Oxygen-transmitting hard contact lenses.

Nine PMMA contact lens wearers with persistent corneal edema were refitted with CAB contact lenses. All of the patients showed less corneal swelling with CAB lenses than with PMMA lenses.     

The pedicle in neurofibromatosis.

Three cases of von Recklinghausen's disease (neurofibromatosis) are described, one with agenesis of a pedicle, another with multiple hypoplastic pedicles, and a third with bilateral hypoplastic pedicles producing a spondylolistesis. These peidcle deficiencies are manifestations of mesodermal dysplasia. Agenesis of the pedicle most likely represents a defect in chondrification. Hypoplasia probably represents a partial lack of development of the pedicle and the ipsilateral arch. Hypoplasia or agenesis of a pedicle should suggest the possibility of underlying neurofibromatosis.     

The effects of chronic administration of some cholinergic and adrenergic drugs on the activity of choline acetyltransferase in the optic lobes of the chick brain

Chicks receiving methadrine, reserpine and 6-hydroxydopamine for 2 or 3 days showed significant increases in optic lobe choline acetyltransferase. Atropine and neostig-mine did not produce this change. The methadrine-induced change occurred within 6 hr. Methadrine did not activate this enzyme in vitro however. This latter finding and the failure of acetoxycycloheximide to decrease measurable enzyme in 6 hr, suggests that the ampheta-mine-induced increase may be due to an increase in synthesis of choline acetyltransferase rather than either a steric activation or a decrease in degradation of the enzyme.     

Testicular hypotrophy does not correlate with grade of adolescent varicocele

PURPOSE: Testicular hypotrophy is the most widely accepted indication for correcting adolescent varicocele. Previous studies in adolescents have shown a relationship between increasing grade of varicocele and the likelihood of testicular hypotrophy. As this relationship has significant clinical implications, we studied the correlation between grade and testicular volume disproportion in our adolescent varicocele population. MATERIALS AND METHODS: We reviewed the adolescent varicocele database at our institution. A total of 168 patients 8 to 21 years old were studied. We routinely calculated testis volumes using scrotal ultrasound. Testicular disproportion was calculated using the equation [(size of unaffected testis) - (size of affected testis)]/(size of unaffected testis) x 100%. Disproportion was categorized as less than 10%, 10% to 20% and more than 20%. Varicoceles were graded by an attending urologist with the patient standing, using the system of Dubin and Amelar. Analysis of variance and Pearson chi-square indicated no significant differences in volume differential between varicocele grades. RESULTS: Mean +/- SD volume differential was 18% +/- 15% for grade I, 25% +/- 20% for grade II and 19% +/- 14% for grade III. ANOVA revealed no significant difference in mean volume differential between the 3 varicocele grades (p = 0.10). When categorizing patients into 3 levels of volume differential (less than 10%, 10% to 20%, more than 20%) no significant correlation was observed between varicocele and volume differential (p = 0.48, chi-square test). CONCLUSIONS: Grade of varicocele does not correlate with presence or severity of testicular disproportion in adolescent boys with varicocele as measured by scrotal ultrasound.     

Nitrous oxide anxiolysis for elective cesarean section

STUDY OBJECTIVE: To determine if inhaled 40% nitrous oxide (N(2)O) via facemask is an effective anxiolytic in women undergoing elective cesarean section under spinal anesthesia. STUDY DESIGN: Prospective, randomized, double-blinded study. SETTING: Tertiary-care women's hospital. PATIENTS: Sixty American Society of Anesthesiologists physical status I and II patients scheduled for elective cesarean section under spinal anesthesia. INTERVENTIONS: Patients were randomized to 2 groups to receive either 100% O2 via facemask or 40% N2O in O2 via facemask. MEASUREMENTS: Vital signs (blood pressure, heart rate, and oxygen saturation) and measured variables (visual analog scale [VAS] anxiety, VAS pain, and sedation scores) were obtained at specific periods during the procedure (preoperatively, entering the operating room, spinal injection, skin incision, uterine incision, delivery, and at the conclusion of the surgical procedure). In addition, surgical time and delivery time, mean dose and percentage of patients requiring ephedrine or phenylephrine boluses, the emesis rate, and Apgar scores were measured. MAIN RESULTS: No differences were noted with respect to maternal mean blood pressure, heart rate, pulse-oximeter oxygen saturation, and sedation or VAS pain scores during the measured periods. No differences were noted in surgical and delivery times, mean dose, or percentage of patients who required ephedrine or phenylephrine to maintain maternal blood pressure, the emesis rate, or 1- and 5-minute Apgar scores. Mean anxiety scores for the N2O group were significantly lower at the time of spinal injection, skin incision, and uterine incision. Multivariate analysis of variance for high-anxiety patients (> or =50 VAS) revealed significantly lower VAS scores in the N2O group, compared with the O2 group again at spinal injection, skin incision, and uterine incision. CONCLUSIONS: Inhaled 40% N2O via facemask provides effective anxiolysis in women undergoing elective cesarean section under spinal anesthesia in patients with high anxiety (> or =50 VAS) at the time of spinal injection, skin incision, and uterine incision.     

