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Serotonin-immunoreactive cells in the lamina propria plexus of the appendix.

The lamina propria of the human appendix possesses a recently defined ganglionated neural plexus with neurosecretory-type component cells. In order to elucidate the functional role of this plexus, immunohistochemical light and electron microscopic studies were performed on 21 appendixes. By light microscopy, 18 specimens showed within the lamina propria neuron-like and neurosecretory-type cells that stained positively with lead hematoxylin and were positive for serotonin. The number of these cells varied from specimen to specimen. No correlation between the number of serotonin-immunoreactive intraepithelial enterochromaffin cells and the number of plexus cells could be established. Electron microscopic examination revealed identical pleomorphic neurosecretory granules within enterochromaffin cells and plexus cells. The site of serotonin storage in these granules was revealed by electron immunocytochemical methods. It is suggested that, under physiologic conditions, the lamina propria plexus has a modulatory role between the epithelium and the deeper mural enteric nervous system mediated by serotonin neurotransmission. Uncontrolled release of serotonin by the plexus may initiate inflammation and elicit pain related to the appendix.

Adolescent

Crohn's disease isolated to the appendix: truths and fallacies.

Twenty-five cases of Crohn's disease confined to the appendix were reported in eight hospitals in Israel during a 15-year period. Review of the histologic slides confirmed the diagnosis in 22 cases. Re-evaluation of these 22 patients included physical examination and radiologic studies of the small and large bowel. Rectosigmoidoscopy was performed in 16 patients. Signs and symptoms of Crohn's disease at other sites in the gastrointestinal tract did not occur during follow-up periods of two to 15 years (mean, 6.4 years) after appendectomy. This study and a review of the literature indicate that in most cases (93 per cent) Crohn's disease initially limited to the appendix is not a predictor of subsequent involvement of another portion of the bowel. It is concluded that the so-called Crohn's disease isolated to the appendix is a form of chronic granulomatous and follicular appendicitis of unknown etiology that is unrelated nosologically in the majority of the cases to Crohn's disease proper.

Adolescent

Diverticulosis of the vermiform appendix in patients with cystic fibrosis.

This paper presents a study of diverticulosis of the vermiform appendix in patients with cystic fibrosis. The records of two hospitals were reviewed. A total of 39 autopsy specimens and 18 surgical specimens were obtained. Diverticulosis of the appendix was found in 14 per cent (eight of 57) of all appendices. Two of these cases also showed diverticulitis. These results stand in contrast to the incidence of diverticulosis of the appendix in the general population, which has been measured at 1 to 2 per cent in various reviews.

Adolescent

Double appendix.

A case of appendix duplication is described. A normal appendix was present in the usual position while a rudimentary second appendix was found to arise separately from the cecum.

Adult

Colonoscopic appearance of the remnant of the appendix after total inversion.

In a series of 395 total colonoscopies, an oblong smooth tumor was seen in the cecum of six patients corresponding to the remnant of the totally inverted appendix. All the patients had undergone a laparotomy during which the appendix was inverted. The histological examination demonstrated a uniform finding without any signs of polyp or malignancy. Our findings stress that the appendix fails to undergo necrosis after total inversion in some cases, in which the changes in the cecum can be readily identified by total colonoscopy.

Adult

CT of the normal appendix.

We conducted a prospective evaluation of the normal vermiform appendix in 203 patients. Conventional CT techniques were utilized with an 8 mm slice thickness and 10 mm slice interval. The normal appendix was definitely identified in 51% of the patients studied. Computed tomographic appearance of the normal appendix is demonstrated, and potential pitfalls are described.

Adolescent

A bullet in the appendix.

An unusual case of a foreign body lodged in the appendix after traumatic intestinal penetration is described. Although rarely found, foreign bodies in the appendix may produce acute appendicitis and other complications which necessitate surgery. An appendectomy is recommended: 1) for all symptomatic patients; 2) in patients with pointed objects retained because such patients are at potential risk for perforation; or 3) in any patient with a foreign body in the appendix who is undergoing intra-abdominal surgery for other reasons.

