Biomedical subjects
R M Kalbag
Publications and source records attributed to R M Kalbag.
Prognostic implications of p53 protein, epidermal growth factor receptor, and Ki-67 labelling in brain tumours.
The expression of p53 protein, epidermal growth factor receptor (EGFR), and Ki-67 nuclear antigen was examined by immunohistochemistry in biopsies of 16 types of human brain tumours, including 43 astrocytomas. P53 protein, almost certainly its mutant form, was expressed in seven of the 16, and EGFR in 11 of the 16 types of tumours. In astrocytomas both the proportion of tumours which expressed p53 or EGFR increased with grade of malignancy as did the mean Ki-67 labelling index (LI): p53-0% in grade 1, 17% in grade 2, 38% in grade 3, 65% in grade 4; EGFR-0% in grade 1, 33% in grade 2, 85% in grade 3, 95% in grade 4; mean Ki-67 L1-1.1% in grades 1 and 2, 8.3% in grade 3, and 13.4% in grade 4. Astrocytomas which expressed p53 or EGFR had a significantly higher Ki-67 LI at P less than 0.05 (11.8% and 10.7%, resp.) than those that did not (6.2% or 4.1%, resp.). Patients with astrocytomas expressing p53 or EGFR had a significantly reduced survival (P = 0.035 and P = 0.007, resp.): only 11% of the p53 + ve and 13% of the EGFR + ve patients were alive at 100 weeks following diagnosis compared to 36% of p53-ve or 60% of EGFR-ve patients. Patients with Ki-67 LI greater than 5% had a reduced survival (P less than 0.0001)--none survived beyond 86 weeks following diagnosis, whilst 63% of patients with less than 5% positive cells were still alive at 100 weeks. The univariate analysis showed that in astrocytomas expression of p53 mutants, EGFR protein, and Ki-67 greater than 5% are associated with malignant progression and poor prognosis. The multivariate analysis revealed that only tumour grade and Ki-67LI were independent prognostic factors for survival.
Five days versus one day of penicillin as prophylaxis in elective neurosurgical operations.
Of 423 patients undergoing elective cranial and spinal operations, infections due to Staphylococcus aureus occurred in 3 of 217 (1.4%) receiving penicillin for 1 day, in none of 206 receiving penicillin for 5 days. There was no significant difference in rates of infection between the two groups receiving penicillin. It is concluded that penicillin for 1 day is as effective as penicillin for 5 days, in the prevention of wound infections due to S. aureus.
Third ventriculostomy for slit ventricle syndrome.
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Simple peroperative antimicrobial chemoprophylaxis in elective neurosurgical operations.
From August 1981 to February 1982 postoperative infections due to different strains of penicillin-resistant Staphylococcus aureus occurred in 20 of 467 patients (4.3%) undergoing elective cranial and spinal operations. These infections were not attributable to defects in procedures or the theatre environment, therefore chemoprophylaxis was instituted. In the following 8 months, when patients were given penicillin G and sulphadiazine for 5 days commencing immediately postoperatively, S. aureus infections occurred in five of 579 patients (0.9%). In a subsequent randomized uncontrolled study, infections occurred in six of 265 patients receiving penicillin (2.3%), three of 270 receiving penicillin and sulphadiazine (1.1%) and one of 45 receiving erythromycin (2.2%) immediately postoperatively for 5 days. In a further study in which 587 patients received penicillin for 5 days commencing immediately preoperatively, infections due to S. aureus occurred in six (1.1%). Infections due to gram-negative organisms were seen in five (0.4%) of 1167 patients in the two uncontrolled studies.
Cerebellar astrocytoma presenting as a syringomyelic syndrome.
Cerebellar astrocytomas comprise about 36% of posterior fossa tumors in childhood. Such tumors presenting with hemorrhage have been reported, but in such cases, the location of the lesion was clinically obvious. This 16-year-old boy presented with a syringomyelic syndrome resulting from hemorrhage in the tumor causing compression of the upper cervical spinal cord. Such a case has not been previously recorded. Possible mechanisms leading to this syndrome are discussed and the relevant literature reviewed.
Four primary tumors in one child.
A child is described who, following surgery and irradiation for malignant choroid plexus papilloma at the age of 11 months, developed three further tumors: A benign myxofibroma of the cranium at the age of 3 1/2 years, an undifferentiated anaplastic tumor of his clavicle at 7 1/2 years, and a chondroblastic osteogenic sarcoma of his pelvis at the age of 12 years. There was no apparent genetic predispositions to malignancy. The latter three neoplasms may have originated either in, or at the edge of, the original radiotherapy field, suggesting that the child has a particular susceptibility to the oncogenic potential of radiotherapy.
