A sorting nexin-1 homologue, Vps5p, forms a complex with Vps17p and is required for recycling the vacuolar protein-sorting receptor.

A number of the Saccharomyces cerevisiae vacuolar protein-sorting (vps) mutants exhibit an altered vacuolar morphology. Unlike wild-type cells that contain 1-3 large vacuolar structures, the class B vps5 and vps17 mutant cells contain 10-20 smaller vacuole-like compartments. To explore the role of these VPS gene products in vacuole biogenesis, we cloned and sequenced VPS5 and characterized its protein products. The VPS5 gene is predicted to encode a very hydrophilic protein of 675 amino acids that shows significant sequence homology with mammalian sorting nexin-1. Polyclonal antiserum directed against the VPS5 gene product detects a single, cytoplasmic protein that is phosphorylated specifically on a serine residue(s). Subcellular fractionation studies indicate that Vps5p is associated peripherally with a dense membrane fraction distinct from Golgi, endosomal, and vacuolar membranes. This association was found to be dependent on the presence of another class B VPS gene product, Vps17p. Biochemical cross-linking studies demonstrated that Vps5p and Vps17p physically interact. Gene disruption experiments show that the VPS5 genes product is not essential for cell viability; however, cells carrying the null allele contain fragmented vacuoles and exhibit defects in vacuolar protein-sorting similar to vps17 null mutants. More than 95% of carboxypeptidase Y is secreted from these cells in its Golgi-modified p2 precursor form. Additionally, the Vps10p vacuolar protein-sorting receptor is mislocalized to the vacuole in vps5 mutant cells. On the basis of these and other observations, we propose that the Vps17p protein complex may participate in the intracellular trafficking of the Vps10p-sorting receptor, as well as other later-Golgi proteins.

Myofibrosarcoma of the adrenal gland.

Adrenal masses have varying presentations. Most commonly, adrenal masses are discovered incidentally on CT or MRI during an evaluation for an unrelated complaint. Although the majority of these are nonfunctional cortical adenomas, hormonally active tumors and adrenocortical carcinoma must also be considered in the differential diagnosis. Rarely, retroperitoneal tumors may mimic an adrenal mass. We report a case of a 49-year-old man with anemia and weight loss who was found to have a large retroperitoneal mass arising from the adrenal gland. Surgical treatment involved en bloc resection of the right kidney, adrenal gland, segments 7 and 8 of the liver, and a portion of the right hemidiaphragm. Final pathology revealed a low-grade myofibrosarcoma. We believe that this is the first case report of a myofibrosarcoma of the adrenal gland. Myofibrosarcomas are rare malignant tumors composed of myofibroblasts that arise from the deep soft tissues. These tumors have a predilection for the head and neck, trunk, or extremities. Myofibrosarcomas can be differentiated from other sarcomas by immunohistochemical staining and pathologic features. We will briefly discuss the workup of an adrenal mass and focus on the diagnosis of myofibrosarcoma.

Incidence of sudden infant death syndrome in Olmsted County, Minnesota: 1945 through 1992.

OBJECTIVE: To apply uniform diagnostic criteria for sudden infant death syndrome (SIDS) for an extended period for comparison of incidence rates from 1945 to 1992 in Olmsted County, Minnesota, to investigate the influence of a person-time or live birth denominator on the estimate of incidence, to calculate the proportionate mortality rate for SIDS over time, and to evaluate the accuracy of death certificates for case ascertainment and the role of interobserver variation in case classification. DESIGN: We retrospectively reviewed the autopsy results and complete medical records for all infant death from 1945 through 1992 for residents of Olmsted County, Minnesota. MATERIAL AND METHODS: Cases were identified from a computerized list of all Olmsted County deaths of infants occurring at ages 48 hours to 365 days. All resident cases were categorized as non-SIDS, possible SIDS, SIDS, or incomplete, on the basis of findings from autopsy and clinical history. Incidence rates were calculated for two different SIDS groups and with use of denominators of person-time and live births. RESULTS: For the study period, 82 cases of SIDS were identified (97% white and 3% Asian). The mean age at death was 12.5 weeks; male infants constituted 59% of cases. No significant trend in seasonal distribution was noted; 73% of deaths occurred between midnight and noon. The incidence rate, defined as SIDS definite and possible deaths per 1,000 resident live births, increased from 0.55 in 1950 through 1953 to 1.28 in 1990 through 1992. The secular trend was best described by a linear model with constant positive slope. Similar trends were observed with other definitions of incidence. During the study period, SIDS as a percentage of total infant deaths dramatically increased, ranging from 2.5 in 1950 through 1953 to 17.9 in 1990 through 1992. The death certificate diagnosis correctly predicted 72% of SIDS cases before 1970 and 100% of cases after 1970. CONCLUSION: Since 1945, the incidence of SIDS apparently has increased, although diagnostic transfer from other causes of death probably contributes to the observed trend. The comparison of live births versus person-time as denominators showed no significant difference in incidence rates. Interobserver reliability is modest for SIDS cases diagnosed before 1970 and may contribute to the variability in reported SIDS incidence rates.

