Lingual lymph nodes: Anatomy,clinical considerations,and oncological significance

Lingual lymph nodes are an inconstant group of in-transit nodes, which are located on the route of lymph drainage from the tongue mucosa to the regional nodes in neck levels I and II. There is growing academic data on the metastatic spread of oral cancer, particularly regarding the spreading of oral tongue squamous cell carcinoma to lingual nodes. These nodes are not currently included in diagnostic and treatment protocols for oral tongue cancer. Combined information on surgical anatomy, clinical observations, means of detection, and prognostic value is presented. Anatomically obtained incidence of lingual nodes ranges from 8.6% to 30.2%. Incidence of lingual lymph node metastasis ranges from 1.3% to 17.1%. It is clear that lymph nodes that bear intervening tissues from the floor of the mouth should be removed to improve loco-regional control. Extended resection volume, which is required for the surgical treatment of lingual node metastasis, cannot be implied to every tongue cancer patient. As these lesions significantly influence prognosis, special efforts of their detection must be made. Reasonably, every tongue cancer patient must be investigated for the existence of lingual lymph node metastasis. Lymphographic tracing methods, which are currently implied for sentinel lymph node biopsies, may improve the detection of lingual lymph nodes.     

Necessary optimality conditions for a generalized problem of production scheduling

This communication concerns a derivation and study of necessary optimality conditions for production scheduling. The continuous-time optimal control problem is stated for the analysis of extremal behaviour of a flexible flow shop. This is accomplished by means of the maximum principle, which is applied to the problem with irregular constraints and three typical forms of objective function.     

In vitro evaluation of ablation parameters of normal and fibrous aorta using smooth excimer laser coronary angioplasty

A modified exeimer laser energy delivery system was used to irradiate 100 segments of normal and fibrous aorta in vitro. The laser beam was scanned into 8 fiber bundles consisting of 50 fibers each resulting in a reduction of the applied pulse energy. The total repetition rate was increased to 150 Hz in order to keep the repetition rate per fiber bundle close to 20 Hz and to minimize thermal injury. The results demonstrate that effective ablation (etch rate per 8 pulses > 2.0 μm) occurred at an energy fluency of 50 mJ/mm² in both normal and fibrous aorta. Tissue damage (carbonization, tissue separation, fissures, cracks, and vacuolization) was in a range of 100 ± 28 to 152 ± 30 μm for normal aorta and in a range of 57 ± 35 to 110 ± 39 μm for fibrous aorta. We conclude that effective ablation of normal and fibrous human aorta can be achieved by the application of smooth excimer laser coronary angioplasty. This improvement of excimer laser technology may result in a reduction of shock wave- and cavitation-induced damage leading to a reduction of tissue injury. However, this awaits further in vitro and in vivo confirmation. © 1993 Wiley-Liss, Inc.     

Infection of the Laboratory Mouse with the Intracellular Pathogen Ehrlichia chaffeensis

To determine the basis of susceptibility and resistance to human monocytic ehrlichiosis (HME), immunocompetent and immunocompromised mice were infected with Ehrlichia chaffeensis and bacterial loads were measured by PCR and by immunohistochemistry. Immunocompetent (C.B-17 and C57BL/6) mice cleared the bacteria within 10 days, but immunocompromised SCID and SCID/BEIGE mice developed persistent infection in the spleen, liver, peritoneal cavity, brain, lung, and bone marrow and became moribund within 24 days. Both immunocompromised strains lack T and B lymphocytes, but the SCID/BEIGE strain is also deficient in natural killer (NK) cell function. During advanced stages of disease, the infections were associated with wasting, splenomegaly, lymphadenopathy, liver granulomas and necroses, intravascular coagulation, and granulomatous inflammation. Histochemical and immunohistochemical localization studies confirmed the presence of bacteria in tissues, and viable bacteria were cultured from infected animals. The data reveal that T and/or B cells play an essential role during resistance of immunocompetent mice to infection with E. chaffeensis and demonstrate the utility of immunocompromised mice as an experimental model for the study of HME.     

