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Biomedical subjects

C De Luca

Publications and source records attributed to C De Luca.

At least 55 records · Page 3Linked to original sources
PubMed1989

[Mechanism of azelaic acid action in acne].

The physiopathologic mechanism of acne seems to be dependent on four main factors: a) sebum production and excretion; b) type of keratinization of the follicular channel; c) microbial colonization of the pilosebaceous unit and d) inflammatory reaction of the perifollicular area. Azelaic acid is effective in the treatment of acne because it possesses an activity against all of these factors. Azelaic acid is a competitive inhibitor of mitochondrial oxidoreductases and of 5 alpha-reductase, inhibiting the conversion of testosterone to 5-dehydrotestosterone. It also possesses bacteriostatic activity to both aerobic and anaerobic bacteria including Propionibacterium acnes. Azelaic acid is an anti-keratinizing agent, displaying antiproliferative cytostatic effects on keratinocytes and modulating the early and terminal phases of epidermal differentiation.

Acne Vulgaris↗
PubMed1986

Relationships between bile salts hydrophilicity and phospholipid composition in bile of various animal species.

Bile salts and phospholipids from bile of chicken, dog, sheep, rat, ox, pig, guinea-pig and man were analyzed by high-performance liquid chromatography. Bile salts showed marked differences in their hydrophilic properties, owing to hydroxyl structure and type of conjugation. Phospholipids were generally similar, containing 90-95% of phosphatidylcholine which was made of molecular species containing palmitic acid in the sn-1 position. The comparative analysis of bile salts and phosphatidylcholines profile demonstrated that bile salts hydrophilicity influences the quantity of phosphatidylcholine in bile but not the quality.

Animals↗
PubMed1985

[Changes in body composition in obese patients on a low-calorie diet].

Energy balance was studied on 4 obese hospitalized subjects kept on hypocaloric diet (489 Kcal - 54% CHO, 10,6% Fat, 35,4% Protein) for 18 +/- 3,7 days. Energy expenditure was measured trough heart-rate monitoring (individual calibrations before and after the study were performed) and nitrogen balance was computed to establish protein loss. Individual qualitative composition of body weight loss was then assessed: 71,4 +/- 5,23% could be attributable to fat loss, 9,38 +/- 3,32% to protein loss, 18,2 +/- 5,5% to water loss. Part of this last figure could be attributable to a slight under-estimation of the method utilized to measure the energy expenditure (heart-rate monitoring).

Adult↗
PubMed1982

Innervation pattern of inferior vena cava in mouse and rat.

The innervation pattern of rat and mouse inferior vena cava was studied using catecholamine fluorescence and cholinesterase histochemical methods. Adrenergic nerve fibers innervate only abdominal portions of the inferior vena cava, while cholinergic nerves are chiefly distributed to the thoracic inferior vena cava and show a gradual decrease in the abdomen. Chemical sympathectomy performed with the neurotoxin 6-hydroxydopamine does not alter the pattern of cholinergic innervation of the inferior vena cava, suggesting the parasympathetic nature of cholinergic nerves.

Adrenergic Fibers↗
PubMed1982

Cholinergic nerves in mouse uterus.

The topographical distribution of cholinergic nerve fibres in the uterus was studied in normal as well as chemically sympathectomized mice. Our analysis was performed using both transverse sections and whole mounts, in order to analyse the distribution of cholinergic nerves within the various layers of the uterus and to study the morphology of nerve plexuses that supply the organ. Cholinergic nerve fibres were found chiefly around the uterine artery and its primary ramifications. Nerve fibres coming from arterial plexuses are distributed to the myometrium and more infrequently to the endometrium. Groups of acetylcholinesterase positive ganglion cells were located in the cervix. The distribution pattern of the cholinergic innervation of mouse uterus shows important topographical differences. In the tubal end of uterine horn the innervation is poor and cholinergic nerve fibres are organized in a sparse plexus. The number and the density of uterine nerves increase gradually proceeding toward the cervix. The cervix shows the richest innervation. The findings that observed nerve fibres are unaltered by chemical sympathectomy and are revealed using short incubation times suggest their parasympathetic nature.

Acetylcholinesterase↗
PubMed1980

Irradiation injuries of the large intestine.

A series of 15 patients suffering from irradiation injuries to the large bowel is reviewed. Ten patients required surgical intervention, initially a diverting stoma in eight; intestinal continuity was re-established in three patients. Loop ileostomy may be preferable to loop transverse colostomy for fecal diversion, as the former is easier for the patient to manage, and ensures that there is no interference with blood supply to the colon should an abdomino-anal pull-through procedure be indicated later to restore continuity. As only three of the patients developed recurrent carcinoma, the initial operation for irradiation injury to the large bowel should be carefully planned so that the patient is not ultimately cured of carcinoma but left with a permanent stoma.

Aged↗
PubMed1979

Fibreoptic colonoscopy. Indications, results and complications.

Fibreoptic colonoscopy was commenced in the Edward Wilson Colon and Rectum Unit at Sydney Hospital in June, 1973. The experience of the first five years of its use is reported. Six hundred and twenty-six examinations have been performed in 568 patients. Fibreoptic colonoscopy has been of particular value in the diagnosis and treatment of colonic polyps. A total of 318 polyps were removed from 184 patients. Their distribution, size and histological features are recorded. Eight complications occurred in the 628 examinations (1.6%). There were six colonic perforations (1.2%) with one death, and two significant haemorrhages (0.4%). This incidence of complications is acceptably low, especially in view of the great benefits obtained by the patient from fibreoptic colonoscopy. The newer instruments, especially the medium length Olympus MB3 colonoscope, have greatly facilitated the examination and, combined with increasing experience, may significantly lower the incidence of complications in the future.

