Prevention of beta-thalassemia in a large Pakistani family through cascade testing

BACKGROUND

We report cascade testing of a large Pakistani family for beta-thalassemia alleles. The family was still practicing consanguineous marriages and was at risk of having more affected births.

OBJECTIVE

The objective of this study was to show that identification of disease carriers in families with index cases in order to create awareness about disease and provide genetic counseling would result in reduction of the frequency of beta-thalassemia in Pakistan.

METHODS

In this large family with an index case, 27 available living members were tested for beta-thalassemia. Carriers of the disease were detected by measuring hemoglobin indices, and amplification refractory mutation system polymerase chain reaction was used for mutation analysis. Genetic counseling was provided to members of this family.

RESULTS

There were already 3 marriages between the carrier members and 1 between a carrier and noncarrier in this large family; 12 (44.4%) members were found to carry the mutant gene, representing a very high carrier rate compared to the 5.4% carrier frequency of beta-thalassemia in the general population of Pakistan. The family was counseled for prevention of affected births. The initially reluctant family gradually became cooperative and seriously attended the genetic counseling sessions.

CONCLUSION

Cascade testing is more practical than general population screening in a country with limited health facilities where consanguineous marriages are practiced. This report emphasizes the need of extensive testing within families with index cases to identify the carriers of beta-thalassemia in order to reduce disease occurrence through awareness and genetic counseling.

A practical profile of integrated safety assessment of near-surface disposal of radwaste at PINSTECH

Near-surface or shallow land disposal of radioactive waste has been the primary practice at the Pakistan Institute of Nuclear Science and Technology (PINSTECH). The adopted choice of this mode of disposal has been based on a study of the site and the quality and quantity of waste generated at the 5 MW reactor with HEU fuel. Specific measures regarding the radiation safety of the workers and environmental protection have been adopted. The waste disposal operations are conducted to meet local regulatory requirements, IAEA recommendations and internationally endorsed principles such as ALARA (as low as reasonably achievable - economic, social and other relevant factors being considered). The data obtained through the years of operational and management experience have manifested the robustness of the disposal system and reliability of the disposal criterion, and have also served to further refine the latter. Consequently, confidence in the current shallow-land-burial practices has increased. Radiological safety of these practices has been assessed by addressing different aspects of the safety and disposal system. These parameters, as indices of a non-exclusive and operational safety model, are presented.

Synthesis of Amine-stabilized Aqueous Colloidal Iron Oxide Nanoparticles

We demonstrate a simple one-step process for the synthesis of iron oxide nanoparticle aqueous colloids using the multifunctional molecule, dodecylamine (DDA), that electrostatically complexes with aqueous iron ions (one precursor Fe(2+) from FeCl(2)), reduces them, and subsequently caps the nanoparticles. The iron oxide particles thus synthesized are of the face-centered cubic (FCC) phase with high degree of monodispersity with appropriate concentration of amine capping molecular layer. The aqueous magnetic nanocrystalline colloids were characterized by TEM, XRD, XPS, TGA/DTA and FTIR spectroscopy techniques. The relaxivity, stability, and hydrodynamic size of the nanoparticles were investigated for potential application in magnetic resonance imaging (MRI). The magnetic properties were also studied by using a superconducting quantum interference device (SQUID) magnetometer at room temperature. We believe that such simple one-step synthesis of biocompatible aqueous nanomagnetic colloids will have viable applications in biomedical imaging, diagnostics and therapeutics.

Peripheral arterial revascularization causing parallel increased activity of pro- and anti-inflammatory mediators

AIM

The aim of this study was to investigate the interaction between the proinflammatory mediator interleukin (IL)-6 and anti-inflammatory mediator IL-10 in ischemia reperfusion injury following peripheral arterial revascularization.

METHODS

Three groups of patients were recruited (group 1: femoral angiography alone [n=14]; group 2: radiologically successful ilio/femoral angioplasty [n=10]; and group 3: peripheral surgical bypass [n=11]). Peripheral venous blood obtained for all patients at pre-procedure and at 1 h and 24 h post-procedure. After centrifugation supernatant plasma was separated and analysed for proinflammatory cytokine IL-6 and anti-inflammatory cytokine IL-10 using enzyme linked immunosorbent assay (ELISA) technique.

