Transcorporeal tunnel approach for unilateral cervical radiculopathy: a 2-year follow-up review and results.

BACKGROUND: The long-term complications of traditional discectomy and fusion surgery have led to the need for minimally invasive procedures that do not require a complete discectomy and fusion. Jho developed an anterior unco-foraminotomy that we have modified, with the approach being more medial than that of Jho, into an anterior transcorporeal tunnel approach which we use for cervical spondylotic unilateral radiculopathy. METHODS: A retrospective analysis was carried out in 30 patients who underwent a transcorporeal "tunnel" anterior micro-foraminotomy for unilateral radicular symptoms with a follow-up more than 2 years. All were operated by a single surgeon using the same technique from the vertebral body proximal to the lesion and proceeding downwards to the herniation. At final follow-up we reviewed the clinical and radiological results. RESULTS: All patients in the immediate post-operative period showed relief of their symptoms, and there were major complications. 3 patients complained about the numbness in the immediate postoperative period which resolved within 3 months. There was a significant improvement in NDI from pre-operative 55.16% to postoperative 5.82% ( P <0.001). Average pre-operative VAS scores for arm and neck were 8.15 and 4.05, respectively; which improved to 1.05 and 1.23 ( P <0.001) postoperatively. There was an average 9% decrease (from 7.8 mm to 7.3 mm) in the post-operative disc height compared to the preoperative disc height; however, it was clinically and radiologically insignificant. The long-term results were favourable and there were no major complications. CONCLUSION: The transcorporeal tunnel approach can be used as an alternative treatment for cervical spondylotic radiculopathy.

Modulation of prolactin release by a 25 kD peptide of human seminal plasma.

Prolactin-regulating factor (PRF) of molecular size of 25 kD has been isolated from human seminal plasma. This 25 kD factor inhibits circulating PRL levels in intact adult male rats to the extent of about 48% at dose level of 10 micrograms. Furthermore, in vitro incubation of pituitary demonstrated that PRF inhibits the release of PRL in the medium. PRF also interferes with the binding of I125 PRL to its receptors in liver, prostate, and spermatozoa. However, I125 PRF itself does not bind to these receptors. PRF seems to modulate PRL release as well as its binding to receptors. A sensitive, specific RIA was developed for PRF. Using the RIA, levels of PRF in seminal plasma were measured. PRF levels were low in vasectomized subjects as compared with controls. A negative correlation was noted with seminal plasma PRF levels and sperm count.

Inhibin-like material--an immunohistologic marker for prostatic origin of metastases.

Immunocytochemical localization of inhibin-like material (ILM) using a specific antiserum generated against ILM of prostatic origin was carried out in metastatic lymph nodes of known primary prostatic tumours and in rectal biopsies showing direct invasion with known prostatic carcinoma. Nine of the 11 metastatic lymph nodes gave positive reaction, which was readily apparent in differentiated tumours showing micro-acinar formation. In poorly differentiated tumours it was often focal and indicated intracytoplasmic staining within randomly scattered cells. Rectal biopsies showing invasion of prostatic carcinoma (4 cases) also showed positive reaction for ILM. Using this experimental protocol, the reaction for metastatic lesions from patients with non-prostatic carcinomas was completely negative indicating the specificity of the test for prostatic origin of metastasis. In conclusion, the present investigation indicates the potential application of ILM in confirming or excluding the prostatic origin of invasive tumour in metastatic lesions.

Role of inhibin in polycystic ovarian syndrome.

The possible role of inhibin in the etiology of polycystic ovarian syndrome (PCO) was studied. In rats PCO was induced by thiouracil and human chorionic gonadotropin (hCG). These animals were grouped under different treatment schedules: inhibin; antibodies to inhibin; ovine follicle stimulating hormone (FSH). In rats treated with antibodies to inhibin, there was a decrease in ovarian weight concomitant with specific increase in serum FSH levels. No changes in serum luteinizing hormone (LH) and prolactin levels were observed. However, testosterone levels were significantly decreased. Histological examination of the ovaries showed a marked arrest in the cyst formation with new growing follicles. In animals treated with inhibin, testosterone levels increased without any accompanying changes in ovarian weight. The circulating levels of prolactin and LH were unaffected. A decrease in serum FSH levels was accompanied by an increase in the number of cysts. The study corroborates the hypothesis that inhibin is involved in the development of PCO syndrome. Hence, an antagonist to inhibin may prove useful for the treatment of women with this condition.

Studies on immunocytochemical localization of inhibin-like material in human prostatic tissue: comparison of its distribution in normal, benign and malignant prostates.

