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Biomedical subjects

D Simon

Publications and source records attributed to D Simon.

At least 253 records · Page 14Linked to original sources
PubMed1994

Intestinal permeability in patients infected with the human immunodeficiency virus.

OBJECTIVE: The etiology of acquired immunodeficiency syndrome (AIDS) enteropathy is unknown. This condition has been associated with malabsorption and villous atrophy. Other disorders with similar findings, including celiac disease, are characterized by altered intestinal permeability. Our objective was to confirm (or reject) our hypothesis that processes that cause increased permeability may occur in patients with AIDS, and thus be a cause of idiopathic diarrhea. METHODS: A lactulose-mannitol differential intestinal permeability test was performed in healthy controls, asymptomatic human immunodeficiency virus (HIV)-positive patients, and AIDS patients with and without diarrhea. RESULTS: Asymptomatic HIV-positive patients lactulose and mannitol recoveries were no different than healthy control patients. AIDS patients without diarrhea had lactulose recovery similar to healthy controls and decreased mannitol recoveries; their mean lactulose:mannitol ratio was no different from that of controls, and less than that of AIDS patients with diarrhea. AIDS patients with diarrhea had increased lactulose recovery and decreased mannitol recovery; their mean lactulose:mannitol ratio was significantly greater than the ratios in all the other groups. CONCLUSIONS: Patients with AIDS and diarrhea have altered intestinal permeability. The decreased absorption of mannitol suggests that the functional absorptive surface of the intestine decreases as HIV disease progresses.

AIDS-Related Opportunistic Infections↗
PubMed1993

Sequence specific binding of the transcription factor c-Ets1 to the human immunodeficiency virus type I long terminal repeat.

Human immunodeficiency virus type I (HIV-1) long terminal repeat (LTR) driven transcription is regulated by a variety of cellular transcription factors. Most work has focused on the two nuclear factor kappa B (NF-kB) elements indispensable for HIV-1 LTR enhancer function. We demonstrate here the specific binding of the transcription factor c-Ets1 to an U3 region of the HIV-1 LTR (nt -141 to -149) using electrophoretic mobility shift analysis with T-cell nuclear extract and in vitro translated protein. This previously not identified Ets binding site is highly conserved among different HIV-1 isolates and maps to an U3 region recently shown to be necessary for viral growth in vitro. The c-Ets proto-oncogene family of transcription factors has yet been associated with HTLV-I and HIV-2 transcription. Our present analysis suggests an important role of c-Ets proteins in HIV-1 transcription.

Base Sequence↗
PubMed1993

Sequence of the cDNA encoding bovine uridine monophosphate synthase.

A 1869-bp cDNA encoding bovine UMP synthase (UMPS), including the 3'-untranslated and 34 bp of the 5'-untranslated regions, was isolated and sequenced. The deduced amino acid sequence shows a high degree of homology to UMPS sequences reported from other species, namely for regions corresponding to the putative catalytic sites. The sequence information will be used to analyse the molecular basis of the deficiency of UMPS (DUMPS) in cattle.

Amino Acid Sequence↗
PubMed1993

Surgical reintervention for differentiated thyroid cancer.

Reoperation was performed in 110 of 185 patients with a differentiated thyroid carcinoma. In 25 patients (23 per cent) the indication for reintervention was a large thyroid remnant and in the other 85 (77 per cent) persistent or recurrent cancer was suspected. In 32 (29 per cent) of the 110 patients undergoing reoperation no evidence of cancer tissue was found. Tumour tissue in 33 patients (30 per cent) was resectable. Of 45 patients (41 per cent) with residual tumour after operation 24 showed only occult thyroid carcinoma with a raised serum thyroglobulin level. Eight of 21 patients with macroscopically persistent tumour died from the disease during a mean follow-up of 2.3 years. In 13 of 38 patients the investigated recurrent tumours were histologically less differentiated than the primary lesions, stressing the importance of total tumour clearance. The treatment of choice for persistent and recurrent differentiated thyroid carcinoma is surgical reintervention, if feasible, before radioiodine and radiation therapy are considered.

