Growth within macrophages increases the efficiency of Mycobacterium avium in invading other macrophages by a complement receptor-independent pathway

Infections caused by organisms of the Mycobacterium avium complex occur in approximately 50 to 60% of patients with AIDS. M. avium is an intracellular pathogen that survives and multiplies within mononuclear phagocytes. In this study, we investigated the uptake of M. avium grown within macrophages (intracellular growth M. avium [IG]) by a second macrophage compared with M. avium cultured in broth (extracellular growth M. avium [EG]). The results showed that IG was six- to eightfold more efficient than EG in entering macrophages. In addition, while an anti-CR3 antibody was able to inhibit approximately 60% of EG uptake by macrophages, it failed to inhibit the entry of IG. In contrast to EG, IG uptake into macrophages was significantly inhibited in the presence of anti-beta1-integrin and anti-transferrin receptor antibodies. Entry into macrophages by alternate receptors was associated with resistance to tumor necrosis factor alpha (TNF-alpha) stimulation. While stimulation with TNF-alpha resulted in inhibition of the growth of EG, it was not associated with inhibition of intracellular growth of IG. Investigation of the reason why M. avium is able to sense the changes in the intracellular environment triggering a change to the invasive phenotype suggests a direct relationship with macrophage apoptosis. These results suggest that intracellular growth is associated with novel mechanisms of M. avium uptake of macrophages and that those mechanisms appear to offer advantages to the bacteria in escaping the host defense.

Acquired toxoplasmosis of a submandibular lymph node in a 9-year-old boy diagnosed by fine-needle aspiration cytology

Toxoplasmosis is a parasitic infection which may be asymptomatic or produce lymphadenopathy, fever and malaise. In children the cervical lymph nodes are most commonly affected. This report describes a case of a 9-year-old boy who presented with submandibular lymphadenopathy associated with a non-vital primary tooth, which persisted following extraction of the tooth. A diagnosis of acquired toxoplasmosis was made on the findings of fine-needle aspiration cytology and subsequently confirmed by serological investigations, thus sparing the patient unnecessary hospitalization and surgery. The patient required amitryptyline as a nocturnal sedative and made a complete recovery within a few months without the need for further intervention.

Oral manifestations seen in association with a case of trisomy for the short arm of chromosome 9

A case of trisomy for the short arm of chromosome 9 in a 13-year-old boy is described. Particular emphasis is placed upon a number of abnormal dental findings, which include enamel hypoplasia, hypodontia, and severe dental crowding. The difficulties of providing comprehensive dental treatment in cases such as these is discussed.

Posttranslational modifications of brain and erythrocyte band 3 during aging and disease

Band 3 performs the same structural and functional activities in adult brain as it does in erythrocytes. It ages as cells and tissues age Our studies, to date, indicate that the anion transport ability of band 3 decreases in brains and lymphocytes from old mice. This decreased transport ability precedes obvious structural changes, such as band 3 degradation and generation of SCA and is the earliest change thus far detected in band 3. The following changes occur in lymphocytes, erythrocytes and brain band 3 with aging: 1) a decreased efficiency of anion transport (decreased Vmax) in spite of an increase in number of anion binding sites (increased K(m)), 2) a decreased glucose transport, 3) 32P labeling in vitro, 4) an increased degradation to smaller fragments as detected by quantitative binding of antibodies to band 3 breakdown products and residue 812-830, and 5) a binding of physiologic IgG autoantibodies in situ. The latter three findings indicate that posttranslational changes occur. In addition, the anion transporter, band 3, undergoes an as yet undefined change that results in binding of "980" antibodies to aged band 3. Posttranslational changes in AD include decreased brain and RBC phosphorylation of a M(r) = 135, 113 and 45 kDa band 3 polypeptides due to the phosphorylation site being already occupied, increased degradation of band 3, alterations in band 3 recognized by antibodies, and decreased anion and glucose transport by blood cells. Band 3 in erythrocytes of AD patients has a different immunological identity from normal band 3 as evidenced by the binding of antibodies described in this study. AD may be preferentially manifested in the brain because neurons accumulate damage throughout the lifetime as they do not regenerate or undergo cell division. We suspect, and our data indicate, that the same mechanism(s) of AD occurs in all cells, but that the manifestations differ due to different cell proteins and functions.

Hypodontia: 2. The management of severe hypodontia

The management of severe lack of teeth in the dental arch presents the clinician with a number of difficulties. In this paper, the second in a series on hypodontia, the problems are outlined and suggestions made as how best to overcome them.

