Role of myeloid cells in ischemic retinopathies: recent advances and unanswered questions

Myeloid cells including microglia and macrophages play crucial roles in retinal homeostasis by clearing cellular debris and regulating inflammation. These cells are activated in several blinding ischemic retinal diseases including diabetic retinopathy, where they may exert both beneficial and detrimental effects on neurovascular function and angiogenesis. Myeloid cells impact the progression of retinal pathologies and recent studies suggest that targeting myeloid cells is a promising therapeutic strategy to mitigate diabetic retinopathy and other ischemic retinal diseases. This review summarizes the recent advances in our understanding of the role of microglia and macrophages in retinal diseases and focuses on the effects of myeloid cells on neurovascular injury and angiogenesis in ischemic retinopathies. We highlight gaps in knowledge and advocate for a more detailed understanding of the role of myeloid cells in retinal ischemic injury to fully unlock the potential of targeting myeloid cells as a therapeutic strategy for retinal ischemia.

DIETARY LIFESTYLE, HYPOALBUMINAEMIA AND ANAEMIA AMONG OLDER ADULTS ATTENDING A PRIMARY CARE CLINIC IN NIGERIA: A CROSS-SECTIONAL STUDY

Introduction

Anaemia has been extensively studied in children and women of reproductive age. However, there are few data on anaemia and related conditions in the elderly from developing countries.

Objectives

To determine the prevalence and severity pattern of anaemia, and assess the relationship between dietary lifestyle, hypoalbuminaemia, and anaemia in older persons.

Methodology

A cross-sectional study involving 378 patients aged≥60 years who presented at the General Outpatient Clinic. Dietary lifestyle was assessed using a structured questionnaire. Samples were collected for packed cell volume and serum albumin. Inferential statistical analyses were used to determine the associations between variables.

Results

A total of 348 respondents completed the study. The mean age of respondents was 67.83 ±7.53 years with female (60.9%) predominance. The prevalence of anaemia and hypoalbuminaemia were 42.2% and 17.8% respectively. Hypoalbuminaemia (β=0.335, 95%CI=0.131-0.229, P<0.001), long duration of co-morbidities (β= - 0.179, 95%CI= -0.165-0.047, P<0.001), one full meal/day (β=0.130, 95%CI=0.224-1.879, P=0.013), and low monthly income (β=0.122, 95%CI=0.179-1.543, P=0.026) were the predictors of anaemia among the elderly in this study.

Conclusion

Data on the predictors of anaemia from this study will be useful in developing guidelines and strategies for managing the condition in primary care settings and other similar sites.

Impact of miR-155 (rs767649 A>T) and miR-146a (rs57095329 A>G) polymorphisms in System Lupus Erythematosus susceptibility in an Egyptian cohort

OBJECTIVE

Systemic Lupus Erythematosus (SLE) is an autoimmune inflammatory disease. miR-155 and miR-146a were expressed in many autoimmune diseases such as rheumatoid arthritis. The aim of this study was to examine miR-155 rs767649 and miR-146a rs57095329 polymorphisms in SLE susceptibility in an Egyptian cohort and to investigate the correlation between them and clinical data and disease activity.

PATIENTS AND METHODS

The two SNPs were analyzed in 120 patients with SLE and 100 healthy controls using RT-PCR.

RESULTS

The TT genotype and T allele of miR-155 rs767649 were associated with a significant increase in the risk of SLE, particularly in females. On the other hand, miR-146a (rs57095329) polymorphism was not associated with SLE risk. The AT/TT genotypes of miR-155 rs767649 showed higher distributions among patients with higher SLEDAI and nephritis.

CONCLUSIONS

This study had demonstrated for the first time the association between miR-155 rs767649 and the risk of development of SLE in an Egyptian cohort, mostly in females.

Missed Elevated Blood Pressure in Triaged Outpatients: A Preliminary Cross-Sectional Multicentre Study in Northern Nigeria

BACKGROUND

Hypertension is a common medical condition but largely undiagnosed, untreated, poorly controlled, and undertreated in low- and middle-income countries. Studies have reported missed hypertension during triage in Emergency Departments; however, little is known about missed elevated blood pressure (EBP) during triage in primary care settings. This study assessed the prevalence and predictors of missed EBP among triaged patients attending General Outpatient Clinics in Northern Nigeria.

