Construct Validity of the Impact of Weight on Quality of Life Questionnaire

KOLOTKIN, RONETTE L, SUSAN HEAD, ALAN BROOKHART. Construct validity of the Impact of Weight on Quality of Life questionnaire. The Impact of Weight on Quality of Life questionnaire (IWQOL) is a 74-item self-report, condition-specific instrument that (1) assesses the effect of weight on quality of life in eight key areas, and (2) may be used as a treatment outcome measure and/or an evaluation tool for healthcare policy makers and third-party payers. This study explores IWQOL construct validity and provides new information on internal consistency, treatment effects, and differences between men and women. IWQOL total scores correlated highly with other measures of overall quality of life, and subscale scores correlated well with counterparts in the assessment battery. Internal consistency estimates for the IWQOL scales generally were high. For the women, 4-week participants, and the total sample, pretreatment-posttreatment differences were significant for all IWQOL scales and total score. For men, treatment differences were significant for the total score and all subscales except for Work and Mobility. Treatment differences for 2-week participants were significant for all scales except for Work. Consistent with previous IWQOL study results, the Comfort With Food scale scores reflected more discomfort at posttreatment as compared with pretreatment. The IWQOL, already translated into French and Italian, currently is demonstrating clinical and research utility as a quality-of-life outcome measure for clinical trials of antiobesity drugs and surgical treatments for patients with obesity.     

Effects of vigorous exercise training and beta -agonist administration on bone response to hindlimb suspension

Bloomfield, Susan A., Beverly E. Girten, and Steven E. Weisbrode. Effects of vigorous exercise training and -agonist administration on bone response to hindlimb suspension.J. Appl. Physiol. 83(1):172-178, 1997.The effectiveness of dobutamine (Dob) inpreventing bone loss during 14 days of hindlimb suspension (Sus) wastested in exercise-trained (Ex; n = 25) and sedentary (Sed; n = 22) rats(age 155 days). One-half of each group was given Dob (2 mg · kg¹ · day¹)or saline (Sal). Histomorphometric measurements at midfemur revealed a17% smaller cortical bone area (CBA) and a 32% lower periostealmineral apposition rate (MAR) in suspended vs. nonsuspended Sed/Salrats. Dob abolished this decline in CBA in Sed/Sus rats, probably via an attenuation of the decrease in periosteal MAR; similarbut nonsignificant effects on cross-sectional moment of inertia wereobserved. Nonsuspended Ex rats had no change in bone CBA when CBA isindexed to body weight. Sus appeared to uncouple the relationshipbetween soleus weight and CBA. Dob attenuated the 43% decline insoleus weight after Sus in Ex but not in Sed rats. In summary, vigorousEx before Sus does not affect loss of bone mass due to unloading; Dobeffectively maintains CBA in Sed rats subjected to suspension.

     

Mycoplasma pneumoniae Pneumonia—Experience at a Referral Center

Mycoplasma pneumoniae pneumonia is usually a benign illness, and respiratory complications and extrapulmonary manifestations occur rarely. In this series, patients admitted to a referral hospital with this disorder had unusual symptoms, signs and findings on chest roentgenograms and laboratory studies. Pneumonia was often severe and extrapulmonary manifestations were frequent, resulting in prolonged hospital stays and illnesses. Although this extreme end of the spectrum of disease caused by M pneumoniae is not representative of this type of pneumonia as seen in outpatients, it is important to realize that patients admitted to hospital with severe, complicated pneumonia frequently have unusual manifestations of a common disease.     

Synchronous cell growth occurs upon synchronizing the two regulatory steps of the Saccharomyces cerevisiae cell cycle

There are two known asynchronous steps in the budding yeast Saccharomyces cerevisiae cell cycle, where an asynchronous step is one which is completed in different lengths of time by different cells in an isogenic population. It is shown here that elimination of the asynchrony due to cell size by preincubation of cells with the mating pheromone alpha-factor, and decreasing the asynchrony in the cdc28 'start' step by lowering the pH, yields highly synchronous cell growth measured as the time period between the emergence of buds. In one experiment, cell budding for 92% of cells occurred within a 12-min period for at least two generations. Under identical conditions, cell number increase is not as synchronous as bud emergence indicating that there is a third asynchronous step, which is concluded to be at cell separation. These results are consistent with there being two--and only two--asynchronous steps in the cell cycle, measured from bud emergence to bud emergence. Surprisingly, these two steps are also the two major regulatory steps of the cell cycle. It is concluded that asynchrony may be a general feature of cell cycle regulatory steps. The asynchrony in the completion of the cdc28 'start' step which occurs in the first cell cycle after alpha-factor washout is shown here to be almost or entirely eliminated for the second passage through this step after alpha-factor washout. The 'true' time between the onset of budding and the point where 50% of cells have budded (called t50BE) is 17 and less than or equal to 2 min for the first and second budding, respectively, after alpha-factor washout. The cell cycle models requiring a transition probability, or asynchrony, at 'start' for every cell cycle are therefore incorrect.     

Discrimination by male ring-tailed Lemurs (Lemur catta) between the scent marks of male and those of female conspecifics

Olfaction plays an important role in the social communication of all prosimians. (The experiment reported in this paper forms part of an intensive chemobehavioral study of olfaction in Lemur catta (ring-tailed lemur) being carried out in this laboratory.) Five male Lemur cattawere tested on their behavioral responses to paired scent stimuli. Responses measured were (1) total investigation time, (2) arm-marking, (3) ABO/BO rubbing, and (4) flehmen. Males showed a strong discrimination between the scent stimuli,giving higher levels of response to female scent on measures 1, 3, and 4. This response suggests an olfactory-related preference by males for female scent under controlled conditions. This preference may be a consequence of the females’ dominance over males and the brevity of estrus in L. catta,both of which would favor such choice behavior.     

