[Optokynetic and ocular dysmetria tests in the diagnosis of atypical internuclear ophthalmoplegia (author's transl)]

In a patient with atypical bilateral internuclear ophthalmoplegia the optokynetic test and the ocular dysmetria test detected an infraclinical bilateral lag of adduction. The optokinetic test showed amplitude asymmetry of nystagmus, which was larger in both eyes when the fast phase was in abduction. The ocular dysmetria test showed in both eyes that saccades were slower in adducting than abducting saccades: the latters overshooted and showed transient nystagmus. Since bilateral internuclear ophthalmoplegia is often indicative of multiple sclerosis, these tests are particularly helpful in those patients who otherwise would require more complex diagnostic investigations.

Resorption of the zygomatic arch after elevation of a depressed fracture and subsequent osteomyelitis: report of case

A case of osteomyelitis of the zygomatic arch with complete resorption has been presented. The cause of osteomyelitis of the facial bones was discussed. Infection of the soft tissue after intraoral elevation of fractured zygomas does occur, but rarely leads to osteomyelitis and subsequent bony resorption of the underlying bone. Antibiotics have reduced the incidence of osteomyelitic infections in the past 20 years; however, a vigorous regimen of preoperative and postoperative attention to aseptic technique, proper antibiotics, and close follow-up is required to control these problems.

Thyroglobulin biosynthesis in a larval (ammocoete) and adult freshwater lamprey (Lampetra planeri Bl.)

1. The biosynthesis of 18-19S thyroglobulin has been studied in a larval and adult freshwater lamprey (Lampetra planeri Bl.). 2. In vivo and in vitro experiments have been performed by injecting into the coelomic cavity or by incubating branchial region labeled constituents of Tg of higher vertebrates (125I, [3H]leucine and various [3H]carbohydrates). 3. Larvae (ammocoetes) and adults incorporate all labels into thyroglobulin (18-19S Tg), containing a small proportion of labeled T3 and T4, as identified by paper chromatography, and very minute amounts of stable iodine. 4. In adults, the biosynthesis of 18-19S Tg proceeds much more rapidly and the labels are incorporated in higher percentage than in larvae. 5. The demonstration of the biosynthesis of the specific thyroid protein, 18-19S Tg, in larvae indicates that the biochemical mechanism of hormonogenesis is present in larval endostyle before the morphological differentiation of thyroid cells and follicles occurring during metamorphosis. 6. Some 18-19S Tg is apparently stored in the endostyle.

Benign intracranial hypertension after minocycline therapy

A case is reported of a young girl who developed benign intracranial hypertension, with severe bilateral papiledema and a left sixth cranial nerve palsy, after minocylcine therapy. This drug is a semisynthetic tetracycline which has proven to pass into the CSF more effectively and to have a greater lipoid solubility than the other antibiotics of the same group.

[Effect of carbamazepine on free and protein-bound tryptophan in the blood of epileptic patients and healthy volunteers]

The Authors estimated the influence of carbamazepine on both free and linked albumin triptofane in the plasma of 6 epileptic patients and of 6 healthy volunteers, during a period of observation lasting 7 days. The relation free/linked triptofane decreased significantly in the epileptic patients after the first day of treatment, while an analogous phenomenon was observed in healthy people only after the seventh day. Part of triptofane disappeared from plasma thus suggesting a cerebral uptake of the synthesis of serotonin. Carbamazepine displaced some unknown compounds from their links with plasmatic albumin, thus allowing triptofane to link itsel. The Authors therefore confirm the role played by anticonvulsive drugs in modifying the pool of free aminoacids in plasma.

Longitudinal changes of brain amino acid content occurring before, during and after epileptic activity

In cats affected with cortical epileptogenic foci induced by penicillin application to and cobalt implantation into the pericruciate area, the brain amino acids contents were determined in the focus as well as in extrafocal areas. In different groups of animals, brain removal for biochemical determinations was performed at different times before, during and after epilepsy and the values compared to controls. The only amino acid to show a significant change before appearance of spikes in both types of epilepsy was taurine, which decreased. Cobalt epilepsy was accompanied by changes in a larger number of amino acids than penicillin epilepsy: in the former the brain content of taurine, GABA, aspartate, glutamate, serine, threonine, glycine and alanine was altered. The changes were proportional to the severity of epilepsy and more prominent in the focus area. After disappearance of spikes the levels of most amino acids returned to normal except for some amino acids, previously unaffected by penicillin epilepsy, which were decreased. It is proposed that the decrease in brain taurine, occurring before the appearance of penicillin and cobalt epilepsy, could increase the excitability of a certain neuronal population and thus, by potentiating the effects on neurons of penicillin and cobalt, contribute to the initiation of epilepsy.

