A growth curve is an empirical model of the evolution of a quantity over time. Growth curves are widely used in biology for quantities such as population size or biomass (in population ecology and demography, for population growth analysis), individual body height or biomass (in physiology, for growth analysis of individuals). Values for the measured property
In this example (Figure 1, see Lac operon for details) the number of bacteria present in a nutrient-containing broth was measured during the course of an 8-hour cell growth experiment. The observed pattern of bacterial growth is bi-phasic because two different sugars were present, glucose and lactose. The bacteria prefer to consume glucose (Phase I) and only use the lactose (Phase II) after the glucose has been depleted. Analysis of the molecular basis for this bi-phasic growth curve led to the discovery of the basic mechanisms that control gene expression.
Cancer research is an area of biology where growth curve analysis plays an important role. In many types of cancer, the rate at which tumors shrink following chemotherapy is related to the rate of tumor growth before treatment. Tumors that grow rapidly are generally more sensitive to the toxic effects that conventional anticancer drugs have on the cancer cells. Many conventional anticancer drugs (for example, 5-Fluorouracil) interfere with DNA replication and can cause the death of cells that attempt to replicate their DNA and divide. A rapidly growing tumor will have more actively dividing cells and more cell death upon exposure to such anticancer drugs.
In the example shown in Figure 2, a tumor is found after the cell growth rate has slowed. Most of the cancer cells are removed by surgery. The remaining cancer cells begin to proliferate rapidly and cancer chemotherapy is started. Many tumor cells are killed by the chemotherapy, but eventually some cancer cells that are resistant to the chemotherapy drug begin to grow rapidly. The chemotherapy is no longer useful and is discontinued.
Children who fall significantly below the normal range of growth curves for body height can be tested for growth hormone deficiency and might be treatable with hormone injections. [1]
Some growth curves for certain biological systems display periods of exponential growth. Typically, periods of exponential growth are of limited duration due to depletion of some rate-limiting resource. [2]
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Chemotherapy is the type of cancer treatment that uses one or more anti-cancer drugs in a standard regimen. Chemotherapy may be given with a curative intent, or it may aim only to prolong life or to reduce symptoms. Chemotherapy is one of the major categories of the medical discipline specifically devoted to pharmacotherapy for cancer, which is called medical oncology.
Bacterial growth is proliferation of bacterium into two daughter cells, in a process called binary fission. Providing no mutation event occurs, the resulting daughter cells are genetically identical to the original cell. Hence, bacterial growth occurs. Both daughter cells from the division do not necessarily survive. However, if the surviving number exceeds unity on average, the bacterial population undergoes exponential growth. The measurement of an exponential bacterial growth curve in batch culture was traditionally a part of the training of all microbiologists; the basic means requires bacterial enumeration by direct and individual, direct and bulk (biomass), indirect and individual, or indirect and bulk methods. Models reconcile theory with the measurements.
This is a list of terms related to oncology. The original source for this list was the US National Cancer Institute's public domain Dictionary of Cancer Terms.
Irofulven or 6-hydroxymethylacylfulvene is an experimental antitumor agent. It belongs to the family of drugs called alkylating agents.
In oncology, the Warburg effect is the observation that most cancer use aerobic glycolysis for energy generation rather than the mechanisms used by non-cancerous cells. This observation was first published by Otto Heinrich Warburg, who was awarded the 1931 Nobel Prize in Physiology for his "discovery of the nature and mode of action of the respiratory enzyme". The existence of the Warburg effect has fuelled popular misconceptions that cancer can be treated by dietary reductions in sugar and carbohydrate.
An antimetabolite is a chemical that inhibits the use of a metabolite, which is another chemical that is part of normal metabolism. Such substances are often similar in structure to the metabolite that they interfere with, such as the antifolates that interfere with the use of folic acid; thus, competitive inhibition can occur, and the presence of antimetabolites can have toxic effects on cells, such as halting cell growth and cell division, so these compounds are used in chemotherapy for cancer.
The Gompertz curve or Gompertz function is a type of mathematical model for a time series, named after Benjamin Gompertz (1779–1865). It is a sigmoid function which describes growth as being slowest at the start and end of a given time period. The right-side or future value asymptote of the function is approached much more gradually by the curve than the left-side or lower valued asymptote. This is in contrast to the simple logistic function in which both asymptotes are approached by the curve symmetrically. It is a special case of the generalised logistic function. The function was originally designed to describe human mortality, but since has been modified to be applied in biology, with regard to detailing populations.
Lapatinib (INN), used in the form of lapatinib ditosylate (USAN) is an orally active drug for breast cancer and other solid tumours. It is a dual tyrosine kinase inhibitor which interrupts the HER2/neu and epidermal growth factor receptor (EGFR) pathways. It is used in combination therapy for HER2-positive breast cancer. It is used for the treatment of patients with advanced or metastatic breast cancer whose tumors overexpress HER2 (ErbB2).
