Comparative measurement of CO2, CH4 and CO at two traffic interjunctions having inflated vehicular flow in Delhi

Vehicular emissions are considered one of the major anthropogenic sources of greenhouse gases and poor air quality in metropolitan cities. This study aims to see the correlation of CO2, CH4, and CO through monitoring over a period from December 2020 to October 2021 covering three seasons' winter, summer, and monsoon at two different traffic locations of Delhi having different traffic volumes, road patterns, and traffic management. The annual average morning concentration of CO2, CH4 and CO was found (533 ± 105), (7.3 ± 3.1), (10.7 ± 3.0) ppm at Najafgarh and (480 ± 70), (5.2 ± 1.8), (7.8 ± 2.8) ppm at Rajendra Place, respectively. A relationship between concentration of all three gases and meteorological parameters such as temperature, humidity, wind speed and wind direction has also been investigated using Pearson correlation coefficient and pollution rose diagram. A comparable pattern in concentration was observed for all three gases in spatial (location) and temporal (diurnal) distribution. The concentration trend of CO2 in different seasons is winter > summer > monsoon, while in the case of CH4 winter = summer > monsoon but not any seasonal trend was noted in CO case. It is observed that CO2 has a good relation with CO (a tracer for vehicular emission) in terms of diurnal variation, whereas, CH4 does not represent a relation with CO and CO2 diurnally, suggesting that vehicles are the source of CO2 but not much contributing to other greenhouse gases like CH4.

Seasonal and diurnal measurement of ambient benzene at a high traffic inflation site in Delhi: Health risk assessment and its possible role in ozone formation pathways

Benzene is the most toxic and hazardous pollutant among volatile organic compounds (VOCs), as it comes under group 1 carcinogens recognized by the International Agency for Research on Cancer (IARC). It also plays a significant role in forming secondary pollutants like ozone. The benzene concentration was measured using a charcoal sorbent tube by active sampling at a traffic junction and analysis was done using GC-FID. The maximum average concentration of benzene in ambient air was found to be 33 μg/m3. A diurnal study of benzene measurement shows higher benzene concentrations in the evening compared to the morning. Seasonal variation of benzene is found to be winter > spring > summer > autumn > monsoon and OFP was found to be 21, 19, 14, 13, and 10 respectively. Cancer (ILCR) and non-cancer (HQ) health risk assessment was done to determine the impact of ambient benzene on the residents of urban areas. The yearly average value of ILCR was found to be 2×10-6 ± 1×10-6 which ranges from acceptable value to three times the WHO acceptable value i.e 1×10-6. The correlation of ozone and its precursor, benzene with meteorological parameters is also evaluated. The correlation of benzene and ozone with solar radiation shows the influence of photochemical reactions on the levels of benzene and ozone at the study site, although it is low.

Physical and chemical properties of PM1 in Delhi: A comparison between clean and polluted days

Considering the significance of PM₁ aerosol in assessing health impacts of air pollution, an extensive analysis of PM₁ samples collected at an urban site in Delhi is presented in this study. Overall, PM₁ contributed to about 50 % of PM_2.5 mass which is alarming especially in Delhi where particle mass loadings are usually higher than prescribed limits. Major portion of PM₁ consisted of organic matter (OM) that formed nearly 47 % of PM₁ mass. Elemental Carbon (EC) contributed to about 13 % of PM₁ mass, whereas SO₄^2- (16 %), NH₄⁺ (10 %), NO₃^- (4 %) and Cl^- (3 %) were the major inorganic ions present. Sampling was performed in two distinctive campaign periods (in terms of meteorological conditions and heating (fire activities), during the year 2019, each spanning two-week time, i.e. (i) September 3rd -16th (clean days), and (ii) November 22nd -December 5th (polluted days). The 24-h averaged mean concentrations of PM_2.5 and BC during clean days (polluted days) were 70.6 ± 26.9 and 3.9 ± 1.0 μg m^-3 (196 ± 104 and 7.6 ± 4.1 μg m^-3) respectively, which were systematically lower (higher) than that of the annual mean (taken from studies conducted at same site in 2019) of 142 and 5.7 μg m^-3, respectively. Changes in characteristic ratios (i.e., organic carbon (OC)/elemental Carbon (EC) and K⁺/EC) show an increase in biomass emissions during polluted days. Increase in biomass emission can be attributed to increase in heating practices (burning of biofuels such as wood logs, straw, and cow-dung cake) in- and around- Delhi because of fall in temperature in winter during second campaign. Furthermore, a significant increase in NO₃^- fraction in PM₁ is observed during second campaign which shows fog processing of NO_X due to conducive meteorological conditions in winters. Also, comparatively stronger correlation of NO₃^- with K⁺ during second campaign (r = 0.98 as compared to r = 0.5 during first campaign) suggests the increased heating practices to be a contributing factor for increased fraction of NO₃^- in PM₁. We observed that during polluted days, meteorological parameters such as dispersion rate also played a major role in intensifying the impact of increased local emissions due to heating activities. Apart from this, change in the direction of regional emission transport to study site and the topology of Delhi are the possible reasons for the elevated pollution level, especially PM₁ in onset of winter in Delhi. This study also suggests that black carbon measurement techniques used in current study (optical absorbance with heated inlet and evolved carbon techniques) can be used as reference techniques to determine the site-specific calibration constant of optical photometers for urban aerosol.

