Surgical Strategies for Tuberculous Spondylodiscitis With Severe Osteoporosis: A Case Illustrating the Challenges of Delayed Intervention

Tuberculous spondylodiscitis (Pott's spine) is a complex extrapulmonary manifestation of tuberculosis (TB) that poses significant medical challenges, characterized by vertebral destruction affecting approximately 2% of all TB cases. The management of this condition involves a multidisciplinary approach, with surgical intervention indicated for specific cases, including those with neurological complications, spinal instability, and kyphosis. We report a case of a 49-year-old female with a confirmed diagnosis of tuberculous spondylodiscitis who had undergone eight months of tuberculostatic therapy. She was referred for neurosurgical consultation due to uncontrollable axial pain, despite favorable clinical and imaging responses, which had rendered her immobile for six months. Imaging revealed a complete collapse of the L5 vertebral body, and a complementary dual x-ray absorptiometry (DEXA) scan demonstrated severe osteoporosis. A two-stage surgical approach was chosen to address her condition, involving corpectomy through an anterior approach, followed by lumbopelvic stabilization. Postoperative recovery was uneventful, with progressive improvement in pain and mobility. This case highlights the challenges of managing tuberculous spondylodiscitis and underscores the significance of early detection to prevent complications like severe osteoporosis. In this case, delayed referral for surgery following an extended period of immobility added complexity to an already difficult case. The severe osteoporosis, with a t-score of -5.7, had a substantial impact on surgical planning, leading to a more robust approach to arthrodesis with substantial lumbopelvic instrumentation in order to mitigate the risks associated with implant failure. This case shows that timely intervention and a comprehensive multidisciplinary approach are essential for the effective management of tuberculous spondylodiscitis, especially in cases complicated by severe osteoporosis.

Survival in crossbred lambs: Breed and heterosis effects

The objective of this study was to estimate genetic and nongenetic effects affecting survival in crossbred lambs during 3 time periods: through 1 d of age ( = 7,933), 2 to 30 d of age ( = 5,370), and 2 to 60 d of age ( = 5,216) in a population being upgraded to the dairy breeds of East Friesian and Lacaune in which lambs were artificially reared on milk replacer. Survival was analyzed for lambs born in 14 yr from 1998 to 2011 using pedigree information from 14,339 animals born in 23 yr from 1989 to 2011. Date of death, sex, age of the dam, birth type, month and year of birth, and breed composition were recorded, and the proportion of retained heterosis was calculated for each animal. Lambs were crossbreds of 2 or more breeds with 14 breeds represented in the population. Due to low mean genetic contribution of the 12 nondairy breeds, they were placed into 2 groups: meat breeds (Hampshire, Suffolk, and Texel) and maternal breeds (Romanov, Finnsheep, Dorset, Targhee, Rambouillet, Polypay, Katahdin, Arcott Rideau, and Commercial). The proportion of individual retained heterosis was positively associated ( < 0.05) with lamb survival from 2 to 30 and from 2 to 60 d of age. The predicted increase in survival of F lambs compared to purebred lambs was +8.8 and +14.6%, respectively. Predicted survival of meat breed lambs and maternal breed lambs was greater ( ≤ 0.01) than Lacaune lambs during all 3 periods. Predicted survival of East Friesian lambs was consistently lower ( ≤ 0.01) than meat breed and maternal breed lambs during all periods. The predicted survival of East Friesian lambs was numerically greater but not significantly different from Lacaune lambs. There was a lower ( < 0.01) survival of females compared to males through 1 d of age (-5.6%), but females had higher ( < 0.01) survival than males in the other 2 periods (2 to 30 d = +3.3% and 2 to 60 d = +6.0%). Through 1 d of age, lambs of triplet and greater birth types had lower ( < 0.01) survival than single lambs (-6.2%), and lambs from 1-yr-old dams had lower ( < 0.01) survival than lambs from 2-yr-old dams (+4.5%). Estimates of heritability of lamb survival were 0.14 (SE = 0.03), 0.03 (SE = 0.04), and 0.06 (SE = 0.03) for the 3 time periods, respectively. An increase in the proportion of individual retained heterosis was the most important genetic factor associated with increased lamb survival in this study.

The genome sequence of the plant pathogen Xylella fastidiosa. The Xylella fastidiosa Consortium of the Organization for Nucleotide Sequencing and Analysis

Xylella fastidiosa is a fastidious, xylem-limited bacterium that causes a range of economically important plant diseases. Here we report the complete genome sequence of X. fastidiosa clone 9a5c, which causes citrus variegated chlorosis--a serious disease of orange trees. The genome comprises a 52.7% GC-rich 2,679,305-base-pair (bp) circular chromosome and two plasmids of 51,158 bp and 1,285 bp. We can assign putative functions to 47% of the 2,904 predicted coding regions. Efficient metabolic functions are predicted, with sugars as the principal energy and carbon source, supporting existence in the nutrient-poor xylem sap. The mechanisms associated with pathogenicity and virulence involve toxins, antibiotics and ion sequestration systems, as well as bacterium-bacterium and bacterium-host interactions mediated by a range of proteins. Orthologues of some of these proteins have only been identified in animal and human pathogens; their presence in X. fastidiosa indicates that the molecular basis for bacterial pathogenicity is both conserved and independent of host. At least 83 genes are bacteriophage-derived and include virulence-associated genes from other bacteria, providing direct evidence of phage-mediated horizontal gene transfer.

