Effects of pelleting conditioner retention time on nursery pig growth performance.

A total of 180 nursery pigs (PIC 327 × 1050; initially 12.6 kg) were used in an 18-d study to determine the effects of pellet mill conditioning parameters and feed form on pig performance. All diets were similar, and different feed processing parameters were used to create experimental treatments. Factors considered were conditioning time (15, 30, or 60 s) and feed form (mash or pelleted). To remove the confounding factor of feed form, pelleted samples were reground to a similar particle size as the mash diet. Treatments included: 1) mash diet without thermal processing (negative control), 2) pelleted diet conditioned for 30 s (positive control), 3) pelleted diet conditioned for 15 s and reground, 4) pelleted diet conditioned for 30 s and reground, and 5) pelleted diet conditioned for 60 s and reground. Pigs were weaned and fed a common acclimation diet for 21 d before the start of the experiment. Growth and feed disappearance were then measured for 18 d. All diets had similar levels of percentage total starch, but thermally processed diets had a 1.67 to 1.87-fold increase in percentage gelatinized starch compared to the mash diet. Average daily gain and G:F did not differ between treatments overall, but pigs fed the positive control pelleted diet had decreased ADFI ( < 0.05) compared to pigs fed all other diets. Preplanned contrasts revealed that pigs fed mash diets tended to have greater ADG ( < 0.10) compared to those fed pelleted and reground diets. This suggests that processing may have had a negative influence on feed utilization, which is further supported by the finding that pigs fed mash diets tended to have greater ADG ( < 0.10) compared to those fed diets that were thermally processed, regardless of regrinding. Considering these results, it was not surprising that pigs fed mash diets had greater ADG and ADFI ( < 0.05) than those fed pelleted diets. When directly comparing diets conditioned at 60 rpm, fed either as whole pellets or reground to mash consistency, pigs fed pelleted diets had improved G:F ( < 0.05) due to lower ADFI ( < 0.05) but similar ADG. The expected improvement in G:F from pelleting (6.8%) was observed but lost when diets were reground to near original mash particle size. This may indicate that diet form from the actual pelleting process impacts G:F more than conditioner retention time.

Evaluation of conditioning time and temperature on gelatinized starch and vitamin retention in a pelleted swine diet.

Two key feed processing parameters, conditioning temperature and time, were altered to determine their effects on concentration of gelatinized starch and vitamin retention in a pelleted finishing swine diet. Diet formulation (corn­soybean meal based with 30% distillers dried grains with solubles) was held constant. Treatments were arranged in a 2 × 3 factorial design plus a control with 2 conditioning temperatures (77 vs. 88°C) and 3 conditioner retention times (15, 30, and 60 s). In addition, a mash diet not subjected to conditioning served as a control for a total of 7 treatments. Samples were collected after conditioning but before pelleting (hot mash), after pelleting but before cooling (hot pellet), and after pelleting and cooling (cold pellet) and analyzed for percentage total starch, percentage gelatinized starch, and riboflavin, niacin, and vitamin D3 concentrations. Total percentage starch was increased by greater conditioning temperature (P = 0.041) but not time (P > 0.10), whereas higher temperature and longer time both increased (P < 0.05) percentage gelatinized starch, with increasing time resulting in a linear increase in percentage starch gelatinization (P = 0.013). The interaction between conditioning temperature and time increased percentage gelatinized starch (P = 0.003) but not percentage total starch (P > 0.10). Sample location also affected both percentage total starch and gelatinized starch (P < 0.05), with the greatest increase in percentage gelatinized starch occurring between hot mash and hot pellet samples. As expected, the pelleting process increased percentage gelatinized starch (P = 0.035; 7.3 vs. 11.7% gelatinized starch for hot mash vs. hot pellet samples, respectively), but there was no difference in total starch concentrations (P > 0.10). Finally, neither conditioning temperature nor time affected riboflavin, niacin, or vitamin D3 concentrations (P > 0.10). In summary, both increasing conditioningtemperature and time effect percentage gelatinized starch, but not to the extent of forcing the diet through a pelleting die.

Bone resorption levels by age and menopausal status in 5,157 women.

