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Biomedical subjects

R Karmali

Publications and source records attributed to R Karmali.

At least 19 recordsLinked to original sources
PubMed2006

Hemophagocytic syndrome associated with extracerebral toxoplasmosis in an HIV-infected patient.

Hemophagocytic syndrome (HPS) is a clinical entity that combines non-specific clinical and biological features. The diagnosis is usually confirmed by a bone marrow examination. HPS may be primary or secondary to a malignancy or to an infectious or autoimmune disease. Since it was first described, various agents have been implicated, including viruses, bacteria, and parasites. In HIV patients, many cases occur with lymphoma or with a variety of opportunistic infections due to CMV, HHV8, Pneumocystis carinii, Mycobacterium tuberculosis, MAC, toxoplasmosis, and even pneumococcus. We report here a case of an AIDS patient presenting a HPS secondary to an extracerebral form of systemic toxoplasmosis that was only revealed by specific PCR in tissue other than the CNS.

Journal Article↗
PubMed2002

Citrate infusion test in the diagnosis of hypocalcemia due to a mutation in the calcium-sensing receptor gene.

The calcium-sensing receptor (Ca-R) is a G-protein-coupled surface receptor that plays a crucial role in calcium homeostasis via parathyroid hormone secretion. Mutations of this receptor can cause a gain in, or loss of, function, leading to hypo- or hypercalcemia, respectively. We report here a family with hypocalcemia in whom a heterozygous missense mutation in exon 4 was demonstrated, predicting a proline to leucine substitution (P221L) in the extracellular part of the Ca-R. Clinical symptoms were limited to fatigue. When serum calcium was further lowered via a citrate infusion, a significant increase in circulating iPTH was observed, although with lower peak values than in normal controls, suggesting a gain in function of the Ca-R. Treatment with calcium supplements and calcitriol led to prohibitive hypercalciuria without normalizing serum calcium. The aims of this case report are: (1) to present a mutation in the Ca-R with a gain in function at a codon where previously loss of function was described, and (2) to suggest that measuring circulating iPTH during a citrate infusion in the presence of familial hypocalcemia is an additional test to diagnose this particular form of hypoparathyroidism.

Journal Article↗
PubMed2000

Pituitary-thyroid feedback hypersensitivity as a novel cause of hypothyroidism in children.

Recognition and treatment of childhood hypothyroidism is essential to prevent serious developmental abnormalities, and neonatal screening based on detection of raised thyrotropin concentrations is routine. We investigated an adolescent who had developmental retardation because of an undiagnosed and novel cause of childhood hypothyroidism associated with normal circulating thyrotropin concentrations. Dynamic testing showed a hypersensitive pituitary-thyroid feedback axis with no evidence of other pituitary or hypothalamic disease, and sequence analysis of four candidate causative genes was negative. A high index of suspicion is required to diagnose and treat this disorder to prevent the consequences of long-term hypothyroidism on development.

Adolescent↗
PubMed1999

1,25-dihydroxyvitamin D3 inhibits parathyroid hormone-related peptide mRNA expression in fetal rat long bones in culture.

When fetal rat long bones are incubated in the presence of 10(-8) M 1,25-dihydroxyvitamin D3 [1,25(OH)2D3], steady-state parathyroid hormone-related peptide (PTHrP) mRNA levels are decreased. This decrease is temporary: it is observed as soon as after 3 h of exposure and reaches a nadir after 6 h. At that time, PTHrP mRNA levels are significantly lower in the experimental than in the control bones. However the inhibitory effect vanishes after 24 h, despite continuous exposure to 1,25(OH)2D3 for even 48 h. This is the first report showing that PTHrP mRNA expression can be regulated in rat fetal long bones in vitro by 1,25(OH)2D3.

Animals↗
PubMed1998

Serum creatine kinase levels in overt and subclinical hypothyroidism.

