All-male production by marker-assisted selection for sex determining loci of admixed Oreochromis niloticus and Oreochromis aureus stocks.

Crossing Oreochromis niloticus (On) females with Oreochromis aureus (Oa) males results in all-male progeny that are essential for effective tilapia farming. However, a reproductive barrier between these species limits mating and mass-fry production. One approach to overcoming this barrier is to select parental stocks of mixed genetic backgrounds, which allow interspecific reproductive recognition, while closely maintaining the genetic profiles for sex-determination (SD) of the respective purebred species. Here, we test this approach in a data set of 160 On × Oa spawns of 109 male and 100 female parents randomly collected from admixed stocks, and genotyped for microsatellite markers representing the known SD loci on linkage groups (LGs) 1, 3, and 23. Following crossbreeding, the most significant paternal effects on male proportions in progeny were found for LG1-BYL018 (P < 2 × 10-32 ) and for LG3-UNH168 × LG23-UNH898 interaction (P < 1 × 10-17 ; R2  = 0.98). Furthermore, a maternal effect for LG3-UNH168 (P < 9 × 10-7 ) was associated with low female proportions in progeny (<7%), indicating a non-Mendelian effect on SD. Eighty-four males (77%) and 30 females (30%) were selected as parents, based on their genetic profiles for the SD loci that were associated with male production. Of these, 51 of 53 crosses produced all-male progeny, while two crosses had low female proportions in their progeny (<4%). This suggests that selection could be improved using the causative sequence variation underlying SD on LG3, since the large non-recombining block of the SD region in purebred Oa readily breaks down in hybrids. Nevertheless, marker-assisted selection for sex determining loci of admixed parental stocks may be used for all-male production.

A duplication of the Anti-Müllerian hormone gene is associated with genetic sex determination of different Oreochromis niloticus strains.

Sex determination (SD) mechanisms are ancient and conserved, yet much diversity is exhibited in primary sex-determining signals that trigger male or female development. In O. niloticus, SD is associated with a male-specific locus on linkage group (LG) 23 which harbors the Y-linked Anti-Müllerian hormone (amh) gene, and a truncated duplication, denoted amhΔy. We have evaluated the possible role of identified indels and SNPs in the amh gene on SD, based on conservation in different O. niloticus strains. A fluorescent assay for the detection of a 5 bp insertion in amhΔy exon VI, efficiently discriminated between XX, XY, and YY genotypes. Concordance rate between amhΔy and sex varied in six Oreochromis strains, from 100% (Ghana) through 90% (Swansea) to 85% (Thai-Chitralada). The association of amhΔy with sex was found to be conserved in all tested O. niloticus strains, and thus supports its key role in SD. However, the previously identified missense SNP (C/T) in amh exon II was found only in the Swansea strain, thus excluding its candidacy for the causal variation of SD across all strains. Effects of markers on LGs 1, 3, and 23 (amhΔy) fully explained sex distribution in one Thai-Chitralada family (R2 = 1.0), whereas in another family only the major effect of LG23 (amhΔy) was significant (R2 = 0.37). Thus, amhΔy on LG23 is associated with genetic SD, either as a single causal gene in different O. niloticus strains, or in combination with segregating genes on LGs 1 and 3 in the Thai-Chitralada hybrid strain.

A programme of iodine supplementation using only iodised household salt is efficient--the case of Poland.

BACKGROUND: Iodine prophylaxis in Poland started in 1935 and has been interrupted twice: by World War II and in 1980 for economic reasons. Epidemiological surveys carried out after the Chernobyl accident in 1989 as well as in 1992/1993 and in 1994 as a 'ThyroMobil' study, revealed increased prevalence of goitre in children and adults. Ninety per cent of Poland was classified as an area of moderate iodine deficiency, and 10%, in the seaside area, as mild iodine deficiency territory. Iodine prophylaxis based on iodisation of household salt was introduced again in 1986 as a voluntary model and in 1997 as a mandatory model with 30+/-10 mg KI/kg salt. OBJECTIVE: The evaluation of the obligatory model of iodine prophylaxis in schoolchildren from the same schools in 1994 and 1999. METHODS: Thyroid volume was determined by ultrasonography. Ioduria in casual morning urine samples was measured using Sandell-Kolthoff's method, within the framework of the ThyroMobil study. RESULTS: Goitre prevalence decreased from 38.4 to 7% and urinary iodine concentration increased from 60.4 to 96.2 microg/l mean values between 1994 and 1999. In four schools the prevalence of goitre diminished below 5%. In 1999, 70% of children excreted over 60 microg I/l, and 36% over 100 microg I/l, whereas in 1994 the values were 44 and 13% respectively. CONCLUSION: The present findings indicate that iodine prophylaxis based only on iodised household salt is highly effective.

