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Biomedical subjects

J Bloch

Publications and source records attributed to J Bloch.

At least 19 recordsLinked to original sources
PubMed1993

Drilling the posterior wall of the petrous pyramid: a microneurosurgical anatomical study.

Posterior approaches to the petroclival area requiring extensive drilling of the posterior pyramidal wall have been described in the last 10 years. If hearing is to be preserved, damage to the inner-ear structures must be avoided; however, the fine points of this pyramidal drilling technique have never been reported in detail. A microneurosurgical anatomical study was undertaken in 15 cadavers to determine the relationships between bone landmarks and labyrinthine structures that could be used to give some practical drilling guidelines. Drilling of the posterior pyramidal wall is facilitated on identification of the intersection of the petrous ridge with the most anterior portion of the bone ledge covering the sigmoid sinus (petrosigmoid intersection), the bony operculum of the endolymphatic sac, and the petrous ridge. Drilling may proceed rather safely at a minimum depth of 2.5 mm in an area 0.9 cm anterior and 1 cm inferior to the petrosigmoid intersection and petrous ridge, respectively. From there, identification of the vestibular aqueduct, genu, and horizontal portion is necessary to safely open the posterior wall of the internal auditory canal. The vestibular aqueduct represents the lateral and superior limits of drilling. The bone between these areas may then be safely drilled to a depth of at least 2.5 mm. A microneurosurgical dissection of the posterior pyramidal wall conducted in cadaveric material according to these guidelines did not violate any inner-ear structures.

Ear, Middle↗
PubMed1993

The mandibular swing-transcervical approach to the skull base: anatomical study. Technical note.

This report describes in a stepwise fashion the surgical anatomy of an approach to the midline and lateral compartments of the skull base (clivus, infralabyrinthine/infratemporal regions). The salient features of this procedure are represented by a mandibulotomy and by detachment of the pharynx from the skull base through a combined oral and cervical approach. There is full neurovascular control of the internal carotid artery and lower cranial nerves with the possibility of complete exposure of the intrapetrous and intracavernous segments of the internal carotid artery on the side of the exposure. This approach, which may be regarded as an expansion of the original work of Krespi, should be considered when dealing aggressively with extensive skull-base lesions invading the midline and lateral compartments of the skull base.

Cadaver↗
PubMed1993

Management of pulmonary blastoma in children.

Pulmonary blastoma is a rare neoplasm, accounting for 0.5 per cent of all primary malignant pulmonary tumors. The clinical features, radiologic findings, and management of five children with pulmonary blastoma are described. The female/male ratio was 4:1. Mean age at presentation was 34 months, with a mean duration of symptoms of 1.8 months. Fever and cough were the most common symptoms. Opacification of the right lung field with mediastinal shift to the left was the predominant roentgenologic feature. The tumor involved the right chest in all patients. Thoracotomy was performed in all patients to establish the diagnosis. Two patients underwent complete resection at the initial operation, an incomplete resection was performed in one patient. Delayed complete resection was performed in another patient. All the patients received combination chemotherapy and one patient also received radiotherapy for primary disease. Two patients with histologic and immunohistochemical evidence of striated muscle differentiation were treated as rhabdomyosarcomas. Both these patients have survived for 24 and 67 months after diagnosis. The tumor recurred in three patients. Recurrence was treated with a combination of surgery, chemotherapy, and radiotherapy. Overall disease-free survival rate was 40 per cent. Long-term follow-up and additional patients are required to provide prognostic information.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1992

Leiomyosarcoma of the rectum.

Leiomyosarcoma of the rectum is a rare entity. Approximately 150 cases have been described in the literature. Differentiation from its benign counterpart, leiomyoma, and other connective-tissue tumors is often difficult, but it is important because each tumor has an entirely different prognosis. The case of a patient in whom an 11 x 5.5 cm leiomyosarcoma of the rectum was surgically excised by abdominoperineal resection is presented. Literature review shows disagreement over the therapeutic approach, most likely due to the lack of a large series of patients with this disease. At present, a selective treatment approach appears to be the most advocated. Lesions less than 2.5 cm in size and limited to the bowel wall can still be treated by wide local excision. More radical surgical resection is indicated for larger tumors and those extending outside the bowel wall.

Aged↗
PubMed1991

[Primary and secondary neonatal negative coagulase staphylococcus infections].

As a rule, coagulase-negative staphylococcal infections in the neonate is an acquired iatrogenic infection. It usually occurs in premature infants with an in-dwelling catheter. Clinical and laboratory criteria are used to differentiate contaminated samplings from true infection. the frequency of methicillin-resistant strains justifies the use of vancomycin combined with an aminoglycoside and, in the first days, with rifampicin, all drugs administered in doses calculated for the post-conception age. This treatment is also administered in mother-to-foetus infections caused by CNS.

