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Biomedical subjects

W A Cook

Publications and source records attributed to W A Cook.

At least 37 records · Page 2Linked to original sources

Industrial hygiene evaluation of thermal degradation products from PVC film in meat-wrapping operations.

An industrial hygiene evaluation is presented concerning experimental data included in the preceding paper on thermal degradation products from hot-wire and "cool"-rod cutting of PVC film but, in this paper, limited to film used in meat-wrapping operations. Room air concentrations of less than 0.2 ppm HCl and less than 0.05 ppm benzene can be maintained by a number of factors, including minimal dilution ventilation. Estimates of room air concentrations of degradation products are presented using average values of amounts produced per cut. The relation of these concentrations to TLV's is given, together with methods of suggesting TLV's for substances not listed by ACGIH or OSHA. Room air concentrations for the 12 degradation products for which TLV's are assigned, based on average values per cut, were no greater than 0.3% of accepted limits. Room air concentrations of DOA are not determinable from available data but present information does not indicate that exposure to DOA causes airway hyperreactivity. The cool rod, rather than the hot wire, is recommended as good industrial hygiene practice, producing no apparent PVC degradation products, even though similar amounts of DOA are volatilized.

Air Pollutants

Urinary calculi in pregnancy.

Despite earlier studies, there remain unanswered questions regarding urinary calculi in pregnancy. The authors studied 11 cases in 11,292 deliveries over 5 years. Eight previous studies were also studied and data were compiled from 96 cases in 138,296 patients. The incidence of urinary calculi in pregnancy is approximately 1 per 1500, with variance in geographic distribution. Symptoms may occur during any trimester but more often during the second and third trimesters. Incidence among multigravidas is twice that of primigravidas. Incidence on right and left sides is consistent. Because spontaneous passage occurs in more than 50% of cases, conservative therapy is the initial treatment of choice. However, if surgical therapy is indicated, maternal and fetal complications are rare.

Adolescent

Asymmetrical gonadal enlargement in adolescent true hermaphrodite with bilateral ovotestes.

A case of gynecomastia and asymmetrical gonadal enlargement in a thirteen and one-half-year-old "male" true hermaphrodite with biopsy-proved bilateral ovotestes is presented. The pathology, genetics, endocrinology, and management of this entity are discussed and compared with instances of hermaphroditism in which there is distinct separation of the ovarian and testicular tissues.

Adolescent

Ultrasound-guided percutaneous nephrostomy in the pediatric patient.

Percutaneous nephrostomy drainage may be established rapidly using ultrasonic guidance in severely ill pediatric patients with obstructive uropathy. B-mode ultrasonography has proved to be rapid, accurate and free of irradiation hazards, making it applicable to children with little or no sedation.

Adult

Dysgerminoma associated with pregnancy.

From a review of 26 reported case (our case being the 27th) of dysgerminoma associated with pregnancy, several salient facts are evident. Torsion and incarceration are common among these rapidly enlarging tumors. Obstetrical complications occurred in nearly half and fetal demise in one quarter of the reviewed cases. Our case was typical of patients presenting with this vexed problems: The patient was under 25 (as were 70%); nulliparous (as were 67%); and the tumor appeared confined to one ovary (as in 89%). Authorities are in dispute as to the treatment of stage IA dysgerminomas, and the association of pregnancy complicates this debate even further. The results of conservative treatment in this series were jarring: There were recurrences in 30% of the 23 stage IA tumors, and the recurrences were all following unilateral oophorectomy. In our case, the grossly normal contralateral ovary was infiltrated with dysgerminoma cells. While treatment of a young woman with a dysgerminoma of 1 ovary is a matter of perplexity, we believe that a unilateral operation should be limited to those women who desire above all earthly things to retain their childbearing capacity.

Adult

Techniques and results of urodynamic evaluation of children.

Simultaneous recording of intravesical pressure, urine flow rate and anal sphincter electromyography was undertaken in 25 children with a variety of urological problems. Urethral pressure profile measurement was obtained in 3 of these patients and was used as an adjunct to cystometry alone in 5 others. The diagnostic patterns that emerged were useful in selecting specific pharmacologic and surgical therapeutic measures.

Adolescent

Needle laparoscopy in patients with suspected bowel adhesions.

Suspected bowel adhesions are generally considered to be a contraindication to laparoscopy. Among 32 patients who were refused laparoscopy for that reason, only 1 patient was found to have adhesions at laparotomy. To attempt preoperative diagnosis of intraabdominal adhesions, needle laparoscopy was performed in 21 patients using a 1.7-mm endoscope. In 20 of the patients it was possible to establish the presence or absence of adhesions and to determine the feasibility of laparoscopic sterilization. This preliminary evaluation suggests that needle laparoscopy may avert bowel perforation in some instances and may permit laparoscopic tubal sterilization to be performed in some women who would otherwise, because of multiple previous operations, be denied laparoscopy.

Female

Fused kidneys: morphologic study and theory of embryogenesis.

A study was made of 50 fused kidneys; 41 postmortem specimens and 9 living patients' records were reviewed. Three patterns of renal fusion were identified--midline fused horseshoe kidney [15], laterally fused horseshoe kidney [21], and crossed renal ectopia [14]. These morphologic renal patterns were correlated with coexisting abnormalities of the urinary tract and other organ systems. A high incidence of hydronephrosis of varied etiology, vertebral, and anorectal defects was found in the laterally fused horseshoe and crossed renal ectopic groups. A theory of embryogenesis was developed to explain the asymmetric patterns of renal fusion exemplified by laterally fused and crossed fused kidneys. It was based on the effects that the lateral flexion and rotation of the hind end in the 4- to 5-mm embryo exert on the relative positions of the nephrogenic cords and wolffian ducts.

Child