Geochemical and mineralogical characteristics of shales from the early to middle Permian Dohol Formation in Peninsular Malaysia: Implications for organic matter enrichment, provenance, tectonic setting, palaeoweathering and paleoclimate

The early to middle Permian Dohol Formation is characterized by a significant presence of shale deposits. While these shales exhibit a low potential to generate hydrocarbons, there is a need to ascertain the possible reasons for the low hydrocarbon generation potential. Also, there are several unidentified properties and attributes associated with these shales in terms of their inorganic geochemical characteristics and their mineralogy. This study is focused on using XRF, ICPMS, and SEM with EDX to determine the mineralogical and geochemical characteristics of these shales and use these data to discuss their provenance history and tectonic setting and interpret the paleoclimatic and paleoweathering conditions. The inorganic geochemical analysis shows that the shales from the Dohol Formation are from a felsic igneous source. The shales were also identified to be from a passive margin based on the bivariate plot of SiO2 vs log (K2O/Na2O) and several multidimensional diagram plots. The CIA and CIW data, as well as the A-CN-K plot, all point to a significant degree of chemical weathering, ranging from mild to intense. The Sr/Cu ratio and C-value, combined with various other geochemical proxies, indicate that the shales were formed in warm-humid climatic conditions. The SEM analysis shows that the samples are mainly composed of kaolinite and illite, and this result was supported by the EDX elemental composition. The high terrigenous influx of sediments, the oxic to sub-oxic conditions in which the sediments were deposited, and finally low marine productivity were found to be the reasons for the low TOC in the shales from the Dohol Formation.

Experimental study of the influence of the degree of saturation on physical and mechanical properties of carbonate rocks in the Jurassic Tuwaiq Mountain Formation (Saudi Arabia)

Understanding the impact of saturation levels on the mechanical and physical properties of limestone and marly limestone deposits is very critical for geotechnical and mechanical studies in the energy and construction industries. This research aims to link the strength characteristics of carbonate rock (limestone and marly limestone) with physical and mechanical properties at saturation levels of 0, 0.25, 50%, 75% and 100%. To complete this work, 100 samples were collected and analysed employing an orderly research facility testing. According to experimental findings, the strength and durability of the limestone and marly limestone declined with rising saturation levels, while the P‐wave velocity Vp showed an upward trend from 0% to 100%. The uniaxial compressive strength (UCS) of the limestones employed in this research significantly decreased (up to 36%) between the dry and saturated stages for limestone samples. While marly limestone, there is a drop (up to 32%) in UCS. The findings of a straightforward regression study show that it is possible to predict the strength properties of rocks directly from various saturation levels. Additionally, a number of various estimate connections were created utilizing independent variables like Vp and saturation level. The experimental outcomes showed that Vp showed an upward tendency with an increasing degree of saturation. The deformability and strength parameters of the samples declined with increasing saturation degrees. The elastic modulus and strength both decrease as clay and water amounts increase. The quality index (QI) number for limestone is 45, which indicates that it has extremely good quality and can be used as a building material at 0% saturation. At 25%, 50%, 75% and 100% saturation, it is evaluated at 43, 40, 33 and 31, respectively. The marly limestone samples have high quality at 0% (QI = 36), but poor quality at 25%, 50%, 75% and 100% saturation (QI = 33, 30, 27 and 23). This research provides a better understanding of the relationship between saturation levels and the mechanical, physical and depositional characteristics of marly limestone and limestone, which might be helpful in industrial studies. Advance examination of distinctive sorts of carbonate rocks can be more supportive of broadening our understanding of this idea.

