Detection of astrovirus in pediatric stool samples by immunoassay and RNA probe

Two new astrovirus assays, a rapid biotin-avidin enzyme immunoassay (EIA) and RNA probe hybridization, were developed and compared with an established astrovirus assay, an indirect EIA, and immune electron microscopy. Sensitivity and specificity were evaluated by using a screening panel of 22 astrovirus-positive and 305 astrovirus-negative fecal specimens. The biotin-avidin assay was equivalent in performance to the reference indirect assay, and both could detect about 10 ng of viral protein. Although the probe was more sensitive than either EIA and could detect higher dilutions of virus in tissue culture and stool specimens, it did not detect more astrovirus-positive fecal specimens. Of the 22 astrovirus-positive specimens detected by the EIAs, 20 were confirmed by immune electron microscopy with hyperimmune rabbit antiserum. To determine the usefulness of EIAs for large epidemiologic studies, EIAs were used to screen 1,289 stool specimens from three studies of children with and without diarrhea. Astrovirus was detected in 3.5% of specimens from children with diarrhea and 1.9% of specimens from those without diarrhea. Our results indicate that the biotin-avidin EIA is an efficient, sensitive, and specific method for routinely screening large numbers of fecal samples and that its application in epidemiologic studies may yield higher rates of astrovirus infection than have been found previously by other methods.

Primary pancreatic tuberculosis

A 71-year-old man developed weight loss, nausea, and night sweats. A PPD skin test was positive; chest films were normal. Abdominal computerized tomography revealed a mass in the head of the pancreas. Laparotomy revealed a 3 cm by 5 cm multi-loculated abscess cavity. Cultures grew Mycobacterium tuberculum. The diagnostic criteria for abdominal tuberculosis include skin test positivity, localized disease, and culture verification. This is the first reported case that fulfills diagnostic criteria for primary pancreatic tuberculosis.

Astrovirus and adenovirus associated with diarrhea in children in day care settings

The relative importance of astrovirus and adenoviruses as etiologic agents of diarrhea among children in day care was examined. Stool specimens from this prospective study were screened for both astrovirus and adenovirus hexon with two new indirect double-antibody assays and for enteric adenoviruses with an EIA specific for serotypes 40 and 41. Astrovirus was detected in a significantly greater percentage of children with diarrhea (4%, 21/524) than of those without (less than 1%, 1/138) (P less than .05); however, no difference between such such children with adenovirus infections was found (8%, 43/565, and 8%, 10/129, respectively). Overall, 30% (13/43) of all adenovirus hexon-positive specimens were enteric serotypes, and by extrapolation, enteric adenoviruses were identified in an equal percentage of children (2%) with and without diarrhea. This study documents the presence of astrovirus and enteric adenoviruses among children in day care in the United States, associates astrovirus with diarrhea in this setting, and suggests that viral agents may be the most common enteric pathogens among children with diarrhea in day care.

Operative procedures not involving the heart after percutaneous transluminal coronary angioplasty

The benefit of coronary artery bypass grafting (CABG) in patients with coronary artery disease (CAD) who require extensive surgical procedures not involving the heart has been established. During the past decade, percutaneous transluminal coronary angioplasty (PTCA) has been developed as an alternative therapy to CABG for patients with CAD. In an attempt to determine the safety of other surgical procedures after PTCA, we retrospectively reviewed 148 patients who underwent 193 surgical procedures from four to 1,867 days after PTCA for CAD. Seventy-two patients had surgical treatment within 90 days of PTCA. Thirty-five patients had CABG prior to PTCA, and 113 had PTCA as the initial treatment for CAD. Four patients died postoperatively, only one death was cardiac in origin. One patient had a myocardial infarction postoperatively (the one cardiac death). Fifteen patients had other cardiac complications (nine patients with arrhythmias and six with myocardial ischemia). Patients operated upon within 90 days of PTCA had no increased cardiac morbidity, although the one myocardial infarction occurred in this group. No difference in cardiac morbidity occurred in patients with multivessel CAD treated by PTCA compared with single vessel disease. However, patients more than 60 years of age had more cardiac problems (16 of 110) than those less than 60 years of age (zero of 38) (p = 0.01). Treatment of CAD by PTCA protects the myocardium from fatal cardiac events and myocardial infarction during subsequent noncardiac operative procedures even early (less than 90 days) in the post-PTCA period. Older patients seem to be at higher risk, however, for nonfatal cardiac complications.

