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Biomedical subjects

A Kaur

Publications and source records attributed to A Kaur.

At least 37 records · Page 2Linked to original sources

Alendronate and estrogen-progestin in the long-term prevention of bone loss: four-year results from the early postmenopausal intervention cohort study. A randomized, controlled trial.

BACKGROUND: Up to 3 years of treatment with alendronate, 5 mg/d, prevents postmenopausal bone loss. OBJECTIVE: To determine whether the effect of alendronate is sustained at 4 years of treatment and persists after treatment is discontinued. DESIGN: Randomized, controlled trial. SETTING: United States and Europe. PARTICIPANTS: 1609 postmenopausal women 45 to 59 years of age. INTERVENTION: Participants were randomly assigned to receive oral alendronate, 5 mg/d or 2.5 mg/d; placebo; or open-label estrogen-progestin. Women in the alendronate groups received alendronate for the first 2 years of the study. Treatment was then continued without change or replaced with placebo for the last 2 years of the study. MEASUREMENTS: Annual measurement of bone mineral density. RESULTS: By year 4, the bone mineral density of participants in the placebo group had decreased by 1% to 6% (P < 0.001). Four years of treatment with 5 mg of alendronate per day increased bone mineral density at the spine (mean change [+/-SE], 3.8%+/-0.3%), hip (mean, 2.9%+/-0.2%), and total body (mean, 0.9%+/-0.2%) (P < 0.001 overall). By year 4, bone mineral density at most skeletal sites was greater in participants who switched from alendronate to placebo than in those who continuously received placebo. In years 3 and 4, bone loss in participants who switched from alendronate to placebo was similar to that seen during years 1 and 2 in those who continuously received placebo. Compared with 5 mg of alendronate per day, estrogen-medroxyprogesterone acetate produced similar increases in bone mineral density and estradiol-norethisterone acetate produced increases that were substantially greater. CONCLUSIONS: Four years of treatment with alendronate or estrogen-progestin prevented postmenopausal bone loss. A residual effect was seen 2 years after alendronate therapy was stopped; however, continuous alendronate treatment was more effective in preventing postmenopausal bone loss than 2 years of alendronate followed by 2 years of placebo.

Alendronate↗

Adenoid cystic carcinoma metastatic to the dura: report of two cases.

Adenoid cystic carcinoma (ACC) originating in the salivary and lacrimal glands usually spreads to the intracranial space by following cranial nerves into the cavernous sinus, temporal bone and cerebellopontine angle. We present two cases in which ACC metastasized extensively to the dura, suggesting that ACC has an affinity for the dura. Case 1, a 43-year-old man, was operated on 12 years earlier for invasive ACC of the right palate. He experienced recurrence of the tumor in the left cavernous sinus and sella, and extensive involvement of the dura of both right and left temporal fossae. Case 2, a 33-year-old woman, had spread of ACC to the right convexity dura and tentorium after undergoing a resection of a left-sided ACC tumor of the lacrimal gland two years earlier. Both patients underwent multiple resections and radiation treatment. Extensive, multifocal, bilateral spread of ACC to the dura in both cases indicates that ACC has an affinity for the dura.

Adult↗

Inhibition of antigen presentation by the glycine/alanine repeat domain is not conserved in simian homologues of Epstein-Barr virus nuclear antigen 1.

Most humans and Old World nonhuman primates are infected for life with Epstein-Barr virus (EBV) or closely related gammaherpesviruses in the same lymphocryptovirus (LCV) subgroup. Several potential strategies for immune evasion and persistence have been proposed based on studies of EBV infection in humans, but it has been difficult to test their actual contribution experimentally. Interest has focused on the EBV nuclear antigen 1 (EBNA1) because of its essential role in the maintenance and replication of the episomal viral genome in latently infected cells and because EBNA1 endogenously expressed in these cells is protected from presentation to the major histocompatibility complex class-I restricted cytotoxic T-lymphocyte (CTL) response through the action of an internal glycine-alanine repeat (GAR). Given the high degree of biologic conservation among LCVs which infect humans and Old World primates, we hypothesized that strategies essential for viral persistence would be well conserved among viruses of this subgroup. We show that the rhesus LCV EBNA1 shares sequence homology with the EBV and baboon LCV EBNA1 and that the rhesus LCV EBNA1 is a functional homologue for EBV EBNA1-dependent plasmid maintenance and replication. Interestingly, all three LCVs possess a GAR domain, but the baboon and rhesus LCV EBNA1 GARs fail to inhibit antigen processing and presentation as determined by using three different in vitro CTL assays. These studies suggest that inhibition of antigen processing and presentation by the EBNA1 GAR may not be an essential mechanism for persistent infection by all LCV and that other mechanisms may be important for immune evasion during LCV infection.