Facies analysis and distribution of Late Palaeogene deep‐water massive sandstones in submarine‐fan lobes, NW Borneo

Deep‐water massive sandstones (DWMS) are characterized by large volumes of sand accumulations which are considered as potential reservoir intervals in deep‐marine environments. Lithological variations and bed thickness statistics are used to interpret the distribution of massive sandstones in a deep‐marine fan‐lobe system. These massive sandstones are interpreted based on lithological heterogeneities and detailed facies analysis in seventeen exposed sections of the Late Palaeogene deposits in Sabah, NW Borneo. Sedimentary logs containing details of lithology textures and structures were used to recognize nine sedimentary facies of DWMS. These lithofacies were then grouped into three sedimentary facies associations: (1) massive facies association with basal part of turbiditic Bouma sequence, (2) massive facies association having soft‐sediment deformation structures, and (3) massive facies association with erosional features. The facies analysis portrays inner to middle submarine fan deposition and was later applied to reconstruct the distribution of a channel‐lobe complex. Individual sandstone bed thicknesses vary from 1 m to more than 8 m and the number of massive sandstones in submarine lobes range from less than 10% to more than 50%. The thicknesses of massive sandstones in channels are more than 8 m, whereas distal lobes have thicknesses from 1–2 m only. These sandstones are concentrated in channels, proximal and medial lobe settings that can also be verified from calculating the average of all maximum thickness of massive sand intervals that is, 8.91 m. The lithological heterogeneities and the processes associated with the deposition of these massive sandstones are vital for potential hydrocarbon reservoirs in the deep‐marine environments around the globe.

Road toward rapid-molecular point of care test to detect novel SARS-coronavirus 2019 (COVID-19): Review from updated literature

Coronavirus disease 2019 (COVID-19) named by the WHO as a result of the global public health emergency. COVID-19 is caused by a new coronavirus named as novel coronavirus (2019-nCOV). From the first case reported in December 2019 it is now a pandemic situation and a major public health emergency. The COVID-19 transmission rate is very high, infecting two to three persons on average with contact to an already infected person. There is a need for the health system, specially in developing countries such as in Pakistan, to combat such a novel disease by rapid, accurate, and high quality diagnostic testing in order to screen suspected cases and also surveillance of the disease. A rapid, accurate and low-cost diagnostic point-of-care device is needed for timely diagnosis of COVID-19 and is essential to combat such outbreaks for compelling preventive measures against the disease spread. This review is to highlight the importance of point-of-care diagnostics device for robust and accurate diagnosis of COVID-19 in physician offices and other urgent healthcare-type settings and encourage academics and stake holders towards advancement in order to control outbreaks and develop the public health surveillance system.

Architectural and biochemical changes in embryonic tissues of maize under cadmium toxicity

Heavy metals greatly alter plant morphology and architecture, however detailed mechanisms of such changes are not fully explored. Two experiments were conducted to investigate the influence of cadmium (CdCl2 · 2.5H2 O) on some germination, morphological, biochemical and histological characteristics of developing embryonic tissue of maize. In the first experiment, maize seeds were germinated in increasing levels of CdCl2 (200-2000 μm) in sand and measurements were taken of changes in germination and seedling development attributes. Based on these parameters, 1000 μM CdCl2 was chosen for detailed biochemical and histological measurements. In the second experiment, seeds were germinated in Petri dishes and supplied with 0 (control) or 1000 μM CdCl2 (Cd-treated). Radicle, plumule, coleoptile and coleorhiza were measured for biochemical and histological changes. The highest amount of Cd was in the coleorhiza and radicle. Free proline, soluble sugars, anthocyanin, soluble phenolics, ascorbic acid, H2 O2 and MDA were significantly higher in coleorhizae, followed by the coleoptile, radicle and plumule. Although the radicle and coleorhiza were relatively poor targets of Cd than the other tissues, Cd stress reduced cortical cell size and vascular tissues, and deformed xylem and phloem parenchyma in all plant parts. In conclusion, the main reason for reduced germination was the influence of Cd on architecture of the coleorhiza and coleoptile, which was the result of oxidative stress and other physiological changes taking place in these tissues.

