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Biomedical subjects

M L Berman

Publications and source records attributed to M L Berman.

At least 145 records · Page 8Linked to original sources
PubMed1982

A previously unidentified gene in the spc operon of Escherichia coli K12 specifies a component of the protein export machinery.

The gene prlA codes for a factor that appears to function in the export of proteins in Escherichia coli. This conclusion is based on the finding that mutations altering the prlA gene product restore export of envelope proteins with defective signal sequences. Previous results showed that the prlA gene lies in an operon (spc) known to code for ten different ribosomal proteins. Our studies show that the prlA gene lies promoter-distal to the last known ribosomal protein gene in this operon. Evidence from gene fusions constructed in vitro suggests that prlA codes for a protein containing at least 300 amino acids. Thus a heretofore unidentified protein specified by a gene within the spc operon appears to be a component of the cellular protein export machinery.

Bacterial Proteins↗
PubMed1981

Survival after extraperitoneal pelvic and paraaortic lymphadenectomy and radiation therapy in cervical carcinoma.

Clinical staging, bipedal lymphangiography, and extraperitoneal pelvic and paraaortic lymphadenectomy were performed in 95 patients with invasive squamous carcinoma of the cervix. Radiation therapy was modified on the basis of findings at operative staging. Patients have been followed from 16 to 91 months, with a mean of 41 months. The accuracy of clinical staging and the relative abilities of lymphangiography and lymphadenectomy to assess the retroperitoneal lymph nodes have been determined. Five-year survival with respect to stage of disease and status of the pelvic and paraaortic lymph nodes was calculated by the life-table method. Seventy-five percent of patients with no lymph node metastases are projected to be alive at 5 years without recurrence. Fifty-six percent with pelvic lymph node metastases and 23% of those with paraaortic lymph node involvement are projected to be free of disease at 5 years. The risk of lymph node metastases increases with either the stage of disease or the volume of the primary tumor independently of stage. The presence of lymph node metastases adversely affects survival regardless of the stage of the primary tumor. Clinical staging as accepted by FIGO is inadequate in that it ignores patients with pelvic or paraaortic lymph node metastases. The accuracy of detection in the individual patient does not increase with the addition of lymphangiography. Operative staging can be performed safely by the extraperitoneal route and radiation therapy can be modified on the basis of the true extent of disease. Radiation therapy fails to cure patients because of distant dissemination of disease as well as an inability of conventional radiotherapeutic techniques to sterilize a large primary tumor volume.

Female↗
PubMed1980

Prognosis and treatment of endometrial cancer.

An understanding of the patterns of spread and prognostic factors influencing survival is necessary to develop rational treatment programs for patients with endometrial cancer. The most important risk factors include the stage of tumor, status of pelvic lymph nodes, depth of myometrial penetration, tumor grade, cell type, and patient age. Because of the inherent inaccuracies of staging based on pelvic examination and the inability to assess the status of lymph nodes or myometrial penetration clinically, errors in management often result when radiation therapy is delivered prior to operation. Therefore, a rationale is offered for primary operative management of patients with Stage I disease, with consideration of adjunctive radiation therapy following operation based on extend of disease and a thorough evaluation of the high-risk factors. It is suggested that patients with more advanced stages of disease be considered for pretreatment operative evaluation. Data are presented which refute theoretical objections to this approach.

Adenocarcinoma↗
PubMed1980

Halothane-induced hepatic necrosis in triiodothyronine-pretreated rats.

