UV absorbance of the human cornea in the 240- to 400-nm range

PURPOSE: To determine the UV absorbance of the corneal layers (epithelium, Bowman layer, stroma) in the 240- to 400-nm range. METHODS: Consecutive slices (100 microm) of human cadaveric corneas were cut, and the UV absorbance of each sample was determined in a scanning spectrophotometer. In some cases the epithelium was scraped off and its absorbance measured separately. RESULTS: The investigation of the UV-B absorption of consecutive corneal slices revealed evidence that UV-B absorption is 1.8 times higher in the anterior 100 microm of the human cornea than in the posterior layers. The UV absorbance of the posterior layers was uniform, showing no further structural dependence. The epithelium and Bowman layer are both effective absorbers of UV-B radiation. CONCLUSIONS: These results suggest that the anterior corneal layers are particularly important in preventing damage by UV-B radiation.     

Rapid direct antibiotic susceptibility testing in endophthalmitis

OBJECTIVE: To compare a new rapid antibiotic susceptibility test (RAST) to the conventional method in patients with endophthalmitis. DESIGN: Prospective nonrandomized comparative trial. PARTICIPANTS: Intraocular aspirates from 24 consecutive patients with endophthalmitis were tested. METHODS: Approximately 0.25 ml of vitreous or anterior chamber aspirate was obtained and tested for antibiotic sensitivity using the Kirby-Bauer agar disk diffusion method. Using this conventional testing method, the aspirates were cultured for bacterial growth before antibiotic susceptibility testing (AST). In contrast, for direct RAST, the aspirates were inoculated directly onto agar plates with antibiotic disks without first culturing for bacterial growth. RESULTS: Of the 24 endophthalmitis aspirates studied, 4 (17%) could not be tested by direct RAST because either more than one bacterial species was present or no bacteria were cultured. The remaining 20 cases provided 467 antibiotic-microorganism combinations. The two methods yielded identical susceptibility results in 409 (88%) of the 467 tests. In 42 tests (9%), a minor discrepancy occurred between the conventional method and RAST, in which one resulted in intermediate susceptibility, whereas the other was either resistant or sensitive. Significant discrepancy, defined as a bacterial sample reported as sensitive in one method yet resistant in the other, occurred with 16 samples (3%). Results of the RAST were available within 6 to 10 hours compared with more than 24 hours for the conventional method. Of clinical significance, the results of the RAST revealed that in 11 cases of epidemic Stenotrophomonas maltophilia endophthalmitis, the bacteria were resistant to the antibiotics prescribed, and change of antibiotic therapy was made on the basis of the RAST results. CONCLUSIONS: RAST provided accurate antibiotic susceptibility results in a much shorter time than did the conventional method. We suggest that conventional AST be performed for confirmation of the RAST results, but initial antibiotic therapy can quite reliably be based on the results of RAST.     

The incidence of acute cardiorespiratory and vascular dysfunction following intramedullary nail fixation of femoral metastasis

Intramedullary nail fixation is a common treatment for metastatic tumors of the femur with overt or impending femoral fracture. This procedure sometimes causes severe cardiorespiratory and vascular dysfunction. The clinical relevance of this is not dear. We reviewed 45 operations in 43 patients, where intramedullary nail fixation was used to treat metastatic femoral fractures and impending fractures. We studied the incidence of intraoperative oxygen desaturation and hypotension associated with intramedullary manipulation as markers of cardiorespiratory and vascular dysfunction. Acute oxygen desaturation and hypotension occurred in 11 of our 45 patients. Of these, 3 died, 2 required intensive care postoperatively and 6 made uneventful recoveries. We hope to highlight a serious complication in this patient group.     

Maprotiline-a double-blind study of a new tetracyclic antidepressant in severe depression.

A double-blind study was carried out comparing the antidepressant properties of maptotiline (a new tetracyclic antidepressant) and amitriptyline. Twenty-one hospitalized severely depressed patients, selected on the basis of clinical and psychometric criteria, completed the trial period of 28 days. The new drug was found to have an order of effectiveness similar to that of amitriptyline and both drugs were effective in agitated as well as retarded forms of depression. For both, the "day of effect", intended as the timing of sharp clinical improvement, tended to occur during the second week of treatment. Both drugs were well tolerated by most patients but one of the maprotiline patients presented a generalized rash which resolved after discontinuation of the drug. In conclusion, maprotiline is seen as an interesting addition to the group of major antidepressant drugs.     

Dopaminergic candidate genes in Tourette syndrome: association between tic severity and 3' UTR polymorphism of the dopamine transporter gene.

