D-glucosamine propanedithioacetal, an efficient chiral auxiliary in beta-lactam chemistry.

The synthesis of some monocyclic beta-lactams (monobactams) by the Staudinger reaction using D-glucosamine propanedithioacetal as chiral auxiliary is reported. The influence of several radicals at C3, C4, and C1' (sugar moiety) as well as other structural aspects are considered in relation to the antielastase activity.     

Morphological embedding and phonetic reduction: the case of triconstituent compounds

In this paper we propose that the internal bracketing of a word with more than two morphemes is reflected in the phonetic implementation. We hypothesize that embedded forms show more phonetic reduction than forms at higher structural levels (‘Embedded Reduction Hypothesis’). This paper tests the prediction of the Embedded Reduction Hypothesis with triconstituent compounds. The analysis of the durational properties of almost 500 compound tokens shows that there is a lengthening effect on the non-embedded constituent, and a shortening effect on the adjacent embedded constituent. Yet, this predicted effect of embedding interacts with other lexical factors, above all the bigram frequency of the embedded compound. At a theoretical level, these effects mean that the durational properties of the cross-boundary constituents are indicative of the hierarchical structure and of the strength of the internal boundary of triconstituent compounds. Hence, morphological structure is reflected in the speech signal.     

Desensitization, two-state receptors and pharmacological parameters

Katz' classical desensitization theory is examined and expanded. Two possible desensitization mechanisms are found to be thermodynamically identical with drug action on a two-state receptor and capable of interpretation as escape from an instability imposed by the activation of the receptor. The expanded theory of desensitization enables classical receptor theory to accomodate unexplained experimental facts such as the "fade" of both agonistic and antagonistic drug action and the metaphilic effect; it also makes it possible to interpret the variable efficacy or intrinsic activity of partial agonists as very rapid desensitization of drug-receptor complexes.     

Age and hypohydration independently influence the peripheral vascular response to heat stress

Seven young (Y, 22-28 yr) and seven middle-aged (MA, 49-60 yr) normotensive men of similar body size, fatness, and maximal oxygen uptake (VO2max) were exposed to a heat challenge in an environmental chamber (48 degrees C, 15% relative humidity). Tests were performed in two hydration states: hydrated (H, 25 ml water/kg body wt 1 h before the test, 2.5 h before exercise) and hypohydrated (Hypo, after 18-20 h of water deprivation). Each test began with a 90-min rest period during which the transiently increased plasma volume and decreased osmolality after drinking in the H condition returned to base line. This period was followed by 30 min of cycle exercise at a mean intensity of 43% VO2max and a 60-min resting recovery period with water ad libitum. Although prior drinking caused no sustained changes in plasma osmolality, Hypo increased plasma osmolality by 7-10 mosmol/kg in both groups. There were no significant age differences in water intake, urine output or osmolality, overall change in body weight, or sweating rate. In the H state, the percent change in plasma volume was less (P less than 0.01) during exercise for the Y group (-5.9 +/- 0.7%) than for the MA group (-9.4 +/- 0.6%). Esophageal temperature (Tes) was higher in the Hypo condition for both groups with no age-related differences. Throughout the 3-h period, mean skin temperature was higher in the Y group and significantly so (P less than 0.05) in the Hypo condition.(ABSTRACT TRUNCATED AT 250 WORDS)     

The role of the pseudo-disaccharide neamine as an intermediate in the biosynthesis of neomycin.

By using wild-type and deoxystreptamine-negative mutants of Streptomyces fradiae grown in media containing [6(-3)H]glucose or [U-14C]glucose, and by subsequent hydrolysis of the labelled neomycin produced, neamines labelled with 3H in both rings I and II, but with 14C in ring I only, were prepared. A mixture of these two forms of neamine was converted by deoxystreptamine-negative Streptomyces rimosus forma paromomycinus into neomycin (not paromomycin) with a 30% yield. The3H: 14C ratio in this neomycin was the same as the measured in neamine produced by hydrolysis of the neomycin, and in unused neamine reisolated from the incubation medium. The 3H:14C ratio in the neomycin was not affected by the presence of unlabelled deoxystreptamine during the incubation. The radioactivity in the neomycin was associated with rings I and II only. It is concluded that the added neamine is incorporated into antibiotic intact, without initial hydrolysis, and that the probable first step in the subunit assembly of neomycin is the formation of neamine.     