Adolescent↗
PubMed1979

Elective resection for diverticular disease.

A series of 119 patients undergoing elective resection for diverticular disease has been reviewed. The indications for resection were classified into two major groups--those with severe infections ("complicated" diverticulitis), comprising 58 patients, and those with minimal infections, comprising 61 patients. The majority of the resections were limited to the sigmoid colon (101 patients). Fifteen patients underwent left hemicolectomy, whilst three had total colectomy. Thirty-six patients (30%) had a proximal defunctioning stoma--18 prior to resection and 19 at the time of resection. Anastomotic defects were noted in 15 patients (12.6%), but these were of clinical significance only in eight (6.7%). There were two deaths (1.7%) and 17 wound infections (14.3%). The group classified as "complicated" diverticulitis included the great majority of the patients requiring colostomy (32 out of 37), almost all those with anastomotic defects (14 out of 15), and most of the patients who had postoperative complications.

Acute Disease↗
PubMed1979

Rectal prolapse.

One hundred and twenty-seven patients with complete rectal prolapse have been reviewed. The condition occurred more commonly in females than males (105 to 22), and at an older age in females (mean age 55 years compared with 40 years for males). Although the diagnosis is usually obvious, the importance of recognizing occult prolapse is stressed, especially in association with benign rectal ulcer, localized proctitis and colitis cystica profunda. Examination of the patient in the squatting position may assit in showing occult prolapse. Associated incontinence occurred in 33 patients (26%). Since 1971 the policy of this Unit has been to perform a Ripstein repair for complete rectal prolapse wherever possible. One hundred and two Ripstein repairs have not been performed. A minimum follow-up period of two years is available for 53 patients, of whom 50 (94%) have had their prolapse cured. Control of prolapse usually improves continence; however, seven (13%) remained incontinent despite surgery. The Ripstein repair is strongly advocated as the most effective operation for cure of complete rectal prolapse.

Adolescent↗
PubMed1979

Ileostomy reconstruction.

A study of 47 patients undergoing ileostomy reconstruction is presented. The most common indications were recession (15 patients) and a desire for a continent type of ileostomy (12 patients). Less frequent indications were stenosis (6 patients), parastomal ulceration (6 patients), prolapse (4 patients), unsatisfactory siting (3 patients), and parastomal hernia (1 patient). Refashioning of the ileostomy at the same site was possible in 17 patients, whilst repositioning at a new site was required in 30 cases. In 28 of these laparotomy was carried out to enable repositioning, but in two cases resiting was performed without laparotomy. After the original operation, reconstruction may become necessary at any time from a few months to over 20 years.

Adolescent↗
PubMed1979

The surgical treatment of anal incontinence.

This study is review of 31 patients undergoing surgery for anal incontinence. Three groups of patients are defined--those with incontinence due to trauma (nine patients), to a combination of trauma and degeneration (five patients), and to degeneration alone (17 patients). Two surgical techniques were used--either a direct repair of the anal sphincter or a postanal repair of the levator ani muscles and external sphincter (Parks operation). In the trauma group and the combined group the more common method used was a direct repair (ten patients)--five underwent a Parks operation. In the degeneration group all but one patient underwent a Parks operation. A defunctioning proximal colostomy was carried out in only four patients--all with incontinence due to trauma. Satisfactory continence was restored in 80% of these patients. Although this is a small series, the results are considered worthwhile and greater awareness and use of the above technique is recommended.

Adult↗
PubMed1978

Prophylactic administration of low-dose heparin in colorectal surgery.

A retrospective study of 192 patients operated on by three members of the Edward Wilson Colon and Rectum Unit, Sydney Hospital, was carried out. All operations performed involved dissection within the pelvis. Prophylactic administration of low-dose heparin was used for 71 of these patients. The incidences of clinical thromboembolic disease were 7 per cent in both the group receiving heparin and the other group. In slightly more than half of the patients, pulmonary emboli occurred in the absence of peripheral deep venous thrombosis. It is suggested that the source of these emboli was thrombosis arising in the pelvic veins.

Colon↗
PubMed1976

Prostaglandins: bone resorption stimulating factors released from monkey gingiva.

Gingival fragments from monkeys have been found to release a factor in vitro into incubation medium which stimulates bone resorption in organ culture. Indomethacin effectively blocks the occurrence of this stimulatory factor in the gingival incubation medium. All of this bone resorptive activity can be accounted for by prostaglandin-like material. The prostaglandins contributing to the bone resorptive activity have been found to be prostaglandins E1 and E2.

Alveolar Process↗
PubMed1976

Glucose-6-phosphate dehydrogenase activity in a hepatoma cell line: preliminary evidence for negative genetic control.

A line of cells, positive for glucose-6-phosphate dehydrogenase activity, has been separated from a negative parental stock derived from the H4-II-E-3C rat hepatoma line. Cytogenetic analyses showed specific marker chromsomes of the parent line were present in the variant. On the other hand, cells of the variant line contained three chromosomes less, on the average, than the total present in parent cells. Karyotypic analyses indicated the diminution in chromosome numbers to be in the subacrocentric group. The appearance of glucose-6-phosphate dehydrogenase associated with loss of chromosomes suggests this enzyme is suppressed or under negative control in the parental stock. The consistent loss of chromosomes of the subacrocentric group suggests that the locus bearing regulatory activity is in this specific group.

Cell Division↗