METHODS

This was a descriptive cross-sectional multi-centre study involving 187 adults randomly selected from patients triaged in four General Outpatient Clinics in northern Nigeria. An investigator-administered questionnaire was employed to obtain data regarding participants' socio-demographic, triage blood pressure (BP) measurement, physician-led BP measurement, and physicians' clinical decision characteristics. Chi-square test and logistic regression analysis were used to determine factors associated with and predictors of missed EBP, respectively.

RESULTS

Participants' mean age was 40.6±14.7years. They were predominantly females (122, 65.2%). EBP was missed in 28 (15%) participants at the triage. Participants' age (>40years) (Odds ratio [OR]=3.82, 95% Confidence interval [CI]=1.43-10.22, P=0.008), study site (OR=0.32, 95% CI=0.12-0.82, P=0.018) and perceived receipt of explanation on BP measurement procedure (OR=2.97, 95% CI=1.25-7.07, P=0.014) were predictors of missed EBP among participants.

CONCLUSION

The prevalence of missed EBP was low but remarkable because of its huge public health implications. Age, study site, perceived receipt of explanation on BP measurement procedure predicted missed EBP. Effective interventions are needed to curtail missed EBP in these and similar settings.

Comparison of multimodal analgesia with thoracic epidural after transthoracic oesophagectomy

BACKGROUND

Thoracic epidural analgesia (TEA) has been regarded as the standard of care after oesophagectomy for pain control, but has several side-effects. Multimodal (intrathecal diamorphine, paravertebral and rectus sheath catheters) analgesia (MA) may facilitate postoperative mobilization by reducing hypotensive episodes and the need for vasopressors, but uncertainty exists about whether it provides comparable analgesia. This study aimed to determine whether MA provides comparable analgesia to TEA following transthoracic oesophagectomy.

METHODS

Consecutive patients undergoing oesophagectomy for cancer between January 2015 and December 2018 were grouped according to postoperative analgesia regimen. Propensity score matching (PSM) was used to account for treatment selection bias. Pain scores at rest and on movement, graded from 0 to 10, were used. The incidence of hypotensive episodes and the requirement for vasopressors were evaluated.

RESULTS

The study included 293 patients; 142 (48.5 per cent) received TEA and 151 (51.5 per cent) MA. After PSM, 100 patients remained in each group. Mean pain scores were significantly higher at rest in the MA group (day 1: 1.5 versus 0.8 in the TEA group, P = 0.017; day 2: 1.7 versus 0.9 respectively, P = 0.014; day 3: 1.2 versus 0.6, P = 0.047). Fewer patients receiving MA had a hypotensive episode (25 per cent versus 45 per cent in the TEA group; P = 0.003) and fewer required vasopressors (36 versus 53 per cent respectively; P = 0.016). There was no significant difference in the overall complication rate (71.0 versus 61.0 per cent; P = 0.136).

CONCLUSION

MA is less effective than TEA at controlling pain, but this difference may not be clinically significant. However, fewer patients experienced hypotension or required vasopressor support with MA; this may be beneficial within an enhanced recovery programme.

Effects of dietary supplementation of a probiotic (Bacillus subtilis) on bone mass and meat quality of broiler chickens