Further observations on carbamazepine plasma levels in epileptic patients. Relationships with therapeutic and side effects

Plasma levels of carbamazepine, phenytoin and phenobarbital were monitored weekly over a period of 9 weeks in 20 epileptic patients unresponsive to treatment. No attempts were made to modify phenytoin and/or phenobarbital plasma levels; emphasis was on achieving carbamazepine plasma levels of 4 to 10 mug per milliliter. A remarkable drop in seizure frequency was attained within 2 to 3 weeks of monitoring, with carbamazepine plasma and concentrations within the desired range. Children disposed of the drug faster than adults. No effects of phenytoin and phenobarbital on carbamazepine plasma levels could be observed, while phenobarbital on carbamazepine plasma levels fluctuated remarkably without any relationship to carbamazepine levels. Transient leukopenia was present in most of the patients, while a significant reversible drop in red blood cells was observed in eight patients. The data reported confirm that with a careful monitoring of drug plasma levels, carbamazepine may exert a definite passive effect on seizure frequency in epileptic patients poorly responsive to therapy.

Role of galactose in the antigenic properties of thyroglobulin

Thyroglobulins (TG) from a "hot" human thyroid nodule and from Fisher rats have been purified and the effects of progressive removal of sialic acid and galactose on the immunoreactive properties of the proteins were studied. Terminal sialic acid and galactose were released by stepwise hydrolysis with neuraminidase and beta-galactosidase. Agalacto-TG shows a slower electrophoretic mobility than native TG, but in polyacrylamide gel electrophoresis and immunoelectrophoresis it migrates in the same position as asialo-TG. In immunodiffusion agalacto-TG forms a spur with native TG and asialo-TG when tested against anti 19S native TG or anti-asialo-TG sera. It is thus shown that galactose in the terminal environment of the oligosaccharide chains of thyroglobulin is essential for the structural groups involved in the antigenic properties of thyroglobulin.

Bioavailability of two carbamazepine preparations during chronic administration to epileptic patients

Two preparations of carbamazepine, as tablets and in syrup, were given for 8 weeks to 20 patients with epilepsy in a randomized crossover study. Weekly plasma levels were 3-21 mg/1 on dosages of 5-24 mg/kg/day. There was no difference in absorption or steady-state level between the two preparations. Carbamazepine 10, 11-oxide was constantly present when the level of carbamazepine was over 5 mg/l, and tended to be lower with the syrup.

Levels of free amino acids in serum and cerebrospinal fluid after administration of taurine to epileptic and normal subjects

The modifications associated with taurine treatment of the free amino acid content of serum and cerebrospinal fluid were investigated in epileptic and control subjects. In patients with epilepsy the main findings were, in the serum, the correction toward normal of the amino acid levels that were low prior to therapy, and in the cerebrospinal fluid, the increase up to above-normal levels of glutamic acid, greatly diminished before treatment. Thus taurine, which has an anticonvulsant action appears to partially correct the amino acid imbalance in epileptics. The monitoring of taurine-induced glutamate changes in the cerebrospinal fluid could help to establish the correct therapeutic dose.

Soradic ulcerative mutilating acropathy with imbalance of free amino acids in the cerebrospinal fluid

A case of sporadic ulcerative mutilating acropathy is described. Muscle biopsy showed signs of neurogenic atrophy. Motor nerve conduction velocity was slightly reduced. The muscles of the foot were completely unresponsive to electric stimulation of both femoral nerves. The content of free amino acids in serum and cerebrospinal fluid was determined by ion exchange chromatography, and compared with a control group. While in serum no significant changes were found, in CSF most amino acids showed great alterations, mainly consisting in an increase. It is suggested that the primary disturbance may be located in the spinal nerve roots.

Defective thyroglobulin synthesis in an experimental rat thyroid tumor: iodination and thyroid hormone synthesis in isolated tumor thyroglobulin

Purified rat tumor thyroglobulin from the experimental rat thyroid tumor, line 1-1C2, was studied for its thyroid hormone content after in vivo and in vitro iodination and compared with normal and desialylated normal rat thyroglobulin. Tumor thyroglobulin had a very low sialic acid and iodine content; after in vivo iodination it contained only small amounts of triiodothyronine (T3) and no detectable thyroxine (T4). After in vitro iodination with 125I it showed a distribution of T3 and T4 very similar to that of normal and desialylated normal thyroglobulin iodinated in vitro. In vitro iodination dissociated tumor and desialylated normal thyroglobulin to a greater extent than normal thyroglobulin. Tumor tissue, on the other hand, showed considerable iodinating activity in the 105,000 X g pellet when studied with exogenous acceptors. These results are compatible with a role for sialic acid in the maturation and migration of thyroglobulin to the iodination site, rpovided that the intracellular distribution of the iodinating enzymes are normal.

