Late-onset visual decline following successful treatment of subfoveal choroidal neovascularisation with photodynamic therapy

Photodynamic therapy (PDT) has been shown in large studies to be capable of achieving closure of choroidal neovascularization (CNV), thereby resulting in stabilization of visual acuity. We report a series of four patients with classic CNV treated with PDT with good initial result but subsequent severe visual loss that may be related to a change in the morphology of the subretinal scar.

Skin and Psyche : Diversionary Symbiosis

A significant proportion of patients with skin diseases have associated psychosocial factors. Not only does psychopathology manifest on the skin in absence of any real skin disease, primary skin disorders can also be exacerbated by emotional stress adversely influencing the homeostasis of immunological and inflammatory processes in deeper layers of the skin. Furthermore, many patients develop emotional problems as a result of having disfiguring skin diseases. In addition, some patients having solely sensory disturbances in absence of primary dermatoses or identifiable medical or neurological conditions, as well as some purely dermatologic conditions such as post-herpetic neuralgia may preferentially need psychotherapeutic modalities to address their underlying psychopathology irrespective of the presenting dermatologic manifestation arising out of 'somatisation' of a psychopathology into physical problems. The most obvious course of action of referral to a psychiatrist or another mental health professional may unfortunately not be readily tenable either due to the perceived stigma associated with psychiatric illness or lack of insight on the part of patients. In the interregnum, effective management of the psychologic or/and psychiatric problems can only be done by the dermatologist provided he has an adequate knowledge base and experience to undertake psychotherapeutic modalities.

Ethnic differences in patient perceptions of heart failure and treatment: the West Birmingham heart failure project

OBJECTIVE

To investigate further the hypothesis that ethnic groups would have different levels of knowledge and perceptions of congestive heart failure (CHF) and treatments for this condition, a cross sectional survey was conducted of patients who were attending the heart failure clinics in two teaching hospitals of Birmingham, UK, that serve a multiethnic population.

METHODS

103 patients with CHF (66 men, 37 women) were surveyed by standard questionnaire: 42 were white, 34 Indo-Asian, 22 Afro-Caribbean, and 5 Oriental.

RESULTS

When asked about their beliefs about control of one's health, 22 (64.7%) of Indo-Asians felt that God/fate controlled their health. The majority of white patients tended to believe that the greatest factor influencing their health was the doctor (15 (35.7%)). Of the total study cohort, only 68 (66%) of patients were aware of their primary diagnosis of heart failure; the majority of Indo-Asians (21 (61.8%)) were not aware of their diagnosis. Half of Indo-Asians (17 (50%)) felt that heart failure was not severe, in contrast to 40.9% (n = 9) of Afro-Caribbeans and only 19.1% (n = 8) of white patients. Of the study cohort, 38 (36.9%) were taking their drugs because their doctor told them to, a response most common among the Indo-Asians. The majority of Indo-Asians (22 (64.7%)) and Afro-Caribbeans (14 (63.6%)) stated that they did not have, or did not know whether they had enough, information about their drug. The corresponding figure for white patients was 21.4% (n = 9). When asked whether they took their medication regularly as prescribed, 7 (31.8%) of Afro-Caribbeans reported that they did not take their drugs regularly.

CONCLUSIONS

Our study has highlighted deficiencies in the knowledge of CHF among patients from ethnic minority groups, as well as deficiencies in the information being given to these patients. There is a clear need to invest more in patient education for CHF, with special emphasis on certain high risk subgroups.

Disposable devices for measuring intraocular pressure: a clinical study to assess their accuracy

AIMS

We conducted a study to compare the accuracy of two commercially available disposable tonometry devices (the acrylic biprism, Tonosafe and the silicone shield, Tonoshield) with the standard Goldmann applanation tonometer (GAT).