38. Effect of Chlorhexidine Rinsed Blood Contamination on Bond Strength of Brackets Bonded with Self-etch Primer- An in Vitro Study

The present invitro type of study has done to check the effect of blood contamination & chlorhexidine combination on the bond strength of brackets bonded with self-etch primer technique. The study consisted of ninety sound human upper premolars (extracted for orthodontic purpose) fixed in a self-cure acrylic block and segregated into three groups of 30 samples each. 0.022 slot metal MBT brackets (Gemini series-3M unitek) were bonded with self-etch primer using Transbond XT composite, CA, USA and light cure for 40 seconds) on clean buccal surface. Teeth were divided into 3 groups-Group A/Control group, Group B, Group C. A computer was used to record the force applied to debond the bonded bracket in the unit of Newton. The analysis of variance indicated that there were significant differences (F value = 6.891, p value=0.002) in bond strengths between the various groups tested. The highest value of shear bond strength occurred when chlorhexidine (Group C) was used to remove the blood contamination (mean=15.874 MPa). When bonding was done in ideal condition (Group A), shear bond strength obtained was slightly lower (mean=14.497 MPa) as compared to Group C. On the other hand, lowest shear bond strength among all three groups occurred when blood contamination (Group B) was removed with water (mean=11.059 MPa). Analysis of the study showed that shear bond strength of orthodontic brackets to enamel significantly decreased during bonding with self-etch primer in blood contamination condition. Self-etch primer displayed considerably superior performance with the use of chlorhexidine instead of water to wash the blood contamination.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

Neurosteroid pregnenolone sulfate, alone, and as augmentation of lurasidone or tandospirone, rescues phencyclidine-induced deficits in cognitive function and social interaction

BACKGROUND

Pregnenolone sulfate (PregS), an endogenous neurosteroid, which negatively and positively modulates gamma amino butyric acid subunit A (GABA_A) and N-methyl D-aspartate (NMDA) receptors (R) respectively, among other potential neuroplastic changes on synaptic processes, has shown some beneficial effects on treating cognitive impairment associated with schizophrenia (CIAS) and negative symptoms. Lurasidone (Lur), an atypical antipsychotic drug (AAPD), and tandospirone (Tan), a 5-HT_1A R partial agonist, have also been reported to improve cognitive or negative symptoms, or both, in some schizophrenia patients.

METHODS

We tested whether PregS, by itself, and in combination with Lur or Tan could rescue persistent deficits produced by subchronic treatment with the NMDAR antagonist, phencyclidine (PCP)-in episodic memory, executive functioning, and social behavior, using novel object recognition (NOR), operant reversal learning (ORL), and social interaction (SI) tasks, in male C57BL/6 J mice.

