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Biomedical subjects

H Hofer

Publications and source records attributed to H Hofer.

At least 55 records · Page 3Linked to original sources

Femoral nerve lesion subsequent to renal transplantation.

Severe femoral neuropathy subsequent to renal transplantation is described in a patient who died in the 5th postoperative week. Postmortem examination revealed a compression of the femoral nerve by an older hematoma of the iliac muscle, ipsilateral to the transplantation, and severe Wallerian degeneration of the nerve beginning at the site of the hematoma. It is postulated that the hematoma resulted from surgical trauma on the iliac muscle and was facilitated by previous anticoagulation and hypertensive vasculopathy. We suggest that every patient with similar symptoms occurring after renal transplantation should be investigated for a retroperitoneal hematoma. If such a hematoma is diagnosed, immediate decompression neurolysis should be performed in order to prevent prolonged recovery time or permanent disability.

Femoral Nerve↗

Morphologic studies in saphenous vein grafts for aorto-coronary bypass surgery. Part I: Morphology of the Graft using ordinary surgical preparation techniques.

Vein bypass grafts in 8 patients were examined by light microscopy (LM) only or, in addition, by transmission electron microscopy (TEM) and scanning electron microscopy (SEM) before stretching, after stretching and immediately before implantation. Before stretching, the endothelium showed only discrete changes and detachment of the endothelium was rare. After stretching severe endothelial damage was evident, including loss of large areas of endothelium and extensive endothelial tears. Before implantation there had been an extension of the tears and the endothelial detachment in individual preparations. The most important factor causing damage is stretching of the vein. The incubation medium may also play a significant role. Damage incurred before operation or during removal, and hypoxia are of lesser importance. By avoiding endothelial damage it should be possible to limit the occurrence of early postoperative thrombosis and possibly severe late changes as well.

Coronary Artery Bypass↗

Morphologic studies in saphenous vein grafts for aorto-coronary bypass surgery. Part II: Influence of a pressure-limited graft dilation.

The evidence of considerable damage caused by stretching to the vein transplants for aorto-coronary bypasses led us to a modified technique of vein dilation that allows control and limitation of the pressure to which the veingraft is exposed. The efficiency of this procedure in terms of reduced damage to the vascular wall was investigated by microscopic and electronmicroscopic methods. It could be shown that the integrity of the intimal layer of vein grafts can be maintained to a high degree. Clinically this implies that the long-term patency rate of aorto-coronary veingrafts may be improved. This will be subject to further coronarographic studies during the follow-up of a present series of patients.

Aged↗

[Modification of urinary pH through ascorbic acid].

The influence of orally administered ascorbic acid on the urinary pH of 10 healthy volunteers and 10 patients with infected urine was investigated. During a four-day period of investigation urinary pH and the concentration of ascorbic acid in the respective urines were measured five times a day. On the second and third day three times a dose of 2 g ascorbic acid was given, while the diet was under control all four days. A correlation between pH decrease and ascorbic acid concentration is only observed if the concentration of the latter is higher than 200 mg%. The mean decrease in urinary pH between days with ascorbic acid supply and days without is -0,16 pH units for the volunteers respectively -0,18 pH units for the patients. Therefore, vitamin C can not be recommended to lower the pH of alkaline urines.

Administration, Oral↗

Electron microscopic study of the origin and formation of Reissner's fiber in the subcommissural organ of Cebus apella (Primates, Platyrrhini).

Two kinds of secretion are formed in cells of the subcommissural organ (SCO) of Cebus apella. The "light secretion" is found in saccules originating from the endoplasmic reticulum. This secretion is stored in the peripheral portion of the cells and is not involved in formation of Reissner's fiber (RF). In close association with the Golgi complex, electron-dense granules are developed, containing a finely granular substance. These granules accumulate beneath the apical plasmalemma of the cell. Their content is discharged into the third ventricle, where it occurs in the form of a thin layer of secretion. This material appears to constitute the RF at the level of the entrance to the mesencephalic aqueduct.

Animals↗

The morphologic diagnosis of analgesic (phenacetin) abuse.

