Several peptides that specifically bind the HIV-1 integrase (IN) and either
inhibit or stimulate its enzymatic activity were developed in our laborato-ries. Kinetic studies using 3¢-end processing and strand-transfer assays were
performed to study the mode of action of these peptides.
Osteoporosis and fractures may increase due to hypoestrogenism in menopause and
cytochrome P450 inducing AEDs. Recent studies suggest lower bone mineral density (BMD)
in adults and children with epilepsy, irrespective of AED treatment.
Both idiopathic epilepsy and symptomatic epilepsy are associated with reduced BMD, with
the greatest reduction in symptomatic generalized epilepsy (Sheth & Hermann, 2008).
However, the pathophysiological underlying mechanisms are far from understood and likely
Hormone resistance syndromes are typically thought of as rare, usually genetic,
disorders with a severe but relatively stereotyped clinical and biochemical profile.
While there are syndromes of severe insulin resistance that conform to
this description, defective insulin action is of much more pervasive biomedical
importance. Even moderate degrees of insulin resistance are closely linked to
a range of common diseases, including Type 2 diabetes, polycystic ovary syndrome,
obesity and hypertension....
In just over ten years, the Textbook of Internal Medicine has become widely regarded as a classic medical text, both for its breadth of coverage and ease of use by
busy students and practitioners. Hundreds of talented individuals contributed to the success of the first three editions. These include the many leading scientists and
scholars who served as editors and authors, and the dozens of supporting staff who met the organizational and logistical challenges associated with so large a
Plants defend themselves from other organisms by elaborating bioactive chemical
defences. This is the essential basis of the use of herbal medicines that still represents a
major therapeutic resort for much of humanity However, at the outset, it must be stated that
any plant that is not part of our evolved dietary cultures is potentially dangerous.
Commercial herbal medicinal preparations approved by expert regulatory authorities have a
significant place in mainstream conventional medicine and in complementary medicine.
COMBINED ORAL CONTRACEPTIVES Mechanism of action
The combined oral contraceptive (COC) pills currently available in the UK are shown in Table 2. They combine an estrogen (ethinylestradiol (EE) in all cases but one) with one of seven progestogens. Aside from secondary contraceptive effects on the cervical mucus and to impede implantation, COCs primarily prevent ovulation. This makes the method highly effective in ‘perfect’ use (Table 1), but it removes the normal menstrual cyle and replaces it with a cycle that is user-produced and based only on the end-organ, i.e. the endometrium.
The authors provided evidence regarding NSAIDs mechanism of
action and NSAIDs management including low-dose aspirin therapy. The discovery of
safe NSAIDs with reduced upper GI toxicity such as selective COX-2 inhibitors is also
presented in this chapter. Vanaskova et al., described the functional disorders of the
GIT, focusing on swallowing dysfunctions in human beings. It is well known that
these disorders are not only difficult to verify and quantify but also difficult to treat.
According to Rubinow, the “one receptor-one action” model of hormone action has been overturned by the robust
evidence for action of steroid hormones through both nuclear and membrane receptors, and by the mounting evidence for
the role of co-regulators in modulation of hormone action. Rubinow argued that the same hormone may simultaneously
exert opposite effects on the same system (e.g., cell survival), and these effects can change with time. More research in
this area is needed to understand why women respond differently to the same hormonal stimuli.
Organic milk production systems rely on ecologically based practices that virtually prohibit the
use of antibiotics and hormones in the cow herd and the use of synthetic chemicals in the
production of cattle feed. Organic milk production systems also attempt to accommodate the
animals’ natural nutritional and behavioral requirements, for example ensuring that dairy cows
have access to pasture (Greene and Kremen).
Synthetic chemicals known as endocrine disruptors are
an excellent example of emerging contaminants where the
threats and consequences for water quality, human health,
and the environment are still not fully understood. Endocrine
disruptors – chemicals that can interfere with hormone
action – have been identified among chemicals used in
agriculture, industry, and households, and for personal
care, including pesticides, disinfectants, plastic additives,
and pharmaceuticals like birth control pills.