Evaluation of the safety and efficacy of vaccination of nursing pigs with living tachyzoites of two strains of Toxoplasma gondii.

The safety of vaccination and persistence and distribution of Toxoplasma gondii stages within tissues following vaccination were examined in 3-day-old nursing pigs vaccinated with living tachyzoites by intravenous and subcutaneous routes of either the TS-4 mutant strain or its parent RH strain of T. gondii. The efficacy of vaccination of nursing pigs with the TS-4 mutant was also examined in pigs challenged orally with oocysts following vaccination. Pigs were vaccinated with 3 x 10(5) living tachyzoites when 3 days old and boosted with 3 x 10(5) living tachyzoites when 17 days old. Group 1 had 2 pigs vaccinated intravenously (i.v.) with Hanks' balanced salt solution (HBSS) and served as a vaccination control. Group 2 and 5 pigs vaccinated i.v. with tachyzoites of the TS-4 mutant; 3 pigs were used to examine the safety, persistence, and distribution of the TS-4 mutant and 2 were used for oocyst challenge. Group 3 had 5 pigs vaccinated i.v. with tachyzoites of the RH strain and all were used to examine the safety, persistence, and distribution of the RH strain within their tissues. Group 4 had 3 pigs vaccinated subcutaneously (s.c.) with tachyzoites of the TS-4 mutant; 1 was used to determine the persistence and distribution of the TS-4 mutant within its tissues and the other 2 pigs were used for GT-1 oocyst challenge studies. Group 5 had 3 pigs vaccinated s.c. with tachyzoites of the RH strain and all were used to examine the safety, persistence, and distribution of the RH strain within their tissues. None of the control pigs or pigs vaccinated with the TS-4 mutant developed clinical signs of disease or died prior to oocyst challenge. The TS-4 mutant was not reisolated from the tissues of vaccinated pigs nor were microscopic lesions present in the tissues of pigs that had been killed and examined at necropsy. Severe disease with clinical signs consisting of dyspnea, inactivity, diarrhea, and ocular lesions was observed in the group 3 pigs vaccinated i.v. with the RH strain. One pig died 7 days after initial vaccination. Microscopic lesions were observed in numerous tissues of all group 3 pigs. Swelling, erythema, and ulcers were observed at the site of inoculation in the group 5 pigs that were vaccinated s.c. with the RH strain. Minimal to no microscopic lesions were observed in these group 5 pigs. The RH strain was reisolated from pigs in both groups vaccinated with this strain.(ABSTRACT TRUNCATED AT 400 WORDS)

Histological findings in corneal stromal abscesses of 11 horses: correlation with cultures and cytology.

Histopathology was compared to culture results and cytology from horses with corneal stromal abscess at the Auburn University and the Ohio State University Veterinary Teaching Hospitals. Significant bacteria were not isolated in culture or seen on histopathology in any of the horses. Although most bacteria infecting equine corneas can be isolated with blood and MacConkey's agars, failure to detect bacterial growth may not rule out infection because anaerobic or intracellular bacteria would not be isolated. The inability to visualise bacterial organisms on histological sections did not rule out their presence in the tissue, because there is often destruction of bacteria by neutrophils, macrophages and antibiotic therapy greatly reducing their numbers. Fungal keratitis was diagnosed by histopathology in 4 of 11 eyes (36%) and keratitis with no aetiological agent in 7 of 11 eyes (64%). Nine of 11 horses (82%) had a prominent neutrophilic stromal infiltrate and 2 (18%) had a predominantly pyogranulomatous reaction. Two of the 4 lesions that showed histological evidence of fungal infection were positive for identifiable fungi on culture and cytology. Fungal cultures of the other 2 cases with histological evidence of mycotic keratitis were negative or grew unidentifiable fungi which were considered pathogenic because, on histopathological sections, fungal hyphae were found deep in the corneal stroma surrounded by an inflammatory reaction. In 3 of 6 cases where fungi were recovered on culture, they were considered contaminants based on lack of evidence of organisms in histopathological sections. Histopathology and the use of special stains were important in the interpretation of culture and cytology results.

