Safety of a nonoxynol-9 vaginal gel in Kenyan prostitutes. A randomized clinical trial

OBJECTIVE

To evaluate the safety and toxicity of once-daily administration of Advantage-24 (Columbia Research Laboratories, Inc., Rockville Centre, NY), a vaginal gel containing 52.5 mg of nonoxynol-9 (N-9), including the effects of this gel on the vaginal and cervical epithelium.

STUDY DESIGN

Randomized, placebo-controlled, double-blind crossover trial, with a 2-week product application period and a 2-week washout period.

METHODS

Female sex workers in Mombasa, Kenya were randomized to one of two sequences, N-9 followed by placebo, or vice versa. Women were instructed to apply one applicator of N-9 or placebo gel vaginally once each day. During each of the two product periods, subjects were evaluated by questionnaire and physical examination, including colposcopy, after 7 and 14 days of product use. The primary outcome was genital epithelial disruption.

RESULTS

Sixty subjects were randomized, of whom 52 (87%) had complete follow-up. There were four episodes of epithelial disruption, three of which occurred during the placebo period and one during the N-9 period. The estimated risk of epithelial disruption associated with N-9 use was 0.33 (95% confidence interval, 0.03-3.26). There was no increased frequency of other, nondisruptive epithelial lesions during N-9 use.

CONCLUSIONS

No genital epithelial toxicity of N-9 vaginal gel was observed. This safety profile suggests that this N-9 product is appropriate for evaluation for human immunodeficiency virus type 1 prevention in a phase III efficacy trial.

A role for apoptosis in the pathogenesis of AIDS-related idiopathic esophageal ulcers

Lack of understanding of the mechanism of tissue destruction associated with idiopathic esophageal ulcers (IEUs) poses a diagnostic and therapeutic dilemma for the clinician. The possible role of apoptosis in IEUs, as suggested by endoscopic and histologic observations, was investigated by examination of archival tissues for apoptosis-related DNA fragmentation using in situ nick end labeling (TUNEL). High levels of apoptosis were observed in mucosal cells immediately adjacent to IEUs. Apoptotic cells were virtually absent in normal control tissues, while the edges and bases of lesions and sloughed-off tissues in IEUs in human immunodeficiency virus (HIV)-infected patients showed elevated levels of apoptotic cell death. However, tissue samples from patients with esophageal ulcerations of known etiology showed no apoptosis of mucosal cells. These data support a role for apoptosis in the pathogenesis of IEUs and suggest a mechanism involving HIV-associated bystander killing of uninfected mucosal cells.

Nasal lesions induced by intranasal administration of benzaikonium chloride in rats

We investigated the lesions of nasal cavity mucous membrane caused by administration of 0.01, 0.05 and 0.10 w/v% Benzalkonium chloride (BZC) solutions in the nasal cavity of rats. No BZC-induced symptoms or nasal lesions were seen in the 0.01 w/v% BZC-treated group. On the other hand, BZC-induced symptoms such as nasal sound and rubbing the nose with forelegs were observed in the 0.05 and 0.10 w/v% BZC-treated groups. Additionally, BZC-induced lesions, including epithelial desquamation, inflammation and edema, occurred in the anterior nasal cavity in the 0.05 and 0.10 w/v% BZC-treated groups, but these lesions were confined to the dorsal meatus and the adjacent nasal septum. These results indicate that 0.01 w/v% BZC solution has no effect on the nasal cavity mucous membrane. However, 0.05 and 0.10 w/v% BZC solutions induce lesions in the nasal cavity mucous membrane due to their irritating effect.

Epidermization in the esophageal mucosa: unusual epithelial changes clearly detected by Lugol's staining

A 58-year-old Japanese man with superficial esophageal cancer accompanied by unusual epithelial changes, including esophageal mucosal epidermization, is reported. Staining with Lugol's iodine clearly showed irregular unstained lesions, which could not be seen clearly macroscopically, in the resected specimen. Histologic examination of the irregular unstained areas showed definite granular and horny layers regarded as epidermization, acanthosis with slight nuclear enlargement, and epithelial atrophy. The immunohistochemical staining patterns of keratins in the epidermized and atrophic lesions were similar to those in the epidermis, and the keratin staining patterns of the acanthotic lesion were similar to those of the oral epithelium.

