Response of rats to diets of equal chemical score: effect of lysine or threonine as the limiting amino acid and of an amino acid excess

The effect of lysine or threonine deficiency with or without excesses of all other amino acids was evaluated in a 21-d feeding study with male rats. Four amino acid mixtures were designed to be first limiting for the rat in lysine or threonine and contained either 0 or 50% excess of nonlimiting amino acids. These mixtures were incorporated into purified diets to provide seven levels [20-140% of the National Research Council (NRC) requirement] of the limiting amino acid. Food intake, body weight gain and carcass composition were measured for each rat to determine the effects of the identity of the limiting amino acid and of amino acid excess on the response to dietary chemical score. Significant effects and/or interactions of the identity of the limiting amino acid (i.e., Lys or Thr) and the presence of excess amino acids were seen for each of the measured responses. At equivalent dietary percentages of the NRC requirement, threonine deficiency supported greater body weight gain than did lysine deficiency. At equivalent deficiencies (Lys vs. Thr) threonine-deficient rats were more susceptible to adverse effects of excess amino acids. When the limiting amino acids were incorporated into the diet through incremental addition of the deficient amino acid mixture, rats responded to levels of lysine or threonine in excess of the NRC requirement. These results suggest that the current NRC requirements for these amino acids are too low and that aspects of the dietary amino acid composition other than the percentage deficit of the limiting amino acid can be important determinants of animal response.     

Effect of moderate exercise on salivary immunoglobulin A and infection risk in humans

The incidence of upper respiratory tract infections (URTI) and salivary immunoglobulin A concentrations [IgA_s] of nine individuals were examined during 12 weeks of moderate exercise training, and compared to ten sedentary controls. Changes in maximal oxygen uptake were assessed at initial, mid-point and final evaluations (T1–3), while changes in [IgA_s] and salivary immunoglobulin concentration-salivary albumin concentration ratio ([IgA_s]:[Alb_s]) were monitored at T1 and T3. During the 12 week period, symptoms of URTI were self-recorded daily. During the period of training the level of fitness significantly increased (P<0.05) in the exercise group. The number of days recording symptoms of influenza, but not of cold, and total light URTI symptoms was significantly reduced in the exercise group during the last weeks of training. A significant increase in [IgA_s] and in [IgA_s]:[Alb_s] was found in the exercise group after training. Both [IgA_s] and [IgA_s]:[Alb_s] were significantly related to the number of days showing symptoms of influenza (P<0.01) and the total number of days of sickness (P<0.05). These data provide quantitative support for the belief that regular, moderate exercise results in an increased [IgA_s] at rest and [IgA_s]:[Alb_s], which may contribute to a decreased risk of infection. Electronic Publication     

Emerging Infections Program—State Health Department Perspective

The Emerging Infections Program (EIP) is a collaboration between the Centers for Disease Control and Prevention and 10 state health departments working with academic partners to conduct active population-based surveillance and special studies for several emerging infectious disease issues determined to need special attention. The Centers for Disease Control and Prevention funds the 10 EIP sites through cooperative agreements. Our objective was to highlight 1) what being an EIP site has meant for participating health departments and associated academic centers, including accomplishments and challenges, and 2) the synergy between the state and federal levels that has resulted from the collaborative relationship. Sharing these experiences should provide constructive insight to other public health programs and other countries contemplating a collaborative federal–local approach to collective public health challenges.     

Effectiveness of somatostatin in regulating pancreatic splenic lobe hormone secretion following 99% pancreatectomy in adult chickens

