A probe for specimen magnetic resonance microscopy

One of the primary limits to spatial resolution in magnetic resonance (MR) microscopy is the limited signal. The purpose of this study is to build a radiofrequency (rf) probe for MR microscopy of fixed specimens at 300 MHz. The design criteria for the probe were (1) high sensitivity; (2) good rf homogeneity; (3) minimization of BO variations. All probes were Helmholtz pairs operating at 300 MHz. Coils were constructed from copper/Teflon/copper microwave substrate which eliminated susceptibility problems from solder and discrete capacitors. Signal-to-noise ratio (SNR) was compared with a conventional solenoid. Phantoms of agar gels and saline-filled tubes were used to characterize the SNR and homogeneity. SNR measurements of the coil pairs showed a marked improvement (up to 60%) over that of the reference solenoid. The region of homogeneity was defined as a 10% variation in signal intensity. This correlated with the coil's inner diameter. Graphs of SNR versus diameter, separation, and copper foil width allowed for optimization of the structure. Using this coil, MR microscopy is now possible on small, fixed specimens with pixels as small as 20 x 20 x 30 microns. Work is currently under way exploiting the SNR and homogeneity provided by this probe to determine the degree to which MR microscopy might add to the pathologists' diagnostic tools.

Human keratinocytes produce but do not process pro-interleukin-1 (IL-1) beta. Different strategies of IL-1 production and processing in monocytes and keratinocytes

Keratinocytes comprise the majority of cells in the epidermis, the interleukin-1 rich layer of tissue contiguous with the outside world. Keratinocytes produce IL-1 alpha and beta mRNA in vitro, but only IL-1 alpha biological activity has been identified in keratinocyte cultures. In contrast, monocytes secrete biological activities attributable to both species of IL-1. Using several monoclonal antibodies to IL-1 beta, significant amounts of IL-1 beta protein could be found in keratinocyte cultures; all of this immunoreactive IL-1 beta was in the 31-kD form. This latent cytokine has been shown to bind inefficiently to the IL-1 receptor and to be (in relative terms) biologically inactive. Chymotrypsin cleaves 31-kD IL-1 beta at Tyr 113-Val 114, generating an 18-kD IL-1 species with activity equivalent to the authentic mature IL-1 beta (NH2-terminal Ala 117). Treatment of 31-kD keratinocyte IL-1 beta with chymotrypsin also generated an 18-kD molecule and significant IL-1 activity. Monocytes contain an IL-1 convertase enzyme that cleaves the IL-1 beta promolecule at Ala 117. We demonstrate here that keratinocytes do not contain such an IL-1 convertase activity, nor do they contain any activity capable of productively processing 31-kD IL-1 beta into a biologically active form. These data suggest that keratinocytes (and other non-bone marrow-derived cells) produce IL-1 beta in an inactive form that can be processed only after leaving the cell.

Effects of indomethacin on prostaglandin E2 and thromboxane B2 contents of tracheal lavage fluids in premature infants

A prospective longitudinal study was conducted in 14 premature infants intubated and receiving ventilatory support from birth, in order to evaluate the levels of prostaglandins E2 (PGE2) and thromboxane B2 (TxB2) in the tracheal lavage fluids (TLF) after treatment with indomethacin. Eight were treated with indomethacin, a cyclooxygenase inhibitor, for patient ductus arteriosus and the others served as controls. Infants who received indomethacin during the first postnatal week had significantly lower levels of eicosanoids in TLF during the first week. Our results suggest that levels of eicosanoids in TLF of premature infants are related to an inflammatory reaction and may serve as an index of the infant's overall clinical condition.

Peri-operative colonoscopy detects synchronous tumours in patients with colorectal cancers

The aim of this study was to assess the value of colonoscopy as a peri-operative investigation in patients treated for colorectal cancer by surgical excision. Patients (134 male, 83 female) undergoing curative resection for colorectal carcinoma between August 1984 and January 1989 had colonoscopy within 3 months of surgery. Eleven patients (5%) had a synchronous cancer, which was diagnosed by colonoscopy in eight. In six of these eight, the diagnosis was made after surgery and 3 patients needed a second colectomy. However, in 3 patients the synchronous cancer was removed endoscopically without the need for further surgical resection. Most synchronous cancers had an earlier pathological stage than the index tumour. The rate of synchronous cancers was higher in patients with synchronous benign polyps (16%) than in those without polyps (3%). Colonoscopy is clearly justified as a peri-operative investigation in all patients undergoing potentially curative resection of colorectal cancer. If possible, the examination should be carried out prior to surgery, to guide the extent of resection.