OBJECTIVE: The purpose of this study was to describe bone resorption activity using a biochemical marker according to the categories of age, menopausal status, and selected drug/supplement use in middle-aged and elderly community-based women. DESIGN: This was a cross-sectional study that assessed urinary cross-linked N-telopeptide of type I collagen (NTx) and used self-report data to group women as premenopausal (Pre), perimenopausal (Peri), postmenopausal without hormone replacement therapy (Post), and postmenopausal with hormone replacement therapy (HRT). RESULTS: Mean NTx values were found to be significantly different by group and controlling for age (p = 0.001), with post hoc tests showing all pairwise group comparisons as significantly different (p = 0.001), except that the Pre and HRT groups were not significantly different. Both the Peri and the Post NTx levels were significantly higher than the Pre and the HRT groups'. NTx values in the Peri group varied with age-the youngest Peri women were similar to Pre women, and the oldest Peri women were similar to Post women. Significantly lower NTx levels were found only in the Post (p = 0.009) and HRT (p < 0.001) groups using diuretics compared with nonuse and only in the HRT group using calcium supplements compared with nonuse (p = 0.006). No differences by thyroid use were found. With a biochemical marker, the results showed that bone resorption activity differences could be demarcated in women according to age, estimated menopausal stage, and selected drug/supplement use. CONCLUSIONS: These results support the usefulness of NTx assessment for indicating bone resorption activity and therefore the potential for osteoporosis or for monitoring the efficacy of antiresorptive therapies.

Characterization of Lyme meningitis and comparison with viral meningitis in children.

OBJECTIVES: The objectives of this study were to characterize Lyme meningitis (LM) in the pediatric population; to compare LM with viral meningitis (VM) with respect to epidemiology, history and physical examination, and laboratory data; and to provide means of early distinction of Lyme neuroborreliosis from other forms of aseptic meningitis. METHODS: This retrospective analysis involved children admitted to Alfred I. duPont Hospital for Children between 1990 and 1996 whose discharge diagnoses indicated viral or aseptic meningitis or Lyme disease. LM was defined as the presence of cerebrospinal fluid (CSF) pleocytosis with positive Lyme serology and/or erythema migrans. Patients were considered to have VM if they exhibited CSF pleocytosis and had a positive viral culture. Demographic, clinical, and laboratory data were collected for each patient, and patients with LM were compared with age-matched patients with VM. RESULTS: Of 179 patient records, 12 patients with LM and 10 patients with VM (all, >2 years old) were identified by using the above criteria. In comparing LM patients with VM patients, we noted no differences among demographic variables. Children with LM had significantly lower temperatures at the time of presentation. The presence of headache, neck pain, and malaise was similar for the two groups, but the duration of these symptoms was significantly longer among LM patients. Five children with LM had cranial neuropathies. All but 1 LM patient exhibited either papilledema, erythema migrans, or cranial neuropathy. These three findings were absent in the VM group. On CSF analysis, LM patients had fewer white blood cells (mean, 80/mm3 versus 301/mm3) and a significantly greater percentage of mononuclear cells than the VM patients. CONCLUSIONS: In this study, in a Lyme-endemic area, LM was about as common as VM in older children who were hospitalized with aseptic meningitis. Attention to pertinent epidemiologic and historical data, along with physical and CSF findings, allows early differentiation of LM from VM.

Serum and cerebrospinal fluid pharmacokinetics of intravenous and oral lamivudine in human immunodeficiency virus-infected children.

We studied the pharmacokinetics of intravenously and orally administered lamivudine at six dose levels ranging from 0.5 to 10 mg/kg of body weight in 52 children with human immunodeficiency virus infection. A two-compartment model with first-order elimination from the central compartment was simultaneously fitted to the serum drug concentration-time data obtained after intravenous and oral administration. The maximal concentration at the end of the 1-h intravenous infusion and the area under the concentration-time curve after oral and intravenous administration increased proportionally with the dose. The mean clearance of lamivudine (+/- standard deviation) in the children was 0.53 +/- 0.19 liter/kg/h (229 +/- 77 ml/min/m2 of body surface area), and the mean half-lives at the distribution and elimination phases were 0.23 +/- 0.18 and 2.2 +/- 2.1 h, respectively. Clearance was age dependent when normalized to body weight but age independent when normalized to body surface area. Lamivudine was rapidly absorbed after oral administration, and 66% +/- 25% of the oral dose was absorbed. Serum lamivudine concentrations were maintained above 1 microM for >/=8 h of 24 h on the twice daily oral dosing schedule with doses of >/=2 mg/kg. The cerebrospinal fluid drug concentration measured 2 to 4 h after the dose was 12% (range, 0 to 46%) of the simultaneously measured serum drug concentration. A limited-sampling strategy was developed to estimate the area under the concentration-time curve for concentrations in serum at 2 and 6 h.