The aim of this study was to investigate the effect of a dietary probiotic supplement on bone mass and meat quality of broiler chickens. Two hundred ten 1-day-old male Ross 708 broiler chicks were divided among 21 floor pens (10 chicks per pen). The pens were randomly distributed to 1 of 3 dietary treatments containing a probiotic, Bacillus subtilis, at 0 (control), 0.25 (0.25X), and 0.5 (0.5X) g/kg (n = 7). Gait score, footpad dermatitis (FPD), leg straightness, and hock burn (HB) were examined at day 33, and a latency-to-lie test was performed at day 34. At the end of the experiment (day 35), plasma, right leg, and litter samples were collected for mineral contents, meat quality, bone morphometric parameters, and litter quality assessments. The results indicated that probiotic-fed birds stood much longer during the latency-to-lie test with a greater tibial length, weight, and strength as well as higher plasma levels of calcium and phosphorus compared with the controls. In addition, probiotic-fed birds' leg muscle had higher color lightness at both 30 min and 5 h postmortem and greater water-holding capacity with a trend for less cooking loss (P = 0.056) and lower pH values (P < 0.05) at 5 h postmortem. Probiotic-fed birds' leg meat was tastier (P < 0.05) at 24 h after slaughter. These probiotic effects were greater in the 0.5X group than in the 0.25X group. There were no treatment effects on other measured parameters including gait score, HB, FPD, tibial lateral and medial wall thickness, diaphysis and medullary canal diameters, robusticity and tibiotarsal indexes, plasma magnesium concentrations, and litter moisture and pH values (P > 0.05). These findings indicate that the probiotic supplement could be a useful management tool for improving broiler production and welfare by enhanced bone mass and meat quality.

Effect of synbiotics on thyroid hormones, intestinal histomorphology, and heat shock protein 70 expression in broiler chickens reared under cyclic heat stress

This study examined effect of a dietary synbiotic supplement on the concentrations of plasma thyroid hormones, expressions of heat shock protein 70 (HSP70), and intestinal histomorphology in broiler chickens exposed to cyclic heat stress (HS). Three hundred and sixty day old male Ross 708 broiler chicks were randomly distributed among 3 dietary treatments containing a synbiotic (PoultryStar meUS) at 0 (control), 0.5 (0.5×), and 1.0 (1.0×) g/kg. Each treatment contained 8 replicates of 15 birds each housed in floor pens in a temperature and lighting controlled room. Heat stimulation was established from days 15 to 42 at 32°C for 9 h daily. The results indicated that under the HS condition, both synbiotic fed groups had lower liver and hypothalamus HSP70 levels (P < 0.001) compared to control group; however, HSP70 mRNA expression was not different among treatments (P > 0.05). There were no treatment effects on the levels of triiodothyronine (T3) and thyroxine (T4) as well as T3/T4 ratio (P > 0.05). Compared to controls, 1.0× HS broilers had greater villus height in the duodenum (P < 0.01), and greater villus height and villus height:crypt depth ratios in the ileum (P < 0.01). There were no differences among treatments on the measured intestinal parameters in the jejunum (P > 0.05). The results suggest that the synbiotic may ameliorate the negative effects of HS on chicken health as indicated by the changes in the intestinal architecture and the levels of HSP70. Dietary synbiotic supplement could be a feasible nutritive strategy for the poultry industry to improve the health and welfare of chickens when exposed to hot environmental temperature.

Effect of a synbiotic supplement on cecal microbial ecology, antioxidant status, and immune response of broiler chickens reared under heat stress

The aim of this study was to examine the effect of a dietary synbiotic supplement on the cecal microflora, antioxidant status, and immune response of broiler chickens under heat stress (HS). A total of 360 one-day-old male Ross 708 broiler chicks were randomly distributed among 3 dietary treatments containing a synbiotic (PoultryStar consists of Bifidobacterium animalis, Enterococcus faecium, Lactobacillus reuteri, Pediococcus acidilactici, and fructooligosaccharides) at 0 (control), 0.5 (0.5X), and 1.0 (1.0X) g/kg. Each treatment contained 8 replicates of 15 birds each housed in floor pens. Heat stimulation was at 32°C for 9 h daily from day 15 to 42. Heat stress-induced changes of cecal bacteria were detected using bacteria-specific agars, and spleen protein concentration and mRNA expression of interleukins and antioxidants were examined using ELISA and real-time PCR, respectively. Under the HS condition, synbiotic fed broilers regardless of dose had lower cecal enumerations of Escherichia coli and coliforms, and a lower heterophil/lymphocyte (H/L) ratio (P < 0.05) compared to controls. 1.0X group also had higher cecal enumerations of Bifidobacterium spp. and Lactobacillus spp., spleen glutathione peroxidase (GPx), and plasma nuclear factor erythroid 2-related factor 2 (Nrf-2), and a lower H/L ratio compared to both control and 0.5X groups (P < 0.05). However, there were no treatment effects on the levels of Enterococcus spp., the circulating monocytes, eosinophils, and basophils, Toll like receptor-4 (TLR-4), interleukin-6 (IL-6), interlukin-10 (IL-10), and their mRNA expression, as well as plasma Kelch-like ECH-associated protein 1 (Keap-1) (P > 0.05). These results suggest that the synbiotic could inhibit the negative effects of HS on broiler health through the reduction of cecal pathogens, regulation of stress reactions, and improvement of antioxidant status.