Metal uptake via phosphate fertilizer and city sewage in cereal and legume crops in Pakistan

Crop irrigation with heavy metal-contaminated effluents is increasingly common worldwide and necessitates management strategies for safe crop production on contaminated soils. This field study examined the phytoavailability of three metals (Cd, Cu, and Zn) in two cereal (wheat, maize) and legume (chickpea, mungbean) crops in response to the application of either phosphatic fertilizer or sewage-derived water irrigation over two successive years. Five fertilizer treatments, i.e. control, recommended nitrogen (N) applied alone and in combination of three levels of phosphorus (P), half, full and 1.5 times of recommended P designated as N0P0, N1P0, N1P0.5, N1P1.0, and N1P1.5, respectively. Tissue concentrations of Cd, Cu, Zn, and P were determined in various plant parts, i.e., root, straw, and grains. On the calcareous soils studied while maximum biomass production was obtained with application of P at half the recommended dose, the concentrations of metals in the crops generally decreased with increasing P levels. Tissue metal concentrations increased with the application of N alone. Translocation and accumulation of Zn and Cu were consistently higher than Cd. And the pattern of Cd accumulation differed among plant species; more Cd being accumulated by dicots than monocots, especially in their grains. The order of Cd accumulation in grains was maize > chickpea > mungbean > wheat. Mungbean and chickpea straws also had higher tissue Cd concentration above permissible limits. The two legume species behaved similarly, while cereal species differed from each other in their Cd accumulation. Metal ion concentrations were markedly higher in roots followed by straw and grains. Increasing soil-applied P also increased the extractable metal and P concentrations in the post-harvest soil. Despite a considerable addition of metals by P fertilizer, all levels of applied P effectively decreased metal phytoavailability in sewage-irrigated soils, and applying half of the recommended dose of P fertilizer was the most feasible solution for curtailing plant metal uptake from soils. These findings may have wide applications for safer crop production of monocot species when irrigating crops with sewage effluent-derived waters.

Virus-neutralizing antibodies to hepatitis C virus

For a long time, the lack of an appropriate cell culture system has hampered the study of neutralizing antibody responses against hepatitis C virus (HCV). However, the last decade has seen the development of several model systems that have significantly advanced our understanding of viral entry and antibody neutralization. Studies of acutely infected patients suggest that a strong and early production of neutralizing antibodies may contribute to control the virus during the acute phase of HCV infection and facilitate viral elimination by cellular immune responses. It also emerges that the early antibody response mainly targets hypervariable region 1 (HVR1) of the envelope glycoprotein E2. This host response can lead to viral escape from neutralization by rapid amino acid changes in this hypervariable region. In contrast, cross-reactive neutralizing antibodies seem to appear later during HCV infection, and several mechanisms contribute to reduce their accessibility to their cognate epitopes. These include the masking of major conserved neutralizing epitopes by HVR1, specific N-linked glycans and the lipid moiety of the viral particle. Other potential mechanisms of evasion from the neutralizing antibody response include a modulation by high-density lipoproteins and interfering antibodies as well as the capacity of the virus to be transferred by cell-to-cell contacts. Finally, the recent identification of several highly conserved neutralizing epitopes provides some opportunities for the design and development of vaccine candidates that elicit a protective humoral immune response.

A biochemical and histopathological evaluation of generalized pulp calcification in young permanent teeth

Pulp calcifications are a frequent finding on bitewing and periapical radiographs in older age-groups but their occurrence in the entire dentition in young subjects is unusual. We report such an unusual occurrence of generalized pulp calcification in a 13-year-old Indian female. Radiographic examination of the dentition revealed pulp calcifications in all permanent teeth, located mostly in the pulp chamber but with some in the root canals. The patient's dental, medical, and family history was noncontributory. Biochemical analysis of the removed pulp calcification from one of the teeth during endodontic treatment showed large amounts of calcium, phosphorus, and carbonate. However, metabolic evaluation of patient through liver and kidney function tests and other blood investigations did not reveal any metabolic disorder. The patient was also evaluated for any systemic, syndromic, or genetic involvement but this was also noncontributory. Therefore, we propose that this unusual case of generalized pulp calcification is of idiopathic origin. In this work, histopathological and biochemical evaluations of the pulp calcification was done to try and understand the initiation and progress of calcifications in pulpal tissue.