RESULTS

Levels of IL-6 at 1 and 24 h were significantly higher in group 3 (P<0.05 and P<0.01, respectively) and at 24 h in group 2 as compared to group 1 (P<0.05). Levels of IL-10 were significantly higher in group 3 at 24 h (P<0.05). In group 2 levels of IL-10 higher than group 1, but this did not reach statistical significance (P=0.07).

CONCLUSIONS

Raised levels of IL-6 at 1 and 24 h in patients undergoing operative peripheral bypass suggest early and persistent proinflammatory activity, similarly patients with successful angioplasty also demonstrated similar persistent proinflammatory activity of IL-6 at 24 h. Raised levels of IL-10 at 24 h represents anti-inflammatory properties of IL-10 counter acting inflammatory response.

Extracellular ATP induces assembly and activation of the myosin light chain phosphatase complex in endothelial cells

OBJECTIVES

Extracellular ATP stabilizes the endothelial barrier and inactivates the contractile machinery of endothelial cells. This inactivation relies on dephosphorylation of the regulatory myosin light chain (MLC) due to an activation of the MLC phosphatase (MLCP). To date, activation and function of MLCP in endothelial cells are only partially understood.

METHODS

Here, the mechanism of extracellular ATP-mediated activation of MLCP was analyzed in human endothelial cells from umbilical veins. Cells were transfected with the endogenous protein phosphatase 1 (PP1)-specific inhibitor-2 (I-2).

RESULTS

Overexpression of I-2 led to inhibition of PP1 activity and abrogation of the ATP-induced dephosphorylation of MLC. This indicates that the PP1 catalytic subunit is the principal phosphatase catalyzing the MLC dephosphorylation induced by extracellular ATP. As demonstrated by immunoprecipitation analysis, extracellular ATP recruits the PP1delta catalytic subunit and the myosin phosphatase targeting subunit (MYPT1) to form a complex. ATP stimulated dephosphorylation of MYPT1 at the inhibitory phosphorylation sites threonine 850 and 696. However, extracellular ATP failed to stimulate MYPT1 dephosphorylation in I-2-overexpressing cells.

CONCLUSIONS

The present study shows for the first time that, in endothelial cells, extracellular ATP causes activation of MLCP through recruitment of PP1delta and MYPT1 into a MLCP holoenzyme complex and PP1-mediated reduction of the inhibitory phosphorylation of MYPT1.

Pre-operative Radial Arterial Diameter Predicts Early Failure of Arteriovenous Fistula (AVF) for Haemodialysis

INTRODUCTION

Long term patency of arteriovenous fistula (AVF) is relevant to the management of end stage renal failure (ESRF) patients on haemodialysis (HD). We evaluated the role of routine radial arterial duplex for imaging radial artery before AVF formation to investigate the relationaship between radial artery internal diameter (ID) and AVF patency.

METHODS

21 patients with ESRF were examined by duplex sonography before AVF formation, 1 day, 1 week, 4 week and 12 weeks post AVF formation. For assessment of AVF patency, patients were divided into 2 groups. Group-1, 11 patients with radial artery ID <1.5mm and Group-2, 10 patients with radial artery ID >1.5mm. Measurement of radial artery blood inflow rate was calculated from mean blood flow velocity and vessel diameter. All AVFs were constructed on the forearm using autologous veins.

RESULTS

In Group-1, 5 patients (45%) showed immediate thrombosis of AVF graft. All patients in group-2 had patent AVF at 12 weeks. Pre-AVF formation radial artery blood inflow rate between two groups was not significantly different (p=0.06). Radial artery blood inflow rate was consistently and significantly higher in group-2 at all later time points with p value of <0.01 (Mann Whitney test).

CONCLUSION

There was a high failure rate of AVF with radial artery ID of <1.5mm. In the presence of small radial arteries primary access AVF in the upper arm should be considered.