Presenting complaints and findings in a group of patients attending a hypodontia clinic

A survey is presented of the complaints and findings in a group of 451 patients referred to a multidisciplinary clinic for the management of hypodontia. The most common complaints were missing teeth, spacing in the dental arches, and poor appearance. The majority of patients were referred by their dental practitioners, and more than half were over 12 years old when first seen. Delayed referral can have educational and social consequences. Changing attitudes to dental care and the maintenance of an intact dentition are resulting in hypodontia, particularly in its more severe forms, becoming of increasing concern to children and their parents. The management of this condition is best organised via multidisciplinary specialist clinics.

Distribution and function of multiple anion transporter proteins in brain tumor cell lines in relation to glucose transport

The anion transport, "band 3," family of proteins in mammalian brain performs the same functions as that of erythroid band 3. These functions are anion transport, ankyrin binding, and generation of senescent cell antigen, an aging antigen that terminates the life of cells. The presence of 5-7 band 3 related proteins in brain tissue was suggested by the reaction of antibodies to synthetic peptides of erythroid band 3 with a number of bands in immunoblots. Since there are a number of different cell types in brain, tissue cultures of neural cell types were examined to determine whether multiple band 3 related proteins are present in each cell type or whether several band 3 related proteins are present in each cell type. The tumor cell lines exhibit anion transport and are inhibited by the anion transport inhibitors 4,4'-diisothiocyano-2,2' disulfonic acid (DIDS), phenylglyoxal, and furosemide. Glucose transport is inhibited by cytochalasin B and the anion transport inhibitor, phenylglyoxal, in these cell lines, but not by 4,4'-diisothiocyano-2,2' disulfonic acid. Furosemide gave partial inhibition of most, but not all, cell lines. Since phenylglyoxal inhibits anion transport by binding to an arginine near the transport site, inhibition of glucose transport by phenylglyoxal suggests that an arginine lies in the substrate binding site. The number of cytochalasin B and DIDS binding sites was quantitated on cell lines as an approximation of the number of glucose transporter and anion transporter sites, respectively.

Osteopathia striata--a case report

Osteopathia striata is an unusual skeletal condition that can affect the bones of the skull quite markedly and result in dental problems that have rarely been discussed in the literature. The characteristic features exhibited by the patient in this case report were dense maxillary and mandibular bone, a high forehead with frontal bossing, a broad nasal bridge, prominent zygomatic arches and thickened angles of the mandible. The mouth opening was limited as a result of sclerosis of the mastoid process, and right lateral excursion of the mandible was reduced, probably because of a deformity of the left condyle.

Formocresol toxicity: is there a suitable alternative for pulpotomy of primary molars?

Some concern has been expressed in recent years about the use of formocresol for vital pulpotomy treatment of primary molars. This paper reviews the literature concerning the toxicity of formocresol and considers the evidence for the use of calcium hydroxide and glutaraldehyde. It is concluded that more work is required in this field before an alternative to formocresol can be recommended and that, in the meantime, a 1:5 dilution of the standard formocresol solution should be used but not included in the zinc oxide-eugenol sublining.

Pulsed nasal and transtracheal oxygen delivery

Oxygen conserving devices, the TTO catheters, electronic pulsed DODS and reservoir cannulas, increase efficacy of oxygen delivery; TTO also improves cosmetic appearance, comfort and compliance. We speculated that pulsing of oxygen transtracheally can increase efficiency of TTO. We modified the DODS to include settable delays and a rapid pre-inspiratory trigger. The first part of the study was performed with nasal oxygen on seven subjects and the second part, with TTO on 17 subjects. Nasal oxygen results indicate improved delivery efficiency with more rapid response. The TTO results indicate no significant change for each delay setting, but there was improvement in delivery efficiency when DODS was combined with TTO vs continuous flow TTO. Thus, early inspiratory delivery increases efficiency of oxygen therapy. Small delays in response time are critical in nasal delivery but not important in TTO. Pulsed TTO is more efficient than continuous flow TTO and merits long-term studies.

The use of the Magnetip double-J ureteral stent in urological practice

The Magnetip* double J type ureteral stent has been used in a wide variety of clinical urological settings. We reviewed the use of the stent in 50 patients. In 45 patients stents were placed in conjunction with extracorporeal shock wave lithotripsy, stone manipulation, obstruction due to pregnancy or malignancy, pyeloplasty and ureteroneocystostomy. In 83 per cent of the attempts the stent was placed successfully. Retrieval with the Magnetriever* was accomplished in 86 per cent of the cases (100 per cent in female and 76 per cent in male patients). Details of stent use are described.