METHODS

A total of 80 eyes of 40 patients were randomly assigned to two groups. Group A (40 eyes) had the intraocular pressure IOP measured using GAT and the acrylic biprism (Tonosafe), while Group B (40 eyes) had IOP measured using GAT and the disposable silicone shield (Tonoshield). IOP was measured using the GAT both before and after the disposable device and average of the two standard Goldmann readings was compared with the IOP measured using the disposable devices.

RESULTS

The mean difference in IOP in Group A was 0.29 mmHg (SD 0.54) (P=0.0018) while in Group B the mean difference in IOP was 2.09 mmHg (SD 1.23) (P<0.0001). The Altman-Bland method was used to assess the agreement between two methods of clinical measurement. This shows a positive bias of 0.29 (95% confidence interval (CI) 0.11-0.46) when using the disposable acrylic biprism and a positive bias of 2.09 (95% CI 1.69-2.48) with the silicone shield.

CONCLUSION

The IOP recorded using the disposable acrylic biprism (Tonosafe) was in close agreement with the standard GAT. However, IOP readings obtained with the silicone shield (Tonoshield) tend to be higher than with the standard GAT. These facts should be kept in mind when recording IOP in clinical situations.

Physiology ofAnabaena khannae andChlorococcum humicola under fluoride stress

Sodium fluoride showed pH-dependent physiological responses in the two test microalgae Anabaena khannae and Chlorococcum humicola. A. khannae showed severe membrane damage with fluoride at low pH with leakage of pigments and electrolytes. Annihilation of photosynthesis along with inhibition in 14C uptake was observed at pH 6 with 50 mg/L fluoride. While respiration was less affected in the cyanobacterium, C. humicola showed 30 % inhibition in respiratory activity. Resistance of C. humicola to fluoride toxicity has been attributed to the hindrance provided by the thick cell envelope, intracellular compartmentation and increase in extracellular pH as a consequence of its metabolism.

Caspase 1 and caspase 8 in HIV infected patients with and without tuberculosis

BACKGROUND

Caspase 8 is involved in apoptosis mediated by Fas and p55 tumor necrosis factor receptor ligation in HIV infection. Apoptosis is partially mediated by interleukin-1beta-converting enzyme (caspase-1).

AIMS

We determined apoptosis, using caspase-1 and caspase-8, among patients with HIV infection, with and without tuberculosis (TB), those with TB alone and healthy individuals.

SETTING AND DESIGN

Cross-sectional analysis of caspase-1 and caspase-8 among patients with HIV infection, with and without TB, those with TB alone and healthy individuals.

MATERIALS AND METHODS

Nineteen HIV infected patients with TB (HIV+/TB+) and 20 with HIV infection without TB (HIV+/TB-) were studied. Fifteen individuals with TB alone were disease controls (HIV-/TB+) and 20 were healthy controls (HIV-/TB-). Caspases were measured by single-step ELISA using commercially available monoclonal antibodies.

STATISTICAL ANALYSIS

Two-way ANOVA and Pearson's correlation coefficient.

RESULTS

Mean CD4 counts of HIV+/TB+ were lower than HIV+/TB- (p<0.05). OD value of caspase 1 in HIV+/TB+ was 0.295+0.05, while that in HIV+/TB- it was 0.302+0.18. It was 0.293+0.07 in HIV-/TB+ and in HIV-/TB- the values were 0.287+0.06. OD value of caspase 8 in HIV+/TB+ was 0.307+ 0.07, lower than HIV+/TB- (0.927+0.25). It was 0.008+0.03 in HIV-/TB+ and in HIV-/TB-, 0.074+0.004. Values of caspase 8 in patients with HIV infection (with/without TB) were higher than those with TB alone or healthy individuals (p<0.01). Levels of caspase 8 in HIV+/TB- were higher than patients with HIV+/TB+ (p<0.01).

CONCLUSION

Levels of caspase-1 are not different irrespective of presence or otherwise of TB and HIV infection. Fas-related apoptosis is higher in HIV infection. With concomitant TB, levels of caspase 8 were lower as compared with those without TB.