[Actinic lesions: computed tomography features]

The authors emphasize the importance of knowing, understanding and identifying the radiation-induced changes in various body organs by radiologists in order to distinguish them from residual or recurrent malignancies. Computed tomography enables the evaluation of the effects and complications of the radiation therapy, besides other image modalities, and its findings are outlined. The clinical correlation, mainly with the time elapsed between the treatment and the examination is very important to establish the diagnosis.

The response to dietary treatment of patients with chronic post-infectious diarrhea and lactose intolerance

The response to dietary treatment of patients with chronic post-infectious diarrhea and lactose intolerance was prospectively studied in 29 infants less than 1 year of age. All had gastroenteritis with diarrhea which persisted for more than 3 weeks. In the hospital, diarrhea continued and lactose intolerance was documented while being fed half-strength cow's milk formula. They were given dietary treatment with one of three formulas used for treatment of diarrhea in infancy. Improvement of diarrhea was more frequently achieved with Pregestimil when given as the initial therapy than with the other two formulas. With Pregestimil nine of 10 patients improved whereas only four of nine infants fed Portagen and one of 10 patients initially treated with soy formula improved. Pregestimil was also effective in three of five patients who initially failed to improve with Portagen and in four of eight patients tried with soy formula with or without carbohydrate. Additionally, in the patients who improved, recovery was more rapidly achieved with Pregestimil than with the other two formulas. Formula failures were due to intolerance to glucose polymers in three patients, possibly to protein in seven infants, and an intolerance to all nutrients in five patients. The improvement of the diarrhea was slower in patients who had evidence of colitis in rectal biopsies regardless of the dietary treatment given, but was not correlated with other variables, i.e., etiology of diarrhea, jejunal histology, or duration of diarrhea prior to treatment. However, as a group, the patients who failed to respond to Pregestimil were younger (less than 3 months of age), had more formula changes and associated infections, and were given more antibiotics; they also had more prolonged diarrhea before treatment and more severe jejunal mucosal lesions and jejunal bacterial overgrowth. The data suggests that Pregestimil seems to be the most effective formula for the treatment of infants with chronic post-infectious diarrhea and lactose intolerance.

Genetic regulation of multispecific antibody responsiveness: improvement of "high" and "low" characters

The five selections carried out in the mouse for high or low antibody responsiveness to various multideterminant immunogens were successful. In all cases the large interline difference was shown to result from the additive effects of several independently segregating loci (polygenic regulation). However, important peculiarities were demonstrated in these original selections concerning either the cellular mechanisms operating or the effect of the selected genes on antibody responses to antigens unrelated with those used for the selection (multi-specific effect). In an attempt to improve and generalize the effect of selection, the 5 high and the 5 low lines were inter-crossed to obtain populations with a balanced proportion of the 5 genomes. These two populations were then submitted to selective breedings in which the phenotypic character was the weighted responses to pluri-antigen immunization. The data obtained in 16 consecutive generations of two selective breedings (general-primary, GP and general-secondary, GS, responses) carried out from these populations are reported. The genetic parameters of the response to GP and GS selections are compared with those obtained in the original selections. The final result of both GP and GS selections demonstrate a marked improvement of the high and low antibody production traits, both quantitatively (interline divergence) and qualitatively (multi-specific effect). The success of GP and GS selections agrees with the concept that distinct groups of genes are preferentially affected by selection according to the nature of the selection antigen and the immunization procedure.

Effect of silica on the genetic regulation of antibody responsiveness

The high (H) and low (L) antibody responder lines of mice produced by selective breeding are characterized by different modifications in immunocompetent cell potentialities, according to the immunization procedure used for the selection process. In selections I and II, the difference in antibody responsiveness between H and L lines was clearly shown to depend mainly on macrophage function: the more rapid catabolism of antigens in L mice was the main cause of the low antibody production. In contrast, up to now, no difference has been observed between H and L mice of selections III and IV in terms of the macrophage accessory role. The administration of silica particles has a well known impairment effect on macrophage activity. Therefore, the effect of silica injection on the kinetics of antibody responses to selection antigens was compared in H and L mice of the four selections. Silica was given either intravenously or locally in one hind footpad 6 or 24 h before immunization by the same route. Silica treatment consistently improved antibody responsiveness in the L mice of selections I and II, but had no effect in the L mice of selections III and IV. The antibody responses of the H lines of the four selections were not substantially modified by silica injections. Therefore, the silica treatment reduced the interline difference in antibody responses in selections I and II only, by interfering with the expression of the genetic modification of macrophage activity. However, a similar effect was not obtained with other substances known to affect macrophages, including dextran sulphate or carrageenan. The results reported here are in agreement with the above-mentioned statement that the genetic modification of macrophage function plays a major role in the interline difference in selections I and II and is not involved in selections III and IV.

