Viruses can be grown through three main methods: inoculation into animals, inoculation into embryonated eggs, and tissue culture. Embryonated eggs are commonly used because they provide an ideal substrate for viral growth and replication. Viruses are inoculated into 7-12 day old chick embryos through the shell and incubated for 2-3 days, then isolated from embryo tissue. While eggs are inexpensive and easy to maintain, different viruses grow in different locations within the egg. Tissue culture involves digesting tissues and mixing individual cells with viral growth medium in flasks, providing a broad method for cultivation but requiring trained technicians. Animal inoculation allows for studying pathogenesis but is expensive and raises welfare issues.
Viruses are obligate intracellular parasites so they depend on host for their survival. They cannot be grown in non-living culture media or on agar plates alone, they must require living cells to support their replication.Cultivation of viruses can be discussed under following headings:
Animal Inoculation
Inoculation into embryonated egg
Cell Culture
Viruses are obligate intracellular parasites so they depend on host for their survival. They cannot be grown in non-living culture media or on agar plates alone, they must require living cells to support their replication.Cultivation of viruses can be discussed under following headings:
Animal Inoculation
Inoculation into embryonated egg
Cell Culture
VIRAL VACCINES
Since viruses are intracellular parasites they will grow only within other living cells.
Methods of viral vaccine production:
Cultivation of virus using free living animals
Fertile eggs
Tissue cultures
Viruses are obligate intracellular parasites which means they can only grow or reproduce inside a host cell.
The primary purpose of virus cultivation:
To isolate and identify viruses in clinical samples.
To do research on the viral structure, replication, genetics, and effects on the host cell.
To prepare viruses for vaccine production.
Isolation of the virus is always considered a gold standard for establishing the viral origin of the disease
topics covered
CULTIVATION OF VIRUSES
Animal inoculation
Embryonated eggs
CAM
Allantoic cavity
Amniotic cavity
Yolk sac
Tissue culture
Organ culture
Explant culture
Cell culture
Primary cell culture
diploid cell culture
Continues cell lines
Viruses are Different From Other Microbes
Viruses are obligate intracellular parasites. They depend totally on their host cells for their existence. Their total host dependence makes it, extremely difficult to get good insight of them natural conditions, because the internal characteristics of the host cells are likely to interfere with the observations. Due to these reasons, it has been found desirable that viruses are cultivated or grown in the laboratory itself.
Laboratory animals
Fertilized Hen’s Egg
Chorioallantoic membrane
Allantoic cavity
Amniotic cavity
Yolk sac
Organ/Tissue/Cell Culture
Growth identified by serological method like neutralization.
Embryonated Egg Chorioallantioc membrane (CAM)
Allantoic cavity
Amniotic cavity
Yolk Sac
Cell Lines/ Tissue cultures Primary
Diploid/ Secondary
Continuous
Animal inoculation Suckling
Embryonated Hen’s Egg
Cultivation of Viruses and Bacteria
Chorioallantoic membrane (CAM) – visible lesions called pocks. Each infectious virus particle forms one pock. e.g. Variola, Vaccinia virus
Allantoic cavity – Influenza virus (vaccine production) & paramyxoviruses
Amniotic cavity – primary isolation of Influenza virus
Yolk sac – Chlamydia, Rickettsia & some viruses
Embryonated eggs:
The Embryonated hen’s egg was first used for cultivation of viruses by Good Pasteur and Burnet (1931). Cultivation of viruses in organized tissues like chick embryo necessitates a different type of approach.. For all practical purposes they all themselves behave as tissue cultures. The process of cultivation of viruses in embryonated eggs depends on the type of egg which is used. The egg used for cultivation must be sterile and the shell should be intact and healthy.
F.M. Burnet in the laboratory
in the early 1950's,
was experimenting
on influenza virus genetics,
using the developing hen's egg
Inoculated eggs are candled
daily to see the chicken
embryos inside.
Animals and chick embryo
were the first method that was used
to cultivate virus. This method is rarely
used as it is not convenient.