Update on community-acquired pneumonia. New pathogens and new concepts in treatment

Recent years have witnessed the emergence of new pathogens linked to community-acquired pneumonia (CAP) along with new antibiotics designed to combat them. In this article, Dr Mandell presents an expert's view on these developments in the context of treatment guidelines for CAP. He also explores monotherapy versus combination therapy, the efficacy of rapid initiation of treatment, and short-course therapy as a hedge against antimicrobial resistance.     

Disk susceptibility of ofloxacin, a new carboxyquinolone.

Ofloxacin, a fluorinated carboxyquinolone, was tested against 485 clinical isolates, and the MICs and disk inhibitory zones were correlated. A critical zone of greater than or equal to 19 mm and an MIC of less than or equal to 2 micrograms/ml indicate susceptibility. An MIC of 4 micrograms/ml and a zone size of 16 to 18 mm is intermediate, and an MIC of greater than or equal to 8 micrograms/ml with a zone size of less than 15 mm indicates resistance. Alternatively, organisms inhibited by an MIC of less than or equal to 4 micrograms/ml with a critical zone diameter of greater than or equal to 15 mm could be considered susceptible. By either of these criteria, major errors in judging susceptibility or resistance are less than 1%.     

Aromatic alkylamine N-acetyltransferase in regional tissues of developing rat brain

The specific activities of N-acetyltransferase (EC 2.3.1.5) were examined in several regions of rat brain of both sexes at various times after birth. The enzyme activity increased with development in whole brain, hippocampus, midbrain, cerebellum and the remainder of brain, peaking around 36 days of age. Lineweaver-Burk plots indicated linear kinetics for N-acetyltransferase in dialyzed supernatant and ammonium sulfate precipitates from the newborn rat brain, whereas enzyme preparation further purified by Bio Gel yielded biphasic kinetics. These data remain consistent with the possibility that there are two forms of N-acetyltransferase in rat brain even from birth.     

Functional and genomic approaches reveal an ancient CHEK2 allele associated with breast cancer in the Ashkenazi Jewish population

Functional and genomic approaches can be integrated to screen efficiently for pathogenic alleles in founder populations. We applied such approaches to analysis of the cancer-associated cell cycle regulator CHEK2 in the Ashkenazi Jewish population. We first identified two extended haplotypes at CHEK2 that co-segregated with breast cancer in high-risk families. We sequenced CHEK2 in a case representing each haplotype and discovered two novel amino acid substitutions, CHEK2.S428F in the kinase domain and CHEK2.P85L in the N-terminal region. To assay these alleles for loss of CHEK2 function, we tested their capacity to complement Rad53 deletion in Saccharomyces cerevisiae. CHEK2.S428F failed to complement Rad53 and thus largely abrogates normal CHEK2 function, whereas CHEK2.P85L complemented Rad53 as well as did wild-type CHEK2. Epidemiologic analyses were concordant with the functional tests. Frequencies of CHEK2.S428F heterozygotes were 2.88% (47/1632) among female breast cancer patients not selected for family history or age at diagnosis and 1.37% (23/1673) among controls (OR=2.13, 95% CI [1.26, 3.69], P=0.004), whereas frequencies of CHEK2.P85L were 0.92% among cases and 0.83% among controls. On the basis of the experience of mothers, sisters and daughters of probands, breast cancer risk due to CHEK2.S428F was estimated as 0.17 (+/-0.08) by age 60. We conclude that CHEK2.S428F increases breast cancer risk approximately 2-fold among Ashkenazi Jewish women, whereas CHEK2.P85L is a neutral allele. In general, these results suggest that selecting probands with extended haplotypes that co-segregate with disease can improve the efficiency of resequencing efforts and that quantitative complementation tests in yeast can be used to evaluate variants in genes with highly conserved function.