Efficacy of surgical treatment in traumatic central cord syndrome

BACKGROUND: Controversy surrounds the treatment of traumatic central cord syndrome (TCCS), as there are strong advocates for nonsurgical treatment for most patients. However, conservative treatment has been shown to yield a longer period of discomfort from pain and weakness in certain cases. METHODS: In a retrospective review of 114 patients presenting with acute or chronic TCCS from 1988-94, four different age groups were separately observed under different treatments. Motor and sensory recovery were assessed. RESULTS: Better results were achieved in younger patients, with or without radiographic abnormalities, and in patients with clinically correlated encroaching cord lesions who received early surgical decompression. CONCLUSIONS: Surgical intervention for TCCS must be addressed with careful clinical and radiographic survey. Removal of offending lesions in the subacute period results in significant motor and sensory improvement in short-term and long-term follow-up.     

Age alters regional distribution of blood flow during moderate-intensity exercise

During dynamic exercise in warm environments, requisite increases in skin and active muscle blood flows are supported by increasing cardiac output (Qc) and redistributing flow away from splanchnic and renal circulations. To examine the effect of age on these responses, six young (Y; 26 +/- 2 yr) and six older (O; 64 +/- 2 yr) men performed upright cycle exercise at 35 and 60% of peak O2 consumption (VO2peak) in 22 and 36 degrees C environments. To further isolate age, the two age groups were closely matched for VO2peak, weight, surface area, and body composition. Measurements included heart rate, Qc (CO2 rebreathing), skin blood flow (from increases in forearm blood flow (venous occlusion plethysmography), splanchnic blood flow (indocyanine green dilution), renal blood flow (p-amino-hippurate clearance), and plasma norepinephrine concentration. There were no significant age differences in Qc; however, in both environments the O group maintained Qc at a higher stroke volume and lower heart rate. At 60% VO2peak, forearm blood flow was significantly lower in the O subjects in each environment. Splanchnic blood flow fell (by 12-14% in both groups) at the lower intensity, then decreased to a greater extent at 60% VO2peak in Y than in O subjects (e.g., -45 +/- 2 vs. -33 +/- 3% for the hot environment, P < 0.01). Renal blood flow was lower at rest in the O group, remained relatively constant at 35% VO2peak, then decreased by 20-25% in both groups at 60% VO2peak. At 60% VO2peak, 27 and 37% more total blood flow was redistributed away from these two circulations in the Y than in the O group at 22 and 36 degrees, respectively. It was concluded that the greater increase in skin blood flow in Y subjects is partially supported by a greater redistribution of blood flow away from splanchnic and renal vascular beds.     

Alfalfa yield response to inoculation with recombinant strains of Rhizobium meliloti with an extra copy of dctABD and/or modified nifA expression

The construction of rhizobial strains which increase plant biomass under controlled conditions has been previously reported. However, there is no evidence that these newly constructed strains increase legume yield under agricultural conditions. This work tested the hypothesis that carefully manipulating expression of additional copies of nifA and dctABD in strains of Rhizobium meliloti would increase alfalfa yield in the field. The rationale for this hypothesis is based on the positive regulatory role that nifA plays in the expression of the nif regulon and the fact that a supply of dicarboxylic acids from the plant is required as a carbon and energy source for nitrogen fixation by the Rhizobium bacteroids in the nodule. These recombinant strains, as well as the wild-type strains from which they were derived, are ideal tools to examine the effects of modifying or increasing the expression of these genes on alfalfa biomass. The experimental design comprised seven recombinant strains, two wild-type strains, and an uninoculated control. Each treatment was replicated eight times and was conducted at four field sites in Wisconsin. Recombinant strain RMBPC-2, which has an additional copy of both nifA and dctABD, increased alfalfa biomass by 12.9% compared with the yield with the wild-type strain RMBPC and 17.9% over that in the uninoculated control plot at the site where soil nitrogen and organic matter content was lowest. These increases were statistically significant at the 5% confidence interval for each of the three harvests made during the growing season. Strain RMBPC-2 did increase alfalfa biomass at the Hancock site; however, no other significant increases or decreases in alfalfa biomass were observed with the seven other recombinant strains at that site. At three sites where this experiment was conducted, either native rhizobial populations or soil nitrogen concentrations were high. At these sites, none of the recombinant strains affected yield. We conclude that RMBPC -2 can increase alfalfa yields under field conditions of nitrogen limitation, low endogenous rhizobial competitors, and sufficient moisture.     