Primary hereditary oxalosis retinopathy.

A female infant had progressive atypical pigmentary retinopathy with type 1 hereditary oxalosis. At the age of 3 months she had a flecked retina type of retinopathy and six months later she exhibited a unique type of atypical pigmentary retinopathy. This latter abnormality was characterized by a dense parafoveal hyperpigmented ring five disc diameters in size, and composed of a confluence of small rings of hyperpigmented retinal pigment epithelium surrounding whitish highly refractile calcium oxalate crystalline deposits.

Nodular goiter and thyroid carcinoma in children and adolescents in a moderate endemic area (lower Silesia-Sudeten endemia) in the last twelve years.

Although thyroid carcinoma is more common in the adult population, the risk of a nodule being malignant is greater in children. The aim of our present investigation was to ascertain the percentage of malignancy in nodular goiter observed in patients from the Lower Silesia region in the last 12 years. The examination included 60 children (12 boys and 48 girls) treated in our clinic from 1987 to June 1998. Age varied from 7 to 18 years (mean 14.8 +/- 2.4), most of them in the age group between 13 and 18 years. The following investigations were performed: TSH, T3, T4, thyroid ultrasonography, fine needle aspiration biopsy and Tc99 scintigraphy of the thyroid. Most of the patients were euthyroid; two children demonstrated pressure symptoms. All the patients were treated by operation. Histological examinations revealed the following: nodular goiter in 19 patients, cystic nodular goiter in 5, follicular adenoma in 20, fetal adenoma in 3, nodular goiter and follicular adenoma in 6, papillary carcinoma in 6, and follicular carcinoma in 1 patient. We concluded that an increased incidence of thyroid cancer has been noted in children with nodular goiter in Lower Silesia during the last 12 years. Thyroid cancer was observed mostly in patients with single nodules and was associated with a high risk of malignancy.

Early surgery for infantile esotropia: results and influence of age upon results.

In 105 patients with infantile esotropia who initially underwent corrective surgery between 5 and 24 months of age successful alignment of the eyes (to within 10 prism diopters of orthophoria) was associated with a higher prevalence of fusion and stereopsis and a lower prevalence of dissociated vertical deviation (DVD). Fusion was most frequent in the patients whose eyes were successfully aligned by 9 months of age, occurring in 92%. Inferior oblique overaction and amblyopia were less frequent when the initial operation had been performed before 12 months of age. Latent nystagmus, DVD, inferior oblique overaction and amblyopia were interrelated in a complex fashion.

Congenital primary upper eyelid entropion.

A case of primary congenital upper eyelid entropion ( PCUEE ) is reviewed. The author proposes a congenital shortness of the levator muscle with anomalous insertion onto the tarsal plate as the etiology, and a new simplified surgical correction is described. The classification of PCUEE as a syndrome with multiple congenital anomalies is supported, and the need for a complete systemic evaluation is stressed. Congenital primary upper eyelid entropion is an exceedingly rare condition. In 1969, Hiles and Wilder reviewed the 13 known cases in the ophthalmic literature, and presented a new case. They suggested the possibility that congenital upper eyelid entropion was part of a syndrome involving multiple systemic anomalies. Surgical correction of the ectropion is usually necessitated by corneal erosion secondary to trichiasis, and a multifarious assortment of surgical procedures has been described. The following is a case report of primary congenital upper eyelid entropion which corroborates the categorization as a syndrome, suggests a pathophysiologic abnormality of the eyelid as the etiology, and describes a new, simplified technique of surgical repair.

Benign episodic bilateral juvenile internal ophthalmoplegia.

A case of benign episodic bilateral juvenile internal ophthalmoplegia in a nine-year-old female is presented. Two separate episodes of sudden onset of bilateral mydriasis and accommodative loss accompanied by headache occurred, without any other physical, neuroophthalmic, or third nerve involvement. Complete resolution occurred over a period of months in both episodes. The differential diagnosis of isolated internal ophthalmoplegia is reviewed, and the episodic unilateral mydriasis syndrome of Hallett and Cogan appears to be similar to the bilateral involvement in the case presented.

Results of large single medial rectus recession.