Silica encapsulation and magnetic properties of FePt nanoparticles

Core-shell nanoparticles have emerged as an important class of functional nanostructures with potential applications in many diverse fields, especially in health sciences. We have used a modified aqueous sol-gel route for the synthesis of size-selective FePt@SiO2 core-shell nanoparticles. In this approach, oleic acid and olyel amine stabilized FePt nanoparticles are first encapsulated through an aminopropoxysilane (APS) monolayer and then subsequent condensation of triethoxysilane (TEOS) on FePt particle surface. These well-defined FePt@SiO2 core-shell nanoparticles with narrow size distribution become colloidal in aqueous media, and can thus be used as carrier fluid for biomolecular complexes. In comparison, the scarce hydrophilic nature of oleic acid monolayers on FePt particle surface yields an edgy partial coating of silica when only TEOS is applied for the surface modification. The synthesized core-shell nanoparticles were characterized by direct techniques of high resolution transmission electron microscopy (HRTEM), EDS and indirectly via UV-vis absorption and FTIR studies. The FePt@SiO2 nanoparticles exhibit essential characteristics of superparamagnetic behavior, as investigated by SQUID magnetometry. The blocking temperatures (T(B)) of FePt and FePt@SiO2 (135 and 80 K) were studied using zero field cooled (ZFC)/field cooled (FC) curves.

Unilateral multicystic dysplastic kidney: long term outcomes

AIMS

To report the long term follow up of children with antenatally detected unilateral multicystic dysplastic kidney (MCDK) with documentation of complications, involution rate with time, and renal function at 10 years.

METHODS

Data were retrieved from a prospective regional registry of patients with MCDK between 1985 and 2004. Children were followed using a common protocol of investigation with follow up ultrasound scans (USS) at 2 (165 patients), 5 (117 patients), and 10 years (43 patients).

RESULTS

Serial USS showed that 33% of the MCDK kidneys had completely involuted at 2 years of age, 47% at 5 years, and 59% at 10 years. No patients developed hypertension, significant proteinuria, or malignancy, but two developed pelviureteric junction obstruction in the contralateral kidney. Twenty seven of 143 children (19%) had vesicoureteric reflux (VUR) (96% mild to moderate VUR) into the contralateral kidney with no difference in the incidence of urinary tract infections or renal scarring between those with or without VUR. The mean estimated glomerular filtration rate (GFR) was 86.4 ml/min/1.73 m2 (range 48-125) in 31 of 43 patients followed to 10 years.

CONCLUSIONS

Conservative management of unilateral MCDK is justified with clinical review and infrequent USS but longer term follow up continues in the 41% still with renal remnants at 10 years and those with impaired GFR. It is suggested that the initial micturating cystogram is deferred unless abnormal USS features are present in the contralateral kidney or ureter.

Effect of pesticide residues on health and different enzyme levels in the blood of farm workers from Gadap (rural area) Karachi-Pakistan

Persons from 14 different fruit and vegetable farm stations from Gadap (rural area), Karachi-Pakistan were examined for the presence of pesticide (cypermethrin, deltamethrin, polytrin-C, diazinon, monocrotophos, DDT and DDE) residues in their blood samples. The present study is concerned with effects of residue on the enzyme levels (GPT, GOT and ALP) as well as the health hazards of pesticide exposed persons. There is a significant increased in the enzyme levels at different stations. Exposed persons complained about liver and kidney dysfunctions and RTI. It may be concluded that exposure of multiple pesticides for prolonged period has affected the normal functioning of different organ systems and possibly produced characteristics clinical effects such as hepatitis, dyspnea and burning sensation in urine.

Calf muscle pump failure in lower limb lymphoedema

Abnormal venous haemodynamics and poor calf muscle pump may play a role in lymphoedema by contributing to production of excess interstitial fluid. Using photoplethysmography (PPG), we compared haemodynamic characteristics between normal and lymphoedematous lower limbs. PPG was performed using an automated infrared-based system, while the patient performed 10 active dorsiflexions of the ankle. This gave values for venous refilling time and venous pump power. A total of 62 limbs (normal = 37; lymphoedematous = 25) were studied. Lymphoedematous limbs showed significantly decreased venous pump power and venous refilling time (s) than normal limbs (24.6±14.1 versus 45.4±16 and 23±15.2 versus >45, respectively; P<0.005 for all the results). The haemodynamic values measured in the normal group showed good consistency and reproducibility. These results were consistent with the previous literature and demonstrate an impaired venous system associated with the development of lymphoedema. Poor muscle pump power may reflect physical disability of the ankle joint to perform dorsiflexion. This factor should be considered when treating this incurable condition.