Genetic diversity among Mycobacterium avium complex strains recovered from children with and without human immunodeficiency virus infection.

The genetic diversity and molecular epidemiology of Mycobacterium avium complex (MAC) infections in children with and without human immunodeficiency virus (HIV) infection were evaluated. Isolates recovered from 136 children were subtyped by sequence analysis of a 360-bp region of the gene (hsp65) encoding a 65-kDa heat-shock protein. Twenty-one distinct hsp65 alleles were identified. On the basis of hsp65 genotype, 6 isolates were not MAC organisms. Of the remaining 130 samples, 61% were M. avium, 37% were Mycobacterium intracellulare, and 2% were species nonspecific MAC. Eighty-eight percent of the isolates obtained from HIV-infected children were M. avium. In contrast, only 38% of the isolates obtained from children without HIV infection were M. avium (chi2 test, P < .001). M. avium isolates were further subtyped by Southern blot analysis with insertion element IS1245. Taken together, no evidence for a single clonal M. avium strain causing infection was detected.

Cryptococcosis in human immunodeficiency virus-infected children.

BACKGROUND: Cryptococcosis is a common opportunistic infection in adults with AIDS. Few cases of cryptococcosis complicating pediatric AIDS have been reported. To our knowledge there are no studies that describe the epidemiology, clinical manifestations and outcome of cryptococcosis in a large population of HIV-infected children. METHODS: We identified the cases of cryptococcosis through a retrospective review of the hospital records of the 473 HIV-infected children prospectively monitored in the Pediatric Branch of the National Cancer Institute during the 8 years from 1987 to 1995. RESULTS: Four (0.85%) patients developed cryptococcosis during the study period. All patients had profound depression of the absolute CD4 counts, a history of previous opportunistic infections, and onset of cryptococcosis in the second decade of life. Cryptococcosis developed as a disseminated infection or a localized process of the lungs. Intermittent fever was the most common presenting manifestation. Serum cryptococcal antigen was positive in all patients and gradually declined after the institution of the antifungal therapy. All patients were treated with amphotericin B with or without flucytosine as initial therapy. Suppressive therapy consisted of fluconazole with or without flucytosine. There were no deaths due to Cryptococcus neoformans. CONCLUSIONS: Cryptococcosis is an infrequent yet treatable opportunistic infection of advanced pediatric AIDS that may present with subtle manifestations and warrants careful consideration in the evaluation of febrile HIV-infected children.

Lamivudine in children with human immunodeficiency virus infection: a phase I/II study. The National Cancer Institute Pediatric Branch-Human Immunodeficiency Virus Working Group.

The safety, tolerability, pharmacokinetic profile, and preliminary activity of lamivudine (2'-deoxy-3'-thiacytidine), a novel cytidine nucleoside analogue with antiretroviral activity, in human immunodeficiency virus (HIV)-infected children beyond the neonatal period were studied. Ninety children received dosages of 1-20 mg/kg/day. Pharmacokinetic evaluation demonstrated serum and cerebrospinal fluid concentrations that increased proportionally to dose. As of January 1994, 11 children had been withdrawn from study for disease progression and 10 because of possible lamivudine-related toxicity, and 6 had died. CD4 and CD8 cell counts remained stable over 24 weeks in therapy-naive children and decrease slightly in previously treated children. Quantitative immune complex-dissociated p24 antigen and HIV RNA were decreased significantly at 12 and 24 weeks. In vitro resistance to lamivudine was documented in sequential virus isolates from some patients by 12 weeks. Lamivudine was well-tolerated and exhibited virologic activity in children, although future use in children is likely to be in combination antiretroviral regimens.

Role of tissue diagnosis in pulmonary involvement in pediatric human immunodeficiency virus infection.

