A validated method for quantifying macrovesicular hepatic steatosis in chronic hepatitis C

Hepatic steatosis is increasingly seen as an important prognostic factor in chronic hepatitis C infection (HCV). The commonly used semiquantitative method of measuring steatosis is based on a study that excluded patients with HCV. Several potentially useful methods of quantifying steatosis using computer-assisted morphometric analysis have been proposed, but none has been validated against a proposed gold standard other than the method they were intended to replace. We present a novel method and propose a gold standard based on manual measurements. The manual method is time consuming but shows little interobserver error, and the mean value of 3 observations by separate investigators is proposed as the gold standard. The computer-assisted method is fast, with a single interactive step that shows minimal interobserver variation. It accurately identifies biopsies with <1% steatosis (7 of 7) and predicts the gold standard value for biopsies with > 1% steatosis with narrow CIs (geometric mean ratio 0.85 with 95% CIs 0.77-0.95). This novel method of computer-assisted morphometric analysis is fast, reliable, and suitable for future research in HCV steatosis. It may be used to reanalyze previous studies. The semiquantitative method of assessing steatosis remains appropriate for clinical purposes.

Review article: the use of biotherapeutic agents in the prevention and treatment of gastrointestinal disease

There is presently a lack of well conducted clinical trials demonstrating any significant benefits of probiotics in humans. With the exception of diarrhoea due to rotavirus infection in children there is little evidence from randomized, double-blind, placebo-controlled studies that bacterial probiotics have a significant beneficial action in preventing diarrhoea of any cause. The yeast Saccharomyces boulardii has been shown to be of benefit in the prevention of antibiotic-associated diarrhoea but not in preventing infection with Clostridium difficile. S. boulardii may also be of benefit in preventing relapse of C. difficile infection. Because of the simplicity of in vitro systems and some animal models, beneficial characteristics of probiotics such as the ability of bacteria to bind to epithelial surfaces are not always transferable to humans. Thus any postulated benefit from consumption of probiotic bacteria should only be accepted as fact after testing in clinical studies. This review outlines our present knowledge of the mode of action of probiotics and presents the data from clinical trials on their use.

Massive hepatosplenomegaly, jaundice and pancytopenia in miliary tuberculosis

A 29-year-old Caucasian woman presented to hospital with a 2-day history of diarrhoea, anorexia and rigors. Investigations showed abnormal liver function tests, hyponatremia, hypoalbuminaemia and lymphopenia. The initial chest radiograph was normal. A bone marrow trephine biopsy showed non-caseating granulomata and she subsequently developed miliary shadowing on the chest radiograph. A transjugular liver biopsy confirmed the presence of acid-alcohol fast bacilli. Despite starting triple therapy for miliary tuberculosis she remained febrile and developed massive hepatosplenomegaly, jaundice and pancytopenia. Standard triple therapy was substituted with ethambutol, streptomycin and oral prednisolone and the patient made a dramatic recovery. The clinical symptoms of miliary tuberculosis are frequently non-specific and the onset of the illness is often insidious. The liver is involved in almost all patients with miliary tuberculosis, but massive hepatosplenomegaly and jaundice are rare. Standard triple-therapy should be discontinued when there is significant liver dysfunction, and corticosteroids should be considered for patients with miliary tuberculosis who fail to respond to conventional therapy.

Human immunodeficiency virus infection impairs hemopoiesis in long-term bone marrow cultures: nonreversal by nucleoside analogues

Hematologic abnormalities are often seen in patients infected with human immunodeficiency virus (HIV). The effect of HIV infection of bone marrow stroma on support of uninfected CD34 progenitor cells in long-term bone marrow culture (LTBMC) was investigated. Results show that HIV-infected bone marrow stroma was unable to adequately support CD34 progenitor cells in vitro. Zidovudine or didanosine was added to cultures in an attempt to reverse the suppressive effects exerted by HIV and to determine whether such suppression was mediated by transfer of HIV infection to progenitor cells. Didanosine failed to reduce the suppressive effects of HIV, whereas zidovudine compounded the observed suppression. HIV infection of bone marrow stroma, while reducing the production of nonadherent cells, did not increase apoptosis and cell death in such cells. In contrast, zidovudine enhanced apoptosis and cell death in nonadherent cells produced by both HIV-infected and control LTBMC.

