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Biomedical subjects

T M Ross

Publications and source records attributed to T M Ross.

7 recordsLinked to original sources
PubMed1992

Total mastectomy is not always mandatory for the treatment of recurrent breast cancer after lumpectomy alone.

To determine the treatment that offered the best local control for isolated local recurrences of breast cancer after lumpectomy without radiotherapy, the authors reviewed 355 patients initially treated by lumpectomy (with or without axillary dissection) without radiotherapy. Local breast cancer recurred in 79 patients. They underwent either repeat partial mastectomy (PM) or completion total mastectomy (TM). Twenty-four patients (5 TM, 19 PM) received radiotherapy. Local control was defined as the absence of further recurrence of breast or chest-wall cancer. The 19 patients treated with repeat PM and radiotherapy had an actuarial local control rate of 82% at 5 years. Those treated with TM (28 patients) [corrected] or TM plus radiation (5 patients) had rates of local control of 60% and 52% respectively. Although there were no significant differences between the TM and PM plus radiotherapy groups, the 27 patients who had a repeat PM without radiotherapy had a significantly lower rate of local control (32%, p < 0.005). Treatment of recurrent breast cancer with PM and radiotherapy is a viable alternative to TM for enhancing local control. Repeat PM alone gave much poorer results. The authors conclude that local cancer recurrences after lumpectomy alone do not necessarily require TM and can often be treated with repeat excision and radiotherapy.

Adult↗
PubMed1991

Long-term ethanol-exposure markedly changes the cellular composition of cerebral glial cultures.

The vulnerability of morphologically distinct glial subpopulations to ethanol toxicity was surveyed in tissue culture. Secondary cultures of rat glia were examined at intervals during 56 days of ethanol treatment for changes in growth and cellular characteristics. Beginning at 6 days in vitro (DIV), the experimental cultures were treated with either 0.2% or 0.5% (w/v) ethanol in the medium; control cultures received ethanol-free medium. Relative to control cultures, the ethanol-treated cultures exhibited a consistent and dose-dependent suppression in cell number. The development of these cultures was documented with sequential phase-contrast photomicrography. Prior to treatment day 5 (11 DIV), the preponderance of cells were epithelioid in configuration; the astrocytic character of these cells was verified by the immunocytochemical localization of glial fibrillary acidic protein. In control cultures, a subpopulation of process-bearing cells was acquired gradually during the first 3 weeks in culture. The majority of these process-bearing cells were considered to be oligodendrocytes due to their position above the astrocytic carpet and by the immunocytochemical localization of galactocerebroside. Exposure to 0.5% ethanol markedly suppressed the acquisition of process-bearing cells. This ethanol-related suppression of process-bearing cells was apparent in the photomicrographic records of culture development and was confirmed by differential cell counts after 50 days of treatment. These results suggest a possible differential sensitivity of oligodendrocytes of their precursors to ethanol toxicity at elevated (0.5% w/v) concentrations.

Animals↗
PubMed1991

Drugs which stimulate or facilitate central cholinergic transmission interact synergistically with delta-9-tetrahydrocannabinol to produce marked catalepsy in mice.

In experiments in which mice were placed with their forepaws over a 4 cm high horizontal bar, delta-9-tetrahydrocannabinol (THC; 10 mg/kg i.p.) delayed descent from the bar. This effect on descent latency was markedly enhanced by physostigmine (0.05 or 0.25 mg/kg s.c.) and oxotremorine (0.04 or 0.08 mg/kg s.c.), administered immediately before THC. These interactions were attenuated by atropine (2.0 mg/kg s.c.) and (-)-scopolamine (1.9 mg/kg s.c.) but not by atropine methyl nitrate (2.11 mg/kg s.c.), which does not readily cross the blood-brain barrier. However, atropine methyl nitrate did prevent salivation induced by oxotremorine in the presence of THC. No synergism was detected between THC and neostigmine (0.047 mg/kg s.c.). Atropine and (-)-scopolamine also decreased the ability of chlordiazepoxide (10 mg/kg s.c.) to enhance the effect of THC on descent latency. The interaction was not antagonized by atropine methyl nitrate or mecamylamine (1.17 or 2.34 mg/kg s.c.). These results point to an involvement of central acetylcholine-releasing pathways in the cataleptic response of mice to THC.

Acetylcholine↗
PubMed1991

An investigation of the involvement of GABA in certain pharmacological effects of delta-9-tetrahydrocannabinol.

Experiments were performed with mice to determine whether doses of the benzodiazepine, flurazepam, or the GABA uptake inhibitor, NO-328, known to potentiate catalepsy induced by delta-9-tetrahydrocannabinol (THC), would also interact synergistically with THC in the production of certain other effects. No synergism was detected either in the production of antinociception (tail flick test) or in a test in which the ability of flurazepam to delay onset of clonic convulsions induced by intravenous infusion of pentylenetetrazole was compared in the presence and absence of THC or cannabidiol. The hypothermic effect of THC was unaffected by NO-328 but enhanced by flurazepam, albeit only at doses higher than those needed to potentiate THC-induced catalepsy. In vitro experiments with guinea pig ileum showed that the ability of THC to inhibit electrically evoked contractions was unaffected by delta-amino-n-valeric acid, a GABA(B) receptor antagonist, and that preparations rendered tolerant to GABA responded normally to THC. Contractions induced by GABA in unstimulated ileal longitudinal muscle were attenuated by THC. We conclude that there is little evidence from our data that any of the THC effects studied were GABA mediated.

Amino Acids↗
PubMed1988

Gracilis muscle repair of rectovaginal fistula after restorative proctocolectomy. Report of two cases.

Gracilis muscle interposition flaps have been used to treat two patients with rectovaginal fistulas. The fistulas occurred following restorative proctocolectomy with a J-shaped ileal reservoir and ileoanal anastomosis. Attempts at local repair of the fistulas had failed. A diverting loop ileostomy was constructed simultaneously. Anterior sphincteroplasty was performed in one patient for associated incontinence. Excellent results were achieved in both patients. The fistulas have healed, and intestinal continuity has been re-established. This procedure can be useful to salvage a pelvic pouch complicated by a rectovaginal fistula.

Adult↗
PubMed1988

Advanced scleroderma bowel: complications and management.

Severe intestinal hypomotility in scleroderma is an uncommon but difficult management problem. We present a case of advanced scleroderma bowel complicated by colonic pseudo-obstruction, which was dramatically improved by subtotal colectomy. Benign pneumoperitoneum due to pneumatosis cystoides intestinales later developed. Symptoms and the pneumoperitoneum resolved with oxygen therapy and total parenteral nutrition, followed by an elemental diet. Our case illustrates how a judicious combination of medical and surgical therapy can be successful in advanced scleroderma bowel. The pathology and pathogenesis of intestinal scleroderma are reviewed to provide an understanding of these complications and a rationale for management.

Colectomy↗