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Biomedical subjects

N K Kaushik

Publications and source records attributed to N K Kaushik.

At least 19 recordsLinked to original sources
PubMed2006

Synthesis, characterization, antibacterial and cytotoxic study of platinum (IV) complexes.

Platinum (IV) complexes [Pt (L)2Cl2] [where, L= benzyl-N-thiohydrazide (L1), (benzyl-N-thio)-1,3-propanediamine (L2), benzaldehyde-benzyl-N-thiohydrazone (L3) and salicylaldehyde-benzyl-N-thiohydrazone (L4)] have been synthesized. The thiohydrazide, thiodiamine and thiohydrazones can exist as thione-thiol tautomer and coordinate as a bidentate N-S ligand. The ligands were found to act in monobasic bidentate fashion. Analytical data reveal that metal to ligand stoichiometry is 1:2. The complexes have been characterized by elemental analysis, IR, mass, electronic and 1H NMR spectroscopic studies. In vitro antibacterial and cytotoxic studies have been carried out for some complexes. Various kinetic and thermodynamic parameters like order of reaction (n), activation energy (Ea), apparent activation entropy (S#) and heat of reaction (DeltaH) have also been carried out for some complexes.

Anti-Bacterial Agents↗
PubMed2006

Platinum (IV) thiohydrazide, thiodiamine and thiohydrazone complexes: a spectral, antibacterial and cytotoxic study.

Some platinum (IV) complexes [Pt(L)2Cl2] [where, L=2-aminopyridine-N-thiohydrazide (L1), (2-aminopyridine-N-thio)-1,3-propanediamine (L2), benzaldehyde-2-aminopyridine-N-thiohydrazone (L3) and salicylaldehyde-2-aminopyrtidine-N-thiohydrazone (L4)] have been synthesized. The thiohydrazides, thiodiamine and thiohydrazones can exist as thione-thiol tautomer and coordinate as a bidentate N-S ligand. The ligands found to act in monobasic bidentate fashion. Analytical data reveals that metal to ligand stoichiometry is 1:2. The complexes have been characterized by elemental analysis, IR, mass, electronic and 1H NMR spectroscopic studies. In vitro antibacterial and cytotoxic study have also been carried out for some complexes.

Anti-Bacterial Agents↗
PubMed2006

Organotin(IV) complexes of thiohydrazides and thiodiamines: synthesis, spectral and thermal studies.

Organotin(IV) complexes of tribenzyltin(IV) chloride and di(para-chlorobenzyl)tin(IV) dichloride with thiohydrazides have been reported. The ligands synthesized were bidentate coordinating through sulphur and terminal nitrogen atoms. These form 1:1 metal-ligand complexes. The following organotin(IV) complexes have been synthesized: (C(6)H(5)CH(2))(3)Sn(L(1))Cl, (p-ClC(6)H(4)CH(2))(2)Sn(L(1))Cl(2), (C(6)H(5)CH(2))(3)Sn(L(1))Cl, (p-ClC(6)H(4)CH(2))(2)Sn(L(2))Cl(2), (C(6)H(5)CH(2))(3)Sn(L(3))Cl, (p-ClC(6)H(4)CH(2))(2)Sn(L(3))Cl(2), where (L(1)): 2-phenylethyl N-thiohydrazide, (L(2)): N-(2-phenylethyl-N-thio)-1,3-propane diamine, (L(3)): N-(2-phenylethyl-N-thio)-1,2-ethane diamine. The complexes were synthesized by directly mixing, refluxing and stirring the ligands with organotin(IV) chlorides in a suitable solvent. The complexes were found to be pure and were characterized by elemental analysis, electronic, infrared, (1)H and (13)C NMR spectroscopy. These complexes were also studied for their thermal decomposition by thermogravimetry (TG) and differential thermal analysis (DTA). Various kinetic and thermodynamic parameters, viz. activation energy (E(a)), order of reaction (n), apparent activation entropy (S(#)) and heat of reaction (DeltaH) have been determined by using Horowitz-Metzger method. It was observed that these complexes are highly stable and the thermal degradation of these complexes is a spontaneous process. The ligands and their tin complexes have also been screened for their fungitoxicity activity and found to be quite active in this respect.

Diamines↗
PubMed2006

In vitro antitumour and antibacterial studies of some Pt(IV) dithiocarbamate complexes.

A few Pt(IV) complexes of the type [Pt(L)(2)Cl(2)] [where L=morpholine dithiocarbamate (L(1)), aniline dithiocarbamate (L(2)), N-(methyl, cyclohexyl) dithiocarbamate (L(3)) and N-(ethyl, cyclohexyl) dithiocarbamate (L(4))] were synthesized. The complexes have been characterized by elemental analysis, molar conductance, IR, electronic, (1)H and (13)C NMR spectroscopic studies. The ligands found to act in monobasic bidentate fashion. Cyclicvoltammetric studies, antibacterial and in vitro antitumour studies were also carried out.

