients.

Conclusions

Variconazole although have adverse effects and used rarely it is the drug preferred in invasive treatments when benefit outweighs the risk. Variconazole is highly expensive drug used in invasive treatments and its adverse drug reactions, and cost need to be monitored.

Prescribing patterns and cost-utility analysis of management of childhood asthma in Saudi Arabia: a retrospective cross-sectional study

Objective

This study is based on a retrospective cross-sectional study to assess the prescribing patterns and cost-utility analysis of management of childhood asthma in Saudi Arabia.

Methods

Prescription data were collected for 1 year from electronic records of pharmacy. The unit dose price was retrieved from pharmacy database and compared with daily price based on WHO Defined Daily Dose (DDD) and Saudi Initiative for Asthma (SINA). The cost of each drug is calculated from average prices of each unit dose of each prescription.

Key findings

In male children (57.98%), asthma was more common in comparison to female children (41.02%) at the studied hospital. Salbutamol (44.55%) was the most commonly prescribed medication followed by budesonide (30.97%) and montelukast (12.82%), whereas prednisolone (0.15%) was the least prescribed medication for the management of childhood asthma. It was found that fixed-dose combination of budesonide and formetrol prescribed for the longest duration of therapy (30 days) and imposed highest cost as well [197.10 SR (52.53 USD)] among all the prescribed medicine.

Conclusion

In this study, inhalation route is the most preferred one for management of asthma; this may be due to their fast therapeutic action. Salbutamol was the most popular drug for quick reliever therapy, while budesonide was the most favoured drug for childhood asthma management. Medication prescribed for the management of childhood asthma at the mentioned study centre adhere to SINA guideline.

Use of Proton Pump Inhibitors in Saudi Arabia: A Cross-Sectional Retrospective Drug Utilization Study

Objective: Chief aim of the current study was to draw attention in the prescribing pattern and utilization of PPIs in one year at a single private hospital of Saudi Arabia. Methods: This is a cross-sectional, retrospective drug utilization research on Proton pump inhibitors (PPIs). The PPI usage pattern of in- and out- patients of Al-Mana Group of Hospital (AGH) Al-Khobar between January 1, 2019 and December 31, 2019 were investigated, including incidence, prevalence, and duration. Results: We observed 27229 items of PPI were dispensed in the inpatient and outpatient pharmacy department of AGH-Al-khobar. Among all the PPI user more than the half {(52.98%, n = 14426), 95%CI (52.0-53.5)} were male. Nearly equal number of PPI users belongs between 18-40 years {(39.22%, n =10680), 95%CI (38.64-39.80)} and 41-60 years {(39.15%, n =10662), 95%CI (38.6-39.75)}. Among all the PPI users 61.46% (n=16736) were from community of Saudi Arabia while 38.53% (n=10493) from Non-Saudi. Among all the dispensed PPIs drugs Pantoprazole is dispensed to the highest number of patients {79% (95%CI, 78.53-79.50) (n=21515), p<0.05} while their average duration of therapy was 18.78 days. All the PPI prescribed to the AGH-Al-khobar patients adhere to the NICE guideline (p-value <0.05). Conclusions: We also observed that PPIs was prescribed in AGH Al-khobar adhere to clinical guidelines. In our study among all the PPI Pantoprazole was prescribed to the highest number of patients, hence their safe and effective use must be warranted.

Utilization and Adherence to Guidelines Recommended for Use of Statins in the Management of Hypercholesterolemia and Their Cost Utility Analysis

Objective: The study was aimed to evaluate utilization and adherence to guidelines recommended in the use of statins for management of cholesterol and their cost utility analysis in a clinical setting in Saudi Arabia. Materials: A cross-sectional retrospective study was conducted in a private hospital in Saudi Arabia. World Health Organization (WHO) Defined Daily Dose (DDD) was used to compute the Daily price of each statins.  Results: The utilization of statins is higher in males, Saudis and people with the age group 40-59 as compared to females or non-Saudis or other age groups. Over all, Atorvastatin was the most preferred statin therapy followed by Rosuvastatin, Simvastatin and Fluvastatin. The average cost unit wise was found to be highest for Atorvastatin SR 5.58 (USD 1.49) being lowest for Rosuvastatin SR 4.02 (USD1.07). Conclusion: The study aimed to evaluate the use of statins for management of cholesterol is found to be consistent with international guidelines given by ACC/AHS. Our study suggests having further research to fully understand the barriers to guideline adherence to have improved utilization and considerably neutral cost effects of statins for all.

Anticoagulant drug utilization pattern and their cost analysis: a retrospective study from Saudi Arabia

Objective

The study was aimed to evaluate the cost and drug utilization pattern of anticoagulant drugs in a clinical setting in Saudi Arabia.

Method

A cross-sectional retrospective study was conducted in a private hospital in Saudi Arabia. World Health Organization, defined daily dose, and American Society of Hematology methods were used to compute the daily price of each anticoagulant agent.

Key findings

Consumption of oral anticoagulants was very less as compared to the parenteral. Apixaban was the most prescribed oral drug, while enoxaparin sodium was the drug of choice among the parenteral. In oral anticoagulants, the unit-wise cost was found to be highest for Rivaroxaban (12.60 SR (3.36 USD) and less for Warfarin (0.82 SR (0.22 USD)). Heparin sodium cost (51.62 SR (13.76 USD) was found to be the most expensive parenteral agent while the least expensive was Phytomenadione (3.76 SR (1.00 USD)).

