Bacteriological and epidemiological studies of streptococcal infections: with particular reference to epidemiological analyses by serological typing of haemolytic streptococci

(1) PREPARATION OF TYPE -SPECIFIC SERA: (a) Vaccine was prepared from Griffith's thirty types of haemolytic streptococci. (b) Rabbits were injected and test-bleedings made at various times to estimate the titre of the serum. (c) The method of preparing type- specific agglutinating sera was described, and particular mention of cross -reactions was made.(2) THE TYPING OF HAEMOLYTIC STREPTOCOCCI: (a) A series of investigations were carried out t determine the most suitable media for growing homogeneous suspensions of haemolytic streptococci. The method of incubation best suited was described. (b) A description of the slide -agglutination method of typing used throughout this work was given.CLINICO- BACTERIOLOGICAL INVESTIGATIONS OF SCARLET FEVER CASES. (3) The procedure adopted in swabbing patients was intimated.(4) There followed a description of the method adopted for storing haemolytic streptococci "in vacuo".(5) Statistical records for the period September 1937 to January 1939 were drawn up and included the total number of admissions of scarlet fever cases to the City Fever Hospital, the total number swabbed, the total number of complications, and the total number of complications swabbed.(6) Monthly graphs and tables indicating the result of typing the above cases was given.(7) The monthly percentage increase and decrease of the various types of haemolytic streptococci were recorded.(8) An investigation was carried out to show whether any difference in the types of haemolytic streptococci found in the throats and noses of scarlet fever cases existed.(9) The next investigation was carried out to determine whether there occurred more than one type of haemolytic streptococcus in the throat swabs of patients on admission to hospital.(10) This investigation was an attempt to ascertain whether any cases, which had been in the wards for some time, had more than one type of haemolytic streptococci in their throats.(11) The results of the last investigation were compared with those found during the first day complications became manifest.(12) Daily swabs were taken in a single ward over a period of 23 days and all the patients typed. All cross- infections were noted.(13) The same investigation was carried out over a period of 46 days.(14) 384 cases showing complications were investigated. The haemolytic streptococci present on admission and those responsible for the complications were noted. Correlations between types and lesions, etc., were recorded.(1 5) An investigation was undertaken showing the decrease of haemolytic streptococci in the throats of patients during their stay in hospital.(16) During the month of May, 1938, twenty cases of scarlet fever were typed and the same done to fifteen cases showing complications. The results were investigated.(17) A statistical record of scarlet fever cases occurring in the City of Edinburgh from the 1/9/37 to 31/12/38 was drawn up.(18) The number of patients per month from the various schools and institutions in Edinburgh was calculated and recorded in tables.A graph comparing the number of school children with all other cases is given.(19) The types of haemolytic streptococci found in school cases and other patients were noted and certain correlations observed.(20) An attempt was made to show that there existed a relationship of types of haemolytic streptococci found in the patients from individual schools.(21) 54 cases of puerperal fever were investigated bacteriologically.(22) Similarly 40 cases of erysipelas were investigated.(23) This was also done with 10 cases of otitis media or mastoiditis, and(24) with 60 cases of tonsillitis.(25) A miscellaneous group of diseases sent into the City Fever Hospital as scarlet fever cases was examined for haemolytic streptococci (42 patients).(26) Eight positive haemolytic streptococci ;swabs from the Third Year Medical Students were examined. This was carried out during a time when "coughs, and colds" were common.(27) 32 cases of respiratory diseases occurring in a rural area were investigated for the presence of haemolytic streptococci. These were typed and compared with the urban strains.(28) The next investigation was carried out to ascertain the presence of haemolytic streptococci in normal throats and to find what correlation there existed between the types found and the various streptococcal infections. The normal throats were those of: (a) 40 nurses from the City Fever Hospital. (b) The positive swabs from a number of nurses from the Western General Hospital, (c) Six resident doctors in the City Fever Hospital. (d) Ten strains from the Third Year Medical students were typed. The period was one when only a few "coughs and colds" were about. (e) 16 families, from whom cases of scarlet fever had been sent to hospital, were visited and all members swabbed, with a view to determining the presence of haemolytic streptococci and observing any correlations. 260 (f) This investigation was carried out upon my own' person to estimate the number of haemolytic streptococci present in throat and nose before and after contact with scarlet fever patients.(29) The presence of haemolytic streptococci on toys and food in the scarlet fever wards was investigated.(30) A similar investigation was carried out on the handkerchiefs of patients.AIR -CONTAMINATION WITH HAEMOLYTIC STREPTOCOCCI IN THE CITY FEVER HOSPITAL WARDS.(31) (a) A research was made to determine the incidence of haemolytic streptococci in the air of fever wards. (b) A similar investigation was done in a puerperal ward; and in (c) an erysipelas ward; and in (d) a diphtheria; and in (e) a measles ward. (f) The first investigation (a) was repeated in a ward with a high complication rate, and repeated in another with a low complication rate. The results were correlated.(32) Air contamination with haemolytic streptococci in the Ear, Nose and Throat Department of the Edinburgh Royal Infirmary was investigated.(33) The next investigation was to determine the presence of haemolytic streptococci and their types in picture houses, buses, trams, shops and open places.(34) An attempt was made to correlate the types found in scarlet fever with those of all other streptococcal infections.(35) A research into the problem of air-borne infection was carried out. The object of this investigation was to determine what effects variations of ventilation, and wet and dry sweeping have on the number of organisms in the air.B. prodigiosus was the organism used in this investigation and was sprayed by means of an atomiser.(36) Cross-contamination in the cubicles of the City Fever Hospital was investigated.(37) The final investigation was an attempt to type those strains of haemolytic streptococci which were either too granular or failed to type by ordinaryj methods