Distal renal tubular acidosis and hypokalemic paralysis in a patient with hypothyroidism

A 43- year- old woman on treatment for primary hypothyroidism presented with 1- day progressive weakness of all her limbs and history of similar episodes in the past. Clinical examination revealed grade 2 hyporeflexive weakness. Investigations revealed features of hypokalemia, metabolic acidosis, alkaline urine, and a fractional bicarbonate excretion of 3.5%, consistent with distal renal tubular acidosis. Antithyroid peroxidase and antithroglobulin antibodies were positive, suggesting an autoimmune basis for the pathogenesis of the functional tubular defect. Bicarbonate therapy resulted in a sustained clinical recovery.

Preparation and evaluation of transdermal drug delivery system of etoricoxib using modified chitosan

In the present investigation chitosan has been chemically modified by treating with two different aldehydes like acetaldehyde and propionaldehyde to form Schiff’s bases. Schiff’s bases of chitosan with acetaldehyde and propionaldehyde were named as polymer A and polymer B, respectively. Fourier Transform Infra Red (FTIR) spectral data have confirmed the reaction carried out on chitosan. Drug free polymeric films of chitosan, chemically modified chitosan and chitosan/hydroxypropylmethylcellulose blend were prepared and evaluated for various physicochemical characters. Further, the films were incorporated with anti-inflammatory drug, etoricoxib using glycerol as plasticizer. The drug loaded films were cross-linked with sodium citrate and studied for permeation characteristics across dialysis membrane and rat skin. All the films were evaluated for bursting strength, swelling index, moisture uptake, thickness uniformity, drug content uniformity, tensile strength, percent elongation at break, percent flatness, water vapour transmission rate and in vitro drug permeation study.

Broader leaves result in better performance of indica rice under drought stress

Leaf growth is one of the first physiological processes affected by changes in plant water status under drought. A decrease in leaf expansion rate usually precedes any reduction in stomatal conductance or photosynthesis. Changes in leaf size and stomatal opening are potential adaptive mechanisms, which may help avoid drought by reducing transpiration rate, and can be used to improve rice genotypes in water-saving cultivation. The indica rice cultivar IR64 and four of its near-isogenic lines (NILs; BC(3)-derived lines) unique for leaf size traits, YTK 124 (long leaves), YTK 127 (broad leaves), YTK 205 (short leaves) and YTK 214 (narrow leaves), were compared in this study for changes in leaf growth and its water status. The plants were subjected to two soil water regimes, well-watered and progressive soil drying measured by the fraction of transpirable soil water (FTSW). Applied drought reduced leaf number, total leaf area, specific leaf area, plant biomass, tiller number, plant height, stomatal conductance, amount of water transpired, leaf relative water content, and leaf water potential more in IR64 and the NILs than in the respective controls; nonetheless, transpiration efficiency (TE) was slightly higher under drought than in the well-watered controls. NILs with broader leaves had higher biomass (and its individual components), less stomatal conductance, and higher TE under drought than NILs with narrow and shorter leaves. Under drought, leaf number was positively correlated with tiller number and plant height; nonetheless, root weight and total biomass, water transpired and TE, and plant height and TE were positively correlated with each other. However, a negative correlation was observed between stomatal conductance and the FTSW threshold at which normalized transpiration started to decline during soil drying. Overall, the IR64-derived lines with broader leaves performed better than NILs with narrow and short leaves under drought.