Factors determining post-stimulation dilatation

Post-stimulation dilatation (PSD) of the femoral artery and vein after cessation of postganglionic sympathetic stimulation were related to the frequency and pulse number of the preceding stimulation. It was found that: 1) A minimum number of pulses (MNP) is needed to evoke PSD. MNP is inversely related to the stimulation frequency. A marked PSD develops after stimulation at 1 Hz when only 100 pulses were applied, whereas, if stimulated at 4 Hz or at higher frequencies, even 2,000 pulses fail to induce PSD. 2) The maximum value, the maximum rate and the overall diameter change of PSD (expressed either in absolute values or in relation to the preceding contraction) are a) directly related to the number of pulses at a constant stimulation frequency, b) for a constant number of pulses the above values are inversely related to the stimulation frequency. 3) The relation of PSD values to the stimulation parameters contradict the assumption that PSD is elicited either by a neurogenic transmitter released by the stimulation, or by an extraneuronal transmitter whose release is associated with the release of noradrenaline. PSD is suggested to be due to a decreased noradrenaline level within the synaptic cleft due to persistence of the reuptake after the release of noradrenaline had ceased.     

Caring for US Children: Barriers to Effective Treatment in Children with the Disease of Obesity

In 2020, impediments to pediatric obesity (PO) treatment remain pervasive, even though these barriers are clearly documented in medical literature. Providers must invest considerable resources to overcome these barriers to care. Notable barriers include gaps in medical education, misperceptions of the disease, weight bias and stigma, exclusion of coverage in health plans, and thus an unsustainable financial framework. Hence, this review offers an updated social‐ecological framework of accessibility to care, wherein each barrier to care or variable is interdependent on the other and each is critical to creating forward momentum. The sum of all these variables is instrumental to overall smooth function, configured as a wheel. To treat PO effectively, all variables must be adequately addressed by stakeholders throughout the health care system in order to holistically comprehend and appreciate undertakings to advance the burgeoning field of PO medicine.     

New developments in the law for obesity discrimination protection

Background:

Obese individuals are frequent targets of weight‐based discrimination, particularly in the employment setting. Victims of weight discrimination have sought legal restitution like others who have suffered from different forms of discrimination. However, in the vast majority of the United States, body weight is not a protected class and weight‐based employment discrimination does not provide a basis for a legal claim. Some have attempted to seek legal recourse under the Rehabilitation Act of 1973 or the Americans with Disabilities Act of 1990 (collectively, the ADA), which protect against discrimination based on mental or physical disabilities in a variety of settings. Until recently, claims of weight discrimination under the ADA have also been largely unsuccessful. However, Congress recently passed the ADA Amendments Act, expanding the definition of what constitutes a disability and incorporating a broad view of ADA's coverage.

Objective:

This short communication provides an update of the law as it relates to employment based discrimination of obese people. The authors propose a legislative direction for future legal recourse.

Design and Methods:

The authors conducted legal research into the ADA Amendments Act, and synthesized this work relating to discrimination against weight in the employment context.

Results:

In light of the ADA Amendments Act, courts and the Equal Employment Opportunity Commission have provided protection for severely obese people from discrimination based on actual or perceived disability in the employment context.

Conclusion:

The authors discuss this positive legal development and additionally propose a targeted solution to address weight discrimination in the employment setting. National polling suggests there is considerable public support for such a measure. The authors thus recommend the implementation of a “Weight Discrimination in Employment Act” modeled after the Age Discrimination in Employment Act to adequately address this pervasive and damaging injustice toward individuals who are affected by obesity.