However, when preparing for bulk virus,
(e.g. antigen or vaccine production)
the usage of chick embryo is useful.
Fertile chicken eggs provide
a convenient, space-saving incubator
for many kinds of animal viruses.
Different viruses can be injected
into an egg at different sites and
the egg can be easily observed
for viral replication throughout
the development of the chicken embryo.
Isolation and cultivation of many avian
Acute scrotum is a general term referring to an emergency condition affecting the contents or the wall of the scrotum.
There are a number of conditions that present acutely, predominantly with pain and/or swelling
A careful and detailed history and examination, and in some cases, investigations allow differentiation between these diagnoses. A prompt diagnosis is essential as the patient may require urgent surgical intervention
Testicular torsion refers to twisting of the spermatic cord, causing ischaemia of the testicle.
Testicular torsion results from inadequate fixation of the testis to the tunica vaginalis producing ischemia from reduced arterial inflow and venous outflow obstruction.
The prevalence of testicular torsion in adult patients hospitalized with acute scrotal pain is approximately 25 to 50 percent
VIRAL VACCINES
Since viruses are intracellular parasites they will grow only within other living cells.
Methods of viral vaccine production:
Cultivation of virus using free living animals
Fertile eggs
Tissue cultures
Viruses are obligate intracellular parasites which means they can only grow or reproduce inside a host cell.
The primary purpose of virus cultivation:
To isolate and identify viruses in clinical samples.
To do research on the viral structure, replication, genetics, and effects on the host cell.
To prepare viruses for vaccine production.
Isolation of the virus is always considered a gold standard for establishing the viral origin of the disease
topics covered
CULTIVATION OF VIRUSES
Animal inoculation
Embryonated eggs
CAM
Allantoic cavity
Amniotic cavity
Yolk sac
Tissue culture
Organ culture
Explant culture
Cell culture
Primary cell culture
diploid cell culture
Continues cell lines
Viruses are Different From Other Microbes
Viruses are obligate intracellular parasites. They depend totally on their host cells for their existence. Their total host dependence makes it, extremely difficult to get good insight of them natural conditions, because the internal characteristics of the host cells are likely to interfere with the observations. Due to these reasons, it has been found desirable that viruses are cultivated or grown in the laboratory itself.
Laboratory animals
Fertilized Hen’s Egg
Chorioallantoic membrane
Allantoic cavity
Amniotic cavity
Yolk sac
Organ/Tissue/Cell Culture
Growth identified by serological method like neutralization.
Embryonated Egg Chorioallantioc membrane (CAM)
Allantoic cavity
Amniotic cavity
Yolk Sac
Cell Lines/ Tissue cultures Primary
Diploid/ Secondary
Continuous
Animal inoculation Suckling
Embryonated Hen’s Egg
Cultivation of Viruses and Bacteria
Chorioallantoic membrane (CAM) – visible lesions called pocks. Each infectious virus particle forms one pock. e.g. Variola, Vaccinia virus
Allantoic cavity – Influenza virus (vaccine production) & paramyxoviruses
Amniotic cavity – primary isolation of Influenza virus
Yolk sac – Chlamydia, Rickettsia & some viruses
Embryonated eggs:
The Embryonated hen’s egg was first used for cultivation of viruses by Good Pasteur and Burnet (1931). Cultivation of viruses in organized tissues like chick embryo necessitates a different type of approach.. For all practical purposes they all themselves behave as tissue cultures. The process of cultivation of viruses in embryonated eggs depends on the type of egg which is used. The egg used for cultivation must be sterile and the shell should be intact and healthy.
F.M. Burnet in the laboratory
in the early 1950's,
was experimenting
on influenza virus genetics,
using the developing hen's egg
Inoculated eggs are candled
daily to see the chicken
embryos inside.
Animals and chick embryo
were the first method that was used
to cultivate virus. This method is rarely
used as it is not convenient.
However, when preparing for bulk virus,
(e.g. antigen or vaccine production)
the usage of chick embryo is useful.