RESULTS

PregS (10, but not 3 mg/kg) significantly rescued subchronic PCP-induced NOR and SI deficits. Co-administration of sub-effective doses (SEDs) of PregS (3 mg/kg) + Lur (0.1 mg/kg) or Tan (0.03 mg/kg) rescued scPCP-induced NOR and SI deficits. Further, PregS (30, but not 10 mg/kg) rescued PCP-induced ORL deficit, as did the combination of SED PregS (10 mg/kg) +SED Lur (1 mg/kg) or Tan (1 mg/kg).

CONCLUSION

PregS was effective alone and as adjunctive treatment for treating two types of cognitive impairments and negative symptoms in this schizophrenia model. Further study of the mechanisms by which PregS alone and in combination with AAPDs and 5-HT_1A R partial agonists, rescues the deficits in cognition and SI in this preclinical model is indicated.

Synthesis of ZnO nanoparticles using leaf extract of Tectona grandis (L.) and their anti-bacterial, anti-arthritic, anti-oxidant and in vitro cytotoxicity activities

The novelty of this present work is the investigation of the anti-bacterial, anti-arthritic, anti-oxidant andin vitrocytotoxicity activities of green synthesized Zinc Oxide Nanoparticles (ZnO NPs) using leaf aqueous extract ofTectona grandis(L.).

Typhoid intestinal perforation: 24 perforations in one patient

Intestine perforation is one of the most dreaded and common complication of typhoid fever remarkably so in developing world; it usually leads to diffuse peritonitis, requiring early surgical intervention. Despite various measures such as safe drinking water supply and safe disposal of waste, intestinal perforation from salmonellosis remains the most common emergency surgery performed. The incidence continues to rise, so also the mortality, despite new antibiotics and improvement in surgical technique. More disturbing is that we now see increasing number of ileal perforations and colonic involvement. We hereby present a case report of 35-year-old male with multiple (24) intestinal perforation in the Ileum and Cecum.

Quantifying uncertainty in measurement of mercury in suspended particulate matter by cold vapor technique using atomic absorption spectrometry with hydride generator

As a result of rapid industrialization several chemical forms of organic and inorganic mercury are constantly introduced to the environment and affect humans and animals directly. All forms of mercury have toxic effects; therefore accurate measurement of mercury is of prime importance especially in suspended particulate matter (SPM) collected through high volume sampler (HVS). In the quantification of mercury in SPM samples several steps are involved from sampling to final result. The quality, reliability and confidence level of the analyzed data depends upon the measurement uncertainty of the whole process. Evaluation of measurement uncertainty of results is one of the requirements of the standard ISO/IEC 17025:2005 (European Standard EN IS/ISO/IEC 17025:2005, issue1:1-28, 2006). In the presented study the uncertainty estimation in mercury determination in suspended particulate matter (SPM) has been carried out using cold vapor Atomic Absorption Spectrometer-Hydride Generator (AAS-HG) technique followed by wet chemical digestion process. For the calculation of uncertainty, we have considered many general potential sources of uncertainty. After the analysis of data of seven diverse sites of Delhi, it has been concluded that the mercury concentration varies from 1.59 ± 0.37 to 14.5 ± 2.9 ng/m³ with 95% confidence level (k = 2).

Evaluation of purity with its uncertainty value in high purity lead stick by conventional and electro-gravimetric methods

BACKGROUND

A conventional gravimetry and electro-gravimetry study has been carried out for the precise and accurate purity determination of lead (Pb) in high purity lead stick and for preparation of reference standard. Reference materials are standards containing a known amount of an analyte and provide a reference value to determine unknown concentrations or to calibrate analytical instruments. A stock solution of approximate 2 kg has been prepared after dissolving approximate 2 g of Pb stick in 5% ultra pure nitric acid. From the stock solution five replicates of approximate 50 g have been taken for determination of purity by each method. The Pb has been determined as PbSO4 by conventional gravimetry, as PbO2 by electro gravimetry. The percentage purity of the metallic Pb was calculated accordingly from PbSO4 and PbO2.