BACKGROUND: Pulmonary complications occur commonly during HIV infection. The aim of this study was to evaluate the clinical value of lung tissue examination in the diagnosis and treatment of pulmonary disorders in children with HIV infection. METHODS: The medical records of 347 children enrolled between January, 1990, and April, 1994, into various antiretroviral therapy protocols were reviewed to identify patients who underwent a lung biopsy. RESULTS: Fourteen patients underwent diagnostic lung biopsies on 16 separate occasions. The most common radiologic findings were nodular infiltrates which were localized in 7 patients and diffuse in 6. Eight patients presented with fever and progressive respiratory distress unresponsive to empiric therapy, whereas the rest had progressive nodular infiltrates. The pathologic diagnoses included opportunistic infection in 7 patients, lymphocytic interstitial pneumonitis in 5, non-Hodgkin's lymphoma in 3 and interstitial fibrosis in 1. The biopsy led to a major change in the treatment of 7 patients which resulted in a significant improvement of the pulmonary process in all of them. In an additional patient the excisional biopsy proved curative. CONCLUSIONS: When patients are selected appropriately, lung biopsy might have a significant impact on therapy and outcome in HIV-infected children with pulmonary infiltrates.

Combined intravenous ganciclovir and foscarnet for children with recurrent cytomegalovirus retinitis.

PURPOSE: Children with the acquired immune deficiency syndrome (AIDS) and cytomegalovirus (CMV) retinitis may not complain of symptoms despite the presence of advanced sight-threatening disease. Although little data exist regarding CMV retinitis in this population, the treatment of this disease may be difficult because of frequent, extensive recurrences after reduction of drug dose from induction to maintenance levels. The authors reported the results of the use of combined ganciclovir and foscarnet for treatment of recurrent CMV retinitis in three children with AIDS. METHODS: Three children with recurrent CMV retinitis were treated with combined ganciclovir and foscarnet administered intravenously. All patients initially received induction dosages of ganciclovir followed by maintenance therapy, at which time they experienced reactivation of their disease. The dosing regimen for induction with the combined therapy was foscarnet (60 mg/kg every 8 hours) and ganciclovir (5 mg/kg daily for 3 weeks). Maintenance with combined therapy consisted of foscarnet (90 mg/ kg daily) and ganciclovir (5 mg/kg daily). RESULTS: All patients showed complete healing of the retinitis during the first 3 weeks of combined therapy. Median survival after initiation of combined therapy was 15 weeks (range, 12-33 weeks). None of the children experienced reactivation of CMV retinitis during combined therapy with ganciclovir and foscarnet. Combined therapy was well tolerated in all patients without major side effects. No patient required discontinuation or interruption of either drug during combined therapy. CONCLUSION: Children with recurrent CMV retinitis may not report visual symptoms, which can delay therapeutic intervention. Therefore, recurrent disease in children should be treated aggressively to avoid potentially devastating visual loss. A combination of ganciclovir and foscarnet appears to be a safe and effective therapeutic option for treatment of recurrent CMV retinitis in children with AIDS. This approach causes no additional toxic reactions and may provide improved long-term control of recurrent CMV retinitis in children.

Pulsatile release patterns of luteinizing hormone and progesterone in relation to symptom onset in women with premenstrual syndrome.

OBJECTIVE: To explore the pulsatile-release characteristics of LH and P in women with premenstrual syndrome (PMS) compared with age-matched phase-matched controls. DESIGN: Prospective, repeated measures, two-group study. SETTING: Human volunteers in an academic research environment. PARTICIPANTS: Six women with rigorously defined prospectively determined PMS; six age-matched phase-matched controls. MAIN OUTCOME MEASURES: Frequency, amplitude, concentration, and coincident pulsatile release characteristics of LH and P at three symptom-related points of the luteal phase. RESULTS: No significant between-group differences in frequency, amplitude, or concentration were found. In pooled data, significant coincident pulsing between LH and P was demonstrated. The length of time between LH and P pulses systematically increased across the luteal phase, a finding not previously reported. In the PMS group only, significant coincident pulsing occurred at an unexpected zero time lag on the symptom-onset sampling day. CONCLUSION: A progressively increasing coupling interval may reflect the gradual decline of the corpus luteum. Presence of a zero time lag between LH and P at symptom onset in women with PMS may indicate an aberrance in corpus luteum response to LH stimulation.

Fungemia in children infected with the human immunodeficiency virus: new epidemiologic patterns, emerging pathogens, and improved outcome with antifungal therapy.