Effects of inflammation and aqueous tear film deficiency on conjunctival morphology and ocular mucus composition in cats.

An experimental model of keratoconjunctivitis sicca (KCS) was produced by removing the lacrimal gland and the gland of the third eyelid from the left eye of 6 cats. The right eye of each cat was left intact and used as a control. After 2 weeks, cats were euthanatized and the central portion of the upper eyelid from both eyes of each cat was excised. Histologic sections were stained with either hematoxylin and eosin or with a battery of biotinylated lectins including concanavalin A (conA), soybean agglutinin (SBA), wheat germ agglutinin (WGA), succinylated wheat germ agglutinin (S-WGA), Ulex europaeus agglutinin I (UEA), Dolichos biflorus agglutinin (DBA), Ricinus communis agglutinin (RCA), peanut agglutinin (PNA), and PNA pretreated with neuraminidase. Consistent differences in histologic features were not observed between conjunctivas with KCS and control conjunctivas. A variable degree of mononuclear cell infiltration of the substantia propria was observed in control conjunctivas and those with KCS. In both groups, conjunctival goblet cell density decreased and epithelial stratification increased as the degree of submucosal inflammatory cell infiltration increased. Lectin binding sites for DBA, WGA, S-WGA, UEA, PNA, and PNA pretreated with neuraminidase were detected on conjunctival goblet cells of conjunctivas with KCS and control conjunctivas. The mucus/glycocalyx layer of conjunctival epithelial cells in both groups of conjunctivas bound lectins RCA, WGA, UEA, and conA, but inconsistently bound S-WGA. In both groups, DBA principally bound to the mucus layer overlying normal epithelium, whereas PNA pretreated with neuraminidase consistently bound to the mucus layer of stratified epithelial surfaces free of goblet cells. Binding of SBA to goblet cells and the mucus/glycocalyx layer was variable.

Effects of intracameral injection of viscoelastic solutions on intraocular pressure in dogs.

Intraocular pressure (IOP) was determined in right eyes of 20 healthy dogs after sodium hyaluronate (1%, n = 5), sodium chondroitin sulfate (4%) and sodium hyaluronate (3%, n = 5), hydroxypropyl methylcellulose (2%, n = 5), or balanced salt solution (control, n = 5) was injected into the anterior chamber. Applanation tonometry was used to measure IOP in both eyes of each dog for up to 168 hours. The 3 viscoelastic solutions resulted in an increased mean IOP by postinjection hours (PIH) 2; from PIH 12 until PIH 72, the IOP was significantly (P less than 0.001) lower than baseline. The control group did not have an increase in IOP at PIH 2; mean IOP decreased below baseline measurements within 2 hours and remained lower until PIH 72. Mean differences in IOP were not found among treated eyes (P = 0.50), and a significant interaction of any treated eyes in a group was not detected (P = 0.21). By PIH 168, the IOP approached baseline values in all groups.

Canine corneal thickness measured by ultrasonic pachymetry.

Ultrasonic pachymetry was used to measure central, superior peripheral, and temporal peripheral corneal thicknesses of 75 dogs (150 eyes) with normal corneas, anterior chambers, and intraocular pressure. Mean corneal thickness averaged over the 2 eyes, 3 locations, and 75 dogs was 562 +/- 6.2 microns. The peripheral cornea was thicker on average than the central cornea by 49.43 +/- 8.45 microns and this difference increased with age at 6.97 +/- 1.3 microns/month of age. Mean corneal thickness changed with age (14.23 +/- 2.26 microns/month), and weight (1.83 +/- 0.38 microns/kg). Females had significantly thinner corneas (22.43 +/- 11.03 microns than males) after adjusting for age and weight.

Corneal thickness measured by ultrasonic pachymetry in cats.

Ultrasonic pachymetry was used to measure central, superior peripheral, and temporal peripheral corneal thickness of 35 cats (70 eyes) with normal corneas, anterior chambers, and intraocular pressures. Mean central corneal thickness for both eyes in 3 locations for 35 cats was 578 +/- 64 microns. Significant differences did not exist between central and peripheral corneal thickness. Corneal thickness increased significantly (P < 0.0001) with age up to 100 months. There was no significant difference in corneal thickness with regard to sex of the cats when adjusted for age.

Scanning electron microscopy of intraocular lenses that had been implanted in dogs.