EngenderHealth, a non-profit organisation that works in reproductive health, has devised a
"client-orientated, provider-efficient" (COPE) approach to improve quality of care and motivate
staff. COPE offers guidance for providers to assess their services, interview patients, and
examine the time that they spend at clinics. This gives staff a better understanding of patients'
perspectives, and enables them to develop a plan of action to improve quality. In some clinics,
COPE has resulted in staff staggering their lunch breaks to reduce patients' waiting time.
The mitogenic toxin fromPasteurella multocida(PMT) is a member of the
dermonecrotic toxin family, which includes toxins fromBordetella, Escheri-chia coliandYersinia. Members of the dermonecrotic toxin family modu-late G-protein targets in host cells through selective deamidation and⁄or
transglutamination of a critical active site Gln residue in the G-protein tar-get, which results in the activation of intrinsic GTPase activity.
Increases in intracellular [Ca
] occur synchronously between cells in the
neuroepithelium. If neuroepithelial cells were capable of generating action
potentials synchronized by gap junctions (direct current electrical coupling),
the influx of Ca
through voltage-activated Ca
channels would lead to
a synchronous increase in intracellular [Ca
The family of testis-specific serine–threonine kinases (TSSKs) consists of
four members whose expression is confined almost exclusively to testis.
Very little is known about their physiological role and mechanisms of
action. We cloned human and mouse TSSK3 and analysed the biochemical
properties, substrate specificity and in vitro activation.
As an essential element, selenium is present in enzymes from
several families, including glutathione peroxidases, and is
thought to exert anticarcinogenic properties. A remarkable
feature of selenium consists of its ability to oxidize thiols
under reducing conditions. Thus, one mode of action
recently suggested is the oxidation of thiol groups of metal-lothionein, thereby providing zinc for essential reactions.
We have previously demonstrated that the steroid hormone
1a,25(OH)2-vitamin D3 [1a,25(OH)2D3] stimulates the
production ofinositol trisphosphate (InsP3), the breakdown
product ofphosphatidylinositol 4,5-biphosphate (PtdInsP2)
by phospholipase C (PtdIns-PLC), and activates the cyto-solic tyrosine kinase c-Src in skeletal muscle cells. In the
present study we examined whether 1a,25(OH)2D3induces
the phosphorylation and membrane translocation ofPLCc
and the mechanism involved in this isozyme activation. ...
Insulin is the principal regulatory hormone involved in the tight regulation of fuel metabolism. In response to blood glucose levels, it is secreted by the b cells of the pancreas and exerts its eﬀects by binding to cell surface receptors that are present on virtually all cell types and tissues. In humans, perturbations in insulin function and/or secretion lead to diabetes mellitus, a severe disorder primarily characterized by an inability to maintain blood glucose homeostasis. Furthermore, it is estimated that 90–95% of diabetic patients exhibit resistance to insulin action....
Parathyroid hormone (PTH)(1–34), which has been established to have a
dual effect on bone metabolism, was recently found to regulate osteosarcoma
cell migration. A significant part of the bone anabolic action of PTH(1–34) is
attributed to fibroblast growth factor (FGF)-2 stimulation.
One of several potential approaches to study mechanisms of action of bio-logically active compounds is to develop their agonists and antagonists. In
the present study, we report the identification of the first known molecule
antagonizing the activity of the plant hormone cytokinin at the receptor
Alterations resulting in enhanced epidermal growth factor receptor (EGFR)
expression or function have been documented in a variety of tumors.
Therefore, EGFR-tyrosine kinase is a promising therapeutic target.
Althoughin vitro andin vivo studies have shown the anti-tumor activity of
EGFR-tyrosine kinase inhibitors against various tumor types, little is
known about the mechanism by which such inhibitors effect their anti-tumor action.