Echinococcus granulosus cyst fluid enhances epithelial-mesenchymal transition

Cystic echinococcosis is characterized by fluid-filled hydatid cysts in the liver and lungs. The cysts are surrounded by a host fibrous layer (the pericyst) which acts to isolate the parasite from surrounding tissues. Previous studies in liver cysts have indicated that the parasite may be a stimulating fibrosis. The aim of this study was to investigate whether hydatid cyst fluid (HCF) could influence the potential for fibrosis to occur in lung tissue by stimulating epithelial to mesenchymal transition (EMT) in a human lung epithelial cell line. An adenocarcinoma-derived alveolar basal epithelial cell line (A549) was used as a model for human alveolar epithelial cells (AEC II). These were cultured in vitro with HCF (UK sheep origin). Assays to investigate cell proliferation, cell migration and expression of cytoskeletal markers showed that HCF could stimulate changes indicative of EMT, including enhanced cell proliferation and migration; increased expression of mesenchymal cytoskeletal markers (fibronectin and vimentin) accompanied by a down-regulation of an epithelial marker (E-cadherin). Molecules within hydatid cyst fluid are capable of inducing phenotypic changes in A549 cells indicating that the parasite has the potential to modify lung epithelial cells which could contribute to fibrotic reactions.

Influence of organic phosphorus on reproductive performance and metabolic profiles of anoestrous Farafra ewes in subtropics at the end of breeding season

The effect of organic phosphorus on metabolic, haematological and hormonal status, restoration of ovarian functions and conception rate in anoestrous Farafra ewes in subtropics were evaluated. Anoestrous Farafra ewes (n = 24; 34.72 ± 0.52 kg body weight) were allocated into two equal groups: control and phosphorus groups. The ewes of phosphorus group were treated with sodium 4-dimethylamino-2-methyl-phenyl-phosphonate as an organic bound phosphorous twice a week for successive 3 weeks. Ovarian follicle development and corpora lutea were checked three times a week till occurrence of oestrus using ultrasonography while pregnancy was confirmed at 30 days post-service. Plasma metabolites, reproductive hormones, thyroid hormones and minerals were detected at weeks -2, -1, 0 (mating day) and + 4 weeks post-oestrus. Phosphorus group had significantly (p < .05) short interval to oestrous resumption if compared to control ewes (2.1 ± 0.8 weeks vs. 4.6 ± 1.1 weeks). In addition, phosphorous supplementation significantly (p < .05) increased the number of antral follicles (developed and their sizes in addition to sizes of corpora lutea (8.72 ± 0.3 mm vs. 7.46 ± 0.9 mm) as well. Number of services per conception (2.6 vs. 1.4; p < .01) was higher in control group than that of phosphorus group. Pregnancy rate (80 vs. 50%) was significantly (p < .01) higher in phosphorus group when compared to control. White blood cells in treated ewes (10.8 ± 0.44; p < .05) and monocytes (2.93 ± 0.13; p < .01) were higher than that of control group (white blood cells; 9.53 ± 0.50 and monocytes; 2.24 ± 0.14). Metabolic parameters did not differ between phosphorus and control groups during different times of treatment. It could be concluded that phosphorous administration to anoestrous Farafra ewes in subtropics could improve reproductive performance and restore ovarian activity at the end of spring and early summer.

