Spontaneous collapse of an iris stromal cyst in a young child

A 4-month-old girl was referred for evaluation of an anterior chamber cyst in the left eye. Examination under anesthesia (EUA) revealed a large iris stromal cyst in the anterior chamber involving the angle and the pupillary border, with touch of the corneal endothelium and anterior lens capsule. Intraocular pressure was normal. There was no anisometropic refractive error by retinoscopy. Close observation with amblyopia management was recommended as the pupil was only partially occluded by the cyst, and there was a clear red reflex around the cyst. Repeat EUA 6 months following diagnosis showed spontaneous collapse of the cyst. There was no recurrence noted at her most recent follow-up, 2 years after presentation, and most of the pupillary axis remains unobstructed by the cyst. The patient continues to be followed to monitor for possible cyst progression, anisometropia, and development of amblyopia. Though rare, spontaneous resolution of an iris stromal cyst may occur and thus, observation may be considered, particularly if the cyst is not causing anterior segment complications or obstruction of the visual axis.

A novel case of Horner syndrome as the presenting sign of craniosynostosis

Craniosynostosis, the premature fusion of cranial sutures, can lead to distortion of skull shape and neurological dysfunction. We present a novel case of Horner syndrome as the presenting sign of craniosynostosis associated with elevated intracranial pressure. A 10-year-old boy presenting for strabismus follow-up was noted to have new-onset anisocoria, greater in the dark, and mild right upper eyelid ptosis. Apraclonidine testing was concerning for Horner syndrome. Neuroimaging demonstrated previously undiagnosed sagittal craniosynostosis with tortuous optic nerves and large cerebrospinal fluid spaces around both optic nerves. The patient was referred to neurosurgery and underwent a lumbar puncture with an opening pressure of 44 cm H2O. He underwent surgical cranial expansion. By six months postoperatively, his anisocoria had resolved.

Recurrent ectopic primary breast adenocarcinoma of the vulva with a 19-year follow-up period

We present a case of an ectopic breast adenocarcinoma of the vulva with metastatic local recurrence and a total follow-up period of 19 years, the longest documented in the literature to our knowledge. Following surgical excision, radiation therapy and hormonal treatment after the recurrence, the patient has remained disease free. This case demonstrates the potential for malignant transformation in accessory breast tissue and highlights the importance of close surveillance and regular physical examinations in patients with a history of ectopic breast malignancy.

Production of toxic shock syndrome toxin 1 in a mouse model of Staphylococcus aureus abscess formation

A mouse model of abscess formation is described in which toxic shock syndrome toxin 1 (TSST-1) is produced by Staphylococcus aureus in vivo. Mice injected intravenously with S. aureus developed renal abscesses within 4-7 days. Kidneys excised from infected mice were cultured quantitatively, and extracts from the kidneys were assayed for TSST-1 with use of a competitive enzyme-linked immunosorbent assay. Animals with less than 10(7) S. aureus/g of kidney had less than 6 ng of TSST-1/mL of extract. Toxin levels ranged from less than 6 ng/mL to 271 ng/mL in kidney extracts from mice with greater than 10(7) S. aureus/g of kidney. Urine from infected mice also contained measurable levels of TSST-1 (range, less than 6-728 ng/mL). Mice developed serum antibodies to TSST-1 by 2 weeks after challenge. Serum samples collected 5-7 days after bacterial challenge did not show biochemical changes typical of a toxic shock-like illness in these animals.

Purified capsular polysaccharide-induced immunity to Staphylococcus aureus infection

In this study, we determined that immunization with capsular polysaccharide from Staphylococcus aureus could protect mice against nonlethal infections induced by encapsulated staphylococci. We immunized mice with either formalin-killed bacteria or purified capsular polysaccharide (PCP) and challenged them with one of three related S. aureus strains that varied in capsule size. Quantitative cultures of blood and kidney from the animals were performed to evaluate protection. Immunization with whole bacteria protected mice against infection with the homologous strain. Mice immunized with PCP were protected when challenged intravenously with either a highly encapsulated S. aureus strain or a microencapsulated mutant but not with an unencapsulated mutant. Protection correlated with capsular antibody levels in the immunized animals. Immunity to staphylococcal infection could be passively transferred to naive animals by using immune serum. These experiments suggest that the S. aureus capsular polysaccharide merits further study as a potential vaccine candidate for preventing staphylococcal infection.

Virulence studies, in mice, of transposon-induced mutants of Staphylococcus aureus differing in capsule size

We used three related strains of Staphylococcus aureus to determine whether capsule size influenced bacterial virulence. Strain SA1 mucoid elaborated a large capsule demonstrable by transmission electron microscopy (TEM). Nonmucoid isolates were derived from strain SA1 mucoid by Tn551 insertional mutagenesis. By TEM, strain JL24 produced a "microcapsule," whereas strain JL25 was unencapsulated. Strain SA1 mucoid had a 50% lethal dose for mice greater than 3,000-fold lower than that of strains JL24 and JL25. Quantitative cultures of blood and kidney from animals challenged intravenously revealed that strain SA1 mucoid was cleared less readily from the bloodstream and kidneys than the nonmucoid mutants. In an in vitro assay, only strain SA1 mucoid demonstrated antibody-dependent, complement-mediated opsonophagocytosis by human leukocytes. Strains JL24 and JL25 were opsonized for phagocytosis by complement alone. Thus a highly encapsulated strain of S. aureus was more virulent in mice than two related nonmucoid strains. The microencapsulated mutant was not more virulent than the unencapsulated mutant.

Chemical characterization and immunogenicity of capsular polysaccharide isolated from mucoid Staphylococcus aureus

In this study we report the isolation and purification of the capsular polysaccharide elaborated by Staphylococcus aureus SA1 mucoid. The capsule was isolated from bacterial extracts and culture supernatants by a series of ethanol precipitations and enzyme digestions, followed by ion-exchange chromatography. Teichoic acid contamination was eliminated by oxidation with sodium metaperiodate, and the final product eluted in the void volume of a Sephacryl S-300 column. The purified capsular polysaccharide was analyzed by gas-liquid chromatography-mass spectroscopy, 13C and 1H nuclear magnetic resonance, amino acid analysis, immunelectrophoresis, and numerous biochemical assays. The major constituents of the capsule were 2-acetamido-2-deoxy-alpha-galacturonic acid (4-O linked), 2-acetamido-2-deoxy-alpha-fucose (3-O linked), and taurine. The polysaccharide also contained O-acetyl groups which were removed by mild alkaline hydrolysis. Serologically and biochemically, the capsule from strain SA1 mucoid appeared very similar to that produced by strain M. Purified capsular polysaccharide was immunogenic in both rabbits and mice. The optimal immunizing dose in mice was 0.1 microgram of purified capsular polysaccharide administered intraperitoneally. SA1 mucoid resisted opsonophagocytic killing by human leukocytes and complement. However, antibodies raised to the purified capsular polysaccharide neutralized the antiphagocytic effect of the capsule.