Conclusion

Apixaban was the preferred oral anticoagulant among all the studied anticoagulants, although Warfarin is the cheapest. Therapeutic drug monitoring was recommended for Warfarin. The study highlights the importance of more studies to measure the advantages and disadvantages of all types of anticoagulants.

Association of Hypertension with Serum Estrogen Level in Postmenopausal Women

Hypertension is a chronic and debilitating disease. Its complications give rise to cardiovascular diseases, stroke in Postmenopausal women. Estrogen deficiency that develops during menopause is likely the etiological factor for development of hypertension in postmenopausal women. Increased incidence of cardiovascular diseases in postmenopausal women may be due to hypertension caused by lower level of estrogen hormone. The study was carried out to observe the association of hypertension with serum estrogen level in postmenopausal women. This cross sectional study was conducted in the Department of Physiology, Dhaka Medical College, Dhaka, during the period of January 2011 to December 2011. A total number of 90 female subjects were selected from different areas of Dhaka city. Among them, 60 postmenopausal women with age ranging from 50 to 60 years were taken as study group and 30 apparently healthy premenopausal women with age ranging from 20 to 30 years were included as control group for comparison. Systolic blood pressure and diastolic blood pressure were recorded in both groups. Serum estrogen level was estimated in order to assess the hormonal level of both groups. Data was analyzed by Unpaired Student's 't' test and Pearson's co-efficient (r) test as applicable. The value of systolic blood pressure was higher in postmenopausal women than those of premenopausal women and result was statistically significant. The level of diastolic blood pressure was also significantly (p<0.001) higher in postmenopausal women in comparison to those of premenopausal women. In postmenopausal women serum estrogen level was lower than premenopausal women and serum estrogen level showed negative correlation with systolic and diastolic blood pressure levels. All these correlation were statistically non significant. Present study revealed that there is association of hypertension with serum estrogen level in postmenopausal women.

Experimental demonstration of Martian soil simulant removal from a surface using a pulsed plasma jet

A plasma jet produced in a small coaxial plasma gun operated at voltages up to 2 kV and working in pure carbon dioxide (CO2) at a few Torr is used to remove Martian soil simulant from a surface. A capacitor with 0.5 mF is charged up from a high voltage source and supplies the power to the coaxial electrodes. The muzzle of the coaxial plasma gun is placed at a few millimeters near the dusty surface and the jet is fired parallel with the surface. Removal of dust is imaged in real time with a high speed camera. Mars regolith simulant JSC-Mars-1A with particle sizes up to 5 mm is used on different types of surfaces made of aluminium, cotton fabric, polyethylene, cardboard, and phenolic.

Glycosylation of purified buffalo heart galectin-1 plays crucial role in maintaining its structural and functional integrity

A buffalo heart galectin-1 purified by gel filtration chromatography revealed the presence of 3.55% carbohydrate content, thus it is the first mammalian heart galectin found to be glycosylated in nature and emphasizes the need to perform deglycosylation studies. Physicochemical comparative analysis between the properties of the native and deglycosylated proteins was carried out to understand the significance of glycosylation. The deglycosylated protein exhibited lesser thermal and pH stability compared to the native galectin. When exposed to thiol blocking reagents, denaturants, and detergents, remarkable differences were observed in the properties of the native and deglycosylated protein. Compared to the native glycosylated protein, the deglycosylated galectin showed enhanced fluorescence quenching when exposed to various agents. CD and FTIR analysis showed that deglycosylation of the purified galectin and its exposure to different chemicals resulted in significant deviations from regular secondary structure of the protein, thus emphasizing the significance of glycosylation for maintaining the active conformation of the protein. The remarkable differences observed in the properties of the native and deglycosylated galectin add an important dimension to the significance of protein glycosylation and its associated biological and clinical relevance.

The actin-bundling protein fascin is overexpressed in colorectal adenomas and promotes motility in adenoma cells in vitro

Background:

Fascin is overexpressed in many cancers, including colorectal, but its role in the malignant transformation of benign colorectal adenomas is unclear.

Methods:

Immunohistochemical analysis of fascin expression was carried out in resected human colorectal adenoma specimens. The effects of forced overexpression of fascin on adenoma cell motility were also analysed.

Results:

We show fascin overexpression in adenomas increasing with tumour size, histological type, and degree of dysplasia and increased cell motility in adenoma cell lines following fascin transfection.

Conclusion:

These data suggest an important role for fascin in the malignant progression of colorectal tumours.

Inhibition of COX-2 with NS-398 decreases colon cancer cell motility through blocking epidermal growth factor receptor transactivation: possibilities for combination therapy

The use of non-steroidal anti-inflammatory drugs has proved of great interest in the prevention and treatment of colorectal cancer, although their precise mechanisms of action remain unclear. Overexpression of cyclooxygenase-2 (COX-2) and subsequent prostaglandin production promote metastasis and have been shown to increase cell motility in vitro.

OBJECTIVE

We have aimed to elucidate whether specific inhibition of COX-2 with NS-398 (NS-398 is a selective inhibitor of COX-2) would be able to inhibit motility of colorectal cancer cells and whether this was modulated through epidermal growth factor receptor (EGFR) transactivation.

MATERIALS AND METHODS

A transwell filter assay was used to study cell motility. Expression of COX-2, EGFR phosphorylation and prostaglandin E(2) (PGE(2)) receptors were assessed by Western blot analysis and reverse transcriptase-polymerase chain reaction. PGE(2) concentrations after NS-398 treatment were estimated by enzyme immunoassay.