In vivo studies were carried out in adult chickens in an attempt to evaluate the effectiveness of somatostatin (SRIF) in regulating hormone secretion from the splenic pancreatic lobe after 99% of the pancreatic mass was surgically ablated. Sixteen days after either sham operation or 99% pancreatectomy, birds were infused iv with SRIF (420 ng/min) alone and then glucose (59 mg/Kg/min) was superimposed on the infusate, or birds were infused iv with glucose alone and then SRIF was superimposed on the infusate. Serial blood samples were taken during the 16-day postoperative period and also at regular intervals during the 75-min observation period. Plasma was analyzed for glucose, insulin (IRI), glucagon (IRG), pancreatic polypeptide (IRAPP), and somatostatin (IRSRIF). Careful standardization of the SRIF radioimmunoassay, as well as analysis of the molecular form of circulating SRIF, indicated that "true" SRIF levels were being estimated in plasma of both groups of chickens. Normal-fed chickens have plasma SRIF levels of 1.12 +/- 0.07 ng/ml which increases 16 days after 99% pancreatectomy to 2.39 +/- 0.15 ng/ml plasma. The latter decreases by 55% with an overnight fast. Glucose infusion, superimposed upon a preexisting SRIF infusion in adult chickens, did not evoke an IRI response in the 99% depancreatized birds equal to that observed in sham-op controls. Although a full SRIF dose-response curve was not generated, the glucose data strongly suggest a reduced sensitivity of insulin-secreting cells to SRIF in pancreoprivic birds. Both bird groups were equally--and markedly--sensitive to the IRG-depressant effects of SRIF; in contrast, the depancreatized chickens were significantly more resistant to the APP-inhibitory effects of SRIF when compared to the sham-op control birds. Thus, 16 days after partial pancreatectomy, the hormone-release mechanisms appeared altered for IRI and IRAPP in response to SRIF. Data obtained when glucose infusions preceded SRIF infusions indicated that A-cell release of glucagon was much more sensitive to glucose (as a depression) in the partially depancreatized birds than in control birds. These same birds were significantly less responsive to the glucose-depressant effect on plasma APP levels. Thus, it appears that 99% pancreatectomy increases the sensitivity of the SRIF, IRI, and IRG release mechanisms in response to glucose 16 days after surgery. The insulin-to-glucagon (I/G) molar ratios indicative of metabolic anabolism can still be achieved by nutrients 16 days after partial pancreatectomy.(ABSTRACT TRUNCATED AT 400 WORDS)     

Laser therapy: a randomized, controlled trial of the effects of low intensity Nd:YAG laser irradiation on lateral epicondylitis

OBJECTIVE: To assess the effectiveness of low intensity laser therapy in the treatment of lateral epicondylitis. DESIGN: A double-masked, placebo-controlled, randomized clinical trial. SETTING: A physical medicine and rehabilitation clinic. PARTICIPANTS: Fifty-two ambulatory men and women (age range, 18-70 yr) with symptomatic lateral epicondylitis of more than 30 days in duration and a normal neurologic examination. INTERVENTION: Subjects were bloc randomized into 2 groups with a computer-generated schedule. All underwent irradiation for 60 seconds at 7 points along the symptomatic forearm 3 times weekly for 4 weeks by a masked therapist. The sole difference between the groups was that the probe of a 1.06-microm continuous wave laser emitted 204 mW/cm2 (12.24 J/cm2) for the treated subjects and was inactive for the control subjects. Subjects were assessed at the beginning, midpoint (session 6), and end (session 12) of treatment, as well as at follow-up 28 to 35 days after their last treatment. MAIN OUTCOME MEASURES: Pain in last 24 hours, tenderness to palpation, and patient's perception of change (benefit). RESULTS: The treated and untreated groups were well matched demographically. Masking was maintained for subjects and therapists; however, the groups did not vary to a statistically significant extent in terms of the main outcome measures either during treatment or at follow-up. Secondary outcome variables, such as grasp and pinch strength, medication use, and pain with grasp and pinch, also failed to statistically differ significantly between the groups. No significant treatment side effects were noted. CONCLUSION: Treatment with low intensity 1.06-microm laser irradiation within the parameters of this study was a safe but ineffective treatment of lateral epicondylitis. Further research seems warranted in this controversial area.     

Birth of Healthy Children After Preimplantation Diagnosis of Thalassemias

Background: Preimplantation genetic diagnosis (PGD) allows couples at risk of having children with thalassemia to ensure the healthy outcome of their pregnancy. Methods: Seventeen PGD clinical cycles were initiated for Cypriot couples at risk of having children with different thalassemia mutations, including IVS1-110, IVSI-6, and IVSII-745. Unaffected embryos for transfer were selected by testing oocytes, using first and second polar body (PB) removal and nested polymerase chain reaction analysis followed by restriction digestion. Results: Unaffected embryos were selected in 16 of 17 PGD cycles. Of 166 oocytes studied from these cycles, 110 were analyzed by sequential analysis of both the first and the second PB, resulting in preselection and transfer of 45 unaffected embryos. This resulted in seven pregnancies and in the birth of five healthy thalassemia-free children. The embryos predicted to have inherited the affected allele were not transferred. Analysis of these embryos confirmed the PB diagnosis. Conclusions: Sequential first and second PB testing of oocytes is reliable for PGD of thalassemia and is a feasible alternative to prenatal diagnosis in high-risk populations.     

