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Biomedical subjects

S Prescott

Publications and source records attributed to S Prescott.

49 records · Page 3Linked to original sources
PubMed1990

Antibiotic compared with antiseptic prophylaxis for prostatic surgery.

Two different regimens of cephalosporin antibiotic prophylaxis were compared with antiseptic lubricating jelly to try to prevent infection and complications in 196 men after prostatic surgery. Pre-operative urine was cultured and prostatic chips (170 cases) were also cultured to define the source of any infection. The use of antibiotics was associated with a reduced risk of postoperative bacteriuria. No serious complications occurred, although 1 patient in the antiseptic treated group developed rigors; 79 of 170 patients (46%) had positive prostatic chip cultures, of whom 74 had sterile pre-operative urine. There was no association between the result of chip culture and the presence of a pre-operative catheter. Culture positive patients had an increased risk of post-operative urine infection, although the same organism was found in the prostate and urine in only 36% of cases of post-operative bacteriuria and in 43 (54%) the organism cultured from the prostate was Staphylococcus albus. This study provides further evidence of the benefit of true prophylactic antibiotic therapy for transurethral prostatic surgery and the prostatic chip data suggest that some of the risk is due to pre-operative contamination of the prostate in the absence of per-operative urinary infection or catheterisation.

Aged↗
PubMed1989

HLA-DR expression by high grade superficial bladder cancer treated with BCG.

The local immune response to intravesical BCG therapy for widespread carcinoma in situ and superficial bladder tumour was assessed using immunohistochemical methods on serial biopsies obtained during treatment. The main findings were the induction of a strong level of HLA-DR expression by urothelial cells which persisted for several months after completion of therapy. This coincided with a mononuclear cell infiltrate in the bladder wall consisting predominantly of activated helper T lymphocytes. Smaller numbers of macrophages, suppressor cytotoxic T lymphocytes and B lymphocytes were also found. These new findings confirm that the inflammatory response to BCG involves the urothelium in an immunological reaction and suggest that the success of immunotherapy with intravesical BCG may be due to enhanced tumour antigen recognition.

Administration, Intravesical↗
PubMed1988

Postoperative urinary retention in general surgical patients.

A prospective study has been performed to measure the incidence of postoperative urinary retention in 280 general surgical patients. Eighteen patients (6 per cent) were catheterized after a range of operations under general anaesthesia. There was no statistical difference in the retention rate between men and women. Increasing age did not predispose to retention of urine. Of 72 patients who had either herniorrhaphy, haemorrhoidectomy or testicular operations, only 1 was catheterized, whereas 16 (23 per cent) of 70 patients undergoing laparotomy were catheterized. Most of these laparotomy patients had upper abdominal procedures carried out. Those having lower abdominal operations were usually catheterized pre-operatively and were excluded from the study. There was a significantly higher incidence of retention among patients who had long anaesthetics (greater than 60 min). There was also a significantly higher incidence of retention among those who were ventilated, relaxed and reversed by atropine and neostigmine. Of those 193 patients who had opiate analgesia, 15 (8 per cent) developed retention of urine, compared with 3 (3 per cent) of the 87 patients who had non-opiate analgesia. There was a significantly higher retention rate among the patients who had opiate analgesia by intravenous infusion compared with those who had opiates by intramuscular bolus injection; 7 patients had painful and 11 had painless retention. This study suggests that postoperative retention of urine is a result more commonly of diminished awareness of bladder sensation, than of factors such as anxiety or local pain.

Adult↗
PubMed1988

Small-caliber skeletal muscle fibers do not suffer necrosis in mdx mouse dystrophy.

The prevalence of internal nuclei in muscle fibers (centronucleation), which is a reliable cumulative index of all prior muscle fiber necrosis, was measured at different ages in different muscles of mdx mice and was correlated with muscle fiber diameter. The prevalence of centronucleated fibers (as percentage of total number of fibers) rose gradually after age 20 days until it reached a peak level of 80% at age 60 days. No significant centronucleation (or necrosis) was observed in the following circumstances: in 4 different limb muscles before age 15 days, in leg muscles that were denervated by peripheral nerve section or rendered immobile by high thoracic cordotomy at 15 days, or in rotator extraocular muscles throughout the animals' life span. In these situations, muscle fiber diameter remained below approximately 20 micron. The mechanism by which small-diameter fibers are resistant to necrosis in mdx dystrophy is unknown, but a similar situation exists in hamster and Duchenne muscular dystrophy.

Animals↗
PubMed1988

Malignant mesothelioma of the tunica vaginalis testis: a case report.

We report a case of malignant mesothelioma of the testicular tunica vaginalis. A preceding hydrocele showed mesothelial hyperplasia of its lining. The tumor was treated surgically as well as with a combination of radiotherapy and chemotherapy but it progressed, resulting in death within 21 months from the diagnosis. The relationship of the tumor to mesothelial hyperplasia and to previous exposure to asbestos is discussed.