The costs and benefits of bone marrow transplantation

The average direct costs of performing a bone marrow transplant (BMT), including the subsequent year, was found to be NZ$27,074 for 43 consecutive transplants. In 29 BMTs a full two year period of follow up was available and a quality of life analysis was carried out on these patients. It was calculated that 59 quality adjusted life years (QALYs) had been gained by the BMT procedure at the time of analysis. By combining these two analyses the cost of each QALY gained by BMT is NZ$13,272. The relatively low cost of BMT is partly due to the extremely low annual costs in second and subsequent years post BMT. In our patients this cost amounted to $195 per year. The costs and benefits of BMT compare very favourably with other complex medical procedures.

Intranasal amphotericin B reduces the frequency of invasive aspergillosis in neutropenic patients

PURPOSE

To retrospectively study the prophylaxis of invasive aspergillosis in neutropenic patients and to relate the frequency of this fungal disease to any causal or modifying factors that could be identified.

PATIENTS AND METHODS

Between 1977 and 1988, 130 patients underwent 158 intensive treatment episodes to control acute leukemia, lymphoma, and aplastic anemia, and the frequency of complicating aspergillus infection was determined.

RESULTS

Proven invasive aspergillus infections occurred in 22 cases, 12 of which were fatal. Invasive aspergillosis was suspected in a further 16 cases and all these patients recovered with amphotericin B treatment. Colonization by Aspergillus in the absence of clinically significant infection was seen in 31 treatment episodes. Invasive aspergillosis involved mainly the upper and lower respiratory tract and skin. Control of the infection was closely related to the control of the underlying disease, with subsequent return of normal marrow function and resolution of neutropenia. The incidence of aspergillus infection has decreased dramatically since 1985, most probably due to the introduction of intranasal amphotericin B. This occurred despite the persistence of aspergillus spores in the hematology ward air during the 1986 to 1988 period.

CONCLUSION

Intranasal aerosolized amphotericin B may protect against invasive aspergillosis, even when neutropenic patients are cared for in conventional wards without HEPA filtration.

The efficiency of intestinal calcium absorption is increased in late pregnancy but not in established lactation

The fractional absorption of calcium (FA-Ca) was measured using a dual non-radioactive Ca isotope technique in 26 control women, 49 women in the last trimester (36 weeks) of pregnancy and 31 of these women in established (20 weeks) lactation. The ratio of the two non-radioactive Ca isotopes was measured, by high precision thermal ionisation mass spectrometry, in urine 12-24 hours after administration and was used to calculate FA-Ca. This is the first study to clearly show that FA-Ca is significantly elevated in late pregnancy but not in established lactation, when compared with control women.

Tick resistance in mast cell-deficient mice: histological studies

Mast cell-deficient W/Wv mice and their mast cell-sufficient +/+ genetic controls were allowed to undergo three successive infestations with Dermacentor variabilis larvae. Histological examination of the skin of infected mice revealed large dermal accumulations of eosinophils and smaller numbers of neutrophils. The numbers of both eosinophils and neutrophils increased significantly in W/Wv and +/+ mice during secondary and tertiary infestations. Mast cell numbers were also found to increase in the skin of +/+ mice during tertiary infestations. Resistance, as measured by decreased larval engorged weights on day 5 of each infestation, was acquired by both strains of mice.