Removal of silver and antimony radionuclides from low-level liquid radioactive waste of a research reactor through different scavenging precipitations

After upgrading the Pakistan Research Reactor-1, the amount of liquid waste and its increased radioactivity content necessitated a pre-disposal treatment to bring the activity down to disposal limits. Amongst several radionuclides in the waste, 110mAg and to some extent 124Sb were of our concern due to their higher production rate. Different possible treatment processes were considered for the treatment of low-salt, low-level liquid waste of the institute. Making use of insolubilities and scavenging properties of certain precipitates of metal ions, some experiments on the actual waste samples were performed for the decontamination of the piled up waste effluent. Suitable reagent(s) and the optimum doses were to be investigated for the treatment and conditioning of the wastewater. Different scavenging agents like ferric chloride, ferrous sulfate, stannous chloride, in situ precipitated manganese hydroxide and lanthanum nitrate were studied for the removal of these two radionuclides. Selectivity of Fe2+ and Fe3+ as scavengers for silver and antimony was investigated. Excellent Decontamination Factors (>1000) were obtained very cost effectively with some of the reagents tried. Based on these experiments, a working procedure making use of Fe(II) hydrous oxide scavenging precipitation for the chemical treatment of the waste effluent was optimized. These experiments are presented.

Influence of atmospheric pollutants on agriculture in developing countries: a case study with three new wheat varieties in Pakistan

The performance of three wheat varieties (Inqilab-91, Punjab-96, Pasban-90) was investigated in open-top chambers with charcoal-filtered air (FA), unfiltered air (UFA) and unchambered field plots (AA) during the 2003-2004 season at a semi-urban site in Lahore, Pakistan. The 8-h daily mean O(3), NO(2) and SO(2) concentrations in UFA and AA remained 72, 28 and 15 ppb, respectively. Plants grown in UFA and AA showed stunted growth and accelerated rate of leaf senescence with pronounced reductions in stomatal conductance (7-24%), net photosynthetic rate (20-22%) and photosynthetic efficiency (9-17%) compared with FA plants. A mid-season harvest of 10-week-old plants revealed reduced plant fresh (14-37%) and dry weights (15-43) in UFA compared to FA counterparts. Grain yield recorded after a full season of growth was drastically reduced in UFA with 43% for Pasban-90, 39% for Punjab-91 and 18% for Inqilab-91 compared with FA control plants. Nutritional quality of seeds was also significantly reduced in UFA and AA with respect to starch, but not in protein and vitamin-E contents when compared with FA plants. This investigation carried out in a major developing country of southeast Asia has shown alarming effects of atmospheric pollutants on both yield and nutritional quality of an important cereal crop that needs urgent attention to maintain the agricultural systems with parallel efforts to reduce the emissions in the region.

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.

Primary gradient defect distal renal tubular acidosis presenting as hypokalaemic periodic paralysis

A 45 year old man presented with recurrent hypokalaemic paralysis. Laboratory investigations revealed renal tubular acidosis as the cause of the hypokalaemia, and dynamic tubular studies suggested a gradient defect as the underlying cause. The patient had associated dextrocardia. To our knowledge, this is the first report of this condition.

Relapsing polychondritis in an elderly male

A 65 years patient presented with left ear swelling, swelling of the nasal bridge with congestion of the eyes. Clinically there was evidence of left auricular chondritis, nasal chondritis and conjunctivitis with a history of multiple similar episodes in the past, features suggestive of relapsing polychondritis. The patient improved with oral prednisolone.

Regional expression of inducible nitric oxide synthase in the kidney in dogs with unilateral ureteral obstruction

PURPOSE

In the early stage of unilateral ureteral obstruction total renal blood flow increases but medullary blood flow decreases, exacerbating medullary tissue hypoxia. We examined the expression of inducible nitric oxide synthase, a product of a hypoxia sensitive gene, in the cortex and medulla in dogs with unilateral ureteral obstruction for 21 hours.

MATERIALS AND METHODS

Hemodynamic and clearance experiments were performed after release of ureteral obstruction in 6 dogs with unilateral ureteral obstruction, followed by Western blot analysis of nitric oxide synthase and immunohistochemistry.

