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Biomedical subjects

J Wood

Publications and source records attributed to J Wood.

At least 271 records · Page 15Linked to original sources
PubMed1980

Neuromorphology and neuropharmacology of the human penis: an in vitro study.

The neuromorphology and neuropharmacology of the human penis are only briefly described in literature. The present study was undertaken to define the adrenergic and cholinergic neuromorphology of the human corpus cavernosum (CC) and corpus spongiosum and to evaluate the in vitro response of the CC to pharmacologic stimulation. Human penile tissue was obtained from six transsexual patients undergoing penectomy. For morphologic study, the tissue was processed for (a) hematoxylin and eosin staining; (b) smooth muscle staining; (c) acetylcholinesterase localization; (d) glyoxylic acid histofluorescence; (e) electron microscopy; and (f) electron microscopy after glutaraldehyde dichromate fixation. In addition, strips of CC were placed in in vitro muscle chambers and tension changes recorded isometrically after stimulation with norepinephrine (NE) and acetylcholine. The CC contains abundant smooth muscle, numerous glyoxylic acidfluorescent (catecholaminergic) fibers and varicosities, and a scant distribution of acetylcholinesterase-positive fibers. Fewer of all these elements were present in the corpus spongiosum. No "polsters" were observed in the CC. Although glutaraldehyde-fixed controls exhibited no typical adrenergic vesicles (small, dense core, measuring 400-600 A in diameter), some small, strongly electron-dense vesicles were found in glutaraldehyde dichromate-fixed tissue and were thought to contain NE. A variety of other vesicles were also encountered. The addition of NE to the in vitro muscle chambers caused a dose-related contraction, which was blocked by pretreatment with phentolamine in all CC strips tested. Acetylcholine in high concentration produced minimal contraction in 2 of 24 strips. Our morphologic and pharmacologic data suggest that the sympathetic nervous system may affect erection by acting not only on the penile vasculature but also by direct action on the smooth muscle of the CC itself.

Acetylcholine↗
PubMed1980

Professional attitudes to patient participation groups: an exploratory study.

An exploratory study of the development of patient participation groups in general practice and general practitioners' attitudes towards them suggests that many general practitioners may not yet be aware of this innovation and may at first react negatively to the idea. This response stems in part from misconceptions about the origins and functions of these groups, a failure to see their relevance to professional objectives, and a fear that they will threaten general practitioners' autonomy and status. In contrast, general practitioners who have formed groups believe they have an important contribution to make to their developing role and have been encouraged by their experience so far. Therefore, at present, patient participation groups should neither be rejected out of hand, nor welcomed as a panacea.

Attitude of Health Personnel↗
PubMed1979

Autonomic innervation of the mammalian penis: a histochemical and physiological study.

The distribution of adrenergic and cholinergic nerves was studied in penile tissue from rat, rabbit, cat, monkey and man. Glyoxylic acid histofluorescence and acetylcholinesterase-positive fibers were found in all tissues examined, but histofluorescent, presumably adrenergic fibers predominated. In general, except in the rabbit, more nerve fibers of both types were found in the corpus cavernosum (CC) than in the corpus spongiosum/penile urethra (CS). The rabbit penis showed slightly more adrenergic fibers in the CC than in the CS and more cholinergic nerves in the CS than in the CC. The CC of the monkey demonstrated an alpha receptor mediated contractile response to norepinephrine (NE) stimulation and no response to acetylcholine (ACh) in an in vitro muscle bath.

Acetylcholinesterase↗
PubMed1979

Increased nuclease activity in cells treated with pppA2'p5'A2'p5' A.

A series of 2'-5'-linked oligo(adenylic acid) triphosphate (2'-5' A) inhibitors of protein synthesis were described recently. These inhibitors are synthesized from ATP by an enzyme activated in interferon-treated cell extracts or rabbit reticulocyte lysates by double-stranded RNA. We show here that 2'-5' A is a potent inhibitor of protein synthesis in intact cells of different origin (human, monkey, hamster, and mouse). At a concentration of 10 nM (in AMP equivalents), protein synthesis is inhibited by 50-85%. There is also a secondary effect on the total RNA synthesis which becomes evident several hours after inhibition of protein synthesis. All of these effects, however, are transient and, after a recovery period, both RNA and protein synthesis resume rates comparable to the appropriate controls. A nuclease activity is detected in cells after treatment with 2'-5'A. The total polyadenylylated RNA is much reduced in comparison to that from untreated cells, and electrophoretic analysis in polyacrylamide slab gels provides evidence for its degradation. Similarly, there is an apparent degradation of ribosomal RNA. Consistent with these results, extracts from cells that had been treated with 2'-5'A manifest an enhanced nuclease activity in vitro on incubation with exogenous RNA. Here, we propose that, as in cell-free systems, the mechanism of action of 2'-5'A in intact cells involves activation of a nuclease. This activation is transient, but the nuclease remains sensitive to further activation by the inhibitor.