Thyroglobulin biosynthesis in "cold" and "hot" nodules in the human thyroid gland

Studies on "cold" and "hot" nodules from human thyroid gland have been carried out to investigate thyroglobulin biosynthesis and to correlate carbohydrates incorporation and thyroid hormone formation in thyroglobulin. The aim of the investigation was to ascertain the role of carbohydrates of the protein molecule in its migration to the iodinating site of the cell. Thyroid slices from two cases with "cold" and two with "hot" nodules were incubated for 30 to 120 min with [3H]leucine, [3H]carbohydrates (ManNAc, Gal, Man, GlcNAc, GalNAc) and 125I. Soluble and particulate iodoproteins, solubilized by digitonin, were identified by density gradient centrifugation and immunoprecipitation; following hydrolysis carbohydrates and iodothyronines were identified by paper chromatography and chemically determined. While the rate of leucine incorporation into TG increased with time in both "cold" and "hot" nodules, the "cold" nodule, with respect to the "hot" tissue, showed: much lower efficiency incorporating carbohydrates and iodine into TG; lower thyroid/medium ratio of radioiodine; less total soluble protein and soluble TG; more particulate protein and solubilized TG; 1/3 of the carbohydrate and iodine chemical content; only minute amounts of labeled iodothyronines in TG compared to normal levels in "hot" tissue. The formation of thyroid hormone, in enzymatically iodinated TG, and the iodinating activity of the 105,000 X g pellet, incubated with low iodine TG, were similar in both "cold" and "hot" tissues. These results demonstrate that the "cold" nodule is able to synthesize thyroglobulin but the protein is defective in its carbohydrate content. The deficient iodine transport into "cold" tissue and impaired hormonal synthesis are confirmed. The incomplete incorporation of carbohydrates into thyroglobulin in the "cold" nodule could be important for the maturation and migration of the molecule to the iodinating site of the cell

Free amino acids in serum of patients with epilepsy: significant increase in taurine

More than half the amino acids determined in serum were lower in patients with epilepsy than in control subjects. Taurine was the only amino acid to be increased in epilepsy. The changes could represent a compensatory metabolic reaction to limit the imbalance of amino acids in epileptic brain and to facilitate uptake of taurine, which has an anticonvulsant action.

The site of sialic acid incorporation into thyroglobulin in the thyroid gland

Iodine incorporation into thyroglobulin is known to occur within the lumen of the thyroid follicle. Since incorporation of sialic acid, which occupies a terminal position in the oligosaccharide chains, is also a later event in thyroglobulin synthesis, the possibility that sialic acid might be incorporated after thyroglobulin secretion was investigated. In one experimental approach normal rat thyroid hemilobes were incubated with radioactive precursors. Thyroglobulin, analyzed by equilibrium centrifugation in RbCl, had a median density which varied according to the moiety labeled in the following increasing order: leucine smaller than galactose smaller than sialic acid smaller than iodine. The molecules having the highest density were labeled only with iodine. In the second approach, thyroid hemilobes were taken from rats treated with cycloheximide for 16 hours to stop protein synthesis and allow nascent molecules to be secreted, and incorporation of precursors into thyroglobulin was analyzed by sucrose gradient centrifugation. Leucine incorporation was 6% of control but the amino acid was found in the NH2-terminal position. N-Acetylmannosamine (sialic acid precursor) and galactose incorporation were also completely inhibited whereas iodine incorporation was 10% of control. Incorporation was not restored by thyrotropin treatment, and the sialyltransferase and iodination systems were reduced only to 50 to 70% of control. The results indicate that sialic acid is incorporated only in nascent thyroglobulin and not in thyroglobulin molecules already secreted into the follicular lumen. A large fraction of the iodine incorporation also seems to occur in newly synthesized thyroglobulin.

Isolation of desialylated and low-iodinated thyroglobulin in an experimental rat thyroid tumour

In an experimental rat thyroid tumour (Wollman line 1-1C2) thyroglobulin (TG) was isolated from soluble iodoproteins by ammonium sulphate fractionation and density gradient ultracentrifugation. The isolated TG was characterized by polyacrylamide gel electrophoresis, microimmunodiffusion, immunoelectrophoresis, analytical ultracentrifugation and by chemical determination of sialic acid and iodine content.

Tumour thyroglobulin has a sedimentation coefficient of 17.7S, which is similar to that of enzymatically desialylated thyroglobulin (18.4S) in the normal rat; tumour TG shows a slower electrophoretic mobility than native TG and similar to rat desialylated TG.

In double immunodiffusion tumour TG is shown to precipitate with an identity reaction with both native and desialylated rat TG; in immunoelectrophoresis it has a slower migration than native TG and is very close to that of enzymatically desialylated TG. Tumour TG has an iodine content of 0.02 % and a sialic content of 0.15 %. Chromatography of the 125I-labelled tumour TG revealed the presence of mono- and diiodothyrosines, a very small amount of triiodothyronine but no thyroxine.

These results suggest that tumour TG, isolated in the experimental rat thyroid tumour, previously shown not to incorporate sialic acid into thyroglobulin, has a different electrophoretic mobility from native TG but is very similar to desialylated rat TG and has a very low sialic acid and iodine content as well as a striking decrease in thyroxine.

Abnormal iodoproteins in human congenital goiter

Soluble iodoproteins from three congenitally goitrousthyroids have been isolated by salt fractionation followed by DEAE-cellulose chromatography, gel filtration and density gradient centrifugation and characterized by analytical ultracentrifugation, polyacrylamide electrophoresis and by immunological procedures. It has been shown that the amount of 19 S thyroglobulin is strikingly decreased, the soluble proteins consisting of several slow-sedimenting iodocompounds: (3 S-6S) not identified as any of the known thyroglobulin subunit. The immunological data suggest that some of the heterogenous 3 S-6 S fractions is related to the thyroglobulin metabolism.