We characterized 27 episodes of fungemia in 22 children infected with the human immunodeficiency virus (HIV). Fungemia in these patients presented as a community-acquired infection in the setting of outpatient total parenteral nutrition or intravenous antibiotic therapy through a chronically indwelling central venous catheter (CVC). Fungemia developed only in patients with CVCs (P < .001). Non-albicans Candida species, Torulopsis glabrata, Rhodotorula rubra, and Bipolaris spicifera constituted 52% of all causes. Fungemia was detected early, within a median of 2.4 days after the onset of new fever, which permitted prompt administration of amphotericin B (mean dosage, 0.7 mg/[kg.day]; median duration, 19 days). CVCs were removed in 23 (85%) of the episodes. We conclude that fungemia in HIV-infected children often presents as a community-acquired infection, is frequently due to newly emerging opportunistic fungi, and can be managed, with a high level of success (95% survival with no posttherapeutic sequelae), by early diagnosis, prompt initiation of amphotericin B therapy, and removal of the CVC.

One year in the life of a woman with premenstrual syndrome: a case study.

Over the course of 1 year (13 menstrual cycles), data were collected on a daily basis using Likert-scale ratings of symptom presence and severity, as well as narrative journal entries. The participant was a 37-year-old healthy woman (mean cycle length = 26.7 days, SD +/- 1.8) with prospectively screened well-defined premenstrual syndrome (PMS), not on hormones or other drugs, and without a psychiatric history. Using the autocorrelation function (ACF), there was evidence for a statistically significant predictive cycle-to-cycle symptom pattern (ACF r = .49, p < .05; Bartlett Band range of significance = +/- .13). Cycle-phase-dependent coexistence of symptoms was noted, along with particular narrative themes, most dramatically exemplified by the theme of death. For this subject, the findings provided evidence for predictive symptom patterns and an effect of symptom presence on her interpretation of her environment and herself.

Clinical and pharmacokinetic evaluation of long-term therapy with didanosine in children with HIV infection.

BACKGROUND: Didanosine has demonstrated promising antiviral activity and a tolerable toxicity profile in short term studies. We describe a cohort of HIV-infected children who were treated for a prolonged period of time with didanosine. METHODS: Children (6 months to 18 years of age) with symptomatic HIV infection or an absolute CD4 count < 0.5 x 10(9) cells/L, received oral didanosine at doses between 20 mg/m2 to 180 mg/m2 every 8 hours. Clinical, immunological, and virological parameters were assessed at least every 2 months. The pharmacokinetics of didanosine were evaluated in 85 patients. RESULTS: Previously untreated children (n = 51) and children who had received prior antiretroviral therapy (n = 52) were enrolled in the study (median time on study 22.6 months; range 2 to 48). The long-term administration of didanosine was well tolerated and no new toxicities were observed. The absolute CD4 count increased by > or = .05 x 10(9) cells/L in 28 of 87 (32%) of patients after 6 months of therapy. Responses were also sustained in 41% of these children after 3 years of therapy. Children entering the study with a CD4 count > 0.1 x 10(9) cells/L (n = 51) had a marked survival advantage (P = .00002) with an estimated survival probability after 3 years of 80% compared to 39% for children with lower CD4 counts. Although the area under the curve of didanosine increased proportionally with the dose, there was considerable interpatient variability at each dose level. There was no apparent relationship between surrogate markers of clinical outcome and plasma drug concentration. CONCLUSIONS: Didanosine was well tolerated with chronic administration, and toxicities were uncommon and usually reversible. In 41% of patients, the CD4 count increased and was maintained at the higher level even after years of treatment.

Clustering of human T lymphotropic virus type I seropositive in Montserrat, West Indies: evidence for an environmental factor in transmission of the virus.

A community survey of human T cell lymphotropic virus type I (HTLV-I) in Montserrat, West Indies, identified 22 instances in which 2 HTLV-I-seropositive adults lived within 60 m of each other (close pairs), compared with 7.8 expected (P < .001). Five of these close pairs were mother-offspring or husband-wife. The remaining 17 pairs were of unrelated members in separate households. The percentages of male-female (41%), female-female (41%), and male-male (18%) types in these 17 pairs were very similar to those among the 1377 similarly defined pairs in which neither or only 1 member was seropositive, affording no support for extramarital heterosexual activity as an explanation for the clustering observed. Thus, the demography of HTLV-I was not accounted for completely by sexual and mother-to-offspring transmission. The predominance of clustering of unrelated HTLV-I-seropositive individuals in locations with high mosquito infestation raised the possibility of sporadic transmission of HTLV-I by hematophagous insects.