Differential effects of interleukin-13 on cytomegalovirus and human immunodeficiency virus infection in human alveolar macrophages

Alveolar macrophages, which form a principal line of defense against a variety of pulmonary pathogens, may themselves be infected by viruses like human immunodeficiency virus-1 (HIV-1), which impair their defensive functions. Interleukin-13 (IL-13), a multifunctional cytokine, has been considered for therapeutic use based on its potent inhibition of HIV-1 in these cells. We have further examined the effects of IL-13 on alveolar macrophages under conditions that reflect those seen in acquired immune deficiency syndrome, where this cell type is often infected by the opportunistic pathogen human cytomegalovirus (HCMV). Alveolar macrophages exposed to both HCMV and HIV-1 consistently exhibited higher levels of HIV-1 replication than cells exposed to HIV-1 alone. HIV-1 production was strongly suppressed in alveolar macrophages treated with IL-13 regardless of whether or not the cultures were coinfected with HCMV. However, IL-13 treatment markedly enhanced the expression of HCMV in otherwise latently infected macrophages in a dose dependent manner. These unexpected differential effects of IL-13 on host-virus interactions are important considerations in guiding its potential therapeutic applications.

Generation of human T lymphocytes from bone marrow CD34+ cells in vitro

Analysis of the events that regulate development of red blood cells or granulocytes has led to therapies altering clinical conditions associated with anemia or neutropenia. The development of therapeutic approaches to target conditions associated with lymphopenia, such as AIDS, has been thwarted by limited techniques for studying T-lymphocyte development. We describe an in vitro system in which human bone marrow CD34+ cells proliferate, acquire the expression of the lymphoid-specific RAG-2 gene and a broad repertoire of rearranged T-cell receptor genes, develop the ability to produce T cell-specific interleukin-2 and achieve a range of T-cell immunophenotypes. The cells also become susceptible to infection with the T-lymphotropic strain of human immunodeficiency virus-1, HIV-1IIIB. This culture system induces human T lymphopoiesis and may permit further analysis of the events regulating human T-lineage differentiation. It provides a preclinical model for screening stem cell gene therapies directed toward AIDS.

Adjuvant itraconazole in the treatment of destructive sphenoid aspergillosis

Paranasal aspergillosis is a potentially progressive continuum of disease, classically described as having four forms: allergic, non-invasive, invasive, and fulminant. The first two have been considered together as extramucosal disease whilst the latter two are both variants of tissue-invasive disease. Sphenoid aspergillosis, given its anatomical location is a more aggressive disease than that found affecting the other paranasal sinuses, even when non-invasive, and may be fatal. This is compounded by the fact that diagnosis is difficult and so may be made late when aspergillosis is consequently more advanced. Intracranial extension may occur via the direct spread of invasive disease or along communicating veins despite intact sinus walls and lack of fungal mucosal penetration. Once this occurs mortality is high. We have successfully treated three cases of destructive sphenoid aspergillosis, two of which had intracranial extension, with surgery and adjuvant anti-fungal chemotherapy including itraconazole. We recommend the use of post-operative itraconazole in all cases of sphenoid sinus aspergillosis. Additionally, when there is evidence of spread to the brain or other adjacent structures we would advocate an initial course of intravenous amphotericin B followed by long-term oral itraconazole.

