Principles of Medical Laboratory Science Practice I – History, Development & Professional Scope

Ancient & Medieval Foundations

• 1550\,BC: Ebers Papyrus
  • Earliest recorded observations on medical diagnostics.
  • Mentioned intestinal parasites: Taenia spp. (tapeworm) & Ascaris spp. (round‐worm).
  • Described three stages of hookworm infection.
• Hindu medicine (pre-Christian era)
  • Physicians noticed that urine from certain individuals attracted ants ⇒ rudimentary recognition of glucosuria (diabetes).
• Medieval period (14th – 17th centuries)
  • "Quack" practitioners used urine color/taste/odor for disease diagnosis (uro‐diagnosis).
  • 14th century: Italian physician at University of Bologna employed Alexandra Giliani to perform tasks now considered medical-technologist work (sample preparation & recording).

Seventeenth-Century Scientific Breakthroughs

• 1670s: Antonie van Leeuwenhoek
  • Perfected single-lens microscopes (up to 270\times magnification).
  • First to describe: red blood cells, protozoa, and classified bacteria by shape (cocci, bacilli, spirilla).
• Marcello Malpighi (1628-1694)
  • Father of pathology & microscopic anatomy.
  • Microscopic study of tissues advanced physiology & embryology.

Nineteenth-Century Pathology & Laboratory Expansion

• Rudolf Carl Virchow (1821-1902)
  • Founded Archives of Pathology, Berlin (1847).
  • Father of modern (cellular) pathology: "Omnis cellula e cellula"—all cells arise from pre-existing cells.
• Introduction of aniline dyes ⇒ histological staining revolution.
• Dr. William Occam (UK)
  • Applied laboratory methods for routine clinical diagnosis.
  • Concept spread to Turkey & wider Europe.

United States Milestones

• 1878: University of Michigan—Dr. Albert B.
  • First chemical laboratory in a U.S. medical school (founded by Dr. Douglas).
• 1884: William Welch
  • Returned from Germany (bacteriology/pathology training).
  • Offered lab to College of Physicians & Surgeons, NY (rejected) ⇒ opened at Bellevue Hospital Medical College—the 1st pathology course in an American medical school.
• 1889: Became 1st Professor of Pathology, Johns Hopkins University; founded its 1st clinical laboratory; routine specimen testing began.
• 1894: Simon Flexner named resident pathologist at Johns Hopkins.

Resistance to Early Labs (late 1800s)

1. Viewed as scientific luxuries.
2. Required additional space.
3. High cost.
4. Tests perceived as too time-consuming.
5. Use of poisonous reagents.

Standardization & Education

• 1900 U.S. census: first enumeration of laboratory personnel.
• 1908: James Todd & Arthur Sanford published “A Manual of Clinical Diagnosis” ⇒ evolution into “Clinical Diagnosis by Laboratory Methods”.
• 1915: Pennsylvania law—every hospital must operate a lab with a full-time medical technologist.
• Post-WWII (≈1942-45): Formal training of medical technicians accelerated (University of Minnesota pioneered curriculum in 1922; U.S. Army programs during WWII).

Philippine Development Timeline

• WWII era: 26th Medical Laboratory of 6th U.S. Army introduced MT practice; relinquished lab to Philippine Department of Health (initially uninterested).
• Dr. Alfredo Pio de Roda with Dr. Mariano Icasiano (1st Manila city health officer) preserved the facility.
  • 1 Oct 1945: Public Health Laboratory established (Calle Herran, Manila) under Dr. de Roda.
• 1947-1953: Informal training of medical technicians led by Dr. de Roda & Dr. Prudencia Sta. Ana.
• 1954: 6-month formal program created by Dr. de Roda, Sta. Ana & Dr. Tirso Briones (syllabus + certificate).
• Mrs. Willa Hilgert-Hedrick (1953)
  • Started first 4-year BS program at Philippine Union College–Manila Adventist Medical Center (PUC-MAMC).
  • Assisted by Antoinette McKelvey (trained under Dr. George Papanicolaou).
  • Curriculum: 3 years didactics at PUC + 18-month clinical internship at Manila Sanitarium & Hospital.
  • First enrollees: Jesse Umali (1st graduate), Adoracion Yutuc, Avelino Oliva.