Beta2 microglobulin as a surrogate marker for HIV infection: good correlation with CD4 counts

To determine if beta-2 microglobulin (beta2M) levels were elevated in our HIV infected patient population and if it could be used as a surrogate marker for disease progression. Thirty-eight HIV infected individuals and 26 age and sex-matched controls were studied. Measurement of CD4 cell count was carried out on a flowcytometer using anti-human CD4 monoclonal antibody and beta2M was measured by an enzyme immunoassay. Mean levels of HIV infected individuals were 1.29 +/- 0.52 mg/L and were significantly higher than 0.74 +/- 0.07 mg/L, the value of controls (p value <0.01). There was a negative correlation between CD4 counts and beta2M levels (r-value-0.79, p value <0.001). Beta2M levels in HIV infected individuals who have no opportunistic infection are elevated and these levels correlate with the CD4 counts. Beta2M can be used for the clinical follow-up of patients with HIV infection.

Removal of 2-fluoro and 2-iodophenol from aqueous solutions using industrial wastes

A comparative study of the adsorbents prepared from several industrial wastes for the removal of 2-fluorophenol and 2-iodophenol has been carried out. The results show that maximum adsorption on carbonaceous adsorbent prepared from fertilizer industry waste has been found to be 35.3 and 235.3 mg g(-1) for 2-fluorophenol and 2-iodophenol, respectively. Compared to carbonaceous adsorbent, the other three adsorbents (viz., blast furnace sludge, dust, and slag) adsorb phenols to a much smaller extent. This has been attributed to the carbonaceous adsorbent having a larger porosity and consequently higher surface area. The adsorption of phenols on this adsorbent has been studied as a function of contact time, concentration and temperature. The adsorption has been found to be endothermic, and the data conform to the Langmuir equation. The further analysis of data indicates that adsorption is a first order process and pore diffusion controlled. A comparative study of adsorption results with those obtained on standard activated charcoal sample shows that prepared adsorbent is about 45% as efficient as standard activated charcoal and therefore, can be fruitfully employed for the removal of phenolic pollutants from wastewaters.

Animal models of hepatic encephalopathy

Hepatic encephalopathy is a neuropsychiatric syndrome associated with acute liver failure, chronic parenchymal liver disease, or portosystemic anastomosis. Many approaches have been used to develop suitable models of hepatic encephalopathy, each with specific advantages and disadvantages. The most commonly used models have been the surgical hepatectomy and liver devascularization procedures, and hepatotoxins such as galactosamine and acetaminophen. Drug-toxicity models may be clinically more relevant. The specific requirements of experiments to study a particular aspect of encephalopathy also influence the choice of animal model. Animal models will play a central role in future research into hepatic encephalopathy to better understand its pathophysiology and to develop newer therapeutic modalities for this condition.

Effect of different aspirin doses on platelet aggregation in patients with stable coronary artery disease

BACKGROUND

Aspirin is widely used as an antiplatelet agent in the primary and secondary prevention of cardiovascular disease. In order to spare prostacyclin formation and reduce gastrointestinal side-effects, very low doses of aspirin have been introduced. However, it remains unclear whether these low doses are equally effective with respect to inhibition of platelet aggregation.

AIMS

In a randomized, controlled study in 60 patients with stable coronary artery disease, the effects on platelet aggregation of five doses (50, 80, 100, 162.5 and 325 mg) of aspirin, which are widely used in clinical practice, given for 70 days, were investigated. Two reagents, adenosine diphosphate (ADP) and epinephrine, were used to induce platelet aggregation in platelet-rich plasma. An age- and sex-matched group of people without coronary artery disease served as the control.

RESULTS

ADP- and epinephrine-induced platelet aggregation was 78.2 +/- 12.8% and 76.7 +/- 15.5% of maximum aggregation in the control group. Aspirin inhibited platelet aggregation in a dose-dependent manner. Minimum platelet aggregation was observed at a dose of 325 mg aspirin (27.5 +/- 17.4% with ADP). Doses of 50 and 80 mg aspirin were much less effective in inhibiting platelet aggregation (59.1 +/- 11.4% and 50.3 +/- 12.1% with ADP, respectively). Doses of 100 and 162.5 mg aspirin produced significantly greater inhibition of platelet aggregation than lower doses (36.2 +/- 11.7% and 38.5 +/- 19.8% platelet aggregation with ADP, respectively).