2-Deoxy-d-glucose is a glucose molecule which has the 2-hydroxyl group replaced by hydrogen, so that it cannot undergo further glycolysis. As such; it acts to competitively inhibit the production of glucose-6-phosphate from glucose at the phosphoglucoisomerase level. 2-Deoxyglucose labeled with tritium or carbon-14 has been a popular ligand for laboratory research in animal models, where distribution is assessed by tissue-slicing followed by autoradiography, sometimes in tandem with either conventional or electron microscopy.
A side population (SP) in flow cytometry is a sub-population of cells that is distinct from the main population on the basis of the markers employed. By definition, cells in a side population have distinguishing biological characteristics, but the exact nature of this distinction depends on the markers used in identifying the side population.
Asparagine synthetase is a chiefly cytoplasmic enzyme that generates asparagine from aspartate. This amidation reaction is similar to that promoted by glutamine synthetase. The enzyme is ubiquitous in its distribution in mammalian organs, but basal expression is relatively low in tissues other than the exocrine pancreas.
Satraplatin is a platinum-based antineoplastic agent that was under investigation as a treatment of patients with advanced prostate cancer who have failed previous chemotherapy. It has not yet received approval from the U.S. Food and Drug Administration. First mentioned in the medical literature in 1993, satraplatin is the first orally active platinum-based chemotherapeutic drug; other available platinum analogues—cisplatin, carboplatin, and oxaliplatin—must be given intravenously.
A mitotic inhibitor, microtubule inhibitor, or tubulin inhibitor, is a drug that inhibits mitosis, or cell division, and is used in treating cancer, gout, and nail fungus. These drugs disrupt microtubules, which are structures that pull the chromosomes apart when a cell divides. Mitotic inhibitors are used in cancer treatment, because cancer cells are able to grow through continuous division that eventually spread through the body (metastasize). Thus, cancer cells are more sensitive to inhibition of mitosis than normal cells. Mitotic inhibitors are also used in cytogenetics, where they stop cell division at a stage where chromosomes can be easily examined.
Checkpoint kinase 1, commonly referred to as Chk1, is a serine/threonine-specific protein kinase that, in humans, is encoded by the CHEK1 gene. Chk1 coordinates the DNA damage response (DDR) and cell cycle checkpoint response. Activation of Chk1 results in the initiation of cell cycle checkpoints, cell cycle arrest, DNA repair and cell death to prevent damaged cells from progressing through the cell cycle.
In oncology, the fact that one round of chemotherapy does not kill all the cells in a tumor is a poorly understood phenomenon called fractional kill, or fractional cell kill.
Safingol is a lyso-sphingolipid protein kinase inhibitor. It has the molecular formula C18H39NO2 and is a colorless solid. Medicinally, safingol has demonstrated promising anticancer potential as a modulator of multi-drug resistance and as an inducer of necrosis. The administration of safingol alone has not been shown to exert a significant effect on tumor cell growth. However, preclinical and clinical studies have shown that combining safingol with conventional chemotherapy agents such as fenretinide, vinblastine, irinotecan and mitomycin C can dramatically potentiate their antitumor effects. In phase I clinical trials, it was found to be safe to co-administer with cisplatin, but caused reversible dose-dependent hepatotoxicity.
Diauxic growth, diauxie or diphasic growth is any cell growth characterized by cellular growth in two phases. Diauxic growth, meaning double growth, is caused by the presence of two sugars on a culture growth media, one of which is easier for the target bacterium to metabolize. The preferred sugar is consumed first, which leads to rapid growth, followed by a lag phase. During the lag phase the cellular machinery used to metabolize the second sugar is activated and subsequently the second sugar is metabolized.
Doxifluridine (5'-deoxy-5-fluorouridine) is a second generation nucleoside analog prodrug developed by Roche and used as a cytostatic agent in chemotherapy in several Asian countries including China and South Korea. Doxifluridine is not FDA-approved for use in the USA. It is currently being evaluated in several clinical trials as a stand-alone or combination therapy treatment.
Lurbinectedin, sold under the brand name Zepzelca, is a medication used for the treatment of small cell lung cancer.
BOLD-100, or sodium trans-[tetrachlorobis (1H-indazole)ruthenate(III)], is a ruthenium-based anti-cancer therapeutic in clinical development. As of February 2024, BOLD-100 was being tested in a Phase 1b/2a clinical trial in 117 patients with advanced gastrointestinal cancers in combination with the chemotherapy regimen FOLFOX. BOLD-100 is being developed by Bold Therapeutics Inc.