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Biomedical subjects

F Trimarchi

Publications and source records attributed to F Trimarchi.

At least 163 records · Page 9Linked to original sources

Homologies of the thyroid sodium-iodide symporter with bacterial and viral proteins.

We have demonstrated that Na+/I- symporter (NIS), a novel thyroid autoantigen, has local amino acid sequence homologies with the other thyroid autoantigens: Thyroglobulin (Tg), thyroid peroxidase (TPO) and thyrotropin receptor (TSH-R). These homologies concern the 4th, 5th, 6th extracellular loop and the beginning of the intracellular tail. We have expanded our studies and found that there are significant local homologies with other 11 proteins, most of them of bacterial or viral origin (e.g., Streptococcus or Herpes). These homologies concern the 2nd and 4th extracellular loop, and both the beginning and the end of the intracellular tail. These 11 homologies were retrieved by a computer-assisted search and extracted out of a database containing almost 300,000 amino acid sequences. These homologies were of magnitude greater than those concerning the three thyroid autoantigens [identities=51.1+/-7.3% vs 25.3+/-7.8% (mean+/-SD), p<0.001; similarities=70.6+/-10.7% vs 43.3+/-8.5%; p<0.001]. In addition, extensive, not local, homology was found with a number of unknown proteins from invertebrates (Drosophila melanogaster and Caenorhabditis elegans) and bacteria such as Bacillus subtilis and Xanthobacter. Previously, we had found that NIS has no extensive homology with Tg or TPO or TSH-R. This is the first demonstration of both extensive and local homologies between one thyroid autoantigen (NIS) and microbiological proteins. Taken together with data of the literature on the homologies between other thyroid antigens (Tg, TPO, TSH-R) and bacteria, the homologies we have now found reinforce the view that both bacterial and viral infections may trigger autoimmune thyroid diseases.

Amino Acid Sequence↗

Extremely high levels of estradiol and testosterone in a case of polycystic ovarian syndrome. Hormone and clinical similarities with the phenotype of the alpha estrogen receptor null mice.

A 19-year-old nulliparous hirsute woman was evaluated for the very high serum levels of testosterone (T) and estradiol (E2) measured in an outside laboratory. Menarche had occurred at 11 years and was followed by regular menses. We confirmed the high levels of T (9-16 ng/ml, nv 0.2-0.8) and E2 (>1,000 pg/ml, nv 30-120). LH and FSH were consistently high (73-118 mU/l and 18-29 mU/l, respectively; LH/FSH ratio=4.1-4.7) and responsive to iv GnRH (LH baseline=118 mU/I, 30 min=290; FSH baseline=25 mU/l, 30 min=46). The unstimulated values contrasted with those (LH=12, FSH=8 mU/I) measured in the outside laboratory, suggesting antigenically anomalous gonadotropins. 17-OH-progesterone was normal (0.5 ng/ml). After 1 mg dexamethasone, serum cortisol was normally suppressed (24-->0.4 microg/dl), T declined minimally (9-->8.6 ng/ml) and E2 remained high (>1,000 pg/ml). An exploratory laparotomy was performed, and two enlarged ovaries with multiple cysts as in a typical polycystic ovarian syndrome (PCOS) were seen. Before the wedge resection of the ovaries, hormones were assayed in the ovary veins (right ovary: T=30 ng/ml, Pg=17 ng/ml, E2=>5,000 pg/ml; left: T=14 ng/ml, Pg=14 ng/ml, E2=>5,000 pg/ml). Histologically, the follicle cysts showed luteinization of the theca interna; there was no evidence for ovary tumor in either ovary. After 21 days of 35 microg ethynyl-E2+2 mg cyproterone acetate (CA), E2=3,000 pg/ml, T=1.4 ng/ml, LH=10.5 mU/l and FSH=4.1 mU/I. After three cycles of the said therapy (but with 50 mg CA in the first 10 days of each cycle), E2 was 1,600 pg/ml, T 1.7 ng/ml, LH 7.1 and FSH 4.6 mU/I. Based on similarities with the phenotype of the alpha estrogen receptor knockout female mice (alphaERKO), one possible explanation for the puzzling clinical and biochemical picture of our patient is resistance of (alphaER to estrogens. This is the first case of PCOS with extremely high E2 and T. Thus, the differential diagnosis of high levels of E2 +/- T should include PCOS.

Adult↗

Epidemiology and clinical characteristics of endemic cretinism in Sicily.

In this study we report the prevalence of endemic cretinism in the general population of two iodine deficient areas in Northeastern Sicily that were described more than 10 yr ago. In addition, the individual characteristics of endemic cretins are considered in order to define the typical expressions of this major iodine deficiency disorder in Sicily. Forty-three mental defectives were identified: 22 were living in an area with three bordering and closely connected municipalities within the province of Messina and with a population of 17,485 inhabitants (prevalence = 0.13%). Three out of the 22 were school-age children. The other community, in the province of Catania, was constituted by a unique and mostly agricultural hamlet, and showed a prevalence of cretinism that was 0.68% (21/3,100). Among the 43 mental defectives, 16 (37%) presented prominent neuromotor and neurosensorial disorders, including deafmutism and were euthyroid, thus conforming to the neurological type of cretinism; 13 (30%) were hypothyroid and exhibited stunted growth without significant neuromotor and neurosensorial impairment (myxedematous cretins). In the remaining 14 individuals (33%) neurological disorders were associated with stunted growth and clinical or biochemical hypothyroidism. These data indicate that also in Sicily endemic cretinism is a continuum of a variety of forms: among these the pure neurological and pure myxedematous forms represent the two extremes. Our observations also indicate that endemic cretinism still represents a major public health problem in Sicily. The finding of 3 endemic cretins younger than 13 yr suggests the persistence of this disorder even in the presence of improved economic, social and nutritional conditions.