Adult

Selective recruitment of lymphocyte subsets to the inflamed appendix.

Total lymphocyte counts and the distribution of lymphocyte subsets were determined in peripheral venous blood and appendiceal mononuclear cells from 60 patients who underwent appendicectomy for the clinical diagnosis of appendicitis. A significant peripheral lymphopenia was observed in the 46 patients with histologically confirmed acute appendicitis which was accompanied by an increase in the appendiceal lymphocyte concentration. There was an even greater depletion of CD45RO+ (memory) T lymphocytes in peripheral blood and an increase in the inflamed appendix. Reciprocal changes were observed in the CD45RA+ (naive) T lymphocyte subset. These changes were reflected in the local arterial and venous CD45RA and CD45RO T lymphocyte subsets. Proliferation studies showed an expanded functional repertoire of T lymphocytes in the inflamed appendix. Selective recruitment of memory T lymphocytes from the peripheral blood to the inflamed appendix was demonstrated.

Acute Disease

Association between mucosal hyperplasia of the appendix and adenocarcinoma of the colon.

Mucosal hyperplasia of the appendix is a seemingly benign change of poorly understood significance, at times found in patients with colorectal malignancy. To determine the incidence of this change and its association with colonic adenocarcinoma, we have examined the appendiceal mucosa in 122 ileocolectomy specimens gathered between 1987 and 1990, and in 273 consecutive appendectomies carried out during 1990 at The Methodist Hospital in Houston, Texas. We found that 23 out of 122 ileocolectomies (18.8%) showed mucosal hyperplasia of the appendix and, of these, 17 (77%) were associated with colorectal malignancy, predominantly of the right side. Moreover, 24 of 273 appendectomies (8.8%) exhibited the presence of mucosal hyperplasia and, of these, six (25%) also were associated with adenocarcinoma of the colon. On the basis of this significant rate of association, we feel that a concomitant colorectal carcinoma should be ruled out in patients who exhibit mucosal hyperplasia of the appendix.

Adenocarcinoma

Bacterial flora of the appendix fossa in appendicitis and postoperative wound infection.

Bacteria were isolated from 153 (47.5%) swabs of the appendix fossa in 322 patients undergoing appendicectomy. The commonest organism was Bacteroides species found in 78% of specimens. Other Gram-negative bacilli such as Klebsiella, or Enterobacter, and Esch. coli were present in 29 and 27% respectively. Gram-positive cocci were less frequently isolated.A positive culture was obtained more commonly in perforated appendicitis (79%) than where chronic fibrosis, lymphoid hyperplasia, or acute appendicitis was present or when the appendix was normal. Bacteroides was isolated twice as often in perforated appendicitis. The incidence of wound infection was 19% and varied according to the state of the appendix, being 63% in perforated appendicitis and 9.5% where lymphoid hyperplasia was present. Bacteroides was isolated from over 90% of the wound infections. In the patients with perforated appendicitis where effective chemotherapy was given the incidence of wound infection was 15% whereas in untreated or inappropriately treated patients it was over 50%. The isolation of bacteroides requires special precautions to be taken both in the collection of the specimen and laboratory culture. It is important that the chemotherapy of postappendicectomy infections include an antibiotic active against bacteroides.

Acute Disease

The normal and abnormal development of the appendix. A radiographic assessment.

Radiographic examinations of the colon in the adult demonstrate a wide variety of contours of the interior cecal segment and appendix. These findings are a result of the normal developmental process of the appendix which can be arbitrarily separated into four stages. Examples of appendiceal development arrested at different stages, as well as variations of the normal adult appendix, are explained and illustrated. Forms of primitive development and lack of development (agenesis) are discussed.

Appendix

Development of the rabbit appendix. I. Electron-microscopic observations.

