Procedure for the sample preparation and handling for the determination of amino acids, monoamines and metabolites from microdissected brain regions of the rat.

A method is described for the analysis of amino acids, monoamines and metabolites by high-performance liquid chromatography with electrochemical detection (HPLC-ED) from individual brain areas. The chromatographic separations were achieved using microbore columns. For amino acids we used a 100x1 mm I.D. C8, 5 microm column. A binary mobile phases was used: mobile phase A consisted of 0.1 M sodium acetate buffer (pH 6.8)-methanol-dimethylacetamide (69:24:7, v/v) and mobile phase B consisted of sodium acetate buffer (pH 6.8)-methanol-dimethylacetamide (15:45:40, v/v). The flow-rate was maintained at 150 microl/min. For monoamines and metabolites we used a 150X1 mm I.D. C18 5 microm reversed-phase column. The mobile phase consisted of 25 mM monobasic sodium phosphate, 50 mM sodium citrate, 27 microM disodium EDTA, 10 mM diethylamine, 2.2 mM octane sulfonic acid and 10 mM sodium chloride with 3% methanol and 2.2% dimethylacetamide. The potential was +700 mV versus Ag/AgCl reference electrode for both the amino acids and the biogenic amines and metabolites. Ten rat brain regions, including various cortical areas, the cerebellum, hippocampus, substantia nigra, red nucleus and locus coeruleus were microdissected or micropunched from frozen 300-microm tissue slices. Tissue samples were homogenized in 50 or 100 microl of 0.05 M perchloric acid. The precise handling and processing of the tissue samples and tissue homogenates are described in detail, since care must be exercised in processing such small volumes while preventing sample degradation. An aliquot of the sample was derivatized to form the tert.-butylthiol derivatives of the amino acids and gamma-aminobutyric acid. A second aliquot of the same sample was used for monamine and metabolite analyses. The results indicate that the procedure is ideal for processing and analyzing small tissue samples.

Blood and amniotic fluid contact sustained by obstetric personnel during deliveries.

OBJECTIVE: The objective of this study was to characterize blood and amniotic fluid contact sustained by obstetric personnel during deliveries. STUDY DESIGN: Trained observers collected data on 1376 person procedures during 230 deliveries at Grady Memorial Hospital from May to October 1989. Rates of contact were compared by means of the chi 2 test. RESULTS: At least one blood or amniotic fluid contact occurred during 79 (39.1%) of 202 vaginal and 14 (50.0%) of 28 cesarean deliveries; a needle stick occurred in 4 (2.0%) of the vaginal deliveries. Obstetricians and midwives had the highest rates of blood and amniotic fluid contact (18.7% and 28.8% of person procedures, respectively). Half of the contacts sustained by midwives might have been prevented by the use of gowns. Most contacts sustained by obstetricians might have been prevented by face shields, impervious gowns, and impervious shoe covers. CONCLUSIONS: Obstetricians and midwives had substantial risk of blood and amniotic fluid contact during delivery; many of their contacts were potentially preventable.

Axenfeld's anomaly associated with Down's syndrome.

We report a case of a patient with Down's syndrome and keratoconus with acute hydrops who was incidentally noted to have Axenfeld's anomaly. We also review the systemic abnormalities associated with Axenfeld's anomaly and the implications of the diagnosis. To our knowledge, Axenfeld's anomaly has not previously been reported in association with Down's syndrome.

Response to a hospitalized case of measles at a medical school affiliated hospital.

A 27-year-old woman was diagnosed as having measles 2 days after being hospitalized for an unrelated complaint. Hospital personnel, medical housestaff, and students were considered at risk for developing measles infection. Over a 7-day period, measles vaccine was administered to individuals born in or after 1957. No secondary measles cases occurred in the hospital. An immediate response to the possibility of nosocomial measles transmission can be successfully undertaken, but ongoing preemployment or preenrollment school programs are more practical and potentially can have a higher rate of compliance.

Blood contacts during surgical procedures.

Operating room personnel are at risk for infection with blood-borne pathogens through blood contact. To describe the nature and frequency of blood contact and its risk factors, trained observers monitored a sample of operations performed by six surgical services at Grady Memorial Hospital, Atlanta, Ga, for 6 months. In 62 (30.1%) of 206 operations, at least one blood contact was observed. Of 1828 operating room person-procedures observed, 96 (5.3%) had 147 blood contacts (133 skin contacts [90%], 10 percutaneous injuries [7%], and four eye splashes [3%]). The mean number of blood contacts per 100 person-procedures was highest for surgeons (18.6). The frequency of percutaneous injury was similar among surgeons and scrub staff (mean, 1.2 per 100 worker-procedures for each group). Risk factors for surgeons' blood contacts were (1) performing a trauma, burn, or orthopedic emergency procedure (odds ratio [OR], 4.1; 95% confidence interval [CI], 2.0 to 8.7); (2) patient blood loss exceeding 250mL (OR, 2.1; 95% CI, 1.2 to 3.7); and (3) being in the operating room longer than 1 hour (OR, 3.3; 95% CI, 1.6 to 7.1). Of 110 blood contacts among surgeons, 81 (74%) were potentially preventable by additional barrier precautions, such as face shields and fluid-resistant gowns. Twenty-one (84%) of 25 blood contacts among surgeons in procedures in which all three risk factors were present were potentially preventable by additional barriers. Of 29 blood contacts among anesthesia and circulating personnel, 20 (69%) would have been prevented by glove use. For surgical procedures in which operating room personnel are at increased risk of blood contact, reevaluation of surgical technique, use of appropriate barrier precautions, and development of puncture-resistant glove materials are indicated.