CONCLUSION

Our results demonstrate that doses of aspirin less than 100 mg are not as effective at inhibiting platelet aggregation as doses greater than 100 mg.

Utilization of industrial waste products as adsorbents for the removal of dyes

A number of low cost adsorbents from steel and fertilizer industries wastes have been prepared and investigated for the removal of anionic dyes such as ethyl orange, metanil yellow and acid blue 113 from aqueous solutions. The results indicate that inorganic wastes, i.e. blast furnace dust, sludge and slag from steel plants are not suitable for the removal of organic materials, whereas a carbonaceous adsorbent prepared from carbon slurry of fertilizer industry was found to adsorb 198, 211 and 219mg/g of ethyl orange, metanil yellow and acid blue 113, respectively. The adsorption of dyes on this adsorbent was studied as a function of contact time, concentration, particle size and temperature by batch method. The adsorption isotherm conformed to Langmuir model and the adsorption was found to be exothermic and physical in nature. Kinetic data conforms to Lagergren's equation with good correlation coefficients varying from 0.9998 to 0.9999 indicating that the adsorption is a first-order process. The adsorption data on carbonaceous adsorbent was compared to a standard activated charcoal sample and it was found that the prepared adsorbent is about 80% as efficient as standard activated charcoal and therefore, can be used as low cost alternative ( approximately 100 US dollars per ton) for colour removal from effluents.

Reduced apoptosis by pentoxiphylline among patients with HIV infection

BACKGROUND

Apoptosis is a significant cause of CD4(+) T cell death. Caspase 8 (FLICE) is involved in apoptosis mediated by Fas and p55 tumor necrosis factor (TNF) receptor ligation. It is also partially mediated by interleukin-1beta (IL-1beta)-converting enzyme (ICE; caspase 1). We and others have shown that pentoxiphylline inhibits TNF-alpha. We used it among patients with HIV infection to determine if 24 weeks of therapy altered the levels of caspase 1 and caspase 8.

PATIENTS AND METHODS

Nineteen HIV-infected patients having no opportunistic infection at the time of recruitment were administered pentoxiphylline 400 mg thrice daily for 24 weeks. Caspase levels were measured using a single-step ELISA using commercially available monoclonal antibodies against caspase 1 and caspase 8.

RESULTS

Mean CD4 counts of the patients were 202.6+/-111.6 (/mm(3)). Mean OD value of caspase 1 among patients before therapy was 0.302+/-0.197 and was higher than that of controls (0.287+/-0.064), but this was not statistically significant. Following 24 weeks of therapy with pentoxiphylline, the OD value declined significantly to 0.164+/-0.028 among patients (p<0.001). Mean OD value of caspase 8 among patients prior to therapy was 0.927+/-0.249. This was significantly higher than that of controls, whose level was 0.0074+/-0.004 (p<0.001). Following 24 weeks of therapy with pentoxiphylline, the OD value declined to 0.199+/-0.064 among patients and this was significantly lower than the value at the start of treatment (p<0.001).

CONCLUSION

Therapy with pentoxiphylline for 24 weeks is associated with a decline in the levels of caspase 1 and caspase 8. Since the drug is known to produce TNF inhibition, this might result in reduced apoptosis and an improved CD4 lymphocyte survival.

