Proteins related to the Nedd4 family of ubiquitin protein ligases interact with the L domain of Rous sarcoma virus and are required for gag budding from cells.

The late assembly (L) domain of retrovirus Gag, required in the final steps of budding for efficient exit from the host cell, is thought to mediate its function through interaction with unknown cellular factors. Here, we report the identification of the Nedd4-like family of E3 ubiquitin protein ligases as proteins that specifically interact with the Rous sarcoma virus (RSV) L domain in vitro and in vivo. We screened a chicken embryo cDNA expression library by using a peptide derived from the RSV p2b sequence, isolating two unique partial cDNA clones. Neither clone interacted with a peptide containing mutations known to disrupt in vivo RSV L domain function or with human immunodeficiency virus type 1 (HIV-1) and equine infectious anemia virus (EIAV) L domain-derived peptides. The WW domain region of one of the clones, late domain-interacting protein 1 (LDI-1), but not the C2 domain, bound RSV Gag and inhibited RSV Gag budding from human 293 cells in a dominant-negative manner, functionally implicating LDI-1 in RSV particle budding from cells. RSV Gag can be coimmune precipitated from cell extracts with an antisera directed at an exogenously expressed hemagglutinin (HA)-tagged LDI-1 or endogenous Nedd4 proteins. These findings mechanistically link the cellular ubiquitination pathway to retrovirus budding.

Proper processing of avian sarcoma/leukosis virus capsid proteins is required for infectivity.

The formation of the mature carboxyl terminus of CA in avian sarcoma/leukemia virus is the result of a sequence of cleavage events at three PR sites that lie between CA and NC in the Gag polyprotein. The initial cleavage forms the amino terminus of the NC protein and releases an immature CA, named CA1, with a spacer peptide at its carboxyl terminus. Cleavage of either 9 or 12 amino acids from the carboxyl terminus creates two mature CA species, named CA2 and CA3, that can be detected in avian sarcoma/leukemia virus (R. B. Pepinsky, I. A. Papayannopoulos, E. P. Chow, N. K. Krishna, R. C. Craven, and V. M. Vogt, J. Virol. 69:6430-6438, 1995). To study the importance of each of the three CA proteins, we introduced amino acid substitutions into each CA cleavage junction and studied their effects on CA processing as well as virus assembly and infectivity. Preventing cleavage at any of the three sites produced noninfectious virus. In contrast, a mutant in which cleavage at site 1 was enhanced so that particles contained CA2 and CA3 but little detectable CA1 was infectious. These results support the idea that infectivity of the virus is closely linked to proper processing of the carboxyl terminus to form two mature CA proteins.

[Personal experience with surgical treatment of thyroid diseases in childhood and adolescence]. / Nase skúsenosti s chirurgickou liecbou detských a adolescentných tyreopátií.

The authors present their experience with operations of goitre in children and adolescents. The great majority of patients was indicated by the paediatric department of the Endocrinological Institute in Lubochna. In the course of 16 years at the surgical department of the hospital and policlinic on Dolný Kubín and in the Central Military Hospital in Ruzomberok 57 patients aged 12-18 years were operated. There were 38 toxic goitres (66.7%), 19 eufunctional ones (33.3%). Fifty-six patients had a benign finding, papillary carcinoma was found once. As to hyperfunctional goitres, in 19 instances Basedow's goitre was involved, toxic juvenila goitre 16x, toxic adenoma 3x. Of the 19 eufunctional goitres nodular goitre was present 14x, diffuse nodular goitre 4x and in one instance abscendent thyroiditis. Bilateral subtotal resections were made 40x, unilateral onces 7x, total unilateral lobectomy 4x, bilateral total lobectomy and restrumectomy 1x. A cyst was extirpated 3x, in one instance an abscess of the gland was treated. In the author's opinion in particular nodular goitres are a problem as they are associated with a frequent incidence of tumours; a follicular adenoma was found 6x, papillary carcinoma once. Carcinoma on a common discrete goitre is not an exception. In carcinoma the method of choice is total bilateral lobectomy. In eufunctional benign lesions the authors recommend resection in the sound tissue with an adequate functional residue. Toxic goitres, in particular of the Basedow type, call for radical surgery, the extent of the operation depends on the character of the disease and experience of the surgeon. The objective is to achieve an eufunctional state.(ABSTRACT TRUNCATED AT 250 WORDS)

[Peritoneal form of adiaspiromycosis (author's transl)]. / Peritoneale Form der Adiasporose.

A female patient, aged 30 years was subjected in 1977 to an appendectomy because of a perforated gangrenous appendix associated with purulent peritonitis. Postoperatively she developed an intractable constipation persisting for more than one year. Because of suspected intestinal stenosis an exploratory laparotomy was performed which failed to disclose the presence of stenosis. Histological studies of excised peritoneal specimens were suggestive of tuberculous peritonitis. Since cultivation failed to provide evidence of mycobacteria and the clinical symptoms were not characteristic of a tuberculous involvement of the peritoneum it was decided to carry out a re-evaluation of the original histological slides. This revealed that the patient was infected with adiaspores of the fungus Emmonsia crescens which were disseminated over the entire peritoneum from the perforated appendix. The difficulties associated with the diagnosis which are due to the striking morphologic similarity between the minute nodules in adiasporosis and those in productive miliary tuberculosis, as well as because of the acid-fast adiaspore capsules, are stressed. Since Emmonsia crescens is spread in some regions of Czechoslovakia it may be expected that humans will come into contact with its spores either by inhalation or by alimentary ingestion.