PubMed Health⌕ Search

Biomedical subjects

J P Lin

Publications and source records attributed to J P Lin.

At least 19 recordsLinked to original sources
PubMed1992

Neurological outcome following neonatal post-haemorrhagic hydrocephalus: the effects of maximum raised intracranial pressure and ventriculo-peritoneal shunting.

UNLABELLED: The neuromotor outcome of 33 survivors of grade 3 or 4 neonatal post-haemorrhagic hydrocephalus born between 1975 and 1988 was assessed at a mean age of 4.7 years (9 months to 13 years). Two outcomes were determined: 12 patients were either normal (10 or had neurological signs without functional impairments (2), while 21/33 were moderately (16), severely (2), or profoundly impaired (3). Intracranial pressure (ICP) was measured in 26/33 patients (4-40 mm Hg): 2 had normal pressures (< 5.6 mm Hg) and were normal. Raised ICP was not significantly different between outcome groups. Twenty-seven children were shunted; 10/27 had five or more operations (up to 14) and all of these had abnormal neurological outcomes, whereas the number of children with 1-4 shunt procedures was equal in both outcome groups. The rise in morbidity after the fourth shunt procedure may be associated with the ventriculitis suffered by 9 of the 10 patients with more than four shunts (P < 0.01): this compares with 4/14 cases of ventriculitis in the children with 2-4 shunts and no cases of infection in the 3/27 who were shunted once. Outcome was independent of antenatal and perinatal factors including the age at or mode of presentation, and was unrelated to grade of intraventricular haemorrhage or parenchymal changes on ultrasound or CT scanning. CONCLUSION: for these small numbers, adverse outcome is statistically related to more than four shunt procedures and ventriculitis but independent of maximum ICP or other perinatal factors.

Birth Weight↗
PubMed1992

Peripheral and central mechanisms of hindfoot equinus in childhood hemiplegia.

A detailed clinical examination of 24 hemiplegic children at a mean age of 9.9 years showed that nine had an obligate toe-strike when walking at a self-selected speed and this was maintained throughout stance. None of the 24 children had a fixed equinus. No association could be found between this pattern of gait equinus and lower-limb atrophy, reduced ankle-joint range, muscle extensibilite, power of dorsiflexors and plantarflexors or actual muscle imbalance at the ankle joint. Gait equinus was independent of reduced compliance of the calf muscles, of a clinical diagnosis of tonic spasticity, of fine-motor dexterity of the toes, and of the side of the hemiplegia. Gait equinus cannot be explained merely in terms of a central paralytic foot-drop. A developmental model of equinus is advanced.

Ankle Joint↗
PubMed1991

Effects of mutations in glycosylation sites and disulphide bonds on processing, CD4-binding and fusion activity of human immunodeficiency virus envelope glycoproteins.

Site-directed mutagenesis was used to study the biological significance of a disulphide bridge and two N-linked oligosaccharides in the CD4-binding region of the envelope glycoproteins of human immunodeficiency virus type 1. Mutagenesis was performed in a phage M13 system at sites corresponding to the cysteine residue (amino acid 402) and the asparagine residues (390 and 447) of the env gene. The mutated env gene was inserted into a recombinant vaccinia virus under the control of the vaccinia virus 7.5K promoter and the expression of mutated env proteins was analysed by SDS-PAGE, a conventional indirect immunofluorescence assay and by a fluorescence-activated cell sorter. Cysteine 402 was found to be essential for the specific cleavage of gp160 into gp120 and gp41, and for intracellular transport of the protein to the cell surface. CD4-binding and syncytium formation assays demonstrated that the disulphide bridge of cysteine 402 stabilized a conformation essential for receptor binding as well as syncytium formation by CD4+ cells. No altered biological activity compared to that of the wild-type proteins could be detected for the mutant proteins lacking the N-glycosylation sites. These data show that the two conserved glycans attached to asparagine residues 390 and 447 do not play any active role in the formation of the disulphide bridge involving cysteine 402 or in the maintenance of an active conformation of the protein, despite their location within the functionally important CD4-binding region.

Amino Acid Sequence↗
PubMed1990

Treatment of disseminated Mycobacterium avium complex infection of beige mice with liposome-encapsulated aminoglycosides.