Overt hypothyroidism is known to be associated with increased serum creatine kinase (CK) levels. However, there is little information on CK levels in subclinical hypothyroidism. The aim of the study was to assess the relationship between CK levels and thyroid function in overt and subclinical hypothyroidism. Thyroid function tests (thyrotropin [TSH], free thyroxine [FT4], free triiodothyronine [FT3]) and the serum levels of CK were obtained from 23 patients admitted to a general hospital for illnesses other than thyroid or muscular diseases, myocardial ischemia, or brain damage. Overt hypothyroidism, based on thyroid function tests, was present in 10 patients, whereas hypothyroidism could be classified as subclinical in the other 13. A positive correlation was observed between CK and thyrotropin, and to a lesser extent between CK and thyroid hormones. Moreover, the correlation between CK and TSH and between CK and FT4 was detectable in subclinical hypothyroidism. Our data suggest that even in subclinical hypothyroidism there is some degree of dysfunction in skeletal muscle metabolism.

Adult↗
PubMed1997

Toxoplasma encephalitis in a HIV patient: unusual involvement of the corpus callosum.

In patients with acquired immuno-deficiency syndrome, the differential diagnosis between primary brain lymphoma and toxoplasma encephalitis is not radiologically always straightforward, especially in the presence of a solitary cerebral lesion. In this context, involvement of the corpus callosum is almost exclusively associated with primary brain lymphoma. We describe here an HIV-infected patient who presented with a single and large cerebral lesion affecting the corpus callosum, suggestive of primary brain lymphoma on MRI-scan but who nonetheless responded clinically and radiologically to an anti-toxoplasma drug trial confirming the diagnosis of toxoplasma encephalitis.

Adult↗
PubMed1995

Effects of gamma-linolenic and dihomo-gamma-linolenic acids on 7,12-dimethylbenz(alpha)anthracene-induced mammary tumors in rats.

The effects of pure gamma-linolenic acid (GLA; C18:3, n-6) and dihomo-gamma-linolenic acid (DGLA; C20:3, n-6) were investigated in 7,12-dimethylbenz(alpha)anthracene (DMBA) (10 mg/rat)-induced mammary tumors in Sprague-Dawley rats. 0.15 g of GLA, DGLA, or corn oil (CO) were administered (two times per week) by oral intubation, for 12 weeks to rats maintained on a 5% (w/w) CO diet. Tumor incidence, tumor multiplicity, and percent of tumor-bearing rats were highest in the CO group. Tumor multiplicity was significantly reduced in the GLA group (p = 0.015). Feeding of GLA and DGLA resulted in significant alterations in levels of these fatty acids in phospholipids of mammary tissue, thymus, colon, liver, stomach, and ovary. These results suggest that GLA may have a small, but significant, inhibitory effect on the development of DMBA-induced mammary tumors in rats.

8,11,14-Eicosatrienoic Acid↗
PubMed1994

Enhanced growth of mammary adenocarcinoma in rats by chloroquine and quinacrine.

This study investigated whether the growth of transplanted mammary tumors is altered in rats by treatment with the antimalarial drugs chloroquine (CQ) and quinacrine (QN). Female inbred F344 rats were divided into three experimental groups. Animals were injected i.p. with either CQ, QN or normal saline for 5 days a week throughout the entire experimental period (25 days). After 7 days of drug treatment each rat received subcutaneously one 2-mm2 aliquot of R3230AC mammary adenocarcinoma in the mid-thoracic region. Eighteen days after implantation, all rats were sacrificed and tumors were excised, weighed and measured. The results indicate that weights and volumes of tumors as well as tumor-to-body weight ratios were significantly higher in CQ and QN-treated animals than those in saline-treated animals. The final body weights of rats treated with QN were significantly lower than those treated with saline. The prostaglandin E2 content of tumors was significantly reduced by CQ treatment. Erythrocyte glutathione reductase activity coefficient and reduced glutathione concentrations remained unaffected by both treatments. These results suggest that CQ and QN have significant stimulatory effects on the growth of mammary adenocarcinoma in rats.

Adenocarcinoma↗
PubMed1994

Paget's disease of bone: five regimens of pamidronate treatment.