Ventilation in operating rooms.
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Low risk of late post-traumatic seizures following severe head injury: implications for clinical trials of prophylaxis.
A randomised, controlled, double-blind clinical trial designed to determine the effectiveness of phenytoin in preventing epilepsy in patients who had suffered a serious head injury is reported. One hundred and sixty-four patients were randomly assigned to treatment with phenytoin or placebo capsules for one year. Patients who had a fit within one week of injury were excluded. Drug levels were monitored throughout with appropriate dosage adjustment; however only 48% of the phenytoin group had plasma levels greater than 40 mumol/l. There were seven deaths during the study. Only 11 patients (six in the phenytoin group and five in the placebo group) developed post-traumatic epilepsy within one year; a further four patients developed seizures between 1 and 2 years after injury. This low incidence of post-traumatic epilepsy (7% (SE 2%) at one year and 10 (SE 2%) at two years) means that future clinical trials of prophylaxis will have to be much larger (at least six fold).
Phenytoin prophylaxis for posttraumatic seizures.
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The membrane external proteins of human astrocytomas in culture.
The cell surface proteins of some human astrocytomas have been investigated. Cell cultures were initiated from the tumours and surface proteins labelled with radioiodine in monolayer cultures. Normal glial and astrocytoma cells were found to possess a common surface protein pattern. In the molecular weight (MW) range of 225,000-75,000 daltons, the protein profile contained 6 well-defined peaks. The 195,000-dalton component (pb) was found liable to resolve into pb and a forerunning component pb'. Component pd (130,000 daltons) similarly showed resolution into subcomponents in 5 out of 9 tumours. The remaining components appeared more homogeneous in electrophoresis. There were also significant quantitative changes in the expression of the various components of the astrocytomas as compared with the normal glial cell line. Component pa was found to be reduced by greater than 70% in 7 out of 9 astrocytomas. The levels of 225,000-dalton proteins were found to be directly proportional to the survival times of the patients. Components pc appeared to be amplified by a factor of 1.6-3.5 in all the astrocytomas as compared with the normal glial line. Increased incorporation of radioiodine was also seen in 7 out of 9 tumours in components with MW of less than 75,000 daltons. The possible significance of the differential expression of the surface components is discussed. It is suggested that some of these changes, especially in component pa, may be associated with the malignant state.
Malignant choroid plexus papilloma with extraneural metastasis. Case report.
The authors describe and discuss a case of malignant choroid plexus papilloma originating in the lateral ventricle of an 11-month-old child. Unusual features include a long survival time of 9 years and the presence of an extraneural malignant deposit, probably metastatic in origin.
Abscesses of the frontal lobe of the brain secondary to covert dental sepsis.
The bacterial species found in pus aspirated from brain abscesses in two patients were typical of those found in dental sepsis. Subsequently apical-root abscesses were demonstrated in the upper jaws of both patients. This evidence strongly suggests that these cerebral abscesses were secondary to dental sepsis which could have spread from the teeth to the frontal lobes by several possible antaomical pathways.
Surgical treatment of trigeminal neuralgia.
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Electrocardiographic abnormalities associated with raised intracranial pressure.
Serial electrocardiographic (E.C.G.) recordings were taken in seven patients suffering from intracranial conditions, for which their intracranial pressure was directly and continuously monitored with a Konigsberg extradural transducer. The E.C.G. changes observed in patients with raised intracranial pressure were prominent U waves, ST-T segment changes, notched T waves, and shortening and prolongation of Q-T intervals. Two patients with normal intracranial pressure showed no E.C.G. abnormalities but also establish a relationship between E.C.G. abnormalities and changing intracranial pressure.
Cervical spinal interbody fusion with Kiel bone.
Experience with the use of the Kiel bone graft in anterior cervical interbody fusion in cervical spondylosis is reported. The survey reviews the results of operations on 73 disc spaces in 65 consecutive patients, from 2 to 5 years after the operation. We have failed to confirm that any bony fusion in the true sense occurs with Kiel bone in anterior cervical interbody fusion. However, the aims of the operations are achieved, namely removal of the disc and osteophyte, fixation of the spine to prevent compression of the neural tissues, distraction of the adjacent vertebral bodies providing increased room in the intervertebral foramina and stability of the spine.
Nodular fasciitis causing unilateral proptosis.
A case report of an unusual case of nodular fasciitis in the orbit presenting with unilateral proptosis is described, and the radiological features are outlined. The histological features are discussed and the benign nature of the lesion stressed. Nodular fasciitis arising in the orbit and presenting as unilateral proptosis has not previously been reported in the literature.
Occipital bone cyst causing lower cranial nerve palsies.
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