Fertile chicken eggs provide
a convenient, space-saving incubator
for many kinds of animal viruses.
Different viruses can be injected
into an egg at different sites and
the egg can be easily observed
for viral replication throughout
the development of the chicken embryo.
Isolation and cultivation of many avian
Acute scrotum is a general term referring to an emergency condition affecting the contents or the wall of the scrotum.
There are a number of conditions that present acutely, predominantly with pain and/or swelling
A careful and detailed history and examination, and in some cases, investigations allow differentiation between these diagnoses. A prompt diagnosis is essential as the patient may require urgent surgical intervention
Testicular torsion refers to twisting of the spermatic cord, causing ischaemia of the testicle.
Testicular torsion results from inadequate fixation of the testis to the tunica vaginalis producing ischemia from reduced arterial inflow and venous outflow obstruction.
The prevalence of testicular torsion in adult patients hospitalized with acute scrotal pain is approximately 25 to 50 percent
New Directions in Targeted Therapeutic Approaches for Older Adults With Mantl...i3 Health
i3 Health is pleased to make the speaker slides from this activity available for use as a non-accredited self-study or teaching resource.
This slide deck presented by Dr. Kami Maddocks, Professor-Clinical in the Division of Hematology and
Associate Division Director for Ambulatory Operations
The Ohio State University Comprehensive Cancer Center, will provide insight into new directions in targeted therapeutic approaches for older adults with mantle cell lymphoma.
STATEMENT OF NEED
Mantle cell lymphoma (MCL) is a rare, aggressive B-cell non-Hodgkin lymphoma (NHL) accounting for 5% to 7% of all lymphomas. Its prognosis ranges from indolent disease that does not require treatment for years to very aggressive disease, which is associated with poor survival (Silkenstedt et al, 2021). Typically, MCL is diagnosed at advanced stage and in older patients who cannot tolerate intensive therapy (NCCN, 2022). Although recent advances have slightly increased remission rates, recurrence and relapse remain very common, leading to a median overall survival between 3 and 6 years (LLS, 2021). Though there are several effective options, progress is still needed towards establishing an accepted frontline approach for MCL (Castellino et al, 2022). Treatment selection and management of MCL are complicated by the heterogeneity of prognosis, advanced age and comorbidities of patients, and lack of an established standard approach for treatment, making it vital that clinicians be familiar with the latest research and advances in this area. In this activity chaired by Michael Wang, MD, Professor in the Department of Lymphoma & Myeloma at MD Anderson Cancer Center, expert faculty will discuss prognostic factors informing treatment, the promising results of recent trials in new therapeutic approaches, and the implications of treatment resistance in therapeutic selection for MCL.
Target Audience
Hematology/oncology fellows, attending faculty, and other health care professionals involved in the treatment of patients with mantle cell lymphoma (MCL).
Learning Objectives
1.) Identify clinical and biological prognostic factors that can guide treatment decision making for older adults with MCL
2.) Evaluate emerging data on targeted therapeutic approaches for treatment-naive and relapsed/refractory MCL and their applicability to older adults
3.) Assess mechanisms of resistance to targeted therapies for MCL and their implications for treatment selection
Couples presenting to the infertility clinic- Do they really have infertility...Sujoy Dasgupta
Dr Sujoy Dasgupta presented the study on "Couples presenting to the infertility clinic- Do they really have infertility? – The unexplored stories of non-consummation" in the 13th Congress of the Asia Pacific Initiative on Reproduction (ASPIRE 2024) at Manila on 24 May, 2024.
micro teaching on communication m.sc nursing.pdfAnurag Sharma
Microteaching is a unique model of practice teaching. It is a viable instrument for the. desired change in the teaching behavior or the behavior potential which, in specified types of real. classroom situations, tends to facilitate the achievement of specified types of objectives.
Recomendações da OMS sobre cuidados maternos e neonatais para uma experiência pós-natal positiva.