Multiple evidence suggests an involvement of the dopamine neurotransmitter system in Tourette syndrome (TS). Therefore, dopaminergic candidate genes are in the center of genetic association analyses of TS. In this study, 103 TS patients and their parents have been characterized for different dopamine-related polymorphisms including the 48 bp variable number of tandem repeats (VNTR) of the dopamine D4 receptor (DRD4) gene, the 40 bp VNTR of the dopamine transporter (DAT1, SLC6A3) gene and the Val158Met polymorphism of the catechol-O-methyltransferase (COMT) gene. In addition, the 120 bp duplication and three single nucleotide polymorphisms (SNPs) were assessed in the promoter region of the DRD4 gene. The -616G allele and the 2-G-A-C haplotype (i.e., the 2-repeat form of the 120 bp sequence approximately -616G approximately -615A approximately -521C combination) were preferentially transmitted, however, these results did not remain significant after correction for multiple testing. Case-control analyses have also been carried out, resulting in negative findings. On the other hand, using a dimensional approach, the DAT1 40 bp VNTR showed an association with the peak tic-severity as measured by the Yale Global Tic Severity Scale. Patients with at least one copy of the 9-repeat allele had significantly more severe symptoms than individuals with the homozygous 10/10 genotype (P = 0.002). In summary, allele frequencies did not differ between cases and controls, but DAT1 genotype accounted for variations of tic severity within the TS group.     

Cerebrospinal fluid amine metabolites, tryptophan and clinical parameters in depression. Part 2. Psychopathological symptoms

The group of 33 severely depressed female patients was divided into 3 equally large subgroups, separately according to their CSF 5-HIAA, HVA, tryptophan and total plasma tryptophan, and the severity of 17 operationally defined psychopathological symptoms was compared between the subgroups containing the highest and lowest biochemical values. Nonparametric statistical testing yielded significant results on several symptoms, when the subgroups were formed from CSF 5-HIAA and HVA. There was only one significant symptom difference between subgroups separated by CSF tryptophan and a few other differences by plasma tryptophan level. The results indicate that lumbar CSF metabolites correlate more with certain individual symptoms than with the global severity of depression.     

Attenuation of the development of murine solid leukemia tumor by physical exercise

The active involvement of physical exercise in the evolution of a variety of cancers is well documented. However, its role in solid leukemia tumor development is essentially unknown. Solid leukemia tumor cells were transplanted into 21 hybrid BDF1 control mice, exercise-trained mice that did not exercise during leukemia and exercise-trained mice that exercised during leukemia. The tumor size of the continuously exercising group was ~50% of that of control and exercise-terminated animals 18 days after the transplantation. The activity of antioxidant enzymes and the levels of lipid peroxidation and 8-hydroxy-2'-deoxyguanosine were not different in the tumors of the three groups. The level of carbonylated proteins was smaller in tumors of continuously exercising animals. The mutant form of cell regulatory protein p53 and vascular endothelial growth factor were present in similar amounts in the tumor cells of each group. On the other hand, the protooncogene Ras and I-kappaB proteins were present in higher concentrations in tumors of continuously exercising rats. The present data suggest that exercise during leukemia attenuates the development of tumors in mice. The selective alteration of regulatory proteins might play a role in the beneficial effects of exercise during leukemia.     

Application of Newton's law to body cooling

Summary Newton's law of cooling was used to analyze the fall in rectal temperature post mortem in 55 cases during refrigeration in a mortuary. As with solids of low thermal conductivity, there was an initial curvilinearity to the semilog plot lasting 1 to 11 hours (related to pelvic circumference) while the proper internal temperature distribution was becoming established. Thereafter there was a linear trend representing a constant percent cooling rater ₁ which lasted up to 24 hours for adults. This was followed by a less steep trend of cooling rater ₂, which was 37% less thanr ₁. This diminution in cooling rate occurred when the rectal temperature fell below 10°C and was ascribed to a reduction in the thermal diffusivity of fat.r ₁ had the highest correlation with pelvic circumference. For the nude body in still airr ₁=15.6% to 18.4% (T _r –T _a )/hour for children, 3.8% to 9.4% for adults. Wind increasedr ₁; the decrease due to clothing was questionable because of the paucity of cases. G. W. Molnar, Ph. D., formerly at the U.S. Army Medical Research Laboratory, Ft. Knox, Ky. H. J. Hurley, Jr., M. D., formerly Captain, M. C., U.S. Army Medical Research Laboratory, Ft. Knox, Ky.     

Fixation of cell-bound antibody in the membrane immunofluorescence test

Fixative treatment to stabilize cell-bound antibody was described and applied in quantitative and qualitative studies of cell membrane antigens by direct and indirect immunofluorescence. Of the several fixatives tested, namely p-formaldehyde (PFA), glutaraldehyde (GA) acetone and osmium tetroxide, PFA appeared to have several advantages compared to the other fixatives. Fixation with PFA under specified conditions did not diminish the fluorescence intensity of cells stained by direct or indirect immunofluorescence and decreased only slightly the reaction of anti-immunoglobulin with cell-bound fixed antibody. Redistribution phenomena as ‘capping’ and dot-formation were abolished or greatly reduced by PFA fixation of the cell-bound antibody in the indirect membrane fluorescence test. The characteristic hand-mirror configuration, due to uropod formation of stimulated lymphocytes was retained if the cells were PFA-fixed at 37°C. After PFA-fixation of stimulated lymphocytes which had been incubated under conditions favouring redistribution of cell-bound antibody it was evident that ‘capping’ was confined to the side of the cells which formed the uropod.