Changing epidemiology of invasive pneumococcal disease among older adults in the era of pediatric pneumococcal conjugate vaccine

Context  A conjugate vaccine targeting 7 pneumococcal serotypes was licensed for young children in 2000. In contrast to the 23-valent polysaccharide vaccine used in adults, the 7-valent conjugate vaccine affects pneumococcal carriage and transmission. Early after its introduction, incidence of invasive pneumococcal disease declined among older adults, a group at high risk for pneumococcal disease. Objective  To determine among adults aged 50 years or older whether incidence of invasive pneumococcal disease, disease characteristics, or the spectrum of patients acquiring these illnesses have changed over the 4 years since pneumococcal conjugate vaccine licensure. Design, Setting, and Population  Population-based surveillance of invasive pneumococcal disease in 8 US geographic areas (total population, 18 813 000), 1998-2003. Main Outcome Measures  Incidence of invasive pneumococcal disease by pneumococcal serotype and other characteristics; frequency among case patients of comorbid conditions and other factors influencing mortality. Results  Incidence of invasive pneumococcal disease among adults aged 50 years or older declined 28% (95% confidence interval [CI], –31% to –24%), from 40.8 cases/100 000 in 1998-1999 to 29.4 in 2002-2003. Among those aged 65 years or older, the 2002-2003 rate (41.7 cases/100 000) was lower than the Healthy People 2010 goal (42 cases/100 000). Among adults aged 50 years or older, incidence of disease caused by the 7 conjugate vaccine serotypes declined 55% (95% CI, –58% to –51%) from 22.4 to 10.2 cases/100 000. In contrast, disease caused by any of the 16 serotypes only in polysaccharide vaccine did not change, and disease caused by serotypes not in either vaccine increased somewhat, from 6.0 to 6.8 cases/100 000 (13%; 95% CI, 1% to 27%). Between 1998-1999 and 2002-2003, the proportion of case-patients with human immunodeficiency virus infection increased from 1.7% (47/2737) to 5.6% (124/2231) (P<.001), and those with any comorbid condition that is an indication for pneumococcal polysaccharide vaccination increased from 62.3% (1842/2955) to 72.0% (1721/2390) (P<.001). Conclusions  Our findings indicate that use of conjugate vaccine in children has substantially benefited older adults. However, persons with certain comorbid conditions may benefit less than healthier persons from the indirect effects of the new vaccine.      

Fetal breech presentation predisposes to subsequent development of septic arthritis of the hip

We postulated a link between breech presentation and septic arthritis of the hip. To examine the potential association between these 2 relatively uncommon entities, we used the Patient Administration Systems and Biostatistics Activity (PASBA) database, which contains coded information derived from hospitalizations and ambulatory encounters at U.S. military hospitals worldwide. Among a cohort of nearly 1 million infants born in a 14-year period, 3.37% were found to be in the breech presentation. The rate of septic arthritis of the hip or pelvis during the first year of life among these breech infants was approximately 1/8000, providing a relative risk of 4.1 (95% confidence interval, <1.4-11.7) compared with the rate among nonbreech infants. Fetal breech presentation predisposes to the development of septic hip during the first year of life.     

Impact of childhood vaccination on racial disparities in invasive Streptococcus pneumoniae infections

Context  Historically, incidence of pneumococcal disease in the United States has been higher among blacks than among whites. Following recommendation of a new 7-valent pneumococcal conjugate vaccine for children in October 2000, the incidence of invasive pneumococcal disease has declined dramatically, but the impact of vaccination on racial disparities in incidence of pneumococcal disease is unknown. Objective  To assess the effect of conjugate vaccine introduction on rates of pneumococcal disease among whites and blacks in the United States. Design, Setting, and Patients  Analysis of data from the Active Bacterial Core Surveillance (ABCs)/Emerging Infections Program Network, an active, population-based surveillance system in 7 states. Patients were 15 923 persons with invasive pneumococcal disease occurring between January 1, 1998, and December 31, 2002. Main Outcome Measures  Age- and race-specific pneumococcal disease incidence rates (cases per 100 000 persons), rate ratios, and rate differences. Results  Between 1998 and 2002, annual incidence rates for invasive pneumococcal disease decreased from 19.0 to 12.1 cases per 100 000 among whites and from 54.9 to 26.5 among blacks. Due to these declines, 14 730 fewer cases occurred among whites and 8780 fewer cases occurred among blacks in the United States in 2002, compared with 2 prevaccine years, 1998 and 1999. Before vaccine introduction, incidence among blacks was 2.9 times higher than among whites (95% confidence interval [CI], 2.7-3.0); in 2002, the black-white rate ratio had been reduced to 2.2 (95% CI, 2.0-2.4). Incidence among black children younger than 2 years went from being 3.3 times higher (95% CI, 3.0-3.7) than among white children in the prevaccine period to 1.6 times higher (95% CI, 1.1-2.2) in 2002. By 2002, 74% of white children and 68% of black children aged 19 to 35 months in the 7 states had received at least 1 dose of pneumococcal conjugate vaccine; 43% of white and 39% of black children received 3 or more doses. Conclusion  Although blacks remain at higher risk of invasive pneumococcal disease, introduction of childhood pneumococcal vaccination has reduced the racial disparity in incidence of pneumococcal disease.