Component failure in removable partial dentures for patients with severe hypodontia

Removable partial dentures (RPDs) are frequently used in the treatment of severe hypodontia. The failure rates and modes of failure of 138 such prostheses incorporating acrylic resin onlays were assessed in a retrospective survey. Failures primarily occurred either early or late in the life of the prostheses. Particular problems identified were the low wear resistance of acrylic resin onlays and poor fixation of resin components to metal bases, especially when space was limited.

A program for transtracheal oxygen delivery. Assessment of safety and efficacy

Over a 2-year period, the safety and efficacy of a program specifically designed for transtracheal oxygen therapy were evaluated in 100 patients with chronic hypoxemia. The four clinically defined phases of the program included patient orientation, evaluation, and selection (phase I); a new needle-wire guide-dilator transtracheal procedure and stent week (phase II); transtracheal oxygen delivery with an immature tract (phase III); and transtracheal oxygen delivery with a mature tract (phase IV). Sequelae and complications were minor, and patient acceptance was high. As compared with the nasal cannula, the transtracheal catheter was associated with a significant reduction in oxygen flow requirement during both rest and exercise. Adequate oxygenation was maintained over time, and erythrocythemia was alleviated with transtracheal delivery. We conclude that transtracheal oxygenation by this method has a low, acceptable morbidity; it is more efficient than nasal cannula delivery and may be more effective in some patients.

Antibiotic-associated interstitial nephritis and nephrotic syndrome

The combination of interstitial nephritis and minimal-change nephrotic syndrome has been well described in adults receiving nonsteroidal anti-inflammatory agents. The association of interstitial nephritis and minimal-change nephrotic syndrome has recently been described in 1 adult patient receiving ampicillin and in 1 patient receiving rifampin. We describe an 8-month-old child who developed reversible interstitial nephritis and minimal-change nephrotic syndrome while taking antibiotics.

How to cheat in morphology: the renal ultrafilter

It is easy to distort the "truth" in morphological reports in order to confirm a previously established dogma by selecting from a field of view only such details which are in accordance with the dogma and by ignoring parts contradictory to it. The renal corpuscle is used in this paper as an example and as a guide to the readers for future fraud.

Polypeptides immunologically related to band 3 are present in nucleated somatic cells

Band 3, the major transmembrane polypeptide of erythrocytes, mediates the exchange of anions (chloride and bicarbonate) across the membrane. We suspected that band 3 was present on nucleated somatic cells as well as erythrocytes because the senescent cell antigen that is immunologically related to band 3 is present on lymphocytes, platelets, adult liver cells, and embryonic kidney cells; and antibodies prepared against the senescent cell antigen isolated from leukocytes react with erythrocyte band 3. For this reason, we examined human fibroblasts, lung cells, neutrophils, mononuclear leukocytes, squamous epithelial (mouth) cells, lung squamous epithelial carcinoma, mouse neuroblastoma cells, and rat hepatocytes for immunoreactive forms of band 3 by using monospecific antibodies to erythrocyte band 3. The results demonstrated that polypeptides sharing common antigenic determinants with erythrocyte band 3 are present in nucleated somatic cells as determined by immunofluorescence, immunoelectron microscopy, and immunoautoradiography. Peptide mapping revealed substantial sequence homology between erythrocyte band 3 and the band 3-like protein of leukocytes. Immunofluorescence studies indicate that the band 3-like proteins in nucleated cells participate in antibody-induced cell surface capping.

Disparate effects of vitamin D treatment upon mitochondrial granulation in proximal and distal renal tubule

The distribution of calcium phosphate granules in mitochondria of proximal and distal renal tubules of nonuremic and uremic children was analyzed by electron microscopy of material obtained by percutaneous kidney biopsy. Although distal tubule had fewer granules/mitochondrion than proximal tubule, uremia induced a significant drop (50%) in both, related to an increase in mitochondria containing O granules and a decrease in mitochondria with 2+ granules. The decrease observed in uremic children was reproduced experimentally by partial nephrectomy in rats. Uremia resulted in a 58% decrease of calcium phosphate granules in rat proximal tubule while a smaller but significant decrease (36%) occurred in distal tubule. Vitamin D deficiency in rats was associated with greatly decreased granulation in proximal tubule (80%) whereas distal tubule was less severely affected (36%). Supplementation of vitamin D to uremic rats restored mitochondrial granulation to normal in proximal tubule in 24 hr, but had no effect in distal tubule since the number of granules/mitochondrion, 0.5 +/- 0.1, remained statistically similar to that of untreated animals. Granulation in both proximal and distal tubule of uremic rats was unaffected by parathyroid hormone administration. Since restoration of granulation occurred only in proximal tubule, the defect in uremia which can be overcome by vitamin D treatment appears localized at the level of the proximal tubular cell membrane, indicating an action of vitamin D on calcium and/or phosphorus translocation into the proximal tubule.