Tuberculous bronchoesophageal fistulae in patients infected with the human immunodeficiency virus: three case reports and review

To our knowledge, < 30 patients with tuberculous bronchoesophageal fistulae have been described in the English-language literature. However, the overall incidence of infection due to Mycobacterium tuberculosis has been increasing during the epidemic of human immunodeficiency virus (HIV) infection. We describe three HIV-infected patients who presented with tuberculous esophagomediastinal fistulae during their initial illness. Fistulous connections appeared to be secondary to mycobacterial mediastinal adenopathy. All fistulae healed with antituberculous therapy and nasogastric feeding, and surgical intervention was not necessary. The combination of mediastinal lymphadenopathy, cough, and retching or vomiting should alert clinicians treating HIV-infected patients to the possibility of tuberculous bronchoesophageal fistulae.

Viral activity in early HIV disease

The commonly accepted paradigm for the natural history of HIV disease has been an acute burst of virus replication followed by years of viral quiescence. A terminal phase of virus activity is accompanied by gradual immunologic failure. Recent studies of the tissue localization of HIV and developments in virus quantitation have prompted a revision of this model. Viral latency has been shown to be only a relative concept by the demonstration of virus accumulation in tissue sites during early disease and quantifiable circulating levels of virus throughout the course of HIV infection. The primacy of HIV infection in AIDS has been further reaffirmed by these studies, but new questions as to its pathogenic effects have been raised.

Diffuse tuberculous parotitis

Parenchymatous parotid tuberculosis diffusely affecting the entire gland is very rare. We present a case, associated with a primary pulmonary focus, that was confirmed after positive identification of alcohol and acid-fast bacilli in gastric washings. Both sites of infection resolved with quadruple anti-tuberculous chemotherapy.

Cellular distribution of nuclear factor kappa B binding activity in rat liver

The cellular localization of nuclear factor kappa B (NF-kappa B) binding activity in rat liver has been investigated using electrophoretic mobility shift assay on extracts of highly purified hepatocytes and Kupffer cells obtained from liver perfused in vivo with collagenase. Constitutive NF-kappa B binding activity was demonstrated in nuclear extracts of control Kupffer cells, and this was not apparently influenced by injection of lipopolysaccharide (LPS) into rats 24 h before perfusion. In contrast, little nuclear NF-kappa B binding activity was present in hepatocytes from control animals, although there was detectable inactive, inhibitor-bound, NF-kappa B in the cytoplasm. However, nuclear NF-kappa B binding activity was increased in hepatocytes from LPS-treated animals and after in vitro culture of control rat hepatocytes. Thus NF-kappa B binding activity has been demonstrated in highly purified hepatocytes and appears to be inducible both in vivo and in vitro. These findings support a role for NF-kappa B in hepatocyte gene regulation which may be important in the modulation of the hepatic acute phase response.

Giardia lamblia as an intestinal pathogen

Giardia lamblia are protozoan parasites which cause human intestinal disease. The life cycle has a multiplying intraduodenal trophozoite and an excreted cyst. Infection occurs after cyst ingestion from faecally contaminated water or by direct faecal-oral transmission in situations of poor sanitary standards, but the zoonotic nature of giardiasis is debated. The pathophysiology may arise from enzyme or active transport deficiencies, synergy with intestinal bacteria or an immunopathological process. Diagnosis is made by microscopic identification of cysts or trophozoites in small bowel samples or faeces. Symptoms are acute with diarrhoea (without blood), abdominal cramps, bloating and flatulence. The treatment of choice is either metronidazole or tinidazole. No vaccine or drug prophylaxis exists, and measures to avoid cyst ingestion should be undertaken.

Human immunodeficiency virus infection of eosinophils in human bone marrow cultures

Normal human bone marrow, cultured in vitro with interleukin 5 to promote eosinophil production and maturation, was inoculated with cell-free isolates of human immunodeficiency virus type 1 (HIV-1). CD4 expression by eosinophil precursors, determined by immunocytochemistry, was found to be greatest early in their maturation with a rapid decline after 28 d in culture. Productive HIV infection of eosinophil precursors was detected 14 d after inoculation, by a combination of immunostaining for HIV-1 p24 and gp41/160 and in situ hybridization for viral RNA, together with assay of culture supernatants for p24 antigen and reverse transcriptase activity. Thus, eosinophils are susceptible to productive HIV-1 infection in vitro and may be an important reservoir for the virus in vivo.