RESULTS

Ureteral obstruction raised mean ureteral pressure plus or minus standard error to 35.0 +/- 7.2 mm. Hg. In dogs with unilateral ureteral obstruction mean renal blood flow was 116 +/- 10 ml. per minute, lower than the 213 +/- 22 ml. per minute in sham operated dogs (p <0.01). After unilateral ureteral obstruction release the mean glomerular filtration rate was 9.5 +/- 2.1 ml. per minute, lower than the 27.3 +/- 1.8 ml. per minute in the contralateral unobstructed kidney (p <0.01). Western blot analysis showed that mean nitric oxide synthase/beta-actin in the cortex of the obstructed kidney was 0.04 +/- 0.01 densitometry units, lower than 0.11 +/- 0.02 densitometry units in the unobstructed contralateral kidney (p <0.05). In contrast, mean nitric oxide synthase/beta-actin in the medulla of the obstructed kidney was 1.29 +/- 0.33 densitometry units, greater than the 0.34 +/- 0.03 densitometry units in the unobstructed kidney (p <0.05). Immunohistochemistry revealed that the increased expression of nitric oxide synthase protein was localized to the endothelium of the vasa recta.

CONCLUSIONS

Unilateral ureteral obstruction enhances nitric oxide synthase expression in the medulla but not in the cortex. This increased expression in the medulla may be the result of increased medullary hypoxia in unilateral ureteral obstruction, possibly contributing to medullary hyperemia after unilateral ureteral obstruction release.

Effects of oxidants on soybean growth and yield in the Pakistan Punjab

Plants of soybean (Glycine max L.) were grown with and without the ozone protectant EDU (N-[2-(2-oxo-1-imidazolidinyl)ethyl]-n2 phenylurea) at a suburban site, a remote rural site and a rural roadside site around the city of Lahore, Pakistan. The development and yield of the plants was determined in two experiments--one immediately post-monsoon and one in the following spring (pre-monsoon). Concentrations of nitrogen dioxide and photochemical oxidants were measured at each site. The effect on yield of EDU at the suburban site (47 and 113% increase in seed weight per plant relative to the untreated plants in the post- and pre-monsoon experiments, respectively) was similar to the effects of filtration on yield on soybean in a parallel open-top chamber study at the same site (77% increase relative to plants subjected to unfiltered air for the pre-monsoon experiment). Effects of EDU on yield were greater at both rural sites than at the suburban site in both experiments, and greater in the spring experiment (182% at the remote rural site and 285% at the rural roadside site) than in the post-monsoon experiment (94% at the remote rural site and 170% at the rural roadside site); oxidant concentrations were also greater at the rural sites than at the suburban site, and greater in the spring experiment than the post-monsoon experiment. The results imply that ozone may be causing significant crop losses in rural areas around Lahore; however, the geographical extent of the problem, and the implications for peri-urban agriculture around other cities of south Asia are uncertain.

CT in pulmonary hydatid disease: unusual appearances

OBJECTIVE

To study the CT features of pulmonary hydatid disease.

PATIENTS

Thirty-two consecutive patients with surgically proven pulmonary hydatid cysts.

SETTING

SheriKashmir Institute of Medical Sciences, Srinagar, Kashmir, India, a tertiary-care referral center.

INTERVENTIONS

CT of the chest was obtained in all cases on Somatom DR double rotate CT scanner (Siemens; Erlangen, Germany).

RESULTS

Forty cysts of different size and shapes were encountered, 34 of them being ruptured. CT density of the cysts varied from - 42 to 160 Hounsfield units (HU; median, 15.5 HU). Apart from the classically described features of pulmonary hydatid disease, a crescent-shaped rim of air at the lower end of the cyst (inverse crescent sign) was seen in three cysts, and a bleb of air in the wall of two as-yet unruptured cysts (signet ring sign). Thick wall (>10 mm) was observed in four cysts, and each of them had associated evidence of infection.

CONCLUSIONS

Inverse crescent sign, signet ring sign, high CT density, and thick wall should be recognized as features of pulmonary hydatid cysts on CT.

The foam mattress-back syndrome

BACKGROUND

Many medical residents used to sleeping on cotton mattresses at home complain of mild to moderate back pain after sleeping on foam mattresses provided in the hospital and hostel rooms.