Nonspecific activation of complement factor 5 by isolated Dermacentor andersoni salivary antigens

Salivary gland extracts from feeding Dermacentor andersoni ticks contain an activity that activated both rabbit and human complement to produce inflammatory cell chemotactic activity. Purified salivary antigens (SGA), isolated from the glands of female ticks with anti-saliva immunoglobulins from tick-resistant rabbits, also induced chemotactin generation. It has been demonstrated previously that the intradermal injection of such SGA into normal animals induces nonspecific inflammatory reactions that mimic the responses accompanying tick feeding on normal animals. The chemotactic activity generated in serum by SGA was mediated either directly or indirectly by C5, as it could be abrogated by antisera directed against C5 but not by anti-C3 sera. That the in vitro generation of C5 by tick salivary proteins has relevance to tick feeding is suggested by the fact that many of the host inflammatory responses elicited by ixodid tick feeding also are effects known to be elicited by C5.

Detection of group B and C rotaviruses by polymerase chain reaction

We adapted the polymerase chain reaction (PCR) to detect the noncultivatable group B and C rotaviruses and introduced a simple and convenient technique to purify viral RNA from stool specimens. Double-stranded RNA present in stool extracts was purified by adsorption to hydroxyapatite and was used as the template for reverse transcription and polymerase amplification. Primer pairs specific for group B (gene 8) and group C (gene 6) rotaviruses were selected to amplify group-characteristic sizes of cDNA copies readily identifiable in ethidium bromide-stained agarose gels. These primer pairs were used separately in individual PCR assays or were pooled with a primer pair specific for group A rotavirus (gene 9) in a combined PCR assay for the simultaneous detection of all three rotavirus groups. The method was very sensitive and was used to identify both human and porcine strains of group B and C rotaviruses in stool specimens. A second PCR amplification with internal group-specific primers served to increase further the sensitivity of the test and to confirm the diagnostic results obtained in the first amplification.

Factors V and VII anticoagulant activities in the salivary glands of feeding Dermacentor andersoni ticks

The salivary glands of Dermacentor andersoni ticks possess anticoagulant activities that can alter the clotting time of rabbit whole blood. Salivary gland extracts from female ticks inhibit both the intrinsic and extrinsic coagulation systems, and maximal activities against both pathways occur when the ticks attain about 250 mg feeding weight. These anticoagulants are directed against both coagulation factors V and VII, but they do not affect factors II or X. Despite this salivary anticoagulant activity, heavily tick-infested rabbits suffer no visible alteration of their peripheral blood coagulability and have no detectable circulating fibrin degradation products, suggesting that the ticks do not secrete a factor with fibrinolytic activity.

Nutritional assessment of children with juvenile chronic arthritis

Nutritional assessment was performed in 38 children with juvenile chronic arthritis (polyarticular [15]; pauciarticular [13]; systemic [10]). This included anthropometric measurements (height, weight, mid-upper arm circumference and four skinfolds) and a 7 day weighed food record. The children were classified according to current type of arthritis which in some cases was not the same as the initial onset type. Mean height Z scores were significantly below the Z score population mean of 0 in the systemic (P = 0.02) and polyarticular (P = 0.009) groups. Mean weight Z scores were also below the mean in the polyarticular group (P = 0.001) but the systemic group did not reach significance. Mean energy intakes were significantly below the recommended dietary intake (RDI) in the systemic (P = 0.01) and polyarticular (P = 0.001) groups. Mean intakes of calcium and zinc were below the RDI of 100% in the polyarticular group (P = 0.0001). Thirteen (34%) of children were taking some form of self-prescribed vitamin and/or mineral supplement. Vitamin C was the most commonly used supplement, despite dietary intakes greatly exceeding the RDI. Nutritional assessment is essential in the management of patients with JCA, in particular those with systemic or polyarticular disease.

Basophils in skin reactions of mast cell-deficient mice infested with Dermacentor variabilis

Acquired resistance to ticks in guinea pigs has been found to be associated with basophil-rich skin reactions. Mice, which are generally believed to possess few, if any basophils, also acquire resistance following repeated tick infestations and this has been found to be associated with increased numbers of dermal mast cells. Mast cell-deficient W/Wv mice have, however, also been shown capable of acquiring resistance after two infestations with Dermacentor variabilis larvae. In the studies described here, we have examined, with the electron microscope, skin reactions in W/Wv and +/+ mice undergoing their third infestation with Dermacentor variabilis. Basophils, along with neutrophils and eosinophils, were identified using established criteria. The possibility that basophils contribute to various pathogenetic mechanisms in these and other strains of mice is discussed.