Free and liposome-encapsulated amikacin are active in vitro against intracellular Mycobacterium avium complex (MAC). To examine whether liposome-encapsulated aminoglycosides might kill intracellular MAC more effectively in vivo, beige mice were infected with MAC strain 101 (serotype 1) and after 1 week were treated intravenously every other day (5 doses total) with amikacin liposomes (0.2, 1, or 4 mg/dose), amikacin solution (0.2, 1, or 2 mg), gentamicin liposomes or gentamicin solution (0.2 or 1 mg), placebo liposomes (without aminoglycosides), or buffer. Amikacin and gentamicin liposomes significantly reduced bacterial counts in blood, liver, and spleen (98.5%, 92.7%, and 92.8%, respectively, for the 1-mg dose of amikacin and 92.8%, 99.7%, and 99.4% for gentamicin; 95.7%, 69.7%, and 89.1%, respectively, for the 0.2-mg dose of amikacin and 49.9%, 76.7%, and 89.1% for gentamicin) compared with placebo liposomes and buffer. Equivalent doses of free drug were not associated with significant decreases in viable bacteria. Thus, aminoglycoside liposomes improved bactericidal effects over conventional treatment in disseminated MAC infection, offering potential application in treating MAC infection in humans.

Amikacin↗
PubMed1990

Successful treatment using gentamicin liposomes of Salmonella dublin infections in mice.

Gentamicin entrapped within stable multilamellar liposomes was used to treat mice after they were infected per os with Salmonella dublin. Of 10 mice, 8 survived after a single intravenous (i.v.) injection of 2 mg of gentamicin liposomes per kg compared with 0 of 10 treated with the same amount of free gentamicin. All mice survived after treatment with a single i.v. or intraperitoneal injection of 20 mg of gentamicin liposomes per kg, whereas that dose of free drug was completely ineffective and caused neuromuscular paralysis when injected rapidly i.v. In mice treated with gentamicin liposomes, there was a steady decrease in the number of salmonellae in spleens for 2 weeks after treatment. High concentrations of gentamicin were present in the spleen for at least 10 days after treatment. Although gentamicin was not detected in the mesenteric lymph nodes of mice treated with gentamicin liposomes, bacterial counts in the nodes also decreased over time. Small numbers of bacteria remained viable in the mesenteric lymph nodes and Peyer's patches but not in the spleens of mice treated with 20 to 80 mg/kg. Mice treated with doses of gentamicin liposomes as high as 80 mg/kg showed only a transient increase in blood urea nitrogen and no rise in serum creatinine. These results confirm that gentamicin in liposomes is less toxic in mice than is free gentamicin and is extremely effective therapy for disseminated Salmonella infections in mice.

Animals↗
PubMed1979

Pseudoaneurysm formation secondary to spontaneous thrombosis of a massive cerebral arteriovenous malformation.

A case of a large cerebral arteriovenous malformation (AVM) with spontaneous partial thrombosis and intracerebral hematoma is reported. The unusual and unique features of the radionuclide brain scan and cerebral angiogram are described. The characteristic angiographic features of residual tortuosity and dilatation or pseudoaneurysm formation at the bifurcations of the feeding arteries in a partially thrombosed cerebral AVM have not been described previously in the literature.

Adult↗
PubMed1979

The value of routine cranial computed tomography in neurologically intact patients with primary carcinoma of the lung.

The most common cerebral metastatic lesion is from carcinoma of the lung. Preoperative cranial computed tomography (CCT) with contrast enhancement was performed in 55 neurologically intact patients with a diagnosis of bronchogenic carcinoma; 3 patients (5%) demonstrated cerebral metastasis. CCT could spare a significant number of such patients from unnecessary surgery, with a net saving substantially greater than its cost.

Brain Neoplasms↗
PubMed1978

Computed tomography in herpes simplex encephalitis.

Nine patients with herpes simplex encephalitis examined by CT scan were reviewed. A total of 15 satisfactory scans was analyzed. The majority of our cases had CT scan abnormalities: lucency 63% (5 of 8, one case with suboptimal scan), mass effect 50% (4 of 8), abnormal contrast enhancement 57% (4 of 7). The earliest CT scan finding was lucency, presented in two out of three cases studied within 48 hours following onset of symptoms. The primary role of CT scan is to support the suspected diagnosis of herpes simplex encephalitis as well as to indicate the best site for brain biopsy and to permit early effective treatment with adenine arabinoside.

