Biomedical subjects

J Fenton

Publications and source records attributed to J Fenton.

At least 73 records · Page 4Linked to original sources

PubMed1978

Electron microscope observations on human fetal striated muscle.

The superior rectus oculi muscle from human fetuses of 5, 9.2, 12 and 24 cm crown--rump length (of ages estimated to be 10, 12, 15 and 23 weeks respectively) have been examined by electron microscopy. "Myotube satellite cells" closely associated with myotubes and myocytes were present in all specimens, but their relative numbers declined with advancing age. Some were small with scanty cytoplasm containing few organelles. Others were rich in organelles, including Golgi apparatus, granular endoplasmic reticulum, comma and dumb-bell shaped dense bodies and centriole or basal body: these cells were numerous in the three smaller specimens but almost absent from the largest. Seemingly active "myotube satellite cells" often extended cytoplasmic processes beyond their confining basal laminae into the endomysial space to contact freelying cells of similar appearance, as well as axon-associated Schwann cells, often to form an extensive network. These "myotube satellite cells" resembled Schwann cells in all respects save association with axons, and it is suggested that they are, indeed, Schwann cells so disposed as to promote axonal growth towards differentiating, but as yet uninnervated, myocytes. Neuromuscular contacts were increasingly numerous with advancing age, usually where several or many axonal terminals contacted a relatively mature (myofilament-rich) muscle cell. Immature myotubes seldom made contact with axonal terminals, even when a closely adjacent (and "coupled") mature muscle cell did so. A sequence of axonal growth and retraction has been proposed which reconciles accounts of early but temporary polyneuronal innervation with commonly accepted ideas regarding the scattered distribution of the muscle components of motor units.

Gestational Age↗

PubMed1978

Electron microscope observations on the changing relationships between unmyelinated axons and Schwann cells in human fetal nerves.

The superior rectus oculi muscle from human fetuses of 5, 9.2, 12 and 24 cm crown-rump length (equivalent to 10, 12, 15 and 23 weeks respectively) and a finger from a 9.5 cm crown-rump length (12 weeks) human fetus were examined by electron microscopy. Very simple relationships between Schwann cells and large bundles of axons were found in the superior rectus muscle of the 5 cm fetus and in the large nerve bundles of the fetal finger. Absence of collagen fibrils in the vicinity of these nerve bundles was also noted. In the superior rectus muscles of the older fetuses the complexity of the Schwann cell/axon relationship increased dramatically, the effect being to envelop single axons in Schwann cell processes. This was also the case in the smaller elaborate bundles in the fetal finger which lay adjacent to move primitive, simply invested nerve bundles. In the examination of near serial sections of Schwann cell/axon bundles it was found that the Schwann cell processes, originally likened to a curtain hanging in fluted folds and slightly twisted, was also badly torn and tattered into longitudinal strips of uneven length. In near serial sections, dramatic changes have been found in the arrangements of Schwann cells and axons. Axons may be singled out and separately invested by the Schwann cell processes, but only for short distances. Lateral transfer of axons from one nerve bundle to another may occur, and loss of axons is apparently not uncommon. The same axon may be of very different diameters at different points along its length.

Axons↗

PubMed1977

[Primary vaginal cancer in adults. Apropos of 72 cases treated at the Fondation Curie from 1956 to 1968].

Primary vaginal cancer are infrequent and amount to 2 or 3 per cent of the gynecological cancers. Their diagnosis is difficult, because many other cancers metastasize in the vagina. The primary vaginal cancer arise mostly after climateric. Adjuvant causes would be a total hysterectomy in the past, prolapsus, prolonged use a pessary or a previous irradiation. The squamous-cell carcinomas, by far the most frequent (91%), are mostly situated in the upper third of the vagina on the anterior and posterior walls. Surgery, being difficult and mutilating is rarely indicated. So the treatment is mainly radiotherapic: external irradiation and intracavitary curietherapy. The radiation techniques are a little different according to the site of the lesion in the lower third or not. The upper lesion can be treated like a cervix cancer. The lower ones are more difficult to handle; for curietherapy, one must use molded apparatus, loaded with Iridium wire, adapted to each special case. The therapeutic results are rather poor:43 per cent for the 5-year cure rate and 36 per cent for the 10-year cure rate: less than for the cervix uteri. The upper lesions have a better prognosis than the lower ones. Results should be improved with an earlier diagnosis, a more accurate radiotherapy and a more precise dosimetry. The non-squamous-cell cancers (adenocarcinomas, sarcomas, mallignant melanomas) are generally rather radio-resistant. They are rare and their prognosis is very poor.

Adult↗

PubMed1976

Letter: Role of the nurse-midwife.

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Kentucky↗

PubMed1976

The nurse midwife.

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Nurse Midwives↗

PubMed1976

[Late sequelae and complications in exclusive high voltage radiotherapy for carcinoma of the cervix uteri (author's transl)].

This study deals with 524 cases of uterine cervix (except stade IV cases) completely treated at the Foundation Curie with esclusive radiotherapy from from 1962 to 1968. The irradiation techniques, as well as the doses given to the tumor and to the critical organs are stated. The various sequelae and complications are described, according to the class and severity. The cases are divided into two groups: 257 cured patients and 267 dead patients. For the cured patients, half of them (49%) had no trouble at all. Among the 130 remaning cases, 16% presented with mild troubles, 23% with moderate sequelae, 9% with marked complications and 3% with severe complications leading to an infirmity. The rectal troubles are frequent (55% of all the troubles) in 40% of the patients; though rarely, they can be severe (6% of the cases). They appear relatively early. The bladder troubles rank second (37% of all the troubles) in 20% of the patients; never severe and without any renal effect, they are more delayed than the former. The skin and soft tissues troubles are only a few (5%) for 5% of the patients. They are mostly mild and moderate. One skin necrosis was noted due for a large part to the very poor general conditions of the patient. The bone troubles are always classified here as marked or severe; they are rare (2,6%) in 2,3% of the patients. Their treatment is satisfactory. One single case of bilateral femur neck fracture gave a permanent infirmity. We have noted no nervous trouble, nor urinary trouble other than the bladder ones, nor bowel troubles aprt from a mild and transient sigmoiditis. The genital troubles noted in 21% of the patients are mostly vaginal adhesion in women over 60 years of age. The sexual troubles, very difficult to analyse, have not been studied here. The treatments of these various troubles have generally been simple, not very compelling, and effective. Only eight patients with severe complications (3%) underwent important therapeutics (fecal diversion, none surgery) and kept an infirmity. One patient (0,4%) died during the post-operative course. For the dead patients, the study is less significant, because of the neoplastic evolution and of the rather short survival. This fact explains that 20% only of the patients (versus 51%) presented with 106 troubles (versus 304). The rectal troubles remain frequent 33%) of the cases), though the bladder troubles, more delayed, are very less numerous (1,8% of the patients). The bone complications are similar in number and quality (2,2% of the patients).

Adult↗

PubMed1975