AIDS clinic--a year on

In March 1987 a clinic under the auspices of the South African Medical Research Council's AIDS Research Unit was established. In the first year of its existence certain issues were identified. These are discussed and a model for future clinics is proposed.

Innovations in human genetics education. Genetic applications for health professionals: an outreach continuing-education model program

A system for extending continuing education in genetics to nurses and other practicing health professionals was developed in an eight-state area. Coordinators from state agencies received special training at the University of Colorado to administer the course in local communities. A combination of classroom instruction, independent study, computer-assisted instruction, and case-study methods for course delivery was included. More than 300 health professionals have completed the course, and 14 coordinators from seven states have been prepared to administer future courses. The model has demonstrated high potential for replication in other regions.

Epidemiological considerations of the present status and future growth of the acquired immunodeficiency syndrome epidemic in South Africa

Limited epidemiological data on acquired immunodeficiency syndrome (AIDS) and human immunodeficiency virus (HIV) infection have been assembled by voluntarily reported AIDS figures, blood donor serum prevalence and high-risk sentinel population and random background population sero-prevalence studies. The HIV epidemic in South Africa can thus be shown to consist of four separate epidemics of which the heterosexual epidemic will undoubtedly constitute the major growth in this country. Intervention must be directed to shrinking the promiscuous core which sustains this epidemic by directing attention at female prostitution and limiting the reproductive rate of the epidemic by energetic and professionally directed education at an early stage of a child's school career. Sexually transmitted diseases will play a major role in the determination of the extent of the heterosexual epidemic.

Neurophysiological abnormalities in genuine female stress urinary incontinence

Perineal sensory and motor function was investigated in 28 women with genuine stress incontinence of urine and compared with a matched control group. Electrosensitivity of the dorsal nerve of the clitoris and of the urethral mucosa was significantly diminished in these patients (eight measurements 'insensitive'). Three different reflex latency measurements (dorsal nerve to external anal sphincter, dorsal nerve to urethral sphincter, urethral mucosa to external anal sphincter) were prolonged in incontinence (14 absent reflexes). Mean motor unit potential duration of the external anal sphincter was also prolonged, reflecting an early neuropathy. Anorectal manometry detected significantly weaker squeeze pressures in stress incontinence although other variables were unaffected.

Neurophysiological dysfunction in young women with intractable constipation

Fifteen women with intractable chronic idiopathic constipation dating from adolescence were investigated by anorectal manometry, neurophysiological evaluation of the conus medullaris and external anal sphincter. Comparison was made with 25 asymptomatic female control subjects. Urological disturbances were common amongst the constipated, in five of whom incidental lumbosacral spinal dysraphism was found. No differences in sphincter pressures or the rectosphincteric reflex were demonstrable between the two groups. Rectal defecatory sensation was blunted and the compliance was increased in the constipated group. The latency of the pudendo-anal reflex was significantly prolonged in idiopathic constipation, two women having an absent reflex (greater than 100 ms). Mean motor unit potential duration of the external anal sphincter was not significantly prolonged in the eight constipated women tested. A central neurogenic deficit is postulated in some women with this disorder.

Interferon status after measles virus infection

Peripheral blood leucocytes from patients who had recently had measles infection were examined for their ability to produce alpha- or gamma-interferon, their antiviral state and the level of E enzyme. These results were compared with peripheral blood leucocytes from healthy control subjects. The results show that while peripheral blood leucocytes from control patients produced alpha- and gamma-interferon, those from the measles patients produced only alpha-interferon. The peripheral blood leucocytes from all the measles patients were in an antiviral state whereas those from only 20% of the controls were in this state. Since gamma-interferon is mainly produced by T lymphocytes, the lack of gamma-interferon production by peripheral blood leucocytes from patients with measles correlates with previously reported depressed T-cell function in patients after measles infection.

The action of cisapride on the chronic constipation of paraplegia

Paraplegic patients have intractable constipation associated with prolonged colonic transit time. The agent Cisapride significantly reduced the colonic transit time from 7.7 days to 5.1 days. It also improved the intraluminal tone in the rectum, resulting in a significant reduction in maximal rectal capacity from 305.8 ml to 224.3 ml. There was a reduction in residual urine volume from 51.5 ml to 27.7 ml. The increased number of stools containing transit markers showed that intraluminal mixing was increased by cisapride. Faecal water remained unchanged. A side effect was retention of urine in one subject after sudden withdrawal of the drug but this was avoided by its gradual reduction over 2 days.