Ophthalmologic findings in Usher syndrome type 2A

Thirty-seven patients, comprising 24 familial cases and 13 isolated patients with Usher syndrome type II (USH2), underwent ophthalmologic examination. Based on the degree of hearing loss, normal vestibular function, and gene-linkage analysis, familial cases were assumed to have USH2A. An analysis of genetic heterogeneity failed to reveal the presence of a second locus in the Dutch population. Although the patients appear to belong to a genetically homogeneous group, remarkable ophthalmologic variability was found. Corrected visual acuity decreased with age and remarkable differences in visual acuity were found within one family. Fundoscopic findings were classified as type A if attenuated vessels and bone corpuscles in all quadrants were found or as type B if findings other than these were found. The prevalence of type A significantly increased with age.     

The effect of a split in WAIS-R VIQ and PIQ scores on patients with cognitive impairment and psychiatric illness

To determine the most effective treatment for acrodermatitis chronica atrophicans, several clinical trials were undertaken in recent years to evaluate whether a 2-week course of ceftriaxone would be superior to oral antibiotics. Of the 46 patients suffering from acrodermatitis chronica atrophicans, 14 were treated with ceftriaxone 2g for 15 days. The remaining patients received either oral penicillin V 1.5 million IU t.i.d. or doxycycline 100 mg b.i.d. for 20 to 30 days. Patients were followed up for at least 1 year. Of the 14 ceftriaxone-treated patients four showed incomplete regression of the inflammatory skin changes after 6 to 12 months. Two out of five patients who were monitored for Borrelia burgdorferi DNA excretion were still positive after 12 months as compared to none of six patients who were treated orally for 20-30 days. Six out of 11 patients treated orally for only 20 days needed retreatment after 6 months because of continuing skin manifestations, neuropathy or arthralgia. A 30-day duration of treatment with oral antibiotics and not the chosen antibiotic is crucial for curing acrodermatitis chronica atrophicans. The duration of treatment with ceftriaxone needed for eradication of Borrelia in acrodermatitis chronica atrophicans has yet to be determined in future studies.     

Identification, ontogeny, and regulation of an interleukin-6-like factor in the rat seminiferous tubule

The present study's aims are to search for the presence of interleukin-6 bioactivity (IL-6) in medium conditioned by various testicular cell types and to investigate the cellular and hormonal regulation of testicular IL-6 production. Sertoli cells prepared from rats of increasing ages (20, 35, and 45 days) secreted IL-6 in vitro, whereas medium conditioned by pachytene spermatocytes, early spermatids, and peritubular cells showed no activity. Lipopolysaccharide (LPS) and latex beads, two known stimulators of monocyte/macrophage IL-6 production, markedly stimulated IL-6 secretion by Sertoli cells at all the ages investigated. Maximum levels of IL-6 were reached after 6 h of culture of Sertoli cells with LPS and after 24 h with latex beads. When Sertoli cells were cocultured with pachytene spermatocytes, early spermatids, or fractions containing residual bodies and cytoplasts from elongated spermatids, only the latter significantly stimulated IL-6 levels. Maximum levels of IL-6 were attained by adding 2 x 10(6) residual bodies to Sertoli cells; a significant increase in IL-6 secretion was seen after 6 h, and maximum levels were observed after 24 h. The levels of IL-6 varied throughout different stages of the seminiferous epithelium cycle; highest levels were observed in stages II-VI and lowest in stages VII-VIII. IL-6 bioactivities induced by LPS and residual bodies and cytoplasts from elongated spermatids could be totally neutralized with a specific monoclonal antibody at all of the ages studied. FSH, phorbol myristate acetate, and IL-1 alpha augmented Sertoli cell IL-6 secretion in a dose-dependent manner. Furthermore, FSH and (Bu)2cAMP differentially stimulated IL-6 secretion during the seminiferous epithelial cycle. It is concluded that the release of IL-6 from Sertoli cells is regulated by a complex interplay between residual bodies and humoral factors.