Early development ofRhizobium-induced root nodules ofParasponia rigida. I. Infection and early nodule initiation

Summary The first of two major steps in the infection process in roots ofParasponia rigida (Ulmaceae) following inoculation byRhizobium strain RP501 involves the invasion ofRhizobium into the intercellular space system of the root cortex. The earliest sign of root nodule initiation is the presence of clumps of multicellular root hairs (MCRH), a response apparently unique amongRhizobium-root associations. At the same time or shortly after MCRH are first visible, cell divisions are initiated in the outer root cortex of the host plant, always subjacent to the MCRH. No infection threads were observed in root hairs or cortical cells in early stages. Rhizobial entry through the epidermis and into the root cortex was shown to occur via intercellular invasion at the bases of MCRH. The second major step in the infection process is the actual infectionper se of host cells by the rhizobia and formation of typical intracellular infection threads with host cell accommodation. This infection step is probably the beginning of the truly symbiotic relationship in these nodules. Rhizobial invasion and infection are accompanied by host cortical cell divisions which result in a callus-like mass of cortical cells. In addition to infection thread formation in some of these host cortical cells, another type of rhizobial proliferation was observed in which large accumulations of rhizobia in intercellular spaces are associated with host cell wall distortion, deposition of electron-dense material in the walls, and occasional deleterious effects on host cell cytoplasm.     

Parametric analysis of dynamic postural responses

A detailed theoretical understanding of postural control mechanisms must be preceded by careful quantification of both the deterministic and stochastic aspects of postural behavior of normal and abnormal subjects under various dynamic conditions. Toward this end, concise parametric transfer function plus noise models were derived for both shoulder and waist position data obtained by applying a linear anteriorposterior bandlimited pseudorandom disturbance to the base of support of human subjects. Model orders as well as model parameters were determined empirically. One advantage of this modeling procedure is the conciseness of the postural models, permitting easy statistical analysis of the data obtained under different dynamic conditions from many subjects. Model features, including pole and zero locations, from 6 normal subjects each tested on 5 consecutive days under 3 input amplitudes and eyes open and closed conditions are presented. The resulting transfer function models consist of only 1 or 2 poles near the integration position on the Z plane unit circle and 0 to 2 zeros. Locations of the poles indicate that the eyes closed responses are more oscillatory, less damped, and with higher gains than the eyes open responses. These transfer functions are similar to nonparametric ones of other authors. The noise model orders are also small. Their spectra are those of low pass systems. Also, the quantity and frequency range of the postural noise is positively related to the amplitude of platform motion as well as related to the presence or absence of vision. Present address: Kresge Hearing Research Institute, University of Michigan Medical School, 1301 E. Ann St., Ann Arbor, MI 48109, USA     

The effect of renal vasodilation and hypotonic volume expansion on water excretion in dogs after anesthesia and surgery

The possible effects of renal vasoconstriction from anesthesia and surgery on water excretion after hypotonic volume expansion (HVE) were studied in 18 well conditioned anesthetized dogs, with and without the infusion of phenoxybenzamine and acetylcholine into the renal artery of the cannulated kidney. In 6 dogs (Group 1 - Control) whose renal artery was infused with isosmotic saline, HVE resulted in a bilateral increase in GFR and UV (p < .05). ERPF, Cosm, C_H2O, U_NaV, U_KV, RBF, RVR and MAP did not change significantly. In 6 other dogs (Group 2), whose cannulated kidney was infused with phenoxybenzamine 50 μg/min before and during HVE, GFR increased on the infused side while CH₂O and UV increased bilaterally (p < .05). ERPF, Cosm, U_NaV, U_KV, RBF, RVR and MAP were not affected significantly. The addition of ADH, 2 mu/min into the phenoxybenzamine infusate, decreased ERPF, RBF and RVR bilaterally and CH₂O on the infused side (p < .05). It had no effect upon GFR, Cosm, U_NaV, U_KV and MAP. In another 6 dogs, (Group 3), whose cannulated renal artery was infused with acetylcholine (20 μg/min) before and during HVE, C_H2O, UV and RVR increased bilaterally (p < .05). ERPF and RBF decreased bilaterally (p < .05), whereas GFR, Cosm, U_NaV and MAP were unaffected. U_KV decreased on the infused side (p < .05). The addition of ADH (2 mu/min)_into the acetylcholine infusate, decreased C_H2O bilaterally and increased Cosm and U_KV on the control side (p < .05). It had no effect on ERPF, GFR, UV, U_NaV, RBF, RVR and MAP. These observations suggest that anesthesia and surgery produce renal vasoconstriction and this together with increased ADH release, interfere with water excretion by the kidney. Previous renal vasodilation prevents these influences of anesthesia and surgery.     

Caprine Arthritis-Encephalitis Virus Is Distinct from Visna and Progressive Pneumonia Viruses as Measured by Genome Sequence Homology

Competitive inhibition of hybridization between ¹²⁵I-labeled caprine arthritis-encephalitis viral RNA and homologous cDNA by heterologous viral RNA shows that the caprine retrovirus shares <20% genome sequence homology with visna and progressive pneumonia viruses. These viruses, however, are indistinguishable in immunodiffusion reactions involving the major structural protein (p28).