Colonic diverticulosis in patients with colorectal cancer and in controls

The barium enemas of 119 patients with colorectal cancer and 119 age-matched controls were examined for evidence of diverticula. Amongst men, 39.6% of patients with colorectal cancer had diverticulosis, compared with 50% in the control group. In the women, 39.3% of patients with colorectal cancer had diverticular disease, compared with 36% of the controls. There appears to be no significant aetiologic association between the two conditions, since they do not occur together more frequently than in controls, although each is reputedly the result of fibre lack.

Constipation in the elderly. A physiologic study

Colorectal motility was studied in 25 elderly patients with chronic constipation and compared with an asymptomatic control group (N = 17). Proctometrograms were performed to measure rectal volumes at sensory threshold and maximal tolerance, and rectal compliance. Anal sphincter pressures and reflexes were measured by conventional techniques. Indices of colonic motility were also assessed. Significant impairment of rectal sensory threshold was apparent in constipation. Six patients presenting with impaction demonstrated functional megarectums. The remaining 19 showed a significant reduction in maximal rectal volume and rectal compliance and 14 extruded the balloon. There were no differences in sphincter length or presence of the rectosphincteric reflex. Four patients had an absent pudendoanal reflex and the remainder significant prolongation. Total gastrointestinal transit times were prolonged in the constipation group, mainly distally due to rectal stasis. In two patients bisacodyl failed to elicit a sigmoid motor response. Constipation in the elderly is not merely due to delayed transit. Neurogenic deficits of sacral spinal cord function may be responsible for abnormalities in rectal motor and sensory function.

Effect of oral activated charcoal on tobramycin clearance

To evaluate the effect of activated charcoal on aminoglycoside pharmacokinetics, six healthy volunteers received tobramycin intravenously with and without multiple oral doses of activated charcoal. Activated charcoal did not have a statistically significant effect on any pharmacokinetic parameter. We conclude that activated charcoal does not enhance tobramycin clearance in subjects with normal renal function when concentrations in serum are within the therapeutic range.

Submucosal collagen changes in the normal colon and in diverticular disease

Full thickness specimens of normal colon (n = 15), and colon from patients with diverticular disease (n = 5) were obtained at operation or autopsy. In the isolated submucosa the ultrastructure of the constituent collagen fibres was examined by transmission electron microscopy. Collagen fibrils in the left colon become smaller (p less than 0.001) and more tightly packed (p less than 0.001) than those in the right colon with increasing age. This difference is accentuated in diverticular disease (p less than 0.01). Factors which contribute to the development of colonic diverticulosis, such as raised intraluminal pressure, may be responsible for premature change in submucosal structure.

Diagnosis of acute pancreatitis: a proposed sequence of biochemical investigations

In 60 controls and 108 patients admitted with acute abdominal pain, Rapignost urinary amylase correctly identified (++) 18 of the 23 patients with acute pancreatitis (AP), with 8 results being equivocal (+), and 1 false negative. This is a suitable screening test for AP, but an equivocal result requires further investigation. In 14 patients with AP the serum amylase was over 1000 U/l with no false-positive results, whereas when 316 U/l was used as the diagnostic threshold, 22 cases were identified (but with 2 false positives). Serum lipase was 100% sensitive in the diagnosis of AP, but there were three false-positive results.

Mucosal proctectomy and colo-anal anastomosis for distal ulcerative proctocolitis

Four patients with long-standing symptomatic ulcerative colitis confined to the left colon and rectum were treated by resection, mucosal proctectomy and colo-anal sleeve anastomosis. There was no operative mortality or anastomotic leakage. Follow-up has ranged from 12 to 66 months (mean 52 months). Loose bowel motions with urgency and frequency of defaecation were troublesome postoperative symptoms. Recurrence of the colitis in the neorectum with extension into the proximal colon occurred in all patients within 3 to 11 months (mean 6 months) of operation. This necessitated total proctocolectomy with ileostomy in three patients (mean 18 months postoperatively). In the fourth patient the recurrence is medically controlled without a stoma more than 5 years after operation. This operation is unsuitable for the treatment of segmental ulcerative proctocolitis.

