Neoadjuvant chemotherapy for osteosarcoma of the extremity: long-term results of the Rizzoli's 4th protocol.

From January 1993 to March 1995, 162 patients with osteosarcoma of extremities were treated according to the IOR/OS-4 protocol. 133 patients had localised disease, while 29 had metastases at diagnosis. These last patients were simultaneously operated upon for their primary and metastatic lesions. Chemotherapy consisted preoperatively of two cycles of high dose methotrexate (HDMTX) and one cycle each of cisplatin (CDP)-doxorubicin (ADM), CDP/ifosfamide (IFO) and IFO/ADM. After surgery, patients were treated with the aforementioned drugs used as single agents. The mean follow-up of all patients was 6.5 years (5.5-8 years). Surgery was a limb salvage in 94% of cases, and the 5-year event-free survival (EFS) and overall survival (OS) rates were 56 and 71% for patients with localised disease, and 17 and 24% for patients with metastases at diagnosis. These results did not differ from those achieved in our previous study (IOR/OS-3) in which IFO was used only postoperatively in poor responders.

Clinical effect of blowing nitrogen gas across the cornea during photorefractive keratectomy.

OBJECTIVE: We evaluated the clinical effects of blowing nitrogen gas over the cornea during photorefractive keratectomy. METHODS: We retrospectively compared clinical outcomes of 32 patients (37 eyes), divided into two groups who had photorefractive keratectomy with nitrogen gas blowing across the cornea (n = 19) and without nitrogen gas (n = 18). All photorefractive keratectomies were performed between April 1991 and August 1992. Ablation zone diameters were 5.0 or 5.5 mm. The average attempted correction was -3.47 +/- 1.76 diopters (D) in the nitrogen gas group, and -3.48 +/- 1.25 D in the non-nitrogen gas group. RESULTS: The nitrogen gas group achieved more accurate corrections than the non-nitrogen gas group, but had a significantly greater amount of corneal haze at all postoperative examinations. Corneal haze was most evident at 1 month and gradually diminished therafter in both groups. At 6 months, videokeratography revealed a central island in 2 eyes (11.1%) of the non-nitrogen gas group. Because of undercorrection (2 eyes) or central island (1 eye), 3 out of 18 eyes in the non-nitrogen gas group were reablated 6 months later. CONCLUSIONS: The non-nitrogen gas group had more undercorrections and a higher frequency rate of central steep islands, but nitrogen gas blowing caused a greater amount of corneal haze.

The role of contact lenses in the management of the radial keratotomy patient.

Approximately 15% of radial keratotomy procedures result in a residual refractive error of at least 1.00 D. Contact lenses may be used in these cases to optimize visual acuity. Patients who have undergone radial keratotomy present unique physiological challenges because of the corneal incisions; wear of lenses can produce epithelial erosion, infiltrative keratitis, neovascularization, and chronic edema. The corneal topography is altered by the surgery, with the central cornea flattened and the midperiphery steepened; these changes influence contact lens design. The lens of choice is a large, thin, rigid gas-permeable lens with a fairly small optic zone. Hydrogel lenses can also be used, but complications of wear can include neovascularization and corneal edema. Toric hydrogel lenses can be used to minimize residual astigmatism.

Surface analysis of hydrogel contact lenses by ESCA.

We used electron spectroscopy for chemical analysis (ESCA) to examine the surface chemistry of polymacon, tefilcon, and bufilcon hydrogel contact lenses. Worn and unworn water-cleaned and surfactant-cleaned lenses were compared. The surface chemistry of unworn lenses, which were used as controls, consisted of approximately 70% carbon, 25% oxygen, and < 10% other elements (i.e., silicon, sulfur, sodium, nitrogen, and zinc). In general, surfactant cleaning removed silicon contamination, but left a residue containing sulfur and zinc. The increase in the nitrogen/carbon (N/C) ratio for worn bufilcon and polymacon lenses was significantly greater than the N/C ratio for unworn bufilcon and polymacon lenses. As a group the worn ionic lenses (bufilcon) showed a greater N/C ratio than the worn nonionic lenses (polymacon, tefilcon). The nitrogen that appears on all worn lenses probably represents adherent as well as adsorbed surface proteins. The highest N/C ratios were found on a pair of pathologically deposited lenses and on the lens with the longest wearing time (2 years). For the bufilcon and polymacon lenses, the differences observed in the ESCA data for the unworn and worn lenses suggest that contact lenses begin interacting with the tear film within 1 minute (the shortest wearing time in this study).

Collagen shields as a vehicle for collecting and studying migratory cells on human corneas.

Collagen shields have been studied in the enhancement of the initial healing of epithelial defects, as an adjunct in the treatment of dry eye, and as a reservoir and delivery system for topical ocular medications. The authors used collagen shields to collect information on the numbers and types of free cells populating the normal and postoperative ocular surface. In addition, correlative microscopic techniques were used to study details of the mechanisms responsible for the dissolution of the shields when applied to the human eye. Collagen shields were applied as a bandage lens on the eyes of patients who underwent extracapsular cataract extraction (n = 10) or penetrating keratoplasty (n = 10) and on normal volunteers (n = 10). The shields were collected at the 1-day postoperative examination and fixed in aldehyde mixtures. Specimens then were processed for correlative light (LM), transmission (TEM), and scanning (SEM) microscopy. Cell accumulation was shown by SEM on both anterior and posterior shield surfaces. Cell adherence occurred primarily on the posterior shield periphery for approximately 2 mm, with the central zone relatively clean. Both LM and TEM evaluation revealed cell counts ranging from 0.066 cells/10(4) microns2 (standard deviation, +/- 0.256) in healthy eyes compared with shields placed on postoperative eyes (194.25 +/- 7.32 cells/10(4) microns2). Various correlative microscopy techniques revealed that most cells were polymorphonuclear leukocytes with a low number of other hematogenous (lymphocytes and monocytes) and exfoliated epithelial cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Applications of hydrophilic disposable contact lenses as therapeutic bandages.

We employed Acuvue (Johnson & Johnson) and SeeQuence (Bausch & Lomb) disposable hydrophilic contact lenses for therapeutic purposes on 39 patients with varying pathology. Concomitant medial therapy was implemented where appropriate. The disposable bandage lens was associated with improved patient symptomatology and objective findings in the majority of cases; complications were infrequent. The disposable hydrophilic lens appears to be a reasonable alternative to traditional hydrophilic bandage lenses.

The effect of a collagen bandage lens on corneal wound healing: a preliminary report.

Collagen bandage lenses were inserted in 24 eyes of white New Zealand rabbits following 8-incision radial keratotomy. Specimens were examined at eight and 24 hours by light and electron microscopy. Treated eyes demonstrated more complete epithelial healing, as evidenced by surface microvilli and differentiation into multi-layers. In the treated eyes there was reduced stromal edema at the wound site, and reactive keratocytes were limited to the wound margins. Collagen bandage lenses therefore may be useful in the treatment of a variety of ocular surface problems.