Effect of genetic modification of antibody responsiveness on resistance to Toxoplasma gondii infection

Resistance to Toxoplasma gondii infection was studied in the high (H/f) and low (L/f) antibody responder lines of mice that were selected on the basis of quantitative antibody responsiveness to the flagellar antigen of Salmonella (selection III). No interline difference was observed in resistance to a highly virulent strain of T. gondii. In contrast, H/f mice were much more resistant than L/f mice to a moderately virulent strain of T. gondii: a 5000-fold difference in terms of the 50% lethal dose was found. The degree of resistance in (H/f X L/f)F1 hybrids was intermediate compared with that in parental lines for both mortality and survival time. The antibody titers to Toxoplasma antigens measured during the course of the infection were significantly higher in H/f than in L/f mice. This interline difference was underestimated because parasite multiplication occurs faster in L/f mice, which increases antigenic stimulation. The stronger resistance of H/f mice is probably due to their higher capacity of antibody production in the course of infection.

Inverse modification of antibody responsiveness to RGG in lines of mice selected for high or low responses to somatic antigen of Salmonella

High (H/s) and low (L/s) antibody responder lines of mice selected according to their response to the somatic (s) antigen of Salmonella (Selection IV) have unexpected inverse capacity for antibody production to rabbit gamma globulin (RGG): H/s mice are low or even nonresponders to this antigen, whereas L/s mice are high responders. It was shown that the phenotypic variability within each line is due to environmental factors. RGG was a selection antigen in Selection V; the high (H/p) and low (L/p) responder mice are therefore considered as homozygous for the RGG genes. Responsiveness to RGG was investigated in F1 and F2 hybrids obtained by crossing the phenotypically similar RGG responder or nonresponder mice of Selections IV and V. The results support the hypothesis that the same genes control the response to RGG in L/s and H/p lines as well as in H/s and L/p lines. This means that the genes specific for RGG responsiveness were independent from those regulating responses to the s antigen. Unaffected by the selective breeding in Selection IV, they have been fixed by chance in an inverse way in H/s and L/s lines.

Contribution to the study of immune hemolysis by toad complement

EA (sheep erythrocytes carrying rabbit antibody) are lysed by toad complement under optimal conditions which include a low concentration of cells (1.54 x 10*8/ml), a low temperature of incubation (30°C) and the same amounts of Ca++ and Mg++ as required for the titration of guinea-pig complement. Kinetic studies of the role of cations mentioned above in immune lysis by toad C have disclosed a fundamental difference as compared to guinea-pig C. In a limited complement system, the lysis by amphibian C is completely blocked by EDTA, even when the chelating agent is added as late as 15 minutes after zero-time. Inhibition by EGTA is only partial and the findings suggest that Mg++ is required not only at the beginning, but also at late stages of the lytic process. It has been speculated that the activation of amphibian complement proceeds mainly by the alternative pathway.

Genetic parameters of the polygenic regulation of antibody responsiveness to flagellar and somatic antigens of salmonellae

Selective breedings of mice were carried out for quantitative antibody responsiveness to flagellar Ag., f (Selection III) or somatic Ag., s (Selection IV) of two non cross-reacting Salmonellae (Salm. tm., Salm. or.) alternated for immunization of consecutive generations. At the selection limit, these selections produced homozygous high (H) and low (L) responder lines for the character investigated: peak agglutinin response to optimal secondary immunization. The responsiveness to both f and s Ags. is submitted to polygenic regulation. The heritability (h2) realized during the selective breeding was 0.37 +/- 0.07 for the response to fAg. and 0.40 +/- 0.1 for the response to s Ag. The respective part of genetic and environmental variance in F2 hybrids was 64% and 36% in selection III and 61% and 39% in selection IV. In the two selections, the dominance variance is negligible (less than 1%), therefore the genetic variance is essentially additive. The additive variance calculated as the heritable fraction of the F2 hybrid variance is somewhat lower, the reason for this difference is discussed. The quantitative antibody response to f Ag. in selection III is controlled by about seven independent loci. The antibody response to s Ag. in selection IV is controlled by about four independent loci. A possible association of relevant genes with the H-2 locus was investigated. In selection III, no significant participation if H-2 linked genes, in the regulation of responses to f and s Ags. of Salm. tm and Salm. or. could be demonstrated. In selection IV a partial contribution of H-2 linked genes was observed concerning responsiveness to both f and s Ags. of Salm. tm. but not Salm. or. Ags. The H-2 effect accounts for 25% of the total interline difference.