RESULTS

Treatment with NS-398 significantly reduced PGE(2) levels and reduced cell migration in the HT29 and HCA7 colorectal carcinoma cell lines and this effect was rescued by addition of PGE(2). Furthermore, specific inhibition of COX-2 with NS-398 reduced EGFR phosphorylation in colorectal cancer cells. Direct inhibition of EGFR activity with AG1478 reduced PGE(2)-stimulated motility, clearly demonstrating that PGE(2 )acts via the EGFR-signalling pathway. The novel combination of NS-398 and AG1478 dramatically reduced migration of colorectal cancer cells.

CONCLUSION

The data presented indicate that the use of NS-398 in chemoprevention and adjuvant therapy for colorectal cancer may work in part, through the inhibition of cell motility. Furthermore, our data suggest that the combined use of non-steroidal anti-inflammatory drugs with EGFR antagonists could be explored further for future use in the clinic.

Cytokine-augmented culture of haematopoietic progenitor cells in a novel three-dimensional cell growth matrix

Studies aimed at the in vitro expansion of haematopoietic progenitor cells (HPCs) have suffered from the conflict of increasing cell numbers while maintaining long-term repopulating ability. We have developed a long-term bone marrow bioreactor culture system resembling the marrow-microenvironment that cultures HPCs in an inert, three-dimensional, porous biomatrix termed Cellfoam. Previous studies have shown that the short-term culture of CD34(+)cells in Cellfoam improved the maintenance and multipotency of haematopoietic stem cells compared to cells cultured on plastic dishes. In this study, we examined the effects of low concentrations of cytokines including stem cell factor (SCF), IL-3, and Flk-2/Flt-3 ligand, on the maintenance, preservation and multipotency of CD34(+) cells cultured for 3 or 6 weeks in Cellfoam. Analysis of cell yields using flow cytometry showed that in SCF and Flk-2/Flt-3 ligand-supplemented cultures as well as cytokine-free cultures, a higher number of CD45(+)34(+) and CD45(+)34(+)38(-) cells is observed in Cellfoam cultures as compared to plastic cultures. The function of cultured cells was evaluated in colony-forming assays. The data demonstrate that Cellfoam cultures supplemented with SCF and Flk-2/Flt-3 ligand resulted in a higher output of colony activity compared to plastic cultures. Analysis of CAFC (29 days) activity also demonstrated that primitive progenitors were maintained to a greater extent in Cellfoam cultures containing either no cytokines or low concentrations of early-acting cytokines. These data suggest that culture of HPCs in three-dimensional bioreactors such as Cellfoam for extended periods may benefit from the addition of low levels of early-acting cytokines, including SCF and Flk-2/Flt-3 ligand, resulting in high yields of cells that are enriched for multipotent haematopoietic progenitors. These findings demonstrate that a three-dimensional matrix promotes the survival of primitive HPCs in culture and may modulate the in vitro effects of cytokines.

TGF-beta1 down-regulates induced expression of both class II MHC and B7-1 on primary murine renal tubular epithelial cells

BACKGROUND

We examined the immunomodulatory effects of transforming growth factor-beta1 (TGF-beta1) on the regulation of class II MHC and costimulatory molecule expression in a primary renal tubular epithelial cell line, called F1K.

METHODS

Class II major histocompatibility complex (MHC), class II transactivator, B7-1, intercellular adhesion molecule-1 (ICAM-1) and interferon-gamma (IFN-gamma) receptor beta chain were evaluated in untreated and cytokine-treated F1K by Northern hybridization analysis and flow cytometry. T cell activation studies were performed to assess TGF-beta1-mediated effects on antigen presenting cell function of F1K.

RESULTS

Pretreatment of F1K with TGF-beta1 markedly inhibited IFN-gamma-induced class II MHC expression, by both FACS and Northern analysis. Total class II transactivator mRNA levels were also diminished by TGF-beta1, indicating that class II MHC modulation in F1K results from inhibition of this intermediate protein. As previous studies demonstrated that cotreatment of F1K cells with IFN-gamma + lipopolysaccharide (LPS) induces B7-1, we evaluated the potential regulatory effects of TGF-beta1 exposure on B7-1 expression. Our studies revealed that B7-1 mRNA and cell-surface expression in IFN-gamma + LPS-treated F1K were decreased by TGF-beta1 pretreatment. Functional studies evaluating TGF-beta1-mediated effects were performed with IFN-gamma + LPS-treated F1K and MR1.3, a nephritogenic CD4+ Th2 clone derived from kidneys of animals with autoimmune glomerulonephritis. Interleukin (IL)-4 production assays demonstrated activation of MR1. 3 by IFN-gamma + LPS-treated cells, but not by IFN-gamma + LPS-treated cells previously exposed to TGF-beta1, indicating that TGF-beta1-mediated inhibition of class II MHC and B7-1 expression alters the antigen presenting cell function of F1K.

CONCLUSIONS

These studies describe the proscriptive influence of TGF-beta1 on class II MHC and B7-1 expression in renal tubular epithelial cells. Such findings indicate that TGF-beta1 alters the antigen presenting cell function of renal tubular epithelial cells in vitro, and suggest a potential mechanism for immunosuppression of T cell-mediated renal immune responses in vivo.

