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Biomedical subjects

P Melis

Publications and source records attributed to P Melis.

At least 19 recordsLinked to original sources

Identification of a new candidate locus for uric acid nephrolithiasis.

Renal stone formation is a common multifactorial disorder, of unknown etiology, with an established genetic contribution. Lifetime risk for nephrolithiasis is approximately 10% in Western populations, and uric acid stones account for 5%-10% of all stones, depending on climatic, dietary, and ethnic differences. We studied a small, isolated founder population in Sardinia, characterized by an increased prevalence of uric acid stones, and performed a genomewide search in a deep-rooted pedigree comprising many members who formed uric acid renal stones. The pedigree was created by tracing common ancestors of affected individuals through a genealogical database based on archival records kept by the parish church since 1640. This genealogical information was used as the basis for the study strategy, involving screening for alleles shared among affected individuals, originating from common ancestors, and utilization of large pedigrees to obtain greater power for linkage detection. We performed multistep linkage and allele-sharing analyses. In the initial stage, 382 markers were typed in 14 closely related affected subjects; interesting regions were subsequently investigated in the whole sample. We identified two chromosomal regions that may harbor loci with susceptibility genes for uric acid stones. The strongest evidence was observed on 10q21-q22, where a LOD score of 3.07 was obtained for D10S1652 under an affected-only dominant model, and a LOD score of 3.90 was obtained using a dominant pseudomarker assignment. The localization was supported also by multipoint allele-sharing statistics and by haplotype analysis of familial cases and of unrelated affected subjects collected from the isolate. In the second region on 20q13.1-13.3, multipoint nonparametric scores yielded suggestive evidence in a approximately 20-cM region, and further analysis is needed to confirm and fine-map this putative locus. Replication studies are required to investigate the involvement of these regions in the genetic contribution to uric acid stone formation.

Alleles↗

Tension decrease during skin stretching in undermined versus not undermined skin: an experimental study in piglets.

In a controlled study using 15 piglets, the efficacy of skin stretching using a skin stretching device was tested by quantifying the tension decrease during skin stretching in undermined and not undermined wounds. The viability of the skin margins was examined in both situations. Thirty standardized wounds was created: around 15 wounds on one flank, the surrounding skin was undermined; whereas around the 15 wounds on the opposite flank, the surrounding skin was not undermined. The force required to close the 9 x 9 cm defect was measured at the beginning, after undermining, and after 30 minutes of skin stretching. Also examined was the wound healing after 1 day and 1 week. A tension decrease of 3.02 N (13.6 percent reduction of the total force that is required to close the wound at the beginning) was seen due to undermining the surrounding skin. Skin stretching for 30 minutes without undermining the skin showed a tension decrease of 6.10 N (26.5 percent). Therefore, the tension decrease due to skin stretching was twice as high in comparison with undermining the skin margins alone. This has been statistically proven to be significant (-d (difference) = 3.08, 95 percent confidence interval = 2.16; 4.00, p < 0.001). When the undermined skin of the wound was stretched for 30 minutes, we measured a total tension decrease of 7.60 N (34.1 percent). There was a statistically significant but small difference in total tension decrease as a result of undermining combined with skin stretching in comparison with skin stretching without undermining (-d = 1.51, 95 percent confidence interval = 0.77; 2.23, p < 0.001). Undermining the surrounding skin involved cutting musculocutaneous perforating vessels. Looking at the viability of the skin, seven wounds, all found in the undermined group, showed skin necrosis after 1 week. Excessive seroma formation was seen in all wounds around which the skin was undermined. In the not undermined wounds, there were no problems in wound healing. In conclusion, skin stretching for only 30 minutes using a skin stretching device significantly reduces wound closing tension. The additional advantage of skin stretching over that of undermining alone is clearly shown. Undermining the wound margins before skin stretching gives a small additional tension decrease but has well-known complications, such as skin-edge necrosis and seroma formation.

Animals↗

Comparison of transthoracic echocardiography with second harmonic imaging with transesophageal echocardiography in the detection of right to left shunts.

We compared the use of transthoracic echocardiography with second harmonic imaging after a peripheral intravenous injection of an agitated saline solution with transesophageal echocardiography (TEE) in the detection of right to left shunts at the cardiac and pulmonary level. Second harmonic mode transthoracic echocardiography and TEE are equally sensitive in detecting right to left shunts in patients undergoing a daily routine TEE.