Successful transfer of late phase eosinophil infiltration in the lung by infusion of helper T cell clones

Bronchial asthma is characterized by chronic eosinophilic inflammation of the bronchial mucosa. Accumulating evidences suggest that activated T cells and T cell cytokines play critical roles in the local accumulation and activation of eosinophils. To further delineate the critical role of T cells on asthma, we tested the possibility whether eosinophilic inflammation of the bronchial mucosa is induced by transferred T cell clones, in the absence of antigen-specific immunoglobulins (IgE, A, and G). Ovalbumin-specific Th2 clones were established and cytokine profiles were determined. Eosinophilic inflammation accompanied with airway hyperresponsiveness occurred only when unprimed mice were transferred with IL-5 producing Th2 clones and challenged by the inhalation of relevant antigen. Increase of IL-5 concentration in bronchoalveolar lavage fluid (BALF) was detected after the challenge, indicating the local production of cytokines by the transferred T cells, and preceded the appearance of the airway eosinophilia. Eosinophil infiltration was completely suppressed by the administration of anti-IL-5 neutralizing antibody, indicating the essential role of IL-5 in this model. The intensity of the eosinophil accumulation in vivo correlated well with the capacity of the T cell clones to produce IL-5 in vitro. We concluded that the existence of IL-5-producing helper T cells is sufficient for the development of the eosinophilic inflammation at the bronchial mucosa upon inhalation challenge of the relevant antigen.

[Ionomer cement as bone substitute in the middle ear of the rabbit]

Ionomer-based cements are obtained by the reaction of an aluminum-fluoro-silicate glass with a polyalcenoic acid. During setting and hardening the cement bonds closely with adjacent hard tissue. The previous implantation of this material in the baboon tibia has held great promise as a possible use in bone replacement. In the present study the cement was tested concerning its biocompatibility and biostability in the middle ears of 64 rabbits. Viscid cement paste was inserted into the epitympanic space of each animal. A preformed cement strut was then placed to serve as a columella between the eardrum and stapes footplate. During a subsequent interval of 28 days up to 2 years middle ear specimens were evaluated under a surgical microscope, following which histologic sections were studied under light microscopic conditions. Findings demonstrated that after insertion of freshly mixed cement a firm adhesion to bone developed that proved to be biocompatible and biostable over time. After 28 days the preformed and fully hardened implants were overgrown by a delicate mucosa normally present in the middle ear. No evidence for any rejection of the implants could be found. The experience available to date indicates that ionomer cement is biocompatible and biostable, easy to handle and workable without splintering. With appropriate use it represents a useful implant material in surgery of the head and neck.

Epidermolytic hyperkeratosis in the lower female genital tract: an uncommon simulant of mucocutaneous papillomavirus infection--a report of two cases

Two examples of epidermolytic hyperkeratosis (EH) involving the female genital tract are described. The first case, an isolated epidermolytic acanthoma, involved the vulva of a 75-year-old woman. The second case involved the vaginal wall of a 40-year-old woman who had similar lesions of the oral mucosa. EH is characterized by epidermal acanthosis, compact papillomatous hyperkeratosis, and dissolution of the suprabasilar epithelium, resulting in perinuclear clear zones. Granular keratohyalin clumping, hypergranulosis, and dyskeratosis resulting in intracellular eosinophilic globules ("cells within a cell" appearance) are additional distinctive findings. Because of the rarity of the lesion in the female genital tract, it may be confused with other lesions that more commonly affect this region. Correct recognition of EH may have significant clinical implications.

Lazaroid U-74500A for warm ischemia and reperfusion injury of the canine small intestine

BACKGROUND

Although lazaroids have been shown to protect various organs from ischemia/reperfusion injury, results obtained in the small intestine have been conflicting.

