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Biomedical subjects

S Kannan

Publications and source records attributed to S Kannan.

At least 127 records · Page 7Linked to original sources
PubMed1990

Experiences with Mycobacterium leprae soluble antigens in a leprosy endemic population.

Rees and Convit antigens prepared from armadillo-derived Mycobacterium leprae were used for skin testing in two leprosy endemic villages to understand their use in the epidemiology of leprosy. In all, 2602 individuals comprising 202 patients with leprosy detected in a prevalence survey, 476 household contacts and 1924 persons residing in non-case households were tested with two antigens. There was a strong and positive correlation (r = 0.85) between reactions to the Rees and Convit antigens. The distribution of reactions was bimodal and considering reactions of 12 mm or more as 'positive', the positivity rate steeply increased with the increase in age. However, the distributions of reactions to these antigens in patients with leprosy, their household contacts and persons living in non-case households were very similar. These results indicate that Rees and Convit antigens are not useful in the identification of M. leprae infection or in the confirmation of leprosy diagnosis in a leprosy endemic population with a high prevalence of nonspecific sensitivity.

Adolescent↗
PubMed1988

Reliability of direct skin smear microscopy in leprosy.

Skin smear direct microscopy is an important tool for diagnosis of leprosy. The study was planned to understand the reproducibility of skin smear reading by a trained technician. Skin smears were collected from known patients of leprosy from the field area. They were stained for acid fast bacilli following the standard cold staining procedure and were read following the Ridley scale. A sample of smears was re-examined on two occasions by the same technician, following blind procedure. There was a systematic under reading on the second occasion, which was attributed to the defective storage of the slides. However, the agreement between second and third examinations was very good (Concordance 81.34%, Kappa 0.74). The finding was confirmed on a repeat examination. It can be concluded that the Direct Skin Smear Microscopy is a reliable and reproducible technique under experimental conditions.

Humans↗
PubMed1978

Lateral Movement of Cations in corn Leaves.

Migration patterns of nutrient elements, viz. (59)Fe, (54)Mn, (65)Zn, and (86)Rb, supplied to young corn (Zea mays) leaves were studied using a modified chromatogram scanner. It was found that the isotopes supplied to one-half of the leaf did not migrate to the other side across the midrib, but moved generally toward the base of the applied part of the leaf.

Journal Article↗
PubMed1978

Studies on molybdenum absorption and transport in bean and rice.

The patterns of molybdenum (MoO(4) (2-)) absorption and transport were investigated in intact bean (Phaseolus vulgaris L.) and rice (Oryza sativa L. cv. I.R.8) plants. The mobility of MoO(4) (2-) absorbed by roots and by leaves was compared with that of a freely mobile element, Rb(+). Although MoO(4) (2-) absorption by bean roots was nearly as high as that of Rb(+), its transport to the shoot was considerably less. When MoO(4) (2-) was fed to one of the primary leaves, most of it was transported to the stem and root. Evidence obtained here showed that MoO(4) (2-) was mobile. Experiments with intact rice seedlings revealed large differences in the absorption and transport of MoO(4) (2-) between the plants grown in CaSO(4) and those in Hoagland solution. Molybdate uptake by excised rice roots was suggested to be an active process since it was greatly inhibited by a metabolic inhibitor. The presence of Mn(2+), Zn(2+), Cu(2+), CI(-), or SO(4) (2-) in the absorption medium reduced MoO(4) (2-) uptake which was markedly enhanced by the presence of Fe(2+).

Journal Article↗
PubMed1975

Absorption and transfer of fe and mn in germinating sorghum.

The absorption of Fe from FeSO(4), FeEDTA, and FeEDDHA (ferric ethylenediaminedi (o-hydroxyphenylacetate)), and Mn from MnSO(4), MnEDTA, and MnEDDHA, by germinating sorghum (Sorghum vulgarie Pers. var. M 35-1) was studied. The seeds were found to absorb Fe and Mn from all the sources, and these ions moved to the scutellum, shoot, and root. EDDHA facilitated greater translocation of Fe and Mn from the seed to the shoot and root. The translocation of Fe was more towards the root than to the shoot, whereas it was the reverse in the case of Mn.We observed that the leaves of seedlings treated with Mn were slightly chlorotic. Further studies revealed that Mn did not affect the translocation of Fe, and possibly interfered with Fe utilization in chlorophyll synthesis.