Adolescent↗
PubMed1977

Computed tomography in the postoperative care of neurosurgical patients.

By its ability to differentiate the densities of various intracranial tissues, computed tomography is an ideal tool to investigate the postoperative course and complications of neurosurgical patients. The most important immediate postoperative complications are intracerebral edema and epidural, subdural or intracerebral hematomas. The extent of surgical resection of neoplasms can also be studied easily by CT. The method of investigation and representative cases are described.

Adolescent↗
PubMed1977

Positive and negative contrast myelography in spinal trauma.

The myelograms of 60 acutely injured patients were reviewed. Positive contrast material (Pantopaque) was preferred in cervical and thoracic trauma manifesting bony deformity, in cervical trauma without bony deformity (in the prone position), in delineating the thoracic spinal cord in the frontal projection, and in lumbar spinal injuries. Negative contrast material (air) was preferred in cervical trauma without bony deformity, to delineate the thoracic spinal cord in the lateral projection and in chronic trauma to demonstrate cord atrophy. An experimental, water-soluble positive contrast material (Amipaque) may show the spinal cord advantageously in both the anteroposterior and lateral projections and may be more extensively used. A protocol has been devised, based on the analysis of the myelographic findings.

Adult↗
PubMed1977

Some aspects of the computed tomography of the head.

Computed tomography demonstrates intracranial neoplasms so clearly that nearly all early work in this field was limited to descriptions of the appearance of various lesions. Only recently have investigators directed their attention to the medical implications of the physical and pathophysiologic phenonmena that characterize this remarkable new technique. This paper will discuss recent work in these two areas and its clinical implications, and will examine the application of computed tomography to the evaluation of the postsurgical and postradiation patient.

Brain Edema↗
PubMed1976

Evaluation of pediatric hydrocephalus by computed tomography.

Computed tomography (CT) is a safe and reliable technique for the study of children with increased head circumference. Hydrocephalic children requiring drainage of cerebrospinal fluid may be shunted on the basis of the CT scan alone and their postsurgical course followed by serial CT scans thereafter. Any additional pneumographic studies required may be performed via the existing shunt tube, eliminating transcerebral catheterization and its attendant complications.

Brain Edema↗
PubMed1976

The normal anterior inferior cerebellar artery. Anatomic-radiographic correlation with emphasis on the lateral projection.

Previous descriptions of the course and anatomic relationships of the anterior inferior cerebellar artery (AICA), as visualized in the lateral projection, have not been found by the authors. Dissection and radiography of 32 injected human cerebella show that AICA and its major branches define the position of the pontomedullary sulcus; supra-olivary fossette; 5th-11th cranial nerves; brachium pontis; flocculus; great horizontal fissure; posterolateral fissure; superior semilunar lobule; inferior semilunar lobule; biventral lobule; foramen of Luschka; and the choroid plexus of the lateral recess of the 4th ventricle. With magnification and high-quality subtraction, AICA and its associated structures may be identified in the lateral projection in the large majority of patients.

Abducens Nerve↗
PubMed1976

The anterior inferior cerebellar artery in mass lesions. Preliminary findings with emphasis on the lateral projection.

Analysis of abnormalities of the configuration of the anterior inferior cerebellar artery in lateral projection facilitates diagnosis of posterior fossa masses. Cerebellopontomedullary angle lesions frequently cause arcuate posterior-inferior displacements of the rostrolateral artery or reversal of curvature of the ascending segment of the meatal loop. Vermian, hemispheric, intra-fourth ventricular, and suitably situated extra-axial masses alter the plane of the lateral loop of the caudomedial artery. Tonsillar herniation may be detected in patients with hypoplastic or absent posterior inferior cerebellar arteries by analyzing the relationship of the biventral segment of the descending or caudomedial artery to the foramen magnum.

Brain Neoplasms↗
PubMed1976

Evaluation of sellar and parasellar masses by computed tomography.

Computed tomography is the method of choice for initial evaluation of patients with potential suprasellar masses. In our experience, CT has proved completely reliable for detecting or ruling out the presence of a suprasellar mass, the direction and degree of parasellar extension, and the presence of any calcific or cystic component of the lesion. When multiple cut CT has been negative, further diagnostic studies have proved unrewarding. When CT has been positive, additional studies have been required in some cases to rule out aneurysm prior to craniotomy.

Adenoma↗