Alanine↗

Diverse host responses and outcomes following simian immunodeficiency virus SIVmac239 infection in sooty mangabeys and rhesus macaques.

Sooty mangabeys naturally infected with simian immunodeficiency virus (SIV) do not develop immunodeficiency despite the presence of viral loads of 10(5) to 10(7) RNA copies/ml. To investigate the basis of apathogenic SIV infection in sooty mangabeys, three sooty mangabeys and three rhesus macaques were inoculated intravenously with SIVmac239 and evaluated longitudinally for 1 year. SIVmac239 infection of sooty mangabeys resulted in 2- to 4-log-lower viral loads than in macaques and did not reproduce the high viral loads observed in natural SIVsmm infection. During acute SIV infection, polyclonal cytotoxic T-lymphocyte (CTL) activity coincident with decline in peak plasma viremia was observed in both macaques and mangabeys; 8 to 20 weeks later, CTL activity declined in the macaques but was sustained and broadly directed in the mangabeys. Neutralizing antibodies to SIVmac239 were detected in the macaques but not the mangabeys. Differences in expression of CD38 on CD8(+) T lymphocytes or in the percentage of naive phenotype T cells expressing CD45RA and CD62L-selection did not correlate with development of AIDS in rhesus macaques. In macaques, the proportion of CD4(+) T lymphocytes expressing CD25 declined during SIV infection, while in mangabeys, CD25-expressing CD4(+) T lymphocytes increased. Longitudinal evaluation of cytokine secretion by flow cytometric analysis of unstimulated lymphocytes revealed elevation of interleukin-2 and gamma interferon in a macaque and only interleukin-10 in a concurrently infected mangabey during acute SIV infection. Differences in host responses following experimental SIVmac239 infection may be associated with the divergent outcome in sooty mangabeys and rhesus macaques.

Animals↗

A comparative study of effects of mouth breathing and normal breathing on gingival health in children.

The present study was conducted to assess the effects of mouth breathing, lip seal and upper lip coverage on gingival health of children. 240 school children aged 10-14 years were selected irrespective of sex race and socioeconomic status. They were divided into two major groups i.e. mouth breathers and normal breathers. These groups were further subdivided into six sub-groups or categories on the basis of lip seal and upper incisor coverage. Gingival index was found to be higher in the mouth breathers than in the normal breathers in the subjects with incompetent lip seal. Increased lip separation and decreased upper lip coverage were all associated with higher levels of Plaque index and Gingival index. No statistical difference existed between mouth breathers and normal breathers with respect to Plaque index.

Adolescent↗

Epstein Barr virus (EBV) antibodies in the diagnosis of NPC--comparison between IFA and two commercial ELISA kits.

BACKGROUND: Antibodies to Epstein Barr Virus (EBV) antigens have been used for the diagnosis of nasopharyngeal carcinoma (NPC). While immunofluorescence assays (IFA) of IgA antiviral capsid and early antigens have been the mainstay of this diagnosis, enzyme immunoassays (ELISA) of various EBV antigens are now available. However in almost all of these assays, the sensitivities and specificities have been calculated using blood donors and normal hospital staff as controls, who may not be the most appropriate controls. We wanted to evaluate the usefulness of IFA and ELISA of various EBV antigens in a clinical setting to distinguish between patients with NPC and those suspected of NPC but being biopsy negative. METHODS: Between January 1987 and June 1988, 322 consecutive patients suspected of NPC and who had a post-nasal biopsy were studied. Blood was taken for EBV tests before diagnosis. Tests included IFA and ELISA IgA anti-VCA and anti-EA and ELISA IgA and IgG anti-ribonucleotide reductase, a cloned EA antigen. RESULTS: IFA IgA anti-VCA together with IFA IgA anti-EA both at a cut-off of 1:10 gave the best discrimination between patients with NPC and those suspected of NPC but were biopsy negative. CONCLUSION: The ELISA IgG anti-ribonucleotide reductase test is convenient to perform and looks very promising. An ELISA using a cocktail of cloned EA peptides may be even better.

Antibodies, Viral↗

Selective involvement of basal ganglia and occipital cortex in a patient with acute endosulfan poisoning.

We report a teenage girl with acute endosulfan poisoning who developed psychosis, generalized tonic-clonic seizures, myoclonic jerks, cortical blindness and limb rigidity. Serial magnetic resonance imaging (MRI) showed bilateral reversible lesions localized to caudate nucleus, putamen and occipital cortex; internal capsule and thalamus were spared. This selective involvement may have a bearing on mechanisms underlying endosulfan toxicity.

