Crustacean eye fine structure seen with scanning electron microscopy

The internal fine structure of crustacean compound eyes has been reexamined with scanning electron microscopy. Several different preparative techniques were used in a comparative study of crab, crayfish, shrimp, and stomatopod eyes. The three-dimensional pattern of photoreceptive, dioptric, and screening components of these eyes has been directly demonstrated, and new insight has been gained into their functional organization. Particularly interesting in apposition eyes is the elaborate array of boundary membranes and protoplasmic strands linking the photoreceptive microvilli to their parent cell cytoplasm across the large intracellular vacuoles surrounding the axial rhabdom. Quantitative application of scanning electron microscopy to this system promises to advance our understanding of its proven high rate of receptor membrane turnover.

Does transcervical resection of the endometrium for menorrhagia really avoid hysterectomy? Life table analysis of a large series

STUDY OBJECTIVE

To determine long-term success and complication rates of transcervical resection of endometrium (TCRE) for menorrhagia.

DESIGN

Retrospective audit of a continuous case series with a minimum of 2 and a maximum of 5 years' follow-up (Canadian Task Force classification II-2).

SETTING

District general hospital and tertiary referral center for gynecologic endoscopy.

PATIENTS

Three hundred eighty consecutive women with menorrhagia.

INTERVENTION

TCRE performed as a day case or with overnight stay between August 1988 and December 1992.

MEASUREMENTS AND MAIN RESULTS

Complications occurred in 6.8% of patients, with a perforation rate of 3.2%. Life table analysis showed a cumulative hysterectomy rate of 12.4% at 1 year, reaching a plateau of 27.4% after 4 years. The rate at 5 years was higher for women under age 45 years (35%) than for those 45 and over (14.9%, p <0.01, Mantel's test x(2)). Women whose operation was performed by a senior surgeon had a lower cumulative hysterectomy rate (12.6%) than those whose surgery was performed at least in part by trainees (38%, p <0.01, Mantel's text x(2)). There was no significant difference in cumulative hysterectomy rates between women who had uterine fibroids and those who did not. Ninety-six percent of hysterectomies were performed in the first 3 years after initial TCRE.

CONCLUSION

Although TCRE for menorrhagia did not avoid hysterectomy in all women, for those considering hysterectomy, it was a conservative procedure with low morbidity and high chance of avoiding the need for major surgery, especially when performed in women over age 45, by an experienced surgeon.

Follow-up report on a randomized controlled trial of laser laparoscopy in the treatment of pelvic pain associated with minimal to moderate endometriosis

OBJECTIVE

To assess the longer term efficacy of laparoscopic laser surgery in the treatment of painful pelvic endometriosis and to observe the natural history of the disease at second-look laparoscopy in a control group.

DESIGN

One-year follow-up of a prospective, randomized, double-blind controlled trial.

SETTING

A referral center for the laparoscopic laser treatment of endometriosis.

PATIENT(S)

Sixty-three patients with pelvic pain and minimal to moderate endometriosis.

INTERVENTION(S)

After the 6-month follow-up visit, the randomization code was broken, and follow-up was continued to 1 year. Symptomatic patients were offered second-look laser laparoscopy.

MAIN OUTCOME MEASURE(S)

Continued symptom relief at 1 year after treatment and findings at second-look laparoscopy in symptomatic controls.

RESULT(S)

Symptom relief continued at 1 year in 90% of those who initially responded. All symptomatic controls had a second-look procedure, with 7 (29%) showing disease progression, 7 (29%) showing disease regression, and 10 (42%) having static disease.

CONCLUSION(S)

The benefits of laser laparoscopy for painful pelvic endometriosis are continued in the majority of patients at 1 year. Untreated painful endometriosis will progress or remain static in the majority of patients but will spontaneously improve in others.

Partial fractionation of oestradiol-binding chromatin from dimethylbenzanthracene-induced rat mammary tumour

The distribution of [6,7-3H]oestradiol-17β binding in chromatin from dimethylbenzanthracene-induced rat mammary adenocarcinoma was studied by differential centrifugation of sonicated nuclei. The evidence suggests that more oestradiol-17β is associated with the 'light' chromatin sedimenting at a higher centrifugal force than with the 'heavy' chromatin. Electron microscopy showed that heterochromatin was present in intact tumour nuclei, but it dispersed during isolation of the nuclei, and probably did not account for the fractionation of chromatin that occurred. No heterochromatin was observed in the centrifuged fractions. The template activity appeared to be higher in the fractions that had bound oestradiol. These results are compatible with the view that oestradiol binds to restricted regions of the chromatin and stimulates local increases in transcription.