Artifacts↗

Impact of second harmonic imaging on the determination of the global and regional left ventricular function by 2D echocardiography: a comparison with MIBI gated SPECT.

AIMS: To evaluate the impact of second harmonic (SH) compared to fundamental mode (FM) imaging on the echocardiographic determination of ejection fraction (EF) and wall motion score index (WMSI), using MIBI gated SPECT as an independent reference. METHODS: Sixty-two consecutive patients underwent an echocardiography study and a MIBI gated SPECT over 24 hours. EF was estimated visually (estimated-E) and was calculated with the Simpson biplane method (Tracing-T), for both FM and SH. WMSI was determined by two independent echo-readers blinded to the nuclear imaging results. The same segmentation and scoring system was used for WMSI determined by MIBI gated SPECT. RESULTS: The percentages of unscored segments because of suboptimal endocardial border detection were 19.5% (FM) and 9.0% (SH). The correlation coefficients (r) between SPECT-EF and echo-EF were: FM (E)=0.705, FM (T)=0.546, SH (E)=0.771, SH (T)=0.743. Agreement between SPECT-EF and echo-EF was acceptable for both imaging modalities (mean of the difference +/- 2 S.D.): -2.8 +/- 18.5 (FM) and -3.5 +/- 16.4 (SH). Correlation coefficients (r) between WMSI calculated by SPECT and by echo were 0.715 (FM) and 0.789 (SH). Agreement between SPECT-WMSI and echo-WMSI was good for all imaging modes but better with SH compared to FM: 0.12 +/- 0.91 (FM), 0.10 +/- 0.77 (SH). The interobserver correlation coefficients (r) for the WMSI were 0.939 (FM) and 0.996 (SH). The agreement between the two observers was better for SH compared to FM. The systematic differences (mean differences) were 0.21 (FM) and -0.01 (SH), and the random differences between both observers (2 S.D.) decreased from 1.55 (FM) to 0.29 (SH). CONCLUSIONS: The use of SH echocardiography decreases the number of unscored segments. This results in an important gain in correlation and agreement for EF determination between echo and SPECT, and in a considerable decline of the interobserver variability for the echo-determined WMSI. WMSI determined by MIBI gated SPECT correlated closely with the SH WMSI, and agreement between both methods was excellent.

Aged↗

High recurrence rate 12 years after primary inguinal hernia repair.

OBJECTIVE: To find out the long term recurrence rate after repair of the inguinal ligament (Griffith) for inguinal hernia in one hospital. DESIGN: Retrospective study. SETTINGS: Teaching hospital, The Netherlands. SUBJECTS AND INTERVENTION: All patients who had had a Griffith repair for a primary inguinal hernia in 1985 were re-examined after at least 12 years by an independent examiner. RESULTS: Of the 102 patients included in the study, 45 patients had died and 17 could not be traced. Of the remaining 40 patients (45 hernias), 10 (22%) had developed recurrences. In 4 patients the asymptomatic hernia was discovered by the investigator. 11 further patients had developed a hernia on the opposite site resulting in a total of 16 patients (40%) with bilateral hernias. CONCLUSIONS: The long term recurrence rate of an inguinal hernia by reconstruction of the inguinal ligament is high and even higher when assessed by physical examination. The high recurrence rate and frequent bilateral recurrence might favour repairs with mesh reinforcement.

Adult↗

Primary skin closure of a large groin defect after inguinal lymphadenectomy for penile cancer using a skin stretching device.

PURPOSE: We describe a method of primary closure of a large skin defect. MATERIALS AND METHODS: A 44-year-old man was treated for penile cancer. After left inguinal lymphadenectomy a large skin defect in the groin remained that could not be closed primarily. Allowing skin to stretch beyond its inherent extensibility with a skin stretching system (Sure-Closure) the wound edges were closed without tension. RESULTS: Primary closure of a large skin defect was possible after cyclic stretching and relaxation of the skin with a skin stretching device. CONCLUSIONS: Large skin defects can be closed primarily using a skin stretching device. The primary advantage of the procedure are its simplicity and avoidance of the need for more complicated reconstructive surgery.

Adult↗

A randomized study comparing methylprednisolone plus chlorambucil versus methylprednisolone plus cyclophosphamide in idiopathic membranous nephropathy.