Adolescent↗

Terminal morphology of two branches arising from a single stem-axon of pretectal (PSm) neurons in the common carp.

The induction of postsynaptic structures by presynaptic terminals is suggested in a teleost brain. Neurons in the nucleus pretectalis superficialis pars magnocellularis (PSm) in the common carp are known to send fibers to the corpus mamillare (CM) and the nucleus lateralis valvulae (NLV). Individual axons of PSm neurons bifurcate (or give off an axon collateral), both of which reach the target areas in the CM and NLV. The morphology of horseradish peroxidase-labeled terminals in the CM and NLV appears quite different in light microscopy. Terminals in the CM appear as a fine network of beaded (2-4 microns in diameter) fibers, while those in the NLV are larger (8-12 microns in transverse diameter) and cup-shaped, partially enveloping the soma of individual NLV neurons. In electron microscopy, however, these synapses in the CM and NLV share several ultrastructural similarities. Small (0.2 to 0.4-micron thick, 0.4 to 0.7-micron long) spine-like protrusions arising from dendrites in the CM, and from cell bodies in the NLV, invaginate into the axon terminals, and the synaptic junctions are always formed at the base of the protrusion in both areas. Development of this unusual morphology is inferred to be directed from the presynaptic side. The morphological similarity of the spine-like protrusions to the "spinule," which is thought to be formed in response to synaptic activation, is discussed.

Animals↗

Neutralising antibody and challenge response to live and inactivated avian adenovirus-1 in broilers.

Immune responses to live and inactivated avian adenovirus-1 were evaluated in broilers by neutralising antibody response and challenge reaction. The neutralising antibody titre was 1:256, 1:64 and 1:32 in live virus, inactivated virus and uninoculated control birds respectively at 3 weeks post inoculation when they were challenged. At one week post challenge the antibody titres were 1:941, 1:247 and 1:375 in live virus, inactivated virus and control birds, respectively. There was a booster effect of challenge in the live virus inoculated group up to 3 weeks post challenge. The post challenge histopathological evaluation of liver, kidneys, lungs and bursa revealed less severe changes in the live virus inoculated group as compared to other groups.

Adenoviridae Infections↗

Primary ectopic meningioma of the palatine tonsil--a case report.

Meningiomas can occur at excranial and extraspinal sites such as the nose, nasopharynx and paranasal sinuses. Meningioma of the tonsil has seldom been described. We report a case of ectopic meningioma of the left palatine tonsil, in a 50-year-old male with no clinical or radiological evidence of an intracranial lesion. Follow-up at six months revealed no evidence of recurrence.

Humans↗

The effects of long-term topical glaucoma medication on conjunctival impression cytology.

Long-term use of topical drugs can induce changes in the conjunctiva and ocular surface. To determine the conjunctival changes resulting from topical glaucoma medication, patients with glaucoma were selected and classified into seven groups, according to the medication received: 24 eyes were treated with betaxolol, 20 eyes with levobunolol, 32 eyes with timolol maleate, 22 eyes with pilocarpine, 52 eyes with beta-blocker and pilocarpine, 34 eyes with beta-blocker and dipivefrin, and 32 eyes with maximum therapy. Patients who were under 18 were excluded, as were those with any history of ocular surgery and other interventions, long-term use of any topically administered medication except glaucoma drugs, and any history or slit-lamp examination evidence of ocular surface disorders. The changes in the conjunctiva of 216 eyes were evaluated by means of ocular surface impression cytology. The medication group showed statistically significant degrees of conjunctival metaplasia when compared to the control group (p < 0.01). The cytological grading was not correlated with age, sex, type of medication, duration of topical treatment or the number of drugs (p > 0.05). Duration of treatment exceeding three months was not correlated with cytological grading. Thus, as far as surgical treatment was concerned, it was concluded that intervention within the first three months after the diagnosis would be most beneficial in the management of glaucoma. The fact that the presence of the preservative benzalkonium chloride was the same in all preparations suggests that it may be the major factor in conjunctival metaplasia.

Administration, Topical↗

Induction of vigorous cytotoxic T-lymphocyte responses by live attenuated simian immunodeficiency virus.