Breast-feeding and diarrheal morbidity

This study used a unique longitudinal survey of more than 3000 mother-infant pairs observed from pregnancy through infancy. The sample is representative of infants from the Cebu region of the Philippines. The sequencing of breast-feeding and diarrheal morbidity events was carefully examined in a longitudinal analysis which allowed for the examination of age-specific effects of feeding patterns. Because the work controlled for a wide range of environmental causes of diarrhea, the results can be generalized to other populations with some confidence. The addition to the breast-milk diet of even water, teas, and other nonnutritive liquids doubled or tripled the likelihood of diarrhea. Supplementation of breast-feeding with additional nutritive foods or liquids further increased significantly the risk of diarrhea; most benefits of breast-feeding alone or in combination with nutritive foods/liquids became small during the second half of infancy. Benefits of breast-feeding were slightly greater in urban environments.

Epidemiological Observations on the Helminth Parasites of Macropus Giganteus Shaw in Victoria

An epidemiological study of the nematode parasites of the eastern grey kangaroo (M. giganteus) was made in an enclosed reserve north of Melbourne, Victoria, Australia. Adult and juvenile kangaroos were collected at approximately 6-weekly intervals and blood, faeces and the entire gastrointestinal tract was obtained. The nematodes present were Globocephaloides trifidospicularis, Rugopharynx australis, R. rosemariae, Pharyngostrongylus kappa, Cloacina spp., Strongyloides sp., Macropostrongylus baylisi, Paramacropostrongylus toraliformis, Alocostoma clelandi, Labiostrongylus spp., Macroponema comani and Macropoxyuris. The majority of nematodes had a seasonal fluctuation. Acquisition commenced in late summer and reached a peak in midwinter before declining in spring. G. trifidospicularis caused considerable mortality in juvenile kangaroos and there was a strong relationship between rising numbers of this species and falling plasma protein, haemoglobin concentration and haematocrit values. This species can cause heavy mortality in juvenile kangaroos in enclosed populations when winter feed is depleted and when the small animals with no fat reserves experience maximum cold stress. Other parasites present included Progamotaenia ewersi, P. festiva, P. macropodis, Triplotaenia fimbriata, T. undosa, Eimeria wilcanniensis, E. macropodis, E. hestermani and E. marsupialum.

Somatic growth in infants receiving prolonged caffeine therapy

We have evaluated the longitudinal growth of 28 premature infants who had been treated by prolonged caffeine therapy (mean: 23.8 weeks). Routine follow-up included at least 5 physical examinations with measurement of length, weight and head circumference at the beginning of caffeine therapy, at mid therapy, at the end of the therapy and at 3 and 6 months after therapy. The distribution of the infants on the growth curves according to weight, length and head circumference showed a regular increase in growth parameters. Analysis of variance was highly significant at p less than 0.0001. We conclude that long term caffeine treatment does not adversely influence growth parameters, at least during early infancy.

Idiopathic constipation by colonic dysfunction. Relationship with personality and anxiety

The personality of two groups of constipated women (by delayed colonic transit or by colonic inertia) was compared to that of two control groups of arthritic patients (rheumatoid or degenerative disease) with the Minnesota Multiphasic Personality Inventory (MMPI). All subjects suffered from chronic pain. Constipated women were found to have significantly higher scores on the hypochondria, hysteria, control, and low back pain scales and a lower score on the masculinity-femininity scale. Discriminant analysis permitted us to sort out constipated from arthritic patients in 83% of the cases, on the basis of only the personality data. In women with constipation by delayed colonic transit, multiple regression analysis demonstrated a close link (r = 0.90; P less than 0.001) between transit time in the ascending colon and levels of anxiety. It is concluded that women with constipation of colonic origin have a different pattern of personality than arthritic women and that severe constipation may play the role of a defense mechanism, where psychophysiologic responses to life stresses replace normal emotional reactions.