To assess whether chlorambucil or cyclophosphamide may have a better therapeutic index in patients with idiopathic membranous nephropathy, we compared two regimens based on a 6-mo treatment, alternating every other month methylprednisolone with chlorambucil or methylprednisolone with cyclophosphamide. Patients with biopsy-proven membranous nephropathy and with a nephrotic syndrome were randomized to be given methylprednisolone (1 g intravenously for 3 consecutive days followed by oral methylprednisolone, 0.4 mg/kg per d for 27 d) alternated every other month either with chlorambucil (0.2 mg/kg per d for 30 d) or cyclophosphamide (2.5 mg/kg per d for 30 d). The whole treatment lasted 6 mo; 3 mo with corticosteroids and 3 mo with one cytotoxic drug. Among 87 patients followed for at least 1 yr, 36 of 44 (82%; 95% confidence interval [CI], 67.3 to 91.8%) assigned to methylprednisolone and chlorambucil entered complete or partial remission of the nephrotic syndrome, versus 40 of 43 (93%; 95% CI, 80.9 to 98.5%) assigned to methylprednisolone and cyclophosphamide (P = 0.116). Of patients who attained remission of the nephrotic syndrome, 11 of 36 in the chlorambucil group (30.5%) and 10 of 40 in the cyclophosphamide group (25%) had a relapse of the nephrotic syndrome between 6 and 30 mo. The reciprocal of plasma creatinine improved in the cohort groups followed for 1 yr for both treatment groups (P < 0.01) and remained unchanged when compared with basal values in the cohort groups followed for 2 and 3 yr. Six patients in the chlorambucil group and two in the cyclophosphamide group did not complete the treatment because of side effects. Four patients in the chlorambucil group but none in the cyclophosphamide group suffered from herpes zoster. One patient per group developed cancer. It is concluded that in nephrotic patients with idiopathic membranous nephropathy both treatments may be effective in favoring remission and in preserving renal function for at least 3 yr.

Adolescent↗

Further linkage evidence for localization of mutational sites for nonsyndromic types of X-linked mental retardation at the pericentromeric region.

We used several microsatellite markers scattered along the X chromosome to search for linkage relationships in a large Sardinian pedigree segregating for nonspecific X-linked mental retardation (MRX). Markers DXS573 and AR, located at chromosomal subregions Xp11.4-p11.22 and Xq11.2-q12, respectively, were found to segregate in full concordance with the disease, leading to a LOD score of 4.21 at zero recombination value. Recombination with the disease was found with markers MAOB and DXS454 located at Xp11.4-p11.3 and Xq21.1-q22, respectively; accordingly, markers distal to Xp11.4 and Xq22 also segregated independently of the disease. These findings provide strong linkage evidence in favor of the localization of one MRX mutational site in the pericentromeric region of the human X chromosome, justifying the assignment of a new symbol (MRX26) to our pedigree. Finally, on the basis of the recombinational events observed in the Xq21-q22 region, we have been able to refine the assignment of marker DXS456 to Xq21.33-q22.

Chromosome Mapping↗

Correction of severe blepharoptosis.

An analysis is made of 81 patients with severe blepharoptosis who underwent correction with autogenous fascia. In case of severe blepharoptosis, which means a levator function of less than 5 mm, correction by levator resection gives insufficient results. Better results are obtained by frontalis suspension, whereby the upper eyelid is connected to the frontalis muscle using fascia lata strips according to Crawford. The operative technique is described in detail. Particular interest has been paid to the width of the vertical lid fissure and symmetry between both upper eyelids after operation. The overall results were rated satisfactory to excellent with an average of 9 mm of postoperative vertical lid fissure. Comparison of the results of unilateral versus bilateral blepharoptosis correction revealed better results in the group of bilateral ptosis correction. In 76% of the bilateral patients, there was an asymmetry of less than 0.5 mm between both palpebral fissures, while in the unilateral group this result was achieved in only 35% of the cases. Symmetry is difficult to achieve in the unilateral group, especially when the vertical lid fissure of the nonptotic eye is 10 mm or more. In these cases, correction of both upper eyelids should be considered. The best time to operate on patients with severe congenital blepharoptosis is around the age of 4 to 5 years, because lagophthalmus after operation is better tolerated and the leg has developed sufficiently to provide an adequate amount of fascia. The correction of severe blepharoptosis by frontalis suspension with autogenous fascia shows a high rate of success and few complications.

