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Biomedical subjects

G Lang

Publications and source records attributed to G Lang.

At least 109 records · Page 6Linked to original sources
PubMed1987

Recording of single unit potentials in human spinal nerve roots: a new diagnostic tool.

Single unit potentials can be recorded directly with wire electrodes during an operation in man. Since averaging is not necessary this recording method is a fast neuromonitoring tool. Using 2 pairs of platinum electrodes it was possible to record extracellular single unit potentials at 2 sites in nerve root filaments in the spinal canal and to determine conduction velocities. Afferent and efferent single unit potentials could be distinguished from each other by a reversed conduction time and a reversed potential change making a differentiation between dorsal and ventral root parts possible. An activity increase due to touching the skin could be recorded. Therefore dermatomes of nerve root filaments and root filaments of dermatomes can be identified during the operation.

Action Potentials↗
PubMed1987

[The relation between melorheostosis and tumors].

Melorheostosis was diagnosed in a 13 year old female. Two years later an x-ray of the skull showed an calcified intracerebral mass. At the age of 18 years the patient died. The autopsy confirmed the diagnosis of melorheostosis and revealed a meningioma of falx cerebri in close proximity to predominantly intraventricular calcified tissue. A neurinoma of the left acoustic nerve was also found. In the literature melorheostosis has been anecdotally described in combination with nevi, hemangiomas, pelvic lipoma, lipoma of the spinal cord, chondrofibromas of the median nerve, tuberous sclerosis and neurofibromatosis. The nature of the relationship between melorheostosis and neoplasms has not been clarified. Those observations as well as the present report indicate an increased frequency of tumors (particularly of the nervous system) in patients with melorheostosis.

Adolescent↗
PubMed1987

[Study by radioactive microspheres of bone microcirculation in aseptic osteonecrosis of the femoral head].

Thirty-two hips affected by aseptic necrosis, four of them post-traumatic and 12 contralateral hips thought to be healthy have been studied by combining superselective arteriography with the injection of radioactive microspheres. It has been possible to show that aseptic necrosis begins with a global ischaemia and is followed by an incomplete revascularisation leaving a necrotic area. On the border between the two areas hypervascularity produces a zone of fragility where microfractures develop with detachment of a sequestrum. The presumed opposite hip is almost always, even in traumatic lesions, the site of a hypovascularity which seems to suggest a predisposition to the lesion. There is a correlation between radiological and clinical worsening and the development of revascularisation in the femoral head.

Femur Head↗
PubMed1987

Nerve fibre counts for an intercostal nerve to cauda equina nerve root anastomosis.

Mean nerve root diameters of thoracal, lumbal and sacral roots have been determined and the corresponding cross section areas calculated. The myelinated axons of these roots have been counted and the axon densities calculated. The myelinated axons of 3 lower intercostal nerves have also been counted. One intercostal nerve has with about 9,000 myelinated fibres enough axons for the regeneration of the ventral (3,000) and dorsal (16,000) myelinated fibres of the sacral roots 3 and 4 together. One intercostal has enough nerve fibres to reconstruct urinary bladder and bowel function on one side. The importance of performing a nerve anastomosis which considers functional aspects has been emphasized.

Aged↗
PubMed1986

[Prolactinoma in the male].

In a retrospective study the medical records of 13 male patients with macroprolactinomas were evaluated concerning anamnestic data, clinical, endocrinological and localisation-diagnostic findings as well as therapeutic measures. The main symptoms were disturbances of vision and impaired potency and impaired libido, respectively. The ophthalmological complaints nearly exclusively caused the patients to see the doctor. Clinically the signs of hypogonadism were found. The diagnosis was ascertained by increased serum prolactin levels, ophthalmological findings, X-ray of the sella, cranial computed tomography as well as angiography of the carotid. The operative treatment did not show any normalization of the serum prolactin levels. The rate of recidivations after exclusive operative treatment was high. An additional medicamentous therapy with dopamine agonists is nearly always necessary after operation. Whether or not bromocriptine shall be used as primary therapy, must be decided on in the individual case.

Adolescent↗
PubMed1986

[Measurement of single action potentials of the dorsal nerve roots in the human].

The method of recording single unit potentials with wire electrodes in animals has been applied to humans. Using two pairs of special electrodes it was possible to record extracellular single unit potentials at two different places in nerve root filaments in the spinal canal with the dura open and to determine conduction velocities. This method may be used in the future for the identification of afferent fibres in the spinal canal during the operation.

Afferent Pathways↗
PubMed1986

Delayed hypotensive response to dialysis in hypertensive patients with end-stage renal disease.