Multiblock poly(ether-ester-amide)s based on polyamide-6 and poly(ethylene glycol), 2 Effect of composition and soft-segment length on the structure of poly(ether-ester-amide)s as revealed by X-ray scattering

Isotropic unannealed and annealed melt-pressed and quenched samples of segmented multiblock poly(ether-ester-amide)s based on polyamide-6 and poly(ethylene glycol)s (PEGs) of molecular weights 400 and 1000 with various hard/soft segment weight ratios were investigated. The effect of composition, segment length and annealing temperature on the crystal structure was studied by differential scanning calorimetry, wide-angle and small-angle X-ray scattering. In addition to the γ-phase, one of the unannealed samples having relatively long hard and soft segments exhibits a high amount of α-phase. This is assumed to be due to the high flexibility of the PEG segments, linking the polyamide blocks thus enhancing their mobility. The lack of hydrogen bonds between the PEG segments facilitates crystallization of the polyamide segments in the more perfect α-modification, which is the most pronounced in the above mentioned sample. Part of the α-phase transforms into the α-phase upon annealing in all copolymer samples studied, similarly to polyamide-6.     

Fiber optic probe for polarized reflectance spectroscopy in vivo: design and performance

We present the design and construction of a fiber optic probe for elastic light scattering spectroscopy in vivo with polarized excitation and polarization sensitive detection. The performance of the fiber probe is evaluated using a suspension of polystyrene spheres placed atop a diffusely scattering substrate, and it demonstrates that the size-dependent characteristics of the scatterers can be extracted in the presence of a highly diffusely scattering background using a linear combination of forward and backward Mie scattering components of the scatterers. Subsequently, Mie theory calculations are performed over a broad range of diagnostically relevant parameters of nuclei-mean diameter, size distribution, and relative refractive index-to understand how the polarized reflectance measurements with the fiber probe can be used to extract morphological information about epithelial tissue. Finally, the feasibility of in vivo measurements with the fiber optic based polarization sensitive light scattering spectroscopy is demonstrated.     

Association of tuberculin-boosted antibody responses with pathology and cell-mediated immunity in cattle vaccinated with Mycobacterium bovis BCG and infected with M. bovis

Vaccine development and our understanding of the pathology of bovine tuberculosis in cattle would be greatly facilitated by definition of the immunological correlates of protection and/or pathology. In this study we analyzed humoral immune responses in Mycobacterium bovis BCG-vaccinated and control cattle (in particular, the relationship between the intradermal comparative tuberculin skin test and serum immunoglobulin G [IgG] responses) against a range of mycobacterial antigens (MPB59, MPB64, MPB70, MPB83, ESAT-6, CFP-10, Acr1, and PstS-1) by multiantigen print immunoassay and conventional enzyme-linked immunosorbent assay. Following M. bovis infection, the comparative tuberculin skin test strongly boosted IgG, IgG1, and IgG2 antibody responses, particularly against MPB83 and MPB70, in unvaccinated cattle but failed to boost these responses, or did so only weakly, in BCG-vaccinated calves. In addition, the skin test-induced increases in MPB83-specific IgG responses correlated positively with bacterial loads and ESAT-6-induced in vitro gamma interferon responses. In conclusion, both the negative correlation of skin test-enhanced MPB83-specific antibody responses with BCG-induced protection and their positive correlation with bacterial loads can serve as useful markers for vaccine efficacy after challenge.     

Enzymes in polymer chemistry, 5. Radical polymerization of different 11-methacryloylamino-undecanoic acid esters and oligoesters esterfied by lipases

11-Methacryloylaminoundecanoic acid ( 1 ) was esterified with the monoalcohols isobutyl alcohol, cyclohexanol, DL -menthol, cholesterol, testosterone and an excess of 12-hydroxylauric acid in the presence of lipase as catalyst. The kinetics of the esterification reactions were followed by ¹H NMR spectroscopy and the results were correlated with sterical effects. The monomers were polymerized radically. The monomeric 12-hydroxylauric acid oligoester 11 as well as its homopolymer 12 were characterized by DSC and viscosity measurements.