Effects of feeding green microalgae on ovarian activity, reproductive hormones and metabolic parameters of Boer goats in arid subtropics

The present study aimed to improve ovarian follicle development and plasma metabolites and hormone concentrations upon supplementation of Boer goats with green microalga (Dunaliella salina; 10 g/head/day) (N = 20; MAT group) compared to control (N = 10; not receive microalgae) in subtropics. Estrus was synchronized in all animals by two intramuscular administration of 12.5 mg dinoprost 11 days a part. MAT group was supplemented with Dunaliella salina for 11 days (from the day of first injection of dinoprost till the second injection). Ovarian performance, steroids, LH, FSH and blood metabolites were assessed every three days during the estrous cycle. Numbers and sizes of ovarian follicles and corpora lutea were significantly (P < 0.05) increased in MAT group. Progesterone, estrogen, FSH and LH were higher in MAT group during estrous cycle. Blood metabolites including glucose, total cholesterol and blood urea nitrogen were significantly (P < 0.05) increased upon D. salina administration. On the other hand, supplementation of D. salina resulted in significant decrease of plasma total protein, albumin, aspartate aminotransferase and alanine aminotransferase. In conclusion, supplementation with D. salina could improve ovarian follicle development and concentrations of plasma metabolites and hormones which subsequently improves reproductive performance of Boer goats.

Histopathological confirmation of disseminated larvae (iL3) of Strongyloides ratti in an immunosuppressed Wistar rat

Human strongyloidiasis research requires a large supply of Strongyloides stercoralis. This can be achieved through in vivo maintenance of Strongyloides stercoralis in Meriones unguiculatus, but isolating a large quantity of Strongyloides stercoralis to establish the colony from an infected patient is too difficult to achieve. Hence, Strongyloides ratti have been used as a model in human strongyloidiasis research. This study describes a successful establishment and maintenance of Strongyloides ratti infection in experimentally immunosuppressed Wistar rats. Large quantities of filariform (iL3) larvae of Strongyloides ratti for research related to human strongyloidiasis have been harvested following this protocol. Molecular detection method based on PCR using species specific primers was used to confirm the species of the harvested infective larvae (iL3). Additionally, the identification of histopathological lesions confirmed the presence of infective larvae (iL3) in the liver and lungs as a result of an increased parasite burden due to hyperinfection and disseminated disease. This pathological presentation was found to be similar to that reported in Strongyloides stercoralis-infected immunocompromised human subjects.

Genetic Characterization of Vibrio cholerae O1 isolates from outbreaks between 2011 and 2015 in Tanzania

Background

Cholera outbreaks have occurred in Tanzania since 1974. To date, the genetic epidemiology of these outbreaks has not been assessed.

Methods

96 Vibrio cholerae O1 isolates from five regions were characterized, and their genetic relatedness assessed using multi-locus variable-number tandem-repeat analysis (MLVA) and whole genome sequencing (WGS).

Results

Of the 48 MLVA genotypes observed, 3 were genetically unrelated to any others, while the remaining 45 genotypes separated into three MLVA clonal complexes (CCs) - each comprised of genotypes differing by a single allelic change. In Kigoma, two separate outbreaks, 4 months apart (January and May, 2015), were each caused by genetically distinct strains by MLVA and WGS. Remarkably, one MLVA CC contained isolates from both the May outbreak and ones from the 2011/2012 outbreak in Dar-es-Salaam. However, WGS revealed the isolates from the two outbreaks to be distinct clades. The outbreak that started in August 2015 in Dar-es-Salaam and spread to Morogoro, Singida and Mara was comprised of a single MLVA CC and WGS clade. Isolates from within an outbreak were closely related differing at fewer than 5 nucleotides. All isolates were part of the 3^rd wave of the 7^th pandemic and were found in four clades related to isolates from Kenya and Asia.

Conclusions

We conclude that genetically related V. cholerae cluster in outbreaks, and distinct strains circulate simultaneously.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-017-2252-9) contains supplementary material, which is available to authorized users.

Update knowledge of dry mouth- A guideline for dentists

BACKGROUND

Dry mouth is usually caused by a reduced salivary flow or by changes in the biochemical composition of saliva.

OBJECTIVE

The aim of this paper is a review of the update literature of dry mouth.