STUDY DESIGN

The canine small intestine was made totally ischemic for 2 hours by occluding the superior mesenteric artery and the superior mesenteric vein with interruption of the mesenteric collateral vessels. A lazaroid compound, U74500A, or a citrate vehicle was given intravenously to each of the six animals for 30 minutes before intestinal ischemia. Intestinal tissue blood flow, lipid peroxidation, neutrophil infiltration, adenine nucleotides and their catabolites, and histologic changes after reperfusion were determined.

RESULTS

Lazaroid treatment attenuated decline of the mucosal and serosal blood flow after reperfusion. Accumulation of lipid peroxidation products and neutrophils in mucosal tissues was markedly inhibited by the treatment. Postischemic energy resynthesis was also augmented by lazaroid. Morphologically, mucosal architectures were better preserved with lazaroid treatment after reperfusion, and recovered to normal by postoperative day 3 in the treated group and by postoperative day 7 in control animals.

CONCLUSIONS

Lazaroids protect the canine small intestine from ischemia/reperfusion injury by inhibiting lipid peroxidation and neutrophil infiltration. Dogs are tolerant of 2-hour normothermic complete intestinal ischemia.

c-myc, c-erbB-1 and c-erbB-2 expressions in urothelial carcinoma

The expression of c-myc, c-erbB-1 and c-erbB-2 in 24 cases of urothelial carcinoma by Southern and northern blot analysis, and immunohistochemistry was examined. The results were compared with the pathological grade and stage. We found elevated mRNA expressions of c-myc and c-erbB-1 in 19 and 11 of 21 cases, respectively, but there was no apparent amplification or rearrangement of these oncogenes in any of the cases examined. By immunohistochemistry using anti-epidermal growth factor receptor antibody, most of the cases showed positive immunoreactivity on the cancer cell membranes, and cancers of higher pathological grade and stage showed more intense staining. By contrast, amplification of c-erbB-2 was detected in four of 24 cases, all of which were assigned to a high pathological grade (G3). Elevated c-erbB-2 mRNA levels appeared to correlate with the pathological grade of the cancers. Positive immunohistochemical reactions to c-erbB-2 were found in the cancer cell membranes in three of 24 cases, which were accompanied by amplification and elevated mRNA levels of c-erbB-2. In conclusion, expressions of c-myc, c-erbB-1 and c-erbB-2 were all elevated in the majority of urothelial carcinomas, but the amplification was not universal.

Seromuscular gastrocystoplasty in rats

Long-term results of seromuscular gastrocystoplasty have not been reported in the literature. In the presented study, a seromuscular gastrocystoplasty technique in rats and related biochemical, physiological, and histopathologic results are discussed. Fifty rats were grouped as follows: control and sham (group A), animals with gastrocystoplasty (group B), and animals with seromuscular gastrocystoplasty (group C). Urine pH, blood pH, and bicarbonate levels, bladder capacity, and end filling pressures were evaluated in all groups. After gastrocystoplasty and seromuscular gastrocystoplasty both group B and C showed a statistically significant increase in bladder capacity. Aciduria developed in 22% of rats in group B. In group A and C aciduria was not noted. No statistically significant difference was observed in blood pH, bicarbonate levels, and end-filling pressure measurements in each group of rats. Significant histopathologic changes of bladder occurred in the gastrocystoplasty group. In the 13 bladders examined histologically in group B, 2 had a papilloma on the mucosal surface of the transplanted gastric patch. The bladder mucosa adjacent to the transplanted gastric patch had pronounced hyperplastic and squamous metaplastic changes. In the 15 bladders examined histologically in group C none had a papilloma on the gastric segments. Squamous metaplasia in the bladder mucosa adjacent to the transplanted gastric patch was noted only in 2 rats of this group. Two rats also had bladder calculi in the lumen. Possible etiologies and differences of gastrocystoplasty and seromuscular gastrocystoplasty related pathological changes between two groups are discussed.