Em consonância com os ODS – Objetivos do Desenvolvimento Sustentável e a Estratégia Global para a Saúde das Mulheres, Crianças e Adolescentes, e aplicando uma abordagem baseada nos direitos humanos, os esforços de cuidados pós-natais devem expandir-se para além da cobertura e da simples sobrevivência, de modo a incluir cuidados de qualidade.
Estas diretrizes visam melhorar a qualidade dos cuidados pós-natais essenciais e de rotina prestados às mulheres e aos recém-nascidos, com o objetivo final de melhorar a saúde e o bem-estar materno e neonatal.
Uma “experiência pós-natal positiva” é um resultado importante para todas as mulheres que dão à luz e para os seus recém-nascidos, estabelecendo as bases para a melhoria da saúde e do bem-estar a curto e longo prazo. Uma experiência pós-natal positiva é definida como aquela em que as mulheres, pessoas que gestam, os recém-nascidos, os casais, os pais, os cuidadores e as famílias recebem informação consistente, garantia e apoio de profissionais de saúde motivados; e onde um sistema de saúde flexível e com recursos reconheça as necessidades das mulheres e dos bebês e respeite o seu contexto cultural.
Estas diretrizes consolidadas apresentam algumas recomendações novas e já bem fundamentadas sobre cuidados pós-natais de rotina para mulheres e neonatos que recebem cuidados no pós-parto em unidades de saúde ou na comunidade, independentemente dos recursos disponíveis.
É fornecido um conjunto abrangente de recomendações para cuidados durante o período puerperal, com ênfase nos cuidados essenciais que todas as mulheres e recém-nascidos devem receber, e com a devida atenção à qualidade dos cuidados; isto é, a entrega e a experiência do cuidado recebido. Estas diretrizes atualizam e ampliam as recomendações da OMS de 2014 sobre cuidados pós-natais da mãe e do recém-nascido e complementam as atuais diretrizes da OMS sobre a gestão de complicações pós-natais.
O estabelecimento da amamentação e o manejo das principais intercorrências é contemplada.
Recomendamos muito.
Vamos discutir essas recomendações no nosso curso de pós-graduação em Aleitamento no Instituto Ciclos.
Esta publicação só está disponível em inglês até o momento.
Prof. Marcus Renato de Carvalho
www.agostodourado.com
ARTIFICIAL INTELLIGENCE IN HEALTHCARE.pdfAnujkumaranit
Artificial intelligence (AI) refers to the simulation of human intelligence processes by machines, especially computer systems. It encompasses tasks such as learning, reasoning, problem-solving, perception, and language understanding. AI technologies are revolutionizing various fields, from healthcare to finance, by enabling machines to perform tasks that typically require human intelligence.
These lecture slides, by Dr Sidra Arshad, offer a quick overview of physiological basis of a normal electrocardiogram.
Learning objectives:
1. Define an electrocardiogram (ECG) and electrocardiography
2. Describe how dipoles generated by the heart produce the waveforms of the ECG
3. Describe the components of a normal electrocardiogram of a typical bipolar leads (limb II)
4. Differentiate between intervals and segments
5. Enlist some common indications for obtaining an ECG
Study Resources:
1. Chapter 11, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 9, Human Physiology - From Cells to Systems, Lauralee Sherwood, 9th edition
3. Chapter 29, Ganong’s Review of Medical Physiology, 26th edition
4. Electrocardiogram, StatPearls - https://www.ncbi.nlm.nih.gov/books/NBK549803/
5. ECG in Medical Practice by ABM Abdullah, 4th edition
6. ECG Basics, http://www.nataliescasebook.com/tag/e-c-g-basics
Ethanol (CH3CH2OH), or beverage alcohol, is a two-carbon alcohol
that is rapidly distributed in the body and brain. Ethanol alters many
neurochemical systems and has rewarding and addictive properties. It
is the oldest recreational drug and likely contributes to more morbidity,
mortality, and public health costs than all illicit drugs combined. The
5th edition of the Diagnostic and Statistical Manual of Mental Disorders
(DSM-5) integrates alcohol abuse and alcohol dependence into a single
disorder called alcohol use disorder (AUD), with mild, moderate,
and severe subclassifications (American Psychiatric Association, 2013).