METHODS

We search in pubmed in the past 10 years using the words «dry mouth», «causes», «symptoms», «treatment» and «dentistry». A large number of papers have been identified. Papers not relevant to the issue were removed reducing the entries to 56 only.

RESULTS

There are no clearly established protocols for the treatment of dry mouth in the literature. Most of identified papers were systematic reviews, non-systematic reviews, and observational studies. The most studied patients were Sjögren's syndrome and the irradiated patients. Treatments are focused on the etiology, prevention, symptomatic, local salivary stimulation and systemic treatments.

CONCLUSION

It can be concluded that there is no clear evidence for the causes and treatment of dry mouth, therefore the majority of the general dental practitioners refer most of the cases to appropriate specialist. Treatment must be individualized, salivary substitutes and mechanical stimulation techniques can be applied.

Spectrum of haematologic malignancies and survival outcomes of adult lymphomas in Maiduguri, north eastern Nigeria--a fourteen year review

BACKGROUND

The incidence of Haematologic malignancies has been shown to vary according to gender, age, geographic region, and histologic subtypes, while cure rates can vary according to region and may be impacted by treatment availability and access to care.

METHOD

This was an institution based review of data from the Medical Records Department, Department of Haematology and Cancer Registry of the Histopathology Department of the University of Maiduguri Teaching Hospital between January 1998 and December 2011. The aim was to study the spectrum of Haematologic malignancies and the survival pattern of adult lymphomas in this region and to compare our findings to studies reported elsewhere.

RESULTS

The Haematologic malignancies represented 6.05% of all cancer cases seen and 0.31% of hospital admissions. Among the Haematologic malignancies, Non-Hodgkins Lymphoma (NHL) was the most frequent, constituting 51.3% while others include: Hodgkins Lymphoma (HL), 26.7% Chronic Myeloid Leukaemia (CML), 5.5%, Acute Myeloblastic leukaemia (AML), 4.2% Multiple Myeloma (MM), 4.2% Acute Lymphoblastic leukaemia (ALL), 3.8%, Chronic Lymphocytic Leukaemia (CLL), 3.4% Myelodysplastic Syndrome (MDS), 0.4% and Chronic Myelofibrosis 0.4%. Haematologic malignancies are more common in younger age group and also more common in males than females. Lymphomas are particularly common in young adults and the incidence tends to fall after 70 years. Similarly, the characteristic bimodal age incidence for HL found in western world has not been seen in this study. The histological subtypes for both NHL and HL are similar to the pattern reported elsewhere. Default rate was high and we found a strong association between cycles of chemotherapy given and survival in lymphoma patients.

CONCLUSION

This study has shown that Haematologic malignancies are not uncommon in our environment. There is need to provide basic facilities and training for immunophenotyping and immunohistochemistry in all cancer treatment centers across the country. Cytotoxic drugs must be subsidized and also be made readily available to all patients with Haematologic malignancies.

Case report: Biphasic presentation of multicystic haemorrhagic metastatic adenocarconoma of the lung

Lung cancer is the one of the leading causes of death worldwide. Adenocarcinoma of the lung makes up over a quarter of all incidence of lung cancer. Multiple case reports describe haemorrhage resulting from primary or metastatic lesions affecting different organs. This case report describes an unusual presentation of a benign lung lesion that later progressed to multiple metastases with a characteristic radiological appearance. A review of prior similar reported cases is also included.

Residency training program: perceptions of residents

BACKGROUND

There is a phobia among doctors for the residency training program, since the establishment of the program over 30 years ago. The reason for establishing the program was mainly to provide the much-needed specialists in medicine.

OBJECTIVES

To ascertain the perception of the residency training program among residents.

MATERIALS AND METHODS

Structured questionnaires were administered to residents at 3 training institutions in Nigeria.

RESULTS

One hundred nineteen (85.5%) questionnaires were returned out of 140. The ages of respondents ranged from 27 to 42 years, the median age being 30 years. There were 110 males and 9 females. One hundred six (89.1%) were junior residents. Ninety (75.6%) were sponsored by the training institutions. Seventy-four (62.25%) felt their consultants were contributing just 50% or less to their training. Sixty-two (52.2%) of the respondents had attended a revision course, conference or seminar within the last 6 months. Majority of the residents would want better remuneration, up-front payment of examination and revision fees, more teaching by the consultants and less emphasis on the provision of services as ways of improving the program.