Influence of Mycobacterium tuberculosis on differential activation of helper T-cells

Host defence against tuberculosis infection involves T-lymphocyte mediated cellular immune responses. In this study we assessed T-cell activation by studying the early signal transduction events and production of cytokines by human CD4+ T-cells. The study constituted of five groups of subjects: (a) untreated acid fast bacilli (AFB)+ve TB patients who have not started anti-tuberculosis therapy (ATT) [New]; (b) patients who have taken ATT for two months [2T]; (c) patients who have taken ATT for six months [6T]; (d) mantoux positive healthy controls [T+ve]; (e) mantoux negative healthy controls [T-ve]. We found that mantoux positive healthy controls produced significantly higher levels of IP3, intracellular Ca2+ and presented increased PKC activity when CD4+ T-cells were stimulated with M. tuberculosis H37Rv cell lysate as compared to mantoux negative controls. Furthermore, decreased expression of CD54 (ICAM-1) and reduced [Ca2+]i were seen in TB patients as compared to T+ve healthy controls. TB patients showed significantly lower levels of IL-2 and IFNgamma and higher levels of IL-4 as compared to normal healthy controls, suggesting a diminished Th1 response. Thus, the reciprocal changes in cytokines, reduced [Ca2+]i levels, and CD54 expression in patients imply phenotype shifting of Th precursors to Th2 type in TB patients.

Imaging bacterial infection with (99m)Tc-ciprofloxacin (Infecton)

AIMS

The diagnosis of deep seated bacterial infections, such as intra-abdominal abscesses, endocarditis, and osteomyelitis, can be difficult and delayed, thereby compromising effective treatment. This study assessed the efficacy of a new radioimaging agent, Tc-99m ciprofloxacin (Infecton), in accurately detecting sites of bacterial infection.

METHODS

Eight hundred and seventy nine patients with suspected bacterial infection underwent Infecton imaging and microbiological evaluation. The sensitivity and specificity of Infecton in detecting sites of bacterial infection were determined with respect to Centres of Disease Control, World Health Organisation, and Dukes's criteria.

RESULTS

Five hundred and seventy four positive and 295 negative images were produced. These included 528 true positives, 46 false positives, 205 true negatives and 90 false negatives, giving an overall sensitivity of 85.4% and a specificity of 81.7% for detecting infective foci. Sensitivity was higher (87.6%) in microbiologically confirmed infections.

CONCLUSIONS

Infecton is a sensitive technique, which aids in the earlier detection and treatment of a wide variety of deep seated bacterial infections. The ability to localise infective foci accurately is also important for surgical intervention, such as drainage of abscesses. In addition, serial imaging with Infecton might be useful in monitoring clinical response and optimising the duration of antimicrobial treatment.

Clinical relevance of intracellular cytokines IL-6 and IL-12 in acute pancreatitis, and correlation with APACHE III score

Pro-inflammatory cytokines are involved in the pathogenesis of acute pancreatitis (AP). Here, we measure and correlate clinically the percentages of peripheral blood mononuclear cells (PBMC) that contain interleukin (IL)-6 and IL-12 and compare these with acute physiology and chronic health evaluation (APACHE III) scores in 30 patients with AP. Severity of AP is determined according to the Atlanta criteria. Patients with severe AP (n = 15) had significantly higher IL-6 values compared to those with mild AP (n = 15). IL-12 levels correlated well with aetiological factors (alcohol and biliary pathology) in patients with AP. Correlation was seen between IL-6 value and APACHE score in severe AP. A score of 30 points was used as the cut off between mild (<30) and severe (>30) cases, with a sensitivity of 80% and specificity of 100%. Cut off percentages for IL-6- and IL-12-positive PBMCs were >25% (positive predictive value [PPV]: 100%) and >9% (PPV: 70%), respectively. Based on these results, it would seem logical to use both APACHE III score and IL-6 percentage to assess severity in patients with AP.

Antitubercular therapy decreases nitric oxide production in HIV/TB coinfected patients

BACKGROUND

Nitric oxide (NO) production is increased among patients with human immunodeficiency virus (HIV) infection and also those with tuberculosis (TB). In this study we sought to determine if there was increased NO production among patients with HIV/TB coinfection and the effect of four weeks chemotherapy on this level.