Intra-abdominal sepsis: an immunocytochemical study of the small intestine mucosa

AIM

To investigate immunocytochemical changes in intestinal tissues from patients with intra-abdominal sepsis, and to relate the changes to the possibility of enhanced bacterial adhesion and translocation.

METHODS

Tissues from 17 patients suffering from intra-abdominal sepsis and from controls were sectioned and stained immunocytochemically for IgA, IgM, secretory component, J chain, and HLA-DR. Differences in the distribution and characteristics of positively staining cells between the patient groups were assessed.

RESULTS

Patients with intra-abdominal sepsis had noticeable reductions in numbers of IgA and IgM plasma cells, reduced J chain staining, and had little immunoglobulin on the surfaces of enterocytes. In contrast, HLA-DR positive cells were increased in the sepsis compared with the control group. The plasma cells present showed cytological changes suggestive of apoptosis.

CONCLUSIONS

Stress associated with sepsis and its immediate causes might result in increased plasma glucocorticoid levels that bring about apoptosis of mucosal plasma cells (or their precursors). The consequent reduction in expression of IgA and IgM may favour bacterial adhesion to the enterocytes and facilitate bacterial translocation into the tissues.

Mucosal prolapse changes in Hirschsprung's disease

The aim of this study was to ascertain the incidence of mucosal prolapse changes in Hirschsprung's disease. Twenty-three random, consecutive resection specimens for this condition were analysed for the histological features of prolapse. Eight cases showed histological evidence suggesting mucosal prolapse at the junction between ganglionic and aganglionic bowel. Thickening and splaying of the muscularis mucosae with extension into the lamina propria, and the presence of metaplastic or hyperplastic tubules with goblet cell and cryptal hypertrophy were the dominant histological features found in the eight cases. In addition, an increase in elastic fibres in the lamina propria and diamond-shaped glands were seen to varying degrees in all eight cases. Mucosal prolapse was more prominent in the older patients and is, therefore, related to duration of symptoms. Differential pressures in ganglionic and aganglionic segments of bowel, together with faecal stream and straining are likely to be of pathogenetic significance.

Histology of the perforated tympanic membrane and its muco-epithelial junction

A histological study was performed on total human tympanic membranes with a central perforation. The specimens originated from 30 consecutive and unselected operations in which a total myringectomy was performed prior to reconstruction by means of a tympanic allograft. Beside excessive thickening of the tympanic membrane in 73%, all membranes showed other histological abnormalities: inflammation (97%), excessive fibrosis (97%), tympanosclerosis (80%), hyperkeratosis (83%), rete riges (43%) and epithelial inclusions (6%). Histological localisation of the muco-epithelial junction showed a medial position in 30%, with extensive middle ear invasion by squamous epithelium in 7%. The surgeon performing myringoplasty should keep these findings in mind and he should closely examine the medial side of the perforated tympanic membrane in order to remove any ingrowing epithelium that otherwise would be trapped.

Criteria for the diagnosis of sinus mycetoma

Recent improvements in the treatment options for fungal disease of the sinuses make rapid distinction between the syndromes of invasive and noninvasive sinusitis necessary. On the basis of the extensive review of the literature detailed here, we developed case-finding criteria for the noninvasive syndrome of sinus mycetoma. Using these criteria, we identified 20 cases of sinus mycetoma in the medical literature and compared findings in these patients to those of five patients with mycetoma evaluated in our clinics. Like those in the literature, our patients appeared immunocompetent and were often first seen for evaluation of symptoms other than those usually associated with sinusitis. Two were first seen with a new-onset seizure disorder and one with nasal obstruction alone. Patients from both groups more commonly had mycetoma in their maxillary sinuses, and fungus failed to grow from the cheesy, grey-green, hyphae-rich material removed at the time of surgery. Clinical features in our five patients, which are not noted in published reports of sinus mycetoma, included frequent atopy, nasal polyps, calcification within the sinus on computed tomography, and an excellent response to surgical treatment. Serendipitously, one patient had both allergic fungal sinusitis and a mycetoma in the same sinus. On the basis of this experience, we have modified our case-finding criteria into proposed diagnostic criteria for sinus mycetoma. The elements of these criteria are designed to: (1) exclude patients with invasive fungal sinusitis and (2) differentiate sinus mycetoma from other forms of noninvasive fungal sinusitis on the basis of specific histopathologic findings. This study and the criteria presented reflect our view that sinus mycetoma represents a distinct but not necessarily isolated element in the spectrum of noninvasive fungal disease of the sinuses.