Modulation of haematopoietic progenitor development by FLT-3 ligand

The Flt-3 receptor is expressed in primitive haematopoietic cells and its ligand exerts proliferative effects on these cells in vitro in synergy with other cytokines. To increase our knowledge of the functional properties of the human Flt-3 ligand (FL) as relating to in vitro expansion of haematopoietic stem cells, the effects on murine haematopoiesis of FL alone or in combination with other growth factors were studied. Analysis of Flk-2/Flt-3 mRNA expression indicated that Flk-2/Flt-3 was preferentially expressed in primitive haematopoietic cell populations. To examine the expression of the Flk-2/Flt-3 receptor on megakaryocyte progenitors (CFU-Meg), Flk-2/Flt-3 positive and negative CD34(+)populations were separated from human bone marrow and cultured in a plasma clot culture system. CFU-Meg colonies were found in the Flk-2/Flt-3 negative fraction. Myeloid (CFU-GM) derived colonies appeared in the presence of FL alone. Neither FL+IL-3 nor FL+IL-3+IL-6 had any effect on the generation of megakaryocyte colonies (CFU-MK), due to the lack of FL receptor expression on megakaryocyte progenitors. Bone marrow cells remaining after 5-fluorouracil (5-FU) treatment of mice represent a very primitive population of progenitors enriched for reconstituting stem cells. This cell population expressed FL receptors, as revealed by RT-PCR analysis. Addition of FL alone did not enhance the replication of such cells in liquid cultures as compared to controls. However, a significantly greater generation of myeloid progenitors (CFU-GM) in clonogenic assays was observed in the presence of FL+IL-3, FL+GM-CSF or FL+CSF-1. In addition, the effects of FL on in vitro expansion of murine haematopoietic stem cells were studied using lineage-negative (lin(-)) Sca-1 positive (Sca-1(+)) c-kit positive (c-kit(+)) marrow cells from 5-FU treated mice. FL enhanced the survival of primitive murine lin(-)Sca-1(+)c-kit(+)cells. FL and IL-6 were able to significantly expand murine progenitor stem cells in vitro and promote their survival. These studies strongly suggest that FL significantly and selectively enhanced the generation of myeloid progenitors in vitro and increased myeloid progenitor responsiveness to later acting growth factors. In addition, FL synergized with IL-6 to support in vitro expansion of haematopoietic progenitors and promoted the survival of lin(-)Sca-1(+)c-kit(+)cells.

Immune reactivity following CD40L blockade: role in autoimmune glomerulonephritis in susceptible recipients

To investigate the role of costimulation in autoimmune glomerulonephritis that develops in the setting of murine chronic graft-vs-host disease (cGVHD), we examined the effects of blocking CD40L, a costimulatory marker expressed on activated CD4+ T cells, in recipient mice. These studies addressed the potential role of CD40L blockade in preventing disease and in downregulating its expression in animals with evidence of autoreactivity. Animals treated acutely with anti-CD40L antibody at disease induction do not develop circulating anti-DNA antibodies, proteinuria, or histologic evidence of renal disease. If treatment is delayed for two weeks, after circulating anti-DNA antibodies are apparent, all animals develop massive proteinuria by 14 weeks after disease induction. Renal histology of kidneys from the delayed treatment and control groups reveal similar glomerular immune deposits, and intense staining for CD4, ICAM-1, and I-A(b) in areas of mononuclear cell infiltration. Long-term treatment studies begun two weeks after disease induction is not disease-protective, as all animals develop massive proteinuria and renal disease by 14 weeks. These studies suggest that early CD40L signaling events are critical to induction of allogeneic interactions and autoreactivity in cGVHD, but that short-term or chronic CD40L blockade, once autoreactivity is evident, does not abrogate systemic autoreactivity and renal involvement.

IFN-gamma and LPS differentially modulate class II MHC and B7-1 expression on murine renal tubular epithelial cells

BACKGROUND

We have investigated inducible class II major histocompatibility complex (MHC) and B7 expression on primary murine renal tubular epithelial cells, called F1K cells, and examined their role in activating nephritogenic T cells derived from kidneys of animals with autoimmune glomerulonephritis.

METHODS

Class II MHC, class II transactivator, and costimulatory molecule expression were evaluated in untreated and cytokine-treated F1K cells by Northern hybridization and flow cytometry. Cell-surface B7-1 expression was evaluated in vitro by immunoprecipitation and in vivo by immunohistochemistry. T-cell activation studies were then performed to assess the functional significance of B7-1 expression on F1K cells.

RESULTS

Coincubation of F1K cells with interferon (IFN)-gamma and lipopolysaccharide (LPS) significantly decreased IFN-gamma-induced class II MHC expression, by both fluorescence-activated cell sorting and Northern analyses. LPS-mediated inhibition of class II MHC in this setting was effected through a decrease in class II transactivator mRNA levels in treated F1K cells. By contrast, IFN-gamma and LPS coincubation induced B7-1 but not B7-2 expression in F1K cells, as detected by Northern analysis, flow cytometry, and immunoprecipitation. In addition, renal tubular staining for B7-1 was apparent in kidneys isolated from IFN-gamma+LPS-treated recipient mice, as well as mice with autoimmune glomerulonephritis. Further studies evaluated the interaction of F1K cells and MR1.3, a nephritogenic CD4+ Th2 clone derived from kidneys of animals with autoimmune glomerulonephritis. Cytokine production assays revealed that F1K cells activated MR1.3 cells if they were pretreated with both IFN-gamma and LPS 48 hours prior to exposure to nephritogenic T cells.