A specific antiserum has been generated against inhibin-like material (ILM) of prostatic origin. Using the immunoperoxidase technique, localization of ILM has been examined in a total of 114 prostates including normal (4 specimens), malignant (46) and hyperplastic (55) tissues. ILM positive immunocytochemical reactions were confined to the cytoplasm and not the nucleus of the prostatic acinar cells in the three categories of prostate, whereas the stroma showed negative reactions. The intensity of positive reactions decreased in the following order: Hyperplasia, incidental and moderately differentiated carcinomas, poorly differentiated carcinomas, whereas metaplasia and granulomatous prostatitis gave negative reactions for ILM. Using this experimental protocol, 200 non-prostatic tissue were found to be completely negative, demonstrating the specificity of the test for prostatic epithelium. These findings indicate a potential use of ILM as a marker of prostatic tissue.

beta 2-Inhibin contains the active core of human seminal plasma beta-inhibin: synthesis and bioactivity.

The complete synthesis of the C-terminal 28 residues segment 67-94 of human seminal plasma beta-Inhibin, called beta 2-Inhibin, is reported. The Inhibin-like activity of the native 94 amino acids beta-Inhibin is compared to that of the synthetic replica of beta 2-Inhibin. In all assays used both peptides effectively suppress the FSH release induced by LHRH but have little effect on the LH release. In the mouse both peptides are equipotent on a mole basis. In the rat the synthetic beta 2-Inhibin is 3-10 times more potent than beta-Inhibin. Both peptides are active in rat anterior pituitary primary culture assays where maximum suppression of FSH release induced by LHRH occurs around 300 pmol/ml of beta 2-Inhibin. In contrast, maximum suppression of FSH release in the mouse pituitary assay occurs at 10-15 pmol/ml of either Inhibin.

Complete amino acid sequence of human seminal plasma beta-inhibin. Prediction of post Gln-Arg cleavage as a maturation site.

The complete sequence of a 94 amino acid human seminal plasma polypeptide exhibiting inhibin-like activity is presented. This molecule, called beta-inhibin, selectively and specifically suppresses the release of pituitary FSH in vivo as well as in vitro. It does not affect the secretion of LH. Such a novel acidic protein contains a very basic C-terminal segment which is easily cleaved by mild tryptic digestion. It is predicted that the FSH inhibiting activity may reside within this region of the molecule. This would imply a post Gln-Arg cleavage to release the basic C-terminal active moiety.

Serum inhibin levels after administration of hCG.

Administration of hCG to normal healthy men caused 40 fold increase in circulating levels of inhibin at 24 hr. FSH levels decreased between 72-120 hr of hCG injection. Although, testosterone levels were maintained at higher levels during hCG therapy for more than 10 days, inhibin and FSH levels returned back to pretreatment levels, indicating involvement of hCG in the regulation of circulating levels of inhibin.

Levels of immunoreactive inhibin-like material in urine during the menstrual cycle.

Using a specific and sensitive radioimmunoassay, the authors determined levels of inhibin-like material in the urine of eight healthy women with normal menstrual cycle length of 28 +/- 4 days. The results revealed a cyclic variation in urinary immunoreactive inhibin levels during the menstrual cycles, with a sharp rise in levels three to four days prior to luteinizing hormone (LH) and follicle-stimulating hormone (FSH) peaks. These levels of immunoreactive inhibin may thus serve as a parameter to detect impending LH surge.

PIP: Using a specific and sensitive radioimmunoassay, the authors determined the levels of inhibinlike material in the urine of 8 healthy women with normal menstrual cycle length of 28 +or- 4 days. The results revealed a cyclic variation in urinary immunoreactive inhibin levels during the menstrual cycles, with a sharp rise in levels 3-4 days prior to luteinizing hormone (LH) and follicle-stimulating hormone peaks. These levels of immunoreactive inhibin may thus serve as a parameter to detect impending LH surge.

Effect of administration of a single dose of testosterone oenanthate on human serum and seminal plasma inhibin concentration.

The effect of a single administration of testosterone oenanthate (250 mg, intra-muscularly) on serum and seminal plasma inhibin concentrations were studied in four adult human volunteers. A significant decrease in serum FSH and LH levels were observed by day 6 when the serum testosterone levels were high. These were followed by a sharp increase in serum and seminal plasma inhibin concentration by day 8 and day 12 respectively. The present investigations also suggest the existence of a positive relationship between the serum and seminal plasma inhibin concentrations.