Journal Article↗
PubMed1970

Effects of growth substances on the absorption and transport of iron plants.

The effects of a number of growth substances on the absorption and translocation of iron were studied in bean plants. Gibberellic acid application to the trifoliate leaf enhanced absorption of Fe applied to the primary leaf. 2-Chloroethyltrimethylammonium chloride increased absorption by the primary leaf while 6-furfurylaminopurine (kinetin) increased the transport of Fe from the primary leaf to other parts. When the roots were pretreated with gibberellic acid, the absorption of Fe by the primary leaf and subsequent transport to the trifoliate leaves were increased. Triiodobenzoic acid reduced the absorption and transport of Fe.Absorption of Fe by roots and transport to other parts were increased by pretreatment of the roots with gibberellic acid, 2-chloroethyltrimethylammonium chloride or N,N-dimethylaminosuccinamic acid for 3 days. An increase in the transport to other parts of Fe absorbed by roots was obtained when roots were exposed to the growth substances following Fe absorption.Absorption and transport of Fe in corn plants were much less than those of Rb and phosphate. Absorption and transport of Fe were greater in plants with decorticated roots than in those with intact roots. N,N-Dimethylaminosuccinamic acid significantly promoted the transport of root-absorbed Fe to the shoots of corn plants.

Journal Article↗
PubMed1969

Factors related to iron absorption by enzymically isolated leaf cells.

The rate of Fe absorption by cells enzymically isolated from tobacco leaves is correlated with the age of the leaves from which the cells are derived. The cells obtained from younger leaves absorb Fe more rapidly than those from older ones. Ca inhibits Fe and Mn absorption. Fe and Mn are mutually antagonistic in their absorption by leaf cells. Ca enhances the inhibition of Mn absorption by Fe, but reduces the inhibition of Fe absorption by Mn. The affinity constant for Fe absorption by leaf cells is low. The chelate EDDHA (ethylenediamine di(o-hydroxyphenylacetate) competitively inhibits Fe absorption.

Journal Article↗
PubMed1969

Penetration of iron and some organic substances through isolated cuticular membranes.

Cuticular membranes were isolated enzymically from tomato fruits and from the dorsal and ventral surfaces of the leaves of Euonymus japonicus. Penetration of Fe from FeSO(4) and FeEDDHA (ferric ethylenediamine di(o-hydroxyphenylacetate) in the absence and presence of urea through the isolated cuticular membranes was studied. Fe from FeSO(4) penetrated more rapidly through the cuticles than Fe from FeEDDHA. Urea reduced the penetration of Fe from FeSO(4) and FeEDDHA. Binding of Fe on the inner surfaces of tomato fruit cuticles was also reduced by EDDHA.The results on the rates of penetration of (14)C-labeled organic substances suggest a possible relationship with their molecular weights. Permeability coefficients for these solutes have been derived for the 3 types of cuticles, using Fick's equation. The penetration rates of all substances through stomatous cuticles far exceeded those through astomatous cutioles.

Journal Article↗
PubMedDate not supplied

Regulation of E-kinase mediated cell-adhesion molecule(s) function by E-NTPase(s): imminent regulatory inter-dependency for cell adhesion.

E-NTPase is a cell membrane bound enzyme, suggested to play a role in maintaining the [NTP](o) and cell adhesion. Attempts to purify this enzyme resulted identification of many proteins co-purifying with E-NTPase. The amino acid sequence of chicken gizzard smooth muscle E-NTPase has been shown to have considerable amino acid sequence homology with mammalian CD39. On the other hand, the purified rat cardiac sarcolemmal E-NTPase showed identical sequence homology with platelet CD36. In this communication, an effort was made to provide rationale for the functional relevance of E-NTPase with reference to cell-adhesion process.

Adenosine Triphosphatases↗
PubMedDate not supplied

Neutrophil chemotaxis: potential role of chemokine receptors in extracellular nucleotide induced Mac-1 expression.