Blepharoptosis↗

X-linked ichthyosis without STS deficiency: clinical, genetical, and molecular studies.

We report on a Sardinian pedigree with congenital ichthyosis associated with normal levels of steroid sulfatase and a normal molecular pattern, as detectable with a cDNA probe for the steroid sulfatase (STS) gene. Though the pattern of transmission of the disease is consistent with X-linked recessive inheritance, this form of ichthyosis was found to segregate independently of genetic polymorphisms detected by probes of the region Xp22.3, where the STS locus has been mapped. The search for close genetic linkages with other polymorphic markers scattered along the entire X chromosome has so far been fruitless. For the time being, the main conclusion derived from these data is that STS deficiency is not a sine qua non for X-linked ichthyosis which may also result from a mutational event at an X-chromosomal site genetically unlinked to the STS locus.

Arylsulfatases↗

Idiopathic membranous nephropathy in the elderly.

In this retrospective non-randomized study we reviewed the outcome for 41 patients with membranous nephropathy older than 65 years at onset and followed for at least 1 year. Twelve of the patients never received any specific treatment (group A), 15 were treated with a 6-month course of methylprednisolone alternated to chlorambucil every other month (group B), and 14 received corticosteroids alone for 3-12 months (group C). At the end of a mean follow-up of 92 +/- 61 months in group A, 53 +/- 35 in group B, and 38 +/- 25 in group C there were significantly more remissions of nephrotic syndrome in group B than in group A (P = 0.035) or in group C (P = 0.010). Moreover patients in group B spent a significantly longer period without nephrotic syndrome than patients in group A (P = 0.000) and C (P = 0.000). Three patients in group A and one in group B died. During the follow-up six patients of group A, two of group B, and five of group C developed renal function deterioration. In patients followed for at least 5 years the mean plasma creatinine increased from a basal of 112 +/- 29 to 239 +/- 287 mumol/l at the 5th year in group A and from 113 +/- 14 to 124 +/- 30 mumol/l in group B. The mean urine protein excretion remained unchanged in group A (basal 4.6 +/- 2.3 versus 4.8 +/- 5.7 g/day at 5 years) while it decreased in group B (from a basal of 6.8 +/- 3.5 to 1.1 +/- 0.4 g/day at 5 years).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Leishmaniasis in Sardinia. III. Soil analysis of a breeding site of three species of sandflies.

Soil analysis was carried out on samples obtained from a breeding-site of the sandflies Phlebotomus perniciosus Newstead, P. perfiliewi perfiliewi Parrot and Sergentomyia minuta (Rondani) in Sardinia. Soil texture, pH, CaCo3, organic matter and water content showed no correlation with the number of sandflies that emerged from the places where soil samples were taken. It appears that pre-imaginal stages of these phlebotomine sandflies are associated with a relatively stable, cool and humid environment protected from sunshine and rain, rich in clay and in organic nitrogen.

Animals↗

Physical and genetic mapping of the CDR gene with particular reference to its position with respect to the FRAXA site.

This study narrows down the localization of the gene coding for the cerebellar degeneration-related protein (CDR 34) to the upper boundary of the FRAXA and reports the finding of two common RFLPs respectively identified at an RsaI site flanking the 3' end of the gene and at a Hincll site flanking its 5' end. Segregation analysis carried out in the CEPH-pedigrees for the new CDR/RsaI-RFLP versus other polymorphic loci of the region has established a tight linkage with the markers DXS105/DX98 and absence of measurable linkage with two clusters of markers respectively located proximally to the FRAXA (F9, DXS102, DXS51, and DXS369) or distally to it (DXS52, DXS304). In addition, two recombinants were found among 23 scorable sibs identified in the Sardinian pedigrees segregating for the Martin-Bell Syndrome (MBS) and the CDR/RsaI variants. The overall evaluation of the in situ and genetic data reported suggest that the CDR locus 1) is located at the upper boundary of the FRAXA site; 2) is distal to DXS51 and proximal to DXS 389; and 3) segregates in a close linkage association with the loci DXS98 and DXS105 and, to a lesser extent, with the locus for MBS.

Antigens, CD34↗