Stroke-associated pneumonia: microbiological data and outcome

INTRODUCTION

Pneumonia is a common complication after acute stroke. It affects the outcome adversely. However, data regarding microbiology of stroke-associated pneumonia and its effect on outcome is scarce.

METHODS

Stroke-associated pneumonia was identified through chart review of all ICD-9 identified adult stroke patients admitted to our hospital over a period of four years (1998-2001). The demographical, laboratory, radiological, microbiological data and outcome of patients with stroke-associated pneumonia were recorded and analysed.

RESULTS

443 patients with stroke were admitted over the four-year period and 102 (23 percent) had stroke-associated pneumonia. Their ages range from 28 to 100 (mean 64+/-14) years. 69 (68 percent) were men. Median length of stay was nine days compared to four days for all stroke patients. 68 (67 percent) patients manifested pneumonia within 48 hours and 34 (33 percent) after 48 hours of admission. Yield of tracheal aspirate cultures was 38 percent and that of chest radiographs was 25 percent. Pseudomonas aeruginosa and Staphylococcus aureus were the most common organisms (12 percent each) followed by Streptococcus pneumoniae and Klebsiella pneumoniae (4 percent each). Patients with infiltrates on chest radiographs were more likely to have positive tracheal aspirate cultures (p-value is 0.003). 35 patients (34 percent) expired during hospital stay. Positive chest radiographs and tracheal aspirates were independent predictors of prolonged hospital stay (p-value is less than 0.005).

CONCLUSION

Pneumonia is a common medical complication of stroke. It is associated with a high mortality and prolongs the hospital stay. The yield of chest radiographs and tracheal aspirates is low. However, these are independent predictors of prolonged hospital stay. Pseudomonas aeruginosa and Staphylococcus aureus are most common organisms in stroke-associated pneumonia.

Gastroprotective effect of cardamom, Elettaria cardamomum Maton. fruits in rats

Cardamom, the fruits of Elettaria cardamomum Maton. (Zingiberaceae) commonly known as "Heel khurd" is used in Unani system of medicine to treat gastrointestinal disorders. A crude methanolic extract (TM), essential oil (EO), petroleum ether soluble (PS) and insoluble (PI) fractions of methanolic extract, were studied in rats at doses of 100-500, 12.5-50, 12.5-150 and 450 mg/kg, respectively for their ability to inhibit the gastric lesions induced by aspirin, ethanol and pylorous ligature. In addition their effects on wall mucus and gastric acid output were recorded. All fractions (TM, EO, PS, PI) significantly inhibited gastric lesions induced by ethanol and aspirin but not those induced by pylorus ligation. TM proved to be active reducing lesions by about 70% in the EtOH-induced ulcer model at 500 mg/kg. The PS fraction reduced the lesions by 50% at 50 and 100mg/kg (no dose response was observed) with similar effect than the PI fraction at 450 mg/kg. In the aspirin-induced gastric ulcer, the best gastroprotective effect was found in the PS fraction, which inhibited lesions by nearly 100% at 12.5mg/kg. In our experimental conditions, the PS extract at doses >or=12.5mg/kg proved to be more active than ranitidine at 50mg/kg.

Radiation protection aspects of shallow land disposal of low and intermediate level liquid and solid radioactive waste at PINSTECH

Operation of Pakistan Research Reactors 1 and 2, radioisotope production plants, and allied laboratories at the Pakistan Institute of Nuclear Science & Technology (PINSTECH) generates radioactive waste effluents of low and intermediate level. These waste materials are managed in a way to keep the human health and the environment free of radiation associated hazards. The prime practice has been of shallow ground or near-surface disposal type. Different measures and operational procedures at the institute, in step with the international norms for the management of low and intermediate level waste, have been adopted. To ensure the safe disposal practices and radiation safety of the workers and of the general public, radiological safety related routines are practiced with due concern. Some safety aspects of the prevailing practices are discussed in this presentation.