Muscle responses of thoroughbreds to conventional race training and detraining

Ten healthy sedentary Thoroughbreds with previous race training experience were trained conventionally for 9 weeks. Muscle biopsy samples were obtained before and after training and after 6 weeks of detraining pasture rest. Biopsy samples were obtained from the right deltoid, triceps, vastus lateralis, middle gluteal, biceps femoris, and semitendinosus muscles. The deep-frozen biopsy samples were analyzed for activities of succinate dehydrogenase (SDH), 3-hydroxy-acylcoenzyme A dehydrogenase (HAD), and phosphorylase (PHOS) and for glycogen concentration. The triceps and gluteal muscle samples were also serially sectioned and stained for myofibrillar actomyosin adenosine triphosphatase (ATPase) activity after alkaline (pH 10.3) and sequential acidic (pH 4.34) ATPase inactivation. Fiber types I (alkaline preincubation), IIA1, IIA2, and IIA3 (sequential acidic preincubation over 5 minutes) were identified and were evaluated for fiber-type distribution and fiber areas. Increases in response to training were observed in deltoid and vastus muscle SDH and gluteal muscle HAD activities, and deltoid muscle glycogen concentration (P less than 0.05 to P less than 0.01). Changes in PHOS activity were not observed. Type-IIA1, -IIA2, and -IIA3 fiber areas in triceps muscle were increased in response to training (P less than 0.05 to P less than 0.01). Changes in fiber-type distribution did not occur in response to training. Changes in muscle enzyme activities, glycogen concentration, fiber types, and fiber areas were not seen from posttraining to detraining. Further increases were observed when detraining values were compared with pretraining values in deltoid, triceps, vastus, gluteal, and biceps femoris muscle SDH activities and in gluteal muscle glycogen concentration (P less than 0.05 to P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Viral agents of gastroenteritis. Public health importance and outbreak management

Each year, infectious gastroenteritis causes greater than 210,000 children in the United States to be hospitalized and 4-10 million children to die worldwide. Since the mid-1970s, knowledge has increased dramatically concerning the viral agents that are responsible for much of this public health burden. Rotavirus, the most common cause of diarrhea among children, infects virtually every child in the United States by the age of 4 years and causes potentially lethal dehydration in 0.75% of children less than 2 years of age. Other recently identified pathogens include the enteric adenoviruses, calicivirus, astrovirus, and the Norwalk family of agents. Conclusive diagnosis of these viruses requires electron microscopic examination of stool specimens, a laboratory technique that is available only at a few large centers, including CDC. Stool samples from an outbreak that are submitted to CDC for detection of viral pathology should be collected in bulk from 10 ill persons during their first 48 hours of illness, while feces are still liquid, and should be stored at 4 C (not frozen). Acute- and convalescent-phase serum samples should be collected from the same persons, plus from an equal number of controls, during the first week of illness and 3 weeks thereafter. Control measures for outbreaks of viral gastroenteritis should focus on the removal of an ongoing common source of infection (e.g., an ill food handler or the contamination of a water supply) and on the interruption of person-to-person transmission that can perpetuate an outbreak in a population after the common source has been removed. Because improvements in environmental hygiene may not be accompanied by reductions of endemic diarrhea caused by viruses, immunization may play an important role in future control; vaccine trials for rotavirus are in progress. In anticipation of vaccine development and use, CDC recently began national surveillance for the viral agents of gastroenteritis. Health-care facilities involved in the detection of rotavirus or the other viral agents of diarrhea can participate.