Detection and estimation of the barley prolamin content of beer and malt to assess their suitability for patients with coeliac disease

Malt, lager, brown ale, bitter and stout were assessed for their barley prolamin (hordein) content. Monoclonal antibody immunoperoxidase staining of electrophoretically separated samples of beer revealed the presence of immunoreactive hordein. Polyclonal antibody based enzyme linked immunosorbant assays (ELISAs) revealed 1.6 mg of hordein per gram of malt and 1.5 mg per pint in the beers. Patients with coeliac disease should avoid ingestion of beer and foods that contain malt since they contain quantifiable amounts of hordein that is known to exacerbate the condition.

Q fever encephalitis

Encephalitis is a rare but documented complication of acute Q fever. We report here the case of a 48-year-old lady who presented with an acute illness characterised by influenza-like symptoms, pneumonia and neurological disturbance but in whom the serology was suggestive of chronic rather than acute Q fever.

The production and characterisation of monoclonal antibodies to wheat gliadin peptides

BALB/c mice maintained on a gluten-free diet were immunised with Frazer's Fraction III (FFIII, a peptic tryptic digest of wheat gluten that exacerbates coeliac disease) in order to overcome oral tolerance. A control group was maintained on normal diet. Serum antibody titres to FFIII were higher in the mice on a gluten-free diet (P less than 0.05). Three monoclonal antibodies to FFIII were produced from splenocytes obtained from mice maintained on a gluten-free diet. The antibodies were characterised by ELISA, immunodot assay and immunoblotting with prolamins from cereals toxic to coeliac patients (wheat, rye, barley, oats) and the non-toxic prolamins from maize and rice. The binding characteristics of the three antibodies to the cereal prolamins were different, implying that the antibodies recognise different cereal protein epitopes. Immunoblotting revealed FFIII to be comprised of antigenically dissimilar peptides.

Gliadin antibody production by small intestinal lymphocytes from patients with coeliac disease

Small intestinal lymphocytes (SIL) were isolated from jejunal biopsies from 9 non-coeliac controls, 6 treated and 5 untreated coeliac patients. Six-day cell culture supernatants were assayed for total IgG, IgM and IgA and specific anti-casein and anti-gliadin antibodies by ELISA. SIL from the untreated patients secreted more total IgM and IgA than SIL from the treated patients and more total IgG, IgM and IgA than SIL from the controls. The untreated patients' cells secreted more specific anti-gliadin IgA than those from the treated patients and more anti-gliadin IgG, IgM and IgA than the controls. SIL from the untreated group released more anti-casein IgM than those from either the treated or control groups. There were no differences in total immunoglobulin, or specific anti-casein or anti-gliadin antibody secretion by SIL from the treated and control groups. Comparison of immunoglobulin release from cells lysed prior to culture and that secreted both after 30-min and 6-day cultures showed that the majority of immunoglobulin had been synthesised in vitro and could not be accounted for by carry-over.

Early biochemical responses of the small intestine of coeliac patients to wheat gluten

The pathogenesis of coeliac disease has been investigated by studying the response of small intestinal hydrolases in patients with coeliac disease subject to gluten challenge. Small intestinal biopsies taken before and two and a half hours after a gluten challenge in five patients with coeliac disease who had been maintained on a gluten free diet were examined by a combination of electron and light microscopy, organ culture, pulse chase biosynthetic labelling, SDS-PAGE and autoradiography. Before the challenge, the small intestinal biopsies showed nearly normal morphology. Two and a half hours after the challenge there was deterioration in villus architecture, distortion of microvillus structure, disorganisation of the intermicrovillus pit region, an increase in lysosome like bodies in the apical cytoplasm of the luminal enterocytes and pronounced hypertrophy of the rough endoplasmic reticulum of these cells. SDS-PAGE of small intestinal biopsies from four treated coeliac patients before gluten challenge revealed normal microvillus membrane and hydrolase composition. There was a generalised reduction but no specific alteration in the pattern of polypeptide synthesis in the mucosa of the small intestine in these subjects two and a half hours after the gluten challenge. These results suggest that the generalised reduction in small intestinal brush border enzymes in coeliac patients is not the primary pathogenetic mechanism and represents a secondary effect.