Lectin histochemistry of the liver in biliary disease, following transplantation and in cholangiocarcinoma

Evidence is accumulating that there are changes in the expression of antigens on biliary epithelium in early primary biliary cirrhosis and graft rejection. If any of the biliary diseases including rejection are associated with specific alterations in biliary glycoprotein structure, lectin histochemistry could be useful for detecting these abnormalities. Lectin histochemistry, using a panel of five lectins with differing carbohydrate specificities, was therefore performed on liver biopsies from patients with primary biliary cirrhosis, sclerosing cholangitis, cholangiocarcinoma, liver transplantation, extrahepatic biliary obstruction and normal liver. Reproducible high-quality lectin histochemistry was obtained on formalin-fixed paraffin-embedded tissue. In normal liver wheat germ agglutinin selectively bound to Kupffer cells, Griffonia simplicifolia II bound to hepatocytes, peanut agglutinin (PNA) bound to portal tract macrophages and liver capsule, and Ulex europaeus I (UEA I) bound to endothelium. Bile ducts were variably bound by all these lectins and soy bean agglutinin. In all the cholestatic biopsies PNA identified 'activated' Kupffer cells but there was no alteration in lectin binding specific to any of the benign conditions studied. Cholangiocarcinoma cells bound PNA and UEA I, so UEA I binding should not be regarded as specific for tumours of endothelial origin.

Use of lectin histochemistry in pancreatic cancer

Lectin peroxidase histochemical analysis was carried out on pancreatic tissue from patients with pancreatic carcinoma and chronic pancreatitis and from subjects with normal pancreas to find a tumour specific pattern of lectin binding that would aid histological and cytological diagnosis. There were striking differences between the lectin binding characteristics of the different cell types in the normal pancreas. Acinar cells were uniformly positive for binding with wheat germ agglutinin and soy bean agglutinin while islet cells were usually negative for these lectins. Ulex europaeus I lectin however, was found not to be specific for endothelium, showing positivity also for acinar and ductal tissue. Griffonia simplicifolia II lectin was found to be highly specific for ductal epithelium, and because of this was tested in a hamster pancreatic cancer model where it was not specific for ductal epithelium, reflecting differing carbohydrate expression in the hamster pancreas. Pancreatic carcinomas and chronic pancreatitis bound all five lectins without any qualitative distinction from each other or from normal pancreatic tissue, but there was increased intensity of peanut agglutinin binding to secreted mucins in pancreatic carcinoma, which may be of potential use in radiolabelled lectin scanning.

Interferon-gamma induces altered oncogene expression and terminal differentiation in A431 cells

In tumor cell lines in which oncogene expression is abnormal, modulation of the expression of the oncogene (myc, src, or ras) by interferons (IFNs) has been observed concurrently with cell growth inhibition or phenotypic reversion. Oncogene expression has also been reported to vary during the differentiation of several neoplastic cell lines. Treatment of monolayer cultures of A431, a human epidermoid carcinoma cell line, with IFN-gamma resulted in rapid morphological alterations and cell death not seen with either IFN-alpha or IFN-beta. These changes were accompanied by elevated expression of mRNA's for p21 (the c-ras gene product) and the epidermal growth factor receptor as well as increases in the biosynthetic rate of their respective proteins. These effects likewise appeared to be specific for IFN-gamma. Growth inhibition by IFN-gamma was also observed when A431 cells were grown in a three dimensional in vitro culture system. Immunohistochemical staining of these "tumoroids" with a differentiation specific, anti-keratin antibody indicated that IFN-gamma enhanced expression of this keratin. This observation suggests that the killing by IFN-gamma of A431 cells may result from an acceleration of terminal differentiation.

