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Biomedical subjects

R Greene

Publications and source records attributed to R Greene.

At least 163 records · Page 9Linked to original sources
PubMed1981

Disproportionate micromelia (Dmm): an incomplete dominant mouse dwarfism with abnormal cartilage matrix.

This paper describes a new autosomal incomplete dominant dwarfism, disproportionate micromelia, which has been characterized genetically and phenotypically, and the cartilage of homozygotes, and heterozygotes has been examined by histochemical, immunofluorescence and biochemical methods. Homozygotes, which die at birth, are disproportionately short and have cleft palates. The heterozygotes appear normal at birth but beginning at 1 week of age dwarfism is apparent and increases during growth. Histochemical and biochemical analyses of the cartilage rudiments of homozygotes at day 18 of gestation demonstrate that the cartilage growth plate is disorganized and the matrix components, collagen and proteoglycan, are altered. Total collagen synthesis is reduced by approximately 30% and the amount of type II collagen is greatly reduced. By immunofluorescence staining with collagen antibodies, it appears that type II collagen is located primarily near the cell surface of chondrocytes but is poorly distributed throughout the remainder of the matrix. The amount of proteoglycan in the cartilage matrix is reduced by approximately 70% as determined by chemical analysis of hexosamines and by [35S]sulfate incorporation. Although the proteoglycans synthesized by the mutant are normal in size and in glycosaminoglycan composition, they were more easily extractable from the matrix than were normal cartilage proteoglycans. Heterozygotes had reduced cartilage matrix proteoglycan by histochemical methods, but the organization of the epiphyseal cartilage was not abnormal. These data suggest that a reduced or abnormal cartilage matrix is the cause of the dwarfism.

Animals↗
PubMed1980

A study of variability in cytologic diagnoses based on pulmonary aspiration specimens.

Reproducibility of cytologic diagnoses of malignancy and accuracy and variability of diagnoses of malignant cell types were assessed in a study of pulmonary aspirates from 100 patients. Original cytologic diagnoses were positive for 60 of the 80 patients who had malignancy (true-positive rate 75%). No false-positive diagnosis was made. Original cytologic diagnoses were negative for 15 of the remaining 20 patients (true-negative rate 75%). In "blindly" reviewing the slides, the pathologist who had made the original diagnoses (Observer A) and another pathologist (Observer B) confirmed the 60 original positive diagnoses. Observer A added four cases, Observer B 11 cases to the positive category. Cell types of original positive cytologic diagnoses and those of subsequent histologic diagnoses agreed for 23 of 33 malignancies (70%). Although two observers increased the proportion of positive cytologic diagnoses, the percentages of agreement with respect to histologic malignant cell types remained similar. For cytologic specimens, intraobserver agreement as to malignant cell types was 83% (50 of 60); interobserver agreement was 80% (48 of 60).

Adenocarcinoma↗
PubMed1980

Inhibition of purified wheat germ DNA dependent RNA polymerase by pyran copolymer.

The inhibition of DNA and RNA polymerases in vitro by pyran copolymer has been shown to be related to its affinity for divalent cations. The present investigation was designed to explore further the nature of this inhibition using completely purified eukaryotic RNA polymerase II from wheat germ. Inhibition was determined as a function of divalent ion concentration and, as previously seen with less pure enzyme preparation, was greatest at low (Mn2+) and least at higher concentrations. No inhibition was observed at concentrations greater than 4.8 mM MgCl2 in the presence of 10 micrograms pyran/mL. The inhibition by pyran copolymer was exerted immediately unlike other polyanions, such as heparin and polynucleotides. This indicates that it stops RNA chain growth immediately as do known chelators of divalent cations. The size of pyran copolymer was shown to affect the extent of inhibition when different sized polymers were fractionated from a heterogenous single lot. However, when sized fractions were obtained from different lots we could not show a size-dependent inhibition. Although the mechanisms by which pyran copolymer exerts its biological effect is unknown, it may well be related to its association with cations. The inhibition of enzymes requiring these cations appears to be a sensitive method of observing such an association.