OBJECTIVE

To determine the relationship of sleeping on foam mattress with the appearance of back pain in a 500 bedded multispecialty tertiary care hospital.

METHODS

One hundred medical residents were interviewed for the appearance of backache after sleeping on 10 cm thick foam mattress provided to them in the hostels. Pain was scored over a visual analog scale of 10 cm. Effect of sleeping on a regular cotton mattress was assessed.

RESULTS

Sixty-three (5 female residents) developed back pain on the morning of a night of sleep over the foam mattress. The pain was mostly of lower back and was not associated with any objective neurodeficit. Four residents on account of the backache reported thirteen episodes of absenteeism. Sixty-one residents had a relief of the pain on going home where they would sleep on regular cotton mattresses, only to recur after sleeping again on the foam mattress in the hospital/hostel.

CONCLUSION

Sleeping on foam mattress is associated with the appearance of backache in medical residents which is reproducible and gets relieved after using regular cotton mattresses.

Hypocomplementemic urticarial vasculitis and lower cranial nerve palsies

A 55 years post menopausal lady presented with puffiness of face, and a pruritic urticarial rash over face and upper trunk of one week duration with accompanying dysphagia. Clinical examination revealed an urticarial rash over face and upper trunk, two small ulcers over floor of mouth and evidence of bilateral VIII, IX and Xth cranial nerve palsies. Hypocomplementemia, negative immune profile and evidence of vasculitis on skin biopsy suggested a diagnosis of hypocomplementemic urticarial vasculitis. The patient responded to a course of steroids.

Mepacrine therapy in niclosamide resistant taeniasis

OBJECTIVE

To evaluate the efficacy of mepacrine (quinacrine) in patients with niclosamide resistant Taenia saginata infection.

METHODS

Eighty six cases with niclosamide resistant Taenia saginata (unresponsive to 2-8 courses of niclosamide) were treated with quinacrine (1 g) administered orally or via a nasogastric tube, and followed at 2, 4, 8 and 12 weeks for recurrence of passage of proglottids and presence of Taenia eggs in the stool examinations. Pre and post-therapy egg counts were obtained and egg viability was tested by staining with methylene blue.

RESULTS

Eighty-one (94.2%) patients responded promptly with passage of the worm within 4-72 hours. The egg counts showed a drastic fall in 79 cases and a fall in viability from a median of 100% to 0% was observed. Only one patient demonstrated a relapse at 4 weeks. Gastrointestinal side effects occurred in 9 cases but were controlled easily by symptomatic therapy.

CONCLUSION

We conclude that quinacrine is a safe, inexpensive, effective and generally well tolerated drug for the treatment of niclosamide resistant Taenia saginata infestations.

Lead exposure in papier mâché workers

Lead exposure was assessed in a random cohort of 70 male papier mâché workers and compared with 35 age and sex matched controls. Blood-lead levels in workers were significantly higher than in controls (Mean 68.07 +/- 44.64 ug/dl vs 25.52 +/- 16.56 ug/dl respectively; P < 0.001). Urinary lead was also higher in workers (128.53 +/- 52.61 ug/l) compared to controls (91.18 +/- 27.06, P < 0.001), but excretion of urinary coproporphyrin in the two groups was not significantly different (102.78 +/- 153.42 vs 70.03 +/- 27.06 ug/l, P > 0.05). Blood levels bore a significant correlation with age but did not bear any correlation with the duration of exposure. Various modes of exposure to lead included hand mixing of paints, skin application of the paint to match shades and making point of the brush using lips and the tongue.

Transvaginal colpo-urethropexy with fibrin sealant: 4 years-follow up in 23 cases

A method of transvaginal colpo-urethropexy, using fibrin sealant was studied clinically. After a fingertip vaginal retropubic dissection, fibrin sealant is instilled in the retropubic space with the intent of inducing fibrosis between the elevated urethro-vesical junction and the retropubic periosteum. Twenty-three patients with urinary stress incontinence underwent this procedure with 82% of satisfactory results and 18% failure. Complications were minimal. In the future, this technique could be useful for ambulatory surgery.