Clinical use of a portable electronic device to measure haematocrit

A small portable device called the blood electrometer (HEM) was developed to assist clinicians to distinguish patients with extreme blood loss from those with normal packed cell volumes. Blood was collected in 5 ml lithium heparin tubes from 80 normal controls and 24 patients in an intensive care unit. BEM and accurate microcentrifugal techniques were compared. Intraclass correlation coefficients between the techniques of r =0,96 and r =0,93 were found in the normal controls and patients respectively. Because the BEM operates on the principle of conductivity, changes in some of the biochemical variables which could influence conductivity were investigated in the patients. Mean plasma total protein and albumin concentrations were lower compared with normal reference ranges. Six of the 24 patients were acidotic and 4 alkalotic. Leucocyte counts obtained randomly from 13 patients were elevated. Changes in measurements which could influence conductivity did not affect the BEM reading. We conclude that the portable BEM could be of great value in circumstances where a fixed power source is not available and rapid haematocrit measurements in a large number of patients are required

Thermal behaviour of glass batch on batch heating

The heating process of a Ba-Sr glass batch was studied in a 40 L pot furnace, using a multiple thermocouple assembly. The effect of several batch parameters on the heating process was measured, including layer thickness, cullet fraction, water content, and pellets. The results were evaluated using a heat penetration batch model. In the model 2 heating stages, below and above a certain batch transition temp., ns, typically 800 to 900 Deg, are distinguished. Values for the temp.-dependent thermal diffusivity of the batch were derived from exptl. temp. distributions in the batch during heating. Below ns, the thermal diffusivity has an almost const. value of 0.4 * 10-6 m2/s for a std. (powder) batch blanket; for n > ns, the net thermal diffusivity strongly increases with temp., due to the formation of primary melt phases. For ns <n <1100 Deg, the av. value is about 1.4 * 10-6 m2/s. A 100% cullet layer has a 50% higher thermal diffusivity for n <ns; pelletizing the batch has little influence on the virtual thermal diffusivity and (extra) wetting has a retarding effect on batch heating due to extra heat absorption. As for the furnace temp., it appears that increasing the temp. of the glass melt is more effective for improving the batch heating rate than increasing the temp. of the combustion chamber. Practical recommendations are given for batch prepn., charging, and heating in industrial glass tanks. [on SciFinder (R)

