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Biomedical subjects

R Hamilton

Publications and source records attributed to R Hamilton.

At least 73 records · Page 4Linked to original sources
PubMed1979

Construction and cloning of rat albumin structural gene sequences.

A recombinant plasmid containing a DNA segment complementary to rat liver albumin mRNA has been constructed, cloned, and used to examine the organization of albumin gene. The 18S fraction of total liver poly(A)-containing RNA was copied into a double-stranded cDNA by avian myeloblastosis virus reverse transcriptase and Escherichia coli DNA polymerase I. The cDNA was inserted into the HindIII site of the plasmid pBR322 via the addition of specific oligonucleotide linkers. Recombinant plasmids were screened by hybrid arrest of mRNA translation and hybridization with specific cDNAs. Thereby, a plasmid was identified that contained a 1200-nucleotide insert corresponding to a segment adjacent to the 5'-terminal region of albumin mRNA. The inserted sequence was used as a hybridization probe to detect five EcoRI fragments of genomic DNA which encode albumin mRNA. These were compared to eight EcoRI fragments identified within the rat genome by albumin cDNA. We conclude that the albumin gene (or genes) is interrupted at more than one site in the coding DNA by intervening sequences. Furthermore, we were able to distinguish those fragments that encode the 5' and 3' ends of the mRNA.

Animals↗
PubMed1979

The sleeve anastomosis in clinical microsurgery. Case report.

Clinical use of the microvascular sleeve anastomosis in 6 elective free tissue transfers is reported. Arterial and venous anastomoses were performed. It was found that with the exception of the distal anastomosis of a vein graft to artery the sleeve anastomosis was simple and efficient. It was concluded that when the vessels to be anastomosed have suitable length and diameter the sleeve anastomosis may well be used. By its use time and effort can be saved, especially in cases requiring multiple anastomoses.

Adult↗
PubMed1979

Neurological prognosis after traumatic quadriplegia. Three-year experience of California Regional Spinal Cord Injury Care System.

Between January, 1974, and December, 1976, 123 patients with traumatic quadriplegia were admitted to the California Regional Spinal Cord Injury Care System. The spinal cord injury resulted from gunshot wounds in five, from a stab wound in one, from neck injuries with no bone damage seen on x-ray studies in 10, and from fracture dislocations of the cervical spine in 107. One-year following-up information was available on 114 patients. Neurological impairment using the Frankel classification system was compared at 72 hours postinjury to the 1-year follow-up examination. Fifty of 62 patients with complete injury at 72 hours were unchanged at 1 year. Five of these 62 patients had developed motor useful function in the legs or became ambulatory by 1 year, but all had sustained serious head injuries at the time of their trauma making initial neurological assessment unreliable. Ten percent of all cases had combined head injury impairing consciousness. Among 103 cognitively intact patients, none with complete injury at 72 hours were walking at 1 year. Of patients with sensory incomplete functions at 72 hours postinjury, 47% were walking at 1 year; 87% of patients with motor incomplete function at 72 hours postinjury were walking at 1 year. Spinal surgery during the first 4 weeks postinjury did not improve neurological recovery. A method of analyzing neurological and functional outcomes of spinal cork injury is presented in order to more accurately evaluate the results of future treatment protocols for acute spinal injury.

Humans↗
PubMed1978

Purification of human interferon by antibody affinity chromatography, using highly absorbed anti-interferon.

Antibodies against partially purified human leucocyte interferon (PIF) were bound to Sepharose 4B and crude interferons applied on this affinity column were purified, up to 8 x 10(5) interferon units (IFU) per mg protein in one step. Antibodies against PIF were absorbed with immobilized crude human leucocyte interferon bound to Sepharose, whereby antibodies against impurities were predominantly removed. Extensively absorbed antisera were coupled to Sepharose and used for antibody affinity chromatography of crude interferon preparations. Leucocyte and fibroblast interferons were purified in one step with around 100% recovery, up to 1 x 10(8) IFU per mg protein, and Namalva interferon up to 2 x 10(7) IFU/mg. SDS electrophoresis of affinity-purified leucocyte interferon revealed that the interferon activity appeared in two bands (19,000 and 23,000 D).

Antibodies↗
PubMed1978

Pancytopenia induced by aminoglutethimide in the treatment of breast cancer.