Anti-Bacterial Agents↗
PubMed2005

Organotin(IV) complexes of thiohydrazones: synthesis, characterization and antifungal study.

Some new organotin(IV) complexes with salicylaldehyde aniline-N-thiohydrazone (L1) and cinamaldehyde aniline-N-thiohydrazone (L2) of the type (p-ClC6H4)3Sn[L] Cl and (p-ClC6H4)2Sn[L]Cl2 have been synthesized (where L = L1 and L2). The complexes and ligands were characterized by elemental analysis and spectral (UV-vis, IR and 1H NMR) studies. In all the complexes, ligands act as bidentate, coordination through sulphur and azomethane nitrogen. Complexes are 1:1 metal ligands complexes. Antifungal studies of some complexes against Rhizoctonia bataticola fungal strain have been carried out.

Antifungal Agents↗
PubMed2004

Triphenyl phosphine adducts of platinum(IV) and palladium(II) dithiocarbamates complexes: a spectral and in vitro study.

Triphenyl phosphine adducts of dithiocarbamate complexes of platinum(IV) and palladium(II) of the type [Pt(L)2PPh3Cl2] and [Pd(L)2PPh3] [L: morpholine dithiocarbamate (L1), aniline dithiocarbamate (L2) and N-(methyl, cyclohexyl) dithiocarbamate (L3)] were prepared and characterized by elemental analysis, electronic, IR, 1H NMR and 13C NMR spectral studies. Thermal studies of the complexes were carried out. In vitro antitumor activity has been screened towards human adenocarcinoma cell lines and showed significant inhibition even at very low concentration.

Antineoplastic Agents↗
PubMed2004

Stroke at moderate altitude.

OBJECTIVE: To know the clinical profile, presence of various risk factors for stroke at moderate altitude and to study its relationship with hypertension and polycythemia at moderate altitude. METHODS: We analyzed the data of 100 patients, consecutively admitted to a hospital situated at an moderate altitude of 2200 meters MSL of Sub-Himalayan ranges and studied the age, gender, geographical distribution, clinical features and presence of various risk factors in relation to stroke. This is not only the first study conducted in Himachal Pradesh but also first study in India to be conducted at moderate altitude (2000-3000 meters MSL). RESULTS: Males outnumbered females (66% males, 34% females) with rural predominance (73% rural, 27% urban). Cerebral infarction (69%) was more common but primary intracerebral haemorrhage (26%) was more common than found in the West. Hypertension (62%) and smoking (60%) were most common risk factors present and polycythemia was not a significant risk factor at this altitude. CONCLUSION: Incidence of stroke was found to be lower than the study conducted at low altitude. incidence of various types of stroke was similar to other Indian studies. The combination of opposite effects of decreased hypertension and increased haematocrit could not be demonstrated at this altitude and smoking was more common than in other studies and other risk factors prevalent were same as that for low altitude.

Adult↗
PubMed2000

The toxicity of a neem insecticide to populations of culicidae and other aquatic invertebrates as assessed in in situ microcosms.

Microcosm trials were conducted with the botanical insecticide Margosan-O(R) to assess the potential hazards of the product to aquatic organisms. Laboratory chronic bioassays with water from the treated microcosms were conducted to provide an estimate of the residual effect of Margosan-O. Results from chronic tests showed Margosan-O toxicity to be greater in the laboratory exposures than in situ with Culicidae larvae exposed to the same concentrations. Residue analyses of the active ingredient, azadirachtin, determined that it had a half-life of 36 to 48 h in water exposed to natural sunlight. Two applications of Margosan-O at the recommended application rate for pests did not harm aquatic invertebrates that are categorized as planktonic and filter feeding (Culex sp. and Daphnia sp.). However, the benthic invertebrate (Chironomus riparius) was affected by multiple applications of neem. These results show that the use of Margosan-O and possibly other neem extracts in or near aquatic environments could lead to disturbances in benthic populations and may cause decreases in numbers of organisms that are important in food web and nutrient cycling processes.

Animals↗
PubMed1993

Serodiagnostic efficiency of phospholipid associated protein of Mycobacterium tuberculosis H37Rv.