RESULTS

On the basis of experimental observations it has been concluded that by conventional gravimetry and electro-gravimetry the purity of Pb was found to be 99.98 ± 0.24 and 99.97 ± 0.27 g/100 g and on the basis of Pb purity the concentration of reference standard solutions were found to be 1000.88 ± 2.44 and 1000.81 ± 2.68 mg kg-1 respectively with 95% confidence level (k = 2). The uncertainty evaluation has also been carried out in Pb determination following EURACHEM/GUM guidelines. The final analytical results quantifying uncertainty fulfills this requirement and gives a measure of the confidence level of the concerned laboratory.

CONCLUSIONS

Gravimetry is the most reliable technique in comparison to titremetry and instrumental method and the results of gravimetry are directly traceable to SI unit. Gravimetric analysis, if methods are followed carefully, provides for exceedingly precise analysis. In classical gravimetry the major uncertainties are due to repeatability but in electro-gravimetry several other factors also affect the final results.

A neutraceutical by design: the clinical application of curcumin in colonic inflammation and cancer

Unquestionably, the natural food additive curcumin, derived from the colorful spice turmeric used in many Asian cuisines, possesses a diverse array of biological activities. These range from its anti-inflammatory, antineoplastic, and metabolic modifying properties to surprising roles in disorders ranging from Alzheimer's disease to cystic fibrosis. Its effects on growth factor receptors, signaling molecules, and transcription factors, together with its epigenetic effects are widely considered to be extraordinary. These pleiotropic attributes, coupled with its safety even when used orally at well over 10 g/day, are unparalleled amongst pharmacological agents. However, there is one drawback; apart from the luminal gastrointestinal tract where its pharmacology predicts that reasonable drug levels can be attained, its broader use is hampered by its poor solubility and hence near undetectable plasma levels. Medicinal chemistry and nanotechnology have resulted in the generation of compounds where the modified drug or its delivery system has improved matters such that this shortcoming has been addressed to some extent, with the surprising finding that it remains safe to use. It is predicted that either the parental compound or its derivatives may eventually find a place in the therapeutic management protocols of several conditions.

Expression of gap junctional connexin proteins in ovine fetal ovaries: effects of maternal diet

Gap junctions have been implicated in the regulation of cellular metabolism and the coordination of cellular functions during growth and differentiation of organs and tissues, and gap junctions play a major role in direct cell-cell communication. Gap junctional channels and connexin (Cx) proteins have been detected in adult ovaries in several species. Furthermore, it has been shown that several environmental factors, including maternal diet, may affect fetal organ growth and function. To determine whether maternal diet affects expression of Cx26, Cx32, Cx37, and Cx43 in fetal ovaries, sheep were fed a maintenance (M) diet with adequate (A) selenium (Se) or high (H) Se levels from 21 d before breeding to day 132 of pregnancy. From day 50 to 132 of pregnancy (tissue collection day), a portion of the ewes from the ASe and HSe groups was fed a restricted (R; 60% of M) diet. Sections of fetal ovaries were immunostained for the presence of Cxs followed by image analysis. All four Cxs were detected, but the distribution pattern differed. Cx26 was immunolocalized in the oocytes from primordial, primary, secondary, and antral follicles; in granulosa and theca layers of secondary and antral follicles; stroma; and blood vessels. Cx32 was in oocytes, granulosa, and theca cells in a portion of antral follicles; Cx37 was on the borders between oocyte and granulosa/cumulus cells of primordial to antral follicles and in endothelium; and Cx43 was on cellular borders in granulosa and theca layers and between oocyte and granulosa/cumulus cells of primordial to antral follicles. Maternal diet affected Cx26 and Cx43 expression, Cx26 in granulosa layer of antral follicles was decreased (P < 0.01) by HSe in the M and R diets, and Cx43 in granulosa layer of primary and granulosa and theca of antral follicles was increased (P < 0.05) by the M diet with HSe. Thus, Cxs may be differentially involved in regulation of fetal ovarian function in sheep. These data emphasize the importance of maternal diet in fetal growth and development.

