Lumbar degenerative spondylolisthesis II: treatment and controversies.

There are various approaches and surgical techniques with the objective of nerve root decompression, restrict mobility, and fusion of the listhesis. Among the techniques, posterior interbody fusion combines direct and indirect root decompression with the fusion between vertebral bodies, placing an autologous bone graft between transverse apophysis and vertebral bodies. Transforaminal lumbar and posterior interbody fusion, on the same way, look to decompress and fuse but with a different approach to the spine. The anterior approach for interbody fusion provides a better fusion rate. Lateral lumbar interbody fusion is considered less invasive, with an anterolateral transpsoas approach. The lumbar fusion technique in degenerative spondylolisthesis must be individualized. Non-fusion decompression is considered a less invasive procedure. Various studies suggest that decompression has better results when fusion is added. Surgery had several potential benefits and greater improvement in those patients who fail conservative management. An optimal technique is not conclusively identified.

El tratamiento de la espondilolistesis degenerativa lumbar es específico para cada etapa de la enfermedad y el manejo quirúrgico no debe de ser la primera elección en la mayoría de los casos. El manejo conservador está basado en el uso de antiinflamatorios no esteroideos, control de peso y rehabilitación. En caso de falla después de cuatro a seis semanas, el siguiente paso es la infiltración facetaria. En caso de dolor persistente, alteraciones neurológicas o claudicación neurogénica el siguiente paso es la cirugía. Existen varios abordajes y técnicas quirúrgicas con el objetivo de descomprimir las raíces nerviosas, restringir la movilidad y fusionar la listesis. Entre las técnicas quirúrgicas, la fusión posterior combina la descompresión directa e indirecta con artrodesis entre los cuerpos vertebrales, colocando injerto entre las apófisis transversas y los cuerpos vertebrales. La artrodesis intersomática transforaminal y posterior buscan de la misma manera la descompresión y fusión, pero con un abordaje distinto. El abordaje anterior para artrodesis intersomática provee la mejor tasa de fusión. La artrodesis intersomática lateral se considera un procedimiento menos invasivo, con un abordaje anterolateral transpsoas. La técnica de artrodesis lumbar en la espondilolistesis debe ser individualizada. La descompresión sin artrodesis se considera un procedimiento menos invasivo; varios estudios sugieren que la descompresión tiene mejores resultados cuando se agrega una artrodesis. La cirugía tiene múltiples beneficios posibles en pacientes en quienes el tratamiento conservador ha fallado. No se ha identificado una técnica óptima de tratamiento.

Degenerative spondylolisthesis I: general principles.

Lumbar degenerative spondylolisthesis is the result of the progression from degenerative changes in the intervertebral disc and facet joints that lead to destabilizing one or more vertebral segments. It is characterized by the anterior sliding of the vertebral body secondary to the sagittalization of the facet joints. Wiltse, Newman, and Macnab classified it as type III. It is a pathology typical of elderly patients that predominate in women with a ratio of 5:1 compared to men; the most affected segment is L4-L5, the listhesis rarely exceeds 30% slip. It may or may not generate clinical manifestations, and the severity of these does not always correlate with the degree of sliding. The cardinal symptom is lumbar pain with or without radicular pain. Neurogenic claudication occurs in 75% of patients; it is caused by blood hypoperfusion secondary to the compression of the nerve roots, manifesting as pain in the lower limbs with variable walking distances. For the diagnosis of degenerative spondylolisthesis, comprehensive evaluation with static, dynamic radiographic studies in a standing position and magnetic resonance imaging are essential. The conservative treatment is the first-line therapy; it includes analgesics, anti-inflammatories, physiotherapy.

La espondilolistesis degenerativa lumbar es el resultado de la progresión de los cambios degenerativos en el disco intervertebral y las articulaciones facetarias que termina por inestabilizar uno o varios segmentos vertebrales. Se caracteriza por el deslizamiento anterior del cuerpo vertebral secundario a la sagitalización de las facetas articulares, Wiltse, Newman y Macnab la clasifican como tipo III. Es una patología propia de los pacientes de la tercera edad, predomina en mujeres con una relación de 5:1 respecto a los varones, el segmento más afectado es L4-L5, el desplazamiento rara vez supera el 30% de deslizamiento. Puede o no generar manifestaciones clínicas y la severidad de éstas, no siempre correlaciona con el grado de listesis. El síntoma cardinal es el dolor lumbar con o sin dolor radicular; mientras que la claudicación neurogénica se presenta en 75% de los pacientes, es causada por la hipoperfusión sanguínea secundaria a la compresión de las raíces nerviosas y se manifiesta como dolor en los miembros inferiores, con la deambulación a distancias variables. Para el diagnóstico de la espondilolistesis degenerativa es indispensable una evaluación integral con estudios radiográficos estáticos, dinámicos en posición de pie y resonancia magnética. La primera línea de tratamiento es el manejo conservador, este incluye analgésicos, antiinflamatorios, fisioterapia.

Application of Fourier transform infrared spectroscopy for monitoring short-chain free fatty acids in Swiss cheese.