Adolescent↗

Endemic cretinism in Sicily.

This work reports the presence of endemic cretinism in a small district located inside an endemic goiter area in north-eastern Sicily, personally described. The study covers 19 mental defectives (11 females and 8 males, mean age 35.8 +/- 15.5 yr) selected on the basis of severe mental retardation recognized by the local doctors. No systematic survey for cretinism was carried out in the total population. Marked mental retardation was evident in all subjects. Nine of them exhibited clinical and biochemical signs of hypothyroidism (myxedematous cretins). The 10 others were clinically euthyroid and had deaf-mutism and/or pyramidal tract dysfunction (neurological cretinism). Familial aggregation of cretinism was also observed. In both myxedematous and neurological cretins and urinary iodine excretion was very low, but not significantly different from that recorded in the euthyroid controls of the same area. The data available do not clarify the pathogenesis of endemic cretinism in Sicily. However, the marked height retardation, the observation of delayed bone maturation and the severity of mental deficiency suggest that thyroid failure was present in early life. The presence of endemic cretinism today in Sicily constitutes a strong argument in favour of the immediate introduction of adequate iodine prophylaxis.

Adolescent↗

Deep lamellar keratoplasty.

PURPOSE: To describe a new technique of lamellar surgery and to compare the results of 150 cases treated with this technique with those observed in as many cases of penetrating keratoplasty (PK). PATIENTS AND METHODS: One hundred and fifty deep lamellar keratoplasty (DLKP) procedures were performed in patients affected by various diseases of the corneal stroma but having a preserved endothelium. Each case was matched with a patient of similar age, gender and pathology who had undergone PK. The following parameters were evaluated: number of rejection episodes, density of endothelial cells, degree of ophthalmometric astigmatism, visual acuity and ocular tension. Statistical analysis was performed with Student's t test to compare patients in a similar clinical setting. RESULTS: No rejection episodes were recorded in the 150 patients who underwent DLKP surgery, whereas rejections occurred in 4% of the patients after PK. A statistically significant higher density of endothelial cells was found in DLKP cases, who also experienced a lower degree of astigmatism than PK patients. A slight but significant improvement in visual acuity was achieved in DLKP patients. CONCLUSION: Our results confirm that DLKP is the preferential procedure when no endothelial damage is involved.

Adolescent↗

Review of experience with retinopathy of prematurity from the Pavia registry (1990-1993).

In this retrospective study we analysed the prevalence of retino-pathy of prematurity (ROP) and its sequelae in a sample of premature infants with birth weight less than 1500 grams. From 1 January 1990 to 31 October 1993, we studied 160 surviving premature infants with very low birth weight (< 1.500 g) referred to the Neonatal Intensive Care Unit of the I.R.C.C.S. Policlinico San Matteo, Pavia, Italy. Thirty percent of these infants suffered from ROP, and 13.7%, with severe ROP, underwent cryotherapy. These latter had very-very low birth weight (< 1.000 g) and low gestational age (< 28 weeks). Follow-up of 69 infants at 12 months for retinal sequelae, refraction defects, bin-ocular vision and ocular motility impairments gave the following results: 1) strabismus 20.3%; 2) > 3D hyperopia 3%; 3) myopia 30.4%; 4) > 5D myopia 3.7%. The incidence of refraction and ocular motility anomalies in patients with acute ROP with spontaneous remission was similar to that of unaffected premature infants. Conversely, in the patients treated with cryotherapy the incidence of strabismus and > 5D myopia was greater than for untreated infants: 30% vs 15.4% (n.s.) and 14.7% vs 0% (p = 0.05), respectively. Cryotherapy was successful in 91.9% of cases and in 37.8% of cases the cicatricial sequelae were limited to peripheral chorioretinal scars.

Cryotherapy↗

Esotropia and pseudoexotropia in acute ROP sequelae: clinical features and suggestions for treatment.

We report five cases with a mixture of esotropia and pseudoexotropia due to macular ectopia related cicatricial retinopathy of prematurity (ROP). On inspection, the patients, aged from 9 to 28 years, presented a divergence of the eyes and a nasally decentralised corneal light reflex. The cover test showed esodeviation. All the cases presented some clinical features common to congenital strabismus. Fundus examination showed temporal traction of vascular and retinal tissues and macular ectopia, referrable to cicatricial sequelae of spontaneously regressed severe ROP. Treatment is limited to follow-up, with attention being paid to the control of retinal damage rather than to resolving the esthetic defects. Despite cryotherapy, these conditions are increasing with the increase in severe ROP and are now relatively frequent. We suggest that they be carefully identified in order to avoid incorrect orthoptic or surgical treatment.

Acute Disease↗