A three-dimensional dynamic simulation model of epithelial tissue renewal

OBJECTIVE

Based on the study of existing simulation and mathematical models, a dynamic simulation and three-dimensional (3-D) visualization model of the normal and pathologic architecture of the nasal epithelium is proposed.

STUDY DESIGN

Positions, sizes, shapes and orientations of the nuclei, basal lamina and lumen were used for 3-D representation of the epithelium. Static modeling was applied to simulate the normal, metaplastic and dysplastic stages of the nasal epithelium. Then, dynamic modeling, starting from a static representation of a normal or a pathologic stage, used the starting values of cell proliferation parameters to simulate a tissue growth process. The basic hypothesis is that consecutive transformations through stages are mainly due to increased cell growth.

RESULTS

Normal tissue renewal and progressive transitions between normality and hyperplasia after exposure to formaldehyde were obtained.

CONCLUSION

A model that allows study of the evolution of the 3-D tissue architecture during the preneoplastic process in external epithelium is now available. Improvement of the model, consisting of adding information concerning cell communication, extracellular matrix and cell cycle modeling, should help to formulate and sharpen hypotheses concerning structural and kinetic dynamics of this tissue during the preneoplastic process.

Mucous membrane plasmacytosis of the upper aerodigestive tract. A case report with effective treatment

We present a case of plasmacytosis of the mucous membrane of the upper aerodigestive tract. This is a rare benign condition characterized by plasma cell infiltration of the mucosa, with only nine cases described previously (Ferreiro et al., 1994). The lesions, which have a cobblestone appearance, cause throat discomfort, dysphonia and mild dyspnoea. All the cases described previously failed to respond to antibiotics, systemic steroids, or to surgical resection. The present case has however responded favourably to intensive and prolonged treatment with beclamethasone oral spray and Corsodyl mouthwashes.

Mast cell and mast cell granule phenotypes in normal and Nippostrongylus-infected rats. A qualitative laser confocal microscopic study

In the rat, the individual mast cell secretory granules may be divided into three subpopulations based on the presence of the specific proteases RMCP-1, RMCP-2, or a variable combination of these two proteases. Mast cells in the tongue only express RMCP-1, both in normal and infected animals, whereas in the other tissue locations studied (lung, intestinal mucosa and submucosa, tracheal epithelium and submucosa) the mast cells contain all three granule subtypes in a wide variation of combinations. These studies demonstrate that there is wide heterogeneity in protease expression in rat mast cells, which may be influenced by local stimulation with environmental tissue factors.

Mucosal substance P receptor expression in HIV infection and inflammatory bowel disease

Gastrointestinal (GI) disease is a common manifestation of HIV infection. Symptoms may result from the acquisition of intestinal infection, but in certain cases functional and mucosal abnormality may result from mucosal HIV infection. The pathogenesis of HIV enteropathy is poorly understood, but a range of neuroenteric disturbances has been described including a reduction in mucosal substance P (SP). Inflammatory bowel disease (IBD) is a generic term used to describe two major clinical entities; Crohn's disease (CD) and ulcerative colitis (UC). Dysregulation of mucosal neuropeptide expression has been implicated in the pathogenesis of CD and UC. Mucosal SP expression has been variously described as increased, normal or reduced in intestinal tissue from patients with IBD. In contrast, uniform increases in mucosal SP receptor (SPR) have been described in patients with IBD using quantitative autoradiography. The purpose of this study was to characterize intestinal mucosal SPR mRNA expression in control, HIV and IBD patients using semiquantitative reverse transcription PCR. Intestinal tissue was obtained during diagnostic colonoscopy from 7 control, 9 HIV-infected and 28 (12 CD and 16 UC) IBD patients. RNA was isolated from the tissue biopsies, reverse transcribed and amplified with primers specific for SPR. SPR mRNA expression was detected in 7/7 (100%) of control, 2/9 (22%) of HIV-infected, 12/12 (100%) of CD and 11/16 (69%) of UC intestinal biopsies. These data demonstrate that SPR mRNA expression is significantly reduced in patients with HIV infection. Reduced mucosal SPR expression may contribute to the mucosal abnormality, altered intestinal motility and GI symptoms associated with HIV infection.