Pr3+-doped GeSx-based glasses for fiber amplifiers at 1.3 mm

The luminescence of Pr3+-doped GeSx-based glasses were studied and compared with those of other sulfide and fluoride glasses. The possibility of highly pump-power-efficient fiber amplifiers based on these GeSx-contg. glasses in the telecommunications window at 1.3 mm is discussed. [on SciFinder (R)

Pr3+-doped GeSx-based glasses for fiber amplifiers at 1.3 mm

The luminescence of Pr3+-doped GeSx-based glasses were studied and compared with those of other sulfide and fluoride glasses. The possibility of highly pump-power-efficient fiber amplifiers based on these GeSx-contg. glasses in the telecommunications window at 1.3 mm is discussed. [on SciFinder (R)

Theory for incongruent crystallization: application to a ZBLAN glass

Equations which describe incongruent nucleation and subsequent crystal growth are derived. A ZrF4-BaF2-LaF3-AlF3-NaF (ZBLAN) glass was used to test the validity of these equations. Nucleation rate measurements were fitted to theory and some growth rate measurements were in reasonable agreement with theor. predictions. Both nucleation theory and crystal growth theory were used for computer simulations of the crystn. behavior during heat treatments. Some heat treatments were performed in a DSC app. to verify the theories. The exptl. results were in good agreement with the numerical data. Using these theor. results it is possible to est. fiber scattering losses due to crystn. Depending on drawing temp., estd. losses can vary from 0.014 (310 Deg) to >=25 decibel/km (320 Deg). [on SciFinder (R)

Vibrations of closed-shell Lennard-Jones icosahedral and cuboctahedral clusters and their effect on the cluster ground state energy

Vibrational spectra of closed shell Lennard-Jones icosahedral and cuboctahedral clusters are calculated for shell numbers between 2 and 9. Evolution of the vibrational density of states with the cluster shell number is examined and differences between icosahedral and cuboctahedral clusters described. This enabled a quantum calculation of quantum ground state energies of the clusters in the quasiharmonic approximation and a comparison of the differences between the two types of clusters. It is demonstrated that in the quantum treatment, the closed shell icosahedral clusters binding energies differ from those of cuboctahedral clusters more than is the case in classical treatment

Heritability of live weight and condition score in a Holstein herd and correlations with milk traits – preliminary estimat

Genetic and environmental parameters for live weight and condition score have been determined for Holstein cows. Genetic correlations with milk traits were also derived. Monthly records were modelled by cubic splines, while the direct, additive effects of animal and the temporary environment (defined as cow environmental effects within lactations) were fitted as random. Lactation number interacted with monthly trends in cow live weight. Cows lost weight in the early part of the lactation. This reduction in live weight was probably because of a loss in body reserves, as suggested by a lower condition score. Cows gained live weight towards the end of lactation. The ultimate live weight of cows increased with parity because of ongoing growth. The heritability (h²) estimate for live weight was high at 0.65 ± 0.04, albeit still within the expected range. Condition score had a medium h² of 0.24 ± 0.05. Genetic and phenotypic correlations of live weight with milk yield were positive, i.e. 0.19 ± 0.14 and 0.12 ± 0.05, respectively, while correlations of condition score with milk yield were negative, i.e. 0.42 ± 0.15 and -0.17 ± 0.04, respectively. Although live weight could be used as an indirect indicator of feed intake and efficiency of milk production, other body conformation traits could also be used. There is a need in the South African dairy industry for a selection index based on production parameters and some traits such as live weight, condition score or specific conformation traits. However, a large participation of animals in milk recording and measurement of such traits is a prerequisite for such developments. South African Journal of Animal Science Vol. 36(2) 2006: 79-8