Adenocarcinoma, Follicular↗
PubMed1993

DUMPS cattle carry a point mutation in the uridine monophosphate synthase gene.

Deficiency of uridine monophosphate synthase (DUMPS) is a monogenic autosomal recessive disorder in cattle, resulting in early embryonic death of homozygous offspring. To identify the mutation responsible for DUMPS, liver RNA from identified, DUMPS heterozygous animals from the Holstein and Red Holstein breeds was reverse transcribed. Amplification of cDNA with sequence-specific primers and subsequent sequencing of the PCR products revealed a mutation (C-->T) with the loss of an AvaI site at codon 405, resulting in a premature stop codon with a truncated C-terminal catalytic subunit of the protein. A direct DNA test based on PCR was developed and subsequently tested on 102 animals. Complete concurrence of deficiency of UMPS and the presence of the described point mutation in heterozygous animals was observed, thus confirming this point mutation as the basic defect in DUMPS cattle.

Animals↗
PubMed1993

Supernumerary marker chromosomes in peripheral blood cells of hepatitis B virus chronic carriers.

Cytogenetic analysis of metaphase chromosome spreads from peripheral blood cells of hepatitis B virus (HBV) chronic carriers revealed supernumerary marker chromosomes in 2 of the 46 individuals tested. Both individuals are phenotypically normal oriental males, and exhibit mosaicism with a 46,XY/47,XY,+mar/48,XY,+2mar profile in one, and a 46,XY/47,XY,+mar profile in other. Based on the reported frequency of unidentified supernumerary chromosomes (1:2,500) in 377,357 amniocentesis samples, the frequency seen (1:23) in the population of HBV chronic carriers sampled here appears unusually high. The possibility of a role for HBV in the generation of marker chromosomes is discussed.

Adult↗
PubMed1993

Cervical tuberculous vertebral osteomyelitis: case report and discussion of the literature.

We report a case of tuberculous vertebral osteomyelitis of the first and second cervical vertebrae with extensive adjacent soft-tissue involvement and extension into the mediastinum and bilateral flanks. The clinical presentation of tuberculous vertebral osteomyelitis depends on the vertebrae involved. The characteristic syndrome, Pott's disease, reflects the consequence of infection of the lower thoracic and lumbar spine, the most common site of tuberculous vertebral osteomyelitis. Cervical involvement is unusual: tuberculosis affects the cervical vertebrae in approximately 0.03% of all cases. Tuberculosis of the atlas and axis is even more rare. Characteristic symptoms reported on presentation include fever, weight loss, night sweats, and neck pain and stiffness. Patients may have no neurological manifestations, but findings can range from single nerve-root compression to quadriplegia. Abscess may extend into the retropharynx, mediastinum, and posterior triangles and along the epidural space. Computerized tomography and magnetic resonance imaging are the most useful imaging procedures. Therapy should consist of administration of antimycobacterial antibiotics and--if indicated by the degree of subluxation, by neurological signs, or by cervical instability--surgical debridement and stabilization.

Adult↗
PubMed1993

Newly acquired peri-telomeric heterochromatin in a transgenic mouse lineage.

Karyotypes of an embryonic stem cell line and normal bone marrow and peripheral blood cells from a transgenic mouse lineage, strain 83, exhibit a novel region of constitutive heterochromatin in the peri-telomeric region of chromosome 3. This heterochromatic region co-localizes with the integration site of the transgene, an 11-Mb tandem insertion of a plasmid containing human beta-globin gene sequences, and is inherited in Mendelian fashion. The significance of this finding is discussed, and a nomenclature for such newly acquired heterochromatic regions is suggested.

Animals↗
PubMed1993

Urinary GH secretion correlates with plasma GH levels during sleep and GHRH stimulation tests but not during the L-dopa stimulation test in prepubertal children.