Late results of mucosal proctectomy and colo-anal sleeve anastomosis for chronic irradiation rectal injury

Ten patients with severe chronic irradiation injury to the rectum were treated by mucosal proctectomy and colo-anal sleeve anastomosis. The indications were: recurrent rectal bleeding (five), stricture (three), fistula (one) and intractable pain (one). Overall follow-up has ranged from 8 to 77 months (mean 40 months). In the present survivors (n = 7) the follow-up ranges from 18 to 77 months (mean 52 months). Six patients have been followed up for more than 3 years and four for more than 5 years. There was no operative mortality. Three anastomotic strictures occurred but the protecting stoma could be closed in all but one patient. Continence was acceptable although urgency and frequency of defaecation were troublesome symptoms. The operation is recommended for life-threatening, haemorrhagic chronic irradiation injury to the rectum.

Electrophysiological observations on the human pudendo-anal reflex

A reproducible electrophysiological technique is described to determine the latency of reflex contraction of the external anal sphincter in response to stimulation of the dorsal genital nerve: the pudendo-anal reflex. This was studied in 38 asymptomatic control subjects and 20 women with neurogenic faecal incontinence, supplemented by determination of the mean motor unit potential duration (MUPD) of the external anal sphincter and anorectal manometry. The reflex latency in the control group was 38.5 +/- 5.8 (SD) ms and appeared to be independent of age or sex. Three patients with faecal incontinence had absent reflexes; the remainder showed significant prolongation of latency (56 +/- 12.2 SD ms) and diminution of amplitude. MUPD was prolonged in incontinence and showed significant correlation with the corresponding reflex latency determination (tau = 0.56, p less than 0.001). The latency of this polysynaptic spinal reflex hence provides a reliable index of neuropathy of the external anal sphincter.

Colonic muscle in diverticular disease

The muscle abnormality in diverticular disease is seen most often in surgically excised specimens in the sigmoid colon, though a pancolonic form of the disease without muscle thickening also exists in the elderly. In terms of physiopathology, the condition has a raised intraluminal pressure operating on the wall locally, this being most readily demonstrated in symptomatic patients. In Western societies the colon loses its tensile properties throughout life. The anatomical and functional evidence is that the colon is outstandingly strong in infancy in both Africans and Europeans, but later the mechanical properties of the African colon become superior and they remain so throughout ensuing decades. The diminished tensile strength and elasticity of the wall is no different in the diverticular and non-diverticular subjects and this suggests that an additional factor, such as pressure, may be necessary in Europeans to cause the mucosal extrusion which constitutes each diverticulum. Fiber fills the colon with bulkier, moister feces, which necessitates less work, especially as it operates for most of the time as a low-pressure system, only occasionally evacuating by mass peristalsis into the rectum. Cereal fiber binds salt and water and there is evidence that this is mostly a physicochemical process, dependent on particle size. Certain types of fibers undergo chemical degradation in the cecum and increase the bacterial population of the stool. Population studies show that diverticular disease subjects consume less fiber and in countries where the fiber intake is reduced, fecal output is lessened, transit is slower, and intraluminal pressure may be rising. As a result of the adoption of high-fiber diets and the use of bulking agents elective operations for diverticular disease are less commonly performed. The number of operations in most Western countries may be increasing because of increasing longevity. Complications often arise after a relatively short history; most are explicable on the basis of sudden pressure increments. The recent important finding in this disease is the change in colonic wall compliance, which probably occurs because of a collagen failure. Contraction of the taeniae may follow elastosis, which may relate to under-filling; this produces the contracted structure seen in the excised colonic specimen. The strength of the colonic wall diminishes throughout life, due to changes in its composition; some of these changes are hastened by self-imposed stresses, which currently seem to be mainly of dietary origin.

The submucosa of the human colon

Full-thickness specimens of colon were obtained at operation or autopsy from 20 patients. The submucosa was isolated from the mucosa and muscularis externa, with confirmation by light microscopy. Submucosal specimens were then fixed and prepared for scanning and transmission electron microscopy, with preservation of their orientation. The submucosa was found to consist of a series of layers of collagen fibres, each layer 0.5-2.0 microns thick. The fibres within each layer were co-directionally orientated. The autopsy specimens were comparable in appearance with the operative ones. The mean diameter of the collagen fibrils was 69 +/- 13 nm, and the mean fibril count per unit area was 159 +/- 58/microns2.