PATIENTS AND METHODS

19 patients with HIV/TB coinfection were studied. They were treated with standard four drug antitubercular therapy and sampled at baseline and four weeks. 20 patients with HIV infection but no opportunistic infections were disease controls and 20 individuals as healthy controls. Nitrite and citrulline, surrogate markers for NO, were measured it spectrophotometrically.

RESULTS

Mean age of HIV/TB patients was 28.4+6.8 years and CD4 count was 116+36.6/mm3. Mean nitrite level among HIV/TB coinfected was 207.6+48.8 nmol/ml. This was significantly higher than 99.7+26.5 nmol/ml, the value for HIV infected without opportunistic infections and 46.4+16.2 nmol/ml, the value for healthy controls (p value <0.01). Level of HIV/TB coinfected declined to 144.5+ 34.4 nmol/ml at four weeks of therapy (p value < 0.05). Mean citrulline among HIV/TB coinfected was 1446.8+468.8 nmol/ml. This was significantly higher than 880.8+ 434.8 nmol/ml, the value for HIV infected without opportunistic infections and 486.6+212.5 nmol/ml, the value for healthy controls (p value <0.01). Levels of HIV/TB infected declined to 1116.2+388.6 nmol/ml at four weeks of therapy (p value <0.05).

CONCLUSION

NO production is elevated among patients with HIV infection, especially so among HIV/TB coinfected, but declines significantly following 4 weeks of antitubercular therapy.

Methylphenols Removal from Water by Low-Cost Adsorbents

A comparative study on the adsorption of methylphenols on adsorbents prepared from several industrial wastes has been carried out. The results show that extent of adsorption on carbonaceous adsorbent prepared from fertilizer industry waste has been found to be 37.3, 40.5, 65.9, and 88.5 mg/g for 2-methylphenol, 4-methylphenol, 2,4-dimethylphenol, and 2,4,6-trimethylphenol, rspectively. As compared to carbonaceous adsorbent, the other three adsorbents viz. blast furnace sludge, dust, and slag adsorb methylphenols to a much smaller extent. This has been accounted for due to the carbonaceous adsorbent having a larger porosity and consequently higher surface area. The adsorption of phenols on this carbonaceous adsorbent as a function of contact time, concentration, and temperature has been studied by the batch method. The adsorption has been found to be endothermic and data conform to the Langmuir equation. The analysis of data indicates that adsorption is a first-order process and pore diffusion-controlled. The efficiency of the carbonaceous adsorbent was assessed by comparing the results with those on a standard activated charcoal sample. It was found that the carbonaceous adsorbent is about 45% as efficient as standard activated charcoal and can therefore be employed for the removal of methylphenols from wastewaters.

Development and validation of hydroxy ethyl starch kits for instant use in gastroesophageal reflux and gastric motility studies

A reduction method based on stannous chloride is described to prepare hydroxy ethyl starch kits for gastrointestinal reflux and gastric motility studies. Following verification of the consistency of radiolabelling, in vitro experiments were carried out to validate 99mTc hydroxy ethyl starch as a liquid phase and solid phase gastric motility imaging radiotracer. Gastroesophageal reflux, liquid phase and solid phase studies were then conducted in 13 adult volunteers to examine the in vivo stability of the radiotracer. High labelling efficiency (>95% when prepared at neutral pH) was consistently achieved, which remained stable in conditions simulating gastric environment. Twelve of the 13 volunteers did not show absorption of any radioactivity from the gastro-intestinal tract. 99mTc hydroxy ethyl starch is a new agent suitable for gastroesophageal reflux and gastric motility studies. It is available in kit form and is a more 'physiological' agent than 99mTc sulphur colloid for preparing a solid radioactive meal. 99mTc hydroxy ethyl starch represents a true carbohydrate meal, and unlike 99mTc sulphur colloid, is easy to prepare and can easily be standardized to produce a standard vegetarian meal.