Scanning electron microscopy was used to evaluate changes on the surfaces of polymethylmethacrylate (PMMA), silicone, and polyhydroxyethylmethacrylate (HEMA) intraocular lenses (IOL) that had been implanted in the anterior chambers of the right eyes of 15 dogs. Five dogs received PMMA IOL; 5 dogs received silicone IOL; and 5 dogs received HEMA IOL. Twenty-eight days after surgery, the IOL were removed and processed for scanning electron microscopy. Nonimplanted IOL of each type were processed identically for comparison. Implanted PMMA IOL had significantly more debris and macrophages on their surfaces than did silicone IOL or HEMA IOL. Silicone IOL had significantly less fibrin deposition than did PMMA or HEMA IOL. Silicone IOL had surface defects attributable to handling by surgical instruments. Implanted HEMA IOL had multiple pits that appeared to be caused by biodegradation.

Clinicopathologic findings after experimental implantation of synthetic intraocular lenses in dogs.

Clinical findings indicate that canine eyes tolerate implantation of polymethylmethacrylate (PMMA) intraocular lenses (IOL) well, although inflammation and ocular damage attributable to the implants is not known. The use of silicone or polyhydroxyethylmethacrylate (HEMA) IOL has not been reported in dogs. In this study, 15 conditioned, mixed-breed dogs were allotted to 3 groups: 5 received PMMA IOL; 5 received silicone IOL; and 5 received HEMA IOL. The IOL optic was inserted into the anterior chamber of the right eye and anchored to the cornea. An identical surgical procedure was done on the left eye, except that no lens optic was inserted. Clinical examination and measurement of corneal thickness were done immediately prior to and after surgery. Aqueous humor samples were collected at the time of surgery and 28 days after surgery. Only mild and transient inflammation was observed in IOL-implanted eyes. On several postoperative days, it was found that PMMA IOL induced significantly greater corneal thickness, aqueous flare, anterior uveal irritation, and corneal edema than did other IOL. Significantly more anterior uveal irritation and increased aqueous humor protein concentration was observed with HEMA IOL than with PMMA or silicone IOL. Silicone IOL induced significantly less fibrin deposition than did PMMA or HEMA IOL.

Effect of epidermal growth factor on healing of corneal endothelial cells in cats.

Epidermal growth factor was injected intracamerally into the anterior chamber of the right eye of 9 cats. The central portion of the cornea in 8 of the 9 cats that had been cryoinjured. Effect of epidermal growth factor on the repair of endothelial cells in cats was evaluated by endothelial specular microscopy. Endothelial cell density and corneal thickness were studied quantitatively, as a measure of endothelial cell function. The repair process also was evaluated qualitatively by studying morphologic changes, developing as a result of reendothelialization and return to normal function. Seemingly, differences between rate of healing of cryoinjured eyes injected with epidermal growth factor and that in nontreated eyes were not significant (P = 0.86). The endothelial repair process was characterized by enlargement and migration of adjacent noninjured cells.

Effects of intracameral injection of viscoelastic solutions on corneal endothelium in dogs.

Contact in vivo wide-field specular microscopy was performed on right eyes of 20 healthy dogs after sodium hyaluronate (1%, n = 5), sodium chondroitin sulfate (4%) and sodium hyaluronate (3%, n = 5), hydroxypropyl methylcellulose (2%, n = 5), or balanced salt solution (control, n = 5) was injected into the anterior chamber. Using computerized morphometric analysis and pachymetry, changes in endothelial cell density, cell morphologic features, and corneal thickness from baseline values were evaluated at postinjection hour (PIH) 72 and PIH 168. Changes were not seen in endothelial cell density or cell morphologic features in any treated eye. The mean corneal thickness of all treated eyes at PIH 72 increased 6%, significantly greater than that of the nontreated eyes (P = 0.03). Mean corneal thickness of treated and nontreated eyes was similar at baseline and PIH 168 in all treatment groups.

Uveal malignant melanoma in a duck.

An adult male Muscovy (Cairina moschata) X Peking (Anas platyrhynchos) duck had a primary malignant uveal melanoma with periocular extension involving the left eye. The periocular mass displaced the globe 1.5 cm laterally. Thoracic metastasis of the ocular neoplasm infiltrated the pectoral muscles, rib cage, and cranial lung lobe on the left side, causing diminished voluntary motion of the left wing. The left orbit was exenterated, but tumor regrowth was evident within 2 weeks. This case was unusual because melanocytic neoplasms are rare in birds.

Pathogenic bacteria and fungi associated with external ocular diseases in dogs: 131 cases (1981-1986).