CONCLUSION

Majority of the residents are sponsored by the training institutions.

Force-frequency relation in frog-ventricle is dependent on the direction of sodium/calcium exchange in diastole

AIM

Force of contraction increases with stimulus-frequency in mammalian and amphibian hearts under control conditions. Here, we have analysed the mechanism of the force-frequency relation (FFR) in frog-ventricle.

METHODS

Circular strips of frog-ventricle were subjected to field-stimulation with frequencies in the range 0.03-0.2 Hz and force recorded on a chart-recorder. In another protocol, varying rest-periods were imposed while the preparation beat steadily at 0.2 Hz and the effect of rest on post-rest beat amplitude was noted.

RESULTS

Under control conditions, a positive FFR and a rest-induced decay of contraction amplitude (RID) were seen in the frequency range 0.03-0.2 Hz. With cadmium, nifedipine, nickel (40 micromol L(-1)), ryanodine and adrenaline (all drugs at 10 micromol L(-1) concentration, except nickel), the positive FFR and RID seen under control conditions persisted. When the bathing solution contained ouabain (10 micromol L(-1)) or low external sodium (40 mmol L(-1)), or high external calcium (5 mmol L(-1)), the FFR turned negative in the frequency range stated above and there were rest-induced potentiations (RIP).

CONCLUSION

When the conditions favour a net leak of calcium in diastole from intracellular stores via the calcium-extrusive mode of sodium-calcium exchanger (NCX), FFR is positive. An increase in frequency lessens the diastolic interval and therefore the diastolic calcium leak, thereby augmenting force. On the other hand, interventions which favour the calcium-acquisitive mode of NCX during diastole, changed the pattern of RID to RIP and converted FFR from positive to negative. With net diastolic calcium uptake, there is better store-filling and therefore higher force at lower frequencies.

STR data for the GenePrint PowerPlex 1.2 system loci from three United Arab Emirates populations

Allele frequencies for the eight STRs included in the GenePrint PowerPlex 1.2 kit were obtained from three population groups that are resident in the United Arab Emirates (UAE); 228 unrelated UAE individuals, 194 unrelated Indian individuals and 197 unrelated Pakistani individuals were analysed.

STR population data for 10 STR loci including the GenePrint PowerPlex 1.2 kit from El-Minia (Central Egypt)

Allele frequencies for 10 STRs including the GenePrint PowerPlex 1.2 loci and also D3S1358, HumvWA and HumFGA were obtained from a sample of unrelated individuals from El-Minia City.

Concordant expression of Hirschsprung's disease in monozygous twins

A monozygous pair of twins with long segment Hirschsprung's disease born to non consanguineous parents is presented. Mother's history was uneventful. In the absence of prenatal and postnatal illness, the concordant lesions in this pair could be attributed to genetic factors.

Factors affecting the outcome of foetal hydrocephaly

In this study, the authors attempt to provide an account of the factors that affect the outcome of hydrocephaly in 26 foetuses. The hydrocephalus was related to a myelomeningocele in 35% of patients. Sixty-two percent of foetuses showed intra-uterine progression of their hydrocephalus and 50% were shunted postnatally. At a mean follow up of 2 years, the outcome was considered "fair" in 54% of patients. Our findings demonstrate that in foetal hydrocephaly a more favourable outcome is expected in patients with hydrocephalus which does not progress in utero, in whom the labour is not induced before 36 weeks of gestation, who are delivered vaginally weighing more than 2.5 kg and have a head circumference below the 95th centile and a CT cortical mantle thickness of 2 cm and more and who are treated by CSF shunting. The diagnosis of the foetal hydrocephaly at or before 28 weeks of gestation and the presence of a myelomeningocele did not affect the outcome significantly. Neurosurgeons are reminded to keep an open mind for infants with foetal hydrocephaly and to offer active treatment to patients with a potentially favourable outcome.