Human lactation: forearm trabecular bone loss, increased bone turnover, and renal conservation of calcium and inorganic phosphate with recovery of bone mass following weaning

The calcium (Ca) metabolism of established human lactation was studied in 40 adult women (mean age 32.4 years) who had been breast-feeding for 6 months (Lac) and in 40 age-matched controls (Con) using fasting urine and blood biochemistry and forearm single-photon bone mineral densitometry (BMD). Serial studies were performed up to 6 months after weaning in Lac women and repeated once in Con women. During lactation the significant findings were (1) a selective reduction (7.1%, P less than 0.03) in BMD at the ultradistal site containing 60% trabecular bone, but not at two more proximal, chiefly cortical bone sites; (2) increased bone turnover affecting bone resorption [fasting hydroxyproline excretion, Lac 2.22 +/- 0.12 mumol/liter GF (mean +/- SEM), Con 1.19 +/- 0.04, P less than 0.001] and affecting bone formation (plasma alkaline phosphatase, Lac 81.9 +/- 2.5 IU/liter, Con 53.5 +/- 2.7, P less than 0.001, and serum osteocalcin, Lac 14.0 +/- 0.7 microgram/liter, Con 7.3 +/- 0.4, P less than 0.001); and (3) renal conservation in the fasting state of both Ca and inorganic phosphate (Pi) with a resultant moderate increase in plasma Pi but not in plasma Ca (total or ionized). There were no differences between the groups in serum parathyroid hormone (PTH, intact and midmolecule assays), 25-hydroxy- and 1,25-dihydroxyvitamin D, nephrogenous cyclic AMP production, or plasma creatinine.(ABSTRACT TRUNCATED AT 250 WORDS)

Intraabdominal surgery during pregnancy

Intraabdominal surgical disease during pregnancy can present a challenge in diagnosis and management for the obstetrician and surgeon. To examine the complications to the fetus and mother and the consequences of a delay in operative intervention, we retrospectively studied all pregnant patients over a 17-year period who had undergone abdominal surgery at one institution. A total of 92 abdominal operations were performed on 90 patients. During the same period, 41,532 deliveries occurred. One in 451 deliveries involved surgical procedures during pregnancy. Thirty-seven patients had surgery for acute appendicitis; 20 patients were operated on for ovarian abnormalities. Postoperatively, there were two maternal deaths: one from cardiac arrhythmia and the other from hepatic failure. The most common postoperative complication was premature labor (19 patients, 21 percent). In 16 of these patients, early tocolysis was begun without fetal loss. There were five fetal deaths. Forty-seven of 72 patients had term deliveries. Intraabdominal surgery during pregnancy carries an acceptable risk to the mother and fetus; complications are related to disease severity and operative delay rather than to the operative procedure itself.

The natural history of transfusion-associated infection with human immunodeficiency virus. Factors influencing the rate of progression to disease

Patients infected by the human immunodeficiency virus (HIV) as a result of blood transfusions are unique in that their dates of infection are well defined and their medical conditions before infection are known. To characterize the natural history of transfusion-associated HIV infection, we studied 694 recipients of blood from 112 donors in whom AIDS later developed and from 31 donors later found to be positive for HIV antibody. Of the recipients tested, 85 were seronegative, 116 were seropositive, and 19 had AIDS. Of 101 HIV-seropositive recipients followed for a median of 55 months after infection, 54 had Centers for Disease Control Class IV disease, including 43 with AIDS. Life-table analysis suggested that AIDS will develop in 49 percent of infected recipients (95 percent confidence limits, 36 to 62 percent) within seven years after infection. As compared with recipients without AIDS, the 43 recipients with AIDS had received more transfusions at the time of infection (median, 21 vs. 7; P = 0.01). HIV-infected blood donors in whom AIDS developed were grouped according to whether AIDS developed within 29 months (the median) after donation (Group 1) or 29 or more months after donation (Group 2). As compared with the 31 recipients of blood from Group 2 blood donors, the 31 recipients of blood from Group 1 donors were more likely to have AIDS four years after infection (49 percent vs. 4 percent; P = 0.005) and illnesses resembling acute retroviral syndrome (14 of 24 vs. 5 of 22; P = 0.03). We conclude that most recipients of HIV-infected blood become seropositive, that AIDS develops in about half these recipients within seven years, and that the risk may be higher when AIDS develops in the blood donor soon after donation.