Medical records of 131 dogs with external ocular diseases were reviewed. Bacteriologic culture of swab specimens from 151 eyes revealed 100 eyes (66.2%) were considered positive for potentially pathogenic microorganisms. Of 127 species of microorganisms (bacterial and fungal) isolated, 50 (39.3%) were Staphylococcus spp (S intermedius, 17.3%). Streptococcus spp were the next most frequently isolated organism at 32 (25.2%), (Str canis, 16.5%). beta-Hemolytic streptococci (17%) were isolated more frequently than were alpha-hemolytic streptococci (9%), and coagulase-positive staphylococcal species (29%) were isolated almost 3 times as often as were coagulase-negative species (11%). Fungal and yeast organisms were isolated from 4.6% of the eyes. In vitro, most Staphylococcus spp were susceptible to cephalothin, bacitracin, and gentamicin, whereas most Streptococcus spp were susceptible to chloramphenicol, erythromycin, carbenicillin, and cephalothin. Pseudomonas spp were sensitive to tobramycin, gentamicin, and amikacin.

Autogenous lamellar corneal grafting in dogs.

Lamellar, autogenous, corneal grafts were performed on 9 clinically normal dogs (1 eye in each of 2 dogs and both eyes in each of 7 dogs) and 7 dogs with corneal disease (1 eye in each dog). Nylon, polyglycolic acid, polyglactin 910, and polydioxanone suture materials were used in 8-0 to 10-0 sizes. The eyes of the normal dogs were examined weekly for up to 16 weeks; corneal endothelium was reestablished in all eyes by 6 weeks after surgery. The eyes of the dogs with corneal disease were reexamined periodically for up to 9 months. Twenty-two of 23 (95.7%) grafts were considered successful in that they were translucent, and the dogs were able to see after surgery. The suture materials that caused the least tissue reaction were nylon and polyglactin 910. This procedure is indicated for chronic descemetoceles and other perforating corneal disease. It has the advantage of rapidly resolving severe corneal disease, with a high degree of success.

Abdominal cryptorchidectomy in the horse, using inguinal extension of the gubernaculum testis.

Removal of abdominal testes was accomplished in 32 horses ranging in age from 6 to 72 months. Twenty were unilateral and 12 were bilateral abdominal cryptorchids. An incision was made over the superficial inguinal ring, and the extension of the gubernaculum testis was identified and grasped with forceps. Traction was applied to this structure until the vaginal process was everted beyond the superficial inguinal ring. The vaginal process was incised and the protruding structure, usually the epididymis, was grasped. The testis was drawn out by gentle traction on the epididymis, and castration was performed in the routine manner.

Orbital neoplasms in cats: 21 cases (1974-1990).

Squamous cell carcinoma was the most common neoplasm found in a review of case records of 21 cats with histopathologically confirmed orbital neoplasms. Other neoplasms found were lymphosarcoma, undifferentiated carcinoma, malignant melanoma, adenocarcinoma, fibrosarcoma, chondroma, and hemangiosarcoma. Three (14%) neoplasms were primary, 15 (71%) were secondary, invading the orbit from adjacent tissues, and 3 (14%) were a manifestation of multicentric disease. The most common clinical sign was exophthalmia, followed by chronic epiphora, enophthalmia, and strabismus. Mean survival time after diagnosis was 1.9 months. Ten cats were euthanatized at the time of diagnosis because of extensive disease. Mean survival time of the other 11 cats was 4.3 months. Skull radiography was helpful in diagnosing orbital neoplasms in 8 of 11 cats that had invasion of the orbit by adjacent neoplasms.

Parosteal osteosarcoma of the mandible in a dog.

A mandibular parosteal osteosarcoma was diagnosed in a 7-year-old Collie with prolapse of the third eyelid. Diagnosis was made by histologic evaluation of a mass removed by surgical excision. The dog was euthanatized because of local recurrence of the tumor, with metastasis to the lungs. Parosteal osteosarcomas are rarely reported in dogs and usually involve long bones in human beings.

Pathogenic bacteria and fungi associated with extraocular disease in the horse.

In 123 cases of external ocular disease in the horse, pathogenic microorganisms isolated with greatest frequency were Streptococcus sp (43.9%), Staphylococcus sp (24.2%), and Pseudomonas sp (13.8%). Fungi were isolated in 4.8% of the cases. In vitro testing showed that most of the Streptococcus sp isolants were sensitive to ampicillin, cephalothin, and carbenicillin. Most of the Staphylococcus sp isolants were sensitive to gentamicin, cephalothin, and bacitracin. Most of the Pseudomonas sp isolants were sensitive to polymyxin B and gentamicin.