Ochratoxin A blood concentration in healthy subjects and bladder cancer cases from Pakistan

ASTRACT: The mycotoxin ochratoxin A (OTA) is a public health issue in many countries. Data on OTA concentrations in foods and in blood are available for several European countries including the Balkan area, as well as for Canada and Japan. Yet, for developing countries such data are scarce. In this study we determined OTA blood levels as biomarker of exposure in bladder cancer patients and in healthy controls from Pakistan. OTA in blood was analyzed after extraction by HPLC with fluorescence detection (limit of detection: <0.03 ng/mL) in 96 patients and in 31 controls. Over 92% of all blood samples (87 patients, 30 controls) contained quantifiable amounts of OTA: The mean OTA concentrations were 0.33 ng/mL (SD 0.42; range: 0.03 to 3.41 ng/mL) in bladder cancer patients, and 0.31 ng/mL (SD 0.29; range: 0.04 to 1.25 ng/mL) in healthy controls. These OTA concentrations are comparable to those reported for the general population in the European Union.

Failure of conservative management after the passage of a distal colonic "cast": report of a case

PURPOSE

The spontaneous passage per rectum of a full-thickness colon "cast" is a rare consequence of acute colonic ischemia. Previous cases have undergone surgery soon afterward because of intractable symptoms. We report a patient who was managed conservatively for 11 months but ultimately required definitive surgery.

METHODS

The clinical, radiographic, pathologic, and endoscopic findings were obtained from the case notes and compared with previously reported cases.

RESULTS

A 67-year-old obese patient underwent a Hartmann's procedure for a perforated diverticular abscess, which was reversed six months later. On the first postoperative night after the reversal, she had a brief hypotensive episode, and three weeks later passed a 21-cm, full-thickness infarcted piece of colon. She did not develop peritonitis and for 11 months experienced only mild symptoms. Under colonoscopic surveillance, the granulation tissue conduit connecting the remaining viable bowel became increasingly stenosed proximally and difficult to dilate. After three rapidly consecutive episodes of large-bowel obstruction, she required a laparotomy to resect the stricture and restore bowel continuity. From a literature review, this is the eighth case of its kind and the first in which such prolonged conservative management has been possible.

CONCLUSIONS

When symptoms permit, it is feasible to manage patients conservatively in the short-term after this unusual event to allow recovery from the initial insult and planning of future surgery. However, definitive treatment is surgical and colonoscopic management should not delay this once the patient is fit for surgery.

Genetic diversity of Escherichia coli recovered from the oral cavity of beef cattle and their relatedness to faecal E. coli

AIMS

To determine the genetic diversity of generic Escherichia coli recovered from the oral cavities of beef cattle and their relatedness to E. coli isolated from the faeces of cattle during pasture grazing and feedlot finishing.

METHODS AND RESULTS

A total of 484 E. coli (248 oral and 236 faecal isolates) were obtained from eight beef cattle after 1 and 5 months of grazing on pasture and after 1 and 5 months in a feedlot. The random amplification of polymorphic DNA (RAPD) method was used to genetically characterize these isolates. The RAPD patterns showed that ca 60% of E. coli recovered from the oral cavities and faeces during pasture and feedlot shared a close genetic relatedness. A number of E. coli with unique RAPD types were also found either in the oral cavities or faeces. Most of the E. coli RAPD types recovered from the oral cavities were shared among animals, but there were also RAPD types which were unique to individual animals. The E. coli populations of the oral cavities were genetically diverse and changed over time.

CONCLUSIONS

This study indicates that there are large numbers of E. coli carried in the oral cavities of beef cattle and those E. coli are closely related to strains found in the faeces. The oral cavities of cattle harbour a genetically diverse E. coli population.

SIGNIFICANCE AND IMPACT OF THE STUDY

The oral cavity may be an important reservoir of enteric pathogens which may transfer to meat during carcass dressing. A better understanding of the molecular ecology of E. coli in cattle would assist the design of approaches to control pathogenic strains during beef production and processing.