Short-chain free fatty acids (FFA) are important sources of cheese flavor and have been reported to be indicators for assessing quality. The objective of this research was to develop a simple and rapid screening tool for monitoring the short-chain FFA contents in Swiss cheese by using Fourier transform infrared spectroscopy (FTIR). Forty-four Swiss cheese samples were evaluated by using a MIRacle three-reflection diamond attenuated total reflectance (ATR) accessory. Two different sampling techniques were used for FTIR/ATR measurement: direct measurement of Swiss cheese slices (approximately 0.5 g) and measurement of a water-soluble fraction of cheese. The amounts of FFA (propionic, acetic, and butyric acids) in the water-soluble fraction of samples were analyzed by gas chromatography-flame ion-ization detection as a reference method. Calibration models for both direct measurement and the water-soluble fraction of cheese were developed based on a cross-validated (leave-one-out approach) partial least squares regression by using the regions of 3,000 to 2,800, 1,775 to 1,680, and 1,500 to 900 cm(-1) for short-chain FFA in cheese. Promising performance statistics were obtained for the calibration models of both direct measurement and the water-soluble fraction, with improved performance statistics obtained from the water-soluble extract, particularly for propionic acid. Partial least squares models generated from FTIR/ATR spectra by direct measurement of cheeses gave standard errors of cross-validation of 9.7 mg/100 g of cheese for propionic acid, 9.3 mg/100 g of cheese for acetic acid, and 5.5 mg/100 g of cheese for butyric acid, and correlation coefficients >0.9. Standard error of cross-validation values for the water-soluble fraction were 4.4 mg/100 g of cheese for propionic acid, 9.2 mg/100 g of cheese for acetic acid, and 5.2 mg/100 g of cheese for butyric acid with correlation coefficients of 0.98, 0.95, and 0.92, respectively. Infrared spectroscopy and chemometrics accurately and precisely predicted the short-chain FFA content in Swiss cheeses and in the water-soluble fraction of the cheese.

Rapid determination of Swiss cheese composition by Fourier transform infrared/attenuated total reflectance spectroscopy.

There is a need for rapid and simple techniques that can be used to predict the quality of cheese. The aim of this research was to develop a simple and rapid screening tool for monitoring Swiss cheese composition by using Fourier transform infrared spectroscopy. Twenty Swiss cheese samples from different manufacturers and degree of maturity were evaluated. Direct measurements of Swiss cheese slices (approximately 0.5 g) were made using a MIRacle 3-reflection diamond attenuated total reflectance (ATR) accessory. Reference methods for moisture (vacuum oven), protein content (Kjeldahl), and fat (Babcock) were used. Calibration models were developed based on a cross-validated (leave-one-out approach) partial least squares regression. The information-rich infrared spectral range for Swiss cheese samples was from 3,000 to 2,800 cm(-1) and 1,800 to 900 cm(-1). The performance statistics for cross-validated models gave estimates for standard error of cross-validation of 0.45, 0.25, and 0.21% for moisture, protein, and fat respectively, and correlation coefficients r > 0.96. Furthermore, the ATR infrared protocol allowed for the classification of cheeses according to manufacturer and aging based on unique spectral information, especially of carbonyl groups, probably due to their distinctive lipid composition. Attenuated total reflectance infrared spectroscopy allowed for the rapid (approximately 3-min analysis time) and accurate analysis of the composition of Swiss cheese. This technique could contribute to the development of simple and rapid protocols for monitoring complex biochemical changes, and predicting the final quality of the cheese.

Physical properties of ice cream containing milk protein concentrates.

Two milk protein concentrates (MPC, 56 and 85%) were studied as substitutes for 20 and 50% of the protein content in ice cream mix. The basic mix formula had 12% fat, 11% nonfat milk solids, 15% sweetener, and 0.3% stabilizer/emulsifier blend. Protein levels remained constant, and total solids were compensated for in MPC mixes by the addition of polydextrose. Physical properties investigated included apparent viscosity, fat globule size, melting rate, shape retention, and freezing behavior using differential scanning calorimetry. Milk protein concentrate formulations had higher mix viscosity, larger amount of fat destabilization, narrower ice melting curves, and greater shape retention compared with the control. Milk protein concentrates did not offer significant modifications of ice cream physical properties on a constant protein basis when substituted for up to 50% of the protein supplied by nonfat dry milk. Milk protein concentrates may offer ice cream manufacturers an alternative source of milk solids non-fat, especially in mixes reduced in lactose or fat, where higher milk solids nonfat are needed to compensate other losses of total solids.

Influence of starter culture ratios and warm room treatment on free fatty acid and amino acid in Swiss cheese.

Quantification of water-soluble volatile free fatty acids (FFA) and free amino acids (FAA) was performed as a ripening index and an indirect measure of flavor development in Swiss-type cheeses. The objective of this research was to assess the effect of warm room treatment (WRT) and usage ratio of starter cultures, Streptococcus thermophilus and Lactobacillus helveticus vs. propionibacteria, on the concentration of FFA and FAA in pilot plant-scale Swiss cheese. A capillary gas chromatograph equipped with a flame ionization detector was used for the analysis of FFA in Swiss cheese. Free amino acids were analyzed by the Cd-ninhydrin method. Starter culture ratios did not affect development of FAA during the cheese ripening. However, duration of WRT had an effect on the concentration of FAA in the Swiss cheese. Free amino acids increased considerably during WRT. A continuous increase in FAA was shown during 70-d ripening time after WRT. The concentrations of C2:0 and C3:0 fatty acids were affected by starter culture ratios after 2-wk WRT, but these differences had mostly disappeared after 3-wk WRT. Similar concentrations of FFA and FAA reported in previous studies were developed in Swiss cheese with a 3-wk WRT and a 0.33:1 ratio of Streptococcus thermophilus and Lactobacillus helveticus to propionibacteria.