The progressive lymphoepithelial development of the rabbit appendix was examined by light and electron microscopy. At 5 days postnatally, the appendix wall primitively resembles the mature organ but lacks both the discrete lymphoid organization and most cell types. The dome appears to be the first recipient of lymphoid cells. By 18 days the lymphoid nodule has become compartmentalized and lymphoid. The epithelium, although not fully developed, is in contact with the lymphocytes of the dome. The 5-week-old appendix has all the lymphoepithelial components of the adult but lacks the size of the mature organ. At all ages reported, plasma cells and dendritic cells are absent. Bacteria, thought to be essential to appendical lymphoid development, are not apparent at 5 or 18 days. The features common to central or peripheral lymphoid tissues are discussed.

Animals

Significance of retained barium in the appendix.

Barium is occasionally retained in the appendix after radiographic examinations of the gastrointestinal tract, and its significance has been debated for many years. This report details three cases in which barium was present in the appendix at the time of acute appendicitis. Review of these three cases and 13 cases previously reported suggests that retained appendiceal barium may be significant when it exists in either of two patterns. In patients with appropriate symptoms, a barium appendicolith has the same significance as a calcified appendicolith, strongly suggesting a diagnosis of appendicitis. Barium outlining a dilated appendical lumen also suggests appendicitis in the appropriate clinical setting. The significance of retained barium in the appendix in asymptomatic patients remains uncertain.

Appendicitis

Mucocele of the appendix: imaging findings.

Mucocele of the appendix, a cystic mass resulting from a dilated appendiceal lumen caused by abnormal accumulation of mucus, is a rare entity that often is not considered when problems of the right lower quadrant are assessed. Preoperative recognition of mucocele of the appendix is important because of the possibility of rupture at surgery with development of pseudomyxoma peritonei and to predict malignant transformation. The appearances of mucoceles of the appendix on sonography, CT, and barium studies are illustrated.

Appendix

Right ureteral occlusion due to isolated Crohn's disease of the appendix.

A case of Crohn's disease limited to the vermiform appendix is described. The patient was initially thought to have an appendiceal abscess. The condition was complicated with right ureteral occlusion. Urinary stasis completely ceased after removal of the appendix. Our patient is apparently the first reported case of obstructive uropathy due to isolated Crohn's disease of the appendix.

Adult

Ultrasonographic findings in diseases of the appendix.

Ultrasonographic findings in patients with diseases of the appendix, including acute appendicitis, suspected appendiceal abscess, and palpable right-lower-quadrant abdominal mass, are described. An appendiceal abscess may manifest as a cystic mass, a mixed solid and cystic mass, or a hypoechoic solid mass. An appendiceal calculus within an abscess can be recognized as a hyperechoic structure with acoustic shadowing. On ultrasonography, acute appendicitis in female patients may mimic tubo-ovarian disease. Ultrasonographic features of isolated Crohn's disease of the appendix and mucocele of the appendix are also described.

Abscess

Arterial vascularization of the vermiform appendix in human fetus.

In 50 human fetuses of the crown-rump length ranging from 88 mm to 185 mm (12 to 20 weeks), the variability of the arterial vascularization of the vermiform appendix was investigated using the injection method. 3 vascularization types were distinguished on the basis of the size and number of the supplying arteries. The obtained results were compared with those reported by other authors who studied vermiform appendix vascularization in adults. In most cases the vermiform appendix is supplied by single ramus arising from ileocolic artery.

Appendix

Motor response to electric spatial stimulation of isolated intact and inflamed human appendix.

The smooth muscle responses to electric stimulation of intact, slightly or severely inflamed, isolated human appendix strips were studied. No changes were noted in the motility of the not inflamed and slightly inflamed appendices, (simple appendicitis), the preparations responded to nervous stimulation with contractions of the same size. The smooth muscle contractions were blocked by atropine, and enhanced by physostigmine, which proves the cholinergic nature of the innervation. The severe inflammation (acute phlegmonous appendicitis) reduced also the contraction and relaxation of the appendix strips. With the advancement of the inflammatory process, the decreased motility of the appendix can play an in vivo role in the rapid progress of the process.

Appendicitis