Hysteresis of the ventricular paced QT interval in response to abrupt changes in pacing rate

The rate of QT adaptation to abrupt changes in pacing rate was studied in seven patients with newly diagnosed complete heart block with a ventricular escape rate of less than 40 beats.min-1. Their median age was 70 (range 36-84) years, and none was taking any cardioactive medication known to affect the QT interval. From a baseline pacing rate of 50 or 110 beats.min-1 the ventricular rate was increased or decreased to a new level. The time taken for the ventricular paced QT interval to complete 90% of the change secondary to the change in rate was found to be 136(16) s (mean(SEM] when the rate was increasing and 189(25) s when the rate was decreasing (p less than 0.01). This time interval was independent of the magnitude of the rate change and the baseline heart rate from which the change occurred. Furthermore, the time course of QT adaptation was found to be exponential and was characterised by a time constant of 49.1(2.2) s when the rate was increasing and 60.4(2.0) s when the rate was decreasing (p less than 0.01). It is concluded that QT measurements in response to a change in pacing rate should take into account the time dependent nature of QT changes.

Western immunoblotting of cereal proteins with monoclonal antibodies to wheat gliadin to investigate coeliac disease

Western immunoblotting was used to investigate the binding of two monoclonal antibodies raised against unfractionated wheat gliadin to different cereal protein fractions separated by SDS-PAGE. Our results confirm the presence of considerable epitope sharing between the gliadin subfractions as well as barley and rye prolamins; however, there was less binding of these antibodies to bands present in oat avenins and maize zeins. The pattern of binding of one of these two antibodies to different cereal prolamins as well as to Frazer's fraction III corresponds closely to the known toxicity of these proteins to patients with coeliac disease.

Detection of wheat gliadin contamination of gluten-free foods by a monoclonal antibody dot immunobinding assay

Unfractionated wheat gliadin was used to produce murine monoclonal antibodies to gliadin. A dot immunobinding assay, using these antibodies, was developed to detect possible gliadin contamination of nominally gluten-free flour, using dilute ethanol extracts spotted onto nitrocellulose membranes. The sensitivity of the assay was less than 10 micrograms/ml of unfractionated gliadin which permitted the detection of trace amounts of gliadin present in certain wheat starch based 'gluten-free' products. The assay detected not only wheat gliadin, but also prolamine extracts of rye, barley and oats; maize, soya and potato extracts as well as the control proteins casein and ovalbumin, gave negative results. The assay is of value as a simple and rapid method of screening foods for their suitability for consumption by patients with coeliac disease.

Timing of infiltration of T lymphocytes induced by gluten into the small intestine in coeliac disease

Jejunal biopsy was performed on control subjects and patients with treated and untreated coeliac disease. Monoclonal antibodies to T lymphocyte surface markers were used to quantify T cell phenotypic subsets in the jejunal mucosa. The patients with untreated coeliac disease had significantly more of both suppressor/cytotoxic and helper/inducer T cells in the surface epithelium than either the control subjects or the treated patients. Serial jejunal biopsy specimens were taken from five treated coeliac patients for six hours after a gluten challenge. In four of these five infiltration of the surface epithelium by both T cell phenotypes, together with deterioration in the villus architecture, had occurred both within two hours of having started the challenge. This suggests that T lymphocytes may have a role in the pathogenesis of coeliac disease.