Extracellular nucleotide-induced stimulation and activation of neutrophil in the inflammatory foci followed by chemotaxis in to inflamed vasculature plays a critical role in inflammatory diseases and coronary artery diseases. The extracellular nucleotides stimulate a P2Y receptor(s) on human PMN with the pharmacological profile similar to that of the P2Y2 receptor. Consequent to the activation of P2Y2, arachidonic acid is formed from the membrane bound lipids by phospholipase A2, which subsequently metabolized by 5 lipoxygenase to form the leukotrienes. Of the several leukotrienes generated, LTB(4) is a potent proinflammatory chemokine. Upon its release LTB(4) binds to the PMN by autocrine manner in the same neutrophil and also in a paracrine manner to other neutrophils, leading to the accelerated Mac-1 expression on PMN membrane resulting chemotaxis. Thus it is suggested that the extracellular nucleotide(s) released from the activated platelets and other damaged cell types exacerbate inflammatory response by leukotriene generation. In turn the leukotriene will act in both autocrine and paracrine manner to amplify the process of chemotaxis in PMN by upregulation of Mac-1 expression.

Animals↗
PubMedDate not supplied

Maternal satisfaction and pain control in women electing natural childbirth.

BACKGROUND AND OBJECTIVES: Many women who choose natural childbirth for labor ultimately request epidural analgesia to control labor pain. Unfortunately, parturients and family members may often be unprepared for epidural anesthesia, which can contribute to disappointment and dissatisfaction with their labor and delivery. This study examines how epidural analgesia for labor influences maternal satisfaction in women who initially choose natural childbirth. METHODS: This study compared pain and maternal satisfaction in women who elected natural childbirth and successfully followed through (n = 23), with those who elected natural childbirth, but requested epidural analgesia during their labor (n = 24). Subjects rated their pain throughout labor and completed pre- and postlabor questionnaires. RESULTS: Women who requested epidural analgesia for pain during labor reported significantly lower pain scores than those women who had natural childbirth (P < .001). However, 88% of women who requested an epidural for pain reported being less satisfied with their childbirth experience than those who did not, despite lower pain intensity. Antenatal survey results suggest that concerns about epidurals and their effect on the baby, greater than anticipated labor pain, perceived failure of requesting an epidural, and longer duration of labor may have accounted for these findings. CONCLUSIONS: This study examined the influence of epidural analgesia in parturients electing natural childbirth. Pain relief alone was not found to improve maternal satisfaction. This study highlights the importance of experience and prelabor expectations on maternal satisfaction with childbirth.

Adult↗
PubMedDate not supplied

TLD reader with photon counting and dc techniques for wide range radiation dose measurement.

A TLD reader incorporating the techniques of photon counting and dc methods has been developed for radiation dose measurements in the range of 10(-6) Gy (10(-2) Gy = 1 rad) to 100 Gy for varied applications in radiation protection and for dosimetry in medical physics. It utilizes state-of-the-art technology and is provided with reproducible heating programmer, glow curve output, digital dose display, check light source and data processing facilities. The reader has been designed for easy operation and maintenance. The precision of the reader is about +/- 6% (1 sigma) for 10(-5) Gy and better than +/- 2% (1 sigma) for doses greater than or equal to 0.5 cGy. Further improvements are being effected to measure doses down to 10(-7) Gy.

Thermoluminescent Dosimetry↗
PubMedDate not supplied

Significance of AgNOR count in differentiating malignant cells from reactive mesothelial cells in serous effusions.

OBJECTIVE: To distinguish reactive mesothelial cells from malignant cells in serous effusions using silver staining of nucleolar organizer regions (AgNOR) applied to ethanol-fixed cytologic preparations. STUDY DESIGN: One hundred aspirated samples of benign and malignant effusions were studied using the one-step silver staining method. Eight cytologically atypical samples were also included in the study. RESULTS: In malignant cells the mean AgNOR count was 4.72 +/- 0.76 (+/- SD), and the AgNORs were irregular in shape, while in benign mesothelial cells AgNORs were comparatively larger, single dots with a mean count of 1.92 +/- 0.23. Of the cytologically atypical samples, five were in the malignant range. The others were within benign limits. Repeat cytology of the second aspirate confirmed that finding. CONCLUSION: AgNOR study appears to be clinically useful as an additional diagnostic tool for use in ascitic and pleural fluid samples when the cytologic diagnosis is difficult.

Adenocarcinoma↗