Sterile corneal ulceration after cataract extraction in patients with collagen vascular disease.

We report the occurrence of sterile corneal ulceration in 11 eyes of eight patients with collagen vascular diseases and dry eyes after cataract extraction with intraocular lens implantation. Keratolysis occurred after both extracapsular and intracapsular cataract extraction and appeared unrelated to the type of intraocular lens. Despite aggressive lubrication and other medical treatment, including systemic immunosuppressive agents, penetrating keratoplasty was often required. Although all eyes were saved, visual outcome was usually poor. The histopathologic finding of polymorphonuclear leukocytes localized near the areas of corneal dissolution provides evidence for the role of polymorphonuclear leukocyte-derived collagenase as a contributing factor in the pathogenesis of sterile corneal ulceration in these patients.

Acanthamoeba keratitis in Tennessee: a growing problem in patients wearing contact lenses.

All physicians evaluating a painful red eye in a contact lens wearer should consider the diagnosis of Acanthamoeba keratitis. Although it remains relatively rare, the incidence of this infection is on the rise. Clues to the correct diagnosis include a corneal abrasion that fails to heal appropriately, pain out of proportion to the clinical findings, and a history of poor contact lens hygiene. Prompt recognition and appropriate ophthalmologic intervention can improve the visual outcome for patients with this devastating corneal infection.

Traumatic wound dehiscence in pseudophakia.

In a series of 11 pseudophakic patients (11 eyes) who sustained wound dehiscence as a result of blunt trauma, five intraocular lenses were dislocated, one was fractured, and two were expulsed. Wound rupture occurred from three days to one year after surgery; the most common cause of injury was a fall. Iris prolapse was observed in all patients, with hyphema observed in seven. Vitreous prolapse occurred in four patients, and three patients developed retinal detachment. Six of the 11 patients had a visual acuity of 20/40 or better after repair. The limbal wound of a pseudophakic eye can dehisce as a consequence of blunt trauma long after surgery, and the position of the intraocular lens can be disrupted. Patients undergoing cataract extraction with intraocular lens implantation should be advised about the importance of long-term protective eyewear.

Mattress bridge sutures for graft fixation in pediatric keratoplasty: new use of an old technique.

Because of decreased scleral rigidity of tissue, penetrating keratoplasty in the pediatric age group is difficult. We have applied an early keratoplasty technique of graft fixation with indirect "bridge" or "overlay" sutures to temporarily stabilize the graft and facilitate wound closure.

Long-term results with Choyce-Tennant anterior chamber intraocular lens implants.

A consecutive series of 200 Choyce-Tennant rigid anterior chamber intraocular lens implants is reported. The minimum follow-up was four years. Eighty-six percent of patients had 20/40 or better visual acuity at their most recent office visit. Low-grade but persistent inflammation required prolonged use of mild topical steroid drops in approximately 40% of patients. The most serious lens-related complication was pupillary block which occurred in 15 patients (7.5%). There was a year-by-year increase in the number of patients with elevated intraocular pressure, with 14 (7.0%) requiring glaucoma treatment by the seventh year postoperatively.

Brown tumor of the orbit. Case report and review of the literature.

Brown tumors, focal bony lesions of hyperparathyroidism, result from the direct effect of parathyroid hormone on bone. While such lesions are not uncommon in primary hyperparathyroidism, brown tumors have been associated less frequently with secondary hyperparathyroidism and have rarely been described as involving the orbital bones. We have found only four such cases previously reported in the ophthalmic literature. We report a case of orbital involvement by brown tumor in a child with chronic renal failure and secondary hyperparathyroidism. Use of long-term hemodialysis has increased the life span of individuals with chronic renal failure and produced an increased population of patients with secondary hyperparathyroidism and resultant bony changes. The ophthalmologist should consider brown tumor in the differential diagnosis of a patient with chronic renal failure and ocular symptomatology.

CT detection of infected synthetic grafts: preliminary report of a new sign.

The diagnosis of infected synthetic grafts is difficult using traditional radiographic techniques. In four cases, computed tomography demonstrated small pockets of gas in the clot around the grafts, a distinctive finding for an infected prosthesis. Further experience is required to determine whether this will prove to be a reliable diagnostic sign. The gas collections in infected grafts differ from normal gas in their multiplicity and occurrence more than 10 days after surgery.