Adenine Nucleotides↗
PubMed1979

Lecturing to general practitioners.

We describe the findings of a telephone interview survey among those who have recently been paid through the Department of Health and Social Security (DHSS) to lecture to general practitioners in the North-Western Region. We report the way the lectures are planned and the lecturers' attitudes and motivation. The findings have implications for both future research and policy.

Education, Medical, Continuing↗
PubMed1979

Primary tumors of the heart: a rewarding challenge.

During a 10-year period 21 patients were treated for tumors of the heart, including 19 myxomas, one fibroma, and one sarcoma. The latter two cases are presented separately, and the 19 myxomas are analyzed together. An unusual association of left-sided myxoma with mitral valve abnormalities was found. In the surgical group (18 patients) there were no deaths and one case of postoperative cerebrovascular accident (CVA) with residual sequelae during a mean follow-up of 55 months. The results show the good prognosis of patients operated upon for myxomas of the heart and that there is no need for routine full-thickness excision of the septum in its treatment.

Adolescent↗
PubMed1979

Enhancement of retrovirus production by anti-interferon serum.

In order to investigate the role of endogenous interferon in retrovirus production by infected or induced cells, the effect of two sera raised against mouse interferon has been tested on various C-type murine viruses. Addition of a highly potent anti-interferon serum to 3T3/IC cells chronically infected by the Moloney strain of MLV results in a considerable increase of virus production, as tested by reverse transcriptase assay. This effect is neutralized by an excess of exogenous interferon. The greatest effect of anti-interferon sera was obtained in the derepression of endogenous retroviruses: in K. BALB/c cells treated by IUDR, anti-interferon serum increases up to 50-fold the expression of the endogenous virus. The extinction of virus production which secondarily occurs after its induction by IUdR is likely to be caused by cellular endogenous interferon. The biological parameters of the viral agent produced in the presence of anti-interferon serum are those of the xenotropic endogenous virus.

Animals↗
PubMed1977

Changes in hospital antibiotic therapy after a quality-of-use study.

During the first quarters of 1976 and 1977, the use of parenteral gentamicin, cloxacillin, ampicillin, and cephalothin was surveyed in 219 (in 1976) and 240 (in 1977) patients admitted to a surgical, a gynaecological, and a medical ward of a teaching hospital. In 1976, therapy was assessed as irrational in 42%, 50%, and 12% of the surgical, gynaecological, and medical patients, respectively; the corresponding figures for 1977 were 24%, 25%, and 22%. The more rational therapy in 1977 was due to a shorter duration of prophylactic therapy; and to fewer patients receiving oral antibiotics just before or after the parenteral antibiotic.

Ampicillin↗
PubMed1977

Echocardiographic spectrum of mitral valve motion in children with and without mitral valve prolapse: the nature of false positive diagnosis.

To examine problems in echocardiographic diagnosis of mitral valve prolapse, multiple crystal cross-sectional echocardiography and single crystal recordings derived from the multiple crystal array were used to study 45 clinically normal children aged 3 to 15 years (Group A), 26 children aged 2 to 10 years with known mitral valve prolapse (Group B), 12 children with a catheterization-proved large left to right shunt at the ventricular level (Group C) and 8 children with catheterization-proved left ventricular outflow tract obstruction (Group D). Children in Groups A and B were not studied hemodynamically. Children in Groups C and D had no evidence of mitral valve prolapse on angiography and were studied echocardiographically to determine the effect of changes in ventricular shape on the patterns of mitral valve motion. In the real time cross-sectional studies, normal patients demonstrated a spectrum of mitral valve motion in which the bodies of the anterior and posterior leaflets became slightly horizontal with systolic ejection. The mitral apparatus assumed a curvilinear funnel shape. Arching of the leaflets into a horizontal configuration was more striking in the presence of either left ventricular dilatation in left to right shunt or involvement of the anterior mitral anulus in subaortic stenosis (two patients) and was associated with false positive M mode tracings suggesting mitral valve prolapse. This latter configuration was easily differentiated from the superior motion of the body of the leaflets in true prolapse. Studies of single crystal M mode recordings derived form the cross-sectional array in known locations from six normal patients revealed M mode patterns of pseudoprolapse in tracings derived from the leaflet body and patterns of normal motion at the free edge. In contrast, superior-posterior prolapse visualized in cross-sectional studies in patients with the click-murmur syndrome was associated with abnormal M mode recordings from all parts of the leaflet, including the free edge, although the abnormalities were most striking in tracings derived from the leaflet body. The M mode echocardiographic findings of mitral valve prolapse in both normal patients and patients with the click-murmur syndrome were dependent upon transducer angulation and the portion of the valve examined. The critical differentiation of the spectrum of normal valve motion from prolapse requires careful evaluation of echoes from the free edge of the leaflet where the posterior and anterior leaflet echoes coapt in early systole.

Adolescent↗