K. Gilbert

Bio: K. Gilbert is an academic researcher from University of Bremen. The author has contributed to research in topics: Population & Genetic distance. The author has an hindex of 5, co-authored 6 publications receiving 90 citations.

Genetic markers among Meiteis and Brahmins of Manipur, India.

Abstract: Genetic polymorphism of 16 red-cell antigens, enzymes, serum proteins and Hb variants was investigated in 214 male and female individuals belonging to the Meiteis and a Brahmin caste group living in Imphal (Manipur, Northeast India). Ethno-historical records suggest that the Meiteis are of Mongoloid origin, while the original Brahmin settlers represent the easternmost part of the so-called Caucasoids. The markers studied are: A1A2BO, MNSs, Rh-system, Duffy, Diego; Gm, Km, Gc, Hp, Tf, Cp; Hb; aP, AK, EsD and LDH. The comparison between the two groups on the basis of the markers studied showed that the Meiteis and Brahmins are very close to each other with respect to most of the loci except Gm, EsD and Hb, where significant statistical differences were found.

Investigations on the variability of haptoglobin, transferrin and Gc polymorphisms in Assam, India.

Abstract: Ten different population groups of Assam – Brahmins, Kalitas, Kaibartas, Rajbanshis, Muslims, Ahoms, Chutias, Kacharis, Karbis and Sandwals – have been typed for haptoglobin and for transferrin (Tf) a

Genetic variation of five blood group polymorphisms in ten populations of Assam, India

Abstract: Six Mongoloid and four Caucasoid populations of Assam, India, were examined for A1A2BO, Rhesus, Duffy and Diego blood groups. The distribution of their phenotypes and allele frequencies are presented. In the perspective of the ethnographic background, the results have been discussed in terms of genetic variability among these populations and probable reasons for its existence. The major groups, namely Caucasoids and Mongoloids, appear to form two separate groups in terms of these blood groups, though evidence is there to suggest intermixture.

Genetic studies among the Siddis of Karnataka, India: A migrant population from Africa

Abstract: 18 polymorphic systems of the blood ? A1A2BO, MNSs, Rhesus (C,c,D,E,e), Duffy, Diego; Haptoglobin (Hp), Ceruloplasmin (Cp), Transferrin subtypes (Tf), Gc subtypes (Gc), Gm (1,2,5), Km (1); red cell acid phosphatase (aP), phosphoglucomutase subtypes (PGMi), adenylate ki nase (AK), adenosine deaminase (ADA), esterase D (EsD), lactate dehydrogenase (LDH), and hae moglobin variants were typed on 237 Siddis from Karnataka (South India), a Negroid population of African descent, which came to India at various periods, starting as early as 1100 AD They were mainly imported as slaves The typing results were compared with that of two other population groups of Karnataka: Havig Brahmins (n = 140) and Muslims (n = 27) as well as with pooled samples of Ethiopia It is seen that the genetic pattern of the Siddis is much more similar to that of Ethiopians than to Havig Brahmins or Muslims One can assume that this is due to the genetic isolation of the Siddis, though some gene flow from Indian side cannot be ruled out completely

The global distribution of the Duffy blood group.

Abstract: Blood group variants are characteristic of population groups, and can show conspicuous geographic patterns. Interest in the global prevalence of the Duffy blood group variants is multidisciplinary, but of particular importance to malariologists due to the resistance generally conferred by the Duffy-negative phenotype against Plasmodium vivax infection. Here we collate an extensive geo-database of surveys, forming the evidence-base for a multi-locus Bayesian geostatistical model to generate global frequency maps of the common Duffy alleles to refine the global cartography of the common Duffy variants. We show that the most prevalent allele globally was FY*A, while across sub- saharan Africa the predominant allele was the silent FY*B ES variant, commonly reaching fixation across stretches of the continent. The maps presented not only represent the first spatially and genetically comprehensive description of variation at this locus, but also constitute an advance towards understanding the transmission patterns of the neglected P. vivax malaria parasite.

Serotonin, memory, and the aging brain.