The phospholipid-associated protein (55-67 kDa) fraction of Mycobacterium tuberculosis H37Rv was purified as the DE-V protein fraction. This DE-V fraction was used for diagnosis of tuberculosis by enzyme-linked immunosorbent assay (ELISA), detecting IgG antibody in sera collected from different categories of tuberculosis patients, i.e. with acid fast bacilli (AFB) culture-positive pulmonary tuberculosis, with AFB culture-negative, but radiologically suspected, pulmonary tuberculosis, extrapulmonary tuberculosis, and control groups of patients suffering from diseases other than tuberculosis (asthma and/or rhinitis, lepromatous leprosy) as well as from healthy volunteers. Encouraging operational ELISA validity could be achieved with 93% sensitivity, 100% specificity, 97% efficiency, 100% positive predictivity and 95% negative predictability even among the extrapulmonary and suspected pulmonary tuberculosis patients. The above assay was insensitive but with 100% specificity among control group of patients suffering from diseases other than tuberculosis. The DE-V protein fraction was associated with phosphatidyl inositol and phosphatidyl inositol mannosides. The dissociation of phospholipid-protein complex decreased ELISA specificity. ELISA reactivity of the DE-V fraction appeared to be thermostable; thus, it may have serodiagnostic utility in developing countries.

Antibodies, Bacterial↗
PubMed1991

Toxicity of microencapsulated permethrin to selected nontarget aquatic invertebrates.

Microencapsulated permethrin (penncapthrin) was evaluated under laboratory conditions for its toxicity toward several nontarget aquatic invertebrates. Average LC50 estimates for selected lotic invertebrates, based on a one hour dosing regime, were: 2.71 mg/L for Simulium vittatum, 4.59 mg/L for Hydropsyche spp., and 13.41 mg/L for Isonychia bicolor. In acute static tests with Daphnia magna, there was no significant difference (p less than or equal to 0.05) between the toxicity of penncapthrin at 96 h (LC50 range: 6.80-22.5 micrograms/L) and the EC formulation at 72 h (LC50 range: 0.6-21 micrograms/L). Comparatively, the toxicity of microencapsulated methyl parathion (penncap-m) was not significantly different from that of penncapthrin toward D. magna, the former having LC50 estimates ranging form 0.3-12.25 micrograms/L. LC50 estimates associated with Daphnia pulex ranged from 19 to 131 micrograms/L. The toxicity of penncapthrin and penncap-m toward D. pulex was difficult to determine because of frequent control mortality due to food deprivation resulting from the need to run tests for longer than 48 h. In successful tests, LC50 estimates ranged from 19 to 28 micrograms/L for penncapthrin and 0.08 to 25 micrograms/L for penncap-m after 72 h exposure. In long term toxicity tests, 95% of D. magna at 1 microgram/L, 44% at 10 micrograms/L, and 20% at 15 micrograms/L survived after 39 days exposure. Less than 15% of D. pulex survived over the same concentration range following 32 days exposure. Despite same drawbacks, long-term toxicity tests were more appropriate than short-term tests for evaluating microencapsulated pesticides because of reduced variability in LC50 estimates and lower control mortality.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Chronic toxicity of a pure and technical grade pentachlorophenol to Daphnia magna.

Chronic toxicity test procedures (static, with renewal) were used to determine the chronic toxicity of sublethal concentrations of a technical formulation of pentachlorophenol (PCP) and pure pentachlorophenol to Daphnia magna. Test organisms 48 +/- 12 h old were exposed for their entire lifespan (i.e., until death) to 0.01, 0.05, 0.1 and 0.5 mg technical PCP/L and 0.01, 0.087 and 0.1 mg pure PCP/L. Criteria used to assess chronic toxicity were mean time to appearance of the primiparous instar in the brood chamber, mean number of days to release of the first brood, mean number of broods produced per female, mean brood size per female, mean number of reproductive days, mean number of young produced per reproductive day per female and survivorship. Pentachlorophenol differentially affected maturation and reproduction but not survivorship or longevity. Mean number of broods produced per daphnid, length of the reproductive period, longevity and survivorship were insensitive criteria relative to mean time to appearance of the primiparous instar, time to release of first brood, brood size, and number of young produced per daphnid per reproductive day. Generally, there was little difference in toxicity of the three concentrations of pure PCP, for they significantly reduced mean brood size and rate of reproduction of young and significantly but differentially affected maturation. Technical PCP, at the highest concentration of 0.5 mg/L, significantly reduced mean brood size and the rate of production of young, and significantly delayed both time to appearance of the primiparous instar and release of the first brood. When differences in toxicity occurred, generally, pure PCP was more toxic than comparable concentrations of technical PCP. Although enhanced maturation was observed there was no compensatory reproduction.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Acute toxicity of pure pentachlorophenol and a technical formulation to three species of Daphnia.