In order to assess the value of urinary growth hormone (GH) as a reflection of central GH release, 42 prepubertal children with short stature and without organic disease were studied. A nocturnal GH profile and L-dopa and GH-releasing hormone (GHRH) tests were performed. Urinary GH was measured by means of a direct immunoradiometric method we have developed, using two monoclonal antibodies. Nocturnal urinary GH values correlated positively with plasma GH values expressed as the area under the curve (r = 0.76; p = 0.0001) or mean peak amplitude (r = 0.73; p = 0.0001). Also, urinary GH values correlated positively with peak plasma GH levels during the GHRH test (r = 0.64; p = 0.001). In contrast, no correlation was observed between peak plasma GH and urinary GH during the L-dopa test (r = 0.29; p = 0.11). This suggests a specific but as yet undetermined effect of L-dopa on urinary GH secretion.

Adolescent↗
PubMed1993

Deficiency of dystrophin-associated proteins in Duchenne muscular dystrophy patients lacking COOH-terminal domains of dystrophin.

Dystrophin, the protein product of the Duchenne muscular dystrophy (DMD) gene, is a cytoskeletal protein tightly associated with a large oligomeric complex of sarcolemmal glycoproteins including dystroglycan, which provides a linkage to the extracellular matrix component, laminin. In DMD, the absence of dystrophin leads to a drastic reduction in all of the dystrophin-associated proteins, causing the disruption of the linkage between the subsarcolemmal cytoskeleton and the extracellular matrix which, in turn, may render muscle cells susceptible to necrosis. The COOH-terminal domains (cysteine-rich and carboxyl-terminal) of dystrophin have been suggested to interact with the sarcolemmal glycoprotein complex. However, truncated dystrophin lacking these domains was reported to be localized to the sarcolemma in four DMD patients recently. Here we report that all of the dystrophin-associated proteins are drastically reduced in the sarcolemma of three DMD patients in whom dystrophin lacking the COOH-terminal domains was properly localized to the sarcolemma. Our results indicate that the COOH-terminal domains of dystrophin are required for the proper interaction of dystrophin with the dystrophin-associated proteins and also support our hypothesis that the loss of the dystrophin-associated proteins in the sarcolemma leads to severe muscular dystrophy even when truncated dystrophin is present in the subsarcolemmal cytoskeleton.

Biopsy↗
PubMed1993

Interrelation between plasma sex hormone-binding globulin and plasma insulin in healthy adult women: the telecom study.

In order to study the relationship between plasma sex-hormone-binding globulin (SHBG) and insulin levels in healthy women, we investigated the association between plasma SHBG and insulin in an occupational sample of 786 nonhormone-using women. Levels of plasma SHBG showed a stepwise decrease with increasing fasting plasma insulin in premenopausal as well as in postmenopausal women. In these cross-sectional data, this significant negative relationship between SHBG and insulin was shown to be independent of age, body mass index, subscapular skinfold, fasting and 2-h plasma glucose in both groups. The etiology and the consequences of this inverse association between SHBG and insulin are unclear. Prospective and clinical studies in women will be necessary to determine the direction and causal nature of the association between SHBG and insulin, as well as its mechanism and its physiological and/or pathophysiological consequences.

Adult↗
PubMed1993

Principals of limited or radical surgery for differentiated thyroid cancer.

Since the late sixties standard total thyroidectomy with or without selective radical neck dissection depending on the extent of the disease has become the routine surgical procedure for differentiated thyroid carcinoma (DTC;-papillary, follicular). This strategy has contributed remarkably to the increase of cure rates for various reasons. Only recently, in the last decade, has limited radicality with only unilateral lobectomy (= hemithyroidectomy) with or without partial contralateral resection been advocated as being sufficient for selected early tumor stages. We have analyzed a series of 252 patients, 174 (69%) being papillary and 78 (31%) follicular. Primary operation was done in 117 patients (46%) while 135 patients (54%) underwent reoperative surgery at this institution for either completion of radicality or because of loco-regional recurrence. From our evaluation we draw the conclusion that limited radicality (unilateral operation or subtotal) is justified only in pT-1-tumors in younger age (< 45 yrs) in order to avoid recurrence and unnecessary reoperation. On the other hand generous indication for reoperation is justified with the overall chance of almost 60% cure rate. All adjuvant treatment, mainly radioiodine should be applied thereafter.