Abstract: Serotonin is widely distributed throughout the central nervous system and is implicated in a variety of neural functions such as pain, feeding, sleep, sexual behavior, cardiac regulation and cognition. This paper is concerned with the last of these. Abnormalities of the serotonergic nervous system are well documented in pathologic studies of Alzheimer's disease and there is evidence suggesting that changes in this system occur in association with non-disease aging. Data on the role of serotonin in learning and memory and on the effects of aging on brain serotonin function are reviewed and discussed in relation to pharmacologic treatment strategies for the memory impairments associated with advancing age.

People of India: Biological diversity and affinities

Abstract: The Indian subcontinent comprises a vast collection of peoples with different morphological, genetic, cultural, and linguistic characteristics. While much of this variability is indigenous, a considerable fraction of it has been introduced through large-scale immigrations into India in historical times. From an evolutionary standpoint, it is of immense interest to quantify biological diversity in contemporary human populations, to study biological affinities and to relate observed patterns of affinities with cultural, linguistic and demographic histories of populations. Such efforts are intended to shed light on the peopling of India. The purpose of this paper is to present a broad overview of the physical (anthropometric) and genetic diversities and affinities of the peoples of India. I shall also attempt to examine how well biological, particularly genetic, diversities and affinities correlate with geographical, socio-cultural, and linguistic diversities and affinities. © 1998 Wiley-Liss, Inc.

A long-term prospective study of optic neuritis: evaluation of risk factors.

Abstract: Eighty-six patients with monosymptomatic optic neuritis of unknown cause were followed prospectively for a median period of 12.9 years. At onset, cerebrospinal fluid (CSF) pleocytosis was present in 46 patients (53%) but oligoclonal immunoglobulin in only 40 (47%) of the patients. The human leukocyte antigen (HLA)-DR2 was present in 45 (52%). Clinically definite multiple sclerosis (MS) was established in 33 patients. Actuarial analysis showed that the cumulative probability of developing MS within 15 years was 45%. Three risk factors were identified: low age and abnormal CSF at onset, and early recurrence of optic neuritis. Female gender, onset in the winter season, and the presence of HLA-DR2 antigen increased the risk for MS, but not significantly. Magnetic resonance imaging detected bilateral discrete white matter lesions, similar to those in MS, in 11 of 25 patients, 7 to 18 years after the isolated attack of optic neuritis. Nine were among the 13 with abnormal CSF and only 2 belonged to the group of 12 with normal CSF (p = 0.01). Normal CSF at the onset of optic neuritis conferred better prognosis but did not preclude the development of MS.

CNS connections with the median raphe nucleus: retrograde tracing with WGA-apoHRP-Gold complex in the rat.

Abstract: In this work we examined the neuronal input to one of the serotoninergic centers in the brain, median raphe nucleus (MR). Special consideration is given to projections of the hypothalamus. To describe the afferents to MR, a retrograde transport technique was used after microinjection of WGA-apoHRP-Gold complex under pressure and subsequent gold-silver intensification on formaldehyde-fixed rat brain sections. Optimal conditions were obtained when the coordinates of the injection site were A +/- 1.5, L +/- 0.15, and H +/- 2.7 according to Paxinos and Watson (The Rat Brain in Stereotaxic Coordinates. New York: Academic Press, '82). Results obtained under these conditions show a heterogeneous distribution of labeled neurons throughout the brain, including a large proportion (+/- 65%) of hypothalamic neurons. Extra-hypothalamic neurons projecting to MR were from the prefrontal cortex, lateral and medial habenular nuclei, the pontine area of the central grey, interpeduncular nucleus, dorsal raphe nucleus, oculomotor and trochlear nuclei, dorsal and laterodorsal tegmental nuclei, parabrachial nuclei, and lateral and interpositus cerebellar nuclei. Hypothalamic neurons connected to MR were found to be from medial and lateral preoptic areas, lateral hypothalamus, dorsomedian nucleus, the perifornical area, and the complex of mammillary bodies. Many other discrete regions contained different densities of labeled perikarya: the medial preoptic nucleus, paraventricular nucleus, retrochiasmatic area, arcuate nucleus, lateral magnocellular nucleus, and the posterior area. The MR appears as an integrative center receiving many neuroanatomically and functionally heterogeneous inputs from the whole brain.