This study was designed to determine the ambulatory arterial blood pressure profile in hypertensive patients with end-stage renal disease during and following hemodialysis. Blood pressure was noninvasively monitored at 15-min intervals for 24 h using a fully automatic portable recorder, while the 10 patients studied followed their customary activities and were not receiving any antihypertensive medications. Prior to dialysis, the blood pressure was 179 +/- 7.0/101 +/- 3.7 mm Hg. After 4 h of dialysis, the systolic blood pressure did not change, while the diastolic blood pressure fell only slightly (178 +/- 4.2/94 +/- 2.4 mm Hg). After dialysis was completed, a progressive fall in both systolic and diastolic blood pressures was observed reaching the lowest value in the 5th h after dialysis (146 +/- 5.5/75 +/- 3.2 mm Hg). Thereafter, the fall in blood pressure was sustained during sleep (147 +/- 1.7/77 +/- 0.9 mm Hg) and during routine daily activities (147 +/- 2.0/78 +/- 1.0 mm Hg). The delayed fall in blood pressure was observed in patients in whom the plasma renin activity was elevated (8.4 +/- 2.4 ng/ml/h) and in patients in whom the plasma renin activity was low or normal (0.9 +/- 0.2 ng/ml/h). Our data suggest that during dialysis vasopressor mechanisms are activated to sustain blood pressure and that following dialysis such mechanisms are attenuated allowing the blood pressure to fall towards normal levels. The delayed fall in blood pressure documented by this study indicates that in many hypertensive patients with end-stage renal disease antihypertensive drug therapy is not required the day after dialysis.

Adult↗
PubMed1986

[Clinical anatomy of the lateral intervertebral region of the 3d-7th cervical vertebrae].

Under consideration of the ventrolateral approach, the Regio intervertebralis lateralis was demonstrated for 25 isolated cervical vertebral columns under clinical-anatomical and morphometrical aspects. For obtaining mean values and as a comparison of the sides, the M. longus colli, the bony structures under special consideration of the Foramen intervertebrale in the cranio-caudal and medio-lateral extension, the A. vertebralis with its Rami spinales, the system of the venous blood pathways, the Ganglion spinalis and the spinal nerve root were examined.

Adolescent↗
PubMed1986

[Clinico-topographical anatomy of the lateral intervertebral region in the area of the 3d to the 7th cervical vertebrae].

Under consideration of the ventrolateral approach, the Regio intervertebralis lateralis was demonstrated for 25 isolated cervical vertebral columns under clinical-topographical and morphometrical aspects. For obtaining mean values and as a comparison of the sides, the M. longus colli, the bony structures under special consideration of the Foramen intervertebrale in the craniocaudal and medio-lateral extension, the Arteria vertebralis with its Rami spinales, the system of the venous blood pathways, the Ganglion spinalis and the spinal nerve root were examined.

Adolescent↗
PubMed1985

Pregnancy-associated beta 1-macroglobulin: detection on the surface of ovarian cancer cell lines.

Pregnancy-associated beta 1-macroglobulin (beta 1-PAM) is a serum protein which can be detected at elevated levels in the blood of many ovarian cancer patients. The presence of the antigen was investigated on the surface of 4 human ovarian cancer lines and 32 other human and rodent cell types and lines by means of immunofluorescent staining and anti-beta 1-PAM-enzyme conjugate. The antigen was detected only on the ovarian lines but no secretion of beta 1-PAM into the culture supernatants was observed. The ovarian cancer cells appeared to display the beta 1-PAM constantly during culture, and enzymic treatment of the cells indicated that detection of the cell-bound antigen with antiserum could be, at least partially, eliminated with proteases but not glycosidases or neuraminidase. The results serve to confirm the association of beta 1-PAM with ovarian cancer.

Antigens, Surface↗
PubMed1985

[Congenital spontaneously ruptured epidermoid cyst of the iris].

At the age of 8 months a healthy boy developed a epidermoid cyst of the iris which increased rapidly in size and ruptured when he was 12 months old. Because of the clinically suspected diagnosis of medulla epithelioma an en-bloc excision was performed. The tumor consisted of keratinizing squamous epithelium producing masses of keratin. After an unremarkable postoperative course lasting four months, the boy developed an immunologic reaction to the tectonic graft in association with Coats' disease six months after the operation.

Corneal Transplantation↗
PubMed1985

[Accidental bilateral asymmetric ruby laser maculopathy].

A 19-year-old man sustained a bilateral coagulation of the macula caused accidentally by a ruby laser rangefinder mounted on a tank. Five days later vision was OD 0.7, OS 0.05; there was a distinct disk of coagulation of the retinal pigment epithelium with clumping of melanin granula, more in the left eye than in the right, and subretinal hemorrhage on the left. Visual improvement corresponded to the asymmetric morphologic findings: Within two months visual acuity in the right eye recovered to 1.0. In the left eye there was a temporary increase to 0.3, then permanent deterioration of vision to 0.05 OS. The macula of the left eye showed massive lipofuscein aggregation in the subretinal space. Fluorescein angiography after two months showed some hyperfluorescence, more in the left than in the right eye, but no fluorescein extravasation. The vision in the left eye is still 0.05 one year after the accident.

Accidents↗