Clinical, epidemiologic, and pulmonary function studies in alpha,-antitrypsin-deficient subjects of Pi Z type

The results of pulmonary function testing and systematic medical history and epidemiologic data collection are reported for 20 persons with alpha 1-antitrypsin deficiency of Pi Z phenotype. The most common symptom, reported in 19 subjects (95 per cent), was dyspnea on exertion; 16 subjects (80 per cent) gave a history of wheezing, and 8 (40 percent) reported chronic cough and sputum production. The 8 women who had been pregnant reported a miscarriage rate of 29 per cent for all pregnancies. Respiratory symptoms and disease were commonly reported in the children of study subjects. Pulmonary function testing revealed abnormalities for 18 of 20 subjects, all of those 26 or more years of age. The test that was most frequently abnormal was the 1-sec forced expiratory volume expressed as a per cent of the forced vital capacity. All pulmonary function studies demonstrated a trend toward increased impairment with increased age, which was evident by the fourth decade. Within this group of persons having severe alpha1-antitrypsin deficiency, there was no correlation between serum concentrations of antitrypsin and subjective or objective indices of pulmonary disease. A group of 7 subjects who were incidentally found to have Pi Z alpha1-antitrypsin deficiency exhibited symptoms and pulmonary function abnormalities comparable to those of 13 subjects who were originally referred for known or suspected pulmonary disease. These data suggest that if interventions such as smoking cessation and occupational counseling are to be effective, they should be initiated before the fourth decade of life.

A comparison of pulmonary function in male smokers and nonsmokers

Results of certain tests of pulmonary function, including a questionnaire, single-breath N2 test of closing capacity, forced expiration, and diffusing capacity were significantly different in groups of male smokers and nonsmokers. The influence of age on these smoking-related changes of pulmonary function was evaluated. The analyses indicated that (1) some tests including number of symptoms; closing capacity, i.e., closing volume plus residual volume as a percentage of total lung capacity; residual volume as a percentage of total lung capacity; Phase III of the single-breath N2 test, and steady-state diffusing capacity (ml of CO/mm Hg - min) revealed significant differences between adjusted mean smoker and nonsmoker values but did not reveal differences associated with age. (2) Tests of forced expiration (1-sec forced expiratory volume/vital capapity, reciprocal of the maximal mid-expiratory flow, maximal flow at 50 per cent of vital capacity; and moments) however, revealed differences between smoker and nonsmoker means )adjusted and unadjusted), as well as increasing smoker-nonsmoker differences with increasing age. It is suggested that the first group of tests probably measured an all-or-none response that occurred with the onset of smoking and was not affected by duration of smoking. The second group of tests probably measured the effects of continued smoking and indicated increasing abnormality associated with longer exposure (years of smoking). Test showing age-related differences between smokers and nonsmokers may reflect cummulative, irreversible changes in pulmonary function to a greater extent than test that do not.

Coding of information about rapid eye movements in the pontine reticular formation of alert monkeys

Neurons in the rostral paramedian zone of the pontine reticular formation (PRF) have distinct frequency changes prior to and during quick eye movements, but generally little or no tonic activity associated with eye position. Evidence indicates that horizontal saccades and quick phases of nystagmus are generated in this region. Firing of units activated with eye movements (burst units) and of units which are inhibited (pause units) was analyzed. Eye movements were described by a vector having an amplitude (A) and an angle (a). These parameters were related to position changes in certain planes by the equation delta pos = A - cos alpha. In each of 80 cells in the PRF which were encountered, the activity could be related to some parameter of the above equation: change of position (delta pos), amplitude (A), or the cosine of the angle between the direction of movement and a reference direction (cos alpha). Units coding amplitude of eye movement or change in position in a particular plane conveyed the information by number of spikes. Units coding direction of movement did so by frequency. In many units, the information coding was precise so that the direction or amplitude of single eye movements could be predicted from the frequency changes of single units. In other units, this could be determined from averages of the frequency changes. Cells coding direction or change in position had frequency maxima only in planes corresponding to the pulling direction of the eye muscles. The results suggest that a vector description is not only a convenient mathematical tool, but is the way eye movements are coded in the PRF and possibly elsewhere in the central nervous system.

The enigma of vestigial tissues

There are several structures and various tissues in the human body that appear to be functionless relics of ancestral or embryonic development. As such they have long been of interest and have been cited in support of theories of evolution and of oncogenesis. Evidence can be adduced to show that these remnants are not necessarily degenerate, nor are they inevitably functionless. Vestigial tissues are especially common in tooth-bearing areas of the mouth, and the span of tooth development from early embryonic life until adolescence affords unique opportunities for studying the part played by embryonic remnants in later life.

Lead. Possible toxicity in urban vs rural rats

The degree of lead poisoning in wild rats from two environments has been studied. Wild rats captured in an urban area had markedly elevated tissue lead compared with values in rural rats. This elevation may have been caused by differences in factors affecting absorption of ingested lead or an elevated respiratory exposure to airborne lead, or both, and lead in precipitated dust. Changes in several biologic indexes (depression of delta-amino levulinic acid dehydratase in kidney and red blood cells, presence of renal intranuclear inclusion bodies, and increased kidney weight) confirmed lead-poisoning in urban rats.

Effects of labyrinthectomy on optokinetic nystagmus (OKN) and optokinetic after-nystagmus (OKAN)

OKN and OKAN were affected by unilateral and bilateral labyrinthectomy. The maximum velocity of slow phases of OKN induced by drum rotations above 60-75 degrees/sec in either direction was lower after unilateral and bilateral labyrinthectomy. The frequency of OKN was also decreased, and the total deviation of the eyes was reduced for OKN induced by these drum speeds. Changes in OKN eventually recovered. OKAN was reduced in duration after unilateral labyrinthectomy, being initially shorter to the ipsilateral than to the contralateral side. OKAN could no longer be evoked after bilateral labyrinthectomy. This loss was permanent. These data demonstrate the importance of the vestibular system in maintenance of OKN and OKAN.

The removal of fission products from milk. The use of the baby monkey (Macaca irus) for the nutritional evaluation of milk treated by 2 processes

The nutritional quality of milk treated by 2 previously described processes for the removal of cationic fission products has been evaluated by the use of the baby monkey (Macaca irus).

The first process involves acidification of the milk to pH 5·2–5·3 and, when the treated milk was tested on baby monkeys, it was found to be nutritionally unsatisfactory. This result confirmed those previously obtained with baby pigs, from which it was concluded that the process cannot be recommended for the treatment of milk intended for young babies.

Two resin beds are used in the second process and no acidification is involved. Milk treated by this process was first tested on baby rats and pigs and then on baby monkeys. No change in the nutritional value of the milk was detected and it was concluded that this is the process which should be used if it should ever become necessary to remove fission products from milk intended for young babies.