Although live attenuated vaccine strains of simian immunodeficiency virus (SIV) have proven highly effective in protecting macaques against challenge with pathogenic SIV strains, little is known about the mechanisms of protective immunity induced by these vaccines. We examined cytotoxic T-lymphocyte (CTL) responses against SIV in animals infected with SIVmac239delta nef (deficient in nef) or SIVmac239delta 3 (deficient in nef, vpr, and upstream sequences in U3). To enhance detection of SIV-specific CTL activity, we stimulated peripheral blood mononuclear cells with autologous B-lymphoblastoid cell lines which had been infected with recombinant vaccinia viruses expressing SIV proteins and subsequently inactivated with psoralen and UV light. Animals chronically infected with SIV239delta nef or SIV239delta 3 mounted vigorous CTL responses against the SIV Gag and Env proteins. This CTL activity was major histocompatibility class restricted and mediated by CD8+ T lymphocytes. CTL responses persisted at relatively high levels for more than 6 years after infection. Limiting dilution precursor frequency assays demonstrated that the frequency of SIV-specific CTLs was as high as 234 CTL precursors per 100,000 cells. Animals acutely infected with SIV239delta nef developed CTL activity by day 14 after infection, coincident with decreases in viral load. Animals acutely infected with SIV239delta 3 developed CTL responses within 4 weeks of infection. Thus, vaccination of juvenile or adult animals with SIV239delta nef or SIV239delta 3 results in the induction of a vigorous CTL response which arises early in the course of infection and persists for years after a single inoculation of virus.

Animals↗

A herpesvirus of rhesus monkeys related to the human Kaposi's sarcoma-associated herpesvirus.

A herpesvirus that is related to but distinct from the Kaposi's sarcoma-associated herpesvirus (KSHV, or human herpesvirus 8) was isolated from rhesus monkeys. The sequence of 10.6 kbp from virion DNA revealed the presence of an interleukin-6 homolog similar to what is present in KSHV and a closer relatedness of the DNA polymerase and glycoprotein B reading frames to those of KSHV than to those of any other herpesvirus. This rhesus monkey herpesvirus replicated lytically and to high titers in cultured rhesus monkey fibroblasts. Antibody testing revealed a high prevalence for at least 10 years in our rhesus monkey colony and a high prevalence in two other colonies that were tested. Thus, rhesus monkeys naturally harbor a virus related to KSHV, which we have called RRV, for rhesus monkey rhadinovirus.

Animals↗

Studies on cellulases of Aspergillus nidulans mutants.

Mutants were characterized as to their morphology, auxotrophy and cellulase production. No apparent correlation was evident among these characters. The degree of repression or enhancement of the three components of the cellulase enzyme in the mutants varied considerably, indicating their separate genetic control. Considerable variations in the enzyme profiles of the mutants were observed as compared to the wild type. Enzyme production was also found to be related to development.

Aspergillus nidulans↗

Epilepsy in rural Haryana--prevalence and treatment seeking behaviour.

A community-based epidemiological study on epilepsy was conducted in rural North India in 1992-94 to estimate the extent of the problem and to study the treatment seeking behaviour of epilepsy patients. A key informant-based survey was conducted by a social worker to enlist suspect epilepsy cases in catchment population (30,000) spreading over in 40 villages of a primary health centre. These cases were verified by a neurologist. The prevalence of epilepsy was 4.2/1000 and it was more in males and in young children (> 6 to 15 years). Majority (81%) had already been diagnosed by qualified doctors. Many (57%) had a fit in last year. In 68% cases the disease onset was in childhood (up to 14 years). Half of the cases had the disease for 6 years or more. Multiple agencies were consulted by most (74%) of them. Faith healers and local practitioners (not medical graduates) were consulted as the first agency in 57% cases. Positive family history was elicited in 36% cases.

Adolescent↗

Isozyme polymorphism of cellulases in Aspergillus terreus.

Maximum cellulase production in Aspergillus terreus was obtained at a temperature of 28 degrees C, pH 4.0 and a substrate concentration of 1% CMC. Variability in cellulase enzyme production and isozyme polymorphism of endo-beta-1,4-glucanase and beta-1,4-glucosidase was studied in 45 natural isolates of A. terreus. Different electrophoretic patterns were evident for endoglucanase. Three zones of activity viz EG 1, EG 11 and EG 111 were observed showing different electrophoretic mobilities. Some of the isolates exhibited the presence of null alleles for EG 1. During development EG 1 and EG 11 were observed throughout while EG 111 appeared on the eighth day. For beta-1,4-glucosidase two zones of activity viz beta-glu 1 and beta-glu 11 were observed. beta-glu 1 showed variable electrophoretic mobilities. beta-glu 1 appeared throughout during development while beta-glu 11 appeared on the twelfth day.

Alleles↗