The acute toxicity of a technical formulation of pentachlorophenol (PCP) and pure pentachlorophenol to three age classes of Daphnia magna, and adult D. pulex and D. galeata mendotae was determined by static toxicity tests. The influence of a number of factors on toxicity of PCP was also examined. The 48-hr LC50 estimates for adult daphnids of the three species exposed to pure PCP were 1.78, 4.59 and 0.51 mg/L, respectively, while those for the technical formulation were 2.57, 3.66 and 0.33 mg/L, respectively. There was little difference in toxicity between the technical and pure PCP; however, toxicity of both forms of PCP was influenced by duration of exposure, age (and/or size) and species of test organism and pH of the test solution. Pentachlorophenol caused a toxic response over a very narrow range of concentrations, with the greatest response occurring immediately between 0 and 24 hr. Pure PCP was equally toxic to all age classes of D. magna but susceptibility to technical PCP decreased with maturation. D. g. mendotae was ten times more sensitive than D. pulex to PCP. Pure PCP was significantly more toxic to D. magna at pH 5.5 than 7.0 with mean 48-hr LC50 values of 0.082 and 1.78 mg PCP/L, respectively. At 12 degrees C, the toxicity of both forms of PCP to D. g. mendotae and D. pulex did not differ significantly from that at 20 degrees C; however, technical PCP was significantly more toxic to D. magna at 12 degrees C for an exposure duration of 48 hr.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗
PubMed1991

Impact of a pulse application of permethrin on the macroinvertebrate community of a headwater stream.

This study evaluated the impact of concentrated pulse (16 microg litre(-1)) of the insecticide permethrin (emulsifiable concentrate) on the macroinvertebrate community of a northern Ontario headwater stream. Post-treatment drift increased by a factor of 2400 within minutes of the arrival of the insecticide. There was a significant (P<0.05) reduction in the abundance of invertebrates in most families as far as 260 m below the point of injection in both kick and artificial substrate samples. Greatest impact was observed in the mayflies, Baetis flavistriga. Heptagenia flavescens, and Epeorus sp., the stonefly, Leuctra tenuis, and the caddisfly, Dolophilodes distinctus. Diptera were not significantly reduced. The number of species occurring 100 m from the point of injection was reduced by 47%, but only by 17% at 260 m. There was no change in the per cent composition of functional feeding groups at any point after treatment. Recovery of most invertebrates was complete within 6 weeks of treatment.

Journal Article↗
PubMed1991

Comparative study of ultrasonography and oral cholecystography in evaluation of gallbladder and biliary tract diseases.

50 cases, aged between 14-60 years, clinically suspected of gall-bladder and biliary tract diseases were evaluated by ultrasonography and oral cholecystography. Ultrasound with a preliminary radiograph of gallbladder region, proved to be more sensitive and reliable procedure than oral cholecystography. Besides providing ancillary information regarding adjacent anatomic structures, it also guided the surgeon to decide preoperatively about the mode of surgery to be employed. Further, from the present study it can be fairly concluded that ultrasound should be used as the primary screening technique for evaluating gallbladder and biliary tract diseases, after plain skiagram of the gallbladder region, since it is non-invasive, more sensitive than OCG and is devoid of use of contrast media and its toxicity.

Adolescent↗
PubMed1991

A comparative study between hysterosalpingography and laparoscopy in case of infertility.

From the present study it can be concluded that both the procedures have their own importance and no one can substitute the other, in diagnosing all the diseases. HSG has been found to be more rewarding in cases of abnormalities of the lumen of uterus and fallopian tubes for their patency. On the other hand laparoscopy has been more rewarding for the abnormalities of the surface of uterus, fallopian tubes and ovaries. It is suggested that in all the cases of infertility both the procedures should be done and the HSG should be done first followed by laparoscopy.

Adolescent↗
PubMed1989

The effect of two applications of atrazine on the water quality of freshwater enclosures.

To simulate runoff from agricultural lands, atrazine was applied to aquatic enclosures (112 m(3)) on 1 June 1983 at a concentration of 0.1 mg litre(-1). Thirty-five days later the nominal concentration was increased to 0.155 mg litre(-1). Treated enclosures became clearer with Secchi disc readings of 3.6 m compared to non-treated controls (2.9 m). Less than 5% of the first atrazine addition disappeared during the first 35 days and little effect on biological activity was observed. However, with the second enrichment the rate of loss of atrazine was rapid (t(1/2) = 150 days), ammonium, calcium, dissolved inorganic carbon and nitrate levels were higher, while oxygen, chlorophyll, dissolved organic carbon and particulate organic carbon concentrations were lower in the treated enclosures. These water quality changes cannot be explained by herbicide-water chemistry interactions alone, thereby suggesting an indirect effect as a consequence of atrazine inhibition on photosynthesis and possibly other microbial processes.

Journal Article↗