CONCLUSIONS

These studies are the first description of a differential regulation of class II MHC and B7-1 expression in renal tubular epithelial cells mediated by IFN-gamma and LPS. Such findings indicate that discrete proinflammatory stimuli could potentiate antigen-presenting capabilities of renal tubular epithelial cells in vivo and further suggest a direct role of such nonprofessional antigen-presenting cells in modulating renal immune responses.

Recombinant adeno-associated virus-based vectors provide short-term rather than long-term transduction of primitive hematopoietic stem cells

Bone marrow stem cells collected from B6-Gpi-1a mice pretreated with 5-fluorouracil were incubated for 2 h at 37 degrees C in the presence of the recombinant adenovirus-associated virus-based vector (rAAV) SSV9. As measured in vitro immediately following transduction, SSV9 was found to be effective in transducing the primitive cobble-stone-area-forming cell (CAFC)-35 subset (60% transduction efficiency). However, this did not predict long-term expression as the presence of the transgene could not be detected six months after transplantation of 1-2 x 106 transduced bone marrow stem cells into lethally irradiated recipients. CAFC analysis of bone marrow cells and Southern blot analysis of bone marrow and spleen cells were negative, and polymerase chain reaction analysis showed less than 0.1% transduction in bone marrow cells. Therefore, based on our study we conclude that rAAV transiently transduces hematopoietic stem cells but fails to integrate into the genome, leading to the loss of the reporter gene within the first six months after transplantation in vivo.

Prolonged eosinophil accumulation in allergic lung interstitium of ICAM-2 deficient mice results in extended hyperresponsiveness

ICAM-2-deficient mice exhibit prolonged accumulation of eosinophils in lung interstitium concomitant with a delayed increase in eosinophil numbers in the airway lumen during the development of allergic lung inflammation. The ICAM-2-dependent increased and prolonged accumulation of eosinophils in lung interstitium results in prolonged, heightened airway hyperresponsiveness. These findings reveal an essential role for ICAM-2 in the development of the inflammatory and respiratory components of allergic lung disease. This phenotype is caused by the lack of ICAM-2 expression on non-hematopoietic cells. ICAM-2 deficiency on endothelial cells causes reduced eosinophil transmigration in vitro. ICAM-2 is not essential for lymphocyte homing or the development of leukocytes, with the exception of megakaryocyte progenitors, which are significantly reduced.

An agonist murine monoclonal antibody to the human c-Mpl receptor stimulates megakaryocytopoiesis

Thrombopoietin (TPO) is a hematopoietic growth factor that stimulates megakaryocytopoiesis and platelet production in vivo and promotes the development of identifiable megakaryocytes in vitro. We have developed a murine monoclonal antibody, BAH-1, raised against human megakaryocytic cells, which specifically recognizes the c-Mpl receptor and shows agonist activity by stimulating megakaryocytopoiesis in vitro. BAH-1 antibody specifically binds to platelets and to recombinant c-Mpl with high affinity. Similar to TPO, BAH-1 alone supported the formation of colony-forming unit-megakaryocyte (CFU-MK) colonies. The combination of BAH-1 plus interleukin-3 or of BAH-1 plus human TPO significantly increased the number of human CFU-MK colonies. In addition, BAH-1 monoclonal antibody stimulated the proliferation and maturation of primary bone marrow megakaryocytes in a dynamic heterogeneous liquid culture system. Individual large megakaryocytes as well as small megakaryocytic cells were observed in cultures of CD34(+) CD41(+) cells in the presence of BAH-1 antibodies. Similar to TPO, BAH-1 antibody induced a significant response of murine immature megakaryocytes as observed by an increase in the detectable numbers of acetylcholinesterase-positive megakaryocytes. No effects of BAH-1 antibody were observed on colony-forming unit-granulocyte-macrophage, burst-forming unit-erythroid, or colony-forming unit-erythroid colonies. In vivo studies showed that BAH-1, alone or in combination with TPO, expands the numbers of megakaryocytic progenitor cells in myelosuppressed mice. This antibody should prove useful in understanding the structure-function aspects of the c-Mpl receptor as well as in evaluating the effects of the sustained activation of this receptor in preclinical models of severe thrombocytopenia.

Modulation of megakaryocytopoiesis by human macrophage-stimulating protein, the ligand for the RON receptor

We observed that human megakaryocytes expressed the heterodimeric tyrosine kinase RON, which serves as a receptor for macrophage-stimulating protein (MSP). MSP appears to be structurally related to hepatocyte growth factor (HGF), which is a pleiotropic growth factor for a broad spectrum of tissues and cell types. The effects of human rMSP and rHGF on permanent human megakaryocytic cell lines as well as on human and murine primary marrow megakaryocytes were studied. MSP enhanced the maturation of the primary bone marrow megakaryocytes and human megakaryocytic cell lines, CMK and DAMI, as assessed by an increase in ploidy content. The increase in ploidy was blocked by specific Abs for MSP and by anti-IL-6 Abs. MSP treatment of primary human marrow megakaryocytes, DAMI cells, or CMK cells resulted in enhanced secretion of IL-6. The addition of MSP to cultures of immature murine megakaryoblasts showed a significant growth response, similar to that of exogenous IL-6. This increased growth of immature murine megakaryoblasts in response to MSP was abrogated either by Abs against MSP or by neutralizing mAbs to IL-6. HGF, over a range of concentrations (10 to 100 ng/ml) alone or in combination with IL-3, granulocyte-macrophage-CSF, or IL-6, had no effect on differentiation of human or murine marrow megakaryocytes. These results indicate that megakaryocytes express a novel tyrosine kinase receptor (RON), and that its ligand, MSP, appears capable of regulating megakaryocyte maturation, possibly via an autocrine mechanism mediated by induction of the cytokine IL-6.