Monoclonal antibody ELISA to quantitate wheat gliadin contamination of gluten-free foods

A sensitive reproducible monoclonal antibody-based sandwich ELISA has been developed to measure the gliadin content of foods. Using the assay we have confirmed that nominally gluten-free products based on wheat starch contain trace amounts of gliadin. The level of gliadin contamination in these foods is sufficient to cause relapse of coeliac disease in specific patients. We have also examined the cross-reactivity of different cereal proteins in the assay and found good correlation with their known toxicity to patients with coeliac disease.

Energy requirements of the respiratory musculature in asthma

Oxygen consumption and carbon dioxide production were measured in 29 asthmatic subjects. Minute ventilation was measured by a rib cage and abdomen-diaphragm displacement method. Expired gases were collected via a tight-fitting mask. Minute ventilation, oxygen consumption, and carbon dioxide production all increased when subjects inspired room air via a mouthpiece (when compared with a tight-fitting mask). By contrast, minute ventilation and carbon dioxide production both decreased when supplementary oxygen replaced room air via the tight-fitting mask (p less than 0.001). No consistent changes in either inspiratory work (estimated from measurement of pleural pressure during quiet breathing), airway resistance, or physiologic dead space could be seen to accompany changes in minute ventilation. It is concluded that the oxygen cost of breathing in asthma is substantial.

Minute ventilation in asthma. Enhancement by mouthpiece and depression by oxygen administration

To evaluate independently the effects of an inspiratory stimulus (a mouthpiece) and a ventilatory depressant (oxygen) on minute ventilation (VE) in asthma, we measured VE with magnetometers in 18 asthmatic subjects. When room air was inspired from a loose-fitting mask, VE was 10.2 +/- 0.6 L/min. When oxygen was substituted for room air, VE decreased (8.4 +/- 0.6). In contrast, when oxygen was given by mouthpiece, VE increased (12.9 +/- 0.7). We conclude that in the clinical setting, the mouthpiece artifact may operate either to exaggerate the tidal breath or to obscure the effect of a respiratory depressant (e.g., oxygen) upon the measurement of resting ventilation.

Primate mesenteric blood flow. Effects of vasopressin and its route of delivery

The effects of vasopressin on blood flow in the superior mesenteric artery and on mean arterial pressure and portal venous pressure were measured in 7 rhesus monkeys. Vasopressin was injected, as either a bolus, or infused both intravenously and intraarterially to assess the influence of the route of administration upon hemodynamic responses. Dose-dependent decreases in superior mesenteric arterial flow were observed during both intraarterial and intravenous injections of vasopressin. No statistically significant differences between the two routes of administration, the decrease in flow, and changes in pressure were observed. Based upon these observations, one might anticipate that intravenously administered vasopressin will be as effective as intraarterially administered vasopressin in reducing mesenteric blood flow, and thus portal venous pressure, in man.

An analysis of contemporary prescribing habits. A comparison between a pediatric group and a military physician

Physicians in practice try in many ways to keep up with the rapidly expanding body of pediatric knowledge. We read the current literature to learn what researchers all over the world are doing. We attend national conferences, meeting colleagues from all parts of the United States. We attend lectures and staff conferences at local teaching hospitals and medical societies, to confer with and to listen to other physicians to whom we at times may refer patients.

Thus, we keep abreast in a general way of what may be termed the principles of prac tice in all parts of the world; but do we know anything at all about what's going on in the office down the street, the one around the corner or in any other office similar to ours in communities much like ours? How do our colleagues in practice handle certain prob lems ? Do they see the same kind of patients that we do? Are we prescribing too many antibiotics? Are we going overboard with drugs?

Clinical Pediatrics, a journal specifically oriented toward men and women engaged in the private practice type care of children, shares this curiosity. Articles about private practice are frequently featured. The following solicited study is an example.

R. G. Arnhold and Alan R. Freedman have individually contributed analytic articles in the past two years about their clinical observations.1 Inasmuch as prescription writ ing by doctors is a topic of perennial interest, Clinical Pediatrics asked these pediatricians at opposite ends of the country to survey and prepare a comparison of their prescription writing habits. This article presents a revealing synthesis of both sets of data.—Editor.