Anti-Bacterial Agents↗
PubMed1986

Aneurysm of the inferior mesenteric artery associated with occlusion of the celiac axis and superior mesenteric artery.

The authors report a case of aneurysm of the inferior mesenteric artery encountered in a 38-year-old man, associated with occlusion of the celiac axis, the superior mesenteric artery and the inferior mesenteric artery distal to the aneurysm. All three arteries were revascularized. In spite of failure in the bypass of the superior mesenteric artery, the patient remained symptom free until his demise four years later, from a probable myocardial infarction. Only 11 cases of aneurysms of the inferior mesenteric artery have been reported in the literature. The causes, diagnosis and treatment of these uncommon lesions are discussed. When occlusion of the celiac axis is associated with that of the superior mesenteric artery, a complete mesenteric revascularization should be attempted whenever possible.

Adult↗
PubMed1986

[Induced prematurity].

Voluntary induction of a premature delivery, which goes against our constant battle to reduce prematurity, represents, at this time, a paradoxical situation which is not exceptional in vasculorenal syndromes and premature rupture of the membranes. Advances in ressuscitation and the care of premature newborn babies, on the one hand, and techniques of artificial induction of labor, on the other hand, account for this obvious paradox. Even advances in artificial induction of labor explain also the decrease in the cesarean sections indications, under such circumstances.

Female↗
PubMed1982

Cloning of cDNA sequences of hormone-regulated genes from the MCF-7 human breast cancer cell line.

cDNA clones corresponding to a mRNA whose level is rapidly increased by addition of oestradiol to the culture medium have been isolated by differential screening of a cDNA library from the breast cancer cell line MCF-7, which contains oestrogen receptors. Such clones will be useful in studies of the DNA sequences required for hormonal induction and to determine whether expression of the corresponding gene is in any way related to the cancerous state. We have also obtained a cDNA clone for a messenger whose level is apparently decreased by steroid hormones.

Breast Neoplasms↗
PubMed1980

Cloning and characterization of DNA sequences complementary to messenger ribonucleic acids coding for the synthesis of two surface antigens of Trypanosoma brucei.

Full length double-stranded complementary DNAs (ds cDNAs) could be synthesized on mRNAs enriched in sequences coding for the synthesis of the variant specific antigens (VSAs) AnTat 1.1 and AnTat 1.8 from Trypanosoma brucei brucei. The size of these ds cDNAs is about 1700 and 1850 base pairs for AnTat 1.1 and AnTat 1.8 respectively. The ds cDNAs were cloned in the plasmid pBR322; two clones harboring a copy of each coding sequence were selected. Both the hybrid-arrested translation and the positive hybridization elution methods confirmed that these recombinants contain VSA-specific inserts. A restriction map was constructed in each case. The two sequences seem to be inserted in a reversed 3'--5' orientation, respective to the plasmid polarity. The AnTat 1.8 cloned sequence is a palindrome probably due to a cloning artefact. Hybridization of the cloned DNAs with "Northern" blots of total or poly(A)+ RNA revealed in each case a single, specific band. The expression of these VSA genes appears thus to be regulated at the transcriptional level.

Antigens, Surface↗
PubMed1980

Evaluation of a language program for young autistic children.

This report presents retrospective data comparing an individualized language development program for preschool autistic children receiving language remediation (experimental subjects) with a group receiving the basic school curriculum only (control subjects). All findings favored the language remediation group, as indicated: (1) experimental subjects made significant gains in one year while the control group required two years; (2) after one year, experimental subjects surpassed controls on four measures; (3) only experimental subjects made significant gains in communicative speech, noteworthy because interpersonal interaction is so difficult for the autistic child; and (4) after two years, 58% of the experimental subjects, but only 14% of the controls, had mastered all seven skills. These results support the hypothesis that an individualized language remediation program facilitates the acquisition of prelinguistic and linguistic skills.

Autistic Disorder↗
PubMed1980

A systematic study of the effect of vitamin C supplementation on the humoral immune response in ascorbate-dependent mammals. I. The antibody response to sheep red blood cells (a T-dependent antigen) in guinea pigs.

We have investigated the humoral immune response to Sheep Red Blood Cells (S.R.B.C.--a T-dependent cellular antigen) in two groups of random-bred guinea pigs. A control group of animals was maintained on "minimal" ascorbate intake, while the test group animals received supplementary vitamin C in their drinking water. Serum haemolytic antibody levels were monitored at various intervals subsequent to immunization with S.R.B.C. The primary antibody response of the ascorbate-supplemented animals differed statistically significantly from that of the controls in two respects. The peak antibody titre was both higher and occurred earlier in the test animals. No significant difference in the antibody response to a secondary injection of antigen was manifest. Our observations suggest that vitamin C stimulates the elaboration of Ig M-type antibodies in particular.

Animals↗