Modulation of megakaryocytopoiesis by human macrophage-stimulating protein, the ligand for the RON receptor

We observed that human megakaryocytes expressed the heterodimeric tyrosine kinase RON, which serves as a receptor for macrophage-stimulating protein (MSP). MSP appears to be structurally related to hepatocyte growth factor (HGF), which is a pleiotropic growth factor for a broad spectrum of tissues and cell types. The effects of human rMSP and rHGF on permanent human megakaryocytic cell lines as well as on human and murine primary marrow megakaryocytes were studied. MSP enhanced the maturation of the primary bone marrow megakaryocytes and human megakaryocytic cell lines, CMK and DAMI, as assessed by an increase in ploidy content. The increase in ploidy was blocked by specific Abs for MSP and by anti-IL-6 Abs. MSP treatment of primary human marrow megakaryocytes, DAMI cells, or CMK cells resulted in enhanced secretion of IL-6. The addition of MSP to cultures of immature murine megakaryoblasts showed a significant growth response, similar to that of exogenous IL-6. This increased growth of immature murine megakaryoblasts in response to MSP was abrogated either by Abs against MSP or by neutralizing mAbs to IL-6. HGF, over a range of concentrations (10 to 100 ng/ml) alone or in combination with IL-3, granulocyte-macrophage-CSF, or IL-6, had no effect on differentiation of human or murine marrow megakaryocytes. These results indicate that megakaryocytes express a novel tyrosine kinase receptor (RON), and that its ligand, MSP, appears capable of regulating megakaryocyte maturation, possibly via an autocrine mechanism mediated by induction of the cytokine IL-6.

Modulation of megakaryocytopoiesis by thrombopoietin: the c-Mpl ligand

We have further characterized the biological activities, mechanism of action, and target cell populations of recombinant human and murine thrombopoietin (rhTPO and rmTPO) in in vitro human and murine model systems. Alone, hTPO or mTPO stimulated the maturation of immature murine megakaryoblasts as measured in a single cell assay. The combination of hTPO or mTPO and interleukin-6 (IL-6) resulted in a further increase in megakaryocyte differentiation in this system. Murine TPO stimulated mouse megakaryocyte progenitor development. Human megakaryocyte progenitor development was potentiated by hTPO alone and further augmented in the presence of the early-acting cytokines (IL-3) or kit ligand/stem cell factor (KL/SCF). To further define the mechanism of action of TPO, neutralization studies were performed with antisera to IL-3, granulocyte-macrophage colony-stimulating factor (GM-CSF), IL-1 beta, and IL-11. No diminution in TPO activity was observed in the presence of these antisera. Moreover, because adhesive interactions are known to modulate hematopoiesis, we studied whether hTPO might alter such interactions between human bone marrow (BM) megakaryocytes and human BM stromal fibroblasts. No changes were observed in either megakaryocyte expression of the surface molecules lymphocyte function-associated antigen-1, very late activation antigen-4, or intercellular adhesion molecule-1 or the adhesion of megakaryocytes to stromal fibroblasts after treatment with the growth factor. Furthermore, no induction of secretion of the cytokines IL-1 alpha, IL-1 beta, GM-CSF, IL-6, granulocyte-CSF, tumor necrosis factor-alpha, transforming growth factor-beta 1, or transforming growth factor-beta 2 by primary human BM megakaryocytes was noted after treatment of the cells with hTPO. To address whether TPO affects very primitive hematopoietic progenitors, we studied the residual cells from the BMs of mice treated with high doses of 5-fluorouracil. Although no effect of mTPO alone was noted on the viability or replication of such primitive murine progenitor populations, the triple combination of IL-3 + KL/SCF + TPO stimulated growth of megakaryocyte progenitors. These results indicate that TPO is a highly lineage-specific growth factor whose primary biological effects are likely to be direct modulation of the growth and maturation of committed megakaryocyte precursors and immature megakaryoblasts.

Urinary excretion of type IV collagen and laminin in the evaluation of nephropathy in NIDDM: comparison with urinary albumin and markers of tubular dysfunction and/or damage

