In cystitis coming on after catheterism in women it seems that the cause of the cystitis is injuries produced in passing the catheter, rather than the use of a dirty one. Walker (N. Y. Med. Jour., Mar. 19, 'OS).
Cystitis is always caused by the pres ence of bacteria. The mere presence of bacteria is insufficient to cause cystitis: a further predisposing cause is necessary. Under favorable conditions any pathog enic organism may give rise to cystitis. The entrance of pathogenic orga-nisms into the bladder may be through the urethra, through the ureter from an in fected kidney, from inflammatory areas in the neighboring parts, and through the blood-stream and the lymphatics. George T. Howland (Med. News, july 15, '99).
Results of experitnents on one hun dred dogs: A lesion of the rectuin in the vicinity of the prostate, whether superficial or deep, is not followed by cystitis, nor are intestinal bacteria found in the urine in these cases, pro vided the bladder at the outset is free from disease, and provided also that the rectal lesion is not followed by either general systemic infection or peritonitis. Serious lesions of the rectum may very readily produce general infection, how ever. Omitting cases of sepsis, cystitis was noted in only one of many cases, and in but one case was there even a transient bacteriuria. Microscopical ex amination showed that, following the slightest trauma of the epithelial sur face of the rectum, numerous bacteria made their way promptly into the lym phatic spaces of the tisitte surrounding the realm', bladder, prostate, and semi nal vesicles:. If the bladder be injured by retention at this stage, the patho genic germs which are sojourning in the neighborhood may succeed in finding en trance and may thus set up a cystitis. Faltin (Centralbl. f. d. Icrankh. d.
Sextmlorgane, Bd. xii, H. G, 1902).
Pathology.—The changes which are produced by cystitis consist in increased vascularity of the mucous membrane; its light-red color being exchanged for one of a dark-crimson hue throughout, deep ening to purple or even black about the neck of the bladder; or the mucous membrane may be ecchymosed, and in places necrotic, and the muscular layer may be exposed. Hremorrhages may oc cur from bursting veins or separating sloughs; or perforation may occur into the surrounding tissues or into the peri toneal cavity. Peritonitis may arise with out actual perforation (John B. Roberts).
In the more chronic cases the epithe lium desquamates vary rapidly; mucus at first and then pus is poured out in large quantity. The urine soon becomes alkaline and is putrescent. Blood is fre quently present. Decomposition precipi tates the salts of the urine and calculi are found in tbe bladder or a calcareous deposit occurs upon the walls of that viscus. When the disease has been of
long duration the muscular wall becomes either hypertrophied and contracted, or its fasciculi become irregularly stretched apart while the mucous membrane sinks into the intervals, giving rise to the con dition known as sacculated, or ribbed, bladder. These depressions or sacs may become large and retain decomposed urine, act as receptacles for calculi, or perforate and give rise to peritonitis or perivesical abscess. The ureters and kid neys soon become involved, and add ma terially to the serious nature of the case.
The commonest cause of infection of the female urinary tract is the bacil lus coli communis, which a study of the cases of acute cystitis definitely proves can and does in a large number of cases set up a. true infection without the aid of any other micro-organism. Marked variations are seen in the virulence of this micro-organism and in its pyogenic properties. Other micro organisms frequently found are the tubercle bacillus, various staphylococci, and the bacillus proteus vulgaris, while numerous varieties of micro-organisms have been less frequently and occasion ally met with, as the bacillus pyocy aneus and typhoid bacillus. The pro portion of cases of infection clue to the bacillus coli communis is greater in women than in men, probably due to the close proximity of the female ure thra to the anus. Besides the entrance of the micro-organisms, other factors are in most cases essential to the de velopment of a cystitis; the chief of these factors are anxinia, malnutrition, trauma of and pressure upon the blad der, congestion of the bladder, and re tention of urine. In cystitis the chief mode of infection is by the urethra, although one nmst also consider as pos sibilities a descending ureteral infection from an infected kidney, pyogenic metastasis by means of the blood- and lymph- currents, and direct transmis sion of the micro-organisms from the intestinal tract, or from some adjacent focus of infection. In pyelitis and pyelonephritis the usual modes of infec tion are along the ureter from an in fected bladder, and by means of the blood- a.nd lymph- currents; in personal cases these modes of infection were found about equally represented. In the great majority of cases of cystitis, both acute and chronic, and in the majority of cases of pyelitis and pyclonephritis, the urine is acid. In cases in which the urine is arnmoniacal the infection can be produced without the aid of any of the accessory etiological factors men tioned above, the irritation of the arn moniacal urine apparently being suffi cient to render the bladder susceptible to infection. In infections of the kid ney due to a urea,-decomposing micro organism a stone is very likely to be present if the ease is at all chronic.