In the DSM-5, all types of substance abuse and dependence have been
combined into a single substance use disorder (SUD) on a continuum
from mild to severe. A diagnosis of AUD requires that at least two of
the 11 DSM-5 behaviors be present within a 12-month period (mild
AUD: 2–3 criteria; moderate AUD: 4–5 criteria; severe AUD: 6–11 criteria).
The four main behavioral effects of AUD are impaired control over
drinking, negative social consequences, risky use, and altered physiological
effects (tolerance, withdrawal). This chapter presents an overview
of the prevalence and harmful consequences of AUD in the U.S.,
the systemic nature of the disease, neurocircuitry and stages of AUD,
comorbidities, fetal alcohol spectrum disorders, genetic risk factors, and
pharmacotherapies for AUD.
Title: Sense of Taste
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the structure and function of taste buds.
Describe the relationship between the taste threshold and taste index of common substances.
Explain the chemical basis and signal transduction of taste perception for each type of primary taste sensation.
Recognize different abnormalities of taste perception and their causes.
Key Topics:
Significance of Taste Sensation:
Differentiation between pleasant and harmful food
Influence on behavior
Selection of food based on metabolic needs
Receptors of Taste:
Taste buds on the tongue
Influence of sense of smell, texture of food, and pain stimulation (e.g., by pepper)
Primary and Secondary Taste Sensations:
Primary taste sensations: Sweet, Sour, Salty, Bitter, Umami
Chemical basis and signal transduction mechanisms for each taste
Taste Threshold and Index:
Taste threshold values for Sweet (sucrose), Salty (NaCl), Sour (HCl), and Bitter (Quinine)
Taste index relationship: Inversely proportional to taste threshold
Taste Blindness:
Inability to taste certain substances, particularly thiourea compounds
Example: Phenylthiocarbamide
Structure and Function of Taste Buds:
Composition: Epithelial cells, Sustentacular/Supporting cells, Taste cells, Basal cells
Features: Taste pores, Taste hairs/microvilli, and Taste nerve fibers
Location of Taste Buds:
Found in papillae of the tongue (Fungiform, Circumvallate, Foliate)
Also present on the palate, tonsillar pillars, epiglottis, and proximal esophagus
Mechanism of Taste Stimulation:
Interaction of taste substances with receptors on microvilli
Signal transduction pathways for Umami, Sweet, Bitter, Sour, and Salty tastes
Taste Sensitivity and Adaptation:
Decrease in sensitivity with age
Rapid adaptation of taste sensation
Role of Saliva in Taste:
Dissolution of tastants to reach receptors
Washing away the stimulus
Taste Preferences and Aversions:
Mechanisms behind taste preference and aversion
Influence of receptors and neural pathways
Impact of Sensory Nerve Damage:
Degeneration of taste buds if the sensory nerve fiber is cut
Abnormalities of Taste Detection:
Conditions: Ageusia, Hypogeusia, Dysgeusia (parageusia)
Causes: Nerve damage, neurological disorders, infections, poor oral hygiene, adverse drug effects, deficiencies, aging, tobacco use, altered neurotransmitter levels
Neurotransmitters and Taste Threshold:
Effects of serotonin (5-HT) and norepinephrine (NE) on taste sensitivity
Supertasters:
25% of the population with heightened sensitivity to taste, especially bitterness
Increased number of fungiform papillae
2. Introduction
• Viruses are extremely small infectious agents that
invade cells of all types.
• Viruses are obligate intracellular parasites so they
depend on host for their survival.
• They cannot be grown in non-living culture media or on
agar plates alone, they must require living cells to
support their replication.
• Viruses have been the culprits in many human
diseases, including smallpox, flu, AIDS, and the ever-
present common cold as well as in plant, bacteria
and archaea also.