Using control charts to help manage accounts receivable.

The relative performance of a healthcare organization's accounts receivable (AR) department is a critical factor affecting an organization's financial well-being. Park Nicollet Medical Center (PNMC), Minneapolis, Minnesota, changed the way it measured its AR department's performance, switching from the rolling averages method of performance measurement to the percentage collected method of performance measurement, and was able to improve its patient accounts management effort.

Orally administered clarithromycin for the treatment of systemic Mycobacterium avium complex infection in children with acquired immunodeficiency syndrome.

OBJECTIVE: To determine the safety, tolerance, pharmacokinetics, and antimycobacterial activity of orally administered clarithromycin in children with acquired immunodeficiency syndrome and disseminated Mycobacterium avium complex (MAC) infection. DESIGN: Phase I study with a 10-day pharmacokinetic phase followed by a 12-week continuation therapy phase. PATIENTS: Twenty-five patients with a median age of 8.3 years were enrolled. Ten were receiving zidovudine and 13 were receiving didanosine at the time of enrollment. INTERVENTION: Clarithromycin suspension was administered to each patient at one of three dose levels: 3.75, 7.5, and 15 mg/kg per dose every 12 hours. Clarithromycin and antiretroviral pharmacokinetics were measured during single-drug and concurrent-drug administration. Clinical and laboratory monitoring was performed biweekly. MEASUREMENTS AND MAIN RESULTS: Clarithromycin was well tolerated at all dose levels. Plasma clarithromycin concentrations increased proportionately with increasing doses, and significant pharmacokinetic interactions were not observed during concurrent administration with zidovudine or didanosine. Decreases in mycobacterial load in blood were observed only at the highest clarithromycin dose level. Decreased susceptibility to clarithromycin developed rapidly (within 12 to 16 weeks) in the majority of MAC strains isolated from study patients.

Zidovudine and didanosine combination therapy in children with human immunodeficiency virus infection.

OBJECTIVE: Zidovudine and didanosine are both beneficial for the treatment of human immunodeficiency virus (HIV) infection in children. Because disease progression and toxicity often limit their long-term use as single agents, new approaches to using nucleoside analogues are necessary to improve current antiretroviral therapy. DESIGN: We conducted a phase I-II study to evaluate the tolerance, pharmacokinetics, and antiviral activity of the combination of zidovudine and didanosine in children with HIV infection. Sixty-eight children who were either previously untreated or who had manifested hematologic toxicity on full-dose zidovudine were enrolled. Eight dose combinations were studied in the previously untreated children, with doses of zidovudine ranging from 90 to 180 mg/m2 every 6 hours and doses of didanosine ranging from 90 to 180 mg/m2 every 12 hours. RESULTS: Fifty-four previously untreated HIV-infected children were enrolled in this part of the study, of whom 49 remained in the study for a minimum of 24 weeks. For children with previous zidovudine-related hematologic toxicity, three dose levels with zidovudine at 60 mg/m2 every 6 hours orally and didanosine ranging from 90 to 180 mg/m2 every 12 hours orally were used. A total of 14 children were enrolled in this part of the study, and 12 remained on therapy for at least 24 weeks. No evidence of new or enhanced toxicity was observed in either group. After 24 weeks, the median CD4 cell count for all patients increased from 331 to 556 cells/mm3 (P = .01). For the previously untreated group, the median increase in CD4 counts was from 386 to 726 cells/mm3 (P = .003). The median p24 antigen concentration (in those with a detectable level at baseline) decreased from 95 to < 31 pg/mL (p < .001). The geometric mean titer of HIV in plasma decreased from 83.1 to 2.7 tissue culture infectious doses/mL (P = .001). CONCLUSIONS: The combination of zidovudine and didanosine was well-tolerated at doses as high as those used in single agent therapy. Potent in vivo antiviral activity was observed. Combination therapy with nucleoside analogues may be an important approach to optimizing the use of these agents in the treatment of HIV infection.