DNA-Directed RNA Polymerases↗
PubMed1980

Fluid accumulation in preexisting pulmonary air spaces.

Four patients with fluid accumulation in preexisting pulmonary air spaces are presented. Three patients developed fluid in an infected bulla; the fourth patient bled into a bulla. The slow spontaneous resolution of the accumulated fluid and the success of a conservative therapeutic approach are emphasized. The characteristic radiologic features of fluid-filled intrapulmonary air spaces are described and criteria for the differentiation from lung abscesses and empyemas are outlined.

Aged↗
PubMed1980

Geographic wage indexing for CETA and Medicare.

The tailoring of grants-in-aid to wage levels in the localities which receive them enjoys growing popularity among Federal policymakers; two ongoing programs illustrate the flexibility of this technique.

Abstracting and Indexing↗
PubMed1979

Compartment syndrome of the interosseous muscles: early recognition and treatment.

A compartment syndrome of the interosseous muscles can be a challenging diagnosis as there is generally no neurovascular compromise to the digits involved. The most sensitive clinical sign is pain with passive motion at the metacarpal phalangeal joint of the involved digit. In this report, a 31-year-old man developed a compartment syndrome of the first, second, and third dorsal interosseous muscles following an injection of heroin in the "snuffbox" area. Compartmental tissue pressure measurements were 80, 75, and 55 mmHg respectively, and were a significant aid in the early diagnosis as well as management.

Adult↗
PubMed1978

Primary urethral tumors in dogs.

In a review of cases of neoplasia in dogs seen at The Animal Medical Center during a 6-year period, 20 cases of primary urethral tumors were found. The majority of these cases were in older dogs (av abe, 10.4 years) and females (18/20). The most common clinical signs were hematuria and stranguria. Nineteen of the 20 tumors were diagnosed clinically, and the most consistent and useful diagnostic method was pneumocystography-cystography, with voiding urethrography. Of the 5 tumor types (squamous cell carcinoma, transitional cell carcinoma, adenocarcinoma, hemangiosarcoma, and embryonic rhabdomyosarcoma), squamous cell carcinoma was the most common (12/20). Metastasis occurred in 6 of the 20 dogs. Because of metastasis to regional lymph nodes and diffuse extent of the tumor in the urethra in many of the dogs, a caudal abdominal approach for surgical excision is recommended if treatment is attempted.

Animals↗
PubMed1978

Benign blood vascular tumors of the mediastinum. Report of four cases and review of the literature.

The authors present 4 new cases and review 77 previously reported cases of benign blood vascular tumors of the mediastinum. The vast majority are hemangiomas (90%), occur in the first four decades of life (75%), and arise in the anterior mediastinum (68%). Compression and/or invasion of adjacent structures is not uncommon. Concomitant extrathoracic extension (2%) and multiple sites of involvement (2%) are rare. The tumors are smoothly outlined, occasionally lobulated and can be accurately identified when phleboliths are present (10%).

Adolescent↗
PubMed1978

"Saber-sheath" trachea: relation to chronic obstructive pulmonary disease.

Sixty male patients with marked coronal narrowing of the intrathoracic trachea (saber-sheath configuration) were compared with 60 controls. Scores were assigned to patients according to separate clinical and radiographic indexes of chronic obstructive pulmonary disease (COPD). Of the 60 patients with the saber-sheath configuration, 57 (95%) had clinical evidence of COPD compared to only 18% in the control group. Of these 57, 26 (45%) lacked conventional radiographic evidence of COPD. This study establishes a strong correlation between saber-sheath trachea and clinical COPD. The value of this radiographic sign is twofold: (1) as an aid in diagnosing COPD when other convincing radiographic evidence is lacking; and (2) to avoid an erroneous assumption that coronal narrowing is due to a mediastinal mass.

Adult↗