Haemostatic abnormalities in multidrug-resistant enteric fever

Twenty-five consecutive patients with multidrug-resistant enteric fever were evaluated and followed for haemostatic abnormalities. Twenty-one (84%) of the patients had evidence of disseminated intravascular coagulation (DIC) and 12 (48%) also had evidence of associated fibrinolysis. Clinical bleeding was observed in 3 (12%) cases, and did not bear any correlation with clotting abnormalities. Protein C activity was found to be decreased in 11 of the 15 cases with DIC, and a block in its activation, as previously postulated, could not be substantiated. DIC was reversed in most cases within 8 days of the institution of specific antibiotic therapy.

Air pollution and its impacts on wheat yield in the Pakistan Punjab

A study using open-top chambers ventilated with ambient or charcoal-filtered air in the vicinity of Lahore, Pakistan, has demonstrated a reduction of 46.7% and 34.8% in the grain yield for two cultivars of winter wheat (Triticum aestivum L.). The 6-h daily mean O(3) concentrations were 25-45 nl litre(-1) and on the basis of experience in North America and Europe, reductions in yield in the present study are substantially greater than might be predicted. The reasons for this discrepancy are discussed, together with implications for the suitability of a simple, relatively cheap, open-top chamber system for developing-country studies on the effects of air pollution on crops.

Effects of air pollution on rice yield in the Pakistan Punjab

A study using open-top chambers ventilated with ambient or charcoal filtered air in the vicinity of Lahore, Pakistan demonstrated reductions of 42% and 37% in the grain yield of two cultivars of rice (Oryza sativa L.). This yield reduction was primarily due to the reduction in mean panicle number per plant, although significant effects of filtration on 1000 grain weight and the number of filled grains per panicle were also detected. The 6-h daily mean O(3) concentrations were only 10-20 nl litre(-1) during the monsoon season, but increased to 30-55 nl litre(-1) later in the growing season, while the mean NO(2) concentration during the experiment was 12 nl litre(-1). On the basis of experience in North America and Japan, the reductions in yield in the present study are substantially greater than might be predicted. The reasons for this discrepancy are discussed, together with the implications for effects on rice yield in other regions of south and south-east Asia.

Measurements of oxygen tension in the cerebral cortex of baboons

A polystyrene-covered platinum electrode (100-150 mum diameter) has been used to measure cortical tissue oxygen tension in baboon brains. The method of preparation, calibration, and the importance of small residual current (less than 40 nA) as an attribute of a reliable electrode, are described. With electrodes of this size, there was a large (16 +/- 12nA/torr) and linear current output with pO2 changes. The effect of avrious gases in addition to oxygen is described; halothane inhalation increases the apparent pO2 and hydrogen, used for blood flow estimations, reduces the recorded pO2. In 48 separate electrode placements in 13 baboons, the mean cortical qo2 was 23.8 +/- 12 mm Hg, with a range from 1-79 mm Hg; following occlusion of one middle cerebral artery, 37 electrodes recorded a pO2 of less then 5 mm Hg pO2 Oscillations were invariably noted in control conditions, independent of blood pressure; these waves disappeared during MCA occlusion and appeared to be augmented following release of the clip. Blood pressure "spikes" produce immediate and synchronous changes in all electrodes entirely different from the spontaneous waves. Such blood pressure changes may mask the true effect of hypercapnia on tissue pO2 and, if ignored, may lead to erroneous assumptions regarding local neural control of the circulation, the increased pO2 secondary to hypertension being regarded as evidence of regional vasodilation. A SUdden change in inspired pO2-the "air test"-was performed in control conditions and following the ischaemic insult, and the rate of change of cortical pO2 compared. The gradient was significantly greater (P less than 0.05) following ischaemia, suggesting a changed ratio in the tissue's flow to oxygen requirements and/or a persisting vasodilatation.