The efficacy of five therapeutic regimens using (3-amino-1-hydroxypropylidene)-1,1- bisphosphonate (APD or pamidronate) was assessed in patients with Paget's disease of bone. These regimens were as follows: (a) pamidronate 600 mg/day given orally during six months; (b) iv infusion of 20 mg daily for 10 days; (c) iv infusion of 40 mg daily for 5 days; (d) iv infusion of 10 mg daily for 4 days and (e) a single iv infusion of 10 mg. Six months after the initiation of therapy, urinary excretion of hydroxyproline and serum alkaline phosphatase activity (expressed as percent of their initial value) were: Group a: 30 +/- 10 (mean +/- SE) and 30 +/- 6, Group b: 55 +/- 8 and 46 +/- 6, Group c: 54 +/- 7 and 57 +/- 6, Group d: 53 +/- 7 and 69 +/- 4, and Group e: 85 +/- 10 and 98 +/- 4 respectively. Oral route was accompanied by digestive intolerance. On the contrary, except for rare and transient "flu-like syndromes", the iv treatment was not associated with any serious secondary effect. Intravenous infusion of pamidronate, 20 mg for 10 days or 40 mg for 5 days, appears as an interesting alternative to the oral route in the treatment of Paget's disease of bone.

Administration, Oral↗
PubMed1993

[Distribution and function of a new hormone: parathyroid hormone-related peptide (PTHrP)].

Several research groups have identified a "parathyroid hormone related peptide" (PTHrP) in tumors of patients presenting with the hypercalcemia of malignancy. The N-terminal domain of this peptide has a high degree of homology with that of the parathyroid hormone (PTH) and shares the PTH biological activities. PTHrP has later been identified in several foetal and adult normal tissues: for instance, it is expressed and secreted by foetal parathyroid glands, and it plays an important role in placental calcium transport; it is also expressed in the uterus of pregnant rats; there it could have a paracrine action on myometer relaxation. We have shown that PTHrP is present in and released in culture by foetal rat long bones. The mRNA of PTHrP is expressed in the periosteal cells of these foetal bones. The local expression and secretion of PTHrP in bone suggests that this new peptide could have a local role in the regulation of bone remodeling and development.

Animals↗
PubMed1993

[Biological aspects of treatment of hyperthyroidism].

A woman treated for hyperthyroidism is described. This case illustrates two aspects of the laboratory follow-up of hyperthyroidism: sequential measurements of sensitive TSH and of the parameters of calcium metabolism.

Adult↗
PubMed1992

Expression of mRNA of parathyroid hormone-related peptide in fetal bones of the rat.

Previous studies have indicated that 19-day-old fetal long bones of the rat contain an adenylyl cyclase-stimulating activity antigenically related to parathyroid hormone-related peptide. To ascertain its origin, Northern blotting and in situ hybridization histochemistry were performed. Results demonstrate that mRNA of parathyroid hormone-related peptide is present in RNA extracted from fetal long bones of the rat and that cells responsible for its production are localized in the periosteum. These cells are not mature osteoblasts because they do not synthesize mRNA of osteocalcin. Thus the present study shows that parathyroid hormone-related peptide could be produced locally, at least in part, in the skeleton of fetal rats.

Animals↗
PubMed1992

Calcium and vitamin D metabolism in granulomatous diseases.

Overproduction of the active metabolite of vitamin D 1,25-dihydroxyvitamin D (1,25(OH)2D) has been described in sarcoidosis and other granulomatous diseases. High circulating concentrations of 1,25(OH)2D lead to increased intestinal absorption of calcium, possibly to enhanced bone resorption, and may result in hypercalcaemia and/or hypercalciuria. Data obtained in vivo and in vitro demonstrated that the unregulated production of 1,25(OH)2D lies within the granulomatous tissue and is controlled by glucocorticoids. This abnormal production of 1,25(OH)2D seems to be a general phenomenon of granulomatous processes, which is not exceptional in sarcoidosis, but appears seldom in tuberculosis. These abnormalities, however, are not pathognomonic of granulomatous processes, since they have been described in other diseases such as lymphomas.

Calcium↗
PubMed1992

n-3 fatty acids: biochemical actions in cancer.

A number of reports indicate that fish n-3 PUFA inhibit the development, growth and progression of several experimental tumors. There emerges a pattern of complex and diverse biochemical actions of n-3 PUFA in different animal tumor models, from the studies undertaken to date to evaluate the underlying mechanisms. These findings, along with the recent epidemiological evidence of an inverse correlation between fish intake and incidence of some human cancers, makes it worthwhile to determine the role of n-3 PUFA in cancer.

Animals↗