Antibacterial activity of some unsymmetrical diorganyltellurium(IV) dichlorides

Six unsymmetrical diorganyltellurium(IV) dichlorides RR'TeCl2 (where R= phenacyl-, 1-naphthacyl-, and styrylacyl- and R' = p-methoxyphenyl, p-hydroxyphenyl-, and 3-methyl-4-hydoxyphenyl-) were tested for their antibacterial activity against gram-positive (Bacillus subtilis ATCC 6633 and Staphylococcus aureus ATCC 25923) and gram-negative (Escherichia coli ATCC 25922. Pseudomonas aeruginosa ATCC 27853 and Salmonella sp.) bacteria. Antibacterial activity was measured by disk diffusion method. Inhibition zones demonstrated that all the compounds showed good activity against gram-negative strains. Phenacyl (3-methyl-4-hydroxyphenyl) tellurium(IV) dichloride and naphthacyl (3-methyl-4-hydroxyphenyl) tellurium(IV) dichloride showed significant activity against both gram-positive and gram-negative strains. Among the tested compounds, the former exhibited maximum activity against gram-positive bacteria, while the latter against all the bacteria under study and styrylacyl (p-methoxyphenyl) tellurium(IV) dichloride against all the three gram-negative bacteria.

Inosine stimulates extensive axon collateral growth in the rat corticospinal tract after injury

The purine nucleoside inosine has been shown to induce axon outgrowth from primary neurons in culture through a direct intracellular mechanism. For this study, we investigated the effects of inosine in vivo by examining whether it would stimulate axon growth after a unilateral transection of the corticospinal tract. Inosine applied with a minipump to the rat sensorimotor cortex stimulated intact pyramidal cells to undergo extensive sprouting of their axons into the denervated spinal cord white matter and adjacent neuropil. Axon growth was visualized by anterograde tracing with biotinylated dextran amine and by immunohistochemistry with antibodies to GAP-43. Thus, inosine, a naturally occurring metabolite without known side effects, might help to restore essential circuitry after injury to the central nervous system.

Analgesic responses to intrathecal morphine in relation to CSF concentrations of morphine-3,beta-glucuronide and morphine-6,beta-glucuronide

This study was performed to determine whether variations in analgesic responses to intrathecal morphine could be explained by cerebrospinal fluid (CSF) concentrations of morphine metabolites. Twenty-four CSF samples were collected at the beginning, middle and end of treatment periods in seven cancer patients with pain of malignant origin. CSF concentrations of morphine-3,beta-glucuronide (M3G) and morphine-6,beta-glucuronide (M6G) metabolites were measured by gas chromatography/mass spectrometry. Analgesic responses to morphine were estimated concurrent with CSF collection using a visual analog scale representing percentages of pain relief. Effective analgesia was defined as > or = 75% pain relief. CSF concentration of M3G and M6G in the 24 samples were 722 +/- 116 ng/ml and 699 +/- 158 ng/ml, respectively. CSF samples were categorized into two groups: (1) those collected during effective analgesia (N=14), and (2) those collected during ineffective analgesia (N=10). M6G levels detected in group 1 samples (effective analgesia) were significantly greater than those found in group 2 samples (ineffective analgesia) (978 +/- 243 ng/ml vs 309 +/- 68 ng/ml, P<0.05). Intergroup differences in CSF M3G concentrations and M3G/M6G ratios were not significant. It is concluded that CSF M6G may be indicative of effectiveness of analgesia in cancer patients subjected to intrathecal morphine.

Necrosis in pontine gliomas: radiation induced or natural history?

PURPOSE

To determine whether the central necrotic lesions that develop in a large number of patients with pontine gliomas are secondary to radiation therapy, specifically high-dose (7,200-7,800 cGy) hyperfractionation radiation therapy, or are part of the biologic progression of this tumor.

MATERIALS AND METHODS

The authors analyzed neuroimaging studies of 31 consecutive patients with pontine-centered gliomas and assessed the time of onset of necrosis, the type and dose of radiation therapy administered, and the length of survival.

RESULTS

Necrosis was present at diagnosis in eight of the 31 patients (26%). Time to appearance and total prevalence of central necrosis did not differ in the standard versus hyperfractionated therapy groups. The time between diagnosis and the appearance of necrosis correlated with length of survival (P = .005, Kendall correlation).

CONCLUSION

In a substantial number of patients, central necrosis in pontine gliomas is not caused by radiation therapy but is an indication of an advanced tumor stage. Children with central necrosis at diagnosis have a significantly shorter median survival than do those without, regardless of the type of therapy administered.