Aminoglutethimide is an investigational agent of proven benefit in the treatment of metastatic breast carcinoma. We report herein a case of aminoglutethimide-induced pancytopenia complicated by bleeding and gram-negative septicemia. Severe pancytopenia is a rare but important side effect of this new drug and is rapidly reversible when the agent is withdrawn.

Aged↗
PubMed1977

Effect of respiratory syncytial virus infection of HeLa-cell macromolecular synthesis.

Cells infected with respiratory syncytial (RS) virus eventually die but there appears to be no specific mechanism for shutting off cellular synthesis of macromolecules. DNA and RNA synthesis, as measured by the incorporation of labelled thymidine or uridine, do not begin to shut down until some time between 11 and 18 h after infection. By 18 h their rates of synthesis are reduced to approx. 50% for DNA and 35% for RNA. Protein synthesis continues throughout the course of infection at approximately the same rate. Synthesis of most of the cellular polypeptides also continues, but the distribution of polypeptides of high and low mol. wt. shifts. The increase in the proportion of those of high mol. wt. includes a peak that represents one of the seven previously identified virion polypeptides. Another consequence of RS virus infection is an increase in glucosamine incorporation, beginning near the end of the virus eclipse period (12 h after infection), which may be associated with virion glycoprotein synthesis. Polyacrylamide-gel electrophoresis of glucosamine-labelled cells reveals that at 18 h after infection two of the three previously identified virion glycoproteins are present.

Cell Survival↗
PubMed1977

Activities of various 4-aminoquinolines against infections with chloroquine-resistant strains of Plasmodium falciparum.

The studies reported here stemmed from a personal report by Geiman on the capacity of the 4-aminoquinoline amodiaquin to inhibit in vitro maturation of ring stages of the chloroquine-resistant Monterey strain of Plasmodium falciparum. This observation, confirmed in owl monkeys infected with this strain, led to a comparison of the activities of chloroquine, amodiaquin, amopyroquin, and dichlorquinazine (12,278 RP) against infections with various chloroquine-susceptible and chloroquine-resistant strains. The results showed that: (i) these 4-aminoquinolines were essentially equally active against infections with chloroquine-susceptible strains and (ii) the activities of amodiaquin, amopyroquin, and dichlorquinazine were reduced significantly in the face of chloroquine resistance, but (iii) well-tolerated doses of these compounds would cure infections with strains that fully resisted treatment with maximally tolerated doses of chloroquine. Two other 4-aminoquinolines, SN-8137 and SN-9584, which also exhibited activity against chloroquine-resistant parasites in vitro, displayed curative activity in monkeys infected with a chloroquine-resistant strain. These observations show that there is cross-resistance among the 4-aminoquinolines, confirming earlier findings, but indicate that the dimensions of this phenomenon are sufficiently limited so that some derivatives are therapeutically effective against infections refractory to maximally tolerated doses of chloroquine.

Aminoquinolines↗
PubMed1977

Acid-base balance and plasma composition in the aestivating lungfish (Protopterus).

Upon entering into aestivation, Protopterus aethiopicus develops a respiratory acidosis. A slow compensatory increase in plasma bicarbonate suffices only to partially restore arterial pH toward normal. The cessation of water intake from the start of aestivation results in hemoconcentration and marked oliguria. The concentrations of most plasma constituents continue to increase progressively, and the electrolyte ratios change. The increase in urea concentration is disproportionately high for the degree of dehydration and constitutes an increasing fraction of total plasma osmolality. Acid-base and electrolyte balance do not reach a new equilibrium within 1 yr in the cocoon.

Acclimatization↗
PubMed1977

Clinical, laboratory, and epidemiologic features of a viral gastroenteritis in infants and children.

We studied 27 infants admitted to the hospital with acute diarrhea caused by human rotavirus (HRV) and obtained additional data on fecal excretion from ten outpatients with the same infection. The disease was characterized by watery diarrhea with fever and vomiting at the onset, isotonic dehydration, compensated metabolic acidosis, and increased concentrations of sodium and chloride but low concentrations of sugar in stools. Diarrhea usually ceased in three to four days when oral feedings were reduced or stopped but recurred mildly in four patients. Of 57 household contacts, 12 were symptomatic, 6 had HRV in their stools, and 19 had significantly increased serum HRV antibody titers. These features of the disease accord with available information on the pathogenesis of HRV infection. Knowledge of the clinical pattern of this newly diagnosable infection should help physicians to recognize and treat quickly this highly infectious, potentially dangerous illness.

Adult↗