Patrick Sourander

Lesions in the Depth of the Brain Produced by a Beam of High Energy Protons

Restricted lesions were produced in the depth of the goats brain by means of cross-fire irradiation with a narrow beam of high-energy protons. The radiosurgical technique and the histopathology of the lesions are described. It was possible to produce circumscribed cerebral lesions of a type well suited for physiologic experimentation without damaging surrounding nervous tissue. The method may also be applied to neurosurgery in man. (auth)

Rett syndrome: Cerebellar pathology

The cerebellar pathology at autopsy of 5 patients with Rett syndrome is described. The patients ranged in age from 7-30 years. All had markedly reduced brain weights with proportionately small cerebella. Microscopic examination revealed loss of Purkinje cells, atrophy, astrocytic gliosis of the molecular and granular cell layers, and gliosis and loss of myelin in the white matter. Cortical atrophy occurred focally along the folia and was often more marked in the tips of the folia. The 2 oldest patients had been treated with phenytoin which may have contributed to the morphologic changes. Atrophy and gliosis increased with age or in patients without phenytoin treatment; the youngest patient demonstrated only minor microscopic changes. In addition to the generalized alterations, 1 patient had several adjacent folia with severe atrophy. The results indicate that cerebellar changes in Rett syndrome consist of general hypoplasia with the addition of atrophy beginning in childhood and progressing over many years.

Rett syndrome: Spinal cord neuropathology

The morphologic changes of the spinal cord in Rett syndrome are described in 2 young women who died at 20 and 30 years of age. Both patients had been in a severely disabled state for many years with tetraparesis and extreme muscle wasting. Degeneration and loss of spinal ganglion nerve cells, in addition to gliosis of both the white and gray matter of the spinal cord, were evident. The number of motor neurons appeared to be reduced and axonal changes suggestive of degeneration were observed in both the ascending and descending tracts.

Muscle changes in protein-deprived young rats

Rats were reared on a standard diet up to the age of 6 weeks when they were divided into two groups. One was fed on a diet containing 14% protein and the other on a diet with only 1.5% protein. The size of the various fibre types of the EDL muscle of both groups was assessed at 6 and 25 weeks of age. All the fibre types of protein-deprived rats were smaller compared to the age-matched controls, the difference being most evident in the 2B fibres. In the protein-deprived rats the 2B fibres atrophied while the type 1 and type 2A fibres simply failed to grow. Histochemical and ultrastructural examination revealed a marked reduction of the subsarcolemmal mitochondria after prolonged protein deprivation; normally large accumulations of mitochondria are seen preferentially in type 2A fibres.

Effects of training on skeletal muscle in protein-deprived rats ☆

The effects of exercise on atrophy of muscle fibres and loss of mitochondria in the extensor digitorum longus (EDL) and soleus muscles were studied in protein deprived rats. They had smaller muscle fibres than aged-matched control rats, the difference being more evident in type 2 than type 1 fibres both in the fast EDL and slow soleus muscles. The loss of weight was more pronounced in the EDL muscle which is composed mainly of type 2 fibres than in the soleus muscle which is composed mainly of type 1 fibres. Protein deprived rats subjected to a programme of periodic running on a treadmill for 12 weeks showed less muscle atrophy than sedentary, protein deprived rats. This effect of exercise in diminishing the degree of atrophy was more pronounced in the type 2 than type 1 fibres. The protein deprived rats which had been sedentary showed a marked loss of subsarcolemmal mitochondria, which was not seen in protein deprived rats undergoing exercise.

Histology of the Surgical Radiolesion in the Human Brain as Produced by High-Energy Protons

Abstract : Changes in the mid brain of a man following irradiation were studied on one side of the spinothalamic tract region by high energy protons to relieve pain. The man was 59 and suffered from intractable pain due to cancer of the lung with spread to the axilla and the supraclavicular region. The irradiated region was sharply demarcated being ovoid in shape with a crenated border. Destruction of myelin sheaths, axons, astrocytes and oligodendroglia occurred in the irradiated region and some tiny perivascular haemorrhages were present. Nuclear debris and collections of macrophages were found at the edge of the necrosis. Little proliferation of astrocytes was seen 9 weeks after irradiation. The changes were exactly similar to those seen in goats 7 and 4 weeks after irradiation with the same dose. Tiny, discrete, rounded, zones of necrosis were seen in man just rostral to the confluent necrosis. They are presumably the result of intersecting beams as they pass to the center of irradiation. (Author)

Nutritional rehabilitation of skeletal muscle in protein-deprived young rats

The effect of severe protein deprivation and subsequent nutritional rehabilitation on the fibre size and mitochondrial enzyme activity of the extensor digitorum longus (EDL) and soleus muscles of the young rat has been examined. Protein deprived rats showed atrophy of type 2 fibres predominantly, reduced histochemical activity of succinic dehydrogenase (SDH) and reduced biochemical activity of citrate synthase. Nutritional rehabilitation indicated by resumption of the original body weight resulted in complete restitution of the weight of the muscles and the size of type 1 and type 2 fibres, but not of the activity of SDH and citrate synthase. The results indicate that regarding size, type 2 fibres tend to be more influenced than type 1 fibres by the nutritional supply. The mitochondrial enzyme activity which is decreased by protein deprivation does not regain the normal levels as quickly as the muscle fibres resume their normal size.

Changes in virulence of attenuated strains of poliomyelitis virus after passages in cultures of human embryonic tissue

Five attenuated strains of poliomyelitis virus, LSc, P 2149, P 2226, P 1553, and P 712, obtained from Dr.A. Sabin were passed in tissue cultures of human embryonic lung. The virulence of different passages was then studied by intracerebral inoculation of rhesus or cynomolgus monkeys and by estimating their efficiency of plating in monkey kidney cultures with an acid agar-overlay. Strain P 1553 gave histologically demonstrable poliomyelitis in most monkeys tested with passages of this strain, and the monkey kidney passage as well as all human cell passages were found not to be of a truly delayed type in plaque tests with acid medium. The LSc and P 2149 strains retained their reduced efficiency of plating under acid agaroverlay through all human cell passages, and no signs of poliomyelitis were found clinically or microscopically in monkeys intracerebrally inoculated with the 3rd, 5th, 8th, and 9th human cell passages of these strains. The results obtained in corresponding tests of the strains P 2226 and P 712 indicate that these strains increased in virulence by passages in human cellsin vitro. The two last passages of both strains were found to be paralytogenic after intracerebral inoculation of rhesus monkeys. They were also less delayed than the foregoing passages in their ability to form plaques under an acid agar-overlay. The strains studied were not the triple plaque-purified variants now available.