Are herbal teas safe for infants and children?

The use of herbal teas is now widespread in our community--even among children. The effect of dosing children with these products is unknown. The authors feel that the potential hazards associated with herbal teas need to be exposed.

Maternal weight gain, smoking and other factors in pregnancy as predictors of infant birth-weight in Sydney women

Two hundred and four (204) women attending a Sydney maternity hospital and their babies were followed throughout pregnancy in a study, which aimed: 1) to describe the distribution of maternal weight gain in present day Australian women and 2) to determine the effect of weight gain and other factors on birth-weight. Maternal weights and skinfold thicknesses were measured serially to give an indication of weight gain. Mean weight gain from conception to term was 14.2kg and mean birth-weight was 3,442g. Maternal predictors of birth-weight such as maternal weight gain, parity, age, education, height, public or private booking status, smoking, prepregnancy weight, and sex of the infant and gestational age were explored using simple and multiple regression analysis. Weight gain was predictive of birth-weight, each kg increase in total weight gain resulting in about a 30g increase in birthweight. Other strong predictors were gestational age, maternal smoking, sex of the infant and maternal parity. Maternal height was less strongly predictive and age and prepregnant weight were not predictive. Smoking mothers had infants who were 268g lighter than those of nonsmoking mothers. However, smokers were also younger, shorter, had less education and were more likely to book as public patients than nonsmokers. After adjusting for all other predictors, the birth-weight of infants whose mothers smoked, was still 224g less than that for nonsmoking mothers.

Trypanosoma theileri associated with T-lymphocytes isolated from a latently infected cow

Trypanosoma theileri infection, latent in a mature Hereford cow, could not be demonstrated in routine blood smears or cultures. Throughout the 2-year period an intravenous injection of dexamethasone consistently produced parasitaemia which was detectable in peripheral blood mononuclear cell (PBMC) cultures. Fractionation techniques such as plastic adherence and Sephadex-G10 fractionation, designed to deplete monocytes and enrich T-lymphocytes, increased trypanosome-positive cultures from 25 to 100%. Removal of B-lymphocytes from Sephadex, non-adherent (SE-NA) cells did not reduce the percentage of positive cultures. Light and transmission electron microscopy of SE-NA PBMC cultured for 36 or 45 h revealed numerous trypanosomes and widespread T-lymphocyte destruction. No trypanosomes were observed in 12-h cultures. A close association, either extra- or intracellular, of a parasitic stage of T. theileri with T-lymphocytes is inferred.

Immunocytochemical identification of bovine Langerhans cells by use of a monoclonal antibody directed against class II MHC antigens

We undertook a study to develop a reliable light microscopic technique for identifying Langerhans cells (LC) in bovine epidermis. Monoclonal antibodies (MCA) detecting bovine class II MHC antigens were used in conjunction with an avidin-biotin-peroxidase complex (ABC) immunocytochemical staining method. The specificity of the MCA for LC was confirmed ultrastructurally by use of gold-labeled second antibody. Epidermal sheets and epidermal single-cell suspensions examined by light microscopy confirm that bovine epidermal LC express class II antigens. Anti-bovine class II MCA is a dependable reagent for identification of LC in normal bovine epidermis.

Prevention of AIDS and HIV infection: needs and priorities for epidemiologic research

By the end of 1987, almost 50,000 cases of acquired immunodeficiency syndrome (AIDS) will have been reported in the United States. Although the primary epidemiology of the disease has been described, much work remains to be done to complete our understanding of the dynamics of transmission and infection with the causative virus, human immunodeficiency virus (HIV). At the state and local level, the highest priorities for epidemiologic research are to understand better the precise populations at risk of prevalent and incident HIV infection, and to use this information to direct and monitor specific prevention programs that are likely to be effective for the populations at risk. These parallel efforts-sophisticated investigative epidemiologic research and applied epidemiologic and serosurveillance studies-must be expanded rapidly and continued for the forseeable future if we are to accomplish the goal of preventing further spread of HIV.