Nitric oxide derivative in bronchoalveolar lavage fluid from patients with idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis is a chronic inflammatory disorder of unknown aetiology with a number of inflammatory cells playing a role in its pathogenesis. In this study, we have attempted to find out the possible role of nitric oxide in its pathogenesis by way of measuring the nitrite and nitrate levels in the bronchoalveolar lavage fluid. Ten patients of histologically proved idiopathic pulmonary fibrosis and 10 controls (5 with normal chest skiagrams and 5 with sarcoidosis) were included in the study Bronchoalveolar lavage was carried out in these cases. The levels of nitrates and nitrites were increased in cases of idiopathic pulmonary fibrosis (0.77+/- 0.36 and 8.93 +/- 2.63 nmol/mg of protein) compared to those in controls (0.38 +/- 0.06 and 3.80 +/- 1.11, respectively for sarcoidosis patients); (0.39 +/- 0.13 and 6.56 +/- 1.61 for subjects with normal chest skiagrams). These differences were statistically significant (p < 0.05 to 0.01). These findings suggest a possible role of nitric oxide in the pathogenesis of idiopathic pulmonary fibrosis.

An analysis of the effects of smoking and other cardiovascular risk factors on obliteration rates after arteriovenous malformation radiosurgery

PURPOSE

To assess the relationships of smoking and other cardiovascular disease risk factors (hypertension, diabetes, hypercholesterolemia, and gender) to rates of radiosurgery-induced obliteration of arteriovenous malformations (AVM).

METHODS AND MATERIALS

We evaluated follow-up imaging and clinical data in 329 AVM patients who received gamma knife radiosurgery at the University of Pittsburgh between 1987 and 1994. There were 113 smokers, 29 hypertensives, 5 diabetics, 4 hypercholesterolemics, 159 male patients, and 170 female patients. All patients had regular clinical or imaging follow-up for a minimum of 3 years after radiosurgery.

RESULTS

Multivariate analysis showed that smoking had no effect on AVM obliteration (p > 0.43). Hypertension, diabetes, and hypercholesterolemia had no discernible effect on AVM obliteration in this study (p > 0.78). However, females aged 12-49 had a statistically significant lower in-field obliteration rate than males (78% vs. 89%, p = 0.0102).

CONCLUSION

Smoking has no effect on AVM obliteration. Hypertension, diabetes, and hypercholesterolemia had no discernible effect in this study. Further study is needed to establish whether estrogen has a vascular protective effect that could partially limit radiosurgical AVM obliteration, as suggested by this study.

In vitro nitrogen fixation, phosphate solubilization, survival and nutrient release by Azotobacter strains in an aquatic system

In vitro nitrogen fixation, phosphate solubilization, survival and nutrient release by the three strains of Azotobacter (Mac-27, nitrogen fixer; PS-21, phosphate solubilizer and MSX-9, a phytohormone producer) in an aquatic system using three different organic substrates (cow-dung, piggery and poultry waste/excreta) were studied. It was shown that Azotobacter can grow and multiply in an aquatic system when fertilized either with cow-dung (100 mg 1(-1)), poultry (50 mg 1(-1)) or piggery (25 mg 1(-1)) waste/ excreta. Mac-27 and MSX-9 strains of Azotobacter fixed higher quantities of nitrogen (0.03-0.12 mg 1(-1) d(-1)) in aquaria water treated with cow-dung, while with poultry and piggery excreta, the three strains of Azotobacter fixed 0.03-0.09 mg 1(-1)d(-1) of nitrogen. O-PO4 concentration was also high in microbial-inoculated aquaria as compared to the controls which decreased with respect to time. Similarly, a decrease in total nitrogen concentration was also observed in the aquaria water after the maximum levels of fixation had been reached. Concomitant with the decrease in total nitrogen concentration, a simultaneous increase in NO3-N, NO2-N and NH4-N was observed. Maximum phytoplankton population was observed in MSX-9, while the population of zooplankton was maximum in Mac-27 inoculated aquaria. These studies indicated that Azotobacter can be used as a biofertilizer for enhancing nitrogen input and phosphate solubilization in fish ponds. Microbial inoculation along with organic substrate, however, has to be repeated at least at biweekly intervals.