Prospective long-term endoscopic and histological follow-up of short segment Barrett's esophagus: comparison with traditional long segment Barrett's esophagus

OBJECTIVES

Barrett's esophagus is associated with adenocarcinoma of the cardia and esophagus, regardless of its extent. The aim of this study was to compare the prevalence and incidence of dysplasia and adenocarcinoma in short segment and traditional long segment Barrett's esophagus.

METHODS

Seventy-four patients with short segment Barrett's and 78 with traditional Barrett's entered the study.

RESULTS

There were no significant differences in age or gender between the two groups of patients with Barrett's esophagus. A greater percentage of patients with short segment barrett's were black (p = 0.04). The prevalence of dysplasia at diagnosis in patients with short segment Barrett's was 8.1% versus 24.4% in patients with traditional Barrett's (p < 0.007). Adenocarcinoma was noted at diagnosis only in patients with traditional Barrett's (p < 0.0005). Twenty-six patients with short segment Barrett's and 29 with traditional Barrett's were followed prospectively for 12-40 months. Dysplasia developed during follow-up in two patients with short segment Barrett's and in six patients with traditional Barrett's (p < 0.05). Neither high grade dysplasia nor cancer developed in any patients with short segment Barrett's. High grade dysplasia did develop in two patients with traditional Barrett's esophagus, and mucosal adenocarcinoma developed in one. The frequency of dysplasia on the latest surveillance examination continued to be significantly higher for patients with traditional Barrett's (p = 0.03). Follow-up surveillance biopsy specimens of Barrett's mucosa frequently demonstrated an absence of goblet cells in patients with short segment Barrett's compared with patients with traditional Barrett's (p < 0.0001).

CONCLUSIONS

The prevalence of dysplasia or adenocarcinoma and the incidence of dysplasia in patients with traditional Barrett's esophagus are significantly higher than in patients with short segment Barrett's esophagus. Further prospective surveillance is required to determine whether the incidence of adenocarcinoma in patients with short segment Barrett's esophagus is significantly lower.

Effect of antimicrobial agents on the piliation of Pseudomonas aeruginosa and adherence to mouse tracheal epithelium

The effect of subminimal inhibitory concentrations (sub-MICs) of antimicrobial agents on the adherence of Pseudomonas aeruginosa (pili+) to trachea mucosal cells, the first stage in the development of P. aeruginosa respiratory tract infections, was investigated. The adherence of P. aeruginosa to the cells of the lower respiratory tract using a model of acid-injured trachea in mice was observed by electron microscopy (transmission and scanning). When P. aeruginosa was cultured with 1/4 MIC of erythromycin, minocycline, clindamycin, ofloxacin or tobramycin at 37 degrees C for 4 hours, the number of pili was significantly reduced (P < 0.01), together with a significant reduction in the number of adherent bacteria at 1/4 MIC of erythromycin (P < 0.01). No suppressive effects of piperacillin or ceftazidime were obtained on the piliation and adhesion of P. aeruginosa. These findings indicate that sub-MICs of erythromycin reduce the adherence of P. aeruginosa to the tracheal mucosa, which may prevent the onset of P. aeruginosa respiratory tract infection.