The efflux of nor-epinephrine from platelets in genetic hypertension

Platelets have been used as a model of sympathetic neurons to study the storage of nor-adrenaline in normotensive individuals belonging to families with essential hypertension for at least two generations. The efflux and initial efflux rate (K) of noradrenaline was determined in 36 young relatives (mean age 29.2 years) and in 20 young controls with no family history of hypertension (mean age 26.5 years). From the groups of relatives all those with definite hypertension had been excluded. Efflux and efflux rate K was significantly higher in young relatives (50.82 +/- 3.84 and 28.2 +/- 6.3) than in the controls (39.2 +/- 0.71 and 15.2 +/- 4.8). Of the relatives 25.2% had higher K values than any of the controls.

Use of captopril as an isolated agent for the management of stable angina pectoris--a double blind randomised trial

In this double blind randomised placebo controlled study, we investigated the antianginal efficacy of oral captopril in 33 patients of angiographically documented coronary artery disease (chronic stable angina). Apart from sublingual nitrates, all other antianginal drugs were withdrawn. Patients were then evaluated both subjectively by questionnaire and objectively by treadmill stress test. No patient had more than mild hypertension and all patients had good left ventricular function. One group of patients received oral captopril while the other group was given placebo. A repeat assessment was done after six weeks and the results compared with baseline. Anginal attacks decreased from 20.11 +/- 1.86 per week on placebo to 9.92 +/- 1.38 (p < 0.01) on captopril as also the number of sublingual nitrates (18.84 +/- 3.01 to 11.14 +/- 2.94, p < 0.01). Assessment by the treadmill stress test showed that in comparison to the pretreatment test, captopril therapy resulted in a significantly increased exercise duration (6.26 +/- 0.21 to 6.98 +/- 0.31 minutes, p < 0.05), total work done (6.76 +/- 0.26 METS to 7.48 +/- 0.29 METS, p < 0.05). In addition there was a significant increase in time to angina (6.16 +/- 0.18 to 6.85 +/- 0.24 min, p < 0.05) and time to 1mm ST depression (5.18 +/- 0.26 to 6.46 +/- 0.30 min, p < 0.01). We conclude that captopril is an effective monotherapy for patients with chronic stable angina and has both antianginal as well as anti-ischemic effects, possibly secondary to direct coronary vasodilation.

Modified cephalic vein guide wire technique for permanent pacemaker implantation

This report describes a modified cephalic vein guide wire technique used for implantation of 18 consecutive pacemakers using bipolar leads. The modified technique appears to be a safe and simple procedure for single chamber permanent pacing. Its use may also be extended in implanting dual chamber pacemakers.

Factors influencing platelet serotonin uptake in essential hypertension

In a study of the mechanism(s) of platelet serotonin uptake alteration in essential hypertension, a total of 90 blood samples were analysed for platelet count and platelet serotonin uptake. These included 20 blood samples each of hypertensives, controls before and after cross-incubation experiments and 10 samples of hypertensives after control of blood pressure. It was observed that serotonin uptake was markedly reduced in hypertensive platelets. Diminished serotonin uptake in essential hypertension correlated directly with diastolic and mean arterial blood pressure and inversely with plasma total cholesterol values. In cross-incubation experiments using control platelets and hypertensive plasma, there was a significant reduction in platelet serotonin uptake (303.06 +/- 86.28 cpm/10(8) vs. 204.26 +/- 66.45 cpm/10(8); P less than 0.001), whereas hypertensive platelets when incubated with control plasma, showed increased serotonin uptake (233.50 +/- 75.19 cpm/10(8) vs. 312.64 +/- 79.54 cpm/10(8); P less than 0.01). Upon control of blood pressure, the platelet serotonin uptake improved significantly (205.45 +/- 70.0 cpm/10(8) vs. 266.77 +/- 61.68 cpm/10(8); P less than 0.05-0.01). From these results, it appears that reduced platelet serotonin uptake in essential hypertension is a reversible phenomenon probably governed by the presence of plasma factor(s) and/or altered platelet-membrane function.