Hepatic centrilobular necrosis developed in rats pretreated with triiodothyronine (T3) and then anesthetized with halothane, 1 per cent, for two hours at an ambient oxygen concentration. Increasing oxygen concentrations decreased the severity of the lesion, there being a significantly (P less than 0.05) less severe lesion with oxygen, 99 per cent, as compared with 21 per cent. Pretreatment with phenobarbital alone resulted in hepatic necrosis only when hypoxia (FIO2 0.14) was also present, and there was no significant worsening of the T3-induced lesion when phenobarbital was added at any oxygen concentration studied. However, the lesion produced by T3 and oxygen, 14 per cent, was significantly worse than the lesion produced by phenobarbital and oxygen, 14 per cent. Glutamic pyruvic transaminase (SGPT) was significantly elevated to 776 (+/- 226) U/1 in the T3-treated rats (10 mg/kg/day, orally) immediately after halothane anesthesia. There was a significant decrease in glutathione to 1.48 (+/- 0.06) mg/g liver 24 hours after T3 administration (1 mg/kg subcutaneously for five days), but no further decrease with continued T3 pretreatment or with halothane anesthesia. Pretreatment with T3 caused a significant decrease in cytochrome P-450 to 0.41 (+/- 0.01) nmol/mg microsomal protein, and halothane anesthesia caused a further significant decrease to 0.27 (+/- 0.04) nmol/mg microsomal protein. The mechanism for the hepatic toxicity of halothane in this model remains to be determined.

Alanine Transaminase↗
PubMed1979

Pretreatment lymphangiography and operative evaluation in carcinoma of the cervix.

Ninety-five patients with cervical carcinoma who were not candidates for definitive operation underwent initial lymphatic and 24-hour nodal phase lymphangiography and lymphadenectomy prior to radiation therapy. Operation by a transperitoneal or extraperitoneal approach consisted of bilateral pelvic and periaortic lymphadenectomy, exploratory laparotomy, and intraperitoneal biopsies as indicated by the findings. Radiation therapy was modified to include proved sites of metastases. Intestinal injuries followed transperitoneal operation and radiation therapy but were uncommon in patients in whom exploration was done by the extraperitoneal route. Eighteen patients (19%) had unsuspected metastases to common iliac or periaortic lymph nodes identified at operation. The characteristics of the primary tumor and the interpretation of the lymphangiogram provided an inaccurate basis on which to modify treatment. As further studies confirm the risk of disseminated disease in those patients with metastases to common iliac and the periaortic lymph nodes, future treatment plans might incorporate adjuvant chemotherapy or immunotherapy in addition to extended-field irradiation.

Evaluation Studies as Topic↗
PubMed1979

Promoter mutations in the transfer RNA gene tyrT of Escherichia coli.

The DNA sequences for nine independent promoter mutants of a tyrosine tRNA gene, tyrT of Escherichia coli, are reported. The nine mutations involve six transitions, two transversions, and one deletion. They are located at four different sites in the first 30 base pairs preceding the start point of transcription. The changes found are: a T.A to A.T transversion at position -8 (two mutants); a T.A to C.G transition at position -8 (three mutants); a T.A to C.G transition at position -13 (two mutants); a T.A to C.G transition at position -16 (one mutant); and a deletion of a G.C base pair at position -26/27 (one mutant). Four of the five different mutant tyrT promoters have alterations at positions that might have been expected from DNA sequence studies with other prokaryote promoters. One of these mutants (a G.C deletion at position -26/27) occurs in a stretch of eight consecutive G.C base pairs which may be characteristic of stable RNA promoters.

Base Sequence↗
PubMed1979

Physostigmine reversal of diazepam-induced hypnosis. A study in human volunteers.

Under randomized double-blind conditions, 1.00 to 1.67 mg of intravenous physostigmine (Antilirium) reversed sleep induced by administration of 0.102 to 0.238 mg/kg body weight of intravenous diazepam in eight healthy human volunteers. Awakening occurred 330 to 740s after initiation of the physostigmine infusion at a rate of 0.5 mg/min every 4 min. Diazepam plasma levels were not significantly different at the start of either the physostigmine or placebo infusion. Physostigmine did not effect plasma binding of diazepam. Six subjects experienced nausea, and one subject developed an arrhythmia. Physostigmine reverses diazepam-induced hypnosis but causes side-effects requiring cautious administration.

Adult↗