Correlation of goblet cell density and mucosal epithelial membrane mucin expression with rose bengal staining in patients with ocular irritation

PURPOSE

This study was designed to compare goblet cell densities and mucosal epithelial membrane mucin (MEM) expression in impression cytology specimens obtained from control subjects and patients with one of the following clinically defined diseases: aqueous tear deficiency (ATD) associated with Sjögren syndrome, ATD not associated with Sjögren syndrome, inflammatory Meibomian gland disease associated with rosacea, and Meibomian gland atrophy. These data were correlated with ocular surface rose Bengal staining scores, Schirmer scores, and HLA-DR antigen staining of conjunctival epithelial cells.

METHODS

Goblet cell density and MEM expression were studied by impression imprints with immunohistochemical staining using an anti-mucosal epithelial membrane mucin antibody in the temporal and inferior bulbar and inferior tarsal conjunctiva of study subjects.

RESULTS

Goblet cell density adjacent to the temporal limbus was significantly reduced at 3 mm posterior to the temporal limbus in both aqueous tear deficiency groups compared with the other groups and in patients with Sjögren syndrome compared with all other groups. In the inferior tarsus, goblet cell density was significantly reduced in patients with non-Sjögren syndrome ATD as compared with all other groups, except those with inflammatory Meibomian gland disease. Mucosal epithelial membrane mucin expression in the bulbar and tarsal conjunctiva was absent in a greater percentage of patients with Sjögren syndrome compared with all other groups. Total ocular surface rose Bengal staining scores were significantly higher in patients with Sjögren syndrome as compared with all other groups and in patients with non-Sjögren syndrome ATD as compared with control groups. Rose Bengal staining scores and Schirmer I test results (without anesthesia) were inversely correlated with bulbar, but not tarsal, conjunctival goblet cell densities, and with the absence of bulbar conjunctival MEM expression.

CONCLUSIONS

These results suggest that reduced goblet cell density and mucosal epithelial cell mucin expression could explain increased rose Bengal staining in patients with aqueous tear deficiency. In addition, MEM may be regarded as a marker for normal differentiation of ocular surface epithelia, with its absence signifying the development of squamous metaplasia.

A prospective evaluation of the endoscopic spectrum of overtube-related esophageal mucosal injury

BACKGROUND

Placement of an overtube is required for endoscopic variceal ligation. The spectrum of overtube-related esophageal mucosal injury is unknown. We made a prospective comparison of two types of overtubes and a determination of the frequency, severity, and risk factors for overtube-related injury.

METHODS

Two overtubes (60F, 20 cm, "new" overtube; and 60F, 25 cm, "old" overtube) were used and placed using the bougie-assisted technique. Mucosal integrity was documented before and after variceal ligation. Overtube contact time, bands number, setting (emergent versus elective), type of overtube, degree of coagulopathy, and development of symptoms after variceal ligation were recorded.

RESULTS

Fifty sessions in 29 patients were analyzed; 24% of sessions were emergent. The old overtube was used in 24 sessions and the new in 26. Mucosal injury occurred in 72% of sessions. Mean overtube contact time was 11.58 +/- 0.97 minutes, the mean number of bands placed per session was 6.4 +/- 0.4, and the mean international normalized ratio was 1.47 +/- 0.06. No risk factors correlated with mucosal injury except for the old overtube, which was associated with tears (p = 0.02).

CONCLUSIONS

Mucosal injury related to the overtube is frequent but clinically unimportant. Because mucosal tears occurred significantly more often with the old overtube, we suggest that its use should be avoided.

Histopathologic study of esophageal atresia and tracheoesophageal fistula in an animal model

A histopathologic study of tracheoesophageal anomalies was conducted on an Adriamycin-treated animal model to determine how closely it resembles the human pattern. Adriamycin was administered (2 mg/kg body weight) to timed-pregnant rats on days 6 through 9 of gestation. The fetuses were recovered at term, dissected and prepared for histological studies. Dissection showed a similar range of variants of tracheoesophageal anomalies as seen in humans. Esophageal atresia with distal tracheoesophageal fistula was by far the most common type. Other varieties were seen such as esophageal atresia without a fistula, tracheal atresia and hypoplastic esophagus with atrophic mucosa, and muscle coat. Serial sectioning of the distal segment showed tracheobronchial elements extending to a variable distance from the origin of the fistula.