Adenocarcinoma, Follicular↗
PubMed1993

[Comments on the epidemiologic aspects of solitary thyroid nodules].

No major criticisms can be raised concerning the paper by Jacques Leclère and co about the Epidemiological Features of the Solitary Thyroid Nodule, but a few short comments can be made, namely, 1) that is difficult to perform any comparison when the tools used for investigations are changing, making impossible any standardization of methods for examination, 2) the need for randomization in order to obtain a representative sample from the total population, 3) that no causal relationship can be concluded from a cross-sectional epidemiological study, on an observational basis.

France↗
PubMed1993

Persistent hypertension after successful adrenal operation.

BACKGROUND: Up to 80% of patients with adrenocortical tumors comprising Conn's or Cushing's syndrome and patients with pheochromocytomas suffer from hypertension. Its implications in cardiovascular disease and its impact on quality of life make it the most important aim in therapeutic efforts. The aim of our study was to assess the long-term results in postoperative blood pressure after adrenalectomy and to evaluate potential risk factors for persistent hypertension. METHODS: Forty four patients with adrenal hypertension operated on between April 1986 and April 1991 underwent follow-up consisting of exact history, hormonal analysis, and adrenal imaging. RESULTS: Forty three patients were reexamined, which showed 11 patients (26%) with hypertension at dismissal from hospital and 17 patients (40%) with hypertension after a median of 2 years. Except for two recurrent tumors in adrenocortical carcinoma all patients were surgically cured. Antihypertensive medication could be reduced in 13 of 17 patients with persistent hypertension. Persistent hypertension did not correlate with the degree of preoperative blood pressure elevation, age, and gender, but it did correlate strongly with history of hypertension. Patients with normal blood pressure level after operation had a mean history of 5.7 years versus 11.5 years in patients with persistent hypertension (p < 0.03). CONCLUSIONS: The success of surgical treatment for adrenal hypertension strongly depends on early diagnosis and surgical intervention.

Adenoma↗
PubMed1993

[Initial results of 132 ethmoidectomies by endonasal approach].

47 cases of nasal polyposis and 19 cases of suppurated ethmoiditis were treated by intranasal ethmoidectomy. Results were evaluated by functional signs and nasosinusal endoscopy. 15 patients, among nasal polyposis, suffered from corticodependent asthma and 5 from Widal's disease. 64 patients were regularly followed-up for 1 to 4 years. Results in polyposis, after two years, in 47% of cases no recurrence was noted, a minor recurrence in 40% of cases, and 13% of failures with predominant Widal's disease. These results with low percentage of complications have lead us to choose intranasal ethmoidectomy. In suppurated ethmoiditis, results are good in 90% of cases if follow up is regular.

Adult↗
PubMed1993

Peritonitis associated with intra-abdominal pathology in continuous ambulatory peritoneal dialysis patients.

Features helpful in diagnosis and associated with death were evaluated in 26 episodes of peritonitis associated with intra-abdominal pathology (IAP) in continuous ambulatory peritoneal dialysis (CAPD) patients. Culture of multiple enteric pathogens, or of a single unusual enteric pathogen, from the dialysate was useful for diagnosis in 22/26 instances. Other diagnostic features (fecal material in dialysate, diarrhea containing dialysate, increasing free air in the abdominal cavity) were infrequently found. A comparison of patients who died (n = 11, 42%) and those who survived revealed that death was associated with bowel gangrene (5/6 died), recovery of bacteroides from the dialysate, more frequent and severe comorbid conditions (bacteremia, pneumonia, intra-abdominal and intracerebral bleeding, septic shock, hepatic failure), the development of severe malnutrition and thrombocytopenia during infection, and multiple surgical procedures until the diagnosis was established. Peritonitis associated with intra-abdominal pathology in CAPD patients is a severe infection with considerable diagnostic difficulty and high mortality. Early exploratory laparotomy upon suspicion of the nature of the peritonitis, usually raised by the recovery of enteric pathogens from the dialysate, may improve mortality.

Gastrointestinal Diseases↗