To clarify the diagnostic relevance of urinary type IV collagen (IV-C) and laminin in diabetic nephropathy, the excretion of these basement membrane proteins were determined by enzyme immunoassay in 172 non-insulin-dependent diabetic patients with different grades of nephropathy and 64 non-diabetic control subjects, and were evaluated in comparison with those of urinary albumin, N-acetyl-beta-D-glucosaminidase (NAG) and alpha 1-microglobulin (alpha 1MG). These excretions were also compared between a group of non-diabetic renal disease (NDRD) patients (n = 24) and a subgroup of the diabetic patients studied (n = 76), whose urinary albumin excretion (UAE) varied within the ranges of micro- and macroalbuminuria. Of the diabetic patients studied, 49.7%, 53.4% and 32.4% had raised urinary albumin, NAG and alpha 1 MG excretion, respectively. In these patients, 54% and 53% exceeded the upper limit of normal for urinary IV-C and laminin. The level of IV-C and laminin excretion and the prevalence of their abnormal excretion showed a trend to increase with increasing grade of nephropathy, as assessed by UAE. In the normoalbuminuric [UAE < 20 mg/g creatinine (Cr)] stage, 28.3% and 26.3% patients had raised urinary IV-C and laminin excretion, respectively. In this stage, the excretion values for IV-C and laminin also rose significantly even when the UAE was < or = 10 mg/g Cr (P < 0.05 and P < 0.005, respectively). There was a close linear relationship between IV-C and laminin excretion (r = 0.73, P < 0.0001), together with their significant relationships with albumin, NAG and alpha 1MG excretion. The relationship of urinary IV-C and laminin with urinary NAG and alpha 1MG excretion remained significant even in normoalbuminuric patients. The normoalbuminuric patients with raised NAG and/or alpha 1MG excretion also had a higher prevalence of raised IV-C and laminin excretion than those with normal NAG and alpha 1MG excretion. The excretion values for IV-C and laminin, and the excretion ratios for IV-C/albumin and laminin/albumin were significantly higher in diabetic patients with evidence of incipient and clinical nephropathy than in NDRD patients, though the two patient groups had a comparable level of serum Cr and UAE. We conclude that the measurement of urinary IV-C and laminin may have potential for the evaluation of diabetic nephropathy. Furthermore, their determination might be helpful for distinguishing diabetic versus non-diabetic etiologies of altered renal function in diabetic patients.

Immunochemical characterisation of megakaryocyte potentiator activity from mouse bone marrow

Megakaryocyte potentiator derived from mouse bone marrow has been shown to be immunologically similar to Interleukin-6 (IL-6). In this study the activity has been characterised by biochemical and immunochemical techniques. The activity is described as a O-linked glycosylated molecule with an apparent MW of 15 Kd and pl of the range pH 5.9-6.35. The data show that mouse bone marrow potentiator activity is a variant of IL-6 and with the potential to enhance megakaryocyte growth.

Serum and urinary type IV collagen concentrations in the assessment of diabetic microangiopathy

We investigated the role of measurement of serum and urinary type IV collagen (IV-C) levels in monitoring diabetic microangiopathy. Furthermore, we compared these levels in diabetic nephropathy and non-diabetic renal disease (NDRD). A one-step sandwich enzyme immunoassay was used to measure IV-C levels in 82 diabetic patients, 33 NDRD patients and 20 healthy non-diabetic control subjects. The diabetic patients were classified into four groups according to urinary albumin/creatinine index (ACI) (mg/g) and serum creatinine (s-Cr) (mg/dl): normoalbuminuria (ACI < 30), microalbuminuria (ACI 30-300), albuminuria (ACI > 300, s-Cr < 1.99 mg/dl) and renal insufficiency (s-Cr > 1.99 mg/dl). Serum and urinary IV-C levels were significantly elevated even in diabetic patients without clinical evidence of microangiopathy compared with control subjects (p < 0.05 and p < 0.01, respectively). Both levels were significantly higher in normoalbuminuric patients than in the control subjects, and in patients with microalbuminuria, albuminuria or renal insufficiency than in normoalbuminuric patients, with significant differences between these groups (serum and urinary IV-C, both p < 0.0001 by ANOVA). Urinary IV-C and albumin levels were significantly correlated, even in normo- and microalbuminuric patients (r = 0.55, p < 0.0001). Serum IV-C in normoalbuminuric patients rose significantly as the degree of retinopathy progressed from background to proliferative stages (p < 0.05). Neither serum nor urinary IV-C levels were influenced by glycemic control. Albuminuric diabetic patients (with and without renal insufficiency) had significantly higher levels of serum IV-C compared with those in proteinuric NDRD patients (p < 0.005), though there was no significant difference in the urinary IV-C level. However, the urinary IV-C/albumin ratio was significantly higher in albuminuric diabetic patients than in proteinuric NDRD patients, even after adjusting for s-Cr and creatinine clearance (p < 0.0001). In conclusion, we suggest that measured serum and urinary IV-C concentrations may serve as new markers for monitoring the development and progression of diabetic microangiopathy, particularly nephropathy. Furthermore, the measurement of serum IV-C concentrations and urinary IV-C/albumin ratios in diabetic patients may allow diabetic nephropathy and non-diabetic renal disease to be differentiated.

A novel method for concentrating urinary type IV collagen based on precipitation with polyethylene glycol: application to its measurement by enzyme immunoassay

We investigated the efficacy of polyethylene glycol (PEG) for effective and reproducible concentration of urinary type IV collagen prior to measurement by enzyme immunoassay (EIA). Human placental type IV collagen at low concentrations (5 and 10 micrograms/L) and urinary type IV collagen were readily precipitated by PEG-4000 added at a concentration of about 150 g/L in the presence of 0.5 g/L gamma-globulin. Type IV collagen measurement by EIA from PEG-concentrated urine samples showed complete recovery and good reproducibility. Analysis of size distribution by Sephacryl S-300HR gel chromatography and Western blotting following polyacrylamide gel electrophoresis confirmed that type IV collagen in PEG-concentrated urine samples was of high molecular weight comparable to that of human placental type IV collagen. After PEG concentration, type IV collagen was detectable by EIA even in the urine of healthy subjects. Significantly higher concentrations of urinary type IV collagen were found in 30 diabetic patients with nephropathy than in 20 healthy subjects [99.5 (8.9) micrograms/L, mean (SEM) versus 21.4 (2.6) micrograms/L, P < 0.0001]. Thus, urinary type IV collagen can be measured effectively by EIA following concentration with PEG. This method has potential for the assessment of the progression of diabetic nephropathy.