Fifty-three patients with esotropia of 14 to 20 prism diopters received a 6-mm recession of one medial rectus muscle. All patients were three to ten years of age, had normal, equal vision, no vertical muscle imbalance, normal neurological status, and were followed for a minimum of two years. Twenty patients had high AC/A ratios, 22 were partially accommodative, four were deteriorated esophorias, four were anisometropes, and three were second operations. The average correction measured 16 prism diopters, ranging from 13 to 22 prism diopters, and 37 patients were aligned to 4 prism diopters or less of strabismus, 10 were microtropes, and all 53 had less than 10 prism diopters deviation. No persistent diplopia or consecutive exotropia was encountered. Stereopsis of 200 seconds or better was found in 75% of patients postoperatively. Large single medial rectus recessions appear to be a safe, effective, and predictable means of restoring ocular alignment and binocular vision in a select group of patients.

Early local steroid therapy of infantile eyelid hemangiomas (local steroid therapy of lid hemangiomas).

Two cases of upper eyelid capillary hemangiomas were successfully treated by local injection of steroids. Both cases required two injections, performed between 11 and 20 weeks of age. No untoward side effects occurred. This treatment would appear to be valuable in preventing the development of ophthalmic sequelae commonly associated with benign observation.

Surgery of infantile esotropia: a critical evaluation of marginal myotomy of the medial recti as a primary and secondary procedure.

Seventeen cases of marginal myotomy were compared to 88 conventional procedures in treatment of infantile esotropia. Successful alignment (within 10 prism diopters of orthophoria) was less frequently attained in the marginal myotomy group than in the conventional group, both after one surgery (18% versus 40%, respectively) and finally (24% versus 65%, respectively). Motor and sensory findings were similar in each group, although fusion and stereopsis were less frequent with marginal myotomy. Even though nearly all patients receiving marginal myotomy were successfully aligned immediately following surgery, a gradual return of esotropia was noted in 12 of 17 patients. The significantly inferior ability of marginal myotomy to produce stable successful alignment in infantile esotropia should incontrovertibly lead to the abandonment of marginal myotomy in favor of the vastly superior recession and/or resection procedures. Twenty-one cases of marginal myotomies of the medial recti performed as secondary procedures were also analyzed. The group receiving myotomy with resection had much better results (4 of 5 successfully aligned, average exo-shift 27.6 P.D.) than the myotomy only group (2 of 17 successfully aligned, average exo-shift 6.6 P.D.). Three of 17 were actually made more esotropic by the myotomy procedure alone. It is concluded that isolated myotomy is an ineffective reoperative procedure, and that by combining myotomy with resection, a fair rate of successful alignment may be achieved.

Infantile non-African Burkitt's lymphoma presenting as bilateral fulminant exophthalmos.

A case of non-african Burkitt's lymphoma presenting an acute bilateral fulminant exophthalmos in an infantile male is reviewed. The rapid progression of proptosis, and the dramatic response to chemotherapy is documented photographically. A brief description on non-African Burkitt's lymphoma and a differential diagnosis of bilateral infantile fulminant exophthalmos is included.

Nutritional nystagmus in infants.

Two infants presented with acquired infantile nystagmus. On examination, they manifested peculiar facies, growth and developmental delay, failure to thrive, and a Wernicke's type of nystagmus. Suspicion of a B vitamin deficiency resulted in correct diagnosis of dietary deficiency and/or enzymatic defect. In both instances, dietary treatment with B vitamins resulted in resolution of the nystagmus and improved growth and development of both individuals. Physicians, especially pediatricians and ophthalmologists, should be alert to the possibility of a Wernicke's type nystagmus in such infants, since the diagnosis may be critical to accurate diagnosis and treatment.

Goiter prevalence in children in Lower and Middle Silesia (Wroclaw--coordinating center).

As a part of the programme concerning iodine deficiency and iodine prophylaxis in Poland, 2518 children of age between 6 and 13 years, living in Lower and Middle Silesia, were studied. The anamnesis was based on a questionnaire answered by parents of the investigated children. The physical examination included measurements of body height and mass, clinical symptoms of thyroid functions as well as size and compactness of the thyroid gland on the basis of WHO classification. Urinary concentration of iodine was measured. The majority of children with goiter were inhabitants of mountainous villages. The goiter was most frequent in the age group 9-10 years. No significant differences in goiter incidence could be found between children consuming and not consuming iodized kitchen salt. The urinary concentration of iodine was low in all children examined. It was concluded that the territory of Lower and Middle Silesia is still a region of moderate endemic goiter. The urinary iodine concentrations is low in children living in Lower and Middle Silesia. The present system of iodine prophylaxis is not adequate and new measures should be urgently introduced.