3. Methods for Cultivation of Virus
•Generally three methods are
employed for the virus cultivation
1.Inoculation of virus into animals
2.Inoculation of virus into
embryonated eggs
3.Tissue culture
4. 1. Animal Inoculation
• Viruses which are not cultivated in embryonated egg
and tissue culture are cultivated in laboratory animals
such as mice, guinea pig, hamster and rabbits are
used.
• The selected animals should be healthy and free from
any communicable diseases.
• Mice (less than 48 hours old) are most commonly
used.
• Mice are susceptible to togavirus and coxsackie viruses
which are inoculated by intracerebral and intranasal
route.
5. Advantages Disadvantages
• Diagnosis, Pathogenesis and
clinical symptoms are
determined.
• Production of antibodies can
be identified.
• Primary isolation of certain
viruses.
• M ice provide a reliable
model for studying viral
replication.
• Used for the study of
immune responses,
epidemiology and
oncogenesis
• Expensive and difficulties
in maintenance of
animals.
• Difficulty in choosing of animals
for particular virus
• Some human viruses cannot be
grown in animals , or can be
grown but do not cause disease.
• Mice do not provide
models for vaccine
development.
• Issues related to animal welfare
systems.
6. 2. Inoculation into embryonated egg
• Good pasture in 1931 first used the embryonated
hen's egg for the cultivation of virus.
• The process of cultivation of viruses in
embryonated eggs depends on the type of egg
which is used.
• Viruses are inoculated into chick embryo of 7-12
days old.
• For inoculation, eggs are first prepared for
cultivation, the shell surface is first disinfected with
iodine and penetrated with a small sterile drill.
7. • After inoculation, the opening is sealed with
gelatin or paraffin and incubated at 36°c for 2-3
days.
• After incubation, the egg is broken and virus is
isolated from tissue of egg.
• Viral growth and multiplication in the egg embryo
is indicated by the death of the embryo by embryo
cell damage or by the formation of typical pocks or
lesions on the egg membranes
• Viruses can be cultivated in various parts of egg
like chorioallantoic membrane, allantoic cavity,
amniotic sac and yolk sac.
8. Embryonated egg has four sites for
cultivation of virus
• 1. Chorioallantoic membrane (CAM): Few
viruses produce lesions called pocks, e.g.
Vaccinia, Variola, HSV 1 and 2
• 2. Yolk sac: Arboviruses (e.g. JEV, Saint Louis
and West Nile virus), Rickettsia, Chlamydia and
Hemophilus ducreyi.
• 3. Amniotic membrane: Influenza culture (for
diagnosis)
• 4. Allantoic cavity: Used for vaccine preparation
for Influenza, Yellow fever (17D), Rabies (Flury).
9. Advantages Disadvantages
• Widely used method for the
isolation of virus and growth.
• Ideal substrate for the viral
growth and replication.
• Isolation and cultivation of
many avian and few
mammalian viruses.
• Cost effective and maintenance
is much easier.
• Less labor is needed.
• The embryonated eggs are
readily available.
• They are free from
contaminating bacteria and
many viruses.
• Widely used method to grow
virus for some vaccine
production.
• The site of inoculation
varies with different viruses.
That is, each virus has
different site for growth and
replication.
• This is very inconvenient.
10. 3. Tissue Culture
• Cultivation of tissue or organ for the growth of
viruses
• • Organ culture: Whole organ is used, tracheal
ring used for coronaviruses
• • Explant culture: Minced organ is used, e.g.
adenoid explant used for Adenovirus
• • Cell Line: Tissues are completely digested and
the individual cells are mixed with viral growth
medium and dispensed in tissue culture flask.
11. Advantages Disadvantages
• Relative ease.
• Broad Spectrum
• Cheaper
• More Sensitive.
• The process requires trained
technicians with experience in
working on a full time basis.
• State health laboratories and
hospital laboratories do not
isolate and identify viruses in
clinical work.
• Tissue or serum for analysis is
sent to central laboratories to
identify virus.