Genetic variants of C2 muscle cells that are defective in synthesis of the alpha-subunit of the acetylcholine receptor

We have analyzed two genetic variants of C2 muscle cells that have reduced levels of binding activity for alpha-bungarotoxin and have found that both synthesize only low levels of the alpha-subunit of the acetylcholine receptor. In both variants the uptake of 22Na in response to carbachol is diminished in proportion to the reduction in toxin-binding activity. In addition, the kinetic and sedimentation properties of the residual toxin-binding activity in both is indistinguishable from that seen in wild-type cells. Immunoblotting experiments on extracts of the variants using subunit-specific antibodies to alpha- and beta-subunits of the acetylcholine receptor demonstrated that the beta-subunit was present, but failed to detect alpha-subunit. In both variants, the amount of alpha-subunit accumulated after a 5-min period of labeling with [35S]methionine was reduced by over 90%, leading to the conclusion that the alpha-subunit is synthesized at greatly reduced rates. Northern blot and S1 nuclease analysis showed no differences between the alpha-subunit mRNA in wild-type and variant cells.

Oligonucleotide mapping of viral ribonucleic acid as an aid in identifying laboratory contaminants of influenza virus

Influenza viruses that were suspected to be laboratory contaminants of clinical specimens because they had antigenic properties identical to standard laboratory strains were examined by T1 oligonucleotide mapping of virion ribonucleic acid. For the three instances reported herein involving thirteen viruses, it was concluded that laboratory contamination had occurred, since in each instance, a standard laboratory strain that had been used in the clinical laboratory before the isolation, had an oligonucleotide map that was either identical to or very similar to those of the "isolates," there was no evidence of spread of these viruses, and in cases where serum samples were available, no serologic evidence existed of infection by these virus strains.

Efficacy of bone marrow, blood, stool and duodenal contents cultures for bacteriologic confirmation of typhoid fever in children

The relative efficacy of cultures made from duodenal contents (obtained by string capsules), bone marrow, blood and rectal swab was compared in 118 pediatric patients, 2 to 13 years old with suspected typhoid fever. Only 47% of children 2 to 6 years old tolerated the string device, as compared with 89% in children 7 to 13 years old (P less than 0.05). The four culture techniques were performed and at least one was positive for Salmonella typhi in 43 patients. Bone marrow cultures were positive in 84% of the confirmed cases, a sensitivity significantly greater than for duodenal contents (42%), blood (44%) and stool (65%) cultures. Higher recovery rates for blood cultures were found during the first week of illness than later (70 vs. 22%). Bone marrow cultures remain the most effective method for the recovery of S. typhi. Stool cultures appear to be more effective in children than in adults. Duodenal contents cultures offer little advantage in young (2 to 6 years old) children.

Healing of spontaneous periodontal defects in dogs treated with xenogeneic demineralized bone

This study was undertaken to histologically, clinically and radiographically evaluate the sequence of healing following implantation of bovine demineralized bone powder (DBP) into severe, spontaneous periodontal defects in beagle dogs. Eight dogs with documented severe periodontitis were treated surgically following initial debridement. One quadrant in each arch was treated with conventional flap surgery and the others were treated with surgery followed by DBP implantation. Animals received postoperative debridement and clinical and radiographic evaluation. Two dogs were sacrificed at 1, 3, 6 or 12 months postoperatively, and the jaws were evaluated histologically. Clinically, DBP was well tolerated by recipients. No evidence of localized inflammatory response or delayed hypersensitivity reaction was noted. Significant reductions in gingival inflammation were noted in both experimental and control sites at 1 month postoperatively compared to preoperative scores. Equivalent periodontal pocket reduction was noted between test and experimental sites and remained significant at 12 months. Radiographically, no differences were noted in the rate of bone loss between control and test sites. Histologic evaluation demonstrated the presence of DBP at 1 month following implantation, but the material was replaced with new bone by the next sacrifice period. Periodontal ligament fibers of standard orientation were seen extending from DBP-induced bone to the root surface by 1 month after implantation. An intact epithelial attachment appeared to be present 1 month after the implantation of DBP. No differences in root surfaces were detected between test and control groups. Ankylosis was a rare finding, noted equally between test and control sites. DBP did not appear to predispose to external root resorption. In later stages, histologic evidence of advancing periodontitis was noted equally in both control and experimental groups. While DBP successfully induced new bone formation, the inability to adequately maintain the periodontal tissues due to bacterial accumulation in this model combined with recurrent pocket formation, precluded any conclusion regarding long-term advantage. Based on these findings, clinical trials of this or similar materials are recommended.