Multiloculated hydrocephalus related to cerebrospinal fluid shunt infection

This study is an attempt to establish that CSF shunt infection has a role in the aetiology of multiloculated hydrocephalus. The authors carried out a review of 12 cases of multiloculated hydrocephalus who were treated at King Khalid University Hospital between 1988-1994. The multiloculation appears to have developed following the shunt infection in all cases. The hydrocephalus was related to an intraventricular haemorrhage (IVH) in 9 patients and was congenital in 2 patients and post-meningitic in 1 patient. The shunt infection was caused by a gram-negative organism in 8 patients and duration of external ventricular drainage ranged from 9-24 (median 13) days. The diagnosis of multiloculated hydrocephalus was made on average 2 months after the shunt infection. In three patients endoscopic fenestration of intraventricular septations was attempted but was effective in only one case. The other patients were managed by two shunts (9 patients) and three shunts (2 patients). At a mean follow-up of 15 months, the shunt revision rate of the patients was 0.4/year. One patient died of multiple brain abscesses and 6 patients remain severely disabled. The poor outcome may also be related to the original IVH as well as the multiloculated hydrocephalus. The study also shows that patients with post-haemorrhagic hydrocephalus, who develop a shunt infection due to gram-negative organisms and in whom the CSF fails to be cleared of the infection following 12 days of external drainage appear to be at risk of developing multiloculated hydrocephalus.

Susceptibility of Brugia malayi and Onchocerca lienalis microfilariae to nitric oxide and hydrogen peroxide in cell-free culture and from IFN gamma-activated macrophages

The susceptibility of Brugia malayi and Onchocerca lienalis microfilariae to H2O2 and NO either in cell-free culture or from IFN gamma-activated macrophages was examined. In cell-free culture, O. lienalis microfilariae were highly susceptible to H2O2 induced toxicity, exhibiting rapid reductions in motility and viability. The addition of exogenous catalase abrogated H2O2-induced killing. In contrast, B. malayi microfilariae were relatively resistant to H2O2, with concentrations as high as 50 microM having no effect on motility or viability. On exposure to NO, both species showed reductions in motility within 5-30 min, but longer was required to see effects on the viability of microfilariae. Parasites incubated with IFN gamma-activated macrophages also exhibited marked reductions in motility and viability. In cultures with B. malayi and activated macrophages, inhibition of these effects was achieved by the addition of either L-NMMA, to abolish NO production, or neutralizing anti-TNF alpha antibodies. Attempts to inhibit parasite killing by the addition of catalase to macrophage cultures were ineffective. The results of this study show that B. malayi and O. lienalis microfilariae have different susceptibility to H2O2, but are equally affected by exposure to NO. Moreover both species are killed by IFN gamma-activated macrophages and in the case of B. malayi, killing is dependent on the generation of NO via TNF alpha.

Laparoscopic cholecystectomy: Initial experience at Riyadh Central Hospital

This paper presents our experience with laparoscopic cholecystectomy during the initial three months since its introduction at Riyadh Central Hospital. One hundred and sixty patients were admitted with gallstone disease. The majority were females (74%) and Saudis (56%). Seventy-six patients (47.5%) were admitted through the emergency department with acute cholecystitis, mucocele of the gallbladder, biliary pancreatitis, biliary colicm or obstructive jaundice. One hundred twenty-seven patients (69.4%) were submitted to laparoscopic cholecystectomy, which was successfully performed on 120 patients (94.5%). Laparoscopic cholecystectomy was converted to open cholecystectomy in seven patients (5.5%). Thirty-three patients (20.6%) were directly submitted to open cholecystectomy for various contraindications to laparoscopic cholecystectomy. Overall, 75% of patients with gallstone disease were treated by laparoscopic cholecystectomy. There was only one major complication (duodenal perforation) of laparoscopic cholecystectomy and no mortality in the series. The average operating time for laparoscopic cholecystectomy and no mortality in the series. The average operating time for laparoscopic cholecystectomy was 175 minutes. The average hospital stay was 3.6 days and 8.9 days following laparoscopic cholecystectomy and open cholecystectomy, respectively.