Modulation of megakaryocytopoiesis by human basic fibroblast growth factor

Basic fibroblast growth factor (bFGF) may act to modulate hematopoiesis in addition to its effects on mesenchymal cells. We studied the effects of bFGF on human and murine primary marrow megakaryocytes. bFGF modestly enhanced the size of the human megakaryocyte colony-forming unit (CFU-MK) and cell numbers per colony, in combination with interleukin-3 (IL-3) or granulocyte-macrophage colony stimulating factor (GM-CSF). Adhesion of human megakaryocytes to bone marrow (BM) stromal fibroblasts was enhanced when either stromal fibroblasts or megakaryocytes were treated with bFGF. This resulted in significantly increased proliferation of megakaryocytes. In addition, bFGF augmented secretion of the cytokines tumor necrosis factor alpha and IL-6 by human primary BM megakaryocytes. Immature murine megakaryocytes showed a significant growth response to bFGF as measured by the single cell growth assay. This effect was abrogated by specific antibodies for bFGF and combination of anti-IL-6 and anti-IL-1 beta antibodies. bFGF has no effect on murine CFU-MK formation, but significantly potentiated CFU-MK formation in the presence of IL-3 or GM-CSF. These results indicate that the effect of bFGF on various megakaryocyte populations is different and that bFGF may affect megakaryocytopoiesis via modulation of megakaryocyte-stromal interactions and via augmentation of cytokine secretion from megakaryocytes.

Persistent diarrhoea: management in algorithmic approach using a low-cost rice-based diet in severely malnourished Bangladeshi children

Easy and successful dietary management of persistent diarrhoea has been a long desired goal. Finding an efficient diet which is economically feasible, and easy to prepare in poor homes of developing countries, has not been easy. A dietary algorithm was followed to test the clinical efficacy of an inexpensive and easy to prepare diet made up with rice powder, egg white, glucose, and soya oil. We studied a cohort of 100 severely malnourished children aged between 3 and 36 months with persistent diarrhoea in Dhaka Shisu (children's) Hospital, Bangladesh, during 1990. Initially on a milk-based diet, 26 children (26 per cent) improved while on a subsequent rice-based diet; 65 (88 per cent) of the remaining 74 children improved within a week, with a mean recovery period of 4 days. Patients who did not improve with the rice-based diet were weaned earlier than those who improved. Nine patients failed to improve on the rice-based diet. They were given a soya formula, and only two improved. The remaining seven patients finally improved when a comminuted chicken diet was given. Eight patients died in the hospital with secondary infections of septicaemia and bronchopneumonia. This study offers a simple and effective algorithm on the management of persistent diarrhoea and also demonstrates the success of a rice-based diet, showing promising and feasible means of management of persistent diarrhoea in patients with severe malnutrition.

The nature of an accessory cell in bone marrow stimulating murine megakaryocytopoiesis

The nature of accessory cells in unstimulated mouse bone marrow that modulates in vitro megakaryocytopoiesis by releasing megakaryocyte potentiator (Mk-potentiator) activity was investigated. An active cell class was identified by the 7/4 and Ia cellular antigens. Bone marrow macrophages were obtained by their defined outgrowth in the presence of growth factors. Bone marrow macrophages grown in the presence of interleukin 3 (IL-3) were more active in producing Mk-potentiator than were macrophages grown in the presence of colony-stimulating factor 1 (CSF-1). The data indicate that the accessory cells producing Mk-potentiator are a select population of bone marrow macrophages that may be responsible for inducing megakaryocyte maturation under steady-state conditions.

Tissue sources of murine megakaryocyte potentiator: biochemical and immunological studies

The immunological and biochemical characteristics of murine megakaryocyte potentiator from lung and bone marrow were examined and compared with thrombopoietic stimulatory factor. Biological activity was not neutralized by anti-erythropoietin, but megakaryocyte potentiator activity from all three sources was abolished or reduced when the preparations were treated with anti-thrombopoietic stimulatory factor or anti-interleukin-6. Megakaryocyte potentiator levels in lung conditioned medium were not found to be enhanced from mice treated with lipopolysaccharide, in contrast to granulocyte-macrophage colony-stimulating factor (GM-CSF) levels. The biochemical properties of murine megakaryocyte potentiator from lung and bone marrow were compared and found to be similar in the elution profiles from anion exchange, gel filtration and reversed phase liquid chromatography. It is concluded that the activities in lung and bone marrow are very similar if not identical, to interleukin-6.

Recombinant interleukin 6 stimulates immature murine megakaryocytes

Human recombinant interleukin 6 (IL-6) was found to stimulate the growth of immature mouse megakaryocytes maximally at 2 ng/ml, leading to significant increases in the number of large megakaryocytes readily detectable by light microscopy. IL-6 did not stimulate megakaryocyte progenitor cells to form colonies of megakaryocytes, but potentiated megakaryocyte colony formation when added in the presence of interleukin 3. The stimulation could be neutralized by an anti-IL-6 serum. The data indicate that IL-6 is a potent differentiation stimulus of megakaryocyte development in cell culture.