Coli surface antigens 1 and 3 of colonization factor antigen II-positive enterotoxigenic Escherichia coli: morphology, purification, and immune responses in humans

Enterotoxigenic Escherichia coli (ETEC) of serotype O6:H16, biotype A, bearing colonization factor antigen II (CFA/II) possesses two distinct coli surface antigens, CS1 and CS3, whereas CFA/II-positive ETEC of serotype O8:H9 manifests only CS3. CS1 has been shown to be fimbrial in nature, but heretofore the morphology of CS3 has not been described. Accordingly, by immune electron microscopy we investigated the morphological characteristics of CS3 on bacterial cells and after purification. CS3 was found to consist of thin (2-nm), flexible, wiry, "fibrillar" fimbriae, visible both on bacteria (O6:H16, biotype A, and O8:H9 strains) and in the pure state. In contrast, CS1 exists as wider (6-nm), rigid fimbriae on the surface of O6:H16, biotype A, strains. By the use of antisera to CS1 and CS3 in immune electron microscopy, immunodiffusion in gel, and immunoblotting techniques, CS1 and CS3 were found to be immunologically as well as morphologically distinct. Six of nine volunteers who developed diarrhea after challenge with an O139:H28 ETEC strain bearing CS1 and CS3 had significant serological rises to purified CS1 and CS3 antigens, suggesting that both antigens are elaborated in vivo, play a role in pathogenesis, and stimulate an immune response.

Radiologically visible fecal gas patterns in "normal" newborns and young infants

A prospective study of abdominal and chest films of 212 babies without symptoms of intra-abdominal disease, aged 1 day-12 weeks, showed that the bubbly "fecal pattern" normally seen in older children is rare in young premature babies in the first two weeks of life. When it is seen, it may represent intramural air bubbles and signal the presence of necrotizing enterocolitis.

Tumour cellularity, oestrogen receptors and prognosis in breast cancer

One hundred and thirty-seven patients with operable breast cancer have been treated by mastectomy and node sampling. At the time of operation, portions of tumour were taken for determination of oestrogen receptor activity. In 91 cases adjacent tissue was taken for fixation and histological assessment of malignant epithelial cell content ('cellularity index'). The patients were followed for two years or more, or until first recurrence or death. Prognosis (probability of staying disease-free) was significantly better in patients whose tumours contained receptors than in those whose tumours were receptor-negative (p less than 0.03). However, the best prognosis was in patients with low receptor positive tumours. Those with highest values had a prognosis almost as poor as patients with receptor-negative tumours. In addition, a new finding emerged: prognosis was better in patients with tumours of low cellularity than in those with tumours of high cellularity (p less than 0.04). Since, for receptor-positive tumours, receptor level was also significantly correlated with cellularity (R = +0.35, p less than 0.01), the relationship between prognosis and receptor level was re-examined after 'correction' of the latter quantity for differences in cellularity: on this basis, again prognosis was better in patients with receptor-positive tumours (p less than 0.02), but there was no longer a tendency for any one sub-group of patients with receptor-positive tumours to fare better than the rest. It is concluded that prognosis in operable breast cancer is related to oestrogen receptor activity (either per mg weight, or per cell) and to cellularity.

Serologic differentiation between antitoxin responses to infection with Vibrio cholerae and enterotoxin-producing Escherichia coli

A ganglioside enzyme-linked immunosorbent assay (ELISA) was used to study and attempt to differentiate between antitoxin responses in persons infected with either Vibrio cholerae or Escherichia coli producing heat-labile enterotoxin. In most cases (69%-94%), experimentally infected North Americans and naturally infected Bangladeshis responded to either infection with significant (greater than twofold) increases in serum antibody titer to both heat-labile enterotoxin and cholera toxin. In all but one instance, the response was higher to the homologous than to the heterologous toxin, and for the Americans the homologous antitoxin titers remained significantly higher for at least one year. Determination of levels of antibodies to purified subunits A and B of cholera toxin by an ELISA showed that V. cholerae infection in most instances induced a significant response to subunit B but rarely to subunit A. E. coli infection, on the other hand, induced only slight increases in antibody titer to either subunit.