A number of different morphologic characteristics were examined to determine their relative values in establishing a purely morphologic diagnosis of phenacetin abuse. These included hyperpigmentation of the skin, the costal cartilages, the liver, and the renal tubules, and capillarosclerosis of the lower urinary tract. Hyperpigmentation of the skin, liver, and renal tubules cannot be used in the diagnosis of phenacetin abuse. Massive brown pigmentation of the costal cartilages in patients under 60 years of age suggests phenacetin abuse, but even this morphologic parameter, when used alone, is insufficient to establish a definite diagnosis. Capillarosclerosis in the lower urinary tract does, however, permit one to diagnose phenacetin abuse with certainty, as it is found exclusively in this condition.

Adolescent↗

Histological and ultrastructural changes in idiopathic facial palsy.

Light- and electron-microscopic findings in the facial nerve are reported in a patient who died 8 months after the onset of acute idiopathic facial palsy. There were signs of regeneration after axonal destruction, and inflammatory infiltrates confined to the intracanalicular part of the nerve were found. These findings suggest a viral or immunological etiology, which may become pathogenetic due to the length and narrowness of the Fallopian canal.

Facial Nerve↗

[Taste buds in the epithelium of the plica sublingualis of New World monkeys (author's transl)].

The Plica sublingualis of new world monkeys was studied microscopically. In Ateles there are approximately 1700 taste buds in the epithelium of the Plica sublingualis, they are fewer in number in Alouatta, Lagothrix, Aotus and are absent in Saimiri and Cebus. The taste buds are situated consistently at the tip of the Plica sublingualis and near the orifices of the submandibular and sublingual salivary glands. From this topographical coincidence it is inferred that the function of the taste buds at the Plica sublingualis might permit a comparison between the fresh saliva with the general saliva in the cavum oris along a gradient.

Animals↗

[The effectiveness of the lead covering in roentgen studies of the pelvis].

This is a report on the protective covering of the infant's pelvis. Comparative measurements of two customary lead covers, phantom measurements and comparative measurements on infants were carried out. Results show that a properly applied lead cover with a correct lead value (at least the equivalent of 1 mm of lead) may be considered a very effective protection against irradiation, a method that reduces irradiation to the gonads by a factor of 100. The initial dosis is at the surface and, as a rule is below 1 mR. The dosis attacking the gonads is most likely within the micro-R-range. Thus we state for practical purposes that a lead protective cover is very effective in X-raying the infant pelvis--indeed it should be mandatory for every pelvic X-ray taken in infants.

Female↗

Effects of systemic administration of 6-hydroxydopamine on the circumventricular organs in nonhuman primates. I. Area postrema.

6-Hydroxydopamine (6-OH-DA) has been shown to produce degenerative changes in noradrenergic nerve terminals and preterminals in the CNS following intracisternal, intraventricular or direct injection into the brain parenchyma. Systemic injection of 6-OH-DA is known to result in degenerative changes in noradrenergic terminals in the peripheral nervous system. However, only a few studies have been carried out on the effects of systemic injections of 6-OH-DA on noradrenergic terminals in the CNS. In the present study cynomolgus and squirrel monkeys were injected intravenously on two successive days with total doses of 350 mg/kg and 150 mg/kg of 6-OH-DA, respectively, and sacrificed at 2 and 24 h following the second injection. Degenerative changes in the area postrema (AP) neurons in all injected animals were characterized by a generalized increase in electron density of cytoplasmic elements in axonal terminals and preterminals. Multilamellar bodies, clusters of clear and dense core vesicles, increased numbers of secondary lysosomes, and an increase in the number of glycogen increased markedly in injected animals, but no other glial alterations were observed. The number of mast cells in the AP was greater in injected than in noninjected animals, both in the perivascular spaces (PVS) and in parenchymal locations. Cell processes in the PVS were occasionally observed to contain electron dense bodies, and degenerative changes were seen in supraependymal processes in some injected animals.

Animals↗

A comparative study on the microscopic anatomy of the sublingua of Tupaia glis (Tupaiiformes).

The microscopic anatomy of the sublingua of Tupaia glis was studied comparatively to find out if there is any possible explanation of the origin and the structural characteristics of the sublingual organ in Callicebus. The sublingua of Tupaia is at a primitive stage, but has nothing at all in common with the sublingual organ. The frenal lamella is not remarkable in this species. There are reasons to assume that the sublingual organ is a modified frenal lamella developed only in Callicebus.

Animals↗