Humans↗
PubMed1987

Glucocorticoid excess induces preferential depletion of myosin in denervated skeletal muscle fibers.

The combined effects of dexamethasone treatment (1 mg/Kg/day) plus denervation (DEX-DEN), were studied at 7, 13, and 28 days by microscopic, biochemical, and physiological techniques in plantaris and soleus muscles of adult rats. The results were compared with corresponding dexamethasone-treated (DEX) and denervated (DEN) muscles and appropriate controls. There was a significantly more marked atrophy of all fiber types in the DEX-DEN plantares at 7 and 13 days than in either DEX or DEN muscles. The degree of atrophy was greatest in type 2B fibers in DEX-DEN plantares. Electron microscopy revealed a severe preferential depletion of thick myofilaments in DEX-DEN plantares and solei but not in DEX or DEN muscles. The thick myofilament depletion in DEX-DEN muscles occurred in addition to a severe overall reduction of myofibrillar caliber. Gel electrophoresis showed a marked preferential decrease of myosin heavy chain in DEX-DEN plantares and solei, but not in either DEX or DEN muscles. Myosin light chains were also markedly reduced in DEX-DEN plantares and solei. In vitro physiological studies showed a marked reduction of the denervation-induced twitch potentiation in DEX-DEN solei. Maximal tetanic tension (20 Hz stimulation) per gram weight of muscle as well as the twitch-tetanus ratio was significantly reduced only in DEX-DEN solei in relation to controls. Myosin depletion in DEX-DEN muscles may be due to a severe preferential inhibition of its synthesis coupled with an accelerated catabolism.

Actins↗
PubMed1986

Calcium-induced damage of skeletal muscle fibers is markedly reduced by calcium channel blockers.

Vascular perfusion of rat hind limbs with a Ca2+-free physiological solution containing ethylenediaminetetraacetate, when followed by a physiological solution with normal concentration of Ca2+, caused a marked rise of creatine kinase (CK) in the venous effluent. When calcium channel blockers were present in the perfusing solutions, no rise of CK occurred. On histological sampling of perfused muscles, CK rise was roughly correlated with muscle fiber damage of the appropriate muscles. Removal of calcium from the plasmalemma of muscle fibers appears to prevent closure of calcium channels, making the muscle fibers susceptible to a deleterious influx of extracellular calcium. This influx can be prevented by the presence of calcium channel blockers in the perfusates.

Animals↗
PubMed1985

Hypophysectomy mitigates skeletal muscle fiber damage in hamster dystrophy.

Ablation of the pituitary gland by a radiofrequency lesion markedly retarded the musculoskeletal growth of young dystrophic hamsters. The prevalence of centronucleated muscle fibers, which is a reliable cumulative index of the microscopic pathological expression of dystrophy, was drastically reduced in quadriceps muscles of 35- and 45-day-old hypophysectomized dystrophic hamsters, compared with sham-operated controls. Mitigation of skeletal muscle fiber damage by musculoskeletal growth retardation may also occur in human dystrophy.

Animals↗
PubMed1983

Reinnervation is followed by necrosis in previously denervated skeletal muscles of dystrophic hamsters.

Hind leg muscles of dystrophic hamsters were continually denervated by multiple crushes of the sciatic nerve to as long as 93 days of age. In these muscles, the prevalence of centronucleated fibers which is a cumulative index of prior necrosis, remained very low. In control dystrophic muscles the prevalence of centronucleated fibers increased steadily to approximately 80% where it leveled off. By omitting further crushes in other groups of animals, previously denervated muscles became adequately reinnervated. In the reinnervated muscles the prevalence of centronucleated fibers steadily increased throughout the necrotic phase of dystrophy at a rate that was comparable to corresponding stages of the natural history of the disease. These experiments indicated that continued denervation was effective in negating skeletal muscle fiber necrosis throughout the necrotic phase and that the electromechanical activity of muscle fibers which allows muscle fiber necrosis was not a time-locked factor.

Animals↗
PubMedDate not supplied

Prevention of skeletal muscle fiber necrosis in hamster dystrophy.

Necrosis and widespread central nucleation of skeletal muscle cells, which are the main features of skeletal muscle pathology in genetically dystrophic hamsters (UMX-7.1 strain), were not present in muscles of 45- to 65-day-old animals which had been surgically denervated at 15 to 18 days of age. Necrosis and widespread central nucleation were also absent in hind leg muscles at 30 to 60 days of age after transection of the high thoracic spinal cord at 15 to 18 days. Normal excitation or contraction of the skeletal muscle fibers in early age appears necessary for the microscopic pathological expression of the dystrophic gene in skeletal muscles in the UMX-7.1 strain hamsters. These experiments constitute a rare and clear example of consistent prevention of skeletal muscle cell destruction in vivo in an inherited myopathy.

Animals↗