Defining the Profession

• Clinical Laboratory Science: discipline providing diagnostic & preventive information via analytical tests on human samples.
• Clinical Laboratory (CLIA '88): any facility examining human specimens for diagnosis, prevention, treatment, or health assessment.

Professional Titles

• Medical Technologist (historical term, early 1900s).
• Clinical Laboratory Scientist (coined 1976 by National Credentialing Agency).
• In the Philippines (RA 005527—Medical Technology Act 1969): detailed legal scope (a-h):
  • Examination of tissues, fluids, secretions by electronic/chemical/microscopic methods (manual & automated).
  • Blood banking.
  • Parasitology, mycology, microbiology.
  • Histopathology & cytotechnology.
  • Clinical research involving human subjects.
  • Preparation/standardization of reagents & stains (exclusive lab use).
  • Quality control.
  • Specimen collection & preservation.

Major Laboratory Areas & Functions

• Clinical Chemistry
  • Quantitative analysis of serum/plasma; e.g., blood glucose, \text{cholesterol}, electrolytes.
  • Occasionally analyzes urine & other body fluids.
• Urinalysis / Clinical Microscopy
  • Three pillars: physical inspection, chemical strip testing, microscopic sediment exam.
  • Used for metabolic & kidney disease monitoring.
• Hematology
  • Study of formed blood elements; CBC, differential, RBC indices.
  • Special tests: bone-marrow aspirate/biopsy for anemia, leukemia.
• Hemostasis & Coagulation
  • Assess bleeding/clotting disorders (PT, aPTT, D-dimer).
  • May be merged with Hematology.
• Blood Bank / Immunohematology
  • Blood collection, typing (ABO, Rh), cross-matching, component preparation.
  • Donor blood rigorously screened for transfusion-transmissible infections.
• Immunology & Serology
  • Studies immune response & disorders.
  • Employs molecular diagnostics (e.g., \text{PCR}) for pathogens, genetic tests, transplant HLA matching, forensic DNA profiling.
• Microbiology
  • Isolation/identification of bacteria, viruses, fungi, parasites.
  • Performs antimicrobial susceptibility testing.
  • Includes detection of potential bioterror agents.
• Histotechnology / Histopathology
  • Tissue processing, embedding, microtomy & special stains for microscopic pathology.
• Cytotechnology
  • Microscopic evaluation of exfoliated cells & fine-needle aspirates (e.g., Pap smears) to distinguish malignant vs. benign cells.

Characteristics of a Clinical Laboratory Scientist

• Physical (NAACLS)
  • Good or corrected eyesight; normal color vision.
  • Ability to sit/stand long periods.
  • Manual dexterity.
  • Overall physical fitness.
• Intellectual/Professional
  • Strong interest in science & mathematics.
  • Detail-oriented; capable of independent critical decision-making.
  • Computer literacy.
  • Cleanliness, orderliness, responsibility.
  • Stress management skills.

Education Pathway (Philippines example)

1. 4-year BS in Medical Laboratory Science / Medical Technology.
   • Core sciences: biology, chemistry, anatomy & physiology.

Pre-Clinical (General Education) – typically Years 1–2

• Human Anatomy & Physiology with Pathophysiology
• General Inorganic & Organic Chemistry
• Analytical Chemistry
• Biochemistry
• Biostatistics & Epidemiology
• Principles of Medical Laboratory Science 1 & 2 (PMLS 1, 2)
• Histology
• Cytogenetics
• MT Laws & Bioethics
• Laboratory Management
• Community & Public Health
• Mycology & Virology
• Basic Pharmacology

Clinical Division (Years 3–4)

• Admission requirements (AUP example)
  • Qualifying examination (≥60 % to pass).
  • Sufficient GPA & completed prerequisite units.
  • Interview/Forum participation.
• 12- to 18-month hospital internship/clinical practicum covering all laboratory areas.

Ethical, Philosophical & Practical Considerations

• Quality control & assurance ensure patient safety; errors can lead to misdiagnosis.
• Biosafety: handling of infectious agents & poisonous reagents demands strict protocols.
• Technological evolution (molecular methods, automation) continually reshapes competency requirements.
• Interdisciplinary relevance: CLS data affect epidemiology, public health policy, personalized medicine, forensic justice & biodefense.