Oestrogen receptor concentration in primary breast cancer and axillary node metastases

The primary tumour and 1-3 invaded, axillary nodes from each of 24 patients were examined both histologically for the proportion of the specimen constituted by malignant epithelial cells ('cellularity index') and biochemically for oestrogen receptor concentration. Both malignant epithelial cell content and oestrogen receptor concentration were significantly higher in the nodal metastases than in the primary tumours, malignant cells constituting approximately half of the former tissue and three quarters of the latter. On average, receptor concentrations were 1.6 x (protein basis) to 2.3 x (wet weight basis) higher in nodes than in the primary tumours, probably due at least in part to the difference in cellularity. When, to eliminate the effect of the latter, receptor concentration in each tumour deposit was 'corrected' using the appropriate 'cellularity index', the difference in receptor concentration between primary and node was significantly diminished, but not quite eliminated. In one patient, progestogen receptor concentrations were also studied and found to be higher in the nodes than in the primary tumour. If the actual quantity of receptor is to be used for predictive/prognostic purposes, then either a different 'cut-off point' should be used for invaded nodes from that used for assessment on the primary tumour, or receptor concentrations should be corrected for differences in cellularity.

Selective Predation by White-Tailed Black Cockatoos on Fruit of Banksia Attenuata Containing the Seed-Eating Weevil Alphitopis Nivea

The cockatoo Calyptorhynchus funereus latirostris excavates the seed-eating weevil Alphitopis nivea from young fruits of Banksia attenuata trees but discards the immature seed. The birds attacked similar proportions of trees in 3 nearby areas that differed, due to previous histories of fires, in number of reproductive structures per tree. However, within areas the cockatoos attacked trees with larger numbers of fruits. In addition, the proportion of fruits containing weevils was greater in those fruits that the cockatoos attacked than in those they did not. The weevils mostly occurred in larger fruits and large size could be a clue enabling selection of fruits by the birds. The birds removed between 1 and 2 weevils per fruit, but if the weevils were absent the birds still destroyed follicles and often the whole fruit.

Gastroschisis and omphalocele. An eight-year review

Until recently confusion has existed concerning the clinical features and surgical treatment of gastroschisis and omphalocele. Since 1971 75 infants with these abdominal wall defects have been treated at our institution. Significant differences (p equal to 0.001 in all instances) were noted between the two diseases. Gastroschisis occurred twice as often as omphalocele and is increasing in frequency. Prematurity was commonly seen with gastroschisis (65%). While the overall incidence of malformations associated with gastroschisis was low (23%), the vast majority of the additional malformations were jejunoileal or colonic atresias. The mortality rate was 12.7% among gastroschisis patients, with only one death attributable to prematurity. All other deaths were preventable, indicating that even lower mortality rates are feasible. Omphalocele was associated with a 23% incidence of premature birth but associated anomalies were present in 66% of the patients. Major cardiac (52%) and chromosomal defects (40%) predominated. In addition, 17% of omphalocele patients had either Cantrell's pentalogy or cloacal/bladder exstrophy. The mortality rate in omphalocele (34%) was nearly three times that of gastroschisis. Nine of ten patients who died from omphalocele died either from major cardiac or chromosomal disease. However, in patients without cardiac or chromosomal defects the survival rate was 94%.

Antiviral activity of colostrum and serum immunoglobulins A and G

Enteric virus-specific IgA and IgG present in paired human sera and colostrums were measured by the enzyme-linked immunosorbent assay (ELISA). Virus-specific IgA was present in all colostrums, but virus-specific IgG could not be detected. The reverse was true when sera were assayed. Most of these colostrums also neutralized either polio virus or reovirus, as did IgA, which was separated from a pool of colostrums by exclusion chromatography. No correlation could be made between levels of neutralizing and ELISA antibody titers in colostrums.