The efflux of nor-epinephrine from platelets in essential hypertension

The precise role of sympathetic nervous system in initiation and/or maintenance of essential hypertension is unclear even today. Platelets have been used as a suitable model for studying neuronal turnover of biogenic amines. The present study comprised of hypertensive subjects (23) and normotensive controls (10). Hypertensive subjects exhibited significantly enhanced norepinephrine efflux from platelets at both 30 minutes and 60 minutes (p less than 0.001). The percent norepinephrine efflux from platelets correlated with diastolic (r = 0.66 and 0.76) and mean arterial blood pressure (r = 0.54 and 0.65) but not with systolic blood pressure. The norepinephrine efflux rate (K) similarly correlated with diastolic and mean arterial blood pressure in hypertensive subjects studied. From the above findings it appears that operative sympathetic nervous system activity is enhanced in essential hypertension. The enhanced efflux of norepinephrine from platelets may also indicate activated state of platelets in hypertension. Both could be important in genesis and complications of essential hypertension.

Sites of right ventricular outflow tract obstruction in tetralogy of Fallot--a retrospective study

Fifty one angiographically proved cases of tetralogy of Fallot (TOF) in the age group of 5-50 years were analysed retrospectively for the level(s) of right ventricular outflow tract (RVOT) obstruction. Mean age was 18.1 +/- 11 yrs. Subvalvular stenosis was found to be the commonest site of RVOT obstruction in 49 (96.1%) patients. Evidence of valvular pulmonary stenosis was seen quite commonly (42/51, 83.9% cases), mostly in association with obstruction at other sites. Supravalvular stenosis was also seen in 17 (33.3%) cases. Higher incidence of pulmonary valvular involvement in patients with TOF, in higher average age of patient population may represent valvular involvement to be an acquired phenomenon.

Clinical relevance of vegetations in infective endocarditis

Two-dimensional echocardiograms of 58 patients with infective endocarditis were examined to determine if presence and/or size of vegetations on echocardiogram were predictive of morbidity and mortality. Group 1 (38 patients) with one or more vegetations, had a significantly higher rate of complications (emboli, congestive heart failure, need for surgery and death) than group 2 (20 patients) without vegetations (p less than 0.001). Analysis of morphologic characteristics of the vegetations in group 1 was of no predictive value for complications in individual patients. In contrast, patients whose echocardiograms demonstrated vegetations on aortic valve had a significantly higher incidence of heart failure, embolisation, surgery and death than those with vegetations on mitral valve. Thus, the detection of vegetations on initial echocardiogram clearly identifies a subgroup at risk for complications, more so if vegetations are present on the aortic valve, but the vegetations size does not predict an adverse clinical outcome.

Stroke as a late sequela of cranial irradiation for childhood brain tumors

Cerebrovascular disease involving large and medium-size vessels is thought to be an uncommon sequela of treatment of childhood brain tumors. We reviewed 11 children who developed cerebrovascular disease manifested by strokes or transient ischemic attacks 6 months to 4 years after treatment of brain tumors, while their tumors were in remission. All had received radiation therapy, and seven had received chemotherapy. One child died of acute bilateral cerebral infarctions due to carotid occlusion on one side and marked stenosis on the other 2 years after receiving radiation therapy for an incompletely resected craniopharyngioma. Pathologically, there was marked subendothelial fibrosis of the vessels of the circle of Willis, with inflammatory changes surrounding some of the vessels. In addition to the widely recognized small-vessel damage caused by radiation and chemotherapy in children (mineralizing microangiopathy), damage to medium and large intracranial vessels may result in late sequelae, manifested by stroke or transient ischemic attacks.

Combination chemotherapy with cyclophosphamide, vincristine, procarbazine, and prednisone (COPP) in children with brain tumors

The chemotherapeutic combination of cyclophosphamide, vincristine, procarbazine, and prednisone (COPP) was used to treat 15 children with recurrent central nervous system tumors and seven children with newly diagnosed brainstem tumors. In patients with recurrent tumors, marginal activity was seen in various histologic types. COPP chemotherapy was clearly ineffective in patients with brainstem tumors. Toxicity consisted of mild to moderate myelosuppression and neurotoxicity.